WorldWideScience

Sample records for river aquatic ecosystem

  1. Regionalizing Aquatic Ecosystems Based on the River Subbasin Taxonomy Concept and Spatial Clustering Techniques

    Directory of Open Access Journals (Sweden)

    Jiahu Zhao

    2011-11-01

    Full Text Available Aquatic ecoregions were increasingly used as spatial units for aquatic ecosystem management at the watershed scale. In this paper, the principle of including land area, comprehensiveness and dominance, conjugation and hierarchy were selected as regionalizing principles. Elevation and drainage density were selected as the regionalizing indicators for the delineation of level I aquatic ecoregions, and percent of construction land area, percent of cultivated land area, soil type and slope for the level II. Under the support of GIS technology, the spatial distribution maps of the two indicators for level I and the four indicators for level II aquatic ecoregion delineation were generated from the raster data based on the 1,107 subwatersheds. River subbasin taxonomy concept, two-step spatial clustering analysis approach and manual-assisted method were used to regionalize aquatic ecosystems in the Taihu Lake watershed. Then the Taihu Lake watershed was divided into two level I aquatic ecoregions, including Ecoregion I1 and Ecoregion I2, and five level II aquatic subecoregions, including Subecoregion II11, Subecoregion II12, Subecoregion II21, Subecoregion II22 and Subecoregion II23. Moreover, the characteristics of the two level I aquatic ecoregions and five level II aquatic subecoregions in the Taihu Lake watershed were summarized, showing that there were significant differences in topography, socio-economic development, water quality and aquatic ecology, etc. The results of quantitative comparison of aquatic life also indicated that the dominant species of fish, benthic density, biomass, dominant species, Shannon-Wiener diversity index, Margalef species richness index, Pielou evenness index and ecological dominance showed great spatial variability between the two level I aquatic ecoregions and five level II aquatic subecoregions. It reflected the spatial heterogeneities and the uneven natures of aquatic ecosystems in the Taihu Lake watershed.

  2. Removal of terrestrial DOC in aquatic ecosystems of a temperate river network

    Science.gov (United States)

    Wollheim, W.M.; Stewart, R. J.; Aiken, George R.; Butler, Kenna D.; Morse, Nathaniel B.; Salisbury, J.

    2015-01-01

    Surface waters play a potentially important role in the global carbon balance. Dissolved organic carbon (DOC) fluxes are a major transfer of terrestrial carbon to river systems, and the fate of DOC in aquatic systems is poorly constrained. We used a unique combination of spatially distributed sampling of three DOC fractions throughout a river network and modeling to quantify the net removal of terrestrial DOC during a summer base flow period. We found that aquatic reactivity of terrestrial DOC leading to net loss is low, closer to conservative chloride than to reactive nitrogen. Net removal occurred mainly from the hydrophobic organic acid fraction, while hydrophilic and transphilic acids showed no net change, indicating that partitioning of bulk DOC into different fractions is critical for understanding terrestrial DOC removal. These findings suggest that river systems may have only a modest ability to alter the amounts of terrestrial DOC delivered to coastal zones.

  3. Radiological bioconcentration factors for aquatic, terrestrial, and wetland ecosystems at the Savannah River site

    International Nuclear Information System (INIS)

    Friday, G.P.; Cummins, C.L.; Schwartzman, A.L.

    1996-01-01

    Since the early 1950s, the Savannah River Site (SRS) released over 50 radionuclides into the environment while producing nuclear defense materials. These releases directly exposed aquatic and terrestrial biota to ionizing radiation from surface water, soil, and sediment, and also indirectly by the ingestion of items in the food chain. As part of new missions to develop waste management strategies and identify cost-effective environmental restoration options, knowledge concerning the uptake and distribution of these radionuclides is essential. This report compiles and summarizes site-specific bioconcentration factors for selected radionuclides released at SRS

  4. Radiological bioconcentration factors for aquatic, terrestrial, and wetland ecosystems at the Savannah River site

    Energy Technology Data Exchange (ETDEWEB)

    Friday, G.P.; Cummins, C.L.; Schwartzman, A.L.

    1996-12-31

    Since the early 1950s, the Savannah River Site (SRS) released over 50 radionuclides into the environment while producing nuclear defense materials. These releases directly exposed aquatic and terrestrial biota to ionizing radiation from surface water, soil, and sediment, and also indirectly by the ingestion of items in the food chain. As part of new missions to develop waste management strategies and identify cost-effective environmental restoration options, knowledge concerning the uptake and distribution of these radionuclides is essential. This report compiles and summarizes site-specific bioconcentration factors for selected radionuclides released at SRS.

  5. Radiological bioconcentration factors for aquatic, terrestrial, and wetland ecosystems at the Savannah River Site

    International Nuclear Information System (INIS)

    Cummins, C.L.

    1994-09-01

    As a result of operations at the Savannah River Site (SRS), over 50 radionuclides have been released to the atmosphere and to onsite streams and seepage basins. Now, many of these radionuclides are available to aquatic and/or terrestrial organisms for uptake and cycling through the food chain. Knowledge about the uptake and cycling of these radionuclides is now crucial in evaluating waste management and clean-up alternatives for the site. Numerous studies have been conducted at the SRS over the past forty years to study the uptake and distribution of radionuclides in the Savannah River Site environment. In many instances, bioconcentration factors have been calculated to quantify the uptake of a radionuclide by an organism from the surrounding medium (i.e., soil or water). In the past, it has been common practice to use bioconcentration factors from the literature because site-specific data were not readily available. However, because of the variability of bioconcentration factors due to experimental or environmental conditions, site-specific data should be used when available. This report compiles and summarizes site-specific bioconcentration factors for selected radionuclides released at the Savannah River Site (SRS). An extensive literature search yielded site-specific bioconcentration factors for cesium, strontium, cobalt, plutonium, americium, curium, and tritium. These eight radionuclides have been the primary radionuclides studied at SRS because of their long half lives or because they are major contributors to radiological dose from exposure. For most radionuclides, it was determined that the site-specific bioconcentration factors were higher than those reported in literature. This report also summarizes some conditions that affect radionuclide bioavailability to and bioconcentration by aquatic and terrestrial organisms

  6. Impacts of fire on nitrogen cycling in aquatic and terrestrial ecosystems in the Yukon-Kuskokwim River Delta, AK

    Science.gov (United States)

    Schade, J. D.; Jardine, L. E.; Bristol, E. M.; Navarro-Perez, E.; Melton, S.; Jimmie, J. A.; Natali, S.; Mann, P. J.; Holmes, R. M.

    2017-12-01

    Global climate change is having a disproportionate impact on northern high latitudes, including rapid increases in temperature, changes in precipitation, and increasing fire frequency and severity. Wildfires have been shown to strongly influence ecosystem processes through acceleration of permafrost thaw and increased nitrogen (N) availability, the effects of which may increase gaseous loss of carbon (C) to the atmosphere, increase primary production by alleviating N limitation, or both. The extent of these fire impacts has not been well-documented in the Arctic, particularly in areas of discontinuous permafrost. In 2015, the Yukon-Kuskokwim River Delta (YK Delta) in southwestern Alaska experienced the largest fire season in recorded history, providing an opportunity to study wildfire impacts on an area particularly vulnerable to permafrost thaw. Our objectives were to study the impacts of these fires on nitrogen availability in a range of land cover classes, including peat plateaus, channel fens, and aquatic ecosystems distributed across the landscapes. We sampled soils from several vegetation patches on burned and unburned peat plateaus, and soil and surface waters from fens, small ponds, and streams downslope of these sites. All water samples were filtered through GFF filters in the field. Soils were transported frozen to the Woods Hole Research Center and extracted in KCl. All water samples and extracts were analyzed for NH4 and NO3 concentrations. We found substantially higher concentrations of extractable NH4 in burned soils, but very little extractable NO3 in either burned or unburned soils. Water samples also showed higher NH4 in aquatic ecosystems in burned watersheds, but, in contrast to soils, showed relatively high NO3 concentrations, particularly in waters from lower landscape positions. Overall, aquatic ecosystems exhibited higher NO3: NH4 ratios than soil extractions, and increasing NO3: NH4 downslope. These results suggest significant export of

  7. Aquatic ecosystems in the coal mining landscape of the upper Olifants River, and the way forward

    CSIR Research Space (South Africa)

    Oberholster, Paul J

    2014-03-01

    Full Text Available can provide guidance on managing water ecosystems in the future at various stages of mining operations, which include understanding the interface between water ecosystems and coal mining activities, assessing the likelihood of coal mining activities...

  8. Movement and fate of mercury in an aquatic ecosystem

    International Nuclear Information System (INIS)

    Baez, A.P.; Nulman, R.

    1975-01-01

    Studies have been initiated of the behaviour and distribution of industrial mercury residues in the aquatic ecosystem represented by the Coatzacoalcos river estuary of Mexico. Mercury concentrations were determined in samples of water, river sediments, aquatic animals, aquatic and river-bank vegetation, local food products and in the hair of local inhabitants. Determinations were made by flameless atomic absorption spectrophotometry and concentrations greater than 50 ppm were found in some samples of bottom muds. (author)

  9. Aquatic macroinvertebrates of the Jablanica river, Serbia

    Directory of Open Access Journals (Sweden)

    Stefanović Katarina S.

    2009-01-01

    Full Text Available Research on the community of aquatic macroinvertebrates was carried out during 2005 and 2006 at four sampling sites along the Jablanica River, a right-hand tributary of the Kolubara River. Fifty-seven taxa were recorded in the course of the investigation. The most diverse group was Ephemeroptera, followed by Trichoptera and Plecoptera. Members of the Rhitrogena semicolorata group were the most abundant. Our results could be the basis for evaluation of the influence of damming of the Jablanica River on the status of its water and can serve as a model for studying the influ­ence of hydromorphological degradation of aquatic ecosystems.

  10. Ecology in Small Aquatic Ecosystems

    DEFF Research Database (Denmark)

    Andersen, Mikkel René

    Small ecosystems are many-fold more abundant than their larger counterparts. Both on regional and global scale small lakes outnumber medium and large lakes and account for a much larger surface area. Small streams are also far more common than rivers. Despite their abundance small ecosystems are ...

  11. Activity concentration of 210Po and 210Pb, its contribution to the radiation dose and distribution coefficient in aquatic ecosystem of major rivers of coastal Karnataka

    International Nuclear Information System (INIS)

    Rajashekara, K.M.; Prakash, V.; Narayana, Y.

    2013-01-01

    Rivers are the major pathways for the transport of weathered materials from the land to the oceans. The geochemical studies on river waters provide an insight into the weathering process that control the distribution of elements in dissolved and particulate phases and their fluxes to the estuaries. Concentrations of natural series radionuclide in fresh water bodies are liable to be much more variable than those in the marine environment since they are heavily influenced by the local geochemistry of the watershed. The concentrations of radioactive materials vary from region to region and this variation is found to be significantly high in some areas. Some of the regions are rich with the flow of major rivers and estuaries of these rivers, and investigations of these riverine and estuarine aquatic environments would throw light on the transportation, distribution and enrichment mechanism of radionuclides. In this context, the activity of 210 Po and 210 Pb were measured in different matrices of aquatic ecosystem of the major rivers namely, Kali, Sharavathi and Netravathi river of Coastal Karnataka

  12. Pulses, linkages, and boundaries of coupled aquatic-terrestrial ecosystems

    Science.gov (United States)

    Tockner, K.

    2009-04-01

    Riverine floodplains are linked ecosystems where terrestrial and aquatic habitats overlap, creating a zone where they interact, the aquatic-terrestrial interface. The interface or boundary between aquatic and terrestrial habitats is an area of transition, contact or separation; and connectivity between these habitats may be defined as the ease with which organisms, matter or energy traverse these boundaries. Coupling of aquatic and terrestrial systems generates intertwining food webs, and we may predict that coupled systems are more productive than separated ones. For example, riparian consumers (aquatic and terrestrial) have alternative prey items external to their respective habitats. Such subsidized assemblages occupy a significant higher trophic position than assemblages in unsubsidized areas. Further, cross-habitat linkages are often pulsed; and even small pulses of a driver (e.g. short-term increases in flow) can cause major resource pulses (i.e. emerging aquatic insects) that control the recipient community. For example, short-term additions of resources, simulating pulsed inputs of aquatic food to terrestrial systems, suggest that due to resource partitioning and temporal separation among riparian arthropod taxa the resource flux from the river to the riparian zone increases with increasing riparian consumer diversity. I will discuss the multiple transfer and transformation processes of matter and organisms across aquatic-terrestrial habitats. Key landscape elements along river corridors are vegetated islands that function as instream riparian areas. Results from Central European rivers demonstrate that islands are in general more natural than fringing riparian areas, contribute substantially to total ecotone length, and create diverse habitats in the aquatic and terrestrial realm. In braided rivers, vegetated islands are highly productive landscape elements compared to the adjacent aquatic area. However, aquatic habitats exhibit a much higher decomposition

  13. Effects of ship-induced waves on aquatic ecosystems.

    Science.gov (United States)

    Gabel, Friederike; Lorenz, Stefan; Stoll, Stefan

    2017-12-01

    Most larger water bodies worldwide are used for navigation, and the intensity of commercial and recreational navigation is expected to further increase. Navigation profoundly affects aquatic ecosystems. To facilitate navigation, rivers are trained and developed, and the direct effects of navigation include chemical and biological impacts (e.g., inputs of toxic substances and dispersal of non-native species, respectively). Furthermore, propagating ships create hydrodynamic alterations, often simply summarized as waves. Although ship-induced waves are recognized as influential stressors, knowledge on their effects is poorly synthesized. We present here a review on the effects of ship-induced waves on the structure, function and services of aquatic ecosystems based on more than 200 peer reviewed publications and technical reports. Ship-induced waves act at multiple organizational levels and different spatial and temporal scales. All the abiotic and biotic components of aquatic ecosystems are affected, from the sediment and nutrient budget to the planktonic, benthic and fish communities. We highlight how the effects of ship-induced waves cascade through ecosystems and how different effects interact and feed back into the ecosystem finally leading to altered ecosystem services and human health effects. Based on this synthesis of wave effects, we discuss strategies for mitigation. This may help to develop scientifically based and target-oriented management plans for navigational waters that optimize abiotic and biotic integrity and their ecosystem services and uses. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Radioactive contamination of aquatic ecosystems following the Chernobyl accident

    International Nuclear Information System (INIS)

    Kryshev, I.I.

