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Sample records for ravenglass saltmarsh cumbria

  1. Implications of sedimentological and hydrological processes on the distribution of radionuclides: the example of a salt marsh near Ravenglass, Cumbria

    International Nuclear Information System (INIS)

    Carr, A.P.; Blackley, M.W.L.

    1986-01-01

    This paper summarizes sedimentological and hydrological studies at a salt marsh site on the north bank of the River Esk near Ravenglass which have a bearing on the fate of the low-level radioactive effluent from the reprocessing facility at Sellafield, Cumbria. A range of techniques has been used including electromagnetic distance measurement (EDM) and pore water pressure studies. The results show that: (a) Over a two-year period there were no significant net changes in salt marsh creek level, although shorter-term (probably seasonal) fluctuations, of the order of 2 cm, occurred. These were attributed to expansion of clay particles during the winter months. Nearby, however, there were vertical changes of the order of 1 m due to erosion. (b) Pore water pressures indicated a dynamic situation with very rapid responses both to tidal fluctuations and to rainfall. During neap tides there was clear evidence for water seeping upwards from the underlying clay/sand interface. Shortlived radionuclides ( 95 Zr/ 95 Nb and 106 Ru) were detected in this zone. (c) soil polygons, once initiated by desiccation, thereafter provide preferential routes for water (and radionuclides) to the sub-surface sediment. These, and other results, are discussed in the context of previous studies. It is concluded that the complexity of the estuarine environment results in most data being site specific. (author)

  2. Joint review of related contracts on bird populations in the Ravenglass Estuary

    International Nuclear Information System (INIS)

    Anderson, N.; Evans, P.R.; Lowe, V.P.W.

    1987-10-01

    Black-headed Gulls breeding at Ravenglass (and at other coastal sites in Cumbria) fed exclusively inland during the breeding season and so they and their young could not have acquired any radionuclides present in the estuarine muds and invertebrates. Levels in the invertebrates and in gull tissues were low; they were slightly higher in Shelducks, which feed on estuarine invertebrates but have nested successfully at Ravenglass in recent years. Gulls and two other ground-nesting bird species have suffered severe disturbance and predation by foxes in recent springs at Ravenglass; Shelducks nest in burrows and have escaped such effects. Levels of radionuclides in birds, particularly gulls, are too low to have caused breeding failures at Ravenglass. (author)

  3. Reasons for the decline in bird numbers breeding near the Ravenglass Estuary

    International Nuclear Information System (INIS)

    Anderson, N.; Evans, P.R.

    1987-07-01

    Black-headed Gulls breeding at Ravenglass (and at other coastal sites in Cumbria) fed exclusively inland during the breeding season and so could not have acquired any radionuclide contaminants present in the estuarine muds and invertebrates. They, and two other ground-nesting bird species have suffered severe disturbance and predation by foxes at Ravenglass in recent years. In contrast, the Shelduck, which nests in holes (and so does not suffer fox predation) but feeds at Ravenglass on estuarine invertebrates, has bred successfully. Levels of heavy metal contaminants in gull tissues and eggs were too low to have caused the observed breeding failures at Ravenglass. Gulls feeding on the estuary before the breeding season, but which then moved to other (inland) breeding sites, nested successfully. (author)

  4. Radionuclides and the birds at Ravenglass

    International Nuclear Information System (INIS)

    Lowe, V.P.W.

    1991-01-01

    Since 1983 concern has been expressed about the apparent decline in numbers of birds in the Ravenglass estuary in west Cumbria, particularly of the black-headed gull colony on the Drigg dunes, and suggestions have been made that this decline might be due to excessive radiation in the birds' food and their general environment. Twelve species of marine invertebrates from Ravenglass, known to be important foods for birds, were analysed, and further samples were taken from sites along the west Cumbrian coast. None of these samples showed excessive contamination with any of the radionuclides analysed. Analysis of a sample of bird carcasses from the area showed oystercatchers (Haematopus ostralegus) and shelduck (Tadorna tadorna) to have some of the highest concentrations of 137 Cs in their tissues; yet their breeding success and populations were not affected. Black-headed gulls were found to be feeding mainly inland, and were the least contaminated with radionuclides of all the birds at Ravenglass, yet this species and its breeding success were in decline. Calculations of the total dose equivalent rate to the whole body of the most contaminated black-headed gull amounted to 9.8 x 10 -4 mSv h -1 (∼ 8.4 x 10 -4 mGy h -1 , whole-body absorbed dose rate), and the background exposure dose was of the order of 8.3 x 10 -4 mGy h -1 . As a minimum chronic dose of 1000 mGy day -1 has been found necessary to retard growth of nestling birds, and 9600 mGy over 20 days of incubation to cause the death of 50% of embryos in black-headed gulls' eggs, the concentrations of radionuclides in the foods, body tissues and general environment were at least three orders of magnitude too low to have had any effects. (author)

  5. Household particulate survey. (Radioactivity in housedust in West Cumbria and its significance)

    International Nuclear Information System (INIS)

    Goddard, A.J.H.; Minski, M.J.; Thornton, I.; Culbard; Akbarian, F.; Buckley, D.

    1986-01-01

    The objective of the research was to identify any enhanced levels of radioactivity in domestic dust and to assess the radiological significance. The work was carried out over a period from March 1984 to March 1986 and encompassed 14 communities in West Cumbria extending about 25 km to the north of Sellafield, 12 km to the south and about 10 km inland, together with a control community (Ascot) in the South of England. Ten houses in each of 12 communities were sampled, but in Ravenglass and Seascale 25 houses were sampled and was repeated to check year-to-year reproducibility. During the study, over three hundred radiochemical separations for plutonium were undertaken and about half that number for americium. Samples were also analysed for gamma emitting radionuclides. (author)

  6. Radionuclides in terrestrial ecosystems

    International Nuclear Information System (INIS)

    Allen, S.E.; Horrill, A.D.; Howard, B.J.; Lowe, V.P.W.; Parkinson, J.A.

    1983-07-01

    The subject is discussed under the headings: concentration and spatial distribution of radionuclides in grazed and ungrazed saltmarshes; incorporation of radionuclides by sheep grazing on an estuarine saltmarsh; inland transfer of radionuclides by birds feeding in the estuaries and saltmarshes at Ravenglass; radionuclides in contrasting types of coastal pastures and taken up by individual plant species found in west Cumbria; procedures developed and used for the measurement of alpha and gamma emitters in environmental materials. (U.K.)

  7. Radionuclide concentrations in bird tissues, their foods and feeding areas near Ravenglass

    International Nuclear Information System (INIS)

    Lowe, V.P.W.

    1987-08-01

    Since 1983, concern has been expressed about an apparent decline in the numbers of waterfowl, waders and gulls in the Ravenglass estuary, particularly of the black-headed gulls nesting on the Drigg dunes; it was suggested this might be due to the radionuclide concentrations in their diet and general environment. Oystercatchers and shelduck had some of the highest concentrations of Cs-137 in their tissues, yet their breeding and numbers remained unaffected. Calculations of the total dose equivalent to the whole body of gulls spending 4 months in the estuary before laying eggs, amounted to 2.8 mSv (≅ 2.4 m Gy), and to the gut lining 40.3 mSv. As a minimum chronic dose of 1000 m Gy d -1 has been found to be necessary to retard the growth of chicks or cause 50% mortality among gull chick embryos before full development, radionuclide concentrations at Ravenglass were at least three orders of magnitude too low to have any effect. 12 species of marine invertebrates were also analysed, but no evidence was found that radionuclides from Sellafield were being accumulated in any species to the point where concentrations were of potential importance to birds feeding on them. (author)

  8. Food Relocalization for Environmental Sustainability in Cumbria

    Directory of Open Access Journals (Sweden)

    Les Levidow

    2011-04-01

    Full Text Available In the past decade, many European farmers have adopted less-intensive production methods replacing external inputs with local resources and farmers’ skills. Some have developed closer relations with consumers, also known as short food-supply chains or agro-food relocalization. Through both these means, farmers can gain more of the value that they have added to food production, as well as greater incentives for more sustainable methods and/or quality products, thus linking environmental and economic sustainability. These systemic changes encounter difficulties indicating two generic needs—for state support measures, and for larger intermediaries to expand local markets. The UK rural county of Cumbria provides a case study for exploring those two needs. Cumbria farmers have developed greater proximity to consumers, as a means to gain their support for organic, territorially branded and/or simply ‘local’ food. This opportunity has been an incentive for practices which reduce transport distances, energy costs and other inputs. Regional authorities have provided various support measures for more closely linking producers with each other and with consumers, together developing a Cumbrian food culture. Going beyond the capacity of individual producers, farmer-led intermediaries have maintained distinctive product identities in larger markets including supermarket chains. Although Cumbria’s agro-food relocalization initiatives remain marginal, they counteract the 1990s trend towards delocalization, while also indicating potential for expansion elsewhere.

  9. Saltmarsh plant responses to eutrophication.

    Science.gov (United States)

    Johnson, David Samuel; Warren, R Scott; Deegan, Linda A; Mozdzer, Thomas J

    2016-12-01

    In saltmarsh plant communities, bottom-up pressure from nutrient enrichment is predicted to increase productivity, alter community structure, decrease biodiversity, and alter ecosystem functioning. Previous work supporting these predictions has been based largely on short-term, plot-level (e.g., 1-300 m 2 ) studies, which may miss landscape-level phenomena that drive ecosystem-level responses. We implemented an ecosystem-scale, nine-year nutrient experiment to examine how saltmarsh plants respond to simulated conditions of coastal eutrophication. Our study differed from previous saltmarsh enrichment studies in that we applied realistic concentrations of nitrate (70-100 μM NO 3 - ), the most common form of coastal nutrient enrichment, via tidal water at the ecosystem scale (~60,000 m 2 creeksheds). Our enrichments added a total of 1,700 kg N·creek -1 ·yr -1 , which increased N loading 10-fold vs. reference creeks (low-marsh, 171 g N·m -2 ·yr -1 ; high-marsh, 19 g N·m -2 ·yr -1 ). Nutrients increased the shoot mass and height of low marsh, tall Spartina alterniflora; however, declines in stem density resulted in no consistent increase in aboveground biomass. High-marsh plants S. patens and stunted S. alterniflora did not respond consistently to enrichment. Nutrient enrichment did not shift community structure, contrary to the prediction of nutrient-driven dominance of S. alterniflora and Distichlis spicata over S. patens. Our mild responses may differ from the results of previous studies for a number of reasons. First, the limited response of the high marsh may be explained by loading rates orders of magnitude lower than previous work. Low loading rates in the high marsh reflect infrequent inundation, arguing that inundation patterns must be considered when predicting responses to estuarine eutrophication. Additionally, we applied nitrate instead of the typically used ammonium, which is energetically favored over nitrate for plant uptake. Thus, the

  10. Aspects of the uptake of radionuclides by sheep grazing on an estuarine saltmarsh

    International Nuclear Information System (INIS)

    Howard, B.J.; Lindley, D.K.

    1985-01-01

    The transfer of 137 Cs, 238 Pu, sup(239/240)Pu and 241 Am to sheep which graze a saltmarsh in the Esk estuary, 7 km south of the Sellafield reprocessing plant in west Cumbria (UK), has been estimated. The concentrations of gamma-emitting radionuclides and of 238 Pu, sup(239/240)Pu and 241 Am were measured in liver, lung, muscle, kidney and bone from saltmarsh ewes and lambs. 137 Cs concentrations in the soft tissues were similar in liver, lung and muscle but were consistently higher in kidney and much lower in bone. The highest concentration of the transuranics was found in liver. Transfer coefficients and concentration factors were calculated for both ewes and lambs. The concentration of 137 Cs in the tissues of 5-month old lambs was higher than in those of their mothers. Therefore, a higher transfer coefficient was obtained for lamb muscle (1.8 x 10 -1 d kg -1 ) than for ewe muscle (6.4 x 10 -2 d kg -1 ). Concentration factors were consistently higher for 137 Cs than for the transuranics. (author)

  11. Studies of environmental radioactivity in Cumbria

    International Nuclear Information System (INIS)

    Pattenden, N.J.; Cambray, R.S.; Playford, K.

    1987-06-01

    Five stations collecting samples of atmospheric deposition were set up in north Cumbria along a line running inland from the coast for about 17 km. Sampling was continuous from September 1980 to September 1981. Monthly samples were analysed for 106 Ru, 137 Cs, 144 Ce, 238 Pu, sup(239,240)Pu, 241 Am, 7 Be and stable Na, Cl and Al. The objective of the work was to measure the deposition of radionuclides as a function of distance from the sea. By estimating the contributions to the deposition of nuclear weapon test material and of the atmospheric discharges from the British Nuclear Fuels plc works at Sellafield, the effects of the transfer to air and land of radionuclides in the sea could be established. The marine radionuclides were due to the discharges to sea from the Sellafield works. The measurements showed that the deposition was largely due to the sea-to-land transfer process. The highest depositions observed were at 20 m from high water mark, the annual values (rounded, in Bq m -2 ) being 106 Ru, 500; 137 Cs, 650; plutonium, 70; 241 Am, 30. The highest concentrations in rainwater for the radionuclides studied were less than 3 per cent of the fresh water limits (drinking only) GDL values. The highest estimated accumulations in soil due to atmospheric deposition were less than 1 per cent of the limits. (author)

  12. Assessing the carbon benefit of saltmarsh restoration

    Science.gov (United States)

    Taylor, Benjamin; Paterson, David; Hanley, Nicholas

    2016-04-01

    The quantification of carbon sequestration rates in coastal ecosystems is required to better realise their potential role in climate change mitigation. Through accurate valuation this service can be fully appreciated and perhaps help facilitate efforts to restore vulnerable ecosystems such as saltmarshes. Vegetated coastal ecosystems are suggested to account for approximately 50% of oceanic sedimentary carbon despite their 2% areal extent. Saltmarshes, conservatively estimated to store 430 ± 30 Tg C in surface sediment deposits, have experienced extensive decline in the recent past; through processes such as land use change and coastal squeeze. Saltmarsh habitats offer a range of services that benefit society and the natural world, making their conservation meaningful and beneficial. The associated costs of restoration projects could, in part, be subsidised through payment for ecosystem services, specifically Blue carbon. Additional storage is generated through the (re)vegetation of mudflat areas leading to an altered ecosystem state and function; providing similar benefits to natural saltmarsh areas. The Eden Estuary, Fife, Scotland has been a site of saltmarsh restoration since 2000; providing a temporal and spatial scale to evaluate these additional benefits. The study is being conducted to quantify the carbon benefit of restoration efforts and provide an insight into the evolution of this benefit through sites of different ages. Seasonal sediment deposition and settlement rates are measured across the estuary in: mudflat, young planted saltmarsh, old planted saltmarsh and extant high marsh areas. Carbon values being derived from loss on ignition organic content values. Samples are taken across a tidal cycle on a seasonal basis; providing data on tidal influence, vegetation condition effects and climatic factors on sedimentation and carbon sequestration rates. These data will inform on the annual characteristics of sedimentary processes in the estuary and be

  13. Cumbria PFT: Leadership Development Programme: interim evaluation report

    OpenAIRE

    Miller, Paul K.; Grimwood, Tom; Relph, Nicola; Bargh, Melissa

    2013-01-01

    This report investigates findings arising from participant feedback evaluations of the introduction day and first two modules (themselves spread over four days) of Cumbria Partnership Foundation Trust’s “Leadership Development” Programme, running 2012-2013, as part of a broader multi-method evaluation. The report summarises both quantitative and qualitative feedback, and synthesises results to provide a more three-dimensional overview. Specifically designed to provide insight into participant...

  14. Recent saltmarsh foraminiferal assemblages from Iceland

    Science.gov (United States)

    Lübbers, Julia; Schönfeld, Joachim

    2018-01-01

    This study reports for the first time boreal to subarctic intertidal foraminiferal assemblages from saltmarshes at Borgarnes and Faskrudsfjördur on Iceland. The composition of living and dead foraminiferal assemblages was investigated along transects from the tidal flat to the highest reach of halophytic plants. The foraminiferal assemblages from Borgarnes showed 18 species in the total foraminiferal assemblage of which only 7 species were recorded in the living fauna. The assemblages were dominated by agglutinated taxa, whereas 3 calcareous species were recorded, of which only Haynesina orbicularis was found in the living fauna. The distribution limit of calcifying species corresponds to the lower boundary of the lower saltmarsh vegetation zone. Furthermore, calcareous tests showed many features of dissolution, which is an indication of a carbonate corrosive environment. The species forming the dead assemblages were mainly derived from the ambient intertidal areas and were displaced by tidal currents into the saltmarsh. The foraminiferal assemblages from Faskrudsfjördur showed two species, of which only one species was recorded in the living fauna. The assemblage was dominated by the agglutinated foraminifer Trochaminita irregularis. The foraminiferal species recorded on Iceland were the same as commonly found elsewhere in Europa. Since no species was found which is endemic to North America, Iceland is considered part of the European bio province. The foraminiferal could have been immigrated to Iceland from Europe through warm water currents, migratory birds or marine traffic since the last Ice Age.

  15. Studies of environmental radioactivity in Cumbria - Pt. 18

    International Nuclear Information System (INIS)

    McKay, W.A.; Walker, M.I.

    1989-04-01

    A small fraction of the radionuclides discharged into coastal waters is blown back onto land in seaspray. Man is exposed directly through inhalation of the spray and indirectly via inhalation of resuspended soil and consumption of food stuffs. Sea to land transfer is most readily observed in Cumbria, and for the actinides plutonium and americium, where doses at the μSv year -1 level result. Another exposure route for some members of the population of the Cumbrian coast is the ingestion of actinides in seafood, particularly in winkles. In predicting the magnitude of sea to land transfer and uptake in seafood and their radiological consequence in the short and long term, some understanding of the processes controlling radionuclide levels in the adjacent near-shore waters is necessary. A recent study of Pu and Am concentrations in the coastal waters near Sellafield, Cumbria is described and discussed in this report. The results suggest that the actinides remain available for sea-to-land transfer in these near-shore waters for more than 6 years following their discharge from Sellafield. During this time, variations in suspended particulate loadings appear to be the most important influence on the seawater concentration. (author)

  16. The Approach to Cleanup at West Cumbria's Nuclear Sites

    International Nuclear Information System (INIS)

    Price, T.

    2006-01-01

    The cleanup of West Cumbria's nuclear sites is one of the most important and demanding managerial, technical and environmental challenges facing the UK over the next century. Considerable progress has already been made in cleaning up the Sellafield, Calder Hall, and Low-level Waste Repository (LLWR) sites but there remains significant challenge ahead. There are more than 200 nuclear facilities at the sites including redundant fuel storage ponds, redundant chemical plants and silos of solid waste and sludge. These legacy buildings exist alongside commercially operating reprocessing and fuel fabrication facilities. They are all linked together by a complex network of services including gas supplies, water supplies, waste disposal routes, and chemical supply routes. Many of the buildings requiring cleanup are very old and date back to the early years of the British nuclear industry. They were not designed with decommissioning in mind, and some require substantial improvement to provide a safe foundation from which to retrieve waste and decommission. The cleanup of these legacy facilities must be carefully balanced with the ongoing operations that provide services to commercial customers. Cleanup must be carried out safely and efficiently, without impacting upon commercial operations whose revenue is vital to funding the Cleanup organizations scope of work. This paper will introduce the cleanup approach at West Cumbria's Sellafield nuclear site. It will provide an overview of what is being done in preparation to meet the formidable but rewarding challenge ahead. (authors)

  17. Biological impacts of oil pollution: saltmarshes. V. 6

    International Nuclear Information System (INIS)

    1997-01-01

    Saltmarshes are priority areas for protection following oil spills, because they can trap and retain large quantities of oil and are difficult to clean. They are included in the 'most vulnerable' category of habitats, as defined by international shoreline vulnerability indices. However, whilst some oiled marshes may take decades to recover, others have shown excellent recovery within one to two years. This report considers factors affecting the fate and effects of oil on saltmarshes, and provides guidelines on clean-up options. The report includes information on the ecology and uses of saltmarshes. (UK)

  18. Studies of environmental radioactivity in Cumbria. Pt. 8

    International Nuclear Information System (INIS)

    Eakins, J.D.; Morgan, A.; Baston, G.M.N.; Pratley, F.A.; Yarnold, L.P.; Burton, P.J.

    1987-05-01

    Measurements are reported of the concentration of 239+240 Pu and 241 Am in samples of surface sand, and in sand cores, collected from the intertidal region of West Cumbria in 1983 and 1984. Measurements on sand cores enabled estimates to be made of the actinide inventories of this region together with those of the Duddon Estuary and Morecambe Bay. The combined 239+240 Pu and 241 Am activities between Silloth and Walney Island represent about 1% of the total alpha-emitting actinide activity discharged from Sellafield up to 1982. The concentrations of 239+240 Pu and 241 Am represent only 0.6 and 1% respectively of the appropriate GDL. Measurements of naturally-occurring alpha emitters in sand are included for comparison. (author)

  19. Studies of environmental radioactivity in Cumbria, Part 12

    International Nuclear Information System (INIS)

    Howorth, J.M.

    1987-12-01

    A mathematical model is described which represents the sea-to-land transfer of actinides discharged into the Irish Sea from the Sellafield reprocessing plant. The model successfully reproduces the marine distribution of plutonium and americium in the Irish Sea between Cumbria and the Isle of Man and evaluates the magnitude of the transfer process to land. The radiological consequences of this transfer are calculated for the years 1954 to 2000 taking into account actual and future predicted discharges. The contribution from nuclear weapon tests and from Sellafield's atmospheric discharges are also evaluated and compared. The calculated annual dose from sea-to-land transfer to the average person living in Seascale reached a maximum of 24 microSieverts in 1973 and declined subsequently to 4 microSieverts by 1985 compared with the recommended ICRP principal limit for the general public of 1000 microSieverts. Corresponding figures for a hypothetical critical group are 35 microSieverts in 1973 and 20 microSieverts in 1985. The dose has decreased less steeply since 1973 than the corresponding decrease in discharges from Sellafield over the same period reflecting recycling of actinides accumulated in sea-bed deposits. Dose calculations for use of the beach at Seascale are also included. (author)

  20. Radionuclide behaviour in a coniferous woodland ecosystem in Cumbria, UK

    International Nuclear Information System (INIS)

    Jones, S.R.; Copplestone, D.; Johnson, M.S.

    1996-01-01

    The behaviour of 134Cs, 137Cs, 238Pu, 239+240Pu and 241Am, in food chains in a semi-natural woodland has been investigated and doses to the ecosystem due to the presence of these radionuclides of anthropogenic origin have been assessed. The woodland is located within 1 km of the coastal British Nuclear Fuels plc (BNFL) reprocessing plant at Sellafield, Cumbria (O.S. Grid Reference: NY 037045) and has received an input of radionuclides primarily through atmospheric discharges from the Sellafield site throughout its operational history of more than 40 years. Deposition has been enhanced by interception by the canopy, such that deposits in the woodland are significantly higher than adjacent pasture land. Within the wood, deposition is greatest along the front (or leading) edge in relation to aerosols transported to the woodland from Sellafield, due to the 'edge effect'. Despite the high radionuclide deposits, relatively low uptake and mobility within the ecosystem was observed. Estimated doses to the ecosystem at around 2 mGy a -1 , were dominated by external irradiation and were well below the levels thought to be necessary to harm terrestrial ecosystems. A provisional conclusion at this stage is that the measures taken to control emissions from Sellafield in line with radiological protection standards for humans have also been adequate to protect this potentially vulnerable ecosystem

  1. Studies of environmental radioactivity in Cumbria. Pt. 8

    International Nuclear Information System (INIS)

    Eakins, J.D.; Morgan, A.; Baston, G.M.N.; Pratley, F.A.; Yarnold, L.P.; Burton, P.J.

    1988-03-01

    Sand cores and surface sand samples have been collected from the sea-facing intertidal regions of West Cumbria, between Silloth and Walney Island. Sand cores were also taken from the Duddon estuary and Morecambe Bay. The samples were collected between June 1983 and March 1984 and have been analysed for 238 Pu, 239+240 Pu and 241 Am. The integrated deposits of 239+240 Pu and 241 Am in intertidal sand between Silloth and Walney Island were about 4.2 and 7 TBq respectively. Combined, this represents about 1% of the total alpha-emitting actinide activity discharged from Sellafield to sea up to 1982; the corresponding value for the Duddon Estuary is about 0.3%. The actinide levels observed are compared to those of natural alpha emitters in intertidal sand. Only on beaches close to Sellafield did levels of discharged alpha emitters exceed those of natural alpha-emitting nuclides. In the vicinity of Sellafield, the annual dose to man from the inhalation of resuspended intertidal material is certainly less than 50 μSv (committed effective dose equivalent) and may be substantially lower. (author)

  2. The Cumbria Rural Health Forum: initiating change and moving forward with technology.

    Science.gov (United States)

    Ditchburn, Jae-Llane; Marshall, Alison

    2016-01-01

    The Cumbria Rural Health Forum was formed by a number of public, private and voluntary sector organisations to collaboratively work on rural health and social care in the county of Cumbria, England. The aim of the forum is to improve health and social care delivery for rural communities, and share practical ideas and evidence-based best practice that can be implemented in Cumbria. The forum currently consists of approximately 50 organisations interested in and responsible for delivery of health and social care in Cumbria. An exploration of digital technologies for health and care was recognised as an initial priority. This article describes a hands-on approach undertaken within the forum, including its current progress and development. The forum used a modified Delphi technique to facilitate its work on discussing ideas and reaching consensus to formulate the Cumbria Strategy for Digital Technologies in Health and Social Care. The group communication process took place over meetings and workshops held at various locations in the county. A roadmap for the implementation of digital technologies into health and social care was developed. The roadmap recommends the following: (i) to improve the health outcomes for targeted groups, within a unit, department or care pathway; (ii) to explain, clarify, share good (and bad) practice, assess impact and value through information sharing through conferences and events, influencing and advocacy for Cumbria; and (iii) to develop a digital-health-ready workforce where health and social care professionals can be supported to use digital technologies, and enhance recruitment and retention of staff. The forum experienced issues consistent with those in other Delphi studies, such as the repetition of ideas. Attendance was variable due to the unavailability of key people at times. Although the forum facilitated collective effort to address rural health issues, its power is limited to influencing and supporting implementation of change

  3. Studies of environmental radioactivity in Cumbria. Part 4 Caesium-137 and plutonium in soils of Cumbria and the Isle of Man

    International Nuclear Information System (INIS)

    Cawse, P.A.

    1980-08-01

    A network of soil sampling sites covering an area of some 2500 km 2 in Cumbria and the whole of the Isle of Man was selected and sampled in 1978. Soils from permanent grassland, coniferous woodland and deciduous woodland were examined, to a depth of 30 cm. The spatial distribution of sampling points is based on a grid of 10 km side. The objective of the study is to provide information on the integrated deposition of Cs-137, Pu-239+240 and Pu-238 from the atmosphere, and to determine the distribution of possible emissions from the nuclear establishment at Windscale in the presence of radioactivity deposited from nuclear weapons fallout, that is superimposed upon the natural background of radioactivity in soil. Results from soil samples collected in 1978 in Cumbria and the Isle of Man are compared with the average integrated deposition for UK soils from nuclear fallout. In the Isle of Man no radioactivity is observed in excess of nuclear weapons fallout, but in Cumbria excess levels of plutonium are detected in coastal lowland areas under permanent grassland probably due to the transport of radioactive material from sea to land. At three sampling sites on grassland and woodland within 2.3 km of the Windscale stacks, the excess plutonium and Cs-137 in soil could be attributed mainly to atmospheric discharges from Windscale. The observed deposition of radioactivity has little radiological significance, based on assessment of risk by inhalation of soil dust that contains plutonium. (author)

  4. Stillbirths in relation to the coastline of Cumbria, 1950-89.

    Science.gov (United States)

    Dummer, T J; Pearce, M S; Dickinson, H O; Charlton, M E; Salotti, J; Parker, L

    1999-04-01

    The nuclear installation at Sellafield, in west Cumbria in the north of England, has discharged radioactive waste into the Irish Sea since 1952. The objective of this paper was to investigate whether women living near to the coast in Cumbria had an increased risk of having stillborn children. A retrospective cohort analysis was carried out using all 259,050 births (4017 stillbirths) to women normally resident in Cumbria during 1950-89, allowing for year of birth, social class and birth order using (i) comparison of observed and expected numbers of stillbirths in distance bands relative to the coast, (ii) comparison of cumulative observed and expected numbers of stillbirths by distance from the coast, and (iii) logistic regression analysis of stillbirth risk in relation to distance from the coast. Comparison of observed and expected numbers of stillbirths in distance bands within 10 km of the coast did not provide evidence of an excess risk of stillbirth closer to the coast. The comparison of the cumulative observed and expected numbers of stillbirths within 10 km of the coast supported this result. Logistic regression analysis of all births in Cumbria showed that distance from the coast did not significantly influence stillbirth risk (P > 0.05). There was no evidence to suggest an increased risk of stillbirth in mothers resident nearer to the coast.

  5. 210Pb sediment dating in coastal transition zones: tropical saltmarshes.

    Science.gov (United States)

    Ruiz-Fernandez, A. C.; Sanchez-Cabeza, J. A.; Carnero-Bravo, V.; Perez-Bernal, L. H.

    2016-12-01

    Sea level rise (SLR) is one of the climate change effects expected to have the largest impact on coastal environments. SLR rates are not uniform around the planet and, therefore, local and regional data and trends are needed for proper adaptation plans. As long term monitoring stations of SLR are very scarce in most of the world, SLR trends obtained from 210Pb-dated sediment cores from tropical saltmarshes have become a practical alternative to obtain SLR trends within the past century, under the assumption that these ecosystems accrete at a similar rate to SLR. However, tropical saltmarshes are challenging environments for 210Pb dating: they are regularly dry, intermittently covered by seawater only during the highest tides, and sedimentary records often reflect the transition between terrestrial and marine environments (e.g. changes in grain size distribution, organic matter content and elemental composition) with all these factors contributing for atypical 210Pb depth profiles. In addition, 137Cs, the chronostratigraphic marker most commonly used to corroborate 210Pb dating, fails to be preserved in the sedimentary record in tropical areas, owing to its solubility in marine waters, if at all detectable. The present study describes the challenges and proposed solutions for 210Pb dating saltmarsh sediment cores from two saltmarsh areas (southern Gulf of California and Yucatan Peninsula) including the use of plutonium isotopes for corroboration purposes. Acknowledgements: projects CONACYT CB2010/153492 and PDCPN201301/214349; UNAM PAPIIT-IN203313 and the PRODEP network "Aquatic contamination: levels and effects" (year 3).

  6. The effects of tidal range on saltmarsh morphology

    Science.gov (United States)

    Goodwin, Guillaume; Mudd, Simon

    2017-04-01

    Saltmarshes are highly productive coastal ecosystems that act simultaneously as flood barriers, carbon storage, pollutant filters and nurseries. As halophytic plants trap suspended sediment and decay in the settled strata, innervated platforms emerge from the neighbouring tidal flats, forming sub-vertical scarps on their eroding borders and sub-horizontal pioneer zones in areas of seasonal expansion. These evolutions are subject to two contrasting influences: stochastically generated waves erode scarps and scour tidal flats, whereas tidally-generated currents transport sediment to and from the marsh through the channel network. Hence, the relative power of waves and tidal currents strongly influences saltmarsh evolution, and regional variations in tidal range yield marshes of differing morphologies. We analyse several sheltered saltmarshes to determine how their morphology reflects variations in tidal forcing. Using tidal, topographic and spectral data, we implement an algorithm based on the open-source software LSDTopoTools to automatically identify features such as marsh platforms, tidal flats, erosion scarps, pioneer zones and tidal channels on local Digital Elevation Models. Normalised geometric properties are then computed and compared throughout the spectrum of tidal range, highlighting a notable effect on channel networks, platform geometry and wave exposure. We observe that micro-tidal marshes typically display jagged outlines and multiple islands along with wide, shallow channels. As tidal range increases, we note the progressive disappearance of marsh islands and linearization of scarps, both indicative of higher hydrodynamic stress, along with a structuration of channel networks and the increase of levee volume, suggesting higher sediment input on the platform. Future research will lead to observing and modelling the evolution of saltmarshes under various tidal forcing in order to assess their resilience to environmental change.

  7. Salt-Marsh Landscapes and the Signatures of Biogeomorphic Feedbacks

    Science.gov (United States)

    D'Alpaos, A.; Marani, M.

    2014-12-01

    Salt marshes are coastal ecosystems which play a large role in the bio-geomorphological evolution of intertidal areas. The dense stands of halophytic plants which populate salt-marsh systems largely contribute to govern their dynamics, influencing marsh hydrodynamics and sediment transport through enhanced flow resistance and settling, and direct particle capture by plant stems. In addition, plants are known to increase vertical accretion through direct organic accretion. Looking across the salt-marsh landscape can one see the signatures of feedbacks between landscape and biota? Field evidence and the results of biomorphodynamic models indeed show that the interplay between physical and biological processes generates some striking biological and morphological patterns at different scales. One such pattern, vegetation zonation, consists in a mosaic of vegetation patches, of approximately uniform composition, displaying sharp transitions in the presence of extremely small topographic gradients. Here we extend the model proposed by Marani et al. (2013) to a two-dimensional framework, furthermore including the effect of direct capture of sediment particles by plant stems. This allows us to account for the effect of the drainage density of tidal networks on the observed biogeomorphic patterns and to model the coupled evolution of marsh platforms and channel networks cutting through them. A number of different scenarios have been modelled to analyze the changes induced in bio-geomorphic patterns by plants with different characteristics, within marshes characterized by different drainage densities, or subjected to changing environmental forcing such as rates of relative sea level rise and sediment supply. Model results emphasize that zonation patterns are a signature of bio-geomorphic feedbacks with vegetation acting as a landscape constructor which feeds back on, directly alters, and contributes to shape tidal environments. In addition, model results show that

  8. Tidally-driven Surface Flow in a Georgia Estuarine Saltmarsh

    Science.gov (United States)

    Young, D.; Bruder, B. L.; Haas, K. A.; Webster, D. R.

    2016-02-01

    Estuarine saltmarshes are diverse, valuable, and productive ecosystems. Vegetation dampens wave and current energy, thereby allowing the estuaries to serve as a nursery habitat for shellfish and fish species. Tidally-driven flow transports nutrients into and out of the estuary, nourishing inshore and offshore vegetation and animals. The effects of vegetation on the marsh hydrodynamics and on the estuary creek and channel flow are, unfortunately, poorly understood, and the knowledge that does exist primarily originates from modeling studies. Field studies addressing marsh surface flows are limited due to the difficulty of accurately measuring the water surface elevation and acquiring concurrent velocity measurements in the dense marsh vegetation. This study partially bridges the gap between the model observations of marsh flow driven by water surface elevation gradients and flume studies of flow through vegetation. Three current meters and three pressure transducers were deployed for three days along a transect perpendicular to the main channel (Little Ogeechee River) in a saltmarsh adjacent to Rose Dhu Island (Savannah, Georgia, USA). The pressure transducer locations were surveyed daily with static GPS yielding highly accurate water surface elevation data. During flood and ebb tide, water surface elevation differences between the marsh and Little Ogeechee River were observed up to 15 cm and pressure gradients were observed up to 0.0017 m of water surface elevation drop per m of linear distance. The resulting channel-to-saltmarsh pressure gradients substantially affected tidal currents at all current meters. At one current meter, the velocity was nearly perpendicular to the Little Ogeechee River bank. The velocity at this location was effectively modeled as a balance between the pressure gradient and marsh vegetation-induced drag force using the Darcy-Weisbach/Lindner's equations developed for flow-through-vegetation analysis in open channel flow.

  9. Saltmarsh boundary modulates dispersal of mangrove propagules: implications for mangrove migration with sea-level rise.

    Directory of Open Access Journals (Sweden)

    Jennifer M Peterson

    Full Text Available Few studies have empirically examined the suite of mechanisms that underlie the distributional shifts displayed by organisms in response to changing climatic condition. Mangrove forests are expected to move inland as sea-level rises, encroaching on saltmarsh plants inhabiting higher elevations. Mangrove propagules are transported by tidal waters and propagule dispersal is likely modified upon encountering the mangrove-saltmarsh ecotone, the implications of which are poorly known. Here, using an experimental approach, we record landward and seaward dispersal and subsequent establishment of mangrove propagules that encounter biotic boundaries composed of two types of saltmarsh taxa: succulents and grasses. Our findings revealed that propagules emplaced within saltmarsh vegetation immediately landward of the extant mangrove fringe boundary frequently dispersed in the seaward direction. However, propagules moved seaward less frequently and over shorter distances upon encountering boundaries composed of saltmarsh grasses versus succulents. We uniquely confirmed that the small subset of propagules dispersing landward displayed proportionately higher establishment success than those transported seaward. Although impacts of ecotones on plant dispersal have rarely been investigated in situ, our experimental results indicate that the interplay between tidal transport and physical attributes of saltmarsh vegetation influence boundary permeability to propagules, thereby directing the initial phase of shifting mangrove distributions. The incorporation of tidal inundation information and detailed data on landscape features, such as the structure of saltmarsh vegetation at mangrove boundaries, should improve the accuracy of models that are being developed to forecast mangrove distributional shifts in response to sea-level rise.

  10. Saltmarsh boundary modulates dispersal of mangrove propagules: implications for mangrove migration with sea-level rise.

    Science.gov (United States)

    Peterson, Jennifer M; Bell, Susan S

    2015-01-01

    Few studies have empirically examined the suite of mechanisms that underlie the distributional shifts displayed by organisms in response to changing climatic condition. Mangrove forests are expected to move inland as sea-level rises, encroaching on saltmarsh plants inhabiting higher elevations. Mangrove propagules are transported by tidal waters and propagule dispersal is likely modified upon encountering the mangrove-saltmarsh ecotone, the implications of which are poorly known. Here, using an experimental approach, we record landward and seaward dispersal and subsequent establishment of mangrove propagules that encounter biotic boundaries composed of two types of saltmarsh taxa: succulents and grasses. Our findings revealed that propagules emplaced within saltmarsh vegetation immediately landward of the extant mangrove fringe boundary frequently dispersed in the seaward direction. However, propagules moved seaward less frequently and over shorter distances upon encountering boundaries composed of saltmarsh grasses versus succulents. We uniquely confirmed that the small subset of propagules dispersing landward displayed proportionately higher establishment success than those transported seaward. Although impacts of ecotones on plant dispersal have rarely been investigated in situ, our experimental results indicate that the interplay between tidal transport and physical attributes of saltmarsh vegetation influence boundary permeability to propagules, thereby directing the initial phase of shifting mangrove distributions. The incorporation of tidal inundation information and detailed data on landscape features, such as the structure of saltmarsh vegetation at mangrove boundaries, should improve the accuracy of models that are being developed to forecast mangrove distributional shifts in response to sea-level rise.

  11. The Skallingen spit, Denmark: birth of a back-barrier saltmarsh

    Science.gov (United States)

    Bartholdy, Jesper; Brivio, Lara; Bartholdy, Anders; Kim, Daehyun; Fruergaard, Mikkel

    2018-04-01

    The formation and evolution of a modern saltmarsh platform on the barrier spit Skallingen in the northernmost part of the Wadden Sea was investigated through historical map records, 12 orthophotos covering the period from 1945 to 2012, sediment cores and cross-sectional creek profiles. The barrier spit, which constitutes the foundation of the saltmarsh platform, formed in about 50 years in the seventeenth century. After its formation the spit was left as a bare sandflat for about 200 years. Along with the development of foredunes, an increased availability of fine-grained sediment and establishment of vegetation in the beginning of the 1890s, the saltmarsh area formed in about 100 years, while the development of a large system of saltmarsh creeks took place in just ca. 50 years. The development of the drainage network, saltmarsh creek morphology and sedimentology during the saltmarsh formation are described in detail and analysed with special attention to the transformation rate from bare sandflat to a genuine vegetation-covered back-barrier saltmarsh.

  12. Investigation of the possible increased incidence of cancer in West Cumbria

    International Nuclear Information System (INIS)

    Rubery, E.D.

    1985-01-01

    The report of the Black Advisory Group on an investigation of the possible increased incidence of cancer in West Cumbria is briefly considered. The Advisory Group was unable to reach definite conclusions as to whether there is a link between discharges of radioactive material from BNFL Sellafield and the incidence of cancer due to uncertainties in the available epidemiological data and the radiation dose estimate data. The implementation of ten recommendations of the Black Advisory Group are briefly described covering epidemiological, radiation protection and organisational matters in an effort to clarify the situation and to enhance public safety. (U.K.)

  13. Radioactivity in freshwater systems in Cumbria (UK) following the Chernobyl accident

    International Nuclear Information System (INIS)

    Camplin, W.C.; Leonard, D.R.P.; Tipple, J.R.; Duckett, L.

    1989-01-01

    Sampling of fish, water, sediments and plants was carried out in freshwater systems in Cumbria (UK) to study the effects of Chernobyl fallout. Radionuclide concentrations were determined by gamma spectrometry and potassium and calcium ion concentrations in water were measured using atomic absorption spectrometry. The results contained in this report cover the period May 1986-March 1988. Caesium-134 and -137 were readily detected in all materials but ruthenium-103 and -106 were also found in a few samples. Trends in caesium concentrations in fish are difficult to establish because of the wide variation between fish of the same species. (author)

  14. Mosquito distribution in a saltmarsh: determinants of eggs in a variable environment.

    Science.gov (United States)

    Rowbottom, Raylea; Carver, Scott; Barmuta, Leon A; Weinstein, Philip; Allen, Geoff R

    2017-06-01

    Two saltmarsh mosquitoes dominate the transmission of Ross River virus (RRV, Togoviridae: Alphavirus), one of Australia's most prominent mosquito-borne diseases. Ecologically, saltmarshes vary in their structure, including habitat types, hydrological regimes, and diversity of aquatic fauna, all of which drive mosquito oviposition behavior. Understanding the distribution of vector mosquitoes within saltmarshes can inform early warning systems, surveillance, and management of vector populations. The aim of this study was to identify the distribution of Ae. camptorhynchus, a known vector for RRV, across a saltmarsh and investigate the influence that other invertebrate assemblage might have on Ae. camptorhynchus egg dispersal. We demonstrate that vegetation is a strong indicator for Ae. camptorhynchus egg distribution, and this was not correlated with elevation or other invertebrates located at this saltmarsh. Also, habitats within this marsh are less frequently inundated, resulting in dryer conditions. We conclude that this information can be applied in vector surveillance and monitoring of temperate saltmarsh environments and also provides a baseline for future investigations into understanding mosquito vector habitat requirements. © 2017 The Society for Vector Ecology.

  15. A regional-scale assessment of local renewable energy resources in Cumbria, UK

    International Nuclear Information System (INIS)

    Gormally, A.M.; Whyatt, J.D.; Timmis, R.J.; Pooley, C.G.

    2012-01-01

    There is increasing focus on the role small-scale decentralised renewable energy developments could play in helping the UK meet its target of over 15% renewable energy by the year 2020 and alter energy behaviours through active community engagement. Upland areas are considered key areas where such community-based developments could occur due to their natural resources and range of community scales. This study uses GIS-based techniques to develop a methodology that assesses the regional-scale potential for community-based renewable electricity across Cumbria and whether a combination of these developments at the community-scale could make a significant contribution to local electricity consumption. This methodology looks at a range of technologies including hydro-power, wind-power, solar PV and bioenergy. The results suggest there is ample resource available for small communities by combining a mix of localised renewable electricity developments, which is highlighted through energy scenarios for a selected community. Further work will investigate whether this potential can be realised in reality by looking at resource resilience and community-level acceptability. - Highlights: ► A mix of wind, solar, bioenergy and hydro-power options are presented for Cumbria, UK. ► High resolution spatial analysis is conducted focussing on localised developments. ► Locations with sufficient renewable electricity potential were identified. ► Renewable options are explored further through a town case study. ► Scenarios consider different scales, mixes and contributions to local energy demand.

  16. Field investigations of the transfer of caesium-137 in the pasture-cow-milk pathway in West Cumbria

    International Nuclear Information System (INIS)

    Sumerling, T.J.

    1983-01-01

    Routine discharges from the nuclear fuel reprocessing installation at Sellafield provide an opportunity to study the behaviour in the environment of several artificially produced radionuclides. Two investigations of the transfer of radionuclides in the pasture-cow-milk pathway are described. The uptake of 137 Cs by cattle grazing sea-washed pasture near Ravenglass has been investigated by in vivo measurements of the animals. A very low coefficient of transfer from feed to meat was estimated. The transfer of several radionuclides, notably 90 Sr, 137 Cs, 239 Pu and 241 Am, is being studied at a dairy farm near Sellafield. Preliminary results for 137 Cs are reported and are found to be in reasonable agreement with model predictions. (author)

  17. Florida's salt-marsh management issues: 1991-98.

    Science.gov (United States)

    Carlson, D B; O'Bryan, P D; Rey, J R

    1999-06-01

    During the 1990s, Florida has continued to make important strides in managing salt marshes for both mosquito control and natural resource enhancement. The political mechanism for this progress continues to be interagency cooperation through the Florida Coordinating Council on Mosquito Control and its Subcommittee on Managed Marshes (SOMM). Continuing management experience and research has helped refine the most environmentally acceptable source reduction methods, which typically are Rotational Impoundment Management or Open Marsh Water Management. The development of regional marsh management plans for salt marshes within the Indian River Lagoon by the SOMM has helped direct the implementation of the best management practices for these marshes. Controversy occasionally occurs concerning what management technique is most appropriate for individual marshes. The most common disagreement is over the benefits of maintaining an impoundment in an "open" vs. "closed" condition, with the "closed" condition, allowing for summer mosquito control flooding or winter waterfowl management. New federal initiatives influencing salt-marsh management have included the Indian River Lagoon-National Estuary Program and the Pesticide Environmental Stewardship Program. A new Florida initiative is the Florida Department of Environmental Protection's Eco-system Management Program with continuing involvement by the Surface Water Improvement and Management program. A developing mitigation banking program has the potential to benefit marsh management but mosquito control interests may suffer if not handled properly. Larvicides remain as an important salt-marsh integrated pest management tool with the greatest acreage being treated with temephos, followed by Bacillus thuringiensis israelensis and methoprene. However, over the past 14 years, use of biorational larvicides has increased greatly.

  18. Signatures of Biogeomorphic Feedbacks in Salt-Marsh Systems

    Science.gov (United States)

    D'Alpaos, Andrea; Marani, Marco

    2015-04-01

    Salt-marsh ecosystems which play a large role in the bio-geomorphological evolution of intertidal areas. Dense stands of halophytic vegetations which populate salt marshes largely control the dynamics of these ecosystems influencing marsh hydrodynamics and sediment transport through enhanced flow resistance and settling, and direct particle capture by plant stems. Moreover, plants are also known to increase vertical accretion through direct organic accretion. Field evidence and the results of biomorphodynamic models indeed show that the interplay between physical and biological processes generates some striking biological and morphological patterns at different scales. One such pattern, vegetation zonation, consists in a mosaic of vegetation patches, of approximately uniform composition, displaying sharp transitions in the presence of extremely small topographic gradients. Here we develop a two-dimensional model which describes the mutual interaction and adjustment between tidal flows, sediment transport and morphology mediated by vegetation influence. The model allows us describe the coupled evolution of marsh platforms and channel networks cutting through them. A number of different scenarios were modelled to analyze the changes induced in bio-geomorphic patterns by plants with different characteristics, within marshes characterized by different drainage densities, or subjected to changing environmental forcing such as rates of relative sea level rise and sediment supply. Model results emphasize that zonation patterns are a signature of bio-geomorphic feedbacks with vegetation acting as a landscape constructor which feeds back on, directly alters, and contributes to shape tidal environments. In addition, model results show that biogeomorphic feedbacks critically affect the response and the resilience of salt-marsh landscapes to changes in the environmental forcing.

  19. Keeping Wartime Memory Alive: An Oral History Project about the Wartime Memories of People with Learning Difficulties in Cumbria

    Science.gov (United States)

    Dias, John; Eardley, Malcolm; Harkness, Elizabeth; Townson, Louise; Brownlee-Chapman, Chloe; Chapman, Rohhss

    2012-01-01

    This article discusses an oral history project funded by the Heritage Lottery. It recorded the memories of eight people with learning difficulties during the Second World War in Cumbria, UK, before their personal histories were lost forever. This qualitative, inclusive research project was supported by various organisations. The process of…

  20. Analysis of the RB1 gene in children with retinoblastoma having residential connections to West Cumbria, England

    Energy Technology Data Exchange (ETDEWEB)

    Cowell, J K [Department of Cancer Genetics, Roswell Park Cancer Institute, Buffalo, NY 14263 (United States); Morris, J A [Department of Pathology, Royal Lancaster Infirmary, Lancaster LA1 4RP (United Kingdom); Tawn, E J [Westlakes Research Institute, Moor Row, Cumbria CA24 3JY (United Kingdom)

    2005-03-01

    Six of eight cases of retinoblastoma previously identified as having a residential association with West Cumbria, England, in which the Sellafield nuclear installation is situated, were examined for the presence of a constitutional RB1 mutation. No mutations were detected, thus providing strong evidence against an environmental or occupational genotoxic effect causing germline mutations in the parents of these children. (note)

  1. A survey of radioactive caesium in soils of Cumbria and North Lancashire

    International Nuclear Information System (INIS)

    Baker, S.J.; Cawse, P.A.

    1990-09-01

    A network of soil sampling sites covering an area of some 2500km 2 in Cumbria was sampled by Harwell Laboratory in 1978. The spatial distribution of sampling points was based on a grid of 10km side, thus providing 30 sites under permanent grassland. In 1979, the grid was extended northwards to Carlisle and in a southerly direction to Fleetwood, Lancashire, giving a further 24 sites. This provided a reference baseline of background radioactivity, mainly arising from the accumulated atmospheric deposition of fallout from nuclear weapons tests over some 30 years, and also determined the distribution of emissions from the nuclear establishment at Sellafield that is superimposed upon the natural background of radioactivity in soil. The grid survey has now been repeated in 1988/89 to record increases in radioactive caesium caused by fallout from the accident at Chernobyl, USSR, in April 1986. The accumulated depositions of 137 Cs recorded to 30cm soil depth in 1988/89 were in the range 2.0 (at Bowness on Solway) to 28kBq/m 2 (at Eskmeals). A comparison of results obtained pre-Chernobyl (in 1978) with post-Chernobyl values assessed ten years later shows increases of 137 Cs accumulations at 18 of the surveys sites, 1.5 to 2-fold at 20 sites, 2 to 4 fold at 13 sites and 4 to 7 fold at St Bees, Harrington and Little Annaside (near Bootle, Cumbria). Ratios of Cs-137/Cs-134 at 0-15cm depth of soil were in the range 3.0 - 26.4 in 1988/89, compared with a ratio of ∼ 3.0 in Chernobyl fallout when decay-corrected. Lowest ratios occurred in west Cumbria which showed the highest accumulations of Cs-137 between 290-330km easting and 480-530km northing. The retention of Cs-137 by the top 15cm of soil in 1988/89 relative to the accumulation to 30cm depth averaged 87% compared with 78% in the pre-Chernobyl survey made in 1978/79, and is attributed to surface accumulation of debris from the accident. (author)

  2. A study of fish and shellfish radioactivity levels within the Cumbria Sea Fisheries District

    International Nuclear Information System (INIS)

    McKay, W.A.; Latawiec, D.

    1986-11-01

    Fish (cod, plaice, whiting and skate), crustacea (shrimp and Nephrops) and mollusc (winkle) samples have been collected from the Cumbria Sea Fisheries District between November 1984 and end of December 1985. The samples have been counted for total beta activity, and a range of gamma and alpha emitters have been determined. The mean levels over the study period are, in general, of the same order as found by MAFF in 1984 in Cumbrian coastal waters and thus the dose from these nuclides on eating this seafood would be expected to be similar to 1984, within the ICRP principal dose limit of 1 mSv year -1 , assuming similar consumption rates. Most of the radiation dose to the critical group within the Cumbrian community comes through winkle consumption. (author)

  3. Tidal events and salt-marsh structure influence black mangrove (Avicennia germinans) recruitment across an ecotone.

    Science.gov (United States)

    Peterson, Jennifer M; Bell, Susan S

    2012-07-01

    Field experiments were conducted at a black mangrove-salt-marsh ecotone in southwest Florida (U.S.A.) to investigate retention of propagules of the black mangrove, Avicennia germinans, by salt-marsh plants as a mechanism of facilitation operating on recruitment success at landward boundaries. Buoyant A. germinans propagules are dispersed by tides, and stranding is required for establishment; therefore, processes that enable stranding should facilitate mangrove recruitment. We expected the physical structure of salt-marsh vegetation to define propagule retention capacity, and we predicted that salt-marsh plants with distinct growth forms would differentially retain propagules. Experimental monoculture plots (1 m2) of salt-marsh plants with different growth forms (Sporobolus virginicus [grass], Sesuvium portulacastrum [succulent forb], and Batis maritima [succulent scrub]) were created, and A. germinans propagules were emplaced into these plots and monitored over time. For comparison, propagules were also placed into natural polyculture plots (1 m2). Polyculture plots contained at least two of the salt-marsh plant taxa selected for monoculture treatments, and S. virginicus was always present within these polyculture plots. Natural polyculture plots retained 59.3% +/- 11.0% (mean +/- SE) of emplaced propagules. Monocultures varied in their propagule retention capacities with plots of S. virginicus retaining on average 65.7% +/- 11.5% of transplanted propagules compared to 7.2% +/- 1.8% by B. maritima and 5.0% +/- 1.9% by S. portulacastrum. Plots containing S. virginicus retained a significantly greater percentage of emplaced propagules relative to the two succulent salt-marsh taxa. Furthermore, propagule entrapment, across all treatments, was strongly correlated with salt-marsh structure (r2 = 0.6253, P = 0.00001), which was estimated using an indirect quantitative metric (lateral obstruction) calculated from digital images of plots. Overall, our findings imply that

  4. The impact of erosion protection by Stone Dams on Salt-Marsh vegetation on Two Wadden Sea Barrier Islands

    NARCIS (Netherlands)

    Loon-Steensma, van J.M.; Slim, P.A.

    2013-01-01

    This paper describes and quantifies the effect of low stone dams on the extent and composition of salt-marsh habitats on two Dutch Wadden islands: Terschelling and Ameland. The stone dams were built to prevent erosion of the salt-marsh edge. Analyses of a series of aerial photographs taken between

  5. Vegetation response to soil salinity and waterlogging in three saltmarsh hydrosequences through macronutrients distribution

    Science.gov (United States)

    Ferronato, Chiara; Speranza, Maria; Ferroni, Lucia; Buscaroli, Alessandro; Vianello, Gilmo; Vittori Antisari, Livia

    2018-01-01

    Saltmarshes consist of soil hydrosequences, where the complex interactions between water tide fluctuations, soil physicochemical properties and plant colonization contribute to the triggering of the pedogenetic processes and consequently to the stability of the saltmarsh edges. In this study, the composition and richness of the vegetation cover were investigated along soil transects in three different saltmarshes. With the aim to investigate the response of the vegetation to the soil hydroperiod and its influence on the availability of soil nutrients, plant and soil samples were collected in four representative sites on each saltmarsh transect (hydrosequence). Among the different species of saltmarshes, L. vulgare and S. europaea colonized intertidal areas, where an accumulation of nutrients (Ca, K, P, S and Na) and organic C and total N (OC and TN, respectively) was found. These intertidal areas are the "critical transition zones", which drive the transition between the terrestrial and the aquatic systems along the increase of soil salinity and water saturation. Among the different element cycles analysed in the soil-plant system, the analysis of the Na and S dynamic, through both bioconcentration and translocation indexes, explains the different adaptation mechanisms to different salinity and waterlogging stressors. The limiting of the species areal was generally associated firstly with a decrease in their Na and S bioconcentration factor and, to a lesser extent, with the increase in their Na and S translocation.

  6. Saltmarsh creek bank stability: Biostabilisation and consolidation with depth

    Science.gov (United States)

    Chen, Y.; Thompson, C. E. L.; Collins, M. B.

    2012-03-01

    The stability of cohesive sediments of a saltmarsh in Southern England was measured in the field and the laboratory using a Cohesive Strength Meter (CSM) and a shear vane apparatus. Cores and sediment samples were collected from two tidal creek banks, covered by Atriplex portulacoides (Sea Purslane) and Juncus maritimus (Sea Rush), respectively. The objectives of the study were to examine the variation of sediment stability throughout banks with cantilevers present and investigate the influence of roots and downcore consolidation on bank stability. Data on erosion threshold and shear strength were interpreted with reference to bank depth, sediment properties and biological influences. The higher average erosion threshold was from the Sea Purslane bank whilst the Sea Rush bank showed higher average vane shear strength. The vertical variation in core sediment stability was mainly affected by roots and downcore consolidation with depth. The data obtained from the bank faces revealed that vertical variations in both erosion threshold and vane shear strength were affected primarily by roots and algae. A quantitative estimate of the relative contributions of roots and downcore consolidation to bank sediment stability was undertaken using the bank stability data and sediment density data. This showed that roots contributed more to the Sea Purslane bank stability than downcore consolidation, whilst downcore consolidation has more pronounced effects on the Sea Rush bank stability.

  7. Study of erosion processes in the Tinto salt-marshes with remote sensing images.

    Science.gov (United States)

    2016-01-01

    Both climatic factors and the sea wave energy are two important factors to study the tidal wetlands. One of the most important wetlands in the Southwest of the Iberian Peninsula is the Tinto salt-marshes, the third largest wetland in Andalusia after ...

  8. Characterization of the nest site preferences of Saltmarsh and Nelson's Sparrows, and hybrids

    Science.gov (United States)

    Saltmarsh Sparrows (hereafter SALS) are named on the National Audubon Society’s current WatchList as a species of global conservation concern (National Audubon Society 2007). Anthropogenic climate change is perhaps the largest threat to SALS populations because sea level ri...

  9. Comparison of Bottomless Lift Nets and Breder Traps for Sampling Salt-Marsh Nekton

    Science.gov (United States)

    Vegetated salt-marsh surfaces provide refuge, forage, and spawning habitat for estuarine nekton, yet are threatened by accelerating rates of sea-level rise in southern New England and elsewhere. Nekton responses to ongoing marsh surface changes need to be evaluated with effective...

  10. Interactions between the range expansion of saltmarsh vegetation and hydrodynamic regimes in the Yangtze Estuary, China

    NARCIS (Netherlands)

    Zhu, Z.; Zhang, L.; Wang, N.; Schwarz, C.; Ysebaert, T.

    2012-01-01

    >Over the last 15 years, rapid invasion of large areas of the saltmarshes of Chongming Island, in the Yangtze Estuary, China by the exotic species Spartina alterniflora has occurred. Two types of advancing fronts are found: the S. alterniflora–mudflat (S–M front) and the S.

  11. The impact of herbivores on nitrogen mineralization rate : consequences for salt-marsh succession

    NARCIS (Netherlands)

    van Wijnen, HJ; van der Wal, R; Bakker, JP

    Soil net N-mineralization rate was measured along a successional gradient in salt-marsh sites that were grazed by vertebrate herbivores, and in 5-year-old exclosures from which the animals were excluded. Mineralization rate was significantly higher at ungrazed than at grazed sites. In the absence of

  12. Petrographic and sedimentological characteristics of drift sediments from the radiotracer experiment array at Drigg, Cumbria

    International Nuclear Information System (INIS)

    Milodowski, A.E.

    1990-11-01

    A detailed petrographic, mineralogical and sedimentological study has been made of five drift sediment cores taken from shallow boreholes at Drigg, Cumbria, forming part of the British Geological Survey's migration test borehole array. The cores correspond to the aquifer in which tests are undertaken. The study shows that several discrete units can be recognised within the aquifer but that these may vary laterally by a considerable amount over short distances. The sands and silts comprising the aquifer zone are generally finely laminated and show an upwards coarsening of grain size. They are interpreted as proximal glacial sediments, possibly having been deposited in a lake or ponded basin. Petrographic analysis shows that most of the porosity is lined by detrital ferruginous illitic clay which coats the sand grains. Some evidence of feldspar dissolution is identified. Pyrite is also present as an important detrital component. In the upper part of the aquifer the pyrite has been largely oxidised to form secondary ferric oxide compounds. However, pyrite increases in abundance with depth and its preservation may reflect a variation in redox across the aquifer. (author)

  13. Factors contributing to radiocaesium variability in upland sheep flocks in west Cumbria (United Kingdom)

    International Nuclear Information System (INIS)

    Beresford, N.A.; Barnett, C.L.; Wright, S.M.; Howard, B.J.; Crout, N.M.J.

    2007-01-01

    Following the Chernobyl accident in 1986, restrictions were placed on the movement and slaughter of sheep within upland areas of the UK because radiocaesium activity concentrations in their meat exceeded 1000 Bq kg -1 fresh weight. Some farms remain under restriction in 2007. From 1991 to 1993 detailed studies were conducted on three sheep farms within the restricted area of west Cumbria to systematically assess the various parameters which may contribute to the observed variability in radiocaesium activity concentrations within sheep flocks. This paper reports the spatial variation in soil and vegetation activity concentrations across the grazed areas at these farms and determines the influence of grazing behaviour on variability in 137 Cs activity concentrations between individual sheep within the flocks. Together with previously reported results, these new data are used to draw conclusions on the factors determining variability within the three flocks. However, the factors are too site specific to be able to generalise the findings to other farms within the restricted areas of the UK

  14. Measurements of α-emitting plutonium and americium in the intertidal sands of west Cumbria, UK

    International Nuclear Information System (INIS)

    Eakins, J.D.; Morgan, A.; Baston, G.M.N.; Pratley, F.W.; Strange, L.P.; Burton, P.J.

    1990-01-01

    Samples of surface sand and sand cores were collected from intertidal regions of west Cumbria between Silloth and Walney Island (including the Duddon Estuary) between 1982 and 1984 and analysed for 238 Pu, 239+240 Pu and 241 Am. Generally, more than 95% of the α-emitting transuranic nuclides were associated with the sand and less than 5% with entrained silt. The greatest concentrations of both plutonium and americium were found at Braystones. Concentrations declined with distance from the Sellafield Works. The largest actinide deposits occurred at Drigg (320 and 720 kBq m -2 of 239+240 Pu and 241 Am respectively). The integrated deposits in intertidal sand between Silloth and Walney Island were about 4.2 and 7.0 TBq respectively, which represent about 1% of the total α-emitting activity discharged to sea from Sellafield Works up to 1982. The corresponding value for the Duddon Estuary is about 0.3%. Only on beaches close to Sellafield did levels of man-made α-emitters exceed those of natural α-emitting nuclides. The radiological consequences of the intertidal inventory of plutonium and americium are shown to be very small and much less than from the seafood pathway. (author)

  15. Measurements of. alpha. -emitting plutonium and americium in the intertidal sands of west Cumbria, UK

    Energy Technology Data Exchange (ETDEWEB)

    Eakins, J.D.; Morgan, A.; Baston, G.M.N.; Pratley, F.W.; Strange, L.P.; Burton, P.J. (UKAEA Harwell Lab. (UK). Environmental and Medical Science Div.)

    1990-01-01

    Samples of surface sand and sand cores were collected from intertidal regions of west Cumbria between Silloth and Walney Island (including the Duddon Estuary) between 1982 and 1984 and analysed for {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am. Generally, more than 95% of the {alpha}-emitting transuranic nuclides were associated with the sand and less than 5% with entrained silt. The greatest concentrations of both plutonium and americium were found at Braystones. Concentrations declined with distance from the Sellafield Works. The largest actinide deposits occurred at Drigg (320 and 720 kBq m{sup -2} of {sup 239+240}Pu and {sup 241}Am respectively). The integrated deposits in intertidal sand between Silloth and Walney Island were about 4.2 and 7.0 TBq respectively, which represent about 1% of the total {alpha}-emitting activity discharged to sea from Sellafield Works up to 1982. The corresponding value for the Duddon Estuary is about 0.3%. Only on beaches close to Sellafield did levels of man-made {alpha}-emitters exceed those of natural {alpha}-emitting nuclides. The radiological consequences of the intertidal inventory of plutonium and americium are shown to be very small and much less than from the seafood pathway. (author).

  16. Doses to Terrestrial Biota in the Vicinity of BNFL Sellafield, Cumbria, UK (invited paper)

    Energy Technology Data Exchange (ETDEWEB)

    Copplestone, D.; Johnson, M.S.; Jackson, D.; Jones, S.R

    2000-07-01

    Source terms and corresponding radionuclide activity concentrations in biota for {sup 134}Cs, {sup 137}Cs, {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am have been assessed for three semi-natural ecosystems in the vicinity of BNFL Sellafield, Cumbria, UK. Estimates of absorbed doses (mGy.d{sup -1}) have been calculated. Doses to key indicator species, Oniscus asellus (detritivorous invertebrate), Carabus violaceous (predatory invertebrate) and Apodemus sylvaticus (granivorous wood mouse) are discussed with reference to the 1 mGy.d{sup -1} level, below which it is postulated that no observable effects on populations in a terrestrial ecosystem occur. Implications for the 'critical group' and 'reference model' approaches for a framework of radiological environmental protection are discussed. The need to assess the most highly exposed species is advanced. New research focused on the application of biomarker techniques as a mechanism for determining the interactions and effects of environmental contaminants on ecosystem structure and functioning is presented. (author)

  17. Measurement of artificial radionuclides in whole diets around the BNF plc reprocessing plant at Sellafield, Cumbria

    International Nuclear Information System (INIS)

    Mondon, K.J.; Walters, B.

    1993-01-01

    The Ministry of Agriculture, Fisheries and Food has conducted a duplicate diet study around the BNF reprocessing plant of Sellafield in Cumbria. Samples were collected from adults and children. The results of analyses for a number of artificial radionuclides are reported; dose calculations using actual food intakes have also been made. Samples were obtained in both winter (phase 1) and summer (phase 11), between which times the Chernobyl accident occurred, making site-specific dose assessment from caesium isotopes difficult in summer samples. Control diets were collected from a coastal area in Lancashire. Average annual doses based on pre-Chernobyl sampling ranged from 2 μSv in control children to 14 μSv in study adults. This range increased to 9-50 μSv in the second phase of the study. Maximum individual doses were 86 μSv in phase 1 and 102 μ in phase 11, these being well within the government's target dose for members of the public. (author)

  18. Mineralogy and petrography of samples of Permo-Triassic sedimentary strata from Cumbria

    International Nuclear Information System (INIS)

    Kemp, S.J.; Milodowski, A.E.; Bloodworth, A.J.

    1989-03-01

    The mineralogy and petrography of Permo-Triassic sediments from Cumbria are described. The samples are duplicates of those selected for sorption experiments by Harwell Laboratory and are considered representative of Permo-Triassic strata underlying the BNFL Sellafield site. The regional geological context of the samples is briefly discussed. X-ray diffraction analysis indicates that the St Bees Sandstone and Eden Shales samples are predominantly composed of quartz with minor feldspar, gypsum and hematite. The clay assemblage is formed of dioctahedral mica and trioctahedral chloride with minor kaolinite. Diagnostic testing also reveals the presence of corrensite, a regularly interstratified chlorite-smectite, in one of the samples. Possible diagenetic processes responsible for corrensite formation, including the alteration of originally deposited smectite by magnesium-rich pore waters, are discussed. Modelling of the diffraction profile indicates that the chlorite and corrensite are iron-rich species. Back scattered electron microscopy shows the samples to be typical red bed sediments exhibiting framework grain dissolution, the breakdown and replacement of unstable ferromagnesian minerals being accompanied by the precipitation of hematite and anatase. Particle-size analysis shows similar distributions for the St Bees Sandstone samples but a greater proportion of clay material in the Eden Shales. (author)

  19. The role of changing climate in driving the shift from perennial grasses to annual succulents in a Mediterranean saltmarsh

    NARCIS (Netherlands)

    Strain, E.M.A.; van Belzen, J.; Comandini, P.; Wong, J.; Bouma, T.J.; Airoldi, L.

    2017-01-01

    Changing climate threatens the structure and function of saltmarshes, which are often severely degraded by other human perturbations. Along the Mediterranean coastline, increasing temperature and decreasing rainfall have been hypothesised to trigger habitat shifts from perennial grasses to annual

  20. Leaching studies of low-level waste as input to radiological assessment at the Drigg disposal site, Cumbria

    International Nuclear Information System (INIS)

    Poulton, J.; Rushbrook, P.E.

    1989-01-01

    Over the period of operation of the low-level waste disposal site at Drigg in Cumbria, several radiological assessments have been carried out. This paper discusses data requirements for such an assessment and in particular describes a project to measure the leaching behaviour of wastes. This project, jointly set up by the staff of BNFL and Environmental Safety Centre at Harwell, began in 1985. The objectives were to determine the processes operating within the waste disposal trenches at Drigg and conditions affecting them. The paper describes the installation and operation of the first of a series of lysimeters designed to simulate conditions in current trenches. (author)

  1. Development of autochthonous microbial consortia for enhanced phytoremediation of salt-marsh sediments contaminated with cadmium

    International Nuclear Information System (INIS)

    Teixeira, Catarina; Almeida, C. Marisa R.; Nunes da Silva, Marta; Bordalo, Adriano A.; Mucha, Ana P.

    2014-01-01

    Microbial assisted phytoremediation is a promising, though yet poorly explored, new remediation technique. The aim of this study was to develop autochthonous microbial consortia resistant to cadmium that could enhance phytoremediation of salt-marsh sediments contaminated with this metal. The microbial consortia were selectively enriched from rhizosediments colonized by Juncus maritimus and Phragmites australis. The obtained consortia presented similar microbial abundance but a fairly different community structure, showing that the microbial community was a function of the sediment from which the consortia were enriched. The effect of the bioaugmentation with the developed consortia on cadmium uptake, and the microbial community structure associated to the different sediments were assessed using a microcosm experiment. Our results showed that the addition of the cadmium resistant microbial consortia increased J. maritimus metal phytostabilization capacity. On the other hand, in P. australis, microbial consortia amendment promoted metal phytoextraction. The addition of the consortia did not alter the bacterial structure present in the sediments at the end of the experiments. This study provides new evidences that the development of autochthonous microbial consortia for enhanced phytoremediation of salt-marsh sediments contaminated with cadmium might be a simple, efficient, and environmental friendly remediation procedure. Capsule abstract: Development of autochthonous microbial consortia resistant to cadmium that enhanced phytoremediation by salt-marsh plants, without a long term effect on sediment bacterial diversity. - Highlights: • Cd resistant microbial consortia were developed and applied to salt-marsh sediments. • In Phragmites australis the consortia amendment promoted metal phytoextraction. • The consortia addition increased Juncus maritimus phytostabilization capacity. • No long term changes on the rhizosediment bacterial structure were observed

  2. Development of autochthonous microbial consortia for enhanced phytoremediation of salt-marsh sediments contaminated with cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Catarina [Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Laboratório de Hidrobiologia e Ecologia, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto (Portugal); Almeida, C. Marisa R.; Nunes da Silva, Marta [Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Bordalo, Adriano A. [Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Laboratório de Hidrobiologia e Ecologia, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto (Portugal); Mucha, Ana P., E-mail: amucha@ciimar.up.pt [Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto (Portugal)

    2014-09-15

    Microbial assisted phytoremediation is a promising, though yet poorly explored, new remediation technique. The aim of this study was to develop autochthonous microbial consortia resistant to cadmium that could enhance phytoremediation of salt-marsh sediments contaminated with this metal. The microbial consortia were selectively enriched from rhizosediments colonized by Juncus maritimus and Phragmites australis. The obtained consortia presented similar microbial abundance but a fairly different community structure, showing that the microbial community was a function of the sediment from which the consortia were enriched. The effect of the bioaugmentation with the developed consortia on cadmium uptake, and the microbial community structure associated to the different sediments were assessed using a microcosm experiment. Our results showed that the addition of the cadmium resistant microbial consortia increased J. maritimus metal phytostabilization capacity. On the other hand, in P. australis, microbial consortia amendment promoted metal phytoextraction. The addition of the consortia did not alter the bacterial structure present in the sediments at the end of the experiments. This study provides new evidences that the development of autochthonous microbial consortia for enhanced phytoremediation of salt-marsh sediments contaminated with cadmium might be a simple, efficient, and environmental friendly remediation procedure. Capsule abstract: Development of autochthonous microbial consortia resistant to cadmium that enhanced phytoremediation by salt-marsh plants, without a long term effect on sediment bacterial diversity. - Highlights: • Cd resistant microbial consortia were developed and applied to salt-marsh sediments. • In Phragmites australis the consortia amendment promoted metal phytoextraction. • The consortia addition increased Juncus maritimus phytostabilization capacity. • No long term changes on the rhizosediment bacterial structure were observed.

  3. The transfer of radionuclides from saltmarsh vegetation to sheep tissues and milk

    Energy Technology Data Exchange (ETDEWEB)

    Beresford, N.A. [Centre for Ecology and Hydrology, CEH-Lancaster, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom)], E-mail: nab@ceh.ac.uk; Howard, B.J. [Centre for Ecology and Hydrology, CEH-Lancaster, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Mayes, R.W.; Lamb, C.S. [Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen AB15 8QH (United Kingdom)

    2007-11-15

    Radionuclides released into the Irish Sea by the Sellafield reprocessing plant are deposited onto tide-washed pastures along the western coast of the United Kingdom. Many of these pastures are grazed by sheep or cattle. This paper describes a controlled feeding study, in which saltmarsh vegetation harvested from close to the Sellafield plant, was fed to lambs and adult female sheep for a period of 8 weeks. Activity concentrations of {sup 60}Co, {sup 95}Nb, {sup 106}Ru, {sup 134}Cs, {sup 137}Cs, {sup 238}Pu, {sup 239,240}Pu and {sup 241}Am were determined in edible tissues and transfer parameters estimated. The activity concentrations of some of the radionuclides will not have been in equilibrium with those in the diet. Nevertheless, the study was reasonably realistic in terms of agricultural management as the period of the study was similar to that for which lambs graze on the saltmarshes. A field study to determine the activity concentrations of {sup 137}Cs and {sup 239,240}Pu in the milk of ewes grazing a saltmarsh close to Sellafield is also described.

  4. Ecotone analysis: assessing the impact of vehicle transit on saltmarsh crab population and ecosystem.

    Science.gov (United States)

    Trave, Claudia; Sheaves, Marcus

    2014-01-01

    The frequent transit of vehicles (recreational or not) through saltpans and saltmarsh fields has been recorded as one of the major causes of physical and ecological damage for these environments. While several studies have been carried out to assess the consequence of this anthropogenic activity on the different local plant species, little is known on its long-term impact on the faunal community. Invertebrates, such as crabs, provide several essential ecological services, and their presence and abundance are tightly connected to that of the saltmarsh plants. Decrease of vegetative cover due to vehicle transit is likely to cause alterations in the morphology and the composition of the saltmarsh ecosystem. In this study we evaluate presence and distribution of the main crustacean species in several impacted sites in Townsville area (Queensland, Australia), to determine possible correlation between vehicle tracks alterations and crab distribution, as well as investigate any possible habitat shift in the mid- and long-term. Results indicate that reduction of plant cover affects species composition and distribution, with different effects based on the unique characteristics of each crab species analysed, resulting in an overall alteration of the assemblage structure.

  5. Comparative analysis of Worldview-2 and Landsat 8 for coastal saltmarsh mapping accuracy assessment

    Science.gov (United States)

    Rasel, Sikdar M. M.; Chang, Hsing-Chung; Diti, Israt Jahan; Ralph, Tim; Saintilan, Neil

    2016-05-01

    Coastal saltmarsh and their constituent components and processes are of an interest scientifically due to their ecological function and services. However, heterogeneity and seasonal dynamic of the coastal wetland system makes it challenging to map saltmarshes with remotely sensed data. This study selected four important saltmarsh species Pragmitis australis, Sporobolus virginicus, Ficiona nodosa and Schoeloplectus sp. as well as a Mangrove and Pine tree species, Avecinia and Casuarina sp respectively. High Spatial Resolution Worldview-2 data and Coarse Spatial resolution Landsat 8 imagery were selected in this study. Among the selected vegetation types some patches ware fragmented and close to the spatial resolution of Worldview-2 data while and some patch were larger than the 30 meter resolution of Landsat 8 data. This study aims to test the effectiveness of different classifier for the imagery with various spatial and spectral resolutions. Three different classification algorithm, Maximum Likelihood Classifier (MLC), Support Vector Machine (SVM) and Artificial Neural Network (ANN) were tested and compared with their mapping accuracy of the results derived from both satellite imagery. For Worldview-2 data SVM was giving the higher overall accuracy (92.12%, kappa =0.90) followed by ANN (90.82%, Kappa 0.89) and MLC (90.55%, kappa = 0.88). For Landsat 8 data, MLC (82.04%) showed the highest classification accuracy comparing to SVM (77.31%) and ANN (75.23%). The producer accuracy of the classification results were also presented in the paper.

  6. Methane and carbon dioxide fluxes from Limonium residues decomposition in saltmarsh soils: effects of tide regime

    Directory of Open Access Journals (Sweden)

    Elisa Pellegrini

    2015-12-01

    Full Text Available The flooding regime of saltmarshes strongly affects organic matter mineralisation, representing a unique situation where oxygen diffusion is either impeded by submersion or favoured by retreating water in regular cycles within the same day. Decomposition of Limonium vulgare Mill. residues in saltmarsh soils was evaluated measuring CO2 and CH4 emissions. Four different saltmarshes from the Grado Lagoon (Northern Adriatic Sea were investigated. Soils were characterised by a similar vegetation (Sarcocornietea class and similar high coverage of L. vulgare (70-75% but differed in redox potential, texture and organic carbon content. Hydromorphic conditions were reproduced in mesocosms, and soils were 20 incubated under fully aerobic, fully anaerobic and transient (6 hours cycles tidal states. Partially decomposed litter (leaves of L. vulgare was added and 22 decomposition processes were monitored through CO2 and CH4 emissions. Larger CO2 emissions were measured under aerobic conditions, in particular in soil samples with coarse texture. Fully anoxic and tidal regimes showed a similar behaviour. On the contrary, CH4 emissions were less dependent upon flooding, showing only slightly larger values under completely submerged conditions. Larger CH4 emissions have been obtained in fine textured soils. Soil organic matter content also influenced gas emissions: larger values corresponded to higher emissions of both CO2 and CH4.

  7. Development of autochthonous microbial consortia for enhanced phytoremediation of salt-marsh sediments contaminated with cadmium.

    Science.gov (United States)

    Teixeira, Catarina; Almeida, C Marisa R; Nunes da Silva, Marta; Bordalo, Adriano A; Mucha, Ana P

    2014-09-15

    Microbial assisted phytoremediation is a promising, though yet poorly explored, new remediation technique. The aim of this study was to develop autochthonous microbial consortia resistant to cadmium that could enhance phytoremediation of salt-marsh sediments contaminated with this metal. The microbial consortia were selectively enriched from rhizosediments colonized by Juncus maritimus and Phragmites australis. The obtained consortia presented similar microbial abundance but a fairly different community structure, showing that the microbial community was a function of the sediment from which the consortia were enriched. The effect of the bioaugmentation with the developed consortia on cadmium uptake, and the microbial community structure associated to the different sediments were assessed using a microcosm experiment. Our results showed that the addition of the cadmium resistant microbial consortia increased J. maritimus metal phytostabilization capacity. On the other hand, in P. australis, microbial consortia amendment promoted metal phytoextraction. The addition of the consortia did not alter the bacterial structure present in the sediments at the end of the experiments. This study provides new evidences that the development of autochthonous microbial consortia for enhanced phytoremediation of salt-marsh sediments contaminated with cadmium might be a simple, efficient, and environmental friendly remediation procedure. Development of autochthonous microbial consortia resistant to cadmium that enhanced phytoremediation by salt-marsh plants, without a long term effect on sediment bacterial diversity. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Spatio-temporal changes of a mangrove–saltmarsh ecotone in the northeastern coast of Florida, USA

    Directory of Open Access Journals (Sweden)

    Wilfrid Rodriguez

    2016-07-01

    Full Text Available General circulation models predict warming trends and changes in temperature and precipitation patterns that have the potential to alter the structure and function of coastal habitats. The purpose of this study was to quantify the expansion and contraction of mangroves and saltmarsh habitats and assess the impact of climate on these landscape changes. The study was conducted in a mangrove/saltmarsh ecotone in Flagler County, FL, near the northern range limit of mangroves along the Atlantic coast of North America. We used time series of historical aerial photography and high-resolution multispectral satellite imagery from 1942 to 2013 to quantify changes in the extent of mangrove and saltmarsh vegetation and compared these changes to climate variables of temperature and precipitation, temperature–seasonality, as well as historical sea-level data. Results showed increases in mangrove extent of 89% between 1942 and 1952, and a continuous increase from 1995 to 2013. Largest decrease in saltmarsh extent occurred between 1942 and 1952 (-136% and between 2008 and 2013 (-81%. We found significant effects of precipitation, temperature, seasonality, and time on mangrove and saltmarsh areal extent. The statistical effect of sea-level was rather small, but we speculate that it might have ecological impacts on these two coastal ecosystems. Results also showed a cyclical dynamism as well as a reversal in habitat dominance, which may be the result of complex interactions between plant habitats and several environmental drivers of change such as species interactions, and hydrological changes induced by sea-level rise, in addition to temperature and precipitation effects. Our results on mangrove/saltmarsh expansion and contraction may contribute to the improvement of management and conservation strategies for coastal ecosystems being impacted by climate change.

  9. Mechanisms for accumulation and migration of technetium-99 in saltmarsh sediments

    International Nuclear Information System (INIS)

    Wigley, F.

    2000-06-01

    This thesis describes the development of analytical methods for both the bulk determination of 99 Tc, and determination of 99 Tc in sequential extracts from sediments. These methods have been used to collect data, which, along with trace and major element data have been used to interpret the mechanisms for 99 Tc input, migration and accumulation in saltmarshes. The inventory of 99 Tc stored in the Thornflatt Saltmarsh, Esk Estuary has also been determined. The routine determination of 99 Tc in bulk samples uses 99m Tc as a yield monitor. Samples are ignited stepwise to 550 deg. C and the 99 Tc is extracted using 8M nitric acid. Many contaminants are precipitated with Fe(OH) 3 and the Tc in the supernant is pre-concentrated and further purified using anion-exchange chromatography. Final separation of Tc from Ru is achieved by extraction of Tc into 5% TnOA in xylene from 2M sulphuric acid. The yield is determined by γ-spectrometric analysis of 99m Tc. Determination of 99 Tc is made by liquid scintillation counting. Typical recoveries are in the order of 70-95% and the method has a detection limit of 1.7 Bq/kg for a sample size of 10g. Determination of Tc in sequential extracts uses operationally defined procedures to extract: exchangeable Tc, reducible Tc and oxidisable Tc. An initial water wash is used to extract any occluded Tc and a final leach in 8 M nitric acid is used to dissolve any residual Tc. The isolation of 99 Tc uses TEVA resin for Extracts 1-4 and the decontamination procedure developed for bulk analysis for Extract 5. 99m Tc was used as a yield monitor, and determination of 99 Tc is by liquid scintillation counting. Limits of detection were dependent on the amount of 99m Tc tracer used but were found to be as low as 2.4 Bq/kg for a sample size of 2g. A study was made of the mechanisms responsible for the accumulation and migration of Tc in estuarine sediments using sediments collected from saltmarshes at Thornflatt, Carlaverock and the Ribble Estuary

  10. The effect of vegetation height and biomass on the sediment budget of a European saltmarsh

    Science.gov (United States)

    Reef, Ruth; Schuerch, Mark; Christie, Elizabeth K.; Möller, Iris; Spencer, Tom

    2018-03-01

    Sediment retention in saltmarshes is often attributed to the presence of vegetation, which enhances accretion by slowing water flow, reduces erosion by attenuating wave energy and increases surface stability through the presence of organic matter. Saltmarsh vegetation morphology varies considerably on a range of spatial and temporal scales, but the effect of different above ground morphologies on sediment retention is not well characterised. Understanding the biophysical interaction between the canopy and sediment trapping in situ is important for improving numerical shoreline models. In a novel field flume study, we measured the effect of vegetation height and biomass on sediment trapping using a mass balance approach. Suspended sediment profilers were placed at both openings of a field flume built across-shore on the seaward boundary of an intertidal saltmarsh in the Dengie Peninsula, UK. Sequential removal of plant material from within the flume resulted in incremental loss of vegetation height and biomass. The difference between the concentration of suspended sediment measured at each profiler was used to determine the sediment budget within the flume. Deposition of material on the plant/soil surfaces within the flume occurred during flood tides, while ebb flow resulted in erosion (to a lesser degree) from the flume area, with a positive sediment budget of on average 6.5 g m-2 tide-1 with no significant relationship between sediment trapping efficiency and canopy morphology. Deposition (and erosion) rates were positively correlated to maximum inundation depth. Our results suggest that during periods of calm conditions, changes to canopy morphology do not result in significant changes in sediment budgets in marshes.

  11. 3D structure of macropore networks within natural and de-embarked estuary saltmarsh sediments: towards an improved understanding of network structural control over hydrologic function

    Science.gov (United States)

    Carr, Simon; Spencer, Kate; James, Tempest; Lucy, Diggens

    2015-04-01

    Saltmarshes are globally important environments which, though occupying biodiversity e.g. the EU Habitats Directive and Birds Directive. However, there is growing evidence that restored saltmarshes, recreated through the return to tidal inundation of previously drained and defended low-lying coastal land, do not have the same species composition even after 100 years and while environmental enhancement has been achieved, there may be consequences for ecosystem functioning This study presents the findings of a comparative analysis of detailed sediment structure and hydrological functioning of equivalent natural and de-embanked saltmarsh sediments at Orplands Farm, Essex, UK. 3D x-ray CT scanning of triplicate undisturbed sediment cores recovered in 2013 have been used to derive detailed volumetric reconstructions of macropore structure and networks, and to infer differences in bulk microporosity between natural and de-embanked saltmarshes. These volumes have been further visualised for qualitative analysis of the main sediment components, and extraction of key macropore space parameters for quantified analysis including total porosity and connectivity, as well as structure, organisation and efficiency (tortuosity) of macropore networks. Although total porosity was significantly greater within the de-embanked saltmarsh sediments, pore networks in these samples were less organised and more tortuous, and were also inferred to have significantly lower micro-porosity than those of the natural saltmarsh. These datasets are applied to explain significant differences in the hydraulic behaviour and functioning observed between natural and de-embarked saltmarsh at Orplands. Piezometer wells and pressure transducers recorded fluctuations in water level at 15 minute intervals over a 4.5 month period (winter 2011-2012). Basic patterns for water level fluctuations in both the natural and de-embanked saltmarsh are similar and reflect tidal flooding. However, in the de

  12. Dose reduction and the application of the ALARP principle to occupational exposure at the nuclear fuel reprocessing plant at Sellafield in Cumbria

    International Nuclear Information System (INIS)

    Anderson, R.W.; Coates, R.

    1991-01-01

    This paper presents information on the application of the ALARP principle to Dose Reduction at the British Nuclear Fuels plc site at Sellafield in Cumbria. The development of the Operational methods employed to effect dose reductions on existing plants and the impact of stringent targets for new plants is described in addition to discussion of the factors initiating the change and the success of the initiatives. (Author)

  13. Separation of Ground and Low Vegetation Signatures in LiDAR Measurements of Salt-Marsh Environments

    NARCIS (Netherlands)

    Wang, C.; Menenti, M.; Stoll, M.P.; Feola, A.; Belluco, E.; Marani, M.

    2009-01-01

    Light detection and ranging (LiDAR) has been shown to have a great potential in the accurate characterization of forest systems; however, its application to salt-marsh environments is challenging because the characteristic short vegetation does not give rise to detectable differences between first

  14. Siltation in the saltmarsh of the Dee Estuary derived from 137Cs analysis of shallow cores

    International Nuclear Information System (INIS)

    Hutchinson, S.M.; Prandle, D.

    1994-01-01

    Shallow cores, 50-100 cm long, extracted at 28 locations in the saltmarsh of the Dee Estuary were analysed for 137 Cs content at 2-cm intervals. These depth profiles of 137 Cs were correlated against a 40-year record of 137 Cs discharges from the nuclear fuel reprocessing plant at Sellafield, some 130 km to the north. To allow for a non-uniform rate of deposition in the saltmarsh, a series of non-linear depth-time relationships was assumed for each core. The best fit of 137 Cs core profiles and 137 Cs discharge records then provided estimates of the most likely rate of deposition at each location. The resulting deposition rates are spatially coherent, lending confidence to these estimates. Over the last 20 years, net deposition ranged from 5 cm at the head of the estuary to 60 cm at the offshore edge closest to the sea. These deposition rates have decreased steadily over this 40-year period with net deposition over the last 20 years only half of the first 20 years. The depth-time relationships derived from this 137 Cs study permit corresponding studies of the magnetic properties in nine of these cores. Results showed a coherent pattern of dispersion away from a source at the head of the estuary. Both the location and depositional history inferred from these data are compatible with the operational history of a major steelworks. (author)

  15. The impact of herbivores on nitrogen mineralization rate: consequences for salt-marsh succession.

    Science.gov (United States)

    van Wijnen, Harm J; van der Wal, René; Bakker, Jan P

    1999-02-01

    Soil net N-mineralization rate was measured along a successional gradient in salt-marsh sites that were grazed by vertebrate herbivores, and in 5-year-old exclosures from which the animals were excluded. Mineralization rate was significantly higher at ungrazed than at grazed sites. In the absence of grazing, mineralization rate increased over the course of succession, whereas it remained relatively low when sites were grazed. The largest differences in mineralization rate between grazed and ungrazed sites were found at late successional stages where grazing pressure was lowest. The amount of plant litter was significantly lower at grazed sites. In addition, the amount of litter and potential litter (non-woody, live shoots) was linearly related to net N-mineralization rate. This implies that herbivores reduced mineralization rate by preventing litter accumulation. Bulk density was higher at grazed salt-marsh sites than at ungrazed sites. This factor may also have contributed to the differences in net N-mineralization rate between grazed and ungrazed sites.

  16. Food availability and predation risk drive the distributional patterns of two pulmonate gastropods in a mangrove-saltmarsh transitional habitat.

    Science.gov (United States)

    Peng, Yisheng; Zhang, Min; Lee, Shing Yip

    2017-09-01

    The pulmonate gastropods, Phallomedusa solida (Martens, 1878) and Ophicardelus ornatus (Férussac, 1821), exhibit characteristic distributional patterns at the upper intertidal zones in estuarine mangrove and saltmarsh habitats on the eastern Australian coast. Past studies suggested inundation condition, soil salinity, and percent of vegetation cover were responsible for these patterns. In this study, the role of environmental parameters, food availability, physical stress, and predation pressure in determining the distributional patterns of these gastropods was evaluated along transects spanning saltmarsh, mangrove, and the ecotone habitats. For both species, the maximum population abundance occurred in the upper saltmarsh and the ecotone between mangrove and saltmarsh at 361.0 and 358.0 ind.m -2 , respectively, which was four times that of the lower saltmarsh. Mangroves were evaluated as the optimal habitat for the pulmonates in terms of the environmental parameters moisture content and food availability. However, due to its longer inundation duration within each tidal cycle, use of the mangrove habitat by the pulmonates was impeded because of difficulties in oxygen acquisition under submerged conditions. Laboratory experiments revealed the oxygen intake of the pulmonates dropped abruptly to 4.3-9.0% of aerial rates when submerged. This result indicated that mangroves were not the optimal habitat for the pulmonates. Furthermore, the visiting frequency of predators (yellowfin bream Acanthopagrus australis and toadfishes, Tetraodontidae) was 1.3 times higher in the mangrove compared to those in the ecotone and upper saltmarsh habitats. Underwater video recording also suggested high mortality of these gastropods at 31.7-88.9% in mangrove and 0.80-0.98 times higher than that in saltmarsh, resulting from the predators preying in the mangrove habitat during high tides. Despite the abiotic factors facilitating the distribution of the pulmonates in the mangrove, the

  17. A Cu tolerant population of the earthworm Dendrodrilus rubidus (Savigny, 1862) at Coniston Copper Mines, Cumbria, UK

    International Nuclear Information System (INIS)

    Arnold, R.E.; Hodson, M.E.; Langdon, C.J.

    2008-01-01

    Dendrodrilus rubidus were sampled from a mine spoil soil at Coniston Copper Mine, an abandoned Cu mine in Cumbria, UK and a Cu-free control site. Earthworms were maintained for 14 d in both Kettering loam and a Moorland soil amended with Cu nitrate. Mortality, condition index, weight change and tissue concentration were determined. In both soils D. rubidus native to the mine site were able to tolerate significantly higher soil Cu concentrations (MWRT, p ≤ 0.001), and exhibited significantly less change in weight (t-test, p ≤ 0.001) and a lower loss in condition (t-test, p ≤ 0.001) than control earthworms. For a given soil Cu concentration tissue Cu concentrations were greater in the mine site earthworms. Low cocoon production and viability from the mine site population prevented the determination of toxicity parameters on the F1 generation and may be an indicator of the cost of tolerance to the population. - Dendrodrilus rubidus at an abandoned Cu mine tolerates high Cu concentrations by accumulating more Cu before toxic effects occur compared to non-native populations

  18. Studies of environmental radioactivity in Cumbria. Pt. 8. Plutonium and americium in the intertidal sands of North-West England

    Energy Technology Data Exchange (ETDEWEB)

    Eakins, J.D.; Morgan, A.; Baston, G.M.N.; Pratley, F.A.; Yarnold, L.P.; Burton, P.J.

    1988-03-01

    Sand cores and surface sand samples have been collected from the sea-facing intertidal regions of West Cumbria, between Silloth and Walney Island. Sand cores were also taken from the Duddon estuary and Morecambe Bay. The samples were collected between June 1983 and March 1984 and have been analysed for /sup 238/Pu, /sup 239+240/Pu and /sup 241/Am. The integrated deposits of /sup 239+240/Pu and /sup 241/Am in intertidal sand between Silloth and Walney Island were about 4.2 and 7 TBq respectively. Combined, this represents about 1% of the total alpha-emitting actinide activity discharged from Sellafield to sea up to 1982; the corresponding value for the Duddon Estuary is about 0.3%. The actinide levels observed are compared to those of natural alpha emitters in intertidal sand. Only on beaches close to Sellafield did levels of discharged alpha emitters exceed those of natural alpha-emitting nuclides. In the vicinity of Sellafield, the annual dose to man from the inhalation of resuspended intertidal material is certainly less than 50 ..mu..Sv (committed effective dose equivalent) and may be substantially lower.

  19. Effects of cellulosic degradation product concentration on actinide sorption on tuffs from the Borrowdale Volcanic Group, Sellafield, Cumbria

    International Nuclear Information System (INIS)

    Baston, G.M.N.; Berry, J.A.; Bond, K.A.; Boult, K.A.; Linklater, C.M.

    1994-01-01

    The Nirex Safety Assessment Research Programme includes an investigation into the effects of cellulosic degradation products on the sorption of radioelements onto geological materials. Previous batch sorption studies have shown that the presence of high concentrations of both authentic cellulosic degradation products (produced by alkaline degradation of wood/tissue) and the well-characterised simulant, gluconate, can cause marked reductions in actinide sorption. This work has now been extended to cover a range of concentrations of both authentic cellulosic degradation products and their simulants, gluconate and iso-saccharinate. Geological samples were from the proposed Nirex underground radioactive waste disposal site at Sellafied, Cumbria. The nuclides studied were thorium and plutonium. In the presence of gluconate or iso-saccharinate, at concentrations above 10 -4 M, the present work has confirmed the trends shown by earlier experiments, with a significant reduction in actinide sorption (R D values reduced by less than a factor of two), and in some cases the results suggested a slight increase (R D values increased by up to a factor of four). (orig.)

  20. Effects of cellulosic degradation product concentration on actinide sorption on tuffs from the Borrowdale Volcanic Group, Sellafield, Cumbria

    Energy Technology Data Exchange (ETDEWEB)

    Baston, G.M.N. [AEA Technology, Decommissioning and Waste Management, Harwell (United Kingdom); Berry, J.A. [AEA Technology, Decommissioning and Waste Management, Harwell (United Kingdom); Bond, K.A. [AEA Technology, Decommissioning and Waste Management, Harwell (United Kingdom); Boult, K.A. [AEA Technology, Decommissioning and Waste Management, Harwell (United Kingdom); Linklater, C.M. [AEA Technology, Decommissioning and Waste Management, Harwell (United Kingdom)

    1994-12-31

    The Nirex Safety Assessment Research Programme includes an investigation into the effects of cellulosic degradation products on the sorption of radioelements onto geological materials. Previous batch sorption studies have shown that the presence of high concentrations of both authentic cellulosic degradation products (produced by alkaline degradation of wood/tissue) and the well-characterised simulant, gluconate, can cause marked reductions in actinide sorption. This work has now been extended to cover a range of concentrations of both authentic cellulosic degradation products and their simulants, gluconate and iso-saccharinate. Geological samples were from the proposed Nirex underground radioactive waste disposal site at Sellafied, Cumbria. The nuclides studied were thorium and plutonium. In the presence of gluconate or iso-saccharinate, at concentrations above 10{sup -4} M, the present work has confirmed the trends shown by earlier experiments, with a significant reduction in actinide sorption (R{sub D} values reduced by less than a factor of two), and in some cases the results suggested a slight increase (R{sub D} values increased by up to a factor of four). (orig.)

  1. The vertical distribution of radionuclides in a Ribble Estuary saltmarsh: transport and deposition of radionuclides

    International Nuclear Information System (INIS)

    Brown, J.E.; McDonald, P.; Parker, A.; Rae, J.E.

    1999-01-01

    Routine discharges of low-level liquid radioactive waste by British Nuclear Fuels plc (BNFL) at Sellafield and Springfields have resulted in enhanced levels of radionuclides in sediments of the Ribble Estuary, NW England, UK. Variations in radionuclide concentrations ( 137 Cs, 230 Th, and 239240 Pu) with depth in a mature saltmarsh core were analysed in order to investigate historical discharge trends and waste-dispersal mechanisms. Core samples from Longton/Hutton Marsh were analysed by gamma-spectrometry and α-spectrometry for radionuclides and by laser granulometry to establish grain-size variations with depth. Distinct subsurface maxima were present for 137 Cs and 239240 Pu with activities as high as 4500 Bq kg -1 for 137 Cs and 600 Bq kg -1 for 239240 Pu. Thorium-230 exhibited complex activity profiles with depth, specific activities ranging between 200 and 2400 Bq kg -1 . The vertical distributions of Sellafield-derived radionuclides ( 137 Cs and 239240 Pu) in mature saltmarsh deposits reflect the time-integrated discharge pattern from Sellafield, implying a transport mechanism that has involved the mixing of sediment labelled with radioactivity from recent discharges and sediment labelled from historical discharge events before deposition. A mechanism involving the transport of contaminated silt therefore seems to dominate. The vertical distribution of Springfields-derived 230 Th in the same areas reflects the annual gross-α discharge pattern from BNFL Springfields. In contrast to the Sellafield-derived radionuclides, a fairly rapid transport mechanism from source to sink is implied, with little or no time for mixing with radionuclides discharged years earlier. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  2. Characterization of mercury and its risk in Nelson's, Saltmarsh, and Seaside Sparrows.

    Directory of Open Access Journals (Sweden)

    Virginia L Winder

    Full Text Available BACKGROUND: Nelson's, Saltmarsh, and Seaside Sparrows (Ammodramus nelsoni, A. caudacutus, and A. maritimus, respectively depend on marsh and wetland habitats--ecosystems in which mercury (Hg bioavailability is notoriously high. The purpose of the present study was to address the potential impact of Hg on these species using first primary and breast feathers as non-destructive biomonitoring tools. METHODS AND PRINCIPAL FINDINGS: Feathers were sampled from wintering sparrows in North Carolina salt marshes (2006-2010. Feather Hg data were used in three risk analysis components (1 Threshold Component--examined feather Hg with regard to published negative effects thresholds; (2 Hg Dynamics Component--examined Hg in sparrows captured multiple times; and (3 Capture Frequency and Survival Component--tested for links between Hg and return frequency and survival. Threshold Component analyses indicated that Hg concentrations in 42-77% of sampled individuals (breast feather n = 879; first primary feather n = 663 were within the range associated with decreased reproduction in other avian species. Hg Dynamics Component analyses demonstrated that Hg increased between first and second captures for Nelson's (n = 9 and Seaside Sparrows (n = 23. Capture Frequency and Survival Component analyses detected a negative relationship between Hg and capture frequency in Nelson's Sparrows (n = 315. However, MARK models detected no effect of Hg on apparent survival in any species. CONCLUSION AND SIGNIFICANCE: This study indicates that current Hg exposure places a considerable proportion of each population at risk. In particular, 52% of all sampled Saltmarsh Sparrows exhibited first primary feather Hg concentrations exceeding those associated with a >60% reduction in reproductive success in other species. This study reports evidence for net annual bioaccumulation, indicating an increased risk in older individuals. These data can be used to inform future population

  3. Characterization of mercury and its risk in Nelson's, Saltmarsh, and Seaside Sparrows.

    Science.gov (United States)

    Winder, Virginia L

    2012-01-01

    Nelson's, Saltmarsh, and Seaside Sparrows (Ammodramus nelsoni, A. caudacutus, and A. maritimus, respectively) depend on marsh and wetland habitats--ecosystems in which mercury (Hg) bioavailability is notoriously high. The purpose of the present study was to address the potential impact of Hg on these species using first primary and breast feathers as non-destructive biomonitoring tools. Feathers were sampled from wintering sparrows in North Carolina salt marshes (2006-2010). Feather Hg data were used in three risk analysis components (1) Threshold Component--examined feather Hg with regard to published negative effects thresholds; (2) Hg Dynamics Component--examined Hg in sparrows captured multiple times; and (3) Capture Frequency and Survival Component--tested for links between Hg and return frequency and survival. Threshold Component analyses indicated that Hg concentrations in 42-77% of sampled individuals (breast feather n = 879; first primary feather n = 663) were within the range associated with decreased reproduction in other avian species. Hg Dynamics Component analyses demonstrated that Hg increased between first and second captures for Nelson's (n = 9) and Seaside Sparrows (n = 23). Capture Frequency and Survival Component analyses detected a negative relationship between Hg and capture frequency in Nelson's Sparrows (n = 315). However, MARK models detected no effect of Hg on apparent survival in any species. This study indicates that current Hg exposure places a considerable proportion of each population at risk. In particular, 52% of all sampled Saltmarsh Sparrows exhibited first primary feather Hg concentrations exceeding those associated with a >60% reduction in reproductive success in other species. This study reports evidence for net annual bioaccumulation, indicating an increased risk in older individuals. These data can be used to inform future population assessments and management for these species.

  4. Are all intertidal wetlands naturally created equal? Bottlenecks, thresholds and knowledge gaps to mangrove and saltmarsh ecosystems

    Science.gov (United States)

    Friess, Daniel A.; Krauss, Ken W.; Horstman, Erik M.; Balke, Thorsten; Bouma, Tjeerd J.; Galli, Demis; Webb, Edward L.

    2011-01-01

    Intertidal wetlands such as saltmarshes and mangroves provide numerous important ecological functions, though they are in rapid and global decline. To better conserve and restore these wetland ecosystems, we need an understanding of the fundamental natural bottlenecks and thresholds to their establishment and long-term ecological maintenance. Despite inhabiting similar intertidal positions, the biological traits of these systems differ markedly in structure, phenology, life history, phylogeny and dispersal, suggesting large differences in biophysical interactions. By providing the first systematic comparison between saltmarshes and mangroves, we unravel how the interplay between species-specific life-history traits, biophysical interactions and biogeomorphological feedback processes determine where, when and what wetland can establish, the thresholds to long-term ecosystem stability, and constraints to genetic connectivity between intertidal wetland populations at the landscape level. To understand these process interactions, research into the constraints to wetland development, and biological adaptations to overcome these critical bottlenecks and thresholds requires a truly interdisciplinary approach.

  5. Saltmarsh Ecology

    African Journals Online (AJOL)

    This series of tertiary level Biology books is aimed at advanced undergraduate students and specialists in other fields. As such, the book succeeds admirably and is clearly written and concise. However, it would have been an even more valuable con- tribution if some additional aspects had been included. At times ...

  6. Ecomorphodynamic Response of Foreshore Saltmarsh to the Implementation of Flood and Erosion Mitigation and Adaptation Structures in a Hypertidal Estuary: Minas Basin, Bay of Fundy, Canada.

    Science.gov (United States)

    Matheson, G.; van Proosdij, D.; Ross, C.

    2017-12-01

    Flood and erosion mitigations and adaptation structures are often implemented in anthropogenically modified coastal regions, such as dykelands, to protect against coastal hazards. If saltmarshes are to be incorporated into a coastal management plan as a source of coastal defence, it is paramount to understand how ecomorphodynamic feedbacks triggered by implementing these structures can impact saltmarshes. This study examines how these structures, in combination with natural drivers, have precipitated changes in foreshore saltmarsh erosion and progradation rates over varying spatial scales in the hypertidal Minas Basin, located in the upper Bay of Fundy, during the past 80 years. Foreshore change rates (in 25m segments) are obtained using empirical field measurements, geomatics techniques in a geographical information system (GIS), as well as imagery and digital surface models (DSMs) derived from an unmanned aerial vehicle (UAV). Furthermore, UAV DSMs were used to determine infill rates and short-term sediment budgets in saltmarsh borrow pits. Natural cyclical foreshore change rates are observed in the Minas Basin, but are often augmented by the presence of anthropogenic structures. Erosion and progradation rates in individual transects have been observed to be as much as -14.9m/yr and 20.1m/yr, respectively. In individual saltmarsh communities, average change rates have been observed to be as much -3.4m/yr and 2.1m/yr across the entire foreshore. Furthermore, results suggest that under specific environmental conditions some structures (e.g. kickers) work in tandem with saltmarshes to protect the upland by precipitating ecomorphodynamic feedbacks that promote saltmarsh progradation. Conversely, other structures (e.g. foreshore rocking) can exacerbate natural cycles of erosion, locally. Borrow pit studies reveal that although local suspended sediment concentrations, which can vary from 50mg/l to 50000mg/l, play an integral role in pit sedimentation, channel geometry

  7. Exploring mechanisms of compaction in salt-marsh sediments using Common Era relative sea-level reconstructions

    Science.gov (United States)

    Brain, Matthew J.; Kemp, Andrew C.; Hawkes, Andrea D.; Engelhart, Simon E.; Vane, Christopher H.; Cahill, Niamh; Hill, Troy D.; Donnelly, Jeffrey P.; Horton, Benjamin P.

    2017-07-01

    Salt-marsh sediments provide precise and near-continuous reconstructions of Common Era relative sea level (RSL). However, organic and low-density salt-marsh sediments are prone to compaction processes that cause post-depositional distortion of the stratigraphic column used to reconstruct RSL. We compared two RSL reconstructions from East River Marsh (Connecticut, USA) to assess the contribution of mechanical compression and biodegradation to compaction of salt-marsh sediments and their subsequent influence on RSL reconstructions. The first, existing reconstruction ('trench') was produced from a continuous sequence of basal salt-marsh sediment and is unaffected by compaction. The second, new reconstruction is from a compaction-susceptible core taken at the same location. We highlight that sediment compaction is the only feasible mechanism for explaining the observed differences in RSL reconstructed from the trench and core. Both reconstructions display long-term RSL rise of ∼1 mm/yr, followed by a ∼19th Century acceleration to ∼3 mm/yr. A statistically-significant difference between the records at ∼1100 to 1800 CE could not be explained by a compression-only geotechnical model. We suggest that the warmer and drier conditions of the Medieval Climate Anomaly (MCA) resulted in an increase in sediment compressibility during this time period. We adapted the geotechnical model by reducing the compressive strength of MCA sediments to simulate this softening of sediments. 'Decompaction' of the core reconstruction with this modified model accounted for the difference between the two RSL reconstructions. Our results demonstrate that compression-only geotechnical models may be inadequate for estimating compaction and post-depositional lowering of susceptible organic salt-marsh sediments in some settings. This has important implications for our understanding of the drivers of sea-level change. Further, our results suggest that future climate changes may make salt

  8. The influence of saltmarsh restoration on sediment dynamics and the potential impact on carbon sequestration

    Science.gov (United States)

    Taylor, Benjamin; Paterson, David

    2017-04-01

    Coastal wetland ecosystems can act as large-capacity carbon sinks, providing a valuable climate change mitigation function. Globally, saltmarshes are estimated to accumulate an average of 244.7g C m-2 yr-1 (Ouyang & Lee 2014). Saltmarsh areas have experienced rapid loss in the recent past of approximately 1-2% per year (Duarte et al. 2008). Efforts to restore these areas could result in additional carbon storage due to extended vegetation cover and altered burial due to changing sediment dynamics. The influence of restoration through transplantation on sediment dynamics within a small estuary on the east coast of Scotland was assessed. Restoration efforts have been implemented since the early 2000s providing examples of old established sites ("old", >10years), young recently planted sites ("young", percentage organic matter content of deposited material is significantly lower in mudflat and young areas (3.78 ± 0.59% and 3.66 ± 0.79% respectively) versus those of natural and old areas (12.08 ± 2.27% and 6.70 ± 1.30% respectively). This relationship suggests that older restored areas are potentially offering the most potential benefit in terms of carbon sequestration, due to higher rates of deposition from the potential load and higher percentage organic content of those deposits. Furthermore, measurements of sediment accretion rates over the same period show natural and old areas to be the most effective at retaining sediment, with average elevation changes of 6.99 ± 1.64mm and 6.56 ± 0.94mm respectively, in comparison to young areas, 4.44 ± 1.58mm, and mudflats, 1.51 ± 1.23mm. Factors influencing these differences could be attributed to type and density of vegetation present and elevation of each area (or immersion period). However, the data suggests restoration could play an important role, which once established, appears to facilitate efficient sediment deposition from potential sediment load and crucially the effective accumulation of organic rich

  9. Physiological and Biochemical Responses of Saltmarsh Plant Spartina alterniflora to Long-term Wave Exposure

    Science.gov (United States)

    Zhou, W.

    2017-12-01

    In recent years, ecosystem-based flood defence, i.e., eco-shoreline or living shoreline, that is more sustainable and cost-effective than conventional coastal engineering structures has been brought into large-scale practice. Numerous laboratory experiments have been performed to explore the wave-attenuation effects of saltmarsh plants that are widely used in eco-shoreline, and yet no study has ever been conducted on the physiological and biochemical responses of saltmarsh plants to long-term wave exposure, presumably due to the constraint that traditional wave generator fails to provide long-term stable wave conditions necessary for physiological experiments. In this study, a long-term shallow water wave environment simulator using crank-yoke mechanism was built in the laboratory to address this gap. Experiments using the wave simulator were conducted for 8 weeks in a greenhouse and the temperature was maintained at 24-30°C. 5‰ artificial sea water was filled in the test tank, and the water was changed every week. After being acclimatized, nine S. alterniflora individual plants (initial height 30 cm) were planted in each of the three streamlined cuboid containers (12cm×12cm×20cm), which were partially submerged in a test tank, and undertook horizontal sinusoidal motion imposed by the crank-yoke mechanism to mimic plants exposed to shallow water waves. The substrate filled in the containers were soils collected from the Yellow River Delta, so were the S. alterniflora plants. A realistic stem density of 400 stems/m2 was tested, which corresponded to a grid spacing of 5.0 cm. Shallow water waves with six wave heights (H: 0.041, 0.055, 0.069, 0.033, 0.044 and 0.056m), one plants submerged depth (0.1m) and two wave periods (2s and 3s) were simulated in the experiments. A no wave condition was also tested as control. Key physiological and biochemical parameters, such as stem length, peroxidase activity, catalase, superoxide dismutase, ascorbate peroxidase, etc

  10. Health risks from radioactive objects on beaches in the vicinity of the Sellafield site in west Cumbria

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Joanne; Etherington, George; Pellow, Peter [Centre for Radiation, Chemical and Environmental Hazards, Public Health England (United Kingdom)

    2014-07-01

    A programme of monitoring carried out since 2006 has found radioactive objects on beaches near the Sellafield nuclear reprocessing site in West Cumbria. These objects comprised particles with sizes smaller than or similar to grains of sand (less than 2 mm) and contaminated pebbles and stones. Public Health England has undertaken an assessment of the health risks to people using the beaches along the Cumbrian coast from these contaminated objects. The assessment has addressed two key aspects. Firstly, estimates have been made of the likelihood that people using the beaches for various activities could come into contact with a radioactive object. Secondly, for the unlikely event that an individual does come into contact with such an object, the resulting radiation doses and associated health risks have been assessed. The ingestion of an 'alpha-rich' particle (a particle for which the content of the alpha-emitting radionuclide americium-241 exceeds the content of caesium-137) has the greatest potential to give rise to significant health risks. The intestinal absorption of a range of particles recovered from West Cumbrian beaches was quantified by means of in vivo uptake studies using laboratory rats, and the results were used to predict doses that would result from the ingestion of a single particle. The conclusion of the assessment, based on the currently available information, is that the overall health risks to beach users are very low and significantly lower than other risks that people accept when using the beaches. The highest calculated lifetime risks of radiation-induced fatal cancer are of the order of one hundred thousand times smaller than the level of risk that the UK Health and Safety Executive considers to be the upper limit for an acceptable level of risk (1 in a million) for members of the public and workers. The exposure route with the greatest potential for deterministic effects, such as localised skin ulceration, is direct irradiation of

  11. A trophic cascade triggers collapse of a salt-marsh ecosystem with intensive recreational fishing.

    Science.gov (United States)

    Altieri, Andrew H; Bertness, Mark D; Coverdale, Tyler C; Herrmann, Nicholas C; Angelini, Christine

    2012-06-01

    Overexploitation of predators has been linked to the collapse of a growing number of shallow-water marine ecosystems. However, salt-marsh ecosystems are often viewed and managed as systems controlled by physical processes, despite recent evidence for herbivore-driven die-off of marsh vegetation. Here we use field observations, experiments, and historical records at 14 sites to examine whether the recently reported die-off of northwestern Atlantic salt marshes is associated with the cascading effects of predator dynamics and intensive recreational fishing activity. We found that the localized depletion of top predators at sites accessible to recreational anglers has triggered the proliferation of herbivorous crabs, which in turn results in runaway consumption of marsh vegetation. This suggests that overfishing may be a general mechanism underlying the consumer-driven die-off of salt marshes spreading throughout the western Atlantic. Our findings support the emerging realization that consumers play a dominant role in regulating marine plant communities and can lead to ecosystem collapse when their impacts are amplified by human activities, including recreational fishing.

  12. Source apportionment of Pb pollution in saltmarsh sediments from southwest England

    Science.gov (United States)

    Iurian, Andra-Rada; Millward, Geoffrey; Taylor, Alex; Marshall, William; Rodríguez, Javier; Gil Ibarguchi, José Ignacio; Blake, William H.

    2017-04-01

    The local availability of metal resources played a crucial role in Britain's development during the industrial revolution, but centuries of mining within Cornwall and Devon (UK) have left a legacy of contamination in river basin and estuary sediments. Improved knowledge of historical heavy metal sources, emissions and pathways will result in a better understanding of the contemporary pollution conditions and a better protection of the environment from legacy contaminants. Our study aims to trace historical sources of Pb pollution in the area of east Cornwall and west Devon, UK, using a multi proxy approach for contaminants stored in saltmarsh sediment columns from 3 systems characterized by different contamination patterns. Source apportionment investigations included the determination of Pb concentration and Pb isotopic composition (204Pb, 206Pb, 207Pb, and 208Pb) for selected down-core sediment samples, and for local ore and parent rock materials. General trends in pollutant loading (e.g. Pb) could be identified, with maximum inputs occurring in the middle of the 19th century and decreasing towards the present day, while an increase in the catchment disturbance was apparent for the last decades. The isotopic ratios of Pb further indicate that sediments with higher Pb content have a less radiogenic signature, these particular inputs being derived from Pb mining and smelting sources in the catchment area. Acknowledgements: Andra-Rada Iurian acknowledges the support of a Marie Curie Fellowship (H2020-MSCA-IF-2014, Grant Agreement number: 658863) within the Horizon 2020.

  13. Trophic shift in young-of-the-year Mugilidae during salt-marsh colonization.

    Science.gov (United States)

    Lebreton, B; Richard, P; Guillou, G; Blanchard, G F

    2013-04-01

    This study investigated the trophic shift of young-of-the-year (YOY) thinlip grey mullet Liza ramada and golden grey mullet Liza aurata during their recruitment in a salt marsh located on the European Atlantic Ocean coast. Stable-isotope signatures (δ(13) C and δ(15) N) of the fishes followed a pattern, having enrichments in (13) C and (15) N with increasing fork length (LF ): δ(13) C in fishes  30 mm δ(13) C ranged from -15.8 to -12.7‰, closer to the level in salt-marsh food resources. Large differences between the δ(15) N values of mugilids and those of food sources (6·0‰ on average) showed that YOY are secondary consumers, similar to older individuals, when feeding in the salt marsh. YOY mugilids shift from browsing on pelagic prey to grazing on benthic resources from the salt marsh before reaching 30 mm LF. The results highlight the role of European salt marshes as nurseries for juvenile mugilids. © 2013 The Authors. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.

  14. Enhancement of natural radioactivity in soils and salt-marshes surrounding a non-nuclear industrial complex

    International Nuclear Information System (INIS)

    Bologon, J.P.; Garca-Tenorio, R.; Garca-Leon, M.

    1995-01-01

    The existence of a very high extension (about 1000 ha) of phosphogypsum piles, sited in the estuary formed by the mouths of the Tinto and Odiel rivers (SW Spain), produce a quite local, but unambiguous radioactive impact in the surrounding salt-marshes. In these piles the main by-product formed in the manufacture of phosphoric acid is stored. The radioactive impact is generated by the deposition and accumulation of radionuclides from the uranium series that previously had been mainly leached or dissolved from the piles by waters that temporally can cover or cross them. Other means of impact, especially through the atmosphere, have been evaluated as negligible or not detectable

  15. Degradation State and Sequestration Potential of Carbon in Coastal Wetlands of Texas: Mangrove Vs. Saltmarsh Ecosystems

    Science.gov (United States)

    Sterne, A. M. E.; Kaiser, K.; Louchouarn, P.; Norwood, M. J.

    2015-12-01

    The estimated magnitude of the organic carbon (OC) stocks contained in the first meter of US coastal wetland soils represents ~10% of the entire OC stock in US soils (4 vs. 52 Pg, respectively). Because this stock extends to several meters below the surface for many coastal wetlands, it becomes paramount to understand the fate of OC under ecosystem shifts, varying natural environmental constraints, and changing land use. In this project we analyze the major classes of biochemicals including total hydrolysable neutral carbohydrates, enantiomeric amino acids, phenols, and cutins/suberins at two study sites located on the Texas coastline to investigate chemical composition and its controls on organic carbon preservation in mangrove (Avicennia germinans) and saltmarsh grass (Spartina alterniflora) dominated wetlands. Results show neutral carbohydrates and lignin contribute 30-70% and 10-40% of total OC, respectively, in plant litter and surface sediments at both sites. Sharp declines of carbohydrate yields with depth occur parallel to increasing Ac/AlS,V ratios indicating substantial decomposition of both the polysaccharide and lignin components of litter detritus. Contrasts in the compositions and relative abundances of all previously mentioned compound classes are further discussed to examine the role of litter biochemistry in OC preservation. For example, the selective preservation of cellulose over hemicellulose in sediments indicates macromolecular structure plays a key role in preservation between plant types. It is concluded that the chemical composition of litter material controls the composition and magnitude of OC stored in sediments. Ultimately, as these ecosystems transition from one dominant plant type to another, as is currently observed along the Texas coastline, there is the potential for OC sequestration efficiency to shift due to the changing composition of OC input to sediments.

  16. The Impact of Epifaunal Predation on the Structure of Macroinfaunal Invertebrate Communities of Tidal Saltmarsh Creeks

    Science.gov (United States)

    Sardá, R.; Foreman, K.; Werme, C. E.; Valiela, I.

    1998-05-01

    The impact of epibenthic predators foraging on macroinfaunal communities was analysed in Great Sippewissett salt marsh (MA, U.S.A.) by installing experimental cages in the most productive sediments of the marsh (77 g dry weight m -2year -1). The most productive macroinfaunal species in these sediments were Marenzelleria viridis(43·1 g dry weight m -2year -1) Heteromastus filiformis(13·7 g dry weight m -2year -1) and Neanthes arenaceodonta(7·6 g dry weight m -2year -1). Macroinfaunal densities peaked in June following the spring recruitment. Density and biomass inside the cages were significantly higher during the growing season, however, density declined in July and August following the seasonal cycle observed outside cages, while biomass did not suffer this decline. The absence of epibenthic predators favored growth and accumulation of larger organisms, especially M. viridis, and included higher presence of predaceous infauna ( Glycera americana, Neanthes succinea, Neanthes virens, Eteone heteropodaand Nemerteans). At the end of the experiment, there was 22·2 g dry weight m -2more macroinfaunal biomass in the complete cages than in ambient sediments. The absence of epibenthic predators also increased secondary production; M. viridisdoubled production in the sediments inside cages compared with outside cages. The most common benthic predaceous fishes in the marsh were the killifishes, Fundulus heteroclitusand Fundulus majalis, and some seasonal invasive fishes ( Gasterosteus aculeatus, Tautoga onitis, Centropristes striatusand Pleuronectes americanus). While invasive fishes preyed mainly on benthic invertebrates and grew faster, resident fishes shifted their diets through the season. The values of macroinfaunal secondary production obtained in these sediments can support the energy requirements of the predators of the marsh; in this way the pulse of secondary production created by the macroinfaunal populations travels up the saltmarsh food web.

  17. Understanding system disturbance and ecosystem services in restored saltmarshes: Integrating physical and biogeochemical processes

    Science.gov (United States)

    Spencer, K. L.; Harvey, G. L.

    2012-06-01

    Coastal saltmarsh ecosystems occupy only a small percentage of Earth's land surface, yet contribute a wide range of ecosystem services that have significant global economic and societal value. These environments currently face significant challenges associated with climate change, sea level rise, development and water quality deterioration and are consequently the focus of a range of management schemes. Increasingly, soft engineering techniques such as managed realignment (MR) are being employed to restore and recreate these environments, driven primarily by the need for habitat (re)creation and sustainable coastal flood defence. Such restoration schemes also have the potential to provide additional ecosystem services including climate regulation and waste processing. However, these sites have frequently been physically impacted by their previous land use and there is a lack of understanding of how this 'disturbance' impacts the delivery of ecosystem services or of the complex linkages between ecological, physical and biogeochemical processes in restored systems. Through the exploration of current data this paper determines that hydrological, geomorphological and hydrodynamic functioning of restored sites may be significantly impaired with respects to natural 'undisturbed' systems and that links between morphology, sediment structure, hydrology and solute transfer are poorly understood. This has consequences for the delivery of seeds, the provision of abiotic conditions suitable for plant growth, the development of microhabitats and the cycling of nutrients/contaminants and may impact the delivery of ecosystem services including biodiversity, climate regulation and waste processing. This calls for a change in our approach to research in these environments with a need for integrated, interdisciplinary studies over a range of spatial and temporal scales incorporating both intensive and extensive research design.

  18. The impact of pre-restoration land-use and disturbance on sediment structure, hydrology and the sediment geochemical environment in restored saltmarshes.

    Science.gov (United States)

    Spencer, Kate L; Carr, Simon J; Diggens, Lucy M; Tempest, James A; Morris, Michelle A; Harvey, Gemma L

    2017-06-01

    Saltmarshes are being lost or degraded as a result of human activity resulting in loss of critical ecosystem services including the provision of wild species diversity, water quality regulation and flood regulation. To compensate, saltmarshes are being restored or re-created, usually driven by legislative requirements for increased habitat diversity, flood regulation and sustainable coastal defense. Yet, there is increasing evidence that restoration may not deliver anticipated ecosystem services; this is frequently attributed to poor drainage and sediment anoxia. However, physical sediment characteristics, hydrology and the sediment geochemical environment are rarely examined in restoration schemes, despite such factors being critical for plant succession. This study presents the novel integration of 3D-computed X-ray microtomography to quantify sediment structure and porosity, with water level and geochemical data to understand the impact of pre-restoration land use and disturbance on the structure and functioning of restored saltmarshes. The study combines a broad-scale investigation of physical sediment characteristics in nine de-embanked saltmarshes across SE England, with an intensive study at one site examining water levels, sediment structure and the sediment geochemical environment. De-embankment does not restore the hydrological regime, or the physical/chemical framework in the saltmarshes and evidence of disturbance includes a reduction in microporosity, pore connectivity and water storage capacity, a lack of connectivity between the sub-surface environment and overlying floodwaters, and impeded sub-surface water flow and drainage. This has significant consequences for the sediment geochemical environment. This disturbance is evident for at least two decades following restoration and is likely to be irreversible. It has important implications for plant establishment in particular, ecosystem services including flood regulation, nutrient cycling and wild

  19. Mercury on national wildlife refuges as a threat to long-term viability of saltmarsh and Nelson’s sparrows in the face of climate induced sea level rise

    Data.gov (United States)

    Department of the Interior — Nelson’s and saltmarsh sparrows (Ammodramus nelsoni and A. caudacutus) have recently been recognized as separate species, and because of their limited distributions...

  20. Morphological response of the saltmarsh habitats of the Guadiana estuary due to flow regulation and sea-level rise

    Science.gov (United States)

    Sampath, D. M. R.; Boski, T.

    2016-12-01

    In the context of rapid sea-level rise in the 21st century, the reduction of fluvial sediment supply due to the regulation of river discharge represents a major challenge for the management of estuarine ecosystems. Therefore, the present study aims to assess the cumulative impacts of the reduction of river discharge and projected sea-level rise on the morphological evolution of the Guadiana estuary during the 21st century. The assessment was based on a set of analytical solutions to simplified equations of tidal wave propagation in shallow waters and empirical knowledge of the system. As methods applied to estimate environmental flows do not take into consideration the fluvial discharge required to maintain saltmarsh habitats and the impact of sea-level rise, simulations were carried out for ten cases in terms of base river flow and sea-level rise so as to understand their sensitivity on the deepening of saltmarsh platforms. Results suggest saltmarsh habitats may not be affected severely in response to lower limit scenarios of sea-level rise and sedimentation. A similar behaviour can be expected even due to the upper limit scenarios until 2050, but with a significant submergence afterwards. In the case of the upper limit scenarios under scrutiny, there was a net erosion of sediment from the estuary. Multiplications of amplitudes of the base flow function by factors 1.5, 2, and 5 result in reduction of the estimated net eroded sediment volume by 25, 40, and 80%, respectively, with respect to the net eroded volume for observed river discharge. The results also indicate that defining the minimum environmental flow as a percentage of dry season flow (as done presently) should be updated to include the full spectrum of natural flows, incorporating temporal variability to better anticipate scenarios of sea-level rise during this century. As permanent submergence of intertidal habitats can be significant after 2050, due to the projected 79 cm rise of sea-level by the year

  1. Stakeholder participation for the legacy ponds and legacy silos (LP and LS) facility at Sellafield, Cumbria. UK: the nature and effectiveness of the dialogue - 16030

    International Nuclear Information System (INIS)

    Whitton, John

    2009-01-01

    The Legacy Ponds and Silos (LP and S) facilities are part of the UK nuclear legacy located at the Sellafield Site, Cumbria. There are four individual facilities containing nuclear wastes that have accumulated over a period of approximately 50 years. Waste retrieval and conditioning, in preparation for decommissioning, is currently being carried out by the site operator. LP and S have recently proposed a re-engagement with stakeholders following the initial engagement in December 2005. This paper reviews this earlier engagement in terms of the nature of dialogue that was carried out when compared against definitions of deliberation provided in the literature. The aim of this paper is to provide those planning future engagement with a better understanding of how the nature of dialogue can vary and uses participation and deliberation as indicators of effective engagement. A concern of those working towards a programme of effective stakeholder participation in 2005 was how to ensure genuine dialogue and stakeholder representation in such a strictly controlled and regulated environment with a technical complexity that challenges technical specialist and lay person alike. LP and S recognised that effective dialogue with stakeholders on the available technical options and their associated societal impacts would form a significant part of this process if options were to prove resilient. However, the challenge presented to LP and S was how to engage stakeholders on a variety of projects, whilst ensuring the output could be used by the projects as part of their technical decision making. Initial contact was made with stakeholders in December 2005, as part of a 'Baseline' Best Practicable Environmental Option (BPEO) study. A BPEO study leads to decisions on waste management based on an integrated assessment of alternative options, on the basis of factors such as the occupational and environmental risks, the environmental impacts, costs and social implications of the options

  2. Short-term effects of salinity reduction and drainage on salt-marsh biogeochemical cycling and Spartina (Cordgrass) production

    Science.gov (United States)

    Portnoy, J.W.; Valiela, I.

    1997-01-01

    To assess the biogeochemical effects of tidal restrictions on salt-marsh sulfur cycling and plant growth, cores of short-form Spartina alterniflora peat were desalinated and kept either waterlogged or drained in greenhouse microcosms. Changes in net Spartina production, and porewater and solid phase chemistry of treated cores were compared to natural conditions in the field collection site over a 21-mo period. Net production among treatments increased significantly in drained and waterlogged peat compared to field conditions during the first growing season. Constantly high sulfide in waterlogged cores accompanied reduced plant growth. Aeration invigorated growth in drained cores but led to oxidization of sulfide minerals and to lowered pH. During the second growing season, growth declined in the drained treatment, probably because of acidification and decreased dissolved inorganic nitrogen. Results are pertinent to the success of current wetland protection and restoration activities in the coastal zone.

  3. Anthropogenic ecological change and impacts on mosquito breeding and control strategies in salt-marshes, Northern Territory, Australia.

    Science.gov (United States)

    Jacups, Susan; Warchot, Allan; Whelan, Peter

    2012-06-01

    Darwin, in the tropical north of Australia, is subject to high numbers of mosquitoes and several mosquito-borne diseases. Many of Darwin's residential areas were built in close proximity to tidally influenced swamps, where long-term storm-water run-off from nearby residences into these swamps has led to anthropogenic induced ecological change. When natural wet-dry cycles were disrupted, bare mud-flats and mangroves were transformed into perennial fresh to brackish-water reed swamps. Reed swamps provided year-round breeding habitat for many mosquito species, such that mosquito abundance was less predictable and seasonally dependent, but constant and often occurring in plague proportions. Drainage channels were constructed throughout the wetlands to reduce pooled water during dry-season months. This study assesses the impact of drainage interventions on vegetation and mosquito ecology in three salt-marshes in the Darwin area. Findings revealed a universal decline in dry-season mosquito abundance in each wetland system. However, some mosquito species increased in abundance during wet-season months. Due to the high expense and potentially detrimental environmental impacts of ecosystem and non-target species disturbance, large-scale modifications such as these are sparingly undertaken. However, our results indicate that some large scale environmental modification can assist the process of wetland restoration, as appears to be the case for these salt marsh systems. Drainage in all three systems has been restored to closer to their original salt-marsh ecosystems, while reducing mosquito abundances, thereby potentially lowering the risk of vector-borne disease transmission and mosquito pest biting problems.

  4. Ingestion and selection of suprabenthic crustaceans by small-sized fishes in a lower saltmarsh system

    Directory of Open Access Journals (Sweden)

    Yoko Wakabara

    1996-01-01

    Full Text Available This study was performed in the lower saltmarsh system of the Arrozal, in the Cananéia lagoon estuarine region (25º02'S - 47º56'W, Brazil. Suprabenthic fauna was surveyed Wlth a small sledge and fishes were captured with casting and set nets to analyse: crustacean fauna as food for local fish species; difference in the diet at different times of the year; if there is diet overlap between species and the feeding behaviour of the species analysed. The fauna of Arrozal is poor in species, dominated mainly by Metamysidopsis alongata atlantica, Acartia lilljeborgi, Atylus minikoi, decapod larvae, and reveals a strong seasonal variation. The fishes were ali camivorous with suprabenthic crustacean as their main food resource. Seasonal changes in food supply are also reflected in the diet. Of the 12 flSh species collected six were opportunistlc feeders whereas six others were selective feeders. Food overlap value of 0.08 for ali of the fish community indicates an almost completely distinct food niches. The increased overlapping of summer food between Cathorops spixii and species of Group 11 and between Oligoplites sp and species of Group I seems to have two different explanations: 1 the mmIDishing of food supply for species feeding on benthic originated suprabenthic crustaceans and 2 overabundance of planktonic forms of suprabenthos as well as a period of high feeding activity of fishes with such diet.O presente estudo foi realizado no infralitoral contíguo à marisma, na Ponta do Arrozal, região estuarina lagunar de Cananéia (25º02'S - 47º56'W, Brasil. A fauna suprabêntica foi amostrada com uma pequena draga e os peixes capturados com tarrafa e rede de espera, com a finalidade de analisar: a composição de espécies dos crustáceos suprabênticos como itens alimentares dos peixes; diferenças na dieta em diferentes época do ano; se ocorre sobreposição alimentar entre as espécies e o comportamento alimentar: das espécies de peixes

  5. Studies of environmental radioactivity in Cumbria. Part 6. The chronology of discharges of caesium-137, plutonium and americium-241 from BNFL Sellafield, as recorded in lake sediments

    Energy Technology Data Exchange (ETDEWEB)

    Eakins, J D; Cambray, R S

    1985-04-01

    A study has been made of the radionuclide content of lake sediments from Cumbria in order to determine the history of discharges of /sup 137/Cs and actinides from the Sellafield works of British Nuclear Fuels plc (BNFL). Sediment cores have been taken from Ullswater and Grasmere, which are remote from Sellafield, in order to establish the behaviour of nuclear weapon fallout nuclides. Cores have also been taken from Barfield Tarn, which is 19 km SE of Sellafield but close to the sea, and from Ponsonby and Harnsey Moss Tarns, close to Sellafield. All sediments were analysed for /sup 137/Cs and sup(239+240)Pu. Additional measurements of /sup 238/Pu and /sup 241/Am were made on samples from the closer tarns. The sediment cores were dated by the /sup 210/Pb method and, where appropriate, by the /sup 137/Cs technique also. The amounts of /sup 137/Cs and sup(239+240)Pu in sediments from Barfield Tarn could be accounted for by fallout from nuclear weapons, although the levels of /sup 241/Am were marginally greater. However in Harnsey Moss Tarn the levels of actinides indicated that they were derived mainly from material originally discharged to sea from Sellafield. Sediment from Ponsonby Tarn contained material derived mainly from discharges to atmosphere.

  6. Seasonal dynamics of dissolved, particulate and microbial components of a tidal saltmarsh-dominated estuary under contrasting levels of freshwater discharge

    Science.gov (United States)

    Bittar, Thais B.; Berger, Stella A.; Birsa, Laura M.; Walters, Tina L.; Thompson, Megan E.; Spencer, Robert G. M.; Mann, Elizabeth L.; Stubbins, Aron; Frischer, Marc E.; Brandes, Jay A.

    2016-12-01

    Tidal Spartina-dominated saltmarshes and estuaries on the Southeast US coast are global hotspots of productivity. In coastal Georgia, tidal amplitudes and saltmarsh productivity are the highest along the Southeast US coast. Coastal Georgia is characterized by a humid subtropical seasonal climate, and inter-annual variability in precipitation, and freshwater discharge. The 2012-2013 timeframe encompassed contrasting levels of discharge for the Savannah River, a major Georgia river, with a 4.3-fold greater discharge in summer 2013 relative to summer 2012. In situ measurements of temperature, salinity, precipitation and Secchi depth, and water samples were collected weekly at high tide throughout 2012 and 2013 from the Skidaway River Estuary, a tidal saltmarsh-dominated estuary in coastal Georgia influenced by Savannah River hydrology. The effects of elevated discharge on the seasonal trends of water column components were evaluated. The shift from low discharge (2012) to high discharge (2013) led to decreased salinity in summer 2013, but no significant increases in inorganic nutrient (NH4, NOx, SiO2 and PO4) concentrations. Dissolved inorganic carbon (DIC) concentrations decreased, and DIC stable isotopic signatures (δ13C-DIC values) were depleted in summer 2013 relative to summer 2012. In 2013 dissolved organic carbon (DOC) concentrations, chromophoric and fluorescent dissolved organic matter (DOM: CDOM, FDOM) intensities, specific UV-absorbance (SUVA254) and relative humic-like fluorescence were all higher than in 2012, indicating that, as discharge increased in 2013, estuarine water became enriched in terrigenous DOM. Secchi depth and particulate organic carbon (POC) and nitrogen (PON) concentrations displayed clear seasonal patterns that were not significantly altered by discharge. However, δ13C-POC and δ15N-PON isotopic signatures indicated higher terrigenous contributions at elevated discharge. Discharge influenced cyanobacterial composition, but did not

  7. Nitrous oxide and methane fluxes vs. carbon, nitrogen and phosphorous burial in new intertidal and saltmarsh sediments

    Energy Technology Data Exchange (ETDEWEB)

    Adams, C.A., E-mail: christopher.adams@uea.ac.uk; Andrews, J.E.; Jickells, T.

    2012-09-15

    Carbon (C), nitrogen (N) and phosphorous (P) burial rates were determined within natural saltmarsh (NSM) and 'managed realignment' (MR) sediments of the Blackwater estuary, UK. Methane (CH{sub 4}) and nitrous oxide (N{sub 2}O) fluxes were measured along with their ability to offset a portion of the C burial to give net C sequestration. C and N densities (C{rho} and N{rho}) of NSM sediments (0.022 and 0.0019 g cm{sup -3}) are comparable to other UK NSM sediments. Less vegetationally developed MR sediments have lower C{rho} and N{rho} (0.012 and 0.0011 g cm{sup -3}) while the more vegetationally developed sites possess higher C{rho} and N{rho} (0.023 and 0.0030 g cm{sup -3}) than NSM. Both NSM and MR areas were small CH{sub 4} (0.10-0.40 g m{sup -2} yr{sup -1}) and N{sub 2}O (0.03-0.37 g m{sup -2} yr{sup -1}) sources. Due to their large Global Warming Potentials, even these relatively small greenhouse gas (GHG) fluxes reduced the net C sequestration within MR marshes by as much as 49%, but by only 2% from NSM. Potential MR areas within the Blackwater estuary (29.5 km{sup 2} saltmarsh and 23.7 km{sup 2} intertidal mudflat) could bury 5478 t C yr{sup -1} and 695.5 t N yr{sup -1}, with a further 476 t N yr{sup -1} denitrified. The saltmarsh MR would also sequester 139.4 t P yr{sup -1}. GHG fluxes would reduce the C burial benefit by 24% giving a C sequestration rate of 4174 t C yr{sup -1}. Similar areas within the Humber estuary (74.95 km{sup 2}) could bury 3597 t C yr{sup -1} and 180 t N yr{sup -1}, with a further 442 t N yr{sup -1} denitrified. GHG fluxes would reduce the C burial benefit by 31% giving a C sequestration rate of 2492 t C yr{sup -1}. Overall, MR sites provide sustainable coastal defence options with significant biogeochemical value and, despite being net sources of CH{sub 4} and N{sub 2}O, can sequester C and reduce estuarine nutrient loads. -- Highlights: Black-Right-Pointing-Pointer We investigated C, N, P, CH{sub 4} and N{sub 2}O fluxes

  8. Radioactive influence of some phosphogypsum piles located at the SW Spain in their surrounding soils and salt-marshes

    Science.gov (United States)

    Bolivar, J. P.; Mosqueda, F.; Vaca, F.; Garcia-Tenorio, R.; Martinez-Sanchez, M. J.; Perez-Sirvent, C.; Martinez-Lopez, S.

    2012-04-01

    In the SW of Spain, just in the confluence of the mouths of the Tinto and Odiel River and in the vicinity of Huelva town, there is a big industrial complex which includes between others an industry devoted during more than 40 years to the production of phosphoric acid, by treating sedimentary phosphate rock by the so-called "wet acid method". As a by-product of the mentioned process it have been produced historically huge amounts of a compound called phosphogypsum, which composition is mostly di-hydrate calcium sulphate containing some of the impurities of heavy metals and natural radionuclides originally present in the raw material. Due to the lack of market for this by-product, it has been mostly piled over some salt-marshes located in the vicinity of the industry, on the bank of the Tinto River. About 100 million tons of phosphogypsum have been piled in an area covering more than 1000 hectares, constituting a clear environmental and radiological anomaly in the zone. The phosphogypsum piles set do not conform obviously a close system. They are interacting with the nearby environment mostly by leaching waters releases from the waters accumulated in them either for its previous use in transporting in suspension the PG from the factory or by rainfall. These waters leaks contain in solution enhanced amounts of heavy metals and radionuclides that can provoke the chemical and radioactive contamination in surroundings soil and salt-marshes areas. In this communication the radioactive influence by the phosphogypsum piles in the surrounding terrestrial environment is evaluated. This contamination is mostly due to radionuclides belonging to the uranium series, which are present originally in the raw material treated in the industry, and afterwards in the generated phosphogypsum, in enhanced amounts in relation to typical soils. In addition, the different dynamics and behavior of different radionuclides will be discussed and analyzed. The gained information in this study

  9. A comparison of the risks of leukaemia in the offspring of the Sellafield workforce born in Seascale and those born elsewhere in West Cumbria with the risks in the offspring of the Ontario and Scottish workforces and the Japanese bomb survivors

    Energy Technology Data Exchange (ETDEWEB)

    Little, M.P. (National Radiological Protection Board, Chilton (United Kingdom)); Wakeford, R. (British Nuclear Fuels plc, Risley (United Kingdom)); Charles, M.W. (Nuclear Electric plc, Berkeley (United Kingdom). Berkeley Technology Centre)

    1994-09-01

    The cases of childhood leukaemia found among children of the Sellafield (West Cumbria), Ontario and Scottish radiation workers and in the offspring of the Japanese bomb survivors are analysed using linear and exponential forms of a relative risk model with total preconception external radiation dose estimates. In particular, the risks among children of the Sellafield workforce born in Seascale and among those born elsewhere in West Cumbria are compared with the risks derived from the other datasets. There is a highly significant inconsistency between the raised paternal preconception exposure excess relative risk coefficients for leukaemia in those children of the Sellafield workforce born in Seascale and the coefficients for children born elsewhere in West Cumbria, those for the offspring of the Ontario or Scottish workforces as well as those for the offspring of the Japanese bomb survivors. These incompatabilities are independent of the models used. In contrast to this, the leukaemia excess relative risk coefficients for paternal preconception exposure of those children of the Sellafield workforce born elsewhere in West Cumbria are not significantly elevated and do not differ significantly from those observed in the Japanese, Ontario and Scottish datasets. (author).

  10. A comparison of the risks of leukaemia in the offspring of the Sellafield workforce born in Seascale and those born elsewhere in West Cumbria with the risks in the offspring of the Ontario and Scottish workforces and the Japanese bomb survivors

    International Nuclear Information System (INIS)

    Little, M.P.; Wakeford, R.; Charles, M.W.

    1994-01-01

    The cases of childhood leukaemia found among children of the Sellafield (West Cumbria), Ontario and Scottish radiation workers and in the offspring of the Japanese bomb survivors are analysed using linear and exponential forms of a relative risk model with total preconception external radiation dose estimates. In particular, the risks among children of the Sellafield workforce born in Seascale and among those born elsewhere in West Cumbria are compared with the risks derived from the other datasets. There is a highly significant inconsistency between the raised paternal preconception exposure excess relative risk coefficients for leukaemia in those children of the Sellafield workforce born in Seascale and the coefficients for children born elsewhere in West Cumbria, those for the offspring of the Ontario or Scottish workforces as well as those for the offspring of the Japanese bomb survivors. These incompatabilities are independent of the models used. In contrast to this, the leukaemia excess relative risk coefficients for paternal preconception exposure of those children of the Sellafield workforce born elsewhere in West Cumbria are not significantly elevated and do not differ significantly from those observed in the Japanese, Ontario and Scottish datasets. (author)

  11. Community composition and activity of anaerobic ammonium oxidation bacteria in the rhizosphere of salt-marsh grass Spartina alterniflora.

    Science.gov (United States)

    Zheng, Yanling; Hou, Lijun; Liu, Min; Yin, Guoyu; Gao, Juan; Jiang, Xiaofen; Lin, Xianbiao; Li, Xiaofei; Yu, Chendi; Wang, Rong

    2016-09-01

    Anaerobic ammonium oxidation (anammox) as an important nitrogen removal pathway has been investigated in intertidal marshes. However, the rhizosphere-driven anammox process in these ecosystems is largely overlooked so far. In this study, the community dynamics and activities of anammox bacteria in the rhizosphere and non-rhizosphere sediments of salt-marsh grass Spartina alterniflora (a widely distributed plant in estuaries and intertidal ecosystems) were investigated using clone library analysis, quantitative PCR assay, and isotope-tracing technique. Phylogenetic analysis showed that anammox bacterial diversity was higher in the non-rhizosphere sediments (Scalindua and Kuenenia) compared with the rhizosphere zone (only Scalindua genus). Higher abundance of anammox bacteria was detected in the rhizosphere (6.46 × 10(6)-1.56 × 10(7) copies g(-1)), which was about 1.5-fold higher in comparison with that in the non-rhizosphere zone (4.22 × 10(6)-1.12 × 10(7) copies g(-1)). Nitrogen isotope-tracing experiments indicated that the anammox process in the rhizosphere contributed to 12-14 % N2 generation with rates of 0.43-1.58 nmol N g(-1) h(-1), while anammox activity in the non-rhizosphere zone contributed to only 4-7 % N2 production with significantly lower activities (0.28-0.83 nmol N g(-1) h(-1)). Overall, we propose that the rhizosphere microenvironment in intertidal marshes might provide a favorable niche for anammox bacteria and thus plays an important role in nitrogen cycling.

  12. [Distribution patterns and pollution assessments of heavy metals in the Spartina alterniflora salt-marsh wetland of Rudong, Jiangsu province].

    Science.gov (United States)

    Zhang, Long-Hui; Du, Yong-Fen; Wang, Dan-Dan; Gao, Shu; Gao, Wen-Hua

    2014-06-01

    . alterniflora is one of important factors to enrich the heavy metal in tidal flat sediment. Thus, ecological risk of the heavy metal is reduced or blocked, due to the filtering effect of salt-marsh, which prevents metals from entering the open sea directly. The distribution of heavy metal is influenced by a combination of colonization time of vegetation, chemical form of metals and their origins.

  13. Assessing saltmarsh resilience to sea-level rise by examining sediment transport trends in the Great Marsh, MA.

    Science.gov (United States)

    Hughes, Z. J.; Georgiou, I. Y.; Gaweesh, A.; Hanegan, K.; FitzGerald, D.; Hein, C. J.

    2017-12-01

    Under accelerating sea-level rise (SLR), marshes are vulnerable to increased inundation, dependent on their ability to accrete vertically or expand into upland areas. Accretion is a function of organic and inorganic contributions from plant biomass and suspended sediment deposition, respectively. Along the east coast of the US, present rates of SLR are higher than they have been for over 1000 years and are expected to increase in the near future. To predict the resilience of saltmarshes, we urgently need improved understanding of spatial patterns of sediment transport and deposition within these systems. This study examines time-series of suspended sediment concentration and flow collected using ADCP-OBS units, deployed throughout the Great Marsh System. We compare the data to model results and observations of short and long term deposition throughout the system. Field observations show that tidal amplitude and phase vary throughout the Great Marsh. Tidal asymmetry increases inland from the estuary mouth, and the maximum phase lag is 2 hours. This effect is strongest during low slack tide; with a delay of only 30-45 minutes at high tide. Tidal velocities exhibit strong asymmetry, reflected in pulses of sediment movement. Sediment transport initiates at mid ebb, peaking 1.5-2.5 hours later, decreasing through low slack tide for 7-9 hours until high slack tide. The results have broad implications for the potential input of inorganic sediment to the marsh platform. Results from a validated Delft3D model reproduce field observations and expand spatial sediment transport trends. We experiment by releasing sediment in different parts of the estuary, mimicking marsh edge or tidal flat erosion, and tracking mud and sand transport trajectories. Sands remains proximal to the erosion site, whereas mud is more mobile and travels farther, reaching the inlet within days of erosion. Longer simulations suggest that despite higher mobility, muds remain mostly in the channels and

  14. Bacterial community shift in the coastal Gulf of Mexico salt-marsh sediment microcosm in vitro following exposure to the Mississippi Canyon Block 252 oil (MC252)

    KAUST Repository

    Koo, Hyunmin; Mojib, Nazia; Huang, Jonathan P.; Donahoe, Rona J.; Bej, Asim K.

    2014-01-01

    In this study, we examined the responses by the indigenous bacterial communities in salt-marsh sediment microcosms in vitro following treatment with Mississippi Canyon Block 252 oil (MC252). Microcosms were constructed of sediment and seawater collected from Bayou La Batre located in coastal Alabama on the Gulf of Mexico. We used an amplicon pyrosequencing approach on microcosm sediment metagenome targeting the V3–V5 region of the 16S rRNA gene. Overall, we identified a shift in the bacterial community in three distinct groups. The first group was the early responders (orders Pseudomonadales and Oceanospirillales within class Gammaproteobacteria), which increased their relative abundance within 2 weeks and were maintained 3 weeks after oil treatment. The second group was identified as early, but transient responders (order Rhodobacterales within class Alphaproteobacteria; class Epsilonproteobacteria), which increased their population by 2 weeks, but returned to the basal level 3 weeks after oil treatment. The third group was the late responders (order Clostridiales within phylum Firmicutes; order Methylococcales within class Gammaproteobacteria; and phylum Tenericutes), which only increased 3 weeks after oil treatment. Furthermore, we identified oil-sensitive bacterial taxa (order Chromatiales within class Gammaproteobacteria; order Syntrophobacterales within class Deltaproteobacteria), which decreased in their population after 2 weeks of oil treatment. Detection of alkane (alkB), catechol (C2,3DO) and biphenyl (bph) biodegradation genes by PCR, particularly in oil-treated sediment metacommunity DNA, delineates proliferation of the hydrocarbon degrading bacterial community. Overall, the indigenous bacterial communities in our salt-marsh sediment in vitro microcosm study responded rapidly and shifted towards members of the taxonomic groups that are capable of surviving in an MC252 oil-contaminated environment.

  15. Bacterial community shift in the coastal Gulf of Mexico salt-marsh sediment microcosm in vitro following exposure to the Mississippi Canyon Block 252 oil (MC252)

    KAUST Repository

    Koo, Hyunmin

    2014-07-10

    In this study, we examined the responses by the indigenous bacterial communities in salt-marsh sediment microcosms in vitro following treatment with Mississippi Canyon Block 252 oil (MC252). Microcosms were constructed of sediment and seawater collected from Bayou La Batre located in coastal Alabama on the Gulf of Mexico. We used an amplicon pyrosequencing approach on microcosm sediment metagenome targeting the V3–V5 region of the 16S rRNA gene. Overall, we identified a shift in the bacterial community in three distinct groups. The first group was the early responders (orders Pseudomonadales and Oceanospirillales within class Gammaproteobacteria), which increased their relative abundance within 2 weeks and were maintained 3 weeks after oil treatment. The second group was identified as early, but transient responders (order Rhodobacterales within class Alphaproteobacteria; class Epsilonproteobacteria), which increased their population by 2 weeks, but returned to the basal level 3 weeks after oil treatment. The third group was the late responders (order Clostridiales within phylum Firmicutes; order Methylococcales within class Gammaproteobacteria; and phylum Tenericutes), which only increased 3 weeks after oil treatment. Furthermore, we identified oil-sensitive bacterial taxa (order Chromatiales within class Gammaproteobacteria; order Syntrophobacterales within class Deltaproteobacteria), which decreased in their population after 2 weeks of oil treatment. Detection of alkane (alkB), catechol (C2,3DO) and biphenyl (bph) biodegradation genes by PCR, particularly in oil-treated sediment metacommunity DNA, delineates proliferation of the hydrocarbon degrading bacterial community. Overall, the indigenous bacterial communities in our salt-marsh sediment in vitro microcosm study responded rapidly and shifted towards members of the taxonomic groups that are capable of surviving in an MC252 oil-contaminated environment.

  16. Historical storage budgets of organic carbon, nutrient and contaminant elements in saltmarsh sediments: Biogeochemical context for managed realignment, Humber Estuary, UK

    International Nuclear Information System (INIS)

    Andrews, J.E.; Samways, G.; Shimmield, G.B.