    1995-01-01

    The dynamics of radioactive contamination of aquatic ecosystems (1986-1990) is considered on the basis of observational data in the near and distant zones of the Chernobyl fallout (the Chernobyl Nuclear Power Plant (CNPP) cooling pond, the Pripyat River, the Dnieper reservoirs, and the Kopor inlet of the Gulf of Finland). Radionuclide accumulation in aquatic biota is analyzed. The results obtained indicate that the radioecological conditions in the water bodies under investigation were in a state of non-equilibrium over a long period of time following the Chernobyl accident. Reduction in the 137 Cs concentration proceeded slowly in most of the aquatic ecosystems. The effect of trophic levels which consisted of increased accumulation of radiocaesium by predatory fish was observed in various parts of the contaminated area. (author)

  15. Deer Island Aquatic Ecosystem Restoration Project

    Science.gov (United States)

    2015-07-01

    across the U.S. Army Corps of Engineers (USACE) requires that a broad base of EWN understanding and support be built . The Deer Island Aquatic...USACE) requires that a broad base of EWN understanding and support be built . The Deer Island Aquatic Ecosystem Restoration Project (Deer Island AERP...Mississippi Wetlands Restoration Projects). The project received additional funding through several public laws in response to hurricane damages

  16. Bioassessment of the ecological integrity of river ecosystems using ...

    African Journals Online (AJOL)

    Bioassessment of the ecological integrity of river ecosystems using aquatic macroinvertebrates: an overview with a focus on South Africa. ... In conclusion, a number of potential avenues for further research regarding the use of macroinvertebrates in the bioassessment of river ecosystems are identified. Keywords: benthic ...

  17. The river ecosystem

    International Nuclear Information System (INIS)

    Descy, J.P.; Lambinon, J.

    1984-01-01

    From the standpoint of the ecologist, a river is an ecosystem characterized by its biocoenosis, in dynamic equilibrium with the abiotic environment. This ecosystem can be envisaged at the structural level by examining its physical, chemical and biological properties, together with the relationships existing between these compartments. The biocoenotic structure of a river is relatively complex: it manifests, among other specific features, the presence of plankton communities which show marked space-time variations. The function of the river ecosystem can be approximated by a study of the relationships between the biotic and abiotic components: primary production, secondary production, recycling of organic matter, etc. Lotic environments are subject to frequent disturbance from various forms of man-made pollution: organic pollution, eutrophization, thermal pollution, mineral pollution, contamination by organic and mineral micropollutants, as well as by radionuclides, mechanical pollution and physical degradation. The biocoenotic effects of these forms of pollution may be evaluated, in particular, using biological indicators (bioindicators): these are either able to show the overall impact of the pollution on the biocoenosis or else they permit the detection and evaluation of certain pollutant forms. (author)

  18. Plants in aquatic ecosystems: current trends and future directions

    NARCIS (Netherlands)

    O’Hare, Matthew T.; Aguiar, Francisca C.; Asaeda, Takashi; Bakker, Elisabeth S.; Chambers, Patricia A.; Clayton, John S.; Elger, Arnaud; Ferreira, Teresa M.; Gross, Elisabeth M.; Gunn, Iain D.M.; Gurnell, Angela M.; Hellsten, Seppo; Hofstra, Deborah E.; Li, Wei; Mohr, Silvia; Puijalon, Sara; Szoszkiewicz, Krzysztof; Willby, Nigel J.; Wood, Kevin A.

    2018-01-01

    Aquatic plants fulfil a wide range of ecological roles, and make a substantial contribution to the structure, function and service provision of aquatic ecosystems. Given their well-documented importance in aquatic ecosystems, research into aquatic plants continues to blossom. The 14th International

  19. Aquatic ecosystem characterisation strategy at a repository site

    Energy Technology Data Exchange (ETDEWEB)

    Kangasniemi, Ville; Ikonen, Ari T.K. [Environmental Research and Assessment EnviroCase, Ltd., Hallituskatu 1 D 4, 28100 Pori (Finland); Lahdenperae, Anne-Maj [Saanio and Riekkola Oy, Laulukuja 4, 00420 Helsinki (Finland); Kirkkala, Teija [Pyhaejaervi Institute, Sepaentie 7, 27500 Kauttua (Finland); Koivunen, Sari [Water and Environment Research of South-West Finland, Telekatu 16, 20360 Turku (Finland)

    2014-07-01

    Olkiluoto Island on the western coast of Finland has been selected as a repository site for spent nuclear fuel disposal. According to regulatory requirements, the safety assessment for the repository should have an assessment timeframe of several millennia. Due to the post-glacial land uplift, the relatively shallow sea areas around Olkiluoto Island will change gradually to lakes, rivers and terrestrial areas. As there are no limnic systems at present Olkiluoto site, the reference area was delineated and reference lakes and rivers were selected as an analogue. For the modelling of the transport and accumulation of possible radionuclide releases in the surface environment, aquatic ecosystems were identified and divided into biotopes. Despite the number of available templates, the division of aquatic environment for the biosphere assessment of the Olkiluoto spent fuel repository was necessary to made separately. In this contribution, the processes behind the identification of aquatic ecosystems (e.g. legislation, physical and chemical properties) together with the biotope selection methodology (e.g. light and bottom conditions) and the challenges related to the amount of variable input parameters for each biotope in the modelling are presented. (authors)

  20. Biota connect aquatic habitats throughout freshwater ecosystem mosaics

    Science.gov (United States)

    Schofield, Kate A.; Alexander, Laurie C.; Ridley, Caroline E.; Vanderhoof, Melanie; Fritz, Ken M.; Autrey, Bradley; DeMeester, Julie; Kepner, William G.; Lane, Charles R.; Leibowitz, Scott; Pollard, Amina I.

    2018-01-01

    Freshwater ecosystems are linked at various spatial and temporal scales by movements of biota adapted to life in water. We review the literature on movements of aquatic organisms that connect different types of freshwater habitats, focusing on linkages from streams and wetlands to downstream waters. Here, streams, wetlands, rivers, lakes, ponds, and other freshwater habitats are viewed as dynamic freshwater ecosystem mosaics (FEMs) that collectively provide the resources needed to sustain aquatic life. Based on existing evidence, it is clear that biotic linkages throughout FEMs have important consequences for biological integrity and biodiversity. All aquatic organisms move within and among FEM components, but differ in the mode, frequency, distance, and timing of their movements. These movements allow biota to recolonize habitats, avoid inbreeding, escape stressors, locate mates, and acquire resources. Cumulatively, these individual movements connect populations within and among FEMs and contribute to local and regional diversity, resilience to disturbance, and persistence of aquatic species in the face of environmental change. Thus, the biological connections established by movement of biota among streams, wetlands, and downstream waters are critical to the ecological integrity of these systems. Future research will help advance our understanding of the movements that link FEMs and their cumulative effects on downstream waters.

  1. Process-based principles for restoring river ecosystems

    Science.gov (United States)

    Timothy J. Beechie; David A. Sear; Julian D. Olden; George R. Pess; John M. Buffington; Hamish Moir; Philip Roni; Michael M. Pollock

    2010-01-01

    Process-based restoration aims to reestablish normative rates and magnitudes of physical, chemical, and biological processes that sustain river and floodplain ecosystems. Ecosystem conditions at any site are governed by hierarchical regional, watershed, and reach-scale processes controlling hydrologic and sediment regimes; floodplain and aquatic habitat...

  2. Radiation exposure of aquatic ecosystem compartments

    International Nuclear Information System (INIS)

    Colonna-Cesari-Florent, L.; Bontoux, J.

    1999-01-01

    In the frame of a normal operation, a nuclear site releases gaseous as well liquid effluents in environment. Limits are defined but if they are acceptable for man, do they allow to preserve species of ecosystem? Two points stand out of this study: the natural radioactivity is dominating in exposure but can one neglect an addition of artificial radioactivity? The species of Rhone river ecosystem are potentially submitted to a thermal and/or chemical stress, only a combined study, taking into account every situation of stress, could lead to a long term preservation of our environmental inheritance. (N.C.)

  3. A community-based framework for aquatic ecosystem models

    DEFF Research Database (Denmark)

    Trolle, Didde; Hamilton, D. P.; Hipsey, M. R.

    2012-01-01

    Here, we communicate a point of departure in the development of aquatic ecosystem models, namely a new community-based framework, which supports an enhanced and transparent union between the collective expertise that exists in the communities of traditional ecologists and model developers. Through...... a literature survey, we document the growing importance of numerical aquatic ecosystem models while also noting the difficulties, up until now, of the aquatic scientific community to make significant advances in these models during the past two decades. Through a common forum for aquatic ecosystem modellers we...... aim to (i) advance collaboration within the aquatic ecosystem modelling community, (ii) enable increased use of models for research, policy and ecosystem-based management, (iii) facilitate a collective framework using common (standardised) code to ensure that model development is incremental, (iv...

  4. Conflicting hydropower development and aquatic ecosystem conservation in Bhutan

    Science.gov (United States)

    Wi, S.; Yang, Y. C. E.

    2017-12-01

    Hydropower is one of the clean energy sources that many Himalayan countries are eager to develop to solve their domestic energy deficit issue such as India, Nepal and Pakistan. Like other Himalayan countries, Bhutan also has a great potential for hydropower development. However, Bhutan is one of few countries that has a domestic energy surplus and export its hydropower generation to neighboring countries (mainly to India). Exporting hydropower is one of the major economic sources in Bhutan. However, constructions of dams and reservoirs for hydropower development inevitably involve habitat fragmentation, causing a conflict of interest with the pursuit of value in aquatic ecosystem conservation. The objectives of this study is to 1) develop a distributed hydrologic model with snow and glacier module to simulate the hydrologic regimes of seven major watersheds in Bhutan; 2) apply the hydrologic model to compute hydropower generation for all existing and potential dams; 3) evaluate cascade impacts of each individual dam on downstream regions by employing three hydro-ecological indicators: the River Connectivity Index (RCI), Dendritic Connectivity Index (DCI), total affected river stretch (ARS), and 4) analyze the tradeoffs between hydropower generation and river connectivity at the national scale by means of a multiple objective genetic algorithm. Modeling results of three Pareto Fronts between ecological indicators and hydropower generation accompany with future energy export targets from the government can inform dam selections that maximizing hydropower generation while minimizing the impact on the aquatic ecosystem (Figure 1a). The impacts of climate change on these Pareto front are also explored to identify robust dam selection under changing temperature and precipitation (Figure 1b).

  5. Economic valuation of aquatic ecosystem services in developing countries

    DEFF Research Database (Denmark)

    Korsgaard, Louise; Schou, Jesper S.

    2010-01-01

    -the silent water user. A promising way of placing aquatic ecosystems on the water agenda is by economic valuation of services sustained by ecosystems. In developing countries, the livelihoods of rural people often depend directly on the provision of aquatic ecosystem services. In such situations, economic......An important challenge of integrated water resources management (IWRM) is to balance water allocation between different users. While economically and/or politically powerful users have well developed methods for quantifying and justifying their water needs, this is not the case for ecosystems...... valuation of ecosystem services becomes particularly challenging. This paper reviews recent literature on economic valuation of aquatic ecosystem services in developing countries. "Market price" is the most widespread method used for valuating marketed ecosystem services in developing countries. "Cost based...

  6. River ecosystem response to prescribed vegetation burning on Blanket Peatland.

    Science.gov (United States)

    Brown, Lee E; Johnston, Kerrylyn; Palmer, Sheila M; Aspray, Katie L; Holden, Joseph

    2013-01-01

    Catchment-scale land-use change is recognised as a major threat to aquatic biodiversity and ecosystem functioning globally. In the UK uplands rotational vegetation burning is practised widely to boost production of recreational game birds, and while some recent studies have suggested burning can alter river water quality there has been minimal attention paid to effects on aquatic biota. We studied ten rivers across the north of England between March 2010 and October 2011, five of which drained burned catchments and five from unburned catchments. There were significant effects of burning, season and their interaction on river macroinvertebrate communities, with rivers draining burned catchments having significantly lower taxonomic richness and Simpson's diversity. ANOSIM revealed a significant effect of burning on macroinvertebrate community composition, with typically reduced Ephemeroptera abundance and diversity and greater abundance of Chironomidae and Nemouridae. Grazer and collector-gatherer feeding groups were also significantly less abundant in rivers draining burned catchments. These biotic changes were associated with lower pH and higher Si, Mn, Fe and Al in burned systems. Vegetation burning on peatland therefore has effects beyond the terrestrial part of the system where the management intervention is being practiced. Similar responses of river macroinvertebrate communities have been observed in peatlands disturbed by forestry activity across northern Europe. Finally we found river ecosystem changes similar to those observed in studies of wild and prescribed forest fires across North America and South Africa, illustrating some potentially generic effects of fire on aquatic ecosystems.