    2008-01-01

    Biogeochemical data from Welwick marsh (Humber Estuary, UK), an actively accreting saltmarsh, provides a decadal-centennial-scale natural analogue for likely future biogeochemical storage effects of managed realignment sites accreting either intertidal muds or saltmarsh. Marsh topographic profiles and progradation history from aerial photographs were combined with 137 Cs and niobium contamination history to establish and verify chronology and sediment mass accumulation. These data, combined with down-core measurements of particulate organic carbon (C org ), organic nitrogen (N org ), particle reactive phosphorus and selected contaminant metal (Zn, Pb, Cu, As and Nb) contents were then used to calculate sediment and chemical storage terms and to quantify changes in these over time. These data are used to help predict likely future biogeochemical storage changes at managed realignment sites in the estuary. The net effect of returning some 26 km 2 of reclaimed land to intertidal environments now (about 25% of the maximum possible realignment storage identified for the estuary) could result in the storage of some 40,000 tonnes a -1 of sediment which would also bury about 800 tonnes a -1 of C org and 40 tonnes a -1 of N org . Particulate contaminant P burial would be around 25 tonnes a -1 along with ∼ 6 tonnes a -1 contaminant Zn, 3 tonnes a -1 contaminant Pb, and ∼ 1 tonnes a -1 contaminant As and Cu. The study also shows that reclamation activities in the outer estuary since the mid-1700s has prevented, in total, the deposition of about 10 million tonnes of sediment, along with 320,000 tonnes of C org and 16,000 tonnes of N org . The study provides a mid-1990s baseline against which future measurements at the site can determine changes in burial fluxes and improvement or deterioration in contaminant metal contents of the sediments. The data are directly relevant for local managed realignment sites but also broadly indicative for sites generally on the European

  17. Assessing the Resilience of a Blue Carbon Store: Characterizing the Lateral Flux of DIC from an East Coast U.S. Saltmarsh using Δ14C and δ13C

    Science.gov (United States)

    Felgate, S. L.; Gonneea, M. E.; Kroeger, K. D.; Chu, S. N.; Wang, A. Z.

    2016-12-01

    Intertidal saltmarshes are highly productive coastal habitats and important blue carbon stores. They commonly exhibit high salinity, low oxygen environmental regimes which lend themselves towards reduced rates of microbial respiration, and the assimilation of atmospheric CO2 into plant biomass tends to outpace the rate at which that biomass is broken down. As a result, a relatively high proportion of CO2 entering the system can be expected to become incorporated into marsh sediment before it can be metabolised, potentially entering storage for thousands of years and providing a sizeable natural carbon sink. However, the rate at which these habitats are now being degraded is substantial and growing: the combined impacts of stressors such as increasing temperature and sea level rise are predicted to reduce global saltmarsh coverage by 30-40% by the end of the century, and many saltmarsh carbon stores can be expected to shift from net sinks to sources within the same time frame. Based on high resolution measurements and modelling in a northeastern U.S. saltmarsh, a recent study reported a marsh DIC export of 414g C m2 yr-1. This is more than twice that put forward in previous estimates, and is larger than the total uptake by plant biomass. This translates into one of the largest carbon fluxes to the coastal ocean found along the U.S. East Coast. Additionally it is possible that the marsh carbon budget is not in balance, with export exceeding carbon fixation rates. Here we characterise this carbon flux using Δ14C and δ13C data to age and source the exported dissolved carbon pools. Carbon isotope mixing models between surface (modern) and porewater (old) carbon sources are constrained by creek samples and porewaters from multiple depths and locations within the marsh. We determine the age of exported carbon to see if carbon stored over the lifetime of the marsh (c. 2000 years) continues to be respired, thereby evaluating the long term resilience of the carbon sink.

  18. Instrumental neutron activation analysis of site-dependent uptake and distribution of trace elements in the saltmarsh plant Aster tripolium from marsh fields in the Schelde estuary, Netherlands

    International Nuclear Information System (INIS)

    Rossbach, M.

    1986-07-01

    As part of an environmental chemical investigation the uptake of heavy metals by a saltmarsh plant Aster tripolium from two differently polluted salt marsh sites of the North Sea between 20 to 30 trace elements were determined in soil and plant organs. A sensitive gamma ray counting system was installed and tested for instrumental activation analyses (INAA). Installations to improve sensitivity as well as conditions necessary for reliable trace element analysis with the aid of Anticompton spectrometers (ACS) are described. The accuracy and reproducibility of the method was determined by the analysis of reference- and control materials of the german environmental specimen bank. In order to characterise the state of pollution of the salt marsh soils pollution-factors for single elements as well as interelemental correlations were evaluated. In addition, uptake and translocation factors of the biological samples were calculated. The many highly significant correlations between elements within the plant organs indicated that uptake appears to be physiologicaly controlled and not dependent on soil concentration. In order to detect further consequences of differing pollution influences within these plants biochemical separation techniques were applied and trace element levels in selected extracts were determined. For the specification of heavy metals gelpermeation chromatography of ethanolic extracts proved to be the most promising method. Furthermore, propositions for the use of trace elements as a fingerprint for pollution status and characterisation of species for referenz- and specimenbank materials have been developed. Aster tripolium as a cadmium accumulating plant can probably be used as an indicator in the monitoring of cadmium polluted salt marsh areas. (orig.) [de

  19. Studies of environmental radioactivity in Cumbria

    International Nuclear Information System (INIS)

    Ramsay, J.D.F.; Raw, G.

    1987-10-01

    The physical characteristics and actinide adsorption behaviour of colloids and fine particulates in Cumbrian coastal sediments and seawater have been determined to assess the role of particles in the sea to land transfer of actinides in seaspray. Procedures have been developed for the separation of particulates into different size and mineral fractions using deflocculation and sedimentation under gravity and centrifugally. These fractions have been characterised using a range of physicochemical techniques. Specific activities of actinides (Pu, Am) adsorbed on these fractions have been correlated with size and mineral composition. Tentative evidence of the role of the fine particulates in sea to land transfer is discussed. (author)

  20. Studies of environmental radioactivity in Cumbria

    International Nuclear Information System (INIS)

    Ramsay, J.D.F.

    1987-04-01

    The physical characteristics and actinide adsorption behaviour of colloids and fine particulates in Cumbrian coastal sediments and seawater have been determined to assess the role of particles in the sea to land transfer of actinides in seaspray. Procedures have been developed for the separation of particulates into different size and mineral fractions using deflocculation and sedimentation under gravity and centrifugally. These fractions have been characterised using a range of physicochemical techniques. Specific activities of actinides (Pu, Am) adsorbed on these fractions have been correlated with size and mineral composition. Tentative evidence of the role of the fine particulates in sea to land transfer is discussed. (author)

  1. Distribution of radionuclides in mussels, winkles and prawns: Pt. 1; Study of organisms under environmental conditions using conventional radio-analytical techniques

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, P [Scottish Research Reactor Centre, East Kilbride (United Kingdom); Baxter, M S; Fowler, S W [International Atomic Energy Agency, Monaco (Monaco). Marine Environment Lab.

    1993-01-01

    Mussels (Mytilus edulis) and winkles (Littorina littorea), collected from Ravenglass, Cumbria, England in the vicinity of the British Nuclear Fuels plc nuclear reprocessing plant at Sellafield, and prawns (Palaemon serratus), landed nearby at Whitehaven, have been investigated to determine the distributions of [alpha]-emitting ([sup 210]Po, [sup 238]Pu, [sup 239] [sup +] [sup 240]Pu, [sup 241]Am) and [gamma]-emitting ([sup 95]Nb, [sup 95]Zr, [sup 103]Ru, [sup 106]Ru, [sup 137]Cs, [sup 241]Am) radionuclides in their tissues and organs. Previous studies have attempted to determine the principal nuclide source to marine organisms by comparing nuclide activity ratios in their tissues, sea water and particulate material. From the environmental samples studied here, no single transport medium appears to dominate uptake. The primary radiological implantation of the observed radionuclide concentrations in Ravenglass mussels and winkles is that, from seafood ingestion, the critical group receives only a small percentage (ca. 10%) of the ICRP-recommended subsidiary dose limit. Dose contributions from [sup 210]Po are higher than those from [sup 239] + [sup 240]Pu in mussels but are less than those from [sup 239] [sup +] [sup 240]Pu in winkles. (Author).

  2. The uptake of plutonium-239, 240, americium-241, strontium-90 into plants

    International Nuclear Information System (INIS)

    Popplewell, D.S.; Ham, G.J.; Johnson, T.E.

    1984-01-01

    This report describes the results of measurements on the uptake of plutonium, americium, strontium-90 and caesium-137 into peas, beet, oats, sweet corn, tomatoes and vegetable marrow grown in tubs containing radioactively-contaminated silts. The silts had been taken from an area of West Cumbria commonly referred to as the Ravenglass estuary. The experiments are categorised as being carried out under non-standard conditions because of the manner in which the radioactivity came to be incorporated into the growth medium. The growth medium was representative of conditions which could arise when the estuarine silt moves inland under the influence of wind and tide and mixes with the adjacent farm land. The silt had been contaminated by radioactive effluents from the nuclear fuels reprocessing plant at Sellafield and this contamination had been brought about by natural means. (Auth.)

  3. Coastal salt-marshes in Albania

    OpenAIRE

    JULIAN SHEHU; ALMA IMERI; RUDINA KOCI; ALFRED MULLAJ

    2014-01-01

    The salt marshes of Albania comprise a narrow belt along the Adriatic and Ionian Seas. They have been the subject of a range of human activities causing habitat loss. Enclosure for agricultural use, ports and other infrastructure has reduced many salt marshes to a narrow fringe along estuary shores. Salt marshes are important for a range of interests. In particular they support a range of specialist plant communities and associated animals (especially breeding and wintering birds) and often h...

  4. Studies of environmental radioactivity in Cumbria. Pt. 13

    International Nuclear Information System (INIS)

    Otlet, R.; Longley, H.; Walker, A.J.

    1989-04-01

    The main objective of the project was to reconstruct a chronology of past 14 C levels in atmospheric CO 2 in the vicinity of the Sellafield reprocessing plant by measuring the 14 C in individual tree rings from trees felled at a number of sites. The profile obtained from the results reflects the build up of the plant operations and related aerial emissions and a conversion of the tree ring records to past annual aerial discharges of 14 C has been attempted. This is compared with values provided from recent estimates of aerial emissions. The effect of dispersion along a coastal transect to a distance of 30km from BNFL Sellafield has also been studied. Comparable, but attenuated profiles to the inland sites are observed although the major peaks are not precisely mirrored along the transect. This is attributed to greater year to year variation due to sea breezes. (author)

  5. Epidemiology of cancer in young persons in West Cumbria

    International Nuclear Information System (INIS)

    Snee, M.P.

    1987-01-01

    A brief report is given of a lecture by Professor Gardner of the MRC in which some of the epidemiological evidence of cancer in young persons in the vicinity of the Sellafield site was reviewed. The studies that the MRC Environmental Epidemiology Unit at Southampton were currently undertaking in relation to Recommendations 1,2 and 3 of the Black Committee 1984 Report were also outlined. Some of the questions put to Professor Gardner after his lecture are briefly discussed. (UK)

  6. Transfer across the human gut of environmental plutonium, americium, cobalt, caesium and technetium: studies with cockles (Cerastoderma edule) from the Irish Sea

    International Nuclear Information System (INIS)

    Hunt, G.J.

    1998-01-01

    Our previous studies have indicated lower values of the gut transfer factor ('f L values') for plutonium and americium in winkles (Littorina littorea) than adopted by ICRP. The present study was undertaken primarily to investigate whether this observation extends to other species. Samples of cockles (Cerastoderma edule) from Ravenglass, Cumbria were eaten by volunteers who provided 24 samples of urine and faeces. Urine samples indicated f L values for cockles which were higher than for winkles; for plutonium these ranged overall up to 7x10 -4 with an arithmetic mean in the range (2-3)x10 -4 , and for americium up to 2.6x10 -4 with an arithmetic mean of 1.2x10 -4 . Limited data based on volunteers eating cockles from the Solway suggest that f L values for americium may be greater at distance from Sellafield. The measured values compare with 5x10 -4 used by the ICRP for environmental forms of both elements, which would appear to provide adequate protection when calculating doses from Cumbrian cockles. Data for other nuclides were obtained by analysing faecal samples from the volunteers who ate the Ravenglass cockles. Cobalt-60 showed an f L value in the region of 0.2, twice the value currently used by ICRP. For 137 Cs, variabilities were indicated in the range 0.08 to 0.43, within the ICRP value of f L =1.0. Technetium-99 gave f L values up to about 0.6, in reasonable conformity with the ICRP value of 0.5. (author)

  7. Studies of environmental radioactivity in Cumbria. Part 5. The magnitude and mechanism of enrichment of seaspray with actinides in West Cumbria

    International Nuclear Information System (INIS)

    Eakins, J.D.; Lally, A.E.; Burton, P.J.; Kilworth, D.R.; Pratley, F.A.

    1982-03-01

    As part of a programme to investigate the transfer to land of radionuclides discharged to the sea from British Nuclear Fuels Ltd, Sellafield, sea spray was collected at several sites between the Solway Firth and Barrow. Samples of seawater and materials from the foreshore were also collected. The samples were analysed for 137 Cs, 238 Pu, 239+240 Pu and 241 Am. It was demonstrated that, in winds up to 10m sec -1 , actinides in sea spray are derived from sediment suspended in seawater in the surf zone. At Eskmeals, in an on-shore wind of 6m sec -1 , 98 per cent of the plutonium and 93 per cent of the sea spray collected on the beach were injected into the atmosphere in the surf zone. Enrichment factors for plutonium in sea spray ranged from 70 to 800 relative to filtered seawater and from 3 to 66 for unfiltered water. Large enrichment factors were also observed for 241 Am but 137 Cs was only slightly enriched in spray. Laboratory experiments were also performed in which spray was generated by bubbling air through vigorously stirred seawater collected from the surf zone on the Cumbrian coast. Similar enrichment factors were obtained. (author)

  8. Mangrove expansion and saltmarsh decline at mangrove poleward limits

    Science.gov (United States)

    Saintilan, Neil; Wilson, Nicholas C.; Rogers, Kerrylee; Rajkaran, Anusha; Krauss, Ken W.

    2014-01-01

    Mangroves are species of halophytic intertidal trees and shrubs derived from tropical genera and are likely delimited in latitudinal range by varying sensitivity to cold. There is now sufficient evidence that mangrove species have proliferated at or near their poleward limits on at least five continents over the past half century, at the expense of salt marsh. Avicennia is the most cold-tolerant genus worldwide, and is the subject of most of the observed changes. Avicennia germinans has extended in range along the US Atlantic coast and expanded into salt marsh as a consequence of lower frost frequency and intensity in the southern USA. The genus has also expanded into salt marsh at its southern limit in Peru, and on the Pacific coast of Mexico. Mangroves of several species have expanded in extent and replaced salt marsh where protected within mangrove reserves in Guangdong Province. In south-eastern Australia, the expansion of Avicennia marina into salt marshes is now well documented, and Rhizophora stylosa has extended its range southward, while showing strong population growth within estuaries along its southern limits in northern New South Wales. Avicennia marina has extended its range southwards in South Africa. The changes are consistent with the pole-ward extension of temperature thresholds co-incident with sea-level rise, although the specific mechanism of range extension might be complicated by limitations on dispersal or other factors. The shift from salt marsh to mangrove dominance on subtropical and temperate shorelines has important implications for ecological structure, function, and global change adaptation.

  9. Food web heterogeneity and succession in created saltmarshes

    Science.gov (United States)

    Nordstrom, M C; Demopoulos, Amanda W.J.; Whitcraft, CR; Rismondo, A.; McMillan, P.; Gonzales, J P; Levin, L A

    2015-01-01

    1. Ecological restoration must achieve functional as well as structural recovery. Functional metrics for reestablishment of trophic interactions can be used to complement traditional monitoring of structural attributes. In addition, topographic effects on food web structure provide added information within a restoration context; often, created sites may require spatial heterogeneity to effectively match structure and function of natural habitats. 2. We addressed both of these issues in our study of successional development of benthic food web structure, with focus on bottom–up driven changes in macroinvertebrate consumer assemblages in the salt marshes of the Venice Lagoon, Italy. We combined quantified estimates of the changing community composition with stable isotope data (13C:12C and 15N:14N) to compare the general trophic structure between created (2–14 years) marshes and reference sites and along topographic elevation gradients within salt marshes. 3. Macrofaunal invertebrate consumers exhibited local, habitat-specific trophic patterns. Stable isotope-based trophic structure changed with increasing marsh age, in particular with regards to mid-elevation (Salicornia) habitats. In young marshes, the mid-elevation consumer signatures resembled those of unvegetated ponds. The mid elevation of older and natural marshes had a more distinct Salicornia-zone food web, occasionally resembling that of the highest (Sarcocornia-dominated) elevation. In summary, this indicates that primary producers and availability of vascular plant detritus structure consumer trophic interactions and the flow of carbon. 4. Functionally different consumers, subsurface-feeding detritivores (Oligochaeta) and surface grazers (Hydrobia sp.), showed distinct but converging trajectories of isotopic change over time, indicating that successional development may be asymmetric between ‘brown’ (detrital) guilds and ‘green’ (grazing) guilds in the food web. 5. Synthesis and applications. Created marsh food webs converged into a natural state over about a decade, with successional shifts seen in both consumer community composition and stable isotope space. Strong spatial effects were noted, highlighting the utility of stable isotopes to evaluate functional equivalence in spatially heterogeneous systems. Understanding the recovery of functional properties such as food web support, and their inherent spatial variability, is key to planning and managing successful habitat restoration.

  10. Response of salt-marsh carbon accumulation to climate change.

    Science.gov (United States)

    Kirwan, Matthew L; Mudd, Simon M

    2012-09-27

    About half of annual marine carbon burial takes place in shallow water ecosystems where geomorphic and ecological stability is driven by interactions between the flow of water, vegetation growth and sediment transport. Although the sensitivity of terrestrial and deep marine carbon pools to climate change has been studied for decades, there is little understanding of how coastal carbon accumulation rates will change and potentially feed back on climate. Here we develop a numerical model of salt marsh evolution, informed by recent measurements of productivity and decomposition, and demonstrate that competition between mineral sediment deposition and organic-matter accumulation determines the net impact of climate change on carbon accumulation in intertidal wetlands. We find that the direct impact of warming on soil carbon accumulation rates is more subtle than the impact of warming-driven sea level rise, although the impact of warming increases with increasing rates of sea level rise. Our simulations suggest that the net impact of climate change will be to increase carbon burial rates in the first half of the twenty-first century, but that carbon-climate feedbacks are likely to diminish over time.

  11. The feasibility of using Pu discharges from Sellafield to investigate the sediment dynamics of the Severn Estuary and the Welsh coast

    Energy Technology Data Exchange (ETDEWEB)

    Dunne, J.A.; Richards, D.A. [School of Geographical Sciences and Bristol Isotope Group, University of Bristol (United Kingdom)

    2014-07-01

    Decades of nuclear weapons testing and very low level radioactive waste discharges from civil nuclear sites have resulted in a global distribution of Pu isotopes. Given that the sources of these isotopes are spatially and temporally well-known, their distribution throughout the environment can provide insight into the processes that have governed their dispersal. Plutonium-239 and {sup 240}Pu have long half-lives and their atomic abundance ratio is indicative of the source, be it atmospheric fallout or releases from the nuclear industry. Plutonium is also strongly adsorbed on sediments. These characteristics make Pu an excellent tool for monitoring ocean currents, tracking sediment transport and examining the fate of the products of nuclear activities. We intend to exploit the discharges of Pu from Sellafield nuclear reprocessing plant to investigate transit times and sediment regime in inter-tidal sediments from proximal (Ravenglass Estuary, Cumbria) and distal (Portishead, North Somerset) sites. Continuing developments in analytical techniques (extraction chromatography and ion exchange) and inductively coupled plasma mass spectrometry (ICP-MS) permit isotopic analysis at low abundances (on the order of femto-grams), with reasonable efficiency and cost in comparison to traditional radiometric techniques. A major advantage of this technique is the ability to distinguish between {sup 239}Pu and {sup 240}Pu, which is not possible with alpha-spectrometry due to similar alpha energies. We present initial results using MC-ICP-MS, following methods in Lindahl et al. (2011). Document available in abstract form only. (authors)

  12. Alpha-emitting 'hot particles' in the vicinity of BNFL Sellafield, Cumbria

    International Nuclear Information System (INIS)

    Whittall, A.J.; Tossell, P.J.

    2000-01-01

    In a survey of environmental samples in the vicinity of BNFL Sellafield, two alpha-emitting radioactive particles were found in samples of grass. One particle appears to be of mineral origin, the other was not definitively identified, but may be a fragment of fuel cladding. Conservative estimates of the activities of these particles are very low. The abundance of radioactive particles in the terrestrial food chain appears to be low, with no evidence for any alpha-emitting hot particles in foodstuffs for consumption by humans. Results suggest that there is no significant dose to man through inhalation or ingestion pathways. (author)

  13. Developments in safety and operations culture in BNFL's thorp reprocessing plant, Sellafield, Cumbria

    International Nuclear Information System (INIS)

    Kett, P.J.

    2000-01-01

    One of the best descriptions of Culture is 'how we do things around here'. In a stable organisation it is extremely difficult to change any type of culture, whether it is an operations, customer service or safety culture. To change culture one of two elements are essential. There must be either a significant external pressure felt by all in the organisation or a change in senior management, with authority to set a new direction for the organisation. BNFL had a unique opportunity through the commissioning and operation of the Thorp Reprocessing Plant at Sellafield to shape a new Safety and Operations Culture. Both the key elements for change were present. Thorp was a high profile flagship plant that had attracted multinational investment. It incorporated new technology. The workforce had volunteered to operate the plant. A strong senior management team was specially selected. The plant was being commissioned in an environment where there was significant opposition by 'anti nuclear' groups. It was essential to both BNFL and the wider international nuclear community that Thorp was commissioned and operated safely. A strong operating culture was developed with safety as the corner stone. The culture comprises three key components. Rigorous plant safety case and risk assessments before work commences and modifications to the plant occur; A high level of involvement by all levels of the workforce in both operations and safety matters; Strong supportive leadership which does not allow safety standards to be compromised and encourages open debate on how to improve. During commissioning and early operation of Thorp the robustness of the Safety and Operations Culture was demonstrated. On several occasions, despite intense commercial pressure, operations were halted until the situation was resolved both technically and procedurally. This paper describes how the Safety and Operations Culture was developed. The key factors for success include recruitment, team selection, training and personal development processes. These factors were combined with an open leadership style that allowed everyone to contribute to the definition of the Safety and Operations Culture. The journey is not complete, and possible future developments will also be described. The effectiveness of the Safety and Operations Culture will be presented. Production targets have been achieved. Occupational and environmental exposures are extremely small, and are well within the plant design standards. Conventional safety standards were transformed from below industry average to well above industry average. (author)

  14. The relationship between sediment and plutonium budgets in a small macrotidal estuary: Esk Estuary, Cumbria, UK

    International Nuclear Information System (INIS)

    Kelly, M.; Emptage, M.; Mudge, S.; Bradshaw, K.; Hamilton-Taylor, J.

    1991-01-01

    During a spring tide, measurements were made of sediment and 239,240 Pu discharges through a cross-section of the Esk estuary. These indicated that over the full tidal cycle, the inner estuary had a net gain of ca. 18 t of sediment and ca. 85 MBq of particulate phase 239,240 Pu, and a probable net loss of ca. 1 to 2 MBq of solution phase 239,240 Pu. Each of these was the net result of large gross discharges of sediment and plutonium into and out of the estuary for which the sea was the main source, with eroded estuarine sediment providing an additional minor source of sediment, of particulate phase plutonium and, via desorption, of solution phase plutonium. A net input with each tide, of sediment and its associated radionuclides, is considered to be typical for the Esk estuary under the normal conditions of low river flows. (author)

  15. Studies of environmental radioactivity in Cumbria: Part 3. Measurements of radionuclides in airborne and deposited material

    International Nuclear Information System (INIS)

    Pattenden, N.J.; Cambray, R.S.; Playford, K.; Eakins, J.D.; Fisher, E.M.R.

    1980-09-01

    Six stations sampling airborne particulate and deposited material were established in the Cumbrian coastal region. The measurements were undertaken to study current atmospheric levels and to discriminate between material from nuclear weapon tests, routine atmospheric discharges from the nuclear reprocessing works at Windscale and other sources, e.g. the sea. The results show that samples of both airborne and deposited material contain radionuclide concentrations in excess of those expected from nuclear weapon fallout. For Pu and 241 Am isotopes, the excess material comes mainly from a seaward direction. The transfer mechanism is probably resuspension, but the actinide levels are much greater than would be expected from the simple transfer of bulk seawater. For 137 Cs, the material in excess of amounts expected from nuclear weapon fallout can be attributed largely to Windscale discharges to air and seaspray containing the bulk seawater concentration of 137 Cs. Other fission products present in amounts exceeding nuclear weapon fallout were 106 Ru, 125 Sb, 134 Cs and 144 Ce. Tritium was also observed in amounts slightly in excess of nuclear weapon fallout. The highest observed annual average concentration in air for Pu isotopes was 0.2% of the derived air concentration, modified for members of the public, of 2.3 mBq/m 3 . (author)

  16. Magnox Swarf Storage Silo Liquor Effluent Management -Sellafield Site, Cumbria, UK - Legacy radioactive waste storage - 59271

    International Nuclear Information System (INIS)

    Le Clere, Stephen

    2012-01-01

    The Sellafield Magnox Swarf Storage Silo (MSSS) was constructed to provide an underwater storage facility for irradiated magnox cladding metal Swarf, as well as miscellaneous beta-gamma waste from several sources. Liquid effluent arisings from hazard reduction activities at this facility represent the toughest effluent treatment challenge within the company's Legacy Ponds and Silos portfolio. The key requirement for hazard reduction has generated many substantial challenges as the facility is readied for decommissioning. This has demanded the production of carefully thought out strategies for managing, and overcoming, the key difficulties to be encountered as hazard reduction progresses. The complexity associated with preparing for waste retrievals from the Magnox Swarf Storage Silo, has also generated the demand for a mix of creativity and perseverance to meet the challenges and make progress. Challenging the status quo and willingness to accept change is not easy and the road to overall hazard reduction for the high hazard MSSS facility will demand the skills and investment of individuals, teams, and entire facility work-forces. The first steps on this road have been taken with the successful introduction of liquor management operations, however much more is yet to be achieved. Clear communication, investing in stakeholder management, perseverance in the face of difficulty and a structured yet flexible programme delivery approach, will ensure the continued success of tackling the complex challenges of treating liquid effluent from a legacy fuel storage silo at the Sellafield Site. (authors)

  17. HPLC studies of aquatic humic compounds and complexes from the Drigg Research Site, Cumbria

    International Nuclear Information System (INIS)

    Smith, B.

    1991-01-01

    This report describes an investigation into the applicability of high performance liquid chromatographic techniques for the separation of the complex mixtures of organic acids commonly found in groundwaters. This work has shown that reverse phase ion-pair chromatography using a large pore stationary phase can be successfully applied to humic material in both natural and concentrated groundwater from the Drigg Research Site. The methodology separates the organic species into a number of well resolved components the majority of which have a molecular weight of greater than 500 Dalton. Separations obtained have been qualitatively and quantitatively analysed using a Diode array spectrophotometer. The components in excess of 500 Dalton show UV absorption spectra similar to humic and fulvic acids where as the component with a molecular weight of less than 500 Dalton shows a sharp UV absorption cutoff at 230 nm. It was noted that this component was not removed by passage through DEAEA cellulose. Reverse phase HPLC was also investigated, and results were found to be consistent with a separation based on an ion-repulsion/size exclusion mechanism. It was concluded that any separation based on this mechanism is likely to suffer from poor inter run reproducibility and must therefore be discounted as a suitable method. Similarly, ion-suppression reverse phase was shown to be equally impracticable, requiring a mobile phase pH of less than 2 to obtain separation (this low pH renders a silica based stationary phase unstable). (author)

  18. Multiple myeloma in South Cumbria 1974-80: problems of health analysis in small communities

    International Nuclear Information System (INIS)

    Jessop, E.G.; Horsley, S.D.

    1985-01-01

    The occurrence of seven cases of multiple myeloma over seven years in a small community 15 miles from a plant reprocessing nuclear fuel caused much local concern. A case control study of 34 confirmed cases in the health district during 1974 to 1980 revealed no excess of known risk factors among the 23 cases for whom informants could be traced. The possible effects of exposure to marine discharges of radioactive material cannot be completely ruled out, but dose estimates make this highly unlikely. Such studies are a necessary response by community physicians to the population they serve but have major practical and theoretical limitations. (author)

  19. Occupational exposure at the nuclear fuel reprocessing plant at Sellafield in Cumbria

    International Nuclear Information System (INIS)

    Coyle, A.; Partington, C.

    1991-01-01

    The nuclear reprocessing plant at Sellafield employs approximately 6500 people in a wide range of activities involving radioactive materials. The exposure to personnel over the period 1978-1989 is reviewed. Information is presented on collective and average dose exposure which both show significant downward trends. The current annual collective dose for reprocessing operations is 21.4 man Sv and the average whole body exposure 3.7 mSv.y -1 , taking account of both internal and external exposure. The introduction of radiological design targets for new plants and the use of formal ALARP assessments on projects has contributed substantially to the observed reduction in dose uptake. Experience also indicates that significant dose reduction can be achieved by heightening the awareness of both managers and workers of the dose implications of their work and working methods. (author)

  20. HPLC studies of aquatic humic compounds and complexes from the Drigg research site, Cumbria

    International Nuclear Information System (INIS)

    Smith, B.

    1992-01-01

    The work described in this report forms part of a multidisciplinary project, the broad objective of which is to study the ability of natural organic compounds present in groundwater to form mobile complexes with radionuclides. Other components of this work include the development of High Performance Liquid Chromatogaphic techniques (HPLC) to extract natural organic material from groundwater with minimal alteration, the separation of those organic fractions that complex with cations, and the development of geochemical speciation models to describe or predict metal binding. 17 Refs., 25 Figs., 4 Tabs

  1. Monitoring of beach contamination following an incident at BNFL, Sellafield, Cumbria in November 1983

    International Nuclear Information System (INIS)

    1985-01-01

    This report jointly produced by RCI/DOE and MAFF presents for the period from November 1983 to July 1984: 1) the monitoring programmes and techniques used by BNFL, DOE and MAFF; 2) the results of the monitoring programmes; 3) actions taken as a consequence of the monitoring results; 4) an outline of the position at the end of July 1984 when the Secretary of State for Environment announced, after consultation with MAFF, the DHSS and NRPB, withdrawal of advice to avoid unnecessary use of the beaches. (UK)

  2. 137Cs uptake by sheep grazing tidally-inundated and inland pastures near the Sellafield reprocessing plant

    International Nuclear Information System (INIS)

    Howard, B.J.

    1987-01-01

    Field investigations into the transfer of 137 Cs from pasture to sheep tissues have been made at two contrasting sites in west Cumbria, close to the nuclear fuel reprocessing plant at Sellafield. These were a saltmarsh bordering on the Esk estuary in 1982 and inland pastures close to the perimeter of the works in 1984. 137 Cs concentrations of sampled vegetation from the saltmarsh were generally two orders of magnitude greater than from the inland pasture due to its inundation with 137 Cs associated with silt. The relatively high 137 Cs content of soil/silt compared to that of vegetation at each site meant that soil contamination of vegetation sometimes accounted for a substantial proportion of its 137 Cs activity (up to 99% on the saltmarsh and 67% on the inland pastures). Considerable seasonal changes occurred in the extent of 137 Cs contamination on the inland pastures, with late winter and early spring levels being up to 20-fold higher than those of the summer. 137 Cs concentrations in tissues of lambs from the saltmarsh were consistently higher than for ewes; this was not true for sheep from the inland pastures. 137 Cs concentrations in kidney were found to be higher than in all other tissues, both in the study flocks and in one of the controls. Transfer coefficients (calculated by dividing the 137 Cs concentration of fresh tissue by the daily intake of 137 Cs) were significantly (P 137 Cs activity due to soil/silt contamination was removed from the estimates of daily intake leaving 137 Cs associated with the vegetation only to contribute to the transfer coefficients. Further studies are required to determine the availability of 137 Cs associated with soil/silt particles which are ingested by animals. (author)

  3. The willingness of farmers to engage with bioenergy and woody biomass production: A regional case study from Cumbria

    International Nuclear Information System (INIS)

    Convery, I.; Robson, D.; Ottitsch, A.; Long, M.

    2012-01-01

    In this paper we explore the willingness of Cumbrian farmers to switch land use from food production to biomass production in a landscape where food production is both heavily subsidised and the area is a centre for tourism. This is against a policy background of a switch of subsidies from food production to environmental benefits, increased concerns about emissions from farming and an increased demand for renewable energy. We identified an awareness of new markets for renewable energy, alongside increasing volatility of other crops (against a background of increasing demand for food). From this, our conclusions are that the main short-term opportunities for increasing biomass production in this region are through intensifying management of existing woodlands. In the medium term, as the financial case for biomass crops becomes more certain, we can envisage a ‘tipping point’ which would favour a switch from marginal agricultural land to biomass. - Highlights: ► Profit motive not driving force. ► Reluctance to change farming methods. ► Logs and chipped wood options.

  4. Decline in the lung cancer hazard: a prospective study of the mortality of iron ore miners in Cumbria

    International Nuclear Information System (INIS)

    Kinlen, L.J.

    1988-01-01

    The mortality of 1947 Cumbrian iron ore miners has been studied over the period 1939-82 in relation to that among other groups of men in England and Wales: (a) all men, (b) men of similar social class, and (c) men living in similar types of (mainly rural) area. Significant excesses were found for deaths from tuberculosis and respiratory diseases compared with each of the reference populations. Lung cancer showed an excess over that in comparable (mainly rural) areas of England and Wales, as reported in a previous study using a proportionate method of analysis and which covered the period 1948-67 but no appreciable excess after 1967. Reasons for this decline are discussed. (author)

  5. Radiation doses to members of the public near to Sellafield, Cumbria, from liquid discharges 1952-98.

    Science.gov (United States)

    Jackson, D; Lambers, B; Gray, J

    2000-06-01

    Liquid wastes containing low levels of radioactivity have been discharged to the Irish Sea from the nuclear fuel reprocessing site at Sellafield since operations began in the early 1950s, and monitoring of radioactivity in foodstuffs has been undertaken over many years. Based on the best available monitoring data, supplemented by modelled values where necessary, doses to local critical groups have been reassessed using the most recent dosimetry. Contemporary habits data have been used where available, again supplemented by assumed habits where necessary. During the 1950s and 1960s the highest doses were received by individuals consuming Cumbrian Porphyra as laverbread, and peak doses around 0.8 to 1.0 mSv year(-1) have been estimated. During the 1970s and 1980s the critical exposure group switched to consumers of local fish and shellfish, with peak doses possibly reaching 2.5 to 3.0 mSv year(-1). Latterly, doses to all marine-related groups have declined to less than 150 to 200 microSv year(-1). At all times, doses have been within the appropriate limits set for members of the public.

  6. Assessment of the present and future implications of radioactive contamination of the Irish Sea coastal region of Cumbria

    International Nuclear Information System (INIS)

    Wilkins, B.T.; Simmonds, J.R.; Cooper, J.R.

    1994-10-01

    An assessment has been made of the doses that could be received by people who make use of the Cumbrian coastal area. Current doses have been estimated for residents and visitors to different parts of the area. By making assumptions about changes in waste management practices at the BNFL Sellafield plant and in the geography of the coastal area, the development of doses over the next 200 years has been assessed. The study was confined to exposure pathways in the terrestrial environment, although the influence of liquid discharges on terrestrial pathways was taken into account. Consumption of marine foodstuffs was outside the scope of the study. As expected, the highest doses would be received by those people who live closest to Sellafield. However, in all cases doses to average individuals were well below the present limit for members of the public specified by ICRP. The general future trend was for doses to decline. Doses were also estimated for particular population groups such as those who spend more time on beaches. While the resultant values were higher than those for average individuals, they were still well within the ICRP limit in all cases. (author)

  7. Characterization of a fluvial aquifer at a range of depths and scales: the Triassic St Bees Sandstone Formation, Cumbria, UK

    Science.gov (United States)

    Medici, Giacomo; West, L. J.; Mountney, N. P.

    2018-03-01

    Fluvial sedimentary successions represent porous media that host groundwater and geothermal resources. Additionally, they overlie crystalline rocks hosting nuclear waste repositories in rift settings. The permeability characteristics of an arenaceous fluvial succession, the Triassic St Bees Sandstone Formation in England (UK), are described, from core-plug to well-test scale up to 1 km depth. Within such lithified successions, dissolution associated with the circulation of meteoric water results in increased permeability ( K 10-1-100 m/day) to depths of at least 150 m below ground level (BGL) in aquifer systems that are subject to rapid groundwater circulation. Thus, contaminant transport is likely to occur at relatively high rates. In a deeper investigation (> 150 m depth), where the aquifer has not been subjected to rapid groundwater circulation, well-test-scale hydraulic conductivity is lower, decreasing from K 10-2 m/day at 150-400 m BGL to 10-3 m/day down-dip at 1 km BGL, where the pore fluid is hypersaline. Here, pore-scale permeability becomes progressively dominant with increasing lithostatic load. Notably, this work investigates a sandstone aquifer of fluvial origin at investigation depths consistent with highly enthalpy geothermal reservoirs ( 0.7-1.1 km). At such depths, intergranular flow dominates in unfaulted areas with only minor contribution by bedding plane fractures. However, extensional faults represent preferential flow pathways, due to presence of high connective open fractures. Therefore, such faults may (1) drive nuclear waste contaminants towards the highly permeable shallow (< 150 m BGL) zone of the aquifer, and (2) influence fluid recovery in geothermal fields.

  8. Results of case-control study of leukaemia and lymphoma among young people near Sellafield nuclear plant in West Cumbria

    International Nuclear Information System (INIS)

    Gardner, M.J.; Snee, M.P.; Hall, A.J.; Powell, C.A.; Downes, S.

    1990-01-01

    The raised incidence of leukaemia, particularly, and non-Hodgkin's lymphoma among children near Sellafield was associated with paternal employment and recorded external dose of whole body penetrating radiation during work at the plant before conception. The association can explain statistically the observed geographical excess. This result suggests an effect of ionising radiation on fathers that may be leukaemogenic in their offspring, though other, less likely, explanations are possible. (author)

  9. Living shorelines enhanced the resilience of saltmarshes to Hurricane Matthew (2016).

    Science.gov (United States)

    Smith, Carter S; Puckett, Brandon; Gittman, Rachel K; Peterson, Charles H

    2018-06-01

    Nature-based solutions, such as living shorelines, have the potential to restore critical ecosystems, enhance coastal sustainability, and increase resilience to natural disasters; however, their efficacy during storm events compared to traditional hardened shorelines is largely untested. This is a major impediment to their implementation and promotion to policy-makers and homeowners. To address this knowledge gap, we evaluated rock sill living shorelines as compared to natural marshes and hardened shorelines (i.e., bulkheads) in North Carolina, USA for changes in surface elevation, Spartina alterniflora stem density, and structural damage from 2015 to 2017, including before and after Hurricane Matthew (2016). Our results show that living shorelines exhibited better resistance to landward erosion during Hurricane Matthew than bulkheads and natural marshes. Additionally, living shorelines were more resilient than hardened shorelines, as they maintained landward elevation over the two-year study period without requiring any repair. Finally, rock sill living shorelines were able to enhance S. alterniflora stem densities over time when compared to natural marshes. Our results suggest that living shorelines have the potential to improve coastal resilience while supporting important coastal ecosystems. © 2018 by the Ecological Society of America.

  10. The history of metals pollution in Narragansett Bay as recorded by salt-marsh sediments

    International Nuclear Information System (INIS)

    Bricker, S.B.

    1990-01-01

    Sediment cores from 5 salt marshes from the head to the mouth of Narragansett Bay and an additional core from a lagoon on Block Island Sound were analyzed for 210 Pb and for Fe, Mn, Cu, Pb, Cr, Zn, Ag, and Ni in order to examine the long-term variation of metal inputs to Narragansett Bay. The 210 Pb results were used to determine accretion rates for each core. Distributions of Fe and Mn were used as indicators of chemical conditions of sediment cores and Cu, Pb, Cr, Zn, Ag, and Ni distributions with time were compared with known or estimated source inputs to examine the long-term variation of pollutant metal inputs to Narragansett Bay. At one location, duplicate cores were sampled to look at variability within a marsh. At another location, a high marsh, receiving predominantly atmospheric inputs and a low marsh, receiving waterborne and atmospheric inputs, were sampled so that atmospheric and tidal contributions could be determined. A comparison was made of the distributions of metals in bay cores and in the lagoon core. All the Rhode Island marshes accrete at rates equal to or greater than the local rise in sea level. Based on the 210 Pb chronologies, pollutant metals began to increase in the mid to late 1800s, corresponding to coal burning emissions to the atmosphere. Steeper increases in the 1900s reflect industrial and sewage discharges. Maximum concentrations were reached in the 1950s and have declined almost continuously since then. Observed reductions were attributable to implementation of and improvements to sewage treatment, and controls on atmospheric emissions

  11. Controls of Carbon Preservation in Coastal Wetlands of Texas: Mangrove vs. Saltmarsh Ecosystems

    Science.gov (United States)

    Sterne, A. M. E.; Louchouarn, P.; Norwood, M. J.; Kaiser, K.

    2014-12-01

    The estimated magnitude of the carbon (C) stocks contained in the first meter of US coastal wetland soils represents ~10% of the entire C stock in US soils (4 vs. 52 Pg, respectively). Because this stock extends to several meters below the surface for many coastal wetlands, it becomes paramount to understand the fate of C under ecosystem shifts, varying natural environmental constraints, and changing land use. In this project we analyze total hydrolysable carbohydrates, amino acids, phenols and stable isotopic data (δ13C) at two study sites located on the Texas coastline to investigate chemical compositions and the stage of decomposition in mangrove and marsh grass dominated wetlands. Carbohydrates are used as specific decomposition indicators of the polysaccharide component of wetland plants, whereas amino acids are used to identify the contribution of microbial biomass, and acid/aldehyde ratios of syringyl (S) and vanillyl (V) phenols (Ac/AlS,V) follow the decomposition of lignin. Preliminary results show carbohydrates account for 30-50 % of organic carbon in plant litter and surface sediments at both sites. Sharp declines of carbohydrate yields with depth occur parallel to increasing Ac/AlS,V ratios indicating substantial decomposition of both the polysaccharide and lignin components of litter detritus. Ecological differences (between marsh grass and mangrove dominated wetlands) are discussed to better constrain the role of litter biochemistry and ecological shifts on C preservation in these anoxic environments.

  12. Bacterial community dynamic associated with autochthonous bioaugmentation for enhanced Cu phytoremediation of salt-marsh sediments.

    Science.gov (United States)

    Almeida, C Marisa R; Oliveira, Tânia; Reis, Izabela; Gomes, Carlos R; Mucha, Ana P

    2017-12-01

    Autochthonous bioaugmentation for metal phytoremediation is still little explored, particularly its application to estuarine salt marshes, but results obtained so far are promising. Nevertheless, understanding the behaviour of the microbial communities in the process of bioaugmentation and their role in improving metal phytoremediation is very important to fully validate the application of this biological technology. This study aimed to characterize the bacterial community dynamic associated with the application of autochthonous bioaugmentation in an experimentation which showed that Phragmites australis rhizosphere microorganisms could increase this salt marsh plant potential to phytoremediate Cu contaminated sediments. Bacterial communities present in the autochthonous microbial consortium resistant to Cu added to the medium and in the sediment at the beginning and at the end of the experiment were characterized by ARISA. Complementarily, the consortium and the sediment used for its production were characterized by next generation sequencing using the pyrosequencing platform 454. The microbial consortium resistant to Cu obtained from non-vegetated sediment was dominated by the genus Lactococcus (46%), Raoultella (25%), Bacillus (12%) and Acinetobacter (11%), whereas the one obtained form rhizosediment was dominated by the genus Gluconacetobacter (77%), Bacillus (17%) and Dyella (3%). Results clearly showed that, after two months of experiment, Cu caused a shift in the bacterial community structure of sediments, an effect that was observed either with or without addition of the metal resistant microbial consortium. Therefore, bioaugmentation application improved the process of phytoremediation (metal translocation by the plant was increased) without inducing long term changes in the bacterial community structure of the sediments. So, phytoremediation combined with autochthonous bioaugmentation can be a suitable technology for the recovery of estuarine areas, contributing for an efficient risk management strategy of these coastal zones. Copyright © 2017. Published by Elsevier Ltd.

  13. Field Testing Of An Expert Model: Can The Model Predict Habitat Potential For Saltmarsh Birds?

    Science.gov (United States)

    Salt marshes are valuable resources, which provide numerous ecosystem services, including flood protection, fish nursery habitat, and nesting habitat for a number of threatened and endangered species. At the present time, due primarily to coastal development and sea level rise,...

  14. Comparison of Bottomless Lift Nets and Breder Traps for Sampling Salt-Marsh Nekton

    Data.gov (United States)

    U.S. Environmental Protection Agency — Data set contains: the length of mummichogs (Fundulus heteroclitus) caught on lift nets and Breder traps from May to September 2002; the sizes of green crabs caught...

  15. Ecosystem engineering effects of Aster tripolium and Salicornia procumbens saltmarsh on macrofaunal community structure

    NARCIS (Netherlands)

    Van der Wal, D.; Herman, P.M.J.

    2012-01-01

    This paper examines how perennial Aster tripolium and annual Salicornia procumbens salt marshes alter the biomass, density, taxon diversity, and community structure of benthic macrofauna, and also examines the role of elevation, sediment grain size, plant cover, and marsh age. Core samples were

  16. Impact of soil nematodes on salt-marsh plants : a pilot experiment

    NARCIS (Netherlands)

    Dormann, CF; van der Wal, R

    2001-01-01

    We tested whether the removal of nematodes by means of nematicide application changed plant performance or influenced plant competition. The study involved the two common plant species Artemisia maritima and Festuca rubra growing in intact sods collected from a temperate salt marsh. Half of the sods

  17. Influence of abiotic factors on spider and ground beetle communities in different salt-marsh systems

    NARCIS (Netherlands)

    Petillon, Julien; Georges, Anita; Canard, Alain; Lefeuvre, Jean-Claude; Bakker, Jan P.; Ysnel, Frederic

    2008-01-01

    Salt marshes are interesting and endangered ecosystems in West-Europe. Nevertheless, their arthropod fauna remains largely unknown and the factors determining assemblages at micro-habitat scale are poorly understood. Few data are also available about the effects of management measures in salt

  18. Salt-marsh restoration : evaluating the success of de-embankments in north-west Europe

    NARCIS (Netherlands)

    Wolters, M; Garbutt, A; Bakker, JP

    De-embankment of historically reclaimed salt marshes has become a widespread option for re-creating salt marshes, but to date little information exists on the success of de-embankments. One reason is the absence of pre-defined targets, impeding the measurement of success. In this review, success has

  19. Habitat recovery in a crude oil-contaminated saltmarsh following biorestoration treatments

    International Nuclear Information System (INIS)

    Lee, K.; Cobanli, S.; Wohlgeschaffen, G.; Venosa, A.D.; Suidan, M.T.; Gauthier, J.; Tremblay, G.H.; Doe, K.

    2002-01-01

    A controlled experiment was performed in a Spartina alterniflora dominated salt marsh in Atlantic Canada in which crude oil was intentionally released. The objective was to assess the feasibility of in situ biostimulation strategies to enhance habitat recovery and to determine the nutrient enrichment in enhancing wetland restoration in the presence and absence of wetland plants. The following four experimental treatments were evaluated: (1) natural attenuation, (2) ammonium nitrate addition with intact plants, (3) ammonium nitrate addition with plants cut back to suppress plant activity, and (4) ammonium nitrate addition with intact plants and with tilling to enrich oxygen penetration. In addition, two unoiled treatments were performed, with and without nutrients. The success of the remedial actions was quantified by determining the rates of oil loss, the recovery of wetland plants and the reduction in interstitial water and sediment toxicity. Results indicated that biodegradation of alkanes and PAHs occurred, but the rates were not greatly enhanced by any of the evaluated treatments. There were other measures of habitat recovery besides the level of residual oil loss. These included alternative methods such as plant recovery, amphipod survival and growth, bacterial activity and physiology. The results were used to determine the total benefit of nutrient enrichment, till and phytoremediation as biorestoration strategies for wetlands impacted by an oil spill. It was concluded that natural attenuation is a feasible spill response option in north-temperate salt marsh environments. 22 refs., 7 figs

  20. How could a freshwater swamp produce a chemical signature characteristic of a saltmarsh?

    Science.gov (United States)

    McCloskey, Terrence; Smith, Christopher G.; Liu, Kam-biu; Marot, Marci E.; Haller, Christian

    2018-01-01

    Reduction–oxidation (redox) reaction conditions, which are of great importance for the soil chemistry of coastal marshes, can be temporally dynamic. We present a transect of cores from northwest Florida wherein radical postdepositional changes in the redox regime has created atypical geochemical profiles at the bottom of the sedimentary column. The stratigraphy is consistent along the transect, consisting of, from the bottom upward, carbonate bedrock, a gray clay, an organic mud section, a dense clay layer, and an upper organic mud unit representing the current saltwater marsh. However, the geochemical signature of the lower organic mud unit suggests pervasive redox reactions, although the interval has been identified as representing a freshwater marsh, an unlikely environment for such conditions. Analyses indicate that this discrepancy results from postdepositional diagenesis driven by millennial-scale environmental parameters. Rising sea level that led to the deposition of the capping clay layer, created anaerobic conditions in the freshwater swamp interval, and isolated it hydrologically from the rest of the sediment column. The subsequent infiltration of marine water into this organic material led to sulfate reduction, the buildup of H2S and FeS, and anoxic conditions. Continued sulfidation eventually resulted in euxinic conditions, as evidenced by elevated levels of Fe, S, and especially Mo, the diagnostic marker of euxinia. Because this chemical transformation occurred long after the original deposition the geochemical signature does not reflect soil chemistry at the time of deposition and cannot be used to infer syn-depositional environmental conditions, emphasizing the importance of recognizing diagenetic processes in paleoenvironmental studies.

  1. Nekton usage in a Caminda Bay Saltmarsh at Grand Isle LA July and October 1998

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — During July and October 1988, a total of 42 samples were collected in salt marsh habitats of the Caminada Bay system near Grand Isle, Louisiana to evaluate the use...

  2. The impact of herbivory and competition on flowering and survival during saltmarsh succession

    NARCIS (Netherlands)

    Dormann, CF; Bakker, JP

    For succession, the establishment and turnover of plants, in terms of generative spreading and renewal, is of crucial importance. Especially the success of seedling establishment into the existing vegetation might be of prime importance for the further development of plant species composition.

  3. Assessing the continuity of the upland sediment cascade, fluvial geomorphic response of an upland river to an extreme flood event: Storm Desmond, Cumbria, UK.

    Science.gov (United States)

    Joyce, Hannah; Hardy, Richard; Warburton, Jeff

    2017-04-01

    Hillslope erosion and accelerated lake sedimentation are often viewed as the source and main storage elements in the upland sediment cascade. However, the continuity of sediment transfer through intervening valley systems has rarely been evaluated during extreme events. Storm Desmond (4th - 6th December, 2015) produced record-breaking rainfall maximums in the UK: 341.4 mm rainfall was recorded in a 24 hour period at Honister Pass, Western Lake District, and 405 mm of rainfall was recorded in a 38 hour period at Thirlmere, central Lake District. The storm was the largest in a 150 year local rainfall series, and exceeded previous new records set in the 2005 and 2009 floods. During this exceptional event, rivers over topped flood defences, and caused damage to over 257 bridges, flooded over 5000 homes and businesses, and caused substantial geomorphic change along upland rivers. This research quantifies the geomorphic and sedimentary response to Storm Desmond along a regulated gravel-bed river: St John's Beck. St John's Beck (length 7.8 km) is a channelised low gradient river (0.005) downstream of Thirlmere Reservoir, which joins the River Greta, and flows through Keswick, where major flooding has occurred, before discharging into Bassenthwaite Lake. St John's Beck has a history of chronic sediment aggradation, erosion and reports of historic flooding date back to 1750. During Storm Desmond, riverbanks were eroded, coarse sediment was deposited across valuable farmland and access routes were destroyed, including a bridge and footpaths, disrupting local business. A sediment budget framework has been used to quantify geomorphic change and sedimentary characteristics of the event along St John's Beck. The volume and sediment size distribution of flood deposits, channel bars, tributary deposits, floodplain scour, riverbank erosion and in-channel bars were measured directly in the field and converted to mass using local estimates of coarse and fine sediment bulk densities. During the event 5000 tonnes of sediment was deposited on floodplains surrounding St John's Beck; 65% of this sediment was deposited in the first 3 km of the reach downstream of Thirlmere Reservoir where the channel is unconfined and channel slope and capacity rapidly decrease. Flood sediment deposits were composed of a single layer of sediment of a similar grain size distribution (mean D90 116 mm), with fines generally sparse. The main source of sediment deposited during the event originated from the channel bed and banks; 1500 tonnes of sediment was stored within channel bars. Approximately 2000 tonnes of sediment was eroded from the riverbanks during the event; with local lateral riverbank recession exceeding 12 m. An estimated 500 tonnes of sediment was scoured from the floodplains along the first 3 km of the reach downstream of Thirlmere Reservoir, with local floodplain scour around a bridge estimated at 300 tonnes. Overall, this sediment budget study demonstrates the importance of valley systems as a major source and sink of sediment along the upland sediment cascade during an extreme flood event.

  4. Proceedings of the OGAMM Meeting (3rd) Held in Keswick-On-Derwentwater, Cumbria, England on September 4-7, 1990

    Science.gov (United States)

    1990-09-07

    and frequency shifting, (4) Investigation of device processes in optical waveguides and fibers; optical bistability for optical memory operation, and...all relative to urea, unless stated otherwise. Compound SHG Colour (1) 0.60 Yellow (2) 0.70 Dark green (3) 0.01 Pale yellow (4) 0.22 Yellow (5) 0.73...LOUGHBOROUGH T. KING UNIVERSITY OF TECHNOLOGY H. Coles N. PHILIPS I - LASER ENCHANCED 1 - OPTICAL & THERMAL DENSIFICATION PROPERTIES 2 - SOLID STATE

  5. Methods and basic data of case-control study of leukaemia and lymphona among young people near Sellafield nuclear plant in West Cumbria

    International Nuclear Information System (INIS)

    Gardner, M.J.; Hall, A.J.; Snee, M.P.; Downes, S.; Powell, C.A.

    1990-01-01

    The methods and basic data of a case-control study of leukaemia and lymphoma among young people near Sellafield are examined for reliability. Fifty-two cases of leukaemia, 22 of non-Hodgkin's lymphoma and 23 of Hodgkins disease occurring in people born in the area and diagnosed there in 1950-85 under the age of 25, and 1001 controls matched for sex and date of birth taken from the same birth registers were used in the study. (author)

  6. 76 FR 49412 - Endangered and Threatened Wildlife; 90-Day Finding on a Petition To List the Saltmarsh Topminnow...

    Science.gov (United States)

    2011-08-10

    ... Threatened or Endangered Under the Endangered Species Act AGENCY: National Marine Fisheries Service (NMFS... endangered under the Endangered Species Act (ESA). We find that the petition presents substantial scientific.... Endangered Species Act'' because NatureServe assessments ``have different criteria, evidence requirements...

  7. The Rhizosphere Zone: A Hot Spot of Microbial Activity and Methylmercury Production in Saltmarsh Sediments of San Francisco Bay, California

    Science.gov (United States)

    Windham-Myers, L.; Marvin-Dipasquale, M.; Voytek, M.; Kirshtein, J.; Krabbenhoft, D. P.; Agee, J. L.; Cox, M.; Kakouros, E.; Collins, J. N.; Yee, D.

    2008-12-01

    Tidal marshes of varying hydrology and salinity have been shown to have high rates of microbial methylmercury (MeHg) production, especially the periodically flooded, higher elevations which are densely vegetated with shallowly rooted plants. The specific influence of emergent wetland plants and their active rhizosphere (root zone) on mercury (Hg) biogeochemistry, however, is poorly understood. Seasonal and spatial patterns of Hg biogeochemistry were examined in 2005 and 2006 at three marshes along a salinity gradient of the Petaluma River, in Northern San Francisco Bay, California. In addition, to directly examine the influence of rhizosphere activity on MeHg production, a suite of devegetation experiments was conducted in 2006 within each marsh using paired vegetated and devegetated plots in two marsh subhabitats: poorly- drained interior sites and well-drained "edge" sites near slough channels. Surface sediment (0-2cm) was sampled in both April and August from these plots, as well as from 1st and 3rd order slough channels that were naturally free of vegetation. Vegetated marsh sites produced 3- to19-fold more MeHg than did slough sites, and MeHg production rates were greater in marsh interior sites compared to more oxic marsh "edge" sites. Microbial biomass (ng DNA gdrysed) was greater in vegetated marsh settings, compared to slough channels, and increased significantly between April and August at all marsh sites. Despite this seasonal increase in microbial biomass, MeHg concentrations and production rates decreased from April to August in vegetated surface sediments. Microbial indicators of methylation also decreased from April to August, including rates of microbial sulfate reduction and the abundance of iron- and sulfate- reducing bacterial DNA. Results from the devegetated plots suggest that root exudation of fermentative labile carbon to surface soils is responsible for the higher microbial biomass, and the higher relative abundance of iron- and sulfate-reducing bacterial DNA in vegetated sites. In contrast to microbial indicators of mercury methylation, no effects of devegetation or seasonal sampling were observed on sediment pools of reactive Hg (Hg(II)R), although the relative abundance of mercuric reductase functional genes (MerA) was reduced by devegetation and was correlated with live root density. These experiments, among others, demonstrate that the presence and activity of emergent wetland plants directly influence Hg cycling in densely rooted surface soils. Development of this shallow and dense rhizosphere is likely to be a primary reason as to why periodically flooded, high elevation marsh sites are a "hot spot" for mercury methylation.

  8. Response of the benthic food web to short- and long-term nutrient enrichment in saltmarsh mudflats

    NARCIS (Netherlands)

    Pascal, P.-Y.; Fleeger, J.W.; Boschker, H.T.S.; Mitwally, H.M.; Johnson, D.S.

    2013-01-01

    We examined the responses of biota at or near the base of the benthic food web to nutrient enrichment in salt marsh mudflats in Plum Island estuary (Massachusetts, USA). To simulate eutrophication, nitrate and phosphate loading rates were increased 10- to 15-fold in creeks fertilized for 2 mo (i.e.

  9. A linear relationship between wave power and erosion determines salt-marsh resilience to violent storms and hurricanes

    Science.gov (United States)

    Leonardi, Nicoletta; Ganju, Neil K.; Fagherazzi, Sergio

    2016-01-01

    Salt marsh losses have been documented worldwide because of land use change, wave erosion, and sea-level rise. It is still unclear how resistant salt marshes are to extreme storms and whether they can survive multiple events without collapsing. Based on a large dataset of salt marsh lateral erosion rates collected around the world, here, we determine the general response of salt marsh boundaries to wave action under normal and extreme weather conditions. As wave energy increases, salt marsh response to wind waves remains linear, and there is not a critical threshold in wave energy above which salt marsh erosion drastically accelerates. We apply our general formulation for salt marsh erosion to historical wave climates at eight salt marsh locations affected by hurricanes in the United States. Based on the analysis of two decades of data, we find that violent storms and hurricanes contribute less than 1% to long-term salt marsh erosion rates. In contrast, moderate storms with a return period of 2.5 mo are those causing the most salt marsh deterioration. Therefore, salt marshes seem more susceptible to variations in mean wave energy rather than changes in the extremes. The intrinsic resistance of salt marshes to violent storms and their predictable erosion rates during moderate events should be taken into account by coastal managers in restoration projects and risk management plans.

  10. Assessing Near-surface Heat, Water Vapor and Carbon Dioxide Exchange Over a Coastal Salt-marsh

    Science.gov (United States)

    Bogoev, I.; O'Halloran, T. L.; LeMoine, J.

    2017-12-01

    Coastal ecosystems play an important role in mitigating the effects of climate change by storing significant quantities of carbon. A growing number of studies suggest that vegetated estuarine habitats, specifically salt marshes, have high long-term rates of carbon sequestration, perhaps even higher than mature tropical and temperate forests. Large amounts of carbon, accumulated over thousands of years, are stored in the plant materials and sediment. Improved understanding of the factors that control energy and carbon exchange is needed to better guide restoration and conservation management practices. To that end, we recently established an observation system to study marsh-atmosphere interactions within the North Inlet-Winyah Bay National Estuarine Research Reserve. Near-surface fluxes of heat, water vapor (H2O) and carbon dioxide (CO2) were measured by an eddy-covariance system consisting of an aerodynamic open-path H2O / CO2 gas analyzer with a spatially integrated 3D sonic anemometer/thermometer (IRGASON). The IRGASON instrument provides co-located and highly synchronized, fast response H2O, CO2 and air- temperature measurements, which eliminates the need for spectral corrections associated with the separation between the sonic anemometer and the gas analyzer. This facilitates calculating the instantaneous CO2 molar mixing ratio relative to dry air. Fluxes computed from CO2 and H2O mixing ratios, which are conserved quantities, do not require post-processing corrections for air-density changes associated with temperature and water vapor fluctuations. These corrections are particularly important for CO2, because they could be even larger than the measured flux. Here we present the normalized frequency spectra of air temperature, water vapor and CO2, as well as their co-spectra with the co-located vertical wind. We also show mean daily cycles of sensible, latent and CO2 fluxes and analyze correlations with air/water temperature, wind speed and light availability.

  11. The significance of spatial and temporal patterns of algal mat deposition in structuring salt-marsh vegetation

    NARCIS (Netherlands)

    Van Soelen, J.; Herman, P.M.J.; Bouma, T.J.

    2006-01-01

    Question: Are there hot spots of algal mat deposition in space and time at the marsh scale and, if so, how does this affect the coexistence of a dominant (Spartina anglica) and gap dependent (Salicornia europaea) species? Location: The Rattekaai salt marsh in the Scheldt estuary in the southwestern

  12. Seed dispersal by small herbivores and tidal water : are they important filters in the assembly of salt-marsh communities?

    NARCIS (Netherlands)

    Chang, ER; Zozaya, EL; Kuijper, DPJ; Bakker, JP

    1. Characteristics of internal seed dispersal (endozoochory) by European Brown Hares were compared with similar dispersal by Brent Geese. Hares deposited more seeds of mid-successional, perennial, high-marsh species than did geese, which deposited more seeds of early successional, annual, low-marsh

  13. Seed dispersal by small herbivores and tidal water: Are they important filters in the assembly of salt-marsh communities?

    NARCIS (Netherlands)

    Chang, E.R.; Zozaya, E.L.; Kuijper, D.P.J.; Bakker, J.P.

    2005-01-01

    1. Characteristics of internal seed dispersal (endozoochory) by European Brown Hares were compared with similar dispersal by Brent Geese. Hares deposited more seeds of mid-successional, perennial, high-marsh species than did geese, which deposited more seeds of early successional, annual, low-marsh

  14. A linear relationship between wave power and erosion determines salt-marsh resilience to violent storms and hurricanes.

    Science.gov (United States)

    Leonardi, Nicoletta; Ganju, Neil K; Fagherazzi, Sergio

    2016-01-05

    Salt marsh losses have been documented worldwide because of land use change, wave erosion, and sea-level rise. It is still unclear how resistant salt marshes are to extreme storms and whether they can survive multiple events without collapsing. Based on a large dataset of salt marsh lateral erosion rates collected around the world, here, we determine the general response of salt marsh boundaries to wave action under normal and extreme weather conditions. As wave energy increases, salt marsh response to wind waves remains linear, and there is not a critical threshold in wave energy above which salt marsh erosion drastically accelerates. We apply our general formulation for salt marsh erosion to historical wave climates at eight salt marsh locations affected by hurricanes in the United States. Based on the analysis of two decades of data, we find that violent storms and hurricanes contribute less than 1% to long-term salt marsh erosion rates. In contrast, moderate storms with a return period of 2.5 mo are those causing the most salt marsh deterioration. Therefore, salt marshes seem more susceptible to variations in mean wave energy rather than changes in the extremes. The intrinsic resistance of salt marshes to violent storms and their predictable erosion rates during moderate events should be taken into account by coastal managers in restoration projects and risk management plans.

  15. Salt-marsh erosion associated with hurricane landfall in southern New England in the fifteenth and seventeenth centuries

    NARCIS (Netherlands)

    Plassche, Orson van de; Erkens, Gilles; Vliet, Frank van; Brandsma, J.; Borg, K. van der; Jong, A.F.M. de

    2006-01-01

    Lithostratigraphic and radiocarbon data from the inland section of Pattagansett River Marsh, Connecticut, show that this sheltered part of the salt marsh underwent significant erosion twice during the past 600 yr, each time followed by rapid and complete infilling of the eroded space with tidal mud

  16. Habitat structure modified by an invasive grass enhances inundation withstanding in a salt-marsh wolf spider

    OpenAIRE

    Pétillon, J.; Lambeets, K.; Montaigne, W.; Maelfait, J.-P.; Bonte, D.

    2010-01-01

    Vegetation and underground structures are known to influence flood avoidance and flood resistance in invertebrates. In bimonthly-flooded European salt marshes, recent invasions by the nitrophilous grass Elymus athericus strongly modified usual habitat structure, notably by the production of a deep litter layer. Consequently, invaded habitats provide more interstitial spaces that may act as a refuge during flood events. By using both controlled and field designs, we tested whether invaded habi...

  17. The challenges faced by social enterprises in North West England

    OpenAIRE

    Mulvey, Gail

    2015-01-01

    On 9th February 2015, a questionnaire was sent out electronically to all businesses in Cumbria and Lancashire that appeared to be social enterprises. The database of email addresses of these businesses was compiled using regional databases such as the Cumbria Social Enterprise Partnership http://www.socialenterpriseincumbria.org/A_to_Z_of_Enterprises, social media and previous UnLtd award winners. The project manager also took printed questionnaire surveys to events in Cumbria (Cumbria Social...

  18. Discharge patterns of radionuclides and the influence of early diagenesis in a salt-marsh of the Ribble Estuary, NW England

    International Nuclear Information System (INIS)

    Brown, J.E.; Parker, A.; Rae, J.E.

    1997-01-01

    Routine discharges of low level liquid radioactive waste from British Nuclear Fuels plc (BNFL) at Sellafield and Springfield have resulted in enhanced levels of radionuclides in sediments of the Ribble Estuary, NW England, UK. The variations in radionuclide concentrations ( 137 Cs, 230 Th, 232 Th, 238 U, 239,240 Pu and 241 Am) with depth were analysed in order to investigate historical discharge trends. The influence of early diagenesis in terms of radionuclide mobility was established by considering geochemical associations of radionuclides through the depth profile. A core from Longton Marsh was analysed by gamma-spectrometry and alpha-spectrometry. Major/trace metal and total organic carbon determinations were also made. Sequential extractions were employed in order to specify radionuclide phase associations. Distinct subsurface maxima were present for 137 Cs, 241 Am and 239,240 Pu with activities as high as 4500 Bq kg -1 for 137 Cs and 800 Bq kg -1 for 241 Am. Thorium-230 and 238 U exhibited complex activity profiles with depth. 137 Cs was found associated predominantly with the residual phase at all depths. Thorium-230 and 239,240 Pu were mainly associated with the organic and sesquioxide phases with some evidence to suggest that plutonium had undergone a phase redistribution below the sediment surface. Caesium-137, 230 Th and 239,240 Pu were deemed useful in terms of establishing core chronologies. (author)

  19. Identifying important spatial and temporal scales and patterns of soil properties in a tidal saltmarsh situated in a mixed red alder and Douglas fir watershed

    Science.gov (United States)

    Sea level rise is expected to drive a loss in salt marsh area and a change in marsh habitat composition, potentially leading to changes in the nitrogen source/sink dynamics of these systems. Estuaries in the Pacific Northwest might be particularly vulnerable to the effect of sal...

  20. Larval salinity tolerance of the South American salt-marsh crab, Neohelice (Chasmagnathus) granulata: physiological constraints to estuarine retention, export and reimmigration

    Science.gov (United States)

    Anger, Klaus; Spivak, Eduardo; Luppi, Tomás; Bas, Claudia; Ismael, Deborah

    2008-06-01

    The semiterrestrial crab Neohelice (= Chasmagnathus) granulata (Dana 1851) is a predominant species in brackish salt marshes, mangroves and estuaries. Its larvae are exported towards coastal marine waters. In order to estimate the limits of salinity tolerance constraining larval retention in estuarine habitats, we exposed in laboratory experiments freshly hatched zoeae to six different salinities (5 32‰). At 5‰, the larvae survived for a maximum of 2 weeks, reaching only exceptionally the second zoeal stage, while 38% survived to the megalopa stage at 10‰. Shortest development and negligible mortality occurred at all higher salt concentrations. These observations show that the larvae of N. granulata can tolerate a retention in the mesohaline reaches of estuaries, with a lower limit of ca. 10 15‰. Maximum survival at 25‰ suggests that polyhaline conditions rather than an export to oceanic waters are optimal for successful larval development of this species. In another experiment, we tested the capability of the last zoeal stage (IV) for reimmigration from coastal marine into brackish waters. Stepwise reductions of salinity during this stage allowed for moulting to the megalopa at 4 10‰. Although survival was at these conditions reduced and development delayed, these results suggest that already the zoea-IV stage is able to initiate the reimmigration into estuaries. After further salinity reduction, megalopae survived in this experiment for up to >3 weeks in freshwater, without moulting to juvenile crabs. In a similar experiment starting from the megalopa stage, successful metamorphosis occurred at 4 10‰, and juvenile growth continued in freshwater. Although these juvenile crabs showed significantly enhanced mortality and smaller carapace width compared to a seawater control, our results show that the late larval and early juvenile stages of N. granulata are well adapted for successful recruitment in brackish and even limnetic habitats.

  1. Seasonal abundance, biomass, diversity, and trophic structure of fish in a salt-marsh tidal creek affected by a coastal power plant

    International Nuclear Information System (INIS)

    Homer, M.

    1976-01-01

    Monthly measurements were made of the seasonal abundance, biomass, species diversity, and trophic composition of fish inhabiting the tidal creeks of salt marshes receiving thermal discharge near Crystal River, Fla. In the warm months (May through September 1974), mean abundance in the creek receiving thermal discharge was 0.46 individuals/m 2 and mean biomass was 2.2 g (preserved weight)/m 2 . In a control area, creek values in the warm months were 6.77 individuals/m 2 and 9.1 g (preserved weight)/m 2 , respectively. During the cold months (October 1974 through February 1975) there were 0.48 individuals/m 2 and 8.3 g (preserved weight)/m 2 in the discharge area and 0.58 individuals/m 2 and 7.4 g preserved weight/m 2 in the control area. In all months except May 1974 and February 1975, species diversity as species per 1000 individuals was higher in the control creek than in the discharge creek. No apparent differences in fish trophic structure were observed

  2. Changes in salt-marsh carabid assemblages after an invasion by the native grass Elymus athericus (Link Kerguélen

    Directory of Open Access Journals (Sweden)

    Anita Georges

    2011-05-01

    Full Text Available As a result of an invasion by the native grass Elymus athericus (Link Kerguélen (Poaceae in the last 10 years, a major change in vegetation cover has occurred in salt marshes of the Mont Saint-Michel bay, Western France. The impact of such an invasion on carabid assemblages, a dominant group of terrestrial arthropods in these habitats and containing several stenotopic species, is investigated here. In our study site, carabid data are available from 1983 and 1984, allowing a comparison of species distribution ranges in salt marshes before (1983–1984 and after (2002 the E. athericus invasion. A total of 16,867 adults belonging to 40 species were caught. By considering the presence-absence of species shared between studies, we show that the invasion by E. athericus promoted the progression of non-coastal species (mainly Pterostichus s.l. spp.. This did however not interfere with resident species distributions, finally resulting in higher carabid species richness in the entire area. The species composition and abundances of carabid assemblages were also compared between natural and invaded stations in 2002. The main result is that abundances of some halophilic species decreased in one invaded plot (in case of Pogonus chalceus (Marsham 1802 whereas the opposite pattern was observed for other species (e.g., Bembidion minimum (Fabricius 1792. Invaded habitats were characterized by lower percentages of halophilic species and higher total species richness.

  3. Comprehensive risk assessment and source identification of selected heavy metals (Cu, Cd, Pb, Zn, Hg, As) in tidal saltmarsh sediments of Shuangtai Estuary, China.

    Science.gov (United States)

    Liu, Chang-Fa; Li, Bing; Wang, Yi-Ting; Liu, Yuan; Cai, Heng-Jiang; Wei, Hai-Feng; Wu, Jia-Wen; Li, Jin

    2017-10-06

    Heavy metals do not degrade and can remain in the environment for a long time. In this study, we analyzed the effects of Cu, Cd, Pb, Zn, Hg, and As, on environmental quality, pollutant enrichment, ecological hazard, and source identification of elements in sediments using data collected from samples taken from Shuangtai tidal wetland. The comprehensive pollution indices were used to assess environmental quality; fuzzy similarity analysis and geoaccumulation index were used to analyze pollution accumulation; correlation matrix, principal component analysis, and clustering analysis were used to analyze pollution source; environmental risk index and ecological risk index were used to assess ecological risk. The results showed that the environmental quality was either clean or almost clean. Pollutant enrichment analysis showed that the four sub-regions had similar pollution-causing metals to the background values of the soil element of the Liao River Plain, which were ranked according to their similarity. Source identification showed that all the elements were correlated. Ecological hazard analysis showed that the environmental risk index in the study area was less than zero, posing a low ecological risk. Ecological risk of the six elements was as follows: As > Cd > Hg > Cu > Pb > Zn.

  4. Nekton usage in a Caminda Bay Saltmarsh at Grand Isle Louisiana from 1988-07-26 to 1988-10-19 (NCEI Accession 0156840)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains count, measurement, and weight information, when available, for Penaeid shrimp species. This data set also contains environmental, habitat,...

  5. The incidence of cancer and leukaemia in young people in the vicinity of the Sellafield site, West Cumbria. Further studies and an update of the situation since the publication of the report of the Black Advisory Group in 1984

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    The report discusses the incidence of cancer and leukaemia among young people living in the vicinity of Sellafield. Possible radiation effects of paternal preconception irradiation in cancer development as well as the risk involved by the general population is considered. Recommendations are provided to improve occupational safety and public health

  6. Rising tides, rising gates: The complex ecogeomorphic response of coastal wetlands to sea-level rise and human interventions

    Science.gov (United States)

    Sandi, Steven G.; Rodríguez, José F.; Saintilan, Neil; Riccardi, Gerardo; Saco, Patricia M.

    2018-04-01

    Coastal wetlands are vulnerable to submergence due to sea-level rise, as shown by predictions of up to 80% of global wetland loss by the end of the century. Coastal wetlands with mixed mangrove-saltmarsh vegetation are particularly vulnerable because sea-level rise can promote mangrove encroachment on saltmarsh, reducing overall wetland biodiversity. Here we use an ecogeomorphic framework that incorporates hydrodynamic effects, mangrove-saltmarsh dynamics, and soil accretion processes to assess the effects of control structures on wetland evolution. Migration and accretion patterns of mangrove and saltmarsh are heavily dependent on topography and control structures. We find that current management practices that incorporate a fixed gate for the control of mangrove encroachment are useful initially, but soon become ineffective due to sea-level rise. Raising the gate, to counteract the effects of sea level rise and promote suitable hydrodynamic conditions, excludes mangrove and maintains saltmarsh over the entire simulation period of 100 years

  7. Committee on Medical Aspects of Radiation in the Environment (COMARE) 4. report. The incidence of cancer and leukaemia in young people in the vicinity of the Sellafield site, West Cumbria: Further studies and an update of the situation since the publication of the report of the Black Advisory Group in 1984

    Energy Technology Data Exchange (ETDEWEB)

    Bridges, B.A.

    1996-12-31

    The Fourth Report of the Committee on Medical Aspects of Radiation in the Environment (COMARE) updates the information on the incidence of cancer and leukaemia in young people in the vicinity of the Sellafield site since the publication of the Black Advisory Group report in 1984. Data are reviewed on radiation exposure and the risk of radiation-induced leukaemia and cancer in young people living in Seascale; possible effects of paternal preconception irradiation in cancer; exposure to chemicals used at and discharged from the Sellafield site and the risk to the general population and offspring of site workers; and the infectious aetiology of childhood cancer. The history of the Royal Ordnance Factories sited at Sellafield and Drigg in the 1940s and a historical review of childhood cancer in Seascale is also given. (UK).

  8. Committee on Medical Aspects of Radiation in the Environment (COMARE) 4. report. The incidence of cancer and leukaemia in young people in the vicinity of the Sellafield site, West Cumbria: Further studies and an update of the situation since the publication of the report of the Black Advisory Group in 1984

    International Nuclear Information System (INIS)

    Bridges, B.A.