  7. Heavy metal pollution characteristics of surface sediments in different aquatic ecosystems in eastern China: a comprehensive understanding.

    Directory of Open Access Journals (Sweden)

    Wenzhong Tang

    Full Text Available Aquatic ecosystems in eastern China are suffering threats from heavy metal pollution because of rapid economic development and urbanization. Heavy metals in surface sediments were determined in five different aquatic ecosystems (river, reservoir, estuary, lake, and wetland ecosystems. The average Cd, Cr, Cu, Ni, Pb, and Zn concentrations were 0.716, 118, 37.3, 32.7, 56.6, and 204 mg/kg, respectively, and the higher concentrations were mainly found in sediment samples from river ecosystems. Cd was the most anthropogenically enriched pollutant, followed by Zn and Pb, indicated by enrichment factors >1.5. According to consensus-based sediment quality guidelines, potential ecological risk indices, and risk assessment codes, all five types of aquatic ecosystems were found to be polluted with heavy metals, and the most polluted ecosystems were mainly rivers. Cd was the most serious pollutant in all five aquatic ecosystems, and it was mainly found in the exchangeable fraction (about 30% of the total Cd concentration, on average. The results indicate that heavy metal contamination, especially of Cd, in aquatic ecosystems in eastern China should be taken into account in the development of management strategies for protecting the aquatic environment.

  8. Contamination of the Aquatic Environment with Neonicotinoids and its Implication for Ecosystems

    Directory of Open Access Journals (Sweden)

    Francisco Sánchez-Bayo

    2016-11-01

    Full Text Available The widespread use of systemic neonicotinoid insecticides in agriculture results first in contamination of the soil of the treated crops, and secondly in the transfer of residues to the aquatic environment. The high toxicity of these insecticides to aquatic insects and other arthropods has been recognized, but there is little awareness of the impacts these chemicals have on aquatic environments and the ecosystem at large. Recent monitoring studies in several countries, however, have revealed a world-wide contamination of creeks, rivers and lakes with these insecticides, with residue levels in the low μg/L (ppb range. The current extent of aquatic contamination by neonicotinoids is reviewed first, and the findings contrasted with the known acute and chronic toxicity of neonicotinoids to various aquatic organisms. Impacts on populations and aquatic communities, mostly using mesocosms, are reviewed next to identify the communities most at risk from those that undergo little or no impact. Finally, the ecological links between aquatic and terrestrial organisms are considered. The consequences for terrestrial vertebrate species that depend mainly on this food source are discussed together with impacts on ecosystem function. Gaps in knowledge stem from difficulties in obtaining long-term experimental data that relates the effects on individual organisms to impacts on populations and ecosystems. The paper concludes with a summary of findings and the implications they have for the larger ecosystem.

  9. Exploring, exploiting and evolving diversity of aquatic ecosystem models

    DEFF Research Database (Denmark)

    Janssen, Annette B G; Arhonditsis, George B.; Beusen, Arthur

    2015-01-01

    Here, we present a community perspective on how to explore, exploit and evolve the diversity in aquatic ecosystem models. These models play an important role in understanding the functioning of aquatic ecosystems, filling in observation gaps and developing effective strategies for water quality...... management. In this spirit, numerous models have been developed since the 1970s. We set off to explore model diversity by making an inventory among 42 aquatic ecosystem modellers, by categorizing the resulting set of models and by analysing them for diversity. We then focus on how to exploit model diversity...... available through open-source policies, to standardize documentation and technical implementation of models, and to compare models through ensemble modelling and interdisciplinary approaches. We end with our perspective on how the field of aquatic ecosystem modelling might develop in the next 5–10 years...

  10. Risk Assessment Considerations for Veterinary Medicines in Aquatic Ecosystems

    Science.gov (United States)

    This chapter provides a critical evaluation of prospective and retrospective risk assessment approaches for veterinary medicines in aquatic ecosystems and provides recommendations for possible alternative approaches for hazard characterization.

  11. Eutrophication in aquatic ecosystems: a scientometric study

    Directory of Open Access Journals (Sweden)

    Jéssica Alves da Costa

    2018-03-01

    Full Text Available Abstract Aim: Reveal the direction for future studies about eutrophication, or even reveal the preoccupation among the scientific community about this environmental problem. With a systematic synthesis of eutrophication studies, scientists may be able to understand the state of the literature on aquatic ecosystems around the world. This study intends to identify the main factors used to control algal blooms and the eutrophication process, the countries and environments which have more research about this theme or even identify the articles’ subjects in different periods (e.g.: Experimental, theoretic, monitoring, conservation. Methods We analyzed all studies published in the Thomson ISI Web of Science on both eutrophication and phytoplankton between 2001 and 2016. Results During the period analyzed, we observed an increase in concern about this subject. Authors from institutions in the USA and China wrote most of the studies. The most important geographic and socioeconomic aspects to determine the publication number were total area and HDI respectively. However, the main determinant for the publication about this subject was international collaboration. Some of the most actual themes in ecology and conservation (e.g.: functional groups, climate change, experiment, perdition models, regional scales, invasive species were addressed in the studies analysed. Invasive species such as Tilapia and Cylindrospermopsis raciborskii were the most cited species on these keywords. Conclusion Despite the current issues addressed in the studies on phytoplankton and eutrophication, some subjects, such as climate change or spatial pattern, were only common in years more recent. Even though studies focusing in functional diversity are highly relevant for conservation, they were not common in any year studied. The major determinant factor related to the increasing in eutrophication knowledge was the international collaboration

  12. DNA barcodes for assessment of the biological integrity of aquatic ecosystems

    Science.gov (United States)

    Water quality regulations and aquatic ecosystem monitoring increasingly rely on direct assessments of biological integrity. Because these aquatic “bioassessments” evaluate the incidence and abundance of sensitive aquatic species, they are able to measure cumulative ecosystem eff...

  13. Herbivores Enforce Sharp Boundaries Between Terrestrial and Aquatic Ecosystems

    NARCIS (Netherlands)

    Sarneel, Judith M.; Huig, N.; Veen, G. F.; Rip, W.; Bakker, E. S.

    2014-01-01

    The transitions between ecosystems (ecotones) are often biodiversity hotspots, but we know little about the forces that shape them. Today, often sharp boundaries with low diversity are found between terrestrial and aquatic ecosystems. This has been attributed to environmental factors that hamper

  14. An automated platform for phytoplankton ecology and aquatic ecosystem monitoring

    NARCIS (Netherlands)

    Pomati, F.; Jokela, J.; Simona, M.; Veronesi, M.; Ibelings, B.W.

    2011-01-01

    High quality monitoring data are vital for tracking and understanding the causes of ecosystem change. We present a potentially powerful approach for phytoplankton and aquatic ecosystem monitoring, based on integration of scanning flow-cytometry for the characterization and counting of algal cells

  15. Modeling dynamics of biological and chemical components of aquatic ecosystems

    International Nuclear Information System (INIS)

    Lassiter, R.R.

    1975-05-01

    To provide capability to model aquatic ecosystems or their subsystems as needed for particular research goals, a modeling strategy was developed. Submodels of several processes common to aquatic ecosystems were developed or adapted from previously existing ones. Included are submodels for photosynthesis as a function of light and depth, biological growth rates as a function of temperature, dynamic chemical equilibrium, feeding and growth, and various types of losses to biological populations. These submodels may be used as modules in the construction of models of subsystems or ecosystems. A preliminary model for the nitrogen cycle subsystem was developed using the modeling strategy and applicable submodels. (U.S.)

  16. Carmel River Lagoon Enhancement Project: Water Quality and Aquatic Wildlife Monitoring, 2006-7

    OpenAIRE

    Perry, William; Watson, Fred; Casagrande, Joel; Hanley, Charles

    2007-01-01

    This is a report to the California Department of Parks and Recreation. It describes water quality and aquatic invertebrate monitoring after the construction of the Carmel River Lagoon Enhancement Project. Included are data that have been collected for two years and preliminary assessment of the enhanced ecosystem. This report marks the completion of 3-years of monitoring water quality and aquatic habitat. The report adopts the same format and certain background text from previous ...

  17. Beyond 2001: a silvicultural odyssey to sustaining terrestrial and aquatic ecosystems? Proceedings of the 2001 national silviculture workshop, May 6-10, Hood River, Oregon.

    Science.gov (United States)

    Sharon Parker; Susan Stevens. Hummel

    2002-01-01

    The 2001 National Silviculture Workshop was held in Hood River, Oregon, and hosted by the Mt. Hood National Forest, the Gifford Pinchot National Forest, and the Pacific Northwest Research Station. The Washington Office Vegetation Management and Protection Research and Forest and Grassland staffs are ongoing sponsors of the biennial workshop, which began in 1973 in...

  18. Riparian spiders as sentinels of polychlorinated biphenyl contamination across heterogeneous aquatic ecosystems

    Science.gov (United States)

    Kraus, Johanna M.; Gibson, Polly P.; Walters, David M.; Mills, Marc A.

    2017-01-01

    Riparian spiders are being used increasingly to track spatial patterns of contaminants in and fluxing from aquatic ecosystems.However, our understanding of the circumstances under which spiders are effective sentinels of aquatic pollution is limited. The present study tests the hypothesis that riparian spiders may be effectively used to track spatial patterns of sediment pollution by polychlorinated biphenyls (PCBs) in aquatic ecosystems with high habitat heterogeneity. The spatial pattern of ΣPCB concentrations in 2 common families of riparian spiders sampled in 2011 to 2013 generally tracked spatial variation in sediment ΣPCBs across all sites within the Manistique River Great Lakes Area of Concern (AOC), a rivermouth ecosystem located on the south shore of the Upper Peninsula, Manistique (MI,USA) that includes harbor, river, backwater, and lake habitats. Sediment ΣPCB concentrations normalized for total organic carbon explained 41% of the variation in lipid-normalized spider ΣPCB concentrations across 11 sites. Furthermore, 2 common riparian spider taxa (Araneidae and Tetragnathidae) were highly correlated (r2> 0.78) and had similar mean ΣPCB concentrations when averaged acrossall years. The results indicate that riparian spiders may be useful sentinels of relative PCB availability to aquatic and riparian food webs in heterogeneous aquatic ecosystems like rivermouths where habitat and contaminant variability may make the use of aquatic taxa lesseffective. Furthermore, the present approach appears robust to heterogeneity in shoreline development and riparian vegetation that support different families of large web-building spiders. Environ Toxicol Chem 2016;9999:1–9. Published 2016 Wiley Periodicals, Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

  19. Riparian spiders as sentinels of polychlorinated biphenyl contamination across heterogeneous aquatic ecosystems.

    Science.gov (United States)

    Kraus, Johanna M; Gibson, Polly P; Walters, David M; Mills, Marc A

    2017-05-01

    Riparian spiders are being used increasingly to track spatial patterns of contaminants in and fluxing from aquatic ecosystems. However, our understanding of the circumstances under which spiders are effective sentinels of aquatic pollution is limited. The present study tests the hypothesis that riparian spiders may be effectively used to track spatial patterns of sediment pollution by polychlorinated biphenyls (PCBs) in aquatic ecosystems with high habitat heterogeneity. The spatial pattern of ΣPCB concentrations in 2 common families of riparian spiders sampled in 2011 to 2013 generally tracked spatial variation in sediment ΣPCBs across all sites within the Manistique River Great Lakes Area of Concern (AOC), a rivermouth ecosystem located on the south shore of the Upper Peninsula, Manistique (MI, USA) that includes harbor, river, backwater, and lake habitats. Sediment ΣPCB concentrations normalized for total organic carbon explained 41% of the variation in lipid-normalized spider ΣPCB concentrations across 11 sites. Furthermore, 2 common riparian spider taxa (Araneidae and Tetragnathidae) were highly correlated (r 2  > 0.78) and had similar mean ΣPCB concentrations when averaged across all years. The results indicate that riparian spiders may be useful sentinels of relative PCB availability to aquatic and riparian food webs in heterogeneous aquatic ecosystems like rivermouths where habitat and contaminant variability may make the use of aquatic taxa less effective. Furthermore, the present approach appears robust to heterogeneity in shoreline development and riparian vegetation that support different families of large web-building spiders. Environ Toxicol Chem 2017;36:1278-1286. Published 2016 Wiley Periodicals, Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America. Published 2016 Wiley Periodicals, Inc. on behalf of SETAC. This article is a US government work and, as such, is in

  20. [Health assessment of river ecosystem in Haihe River Basin, China].

    Science.gov (United States)

    Hao, Li-Xia; Sun, Ran-Hao; Chen, Li-Ding

    2014-10-01

    With the development of economy, the health of river ecosystem is severely threatened because of the increasing effects of human activities on river ecosystem. In this paper, the authors assessed the river ecosystem health in aspects of chemical integrity and biological integrity, using the criterion in water quality, nutrient, and benthic macroinvertebrates of 73 samples in Haihe River Basin. The research showed that the health condition of river ecosystem in Haihe River Basin was bad overall since the health situation of 72. 6% of the samples was "extremely bad". At the same time, the health situation in Haihe River Basin exhibited obvious regional gathering effect. We also found that the river water quality was closely related to human activities, and the eutrophication trend of water body was evident in Haihe River Basin. The biodiversity of the benthic animal was low and lack of clean species in the basin. The indicators such as ammonia nitrogen, total nitrogen and total phosphorus were the key factors that affected the river ecosystem health in Haihe River Basin, so the government should start to curb the deterioration of river ecosystem health by controlling these nutrients indicators. For river ecosystem health assessment, the multi-factors comprehensive evaluation method was superior to single-factor method.

  1. Development phase of corrosion program in aquatic ecosystems

    International Nuclear Information System (INIS)

    Moreira, P.A.

    1983-01-01

    Providences adopted to implantation of corrosion program in aquatic ecosystems, developed by CDTN, NUCLEN and FURNAS are presented. The area, the atmospheric exposition station of Angra dos Reis, the marine floating, the material to test specimen and its preparation are described. (C.M.) [pt

  2. A community-based framework for aquatic ecosystem models

    NARCIS (Netherlands)

    Trolle, D.; Hamilton, D.P.; Hipsey, M.R.; Bolding, K.; Bruggeman, J.; Mooij, W.M.; Janse, J.H.; Nielsen, A.; Jeppesen, E.; Elliott, J.A.; Makler-Pick, V.; Petzoldt, T.; Rinke, K.; Flindt, M.R.; Arhonditsis, G.B.; Gal, G.; Bjerring, R.; Tominaga, K.; Hoen, 't J.; Downing, A.S.; Marques, D.M.; Fragoso, C.R.; Sondergaard, M.; Hanson, P.C.

    2012-01-01

    Here, we communicate a point of departure in the development of aquatic ecosystem models, namely a new community-based framework, which supports an enhanced and transparent union between the collective expertise that exists in the communities of traditional ecologists and model developers. Through a

  3. Measurement of undisturbed di-nitrogen emissions from aquatic ecosystems

    Science.gov (United States)

    Qin, Shuping, Clough, Timothy, Lou, Jiafa; Hu, Chunsheng; Oenema, Oene; Wrage-Mönnig, Nicole; Zhang, Yuming

    2016-04-01

    Increased production of reactive nitrogen (Nr) from atmospheric di-nitrogen (N2) during the last century has greatly contributed to increased food production1-4. However, enriching the biosphere with Nr through N fertilizer production, combustion, and biological N2 fixation has also caused a series of negative effects on global ecosystems 5,6, especially aquatic ecosystems7. The main pathway converting Nr back into the atmospheric N2 pool is the last step of the denitrification process, i.e., the reduction of nitrous oxide (N2O) into N2 by micro-organisms7,8. Despite several attempts9,10, there is not yet an accurate, fast and direct method for measuring undisturbed N2 fluxes from denitrification in aquatic sediments at the field scale11-14. Such a method is essential to study the feedback of aquatic ecosystems to Nr inputs1,2,7. Here we show that the measurement of both N2O emission and its isotope signature can be used to infer the undisturbed N2 fluxes from aquatic ecosystems. The microbial reduction of N2O increases the natural abundance of 15N-N2O relative to 14N-N2O (δ15N-N2O). We observed linear relationships between δ15N-N2O and the logarithmic transformed N2O/(N2+N2O) emission ratios. Through independent measurements, we verified that the undisturbed N2 flux from aquatic ecosystems can be inferred from measurements of N2O emissions and the δ15N-N2O signature. Our method allows the determination of field-scale N2 fluxes from undisturbed aquatic ecosystems, and thereby allows model predictions of denitrification rates to be tested. The undisturbed N2 fluxes observed are almost one order of magnitude higher than those estimated by the traditional method, where perturbation of the system occurs, indicating that the ability of aquatic ecosystems to remove Nr may have been severely underestimated.

  4. Potential effects of climate change on aquatic ecosystems of the Great Plains of North America

    Science.gov (United States)

    Covich, A.P.; Fritz, S.C.; Lamb, P.J.; Marzolf, R.D.; Matthews, W.J.; Poiani, K.A.; Prepas, E.E.; Richman, M.B.; Winter, T.C.

    1997-01-01

    The Great Plains landscape is less topographically complex than most other regions within North America, but diverse aquatic ecosystems, such as playas, pothole lakes, ox-bow lakes, springs, groundwater aquifers, intermittent and ephemeral streams, as well as large rivers and wetlands, are highly dynamic and responsive to extreme climatic fluctuations. We review the evidence for climatic change that demonstrates the historical importance of extremes in north-south differences in summer temperatures and east-west differences in aridity across four large subregions. These physical driving forces alter density stratification, deoxygenation, decomposition and salinity. Biotic community composition and associated ecosystem processes of productivity and nutrient cycling respond rapidly to these climatically driven dynamics. Ecosystem processes also respond to cultural effects such as dams and diversions of water for irrigation, waste dilution and urban demands for drinking water and industrial uses. Distinguishing climatic from cultural effects in future models of aquatic ecosystem functioning will require more refinement in both climatic and economic forecasting. There is a need, for example, to predict how long-term climatic forecasts (based on both ENSO and global warming simulations) relate to the permanence and productivity of shallow water ecosystems. Aquatic ecologists, hydrologists, climatologists and geographers have much to discuss regarding the synthesis of available data and the design of future interdisciplinary research. ?? 1997 by John Wiley & Sons, Ltd.

  5. Effects of ionizing radiation on aquatic organisms and ecosystems

    International Nuclear Information System (INIS)

    1976-01-01

    A panel of experts in November 1971 specifically considered the effects of ionizing radiation on aquatic organisms and ecosystems and formulated detailed suggestions for research in the area. A further panel meeting took place in April 1974. The results of the work are presented in this report which is divided into 3 chapters in the first chapter the concentrations of natural and artificial radionuclides in aquatic environments and the radiation dose rates received by aquatic organisms are discussed. In particular, simple dosimetry models for phytoplankton, zooplankton, mollusca, crustacea and fish are presented which permit the estimation of the dose rates from incorporated radionuclides and from radionuclides in the external environment. In the second chapter the somatic and genetic effects of ionizing radiation on aquatic organisms are reviewed. Somatic effects are discussed separately as effects due to short-term (acute) exposure to near-lethal doses of radiation. Great attention is paid to the effects due to long-term (chronic) exposure at lower doses rates. Consideration is given to behaviour, repair mechanisms and metabolic stimulation after exposure, and also the influence of environmental factors on radiation effects. In the third chapter the potential effects of low-level irradiation on aquatic populations are considered. First, the possible consequences of somatic effects on egg and larval mortality, stock-recruitment, fecundity and ecosystem stability are discussed. Subsequently, the assessment of genetic effects as they relate to population genetics and increased mutation rates are considered

  6. 76 FR 10892 - Aquatic Ecosystems, Water Quality, and Global Change: Challenges of Conducting Multi-Stressor...

    Science.gov (United States)

    2011-02-28

    ...: EPA is announcing the release of the draft report titled, ``Aquatic Ecosystems, Water Quality, and... relative vulnerability of water quality and aquatic ecosystems, across the United States, to the potential... mailing address, and the document title, ``Aquatic Ecosystems, Water Quality, and Global Change...

  7. 76 FR 55060 - Aquatic Ecosystems, Water Quality, and Global Change: Challenges of Conducting Multi-Stressor...

    Science.gov (United States)

    2011-09-06

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9459-7] Aquatic Ecosystems, Water Quality, and Global Change... entitled, Aquatic Ecosystems, Water Quality, and Global Change: Challenges of Conducting Multi- stressor... vulnerability of water quality and aquatic ecosystems across the United States to the potential impacts of...

  8. Beaver-mediated lateral hydrologic connectivity, fluvial carbon and nutrient flux, and aquatic ecosystem metabolism

    Science.gov (United States)

    Wegener, Pam; Covino, Tim; Wohl, Ellen

    2017-06-01

    River networks that drain mountain landscapes alternate between narrow and wide valley segments. Within the wide segments, beaver activity can facilitate the development and maintenance of complex, multithread planform. Because the narrow segments have limited ability to retain water, carbon, and nutrients, the wide, multithread segments are likely important locations of retention. We evaluated hydrologic dynamics, nutrient flux, and aquatic ecosystem metabolism along two adjacent segments of a river network in the Rocky Mountains, Colorado: (1) a wide, multithread segment with beaver activity; and, (2) an adjacent (directly upstream) narrow, single-thread segment without beaver activity. We used a mass balance approach to determine the water, carbon, and nutrient source-sink behavior of each river segment across a range of flows. While the single-thread segment was consistently a source of water, carbon, and nitrogen, the beaver impacted multithread segment exhibited variable source-sink dynamics as a function of flow. Specifically, the multithread segment was a sink for water, carbon, and nutrients during high flows, and subsequently became a source as flows decreased. Shifts in river-floodplain hydrologic connectivity across flows related to higher and more variable aquatic ecosystem metabolism rates along the multithread relative to the single-thread segment. Our data suggest that beaver activity in wide valleys can create a physically complex hydrologic environment that can enhance hydrologic and biogeochemical buffering, and promote high rates of aquatic ecosystem metabolism. Given the widespread removal of beaver, determining the cumulative effects of these changes is a critical next step in restoring function in altered river networks.

  9. Benthic algae compensate for phytoplankton losses in large aquatic ecosystems.

    Science.gov (United States)

    Brothers, Soren; Vadeboncoeur, Yvonne; Sibley, Paul

    2016-12-01

    Anthropogenic activities can induce major trophic shifts in aquatic systems, yet we have an incomplete understanding of the implication of such shifts on ecosystem function and on primary production (PP) in particular. In recent decades, phytoplankton biomass and production in the Laurentian Great Lakes have declined in response to reduced nutrient concentrations and invasive mussels. However, the increases in water clarity associated with declines in phytoplankton may have positive effects on benthic PP at the ecosystem scale. Have these lakes experienced oligotrophication (a reduction of algal production), or simply a shift in autotrophic structure with no net decline in PP? Benthic contributions to ecosystem PP are rarely measured in large aquatic systems, but our calculations based on productivity rates from the Great Lakes indicate that a significant proportion (up to one half, in Lake Huron) of their whole-lake production may be benthic. The large declines (5-45%) in phytoplankton production in the Great Lakes from the 1970s to 2000s may be substantially compensated by benthic PP, which increased by up to 190%. Thus, the autotrophic productive capacity of large aquatic ecosystems may be relatively resilient to shifts in trophic status, due to a redirection of production to the near-shore benthic zone, and large lakes may exhibit shifts in autotrophic structure analogous to the regime shifts seen in shallow lakes. © 2016 John Wiley & Sons Ltd.

  10. Selenium concentration in compartments of aquatic ecosystems in Central Chile

    Energy Technology Data Exchange (ETDEWEB)

    Pinochet, H.; Gregori, I. de; Cavieres, M.F. [Catholic University of Valparaiso, Valparaiso (Chile). Chemical Institute

    2002-07-01

    A study was conducted during 1995-96 to evaluate Se concentration in water, sediment, and plants from aquatic ecosystems of central Chile, an area particularly affected by mining activities. Samples were collected from Panquehue, Chagres, and Ocoa along the Acongua River (presumably receives discharges from a copper refinery and a copper mine). Samples were also collected from one site on the Puchuncavi Stream (directly contaminated by both a coal power plant and a copper refinery). In addition, samples were also collected from one site on the Limache Stream (an urban area with no Se-contaminating sources). The sediment and plant samples collected in Puchuncavi had higher Se levels, which were statistically different to the concentration in samples from other sites. Sediments from Puchuncavi and Ocoa had the highest levels of Se (520 plus or minus 46 and 440 plus or minus 10 {mu} g/kg, respectively) while the plant (Jussiaea repens (Ludwigia repens)) collected in Puchuncavi had an Se concentration 6.5 times higher than the sample collected in Panquehue (116 plus or minus 154 and 182 plus or minus 54 {mu} g/kg, respectively). Puchuncavi water had more acidic pH than water from the other sites thus decreasing Se solubility. Se concentrations in sediment and water collected in Chagres were lower than the concentration determined in sediment and water from either Ocoa or Panquehue. Plant/water and plant/sediment accumulation factors and a sediment/water distribution factor were similar for all sampling sites, except Puchuncavi (accumulation and distribution factors are higher than at the other sites). Hydrocotyle ranunculoides had practically the same plant/sediment accumulation factor at all sites while the accumulation factor for J. repens varied according to site. The samples collected in the Limache stream had Se at equal or even higher concentration than the other samples collected from presumably contaminated sites (except Puchuncavi). 19 refs.

  11. Tritium behavior in an aquatic ecosystem

    International Nuclear Information System (INIS)

    Komatsu, K.