    1996-01-01

    The Fourth Report of the Committee on Medical Aspects of Radiation in the Environment (COMARE) updates the information on the incidence of cancer and leukaemia in young people in the vicinity of the Sellafield site since the publication of the Black Advisory Group report in 1984. Data are reviewed on radiation exposure and the risk of radiation-induced leukaemia and cancer in young people living in Seascale; possible effects of paternal preconception irradiation in cancer; exposure to chemicals used at and discharged from the Sellafield site and the risk to the general population and offspring of site workers; and the infectious aetiology of childhood cancer. The history of the Royal Ordnance Factories sited at Sellafield and Drigg in the 1940s and a historical review of childhood cancer in Seascale is also given. (UK)

  9. Attenuation of Neuroinflammatory Responses in Lipopolysaccharide ...

    African Journals Online (AJOL)

    HP

    To evaluate the anti-neuroinflammatory effects of S. asparagoides. (SAE) extract, LPS ... asparagoides), a salt-marsh plant from the family ..... photon emission tomography to identify patients with probable Alzheimer's disease. Euro J Nucl Med ...

  10. Assessing habitat type in KZN estuaries using VHR remote sensing imagery

    CSIR Research Space (South Africa)

    Lück-Vogel, Melanie

    2014-10-01

    Full Text Available : - Various degrees of flooding between images in saltmarsh, groundwater fed, reeds, juncus, mangroves - Rapid vegetation succession from grass/shrubs to swamp forest - Single flood events eradicated entire submerged vegetation patches - Salinity changes... in saltmarsh, groundwater fed, reeds, juncus, mangroves - Rapid vegetation succession from grass/shrubs to swamp forest - Single flood events eradicated entire submerged vegetation patches - Salinity changes (?) prompted shift from submerged to reeds...

  11. Nest trampling and ground nesting birds: Quantifying temporal and spatial overlap between cattle activity and breeding redshank.

    Science.gov (United States)

    Sharps, Elwyn; Smart, Jennifer; Mason, Lucy R; Jones, Kate; Skov, Martin W; Garbutt, Angus; Hiddink, Jan G

    2017-08-01

    Conservation grazing for breeding birds needs to balance the positive effects on vegetation structure and negative effects of nest trampling. In the UK, populations of Common redshank Tringa totanus breeding on saltmarshes declined by >50% between 1985 and 2011. These declines have been linked to changes in grazing management. The highest breeding densities of redshank on saltmarshes are found in lightly grazed areas. Conservation initiatives have encouraged low-intensity grazing at nest trampling. If livestock distribution is not spatially or temporally homogenous but concentrated where and when redshank breed, rates of nest trampling may be much higher than expected based on livestock density alone. By GPS tracking cattle on saltmarshes and monitoring trampling of dummy nests, this study quantified (i) the spatial and temporal distribution of cattle in relation to the distribution of redshank nesting habitats and (ii) trampling rates of dummy nests. The distribution of livestock was highly variable depending on both time in the season and the saltmarsh under study, with cattle using between 3% and 42% of the saltmarsh extent and spending most their time on higher elevation habitat within 500 m of the sea wall, but moving further onto the saltmarsh as the season progressed. Breeding redshank also nest on these higher elevation zones, and this breeding coincides with the early period of grazing. Probability of nest trampling was correlated to livestock density and was up to six times higher in the areas where redshank breed. This overlap in both space and time of the habitat use of cattle and redshank means that the trampling probability of a nest can be much higher than would be expected based on standard measures of cattle density. Synthesis and applications : Because saltmarsh grazing is required to maintain a favorable vegetation structure for redshank breeding, grazing management should aim to keep livestock away from redshank nesting habitat between mid

  12. Rationality and ritual

    International Nuclear Information System (INIS)

    Wynne, B.

    1982-01-01

    The book concerns the Windscale Public Inquiry, held to investigate the application by British Nuclear Fuels to build a 1200 tonne per year thermal oxide reprocessing plant (THORP) for spent nuclear fuels from Britain and overseas. The subject is discussed under the headings: introduction (international dimensions; the Windscale Inquiry; conflict resolution and social drama; public debate and the sociology of knowledge); the decision-making legacy; oxide reprocessing - the background; the public inquiry tradition - a comparative perspective; the emergence of THORP from a private to a public issue (local and national planning politics); the process and impact of the Inquiry (opposition groups); judicial rationality, expert conflict, and political authority); the rationality and politics of analysis (proliferation; radiation risks; relative risks; the Ravenglass issue; discharge targets; general radiation protection arrangements); conclusion. (U.K.)

  13. The role of herbicides in the erosion of salt marshes in eastern England

    International Nuclear Information System (INIS)

    Mason, C.F.; Underwood, G.J.C.; Baker, N.R.; Davey, P.A.; Davidson, I.; Hanlon, A.; Long, S.P.; Oxborough, K.; Paterson, D.M.; Watson, A.

    2003-01-01

    Herbicide run-off stresses saltmarsh diatoms and higher plants and may increase erosion. - Laboratory studies and field trials were conducted to investigate the role of herbicides on saltmarsh vegetation, and their possible significance to saltmarsh erosion. Herbicide concentrations within the ranges present in the aquatic environment were found to reduce the photosynthetic efficiency and growth of both epipelic diatoms and higher saltmarsh plants in the laboratory and in situ. The addition of sublethal concentrations of herbicides resulted in decreased growth rates and photosynthetic efficiency of diatoms and photosynthetic efficiency of higher plants. Sediment stability also decreased due to a reduction in diatom EPS production. There was qualitative evidence that diatoms migrated deeper into the sediment when the surface was exposed to simazine, reducing surface sediment stability by the absence of a cohesive biofilm. Sediment loads on leaves severely reduced photosynthesis in Limonium vulgare. This, coupled with reduced carbon assimilation from the effects of herbicides, could have large negative consequences for plant productivity and over winter survival of saltmarsh plants. The data support the hypothesis that sublethal herbicide concentrations could be playing a role in the increased erosion of salt marshes that has occurred over the past 40 years

  14. Plutonium and Cs-137 in autopsy tissues in Great Britain

    International Nuclear Information System (INIS)

    Popplewell, D.S.; Ham, G.J.; Dodd, N.J.; Shuttler, S.D.

    1988-01-01

    Tissues removed at autopsy from members of the general public contain significantly higher concentrations of plutonium and 137 Cs in west Cumbrians than in people from three other regions of Great Britain. Several autopsy cases from Cumbria showed unusually high values of plutonium. Subsequently it was found that the subjects had been former employees of British Nuclear Fuels. 7 refs.; 8 tabs

  15. British Nuclear Fuels - a dirty business

    International Nuclear Information System (INIS)

    Bunyard, P.

    1983-01-01

    The radioactive discharges from British Nuclear Fuels Sellafield, Cumbria, reprocessing plant to the sea are discussed. Statements that have been made by various individuals and groups about the contamination of the sea, the coast and places inland, and the biological effects of plutonium and americium, are discussed in detail. Particular stress is placed on statements about increased incidence of cancers. (U.K.)

  16. Assessing the geographic origin of the invasive grey squirrel using DNA sequencing: Implications for management strategies

    Directory of Open Access Journals (Sweden)

    Claire D. Stevenson-Holt

    2015-01-01

    Full Text Available The invasive grey squirrel Sciurus carolinensis has become a major pest species causing negative effects to forestry and biodiversity. This study aims to assess the origin of grey squirrel within Cumbria using phylogeographic analysis to aid in management and control. The work reported analysed mitochondrial DNA sequences in the D-Loop gene of 73 grey squirrel individuals from multiple locations in the UK. The results indicate that individuals in north Cumbria are derived from individuals from Scotland and North East England. Other individuals in north Cumbria share a unique haplotype with south Cumbria and Lancashire suggesting a southerly origin and movement around or over the Cumbrian Mountain range which is thought of as a barrier to movements. The assessment of invasive species geographical origin and the identification of potential wildlife transit corridors through natural barriers are becoming more important as species shift range in response to environmental and ecological changes. With the grey squirrel population expansion also occurring in Italy, the European red squirrel may become threatened across its entire range. It is crucial to understand the population origins of the invasive grey squirrel and landscape usage to successfully manage the incursion routes and control the population.

  17. Radionuclides in house dust

    Energy Technology Data Exchange (ETDEWEB)

    Fry, F A; Green, N; Dodd, N J; Hammond, D J

    1985-04-01

    Discharges of radionuclides from the British Nuclear Fuel plc (BNFL) reprocessing plant at Sellafield in Cumbria have led to elevated concentrations radionuclides in the local environment. The major routes of exposure of the public are kept under review by the appropriate authorising Government departments and monitoring is carried out both by the departments and by BNFL itself. Recently, there has been increasing public concern about general environmental contamination resulting from the discharges and, in particular, about possible exposure of members of the public by routes not previously investigated in detail. One such postulated route of exposure that has attracted the interest of the public, the press and Parliament arises from the presence of radionuclides within houses. In view of this obvious and widespread concern, the Board has undertaken a sampling programme in a few communities in Cumbria to assess the radiological significance of this source of exposure. From the results of our study, we conclude that, although radionuclides originating rom the BNFL site can be detected in house dust, this source of contamination is a negligible route of exposure for members of the public in West Cumbria. This report presents the results of the Board's study of house dust in twenty homes in Cumbria during the spring and summer of 1984. A more intensive investigation is being carried out by Imperial College. (author)

  18. Getting the right balance. Matching engagement programmes to stakeholder capacity

    International Nuclear Information System (INIS)

    Williams, Shirley

    2008-01-01

    This paper looks at the history of community engagement in nuclear issues during the lifespan of the Sellafield nuclear reprocessing plant in Cumbria, UK. It examines the impact of current engagement practices on stakeholder capacity to engage, and proposes solutions to help achieve a more balanced approach. (author)

  19. Transport of plutonium nitrate

    International Nuclear Information System (INIS)

    1982-02-01

    This leaflet discusses the subject under the headings: why do we need plutonium; why must we transport it; what action is carried out; how is it moved; what are the risks. The transport of the material in specially designed containers, from Dounreay in Caithness by road and sea to Sellafield in Cumbria, is described. (U.K.)

  20. Public relations activities in BNFL

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, B. [British Nuclear Fuels plc, Cheshire (United Kingdom)

    1993-12-31

    British Nuclear Fuels plc (BNFL) is a major industrial company employing 15,000 people and supporting another 50,000 jobs in British industry through it`s isnvestment program. BNFL is frequently in the news, mainly because of the Sellafield reprocessing plant in West Cumbria. The company`s public relation policy is described in this report.

  1. Mangrove microclimates alter seedling dynamics at the range edge.

    Science.gov (United States)

    Devaney, John L; Lehmann, Michael; Feller, Ilka C; Parker, John D

    2017-10-01

    Recent climate warming has led to asynchronous species migrations, with major consequences for ecosystems worldwide. In woody communities, localized microclimates have the potential to create feedback mechanisms that can alter the rate of species range shifts attributed to macroclimate drivers alone. Mangrove encroachment into saltmarsh in many areas is driven by a reduction in freeze events, and this encroachment can further modify local climate, but the subsequent impacts on mangrove seedling dynamics are unknown. We monitored microclimate conditions beneath mangrove canopies and adjacent open saltmarsh at a freeze-sensitive mangrove-saltmarsh ecotone and assessed survival of experimentally transplanted mangrove seedlings. Mangrove canopies buffered night time cooling during the winter, leading to interspecific differences in freeze damage on mangrove seedlings. However, mangrove canopies also altered biotic interactions. Herbivore damage was higher under canopies, leading to greater mangrove seedling mortality beneath canopies relative to saltmarsh. While warming-induced expansion of mangroves can lead to positive microclimate feedbacks, simultaneous fluctuations in biotic drivers can also alter seedling dynamics. Thus, climate change can drive divergent feedback mechanisms through both abiotic and biotic channels, highlighting the importance of vegetation-microclimate interactions as important moderators of climate driven range shifts. © 2017 by the Ecological Society of America.

  2. Tidal exchange of larvae of Sesarma catenata (Decapoda, Brachyura)

    African Journals Online (AJOL)

    The tidal exchange of larvae of the salt-marsh grapsid crab Sesarma catenata was studied in the Swartkops estuary, a tidally driven, shallow estuary in Algoa Bay, South Africa. Plankton samples were collected bimonlhly during spring and neap tides from October to March at the tidal inlet. Samples were collected hourly for ...

  3. Changes to habitats over time in Narragansett Bay and setting management targets using BCG approaches

    Science.gov (United States)

    We compare changes in the distributions of seagrass, benthic, macroalgal, saltmarsh, and shellfish habitat in Narragansett Bay (U.S.A.) since the 1700s to changes in stressors and management decisions over the same time period, and describe a method that management programs can u...

  4. The Importance of Wind-induced Sediment Fluxes on Tidal Flats

    NARCIS (Netherlands)

    Colosimo, I.; van Prooijen, Bram; van Maren, D.S.; Winterwerp, J.C.; Reniers, A.J.H.M.

    2017-01-01

    Port maintenance and nature preservation are two often conflicting aspects of coastal management. Within a Pilot Project in the Western Wadden Sea (the Netherlands - see Figure1a) we test a win-win solution that could reduce harbour siltation while simultaneously stimulate saltmarsh

  5. Habitat differentiation vs. isolation-by-distance : the genetic population structure of Elymus athericus in European salt marshes

    NARCIS (Netherlands)

    Bockelmann, AC; Reusch, TBH; Bijlsma, R; Bakker, JP

    We investigated genetic differentiation among populations of the clonal grass Elymus athericus, a common salt-marsh species occurring along the Wadden Sea coast of Europe. While E. athericus traditionally occurs in the high salt marsh, it recently also invaded lower parts of the marsh. In one of the

  6. COLONIZATION AND DIFFERENTIATION IN THE CLONAL PERENNIAL AGROSTIS-STOLONIFERA

    NARCIS (Netherlands)

    Kik, C; van Andel, Jelte; van Delden, Wilke; Joenje, W; Bijlsma, Rudolf

    1990-01-01

    (1) Colonization and differentiation were studied in four populations (inland meadow, salt-marsh, polder and sand-dune) of the widespread grass Agrostis stolonifera. A common-garden experiment showed that the overall population variability could be divided, through the use of principal component

  7. Decapoda, Brachyura

    African Journals Online (AJOL)

    1992-10-02

    Oct 2, 1992 ... The tidal exchange of larvae of the salt-marsh grapsid crab Sesarma catenata was studied in the ... gests that one of two generic mechanisms of larval dispersal .... den~y. in order, to eliminate possible time-dependent.

  8. Danish attitudes and reactions to the threat of sea-level rise

    DEFF Research Database (Denmark)

    Fenger, Jes; Buch, Erik; Jakobsen, Per Roed

    2008-01-01

    , where the approach has largely been a "wait and see" attitude. Economical evaluations have been either unofficial or absent. More attention has been paid to the impacts on coastal ecosystems, especially saltmarshes and sand dunes. Here the choice of action will depend on attitudes to and weighing...

  9. Spatial patterns in accretion on barrier-island salt marshes

    NARCIS (Netherlands)

    Groot, de A.V.; Veeneklaas, R.M.; Kuijper, D.P.J.; Bakker, J.P.

    2011-01-01

    On minerogenic barrier-island salt marshes, sedimentation is spatially heterogeneous. Although the main forcing factors for sedimentation are known, much less is known about the characteristic sizes of this spatial patterning. Such patterning gives information on the spatial component of salt-marsh

  10. Tracing organic matter sources of estuarine tidal flat nematodes with stable carbon isotopes

    NARCIS (Netherlands)

    Moens, T.; Luyten, C.; Middelburg, J.J.; Herman, P.M.J.; Vincx, M.

    2002-01-01

    The present study explores the use of stable carbon isotopes to trace organic matter sources of intertidal nematodes in the Schelde estuary (SW Netherlands). Stable carbon isotope signatures of nematodes from a saltmarsh and 4 tidal flat stations were determined in spring and winter situations, and

  11. Marsh loss due to cumulative impacts of Hurricane Isaac and the DWH oil spill in Louisiana

    NARCIS (Netherlands)

    Khanna, Shruti; Ferreira Dos Santos, M.J.; Shapiro, Kristen; Lay, Mui; Ustin, Susan L.

    Coastal ecosystems are greatly endangered due to anthropogenic development and climate change. Multiple disturbances may erode the ability of a system to recover from stress if there is little time between disturbance events. We evaluated the ability of the saltmarshes in Barataria Bay, Louisiana,

  12. Priority substances in a SW European coastal lagoon - Ria Formosa, Portugal. Twenty years of temporal evolution of metals and butyltins

    Science.gov (United States)

    Moreira da Silva, Manuela; Carvalho, Pedro; Paquete, Rita; Nuno Duarte, Duarte; Chícharo, Luís

    2013-04-01

    In the last years the European Union has decided to specifically include nickel, cadmium, plumb and TBT in its list of priority substances in water. Trace metals pose a significant threat to organisms because above threshold availability, act as enzyme inhibitors resulting in adverse ecological effects to sediment-associated biota (e.g. macrophytes, benthos, demersal fish) and to higher-biota (e.g. pelagic fish and aquatic birds). Since 2003 International Maritime Organization called for a ban of the application of tributyltin-based paints. Wide distribution, high hydrophobicity, and persistence of organotin compounds have raised concern about their bioaccumulation, their potential biomagnification in the food webs, and their adverse effects to human health and environment, particularly most recent reviews focuses on possible endocrine disrupting effects of OT's (Galloway, 2006; Nakanishi, 2007; Takahashi et al., 1999; Veltman et al., 2006). Saltmarshes are highly heterogeneous environments that have been suffered pressures by the increasing urbanization and industrialization in the adjacent areas. Saltmarsh sediments integrate inputs of contaminants, like metals and organotin compounds and may act as long-term sources of contaminants. At the Ria Formosa saltmarsh several activities were responsible for long-term contaminants, some of them considered priority substances. This work aims to provide information about the present levels and temporal evolution in the last decades of metals (Mn, Zn, Cu, Cr, Ni, Pb, Mo, Cd and Ag, in addition to Fe and Al) and butyltins (TBT, DBT and MBT) in saltmarsh sediments at south of Portugal. Metals were analysed by atomic absorption spectrometry-AAS. Butyltins were determined, after derivatization, by solid phase micro extraction combined with gas chromatography with mass spectrometry (MS/MS). Results showed that legislation was an effective instrument for the decreasing of contamination levels, to sustainable values to ecosystem

  13. Radionuclides in house dust

    CERN Document Server

    Fry, F A; Green, N; Hammond, D J

    1985-01-01

    Discharges of radionuclides from the British Nuclear Fuel plc (BNFL) reprocessing plant at Sellafield in Cumbria have led to elevated concentrations radionuclides in the local environment. The major routes of exposure of the public are kept under review by the appropriate Government departments and monitoring is carried out both by the departments and by BNFL itself. Recently, there has been increasing public concern about general environmental contamination resulting from the discharges and, in particular, about possible exposure of members of the public by routes not previously investigated in detail. One such postulated route of exposure that has attracted the interest of the public, the press and Parliament arises from the presence of radionuclides within houses. In view of this obvious and widespread concern, the Board has undertaken a sampling programme in a few communities in Cumbria to assess the radiological significance of this source of exposure. From the results of our study, we conclude that, alt...

  14. Use of the objective structured clinical examination for assessment of vocational trainees for general practice

    OpenAIRE

    Walker, Robert; Walker, Barrie

    1987-01-01

    General practice training schemes currently have no structured methods of assessment and most rely on a variety of subjective ratings of performance. In West Cumbria the `objective structured clinical examination' has been used to assess training performance in areas covered by small group teaching during the preceding terms. Consultation skills, interpretation of clinical data and a number of aspects of practice management were tested. The examination was conducted in the local postgraduate ...

  15. The development of quality assurance systems for radioactive waste at BNFL Sellafield

    International Nuclear Information System (INIS)

    Lake, M.W.

    1989-01-01

    BNFL reprocesses spent fuel as Sellafield, in West Cumbria, where it is a site licence requirement for formal QA arrangements to be established in respect of nuclear safety related plant. The forms of radioactive waste which are generated on site: HLW, ILW and LLW are made up of arisings which can be solid, liquid or gaseous. This paper discusses how implementation of the company's QA policy has been achieved by formally documenting and establishing the controls needed to manage plant, processes and people

  16. The food chain transfer of radionuclides through semi-natural habitats

    International Nuclear Information System (INIS)

    Copplestone, David.

    1996-07-01

    The behaviour of 134 Cs, 137 Cs, 238 Pu, 239+240 Pu and 241 Am in food chains in three semi-natural ecosystems: a coniferous woodland, a salt marsh and a sand dune have been investigated. These sites, within the environs of the Sellafield nuclear complex in Cumbria, are subject to both anthropogenic and historic inputs of radioactivity. Inputs to these ecosystems have been assessed, as well as activity in soils, vegetation, litter, invertebrates and small mammals. (author)

  17. Conflict generation and avoidance: contradictions in the development of civil nuclear power in Britain

    International Nuclear Information System (INIS)

    Kemp, R.

    1982-01-01

    The subject is discussed under the headings: introduction (role of state power in the development of nuclear energy); the employment effects of nuclear plant construction ((i) the case of North West Wales; (ii) the case of Windscale, Cumbria); local class structure and labour market segmentation; state policy and nuclear energy ((i) the position of Windscale; (ii) the position of the Cabinet); state policy and public decision making; conclusions. (U.K.)

  18. Chemical speciation modelling of groundwater in a shallow glacial sand aquifer part 1 General parameters

    OpenAIRE

    Falck, W.E.; Quinn, G.W.; Duffield, J.R.; Williams, D.R.

    1988-01-01

    The aim of the work detailed in this report has been to gain a better understanding of the speciation chemistry controlling the aqueous chemical forms of elements and compounds normally present in groundwaters found at the BGS in situ migration experiment at Drigg, Cumbria. This will form the basis of future modelling studies designed to interpret in situ tracer experiments using 60Co in the presence of naturally occurring organic complexants. Total element concentrations in re...

  19. The geomicrobiology of used and disused mines in Britain

    International Nuclear Information System (INIS)

    Christofi, N.; Philp, J.C.; West, J.M.; Robbins, J.E.

    1984-03-01

    Several used and disused mines in Britain have been analysed for microbial presence, content and activity. The sites sampled are located in Cornwall, Derbyshire and Cumbria. The mines in Cornwall can be called 'working' and were being operated at the time of sampling. The mine in Derbyshire was disused until recently re-opened by cavers while the mines in Cumbria had remained closed up to the time of sampling. Waters and solid materials have been sampled where detailed microbiology has been undertaken. In Cumbria a detailed description of structures of biological interest was carried out. Both heterotrophic and autotrophic microorganisms have been found in some waters and on mine walls. The actual content of each mine is different according to local conditions and chemistries. The results of the microbiological analyses are given. The origin of these microorganisms cannot be determined although it is likely that they have been introduced by water running down mine shafts from surface strata and/or from excavation processes. Activity measurements have shown that waters in some mines are organic carbon limited. There are indications from the working mines that such carbon would be available from autotrophic populations present within the ecosystem or from backfill material. (author)

  20. Sedimentation studies relevant to low-level radioactive effluent dispersal in the Irish Sea. Part III. An evaluation of possible mechanisms for the incorporation of radionuclides into marine sediments

    International Nuclear Information System (INIS)

    Kirby, R.; Parker, W.R.; Pentreath, R.J.; Lovett, M.B.

    1983-01-01

    Based on circumstantial evidence the Cumbrian mud area was previously interpreted as accretionary. There are no measurements confirming that riverborne sediment reaches the mud area and the postulated subtidal sources appear to be sealed by a lag gravel. In contrast, fine sediment deposited in Liverpool Bay is known to return to the Ribble, Mersey and Dee. Similarly 'hot' particles originating in the Sellafield outfall are implied to travel, perhaps accompanied by natural fine sediment, into the Ravenglass Estuary and elsewhere. The likely interpretation is that fine sediment accumulating in the coastal zone of the eastern Irish Sea is partly derived from seawards. Possible sources are coast erosion and the unconsolidated mud areas themselves. Radionuclide profiles from the Cumbrian mud area have previously been interpreted as confirming the accretionary hypothesis. In fact three principal types of radionuclide profiles occur, which are interpreted here to indicate progressively more efficient bioturbation. Burrowing animals may also supply uncontaminated sediment to the bed, where it absorbs radionuclides before, in part, being redeposited locally. This implies that no large external sediment source is necessary to explain the radionuclide profiles encountered. We thus interpret the area as a relatively stable sedimentary regime dominated by biological processes. (author)

  1. Construction of a field trap for initiating an ovipositional response in Aedes taeniorhynchus.

    Science.gov (United States)

    Wallace, F L

    1996-09-01

    An oviposition trap was constructed for the black saltmarsh mosquito, Aedes taeniorhynchus. The trap consisted of a 50 x 60-cm piece of contaminated 100% cotton bath towel, saturated with 85% tap water, a container, and a cover of dried plant parts placed over the contaminated toweling. This combination initiated oviposition. Contamination of the toweling was due to populations of bacteria and fungi. The eggs recovered were free from soil and debris.

  2. Persistence of Gulf War oil versus intertidal morphology and sediments - one year later

    International Nuclear Information System (INIS)

    Montello, T.M.; Hayes, M.O.; Michel, J.; Al-Momen, A.H.; Al-Mansi, A.M.; Aurand, D.V.

    1993-01-01

    A study of the persistence of oil in the intertidal habitats of the Saudi Arabian coast was carried out one year after the Gulf war spill in conjunction with the National Oceanic and Atmospheric Administration ship Mt. Mitchell's ROPME Sea Cruise. A total of 10 kilometers of transects were surveyed at 20 stations, representing heavily oiled sheltered beaches, tidal flats, algal mats, halophyte saltmarshes, and mangroves at the heads of bays

  3. Grounds Conservation Management Plan (1982-1991), Fish and Wildlife Management Plan (1982-1991), Forest Resource Management Plan (1979-1988).

    Science.gov (United States)

    1985-06-01

    cattails and phragmites interspersed with other marsh plants such as bulrushes, smooth (saltmarsh) cordgrass, smartweed, marshmallow , and sedges. 9...cutgrasses (Leersia spp.) and crimson-eyed marshmallows just below the dam. Above the dam are sparse stands of muskgrass (Chara spp.). The upper reaches of...Gambo (far above the dam) are dominated by pickeral plant (Pontedoria cordata), crimson-eyed marshmallow , spikerushes and denser stands of muskgrass

  4. Environmental Impact Analysis Process. Environmental Assessment Proposed SMC Military Family Housing, San Pedro, California

    Science.gov (United States)

    1998-12-01

    catches birds on the wing; eats some insects ; nests on the ground on ledges. Rallus longirostris levipes light-footed clapper rail E E Occupies and...nests in saltmarsh habitats; feeds in shallow water and on mudflats; diet comprised of small fish, crabs, crayfish, insects and some plants; nests in...occidentalis western yellow- billed cuckoo none E Likes to nest in riparian thickets of willows and cottonwoods with understory of nettles , wild grapes or

  5. Stratigraphic response of salt marshes to slow rates of sea-level change

    Science.gov (United States)

    Daly, J.; Bell, T.

    2006-12-01

    Conventional models of salt-marsh development show an idealized spatial relationship between salt-marsh floral and foraminiferal zones, where the landward margin of the marsh gradually migrates inland in response to sea-level rise. This model predicts that transgression will result in persistent and possibly expanded salt marshes at the surface, depending on a variety of factors including sediment supply, hydrologic conditions, tidal range, and rate of sea-level rise. However, in areas with abundant sediment supply and slow rates of sea- level rise, the extent of back-barrier salt marshes may decline over time as the barrier-spits mature. Sea level around the northeast coast of Newfoundland is rising at a very slow rate during the late Holocene (flora. These transitions are interpreted to reflect the progradation of the spit, decreased tidal exchange in the back-barrier, and increased influence of freshwater streams discharging into the back-barrier setting. Decreased marine influence on the back-barrier environment leads to a floral and faunal shift associated with a regressive stratigraphy in an area experiencing sea-level rise. For studies of Holocene sea-level change requiring salt-marsh stratigraphic records, it is necessary to account for changing micro-environments to locate sites appropriate for study; salt marshes may play an important role in defining the record, but may not exist at the surface to guide investigation.

  6. Morphological differences between habitats are associated with physiological and behavioural trade-offs in stickleback (Gasterosteus aculeatus).

    Science.gov (United States)

    Seebacher, Frank; Webster, Mike M; James, Rob S; Tallis, Jason; Ward, Ashley J W

    2016-06-01

    Local specialization can be advantageous for individuals and may increase the resilience of the species to environmental change. However, there may be trade-offs between morphological responses and physiological performance and behaviour. Our aim was to test whether habitat-specific morphology of stickleback (Gasterosteus aculeatus) interacts with physiological performance and behaviour at different salinities. We rejected the hypothesis that deeper body shape of fish from habitats with high predation pressure led to decreases in locomotor performance. However, there was a trade-off between deeper body shape and muscle quality. Muscle of deeper-bodied fish produced less force than that of shallow-bodied saltmarsh fish. Nonetheless, saltmarsh fish had lower swimming performance, presumably because of lower muscle mass overall coupled with smaller caudal peduncles and larger heads. Saltmarsh fish performed better in saline water (20 ppt) relative to freshwater and relative to fish from freshwater habitats. However, exposure to salinity affected shoaling behaviour of fish from all habitats and shoals moved faster and closer together compared with freshwater. We show that habitat modification can alter phenotypes of native species, but local morphological specialization is associated with trade-offs that may reduce its benefits.

  7. Woody plant encroachment of grasslands: a comparison of terrestrial and wetland settings.

    Science.gov (United States)

    Saintilan, Neil; Rogers, Kerrylee

    2015-02-01

    A global trend of woody plant encroachment of terrestrial grasslands is co-incident with woody plant encroachment of wetland in freshwater and saline intertidal settings. There are several arguments for considering tree encroachment of wetlands in the context of woody shrub encroachment of grassland biomes. In both cases, delimitation of woody shrubs at regional scales is set by temperature thresholds for poleward extent, and by aridity within temperature limits. Latitudinal expansion has been observed for terrestrial woody shrubs and mangroves, following recent warming, but most expansion and thickening has been due to the occupation of previously water-limited grassland/saltmarsh environments. Increases in atmospheric CO₂, may facilitate the recruitment of trees in terrestrial and wetland settings. Improved water relations, a mechanism that would predict higher soil moisture in grasslands and saltmarshes, and also an enhanced capacity to survive arid conditions, reinforces local mechanisms of change. The expansion of woody shrubs and mangroves provides a negative feedback on elevated atmospheric CO₂ by increasing carbon sequestration in grassland and saltmarsh, and is a significant carbon sink globally. These broad-scale vegetation shifts may represent a new stable state, reinforced by positive feedbacks between global change drivers and endogenic mechanisms of persistence in the landscape.

  8. Surface evolution and carbon sequestration in disturbed and undisturbed wetland soils of the Hunter estuary, southeast Australia

    Science.gov (United States)

    Howe, A. J.; Rodríguez, J. F.; Saco, P. M.

    2009-08-01

    The aim of this work was to quantify the soil carbon storage and sequestration rates of undisturbed natural wetlands and disturbed wetlands subject to restriction of tidal flow and subsequent rehabilitation in an Australian estuary. Disturbed and undisturbed estuarine wetlands of the Hunter estuary, New South Wales, Australia were selected as the study sites for this research. Vertical accretion rates of estuarine substrates were combined with soil carbon concentrations and bulk densities to determine the carbon store and carbon sequestration rates of the substrates tested. Relationships between estuary water level, soil evolution and vertical accretion were also examined. The carbon sequestration rate of undisturbed wetlands was lower (15% for mangrove and 55% for saltmarsh) than disturbed wetlands, but the carbon store was higher (65% for mangrove and 60% for saltmarsh). The increased carbon sequestration rate of the disturbed wetlands was driven by substantially higher rates of vertical accretion (95% for mangrove and 345% for saltmarsh). Estuarine wetland carbon stores were estimated at 700-1000 Gg C for the Hunter estuary and 3900-5600 Gg C for New South Wales. Vertical accretion and carbon sequestration rates of estuarine wetlands in the Hunter are at the lower end of the range reported in the literature. The comparatively high carbon sequestration rates reported for the disturbed wetlands in this study indicate that wetland rehabilitation has positive benefits for regulation of atmospheric carbon concentrations, in addition to more broadly accepted ecosystem services.

  9. A study of plutonium and americium concentrations in seaspray on the southern Scottish coast

    International Nuclear Information System (INIS)

    McKay, W.A.; Strange, L.; Walker, M.I.; Halliwell, C.M.

    1992-01-01

    Seaspray and seawater have been collected from the southern Scottish coast and, for comparison, Cumbria in northwest England during 1989 and 1991. The occurrence of sea-to-land transfer of the actinides plutonium and americium in seaspray was observed on these coasts using muslin screens (a semi-quantitative technique most efficient for collecting large spray droplets) and high volume conventional air samplers. The actinides and fine particulate in the spray were present in relatively higher concentrations than measured in the adjacent seawater, i.e. the spray was enriched in particulate actinides. The net efficiency of the muslim screens in collecting airborne plutonium isotopes and 241 Am generally appeared to be about 20%. A review of earlier published concentrations of 239+240 Pu and 241 Am measured in aerosol and deposition for over a year several tens of metres inland was carried out. This suggested that airborne activities are up to a factor of 5 times higher in Cumbria than southern Scotland. However, neither the new data collected in 1989 and 1991 nor this older data suggests any enhancement of seaspray actinide enrichment in southern Scotland compared to Cumbria. This finding contrasts with earlier, more limited, comparisons that have been carried out which suggested such a difference. There is clear evidence of considerable localised spatial and temporal variability in aerosol actinide enrichment over the beaches in both areas. Enrichments varies between 20 and 500 relative to the adjacent surf zone waters. However, the average enrichment in spray based on the continuous measurements made further inland is likely to be at the lower end of this range. (author)

  10. The evaluation, design and implementation of an automated storage and retrieval system for uranium trioxide powder (UO3) at Sellafield

    International Nuclear Information System (INIS)

    Fitt, C.R.; Mather, K.

    1993-01-01

    The paper initially sets out the methods used to evaluate the requirements for an automated system to store and retrieve drums of radioactive Uranium Trioxide (UO3) power arising from the Thermal Oxide Reprocessing Plant (THORP) at Sellafield Cumbria. This is followed by a description of the configuration of storage vaults used and of the development of a Self Guided Vehicle (SGV) to operate remotely within these vaults. The system evolved is based on a combination of well proven mechanical equipment and control techniques and the implementation of the design together with testing and control procedures are described. (author)

  11. Remote viewing system development in BNFL

    International Nuclear Information System (INIS)

    Case, D.R.; Garlick, D.R.; Crawford, G.; Montgomerie, J.

    1996-01-01

    The application of imaging systems to BNFL's plants is primarily provided by the Company's Engineering Group. Many systems have been developed for active service and several new developments are currently in an advanced stage of implementation. BNFL has acquired extensive experience of remote viewing from a series of projects undertaken for the Sellafield site in West Cumbria. Applications vary in size and complexity, from simple identification of bar-codes to more complex schemes for remotely storing UO 3 drums. Some are high speed and highly repetitive, whereas others are low speed but require high precision. In this paper the authors outline a selection of current applications. (UK)

  12. Cumbrian Alchemy (2012-2014)

    International Nuclear Information System (INIS)

    Williams, Robert; McGovern Wilson, Bryan

    2015-01-01

    The Cumbrian Alchemy project explores issues emerging from an enquiry into convergent relationships among the nuclear and other energy industries, archaeological monuments and oral traditions of the North Lancashire and Cumbrian region in the north-west of England. Topically, it focuses on ideas of 'places of power', issues and discourse associated with hazardous industrial sites, long-term nuclear repositories, matters of 'deep-time' with respect to the recording and remembering of these repositories, language preservation and stewardship of the land. The project was supported by Arts Council England and the University of Cumbria

  13. The chemical speciation of 137Cs in sheepmeat

    International Nuclear Information System (INIS)

    Pang, T.Y.M.; Taylor, D.M.; Williams, D.R.

    1996-01-01

    Minced sheep muscle, homogenised liver and fragmented rib or cortical bone, from sheep grazing near Bootle, Cumbria, U.K., which had been stored for some months at -20 o C, were extracted at 4 o C with an isotonic 0.15 M NaCl-0.02 M phosphate buffer at pH 7.4. Each successive extraction released about 50% of the total 137 Cs remaining in the tissue. Passage of the extracts through a column of the cation-exchanger Dowex 50 x 8 indicated that essentially all the extracted 137 Cs was in cationic form. (author)

  14. Apparent clusters of childhood lymphoid malignancy in Northern England

    International Nuclear Information System (INIS)

    Craft, A.W.; Openshaw, S.; Birch, J.

    1984-01-01

    The authors have reanalysed their previous data on the incidence of childhood malignancy in the North of England by very small geographical areas. Seascale, which ranks first by Poisson probability for all lymphoid malignancies is the village closest to the Sellafield plant. However, it is not unique in the region; nor are wards of apparent excess confined to coastal areas of Cumbria. The highest rate of lymphoid malignancies is in Whittingham, a village in north Northumberland. For other varieties of childhood cancer, there is a similar spread of 'Highly ranked', but different, wards throughout the region. (U.K.)

  15. Radioactive waste disposal assessment - overview of biosphere processes and models

    International Nuclear Information System (INIS)

    Coughtrey, P.J.

    1992-09-01

    This report provides an overview of biosphere processes and models in the general context of the radiological assessment of radioactive waste disposal as a basis for HMIP's response to biosphere aspects of Nirex's submissions for disposal of radioactive wastes in a purpose-built repository at Sellafield, Cumbria. The overview takes into account published information from the UK as available from Nirex's safety and assessment research programme and HMIP's disposal assessment programme, as well as that available from studies in the UK and elsewhere. (Author)

  16. Medical response to effects of ionising radiation

    International Nuclear Information System (INIS)

    Terrell, J.D.

    1989-01-01

    This paper will first of all deal with a scenario in which a radiation hazard arises within the DPH's Health District and, building on this, will go on to consider a modified role for the Community Physician where a hazard arises outside his District but poses some threat to it. The submissions made on the role of the Community Physician as Director of Public Health of a District Health Authority are based on experience of exercises conducted over recent years in relation to a possible incident at Sellafield in West Cumbria. (author)

  17. Remote viewing system development in BNFL

    International Nuclear Information System (INIS)

    Case, D.R.; Garlick, D.R.; Crawford, G.; Montgomerie, J.

    1996-01-01

    The application of imaging systems to BNFL's plants is primarily provided by the Company's Engineering Group. Many systems have been developed for active service and several new developments are currently in an advanced stage of implementation. BNFL has acquired extensive experience of remote viewing from a series of projects undertaken for the Sellafield site in West Cumbria. Applications vary in size and complexity, from simple identification of bar-codes to more complex schemes for remotely storing UO 3 drums. Some are high speed and highly repetitive, whereas others are low speed but require high precision. In this paper the authors shall outline a selection of current applications. (Author)

  18. The geology and hydrogeology of Sellafield: an overview

    International Nuclear Information System (INIS)

    Chaplow, Robert

    1996-01-01

    Nirex is responsible for providing and managing a national facility for solid intermediate-level and low-level radioactive waste. Geological and hydrogeological investigations have been in progress at Sellafield in west Cumbria since 1989 aimed at determining whether or not the site is suitable for such a deep repository. Geological investigations have included the drilling of 20 deep boreholes with over 20 000 metres of drilling, together with almost 2000 line kilometres of seismic surveys and over 8000 line kilometres of airborne geophysical surveys. Hydrogeological testing and groundwater sampling and testing have provided additional information on the ground conditions at the site. (author)

  19. The Drigg low-level waste site

    International Nuclear Information System (INIS)

    1992-01-01

    Safe disposal of waste is a vital aspect of any industrial operation whether it be production of plastics, steel or chemicals or handling of radioactive materials. Appropriate methods must be used in every case. Radioactive waste falls into three distinct categories - high, intermediate and low-level. It is the solid low-level waste making up over 90% of the total which this booklet discusses. British Nuclear Fuels plc (BNFL) operates a site for the disposal of solid low-level waste at Driggs, some six kilometres south of Sellafield in West Cumbria. The daily operations and control of the site, the responsibility of the BNFL Waste Management Unit is described. (author)

  20. The distribution and dynamics of radionuclides in the terrestrial environment

    International Nuclear Information System (INIS)

    Horrill, A.D.; Howson, G.

    1988-10-01

    Caesium-137, plutonium-238 and plutonium-239/240 have been determined in soils and vegetation from West Cumbria. Determinations have been made with reference to the land use which is dominated by grassland management. It can be shown statistically that with respect to caesium-137 land use can affect all soil and vegetation inventory. Indications are that a similar situation holds for the plutonium isotopes. A small data bank of information has been gathered on the land management and farming practices of the study area. (author)

  1. The role of MAFF [Ministry of Agriculture, Fisheries and Food] following a nuclear accident

    International Nuclear Information System (INIS)

    Segal, M.G.

    1989-01-01

    MAFF has an important role in any incident involving release of radioactivity into the environment. The Ministry monitors both food and pasture for grazing animals, and can act to protect the public from exposure to unacceptable levels of contamination in food. Detailed emergency plans exist for both UK and overseas accidents. Following the Chernobyl accident in 1986, restrictions were enforced on the movement of sheep in parts of Cumbria, Wales and Scotland, and some are still in force. This work is backed up by an extensive research programme into the behaviour of radionuclides in the environment and the food-chain, and detailed analyses of actual diets. (author)

  2. A comparison of the risks of childhood leukaemia from parental pre-conception exposure to radiation in the Sellafield and Dounreay workforces and the Japanese bomb survivors

    International Nuclear Information System (INIS)

    Little, M.P.

    1991-01-01

    The cases of childhood leukemia found among children of the Sellafield (West Cumbria) and Dounreay (Caithness) workforces and those observed in the offspring of the Japanese bomb survivors are analysed using exponential and linear forms of a relative risk model and employing dose estimates both for the period 6 months pre-conception and also for total pre-conception doses. The leukemia relative risk coefficients for paternal (whole-body) exposure in these pre-conception periods for children in Caithness are found to be statistically compatible with those of the children of Sellafield workers but also with the (gonadal dose) coefficients applying to the offspring of the bomb survivors. There remains the need to explain adequately the absence of a discernibly raised risk of childhood leukaemia in the offspring of the Japanese bomb survivors if the statistical association between paternal pre-conception radiation and the raised incidence of childhood leukaemia found in the West Cumbria study represents a causal relationship. (author)

  3. Father's occupational exposure to radiation and the raised level of childhood leukemia near the Sellafield Nuclear Plant

    International Nuclear Information System (INIS)

    Gardner, M.J.

    1991-01-01

    The first indications that childhood leukemia rates may be raised near the Sellafield nuclear plant in West Cumbria, England, came from largely anecdotal evidence in a television program Windscale: The Nuclear Laundry shown during 1983. During subsequent years, various epidemiological studies have investigated the claim in more detail. Geographical analyses of childhood leukemia incidence in the northern region and mortality in England and Wales using routinely available data made the first contribution. As a result, it was confirmed that leukemia rates in the area, particularly the neighboring village of Seascale, were high compared to other districts, although not totally extreme. Cohort studies of children born in Seascale or attending schools in Seascale were carried out to resolve some of the difficulties of interpretation of geographical analysis. Cohort studies indicated that the excess of leukemia was concentrated among children born in Seascale and was not found among those moving in after birth and suggested that any causal factors may be acting before birth or very early in life. A case-control study of leukemia (and lymphoma) among young people in West Cumbria has examined potentially important individual factors in detail. The study demonstrated a relationship between the raised incidence of leukemia in children and father's recorded external radiation dose during work at Sellafield before his child's conception. The association can effectively explain statistically the observed geographical excess

  4. Terrestrial laser scanning to quantify above-ground biomass of structurally complex coastal wetland vegetation

    Science.gov (United States)

    Owers, Christopher J.; Rogers, Kerrylee; Woodroffe, Colin D.

    2018-05-01

    Above-ground biomass represents a small yet significant contributor to carbon storage in coastal wetlands. Despite this, above-ground biomass is often poorly quantified, particularly in areas where vegetation structure is complex. Traditional methods for providing accurate estimates involve harvesting vegetation to develop mangrove allometric equations and quantify saltmarsh biomass in quadrats. However broad scale application of these methods may not capture structural variability in vegetation resulting in a loss of detail and estimates with considerable uncertainty. Terrestrial laser scanning (TLS) collects high resolution three-dimensional point clouds capable of providing detailed structural morphology of vegetation. This study demonstrates that TLS is a suitable non-destructive method for estimating biomass of structurally complex coastal wetland vegetation. We compare volumetric models, 3-D surface reconstruction and rasterised volume, and point cloud elevation histogram modelling techniques to estimate biomass. Our results show that current volumetric modelling approaches for estimating TLS-derived biomass are comparable to traditional mangrove allometrics and saltmarsh harvesting. However, volumetric modelling approaches oversimplify vegetation structure by under-utilising the large amount of structural information provided by the point cloud. The point cloud elevation histogram model presented in this study, as an alternative to volumetric modelling, utilises all of the information within the point cloud, as opposed to sub-sampling based on specific criteria. This method is simple but highly effective for both mangrove (r2 = 0.95) and saltmarsh (r2 > 0.92) vegetation. Our results provide evidence that application of TLS in coastal wetlands is an effective non-destructive method to accurately quantify biomass for structurally complex vegetation.

  5. Predicting the retreat and migration of tidal forests along the northern Gulf of Mexico under sea-level rise

    Science.gov (United States)

    Doyle, T.W.; Krauss, K.W.; Conner, W.H.; From, A.S.

    2010-01-01

    Tidal freshwater forests in coastal regions of the southeastern United States are undergoing dieback and retreat from increasing tidal inundation and saltwater intrusion attributed to climate variability and sea-level rise. In many areas, tidal saltwater forests (mangroves) contrastingly are expanding landward in subtropical coastal reaches succeeding freshwater marsh and forest zones. Hydrological characteristics of these low-relief coastal forests in intertidal settings are dictated by the influence of tidal and freshwater forcing. In this paper, we describe the application of the Sea Level Over Proportional Elevation (SLOPE) model to predict coastal forest retreat and migration from projected sea-level rise based on a proxy relationship of saltmarsh/mangrove area and tidal range. The SLOPE model assumes that the sum area of saltmarsh/mangrove habitat along any given coastal reach is determined by the slope of the landform and vertical tide forcing. Model results indicated that saltmarsh and mangrove migration from sea-level rise will vary by county and watershed but greater in western Gulf States than in the eastern Gulf States where millions of hectares of coastal forest will be displaced over the next century with a near meter rise in relative sea level alone. Substantial losses of coastal forests will also occur in the eastern Gulf but mangrove forests in subtropical zones of Florida are expected to replace retreating freshwater forest and affect regional biodiversity. Accelerated global eustacy from climate change will compound the degree of predicted retreat and migration of coastal forests with expected implications for ecosystem management of State and Federal lands in the absence of adaptive coastal management.

  6. Gene flow connects coastal populations of a habitat specialist, the Clapper Rail Rallus crepitans

    Science.gov (United States)

    Coster, Stephanie S.; Welsh, Amy B.; Costanzo, Gary R.; Harding, Sergio R.; Anderson, James T.; Katzner, Todd

    2018-01-01

    Examining population genetic structure can reveal patterns of reproductive isolation or population mixing and inform conservation management. Some avian species are predicted to exhibit minimal genetic differentiation among populations as a result of the species high mobility, with habitat specialists tending to show greater fine‐scale genetic structure. To explore the relationship between habitat specialization and gene flow, we investigated the genetic structure of a saltmarsh specialist with high potential mobility across a wide geographic range of fragmented habitat. Little variation among mitochondrial sequences (620 bp from ND2) was observed among 149 individual Clapper Rails Rallus crepitans sampled along the Atlantic coast of North America, with the majority of individuals at all sampling sites sharing a single haplotype. Genotyping of nine microsatellite loci across 136 individuals revealed moderate genetic diversity, no evidence of bottlenecks, and a weak pattern of genetic differentiation that increased with geographic distance. Multivariate analyses, Bayesian clustering and an AMOVA all suggested a lack of genetic structuring across the North American Atlantic coast, with all individuals grouped into a single interbreeding population. Spatial autocorrelation analyses showed evidence of weak female philopatry and a lack of male philopatry. We conclude that high gene flow connecting populations of this habitat specialist may result from the interaction of ecological and behavioral factors that promote dispersal and limit natal philopatry and breeding‐site fidelity. As climate change threatens saltmarshes, the genetic diversity and population connectivity of Clapper Rails may promote resilience of their populations. This finding helps inform about potential fates of other similarly behaving saltmarsh specialists on the Atlantic coast.

  7. Quantifying Vegetation Structure with Lightweight, Rapid-Scanning Terrestrial Lidar

    Science.gov (United States)

    Paynter, I.; Genest, D.; Saenz, E. J.; Strahler, A. H.; Li, Z.; Peri, F.; Schaaf, C.

    2016-12-01

    Light Detection and Ranging (lidar) is proving a competent technology for observing vegetation structure. Terrestrial laser scanners (TLS) are ground-based instruments which utilize hundreds of thousands to millions of lidar observations to provide detailed structural and reflective information of their surroundings. TLS has enjoyed initial success as a validation tool for satellite and airborne estimates of vegetation structure, and are producing independent estimates with increasing accuracy. Reconstruction techniques for TLS observations of vegetation have also improved rapidly, especially for trees. However, uncertainties and challenges still remain in TLS modelling of vegetation structure, especially in geometrically complex ecosystems such as tropical forests (where observation extent and density is hampered by occlusion) and highly temporally dynamic coastal ecosystems (such as saltmarshes and mangroves), where observations may be restricted to narrow microstates. Some of these uncertainties can be mitigated, and challenges met, through the use of lidar instruments optimized for favorable deployment logistics through low weight, rapid scanning, and improved durability. We have conducted studies of vegetation structure in temperate and tropical forests, saltmarshes and mangroves, utilizing a highly portable TLS with considerable deployment flexibility, the Compact Biomass Lidar (CBL). We show results from studies in the temperate Long Term Ecological Research site of Harvard Forest (MA, USA); the tropical forested long-term Carbono sites of La Selva Biological Station (Sarapiqui, Costa Rica); and the saltmarsh LTER of Plum Island (MA, USA). These results demonstrate the improvements to observations in these ecosystems which are facilitated by the specifications of the CBL (and similar TLS) which are optimized for favorable deployment logistics and flexibility. We show the benefits of increased numbers of scanning positions, and specialized deployment

  8. The morphological development of newly inundated intertidal areas: the mechanisms driving the early evolution of an estuarine environment designed and constructed by humans

    Science.gov (United States)

    Dale, Jonathan; Burgess, Heidi; Cundy, Andrew

    2017-04-01

    Intertidal saltmarsh and mudflat habitats are of global importance due to the ecosystem, economic and cultural services they provide. These services include wildlife habitat provision and species diversity, immobilisation of pollutants and protection from coastal flooding. Saltmarsh and mudflat environments are, however, being lost and degraded due to erosion caused by rising sea levels and increased storminess. These losses are exacerbated by anthropogenic influences including land reclamation, increased coastal development and the construction of coastal flood defences which prevent the landwards migration of saltmarsh and mudflat environments, resulting in coastal squeeze. To compensate for saltmarsh and mudflat losses areas of the coastal hinterland are being inundated by breaching defences and constructing new defences inland, thus extending or constructing new estuarine environments; a processes known as de-embankment or managed realignment. Morphological engineering and landscaping within managed realignment sites prior to site inundation varies depending on the aims of the scheme. However, there is a shortage of data on the morphological evolution within these sites post site inundation impeding the ability of coastal engineers to effectively design and construct future sites. To date there has been a focus on the colonisation of marine macro fauna and flora within newly inundated managed realignment sites, which can be relatively rapid and easily quantified. Little is known of the morphological evolution in response to altered sedimentary processes, its driving mechanisms and therefore the success and ecological sustainability of these sites. This study evaluates the post-inundation morphological development of the largest open coast managed realignment site in Europe, at Medmerry on the south coast of the United Kingdom. Inundated in September 2013, the Medmerry Managed Realignment Site consists of a mosaic of former agricultural land and areas of lower

  9. Sex- and habitat-specific movement of an omnivorous semi-terrestrial crab controls habitat connectivity and subsidies: a multi-parameter approach.

    Science.gov (United States)

    Hübner, Lena; Pennings, Steven C; Zimmer, Martin

    2015-08-01

    Distinct habitats are often linked through fluxes of matter and migration of organisms. In particular, intertidal ecotones are prone to being influenced from both the marine and the terrestrial realms, but whether or not small-scale migration for feeding, sheltering or reproducing is detectable may depend on the parameter studied. Within the ecotone of an upper saltmarsh in the United States, we investigated the sex-specific movement of the semi-terrestrial crab Armases cinereum using an approach of determining multiple measures of across-ecotone migration. To this end, we determined food preference, digestive abilities (enzyme activities), bacterial hindgut communities (genetic fingerprint), and the trophic position of Armases and potential food sources (stable isotopes) of males versus females of different sub-habitats, namely high saltmarsh and coastal forest. Daily observations showed that Armases moved frequently between high-intertidal (saltmarsh) and terrestrial (forest) habitats. Males were encountered more often in the forest habitat, whilst gravid females tended to be more abundant in the marsh habitat but moved more frequently. Food preference was driven by both sex and habitat. The needlerush Juncus was preferred over three other high-marsh detrital food sources, and the periwinkle Littoraria was the preferred prey of male (but not female) crabs from the forest habitats; both male and female crabs from marsh habitat preferred the fiddler crab Uca over three other prey items. In the field, the major food sources were clearly vegetal, but males have a higher trophic position than females. In contrast to food preference, isotope data excluded Uca and Littoraria as major food sources, except for males from the forest, and suggested that Armases consumes a mix of C4 and C3 plants along with animal prey. Digestive enzyme activities differed significantly between sexes and habitats and were higher in females and in marsh crabs. The bacterial hindgut community

  10. Características geológicas, hidrológicas y del manglar en la planicie costera de Nayarit, México

    Directory of Open Access Journals (Sweden)

    Guadalupe de la Lanza

    1996-01-01

    Full Text Available The different geoforms of the coastal zone are consecuence of environmental changes (hydrology, climate, marine hydrodynamic and organic growth. The coastal plain of Nayarit is an example of the confluence of these factors which result in saltmarshes, lagoons, deltas, meanders, channels, swamps, all of which are bordered by high mangrove density. These characteristics coastal plain structures are exploited for human activities. In this paper the geologic, and hydrologic evolution, as well as the mangrove vegetation distribution was analized, using a LANDSAT image, which covers 108 113 ha, with heterogeneus species distribution and predominance of Laguncularia racemosa followed by Rhizophora mangle.

  11. Radiological and alimentary assessment of the agriculture using phosphogypsum (PG) in agricola soils recovery in Guadalquivir. Final report; Evaluacion de la seguridad alimentaria y radiologica en la aplicacion del fosfoyeso como enmienda de suelos agricolas recuperados en las marismas del Gualquivir Informe Final

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, J. M.

    2006-07-01

    The main goal of this Project has been the radiological and alimentary assessment of the agriculture use of phosphogypsum (PG), a by-product of the fertilizer industry, as Ca-amendment in reclaimed salt-marsh soils in SW Spain. The work-plan included: PG characterization (concentrations of radionuclide and heavy metals, {sup 2}22Rn exhalation from PG stacks), experimental field studies attending to the effect of PG in agriculture soils and drainage waters, and studies on soil-to-plant transfer of radionuclides and heavy metals (through both, field and greenhouse studies).

  12. The Effectiveness, Costs and Coastal Protection Benefits of Natural and Nature-Based Defences.

    Science.gov (United States)

    Narayan, Siddharth; Beck, Michael W; Reguero, Borja G; Losada, Iñigo J; van Wesenbeeck, Bregje; Pontee, Nigel; Sanchirico, James N; Ingram, Jane Carter; Lange, Glenn-Marie; Burks-Copes, Kelly A

    2016-01-01

    There is great interest in the restoration and conservation of coastal habitats for protection from flooding and erosion. This is evidenced by the growing number of analyses and reviews of the effectiveness of habitats as natural defences and increasing funding world-wide for nature-based defences-i.e. restoration projects aimed at coastal protection; yet, there is no synthetic information on what kinds of projects are effective and cost effective for this purpose. This paper addresses two issues critical for designing restoration projects for coastal protection: (i) a synthesis of the costs and benefits of projects designed for coastal protection (nature-based defences) and (ii) analyses of the effectiveness of coastal habitats (natural defences) in reducing wave heights and the biophysical parameters that influence this effectiveness. We (i) analyse data from sixty-nine field measurements in coastal habitats globally and examine measures of effectiveness of mangroves, salt-marshes, coral reefs and seagrass/kelp beds for wave height reduction; (ii) synthesise the costs and coastal protection benefits of fifty-two nature-based defence projects and; (iii) estimate the benefits of each restoration project by combining information on restoration costs with data from nearby field measurements. The analyses of field measurements show that coastal habitats have significant potential for reducing wave heights that varies by habitat and site. In general, coral reefs and salt-marshes have the highest overall potential. Habitat effectiveness is influenced by: a) the ratios of wave height-to-water depth and habitat width-to-wavelength in coral reefs; and b) the ratio of vegetation height-to-water depth in salt-marshes. The comparison of costs of nature-based defence projects and engineering structures show that salt-marshes and mangroves can be two to five times cheaper than a submerged breakwater for wave heights up to half a metre and, within their limits, become more cost

  13. The Effectiveness, Costs and Coastal Protection Benefits of Natural and Nature-Based Defences.

    Directory of Open Access Journals (Sweden)

    Siddharth Narayan

    Full Text Available There is great interest in the restoration and conservation of coastal habitats for protection from flooding and erosion. This is evidenced by the growing number of analyses and reviews of the effectiveness of habitats as natural defences and increasing funding world-wide for nature-based defences-i.e. restoration projects aimed at coastal protection; yet, there is no synthetic information on what kinds of projects are effective and cost effective for this purpose. This paper addresses two issues critical for designing restoration projects for coastal protection: (i a synthesis of the costs and benefits of projects designed for coastal protection (nature-based defences and (ii analyses of the effectiveness of coastal habitats (natural defences in reducing wave heights and the biophysical parameters that influence this effectiveness. We (i analyse data from sixty-nine field measurements in coastal habitats globally and examine measures of effectiveness of mangroves, salt-marshes, coral reefs and seagrass/kelp beds for wave height reduction; (ii synthesise the costs and coastal protection benefits of fifty-two nature-based defence projects and; (iii estimate the benefits of each restoration project by combining information on restoration costs with data from nearby field measurements. The analyses of field measurements show that coastal habitats have significant potential for reducing wave heights that varies by habitat and site. In general, coral reefs and salt-marshes have the highest overall potential. Habitat effectiveness is influenced by: a the ratios of wave height-to-water depth and habitat width-to-wavelength in coral reefs; and b the ratio of vegetation height-to-water depth in salt-marshes. The comparison of costs of nature-based defence projects and engineering structures show that salt-marshes and mangroves can be two to five times cheaper than a submerged breakwater for wave heights up to half a metre and, within their limits, become

  14. Transfer of radiocesium from different environmental sources to ewes and suckling lambs

    International Nuclear Information System (INIS)

    Howard, B.J.; Mayes, R.W.; Beresford, N.A.; Lamb, C.S.

    1989-01-01

    Indoor experiments are described that compare the transfer of radiocesium to ewe and lamb tissues from different sources. Lactating ewes were fed either perennial ryegrass contaminated by Chernobyl fallout, or saltmarsh vegetation contaminated by marine discharges from the Sellafield reprocessing plant. The transfer to ewe tissues and milk was greater from the Chernobyl contaminated herbage than from saltmarsh vegetation. Lambs receiving a mixture of vegetation and milk were given radiocesium from one of the two vegetation sources or from milk obtained from the experimental ewes. Transfer to lamb tissues declined in the order milk greater than Chernobyl fallout greater than Sellafield discharge. The radiocesium transfer to lamb tissues exceeded that to ewe tissues. Transfer coefficients for 137Cs in the Chernobyl fallout were higher than most previously published figures at 0.12 d kg-1 for ewe muscle and 0.50 d kg-1 for lamb muscle. The transfer coefficient for 137Cs from ewe milk to lamb muscle was 1.20 d kg-1

  15. The distribution and remobilisation of plutonium and americium in estuaries of the eastern Irish Sea: a review

    International Nuclear Information System (INIS)

    Toole, J.

    1993-01-01

    The plutonium and americium components in the authorised discharges from BNFL Sellafield are rapidly removed from Irish Sea seawater onto the particulate phase. These actinides tend to be concentrated in fine sediment deposits on the Irish Sea bed and in estuaries where fine sediment accumulates. This paper focuses on these estuarine areas and brings together the available data on the levels and distributions of Pu and Am within the estuarine sediments. The results from field and laboratory experiments which have been undertaken in order to determine the degree of Pu and Am remobilisation, and the mechanism responsible, are also reviewed. These sediment-associated actinides may undergo both chemical and physical remobilisation, leading to increased dissolved concentrations in low-salinity waters and to apparent losses from the estuary on the sediment phase under certain conditions. Saltmarsh sediments are demonstrated to be the most important reservoirs for Pu and Am. The radiological significance of the levels of Pu and Am found in these and in other sediments is summarised, by comparison with GDLs. The appropriateness of GDLs for assessing the radiological significance of Pu and Am in these saltmarsh sediments is discussed. A more site-specific assessment methodology is recommended. (author)

  16. The contaminant legacy from historic coastal landfills and their potential as sources of diffuse pollution.

    Science.gov (United States)

    O'Shea, Francis T; Cundy, Andrew B; Spencer, Kate L

    2018-03-01

    Prior to modern environmental regulation landfills in low-lying coastal environments were frequently constructed without leachate control, relying on natural attenuation within inter-tidal sediments to dilute and disperse contaminants reducing environmental impact. With sea level rise and coastal erosion these sites may now pose a pollution risk, yet have received little investigation. This work examines the extent of metal contamination in saltmarsh sediments surrounding a historic landfill in the UK. Patterns of sediment metal data suggest typical anthropogenic pollution chronologies for saltmarsh sediments in industrialised nations. However, many metals were also enriched at depth in close proximity to the landfill boundary and are indicative of a historical leachate plume. Though this total metal load is low, e.g., c. 1200 and 1650kg Pb and Zn respectively, with >1000 historic landfills on flood risk or eroding coastlines in the UK this could represent a significant, yet under-investigated, source of diffuse pollution. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Unpreferred plants affect patch choice and spatial distribution of European brown hares

    Science.gov (United States)

    Kuijper, D. P. J.; Bakker, J. P.

    2008-11-01

    Many herbivore species prefer to forage on patches of intermediate biomass. Plant quality and forage efficiency are predicted to decrease with increasing plant standing crop which explains the lower preference of the herbivore. However, often is ignored that on the long-term, plant species composition is predicted to change with increasing plant standing crop. The amount of low-quality, unpreferred food plants increases with increasing plant standing crop. In the present study the effects of unpreferred plants on patch choice and distribution of European brown hare in a salt-marsh system were studied. In one experiment, unpreferred plants were removed from plots. In the second experiment, plots were planted with different densities of an unpreferred artificial plant. Removal of unpreferred plants increased hare-grazing pressure more than fivefold compared to unmanipulated plots. Planting of unpreferred plants reduced hare-grazing pressure, with a significant reduction of grazing already occurring at low unpreferred plant density. Spatial distribution of hares within this salt-marsh system was related to spatial arrangement of unpreferred plants. Hare-grazing intensity decreased strongly with increasing abundance of unpreferred plants despite a high abundance of principal food plants. The results of this study indicate that plant species replacement is an important factor determining patch choice and spatial distribution of hares next to changing plant quality. Increasing abundance of unpreferred plant species can strengthen the decreasing patch quality with increasing standing crop and can decrease grazing intensity when preferred food plants are still abundantly present.

  18. Hard science is essential to restoring soft-sediment intertidal habitats in burgeoning East Asia.

    Science.gov (United States)

    Lee, Shing Yip; Khim, Jong Seong

    2017-02-01

    Intertidal soft-sediment ecosystems such as mangrove, saltmarsh, and tidal flats face multiple stresses along the burgeoning East Asia coastline. In addition to direct habitat loss, ecosystem structure, function, and capacity for ecosystem services of these habitats are significantly affected by anthropogenic loss of hydrologic connectivity, introduction of invasive exotic species, and chemical pollution. These dramatic changes to ecosystem structure and function are illustrated by four case studies along the East Asian coast: the Mai Po Marshes in Hong Kong, the Yunxiao wetlands in Fujian, China, and the Lake Sihwa and Saemangeum tidal flats in Korea. While investment in restoration is increasing significantly in the region, the lack of key basic knowledge on aspects of the behaviour of intertidal soft-sediment ecosystems, particularly those in Asia, impairs the effectiveness of these efforts. The relationship between biodiversity and ecosystem function for relatively species-poor mangrove, seagrass, and saltmarsh systems has implications for restoration targeting monospecific plantations. The trajectory of recovery and return of ecosystem function and services is also poorly known, and may deviate from simple expectations. As many introduced species have become established along the East Asian coast, their long-term impact on ecosystem function as well as the socio-economics of coastal communities demand a multidisciplinary approach to assessing options for restoration and management. These knowledge gaps require urgent attention in order to inform future restoration and management of intertidal soft-sediment ecosystems in fast-developing East Asia. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Effects of Land Use Changes on the Ecosystem Service Values of Coastal Wetlands

    Science.gov (United States)

    Camacho-Valdez, Vera; Ruiz-Luna, Arturo; Ghermandi, Andrea; Berlanga-Robles, César A.; Nunes, Paulo A. L. D.

    2014-10-01

    Changes in the coastal landscape of Southern Sinaloa (Mexico), between 2000 and 2010, were analyzed to relate spatial variations in wetlands extent with the provision and economic value of the ecosystem services (ES). Remote sensing techniques applied to Landsat TM imagery were used to evaluate land use/land cover changes while the value transfer method was used to assess the value of ES by land cover category. Five wetland types and other four land covers were found as representative of the coastal landscape. Findings reveal a 14 % decrease in the saltmarsh/forested mangrove area and a 12 % increase in the area of shrimp pond aquaculture (artificial wetland) during the study period. ES valuation shows that the total value flow increased by 9 % from 215 to 233 million (2007 USD) during the 10-year period. This increase is explained as result of the high value worldwide assigned to saltmarsh. We recognize limitations in the transfer-based approach in quantifying and mapping ES values in the region, but this method provides with value estimates spatially defined, and also provides some guidance in the preliminary screening of policies and projected development in the context of data-scarce regions.

  20. An analysis of leukaemia, lymphoma and other malignancies together with certain categories of non-cancer mortality in the first generation offspring (F[sub 1]) of the Japanese bomb survivors

    Energy Technology Data Exchange (ETDEWEB)

    Little, M.P. (National Radiological Protection Board, Chilton (United Kingdom)); Wakeford, R. (British Nuclear Fuels plc, Risley (United Kingdom)); Charles, M.W. (Nuclear Electric plc, Berkeley (United Kingdom). Berkeley Technology Centre)

    1994-09-01

    The absence of any significant excess of childhood leukaemia in the offspring of the Japanese bomb survivors has provided strong evidence against a causal interpretation of the association between paternal preconception radiation dose and the incidence of childhood leukaemia in the offspring of employees at the Sellafield nuclear installation, West Cumbria. The use of the Japanese data has, however, been questioned on the basis that leukaemia cases may have been under-recorded in the years immediately following the bombings. In order to investigate possible misdiagnoses of leukaemia cases in the first generation offspring (F[sub 1]) of the Japanese bomb survivors, analyses have been undertaken of cases of leukaemia, non-Hodgkin's lymphoma (NHL), and all other malignancies, together with deaths due to blood diseases, deaths due to infectious diseases and deaths from unknown causes. (author).

  1. Successful public relations for a better public acceptance - a case study on Sellafield

    International Nuclear Information System (INIS)

    Duncan, C.; Prestwood, J.

    1998-01-01

    The Sellafield story is not unique but it can be used as one example of what can be achieved in a community close to a nuclear site. Over the past 12 years BNFL staff at Sellafield have worked diligently to win public acceptance in the local community around Sellafield. It has been an excellent example of teamwork, involving the workforce and the local community. It has taken a great deal of effort and finance and painstaking attention to even the most trivial issues to gain the publics' trust. Today, Sellafield and its activities underpin the economy of West Cumbria. The site employs just under 7000 people directly with a further 1500 in contracting roles

  2. Iodine speciation and diffusion in a sand-groundwater system

    International Nuclear Information System (INIS)

    Higgo, J.J.W.; Haigh, D.G.; Allen, M.R.; Williams, G.M.; Warwick, P.

    1991-01-01

    This study lies within the Mirage II research programme (migration of radionuclides in the geosphere) set up by the Commission of the European Communities and supported by the UK Department of the Environment. The work forms part of the project entilled In situ determination of the effects of organics on the mobility of radionuclides in controlled conditions of groundwater flow which is being carried out by the British Geological Survey at Drigg in Cumbria, on land owned by British Nuclear Fuel plc. The study involves the detailed geochemical and hydrogeological characterization of a confined aquifer of glacial sand, the laboratory scale investigation of radionuclide sorption processes and how these are affected by the presence of natural and anthropogenic organic compounds. Ultimately the results of field hydraulic testing and laboratory studies of radionuclide sorption will be used to predict the outcome of a field tracer experiment using conservative and reactive radionuclide species

  3. Radioactive lobsters put squeeze on Sellafield

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1996-11-01

    British Nuclear Fuels is facing a new controversy over its Sellafield Works in Cumbria. Levels of the radioactive isotope technetium-99 in lobsters close to the works have risen 40-fold since 1993 -and now far exceed EC standards for contamination of food after a nuclear accident. Radioactive doses to local seafood consumers have been rising steeply since BNFL commissioned a new enhanced actinide removal plant (EARP) in 1994. The Environment Agency has now asked BNFL to consider ways of reducing technetium-99 discharges from the plant - but the company is also under pressure to maintain throughput to meet the safety concerns of the Nuclear Installations Inspectorate (NII) and avoid disrupting the reprocessing of spent Magnox reactor fuel. (UK).

  4. Radioactive lobsters put squeeze on Sellafield

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    British Nuclear Fuels is facing a new controversy over its Sellafield Works in Cumbria. Levels of the radioactive isotope technetium-99 in lobsters close to the works have risen 40-fold since 1993 -and now far exceed EC standards for contamination of food after a nuclear accident. Radioactive doses to local seafood consumers have been rising steeply since BNFL commissioned a new enhanced actinide removal plant (EARP) in 1994. The Environment Agency has now asked BNFL to consider ways of reducing technetium-99 discharges from the plant - but the company is also under pressure to maintain throughput to meet the safety concerns of the Nuclear Installations Inspectorate (NII) and avoid disrupting the reprocessing of spent Magnox reactor fuel. (UK)

  5. Nirex plans for low and intermediate level waste

    International Nuclear Information System (INIS)

    Mathieson, J.

    1995-01-01

    Two main events have dominated Nirex's recent history: the Radioactive Waste Review and the Company's plans to build a Rock Characterisation facility at its investigation site near Sellafield in Cumbria. The outcome of the former was announced in a White Paper in July 1995. Decisions on the RCF are subject to a public inquiry starting in September 1995. Given a successful result and confirmation that the site could meet the safety target, a deep repository for intermediate and some low level waste could be available by 2011 or thereabouts. As financing of Nirex's activities is in line with the ''polluter pays'' principle, the Company is aiming to deliver a cost-effective disposal system which complies fully with the stringent safety requirements placed on it. (author)

  6. α-particle radioactivity of hot particles from the Esk estuary

    International Nuclear Information System (INIS)

    Hamilton, E.I.

    1981-01-01

    Transuranium radionuclides (Pu, Am and Cm) present in effluents discharged into the north-east Irish Sea by British Nuclear Fuels Limited, Windscale, Cumbria, UK, are found in sediment and biota of the Esk estuary approximately 10 km to the south. The site of the present investigation was at Newbiggin and the materials examined were suspended particulate debris samples at the sea surface, bottom sediments and some forms of biota collected in September 1977. It is shown here that hot particles (defined as small volumes of material emitting α particles recorded in a dielectric detector as dense clusters of tracks from a common origin) found in the estuary are likely to be original effluent debris derived from the processing of Magnox uranium fuel elements and not formed in situ as a result of natural processes common to the estuary. (author)

  7. Extraction and characterisation of aqueous organic acids from natural waters

    International Nuclear Information System (INIS)

    Smith, B.; Moody, P.M.; Higgo, J.J.W.

    1993-01-01

    Humic and fulvic acids were extracted from large volumes of groundwater associated with the Broubster and Needle's Eye natural analogue sites, and the BGS research site at Drigg in Cumbria. Extractions were performed by both batchwise extraction and radial flow chromatography using DEAE-cellulose. Retained humic substances were eluted using NaOH and separated into humic and fulvic components by acidification to pH 1. After separation the humic component was purified by repetitive precipitation and dissolution whilst the fulvic component was purified by absorption chromatography. The resulting humic substances were shown to be of high purity with respect to metallic elements, with less than 1% of available sites being occupied. During elution the association of trace elements with humic substances was monitored and a high degree of association between humic substances, U and the Rare Earth Elements was noted. (author)

  8. Child leukaemia around Sellafield: local community attitudes and the Black Report

    International Nuclear Information System (INIS)

    Macgill, S.M.; Berhout, F.G.

    1985-12-01

    The purpose of this paper is to evaluate the relevance of the Black Report to the communities whose situation it was primarily addressing - the communities of the towns and villages around Sellafield in West Cumbria. The authors are concerned (1) with examining in what ways and to what extent the Black Report was received by these communities, (2) with examining the extent to which these communities were reassured by the report's message (and, prior to that, in need of reassurance); and, (3) with revealing and examining the terms in which local people themselves speak about the report and related issues. Through a comprehensive linguistic analysis of these aspects the authors are concerned, inter alia, to recast the research priorities and methodology of work on risk 'perception'. The analysis and evaluation below draws on an original local attitude survey and is set against a number of contextual points. (author)

  9. Nuclear fuel reprocessing in the UK

    International Nuclear Information System (INIS)

    Allardice, R.; Harris, D.; Mills, A.

    1983-01-01

    Nuclear fuel reprocessing has been carried out on an industrial scale in the United Kingdom since 1952. Two large reprocessing plants have been constructed and operated at Windscale, Cumbria and two smaller specialized plants have been constructed and operated at Dounreay, Northern Scotland. At the present time, the second of the two Windscale plants is operating, and Government permission has been given for a third reprocessing plant to be built on that site. At Dounreay, one of the plants is operating in its original form, whilst the second is now operating in a modified form, reprocessing fuel from the prototype fast reactor. This chapter describes the development of nuclear fuel reprocessing in the UK, commencing with the research carried out in Canada immediately after the Second World War. A general explanation of the techniques of nuclear fuel reprocessing and of the equipment used is given. This is followed by a detailed description of the plants and processes installed and operated in the UK

  10. The role of the national low level waste repository operator in delivering new solutions for the management of low level wastes in the UK - 16217

    International Nuclear Information System (INIS)

    Walkingshaw, Martin

    2009-01-01

    The UK National Low Level Waste Repository (LLWR) is located near to the village of Drigg in West Cumbria. It is the principal site for disposal of solid Low Level Radioactive Waste (LLW) in the United Kingdom. This paper describes the program of work currently being undertaken by the site's operators, (LLW Repository Ltd and its newly appointed Parent Body Organisation), to extend the life of the LLWR and reduce the overall cost of LLW management to the UK taxpayer. The current focus of this program is to prevent disposal capacity being taken up at LLWR by waste types which lend themselves to alternative treatment and/or disposition routes. The chosen approach enables consignors to segregate LLW at source into formats which allow further treatment for volume reduction or, (for wastes with lower levels of activity), consignment in the future to alternative disposal facilities. Segregated waste services are incorporated into LLW Disposal commercial agreements between the LLWR operator and waste consignors. (author)

  11. A dynamic compartmental food chain model of radiocaesium transfer to Apodemus sylvaticus in woodland ecosystems

    International Nuclear Information System (INIS)

    Toal, M.E.; Copplestone, D.; Johnson, M.S.; Jackson, D.; Jones, S.R.

    2001-01-01

    A study was undertaken to quantify the activity concentrations of 137Cs in Apodemus sylvaticus (the woodmouse) in two woodland sites, Lady Wood and Longrigg Wood, adjacent to British Nuclear Fuels Ltd. (BNFL) Sellafield, Cumbria, UK. A deterministic dynamic compartmental food chain model was also constructed to predict 137Cs activity concentration [Bq kg -1 dry weight (dw)] in A. sylvaticus on a seasonal basis given the activity concentrations in its diet. Within the coniferous woodland site (Lady Wood), significant differences were found between seasons (P x / 2.3 Bq kg -1 dw) being attributed to mycophagy. Fungal concentrations ranged from 2-3213 Bq kg -1 dw. The modelled activity concentrations fell between the confidence intervals of the observed data in four of the six seasonal cohorts sampled. Disparities between predicted and observed activity concentrations are attributed to uncertainties surrounding the fundamental feeding ecology of small mammals

  12. Child leukaemia around Sellafield: local community attitudes and the Black Report

    Energy Technology Data Exchange (ETDEWEB)

    Macgill, S M; Berhout, F G

    1985-01-01

    The purpose of this paper is to evaluate the relevance of the Black Report to the communities whose situation it was primarily addressing - the communities of the towns and villages around Sellafield in West Cumbria. The authors are concerned (1) with examining in what ways and to what extent the Black Report was received by these communities, (2) with examining the extent to which these communities were reassured by the report's message (and, prior to that, in need of reassurance); and, (3) with revealing and examining the terms in which local people themselves speak about the report and related issues. Through a comprehensive linguistic analysis of these aspects the authors are concerned, inter alia, to recast the research priorities and methodology of work on risk 'perception'. The analysis and evaluation draws on an original local attitude survey and is set against a number of contextual points.

  13. Childhood cancer and nuclear installations: a review

    International Nuclear Information System (INIS)

    Muirhead, C.R.

    1998-01-01

    Many epidemiological studies of childhood cancer around nuclear installations have been conducted in recent years. This article reviews results from Great Britain and elsewhere. Geographical studies have indicated raised risks of childhood leukaemia around some British nuclear installations. However, environmental assessments suggest that the findings are unlikely to be due to radioactive releases from the sites. Case-control studies have allowed more detailed investigation of putative risk factors than is possible from geographical studies. In particular, a recent national study in Britain does not support the hypothesis raised by an earlier study in West Cumbria that paternal radiation exposure prior to conception may increase the risk of leukaemia and non-Hodgkin's lymphoma in offspring. Other studies suggest that childhood leukaemia may have an infective basis, although there is still uncertainty about whether this would explain the findings around nuclear installations. The UK Childhood Cancer Study may provide more information on the causes of these diseases. (author)

  14. A laboratory and field study of 210Po depuration by edible winkles (Littorina littorea L.) from the Cumbrian coast (north-eastern Irish Sea)

    International Nuclear Information System (INIS)

    Swift, D.J.; Smith, D.L.; Allington, D.J.; Winpenny, K.

    1995-01-01

    Edible winkles from Saltom Bay, Cumbria (north-eastern Irish Sea) had flesh 210 Po concentrations in excess of 200 Bq kg -1 (wet). This came from liquid waste discharged under authorisation from a chemical plant producing phosphoric acid. This labelling of the winkles under natural conditions was exploited to determine the 210 Po depuration rate and biological half-time. Winkles transferred to Lowestoft and depurated in flowing seawater had biological half-times ranging from 82 to 119 days depending on temperature. After the chemical plant was shut, changes in Saltom Bay winkle flesh contents of 210 Po, 210 Pb and cadmium were followed by monthly samples. The biological half-time in the environment for the decrease in 210 Po after the plant closed was estimated at about 92 days. (author)

  15. Plutonium in autopsy tissues in Great Britain

    International Nuclear Information System (INIS)

    Popplewell, D.S.; Ham, G.J.; Johnson, T.E.; Barry, S.F.

    1985-01-01

    From time to time the authors have measured the Pu content of tissues taken at autopsy from people who had worked in the Pu-processing industries including some from Sellafield Works in Cumbria. During the work it became apparent that the results would be more enlightening if they could be compared with the levels of Pu in people who had not worked in the nuclear energy industries. With the objective of making this comparison, the authors commenced a series of Pu analyses on tissues removed at autopsy from members of the general public, who might be expected to have received their body deposits of Pu from fallout from atmospheric nuclear weapons explosions. This note augments some results reported previously in summary form

  16. Radioactive waste disposal at Sellafield, UK: site selection, geological and engineering problems

    International Nuclear Information System (INIS)

    Haszeldine, R.S.; Smythe, D.K.

    1996-01-01

    UK Nirex is the company charged with finding a suitable site for the underground disposal of radioactive waste in the United Kingdom. Since 1991, Nirex has concentrated its investigation work at a site owned by British Nuclear Fuels Ltd near Sellafield. Planning permission was sought in 1994 for the development of an underground Rock Characterisation Facility at the site. A public Planning Inquiry began in September 1995. A wide range of scientific and technical objections were put by expert witnesses against the Nirex proposal. These witnesses were co-ordinated by three Objecting Organisations - Cumbria County Council, Friends of the Earth and Greenpeace. Their written evidence is presented in the 34 chapters of this book and separate abstracts have been written for each contribution. (UK)

  17. Studies on selected organic-metal interactions of importance in the environment

    International Nuclear Information System (INIS)

    Mason, Ian.

    1995-10-01

    This research project investigated the interaction between natural organics acids and selected metal ions. The aims of the project was to provide quantitative data on the speciation of metal ions when placed in systems containing natural organic acids. It was envisaged that such data will assist in the risk assessment of the Drigg low level waste site in Cumbria. The formation and complexing ability of these natural organic acids is discussed and the classing of these acids into high molecular weight organic acids and low molecular weight organic acids. Initial investigations used a potentiometric technique to study the interaction between nickel and europium and selected low molecular weight organic acids which were thought to occur in significant concentrations in soils and groundwaters. These experiments confirmed existing critically assessed literature values, and provided an experimental methodology for further 'in-house' measurement of such values. In addition, studies were also performed on systems containing two competing organic acids. (author)

  18. Annual report and accounts 1988/89

    International Nuclear Information System (INIS)

    1989-01-01

    British Nuclear Fuel's (plc) (BNFL) operations over the year 1988/9 are reviewed. The financial position is presented and the accounts explained. These show that the year was one of growth. BNFL manufactures nuclear fuel and fuel products at Springfields near Preston, enriches uranium by a centrifuge process at Capenhurst near Chester, reprocesses and manages waste at Sellafield in West Cumbria and has a headquarters and engineering design facility at Risley near Warrington. BNFL also owns and operates two nuclear power stations at Calder Hall on the Sellafield site and at Chapelcross in Southern Scotland. Each aspect of the company's activities is reviewed briefly and an overview given in reports of the Chairman and Chief Executive. Over 90% of BNFL's turnover is associated with the production of electricity by nuclear power. The government's decision to withdraw the nuclear power stations from the privatisation of the electricity supply industry has created uncertainty over the long-term position of BNFL. (UK)

  19. Annual report 1989 1990

    International Nuclear Information System (INIS)

    1991-01-01

    The Company's task is to develop a deep underground disposal site for low and intermediate-level radioactive wastes. The work described in this Report follows on from the announcement by the Government that it accepted the Company's recommendation to investigate the potential of the two sites at Dounreay in Caithness and Sellafield in Cumbria for a deep underground radioactive waste repository. The work of the Company has, therefore, focused on these two areas to ensure that a full understanding of their potential is obtained. In assessing this potential, full account will be taken of comprehensive research which is being carried out both nationally and internationally. The progress made in the year is set out in the Report. The work is set out in chapters which summarize the years events, then look at the deep repository programme, disposal safety research and development, inventing packaging and transport and the public information programme. The directors report and accounts are also included. (author)

  20. Annual report 1988-1989

    International Nuclear Information System (INIS)

    1989-01-01

    The report for 1988/89 records the development of the British programme which is intended to bring a deep disposal site for low and intermediate level radioactive wastes into commercial operation in the early years of the next century. Following two years of intensive research, design development, analysis of suitable environments, and public discussion by the Company, the Government accepted our recommendation that sites at Sellafield in Cumbria and Dounreay in Caithness should be given priority over others to see if one or the other is suitable on detailed analysis for the siting of a deep repository. Both sites, with others, had shown up well in the sifting of a short-list of possible sites. They had the merit of being in areas where there is already some measure of local support for nuclear operations, and they should be fully evaluated before further consideration of the other possibilities. (author)

  1. The in vivo measurement of radiocaesium activity in lambs

    International Nuclear Information System (INIS)

    Sherlock, J.C.; Andrews, D.; Dunderdale, J.; Shaw, P.; Lally, A.

    1988-01-01

    Contamination of certain areas of the UK with radiocaesium from the Chernobyl accident led to restrictions being placed on the movement of lambs in these areas. To determine whether part of an area met the criteria for derestriction required the laboratory monitoring of meat from lambs sacrificed for the purpose. This was a slow process because there was no means of knowing which parts of an area had the lowest activity levels in lambs, that is where the chances of removing restrictions were the greatest. A rapid, simple and cheap method for the in vivo monitoring of caesium activity in lambs was developed. Correlation between the results from this method and in-laboratory measurements was reasonable. The method was used successfully to monitor lambs in Cumbria and north Wales during July and August 1986. (author)

  2. Steel construction in the nuclear reprocessing industry

    International Nuclear Information System (INIS)

    Jordan, G.W.

    1990-01-01

    Over the past decade British Nuclear Fuels plc (BNFL) has pursued a large capital expenditure programme at Sellafield in Cumbria. This has used large quantities of structural steelwork. For example, Thorp plant for reprocessing spend AGR and LWR fuels, due for completion in 1992, has 20,000 tonnes. The design of these plants has been entrusted to BNFL Engineering based at Risley near Warrington, England. These safety-related structures are designed, as required by the Nuclear Installations Inspectorate, to withstand the effects of environmental hazards such as extremes of earthquake, wind, temperature, ice, snow, flooding, and lightning strikes. In some cases they may be subjected to impact loading from possible mishandling of lifted loads such as fuel transportation flasks. Design criteria for these structures have been developed by BNFL Engineering. Some examples are mentioned. (author)

  3. Use of the Cumbrian coastal area

    International Nuclear Information System (INIS)

    1991-12-01

    The primary objective of the research was to establish the recreational usage made of the Cumbrian coastal area. Observations of the numbers of adults and children in each area included in the study were undertaken, as well as an interview survey among adults which identified patterns of use by different groups. The interview survey comprised 7070 interviews, 80% of which were with residents of, rather than visitors to, Cumbria. Additional investigations and analyses were conducted to: determine hours of occupancy at coastal areas; observe usage made of particular areas outside the locations and times of the main survey; assess the usage made of coastal areas and inland waterways by members of the public likely to be excluded from the main study (eg. bird watchers, water-sport participants). (author)

  4. Monte Carlo calculations of the neutron coincidence gate utilisation factor for passive neutron coincidence counting

    CERN Document Server

    Bourva, L C A

    1999-01-01

    The general purpose neutron-photon-electron Monte Carlo N-Particle code, MCNP sup T sup M , has been used to simulate the neutronic characteristics of the on-site laboratory passive neutron coincidence counter to be installed, under Euratom Safeguards Directorate supervision, at the Sellafield reprocessing plant in Cumbria, UK. This detector is part of a series of nondestructive assay instruments to be installed for the accurate determination of the plutonium content of nuclear materials. The present work focuses on one aspect of this task, namely, the accurate calculation of the coincidence gate utilisation factor. This parameter is an important term in the interpretative model used to analyse the passive neutron coincidence count data acquired using pulse train deconvolution electronics based on the shift register technique. It accounts for the limited proportion of neutrons detected within the time interval for which the electronics gate is open. The Monte Carlo code MCF, presented in this work, represents...

  5. The battle of Britain's nuclear dustbin

    International Nuclear Information System (INIS)

    Webb, Jeremy.

    1993-01-01

    A political row is brewing about the government's Nuclear Industry Radioactive Waste Executive's (NIREX's) plans to excavate a deep-level radioactive waste repository beneath the Sellafield plant in Cumbria. Following concerns over the deterioration of the packaging of radioactive waste at some sites in the United Kingdom, ministers are being urged to approve the plan. The repository, which will house low-level and intermediate-level waste is opposed by the Treasury on economic grounds and by Friends of the Earth as being unnecessary, and of dubious safety. Government ministers will have to work closely with the Nuclear Installations Inspectorate and other interested parties to formulate a workable policy for this repository in particular, as well as for nuclear waste management and decommissioning generally. (UK)

  6. Chernobyl derived activity in sheep: variation within a single flock and with time

    International Nuclear Information System (INIS)

    Walters, B.

    1988-01-01

    The continuous monitoring of the caesium contents of sheep grazing a high fell in Cumbria, UK, is described. The technique of in-vivo monitoring, using portable NaI crystal detectors, is shown to be robust and capable of producing accurate quantitative data. Results are presented from the monitoring of 100 sheep at fortnightly intervals over a period of 13 weeks. The peak average activity (1300 Bq kg -1 ) was reached five weeks after introduction of the sheep to grazing land with up to 2000 Bq kg -1 in herbage. Activity had fallen, on average, to 68% of the peak value after eight weeks. The variation in activity between individual sheep is large and usually symmetrically distributed. The temporal trend of activity in the whole flock is a combination of the many disparate individual trends. The technique has allowed the variation between animals and individual time trends to be followed. (author)

  7. Radioactivity in surface and coastal waters of the British Isles, 1982

    International Nuclear Information System (INIS)

    Hunt, G.J.

    1984-01-01

    The subject is covered in sections, entitled: introduction: discharges of [liquid, solid] radioactive waste; methods of analysis and of presentation and interpretation of results; British Nuclear Fuels plc (BNFL) Sellafield, Cumbria (the fish and shellfish consumption pathway; external exposure; porphyra/ laverbread pathway; other surveys); Springfields, Lancashire; Capenhurst, Cheshire; Chapelcross, Dumfriesshire); United Kingdom Atomic Energy Authority (Atomic Energy Establishment, Winfrith, Dorset; Dounreay Nuclear Power Development Establish-ment, Caithness); nuclear power stations operated by the electricity boards (Berkeley, Gloucestershire and Oldbury, Avon; Bradwell, Essex; Dungeness, Kent; Hartlepool, Cleveland; Heysham, Lancashire; Hinkley Point, Somerset; Hunterston, Ayrshire; Sizewell, Suffolk; Trawsfynydd, Gwynedd; Wylfa, Gwynedd; naval establishments; Amersham International plc; Channel Islands monitoring; summary and conclusions. (U.K.)

  8. The MOX Demonstration Facility - the stepping stone to commercial MOX production

    International Nuclear Information System (INIS)

    Macdonald, A.G.

    1994-01-01

    The paper provides an insight into MOX fuel and the economic benefits of its use in pressurized water reactors (PWRs). BNFL and AEA are collaborating in the design, construction and operation of a thermal MOX Demonstration Facility (MDF) on the AEA Windscale site in Cumbria. The process flowsheet and equipment employed in MDF are discussed and the special precautions required to handle plutonium bearing materials are highlighted. The process flowsheet includes the short binderless route which has been specially developed for use in MDF and results in fuel pellets with an homogeneous structure. MDF is the forerunner to the design and construction of a larger scale Sellafield MOX Plant and hence is the stepping-stone to commercial MOX production. (author)

  9. Communicating risk: news media reportage of a significant nuclear contamination incident in the UK

    International Nuclear Information System (INIS)

    Walker, G.P.; Macgill, S.M.

    1988-02-01

    The way the mass media reported a controversial discharge incident at British Nuclear Fuel's reprocessing plant at Sellafield in Cumbria in November 1983 is discussed. Apart from the Windscale fire in 1957 this was the most serious radiation incident at any nuclear installation in the United Kingdom. The aim of the study was to use that incident to develop a more complete understanding of the way information about risk is communicated through the news media. Two issues, in particular, are assessed. First, the accuracy of the reports of events and how factual, technical or scientific aspects of risk are portrayed through the news media. Secondly, risk evaluation is studied: what value judgements are made, what sentiments of alarm, danger and hazard are presented. (author)

  10. Strengthening Technical Specialist Training for an Expanding Nuclear Power Programme in the UK

    International Nuclear Information System (INIS)

    Robertson, John L.

    2014-01-01

    NTSTS: Future Plans: • Introduce new pathway in Nuclear Reactor Operations into FD/BEng (Plant Engineering) programmes. • Outline curriculum based on INPOs Nuclear Uniform Curriculum for Power Plant Technician, Maintenance and Non-licensed Operations Personnel. • Procurement of generic Pressurised Water Reactor Simulation Suite – due for delivery/commissioning by Sep 2014 • Gen 2 has established a partnership with Tecnatom SA of Spain – experienced in operator training for PWR and BWR. • Proposals to establish a bespoke Reactor Operations Training Centre (ROTC) close to NuGen’s planned AP1000 new build at Moorside, West Cumbria. • In longer term, ROTC could house full scope AP1000 simulator for licensed operator training

  11. The biological transport of radionuclides in grassland and freshwater ecosystems

    International Nuclear Information System (INIS)

    Rudge, S.A.

    1989-12-01

    This thesis examines the biological transport of radionuclides through terrestrial and aquatic ecosystems, with particular reference to radiocaesium. The semi-natural grassland habitat was located at Drigg, W. Cumbria, contaminated primarily by radioactive fallout, from several sources over the past decade. Advantage was made of the deposition of radionuclides from the Chernobyl reactor incident, which occurred during the early stages of the investigation. The study examined the distribution of radiocaesium for the major components of the grassland ecosystem, within the soil-plant-invertebrate-small mammal food chain. Data concerning temporal fluctuation of radionuclide transfer factors between food chain components are presented. The final section examines the spatial distribution of radiocaesium in sediment and the freshwater eel (Anguilla anguilla) in a small stream contaminated by radioactive effluent. The relationship between activity levels in eels and the sediments in which they rest and forage was investigated. Factors influencing uptake of radiocaesium in freshwater fish were also examined. (author)

  12. The Windscale experiment

    International Nuclear Information System (INIS)

    Blackith, Robert

    1984-01-01

    The discharge of radioactive waste into the Irish Sea from the Windscale reprocessing plant in Cumbria is discussed from an Irish viewpoint. A history of accidents at the plant is reviewed, and past, present and future levels of discharge to the environment are outlined. The effect on the Irish population of discharges to the marine environment is evaluated by consideration of the food chain and the exposure pathways to man, in particular the concentration of radioactive caesium and plutonium in the flesh of fish in the Irish Sea. The general health effects attributed to radiation exposures are given, and a cluster of Downs Syndrome babies born to mothers who were at the same school in Co. Louth is attributed to increased exposure during the 1957 fire at the Windscale plant. The author concludes that, because of military implications and the need for plutonium for nulcear weapons, the reprocessing plant will continue to operate, but with greatly reduced levels of discharges permitted

  13. Windscale experiment. A study of Windscale's pollution of the Irish Sea

    Energy Technology Data Exchange (ETDEWEB)

    Blackith, R

    1984-01-01

    The discharge of radioactive waste into the Irish Sea from the Windscale reprocessing plant in Cumbria is discussed from an Irish viewpoint. A history of accidents at the plant is reviewed, and past, present and future levels of discharge to the environment are outlined. The effect on the Irish population of discharges to the marine environment is evaluated by consideration of the food chain and the exposure pathways to man, in particular the concentration of radioactive caesium and plutonium in the flesh of fish in the Irish Sea. The general health effects attributed to radiation exposures are given, and a cluster of Downs Syndrome babies born to mothers who were at the same school in Co. Louth is attributed to increased exposure during the 1957 fire at the Windscale plant. The author concludes that, because of military implications and the need for plutonium for nulcear weapons, the reprocessing plant will continue to operate, but with greatly reduced levels of discharges permitted.

  14. The origin, composition and distribution of 'hot particles' derived from the nuclear industry and dispersed in the environment

    International Nuclear Information System (INIS)

    Hamilton, E.I.; Clifton, R.J.

    1987-10-01

    Today, recent sediments of the Esk estuary, Cumbria, contain few hot particles derived from BNF compared with those deposited during peak releases of 1972-74. Overall the hot particles account for about 10% of the total alpha particle activity of the sediments. At some horizons, in buried sediments, concentrations of hot particles probably represent rapid transport on the sea surface under conditions of minimum erosion. Similar particles, usually less well defined, occur in accreting sediments but are corroded. Representative types of the most radioactive particles have been isolated and contain Pu, Am and Cm but only trace amounts of naturally occuring alpha emitters. Microprobe analysis of these particles often shows the presence of fairly pure uranium as the major element. On the basis of radioactivity and elemental composition many of these particles appear to be irradiated nuclear fuel debris. (author)

  15. Safety assessment and licensing issues of low level radioactive waste disposal facilities in the United Kingdom

    Energy Technology Data Exchange (ETDEWEB)

    Fearnley, I. G. [British Nuclear Fuels Ltd., Sellafield (United Kingdom)

    1997-12-31

    More than 90% of radioactive waste generated in the United Kingdom is classified as low level and is disposed of in near surface repositories. BNFL owns and operates the principal facility for the disposal of this material at Drigg in West Cumbria. In order to fully optimise the use of the site and effectively manage this `national` resource a full understanding and assessment of the risks associated with the performance of the repository to safely contain the disposed waste must be achieved to support the application for the site authorization for disposal. This paper describes the approaches adopted by BNFL to reviewing these risks by the use of systematic Safety and Engineering Assessments supported in turn by experimental programmes and computations models. (author). 6 refs., 1 tab., 4 figs.

  16. An analysis of leukaemia, lymphoma and other malignancies together with certain categories of non-cancer mortality in the first generation offspring (F1) of the Japanese bomb survivors

    International Nuclear Information System (INIS)

    Little, M.P.; Wakeford, R.; Charles, M.W.

    1994-01-01

    The absence of any significant excess of childhood leukaemia in the offspring of the Japanese bomb survivors has provided strong evidence against a causal interpretation of the association between paternal preconception radiation dose and the incidence of childhood leukaemia in the offspring of employees at the Sellafield nuclear installation, West Cumbria. The use of the Japanese data has, however, been questioned on the basis that leukaemia cases may have been under-recorded in the years immediately following the bombings. In order to investigate possible misdiagnoses of leukaemia cases in the first generation offspring (F 1 ) of the Japanese bomb survivors, analyses have been undertaken of cases of leukaemia, non-Hodgkin's lymphoma (NHL), and all other malignancies, together with deaths due to blood diseases, deaths due to infectious diseases and deaths from unknown causes. (author)

  17. You're not to dance with the girls: oral history, changing perception and practice.

    Science.gov (United States)

    Mee, Steve

    2010-03-01

    The learning disability nursing course at the University of Cumbria features people with a learning disability presenting an oral history of their past in a long-stay institution. These are powerful stories which frequently portray very negative life experiences. Student feedback suggests that the resulting learning is profound, possibly transformative and offering a different type of learning to a 'traditional' lesson. Students report that they experience different and more positive perceptions of people with a learning disability. They have a new respect for people who have survived these experiences. This change of perception may, in part, be due to observing people with a learning disability in positive roles such as storyteller, teacher and carer. The students reported that in subsequent placements their professional practice changed as a result of these insights. These changes include being more outspoken against bad practice and being able to listen more effectively.

  18. The effect of organics on the sorption of strontium, caesium, iodine, neptunium, uranium and europium by glacial sand

    International Nuclear Information System (INIS)

    Haigh, D.; Higgo, J.J.W.; Williams, G.M.; Hooker, P.J.; Ross, C.A.M.; Falck, W.E.; Allen, M.A.; Warwick, P.

    1991-01-01

    This study has been undertaken within the Commission of the European Communities MIRAGE II program on the determination of radionuclides in the geosphere. Preliminary batch sorption experiments have been carried out to study the behaviour of strontium, caesium, iodine, europium and uranium in a glacial sand-groundwater system. The effect of (i) the presence or absence of natural organic material and (ii) the addition of increasing quantities of EDTA or acetate on the distribution ratios was determined. In some cases speciation modelling was used as an aid to designing the experiments and interpreting the results. The aim of this work was to select suitable tracers for use in field experiments at Drigg. Cumbria and the results are intended to aid the design of future experiments rather than to provide a complete analysis of the radionuclide-organic interactions. 11 tabs., 49 refs

  19. Currents in the Eastern Irish Sea

    International Nuclear Information System (INIS)

    Howarth, M.J.

    1983-01-01

    Low level radioactive waste is discharged from the nuclear re-processing plant at Sellafield, Cumbria. Its movement away from the discharge point is determined by the Irish Sea's dynamics, both for the soluble compounds and for those compounds which become attached to the sediment. Near Sellafield the tidal currents are weak and parallel to the shore, becoming stronger east/west to the north and south of the Isle of Man. Wind driven currents near Sellafield are predominantly north-westward, strongest near the coast, and oppose the other low frequency currents. Hence, the soluble effluent will initially be dispersed parallel to the shore by the weak tidal currents, moving episodically, southeastward during weak winds and northwestward during storms. Eventually it will leave the Irish Sea, flowing northward through the North Channel. (author)

  20. Distribution of radioactivity in the Esk Estuary and its relationship to sedimentary processes

    International Nuclear Information System (INIS)

    Kelly, M.; Emptage, M.

    1992-01-01

    In the Esk Estuary, Cumbria, the distribution of sediment lithology and facies has been determined and related to radionuclide surface and sub-surface distribution. The total volume of sediment contaminated with artificial radionuclides is estimated at 1.2 Mm 3 and the inventory of 137 Cs at 4.5 TBq. The fine grained sediments of the bank facies are the main reservoir for radionuclides, comprising 73% of the 137 Cs inventory. Time scales for the reworking of these sediments are estimated at tens to hundreds of years. Measurements of sediment and radionuclide deposition demonstrate that direct sediment deposition is the main method for radionuclide recruitment to the deposits but solution labelling can also occur. Bioturbation and other diagenetic processes modify the distribution of radionuclides in the deposits. Gamma dose rates in air can be related to the sediment grain size and sedimentation rate. (Author)

  1. Successful public relations for a better public acceptance - a case study on Sellafield

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, C. [British Nuclear Fuels plc, Risley (United Kingdom); Prestwood, J. [British Nuclear Fuels plc, Sellafield (United Kingdom)

    1998-12-31

    The Sellafield story is not unique but it can be used as one example of what can be achieved in a community close to a nuclear site. Over the past 12 years BNFL staff at Sellafield have worked diligently to win public acceptance in the local community around Sellafield. It has been an excellent example of teamwork, involving the workforce and the local community. It has taken a great deal of effort and finance and painstaking attention to even the most trivial issues to gain the publics` trust. Today, Sellafield and its activities underpin the economy of West Cumbria. The site employs just under 7000 people directly with a further 1500 in contracting roles.

  2. HSE investigation of leukaemia and other cancers in the children of male workers at Sellafield

    International Nuclear Information System (INIS)

    1994-01-01

    This report presents two findings of the U.K. Health and Safety Executive study group responsible for examining the conclusions of the Gardner Report that ''the raised incidence of leukaemia particularly, and non-Hodgkin's lymphoma, among children near Sellafield was associated with paternal employment and recorded external dose of whole body penetrating radiation during work at the plant before conception''. The HSE report is divided into three:- the Case-only study and the Radiation Dose study, concerned with the 11 case fathers who had worked at Sellafield. The third part, the Case-control study, is an epidemiological study which seeks to identify all cancer cases diagnosed before the age of 25, where the children concerned had been born in West Cumbria to fathers who were Sellafield employees. The search included the whole country from January 1980 to September 1989. (UK)

  3. Safety assessment and licensing issues of low level radioactive waste disposal facilities in the United Kingdom

    International Nuclear Information System (INIS)

    Fearnley, I. G.

    1997-01-01

    More than 90% of radioactive waste generated in the United Kingdom is classified as low level and is disposed of in near surface repositories. BNFL owns and operates the principal facility for the disposal of this material at Drigg in West Cumbria. In order to fully optimise the use of the site and effectively manage this 'national' resource a full understanding and assessment of the risks associated with the performance of the repository to safely contain the disposed waste must be achieved to support the application for the site authorization for disposal. This paper describes the approaches adopted by BNFL to reviewing these risks by the use of systematic Safety and Engineering Assessments supported in turn by experimental programmes and computations models. (author). 6 refs., 1 tab., 4 figs

  4. Radiocaesium variability in upland sheep flocks

    Energy Technology Data Exchange (ETDEWEB)

    Beresford, N.A

    2002-07-01

    Following the 1986 Chernobyl accident large areas of uplands in the United Kingdom were contaminated by radiocaesium. Consequently, the level of radiocaesium in the tissues of some sheep exceeded 1000 Bq kg{sup -1} fresh weight This is the limit adopted within the UK above which meat cannot enter the food chain. In 1986, restrictions were placed on the movement and slaughter of sheep in areas of west Cumbria, north Wales and Scotland. Whilst the number of farms under restriction has reduced considerably, some still remain restricted in 2002. Although a number of workers had noted considerable variability between the radiocaesium activities of individuals within sheep flocks there had been no analyses of causal effects. The work described here, combined studies on three upland farms within west Cumbria with controlled feeding experiments, to systematically assess the parameters which may contribute to such variability. Results from all three farms demonstrate a temporally consistent ranking of the {sup 137}Cs activity concentration of individual sheep within the study flocks. As there was also a correlation between the {sup 137}Cs activity concentration of ewes and their pre-weaned lambs it is likely that the same ewes are producing lambs in excess of the intervention limit in subsequent years. It is difficult to generalise as to which factors will contribute to {sup 137}Cs variability within a given upland flock; factors contributing to variation were not consistent between the study farms. However, the location grazed and/or vegetation selected by animals was a causal factor to the observed variability at all three farms. The transfer of radiocaesium from the diet to muscle of sheep was found to be determined by live-weight change and dry matter intake. Subsequent studies have suggested that protein turnover may be a potential mechanism for the relationship between dry matter intake and radiocaesium transfer. This hypothesis is supported by current understanding

  5. UK regulatory standards - the 'Guidance on requirements for authorisation'

    International Nuclear Information System (INIS)

    Williams, C.R.

    1999-01-01

    In the United Kingdom, disposal of radioactive waste requires an authorisation under the Radioactive Substances Act 1993. The power to grant such authorisations rests with the Environment Agency for disposals in England and Wales, and with similar Agencies in Scotland and Northern Ireland - namely the Scottish Environment Protection Agency (SEPA) and the Environment and Heritage Service (EHS) of the Department of the Environment for Northern Ireland. In 1997, following two rounds of consultation, the Environment Agency jointly with SEPA and EHS published a document 'Disposal Facilities on Land for Low and Intermediate Level Radioactive Wastes: Guidance on Requirements for Authorisation' - the GRA document. The GRA document outlines the regulatory framework governing the disposal of radioactive waste, general guidance on procedures, the principles and criteria against which proposals for a disposal facility will be assessed, and the radiological and technical requirements which a facility will be expected to meet. In particular, the document states that, in the period after control is withdrawn, the assessed radiological risk from a facility to a representative member of the potentially exposed group at greatest risk should be consistent with a risk target of 10 -6 per year. The document also specifies the information which a developer will need to provide, to demonstrate that a proposal is consistent with the principles and requirements, and identifies other, non-risk-based, criteria. In March 1997, the Secretary of State for the Environment rejected a planning appeal by United Kingdom Nirex Ltd for an underground Rock Characterisation Facility located near Sellafield in Cumbria. That decision has effectively delayed the construction of any deep repository in the UK. Subsequently a House of Lords Select Committee has commenced a major review of nuclear waste management. The Environment Agency continues to be responsible for the authorisation of the shallow

  6. Radiocaesium variability in upland sheep flocks

    International Nuclear Information System (INIS)

    Beresford, N.A.

    2002-01-01

    Following the 1986 Chernobyl accident large areas of uplands in the United Kingdom were contaminated by radiocaesium. Consequently, the level of radiocaesium in the tissues of some sheep exceeded 1000 Bq kg -1 fresh weight This is the limit adopted within the UK above which meat cannot enter the food chain. In 1986, restrictions were placed on the movement and slaughter of sheep in areas of west Cumbria, north Wales and Scotland. Whilst the number of farms under restriction has reduced considerably, some still remain restricted in 2002. Although a number of workers had noted considerable variability between the radiocaesium activities of individuals within sheep flocks there had been no analyses of causal effects. The work described here, combined studies on three upland farms within west Cumbria with controlled feeding experiments, to systematically assess the parameters which may contribute to such variability. Results from all three farms demonstrate a temporally consistent ranking of the 137 Cs activity concentration of individual sheep within the study flocks. As there was also a correlation between the 137 Cs activity concentration of ewes and their pre-weaned lambs it is likely that the same ewes are producing lambs in excess of the intervention limit in subsequent years. It is difficult to generalise as to which factors will contribute to 137 Cs variability within a given upland flock; factors contributing to variation were not consistent between the study farms. However, the location grazed and/or vegetation selected by animals was a causal factor to the observed variability at all three farms. The transfer of radiocaesium from the diet to muscle of sheep was found to be determined by live-weight change and dry matter intake. Subsequent studies have suggested that protein turnover may be a potential mechanism for the relationship between dry matter intake and radiocaesium transfer. This hypothesis is supported by current understanding of protein-dry matter

  7. Validation of a physically based catchment model for application in post-closure radiological safety assessments of deep geological repositories for solid radioactive wastes.

    Science.gov (United States)

    Thorne, M C; Degnan, P; Ewen, J; Parkin, G

    2000-12-01

    The physically based river catchment modelling system SHETRAN incorporates components representing water flow, sediment transport and radionuclide transport both in solution and bound to sediments. The system has been applied to simulate hypothetical future catchments in the context of post-closure radiological safety assessments of a potential site for a deep geological disposal facility for intermediate and certain low-level radioactive wastes at Sellafield, west Cumbria. In order to have confidence in the application of SHETRAN for this purpose, various blind validation studies have been undertaken. In earlier studies, the validation was undertaken against uncertainty bounds in model output predictions set by the modelling team on the basis of how well they expected the model to perform. However, validation can also be carried out with bounds set on the basis of how well the model is required to perform in order to constitute a useful assessment tool. Herein, such an assessment-based validation exercise is reported. This exercise related to a field plot experiment conducted at Calder Hollow, west Cumbria, in which the migration of strontium and lanthanum in subsurface Quaternary deposits was studied on a length scale of a few metres. Blind predictions of tracer migration were compared with experimental results using bounds set by a small group of assessment experts independent of the modelling team. Overall, the SHETRAN system performed well, failing only two out of seven of the imposed tests. Furthermore, of the five tests that were not failed, three were positively passed even when a pessimistic view was taken as to how measurement errors should be taken into account. It is concluded that the SHETRAN system, which is still being developed further, is a powerful tool for application in post-closure radiological safety assessments.

  8. Reconstructing historical trends in metal input in heavily-disturbed, contaminated estuaries: studies from Bilbao, Southampton Water and Sicily

    International Nuclear Information System (INIS)

    Cundy, A.B.; Croudace, I.W.; Cearreta, A.; Irabien, M.J.

    2003-01-01

    Estuaries may be important reservoirs for contaminants as they tend to act as sinks for fine, contaminant-reactive sediments, and, historically, they have acted as centres for industrial and urban development. Analysis of dated sediment cores from these areas may allow historical trends in heavy metal input to be reconstructed, and recent and historical inputs of metal contaminants to be compared. Undisturbed saltmarsh settings have been used widely in the reconstruction of historical trends in metal input as saltmarshes provide a stable, vegetated substrate of dominantly fine sediments, and are less prone to erosion and reworking than adjacent mudflat areas. In comparison, much less research on historical pollution trends has been undertaken at estuarine sites which are prone to severe local disturbance, such as intertidal areas which are routinely dredged or where sedimentary processes have been modified by human activities such as shipping, salt working, port activities, land claim etc. This paper assesses the usefulness of 210 Pb and 137 Cs dating, combined with geochemical studies, in reconstructing historical trends in heavy metal input and sediment accretion in 3 heavily-modified, industrialised estuarine areas in Europe: the Bilbao estuary (Spain), Southampton Water (UK), and the Mulinello estuary (Sicily). Of these sites, only a salt marsh core from the Mulinello estuary provides a high-resolution record of recent heavy metal inputs. In Southampton Water only a partial record of changing metal inputs over time is retained due to land-claim and possible early-diagenetic remobilisation, while at Bilbao the vertical distribution of heavy metals in intertidal flats is mainly controlled by input on reworked sediment particles and variations in sediment composition. Where 137 Cs and 210 Pb distributions with depth allow a chronology of sediment deposition to be established, and early-diagenetic remobilisation has been minimal, mudflat and saltmarsh cores from

  9. Sedimentary controls on modern sand grain coat formation

    Science.gov (United States)

    Dowey, Patrick J.; Worden, Richard H.; Utley, James; Hodgson, David M.

    2017-05-01

    Coated sand grains can influence reservoir quality evolution during sandstone diagenesis. Porosity can be reduced and fluid flow restricted where grain coats encroach into pore space. Conversely pore-lining grain coats can restrict the growth of pore-filling quartz cement in deeply buried sandstones, and thus can result in unusually high porosity in deeply buried sandstones. Being able to predict the distribution of coated sand grains within petroleum reservoirs is thus important to help find good reservoir quality. Here we report a modern analogue study of 12 sediment cores from the Anllóns Estuary, Galicia, NW Spain, collected from a range of sub-environments, to help develop an understanding of the occurrence and distribution of coated grains. The cores were described for grain size, bioturbation and sedimentary structures, and then sub-sampled for electron and light microscopy, laser granulometry, and X-ray diffraction analysis. The Anllóns Estuary is sand-dominated with intertidal sand flats and saltmarsh environments at the margins; there is a shallowing/fining-upwards trend in the estuary-fill succession. Grain coats are present in nearly every sample analysed; they are between 1 μm and 100 μm thick and typically lack internal organisation. The extent of grain coat coverage can exceed 25% in some samples with coverage highest in the top 20 cm of cores. Samples from muddy intertidal flat and the muddy saltmarsh environments, close to the margins of the estuary, have the highest coat coverage (mean coat coverage of 20.2% and 21.3%, respectively). The lowest mean coat coverage occurs in the sandy saltmarsh (10.4%), beyond the upper tidal limit and sandy intertidal flat environments (8.4%), close to the main estuary channel. Mean coat coverage correlates with the concentration of clay fraction. The primary controls on the distribution of fine-grained sediment, and therefore grain coat distribution, are primary sediment transport and deposition processes that

  10. Persistence of bacterial pathogens, antibiotic resistance genes, and enterococci in tidal creek tributaries.

    Science.gov (United States)

    Jones, Chance E; Maddox, Anthony; Hurley, Dorset; Barkovskii, Andrei L

    2018-05-19

    Intertidal creeks form the primary hydrologic link between estuaries and land-based activities on barrier islands. Fecal indicators Enterococcus spp. (Entero1), pathogens Shigella spp. (ipaH), Salmonella spp. (invA), E. coli of EHEC/EPEC groups (eaeA), E. coli of EAEC, EIEC, and UPEC groups (set1B), E. coli of STEC group (stx1); and tetracycline resistance genes (tet(B), tet(C), tet(D), tet(E), tet(K), tet(Q), tet(W), and tet(X); TRG) were detected in the headwater of Oakdale Creek (Sapelo Island, GA) receiving runoffs from Hog Hammock village. Excavation of drainage ditches around the village caused a high increase in the incidence of the above determinants. Water samples were collected from the headwater, transferred to diffusion chambers, submersed in the headwater, saltmarsh, and mouth of the creek; and the determinants were monitored for 3 winter months. With some exceptions, their persistence decreased in order headwater > saltmarsh > mouth. Genes associated with Enterococcus spp. were the most persistent at all the sites, following in the headwater with determinants for Salmonella spp. and E. coli of EAEC, EIEC, and UPEC groups. In the mouth, the most persistent gene was eaeA indicating EHEC, EPEC, and STEC. Tet(B) and tet(C) persisted the longest in headwater and saltmarsh. No TRG persisted after 11 days in the mouth. Most determinants revealed correlations with temperature and pH, and inverse correlations with dissolved oxygen. Decay rates of the above determinants varied in the range of -0.02 to -0.81/day, and were up to 40 folds higher in the saltmarsh and mouth than in the headwater. Our data demonstrated that water parameters could to some extent predict a general trend in the fate of virulence and antibiotic resistance determinants in tidal creek tributaries but strongly suggested that their persistence in these tributaries cannot be predicted from that of enterococci, or extrapolated from one biological contaminant to another. Copyright

  11. A Mid-Holocene Relative Sea-Level Stack, New Jersey, USA

    Science.gov (United States)

    Horton, B.; Walker, J. S.; Kemp, A.; Shaw, T. J.; Kopp, R. E.

    2017-12-01

    Most high resolution (decimeter- and decadal-scale) relative sea-level (RSL) records using salt-marsh microfossils as a proxy only extend through the Common Era, limiting our understanding of driving mechanisms of RSL change and how sea-level is influenced by changing climate. Records beyond the Common Era are limited by the depth of continuous sequences of salt-marsh peat suitable for high resolution reconstructions, as well as contamination by local processes such as sediment compaction. In contrast, sequences of basal peats have produced compaction-free RSL records through the Holocene, but at a low resolution (meter- and centennial-scale). We devise a new Multi-Proxy Presence/Absence Method (MP2AM) to develop a mid-Holocene RSL stack. We stack a series of 1 m basal peat cores that overlap along a uniform elevational gradient above an incompressible basal sand. We analyzed three sea-level indicators from 14 cores: foraminifera, testate amoebae, and stable carbon isotope geochemistry. To reconstruct RSL, this multi-proxy approach uses the timesaving presence/absence of forams and testates to determine the elevation of the highest occurrence of forams and the lowest occurrence of testates in each basal core. We use stable carbon isotope geochemistry to determine the C3/C4 vegetation boundary in each core. We develop age-depth models for each core using a series of radiocarbon dates. The RSL records from each 1 m basal core are combined to create a stack or, in effect, one long core of salt-marsh material. This method removes the issue of compaction to create a continuous RSL record to address temporal changes and periods of climate and sea-level variability. We reconstruct a southern NJ mid-Holocene RSL record from Edwin B. Forsythe National Wildlife Refuge, where Kemp et al. (2013) completed a 2500 yr RSL record using a foraminifera-based transfer function approach. Preliminary radiocarbon dates suggest the basal sequence is at least 4246-4408 cal yrs BP

  12. Mechanisms and ecological role of carbon transfer within coastal seascapes.

    Science.gov (United States)

    Hyndes, Glenn A; Nagelkerken, Ivan; McLeod, Rebecca J; Connolly, Rod M; Lavery, Paul S; Vanderklift, Mathew A

    2014-02-01

    Worldwide, coastal systems provide some of the most productive habitats, which potentially influence a range of marine and terrestrial ecosystems through the transfer of nutrients and energy. Several reviews have examined aspects of connectivity within coastal seascapes, but the scope of those reviews has been limited to single systems or single vectors. We use the transfer of carbon to examine the processes of connectivity through multiple vectors in multiple ecosystems using four coastal seascapes as case studies. We discuss and compare the main vectors of carbon connecting different ecosystems, and then the natural and human-induced factors that influence the magnitude of effect for those vectors on recipient systems. Vectors of carbon transfer can be grouped into two main categories: detrital particulate organic carbon (POC) and its associated dissolved organic and inorganic carbon (DOC/DIC) that are transported passively; and mobile consumers that transport carbon actively. High proportions of net primary production can be exported over meters to hundreds of kilometers from seagrass beds, algal reefs and mangroves as POC, with its export dependent on wind-generated currents in the first two of these systems and tidal currents for the last. By contrast, saltmarshes export large quantities of DOC through tidal movement, while land run-off plays a critical role in the transport of terrestrial POC and DOC into temperate fjords. Nekton actively transfers carbon across ecosystem boundaries through foraging movements, ontogenetic migrations, or 'trophic relays', into and out of seagrass beds, mangroves or saltmarshes. The magnitude of these vectors is influenced by: the hydrodynamics and geomorphology of the region; the characteristics of the carbon vector, such as their particle size and buoyancy; and for nekton, the extent and frequency of migrations between ecosystems. Through a risk-assessment process, we have identified the most significant human disturbances

  13. Automated Detection of Salt Marsh Platforms : a Topographic Method

    Science.gov (United States)

    Goodwin, G.; Mudd, S. M.; Clubb, F. J.

    2017-12-01

    Monitoring the topographic evolution of coastal marshes is a crucial step toward improving the management of these valuable landscapes under the pressure of relative sea level rise and anthropogenic modification. However, determining their geometrically complex boundaries currently relies on spectral vegetation detection methods or requires labour-intensive field surveys and digitisation.We propose a novel method to reproducibly isolate saltmarsh scarps and platforms from a DEM. Field observations and numerical models show that saltmarshes mature into sub-horizontal platforms delineated by sub-vertical scarps: based on this premise, we identify scarps as lines of local maxima on a slope*relief raster, then fill landmasses from the scarps upward, thus isolating mature marsh platforms. Non-dimensional search parameters allow batch-processing of data without recalibration. We test our method using lidar-derived DEMs of six saltmarshes in England with varying tidal ranges and geometries, for which topographic platforms were manually isolated from tidal flats. Agreement between manual and automatic segregation exceeds 90% for resolutions of 1m, with all but one sites maintaining this performance for resolutions up to 3.5m. For resolutions of 1m, automatically detected platforms are comparable in surface area and elevation distribution to digitised platforms. We also find that our method allows the accurate detection of local bloc failures 3 times larger than the DEM resolution.Detailed inspection reveals that although tidal creeks were digitised as part of the marsh platform, automatic detection classifies them as part of the tidal flat, causing an increase in false negatives and overall platform perimeter. This suggests our method would benefit from a combination with existing creek detection algorithms. Fallen blocs and pioneer zones are inconsistently identified, particularly in macro-tidal marshes, leading to differences between digitisation and the automated method

  14. Radioactivity and wildlife

    International Nuclear Information System (INIS)

    Kennedy, V.H.; Horrill, A.D.; Livens, F.R.

    1990-01-01

    The official assumption is that if levels of radioactivity are safe for humans, they are safe for wildlife too. NCC sponsored a research project by the Institute of Terrestrial Ecology to find out what was known in this field. It appears that the assumption is justified to a certain extent in that mammals are identified as the organisms most vulnerable to the damaging effects of radioactivity. Other general principles are put forward: where there are radioactive discharges to the marine environment, coastal muds and saltmarshes can be particularly contaminated; upland habitats, with low nutrient status and subject to high rainfall, are likely to accumulate radioactivity from atmospheric discharges (e.g. Chernobyl, the wildlife effects of which are reported here). The document concludes that no deleterious effects of radioactivity on wild plants and animals have been detected in the UK, but acknowledges that there are still many gaps in our knowledge of the behaviour of radioisotopes in the natural environment. (UK)

  15. Climate related sea-level variations over the past two millennia.

    Science.gov (United States)

    Kemp, Andrew C; Horton, Benjamin P; Donnelly, Jeffrey P; Mann, Michael E; Vermeer, Martin; Rahmstorf, Stefan

    2011-07-05

    We present new sea-level reconstructions for the past 2100 y based on salt-marsh sedimentary sequences from the US Atlantic coast. The data from North Carolina reveal four phases of persistent sea-level change after correction for glacial isostatic adjustment. Sea level was stable from at least BC 100 until AD 950. Sea level then increased for 400 y at a rate of 0.6 mm/y, followed by a further period of stable, or slightly falling, sea level that persisted until the late 19th century. Since then, sea level has risen at an average rate of 2.1 mm/y, representing the steepest century-scale increase of the past two millennia. This rate was initiated between AD 1865 and 1892. Using an extended semiempirical modeling approach, we show that these sea-level changes are consistent with global temperature for at least the past millennium.

  16. Test of a mosquito eggshell isolation method and subsampling procedure.

    Science.gov (United States)

    Turner, P A; Streever, W J

    1997-03-01

    Production of Aedes vigilax, the common salt-marsh mosquito, can be assessed by determining eggshell densities found in soil. In this study, 14 field-collected eggshell samples were used to test a subsampling technique and compare eggshell counts obtained with a flotation method to those obtained by direct examination of sediment (DES). Relative precision of the subsampling technique was assessed by determining the minimum number of subsamples required to estimate the true mean and confidence interval of a sample at a predetermined confidence level. A regression line was fitted to cube-root transformed eggshell counts obtained from flotation and DES and found to be significant (P eggshells present. Eggshells obtained with the flotation method can be used to predict those from DES using the following equation: DES count = [1.386 x (flotation count)0.33 - 0.01]3.

  17. Review of sediment stabilisation techniques. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-31

    The best sites for tidal power schemes are found in estuaries with high tidal ranges which have complex ecosystems and include a wide and diverse range of habitats. If the tidal power is to be developed, therefore, it is important to determine the likely effect on the environment and any ameliorative measures which may be necessary. One possible change is likely to be the erosion of material from the bed or shoreline of the estuary, and possibly the adjacent coast. This is of particular concern if intertidal sandflats, mudflats and saltmarsh are affected, as these are important wildlife habitats. Moreover, largescale movement of sediments would be undesirable. Results of a desk study of methods of preventing the erosion of sediment deposits in or near an estuary in the conditions that may occur following the construction of a tidal power barrage are presented. (author).

  18. Review of sediment stabilisation techniques

    International Nuclear Information System (INIS)

    1992-01-01

    The best sites for tidal power schemes are found in estuaries with high tidal ranges which have complex ecosystems and include a wide and diverse range of habitats. If the tidal power is to be developed, therefore, it is important to determine the likely effect on the environment and any ameliorative measures which may be necessary. One possible change is likely to be the erosion of material from the bed or shoreline of the estuary, and possibly the adjacent coast. This is of particular concern if intertidal sandflats, mudflats and saltmarsh are affected, as these are important wildlife habitats. Moreover, largescale movement of sediments would be undesirable. Results of a desk study of methods of preventing the erosion of sediment deposits in or near an estuary in the conditions that may occur following the construction of a tidal power barrage are presented. (author)

  19. Modelling Water Level Influence on Habitat Choice and Food Availability for Zostera Feeding Brent Geese Branta bernicla in Non-Tidal Areas

    DEFF Research Database (Denmark)

    Clausen, P.

    2000-01-01

    of water level fluctuations on the habitat use. A second model was developed to estimate the impact of water level on Zostera availability. The first model was successful in demonstrating that fluctuations in water levels had considerable influence on habitat use by the brent geese, i.e. they fed...... on Zostera at low water levels and on saltmarshes during high water levels, particularly so in early spring, and that the switch between habitats occurred within a narrow water level span of ca 30 cm. The second model demonstrated that the switch between habitats could be explained by lowered availability...... of Zostera as water levels increased. By combining the output from the two models, differences between years could partly be explained by differences in Zostera availability in the early spring period (21 March - 25 April), whereas a more complicated situation was detected later in spring (26 April - 31 May...

  20. The effect of reciprocal treatments with ozone and ultraviolet-B radiation on photosynthesis and growth of perennial grass Elymus athericus

    International Nuclear Information System (INIS)

    Staaij, J.W.M. van de; Tonneijck, A.E.G.; Rozema, J.

    1997-01-01

    The impact on plant growth of the simultaneously changing factors of the global climate, rising tropospheric O 3 concentrations and increasing UV-B radiation fluxes, has been tested in a combined glasshouse and growth chamber experiment. The saltmarsh grass species Elymus athericus was sequentially fumigated for two weeks with O 3 and for another two weeks irradiated with UV-B (vv). Exposure to elevated UV-B did not negatively affect photosynthesis or plant growth. Fumigation with O 3 had a depressing effect on net photosynthesis, the number and biomass of flowers, the number of leaves and the number of shoots. O 3 -induced damage only was observed in plants which had been fumigated during the last two weeks of the experiment. Since interactive responses were not observed, results suggest different primary target sites for O 3 and UV-B within the plant

  1. Soil organic matter degradation and enzymatic profiles of intertidal and subaqueous soils

    Science.gov (United States)

    Ferronato, Chiara; Marinari, Sara; Bello, Diana; Vianello, Gilmo; Trasar-Cepeda, Carmen; Vittori Antisari, Livia

    2017-04-01

    The interest on intertidal and subaqueous soils has recently arisen because of the climate changes forecasts. The preservation of these habitats represents an important challenge for the future of humanity, because these systems represent an important global C sink since soil organic matter (SOM) on intertidal and subaqueous soils undergoes very slow degradation rates due to oxygen limitation. Publications on SOM cycle in saltmarshes are very scarce because of the difficulties involved on those studies i.e. the interaction of many abiotic and biotic factors (e.g., redox changes, water and bio-turbation processes, etc) and stressors (e.g., salinity and anoxia). However, saltmarshes constitute an unique natural system to observe the influence of anoxic conditions on SOM degradation, because the tide fluctuations on the soil surface allow the formation of provisionally or permanently submerged soils. With the aim to investigate the quality of SOM in subaqueous soils, triplicates of subaqueous soils (SASs), intertidal soils (ITSs) and terrestrial soils (TESs) were collected in the saltmarshes of the Baiona Lagoon (Northern Italy) and classified according to their pedogenetic horizons. The SOM quality on each soil horizon was investigated by quantifying SOM, total and water-soluble organic carbon (TOC, WSC) and microbial biomass carbon (MBC). Given the contribution of soil enzymes to the degradation of SOM, some enzymatic assays were also performed. Thereafter, soil classification and humus morpho-functional classification were used to join together similar soil profiles to facilitate the description and discussion of results. Soils were ranked as Aquent or Wassent Entisols, with an A/AC/C pedosequence. SOM, TOC and MBC were statistically higher in A than in AC and C horizons. Among the A horizons, ITSs were those showing the highest values for these parameters (11% TOC, 1.6 mg kg-1 MBC, 0.9 mg kg-1 WSC). These results, combined with the morpho-functional classification

  2. A global standard for monitoring coastal wetland vulnerability to accelerated sea-level rise

    Science.gov (United States)

    Webb, Edward L.; Friess, Daniel A.; Krauss, Ken W.; Cahoon, Donald R.; Guntenspergen, Glenn R.; Phelps, Jacob

    2013-01-01

    Sea-level rise threatens coastal salt-marshes and mangrove forests around the world, and a key determinant of coastal wetland vulnerability is whether its surface elevation can keep pace with rising sea level. Globally, a large data gap exists because wetland surface and shallow subsurface processes remain unaccounted for by traditional vulnerability assessments using tide gauges. Moreover, those processes vary substantially across wetlands, so modelling platforms require relevant local data. The low-cost, simple, high-precision rod surface-elevation table–marker horizon (RSET-MH) method fills this critical data gap, can be paired with spatial data sets and modelling and is financially and technically accessible to every country with coastal wetlands. Yet, RSET deployment has been limited to a few regions and purposes. A coordinated expansion of monitoring efforts, including development of regional networks that could support data sharing and collaboration, is crucial to adequately inform coastal climate change adaptation policy at several scales.

  3. Contrasting records of sea-level change in the eastern and western North Atlantic during the last 300 years

    Science.gov (United States)

    Long, A. J.; Barlow, N. L. M.; Gehrels, W. R.; Saher, M. H.; Woodworth, P. L.; Scaife, R. G.; Brain, M. J.; Cahill, N.

    2014-02-01

    We present a new 300-year sea-level reconstruction from a salt marsh on the Isle of Wight (central English Channel, UK) that we compare to other salt-marsh and long tide-gauge records to examine spatial and temporal variability in sea-level change in the North Atlantic. Our new reconstruction identifies an overall rise in relative sea level (RSL) of c. 0.30 m since the start of the eighteenth century at a rate of 0.9±0.3 mm yr. Error-in-variables changepoint analysis indicates that there is no statistically significant deviation from a constant rate within the dataset. The reconstruction is broadly comparable to other tide-gauge and salt-marsh records from the European Atlantic, demonstrating coherence in sea level in this region over the last 150-300 years. In contrast, we identify significant differences in the rate and timing of RSL with records from the east coast of North America. The absence of a strong late 19th/early 20th century RSL acceleration contrasts with that recorded in salt marsh sediments along the eastern USA coastline, in particular in a well-dated and precise sea-level reconstruction from North Carolina. This suggests that this part of the North Carolina sea level record represents a regionally specific sea level acceleration. This is significant because the North Carolina record has been used as if it were globally representative within semi-empirical parameterisations of past and future sea-level change. We conclude that regional-scale differences of sea-level change highlight the value of using several, regionally representative RSL records when calibrating and testing semi-empirical models of sea level against palaeo-records. This is because by using records that potentially over-estimate sea-level rise in the past such models risk over-estimating sea-level rise in the future.

  4. Modeled Sea Level Rise Impacts on Coastal Ecosystems at Six Major Estuaries on Florida’s Gulf Coast: Implications for Adaptation Planning

    Science.gov (United States)

    Birch, Anne P.; Brenner, Jorge; Gordon, Doria R.

    2015-01-01

    The Sea Level Affecting Marshes Model (SLAMM) was applied at six major estuaries along Florida’s Gulf Coast (Pensacola Bay, St. Andrews/Choctawhatchee Bays, Apalachicola Bay, Southern Big Bend, Tampa Bay and Charlotte Harbor) to provide quantitative and spatial information on how coastal ecosystems may change with sea level rise (SLR) and to identify how this information can be used to inform adaption planning. High resolution LiDAR-derived elevation data was utilized under three SLR scenarios: 0.7 m, 1 m and 2 m through the year 2100 and uncertainty analyses were conducted on selected input parameters at three sites. Results indicate that the extent, spatial orientation and relative composition of coastal ecosystems at the study areas may substantially change with SLR. Under the 1 m SLR scenario, total predicted impacts for all study areas indicate that coastal forest (-69,308 ha; -18%), undeveloped dry land (-28,444 ha; -2%) and tidal flat (-25,556 ha; -47%) will likely face the greatest loss in cover by the year 2100. The largest potential gains in cover were predicted for saltmarsh (+32,922 ha; +88%), transitional saltmarsh (+23,645 ha; na) and mangrove forest (+12,583 ha; +40%). The Charlotte Harbor and Tampa Bay study areas were predicted to experience the greatest net loss in coastal wetlands The uncertainty analyses revealed low to moderate changes in results when some numerical SLAMM input parameters were varied highlighting the value of collecting long-term sedimentation, accretion and erosion data to improve SLAMM precision. The changes predicted by SLAMM will affect exposure of adjacent human communities to coastal hazards and ecosystem functions potentially resulting in impacts to property values, infrastructure investment and insurance rates. The results and process presented here can be used as a guide for communities vulnerable to SLR to identify and prioritize adaptation strategies that slow and/or accommodate the changes underway. PMID:26207914

  5. High-resolution tide projections reveal extinction threshold in response to sea-level rise.

    Science.gov (United States)

    Field, Christopher R; Bayard, Trina S; Gjerdrum, Carina; Hill, Jason M; Meiman, Susan; Elphick, Chris S

    2017-05-01

    Sea-level rise will affect coastal species worldwide, but models that aim to predict these effects are typically based on simple measures of sea level that do not capture its inherent complexity, especially variation over timescales shorter than 1 year. Coastal species might be most affected, however, by floods that exceed a critical threshold. The frequency and duration of such floods may be more important to population dynamics than mean measures of sea level. In particular, the potential for changes in the frequency and duration of flooding events to result in nonlinear population responses or biological thresholds merits further research, but may require that models incorporate greater resolution in sea level than is typically used. We created population simulations for a threatened songbird, the saltmarsh sparrow (Ammodramus caudacutus), in a region where sea level is predictable with high accuracy and precision. We show that incorporating the timing of semidiurnal high tide events throughout the breeding season, including how this timing is affected by mean sea-level rise, predicts a reproductive threshold that is likely to cause a rapid demographic shift. This shift is likely to threaten the persistence of saltmarsh sparrows beyond 2060 and could cause extinction as soon as 2035. Neither extinction date nor the population trajectory was sensitive to the emissions scenarios underlying sea-level projections, as most of the population decline occurred before scenarios diverge. Our results suggest that the variation and complexity of climate-driven variables could be important for understanding the potential responses of coastal species to sea-level rise, especially for species that rely on coastal areas for reproduction. © 2016 John Wiley & Sons Ltd.

  6. Modeled Sea Level Rise Impacts on Coastal Ecosystems at Six Major Estuaries on Florida's Gulf Coast: Implications for Adaptation Planning.

    Science.gov (United States)

    Geselbracht, Laura L; Freeman, Kathleen; Birch, Anne P; Brenner, Jorge; Gordon, Doria R

    2015-01-01

    The Sea Level Affecting Marshes Model (SLAMM) was applied at six major estuaries along Florida's Gulf Coast (Pensacola Bay, St. Andrews/Choctawhatchee Bays, Apalachicola Bay, Southern Big Bend, Tampa Bay and Charlotte Harbor) to provide quantitative and spatial information on how coastal ecosystems may change with sea level rise (SLR) and to identify how this information can be used to inform adaption planning. High resolution LiDAR-derived elevation data was utilized under three SLR scenarios: 0.7 m, 1 m and 2 m through the year 2100 and uncertainty analyses were conducted on selected input parameters at three sites. Results indicate that the extent, spatial orientation and relative composition of coastal ecosystems at the study areas may substantially change with SLR. Under the 1 m SLR scenario, total predicted impacts for all study areas indicate that coastal forest (-69,308 ha; -18%), undeveloped dry land (-28,444 ha; -2%) and tidal flat (-25,556 ha; -47%) will likely face the greatest loss in cover by the year 2100. The largest potential gains in cover were predicted for saltmarsh (+32,922 ha; +88%), transitional saltmarsh (+23,645 ha; na) and mangrove forest (+12,583 ha; +40%). The Charlotte Harbor and Tampa Bay study areas were predicted to experience the greatest net loss in coastal wetlands The uncertainty analyses revealed low to moderate changes in results when some numerical SLAMM input parameters were varied highlighting the value of collecting long-term sedimentation, accretion and erosion data to improve SLAMM precision. The changes predicted by SLAMM will affect exposure of adjacent human communities to coastal hazards and ecosystem functions potentially resulting in impacts to property values, infrastructure investment and insurance rates. The results and process presented here can be used as a guide for communities vulnerable to SLR to identify and prioritize adaptation strategies that slow and/or accommodate the changes underway.

  7. Radioactive characterization of leachates and efflorescences in the neighbouring areas of a phosphogypsum disposal site as a preliminary step before its restoration

    International Nuclear Information System (INIS)

    Gázquez, M.J.; Mantero, J.; Mosqueda, F.; Bolívar, J.P.; García-Tenorio, R.

    2014-01-01

    After the recent closure of certain phosphoric acid plants located in the South-West of Spain, it has been decided to restore a big extension (more than six hundred hectares) of salt-marshes, where some million tonnes of phosphogypsum (PG), the main by-product generated by these plants, had been disposed of. This PG is characterized by its content of high activity concentrations of several radionuclides from the uranium series, mainly 226 Ra, 210 Pb, and 210 Po and, to a lesser extent, U-isotopes. The PG disposal area can be considered as a potential source of radionuclides into their nearby environment, through the waters which percolate from them and through the efflorescences formed in their surroundings. For this reason, a detailed radioactive characterization of the mentioned waters and efflorescences has been considered essential for a proper planning of the restoration tasks to be applied in the near future in the zone. To this end, U-isotopes, 234 Th, 230 Th, 226 Ra, 210 Pb and 210 Po activity concentrations have been determined by applying both alpha-particle and gamma-ray spectrometric techniques to selected water and efflorescence aliquots collected in the area. The analysis of the obtained results has enabled to obtain information about the geochemical behaviour in the area of the different radionuclides analyzed; and the conclusion to be drawn that, in the restoration plan under preparation, both the prohibition of outflowing waters from the disposal area to the neighbouring salt-marshes, and the removal of all the efflorescences now disseminated in their surroundings are essential. - Highlights: • A radioactive analysis of efflorescences and leaching water has been carried out. • Water contains very high concentrations of radionuclides from the uranium series. • Efflorescence shows a high activity concentrations of 238 U and 210 Pb. • This information is essential for the future restoration of a phosphogypsum piles

  8. Hydrologic influence on redox dynamics in estuarine environments

    Science.gov (United States)

    Michael, H. A.; Kim, K. H.; Guimond, J. A.; Heiss, J.; Ullman, W. J.; Seyfferth, A.

    2017-12-01

    Redox conditions in coastal aquifers control reactions that impact nutrient cycling, contaminant release, and carbon budgets, with implications for water resources and ecosystem health. Hydrologic changes can shift redox boundaries and inputs of reactants, especially in dynamic coastal systems subject to fluctuations on tidal, lunar, and longer timescales. We present two examples of redox shifts in estuarine systems in Delaware, USA: a beach aquifer and a saltmarsh. Beach aquifers are biogeochemical hot spots due to mixing between fresh groundwater and infiltrating seawater. At Cape Henlopen, DE, geochemical measurements identified reactions in the intertidal aquifer that include cycling of carbon, nitrogen, iron, and sulfur. Measurements and modeling illustrate that redox potential as well as the locations of redox reactions shift on tidal to seasonal timescales and in response to changing beach and aquifer properties, impacting overall rates of reactions such as denitrification that reduces N loads to coastal waters. In the St. Jones National Estuarine Research Reserve, tidal fluctuations in channels cause periodic groundwater-surface water exchange, water table movement, and intermittent flooding that varies spatially across the saltmarsh. These changes create shifts in redox potential that are greatest near channels and in the top 20 cm of sediments. The magnitude of redox change depends on hydrologic setting (near channels or in marsh interior), hydrologic conditions (tidal stage, seasonal shifts), as well as prevalence of macropores created by crab burrows that change seasonally with crab activity. These shifts correspond to changes in porewater chemistry that have implications for nutrient cycling and carbon export to the ocean. Understanding hydrologic influence on redox geochemistry is critical for predicting how these systems and their ecosystem services may change in the future in response to anthropogenic and climate change.

  9. Chronic exposure to soil salinity in terrestrial species: Does plasticity and underlying physiology differ among specialized ground-dwelling spiders?

    Science.gov (United States)

    Renault, D; Puzin, C; Foucreau, N; Bouchereau, A; Pétillon, J

    2016-07-01

    In salt marshes, the alternation of low and high tides entails rapid shifts of submersion and aerial exposure for terrestrial communities. In these intertidal environments, terrestrial species have to deal with an osmotic loss in body water content and an increase in sodium chloride concentration when salt load increases. In salt marshes, spiders represent an abundant arthropod group, whose physiological ecology in response to variations of soil salinity must be further investigated. In this study, we compared the effect of salinity on the survival and physiology of three species of Lycosidae; two salt marsh species (Arctosa fulvolineata and Pardosa purbeckensis) and one forest species (P. saltans). Spiders were individually exposed at three salinity conditions (0‰, 35‰ and 70‰) and survival, changes in body water content, hemolymph ions (Na(+), Ca(2+), Mg(2+), K(+); ICP-MS technique) and metabolites (mainly amino acids, polyols, sugars; LC and GC techniques) were assessed. The survival of the forest species P. saltans was very quickly hampered at moderate and high salinities. In this spider, variations of hemolymph ions and metabolites revealed a quick loss of physiological homeostasis and a rapid salt-induced dehydration of the specimens. Conversely, high survival durations were measured in the two salt-marsh spiders, and more particularly in A. fulvolineata. In both P. purbeckensis and A. fulvolineata, the proportion of Na(+), Ca(2+), Mg(2+), K(+) remained constant at the three experimental conditions. Accumulation of hemolymph Na(+) and amino acids (mainly glutamine and proline) demonstrated stronger osmoregulatory capacities in these salt-marsh resident spiders. To conclude, even if phylogenetically close (belonging to the same, monophyletic, family), we found different physiological capacities to cope with salt load among the three tested spider species. Nevertheless, physiological responses to salinity were highly consistent with the realized

  10. Endogenous and exogenous factors controlling temporal abundance patterns of tropical mosquitoes.

    Science.gov (United States)

    Yang, Guo-Jing; Brook, Barry W; Whelan, Peter I; Cleland, Sam; Bradshaw, Corey J A

    2008-12-01

    The growing demand for efficient and effective mosquito control requires a better understanding of vector population dynamics and how these are modified by endogenous and exogenous factors. A long-term (11-year) monitoring data set describing the relative abundance of the saltmarsh mosquito (Aedes vigilax) in the greater Darwin region, northern Australia, was examined in a suite of Gompertz-logistic (GL) models with and without hypothesized environmental correlates (high tide frequency, rainfall, and relative humidity). High tide frequency and humidity were hypothesized to influence saltmarsh mosquito abundance positively, and rainfall was hypothesized to correlate negatively by reducing the availability of suitable habitats (moist substrata) required by ovipositing adult female mosquitoes. We also examined whether environmental correlates explained the variance in seasonal carrying capacity (K) because environmental stochasticity is hypothesized to modify population growth rate (r), carrying capacity, or both. Current and lagged-time effects were tested by comparing alternative population dynamics models using three different information criteria (Akaike's Information Criterion [corrected; AIC(c)], Bayesian Information Criterion [BIC], and cross-validation [C-V]). The GL model with a two-month lag without environmental effects explained 31% of the deviance in population growth rate. This increased to > 70% under various model combinations of high tide frequency, rainfall, and relative humidity, of which, high tide frequency and rainfall had the highest contributions. Temporal variation in K was explained weakly by high tide frequency, and there was some evidence that the filling of depressions to reduce standing water availability has reduced Aedes vigilax carrying capacity over the study period. This study underscores the need to consider simultaneously both types of drivers (endogenous and exogenous) when predicting mosquito abundance and population growth

  11. The cost and feasibility of marine coastal restoration.

    Science.gov (United States)

    Bayraktarov, Elisa; Saunders, Megan I; Abdullah, Sabah; Mills, Morena; Beher, Jutta; Possingham, Hugh P; Mumby, Peter J; Lovelock, Catherine E

    2016-06-01

    Land-use change in the coastal zone has led to worldwide degradation of marine coastal ecosystems and a loss of the goods and services they provide. Restoration is the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed and is critical for habitats where natural recovery is hindered. Uncertainties about restoration cost and feasibility can impede decisions on whether, what, how, where, and how much to restore. Here, we perform a synthesis of 235 studies with 954 observations from restoration or rehabilitation projects of coral reefs, seagrass, mangroves, salt-marshes, and oyster reefs worldwide, and evaluate cost, survival of restored organisms, project duration, area, and techniques applied. Findings showed that while the median and average reported costs for restoration of one hectare of marine coastal habitat were around US$80000 (2010) and US$1600000 (2010), respectively, the real total costs (median) are likely to be two to four times higher. Coral reefs and seagrass were among the most expensive ecosystems to restore. Mangrove restoration projects were typically the largest and the least expensive per hectare. Most marine coastal restoration projects were conducted in Australia, Europe, and USA, while total restoration costs were significantly (up to 30 times) cheaper in countries with developing economies. Community- or volunteer-based marine restoration projects usually have lower costs. Median survival of restored marine and coastal organisms, often assessed only within the first one to two years after restoration, was highest for saltmarshes (64.8%) and coral reefs (64.5%) and lowest for seagrass (38.0%). However, success rates reported in the scientific literature could be biased towards publishing successes rather than failures. The majority of restoration projects were short-lived and seldom reported monitoring costs. Restoration success depended primarily on the ecosystem, site selection, and techniques

  12. Placing barrier-island transgression in a blue-carbon context

    Science.gov (United States)

    Theuerkauf, Ethan J.; Rodriguez, Antonio B.

    2017-07-01

    Backbarrier saltmarshes are considered carbon sinks; however, barrier island transgression and the associated processes of erosion and overwash are typically not included in coastal carbon budgets. Here, we present a carbon-budget model for transgressive barrier islands that includes a dynamic carbon-storage term, driven by backbarrier-marsh width, and a carbon-export term, driven by ocean and backbarrier shoreline erosion. To examine the impacts of storms, human disturbances and the backbarrier setting of a transgressive barrier island on carbon budgets and reservoirs, the model was applied to sites at Core Banks and Onslow Beach, NC, USA. Results show that shoreline erosion and burial of backbarrier marsh from washover deposition and dredge-spoil disposal temporarily transitioned each site into a net exporter (source) of carbon. The magnitude of the carbon reservoir was linked to the backbarrier setting of an island. Carbon reservoirs of study sites separated from the mainland by only backbarrier marsh (no lagoon) decreased for over a decade because carbon storage could not keep pace with erosion. With progressive narrowing of the backbarrier marsh, these barriers will begin to function more persistently as carbon sources until the reservoir is depleted at the point where the barrier welds with the mainland. Undeveloped barrier islands with wide lagoons are carbon sources briefly during erosive periods; however, at century time scales are net carbon importers (sinks) because new marsh habitat can form during barrier rollover. Human development on backbarrier saltmarsh serves to reduce the carbon storage capacity and can hasten the transition of an island from a sink to a source.

  13. Light and Dark: a Mixed Mode Exhibition and Art Installation Project

    Science.gov (United States)

    Walsh, R. W.

    2016-12-01

    From June to July 2016, the University of Central Lancashire, Preston, England delivered a Science and Technology Facilities Council funded exhibition and art installation project entitled `Exploring Light and Dark' in collaboration with the Beacon Museum, Whitehaven, Cumbria. Whitehaven is a small harbor town on the far west coast of Cumbria, England. With a population of about 24,000, it is located outside of the Lake District National Park. The major industry is the nearby Sellafield nuclear complex, with which a large proportion of the population has links. We showcased the work of some of our science teams in the areas of astrophysics, ecology and engineering. Visitors were able to experience new ways of learning about research through our audio visual exhibits including films, interpretation boards and hands-on activities. The center-piece was a 3.5m high semi-circular projection of the EUV images of the Sun obtained from NASA's Solar Dynamic Observatory. Specifically visitors explored the following questions: What's a Stellar Explosion? What do you know about the Sun, our closest star? Do you know what a Black Hole is? Why do certain worms react to White Night light conditions? What's a Light Echo? How are plasmas created? How are stars born? What do stone circles tell us about what our ancestors thought about the Sun, the moon and the stars? The programme of activities also included Storytelling (a local storyteller incorporated the folklore about the Sun with science research) and Choreography (a dance artist delivered interpretive dance workshops about the lifecycle of stars). Consequently, 2500 individuals visited the exhibition over the four-week period. A full evaluation of this exhibition is currently being undertaken and a summary of findings will be presented at this meeting. This will outline how this broad mix of scientists has critically reflected on the range of science communication techniques employed in "Light and Dark" with a view to sharing

  14. A study of geographical variations in the concentrations of plutonium and radiostrontium in human teeth throughout the British Isles

    International Nuclear Information System (INIS)

    O'Donnell, Rauiri

    1993-05-01

    Concern has been expressed about the impact on humans of plutonium and radiostrontium releases from nuclear installations in the United Kingdom, with public interest focusing on reported leukaemia clusters in the vicinity of some of these installations. In particular, it is not clear whether such discharges result in and increase in the body burden of plutonium and radiostrontium (present as a consequence of global fallout) in the local population. In this collaborative study the comparative exposures to 239,240Pu and 90Sr of different geographically located child populations in the British Isles have been examined using teeth removed from children for orthodontic purposes. Minute traces on 239,240Pu were found to be present in children's teeth. The overall mean concentration was 5+4 mBq/kg (ash), which is three orders of magnitude lower than reported total activities. Approximately 75% of the samples analysed showed concentrations below the mean value. Although there is considerable scatter in the data, there is some evidence of a marginal enhancement in the 239,240Pu concentration measured in the general vicinity of Cumbria, where the BNF plc. nuclear fuel reprocessing complex is located. Concentrations of 90Sr in teeth exceeded those of plutonium by three orders of magnitude, the overall mean being 8+5Bq/kg (ash). However, there was no evidence of any enhancement in the levels throughout Cumbria. No correlation was observed between 239,240Pu or 90Sr concentrations and mean annual rainfall, not was there any correlation between the levels of these radionuclides in the same samples. The plutonium and radiostrontium concentrations measured in teeth are similar to those reported for human bone in the British Isles and suggests that teeth can be used as an indicator of skeletal burden. On the basis of the above mentioned data, estimates have been made of the approximate risks of leukaemia and non-Hodgkins lymphoma assuming chronic intakes of these radionuclides. The

  15. The report of the Black Advisory Group and the implementation of its recommendations

    International Nuclear Information System (INIS)

    Rubery, E.D.

    1986-01-01

    The report of the Black Inquiry concluded that mortality in the whole of west Cumbria was near to the national average, but this finding did not preclude the existence of local pockets of high incidence. In particular, studies available to the Group did show that incidence of lymphoid malignancy in young people under the age of 15 in Seascale and mortality from leukaemia in those under 25 years in former Millom Rural District, which includes Seascale, were above the expected level. When estimates of the average doses of radiation received by members of the public living in the area were calculated, these doses seemed to be insufficient to explain the observed excess. The Group gave a qualified reassurance to the people who were concerned about a possible health hazard in the neighbourhood of Sellafield, stressed the uncertainties with regard to both available epidemiological data and estimation of radiation doses, and made 10 recommendations for further work, which were accepted by government. Progress on their implementation is described. (author)

  16. Floodplain Connectivity and implications for flooding and floodplain function

    Science.gov (United States)

    Barrow, E.