    1982-01-01

    Tritium behavior in aquatic organisms through a model food chain was investigated. In this model food chain, tritium in water reaches bacteria or Japanese killifish via diatoms and brine shrimps. Tritium accumulation in these organisms as organic bound form was expressed as the R value which is defined as the ratio of tritium specific activity in lyophilized organisms (μCi/gH) to that in water (μCi/gH). The maximum R values were 0.5 in diatoms: Chaetoceros gracilis, 0.2 in bacteria: Escherichia coli, 0.5 in brine shrimps: Artemia salina, and 0.32 in Japanese killifish: Oryzias latipes under the growing condition in which tritium accumulation was due to tritium in tritiated water and not tritiated foods. Brine shrimps and Japanese killifish were grown from larve to adult in tritiated sea water and were fed on tritiated foods (model food chain). Their R values were 0.70 and 0.67, respectively. Bacteria, which grew in tritiated water by adding the hydrolysate of tritiated brine shrimps, showed a maximum R value at 0.32. The R values of each organ of Japanese killifish and of DNA and the nucleotides purified from brine shrimps growing in tritiated water with or without tritiated food were measured to estimate the tritium distribution in the body or various molecules of the organisms. These results did not indicate concentration of tritium in specific organs or compounds. The changes of specific activity of tritium in these organisms were measured when they were transferred to non-tritiated water. These retention of tritium was not only different among the tissues but also depended on whether or not the organisms were reared with tritiated foods. (author)

  12. DOC removal paradigms in highly humic aquatic ecosystems.

    Science.gov (United States)

    Farjalla, Vinicius F; Amado, André M; Suhett, Albert L; Meirelles-Pereira, Frederico

    2009-07-01

    Dissolved humic substances (HS) usually comprise 50-80% of the dissolved organic carbon (DOC) in aquatic ecosystems. From a trophic and biogeochemical perspective, HS has been considered to be highly refractory and is supposed to accumulate in the water. The upsurge of the microbial loop paradigm and the studies on HS photo-degradation into labile DOC gave rise to the belief that microbial processing of DOC should sustain aquatic food webs in humic waters. However, this has not been extensively supported by the literature, since most HS and their photo-products are often oxidized by microbes through respiration in most nutrient-poor humic waters. Here, we review basic concepts, classical studies, and recent data on bacterial and photo-degradation of DOC, comparing the rates of these processes in highly humic ecosystems and other aquatic ecosystems. We based our review on classical and recent findings from the fields of biogeochemistry and microbial ecology, highlighting some odd results from highly humic Brazilian tropical lagoons, which can reach up to 160 mg C L(-1). Highly humic tropical lagoons showed proportionally lower bacterial production rates and higher bacterial respiration rates (i.e., lower bacterial growth efficiency) than other lakes. Zooplankton showed similar delta(13)C to microalgae but not to humic DOC in these highly humic lagoons. Thus, the data reviewed here do not support the microbial loop as an efficient matter transfer pathway in highly humic ecosystems, where it is supposed to play its major role. In addition, we found that some tropical humic ecosystems presented the highest potential DOC photo-chemical mineralization (PM) rates reported in the literature, exceeding up to threefold the rates reported for temperate humic ecosystems. We propose that these atypically high PM rates are the result of a joint effect of the seasonal dynamics of allochthonous humic DOC input to these ecosystems and the high sunlight incidence throughout the year

  13. Freshwater ecosystems and aquatic insects: a paradox in biological invasions.

    Science.gov (United States)

    Fenoglio, Stefano; Bonada, Núria; Guareschi, Simone; López-Rodríguez, Manuel J; Millán, Andrés; Tierno de Figueroa, J Manuel

    2016-04-01

    Biological invasions have increased significantly in response to global change and constitute one of the major causes of biodiversity loss. Insects make up a large fraction of invasive species, in general, and freshwaters are among the most invaded ecosystems on our planet. However, even though aquatic insects dominate most inland waters, have unparalleled taxonomic diversity and occupy nearly all trophic niches, there are almost no invasive insects in freshwaters. We present some hypotheses regarding why aquatic insects are not common among aquatic invasive organisms, suggesting that it may be the result of a suite of biological, ecological and anthropogenic factors. Such specific knowledge introduces a paradox in the current scientific discussion on invasive species; therefore, a more in-depth understanding could be an invaluable aid to disentangling how and why biological invasions occur. © 2016 The Author(s).

  14. HAZARDOUS MATERIALS IN AQUATIC ENVIRONMENTS OF THE MISSISSIPPI RIVER BASIN

    Energy Technology Data Exchange (ETDEWEB)

    John A. McLachlan

    2003-12-01

    In December 1992, the CBR was awarded a five-year grant of $25M from the US Department of Energy Office of Environmental Management (DOE-EM) to study pollution in the Mississippi River system. The ''Hazardous Materials in Aquatic Environments of the Mississippi River Basin'' project was an interdisciplinary, collaborative research and education project aimed at elucidating the nature and magnitude of toxic materials that contaminate aquatic environments. This project funded 15 collaborative cluster multi-year projects and 41 one-year initiation projects out of 165 submitted research proposals. This project was carried out by 134 research and technical support faculty from Xavier University (School of Arts and Sciences, and College of Pharmacy) and Tulane University (Schools of Liberal Arts and Sciences, Engineering, Medicine, and Public Health and Tropical Medicine), and 173 publications and 140 presentations were produced. More than 100 graduate and undergraduate students were trained through these collaborative cluster and initiation research projects. Nineteen Tulane graduate students received partial funding to conduct their own competitively-chosen research projects, and 28 Xavier undergraduate LIFE Scholars and 30 LIFE Interns were supported with DOE funding to conduct their mentored research projects. Studies in this project have defined: (1) the complex interactions that occur during the transport of contaminants, (2) the actual and potential impact on ecological systems and health, and (3) the mechanisms through which these impacts might be remediated. The bayou and spoil banks of Bayou Trepagnier were mapped and analyzed in terms of risks associated with the levels of hydrocarbons and metals at specific sample sites. Data from contaminated sample sites have been incorporated into a large database and used in GIS analyses to track the fate and transport of heavy metals from spoil banks into the surrounding marsh. These data are crucial

  15. Occurrence, fate and effects of azoxystrobin in aquatic ecosystems

    OpenAIRE

    Rodrigues, Elsa Teresa Santos

    2016-01-01

    Tese de doutoramento em Biociências, na especialidade de Toxicologia, apresentada ao Departamento de Ciências da Vida da Faculdade de Ciências e Tecnologia da Universidade de Coimbra After a literature review to find relevant research on the occurrence, fate and effects of azoxystrobin, the world’s leading agricultural fungicide, in aquatic ecosystems, strengths and gaps were identified in the database. Data revealed that validated analytical methods for complex matrices are very limited a...

  16. Behaviour of 134Cs in the aquatic ecosystems

    International Nuclear Information System (INIS)

    Xu Yinliang; Chen Chuanqun

    1992-07-01

    The diminution of 134 Cs in the aquatic phases and the absorption of 134 Cs by aquatic lives observe the exponential expression. i.e. Y Ae be . The relationships between the enrichment factor of 134 Cs(K) and the time(t) in the aquatic lives can be represented by a linear equation, K A + Bt. The value of K in the Alternanthera philoxeroides was about 560. That can be used for monitoring and purifying the water phase contaminated by 134 Cs. Fish can absorb 134 Cs from water phase and store it in liver and kidney. The specific activity of 134 Cs in fish flesh was low but the percentage of radioactivity was high that was about 30% of total radioactivity in the fish. River mud can strongly absorb 134 Cs and reduce the absorption by aquatic lives. It is a good adsorbent and purifying agent with low cost for treatment of 134 Cs. The K + can prevent aquatic lives from absorbing Cs + because of antagonistic function

  17. Biological indication in aquatic ecosystems. Biological indication in limnic and coastal ecosystems - fundamentals, techniques, methodology

    International Nuclear Information System (INIS)

    Gunkel, G.

    1994-01-01

    Biological methods of water quality evaluation today form an integral part of environmental monitoring and permit to continuously monitor the condition of aquatic ecosystems. They indicate both improvements in water quality following redevelopment measures, and the sometimes insidious deterioration of water quality. This book on biological indication in aquatic ecosystems is a compendium of measurement and evaluation techniques for limnic systems by means of biological parameters. At present, however, an intense discussion of biological evaluation techniques is going on, for one thing as a consequence of the German reunification and the need to unify evaluation techniques, and for another because of harmonizations within the European Community. (orig./EF) [de

  18. [Impacts of hydroelectric cascade exploitation on river ecosystem and landscape: a review].

    Science.gov (United States)

    Yang, Kun; Deng, Xi; Li, Xue-Ling; Wen, Ping

    2011-05-01

    Hydroelectric cascade exploitation, one of the major ways for exploiting water resources and developing hydropower, not only satisfies the needs of various national economic sectors, but also promotes the socio-economic sustainable development of river basin. unavoidable anthropogenic impacts on the entire basin ecosystem. Based on the process of hydroelectric cascade exploitation and the ecological characteristics of river basins, this paper reviewed the major impacts of hydroelectric cascade exploitation on dam-area ecosystems, river reservoirs micro-climate, riparian ecosystems, river aquatic ecosystems, wetlands, and river landscapes. Some prospects for future research were offered, e.g., strengthening the research of chain reactions and cumulative effects of ecological factors affected by hydroelectric cascade exploitation, intensifying the study of positive and negative ecological effects under the dam networks and their joint operations, and improving the research of successional development and stability of basin ecosystems at different temporal and spatial scales.

  19. Controlled Environments Enable Adaptive Management in Aquatic Ecosystems Under Altered Environments

    Science.gov (United States)

    Bubenheim, David L.

    2016-01-01

    Ecosystems worldwide are impacted by altered environment conditions resulting from climate, drought, and land use changes. Gaps in the science knowledge base regarding plant community response to these novel and rapid changes limit both science understanding and management of ecosystems. We describe how CE Technologies have enabled the rapid supply of gap-filling science, development of ecosystem simulation models, and remote sensing assessment tools to provide science-informed, adaptive management methods in the impacted aquatic ecosystem of the California Sacramento-San Joaquin River Delta. The Delta is the hub for California's water, supplying Southern California agriculture and urban communities as well as the San Francisco Bay area. The changes in environmental conditions including temperature, light, and water quality and associated expansion of invasive aquatic plants negatively impact water distribution and ecology of the San Francisco Bay/Delta complex. CE technologies define changes in resource use efficiencies, photosynthetic productivity, evapotranspiration, phenology, reproductive strategies, and spectral reflectance modifications in native and invasive species in response to altered conditions. We will discuss how the CE technologies play an enabling role in filling knowledge gaps regarding plant response to altered environments, parameterization and validation of ecosystem models, development of satellite-based, remote sensing tools, and operational management strategies.

  20. Fuzzy model for risk assessment of persistent organic pollutants in aquatic ecosystems

    International Nuclear Information System (INIS)

    Seguí, X.; Pujolasus, E.; Betrò, S.; Àgueda, A.; Casal, J.; Ocampo-Duque, W.; Rudolph, I.; Barra, R.; Páez, M.; Barón, E.; Eljarrat, E.; Barceló, D.; Darbra, R.M.

    2013-01-01

    We developed a model for evaluating the environmental risk of persistent organic pollutants (POPs) to aquatic organisms. The model is based on fuzzy theory and uses information provided by international experts through a questionnaire. It has been tested in two case studies for a particular type of POPs: brominated flame retardants (BFRs). The first case study is related to the EU-funded AQUATERRA project, with sampling campaigns carried out in two Ebro tributaries in Spain (the Cinca and Vero Rivers). The second one, named the BROMACUA project, assessed different aquatic ecosystems in Chile (San Vicente Bay) and Colombia (Santa Marta Marsh). In both projects, the BFRs under study were polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD). However, the model can be extrapolated to other POPs and to different aquatic ecosystems to provide useful results for decision-makers. -- The risk of POPs for aquatic organisms was assessed at several sites around the world, using a fuzzy-based model to provide useful results for decision-makers

  1. A new framework to evaluate ecosystem health: a case study in the Wei River basin, China.

    Science.gov (United States)

    Wu, Wei; Xu, Zongxue; Zhan, Chesheng; Yin, Xuwang; Yu, Songyan

    2015-07-01

    Due to the rapid growth of the population and the development of economies in the Guanzhong district, central China, the river ecosystem is gradually deteriorating, which makes it important to assess the aquatic ecosystem health and take measures to restore the damaged ecosystem. An index of catchment ecosystem health has been developed to assist large-scale management of watersheds by providing an integrated measure of ecosystem health, including aquatic and terrestrial ecosystem. Most researches focus on aquatic ecosystem or terrestrial ecosystem, but little research integrates both of them to assess the catchment ecosystem health. In this paper, we combine these two aspects into catchment ecosystem health. Ecosystem indicators derived from field samples and modeling are identified to integrate into ecosystem health. These included indicators of ecological landscape pattern (based on normalized difference vegetation index (NDVI), vegetation cover, dominance index, Shannon's diversity index, Shannon's evenness index, and fragmentation index), hydrology regime (based on 33 hydrological parameters), physical form condition (based on substrate, habitat complexity, velocity/depth regimes, bank stability, channel alteration), water quality (based on electrical conductivity (Cond), dissolved oxygen (DO), NH3_N, total nitrogen (TN), total phosphorus (TP), chemical oxygen demand-permanganate (CODMn)), and biological quality (based on fish abundance). The index of ecosystem health is applied in the Guanzhong district, and the ecosystem health was fair. The ecosystem health in the upstream to Linjiacun (U-L) and Linjiacun to Weijiabao (L-W) reaches was in good situation, while that in Weijiabao to Xianyang (W-X), Xianyang-Weijiabao (X-W), and Weijiabao to Tongguan (W-T) reaches was in fair situation. There is a trend that the ecosystem health in the upstream was better than that in the downstream. The ecosystem health assessment is expected to play a key role in future

  2. Microplastics in aquatic environments: Implications for Canadian ecosystems.

    Science.gov (United States)

    Anderson, Julie C; Park, Bradley J; Palace, Vince P

    2016-11-01

    Microplastics have been increasingly detected and quantified in marine and freshwater environments, and there are growing concerns about potential effects in biota. A literature review was conducted to summarize the current state of knowledge of microplastics in Canadian aquatic environments; specifically, the sources, environmental fate, behaviour, abundance, and toxicological effects in aquatic organisms. While we found that research and publications on these topics have increased dramatically since 2010, relatively few studies have assessed the presence, fate, and effects of microplastics in Canadian water bodies. We suggest that efforts to determine aquatic receptors at greatest risk of detrimental effects due to microplastic exposure, and their associated contaminants, are particularly warranted. There is also a need to address the gaps identified, with a particular focus on the species and conditions found in Canadian aquatic systems. These gaps include characterization of the presence of microplastics in Canadian freshwater ecosystems, identifying key sources of microplastics to these systems, and evaluating the presence of microplastics in Arctic waters and biota. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  3. Aquatic biodiversity in forests: A weak link in ecosystem services resilience

    Science.gov (United States)

    Penaluna, Brooke E.; Olson, Deanna H.; Flitcroft, Rebecca L; Weber, Matthew A.; Bellmore, J. Ryan; Wondzell, Steven M.; Dunham, Jason B.; Johnson, Sherri L.; Reeves, Gordon H.