    2017-12-01

    Regime theory suggests that floodplains should be inundated on average once every two years to maintain form and function of both the river and the floodplain. Natural disconnection along non-alluvial reaches and where the river has moved to flow against terrace edges is to be expected, however, disconnectivity caused by river management is now affecting increasing lengths of watercourses. This study utilises aerial Lidar data to determine the relative height difference between the watercourse and adjacent valley bottoms to assess the degree of disconnectivity along main river systems across Cumbria in the UK. The results reveal that many rivers are now poorly connected to their floodplains which are now largely non-functional. Floodplain geomorphic units, although often present, are currently inactive and water table levels are reduced resulting in a loss of wetland in favour of ruderal species tolerant of drier conditions. The causes of such widespread disconnectivity may be attributed to historic dredging and straightening of these rivers and revetment and riparian tree planting has further exacerbated the problem restricting lateral activity and the subsequent development of new areas of connected floodplain. The high degree of disconnection has implications for future river management and river restoration and these are discussed.

  17. BNFL's application of computer aided engineering to 'THORP' thermal oxide reprocessing plant

    International Nuclear Information System (INIS)

    Hall-Wilton, M.J.

    1990-01-01

    BNFL are currently constructing facilities at Sellafield, Cumbria to reprocess thermal oxide fuel for U.K., European and Japanese utilities. Faced with a 3.5bn pound capital program to provide new facilities at Sellafield, BNFL took the opportunity to embrace the new computer aided engineering technologies then emerging in 1981. To give some idea of the commitment made by BNFL to the above many millions of pounds has been invested in hardware, and more on software and people. The 'THORP' (Head End and Chemical Separation Plant) project represents 1.5bn pounds. The introduction of computer aided engineering has provided a clash free design with full assurance that all materials and components used are compatible. Planning in the design offices in conjunction with an experienced construction management team enables the sequence of piping installation to be determined long before the construction teams enter the work area. This planning aspect has been significantly improved by using EVS (Enhanced Visualisation System). The use of supercomputing graphics facilities is stimulating demands from areas of engineering who have previously not sought to use magnetic data from a variety of sources. The result is mainly due to the data being easily accessible to users who have very little computing experience. (N.K.)

  18. Planning and plutonium. Evidence of the Town and Country Planning Association to the Public Inquiry into an oxide reprocessing plant at Windscale

    International Nuclear Information System (INIS)

    1978-01-01

    The case of the Town and Country Planning Association of Great Britain at the Public Inquiry into the proposed uranium oxide reprocessing plant at Windscale, Cumbria, in the summer of 1977, is presented. The bulk of the book consists of the evidence of the Association's eight witnesses, several of whom have international reputations in their field. The main matters covered by the evidence are the economics of nuclear power compared with other sources of energy; energy demand and supply forecasts in the UK, and the timing and length of the so-called energy gap, together with alternative ways of filling it and the prospects for coal, oil and gas; the risks of proliferation of nuclear weapons; the hazards of low-level radiation to the environment, the general public and workers in nuclear installations, and the inadequacy of current standards; the need for environmental impact analysis before approval is given to major nuclear installations, with reference to United States and British experience; the national, regional and local planning considerations such as employment, housing and visual impact. The evidence is put into context with introductory material on the purpose and terms of reference of the Inquiry, the main events leading up to it, and a general statement of the Association's case. The book ends with a philosophical comment on the alternatives to a plutonium future

  19. Annual report and accounts 1991/92

    International Nuclear Information System (INIS)

    1992-01-01

    The primary objective of British Nuclear Fuels plc (BNFL) is to supply a safe and efficient nuclear fuel cycle service. Springfields near Preston is the site of our fuel manufacturing operations, while Capenhurst near Chester is responsible for uranium enrichment. We reprocess irradiated nuclear fuel at Sellafield in West Cumbria, the site also of our multi-million pound investment programme which includes the Thermal Oxide Reprocessing Plant (THORP) and a range of facilities for the treatment and storage of waste produced during reprocessing operations. We also operate two nuclear power stations -Calder Hall on the Sellafield site and Chapelcross in Southern Scotland. Risley in Cheshire is the focus for our engineering design activities and the Company's Central Services Unit. The Head Office is also based at Risley. Fuel cycle services associated with the production of nuclear-generated electricity accounts for around 90% of our work. The report includes the chairman's review of the year, the Chief Executive's Report and summaries of the activities of the UK Group, International Group, Engineering Group and the Central Services Unit. The accounts are presented. (author)

  20. Quantifying River Channel Stability at the Basin Scale

    Directory of Open Access Journals (Sweden)

    Philip J. Soar

    2017-02-01

    Full Text Available This paper examines the feasibility of a basin‐scale scheme for characterising and quantifying river reaches in terms of their geomorphological stability status and potential for morphological adjustment based on auditing stream energy. A River Energy Audit Scheme (REAS is explored, which involves integrating stream power with flow duration to investigate the downstream distribution of Annual Geomorphic Energy (AGE. This measure represents the average annual energy available with which to perform geomorphological work in reshaping the channel boundary. Changes in AGE between successive reaches might indicate whether adjustments are likely to be led by erosion or deposition at the channel perimeter. A case study of the River Kent in Cumbria, UK, demonstrates that basin‐wide application is achievable without excessive field work and data processing. However, in addressing the basin scale, the research found that this is inevitably at the cost of a number of assumptions and limitations, which are discussed herein. Technological advances in remotely sensed data capture, developments in image processing and emerging GIS tools provide the near‐term prospect of fully quantifying river channel stability at the basin scale, although as yet not fully realized. Potential applications of this type of approach include system‐wide assessment of river channel stability and sensitivity to land‐use or climate change, and informing strategic planning for river channel and flood risk management.

  1. Use of Formal Procedures in Developing Dialogue Between Operator and Regulator on Radioactive Waste Disposal

    International Nuclear Information System (INIS)

    Yearsley, Roger; Duerden, Susan; Bennett, David

    2001-01-01

    The Environment Agency (the Agency) is responsible, in England and Wales, for authorisation of radioactive waste disposal under the Radioactive Substances Act 1993. British Nuclear Fuels plc (BNFL) is currently authorised to dispose of solid low level radioactive waste at its Drigg site near Sellafield in Cumbria. Drigg is the primary site for the disposal of solid low level radioactive waste generated by the UK nuclear industry. A small facility operated by United Kingdom Atomic Energy Authority (UKAEA) at Dounreay on the north coast of Scotland is used solely for wastes arising on the UKAEA site. Drigg also offers a disposal route for smaller users of radioactive substances, such as hospitals and universities. Significant benefits have been derived from implementing a formal Issue Resolution Procedure as part of a soundly based process for dialogue between the Agency and BNFL. Benefits include improved understanding of the Agency's expectations, which has in turn led to improvements in BNFL's documentation and technical approach. The Agency considers the use of a formal Issue Resolution Procedure has placed the dialogue with BNFL on firm foundations for the planned assessment of the PostClosure Safety Case for Drigg when it is submitted in September 2002

  2. Radioactivity and United Kingdom estuaries: an overview identifying research priorities

    International Nuclear Information System (INIS)

    Hamilton, E.I.; Clifton, R.J.; Stevens, H.E.

    1985-05-01

    The report consists of the results of an evaluation of research priorities for the environmental radioactivity of estuaries, (and near shore waters) of the United Kingdom. The format of this report is:(i) general conclusions for the future requirements for research in the field of environmental radioactivity; (ii) an overview of some specific recommendations for research; and (iii) an appendix in which a comprehensive evaluation of the research priorities for specific areas of research are given. On the basis that man is the prime target for concern and protection, special attention has been given to the environment in the vicinity of the British Nuclear Fuels (BNFL) reprocessing plant at Sellafield, Cumbria, which is the source of major releases of a variety of radionuclides into the natural environment. Subjects covered in the Appendix are: site factors; pathways to man; source term; hot particles; terrestrial inputs; surveys and monitoring; analysis; organics; field versus laboratory data; biology; bioaccumulation factors; some bioaccumulators of radioactivity; bioturbation; bacteria; genetics; natural change; sediment; resuspension; surfaces; Ksub(d) factors; pore liquids; diagenesis and the ageing processes; airborne transport of radionuclides; models; natural radioactivity; public opinion; recreation; the ICRP; the ALARA principle; decommissioning of nuclear power stations; identification of research requirements; environmental radioactivity - the national effort. (U.K.)

  3. Biological transport of radiocaesium in a semi-natural grassland ecosystem: Pt.1

    International Nuclear Information System (INIS)

    Rudge, S.A.; Johnson, M.S.; Leah, R.T.

    1993-01-01

    An unused area of the British Nuclear Fuels plc low level disposal site at Drigg in Cumbria, together with a control site in Cheshire, have been used to investigate the behaviour of 137 Cs in semi-natural grasslands over the period 1985-1988. Both sites showed significant inputs of 137 Cs and 134 Cs from the Chernobyl incident in 1986, estimated at up to 7330 Bq/m 2 at Drigg and less than 230 Bq/m 2 in Cheshire. Surface soil horizons showed the highest levels of 137 Cs and 134 Cs. During the study period, the dominant contribution to radiocaesium in soil and vegetation was from Chernobyl. Significant inter-specific variation in caesium concentrations of grasses was observed with an exponential decrease from June 1986 through to the summer of 1987, followed by secondary peak in autumn 1987. Samples collected in the spring of 1988 showed 137 Cs concentrations approaching pre-Chernobyl levels. Marked inter-specific and temporal differences in concentrations of radio-caesium were recorded for invertebrate populations. Radioactivity levels in herbivorous invertebrates were approximately proportional to levels in their diets with concentration decreasing form the 1986 summer peak recorded after the input of Chernobyl radioactivity to the low levels observed during the summer of 1987. Herbivorous and predatory invertebrates showed similar concentrations of 137 Cs but both groups were lower in radiocaesium than detritivorous species. (Author)

  4. Radionuclides in terrestrial ecosystems

    International Nuclear Information System (INIS)

    Howard, B.J.; Kennedy, V.H.; Nelson, A.

    1983-06-01

    A bibliographical database has been developed to provide quick access to research and background literature in the field of radioecology. This is a development of an earlier database described by Nelson (Bocock 1981). ITE's particular fields of interest have led to a subject bias in the bibliography towards studies in Cumbria, especially those concerned with radionuclides originating from the reprocessing plant at Sellafield, and towards ecological research studies that are complementary to radionuclide studies. Other subjects covered, include the chemistry of radionuclides, budgets and transfers within ecosystems and techniques for the analysis of environmental samples. ITE's research objectives have led to the establishment of a specialized database which is intended to complement rather than compete with the large international databases made available by suppliers such as IRS-DIALTECH or DIALOG. Currently the database holds about 1900 references which are stored on a 2 1/2 megabyte hard disk on a Digital PDP11/34 computer operating under a time shared system. The references follow a standard format. (author)

  5. Radiological assessment of the Esk Estuary

    International Nuclear Information System (INIS)

    Howorth, J.M.; Barr, H.M.; Toole, J.; Strange, L.P.

    1993-01-01

    An assessment has been carried out of the radiological impact of artificial radionuclides in the Esk estuary in Cumbria, UK. Measurements were made of the distributions of 137 Cs, 239 + 240 Pu, and 241 Am in water, surface bed sediments and core profiles. The highest measured concentrations in surface sediments were 2.8 Bq g -1 of 137 Cs, 3.1 Bq g -1 of 239 + 240 Pu and 4.7 Bq g -1 of 241 Am. These values represent significant decreases from similar measurements made in 1970-1980. The measured behaviour of the actinides in low salinity water at the head of the estuary supports previous observations of actinide remobilisation from the bed. A model has been developed which simulates the long-term behaviour of radioactivity in the estuary. The model incorporates representations of tidal mixing, sediment transport, seasonal and long-term sediment accretion. The model also represents long-term build-up in salt marsh regions. The model gives good agreement with measured distributions of 137 Cs, but tends to underestimate actinide concentrations by factors of 2-3. Dose calculations show the importance of radionuclide uptake through livestock grazing sea-washed pasture alongside the estuary. 137 Cs and 241 Am are identified as the most important radionuclides considered in the assessment. (Author)

  6. Status, Trends, and Advances in Earthworm Research and Vermitechnology

    International Nuclear Information System (INIS)

    Karmegam, N.; Kale, R.D.; Kale, R.D.; Daniel, T.; Alam, M.N.; Rodriguez, M.G.

    2010-01-01

    In this special issue reflect the developments in the fields of earthworm research and vermitechnology. Charles Darwins observation on earthworms is a milestone in understanding the soil biology and enormous contribution to some aspects of the genesis of humus and of its role in soils. Earthworms are the best known soil inhabiting animals commonly called friends of farmers due to the beneficial role they play in soil. The research on earthworms has gained importance in India as well as in other countries. In the year 1981, an international symposium entitled Earthworm Ecology: Darwin to Vermiculture was held at Cumbria, UK, to commemorate the centenary celebration of Darwins book The Formation of Vegetable Mould through the Action of Worms, with Observations on Their Habits that was published in 1881 by Murray, London, UK. In the year 2000, Vermillenium-an international workshop and symposium- was held at Kalamazoo, USA, to realize the progress achieved in this field after a decade (since 1991). Recently, Ninth International Symposium on Earthworm Ecology (ISEE-9) that was held at Xalapa, Mexico, during the 5th to 10th of September 2010 clearly proved the importance of earthworms and vermitechnology by the participation of scientists from different countries. About 300 papers were received from the researchers across the world

  7. Community involvement: stake holder learning in the UK and in Canada

    International Nuclear Information System (INIS)

    Hetherington, J.

    2003-01-01

    Copeland District in west Cumbria in the North-West Region of England, is 'home' to the major UK (Sellafield) reprocessing plants (including THORP). The Sellafield site includes major stores for Intermediate (ILW) and High Level Waste (HLW), while the nearby Drigg national site provides a facility for the managed surface disposal of Low Level Waste (LLW). Together these facilities dominate the local economy, proving some 10 000 jobs and making a key contribution to the local economy. In the 1990's the area was also highlighted as the potential location for a national ILW deep waste repository. This paper offers a reflection from a UK community perspective on the deliberations of the FSC Canadian Workshop. It provides, as background, an initial introductory account of: the development of radioactive waste and liabilities management policy in the UK, the significance of the failure of the Nirex RCF proposals, the success of new dialogue approaches, and the new wide ranging UK radioactive waste management consultation process. It then compares the economic and social issues arising at Sellafield with issues identified in the Canadian programmes and experiences as presented at the Workshop. (author)

  8. Measurements of whole-body radioactivity in the UK population

    International Nuclear Information System (INIS)

    Fenwick, J.D.; Boddy, K.; McKenzie, A.L.; Oxby, C.B.

    1992-01-01

    A national survey of whole-body radioactivity was undertaken. A mobile whole-body counter visited collaborating Medical Physics Departments and Hospitals in England and Wales. Data were also obtained from an installed whole-body counter at the West Cumberland Hospital, Whitehaven, and from a control site at Addenbrooke's Hospital, Cambridge. 1657 volunteer members of the public were measured, including 162 children. 36% of volunteers had been measured in a similar survey 2 years earlier, and showed between a two and five fold reduction in body radiocaesium. No radiocaesium was detected in 54% of people measured. Measurements showed a progressive fall over the course of the study, reaching a baseline of 0.3 Bq 137 Cs/gK. In 1989, the additional radiation dose incurred from radiocaesium varied from a maximum of 4.1 μSv in Cumbria to 1.5 μSv in the South East, compared with the average annual radiation dose of 2500 μSv due to all other causes. No other gamma-emitting radionuclides were found. Results are consistent with Chernobyl as the source of the radiocaesium detected. (author)

  9. The mobility of radiocaesium in lake sediment and implications for dating studies

    International Nuclear Information System (INIS)

    Smith, J.T.; Nolan, L.; Ireland, D.G.; Comans, R.N.J.

    1998-01-01

    The experiments to study the uptake of radiocaesium by sediment cores from Esthwaite Water, Cumbria, UK in order to develop a model to simultaneously describe uptake of radiocaesium from the water column and diffusion of activity within the sediment has been carried out. By measuring the rate of diffusion of activity through the sediment and sediment pore waters as a function of time the validity of the equilibrium approach to modelling radiocaesium sorption and mobility in sediments has been assessed. By comparison with in situ measurements was found, that rates of diffusion of activity introduced by diffusion across the sediment-water interface (as in the experiments) were approximately one order of magnitude greater than those determined from Chernobyl and weapons test activity-depth profiles. Modelling of the removal of activity from Esthwaite Water showed that the majority of the activity was transported to the sediments by attachment to and settling of suspended particles. It is concluded that activity deposited on particulates (forming the majority of activity observed in situ) was more strongly bound to sediments than that introduced by direct diffusion. This explanation is consistent with observed 'two-phase' 137 Cs profiles in sediments. Predictions of future evolution of the weapons test peak are made on the basis of these studies. It is shown that the peak in the activity-depth profile will remain an important marker for dating studies for the forseeable future

  10. New approaches to evaluating the genetic effects of the atomic bombs

    International Nuclear Information System (INIS)

    Neel, J.V.

    1995-01-01

    In the aftermath of the atomic bombings of Hiroshima and Nagasaki fifty years ago, one of the compelling biomedical questions that arose concerned the genetic effects of this exposure. More recently, revelations of the extent of industrial or accidental exposures in the former Soviet Union and charges that employment in the Sellafield Nuclear Reprocessing Plant in West Cumbria, England has resulted in a gene-mediated increase in children of plant employees have served to keep in the public mind the issue of the genetic risks of exposure to ionizing radiation. The study of the genetic effects of the atomic bombs has moved from the gross morphological level of congenital malformations to the examination of DNA. However, were the need for such genetic studies to arise in the foreseeable future, despite this impressive progress in DNA-oriented systems, the documentation of congenital defect, genetic disease and child survival would still be an essential component of any future study. Whatever the geneticists may think, the phenotypic well-being and survival of children are still the primary indicators on which the public, who ultimately supports these studies, will base its judgement of risk. 28 refs

  11. A new model validation database for evaluating AERMOD, NRPB R91 and ADMS using krypton-85 data from BNFL Sellafield

    International Nuclear Information System (INIS)

    Hill, R.; Taylor, J.; Lowles, I.; Emmerson, K.; Parker, T.

    2004-01-01

    The emission of krypton-85 ( 85 Kr) from nuclear fuel reprocessing operations provide a classical passive tracer for the study of atmospheric dispersion. This is because of the persistence of this radioisotope in the atmosphere, due to its long radioactive halflife and inert chemistry; and the low background levels that result due to the limited number of anthropogenic sources globally. The BNFL Sellafield site in Cumbria (UK) is one of the most significant point sources of 85 Kr in the northern hemisphere, with 85 Kr being discharged from two stacks on the site, MAGNOX and THORP. Field experiments have been conducted since October 1996 using a cryogenic distillation technique (Janssens et al., 1986) to quantify the ground level concentration of 85 Kr. This paper reports on the construction of a model validation database to allow evaluation of regulatory atmospheric dispersion models using the measured 85 Kr concentrations as a tracer. The results of the database for local and regional scale dispersion are presented. (orig.)

  12. Radioactive substances monitoring programme. Report for 1995

    International Nuclear Information System (INIS)

    1995-01-01

    The Radioactive Substances Act 1993 provides for controls to be exercised over the use and keeping of radioactive materials and the accumulation and disposal of radioactive wastes. The Environment Agency (the Agency) has been responsible for administration and enforcement of the Act in England and Wales since its formation on 1 April 1996. Prior to this date the work was undertaken by Her Majesty's Inspectorate of Pollution (HMIP). In support of its regulatory functions HMIP commissioned independent monitoring. This report presents the results from monitoring undertaken in 1995. The 1995 HMIP programme required operators of certain sites to provide samples of their liquid effluents for independent radiochemical analysis. The results provide checks on site operators' returns and insights into their quality assurance (QA) procedures and analytical techniques. The analyses were undertaken by the Laboratory of the Government Chemist (LGC) at its laboratories in Teddington, Middlesex. The programme also included checks on solid low level radioactive waste destined for land disposal at the site operated by British Nuclear Fuels plc (BNFL) at Drigg in Cumbria. (author)

  13. Environmental effects of radionuclides--observations on natural ecosystems.

    Science.gov (United States)

    Copplestone, D; Toal, M E; Johnson, M S; Jackson, D; Jones, S R

    2000-03-01

    To better quantify risk to non-human species from exposure to environmental radioactivity, understanding of the behaviour of radionuclides in the biosphere needs to be increased. This study outlines current thinking on ecological risk assessment (ERA) methodology and applies the indicator species or critical groups approach to biota inhabiting a semi-natural coniferous woodland contaminated with the radionuclides 137Cs, 238Pu, 239+240Pu and 241Am. The majority of these radionuclides originate from routine aerial emissions from the nuclear fuel reprocessing plant at BNFL, Sellafield, Cumbria, UK. Radionuclide activity concentrations have been determined in biota from the woodland and estimates of absorbed dose rates (mGy d(-1)) have been calculated using the dosimetric models outlined. Dose rates to the key indicator species, Oniscus asellus, Carabus violaceous and Apodemus sylvaticus (detritivorous invertebrate, predatory invertebrate and the granivorous wood mouse) have been determined at 3.0 x 10(-3) mGy d(-1), 2.2 x 10(-3) mGy d(-1) and 1.0 x 10(-3) mGy d(-1) respectively. The values are at least three orders of magnitude lower than the 1 mGy d(-1) level below which no observable effects on populations in a terrestrial ecosystem are thought to occur. Limitations of this approach are discussed.

  14. R. v. Secretary of State for the Environment and others ex parte Greenpeace Limited and others

    International Nuclear Information System (INIS)

    Potts, J.

    1994-01-01

    When in April 1992, British Nuclear Fuels Limited (BNFL) applied for authorization to discharge radioactive wastes into sea and air as a result of starting to operate its newly constructed thermal oxide reprocessing plant (THORP) at Sellafield Cumbria, a legal challenge to the Secretary of State's authorization was made by Greenpeace Limited, the environmental campaign group, and Lancashire County Council. They sought to show that the Secretary of State for the Environment had acted illegally in granting authority, because it had not been shown that the nuclear waste emission would produce a net benefit to the public, because no public inquiry had been held into whether the economic benefits outweighed the perceived detrimental effects, and because no authorization can occur without an environmental impact assessment to comply with European Community rules. While these points were proved at the judicial review, administrative law principals meant that the decision went against the complainants, but no costs were awarded showing the courts distaste for the judgement it was obliged to make. (UK)

  15. Deep underground disposal of radioactive waste in the United Kingdom

    International Nuclear Information System (INIS)

    Mathieson, J.

    1995-01-01

    The UK Government's radioactive waste disposal policy is for intermediate-level waste, and low-level waste as necessary, to be buried in a deep underground repository, and Nirex is the company, owned by the nuclear industry, charged with developing that deep facility. The Company's current focus is on surface-based geological investigations to determine the suitability of a potential repository site near Sellafield, Cumbria, in north-west England. Nirex's next step is to construct a deep underground laboratory (rock characterization facility, or RCF). Subject to a successful outcome from these investigations, Nirex will submit a planning application for the 650m deep repository at the end of this decade; this will be the subject of a further public inquiry. The timetable for the project assumes that a deep repository, capable of taking 400,000m 3 of waste, will be available by about 2010. In 1994, the UK Government began reviewing the future of the nuclear power industry and, as a separate exercise, radioactive waste management and disposal policy. Both reviews involved widespread consultations. The radwaste review has concentrated on three aspects: general policies; legal aspects of disposal (including safety requirements); and the principles of site selection and the protection of human health. Preliminary conclusions of the main radwaste review were published in August 1994. These confirmed that government continued to favor disposal rather than extended surface storage of waste. The final outcome of the review, including institutional aspects, is expected in the Spring of 1995

  16. The politics of radioactive waste disposal

    International Nuclear Information System (INIS)

    Kemp, R.

    1992-01-01

    Plans for radioactive waste disposal have been among the most controversial of all environmental policies, provoking vociferous public opposition in a number of countries. This book looks at the problem from an international perspective, and shows how proposed solutions have to be politically and environmentally, as well as technologically acceptable. In the book the technical and political agenda behind low and intermediate level radioactive waste disposal in the UK, Western Europe, Scandinavia and North America is examined. The technical issues and the industrial proposals and analyses and factors which have been crucial in affecting relative levels of public acceptability are set out. Why Britain has lagged behind countries such as Sweden and France in establishing Low Level Waste (LLW) and Intermediate Level Waste (ILW) sites, the strength of the 'not in my backyard' syndrome in Britain, and comparisons of Britain's decision-making process with the innovative and open pattern followed in the US and Canada are examined. An important insight into the problems facing Nirex, Britain's radioactive waste disposal company, which is seeking to establish an underground waste site at Sellafield in Cumbria is given. (author)

  17. Barrow hazards survey

    International Nuclear Information System (INIS)

    1980-06-01

    Following a series of public meetings at which PERG presented the results of a literature review and site specific accident study of the hazards of the maritime transport of spent nuclear reactor fuel to Barrow (en route to the Windscale reprocessing works), PERG was requested by the Planning Committee of Barrow Town Council to prepare an assessment of the interaction of the hazards arising from the concentration of nuclear activities in the area with those of a proposed gas-terminal. This report presents a preliminary review of the Environmental Impact Assessments prepared by the Borough Surveyor and a critical appraisal of the hazard analyses undertaken by the Health and Safety Executive, and the consultants to Cumbria County Council on this matter, the Safety and Reliability Directorate of the United Kingdom Atomic Energy Authority. After a general and historical introduction, the document continues under the following headings: a description of the hazards (BNFL spent fuel shipments; the gas terminal; gas condensate storage; the Vickers shipyard (involving nuclear powered submarines)); the interaction of hazards; planning implications and democratic decisions; recommendations. (U.K.)

  18. Nuclear fuel reprocessing in the UK

    International Nuclear Information System (INIS)

    Allardice, R.H.; Harris, D.W.; Mills, A.

    1983-01-01

    Nuclear fuel reprocessing has been carried out on an industrial scale in the United Kingdom since 1952. Two large reprocessing plants have been constructed and operated at Windscale, Cumbria and two smaller specialized plants have been constructed and operated at Dounreay, Northern Scotland. At the present time, the second of the two Windscale plants is operating, and Government permission has been given for a third reprocessing plant to be built on that site. At Dounreay, one of the plants is operating in its original form, whilst the second is now operating in a modified form, reprocessing fuel from the prototype fast reactor. This chapter describes the development of nuclear fuel reprocessing in the UK, commencing with the research carried out in Canada immediately after the Second World War. A general explanation of the techniques of nuclear fuel reprocessing and of the equipment used is given. This is followed by a detailed description of the plants and processes installed and operated in the UK. (author)

  19. English Medieval Churches, 'Festival Orientation' and William Wordsworth

    Science.gov (United States)

    Hoare, Peter G.; Ketel, Hans

    2015-05-01

    A church that is shown to be aligned with sunrise or sunset on the feast day of the saint to whom the building was dedicated is said to display 'festival orientation'. The earliest work to touch upon this practice in English dates from c. 1678. William Wordsworth gave impetus to the subject in two poems published in 1827; he also played a part in the design of St Mary's chapel (1823-4), Rydal, Cumbria in the English Lake District. The 14th-century St Catherine's chapel at Houghton St Giles, Norfolk, was constructed for the use of pilgrims on their way to nearby Walsingham. Careful measurement of the orientation and eastern horizon of these two buildings has shown that St Mary's is aligned with sunrise on the Marian festival of The Visitation (2 July), and St Catherine's is directed towards the rising Sun on the feast of St Catherine of Alexandria (25 November). It is only by taking into account the character of the horizon that meaningful tests for festival orientation may be carried out.

  20. Overview of the site selection, geological and engineering problems facing radioactive waste disposal at Sellafield, UK

    International Nuclear Information System (INIS)

    Haszeldine, R.S.; Smythe, D.K.

    1996-01-01

    UK Nirex Ltd is the company charged with finding a suitable site for the disposal of radioactive waste in the United Kingdom. Since 1991, Nirex has concentrated its site investigation work at Longlands Farm which is owned by British Nuclear Fuels Ltd and is near their Sellafield site. Planning permission was sought for the development of an underground Rock Characterisation Facility (RCF) at the site in 1994. A public Planning Inquiry began in September 1995. A wide range of scientific and technical objections were put by expert witnesses against the Nirex Proposal. These witnesses were co-ordinated by three Objecting Organisations - Cumbria County Council, Friends of the Earth and Greenpeace. Their written evidence is presented in this book. The grounds of the objections include: the inadequacy of the methodology adopted by Nirex for site selection and investigation; The unsuitability of the site geology, hydrology and geochemistry; that construction of the RCF would destroy the data essential to deciding site suitability; that the RCF would provide a conduit for the release of radioactivity; a number of features in the Nirex risk assessment that would lead to an underestimation of the potential risks of a repository at this site. (UK)

  1. Application of the ERICA Integrated Approach to the Drigg coastal sand dunes

    Energy Technology Data Exchange (ETDEWEB)

    Wood, M.D. [Institute for Sustainable Water Integrated Management and Ecosystem Research (SWIMMER)/School of Biological Sciences, Nicholson Building, University of Liverpool, Liverpool, Merseyside L69 3GP (United Kingdom)], E-mail: mwood@liv.ac.uk; Marshall, W.A. [Westlakes Scientific Consulting Ltd., Princess Royal Building, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3LN (United Kingdom); Beresford, N.A. [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, Lancashire LA1 4AP (United Kingdom); Jones, S.R. [Westlakes Scientific Consulting Ltd., Princess Royal Building, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3LN (United Kingdom); Howard, B.J. [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, Lancashire LA1 4AP (United Kingdom); Copplestone, D. [Environment Agency, P.O. Box 12, Richard Fairclough House, Knutsford Road, Latchford, Warrington, Cheshire WA4 1HG (United Kingdom); Leah, R.T. [Institute for Sustainable Water Integrated Management and Ecosystem Research (SWIMMER)/School of Biological Sciences, Nicholson Building, University of Liverpool, Liverpool, Merseyside L69 3GP (United Kingdom)

    2008-09-15

    The EC-funded project 'Environmental Risks from Ionising Contaminants: Assessment and Management' (ERICA) developed an 'Integrated Approach' for assessing the impact of ionising radiation on ecosystems. This paper presents the application of the ERICA Integrated Approach, supported by a software programme (the ERICA Tool) and guidance documentation, to an assessment of the Drigg coastal sand dunes (Cumbria, UK). Targeted sampling provided site-specific data for sand dune biota, including amphibians and reptiles. Radionuclides reported included {sup 90}Sr, {sup 99}Tc, {sup 137}Cs, {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am. Site-specific data were compared to predictions derived using the ERICA Tool. Some under- and over-predictions of biota activity concentrations were identified but can be explained by the specific ecological characteristics and contamination mechanism of the dunes. Overall, the results indicated no significant impact of ionising radiation on the sand dune biota and the Integrated Approach was found to be a flexible and effective means of conducting a radiation impact assessment.

  2. Environmental effects of radionuclides - observations on natural ecosystems

    International Nuclear Information System (INIS)

    Copplestone, D.; Toal, M.E.; Johnson, M.S.; Jackson, D.; Jones, S.R.

    2000-01-01

    To better quantify risk to non-human species from exposure to environmental radioactivity, understanding of the behaviour of radionuclides in the biosphere needs to be increased. This study outlines current thinking on ecological risk assessment (ERA) methodology and applies the indicator species or critical groups approach to biota inhabiting a semi-natural coniferous woodland contaminated with the radionuclides 137 Cs, 238 Pu, 239+240 Pu and 241 Am. The majority of these radionuclides originate from routine aerial emissions from the nuclear fuel reprocessing plant at BNFL, Sellafield, Cumbria, UK. Radionuclide activity concentrations have been determined in biota from the woodland and estimates of absorbed dose rates (mGy d -1 ) have been calculated using the dosimetric models outlined. Dose rates to the key indicator species, Oniscus asellus, Carabus violaceous and Apodemus sylvaticus (detritivorous invertebrate, predatory invertebrate and the granivorous wood mouse) have been determined at 3.0x10 -3 mGy d -1 , 2.2x10 -3 mGy d -1 and 1.0x10 -3 mGy d -1 respectively. The values are at least three orders of magnitude lower than the 1 mGy d -1 level below which no observable effects on populations in a terrestrial ecosystem are thought to occur. Limitations of this approach are discussed. (author)

  3. Accumulation of Sellafield-derived radiocarbon ((14)C) in Irish Sea and West of Scotland intertidal shells and sediments.

    Science.gov (United States)

    Tierney, Kieran M; Muir, Graham K P; Cook, Gordon T; MacKinnon, Gillian; Howe, John A; Heymans, Johanna J; Xu, Sheng

    2016-01-01

    The nuclear energy industry produces radioactive waste at various stages of the fuel cycle. In the United Kingdom, spent fuel is reprocessed at the Sellafield facility in Cumbria on the North West coast of England. Waste generated at the site comprises a wide range of radionuclides including radiocarbon ((14)C) which is disposed of in various forms including highly soluble inorganic carbon within the low level liquid radioactive effluent, via pipelines into the Irish Sea. This (14)C is rapidly incorporated into the dissolved inorganic carbon (DIC) reservoir and marine calcifying organisms, e.g. molluscs, readily utilise DIC for shell formation. This study investigated a number of sites located in Irish Sea and West of Scotland intertidal zones. Results indicate (14)C enrichment above ambient background levels in shell material at least as far as Port Appin, 265 km north of Sellafield. Of the commonly found species (blue mussel (Mytilus edulis), common cockle (Cerastoderma edule) and common periwinkle (Littorina littorea)), mussels were found to be the most highly enriched in (14)C due to the surface environment they inhabit and their feeding behaviour. Whole mussel shell activities appear to have been decreasing in response to reduced discharge activities since the early 2000s but in contrast, there is evidence of continuing enrichment of the carbonate sediment component due to in-situ shell erosion, as well as indications of particle transport of fine (14)C-enriched material close to Sellafield. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Travelling for treatment; does distance and deprivation affect travel for intensity-modulated radiotherapy in the rural setting for head and neck cancer?

    Science.gov (United States)

    Cosway, B; Douglas, L; Armstrong, N; Robson, A

    2017-06-01

    NHS England has commissioned intensity-modulated radiotherapy for head and neck cancers from Newcastle hospitals for patients in North Cumbria. This study assessed whether travel distances affected the decision to travel to Newcastle (to receive intensity-modulated radiotherapy) or Carlisle (to receive conformal radiotherapy). All patients for whom the multidisciplinary team recommended intensity-modulated radiotherapy between December 2013 and January 2016 were included. Index of multiple deprivation scores and travel distances were calculated. Patients were also asked why they chose their treating centre. Sixty-nine patients were included in this study. There were no significant differences in travel distance (p = 0.53) or index of multiple deprivation scores (p = 0.47) between patients opting for treatment in Carlisle or Newcastle. However, 29 of the 33 patients gave travel distance as their main reason for not travelling for treatment. Quantitatively, travel distance and deprivation does not impact on whether patients accept intensity-modulated radiotherapy. However, patients say distance is a major barrier for access. Future research should explore how to reduce this.

  5. A world's waste

    International Nuclear Information System (INIS)

    Carr, Kevin; Rugg, Judith; Palmer, Roger

    1987-01-01

    A World's Waste·An Exhibition that challenges a number of preconceptions about the nuclear industry and the environment while at the same time pushing back the limits of conventional uses of photography and the visual arts. Drawing on a variety of disciplines and utilising means of visual presentation beyond the scope of many exhibitions, this in-depth look at the impact of Sellafield and the nuclear industry on life in Cumbria and beyond attempts through a variety of media from painting through photography to video, performance and installation work, to picture the invisible: radiation and its consequences for the world. Through varied approaches the work selected for exhibition adds a number of voices to a discussion divided between knowledge based on over complex information pitted against opinion reacting from emotion. The catalogue to the exhibition adds a series of articles which go with the art work. The anti-nuclear articles are balanced by BNFLs contributions which put forward the pro-nuclear viewpoint. (author)

  6. Plutonium and americium in air on the coasts of the Irish Sea

    International Nuclear Information System (INIS)

    Playford, K.

    1991-01-01

    Measurements of artificial radionuclides in air, deposition and seawater were carried out at coastal and inland locations in Cumbria, south-west Scotland, Northern Ireland and North Wales. The measurements were undertaken to determine the distribution of artificial radionuclides in the coastal environment attributable to discharges from Sellafield and to investigate the mechanisms responsible for the increased radionuclide concentration in the marine aerosol and their subsequent transfer to land. A number of different sampling methods were used and the contribution each method could make to the understanding of the marine aerosol was assessed. Measurements of the size distribution of the marine aerosol was also undertaken. The measurements demonstrated that the actinide concentrations measured in the air and deposition at coastal locations could be related to near shore sea water concentrations, but that no direct proportionality existed. It was also determined that a significant proportion of the material transferred from sea to land was associated with larger particulate present in the marine aerosol during conditions of above average onshore winds. (author)

  7. What they don't know can hurt us

    International Nuclear Information System (INIS)

    Mays, C.

    1993-01-01

    ''A public information campaign to support a proposed national deep repository for low and intermediate level radioactive waste'' is the title of a research and development project funded by the Commission of the European Communities, DG 12. The primary objective of the project is to gain support in Cumbria (UK) for a radioactive waste repository at Sellafield through the dissemination of factual information in various forms accessible to the public. The repository information effort is a joint project of UK Nirex and BNFL. Data collection in survey and interview form will enable changes in support to be measured. Dr Peter Allen of Robens Institute, Surrey, carried out a first wave of local opinion research in June 1992. The present author carried out analysis of this data in comparison with French data, comparison reported below. A second objective is to generate information suitable for detailed consideration by other European Community Member States, through evaluation of the fit between public information needs, and strategies and methods applied by institutions in the United Kingdom and in France. The present researcher is primarily concerned with this second objective. The initiation of an information campaign in the nuclear field, as an example of risk communication, provides a favorable opportunity to examine and evaluate the presuppositions guiding institutional action. (author)

  8. Performance assessment for low-level waste disposal in the UK

    Energy Technology Data Exchange (ETDEWEB)

    Ashworth, A.B. [UK Dept. of the Environment, London (United Kingdom)

    1995-12-31

    British Nuclear Fuels plc (BNFL) operate a site for the disposal of Low Level Radioactive Waste at Drigg in West Cumbria, in North-West England. HMIP are responsible for the regulation of the site with regard to environmental discharges of radioactive materials, both operational and post-closure. This paper is concerned with post-closure matters only. Two post-closure performance assessments have been carried out for this site: one by the National Radiological Protection Board (NRPB) in 1987; and a subsequent one carried out on behalf of HMIP, completed in 1991. Currently, BNFL are preparing a Safety Case for continued operation of the Drigg site, and it expected that the core of this Case will comprise BNFL`s own analysis of post-closure performance. HMIP has developed procedures for the assessment of this Case, based upon experience of the previous Drigg assessments, and also upon the experience of similar work carried out in the assessment of Intermediate Level Waste (ILW) disposal at both deep and shallow potential sites. This paper describes the more important features of these procedures.

  9. Exposure of birds to radionuclides and other contaminants in Special Protection Areas (SPAs) in North-West England

    International Nuclear Information System (INIS)

    Marshall, K.; Watson, S.; McDonald, P.; Copplestone, D.; Watts, S.J.

    2010-01-01

    There has been a decline in the population of some bird species at Morecambe Bay and the Solway Firth Special Protected Areas in North-West England during the last fifty years. It was suggested that the declines were caused, in part, by contaminants in the food and environment, primarily from the radioactive effluent discharge from the Sellafield Ltd nuclear fuel reprocessing plant in Cumbria. This study analysed bird feathers and tissues, vegetation and sediment for radionuclides, metals and persistent organic compounds. The non-radionuclide results were all low compared to relevant action limits. The ERICA model was used with field data to estimate the radiological dose to birds from exposure to 137 Cs and 241 Am with results between 1.26 to 3.83 μGy h -1 , below the ERICA screening level of 10 μGy h -1 and within the IAEA 40 μGy h -1 guideline value below which potential adverse impacts on biota are unlikely. The study showed no link between bird population decline and anthropogenic discharges to the SPAs.

  10. Environmental effects of radionuclides - observations on natural ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Copplestone, D. [Industrial Ecology Research Centre, School of Biological Sciences, University of Liverpool, Liverpool L69 3BX (United Kingdom). E-mail: copplest at liv.ac.uk; Toal, M.E.; Johnson, M.S. [Industrial Ecology Research Centre, School of Biological Sciences, University of Liverpool, Liverpool L69 3BX (United Kingdom); Jackson, D.; Jones, S.R. [Westlakes Scientific Consulting, Princess Royal Building, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3LN (United Kingdom)

    2000-03-01

    To better quantify risk to non-human species from exposure to environmental radioactivity, understanding of the behaviour of radionuclides in the biosphere needs to be increased. This study outlines current thinking on ecological risk assessment (ERA) methodology and applies the indicator species or critical groups approach to biota inhabiting a semi-natural coniferous woodland contaminated with the radionuclides {sup 137}Cs, {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am. The majority of these radionuclides originate from routine aerial emissions from the nuclear fuel reprocessing plant at BNFL, Sellafield, Cumbria, UK. Radionuclide activity concentrations have been determined in biota from the woodland and estimates of absorbed dose rates (mGy d{sup -1}) have been calculated using the dosimetric models outlined. Dose rates to the key indicator species, Oniscus asellus, Carabus violaceous and Apodemus sylvaticus (detritivorous invertebrate, predatory invertebrate and the granivorous wood mouse) have been determined at 3.0x10{sup -3} mGy d{sup -1}, 2.2x10{sup -3} mGy d{sup -1} and 1.0x10{sup -3} mGy d{sup -1} respectively. The values are at least three orders of magnitude lower than the 1 mGy d{sup -1} level below which no observable effects on populations in a terrestrial ecosystem are thought to occur. Limitations of this approach are discussed. (author)

  11. In situ radionuclide migration studies in a shallow sand aquifer (Part 1)

    International Nuclear Information System (INIS)

    Williams, G.M.; Alexander, L.S.; Hitchman, S.P.; Hooker, P.J.; Noy, D.J.; Ross, C.A.M.; Stuart, A.; West, J.M.

    1985-07-01

    As a result of a study of the geology of the British Nuclear Fuels premises at Drigg, Cumbria, the British Geological Survey identified a shallow glacial sand deposit approximately 1.5m thick, interbedded between two clay horizons. An array of boreholes has been contructed in this sand in order to study the migration of radionuclides introduced into the formation under controlled conditions of groundwater flow. Conservative tracers used in the field test include chloride (as NaCl, detected using a specific ion electrode) and iodine-131 (as NaI, detected radiometrically using a NaI (T1) crystal). Strontium-85 (as the chloride) has been used as a chemically reactive tracer in conjuction with 131 I. The principal research objectives of the programme are as follows:- (1) to undertake laboratory batch sorption experiments using core material from the field site in order to choose those nuclides of radiological interest that would migrate sufficiently quickly for their behaviour to be studied in a field experiment within a reasonable time period. (2) to identify and quantify the mechanisms for nuclide/sediment interaction by determination of the geochemical distribution of 85 Sr in contaminated cores using a sequential leaching procedure. (3) to obtain appropriate data on the hydraulic characteristics of the sand formation in order to construct a mathematical model to describe groundwater flow and reactive mass transport. (author)

  12. Application of model based predictive control to a solvent extraction plant

    International Nuclear Information System (INIS)

    Harper, W.J.

    1995-01-01

    British Nuclear Fuels plc. (BNFL) is the most experienced nuclear fuel company in the world, having supplied nuclear fuel cycle services in the UK and overseas for over forty years. BNFL is one of only two companies in the world that is able to offer nuclear fuel manufacture, enrichment, reprocessing and waste management services. In addition to its work for the UK Nuclear Power Programme, BNFL has developed a substantial export business with nuclear power plant operators in Western Europe, Japan and North America, which now accounts for 18% of the annual turnover. BNFL's plants re situated in North West England and Southern Scotland. Nuclear fuel and fuel products are manufactured at Springfields near Preston; uranium enrichment by the centrifuge process is carried out at Capenhurst, near Chester; reprocessing and waste management services are provided at Sellafield, West Cumbria. The Company's headquarters and engineering design facilities are based at Risley, near Warrington. BNFL also owns and operates two (MAGNOX) nuclear power stations-Calder Hall, on the Sellafield site, the Chapelcross, near Dumfries in Southern Scotland

  13. Temporal and spatial responses of the bioindicator Fucus to discharges of 99Tc in the eastern Irish Sea

    International Nuclear Information System (INIS)

    McDonald, P.; Busby, R.G.; McCartney, M.

    1999-01-01

    Technetium-99 is a radioactive isotope discharged under authorisation to the Irish Sea from the British Nuclear Fuels plc Sellafield reprocessing plant in Cumbria via a marine pipeline. An increase in 99 Tc discharges from Sellafield in recent years has provided an ideal opportunity to undertake a more detailed investigation of its environmental behaviour. Here, the temporal and spatial response of Fucus sp. to the increased discharges has been investigated and its role as a bioindicator assessed. Initial investigations in 1995, have confirmed the expectation that Fucus does act as an effective bioindicator of 99 Tc, with easily detectable 99 Tc concentrations (1 - 15 kBq kg -1 wet weight) being encountered, providing a time integrated signal of 99 Tc discharges. Analysis of subsequent samples collected during 1996, however, have shown significant short-term peaks in Fucus 99 Tc concentrations close to Sellafield (up to 90 kBq kg -1 wet weight) and this can be related to peaks in 99 Tc seawater concentrations. This type of response suggests that Fucus has a means of rapidly accumulating 99 Tc, although the rate at which this accumulated component may be eliminated remains unclear. This effect was only observed at sites close to Sellafield (within 15 km). Relatively constant 99 Tc concentrations in Fucus were found at more distant sites (50 - 150 km). (author)

  14. Incorporation of plutonium, americium and curium into the Irish Sea seabed by biological activity

    Energy Technology Data Exchange (ETDEWEB)

    Kershaw, P J; Swift, D J; Pentreath, R J; Lovett, M B

    1984-12-01

    Bioturbation was considered as a potentially significant mechanism for the incorporation of long-lived radionuclides into the seabed and in particular the activities of a large echiuran Maximulleria lankesteri. Radionuclides of the transuranium elements plutonium, americium and cirium are discharged into the Irish Sea under authorization as part of the low-level liquid effluent from the British Nuclear Fuels plc reprocessing plant at Sellafield, Cumbria, England. The distribution of Pu-239, 240, Pu-238, Am-241, Cm-244 and Cm-242 concentrations and the Pu-239, 240/Pu-238 quotient in samples taken in April and May 1983 from the sediment surface, burrow linings, sediments adjacent to burrows, and the gut contents and body of a large M. lankesteri clearly indicate that bioturbation is responsible, at least in part, for the incorporation of these radionuclides to depths of up to 140 cm. This area of sediments represents a significant present-day sink, but the permanence of this sink and the likelihood that radioactivity will be remobilized and be returned to man, depends on a large number of factors. 15 references, 18 figures.

  15. Measurements of cesium-137 in residents of Seascale and its environs

    Energy Technology Data Exchange (ETDEWEB)

    Fry, F A; Sumerling, T J

    1984-07-01

    Measurements of the body content of cesium-137 have been made on almost 300 members of the public residing in or near Seascale, a community in west Cumbria close to the nuclear installation at Sellafield operated by British Nuclear Fuels plc. The major objective of this study was to compare the levels found in the population with those predicted from environmental measurements. No artificially-produced radionuclides were detected in the overwhelming majority of those measured. Cesium-137 was detected in about 7% of the measured population but, in general, the levels were much lower than those expected. The highest body content found was comparable with the average predicted from environmental measurements and estimates of food consumption rates; this body content corresponds to intake of cesium-137 at a rate of somewhat less than 2% of the appropriate annual limit on intake for members of the public. From this study, it is concluded that contamination of foodstuffs with cesium-137 leads to exposure of the local population at levels that are of low radiological significance, and that estimates of intake obtained from environmental monitoring data are cautious for most of the population.

  16. Natural radionuclides in the UK marine environment

    Energy Technology Data Exchange (ETDEWEB)

    Rollo, S F.N.; Camplin, W C; Allington, D J; Young, A K [Ministry of Agriculture, Fisheries and Food, Lowestoft (United Kingdom). Fisheries Radiobiological Lab.

    1992-01-01

    The importance of natural radionuclides giving rise to radiation exposure of man from marine consumption pathways has been known for some time. However, the extent of surveys of levels in marine biota has been limited. This paper presents new data on concentrations of natural radionuclides in fish, shellfish and seaweeds taken from coastal sampling locations in the U.K. Sampling included areas where levels due to natural sources would be predominant, but efforts were made to study potential sources of technologically enhanced discharges to seas and rivers, particularly the phosphogypsum plant at Whitehaven in Cumbria. The highest concentrations (up to 371 Bq.kg[sup -1] (wet) [sup 210]Po) were observed in winkles near Whitehaven. The general levels at sites remote from known sources were much lower. Monthly concentrations in molluscs at a single location were elevated by approximately a factor of 2 during the summer months. An assessment of the expected doses to members of the public from marine consumption pathways is made. (author).

  17. LLW disposal wasteform preparation in the UK: the role of high force compaction

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, L. F.; Fearnley, I. G. [British Nuclear Fuels Ltd., Sellafield (United Kingdom)

    1991-07-01

    British Nuclear Fuels plc (BNFL) owns and operates the principal UK solid low level radioactive waste (LLW) disposal site. The site is located at Drigg in West Cumbria some 6 km to the south east of BNFL's Sellafield reprocessing complex. Sellafield is the major UK generator of LLW, accounting for about 85% of estimated future arisings of raw (untreated, unpackaged) waste. Non-Sellafield consignors to the Drigg site include other BNFL production establishments, nuclear power stations, sites of UKAEA, Ministry of Defence facilities, hospitals, universities, radioisotope production sites and various other industrial organisations. In September 1987, BNFL announced a major upgrade of operations at the Drigg site aimed at improving management practices, the efficiency of space utilisation and enhancing the visual impact of disposal operations. During 1989 a review of plans for compaction and containerisation of Sellafield waste identified that residual voidage in ISO freight containers could be significant even after the introduction of compaction. Subsequent studies which examined a range of compaction and packaging options concluded that the preferred scheme centred on the use of high force compaction (HFC) of compactable waste, and grouting to take up readily accessible voidage in the wasteform. The paper describes the emergence of high force compaction as the preferred scheme for wasteform preparation and subsequent benefits against the background of the overall development of Low Level Waste disposal operations at Drigg.

  18. LLW disposal wasteform preparation in the UK: the role of high force compaction

    International Nuclear Information System (INIS)

    Johnson, L. F.; Fearnley, I. G.

    1991-01-01

    British Nuclear Fuels plc (BNFL) owns and operates the principal UK solid low level radioactive waste (LLW) disposal site. The site is located at Drigg in West Cumbria some 6 km to the south east of BNFL's Sellafield reprocessing complex. Sellafield is the major UK generator of LLW, accounting for about 85% of estimated future arisings of raw (untreated, unpackaged) waste. Non-Sellafield consignors to the Drigg site include other BNFL production establishments, nuclear power stations, sites of UKAEA, Ministry of Defence facilities, hospitals, universities, radioisotope production sites and various other industrial organisations. In September 1987, BNFL announced a major upgrade of operations at the Drigg site aimed at improving management practices, the efficiency of space utilisation and enhancing the visual impact of disposal operations. During 1989 a review of plans for compaction and containerisation of Sellafield waste identified that residual voidage in ISO freight containers could be significant even after the introduction of compaction. Subsequent studies which examined a range of compaction and packaging options concluded that the preferred scheme centred on the use of high force compaction (HFC) of compactable waste, and grouting to take up readily accessible voidage in the wasteform. The paper describes the emergence of high force compaction as the preferred scheme for wasteform preparation and subsequent benefits against the background of the overall development of Low Level Waste disposal operations at Drigg

  19. A hotel-based outbreak of Salmonella enterica subsp. Enterica serovar Enteritidis (Salmonella Enteritidis) in the United Kingdom, 2006.

    Science.gov (United States)

    Calvert, N; Murphy, L; Smith, A; Copeland, D

    2007-03-01

    An outbreak of food-borne Salmonella Enteritidis PT4 occurred in Cumbria, in north-west England, in the summer of 2006. Fifteen people, all with positive stool samples, met the case definition; three of these were admitted to hospital, including one patient who died. Preliminary investigations suggested a link to a meal served at a local hotel. A case control study was implemented, together with microbiological and environmental investigations. Fifteen microbiologically confirmed cases and 27 unmatched controls were included in the study, controls being randomly selected from people who had eaten at the hotel on the same day. The epidemiological evidence indicated a very strong association between infection and consumption of tiramisu made with raw shell eggs, although none were available for microbiological investigation. These results are in line with other salmonellosis outbreaks that have been associated with the use of raw shell eggs in food manufacturing and production. This paper highlights the continuing need for a greater awareness by those who work in the food industry of the health risks associated with the consumption of raw shell eggs.

  20. Laboratory and field studies of biogenic volatile organic compound emissions from Sitka spruce (Picea sitchensis Bong.) in the United Kingdom

    Science.gov (United States)

    Street, Rachel A.; Duckham, S. Craig; Hewitt, C. Nicholas

    1996-10-01

    Isoprene and monoterpene emission rates were measured from Sitka spruce (Picea sitchensis Bong.) with a dynamic flow-through branch enclosure, both in the laboratory and in the field in the United Kingdom. In the laboratory, emission rates of isoprene comprised over 94% of the identified VOC species, and were exponentially related to temperature over a period of 1 day. This exponential relationship broke down at ˜33°C. Field measurements were taken on five sampling days in 1992 and 1993, in Grizedale Forest, Cumbria. Total emission rates were in the range 36-3771 ng g-1 h-1. Relative emissions were more variable than suggested by laboratory measurements, with monoterpenes contributing at least 64% to the total emissions in most cases. There was a significant variation in the basal emission rate both across the growing season and between different ages of vegetation, the causes of which are as yet unknown. Total emission rates, in July 1993, were estimated to be between 0.01 and 0.27% of assimilated carbon.

  1. Simulating the long-term chemistry of an upland UK catchment: Major solutes and acidification

    Energy Technology Data Exchange (ETDEWEB)

    Tipping, E. [Centre for Ecology and Hydrology (Lancaster), Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom)]. E-mail: et@ceh.ac.uk; Lawlor, A.J. [Centre for Ecology and Hydrology (Lancaster), Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Lofts, S. [Centre for Ecology and Hydrology (Lancaster), Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom)

    2006-05-15

    CHUM-AM was used to investigate changes in soil and water chemical variables in four moorland sub-catchments in Cumbria UK, to which non-marine S deposition has declined by 65% since the 1970s. The principal processes represented in the model comprise N and S uptake and release, water movements, the binding of cations by soil organic matter, chemical interactions in solution, and chemical weathering. CHUM-AM reproduced reasonably well the current soil pH and pools of N and S, and changes in streamwater chemistry over the period 1970-2000, notably decreases in the concentrations of alkaline earth cations and sulphate, and increases in pH. The model also predicts streamwater pH-Al relationships in agreement with observations. Predictive calculations suggest that constant atmospheric deposition of N at present rates will lead to N saturation and re-acidification, whereas a 50% reduction in N would stabilise soil and streamwater pH at about the present levels. - CHUM-AM accounts for recovery from acidification due to sulphur deposition, but predicts re-acidification if nitrogen deposition is not reduced.

  2. Simulating the long-term chemistry of an upland UK catchment: Heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Tipping, E. [Centre for Ecology and Hydrology (Lancaster), Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom)]. E-mail: et@ceh.ac.uk; Lawlor, A.J. [Centre for Ecology and Hydrology (Lancaster), Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Lofts, S. [Centre for Ecology and Hydrology (Lancaster), Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Shotbolt, L. [Environment Department, University of York, Heslington, York YO10 5DD (United Kingdom)

    2006-05-15

    CHUM-AM was used to investigate the behaviours of atmospherically-deposited heavy metals (Ni, Cu, Zn, Cd and Pb) in three moorland sub-catchments in Cumbria UK. The principal processes controlling cationic metals are competitive partitioning to soil organic matter, chemical interactions in solution, and chemical weathering. Metal deposition histories were generated by combining measured data for the last 30 years with local lake sediment records. For Ni, Cu, Zn and Cd, default parameters for the interactions with organic matter provided reasonable agreement between simulated and observed present-day soil metal pools and average streamwater concentrations. However, for Pb, the soil binding affinity in the model had to be increased to match the observations. Simulations suggest that weakly-sorbing metals (Ni, Zn, Cd) will respond on timescales of decades to centuries to changes in metal inputs or acidification status. More strongly-sorbing metals (Cu, Pb) will respond over centuries to millennia. - Catchment turnover times for the strongly-retained metals Cu and Pb are of the order of centuries, whereas those for the more mobile Ni, Zn and Cd are appreciably shorter.

  3. Development and Presentation of the Drigg Post-Closure Safety Case

    International Nuclear Information System (INIS)

    Kelly, Eugene; Watts, Len; Grimwood, Paul

    2001-01-01

    Drigg is an operational facility for the near-surface disposal of solid low level radioactive waste (LLW). The disposal facility is located in Cumbria, north-west England, near the Sellafield nuclear site, and is owned and operated by British Nuclear Fuels plc (BNFL). Disposals at Drigg are carried out under the terms of an authorisation granted by the UK Environment Agency. Periodically the Drigg authorisation is subject to formal regulatory review. The current regulatory guidance, 'Disposal Facilities on Land for Low and Intermediate Level Radioactive Wastes: Guidance on Requirements for Authorisation' (the GRA) was published in 1997 and contains guidance on the principles and requirements against which the Environment Agency will consider applications for disposal authorisation. BNFL has undertaken to produce an updated Drigg postclosure safety case (PCSC) in September 2002 to support the next authorisation review. In preparation for this, BNFL published a 'Status Report on the Development of the 2002 Drigg PCSC' in March 2000. This paper discusses the main components of the Drigg PCSC and how they relate to each other. Central to the safety case will be a systematic, post-closure radiological safety assessment (PCRSA). However the main focus of this paper is on the other main components of the PCSC which are presented in conjunction with the PCRSA to make a complete and integrated safety case. In addition other confidence building activities which are key to developing and presenting the safety case are discussed, in particular communications with the stakeholders

  4. Occupational cancer and radiation

    International Nuclear Information System (INIS)

    Brahams, D.

    1988-01-01

    There have been two High Court actions and seven inquests in the UK, with reference to the debate on occupational hazards of long term, low dose exposure. In July, 1987, two cases alleging that workers in the nuclear industry had contracted cancer due to their exposure to radiation at work had to be abandoned halfway through the trial after the judge had heard the medical evidence. A 57-year old man claimed that Hodgkin's disease had been caused by radiation while at work at Sellafield. However, medical opinion was that Hodgkin's disease had never been accepted as caused by radiation. In the second case a man who had died of stomach cancer at the age of 54 after working for UKAEA at Dounreay for 7 years, had received 190 mSv. The defendants' experts rated the likelihood of radiation as the cause at 3-6%; the plaintiffs' experts had suggested 30-50%. Seven inquest juries sitting in West Cumbria from 1983 to 1988 have brought in three verdicts of death caused by an industrial disease, three open verdicts, and one of natural causes. The men had all worked for BNFL at Sellafield for many years. (author)

  5. Turbulence structure of the atmosphere in a region of complex terrain and near to a major industrial installation

    International Nuclear Information System (INIS)

    Robinson, L.; Teasdale, I.

    1996-01-01

    The Sellafield nuclear reprocessing plant in Cumbria discharges a variety of pollutants to both the marine environment and the atmosphere. Understanding the dispersion of this effluence is of prime importance for the industry, which must demonstrate safety to national regulatory bodies. Accurate modelling of the air flow in the region is one of the key ingredients towards correct prediction of the ground level concentrations of emissions. Work is being carried out to assess the suitability of the computer code FLOWSTAR for the task of predicting the atmospheric flow. Its predictions include means of the turbulent statistics within the boundary layer of the atmosphere. This paper will concentrate on the comparison of the predictions of these turbulence statistics at key points with the values measured by sonic anemometry. It is the turbulence, quantified by the standard deviations σ u , σ v and σ w of the wind vector's components that is responsible for the local dispersion of pollution and for inducing many other boundary layer changes. The high frequency variation in the wind vector brings about the necessity for rapid response equipment such as the sonic anemometer

  6. The economics of nuclear power programmes in the United Kingdom

    International Nuclear Information System (INIS)

    Jones, P.L.

    1984-01-01

    In Chapter 1 an overview of the technology involved in the operation of various nuclear reactor types, both thermal and fast breeder, is provided, and the operations that comprise the alternative nuclear fuel cycles examined. Chapter 2 traces the historical development of the uranium market and highlights the effect that institutional arrangements such as the formation of a cartel has had on the market price of uranium. The prospects for increased uranium exploration activity and likely demand scenarios are then reviewed. In Chapter 3 the economic viability of reprocessing 'spent' nuclear fuel in the UK is analysed within the context of the decision to proceed with the construction of the thermal-oxide reprocessing plant (THORP) at Windscale in Cumbria. The various radioactive waste substances emanating from nuclear fuel-cycle operations undertaken in the UK are described in Chapter 4 and the prospects for their safe management and disposal examined. Chapter 5 provides an economic appraisal of both coal and nuclear-fuelled electricity generating plant based on the criterion of social cost. The results are used as the data-input for an appraisal of the investment in generating plant that will be required in the UK to supply four different electricity demand scenarios. The conclusions are discussed in Chapter 6. (author)

  7. Application of the ERICA Integrated Approach to the Drigg coastal sand dunes

    International Nuclear Information System (INIS)

    Wood, M.D.; Marshall, W.A.; Beresford, N.A.; Jones, S.R.; Howard, B.J.; Copplestone, D.; Leah, R.T.

    2008-01-01

    The EC-funded project 'Environmental Risks from Ionising Contaminants: Assessment and Management' (ERICA) developed an 'Integrated Approach' for assessing the impact of ionising radiation on ecosystems. This paper presents the application of the ERICA Integrated Approach, supported by a software programme (the ERICA Tool) and guidance documentation, to an assessment of the Drigg coastal sand dunes (Cumbria, UK). Targeted sampling provided site-specific data for sand dune biota, including amphibians and reptiles. Radionuclides reported included 90 Sr, 99 Tc, 137 Cs, 238 Pu, 239+240 Pu and 241 Am. Site-specific data were compared to predictions derived using the ERICA Tool. Some under- and over-predictions of biota activity concentrations were identified but can be explained by the specific ecological characteristics and contamination mechanism of the dunes. Overall, the results indicated no significant impact of ionising radiation on the sand dune biota and the Integrated Approach was found to be a flexible and effective means of conducting a radiation impact assessment

  8. Reconstructing Common Era relative sea-level change on the Gulf Coast of Florida

    Science.gov (United States)

    Gerlach, Matthew J.; Engelhart, Simon E.; Kemp, Andrew C.; Moyer, Ryan P.; Smoak, Joseph M.; Bernhardt, Christopher E.; Cahill, Niamh

    2017-01-01

    To address a paucity of Common Era data in the Gulf of Mexico, we reconstructed ~ 1.1 m of relative sea-level (RSL) rise over the past ~ 2000 years at Little Manatee River (Gulf Coast of Florida, USA). We applied a regional-scale foraminiferal transfer function to fossil assemblages preserved in a core of salt-marsh peat and organic silt that was dated using radiocarbon and recognition of pollution, 137Cs and pollen chronohorizons. Our proxy reconstruction was combined with tide-gauge data from four nearby sites spanning 1913–2014 CE. Application of an Errors-in-Variables Integrated Gaussian Process (EIV-IGP) model to the combined proxy and instrumental dataset demonstrates that RSL fell from ~ 350 to 100 BCE, before rising continuously to present. This initial RSL fall was likely the result of local-scale processes (e.g., silting up of a tidal flat or shallow sub-tidal shoal) as salt-marsh development at the site began. Since ~ 0 CE, we consider the reconstruction to be representative of regional-scale RSL trends. We removed a linear rate of 0.3 mm/yr from the RSL record using the EIV-IGP model to estimate climate-driven sea-level trends and to facilitate comparison among sites. This analysis demonstrates that since ~ 0 CE sea level did not deviate significantly from zero until accelerating continuously from ~ 1500 CE to present. Sea level was rising at 1.33 mm/yr in 1900 CE and accelerated until 2014 CE when a rate of 2.02 mm/yr was attained, which is the fastest, century-scale trend in the ~ 2000-year record. Comparison to existing reconstructions from the Gulf coast of Louisiana and the Atlantic coast of northern Florida reveal similar sea-level histories at all three sites. We explored the influence of compaction and fluvial processes on our reconstruction and concluded that compaction was likely insignificant. Fluvial processes were also likely insignificant, but further proxy evidence is needed to fully test this hypothesis. Our results

  9. Holocene sea-level changes in the Falkland Islands

    Science.gov (United States)

    Newton, Tom; Gehrels, Roland; Daley, Tim; Long, Antony; Bentley, Mike

    2014-05-01

    In many locations in the southern hemisphere, relative sea level (RSL) reached its maximum position during the middle Holocene. This highstand is used by models of glacial isostatic adjustment (GIA) to constrain the melt histories of the large ice sheets, particularly Antarctica. In this paper we present the first Holocene sea-level record from the Falkland Islands (Islas Malvinas), an archipelago located on the Patagonian continental shelf about 500 km east of mainland South America at a latitude of ca. 52 degrees. Unlike coastal locations in southernmost South America, Holocene sea-level data from the Falklands are not influenced by tectonics, local ice loading effects and large tidal ranges such that GIA and ice-ocean mass flux are the dominant drivers of RSL change. Our study site is a salt marsh located in Swan Inlet in East Falkland, around 50 km southwest of Stanley. This is the largest and best developed salt marsh in the Falkland Islands. Cores were collected in 2005 and 2013. Lithostratigraphic analyses were complemented by analyses of foraminifera, testate amoebae and diatoms to infer palaeoenvironments. The bedrock, a Permian black shale, is overlain by grey-brown organic salt-marsh clay, up to 90 cm thick, which, in a landward direction, is replaced by freshwater organic sediments. Overlying these units are medium-coarse sands with occasional pebbles, up to 115 cm thick, containing tidal flat foraminifera. The sandy unit is erosively overlain by a grey-brown organic salt-marsh peat which extends up to the present surface. Further away from the sea this unit is predominantly of freshwater origin. Based on 13 radiocarbon dates we infer that prior to ~9.5 ka sea level was several metres below present. Under rising sea levels a salt marsh developed which was suddenly drowned around 8.4 ka, synchronous with a sea-level jump known from northern hemisphere locations. Following the drowning, RSL rose to its maximum position around 7 ka, less than 0.5 m above

  10. Eco-geomorphological Response of an Estuarine Wetland to Changes in the Hydraulic Regime

    Science.gov (United States)

    Howe, A.; Rodrí Guez, J.

    2006-12-01

    In the Hunter Estuary, NSW, Australia, tidal regimes of numerous wetlands have been affected by extensive anthropomorphic intervention, including harbour dredging, land reclamation, and construction of infrastructure. The importance of these wetlands to ecosystem services such as primary productivity, flood attenuation and water quality enhancement has led to an increased effort to rehabilitate degraded sites by reintroduction of tidal flows. Because of the complex and dynamics interactions among hydraulic regime, vegetation and geomorphology, it is difficult to predict how wetlands will respond to the reintroduction of these flows and whether the resulting habitat distribution will achieve desired management outcomes. Eco-geomorphology research conducted at a rehabilitated wetland comprised of mangrove forest and saltmarsh has tracked the response of estuarine vegetation distribution and wetland geomorphology to reinstatement of tidal flows following removal of impediments in 1995. The wetland is an important site for migratory shorebirds and is highly compartmentalized due to the presence of roads and culverts. Our research methodology integrates historical analysis, field measurements and laboratory experiments. Historical analysis matched vegetation evolution obtained from aerial photography to bird roosting habitat use, which is in decline. Field data collection carried out in the last two years included topographic, vegetation and soil surveys; velocity, water quality and water level profiling; and high precision measurements of substrate shallow subsidence and vertical accretion. Laboratory studies focussed on the effects of estuarine vegetation on flow resistance. All this information has allowed for the characterization and conceptualization of the system, which includes zones with different tidal attenuation levels and vegetation distribution. It was found that an increased tidal frame resulting from hydraulic manipulation lead to a landward shift in

  11. Modelling the impacts of barrier-island transgression and anthropogenic disturbance on blue carbon budgets

    Science.gov (United States)

    Theuerkauf, E. J.; Rodriguez, A. B.

    2017-12-01

    The size of backbarrier saltmarsh carbon reservoirs are dictated by transgressive processes, such as erosion and overwash, yet these processes are not included in blue carbon budgets. These carbon reservoirs are presumed to increase through time if marsh elevation is keeping pace with sea-level rise. However, changes in marsh width due to erosion and overwash can alter carbon budgets and reservoirs. To explore the impacts of these processes on transgressive barrier island carbon budgets and reservoirs we developed and tested a transect model. The model couples a carbon storage term driven by backbarrier marsh width and a carbon export term driven by ocean and backbarrier shoreline erosion. We tested the model using data collected from two transgressive barrier islands in North Carolina with different backbarrier settings. Core Banks is an undeveloped barrier island with a wide backbarrier marsh and lagoon, hence, landward migration of the island (rollover) is unimpeded. Barrier rollover is impeded at Onslow Beach as there is no backbarrier lagoon and the island is immediately adjacent to steeper mainland topography. Sediment cores were collected to determine carbon storage rates as well as the quantity of carbon exported from eroding marsh. Backbarrier marsh erosion rates, ocean shoreline erosion rates, and changes in marsh width were determined from aerial photographs. Output from the model indicated that hurricane erosion and overwash as well as human disturbance from the construction of the Intracoastal Waterway temporarily transitioned the Onslow Beach sites to carbon sources. Through time, the carbon reservoir at this barrier continued to decrease as carbon export outpaced carbon storage. The carbon reservoir will continue to exhaust as the ocean shoreline migrates landward given the inability for new marsh to form during island rollover. At Core Banks, barrier rollover is unimpeded and new saltmarsh can form during transgression. The Core Banks site only

  12. Microbial ecology of acid strip mine lakes in southern Indiana

    International Nuclear Information System (INIS)

    Gyure, R.A.

    1986-01-01

    In this study, the author examined the limnology and microbial ecology of two acid strip mine lakes in the Greene-Sullivan State Forest near Dugger, Indiana. Reservoir 29 is a larger lake (225 ha) with water column pH of 2.7 and sediment pH of 3.8. Lake B, a smaller (20 ha) lake to the south of Reservoir 29, also has an acidic water column (pH 3.4) but more neutral sediments (pH 6.2). Both have very high sulfate concentrations: 20-30 mM in the water column and as high as 100 mM in the hypolimnion of Lake B. Low allochthonous carbon and nutrient input characterize these lakes as oligotrophic, although algal biomass is higher than would be expected for this trophic status. In both lakes, algal populations are not diverse, with a few species of single-celled Chlorophyta and euglenoids dominating. Algal biomass is concentrated in a thin 10 cm layer at the hypolimnion/metalimnion interface, although light intensity at this depth is low and severely limits productivity. Bacterial activity based on 14 C-glucose incorporation is highest in the hypolimnion of both lakes, and sulfate-reduction is a dominant process in the sediments. Rates of sulfate-reduction compare with those in other freshwater environments, but are not as high as rates measured in high sulfate systems like saltmarsh and marine sediments

  13. Linking social, ecological, and physical science to advance natural and nature-based protection for coastal communities.

    Science.gov (United States)

    Arkema, Katie K; Griffin, Robert; Maldonado, Sergio; Silver, Jessica; Suckale, Jenny; Guerry, Anne D

    2017-07-01

    Interest in the role that ecosystems play in reducing the impacts of coastal hazards has grown dramatically. Yet the magnitude and nature of their effects are highly context dependent, making it difficult to know under what conditions coastal habitats, such as saltmarshes, reefs, and forests, are likely to be effective for saving lives and protecting property. We operationalize the concept of natural and nature-based solutions for coastal protection by adopting an ecosystem services framework that propagates the outcome of a management action through ecosystems to societal benefits. We review the literature on the basis of the steps in this framework, considering not only the supply of coastal protection provided by ecosystems but also the demand for protective services from beneficiaries. We recommend further attention to (1) biophysical processes beyond wave attenuation, (2) the combined effects of multiple habitat types (e.g., reefs, vegetation), (3) marginal values and expected damage functions, and, in particular, (4) community dependence on ecosystems for coastal protection and co-benefits. We apply our approach to two case studies to illustrate how estimates of multiple benefits and losses can inform restoration and development decisions. Finally, we discuss frontiers for linking social, ecological, and physical science to advance natural and nature-based solutions to coastal protection. © 2017 New York Academy of Sciences.

  14. A chronology of hurricane landfalls at Little Sippewissett Marsh, Massachusetts, USA, using optical dating

    Science.gov (United States)

    Madsen, A. T.; Duller, G. A. T.; Donnelly, J. P.; Roberts, H. M.; Wintle, A. G.

    2009-08-01

    Optical dating has been applied to sediments preserved in Little Sippewissett Marsh, Massachusetts, USA, which are associated with overwashing of the beach barrier during hurricane strikes on the coast. The aims were to determine the hurricane landfall frequency, and make comparisons with independent age control and the historical record. Written sources of hurricane activity along the American east coast are only considered reliable back to the mid 19th century, but the sedimentary record is potentially much longer. Optical dating was applied to quartz grains extracted from thirteen samples within a sediment core from the salt-marsh. Variability in the luminescence characteristics between aliquots was observed and ~ 33% of the measured aliquots were discarded based upon the ratio of the fast component to the medium component. The majority of the samples gave normal dose distributions implying homogeneous resetting of the luminescence signal at the time of deposition, but three of the samples required application of the minimum age model (MAM). Ages ranging between 20 ± 2 and 594 ± 38 years were obtained and are broadly in agreement with independent chronologies, thus demonstrating the potential of optical dating in this setting. The hurricane record based upon optical dating extends approximately 300 years further back in time than the official National Oceanic Atmospheric Administration (NOAA) record. The localised nature of hurricane landfalls means that it will be necessary to collect multiple cores from a number of different sites in order to build up a complete hurricane record for this part of the coast.

  15. Chemical Fouling Reduction of a Submersible Steel Spectrophotometer in Estuarine Environments Using a Sacrificial Zinc Anode.

    Science.gov (United States)

    Tait, Zachary S; Thompson, Megan; Stubbins, Aron

    2015-07-01

    The availability of in situ spectrophotometers, such as the S::CAN spectro::lyser, has expanded the possibilities for high-frequency water quality data collection. However, biological and chemical fouling can degrade the performance of in situ spectrophotometers, especially in saline environments with rapid flow rates. A complex freshwater washing system has been previously designed to reduce chemical fouling for the S::CAN spectro::lyser spectrophotometer. In the current study, we present a simpler, cheaper alternative: the attachment of a sacrificial zinc anode. Results are presented detailing the S::CAN spectro::lyser performance with and without the addition of the sacrificial anode. Attachment of the zinc anode provided efficient corrosion protection during 2-wk deployments in a highly dynamic (average tidal range, 2.5 m) saline tidal saltmarsh creek at Groves Creek, Skidaway Institute of Oceanography, Savannah, GA. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  16. Coordinating across scales: Building a regional marsh bird monitoring program from national and state Initiatives

    Science.gov (United States)

    Shriver, G.W.; Sauer, J.R.

    2008-01-01

    Salt marsh breeding bird populations (rails, bitterns, sparrows, etc.) in eastern North America are high conservation priorities in need of site specific and regional monitoring designed to detect population changes over time. The present status and trends of these species are unknown but anecdotal evidence of declines in many of the species has raised conservation concerns. Most of these species are listed as conservation priorities on comprehensive wildlife plans throughout the eastern U.S. National Wildlife Refuges, National Park Service units, and other wildlife conservation areas provide important salt marsh habitat. To meet management needs for these areas, and to assist regional conservation planning, survey designs are being developed to estimate abundance and population trends for these breeding bird species. The primary purpose of this project is to develop a hierarchical sampling frame for salt marsh birds in Bird Conservation Region (BCR) 30 that will provide the ability to estimate species population abundances on 1) specific sites (i.e. National Parks and National Wildlife Refuges), 2) within states or regions, and 3) within BCR 30. The entire breeding range of Saltmarsh Sharp-tailed and Coastal Plain Swamp sparrows are within BCR 30, providing an opportunity to detect population trends within the entire breeding ranges of two priority species.