    2017-01-01

    The diversity of aquatic ecosystems is being quickly reduced on many continents, warranting a closer examination of the consequences for ecological integrity and ecosystem services. Here we describe intermediate and final ecosystem services derived from aquatic biodiversity in forests. We include a summary of the factors framing the assembly of aquatic biodiversity in forests in natural systems and how they change with a variety of natural disturbances and human-derived stressors. We consider forested aquatic ecosystems as a multi-state portfolio, with diverse assemblages and life-history strategies occurring at local scales as a consequence of a mosaic of habitat conditions and past disturbances and stressors. Maintaining this multi-state portfolio of assemblages requires a broad perspective of ecosystem structure, various functions, services, and management implications relative to contemporary stressors. Because aquatic biodiversity provides multiple ecosystem services to forests, activities that compromise aquatic ecosystems and biodiversity could be an issue for maintaining forest ecosystem integrity. We illustrate these concepts with examples of aquatic biodiversity and ecosystem services in forests of northwestern North America, also known as Northeast Pacific Rim. Encouraging management planning at broad as well as local spatial scales to recognize multi-state ecosystem management goals has promise for maintaining valuable ecosystem services. Ultimately, integration of information from socio-ecological ecosystems will be needed to maintain ecosystem services derived directly and indirectly from forest aquatic biota.

  4. Physical heterogeneity and aquatic community function in river networks: A case study from the Kanawha River Basin, USA

    Science.gov (United States)

    Thoms, M. C.; Delong, M. D.; Flotemersch, J. E.; Collins, S. E.

    2017-08-01

    The geomorphological character of a river network provides the template upon which evolution acts to create unique biological communities. Deciphering commonly observed patterns and processes within riverine landscapes resulting from the interplay between physical and biological components is a central tenet for the interdisciplinary field of river science. Relationships between the physical heterogeneity and food web character of functional process zones (FPZs) - large tracts of river with a similar geomorphic character -in the Kanawha River (West Virginia, USA) are examined in this study. Food web character was measured as food chain length (FCL), which reflects ecological community structure and ecosystem function. Our results show that the same basal resources were present throughout the Kanawha River but that their assimilation into the aquatic food web by primary consumers differed between FPZs. Differences in the trophic position of higher consumers (fish) were also recorded between FPZs. Overall, the morphological heterogeneity and heterogeneity of the river bed sediment of FPZs were significantly correlated with FCL. Specifically, FCL increases with greater FPZ physical heterogeneity. The result of this study does not support the current paradigm that ecosystem size is the primary determinant of food web character in river ecosystems.

  5. Aquatic ecosystem protection and restoration: Advances in methods for assessment and evaluation

    Science.gov (United States)

    Bain, M.B.; Harig, A.L.; Loucks, D.P.; Goforth, R.R.; Mills, K.E.

    2000-01-01

    Many methods and criteria are available to assess aquatic ecosystems, and this review focuses on a set that demonstrates advancements from community analyses to methods spanning large spatial and temporal scales. Basic methods have been extended by incorporating taxa sensitivity to different forms of stress, adding measures linked to system function, synthesizing multiple faunal groups, integrating biological and physical attributes, spanning large spatial scales, and enabling simulations through time. These tools can be customized to meet the needs of a particular assessment and ecosystem. Two case studies are presented to show how new methods were applied at the ecosystem scale for achieving practical management goals. One case used an assessment of biotic structure to demonstrate how enhanced river flows can improve habitat conditions and restore a diverse fish fauna reflective of a healthy riverine ecosystem. In the second case, multitaxonomic integrity indicators were successful in distinguishing lake ecosystems that were disturbed, healthy, and in the process of restoration. Most methods strive to address the concept of biological integrity and assessment effectiveness often can be impeded by the lack of more specific ecosystem management objectives. Scientific and policy explorations are needed to define new ways for designating a healthy system so as to allow specification of precise quality criteria that will promote further development of ecosystem analysis tools.

  6. Riparian spiders as sentinels of PCB contamination across heterogeneous aquatic ecosystems

    Science.gov (United States)

    Riparian spiders are being used increasingly to track spatial patterns of contaminants in and fluxing from aquatic ecosystems. However, our understanding of the circumstances under which spiders are effective sentinels of aquatic pollution is limited. The present study tests the ...

  7. Measuring ecological change of aquatic macrophytes in Mediterranean rivers

    OpenAIRE

    Dodkins, Ian; Aguiar, Francisca; Rivaes, Rui; Albuquerque, António; Rodriguez-Gonzalez, Patricia; Ferreira, Maria Teresa

    2012-01-01

    A metric was developed for assessing anthropogenic impacts on aquatic macrophyte ecology by scoring macrophyte species along the main gradient of community change. A measure of ecological quality was then calculated by Weighted Averaging (WA) of these species scores at a monitoring site, and comparison to a reference condition score. This metric was used to illustrate the difficulties of developing aquatic macrophyte indices based on indicator species in Mediterranean rivers. The ...

  8. Stochastic models for predicting environmental impact in aquatic ecosystems

    International Nuclear Information System (INIS)

    Stewart-Oaten, A.

    1986-01-01

    The purpose of stochastic predictions are discussed in relation to the environmental impacts of nuclear power plants on aquatic ecosystems. One purpose is to aid in making rational decisions about whether a power plant should be built, where, and how it should be designed. The other purpose is to check on the models themselves in the light of what eventually happens. The author discusses the role or statistical decision theory in the decision-making problem. Various types of stochastic models and their problems are presented. In addition some suggestions are made for generating usable stochastic models, and checking and improving on them. 12 references

  9. Radioactive background in principal components of the Jihlava River ecosystem

    International Nuclear Information System (INIS)

    Stanek, Z.; Penaz, M.; Trnkova, J.; Wohlgemuth, E.

    1980-01-01

    In 1976 through to 1978, the radioactive background was investigated in the various components of the Jihlava River ecosystem. The investigations involved total β-activity, 40 K, residual β-activity, sup(nat)U, 226 Ra and, in some of the samples, also 210 Pb, 90 Sr and 137 Cs. The analyses included water, bottom sediments, samples of aquatic macrophytes (Batrachium fluitans), samples of aquatic invertebrates (Herpobdella octoculata, Anodonta cygnea, Asellus aquaticus, larval Ephemeroptera, larval Trichoptera, exuviae of pupae of Chironomidae) and samples of the tissues of 8 species of fishes (Salmo trutta m. fario, Cyprinus carpio, Rutilus rutilus, Leuciscus cephalus, Leuciscus leuciscus, Chondrostoma nasus, Gobio gobio, Barbus barbus). The activity of the radionuclides under study corresponded to the values reported for uncontaminated streams. (author)

  10. Agrochemical residue-biota interactions in soil and aquatic ecosystems

    International Nuclear Information System (INIS)

    1980-01-01

    Two FAO/IAEA coordinated research programmes are concerned with isotopic tracer-aided studies of agrochemical residue-biota interactions in soils and aquatic ecosystems. They currently involve 18 studies in 14 countries: Brazil, Canada, Egypt, F.R. Germany, Hungary, India, Indonesia, Iraq, Israel, Malaysia, Thailand, Turkey, USA and USSR. The aim was to develop, standardize and apply labelled substrate techniques for comparative assays of primary autotrophic and microheterotrophic production and decay, and complementary tracer techniques to determine the fate, persistence and bioconcentration of trace contaminants. Comparable data were studied concerning the current status of water bodies and likely changes due to contaminants. Soil capacity to decompose undesirable contaminants and residues, and to promote desirable transformations were studied. The techniques were also applied as a diagnostic and prognostic tool, with priority given to rice ecosystems

  11. Stimulation of microbial nitrogen cycling in aquatic ecosystems by benthic macrofauna: mechanisms and environmental implications

    OpenAIRE

    P. Stief

    2013-01-01

    Invertebrate animals that live at the bottom of aquatic ecosystems (i.e., benthic macrofauna) are important mediators between nutrients in the water column and microbes in the benthos. The presence of benthic macrofauna stimulates microbial nutrient dynamics through different types of animal–microbe interactions, which potentially affect the trophic status of aquatic ecosystems. This review contrasts three types of animal–microbe interactions in the benthos of aquatic ecosystems: (i) e...

  12. Radioecological impact of the Chernobyl accident on continental aquatic ecosystems

    International Nuclear Information System (INIS)

    Foulquier, L.; Baudin-Jaulent, Y.

    1989-09-01

    The pooling of knowledge on water, sediments, aquatic plants and fish allowed an evaluation report to be drawn up on the impact of Chernobyl accident and to extract data on the mechanisms in the transfer of certain radionuclides in rivers and lakes. The radioactivity is related to the level of deposits, essentially, in wet form. Differences in radioactivity levels are noted owing to the distance from Chernobyl, the atmospheric streams and pluviometric conditions. The most commonly detected radionuclides are: 131 I, 132 Te, 134+137 Cs, 103+106 Ru, 110m Ag and, to a lesser degree, 89 Sr and 90 Sr. Very quickly, 137 Cs becomes dominant. The peak of radioactivity in rivers occurred very soon after the accident. It was of short duration and the decrease in radioactivity was very quick due to dilution. In lakes, this decay was much slower. In sediment, the radioactivity varied in time owing either to new deposits or to the migration of those deposits downstream in the river basins. The radionuclides present in fallout can be quickly detected using aquatic plant. In certain areas, the concentration of 137 Cs increased 200-fold in a few hours. In fish, the presence of 134+137 Cs, 103+106 Ru, 110m Ag and 90 Sr are noted. The only radionuclide of which fixing dynamics can be followed is 137 Cs. River fish was only subjected to water and food with a high radioactivity for a very short time and their 137 Cs concentration remained constantly low. The effective half-life of 137 Cs observed in situ for fish is from 100 to 200 days. For lacustrine fish, we observe differences in radiocontamination, according to the regions (from 48,000 Bq.kg -1 w.w., in Sweden, to 110 in the North of Corsica or the Netherlands), in lakes (in Northern Italy, 137 Cs concentrations in fish are higher in small lakes), and species

  13. Water reservoirs - aquatic ecosystems subject to eutrophication processes

    International Nuclear Information System (INIS)

    Ionita, Veronica

    1997-01-01

    The paper presents some aspects relating to eutrophication of Batca Doamnei and Reconstructia hydropower lakes situated near Piatra Neamt town. The presence of phosphorus salts in the two water reservoirs (ten times the admissible content) is responsible for excessive growth of plants. In Reconstructia lake the diversity of species is also explained by the existence of large amounts of nitrogen salts. The general characteristic of aquatic macrophyte is the resistance to large variations of environmental factors (water level, currents, temperature, turbidity, organic material content), adaptation to water pollution conditions and development of adverse condition resistant forms. Besides Cladophora, a harmful species in fishing waters when growing excessively, others species are favorable to aquatic life and help to the consolidation of complex lake biocenoses, providing support, food and habitation for many small animal species which also favor other species economically valuable. The aquatic macrophytes are true biological filters which maintain the natural auto-purging potential of the waters. Taking into consideration these facts, the direct and indirect effects of plant destruction on the whole ecosystem should be carefully analyzed

  14. Aquatic noise pollution: implications for individuals, populations, and ecosystems.

    Science.gov (United States)

    Kunc, Hansjoerg P; McLaughlin, Kirsty Elizabeth; Schmidt, Rouven

    2016-08-17

    Anthropogenically driven environmental changes affect our planet at an unprecedented scale and are considered to be a key threat to biodiversity. According to the World Health Organization, anthropogenic noise is one of the most hazardous forms of anthropogenically driven environmental change and is recognized as a major global pollutant. However, crucial advances in the rapidly emerging research on noise pollution focus exclusively on single aspects of noise pollution, e.g. on behaviour, physiology, terrestrial ecosystems, or on certain taxa. Given that more than two-thirds of our planet is covered with water, there is a pressing need to get a holistic understanding of the effects of anthropogenic noise in aquatic ecosystems. We found experimental evidence for negative effects of anthropogenic noise on an individual's development, physiology, and/or behaviour in both invertebrates and vertebrates. We also found that species differ in their response to noise, and highlight the potential underlying mechanisms for these differences. Finally, we point out challenges in the study of aquatic noise pollution and provide directions for future research, which will enhance our understanding of this globally present pollutant. © 2016 The Author(s).