  17. Sustainability of future coasts and estuaries: A synthesis

    Science.gov (United States)

    Newton, Alice; Harff, Jan; You, Zai-Jin; Zhang, Hua; Wolanski, Eric

    2016-12-01

    Coasts are at the nexus of the Anthropocene, where land, marginal seas and atmosphere meet along a thin strip that is inhabited by nearly half the human population (Wolanski and Elliott, 2015). Coasts are often fringed by rich habitats such as mangroves, salt-marshes, inter-tidal mud and sand flats, seagrass meadows, kelp forests and coral reefs that provide a valuable range of ecosystem services to humans and to the adjacent marginal seas (Van den Belt and Costanza, 2011). It is the highly dynamic system that is constantly being reshaped by changing natural forces and anthropogenic activities. Coastal systems and human societies form coastal social-ecological systems that increasingly face multiple pressures, which threaten their ecological and economical sustainability. Common pressures include changes to land use and hydrology, land reclamation, coastal sand mining, harbour dredging, pollution and eutrophication, overexploitation such as overfishing, all in the context of climate change. During the 20th Century, coastal scientists studied the problems and issues arising along the coasts (Ramesh et al., 2015). Now, in the 21st Century, their focus must increasingly be about how to solve these problems and issues through better management and innovative approaches. To study these matters, two workshops were held in Yantai, P.R. China, in September 2015, hosted by the Yantai Institute of Coastal Zone Research, CAS. The outcome of these workshops is this special issue of Estuarine, Coastal and Shelf Science.

  18. Extended late Holocene relative sea-level histories for North Carolina, USA

    Science.gov (United States)

    Kemp, Andrew C.; Kegel, Jessica J.; Culver, Stephen J.; Barber, Donald C.; Mallinson, David J.; Leorri, Eduardo; Bernhardt, Christopher E.; Cahill, Niamh; Riggs, Stanley R.; Woodson, Anna L.; Mulligan, Ryan P.; Horton, Benjamin P.

    2017-01-01

    We produced ∼3000-year long relative sea-level (RSL) histories for two sites in North Carolina (USA) using foraminifera preserved in new and existing cores of dated salt-marsh sediment. At Cedar Island, RSL rose by ∼2.4 m during the past ∼3000 years compared to ∼3.3 m at Roanoke Island. This spatial difference arises primarily from differential GIA that caused late Holocene RSL rise to be 0.1–0.2 mm/yr faster at Roanoke Island than at Cedar Island. However, a non-linear difference in RSL between the two study regions (particularly from ∼0 CE to ∼1250 CE) indicates that additional local- to regional-scale processes drove centennial-scale RSL change in North Carolina. Therefore, the Cedar Island and Roanoke Island records should be considered as independent of one another. Between-site differences on sub-millennial timescales cannot be adequately explained by non-stationary tides, sediment compaction, or local sediment dynamics. We propose that a period of accelerating RSL rise from ∼600 CE to 1100 CE that is present at Roanoke Island (and other sites north of Cape Hatteras at least as far as Connecticut), but absent at Cedar Island (and other sites south of Cape Hatteras at least as far as northeastern Florida) is a local-to regional-scale effect of dynamic ocean and/or atmospheric circulation.

  19. Density, size structure, shell orientation and epibiontic colonization of the fan mussel Pinna nobilis L. 1758 (Mollusca: Bivalvia in three contrasting habitats in an estuarine area of Sardinia (W Mediterranean

    Directory of Open Access Journals (Sweden)

    Piero Addis

    2009-03-01

    Full Text Available We investigated the spatial distribution, size structure, shell orientation and valve colonization by epibionts of the endangered Mediterranean bivalve Pinna nobilis in three continuous but different habitats in the Gulf of Oristano (Sardinia, western Mediterranean. The sampling stations chosen were: an estuarine area (E of coastal salt-marshes characterized by unvegetated sea-bottoms; and two areas in a seagrass meadow characterized by an extensive Posidonia oceanica meadow (Mw and patched mixed meadows of P. oceanica and Cymodocea nodosa (Me. We found significant differences in mean densities among stations and the highest value was found in the estuarine area. Shell orientation showed that there was uniform circular distribution of specimens in the Mw station and a unimodal distribution in the Me and E stations, where specimens were set at 0°N and 10°NNE, which is a pattern related to sea drift. Shell epibiosis displayed differences between habitats. The highest valve colonization was in the estuary, with filamentous dark algae and Ostrea edulis reaching almost 90 percent of shell coverage. This study provides new information on habitat preferences and data for assessing local populations of P. nobilis that is useful for its conservation and improving the knowledge of its ecology.

  20. Spatial and seasonal variation in heavy metals in the sediments and biota of two adjacent estuaries, the Orwell and the Stour, in eastern England

    International Nuclear Information System (INIS)

    Wright, P.; Mason, C.F.

    1999-01-01

    A study was made of the concentrations of the elements As, Cd, Cu, Hg, Mn, Ni, Pb and Zn in the sediments and biota of two adjacent estuaries, the Orwell and Stour, in eastern England. The Orwell Estuary, with its urbanized head, was more contaminated with heavy metals than the Stour Estuary. Generally, in both estuaries, concentrations of metals were highest towards the head and the mouth. Saltmarsh sediments accumulated higher concentrations of most metals than mudflat sediments. Metal concentrations in the biota showed marked interspecific differences; Mytilus edulis had higher concentrations of Cd, Littorina littorea higher concentrations of Cu and Mn and Arenicola marina higher concentrations of Hg. Invertebrates from the Orwell had higher metal concentrations than those from the Stour. Algae had generally lower levels of metals than invertebrates. Metal concentrations were greatest and more variable in the top 10 cm of sediment. Metals were at greatest concentrations in winter and lowest in summer in sediments, algae and invertebrates. Mercury concentration increased with size in the three invertebrate species studied, but Cd and Zn generally were at higher concentrations in younger animals. Comparisons of sediments with average shale values indicated anthropogenic enrichment with several metals but it was considered that only Pb, at some sites, and possibly Hg posed potential threats to the ecology of the estuaries. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  1. Land claim and loss of tidal flats in the Yangtze Estuary.

    Science.gov (United States)

    Chen, Ying; Dong, Jinwei; Xiao, Xiangming; Zhang, Min; Tian, Bo; Zhou, Yunxuan; Li, Bo; Ma, Zhijun

    2016-04-01

    Tidal flats play a critical role in supporting biodiversity and in providing ecosystem services but are rapidly disappearing because of human activities. The Yangtze Estuary is one of the world's largest alluvial estuaries and is adjacent to the most developed economic zone in China. Using the Yangtze Estuary as a study region, we developed an automatic algorithm to estimate tidal flat areas based on the Land Surface Water Index and the Normalized Difference Vegetation Index. The total area of tidal flats in the Yangtze Estuary has decreased by 36% over the past three decades, including a 38% reduction in saltmarshes and a 31% reduction in barren mudflats. Meanwhile, land claim has accumulated to 1077 km(2), a value that exceeds the area of the remaining tidal flats. We divided the Yangtze Estuary into Shanghai and Jiangsu areas, which differ in riverine sediment supply and tidal flat management patterns. Although land claim has accelerated in both areas, the decline in tidal flat area has been much greater in Jiangsu than in Shanghai because of abundant supplies of sediment and artificial siltation in the latter area. The results highlight the need for better coastal planning and management based on tidal flat dynamics.

  2. Influence of salinity on prevalence of the parasite Loxothylacus panopaei in the xanthid Panopeus obesus in SW Florida.

    Science.gov (United States)

    Tolley, S Gregory; Winstead, James T; Haynes, Lesli; Volety, Aswani K

    2006-06-23

    This study was conducted to examine the potential influence of salinity, a proxy for freshwater inflow, on the prevalence of the castrator parasite Loxothylacus panopaei on saltmarsh mud crabs Panopeus obesus on SW Florida oyster reefs. Spatial and seasonal patterns of the presence of potential host crabs and the prevalence of the parasite were assessed in the Caloosahatchee, Estero, and Faka Union estuaries. Lift nets (1 m2) containing 5 1 of oyster clusters were deployed on intertidal reefs at 3 sites along the salinity gradient of each estuary. Nets were deployed during 3 seasonally dry and 3 seasonally wet months for a period of 30 d. P. obesus densities tended to increase downstream in higher salinity waters, with crabs being absent from the upper station in the Caloosahatchee during both seasons and absent from the upper station of the Faka Union during wet months. Parasite prevalence was reduced upstream in each estuary during wet months compared to dry months, and for those estuaries that experienced higher relative levels of freshwater inflow. Furthermore, parasite prevalence was positively correlated with the mean salinity of capture of host crabs. Based on the distribution of P. obesus and the above patterns related to salinity, it appears that freshwater inflow and seasonal rains might regulate the prevalence of this parasite in SW Florida by creating spatiotemporal, low salinity refuges for its host.

  3. Hemigrapsus sanguineus in Long Island salt marshes: experimental evaluation of the interactions between an invasive crab and resident ecosystem engineers

    Directory of Open Access Journals (Sweden)

    Bradley J. Peterson

    2014-07-01

    Full Text Available The invasive Asian shore crab, Hemigrapsus sanguineus, has recently been observed occupying salt marshes, a novel environment for this crab species. As it invades this new habitat, it is likely to interact with a number of important salt marsh species. To understand the potential effects of H. sanguineus on this ecosystem, interactions between this invasive crab and important salt marsh ecosystem engineers were examined. Laboratory experiments demonstrated competition for burrows between H. sanguineus and the native fiddler crab, Uca pugilator. Results indicate that H. sanguineus is able to displace an established fiddler crab from its burrow. Feeding experiments revealed that the presence of H. sanguineus has a significantly negative impact on the number as well as the biomass of ribbed mussels (Geukensia demissa consumed by the green crab, Carcinus maenas, although this only occurred at high predator densities. In addition, when both crabs foraged together, there was a significant shift in the size of mussels consumed. These interactions suggests that H. sanguineus may have long-term impacts and wide-ranging negative effects on the saltmarsh ecosystem.

  4. Hemigrapsus sanguineus in Long Island salt marshes: experimental evaluation of the interactions between an invasive crab and resident ecosystem engineers.

    Science.gov (United States)

    Peterson, Bradley J; Fournier, Alexa M; Furman, Bradley T; Carroll, John M

    2014-01-01

    The invasive Asian shore crab, Hemigrapsus sanguineus, has recently been observed occupying salt marshes, a novel environment for this crab species. As it invades this new habitat, it is likely to interact with a number of important salt marsh species. To understand the potential effects of H. sanguineus on this ecosystem, interactions between this invasive crab and important salt marsh ecosystem engineers were examined. Laboratory experiments demonstrated competition for burrows between H. sanguineus and the native fiddler crab, Uca pugilator. Results indicate that H. sanguineus is able to displace an established fiddler crab from its burrow. Feeding experiments revealed that the presence of H. sanguineus has a significantly negative impact on the number as well as the biomass of ribbed mussels (Geukensia demissa) consumed by the green crab, Carcinus maenas, although this only occurred at high predator densities. In addition, when both crabs foraged together, there was a significant shift in the size of mussels consumed. These interactions suggests that H. sanguineus may have long-term impacts and wide-ranging negative effects on the saltmarsh ecosystem.

  5. Extended late Holocene relative sea-level histories for North Carolina, USA

    Science.gov (United States)

    Kemp, Andrew C.; Kegel, Jessica J.; Culver, Stephen J.; Barber, Donald C.; Mallinson, David J.; Leorri, Eduardo; Bernhardt, Christopher E.; Cahill, Niamh; Riggs, Stanley R.; Woodson, Anna L.; Mulligan, Ryan P.; Horton, Benjamin P.

    2017-03-01

    We produced ∼3000-year long relative sea-level (RSL) histories for two sites in North Carolina (USA) using foraminifera preserved in new and existing cores of dated salt-marsh sediment. At Cedar Island, RSL rose by ∼2.4 m during the past ∼3000 years compared to ∼3.3 m at Roanoke Island. This spatial difference arises primarily from differential GIA that caused late Holocene RSL rise to be 0.1-0.2 mm/yr faster at Roanoke Island than at Cedar Island. However, a non-linear difference in RSL between the two study regions (particularly from ∼0 CE to ∼1250 CE) indicates that additional local- to regional-scale processes drove centennial-scale RSL change in North Carolina. Therefore, the Cedar Island and Roanoke Island records should be considered as independent of one another. Between-site differences on sub-millennial timescales cannot be adequately explained by non-stationary tides, sediment compaction, or local sediment dynamics. We propose that a period of accelerating RSL rise from ∼600 CE to 1100 CE that is present at Roanoke Island (and other sites north of Cape Hatteras at least as far as Connecticut), but absent at Cedar Island (and other sites south of Cape Hatteras at least as far as northeastern Florida) is a local-to regional-scale effect of dynamic ocean and/or atmospheric circulation.

  6. Nutritional support of estuary perch ( Macquaria colonorum) in a temperate Australian inlet: Evaluating the relative importance of invasive Spartina

    Science.gov (United States)

    Hindell, J. S.; Warry, F. Y.

    2010-12-01

    The invasive saltmarsh grass Spartina is widely considered a threat to the health of coastal ecosystems in south-eastern Australia, however, the ecological impacts of Spartina on estuarine communities are poorly understood. The largest infestation of Spartina in Victoria occurs in Anderson Inlet. The relative contribution of Spartina, vs. non-invasive autotrophs, to the nutrition of an estuarine fish, Macquaria colonorum was assessed using stable isotopes and gut content analyses. The δ 13C and δ 15N compositions of autotrophs and M. colonorum varied spatially across the study area. Based on gut content analyses, adults and juveniles were between two and three trophic levels above autotrophs. Isosource modelling of δ 13C signatures, suggested several autotrophs contributed to the nutrition of M. colonorum with a combination of seagrass and Spartina likely important contributors, particularly for adults. Isotopic sulphur was subsequently used to distinguish between seagrass and Spartina. Modelling of δ 13C and δ 34S signatures of M. colonorum and a subset of autotrophs again indicated a combination of seagrass and Spartina was likely a major contributor to nutritional support of M. colonorum. Given the limited areal extent of seagrass within Anderson Inlet, current Spartina eradication programs may compromise the nutritional support of M. colonorum.

  7. Quantifying the effectiveness of shoreline armoring removal on coastal biota of Puget Sound.

    Science.gov (United States)

    Lee, Timothy S; Toft, Jason D; Cordell, Jeffery R; Dethier, Megan N; Adams, Jeffrey W; Kelly, Ryan P

    2018-01-01

    Shoreline armoring is prevalent around the world with unprecedented human population growth and urbanization along coastal habitats. Armoring structures, such as riprap and bulkheads, that are built to prevent beach erosion and protect coastal infrastructure from storms and flooding can cause deterioration of habitats for migratory fish species, disrupt aquatic-terrestrial connectivity, and reduce overall coastal ecosystem health. Relative to armored shorelines, natural shorelines retain valuable habitats for macroinvertebrates and other coastal biota. One question is whether the impacts of armoring are reversible, allowing restoration via armoring removal and related actions of sediment nourishment and replanting of native riparian vegetation. Armoring removal is targeted as a viable option for restoring some habitat functions, but few assessments of coastal biota response exist. Here, we use opportunistic sampling of pre- and post-restoration data for five biotic measures (wrack % cover, saltmarsh % cover, number of logs, and macroinvertebrate abundance and richness) from a set of six restored sites in Puget Sound, WA, USA. This broad suite of ecosystem metrics responded strongly and positively to armor removal, and these results were evident after less than one year. Restoration responses remained positive and statistically significant across different shoreline elevations and temporal trajectories. This analysis shows that removing shoreline armoring is effective for restoration projects aimed at improving the health and productivity of coastal ecosystems, and these results may be widely applicable.

  8. Accounting for black carbon lowers estimates of blue carbon storage services.

    Science.gov (United States)

    Chew, Swee Theng; Gallagher, John B

    2018-02-07

    The canopies and roots of seagrass, mangrove, and saltmarsh protect a legacy of buried sedimentary organic carbon from resuspension and remineralisation. This legacy's value, in terms of mitigating anthropogenic emissions of CO 2 , is based on total organic carbon (TOC) inventories to a depth likely to be disturbed. However, failure to subtract allochthonous recalcitrant carbon overvalues the storage service. Simply put, burial of oxidation-resistant organics formed outside of the ecosystem provides no additional protection from remineralisation. Here, we assess whether black carbon (BC), an allochthonous and recalcitrant form of organic carbon, is contributing to a significant overestimation of blue carbon stocks. To test this supposition, BC and TOC contents were measured in different types of seagrass and mangrove sediment cores across tropical and temperate regimes, with different histories of air pollution and fire together with a reanalysis of published data from a subtropical system. The results suggest current carbon stock estimates are positively biased, particularly for low-organic-content sandy seagrass environs, by 18 ± 3% (±95% confidence interval) and 43 ± 21% (±95% CI) for the temperate and tropical regions respectively. The higher BC fractions appear to originate from atmospheric deposition and substantially enrich the relatively low TOC fraction within these environs.

  9. Estimating chlorophyll content of spartina alterniflora at leaf level using hyper-spectral data

    Science.gov (United States)

    Wang, Jiapeng; Shi, Runhe; Liu, Pudong; Zhang, Chao; Chen, Maosi

    2017-09-01

    Spartina alterniflora, one of most successful invasive species in the world, was firstly introduced to China in 1979 to accelerate sedimentation and land formation via so-called "ecological engineering", and it is now widely distributed in coastal saltmarshes in China. A key question is how to retrieve chlorophyll content to reflect growth status, which has important implication of potential invasiveness. In this work, an estimation model of chlorophyll content of S. alterniflora was developed based on hyper-spectral data in the Dongtan Wetland, Yangtze Estuary, China. The spectral reflectance of S. alterniflora leaves and their corresponding chlorophyll contents were measured, and then the correlation analysis and regression (i.e., linear, logarithmic, quadratic, power and exponential regression) method were established. The spectral reflectance was transformed and the feature parameters (i.e., "san bian", "lv feng" and "hong gu") were extracted to retrieve the chlorophyll content of S. alterniflora . The results showed that these parameters had a large correlation coefficient with chlorophyll content. On the basis of the correlation coefficient, mathematical models were established, and the models of power and exponential based on SDb had the least RMSE and larger R2 , which had a good performance regarding the inversion of chlorophyll content of S. alterniflora.

  10. One-dimensional Analytical Modelling of Floating Seed Dispersal in Tidal Channels

    Science.gov (United States)

    Shi, W.; Purnama, A.; Shao, D.; Cui, B.; Gao, W.

    2017-12-01

    Seed dispersal is a primary factor influencing plant community development, and thus plays a critical role in maintaining wetland ecosystem functioning. However, compared with fluvial seed dispersal of riparian plants, dispersal of saltmarsh plant seeds in tidal channels is much less studied due to its complex behavior, and relevant mathematical modelling is particularly lacking. In this study, we developed a one-dimensional advection-dispersion model to explore the patterns of tidal seed dispersal. Oscillatory tidal current and water depth were assumed to represent the tidal effects. An exponential decay coefficient λ was introduced to account for seed deposition and retention. Analytical solution in integral form was derived using Green's function and further evaluated using numerical integration. The developed model was applied to simulate Spartina densiflora seed dispersal in a tidal channel located at the Mad River Slough in North Humboldt Bay, California, USA, to demonstrate its practical applicability. Model predictions agree satisfactorily with field observation and simulation results from Delft3D numerical model. Sensitivity analyses were also conducted to evaluate the effects of varying calibrated parameters on model predictions. The range of the seed dispersion as well as the distribution of the seed concentration were further analyzed through statistical parameters such as centroid displacement and variance of the seed cloud together with seed concentration contours. Implications of the modelling results on tidal marsh restoration and protection, e.g., revegetation through seed addition, were also discussed through scenario analysis. The developed analytical model provides a useful tool for ecological management of tidal marshes.

  11. Evolving Landscapes: the Effect of Genetic Variation on Salt Marsh Erosion

    Science.gov (United States)

    Bernik, B. M.; Blum, M. J.

    2014-12-01

    Ecogeomorphic studies have demonstrated that biota can exert influence over geomorphic processes, such as sediment transport, which in turn have biotic consequences and generate complex feedbacks. However, little attention has been paid to the potential for feedback to arise from evolutionary processes as population genetic composition changes in response to changing physical landscapes. In coastal ecosystems experiencing land loss, for example, shoreline erosion entails reduced plant survival and reproduction, and thereby represents a geomorphic response with inherent consequences for evolutionary fitness. To get at this topic, we examined the effect of genetic variation in the saltmarsh grass Spartina alterniflora, a renowned ecosystem engineer, on rates of shoreline erosion. Field transplantation studies and controlled greenhouse experiments were conducted to compare different genotypes from both wild and cultivated populations. Plant traits, soil properties, accretion/subsidence, and rates of land loss were measured. We found significant differences in rates of erosion between field plots occupied by different genotypes. Differences in erosion corresponded to variation in soil properties including critical shear stress and subsidence. Plant traits that differed across genotypes included belowground biomass, root tensile strength, and C:N ratios. Our results demonstrate the importance of genetic variation to salt marsh functioning, elucidating the relationship between evolutionary processes and ecogeomorphic dynamics in these systems. Because evolutionary processes can occur on ecological timescales, the direction and strength of ecogeomorphic feedbacks may be more dynamic than previously accounted for.

  12. A re-examination of the Salicornias (Amaranthaceae of Saudi Arabia and their polymorphs

    Directory of Open Access Journals (Sweden)

    Turki Ali Al-Turki

    2017-11-01

    Full Text Available During the period from 1964 to 1999 Saudi Arabian species of Salicornia were wrongly treated under the European species, S. europaea L. Recent explorations proved that there are two separate allopatric species of Salicornia in Saudi Arabia, one inhabiting the inland salt-marshes of the Najd (highlands and the other inhabiting the Arabian Gulf Coast (lowlands. Morphological, ecological and exploratory studies confirm that they are two distinct species. The two species differ in features of bark, axillary spikes, basal vegetative segment(s of spike, fertile segments, colour of senescent plants, and flowering, fruiting and germination phenology. As both the species have been described earlier from Iran, they are now new records for Saudi Arabia. The species are, S. persica ssp. iranica (Akhani Kadereit & Piirainen and S. sinus-persica Akhani. S. sinus-persica, of which the status was thought doubtful has been confirmed. Both the species have been described and illustrated. Each species comprises a number of polymorphs. As leaves and flowers are rudimentary, confusing species circumscriptions, a proliferation of binomials has resulted in the taxonomy of Salicornia. To mitigate such confusion, the full range of variability of the Saudi Arabian species has been documented.

  13. The role of certain infauna and vascular plants in the mediation of redox reactions in marine sediments

    Science.gov (United States)

    Hines, Mark E.

    1992-01-01

    The mechanisms by which certain animals and plants affect redox processes in sediments was examined by studying three environments: (1) subtidal sediments dominated by the deposit-feeding polychaete Heteromastus filiformis; (2) a saltmarsh inhabited by the tall form of Spartina alterniflora; and (3) tropical carbonate sediments inhabited by three species of seagrasses. S-35-sulfide production rates were compared to pool sizes of dissolved sulfide and dissolved iron. In all of the sediments studied, rates of sulfide reduction were enhanced by macroorganisms while the rate of turnover of dissolved sulfide increased. The polychaete enhanced microbial activity and redox cycling primarily by subducting particles of organic matter and oxidized iron during sediment reworking. The Spartina species enhanced anaerobic activity by transporting primarily dissolved organic matter and oxidants. Although the final result of both animal and plant activities was the enhancement of sub-surface cycling of sulfur and iron, decreased dissolved sulfide and increased dissolved iron concentrations, the mechanisms which produced these results differed dramatically.

  14. Coupled Wave Energy and Erosion Dynamics along a Salt Marsh Boundary, Hog Island Bay, Virginia, USA

    Directory of Open Access Journals (Sweden)

    Anthony M. Priestas

    2015-09-01

    Full Text Available The relationship between lateral erosion of salt marshes and wind waves is studied in Hog Island Bay, Virginia USA, with high-resolution field measurements and aerial photographs. Marsh retreat is compared to wave climate calculated in the bay using the spectral wave-model Simulating Waves Nearshore (SWAN. We confirm the existence of a linear relationship between long-term salt marsh erosion and wave energy, and show that wave power can serve as a good proxy for average salt-marsh erosion rates. At each site, erosion rates are consistent across several temporal scales, ranging from months to decades, and are strongly related to wave power. On the contrary, erosion rates vary in space and weakly depend on the spatial distribution of wave energy. We ascribe this variability to spatial variations in geotechnical, biological, and morphological marsh attributes. Our detailed field measurements indicate that at a small spatial scale (tens of meters, a positive feedback between salt marsh geometry and wave action causes erosion rates to increase with boundary sinuosity. However, at the scale of the entire marsh boundary (hundreds of meters, this relationship is reversed: those sites that are more rapidly eroding have a marsh boundary which is significantly smoother than the marsh boundary of sheltered and slowly eroding marshes.

  15. A Climate Change Adaptation Strategy for Management of ...

    Science.gov (United States)

    Sea level rise is causing shoreline erosion, increased coastal flooding, and marsh vulnerability to the impact of storms. Coastal marshes provide flood abatement, carbon and nutrient sequestration, water quality maintenance, and habitat for fish, shellfish, and wildlife, including species of concern, such as the saltmarsh sparrow (Ammodramus caudacutus). We present a climate change adaptation strategy (CCAS) adopted by scientific, management, and policy stakeholders for managing coastal marshes and enhancing system resiliency. A common adaptive management approach previously used for restoration projects was modified to identify climate-related vulnerabilities and plan climate change adaptive actions. As an example of implementation of the CCAS, we describe the stakeholder plans and management actions the US Fish and Wildlife Service and partners developed to build coastal resiliency in the Narrow River Estuary, RI, in the aftermath of Superstorm Sandy. When possible, an experimental BACI (before-after, control-impact) design, described as pre- and post-sampling at the impact site and one or more control sites, was incorporated into the climate change adaptation and implementation plans. Specific climate change adaptive actions and monitoring plans are described and include shoreline stabilization, restoring marsh drainage, increasing marsh elevation, and enabling upland marsh migration. The CCAS provides a framework and methodology for successfully managing coa

  16. Transuranics Laboratory, achievements and performance; Laboratorio de Transuranicos, logros y fundamento

    Energy Technology Data Exchange (ETDEWEB)

    Gasco, C.; Anton, M. P.

    2004-07-01

    The Marine and Aquatic Radioecology Group (MARG) was established in 1985 with the main scope of analysing the consequences of the Palomares accident in the adjacent Mediterranean ecosystem. From then on and up to now , this Group has extended its investigations to other European marine environments, such as the Spanish Mediterranean margin, the Artic and the Atlantic. The main research of long-lived radionuclides (plutonium, americium and Cs-137) determining the orography influence, riverine inputs and their geo-chemical associations. This group is currently accomplishing new challenges on the radioecology field such as the development of techniques for transuranics speciation to determine their geo-chemical association to the main sediment compounds. Natural and anthropogenic radionuclides distribution on salt-marsh areas affected by dry-wet periods is being studied as well as the possibilities of fusing crossed techniques for dating recent sediments (pollen, anthropogenic, ''210 Pb, etc). The Laboratory performance description, the procedures used, calculations, challenges and gaps are described in this report. (Author) 22 refs.

  17. Transuranics Laboratory, achievements and performance

    International Nuclear Information System (INIS)

    Gasco, C.; Anton, M. P.

    2004-01-01

    The Marine and Aquatic Radioecology Group (MARG) was established in 1985 with the main scope of analysing the consequences of the Palomares accident in the adjacent Mediterranean ecosystem. From then on and up to now , this Group has extended its investigations to other European marine environments, such as the Spanish Mediterranean margin, the Artic and the Atlantic. The main research of long-lived radionuclides (plutonium, americium and Cs-137) determining the orography influence, riverine inputs and their geo-chemical associations. This group is currently accomplishing new challenges on the radioecology field such as the development of techniques for transuranics speciation to determine their geo-chemical association to the main sediment compounds. Natural and anthropogenic radionuclides distribution on salt-marsh areas affected by dry-wet periods is being studied as well as the possibilities of fusing crossed techniques for dating recent sediments (pollen, anthropogenic, ''210 Pb, etc). The Laboratory performance description, the procedures used, calculations, challenges and gaps are described in this report. (Author) 22 refs

  18. Environmental characteristics of shallow bottoms used by Greater Flamingo Phoenicopterus roseus in a northern Adriatic lagoon

    Directory of Open Access Journals (Sweden)

    Scarton Francesco

    2017-12-01

    Full Text Available Since the beginning of this century, Greater Flamingo Phoenicopterus roseus flocks have been observed regularly when feeding in the large extensions of shallow bottoms in the Lagoon of Venice (NE Italy, the largest lagoon along the Mediterranean. Nowadays thousands of flamingos are present throughout the year. Between 2013 and 2017 I collected data on the environmental features of the shallow bottoms used by feeding flocks, along with measurements of flight initiation distance (FID of Greater Flamingo in response to the approach of boats and pedestrians. Shallow bottoms were shown to be used when covered with approximately 10 to 60 cm of water. All the feeding sites were in open landscapes, with low occurrence of saltmarshes in a radius of 500 m. The bottoms were barely covered with seagrasses (<4% of the surface around the survey points and were mostly silty. Feeding flocks were on average 1.2 km far from the nearest road or dyke, while the mean distance from channels that could be used by boats was about 420 m. The mean FID caused by boats or pedestrians was 241 m ± 117 m (N = 31, ± 1 SD without significant differences between those for the two disturbance sources. The use of shallow bottoms by the Greater Flamingo appears governed primarily by the tidal cycle, but boat disturbance probably modifies this effect. According to FID values, a set-back distance of 465 m is suggested to reduce the disturbance caused by boats and pedestrians to the flamingo feeding flocks.

  19. Is it possible to use 'twin cores' as a unique sedimentary record? An experimental design based on sediment color

    International Nuclear Information System (INIS)

    Veiga-Pires, C; Mestre, N C

    2009-01-01

    Sedimentary cores are widely used for studying Quaternary records. However, the amount of sediment that is available is proportional to the diameter of the core, which is rarely bigger than 15 cm. One way to obtain more sediment is to use two cores retrieved from almost the same location and use them as if they represent a unique sedimentary record. In the present work, an experimental design has been applied to verify if 'twin cores' from an estuary can be considered as representing the same sedimentary record with twice the amount of sediment to study. Because sediment can be characterized based on its color, the variables used as replicates in the experimental design are the three Lab CIE colors acquired with a X-Rite Colortron spectrophotometer. Sediment cores were retrieved from the upper saltmarsh of Gilao River's estuary, southern Portugal. Twin cores, with in between distances of 50 cm, 100 cm and 200 cm, from two different sites were analysed. Results from a nested ANOVA show that even for the closest twin cores (50 cm apart) there is at least one color variable that shows significant variations between the profiles of both cores. These results clearly show that 'twin cores' cannot be used as a unique sedimentary record without any previous testing, at least in such transitional regions.

  20. Bounding uncertainty in volumetric geometric models for terrestrial lidar observations of ecosystems.

    Science.gov (United States)

    Paynter, Ian; Genest, Daniel; Peri, Francesco; Schaaf, Crystal

    2018-04-06

    Volumetric models with known biases are shown to provide bounds for the uncertainty in estimations of volume for ecologically interesting objects, observed with a terrestrial laser scanner (TLS) instrument. Bounding cuboids, three-dimensional convex hull polygons, voxels, the Outer Hull Model and Square Based Columns (SBCs) are considered for their ability to estimate the volume of temperate and tropical trees, as well as geomorphological features such as bluffs and saltmarsh creeks. For temperate trees, supplementary geometric models are evaluated for their ability to bound the uncertainty in cylinder-based reconstructions, finding that coarser volumetric methods do not currently constrain volume meaningfully, but may be helpful with further refinement, or in hybridized models. Three-dimensional convex hull polygons consistently overestimate object volume, and SBCs consistently underestimate volume. Voxel estimations vary in their bias, due to the point density of the TLS data, and occlusion, particularly in trees. The response of the models to parametrization is analysed, observing unexpected trends in the SBC estimates for the drumlin dataset. Establishing that this result is due to the resolution of the TLS observations being insufficient to support the resolution of the geometric model, it is suggested that geometric models with predictable outcomes can also highlight data quality issues when they produce illogical results.

  1. Tracking orthographic learning in children with different types of dyslexia

    Directory of Open Access Journals (Sweden)

    Hua-Chen eWang

    2014-07-01

    Full Text Available Previous studies have found that children with reading difficulties need more exposures to acquire the representations needed to support fluent reading than typically developing readers (e.g., Ehri & Saltmarsh, 1995. Building on existing orthographic learning paradigms, we report on an investigation of orthographic learning in poor readers using a new learning task tracking both the accuracy (untimed exposure duration and fluency (200ms exposure duration of learning novel words over trials. In study 1, we used the paradigm to examine orthographic learning in children with specific poor reader profiles (9 with a surface profile, 9 a phonological profile and 9 age-matched controls. Both profiles showed improvement over the learning cycles, but the children with surface profile showed impaired orthographic learning in spelling and orthographic choice tasks. Study 2 explored predictors of orthographic learning in a group of 91 poor readers using the same outcome measures as in Study 1. Consistent with earlier findings in typically developing readers, phonological decoding skill predicted orthographic learning. Moreover, orthographic knowledge significantly predicted orthographic learning over and beyond phonological decoding. The two studies provide insights into how poor readers learn novel words, and how their learning process may be compromised by less proficient orthographic and/or phonological skills.

  2. Quantifying the effectiveness of shoreline armoring removal on coastal biota of Puget Sound

    Directory of Open Access Journals (Sweden)

    Timothy S. Lee

    2018-02-01

    Full Text Available Shoreline armoring is prevalent around the world with unprecedented human population growth and urbanization along coastal habitats. Armoring structures, such as riprap and bulkheads, that are built to prevent beach erosion and protect coastal infrastructure from storms and flooding can cause deterioration of habitats for migratory fish species, disrupt aquatic–terrestrial connectivity, and reduce overall coastal ecosystem health. Relative to armored shorelines, natural shorelines retain valuable habitats for macroinvertebrates and other coastal biota. One question is whether the impacts of armoring are reversible, allowing restoration via armoring removal and related actions of sediment nourishment and replanting of native riparian vegetation. Armoring removal is targeted as a viable option for restoring some habitat functions, but few assessments of coastal biota response exist. Here, we use opportunistic sampling of pre- and post-restoration data for five biotic measures (wrack % cover, saltmarsh % cover, number of logs, and macroinvertebrate abundance and richness from a set of six restored sites in Puget Sound, WA, USA. This broad suite of ecosystem metrics responded strongly and positively to armor removal, and these results were evident after less than one year. Restoration responses remained positive and statistically significant across different shoreline elevations and temporal trajectories. This analysis shows that removing shoreline armoring is effective for restoration projects aimed at improving the health and productivity of coastal ecosystems, and these results may be widely applicable.

  3. Geochemical factors promoting die-back gap formation in colonizing patches of Spartina densiflora in an irregularly flooded marsh

    Science.gov (United States)

    Mirlean, Nicolai; Costa, Cesar S. B.

    2017-04-01

    Circular (RP) and ring-shape (RP) patches of vegetation in intertidal flats have been associated with the radial expansion of tussock growth forms and die-back gap in older central stands, respectively. RP formation has not yet been sufficiently explained. We accomplished a comparative geochemical study of CP and RP structures of Spartina densiflora within a single saltmarsh in a microtidal estuary (changing in water level and salinity. During high-water period dissolved H2S was frequently low in pore waters of S. densiflora structures due to reactive-Fe, which scavenge the sulfide from solution and form solid sulfides. During less flooded-brackish water period, pore water pH goes down below 4 inside the vegetated bordering areas of RP. In these locations the concentration of soluble sulfides dramatically increases up to 140 μM L-1. The high concentration of protons in pore water is the result of solid sulfides atmospheric oxidation to sulfuric acid. High dissolution of H2S, along with the low pH, creates a toxic environment for S. densiflora and die-back central gap formation in RP. CP structure was 5 cm higher in the intertidal than RP but shows frequent presence of a water layer, less severe oxidation of sulfides and limited building-up of toxic condition to plants. Development of S. densiflora RP probably indicates the uplift of sediment by this bioengineer grass and/or periodic lowering of the water surface below a certain critical level.

  4. Sediment nickel bioavailability and toxicity to estuarine crustaceans of contrasting bioturbative behaviors--an evaluation of the SEM-AVS paradigm.

    Science.gov (United States)

    Chandler, G Thomas; Schlekat, Christian E; Garman, Emily R; He, Lijian; Washburn, Katherine M; Stewart, Emily R; Ferry, John L

    2014-11-04

    Robust sediment quality criteria require chemistry and toxicity data predictive of concentrations where population/community response should occur under known geochemical conditions. Understanding kinetic and geochemical effects on toxicant bioavailability is key, and these are influenced by infaunal sediment bioturbation. This study used fine-scale sediment and porewater measurement of contrasting infaunal effects on carbon-normalized SEM-AVS to evaluate safe or potentially toxic nickel concentrations in a high-binding Spartina saltmarsh sediment (4%TOC; 35-45 μmol-S2-·g(-1)). Two crustaceans producing sharply contrasting bioturbation--the copepod Amphiascus tenuiremis and amphipod Leptocheirus plumulosus--were cultured in oxic to anoxic sediments with SEM[Ni]-AVS, TOC, porewater [Ni], and porewater DOC measured weekly. From 180 to 750 μg-Ni·g(-1) sediment, amphipod bioturbation reduced [AVS] and enhanced porewater [Ni]. Significant amphipod uptake, mortality, and growth-depression occurred at the higher sediment [Ni] even when [SEM-AVS]/foc suggested acceptable risk. Less bioturbative copepods produced higher AVS and porewater DOC but exhibited net population growth despite porewater [Ni] 1.3-1.7× their aqueous [Ni] LOEC. Copepod aqueous tests with/without dissolved organic matter showed significant aqueous DOC protection, which suggests porewater DOC attenuates sediment Ni toxicity. The SEM[Ni]-AVS relationship was predictive of acceptable risk for copepods at the important population-growth level.

  5. Decomposition of [14C]lignocelluloses of Spartina alterniflora and a comparison with field experiments

    International Nuclear Information System (INIS)

    Wilson, J.O.

    1985-01-01

    Decomposition of lignocelluloses from Spartina alterniflora in salt-marsh sediments was measured by using 14 C-labeled compounds. Rates of decomposition were fastest in the first 4 days of incubation and declined later. Lignins labeled in side chains were mineralized slightly faster than uniformly labeled lignins; 12% of the [side chain- 14 C]lignin-labeled lignocellulose was mineralized after 816 h of incubation, whereas only 8% of the [U- 14 C]lignin-labeled lignocelluloses were degraded during this period. The carbohydrate moiety within the lignocellulose complex was degraded about four times faster than the lignin moiety; after 816 h of incubation, 29 to 37% of the carbohydrate moiety had been mineralized. Changes in concentration of lignin and cellulose in litter of S. alterniflora were followed over 2 years of decay. Cellulose disappeared from litter more rapidly than lignin; 50% of the initial content of cellulose was lost after 130 days, whereas lignin required 330 to 380 days for 50% loss. The slow loss of lignin compared with other litter components resulted in a progressive enrichment of litter in lignin content. The rates of mineralization of [ 14 C]lignocelluloses in marsh sediments were similar to the rates of lignocellulose decomposition in litter on the marsh

  6. On autochtonous organic production and its implication for the consolidation of temperate salt marshes

    DEFF Research Database (Denmark)

    Bartholdy, Jesper; Bartholdy, Anders; Kim, Daehyun

    2014-01-01

    decomposes with a decreasing organic content until about 15 cm below the surface. Hereunder the decomposition of organic material seems to stabilize at a very low level. The constant rate of the below ground organic production results in a larger concentration of this type of organic matter in the slowest......The organic production related to minerogene salt marsh deposits represents a challenge to all attempts to model the development of these areas, and evaluate their chances of survival under different sea level scenarios. Salt marsh deposits on a typical temperate backbarrier saltmarsh area...... at the Skallingen barrierspit (Denmark) were investigated for autochthonous or below ground organic production, which was found to have a mean value of 0.14 kg m− 2 y− 1 or about 0.1 mm y− 1. This production is concentrated in the upper approximately 5 cm of the salt marsh. Below this level the organic material...

  7. Habitat heterogeneity influences restoration efficacy: Implications of a habitat-specific management regime for an invaded marsh

    Science.gov (United States)

    Tang, Long; Gao, Yang; Wang, Cheng-Huan; Li, Bo; Chen, Jia-Kuan; Zhao, Bin

    2013-07-01

    Invasive species have to be managed to prevent adverse consequences. Spartina alterniflora has invaded many marshes where salinity and inundation are often key factors affecting vegetation. The former was surface clipped twice and native Phragmites australis was planted in invaded zones to examine the effects of habitat properties on the efficacy of invader control and native restoration. The results showed that two clipping treatments almost eliminated S. alterniflora in the zones with long inundation periods of 80 h/15 d but stimulated compensatory growth of S. alterniflora in the zones with short inundation periods. Transplanted P. australis performed better over time in zones with low salinity (removal of the above-ground parts of S. alterniflora should be used only in the middle tidal zones and that native vegetation should be planted in zones above the mean high water level while the others zones in the saltmarsh should be restored to mud flats. Usually, invasive plants can flourish in highly heterogeneous habitats, which can influence management efficacy by influencing the re-growth of treated invaders and the performance of restored native species. Therefore, habitat-specific management regimes for invasive species can be expected to be more efficient because of their dependence on specific habitats.

  8. Landslide response signatures from storm Desmond (UK)/Synne (Norway), December 2015.

    Science.gov (United States)

    Dijkstra, Tom; Freeborough, Katy; Reeves, Helen; Nykjaer, Boje Soren; Sund, Monica; Devoli, Graziella; Banks, Vanessa

    2016-04-01

    Great Britain (GB) and coastal Norway share a common humid maritime climate and annually receive precipitation in the form of cyclonic low-pressure systems or as extra-tropical storms that travel across the Atlantic. Extreme meteorological events capable of triggering floods and landslides are becoming more frequent, with both GB and Norway being affected by a sequence of record-breaking precipitation events in the past decade. On the 5th and 6th of December 2015, storms Desmond/Synne struck northern GB and southwestern Norway with record-breaking rainfall; >340 mm in 24-hour in Cumbria (or 200% of long term average) and daily accumulations in Norway in excess of 140 mm and 236 mm/48hr. Landscape responses to hydro-meteorological stress are non-uniform and the result of a complex interaction of processes. Therefore, event-specific analysis provides an important tool to further our understanding, particularly to enhance the quality of daily landslide hazard assessments (DLHA) issued by the Norwegian Water Resources and Energy Directorate (NVE) and the British Geological Survey (BGS). The application of precipitation thresholds provides a useful first approximation for landslide triggering. However, antecedent conditioning of slopes and the spatial variability of precipitation signatures are important factors in determining the location of landslides. Given the magnitude of storms Desmond/Synne a much larger population of landslides was expected to occur. Within one month of the events occurring some 25 events are recorded in GB and circa 30 events in Norway. In GB most of these events are relatively small scale, dominated by translational slides and flows and about 80% of cases reported to occur along transport infrastructure. In Norway, roughly equal numbers of debris flows, shallow slides, rock falls, slush flows and snow avalanches are recorded in close proximity to infrastructure. As the media largely focused on simultaneous severe consequences of extensive

  9. Quantifying the morphodynamics of river restoration schemes using Unmanned Aerial Vehicles (UAVs)

    Science.gov (United States)

    Williams, Richard; Byrne, Patrick; Gilles, Eric; Hart, John; Hoey, Trevor; Maniatis, George; Moir, Hamish; Reid, Helen; Ves, Nikolas

    2017-04-01

    River restoration schemes are particularly sensitive to morphological adjustment during the first set of high-flow events that they are subjected to. Quantifying elevation change associated with morphological adjustment can contribute to improved adaptive decision making to ensure river restoration scheme objectives are achieved. To date the relatively high cost, technical demands and challenging logistics associated with acquiring repeat, high-resolution topographic surveys has resulted in a significant barrier to monitoring the three-dimensional morphodynamics of river restoration schemes. The availability of low-cost, consumer grade Unmanned Aerial Vehicles that are capable of acquiring imagery for processing using Structure-from-Motion Multi-View Stereo (SfM MVS) photogrammetry has the potential to transform the survey the morphodynamics of river restoration schemes. Application guidance does, however, need to be developed to fully exploit the advances of UAV technology and SfM MVS processing techniques. In particular, there is a need to quantify the effect of the number and spatial distribution of ground targets on vertical error. This is particularly significant because vertical errors propagate when mapping morphological change, and thus determine the evidence that is available for decision making. This presentation presents results from a study that investigated how the number and spatial distribution of targets influenced vertical error, and then used the findings to determine survey protocols for a monitoring campaign that has quantified morphological change across a number of restoration schemes. At the Swindale river restoration scheme, Cumbria, England, 31 targets were distributed across a 700 m long reach and the centre of each target was surveyed using RTK-GPS. Using the targets as General Control Points (GCPs) or checkpoints, they were divided into three different spatial patterns (centre, edge and random) and used for processing images acquired

  10. The challenges of modelling phosphorus in a headwater catchment: Applying a 'limits of acceptability' uncertainty framework to a water quality model

    Science.gov (United States)

    Hollaway, M. J.; Beven, K. J.; Benskin, C. McW. H.; Collins, A. L.; Evans, R.; Falloon, P. D.; Forber, K. J.; Hiscock, K. M.; Kahana, R.; Macleod, C. J. A.; Ockenden, M. C.; Villamizar, M. L.; Wearing, C.; Withers, P. J. A.; Zhou, J. G.; Barber, N. J.; Haygarth, P. M.

    2018-03-01

    There is a need to model and predict the transfer of phosphorus (P) from land to water, but this is challenging because of the large number of complex physical and biogeochemical processes involved. This study presents, for the first time, a 'limits of acceptability' approach of the Generalized Likelihood Uncertainty Estimation (GLUE) framework to the Soil and Water Assessment Tool (SWAT), in an application to a water quality problem in the Newby Beck catchment (12.5 km2), Cumbria, United Kingdom (UK). Using high frequency outlet data (discharge and P), individual evaluation criteria (limits of acceptability) were assigned to observed discharge and P loads for all evaluation time steps, identifying where the model was performing well/poorly and to infer which processes required improvement in the model structure. Initial limits of acceptability were required to be relaxed by a substantial amount (by factors of between 5.3 and 6.7 on a normalized scale depending on the evaluation criteria used) in order to gain a set of behavioral simulations (1001 and 1016, respectively out of 5,000,000). Of the 39 model parameters tested, the representation of subsurface processes and associated parameters, were consistently shown as critical to the model not meeting the evaluation criteria, irrespective of the chosen evaluation metric. It is therefore concluded that SWAT is not an appropriate model to guide P management in this catchment. This approach highlights the importance of high frequency monitoring data for setting robust model evaluation criteria. It also raises the question as to whether it is possible to have sufficient input data available to drive such models so that we can have confidence in their predictions and their ability to inform catchment management strategies to tackle the problem of diffuse pollution from agriculture.

  11. Defining landscape resistance values in least-cost connectivity models for the invasive grey squirrel: a comparison of approaches using expert-opinion and habitat suitability modelling.

    Directory of Open Access Journals (Sweden)

    Claire D Stevenson-Holt

    Full Text Available Least-cost models are widely used to study the functional connectivity of habitat within a varied landscape matrix. A critical step in the process is identifying resistance values for each land cover based upon the facilitating or impeding impact on species movement. Ideally resistance values would be parameterised with empirical data, but due to a shortage of such information, expert-opinion is often used. However, the use of expert-opinion is seen as subjective, human-centric and unreliable. This study derived resistance values from grey squirrel habitat suitability models (HSM in order to compare the utility and validity of this approach with more traditional, expert-led methods. Models were built and tested with MaxEnt, using squirrel presence records and a categorical land cover map for Cumbria, UK. Predictions on the likelihood of squirrel occurrence within each land cover type were inverted, providing resistance values which were used to parameterise a least-cost model. The resulting habitat networks were measured and compared to those derived from a least-cost model built with previously collated information from experts. The expert-derived and HSM-inferred least-cost networks differ in precision. The HSM-informed networks were smaller and more fragmented because of the higher resistance values attributed to most habitats. These results are discussed in relation to the applicability of both approaches for conservation and management objectives, providing guidance to researchers and practitioners attempting to apply and interpret a least-cost approach to mapping ecological networks.

  12. Defining landscape resistance values in least-cost connectivity models for the invasive grey squirrel: a comparison of approaches using expert-opinion and habitat suitability modelling.

    Science.gov (United States)

    Stevenson-Holt, Claire D; Watts, Kevin; Bellamy, Chloe C; Nevin, Owen T; Ramsey, Andrew D

    2014-01-01

    Least-cost models are widely used to study the functional connectivity of habitat within a varied landscape matrix. A critical step in the process is identifying resistance values for each land cover based upon the facilitating or impeding impact on species movement. Ideally resistance values would be parameterised with empirical data, but due to a shortage of such information, expert-opinion is often used. However, the use of expert-opinion is seen as subjective, human-centric and unreliable. This study derived resistance values from grey squirrel habitat suitability models (HSM) in order to compare the utility and validity of this approach with more traditional, expert-led methods. Models were built and tested with MaxEnt, using squirrel presence records and a categorical land cover map for Cumbria, UK. Predictions on the likelihood of squirrel occurrence within each land cover type were inverted, providing resistance values which were used to parameterise a least-cost model. The resulting habitat networks were measured and compared to those derived from a least-cost model built with previously collated information from experts. The expert-derived and HSM-inferred least-cost networks differ in precision. The HSM-informed networks were smaller and more fragmented because of the higher resistance values attributed to most habitats. These results are discussed in relation to the applicability of both approaches for conservation and management objectives, providing guidance to researchers and practitioners attempting to apply and interpret a least-cost approach to mapping ecological networks.

  13. The graphite deposit at Borrowdale (UK): A catastrophic mineralizing event associated with Ordovician magmatism

    Science.gov (United States)

    Ortega, L.; Millward, D.; Luque, F. J.; Barrenechea, J. F.; Beyssac, O.; Huizenga, J.-M.; Rodas, M.; Clarke, S. M.

    2010-04-01

    The volcanic-hosted graphite deposit at Borrowdale in Cumbria, UK, was formed through precipitation from C-O-H fluids. The δ 13C data indicate that carbon was incorporated into the mineralizing fluids by assimilation of carbonaceous metapelites of the Skiddaw Group by andesite magmas of the Borrowdale Volcanic Group. The graphite mineralization occurred as the fluids migrated upwards through normal conjugate fractures forming the main subvertical pipe-like bodies. The mineralizing fluids evolved from CO 2-CH 4-H 2O mixtures (XCO 2 = 0.6-0.8) to CH 4-H 2O mixtures. Coevally with graphite deposition, the andesite and dioritic wall rocks adjacent to the veins were intensely hydrothermally altered to a propylitic assemblage. The initial graphite precipitation was probably triggered by the earliest hydration reactions in the volcanic host rocks. During the main mineralization stage, graphite precipitated along the pipe-like bodies due to CO 2 → C + O 2. This agrees with the isotopic data which indicate that the first graphite morphologies crystallizing from the fluid (cryptocrystalline aggregates) are isotopically lighter than those crystallizing later (flakes). Late chlorite-graphite veins were formed from CH 4-enriched fluids following the reaction CH 4 + O 2 → C + 2H 2O, producing the successive precipitation of isotopically lighter graphite morphologies. Thus, as mineralization proceeded, water-generating reactions were involved in graphite precipitation, further favouring the propylitic alteration. The structural features of the pipe-like mineralized bodies as well as the isotopic homogeneity of graphite suggest that the mineralization occurred in a very short period of time.

  14. Keeping agricultural soil out of rivers: evidence of sediment and nutrient accumulation within field wetlands in the UK.

    Science.gov (United States)

    Ockenden, Mary C; Deasy, Clare; Quinton, John N; Surridge, Ben; Stoate, Chris

    2014-03-15

    Intensification of agriculture has resulted in increased soil degradation and erosion, with associated pollution of surface waters. Small field wetlands, constructed along runoff pathways, offer one option for slowing down and storing runoff in order to allow more time for sedimentation and for nutrients to be taken up by plants or micro-organisms. This paper describes research to provide quantitative evidence for the effectiveness of small field wetlands in the UK landscape. Ten wetlands were built on four farms in Cumbria and Leicestershire, UK. Annual surveys of sediment and nutrient accumulation in 2010, 2011 and 2012 indicated that most sediment was trapped at a sandy site (70 tonnes over 3 years), compared to a silty site (40 tonnes over 3 years) and a clay site (2 tonnes over 3 years). The timing of rainfall was more important than total annual rainfall for sediment accumulation, with most sediment transported in a few intense rainfall events, especially when these coincided with bare soil or poor crop cover. Nutrient concentration within sediments was inversely related to median particle size, but the total mass of nutrients trapped was dependent on the total mass of sediment trapped. Ratios of nutrient elements in the wetland sediments were consistent between sites, despite different catchment characteristics across the individual wetlands. The nutrient value of sediment collected from the wetlands was similar to that of soil in the surrounding fields; dredged sediment was considered to have value as soil replacement but not as fertiliser. Overall, small field wetlands can make a valuable contribution to keeping soil out of rivers. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Reconstructing historical radionuclide concentrations along the east coast of Ireland using a compartmental model

    International Nuclear Information System (INIS)

    Smith, C.N.; Clarke, S.; McDonald, P.; Goshawk, J.A.; Jones, S.R.

    2000-01-01

    A mathematical model is presented that simulates the annually averaged transport of radionuclides, originating from the BNFL reprocessing plant at Sellafield, throughout the Irish Sea. The model, CUMBRIA77, represents the processes of radionuclide transport and dispersion in the marine environment and allows predictions of radionuclide concentration in various environmental media, including biota, to be made throughout the whole of the Irish Sea. In this paper we describe the use of the model to reconstruct the historical activity concentrations of 137Cs and 239+240Pu in a variety of environmental media in the western Irish Sea and along the Irish east coast back to 1950. This reconstruction exercise is of interest because only limited measurements of 137Cs and 239+240Pu activity are available prior to the 1980s. The predictions were compared to the available measured data to validate their accuracy. The results of the reconstruction indicate that activity concentrations of 137Cs in the western Irish Sea follow a similar, though slightly delayed and smoothed, profile to the discharges from the Sellafield site, with concentrations at the time of peak discharge (the mid-1970s) being around an order of magnitude higher than those measured in the 1980s and 1990s. By contrast, the concentrations of 239+240Pu at the time of peak discharges were similar to those presently measured. These differences reflect the distinct marine chemistries of the two nuclides, in particular the higher propensity of plutonium to bind to sediments leading to extended transport times. Despite these differences in behaviour the doses to Irish seafood consumers from 137Cs remain significantly higher than those from 239+240Pu

  16. Renal telemedicine through video-as-a-service delivered to patients on home dialysis: A qualitative study on the renal care team members' experience.

    Science.gov (United States)

    Ditchburn, Jae-Llane; Marshall, Alison

    2017-09-01

    The Lancashire Teaching Hospitals NHS Trust in the UK has been providing renal care through video-as-a-service (VAAS) to patients since 2013, with support from the North West NHS Shared Infrastructure Service, a collaborative team that supports information and communication technology use in the UK National Health Service. Renal telemedicine offered remotely to patients on home dialysis supports renal care through the provision of a live high-quality video link directly to unsupported patients undergoing haemodialysis at home. Home haemodialysis is known to provide benefits to patients, particularly in making them more independent. The use of a telemedicine video-link in Lancashire and South Cumbria, UK, further reduces patient dependence on the professional team. The purpose of this paper is to present the perspectives of the renal care team members using the renal telemedicine service to understand the perceived benefits and issues with the service. Ten semi-structured interviews with members of the renal care team (two renal specialists, one matron, two renal nurses, one business manager, one renal technical services manager, two IT technicians and one hardware maintenance technician) were conducted. Thematic analysis was undertaken to analyse the qualitative data. A range of incremental benefits to the renal team members were reported, including more efficient use of staff time, reduced travel, peace of mind and a strong sense of job satisfaction. Healthcare staff believed that remote renal care through video was useful, encouraged concordance and could nurture confidence in patients. Key technological issues and adjustments which would improve the renal telemedicine service were also identified. The impact of renal telemedicine was positive on the renal team members. The use of telemedicine has been demonstrated to make home dialysis delivery more efficient and safe. The learning from staff feedback could inform development of services elsewhere. © 2017

  17. Consideration of post-closure controls for a near surface low level waste disposal site

    International Nuclear Information System (INIS)

    Clegg, R.; Pinner, A.; Smith, A.; Quartermaine, J.

    1997-01-01

    There is currently an ongoing programme of disposal of low level radioactive wastes by British Nuclear Fuels plc (BNFL) at Drigg, Cumbria, and this programme is likely to continue through the first few decades of the 21st century. Although control of the site is anticipated for a period of about 100 years post-closure, eventually restrictions on access will lapse. Thereafter, the possibility of human actions leading to exposure to, and/or exhumation of, the wastes exists and has to be addressed in post-closure radiological performance assessments. Potential modes of intrusion into the Drigg site have been studied using a suite of computer codes developed specifically for this purpose. Required inputs to these codes include information on possible future uses of the site and the various human actions associated with those uses. This information was obtained from a group of experts using formal elicitation procedures. Although the most likely site uses, notably those involving agricultural activities, are unlikely to result in intrusion into the wastes, others, such a urban development, do have the potential to result in such intrusion. In these circumstances, it seemed appropriate to give consideration to the degree to which documentary records and markers could protect the Drigg site against intrusive activities. Overall, it is concluded that provided that a variety of documentary records are established, ranging from local council archives to mass produced maps, then memory of the site can realistically be assumed whilst civilization continues to exist. However, if this first line of defence fails, markers constitute a second warning system. Finally, assessment calculations can be used to demonstrate that, even if these two lines of defence fail, risks from intrusion and radiation doses contingent upon intrusive events having occurred would not be unacceptably large. (author). 10 refs, 1 fig., 1 tab

  18. The systematic roles of SKI and SSI in the Swedish nuclear waste management system. Syncho`s report for project RISCOM

    Energy Technology Data Exchange (ETDEWEB)

    Espejo, R. [Syncho, Solihull (United Kingdom); Gill, A. [Syncho, Oxon (United Kingdom)

    1998-01-01

    The purpose of this report is to share and summarize our findings about the regulatory roles of SKI/SSI in the context of the Swedish Nuclear System (SNS), with an emphasis on nuclear waste management. The driving force in this review is to make decision processes more transparent. What is reported is based on interviews conducted with employees at SKI/SSI/SKB during early December 1996, the presentation to SKI/SSI in January 1997, discussions during the Shap Wells meeting in Cumbria during March 1997 and RISCOM internal discussions. We offer two hypotheses about the way the Nuclear Waste Management System (NWMS) appears to work. We choose one and derive from it a view about structural issues in SNS and NWMS. The conclusion is a set of systemic roles for the regulators. It is the comparison between these systemic roles and the actual situation that may trigger some adjustments in the system. Our hope is that these findings will make apparent feasible and desirable changes in the system in order to increase the chances for transparent decisions in the Nuclear Waste Management System. In summary, Section 2 includes a general background of the NWMS based on interviews and general information. Section 3 makes a more focused attempt to work out the issues expressed by people in the interviews. Section 4 discusses at a more conceptual level systemic ideas such as the unfolding of complexity. Section 5 is an attempt to organize viewpoints about the NWMS and offers hypotheses to support a preliminary diagnosis of the system in Section 6. We call this section `A problem of identity`. It is only in Section 7 that basic systemic arguments are unfolded with the intention of supporting an appreciation of SKI/SSI`s regulatory roles in the nuclear industry as a whole and nuclear waste management in particular. Section 8 offers a summary of conclusions.

  19. Assessment of the Impact of Radioactive Disposals and Discharges from the United Kingdom Low Level Waste Repository on the Ecosystem

    International Nuclear Information System (INIS)

    Barber, N.

    2009-01-01

    This paper describes an assessment of the impacts to ecosystems and wildlife species from radioactive discharges and disposals at the United Kingdom's low level waste disposal facility in West Cumbria. The assessment was undertaken in response to a requirement in the site's current authorisation and comprised a detailed desk based review along with an exercise to screen relevant monitoring data from the site against generic assessment criteria and undertake a numerical risk assessment. Much of the site is vegetated, comprising a variety of habitats including grassland, relict dune heath and surface water bodies. Furthermore, the site is located adjacent to a coastal/estuarine area which is protected as it provides a habitat of high ecological value and species of animals and plants are present that are rare, endangered or vulnerable. However, the current impact of aerial and liquid radioactive discharges from the low level waste repository on ecosystems and wildlife species is considered to be low. Site monitoring data also indicate that there has been a reduction of radionuclide activities in ground and surface water and leachates over time, a result of measures initiated to minimise rainwater infiltration and improve leachate management associated with the disposal area. A quantitative assessment was undertaken to assess future impacts to relevant terrestrial, fresh water and marine ecosystems. This showed that modelled peak radionuclide concentrations in the first 4,000 years after site closure were not sufficiently high to cause potential impact to any of these ecosystems or associated wildlife. This cut-off date was chosen as it is considered probable that, due to the effects of future climate and landscape change and, unless actions are taken to defend the coastline, the site is likely to be disrupted by coastal erosion in the next 4,000 years. (authors)

  20. Radiological protection issues during primary filter housing replacement in a high alpha, beta-gamma shielded facility at Dounreay

    International Nuclear Information System (INIS)

    Mowat, D.; Watkin, T.

    2006-01-01

    Dounreay, on the north coast of Scotland, was home to the United Kingdom Fast Breeder Reactor (F.B.R.) development programme. F.B.R. use excess, non-moderated ('fast') neutrons to convert (breed) uranium, in elements positioned at the outer edges of the reactor core, into plutonium which can then be used as fuel.Site construction began in 1955 and three reactors were built and operated; the Dounreay Materials Test Reactor (D.M.T.R.) 1958-1969, the Dounreay Fast Reactor (D.F.R.) 1959-1977 and the Prototype Fast Reactor (P.F.R.) 1974-1994. The D.F.R. was conventionally fuelled by highly enriched uranium whereas the P.F.R. used a ceramic form of plutonium oxide (PuO 2 ) as its fuel. Dounreay was almost entirely self-sufficient in that a fuel cycle (chemical reprocessing) area was constructed complete with recovery plants, laboratories, waste storage and other support services buildings. Liquid plutonium nitrate product was sent to Sellafield, in Cumbria, to convert for future use, and the fuel elements were then fabricated at Springfields. Eventually, recovered P.F.R. plutonium was loaded back into the reactor, closing the fuel cycle. As a matter of interest for this paper, a Post Irradiation Examination (P.I.E.) facility, D2001, was built in the early 1960' s. The Plant was equipped with a suite of ten north and south side cells built to a high level of containment within which irradiated P.F.R. fuel could be remotely disassembled and examined. This work supported the continuing development of F.B.R. design and technology and the Plant has operated very successfully throughout its lifetime. A programme of improvement was implemented to enhance reliability, productivity and to modernize the facility to meet current nuclear and engineering standards. The experience of this work is detailed in this paper. (N.C.)

  1. How not to reduce plutonium stocks. The danger of MOX-fuelled nuclear reactors

    International Nuclear Information System (INIS)

    1999-01-01

    Plutonium is a radioactive by-product of nuclear reactor operation and one of the most toxic substances known. The world would be a safer place if the governments of countries with stocks of it, including Britain, would adopt effective policies for reducing and managing them. Two recent authoritative reports recommend that the British government take urgent action to reduce its 'civil' plutonium stock - currently one quarter of the world's total and set to rise to about two-thirds by the year 2010. The March 1999 House of Lords report, Management of Nuclear Waste, concludes that British government policy on plutonium 'should be the maintenance of the minimum strategic stock, and the declaration of the remainder as waste'. A report from the Royal Society, Britain's main learned society, meanwhile states that: 'In addition to disposing of some of the plutonium already in the stockpile, steps should be taken to reduce the amount added to it each year, primarily by reducing the amount of reprocessing carried out'. The government's reply to the House of Lords is expected to be followed by a public consultation before changes in legislation are proposed. But, at the same time, the government is considering an application from British Nuclear Fuels Limited (BNFL), the government-owned company which separates plutonium from spent nuclear fuel rods, for a licence to operate a new plant at Sellafield in Cumbria to produce mixed-oxide (MOX) nuclear fuel from its plutonium stockpile. The nuclear industry justifies the Sellafield MOX plant as one way of reducing plutonium stocks. But critics point out that this is not a rational way to manage plutonium. This briefing aims to contribute to an informed debate during the current flurry of British government nuclear policymaking by explaining why. (author)

  2. An intercomparison of sampling techniques among five European laboratories for measurements of radiocaesium in upland pasture and soil

    International Nuclear Information System (INIS)

    Nielsen, S.P.; Aarkrog, A.; Colgan, P.A.; McGee, E.; Synnott, H.J.; Johansson, K.J.; Horrill, A.D.; Kennedy, V.H.; Barbayiannis, N.

    1992-02-01

    An intercomparison of sampling procedures used by five European laboratories for the determination of radiocaesium in vegetation and peaty soil was carried out at two locations in Cumbria. The soil sampling procedures included th ecollection of depth profiles in order to obtain information on the vertical distribution of radiocaesium in addition to the total deposition. The number of samples taken by each laboratory varied from one to five. The multiple sampling has given information on the homogeneity of the parameters studied at each location. The parameters comprise soil bulk densities, total deposition of 137 Cs, deposition of 137 Cs in three soil layers, biomass densities, concentrations of 137 Cs in pasture, and activity ratios ( 134 Cs/ 137 Cs) in soil and vegetation. The determination of total deposition of 137 Cs gave no indication of differences between the laboratories. The total depositions of 134 Cs and 137 Cs observed at one site were compared with levels obtained from another study and the two sets of data were found to be in good agreement. The results from the soil profiles do indicate significant differences between laboratories. This covers the vertical distributions of 137 Cs deposition including the 134 Cs/ 137 Cs-activity ratios as well as the soil bulk densities. One laboratory using a coring technique observed difficulties during sampling due to compression of the soil. The coring technique should thus be avoided or applied with extreme care for the sampling of depth profiles in peaty soil. The results from the sampling of pasture show no indication of differences between the laboratories. For the parameters studied the observed variabilities across soil depths and locations range from 10% to 82% in terms of relative standard deviations. A comparison across all results at the two locations indicate a 50% higher field variability at one of the sites relative to the other. (au) (24 tabs., 9 ills., 3 refs.)

  3. Reduced nutrient pollution in a rural stream following septic tank upgrade and installation of runoff retention measures.

    Science.gov (United States)

    Ockenden, M C; Quinton, J N; Favaretto, N; Deasy, C; Surridge, B

    2014-07-01

    Surface water quality in the UK and much of Western Europe has improved in recent decades, in response to better point source controls and the regulation of fertilizer, manure and slurry use. However, diffuse sources of pollution, such as leaching or runoff of nutrients from agricultural fields, and micro-point sources including farmyards, manure heaps and septic tank sewerage systems, particularly systems without soil adsorption beds, are now hypothesised to contribute a significant proportion of the nutrients delivered to surface watercourses. Tackling such sources in an integrated manner is vital, if improvements in freshwater quality are to continue. In this research, we consider the combined effect of constructing small field wetlands and improving a septic tank system on stream water quality within an agricultural catchment in Cumbria, UK. Water quality in the ditch-wetland system was monitored by manual sampling at fortnightly intervals (April-October 2011 and February-October 2012), with the septic tank improvement taking place in February 2012. Reductions in nutrient concentrations were observed through the catchment, by up to 60% when considering total phosphorus (TP) entering and leaving a wetland with a long residence time. Average fluxes of TP, soluble reactive phosphorus (SRP) and ammonium-N (NH4-N) at the head of the ditch system in 2011 (before septic tank improvement) compared to 2012 (after septic tank improvement) were reduced by 28%, 9% and 37% respectively. However, TP concentration data continue to show a clear dilution with increasing flow, indicating that the system remained point source dominated even after the septic tank improvement.

  4. Variability in the supply, distribution and transport of the transient tracer 99Tc in the NE Atlantic

    Science.gov (United States)

    Kershaw, Peter John; Heldal, Hilde Elise; Mork, Kjell Arne; Rudjord, Anne Liv

    2004-01-01

    In April 1994, a new waste treatment plant, the Enhanced Actinide Removal Plant (EARP), began operation at the nuclear reprocessing facilities at Sellafield in Cumbria, UK. EARP was introduced primarily to reduce the discharges of plutonium and americium, and does not remove technetium-99 ( 99Tc) from the effluents. An increased waste throughput from Sellafield since 1994 has resulted in increased discharges of 99Tc into the Irish Sea. Studies of the propagation of 99Tc from the Irish Sea into the North Sea post-EARP showed much more rapid transport than reported for other radionuclides prior to EARP. The purpose of the present study was fourfold: to extend the geographical range of sampling to allow the continuing spread of EARP-related 99Tc to be followed; to place the results in an appropriate oceanographic setting; to test whether the apparent initial rapid transport had been maintained; and to provide a dataset which could be used for model development and validation. Our results confirm that the EARP-related 99Tc contamination had reached Arctic waters by 2000. The 99Tc concentration was an order of magnitude higher than background levels in the Norwegian Coastal Current (NwCC) outside Tromsø in June/July 1999, and ˜6 times higher than background levels in the West Spitsbergen Current (WSC) in May/June 2000. Our results suggest that, following the initial rapid transport of 99Tc from the Irish Sea into the North Sea in 1994-1995, the transport rate from the North Sea and northwards with the NwCC and WSC slowed markedly, in apparent correspondence with variations in the North Atlantic Oscillation (NAO) winter index.

  5. Accumulation of Sellafield-derived radiocarbon ("1"4C) in Irish Sea and West of Scotland intertidal shells and sediments

    International Nuclear Information System (INIS)

    Tierney, Kieran M.; Muir, Graham K.P.; Cook, Gordon T.; MacKinnon, Gillian; Howe, John A.; Heymans, Johanna J.; Xu, Sheng

    2016-01-01

    The nuclear energy industry produces radioactive waste at various stages of the fuel cycle. In the United Kingdom, spent fuel is reprocessed at the Sellafield facility in Cumbria on the North West coast of England. Waste generated at the site comprises a wide range of radionuclides including radiocarbon ("1"4C) which is disposed of in various forms including highly soluble inorganic carbon within the low level liquid radioactive effluent, via pipelines into the Irish Sea. This "1"4C is rapidly incorporated into the dissolved inorganic carbon (DIC) reservoir and marine calcifying organisms, e.g. molluscs, readily utilise DIC for shell formation. This study investigated a number of sites located in Irish Sea and West of Scotland intertidal zones. Results indicate "1"4C enrichment above ambient background levels in shell material at least as far as Port Appin, 265 km north of Sellafield. Of the commonly found species (blue mussel (Mytilus edulis), common cockle (Cerastoderma edule) and common periwinkle (Littorina littorea)), mussels were found to be the most highly enriched in "1"4C due to the surface environment they inhabit and their feeding behaviour. Whole mussel shell activities appear to have been decreasing in response to reduced discharge activities since the early 2000s but in contrast, there is evidence of continuing enrichment of the carbonate sediment component due to in-situ shell erosion, as well as indications of particle transport of fine "1"4C-enriched material close to Sellafield. - Highlights: • We measure "1"4C activity in shells and sediment at sites on the UK west coast. • Mussel shell activity varies in response to average "1"4C discharges from Sellafield. • Shell activities reflect species feeding habits and ecological niche. • NE Irish Sea inorganic sediment activity will gradually increase. • Increases in sediment activity will occur at remote sites on the Scottish west coast.

  6. Biological responses to acidification reversal in Cumbrian streamwaters - invertebrates and bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Tipping, E.; Bass, J.A.B.; Blackburn, J.H.; Hardie, D.J.; Mallinson, H.E.H.; Simon, B.M.

    2000-07-01

    The stream waters of the upper Duddon catchment, situated in the south-west of the English Lake District, have been acidified as a result of acid deposition. However, there is now strong chemical evidence for recovery, as the acidity of deposition decreases. The present study was carried out in order to investigate possible improvements in biological response. This report describes the results of sampling and analysis, carried out to obtain biological data in 1999 for comparison with data obtained in the 1960s and early 1970s for invertebrates and in the 1980s for bacteria. Macro-invertebrate studies were carried out in five streams which had records from the 1960s and 1970s, and which covered a range of pH (ca. 5 to ca. 7). Significantly more macro-invertebrate taxa were found in all the streams in 1999. The macro-invertebrate diversity was greater in 1999, as judged by the Margalef diversity index. There have been significant increases in the values of a macro-invertebrate based acidification index between the 1960s/1970s and the present, consistent with a decrease in stream water acidity. Species of the bacterium Cytophaga, which participates in the decomposition of plant litter, are absent from streams of low pH. Cytophaga was detected in a stream from which it had previously absent, which is consistent with an increase in pH. Taking the results of the present study together with those of previous ones showing that stream and lake acidity in Cumbria have decreased over the last 20-30 years, it can be concluded that decreases in acid deposition (of S) have led to improvements in water quality, and thereby to positive biological responses. (author)

  7. Identifying optimal agricultural countermeasure strategies for a hypothetical contamination scenario using the strategy model

    International Nuclear Information System (INIS)

    Cox, G.; Beresford, N.A.; Alvarez-Farizo, B.; Oughton, D.; Kis, Z.; Eged, K.; Thorring, H.; Hunt, J.; Wright, S.; Barnett, C.L.; Gil, J.M.; Howard, B.J.; Crout, N.M.J.

    2005-01-01

    A spatially implemented model designed to assist the identification of optimal countermeasure strategies for radioactively contaminated regions is described. Collective and individual ingestion doses for people within the affected area are estimated together with collective exported ingestion dose. A range of countermeasures are incorporated within the model, and environmental restrictions have been included as appropriate. The model evaluates the effectiveness of a given combination of countermeasures through a cost function which balances the benefit obtained through the reduction in dose with the cost of implementation. The optimal countermeasure strategy is the combination of individual countermeasures (and when and where they are implemented) which gives the lowest value of the cost function. The model outputs should not be considered as definitive solutions, rather as interactive inputs to the decision making process. As a demonstration the model has been applied to a hypothetical scenario in Cumbria (UK). This scenario considered a published nuclear power plant accident scenario with a total deposition of 1.7 x 10 14 , 1.2 x 10 13 , 2.8 x 10 10 and 5.3 x 10 9 Bq for Cs-137, Sr-90, Pu-239/240 and Am-241, respectively. The model predicts that if no remediation measures were implemented the resulting collective dose would be approximately 36 000 person-Sv (predominantly from 137 Cs) over a 10-year period post-deposition. The optimal countermeasure strategy is predicted to avert approximately 33 000 person-Sv at a cost of approximately pound 160 million. The optimal strategy comprises a mixture of ploughing, AFCF (ammonium-ferric hexacyano-ferrate) administration, potassium fertiliser application, clean feeding of livestock and food restrictions. The model recommends specific areas within the contaminated area and time periods where these measures should be implemented

  8. Radiocaesium variability within sheep flocks. Relationships between the 137Cs activity concentrations of individual ewes within a flock and between ewes and their progeny

    International Nuclear Information System (INIS)

    Beresford, N.A.; Barnett, C.L.; Crout, N.M.J.; Morris, C.C.

    1995-01-01

    As a consequence of radiocaesium deposition following the Chernobyl accident the movement and slaughter of sheep were restricted within some upland areas of the United Kingdom. Considerable variability in the radiocaesium activity concentrations between individual sheep within flocks has been recorded. This paper reports studies conducted to investigate the reasons for this within flock variability on three farms in the restricted area of west Cumbria. On each farm, study sheep were selected and live-monitored over the period 1991-93. Results from all three study farms showed a correlation in the 137 Cs activity concentration of individual sheep on different monitoring occasions. This observation suggested that a few sheep on each farm are likely to be responsible for the continuation of restrictions on many of the affected holdings. Comparisons between monitoring data obtained in summer and autumn months were better correlated than those involving data collected in the winter and spring. Prior to weaning there was a linear relationship between the 137 Cs levels in the muscle of a lamb and that in the muscle of its dam. Given these observations it is suggested that, in successive years, ewes identified as consistently having high radiocaesium levels in their muscle will produce lambs which will also have comparatively high levels of radiocaesium; the limited data available support this hypothesis. However, no relationship between the 137 Cs activity concentration of a ewe and its lamb was evident post-weaning, thereby discounting any possibility of an inherited effect. On one of the farms a significant difference was found between the 137 Cs activity concentration of different breeds of sheep

  9. The systemic roles of SKI and SSI in the Swedish nuclear waste management system. Syncho's report for project RISCOM

    International Nuclear Information System (INIS)

    Espejo, R.; Gill, A.