  15. Studies on transfer, bioaccumulation and disappearance of glyphosate in the aquatic ecosystem by utilizing 14C tracer technique

    International Nuclear Information System (INIS)

    Zhu Guonian; Guo Jiangfeng; Sun Jinhe

    2002-01-01

    Studies on transfer, bioaccumulation and disappearance of glyphosate in the aquatic environment were conducted with methods of model tests and outdoor trials in the aquatic ecosystem. The result showed that glyphosate transferred rapidly into sediment and hormwort (Ceratopyllum demersum L.) after applied; and then, it was taken up faster and accumulated more by topmouth gudgeon (Psudorasobora parva) 5-10 days after application. The partitioning coefficient (sediment-water) and bioconcentration factors of glyphosate were 8.59, 27.96 and 45.79, respectively, in day 20. The concentration of glyphosate residue in the aquatic ecosystem followed the order of topmouth gudgeon > hormwort > sediment > water. And it was also indicated that glyphosate transferred and disappeared extremely fast in both pond and river after application

  16. Hazardous materials in aquatic environments of the Mississippi River Basin

    International Nuclear Information System (INIS)

    1993-01-01

    Tulane and Xavier Universities have singled out the environment as a major strategic focus for research and training for now and by the year 2000. In December, 1992, the Tulane/Xavier CBR was awarded a five year grant to study pollution in the Mississippi River system. The ''Hazardous Materials in Aquatic Environments of the Mississippi River Basin'' project is a broad research and education program aimed at elucidating the nature and magnitude of toxic materials that contaminate aquatic environments of the Mississippi River Basin. Studies include defining the complex interactions that occur during the transport of contaminants, the actual and potential impact on ecological systems and health, and the mechanisms through which these impacts might be remediated. The Mississippi River Basin represents a model system for analyzing and solving contamination problems that are found in aquatic systems world-wide. These research and education projects are particularly relevant to the US Department of Energy's programs aimed at addressing aquatic pollution problems associated with DOE National Laboratories. First year funding supported seven collaborative cluster projects and twelve initiation projects. This report summarizes research results for period December 1992--December 1993

  17. Investigation of the factors influencing radiocesium concentrations of fish inhabiting natural aquatic ecosystems

    International Nuclear Information System (INIS)

    Jinks, S.M.

    1975-01-01

    Distributions of radioactive and stable cesium were determined in water, sediment, and biota from eight different aquatic ecosystems between 1971 and 1973. The ecosystems included four lakes, fresh and brackish water regions of the Hudson River estuary, and two coastal marine sites. In the Hudson River estuary, the distribution of radiocesium between suspended and dissolved phases in water was found to be a function of salinity. Mean rates of deposition of suspended radiocesium into bottom sediment are calculated from the temporal changes in concentrations of the media, and observed depth distributions in sediment are semi-quantitatively described. Desorption by salt water is identified as the major mechanism for transport of radiocesium from bottom sediment in the lower estuary, and half-times for removal by this mechanism are estimated to be 1.5 to 2.0 years. Suspended-dissolved distributions of radiocesium in water, and depth distributions in sediment are also presented for lake and marine systems. Accumulation of radiocesium by fish is examined in relation to radiocesium distributions in water, sediment, and other biota, and to the chemical characteristics of each ecosystem. Radiocesium dissolved in water was the primary source to the fish in all ecosystems. Sediment inventories of 137 Cs constituted a secondary source which provided as much as 50 percent of the radiocesium in benthic feeding fish in the Hudson River. Dietary intake of 137 Cs is shown to be inversely related to the potassium concentration in the ambient water, and results in an inverse proportionality between the concentration factor in fish and the potassium concentrations in the different freshwater and estuarine ecosystems

  18. Managing aquatic ecosystems and water resources under multiple stress--an introduction to the MARS project.

    Science.gov (United States)

    Hering, Daniel; Carvalho, Laurence; Argillier, Christine; Beklioglu, Meryem; Borja, Angel; Cardoso, Ana Cristina; Duel, Harm; Ferreira, Teresa; Globevnik, Lidija; Hanganu, Jenica; Hellsten, Seppo; Jeppesen, Erik; Kodeš, Vit; Solheim, Anne Lyche; Nõges, Tiina; Ormerod, Steve; Panagopoulos, Yiannis; Schmutz, Stefan; Venohr, Markus; Birk, Sebastian

    2015-01-15

    Water resources globally are affected by a complex mixture of stressors resulting from a range of drivers, including urban and agricultural land use, hydropower generation and climate change. Understanding how stressors interfere and impact upon ecological status and ecosystem services is essential for developing effective River Basin Management Plans and shaping future environmental policy. This paper details the nature of these problems for Europe's water resources and the need to find solutions at a range of spatial scales. In terms of the latter, we describe the aims and approaches of the EU-funded project MARS (Managing Aquatic ecosystems and water Resources under multiple Stress) and the conceptual and analytical framework that it is adopting to provide this knowledge, understanding and tools needed to address multiple stressors. MARS is operating at three scales: At the water body scale, the mechanistic understanding of stressor interactions and their impact upon water resources, ecological status and ecosystem services will be examined through multi-factorial experiments and the analysis of long time-series. At the river basin scale, modelling and empirical approaches will be adopted to characterise relationships between multiple stressors and ecological responses, functions, services and water resources. The effects of future land use and mitigation scenarios in 16 European river basins will be assessed. At the European scale, large-scale spatial analysis will be carried out to identify the relationships amongst stress intensity, ecological status and service provision, with a special focus on large transboundary rivers, lakes and fish. The project will support managers and policy makers in the practical implementation of the Water Framework Directive (WFD), of related legislation and of the Blueprint to Safeguard Europe's Water Resources by advising the 3rd River Basin Management Planning cycle, the revision of the WFD and by developing new tools for

  19. Program GICC - AQUABIO. Possible consequences of the climatic change on the aquatic and river french biocenoses. Final report

    International Nuclear Information System (INIS)

    Pont, D.

    2003-11-01

    The consequences of the climatic change can modify the ecosystems. The aim of this research program is to analyze the impacts of the climatic change on the propagation of the exotic species in France in aquatic and river environment, the population of macro invertebrates and fishes in the french rivers and the socio economic challenges. The methodology is based on the simulation from the exploitation of great data bases and the combination of many approaches at different scales. (A.L.B.)

  20. Environmental bacteriophages : viruses of microbes in aquatic ecosystems

    Directory of Open Access Journals (Sweden)

    Télesphore eSIME - NGANDO

    2014-07-01

    Full Text Available Since the discovery 2-3 decades ago that viruses of microbes are abundant in marine ecosystems, viral ecology has grown increasingly to reach the status of a full scientific discipline in environmental sciences. A dedicated ISVM society, the International Society for Viruses of Microorganisms (http://www.isvm.org/, was recently launched. Increasing studies in viral ecology are sources of novel knowledge related to the biodiversity of living things, the functioning of ecosystems, and the evolution of the cellular world. This is because viruses are perhaps the most diverse, abundant, and ubiquitous biological entities in the biosphere, although local environmental conditions enrich for certain viral types through selective pressure. They exhibit various lifestyles that intimately depend on the deep-cellular mechanisms, and are ultimately replicated by members of all three domains of cellular life (Bacteria, Eukarya, Archaea, as well as by giant viruses of some eukaryotic cells. This establishes viral parasites as microbial killers but also as cell partners or metabolic manipulators in microbial ecology. The present chapter sought to review the literature on the diversity and functional roles of viruses of microbes in environmental microbiology, focusing primarily on prokaryotic viruses (i.e. phages in aquatic ecosystems, which form the bulk of our knowledge in modern environmental viral ecology.

  1. Benefits of riparian forest for the aquatic ecosystem assessed at a large geographic scale

    Directory of Open Access Journals (Sweden)

    Van Looy K.

    2013-04-01

    Full Text Available Claimed benefits of riparian forest cover for the aquatic ecosystem include purification, thermal control, organic matter input and habitat provision, which may improve physicochemical and biotic quality. However, these beneficial effects might be flawed by multiple stressor conditions of intensive agriculture and urbanization in upstream catchments. We examined the relationship between riparian forest cover and physicochemical quality and biotic integrity indices in extensive large scale datasets. Measurements of hydromorphological conditions and riparian forest cover across different buffer widths for 59 × 103 river stretches covering 230 × 103 km of the French river network were coupled with data for physicochemical and biotic variables taken from the national monitoring network. General linear and quantile regression techniques were used to determine responses of physicochemical variables and biological integrity indices for macroinvertebrates and fish to riparian forest cover in selections of intermediate stress for 2nd to 4th order streams. Significant responses to forest cover were found for the nutrient variables and biological indices. According to these responses a 60% riparian forest cover in the 10 m buffer corresponds to good status boundaries for physicochemical and biotic elements. For the 30 m buffer, the observed response suggests that riparian forest coverage of at least 45% corresponds with good ecological status in the aquatic ecosystem. The observed consistent responses indicate significant potential for improving the quality of the aquatic environment by restoring riparian forest. The effects are more substantial in single-stressor environments but remain significant in multi-stressor environments.

  2. Accumulation of americium-241 in the biomass of aquatic plants of the Yenisei river: experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Zotina, T.A.; Bolsunovsky, A.Y.A.; Bondareva, L.G. [Institute of Biophysics SB RAS, Akademgorodok, Krasnoyarsk (Russian Federation)

    2004-07-01

    Due to the operation of the Mining-and-Chemical Combine (Krasnoyarsk-26), which has been manufacturing weapons-grade plutonium for several decades, the Yenisei River is contaminated with transuranic elements (including {sup 241}Am). {sup 241}Am was found in the riverside soil, sediment and in the biomass of aquatic plants (Bolsunovsky et al., 1999, 2002). Aquatic plants are an important link in the migration of radionuclides in an aquatic ecosystem. In laboratory experiments, we investigated accumulation of {sup 241}Am by the submerged macrophyte from the Yenisei River: the pond weed (Elodea canadensis) and the aquatic moss (Fontinalis antipyretica), and release of {sup 241}Am from the biomass. The content of {sup 241}Am was measured on a Canberra (USA) gamma-spectrometer. The experiments showed that specific accumulation and concentration factors of {sup 241}Am in the plants were in inverse proportion to their biomass. We obtained new data on release of {sup 241}Am from the biomass of macrophyte. Americium-241 was more firmly fixed in the biomass of the aquatic moss. In 12 months, the biomass of the aquatic moss released about 30% of the initial americium activity into the water. To compare, the biomass of the pond weed released into the water medium up to 64% of the initial {sup 241}Am activity in 1.5 4 months. The release rate was dependent on the decomposition rate of the plant biomass. The experiments showed that submerged macrophyte of the Yenisei River can accumulate considerable activities of {sup 241}Am and retain americium for long periods of time in biomass. (author)

  3. Accumulation of americium-241 in the biomass of aquatic plants of the Yenisei river: experimental study

    International Nuclear Information System (INIS)

    Zotina, T.A.; Bolsunovsky, A.Y.A.; Bondareva, L.G.

    2004-01-01

    Due to the operation of the Mining-and-Chemical Combine (Krasnoyarsk-26), which has been manufacturing weapons-grade plutonium for several decades, the Yenisei River is contaminated with transuranic elements (including 241 Am). 241 Am was found in the riverside soil, sediment and in the biomass of aquatic plants (Bolsunovsky et al., 1999, 2002). Aquatic plants are an important link in the migration of radionuclides in an aquatic ecosystem. In laboratory experiments, we investigated accumulation of 241 Am by the submerged macrophyte from the Yenisei River: the pond weed (Elodea canadensis) and the aquatic moss (Fontinalis antipyretica), and release of 241 Am from the biomass. The content of 241 Am was measured on a Canberra (USA) gamma-spectrometer. The experiments showed that specific accumulation and concentration factors of 241 Am in the plants were in inverse proportion to their biomass. We obtained new data on release of 241 Am from the biomass of macrophyte. Americium-241 was more firmly fixed in the biomass of the aquatic moss. In 12 months, the biomass of the aquatic moss released about 30% of the initial americium activity into the water. To compare, the biomass of the pond weed released into the water medium up to 64% of the initial 241 Am activity in 1.5 4 months. The release rate was dependent on the decomposition rate of the plant biomass. The experiments showed that submerged macrophyte of the Yenisei River can accumulate considerable activities of 241 Am and retain americium for long periods of time in biomass. (author)

  4. Global distribution of dissolved organic matter along the aquatic continuum: Across rivers, lakes and oceans.

    Science.gov (United States)

    Massicotte, Philippe; Asmala, Eero; Stedmon, Colin; Markager, Stiig

    2017-12-31

    Based on an extensive literature survey containing more than 12,000 paired measurements of dissolved organic carbon (DOC) concentrations and absorption of chromophoric dissolved organic matter (CDOM) distributed over four continents and seven oceans, we described the global distribution and transformation of dissolved organic matter (DOM) along the aquatic continuum across rivers and lakes to oceans. A strong log-linear relationship (R 2 =0.92) between DOC concentration and CDOM absorption at 350nm was observed at a global scale, but was found to be ecosystem-dependent at local and regional scales. Our results reveal that as DOM is transported towards the oceans, the robustness of the observed relation decreases rapidly (R 2 from 0.94 to 0.44) indicating a gradual decoupling between DOC and CDOM. This likely reflects the decreased connectivity between the landscape and DOM along the aquatic continuum. To support this hypothesis, we used the DOC-specific UV absorbance (SUVA) to characterize the reactivity of the DOM pool which decreased from 4.9 to 1.7m 2 × gC -1 along the aquatic continuum. Across the continuum, a piecewise linear regression showed that the observed decrease of SUVA occurred more rapidly in freshwater ecosystems compared to marine water ecosystems, suggesting that the different degradation processes act preferentially on CDOM rather than carbon content. The observed change in the DOM characteristics along the aquatic continuum also suggests that the terrestrial DOM pool is gradually becoming less reactive, which has profound consequences on cycling of organic carbon in aquatic ecosystems. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Exploring, exploiting and evolving diversity of aquatic ecosystem models: a community perspective

    NARCIS (Netherlands)

    Janssen, A.B.G.; Gerla, D.J.