    1998-01-01

    The purpose of this report is to share and summarize our findings about the regulatory roles of SKI/SSI in the context of the Swedish Nuclear System (SNS), with an emphasis on nuclear waste management. The driving force in this review is to make decision processes more transparent. What is reported is based on interviews conducted with employees at SKI/SSI/SKB during early December 1996, the presentation to SKI/SSI in January 1997, discussions during the Shap Wells meeting in Cumbria during March 1997 and RISCOM internal discussions. We offer two hypotheses about the way the Nuclear Waste Management System (NWMS) appears to work. We choose one and derive from it a view about structural issues in SNS and NWMS. The conclusion is a set of systemic roles for the regulators. It is the comparison between these systemic roles and the actual situation that may trigger some adjustments in the system. Our hope is that these findings will make apparent feasible and desirable changes in the system in order to increase the chances for transparent decisions in the Nuclear Waste Management System. In summary, Section 2 includes a general background of the NWMS based on interviews and general information. Section 3 makes a more focused attempt to work out the issues expressed by people in the interviews. Section 4 discusses at a more conceptual level systemic ideas such as the unfolding of complexity. Section 5 is an attempt to organize viewpoints about the NWMS and offers hypotheses to support a preliminary diagnosis of the system in Section 6. We call this section 'A problem of identity'. It is only in Section 7 that basic systemic arguments are unfolded with the intention of supporting an appreciation of SKI/SSI's regulatory roles in the nuclear industry as a whole and nuclear waste management in particular. Section 8 offers a summary of conclusions

  10. Voluntarism, public engagement and the role of geoscience in radioactive waste management policy-making

    Science.gov (United States)

    Bilham, Nic

    2014-05-01

    In the UK, as elsewhere in Europe, there has been a move away from previous 'technocratic' approaches to radioactive waste management (RWM). Policy-makers have recognised that for any RWM programme to succeed, sustained engagement with stakeholders and the public is necessary, and any geological repository must be constructed and operated with the willing support of the community which hosts it. This has opened up RWM policy-making and implementation to a wider range of (often contested) expert inputs, ranging across natural and social sciences, engineering and even ethics. Geoscientists and other technical specialists have found themselves drawn into debates about how various types of expertise should be prioritised, and how they should be integrated with diverse public and stakeholder perspectives. They also have a vital role to play in communicating to the public the need for geological disposal of radioactive waste, and the various aspects of geoscience which will inform the process of implementing this, from identifying potential volunteer host communities, to finding a suitable site, developing the safety case, construction of a repository, emplacement of waste, closure and subsequent monitoring. High-quality geoscience, effectively communicated, will be essential to building and maintaining public confidence throughout the many decades such projects will take. Failure to communicate effectively the relevant geoscience and its central role in the UK's radioactive waste management programme arguably contributed to West Cumbria's January 2013 decision to withdraw from the site selection process, and may discourage other communities from coming forward in future. Across countries needing to deal with their radioactive waste, this unique challenge gives an unprecedented urgency to finding ways to engage and communicate effectively with the public about geoscience.

  11. The puzzle of high heads beneath the West Cumbrian coast, UK: a possible solution

    Science.gov (United States)

    Black, John H.; Barker, John A.

    2016-03-01

    A region of high heads within the Borrowdale Volcanic Group (BVG; a fractured crystalline rock) beneath the coastal plain of West Cumbria, England (UK), is identified as a possible relic left over by the Late Devensian ice sheet. It was found during investigations in the 1990s. Contemporary modelling work failed to produce a satisfactory explanation of the high heads compatible with the `cold recharge' isotopic signature of the groundwater. This study has reassessed the original hydraulic testing results. By plotting density-adjusted heads versus their depth below the water table in the immediate vicinity of the borehole in which they were measured, a depth profile resembling a `wave' was revealed with a peak value located at 1,100 m depth. The possibility that this wave represents relic heads from the last major ice sheet has been assessed using one-dimensional mathematical analysis based on a poroelastic approach. It is found that a wet-based ice sheet above the West Cumbrian coast was probably thick enough and sufficiently long-lasting to leave such relic heads providing that the hydraulic diffusivity of the BVG is in the order of 10-6 m s-1. Initial assessment 20 years ago of the long-interval slug tests suggested that such low values are not likely. More recent interpretation argues for such low values of hydraulic diffusivity. It is concluded that ice sheet recharge is the most likely cause of the raised heads, that the BVG contains significant patches of very low conductivity rock, and that long-interval single-hole tests should be avoided in fractured crystalline rock.

  12. In situ radionuclide migration studies in a shallow sand aquifer. Part. 1. Part. 2: appendices

    International Nuclear Information System (INIS)

    Williams, G.M.; Alexander, L.S.; Hitchman, S.P.; Hooker, P.J.; Noy, D.J.; Ross, C.A.M.; Stuart, A.; West, J.M.

    1986-01-01

    As a result of a study of the geology of the British Nuclear Fuels premises at Drigg, Cumbria, the British Geological Survey identified a shallow glacial sand deposit approximately 1.5m thick, interbedded between two clay horizons. An array of boreholes has been constructed in this sand in order to study the migration of radionuclides introduced into the formation under controlled conditions of groundwater flow. Conservative tracers used in the field test include chloride (as NaCl) and iodine-131 (as NaI). Strontium-85 (as the chloride) has been used as a chemically reactive tracer in conjunction with 131 I. The principal research objectives of the programme are as follows: (1) To undertake laboratory batch sorption experiments using core material from the field site in order to choose those nuclides of radiological interest that would migrate sufficiently quickly for their behaviour to be studied in a field experiment within a reasonable time period. (2) To identify and quantify the mechanisms for nuclide/sediment interaction by determination of the geochemical distribution of 85 Sr in contaminated cores using a sequential leaching procedure. (3) To obtain appropriate data on the hydraulic characteristics of the sand formation in order to construct a mathematical model to describe groundwater flow and reactive mass transport. Part 2 of this report contains the following appendices: (1) Calculation of sorption parameters. (2) A low-cost manifold system for use with multi-level samplers. (3) Radioactivity curves for 131 I and 85 Sr. (4) Results of particle size analysis for sand aquifers

  13. The discharges from Sellafield how big a risk for the Irish population?

    Energy Technology Data Exchange (ETDEWEB)

    O` Flaherty, T [Radiological Protection Inst. of Ireland (Ireland)

    1996-10-01

    The site operated by British Nuclear Fuels Ltd (BNFL) at Sellafield in Cumbria was established just after World War II to produce plutonium for the manufacture of nuclear weapons. Plutonium was obtained by extracting it from nuclear fuel which had been irradiated in an early type of nuclear reactor. This procedure was the forerunner of what ultimately became the main commercial activity at Sellafield, the reprocessing of spent nuclear fuel to recover re-usable uranium and plutonium An unavoidable consequence of nuclear fuel reprocessing is the necessity to discharge from the site very large volumes of low-level radioactive waste in liquid form. In the case of Sellafield this waste is discharged into the Irish Sea. Due to a plant malfunction the rates of discharge greatly increased in the mid-1970s, and became a matter of serious concern to the people of Ireland and to successive Irish Governments. In more recent years the rates of discharge have fallen again to lower levels, but this has not diminished concern in Ireland to any significant degree. This paper summarises the results of Irish monitoring of radioactivity levels in the Irish Sea which has been in progress since the late 1970s. From these results it quantifies the radiation doses received by people in Ireland in consequence of the discharges from Sellafield, and estimates the degree of risk of increased cancer levels in the Irish population as a result. The RPII`s monitoring programme has been expanded since 1993 in the light of the bringing into operation of the new Thermal Oxide Reprocessing Plant (Thorp) and now includes the monitoring of gaseous discharges to the atmosphere. The paper includes some initial results of this expanded programme.

  14. Radiation and stillbirths in Sellafield workers

    International Nuclear Information System (INIS)

    Anon.

    1999-01-01

    Full text: In The Lancet (23 October 1999), Dr Louise Parker and colleagues from the Departments of Child Health and Statistics, University of Newcastle upon Tyne, UK, report the findings of a new study on stillbirths among offspring of male radiation workers at Sellafield. By linking the birth registration and stillbirth records in Cumbria from 1950 to 1989 to the database of workers at Sellafield, Dr Parker's team examined the stillbirth risk according to the father's exposure to radiation before conception of the child. From the birth documents of 248 097 livebirths and 3715 stillbirths, the team identified 130 stillbirths and 9078 livebirths to wives and partners of male radiation workers employed at Sellafield. Lifetime exposure, and that in the 90 days before conception, was derived from annual-exposure summaries for each worker. Exposures recorded on individual film badges for the fathers of each stillborn child and for four matched controls were also examined. The researchers found that although, as a group, babies of radiation workers were not more likely to be stillborn than babies of other Cumbrian fathers, there was an increased risk of stillbirth with increasing exposure of a father to external radiation. Although confounding factors also associated with stillbirth, such as whether the mother smoked, cannot be completely excluded, the researchers state that 'extensive checks confirmed that the statistical models were a good fit to the data and there was no statistical evidence of unmeasured factors'. However, the researchers are cautious in drawing any conclusions regarding causality. In the Commentary given in The Lancet, Hazel Inskip from the University of Southampton advises that the possible risk of stillbirth should be kept in perspective, and comments that 'there is no obvious mechanism for the association', but does concede that 'the greater increase in risk for stillbirths with neural-tube defects is at least focused on a more specific disorder

  15. The Small Area Health Statistics Unit: a national facility for investigating health around point sources of environmental pollution in the United Kingdom.

    Science.gov (United States)

    Elliott, P; Westlake, A J; Hills, M; Kleinschmidt, I; Rodrigues, L; McGale, P; Marshall, K; Rose, G

    1992-01-01

    STUDY OBJECTIVE--The Small Area Health Statistics Unit (SAHSU) was established at the London School of Hygiene and Tropical Medicine in response to a recommendation of the enquiry into the increased incidence of childhood leukaemia near Sellafield, the nuclear reprocessing plant in West Cumbria. The aim of this paper was to describe the Unit's methods for the investigation of health around point sources of environmental pollution in the United Kingdom. DESIGN--Routine data currently including deaths and cancer registrations are held in a large national database which uses a post code based retrieval system to locate cases geographically and link them to the underlying census enumeration districts, and hence to their populations at risk. Main outcome measures were comparison of observed/expected ratios (based on national rates) within bands delineated by concentric circles around point sources of environmental pollution located anywhere in Britain. MAIN RESULTS--The system is illustrated by a study of mortality from mesothelioma and asbestosis near the Plymouth naval dockyards during 1981-87. Within a 3 km radius of the docks the mortality rate for mesothelioma was higher than the national rate by a factor of 8.4, and that for asbestosis was higher by a factor of 13.6. CONCLUSIONS--SAHSU is a new national facility which is rapidly able to provide rates of mortality and cancer incidence for arbitrary circles drawn around any point in Britain. The example around Plymouth of mesothelioma and asbestosis demonstrates the ability of the system to detect an unusual excess of disease in a small locality, although in this case the findings are likely to be related to occupational rather than environmental exposure. PMID:1431704

  16. Finding a Solution-The Importance of Transparency

    Energy Technology Data Exchange (ETDEWEB)

    Dalton, J.; Atherton, E.

    2002-02-28

    In 1997 Nirex failed to obtain planning permission to build an underground laboratory (Rock Characterization Facility) near the Sellafield nuclear site in Cumbria, North-West England. This stopped the UK's deep disposal programme. Since then there has been much discussion on how the UK should take the issue of long-term radioactive waste management forward. As part of its contribution to the ongoing debate, Nirex needed to reassess how its role in finding a long-term solution could be better played given its history. It has been suggested that the processes required to deal with such a contentious issue, the conduct of individuals and the structural relationships between organizations, all need to change if any progress is to be made. Specifically, one of the difficulties of the past was the lack of a mechanism to allow all stakeholders and the public to clearly see what had been decided and for what reasons. Nirex believes that central to these changes needs to be a strong ethical framework based on transparency. In order to assess the impact of these initiatives and its performance against them, Nirex commissioned (in 2001) an independent assessment of views from different stakeholder groups. The results of this assessment are presented. In summary, this showed that there is widespread support for these policies and the approach to increased focus on dialogue with stakeholders. In this latter respect, the way in which Nirex is now operating allows the stakeholders to have a direct access to, and influence on, its work programme and this is described.

  17. Ventilation design for containment and the effects on energy consumption at Sellafield

    International Nuclear Information System (INIS)

    Doig, R.; Scattergood, B.; Standring, T.

    1997-01-01

    Nuclear reprocessing plants are designed to contain some radioactive process, minimise the risk of loss of containment and to limit the discharge of material to the environment. The physical containment systems, provided by the building and process vessels, are generally insufficient measures on their own to safeguard against release of contamination. This passive' containment must be enhanced by an active' containment - the ventilation system. The ventilation system is designed to provide a depression gradient so that air flows from areas of lesser to greater contamination potential and thereby limit the possibility of migration of contamination. The ventilation design is dominated by the extract system, which is used to create the differential pressures required to obtain the desired depression gradient. The resultant, contaminated, exhaust air requires considerable clean-up equipment to treat it prior to discharge to atmosphere. Within the nuclear industry, safety has always been paramount and will continue to be so, however, in recent years additional requirements have grown in importance and one of these has been energy conservation. At the same time, pressure has increased from the industry regulators to reduce discharges to atmosphere. A case study has been carried out on an existing plant at Sellafield, Cumbria, to review energy consumption and potential savings. This review was based on operational experience and evolution in containment and ventilation design which have occurred in intervening years. Completed in 1984, at a capital cost in excess of Pound 300m, the Fuel Handling Plant (FHP) at Sellafield, has one of the largest heating and ventilation systems in Europe. Costing approximately Pound 11m, the various ventilation systems comprise some 27 individual sub-systems using 58 fans, some 1,000 dampers and approximately 10 miles of ductwork spread over three buildings (integrated to form one whole). (UK)

  18. Field verification of advanced transport models of radionuclides in heterogeneous soils

    International Nuclear Information System (INIS)

    Visser, W.; Meurs, G.A.M.; Weststrate, F.A.

    1991-01-01

    This report deals with a verification study of advanced transport models of radionuclides in heterogeneous soils. The study reported here is the third phase of a research program carried out by Delft Geotechnics concerning the influence of soil heterogeneities on the migration of radionuclides in the soil and soil-water system. Phases 1 and 2 have been reported earlier in the EC Nuclear Science and technology series (EUR 12111 EN, 1989). The verification study involves the predictive modelling of a field tracer experiment carried out by the British Geological Survey (BGS) at Drigg, Cumbria (UK). Conservative (I 131 , Cl-, H 3 ) as well as non-conservative (Co-EDTA) tracers were used. The inverse modelling shows that micro dispersion may be considered as a soil constant related to grainsize. Micro dispersion shows a slow increase with distance from the source. This increase is caused by mass transfer between adjacent layers of different permeability. Macro dispersion is observed when sampling over a larger interval then permitted by the detail with which the heterogeneity is described in the model. The prediction of the migration of radionuclides through heterogeneous soils is possible. The advection dispersion equation seems to be an adequate description of the migration of conservative tracers. The models based on this equation give comparable results on a small field test scale (3.5 m). The prediction of the migration of adsorbing species is more difficult. The mathematical descriptions seem appropriate, but the heterogeneity in soils seems to create a higher order of uncertainty which can not be described as yet with calculation strategies available at this moment

  19. The design, manufacture, and testing of a new generation of ISO freight container for certification as an IP-2 package in compliance with the IAEA Regulations for the Safe Transport of Radioactive Material, 1985 edition (as amended 1990)

    International Nuclear Information System (INIS)

    Urch, K.C.

    1997-01-01

    Solid low level radioactive waste (LLW) which arises at nuclear power stations and other nuclear facilities in the UK, is routinely transported to British Nuclear Fuels' site at Drigg in Cumbria for disposal. A requirement was identified for the use of a refurbished ISO freight container of the full-height design, to transport drummed LLW to the site of a supercompaction facility prior to disposal at Drigg. This paper describes the reasoned technical justification employed for certifying the refurbished ISO freight container, Design No. 2912B, as an IP-2 package under Paragraph 523 of the IAEA Transport Regulations and the development of a new generation of ISO Freight container, Design No. 2044. It was recognised that the use of a refurbished container was only an interim measure and because of significant changes in the acceptance criteria for disposal, the increased use of high force compaction techniques and the proposed amendments to the IAEA Transport Regulations, Nuclear Electric embarked upon the development of a new generation of ISO freight containers. The new container design (Design No. 2044) incorporates a readily decontaminable stainless steel interior, a comprehensive load restraint system designed for the transport of single and multiple packages, and is lined with a polyurethane foam between the inner and outer skins. It is designed to transport 70 off, 200 litre drums of LLW (stacked in two layers) and other payloads of size not greater than 4 m long x 2 m wide and 20 tonnes in weight. The container was subjected to a range of tests to prove compliance with the ISO standard and the IAEA Transport Regulations. Following the preparation of the required documentation, in particular a Safety Case and comprehensive Operating and Maintenance Instructions, a Certificate of Regulatory Compliance was issued by the appropriate authority certifying the container as an Industrial Package Type 2 (IP-2) suitable for the transport of drummed LLW and other

  20. Using Conditional Analysis to Investigate Spatial and Temporal patterns in Upland Rainfall

    Science.gov (United States)

    Sakamoto Ferranti, Emma Jayne; Whyatt, James Duncan; Timmis, Roger James

    2010-05-01

    The seasonality and characteristics of rainfall in the UK are altering under a changing climate. Summer rainfall is generally decreasing whereas winter rainfall is increasing, particularly in northern and western areas (Maraun et al., 2008) and recent research suggests these rainfall increases are amplified in upland areas (Burt and Ferranti, 2010). Conditional analysis has been used to investigate these rainfall patterns in Cumbria, an upland area in northwest England. Cumbria was selected as an example of a topographically diverse mid-latitude region that has a predominately maritime and westerly-defined climate. Moreover it has a dense network of more than 400 rain gauges that have operated for periods between 1900 and present day. Cumbria has experienced unprecedented flooding in the past decade and understanding the spatial and temporal changes in this and other upland regions is important for water resource and ecosystem management. The conditional analysis method examines the spatial and temporal variations in rainfall under different synoptic conditions and in different geographic sub-regions (Ferranti et al., 2009). A daily synoptic typing scheme, the Lamb Weather Catalogue, was applied to classify rainfall into different weather types, for example: south-westerly, westerly, easterly or cyclonic. Topographic descriptors developed using GIS were used to classify rain gauges into 6 directionally-dependant geographic sub-regions: coastal, windward-lowland, windward-upland, leeward-upland, leeward-lowland, secondary upland. Combining these classification methods enabled seasonal rainfall climatologies to be produced for specific weather types and sub-regions. Winter rainfall climatologies were constructed for all 6 sub-regions for 3 weather types - south-westerly (SW), westerly (W), and cyclonic (C); these weather types contribute more than 50% of total winter rainfall. The frequency of wet-days (>0.3mm), the total winter rainfall and the average wet day

  1. Phase 1 studies summary of major findings of the South Bay Salt Pond Restoration Project, South San Francisco Bay, California

    Science.gov (United States)

    Valoppi, Laura

    2018-04-02

    Executive SummaryThe South Bay Salt Pond Restoration Project (Project) is one of the largest restoration efforts in the United States. It is located in South San Francisco Bay of California. It is unique not only for its size—more than 15,000 acres—but also for its location adjacent to one of the nation’s largest urban areas, home to more than 4 million people (Alameda, Santa Clara, and San Mateo Counties). The Project is intended to restore and enhance wetlands in South San Francisco Bay while providing for flood management, wildlife-oriented public access, and recreation. Restoration goals of the project are to provide a mosaic of saltmarsh habitat to benefit marsh species and managed ponds to benefit waterbirds, throughout 3 complexes and 54 former salt ponds.Although much is known about the project area, significant uncertainties remain with a project of this geographic and temporal scale of an estimated 50 years to complete the restoration. For example, in order to convert anywhere from 50 to 90 percent of the existing managed ponds to saltmarsh habitat, conservation managers first enhance the habitat of managed ponds in order to increase use by waterbirds, and provide migratory, wintering, and nesting habitat for more than 90 species of waterbirds. Project managers have concluded that the best way to address these uncertainties is to carefully implement the project in phases and learn from the outcome of each phase. The Adaptive Management Plan (AMP) identifies specific restoration targets for multiple aspects of the Project and defines triggers that would necessitate some type of management action if a particular aspect is trending negatively. U.S. Geological Survey (USGS) biologist Laura Valoppi served as the project Lead Scientist and oversaw implementation of the AMP in coordination with other members of the Project Management Team (PMT), comprised of representatives from the California State Coastal Conservancy, California Department of Fish and

  2. Estimates of future inundation of salt marshes in response to sea-level rise in and around Acadia National Park, Maine

    Science.gov (United States)

    Nielsen, Martha G.; Dudley, Robert W.

    2013-01-01

    Salt marshes are ecosystems that provide many important ecological functions in the Gulf of Maine. The U.S. Geological Survey investigated salt marshes in and around Acadia National Park from Penobscot Bay to the Schoodic Peninsula to map the potential for landward migration of marshes using a static inundation model of a sea-level rise scenario of 60 centimeters (cm; 2 feet). The resulting inundation contours can be used by resource managers to proactively adapt to sea-level rise by identifying and targeting low-lying coastal areas adjacent to salt marshes for conservation or further investigation, and to identify risks to infrastructure in the coastal zone. For this study, the mapping of static inundation was based on digital elevation models derived from light detection and ranging (LiDAR) topographic data collected in October 2010. Land-surveyed control points were used to evaluate the accuracy of the LiDAR data in the study area, yielding a root mean square error of 11.3 cm. An independent accuracy assessment of the LiDAR data specific to salt-marsh land surfaces indicated a root mean square error of 13.3 cm and 95-percent confidence interval of ± 26.0 cm. LiDAR-derived digital elevation models and digital color aerial photography, taken during low tide conditions in 2008, with a pixel resolution of 0.5 meters, were used to identify the highest elevation of the land surface at each salt marsh in the study area. Inundation contours for 60-cm of sea-level rise were delineated above the highest marsh elevation for each marsh. Confidence interval contours (95-percent,± 26.0 cm) were delineated above and below the 60-cm inundation contours, and artificial structures, such as roads and bridges, that may present barriers to salt-marsh migration were mapped. This study delineated 114 salt marshes totaling 340 hectares (ha), ranging in size from 0.11 ha (marshes less than 0.2 ha were mapped only if they were on Acadia National Park property) to 52 ha, with a median

  3. Quantifying Trophic Interactions and Carbon Flow in Louisiana Salt Marshes Using Multiple Biomarkers

    Science.gov (United States)

    Polito, M. J.; Lopez-Duarte, P. C.; Olin, J.; Johnson, J. J.; Able, K.; Martin, C. W.; Fodrie, J.; Hooper-Bui, L. M.; Taylor, S.; Stouffer, P.; Roberts, B. J.; Rabalais, N. N.; Jensen, O.

    2017-12-01

    Salt marshes are critical habitats for many species in the northern Gulf of Mexico. However, given their complex nature, quantifying trophic linkages and the flow of carbon through salt marsh food webs is challenging. This gap in our understanding of food web structure and function limits our ability to evaluate the impacts of natural and anthropogenic stressors on salt marsh ecosystems. For example, 2010 Deepwater Horizon (DWH) oil spill had the potential to alter trophic and energy pathways. Even so, our ability to evaluate its effects on Louisiana salt marsh food webs was limited by a poor basis for comparison of the pre-spill baseline food web. To be better equipped to measure significant alterations in salt marsh ecosystems in the future, we quantified trophic interactions at two marsh sites in Barataria Bay, LA in May and October of 2015. Trophic structure and carbon flow across 52 species of saltmarsh primary producers and consumers were examined through a combination of three approaches: bulk tissue stable isotope analysis (δ13C, δ15N, δ34S), dietary fatty acid analysis (FAA), and compound-specific stable isotope analysis of essential amino acids (δ13C EAA). Bulk stable isotope analysis indicated similar trophic diversity between sites and seasons with the use of aquatic resources increasing concomitantly with trophic level. FAA and δ13C EAA biomarkers revealed that marsh organisms were largely divided into two groups: those that primarily derive carbon from terrestrial C4 grasses, and those that predominately derive carbon from a combination of phytoplankton and benthic microalgal sources. Differences in trophic structure and carbon flow were minimal between seasons and sites that were variably impacted by the DWH spill. These data on salt marsh ecosystem structure will be useful to inform future injury assessments and restoration initiatives.

  4. Examining the evidence for a recent acceleration in the rate of sea-level rise using combined instrumental and proxy data, North Carolina, USA

    Science.gov (United States)

    Kemp, A.; Horton, B. P.

    2007-12-01

    Whilst accelerated rates of relative sea-level (RSL) rise are potentially one of the most devastating impacts of future climate change, our understanding of decadal scale changes in sea-level is poor. This paper seeks to address this knowledge gap by combining tide gauge and high-precision geological reconstructions of relative sea-level of sufficient resolution and duration to detect any recent acceleration in the rate of sea-level rise. We offer a high resolution relative sea-level history for the last ~2000 years from the Albemarle - Pamlico Estuarine System in North Carolina. Contemporary foraminifera were collected from five back barrier marshes to create a regional scale modern training set. The use of multiple marshes from a region increases the ecological and environmental diversity included within the training set and reduces the probability of a no modern analogue outcome. To merge the five spatially distinct sites and to relate each to local tide levels we used the VDatum transformation tool. This method relates all samples to a common orthometric datum (NAVD88) and reduces error. We developed an accurate and precise transfer function to reconstruct former sea levels based upon the modern observable relationship between foraminifera and elevation with respect to the tidal frame. We applied the transfer function to salt-marsh core(s) from Sand Point (Roanoke Island), North Carolina to produce a late Holocene RSL record. An age-depth model was produced from composite chronologies of 210Pb, 14C and pollen chrono-horizons. We validated our approach by comparing geological based reconstructions and instrumental tide gauge records. Our records show that in the last ~2000 years sea level has risen at a background rate of ~1.1mm/yr. There is evidence for two recent accelerations in the rate of sea-level rise during the late 19th and 20th centuries to a current rate of ~4mm/yr.

  5. Geologic record of Hurricane impacts on the New Jersey coast

    Science.gov (United States)

    Nikitina, Daria; Horton, Benjamin; Khan, Nicole; Clear, Jennifer; Shaw, Timothy; Enache, Mihaela; Frizzera, Dorina; Procopio, Nick; Potapova, Marina

    2016-04-01

    Hurricanes along the US Atlantic coast have caused significant damage and loss of human life over the last century. Recent studies suggest that intense-hurricane activity is closely related to changes of sea surface temperatures and therefore the risk of hurricane strikes may increase in the future. A clear understanding of the role of recent warming on tropical cyclone activity is limited by the shortness of the instrumental record. However, the sediment preserved beneath coastal wetlands is an archive of when hurricanes impacted the coast. We present two complimenting approaches that help to extend pre-historic record and assess frequency and intensity of hurricane landfalls along the New Jersey cost; dating overwash deposits and hurricane-induced salt-marsh erosion documented at multiple sites. The stratigraphic investigation of estuarine salt marshes in the southern New Jersey documented seven distinctive erosion events that correlate among different sites. Radiocarbon dates suggest the prehistoric events occurred in AD 558-673, AD 429-966, AD 558-673, Ad 1278-1438, AD 1526-1558 or AD 1630-1643 (Nikitina et al., 2014). Younger sequences correspond with historical land-falling hurricanes in AD 1903 and AD 1821 or AD 1788. Four events correlate well with barrier overwash deposits documented along the New Jersey coast (Donnelley et al., 2001 and 2004). The stratigraphic sequence of salt High resolution sedimentary-based reconstructions of past intense-hurricane landfalls indicate that significant variability in the frequency of intense hurricanes occurred over the last 2000 years.

  6. Modelling the transport and decay processes of microbial tracers in a macro-tidal estuary.

    Science.gov (United States)

    Abu-Bakar, Amyrhul; Ahmadian, Reza; Falconer, Roger A

    2017-10-15

    The Loughor Estuary is a macro-tidal coastal basin, located along the Bristol Channel, in the South West of the U.K. The maximum spring tidal range in the estuary is up to 7.5 m, near Burry Port Harbour. This estuarine region can experience severe coastal flooding during high spring tides, including extreme flooding of the intertidal saltmarshes at Llanrhidian, as well as the lower industrial and residential areas at Llanelli and Gowerton. The water quality of this estuarine basin needs to comply with the designated standards for safe recreational bathing and shellfish harvesting industries. The waterbody however, potentially receives overloading of bacterial inputs that enter the estuarine system from both point and diffuse sources. Therefore, a microbial tracer study was carried out to get a better understanding of the faecal bacteria sources and to enable a hydro-environmental model to be refined and calibrated for both advection and dispersion transport. A two-dimensional hydro-environmental model has been refined and extended to predict the highest water level covering the intertidal floodplains of the Loughor Estuary. The validated hydrodynamic model for both water levels and currents, was included with the injected mass of microbial tracer, i.e. MS2 coliphage from upstream of the estuary, and modelled as a non-conservative tracer over several tidal cycles through the system. The calibration and validation of the transport and decay of microbial tracer was undertaken, by comparing the model results and the measured data at two different sampling locations. The refined model developed as a part of this study, was used to acquire a better understanding of the water quality processes and the potential sources of bacterial pollution in the estuary. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Holocene palaeoenvironmental history of the Amazonian mangrove belt

    Science.gov (United States)

    Cohen, Marcelo Cancela Lisboa; Pessenda, Luiz Carlos Ruiz; Behling, Hermann; de Fátima Rossetti, Dilce; França, Marlon Carlos; Guimarães, José Tasso Felix; Friaes, Yuri; Smith, Clarisse Beltrão

    2012-11-01

    Wetland dynamic in the northern Brazilian Amazon region during the Holocene was reviewed using palynological, carbon and nitrogen isotopes records, and C/N ratio previously published. The integration of 72 radiocarbon dates recorded in 34 sediment cores sampled along the marine and fluvial littoral, and mainly influenced by the Amazon River, reveals that marine influence and mangrove vegetation were wider than today on the mouth of Amazon River between >8990-8690 and 2300-2230 cal yr BP, forming a continuous mangrove belt along the northern Brazilian Amazon littoral. The establishment of this mangrove strip is a direct consequence of the marine incursion caused by post-glacial sea-level rise possibly associated with tectonic subsidence during the Early and Middle Holocene. In the Late Holocene, in areas influenced by the Amazon River discharge, the mangroves were replaced by freshwater vegetation, and the coast morphology evolved from an estuarine dominated into a rectilinear coast due to coastal progradation. Nevertheless, the marine-influenced littoral, which is currently dominated by mangroves and salt-marsh vegetation, has persistently had brackish water vegetation over tidal mud flats throughout the entire Holocene. Likely, the fragmentation of this continuous mangrove line during the Late Holocene was caused by the increase of river freshwater discharge associated to the change from dry into wet climates in the Late Holocene. This caused a significant decrease of tidal water salinity in areas near the mouth of Amazon River. These changes in the Amazon discharge are probably associated with dry and wet periods in the northern Amazon region during the Holocene.

  8. Long-term environmental and health implications of morphological change and sediment transport with respect to contaminants

    Science.gov (United States)

    Sneddon, Christopher; Copplestone, David; Tyler, Andrew; Hunter, Peter; Smith, Nick

    2014-05-01

    The EPSRC-funded Adaptation and Resilience of Coastal Energy Supply (ARCoES) project encompasses four research strands, involving 14 institutions and six PhD studentships. ARCoES aims to determine the threats posed to future energy generation and the distribution network by flooding and erosion, changing patterns of coastal sedimentation, water temperature and the distribution of plants and animals in the coastal zone. Whilst this research has direct benefits for the operation of coastal power stations, ARCoES aims to have a wider stakeholder engagement through assessing how the resilience of coastal communities may be altered by five hundred years of coastal evolution. Coastal evolution will have substantial implications for the energy sector of the North West of England as former waste storage sites are eroded and remobilised within the intertidal environment. The current intertidal environmental stores of radioactivity will also experience reworking as ocean chemistry changes and saltmarsh chronologies are reworked in response to rising sea levels. There is a duel requirement to understand mass sediment movement along the North West coast of England as understanding the sediment transport dynamics is key to modelling long term coastal change and understanding how the environmental store of radioactivity will be reworked. The University of Stirling is researching the long-term environmental and health implications of remobilisation and transport of contaminated sediments around the UK coastline. Using a synergy of hyperspectral and topographic information the mobilisation of sediment bound contaminants within the coastal environment will be investigated. Potential hazards posed by contaminants are determined by a set of environmental impact test criteria which evaluate the bio-accessibility and ionising dose of contaminants. These test criteria will be used to comment on the likely environmental impact of modelled sediment transport and anticipated changes in

  9. Reviews and syntheses: Hidden forests, the role of vegetated coastal habitats in the ocean carbon budget

    Science.gov (United States)

    Duarte, Carlos M.

    2017-01-01

    Vegetated coastal habitats, including seagrass and macroalgal beds, mangrove forests and salt marshes, form highly productive ecosystems, but their contribution to the global carbon budget remains overlooked, and these forests remain hidden in representations of the global carbon budget. Despite being confined to a narrow belt around the shoreline of the world's oceans, where they cover less than 7 million km2, vegetated coastal habitats support about 1 to 10 % of the global marine net primary production and generate a large organic carbon surplus of about 40 % of their net primary production (NPP), which is either buried in sediments within these habitats or exported away. Large, 10-fold uncertainties in the area covered by vegetated coastal habitats, along with variability about carbon flux estimates, result in a 10-fold bracket around the estimates of their contribution to organic carbon sequestration in sediments and the deep sea from 73 to 866 Tg C yr-1, representing between 3 % and 1/3 of oceanic CO2 uptake. Up to 1/2 of this carbon sequestration occurs in sink reservoirs (sediments or the deep sea) beyond these habitats. The organic carbon exported that does not reach depositional sites subsidizes the metabolism of heterotrophic organisms. In addition to a significant contribution to organic carbon production and sequestration, vegetated coastal habitats contribute as much to carbonate accumulation as coral reefs do. While globally relevant, the magnitude of global carbon fluxes supported by salt-marsh, mangrove, seagrass and macroalgal habitats is declining due to rapid habitat loss, contributing to loss of CO2 sequestration, storage capacity and carbon subsidies. Incorporating the carbon fluxes' vegetated coastal habitats' support into depictions of the carbon budget of the global ocean and its perturbations will improve current representations of the carbon budget of the global ocean.

  10. From grey to green: Efficacy of eco-engineering solutions for nature-based coastal defence.

    Science.gov (United States)

    Morris, Rebecca L; Konlechner, Teresa M; Ghisalberti, Marco; Swearer, Stephen E

    2018-05-01

    Climate change is increasing the threat of erosion and flooding along coastlines globally. Engineering solutions (e.g. seawalls and breakwaters) in response to protecting coastal communities and associated infrastructure are increasingly becoming economically and ecologically unsustainable. This has led to recommendations to create or restore natural habitats, such as sand dunes, saltmarsh, mangroves, seagrass and kelp beds, and coral and shellfish reefs, to provide coastal protection in place of (or to complement) artificial structures. Coastal managers are frequently faced with the problem of an eroding coastline, which requires a decision on what mitigation options are most appropriate to implement. A barrier to uptake of nature-based coastal defence is stringent evaluation of the effectiveness in comparison to artificial protection structures. Here, we assess the current evidence for the efficacy of nature-based vs. artificial coastal protection and discuss future research needs. Future projects should evaluate habitats created or restored for coastal defence for cost-effectiveness in comparison to an artificial structure under the same environmental conditions. Cost-benefit analyses should take into consideration all ecosystem services provided by nature-based or artificial structures in addition to coastal protection. Interdisciplinary research among scientists, coastal managers and engineers is required to facilitate the experimental trials needed to test the value of these shoreline protection schemes, in order to support their use as alternatives to artificial structures. This research needs to happen now as our rapidly changing climate requires new and innovative solutions to reduce the vulnerability of coastal communities to an increasingly uncertain future. © 2018 John Wiley & Sons Ltd.

  11. A brief review of 210Pb sediment dating models and uncertainties in a world of global change

    Science.gov (United States)

    Sanchez-Cabeza, J. A.; Ruiz-Fernandez, A. C.

    2016-12-01

    Irrespective of the model names used, assumptions and (usually forgotten) uncertainties, the fact is that 210Pb sediment dating is an increasingly relevant tool in our world of global change. 210Pb dating results are needed to assess historical trends of sea level rise, quantify blue carbon fluxes and reconstruct environmental records of biogeochemical proxies for diverse processes in the aquatic ecosystems (such as ocean acidification, hypoxia and pollution). Although in the past 210Pb profiles departing from "ideal" decay trends were usually discarded, all profiles have useful information. In this work we review the principles and assumptions of the most common 210Pb dating models, and propose a logical formulation and classification of the models. 210Pb dating models provide two kinds of results: chronologies (i.e. age models) and accumulation rates. In many cases, the use of sediment and/or mass accumulation rates (SAR and MAR) is needed to assess environmental fluxes or, simply, to describe changes, such as catchment erosion or saltmarsh accretion. Although uncertainty quadratic propagation is a well-known technique, it requires that all variables are fully independent and requires demanding mathematical expressions which might lead to wrong results. We present here a Monte Carlo method that makes calculation easier and, likely, error-free. Not unexpectedly, the most important uncertainty sources are measurement uncertainties, which impose limitations on common techniques such as gamma spectrometry. 210Pb chronology does not cover all anthropogenic impacts, such as those caused by ancient civilizations, so radiocarbon also plays an important role in this kind of work. We also conceptually revise the limitations of both techniques and encourage scientists to link both dating techniques with a symmetrically open mind. Acknowledgements: projects CONACYT PDCPN2013-01/214349 and CB2010/153492, UNAM PAPIIT-IN203313, PRODEP network "Aquatic contamination: levels and

  12. 224Ra distribution in surface and deep water of Long Island Sound: sources and horizontal transport rates

    International Nuclear Information System (INIS)

    Torgersen, T.; O'Donnell, J.; DeAngelo, E.; Turekian, K.K.; Turekian, V.C.; Tanaka, N.

    1997-01-01

    Measurements of surface water and deep water 224 Ra(half-life 3.64 days) distributions in Long Island Sound (LIS) were conducted in July 1991. Because the pycnocline structure of LIS had been in place for about 50 days in July (long compared to the half-life of 224 Ra) in the surface water and the deep water operate as separate systems. In the surface water, the fine-grain sediments of nearshore and saltmarsh environments provide a strong source of 224 Ra, which is horizontally mixed away from the short to central LIS. A one-dimensional model of 224 Ra distribution suggests a cross-LIS horizontal eddy dispersivity of 5-50 m 2 s -1 . In the deep water, the mid-LIS sediment flux of 224 Ra is enhanced by ∼ 2x relative to the periphery, and the horizontal eddy flux is from central LIS to the periphery. A second one-dimensional model suggests a cross-LIS horizontal eddy dispersivity below the thermocline of 5-50 m 2 -1 . 224 Ra fluxes into the deep water of the central LIS are likely enhanced by (1) inhomogeneous sediment or (2) a reduced scavenging of 224 Ra in the sediments of central LIS brought about by low oxygen conditions (hypoxia) and the loss of the MnO 2 scavenging layer in the sediments. These rates of horizontal eddy dispersivity are significantly less than the estimate of 100-650 m 2 s -1 (Riley, 1967) but are consistent with the transport necessary to explain the dynamics of oxygen depletion in summer LIS. These results demonstrate the use of 224 Ra for quantifying the parameters needed to describe estuarine mixing and transport. (Author)

  13. Detecting wetland changes in Shanghai, China using FORMOSAT and Landsat TM imagery

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Bo; Zhou, Yun-xuan; Thom, Ronald M.; Diefenderfer, Heida L.; Yuan, Qing

    2015-07-14

    Understanding the state of wetland ecosystems and their changes at the national and local levels is critical for wetland conservation, management, decision-making, and policy development practices. This study analyzed the wetlands in Shanghai, a province-level city, using remote sensing, image processing, and geographic information systems (GIS) techniques based on the Chinese national wetland inventory procedure and standards. FORMOSAT imagery acquired in 2012 and Navy nautical charts of the Yangtze estuarine area were used in conjunction with object-oriented segmentation, expert interpretation, and field validation to determine wetland status. Landsat imagery from 1985, 1995, 2000, 2003 and 2013 as well as social-economic data collected from 1985 to 2013 were used to further assess wetland changes. In 2013, Shanghai contained 376,970.6 ha of wetlands, and 78.8% of all wetlands were in marine or estuarine systems. Estuarine waters comprised the single largest wetland category. Between the first national wetland inventory in 2003 and the second national wetland inventory in 2013, Shanghai lost 50,519.13 ha of wetlands, amounting to a mean annual loss rate of 1.2% or an 11.8% loss over the decade. Declines were proportionately higher in marine and estuarine wetlands, with an annual loss of 1.8%, while there was a sharp increase of 1882.6% in constructed water storage areas for human uses. Diking, filling, impoundment and reclamation, which are all attributable to the economic development and urbanization associated with population increases, were the major factors that explained the gain and loss of wetlands. Additional factors affecting wetland losses and gains include sediment trapping by the hydropower system, which reduces supply to the estuary and erodes wetlands, and sediment trapping by the jetties, spur dikes, and diversion bulwark associated with a navigation channel deepening project, which has the converse effect, increasing saltmarsh wetland area at

  14. Characterization of Spartina alterniflora as feedstock for anaerobic digestion

    International Nuclear Information System (INIS)

    Yang, Shiguan; Zheng, Zheng; Meng, Zhuo; Li, Jihong

    2009-01-01

    Smooth cordgrass (Spartina alterniflora), a saltmarsh plant with high production, was characterized for its potential for use as feedstock for anaerobic digestion processes. The anaerobic digestibility and biogas yield of S. alterniflora were evaluated by anaerobic batch digestion experiments performed at 35 ± 1 C at initial volatile solids (VS) of 6%. The nutrient content analysis indicated that S. alterniflora contained the required nutrition for anaerobic microorganisms, but its high C/N of 58.8, high K and Na contents of 8.1, 22.7 g kg -1 , respectively, may be disadvantageous to its anaerobic digestion. The cumulative biogas yield was determined to be 358 L kg -1 VS and the biodegradation efficiency was 45% after 60 days of digestion. The methane content of biogas increased from 53% on day 3 to around 62% after 13 days of digestion. The changes of volatile fatty acids (VFAs) indicated that the acidification of S. alterniflora was propionate-type fermentation with proportion of acetate and propionate ranging from 54.8% to 98.4%, and the hydrolysis of lignocellulose was the rate-limiting step for its anaerobic digestion. The analysis of cations suggested that K + and Mg 2+ , with the maximum concentration of 1.35 and 0.43 g L -1 in fermentation liquor, respectively, could be inhibitory to the anaerobic digestion of S. alterniflora. It is concluded that S. alterniflora can be transformed into clean energy by anaerobic digestion and the high contents of K, Na, Ca and Mg may be the inhibitory factors when S. alterniflora is digested by continuous or semi-continuous anaerobic process. (author)

  15. Sea-level rise and refuge habitats for tidal marsh species: can artificial islands save the California Ridgway's rail?

    Science.gov (United States)

    Overton, Cory T.; Takekawa, John Y.; Casazza, Michael L.; Bui, Thuy-Vy D.; Holyoak, Marcel; Strong, Donald R.

    2014-01-01

    Terrestrial species living in intertidal habitats experience refuge limitation during periods of tidal inundation, which may be exacerbated by seasonal variation in vegetation structure, tidal cycles, and land-use change. Sea-level rise projections indicate the severity of refuge limitation may increase. Artificial habitats that provide escape cover during tidal inundation have been proposed as a temporary solution to alleviate these limitations. We tested for evidence of refuge habitat limitation in a population of endangered California Ridgway's rail (Rallus obsoletus obsoletus; hereafter California rail) through use of artificial floating island habitats provided during two winters. Previous studies demonstrated that California rail mortality was especially high during the winter and periods of increased tidal inundation, suggesting that tidal refuge habitat is critical to survival. In our study, California rail regularly used artificial islands during higher tides and daylight hours. When tide levels inundated the marsh plain, use of artificial islands was at least 300 times more frequent than would be expected if California rails used artificial habitats proportional to their availability (0.016%). Probability of use varied among islands, and low levels of use were observed at night. These patterns may result from anti-predator behaviors and heterogeneity in either rail density or availability of natural refuges. Endemic saltmarsh species are increasingly at risk from habitat change resulting from sea-level rise and development of adjacent uplands. Escape cover during tidal inundation may need to be supplemented if species are to survive. Artificial habitats may provide effective short-term mitigation for habitat change and sea-level rise in tidal marsh environments, particularly for conservation-reliant species such as California rails.

  16. Coastal Zone Ecosystem Services: from science to values and decision making; a case study.

    Science.gov (United States)

    Luisetti, T; Turner, R K; Jickells, T; Andrews, J; Elliott, M; Schaafsma, M; Beaumont, N; Malcolm, S; Burdon, D; Adams, C; Watts, W

    2014-09-15

    This research is concerned with the following environmental research questions: socio-ecological system complexity, especially when valuing ecosystem services; ecosystems stock and services flow sustainability and valuation; the incorporation of scale issues when valuing ecosystem services; and the integration of knowledge from diverse disciplines for governance and decision making. In this case study, we focused on ecosystem services that can be jointly supplied but independently valued in economic terms: healthy climate (via carbon sequestration and storage), food (via fisheries production in nursery grounds), and nature recreation (nature watching and enjoyment). We also explored the issue of ecosystem stock and services flow, and we provide recommendations on how to value stock and flows of ecosystem services via accounting and economic values respectively. We considered broadly comparable estuarine systems located on the English North Sea coast: the Blackwater estuary and the Humber estuary. In the past, these two estuaries have undergone major land-claim. Managed realignment is a policy through which previously claimed intertidal habitats are recreated allowing the enhancement of the ecosystem services provided by saltmarshes. In this context, we investigated ecosystem service values, through biophysical estimates and welfare value estimates. Using an optimistic (extended conservation of coastal ecosystems) and a pessimistic (loss of coastal ecosystems because of, for example, European policy reversal) scenario, we find that context dependency, and hence value transfer possibilities, vary among ecosystem services and benefits. As a result, careful consideration in the use and application of value transfer, both in biophysical estimates and welfare value estimates, is advocated to supply reliable information for policy making. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  17. Experimental and numerical analysis of coastal protection provided by natural ecosystems

    Science.gov (United States)

    Maza, M.; Lara, J. L.; Losada, I. J.; Nepf, H. M.

    2016-12-01

    The risk of flooding and erosion is increasing for many coastal areas owing to global and regional changes in climate conditions together with increasing exposure and vulnerability. After hurricane Katrina (2005) and Sandy (2012) and the tsunami in Indonesia (2004), coastal managers have become interested in low environmental impact alternatives, or nature-based solutions, to protect the coast. Although capacity for coastal ecosystems to damp flow energy has been widely recognized, they have not been firmly considered in the portfolio of coastal protection options. This is mainly due to the complexity of flow-vegetation interaction and of quantifying the value of coastal protection provided by these ecosystems. This complex problem involves different temporal and spatial scales and disciplines, such as engineering, ecology and economics. This work aims to make a step forward in better understanding the physics involved in flow-vegetation interaction leading to new formulations and parameterizations to address some unsolved questions in literature: the representation of plants and field properties; the influence of wave parameters on the relevant processes; the role of the combined effect of waves and currents and the effect of extreme events on vegetation elements. The three main coastal vegetated ecosystems (seagrasses, saltmarshes and mangroves) are studied with an experimental and numerical approach. Experimental analysis is carried out using mimics and real vegetation, considering different flow and vegetation parameters and characterizing flow energy attenuation for the different scenarios. Numerical simulations are performed using 2-D and 3-D Navier-Stokes models in which the effect of vegetation is implemented and validated. These models are used to extend experimental results by simulating different vegetation distributions and analyzing variables such as high-spatial-resolution free surface and velocity data and forces exerted on vegetation elements.

  18. Processes controlling the retreat of the Isles Dernieres, a Louisiana barrier-island chain

    Science.gov (United States)

    Dingler, John R.; Reiss, Thomas E.

    1991-01-01

    The Isles Dernieres is a low-lying, transgressive barrier-island chain situated about 150 km west of the modern Mississippi delta. Much of the Isles Dernieres consists of highly dissected salt-marsh muds that lie at or slightly above sea level and are covered by a veneer of sand along the shoreline facing the Gulf of Mexico. Maximum berm elevations are generally less than 1.5 m above mean sea level. Since the mid-1800s, the initial island has been fragmented into four islands, and the beach face has retreated landward at a rate of more than 10 m/yr. The dominant processes controlling degradation of the chain are cold fronts that pass through the area several times each year and occasional hurricanes. Beach surveys over a 2-year period on the Isles Dernieres document irreversible beach-face retreat in conjunction with multiple cold fronts and one major hurricane (Gilbert). Although both the hurricane and the cold fronts caused the island to erode, the erosional patterns of the two storm types differed from each other. During the two years, over 60 cold fronts collectively caused about 37 m of beach-face retreat, whereas Gilbert itself produced more than 40 m of retreat. A major difference between the two storm types was in the percentage of washover sand produced by each. Commonly, the cold fronts did not create enough of a storm surge to overtop the berm, so most of the material removed from the beach face must have moved offshore or alongshore. Gilbert, in contrast, inundated the study site, and essentially all the sand removed from the beach face moved to the backshore.

  19. Combined influence of sedimentation and vegetation on the soil carbon stocks of a coastal wetland in the Changjiang estuary

    Science.gov (United States)

    Zhang, Tianyu; Chen, Huaipu; Cao, Haobing; Ge, Zhenming; Zhang, Liquan

    2017-07-01

    Coastal wetlands play an important role in the global carbon cycle. Large quantities of sediment deposited in the Changjiang (Yangtze) estuary by the Changjiang River promote the propagation of coastal wetlands, the expansion of saltmarsh vegetation, and carbon sequestration. In this study, using the Chongming Dongtan Wetland in the Changjiang estuary as the study area, the spatial and temporal distribution of soil organic carbon (SOC) stocks and the influences of sedimentation and vegetation on the SOC stocks of the coastal wetland were examined in 2013. There was sediment accretion in the northern and middle areas of the wetland and in the Phragmites australis marsh in the southern area, and sediment erosion in the Scirpus mariqueter marsh and the bare mudflat in the southern area. More SOC accumulated in sediments of the vegetated marsh than in the bare mudflat. The total organic carbon (TOC) stocks increased in the above-ground biomass from spring to autumn and decreased in winter; in the below-ground biomass, they gradually increased from spring to winter. The TOC stocks were higher in the below-ground biomass than in the above-ground biomass in the P. australis and Spartina alterniflora marshes, but were lower in the below-ground biomass in S. mariqueter marsh. Stocks of SOC showed temporal variation and increased gradually in all transects from spring to winter. The SOC stocks tended to decrease from the high marsh down to the bare mudflat along the three transects in the order: P. australis marsh > S. alterniflora marsh > S. mariqueter marsh > bare mudflat. The SOC stocks of the same vegetation type were higher in the northern and middle transects than in the southern transect. These results suggest that interactions between sedimentation and vegetation regulate the SOC stocks in the coastal wetland in the Changjiang estuary.

  20. Hurricane-induced Sediment Transport and Morphological Change in Jamaica Bay, New York

    Science.gov (United States)

    Hu, K.; Chen, Q. J.

    2016-02-01

    Jamaica Bay is located in Brooklyn and Queens, New York on the western end of the south shore of the Long Island land mass. It experienced a conversion of more than 60% of the vegetated salt-marsh islands to intertidal and subtidal mudflats. Hurricanes and nor'easters are among the important driving forces that reshape coastal landscape quickly and affect wetland sustainability. Wetland protection and restoration need a better understanding of hydrodynamics and sediment transport in this area, especially under extreme weather conditions. Hurricane Sandy, which made landfall along east coast on October 30, 2012, provides a critical opportunity for studying the impacts of hurricanes on sedimentation, erosion and morphological changes in Jamaica Bay and salt marsh islands. The Delft3D model suit was applied to model hydrodynamics and sediment transport in Jamaica Bay and salt marsh islands. Three domains were set up for nesting computation. The local domain covering the bay and salt marshes has a resolution of 10 m. The wave module was online coupled with the flow module. Vegetation effects were considered as a large number of rigid cylinders by a sub-module in Delft3D. Parameters in sediment transport and morphological change were carefully chosen and calibrated. Prior- and post-Sandy Surface Elevation Table (SET)/accretion data including mark horizon (short-term) and 137Cs and 210Pb (long-term) at salt marsh islands in Jamaica Bay were used for model validation. Model results indicate that waves played an important role in hurricane-induced morphological change in Jamaica Bay and wetlands. In addition, numerical experiments were carried out to investigate the impacts of hypothetic hurricanes. This study has been supported by the U.S. Geological Survey Hurricane Sandy Disaster Recovery Act Funds.

  1. Preparing for Sea-level Rise: Conflicts and Opportunities in Coastal Wetlands Coexisting with Infrastructure

    Science.gov (United States)

    Rodriguez, J. F.; Saco, P. M.; Sandi, S. G.; Saintilan, N.; Riccardi, G.

    2017-12-01

    Even though on a large scale the sustainability and resilience of coastal wetlands to sea-level rise depends on the slope of the landscape and a balance between the rates of soil accretion and the sea-level rise, local man-made flow disturbances can have comparable effects. Coastal infrastructure controlling flow in the wetlands can pose an additional constraint on the adaptive capacity of these ecosystems, but can also present opportunities for targeted flow management to increase their resilience. Coastal wetlands in SE Australia are heavily managed and typically present infrastructure including flow control devices. How these flow control structures are operated respond to different ecological conservation objectives (i.e. bird, frog or fish habitat) that can sometimes be mutually exclusive. For example, promoting mangrove establishment to enhance fish habitat results in saltmarsh decline thus affecting bird habitat. Moreover, sea-level rise will change hydraulic conditions in wetlands and may result in some flow control structures and strategies becoming obsolete or even counterproductive. In order to address these problems and in support of future management of flows in coastal wetlands, we have developed a predictive tool for long-term wetland evolution that incorporates the effects of infrastructure and other perturbations to the tidal flow within the wetland (i.e. vegetation resistance) and determines how these flow conditions affect vegetation establishment and survival. We use the model to support management and analyse different scenarios of sea-level rise and flow control measures aimed at preserving bird habitat. Our results show that sea-level rise affects the efficiency of management measures and in some cases may completely override their effect. It also shows the potential of targeted flow management to compensate for the effects of sea-level rise.

  2. First results on enzymatic activities in two salt marsh soils under different hydromorphic level and vegetation

    Directory of Open Access Journals (Sweden)

    Carmen Trasar-Cepeda

    2015-12-01

    Full Text Available Salt-marsh soils are soils characterized by non-permanent hydric saturation that, depending on factors like duration of submersion periods, are dominated by different salt-tolerant plant species. The composition of microbial communities is an essential component in trophic dynamics and biogeochemical processes in salt marshes, and determines the level of enzymatic activities, which catalyze the conversion of complex molecules into simpler ones. Despite of this, the enzymatic activities in marsh-soils has not yet been investigated. The aim of this study was to analyze the enzymatic activities in two soil profiles of marsh-soils under different water saturation level and dominated by different plant species [Juncus maritimus Lam and Spartina maritima (Curtis Fernald (Sp]. In both soils, the enzymatic activities were much lower than the levels typically found in terrestrial ecosystems. The enzymatic activities were measured both in air-dried and in re-moistened and incubated soil samples. In air-dried samples, the enzymatic activities were higher in Juncus than in Spartina soil and tended to decrease with depth, being sharper the decrease in Juncus than in Spartina soil. Re-moistened and pre-incubated soils showed a general increase in all the enzymatic activities and throughout the whole soil profile, especially in Spartina soils. Hydrolase activities showed a strong and positive relationship with organic matter content both in air-dried and in re-moistened soil samples, higher in these latter. In general, oxidoreductase activities only showed this relationship in re-moistened soil samples. More studies, preferably using freshly collected soil samples, are needed to understand the relationship between enzymatic activities and these environmental conditions.

  3. Blackbird Creek Monitoring Program to Study the impact of Climate Change and Land Use

    Science.gov (United States)

    Ozbay, G.; Chintapenta, L. K.; Roeske, K. P.; Stone, M.; Phalen, L.

    2014-12-01

    The Blackbird Creek Monitoring Program at Delaware State University continues to utilize various perspectives to study the dynamics of one of Delaware's most pristine ecosystems. The water quality of Blackbird Creek has been constantly monitored for 3 years and correlated with the rain and storm events. Soil nutrients composition has been studied by extracting the water associated with soil aggregates and analyzing the levels of different nutrients. Soil quality is also assessed for heavy metals to identify potential human impact that may affect the health of ecosystem. Within the Blackbird Creek there is a threat to native plant communities from invasive plant species as they alter the ecosystem dynamics. Saltmarsh cord grass (Spartina alterniflora) and common reed (Phragmites australius) are the common wetland plants. Aerial mapping of the creek has been conducted to determine the area covered by invasive plant species. The microbial community structure plays a key role in soil carbon and nitrogen cycles in the ecosystem. Molecular analysis has been performed to study the microbial diversity with respect to the type of marsh grasses. This program has also incorporated the use of diatoms as biological indicators to assess the health of ecosystem and correlate that data with physical and chemical water quality data. The abundance and diversity of macro fauna such as blue crabs, fish and other significant species has also been studied. Stable isotopic analysis of these macro fauna has also been performed to study the food web. The results from this program will be helpful in addressing environmental challenges and designing management strategies.

  4. Selection of an omnivorous diet by the mangrove tree crab Aratus pisonii in laboratory experiments

    Science.gov (United States)

    Erickson, Amy A.; Feller, Ilka C.; Paul, Valerie J.; Kwiatkowski, Lisa M.; Lee, Woody

    2008-02-01

    Observational studies on leaf damage, gut content analyses, and crab behaviour have demonstrated that like numerous other mangrove and salt-marsh generalists, the mangrove tree crab Aratus pisonii feeds on a variety of food resources. This study is the first that experimentally tests feeding preferences of A. pisonii, as well as the first to test experimentally whether chemical composition of food resources is responsible for food selection. Feeding preferences were determined among a variety of plant, algal, and animal resources available in the field both in Florida and Belize, using multiple-choice feeding assays, where male and female crabs simultaneously were offered a variety of food items. To test whether chemistry of food resources was responsible for feeding preferences, chemical extracts of food resources were incorporated in an agar-based artificial food, and used in feeding assays. Results of feeding assays suggest that crabs prefer animal matter from ˜ 2.5 to 13× more than other available resources, including leaves of the red mangrove Rhizophora mangle, which contribute the most to their natural diet. Artificial feeding assays also demonstrated that chemical cues were responsible for selection of animal matter, up to 25× more than other available resources. Non-polar extracts (derived from extraction in 1:1 ethyl actetate:methanol) stimulated feeding the most, suggesting that fatty acids, triglycerides, or sterols may be important for growth, reproduction, or survival. Results for both sexes were similar across most assays. While chemical composition of food resources appears to play some role in selection, this does not discount the potential role of other factors, such as resource availability, competition, predation, or reproductive requirements in influencing feeding preferences. Bioassay-guided fractionation of extracts should aid in determining chemical constituents that play the greatest role in determining feeding preferences.

  5. Migration Rate Of Tidal Meanders: Inferences From The Venice Lagoon

    Science.gov (United States)

    Finotello, A.; D'Alpaos, A.; Ghinassi, M.; Lanzoni, S.; Marani, M.; Rinaldo, A.

    2015-12-01

    Meandering channels are ubiquitous features of tidal landscapes. However, despite their fundamental role on the eco-morphodynamic evolution of these landscapes, tidal meanders have received less attention when compared to their fluvial counterparts. Improving current understanding of tidal meander migration, a largely-examined topic in fluvial landscapes, is a key step to highlight analogies and differences between tidal and fluvial cases. The migration of about 400 meander bends, belonging to 40 salt-marsh channels in the Northern Venice Lagoon (Italy), from 1968 to nowadays, has been investigated by means of both a classical method in fluvial frameworks and new procedure. Similarities with fluvial meanders occur, although important difference also emerge. Meanders cutting through the San Felice marsh follow the relationship between cartesian length and channel width, typical of meanders developed within different settings. However, meander migration rates proved to be smaller than those characterizing fluvial meanders. Indeed, the analysis of meander migration suggests a mean migration rate of about 0.10 m/year, consistent with the few data available in the literature. As for the fluvial case, the maximum-potential migration rate (i.e. the envelope curve of the relationship between migration rate and bend radius, both divided by channel width) reaches a maximum for radius-over-width ratio included between 2 and 3, regardless of the considered method. Nevertheless, the new-proposed method allows us to provide a more objective and continuous characterization. By using this new procedure, the channel curvature has finally been Fourier-analyzed, confirming the importance of even harmonics along the curvature spectrum. A correlation between migration rates and dominant harmonics seems to drive the evolution of tidal meanders and might represent a key-feature to distinguish them from their fluvial counterparts.

  6. Multi-proxy Characterization of Two Recent Storm Deposits Attributed to Hurricanes Rita and Ike in the Chenier Plain of Southwestern Louisiana

    Science.gov (United States)

    Yao, Q.; Liu, K. B.; Ryu, J.

    2017-12-01

    The Chenier Plain in southwestern Louisiana owes its origin to dynamic depositional processes that are dominated by delta-switching of the Mississippi River to the east, while frequent hurricane activities also play an important role in its geomorphology and sedimentary history. However, despite several studies in the literature, the sediment-stratigraphic characteristics of recent or historic hurricane deposits are still not well documented from the Chenier Plain. In 2005 and 2008, Hurricane Rita (category 3) and Ike (category 2) made landfall on the coasts of Louisiana and Texas. Remote sensing images confirm that the Rockefeller Wildlife Refuge, located at the east end of the Louisiana Chenier Plain, was heavily impacted by both hurricanes. We analyzed the lithology and chemical stratigraphy of three 30 cm sediment monoliths (ROC-1, ROC-2, and ROC-3) recovered from a coastal saltmarsh in the Rockefeller Wildlife Refuge to identify the event deposits attributed to these two storms. Each monolith contains 2 distinct light-colored clastic sediment layers imbedded in brown organic clay. The loss-on-ignition and X-ray fluorescence results show that the hurricane layers have increased contents of Ca, Sr, Zr, and carbonates and decreased contents of water and organics. Surprisingly, despite its greater intensity and more severe impacts, Hurricane Rita left a much thinner storm deposit than did Hurricane Ike in all monoliths. Satellite data reveal that Hurricane Rita caused significant coastal erosion and shoreline recession, rendering the sampling sites much closer to the beach and ocean and therefore more prone to storm surges and overwash deposition than when Hurricane Ike struck three years later. Our results suggest that site-to-sea distance, which affects a study site's paleotempestological sensitivity, can play a bigger role in affecting the thicknesses of storm deposits than the intensity of the hurricane.

  7. Environmental tracers for elucidating the weathering process in a phosphogypsum disposal site: Implications for restoration

    Science.gov (United States)

    Pérez-López, Rafael; Nieto, José M.; de la Rosa, Jesús D.; Bolívar, Juan P.

    2015-10-01

    This study provides geochemical data with the aim of identifying and tracing the weathering of phosphogypsum wastes stack-piled directly on salt-marshes of the Tinto River (Estuary of Huelva, SW Spain). With that purpose, different types of highly-polluted acid solutions were collected in the stack. Connection between these solutions and the estuarine environment was studied by geochemical tracers, such as rare earth elements (REE) and their North American Shale Composite (NASC)-normalized patterns and Cl/Br ratios. Phosphogypsum-related wastewaters include process water stored on the surface, pore-water contained in the phosphogypsum profile and edge outflow water emerging from inside the stack. Edge outflow waters are produced by waterlogging at the contact between phosphogypsum and the nearly impermeable marsh surface and discharge directly into the estuary. Process water shows geochemical characteristics typical of phosphate fertilizers, i.e. REE patterns with an evident enrichment of heavy-REE (HREE) with respect to middle-REE (MREE) and light-REE (LREE). By contrast, REE patterns of deeper pore-water and edge outflows are identical to those of Tinto River estuary waters, with a clear enrichment of MREE relative to LREE and HREE denoting influence of acid mine drainage. Cl/Br ratios of these solutions are very close to that of seawater, which also supports its estuarine origin. These findings clearly show that process water is not chemically connected with edge outflows through pore-waters, as was previously believed. Phosphogypsum weathering likely occurs by an upward flow of seawater from the marsh because of overpressure and permeability differences. Several recommendations are put forward in this study to route restoration actions, such as developing treatment systems to improve the quality of the edge outflow waters before discharging to the receiving environment.

  8. Shoreline clean-up methods : biological treatments

    Energy Technology Data Exchange (ETDEWEB)

    Massoura, S.T. [Oil Spill Response Limited, Southampton (United Kingdom)

    2009-07-01

    The cleanup of oil spills in shoreline environments is a challenging issue worldwide. Oil spills receive public and media attention, particularly in the event of a coastal impact. It is important to evaluate the efficiency and effectiveness of cleanup methods when defining the level of effort and consequences that are appropriate to remove or treat different types of oil on different shoreline substrates. Of the many studies that have compared different mechanical, chemical and biological treatments for their effectiveness on various types of oil, biological techniques have received the most attention. For that reason, this paper evaluated the effectiveness and effects of shoreline cleanup methods using biological techniques. It summarized data from field experiments and oil spill incidents, including the Exxon Valdez, Sea Empress, Prestige, Grand Eagle, Nakhodka, Guanabara Bay and various Gulf war oil spills. Five major shoreline types were examined, notably rocky intertidal, cobble/pebble/gravel, sand/mud, saltmarsh, and mangrove/sea-grass. The biological techniques that were addressed were nutrient enrichment, hydrocarbon-utilizing bacteria, vegetable oil biosolvents, plants, surf washing, oil-particle interactions and natural attenuation. The study considered the oil type, volume and fate of stranded oil, location of coastal materials, extent of pollution and the impact of biological techniques. The main factors that affect biodegradation of hydrocarbons are the volume, chemical composition and weathering state of the petroleum product as well as the temperature, oxygen availability of nutrients, water salinity, pH level, water content, and microorganisms in the shoreline environment. The interaction of these factors also affect the biodegradation of oil. It was concluded that understanding the fate of stranded oil can help in the development of techniques that improve the weathering and degradation of oil on complex shoreline substrates. 39 refs.

  9. Effects of salinity and flooding on post-hurricane regeneration potential in coastal wetland vegetation.

    Science.gov (United States)

    Middleton, Beth A

    2016-08-01

    The nature of regeneration dynamics after hurricane flooding and salinity intrusion may play an important role in shaping coastal vegetation patterns. The regeneration potentials of coastal species, types and gradients (wetland types from seaward to landward) were studied on the Delmarva Peninsula after Hurricane Sandy using seed bank assays to examine responses to various water regimes (unflooded and flooded to 8 cm) and salinity levels (0, 1, and 5 ppt). Seed bank responses to treatments were compared using a generalized linear models approach. Species relationships to treatment and geographical variables were explored using nonmetric multidimensional scaling. Flooding and salinity treatments affected species richness even at low salinity levels (1 and 5 ppt). Maritime forest was especially intolerant of salinity intrusion so that species richness was much higher in unflooded and low salinity conditions, despite the proximity of maritime forest to saltmarsh along the coastal gradient. Other vegetation types were also affected, with potential regeneration of these species affected in various ways by flooding and salinity, suggesting relationships to post-hurricane environment and geographic position. Seed germination and subsequent seedling growth in coastal wetlands may in some cases be affected by salinity intrusion events even at low salinity levels (1 and 5 ppt). These results indicate that the potential is great for hurricanes to shift vegetation type in sensitive wetland types (e.g., maritime forest) if post-hurricane environments do not support the regeneration of extent vegetation. This article is a U.S. Government work and is in the public domain in the USA. © Botanical Society of America (outside the USA) 2016.

  10. Secondary toxicity in raptors caused by white phosphorus

    Science.gov (United States)

    Sparling, D.W.

    1995-01-01

    White phosphorus (WP) has caused waterfowl die-offs in a tidal saltmarsh used by the U.S. Army for artillery practice for > 40 years. Bald (Haliaeetus leucocephalus)and golden (Aquila chrysaetos) eagles have been observed feeding on dead and dying waterfowl on the marsh and may be exposed to WP through ingestion of contaminated birds. One carcass of each eagle species has been found with measurable levels of WP in fat. To determine if raptors can become intoxicated by ingesting prey that have been exposed to WP we fed live, 10-day-old white leghorn chicks three sublethal doses of WP. Six hrs after the last dose we euthanized the chicks and separated them into two groups--one with the digestive system from gizzard anteriorly removed (NoGut) and one with the digestive system intact and a 1.1 mg pellet of WP implanted deep into the crop (Pel). A third group of same-aged chicks unexposed to WP was used for controls. Fifteen kestrels (Fa/co sparverius) were randomly assigned to each of the treatments and 10 to the control diet. By 7 d of the study 8 of the kestrels had died on the Pel and 3 on the NoGut diet. Survivors on the Pel diet had significantly lower hematocrit, hemoglobin, final body weights and greater liver/body weight ratios and weight loss than control birds. The study showed that raptors and possibly other predators are at risk both when consuming flesh of prey that have succumbed to WP poisoning and when ingesting WP pellets that are incorporated in body parts but that the risk is greater when pellets are present.

  11. Long-term organic carbon sequestration in tidal marsh sediments is dominated by old-aged allochthonous inputs in a macrotidal estuary.

    Science.gov (United States)

    Van de Broek, Marijn; Vandendriessche, Caroline; Poppelmonde, Dries; Merckx, Roel; Temmerman, Stijn; Govers, Gerard

    2018-02-12

    Tidal marshes are vegetated coastal ecosystems that are often considered as hotspots of atmospheric CO 2 sequestration. Although large amounts of organic carbon (OC) are indeed being deposited on tidal marshes, there is no direct link between high OC deposition rates and high OC sequestration rates due to two main reasons. First, the deposited OC may become rapidly decomposed once it is buried and, second, a significant part of preserved OC may be allochthonous OC that has been sequestered elsewhere. In this study we aimed to identify the mechanisms controlling long-term OC sequestration in tidal marsh sediments along an estuarine salinity gradient (Scheldt estuary, Belgium and the Netherlands). Analyses of deposited sediments have shown that OC deposited during tidal inundations is up to millennia old. This allochthonous OC is the main component of OC that is effectively preserved in these sediments, as indicated by the low radiocarbon content of buried OC. Furthermore, OC fractionation showed that autochthonous OC is decomposed on a decadal timescale in saltmarsh sediments, while in freshwater marsh sediments locally produced biomass is more efficiently preserved after burial. Our results show that long-term OC sequestration is decoupled from local biomass production in the studied tidal marsh sediments. This implies that OC sequestration rates are greatly overestimated when they are calculated based on short-term OC deposition rates, which are controlled by labile autochthonous OC inputs. Moreover, as allochthonous OC is not sequestered in-situ, it does not contribute to active atmospheric CO 2 sequestration in these ecosystems. A correct assessment of the contribution of allochthonous OC to the total sedimentary OC stock in tidal marsh sediments as well as a correct understanding of the long-term fate of locally produced OC are both necessary to avoid overestimations of the rate of in-situ atmospheric CO 2 sequestration in tidal marsh sediments. © 2018 John

  12. Climate Change and Intertidal Wetlands

    Directory of Open Access Journals (Sweden)

    Pauline M. Ross

    2013-03-01

    Full Text Available Intertidal wetlands are recognised for the provision of a range of valued ecosystem services. The two major categories of intertidal wetlands discussed in this contribution are saltmarshes and mangrove forests. Intertidal wetlands are under threat from a range of anthropogenic causes, some site-specific, others acting globally. Globally acting factors include climate change and its driving cause—the increasing atmospheric concentrations of greenhouse gases. One direct consequence of climate change will be global sea level rise due to thermal expansion of the oceans, and, in the longer term, the melting of ice caps and glaciers. The relative sea level rise experienced at any one locality will be affected by a range of factors, as will the response of intertidal wetlands to the change in sea level. If relative sea level is rising and sedimentation within intertidal wetlands does not keep pace, then there will be loss of intertidal wetlands from the seaward edge, with survival of the ecosystems only possible if they can retreat inland. When retreat is not possible, the wetland area will decline in response to the “squeeze” experienced. Any changes to intertidal wetland vegetation, as a consequence of climate change, will have flow on effects to biota, while changes to biota will affect intertidal vegetation. Wetland biota may respond to climate change by shifting in distribution and abundance landward, evolving or becoming extinct. In addition, impacts from ocean acidification and warming are predicted to affect the fertilisation, larval development, growth and survival of intertidal wetland biota including macroinvertebrates, such as molluscs and crabs, and vertebrates such as fish and potentially birds. The capacity of organisms to move and adapt will depend on their life history characteristics, phenotypic plasticity, genetic variability, inheritability of adaptive characteristics, and the predicted rates of environmental change.

  13. Climate change and intertidal wetlands.

    Science.gov (United States)

    Ross, Pauline M; Adam, Paul

    2013-03-19

    Intertidal wetlands are recognised for the provision of a range of valued ecosystem services. The two major categories of intertidal wetlands discussed in this contribution are saltmarshes and mangrove forests. Intertidal wetlands are under threat from a range of anthropogenic causes, some site-specific, others acting globally. Globally acting factors include climate change and its driving cause-the increasing atmospheric concentrations of greenhouse gases. One direct consequence of climate change will be global sea level rise due to thermal expansion of the oceans, and, in the longer term, the melting of ice caps and glaciers. The relative sea level rise experienced at any one locality will be affected by a range of factors, as will the response of intertidal wetlands to the change in sea level. If relative sea level is rising and sedimentation within intertidal wetlands does not keep pace, then there will be loss of intertidal wetlands from the seaward edge, with survival of the ecosystems only possible if they can retreat inland. When retreat is not possible, the wetland area will decline in response to the "squeeze" experienced. Any changes to intertidal wetland vegetation, as a consequence of climate change, will have flow on effects to biota, while changes to biota will affect intertidal vegetation. Wetland biota may respond to climate change by shifting in distribution and abundance landward, evolving or becoming extinct. In addition, impacts from ocean acidification and warming are predicted to affect the fertilisation, larval development, growth and survival of intertidal wetland biota including macroinvertebrates, such as molluscs and crabs, and vertebrates such as fish and potentially birds. The capacity of organisms to move and adapt will depend on their life history characteristics, phenotypic plasticity, genetic variability, inheritability of adaptive characteristics, and the predicted rates of environmental change.

  14. Dynamics of sediment carbon stocks across intertidal wetland habitats of Moreton Bay, Australia.

    Science.gov (United States)

    Hayes, Matthew A; Jesse, Amber; Hawke, Bruce; Baldock, Jeff; Tabet, Basam; Lockington, David; Lovelock, Catherine E

    2017-10-01

    Coastal wetlands are known for high carbon storage within their sediments, but our understanding of the variation in carbon storage among intertidal habitats, particularly over geomorphological settings and along elevation gradients, is limited. Here, we collected 352 cores from 18 sites across Moreton Bay, Australia. We assessed variation in sediment organic carbon (OC) stocks among different geomorphological settings (wetlands within riverine settings along with those with reduced riverine influence located on tide-dominated sand islands), across elevation gradients, with distance from shore and among habitat and vegetation types. We used mid-infrared (MIR) spectroscopy combined with analytical data and partial least squares regression to quantify the carbon content of ~2500 sediment samples and provide fine-scale spatial coverage of sediment OC stocks to 150 cm depth. We found sites in river deltas had larger OC stocks (175-504 Mg/ha) than those in nonriverine settings (44-271 Mg/ha). Variation in OC stocks among nonriverine sites was high in comparison with riverine and mixed geomorphic settings, with sites closer to riverine outflow from the east and south of Moreton Bay having higher stocks than those located on the sand islands in the northwest of the bay. Sediment OC stocks increased with elevation within nonriverine settings, but not in riverine geomorphic settings. Sediment OC stocks did not differ between mangrove and saltmarsh habitats. OC stocks did, however, differ between dominant species across the research area and within geomorphic settings. At the landscape scale, the coastal wetlands of the South East Queensland catchments (17,792 ha) are comprised of approximately 4,100,000-5,200,000 Mg of sediment OC. Comparatively high variation in OC storage between riverine and nonriverine geomorphic settings indicates that the availability of mineral sediments and terrestrial derived OC may exert a strong influence over OC storage potential across