    2015-01-01

    Here, we present a community perspective on how to explore, exploit and evolve the diversity in aquatic ecosystem models. These models play an important role in understanding the functioning of aquatic ecosystems, filling in observation gaps and developing effective strategies for water quality

  6. Direct and terrestrial vegetation-mediated effects of environmental change on aquatic ecosystem processes

    Science.gov (United States)

    Becky A. Ball; John S. Kominoski; Heather E. Adams; Stuart E. Jones; Evan S. Kane; Terrance D. Loecke; Wendy M. Mahaney; Jason P. Martina; Chelse M. Prather; Todd M.P. Robinson; Christopher T. Solomon

    2010-01-01

    Global environmental changes have direct effects on aquatic ecosystems, as well as indirect effects through alterations of adjacent terrestrial ecosystem structure and functioning. For example, shifts in terrestrial vegetation communities resulting from global changes can affect the quantity and quality of water, organic matter, and nutrient inputs to aquatic...

  7. Assessment of variables controlling nitrate dynamics in groundwater: is it a threat to surface aquatic ecosystems?

    Science.gov (United States)

    Rasiah, V; Armour, J D; Cogle, A L

    2005-01-01

    The impact of fertilised cropping on nitrate-N dynamics in groundwater (GW) was assessed in a catchment from piezometers installed: (i) to different depths, (ii) in different soil types, (iii) on different positions on landscape, and (iv) compared with the Australian and New Zealand Environmental and Conservation Council guideline values provided for different aquatic ecosystems. The GW and NO(3)-N concentration dynamics were monitored in 39 piezometer wells, installed to 5-90 m depth, under fertilized sugarcane (Saccharum officinarum-S) in the Johnstone River Catchment, Australia, from 1999 January through September 2002. The median nitrate-N concentration ranged from 14 to 1511 microg L(-1), and the 80th percentile from 0 to 1341 microg L(-1). In 34 out of the 39 piezometer wells the 80th percentile or 80% of the nitrate-N values were higher than 30 microg L(-1), which is the maximum trigger value provided in the ANZECC table for sustainable health of different aquatic ecosystems. Nitrate-N concentration decreased with increasing well depth, increasing depth of water in wells, and with decreasing relief on landscape. Nitrate-N was higher in alluvial soil profiles than on those formed in-situ. Nitrate-N increased with increasing rainfall at the beginning of the rainy season, fluctuated during the peak rainy period, and then decreased when the rain ceased. The rapid decrease in GW after the rains ceased suggested potential existed for nitrate-N to be discharged as lateral-flow into streams. This may contribute towards the deterioration in the health of down-stream aquatic ecosystems.

  8. Remedial measures against high levels of radioisotopes in aquatic ecosystems

    International Nuclear Information System (INIS)

    Voitsekhovitch, O.; Haakanson, L.

    2000-01-01

    This Annex has been prepared within the framework of the Aquatic Working Group of the co-ordinated Research Programme on Validation of the Environmental Model Predictions (VAMP). The main objectives of this Annex are: (1) To provide an outline of a broad set of remedial measures and strategies tested and suggested for aquatic systems to speed up the recovery after the nuclear accident at Chernobyl in April 1986. This Report covers case studies from rivers and lakes and includes results from field and laboratory experiments, as well as measures directed at reducing radioisotopes in food by different food preparation procedures in the home. (2) To provide results from selected case studies, focusing on general, strategic results rather than site-specific details. (3) To provide conclusions which specifically address practical matters concerning how to select remedial measures in different situations, how to avoid inefficient measures, and to suggest important areas for future research. (4) To provide an analysis of the concept of lake sensitivity using both empirical and modelled data. One and the same fallout may give rise to very different radionuclide concentrations in water and biota depending on the characteristics of the lake and its catchment

  9. The Relative Influence of Aquatic and Terrestrial Processes on Methylmercury Transport in River Basins

    Science.gov (United States)

    Burns, D. A.; Bradley, P. M.; Marvin-DiPasquale, M. C.; Aiken, G.; Brigham, M. E.

    2012-12-01

    Conceptual understanding of the mercury (Hg) cycle in river basins is important for the development of improved Hg models that can inform Hg emissions policies, and, therefore, decrease the health risk that stems from widespread high Hg levels found in fresh water fish throughout the US and globally. Distinguishing the relative roles of aquatic and terrestrial ecosystems in Hg transport and transformation is fundamental to improved Hg risk management. The principal zones where Hg is transformed to its methyl form (MeHg), the transport of that MeHg to aquatic ecosystems, and subsequent bioaccumulation in aquatic food webs have been the focus of our investigations for more than 10 years in several small river basins across the US. Our data indicate that most MeHg in these rivers originates at the interface of the terrestrial and aquatic ecosystem in wetlands and riparian areas where anaerobic conditions and abundant organic matter favor methylation. Key factors in addition to methylation potential are those that influence the hydrologic transport of MeHg to adjacent streams and rivers such as hydraulic conductivity in the shallow subsurface and the depth of the water table in riparian areas. The presence and quality of organic matter in wetland soils and in water that moves through wetland areas also plays a pivotal role in MeHg source and transport. We discuss how these factors affect aquatic MeHg concentrations in light of a recently completed investigation of the Hg cycle in river basins in the Adirondack Mountains of New York and Coastal Plain of South Carolina. At each site, MeHg originates primarily in riparian wetland areas and is transported to the streams via shallow groundwater flow. The presence of open water bodies in these basins favors losses of MeHg by any of several processes, though smaller open water bodies may act as net MeHg sources. Ongoing work is building on this conceptualization of the Hg cycle through development of a model based on the

  10. Spatial and temporal effects of olive mill wastewaters to stream macroinvertebrates and aquatic ecosystems status.

    Science.gov (United States)

    Karaouzas, Ioannis; Skoulikidis, Nikolaos T; Giannakou, Urania; Albanis, Triantafyllos A

    2011-12-01

    Olive mill wastewater (OMW) is one of the major and most challenging organic pollutants in olive oil production countries. However, the knowledge about the in-situ effects of olive mill wastewaters to lotic ecosystems and their benthic organisms is very limited. To resolve this, eight sampling sites were selected upstream and downstream the outflow of several olive mills to assess the spatial and temporal effects of OMW to stream macroinvertebrates and to ecological status of stream ecosystems. Biotic (macroinvertebrates) and abiotic (physicochemical, hydromorphological) data were monitored for two years thus following the biennial cycle of olive growth and production and hydrological variation (drought-wet years). The results of this study revealed the spatial and temporal structural deterioration of the aquatic community due to OMW pollution with consequent reduction of the river capacity for reducing the effects of polluting substances through internal mechanisms of self-purification. OMW, even highly diluted, had dramatic impacts on the aquatic fauna and to the ecological status of the receiving stream ecosystems. The organic load of the wastewater expressed as BOD(5), COD and TSS, substrate contamination (sewage bacteria) and distance from the mill outlet, were the most important factors affecting macroinvertebrate assemblages while the typology (i.e. slope, altitude) and hydrology of the stream site (i.e. mountainous-lowland) and the intensity and volume of the wastewater were the most important determinants of self-purification processes. As OMW are usually being discharged in small size streams that are not considered in the Water Framework Directive 2000/60/EC, there is a need for including such systems into monitoring and assessment schemes as they may significantly contribute to the pollution load of the river basin. Furthermore, guidelines to manage these wastes through technologies that minimise their environmental impact and lead to a sustainable use

  11. Landscape level influence: aquatic primary production in the Colorado River of Glen and Grand canyons

    Science.gov (United States)

    Yard, M. D.; Kennedy, T.; Yackulic, C. B.; Bennett, G. E.

    2012-12-01

    Irregular features common to canyon-bound regions intercept solar incidence (photosynthetic photon flux density [PPFD: μmol m-2 s-1]) and can affect ecosystem energetics. The Colorado River in Grand Canyon is topographically complex, typical of most streams and rivers in the arid southwest. Dam-regulated systems like the Colorado River have reduced sediment loads, and consequently increased water transparency relative to unimpounded rivers; however, sediment supply from tributaries and flow regulation that affects erosion and subsequent sediment transport, interact to create spatial and temporal variation in optical conditions in this river network. Solar incidence and suspended sediment loads regulate the amount of underwater light available for aquatic photosynthesis in this regulated river. Since light availability is depth dependent (Beer's law), benthic algae is often exposed to varying levels of desiccation or reduced light conditions due to daily flow regulation, additional factors that further constrain aquatic primary production. Considerable evidence suggests that the Colorado River food web is now energetically dependent on autotrophic production, an unusual condition since large river foodwebs are typically supported by allochthonous carbon synthesized and transported from terrestrial environments. We developed a mechanistic model to account for these regulating factors to predict how primary production might be affected by observed and alternative flow regimes proposed as part of ongoing adaptive management experimentation. Inputs to our model include empirical data (suspended sediment and temperature), and predictive relationships: 1) solar incidence reaching the water surface (topographic complexity), 2) suspended sediment-light extinction relationships (optical properties), 3) unsteady flow routing model (stage-depth relationship), 4) channel morphology (photosynthetic area), and 5) photosynthetic-irradiant response for dominant algae (Cladophora

  12. Diets and abundances of aquatic and semi-aquatic reptiles in the Alligator Rivers Region

    International Nuclear Information System (INIS)

    Shine, R.

    1986-01-01

    The mining and milling of uranium in the Alligator River Region in the Northern Territory has raised the possibility that heavy metals and radionuclides might escape into the aquatic system and be accumulated by the reptilian fauna. Aquatic and semi-aquatic reptiles are regularly eaten by Aboriginal people of the region, and data on diets and reproduction of these species, as well as on their dispersion and abundance, are essential before the possibility that reptiles might act as pathways for these contaminants to Aboriginals can be assessed. The objectives of this study were to provide quantitative data on the diets of filesnakes, sand goannas and water goannas, to provide information on seasonal changes in their abundance and distribution within the Magela Creek system; and to describe their reproductive cycles

  13. Macroinvertebrate distribution and aquatic ecology in the Ruoergai (Zoige) Wetland, the Yellow River source region

    Science.gov (United States)

    Zhao, Na; Xu, Mengzhen; Li, Zhiwei; Wang, Zhaoyin; Zhou, Hanmi

    2017-09-01

    The Ruoergai (Zoige) Wetland, the largest plateau peatland in the world, is located in the Yellow River source region. The discharge of the Yellow River increases greatly after flowing through the Ruoergai Wetland. The aquatic ecosystem of the Ruoergai Wetland is crucial to the whole Yellow River basin. The Ruoergai wetland has three main kinds of water bodies: rivers, oxbow lakes, and marsh wetlands. In this study, macroinvertebrates were used as indicators to assess the aquatic ecological status because their assemblage structures indicate long-term changes in environments with high sensitivity. Field investigations were conducted in July, 2012 and in July, 2013. A total of 72 taxa of macroinvertebrates belonging to 35 families and 67 genera were sampled and identified. Insecta was the dominant group in the Ruoergai Basin. The alpha diversity of macroinvertebrates at any single sampling site was low, while the alpha diversity on a basin-wide scale was much higher. Macroinvertebrate assemblages in rivers, oxbow lakes, and marsh wetlands differ markedly. Hydrological connectivity was a primary factor causing the variance of the bio-community. The river channels had the highest alpha diversity of macroinvertebrates, followed by marsh wetlands and oxbow lakes. The density and biomass of Gastropoda, collector filterers, and scrapers increased from rivers to oxbow lakes and then to marsh wetlands. The river ecology was particular in the Ruoergai Wetland with the high beta diversity of macroinvertebrates, the low alpha diversity of macroinvertebrates, and the low taxa richness, density, and biomass of EPT (Ephemeroptera, Plecoptera, Trichoptera). To maintain high alpha diversity of macroinvertebrates macroinvertebrates in the Ruoergai Wetland, moderate connectivity of oxbow lakes and marsh wetlands with rivers and measures to control headwater erosion are both crucial.

  14. Effects of potash mining on river ecosystems: An experimental study.

    Science.gov (United States)

    Cañedo-Argüelles, Miguel; Brucet, Sandra; Carrasco, Sergi; Flor-Arnau, Núria; Ordeix, Marc; Ponsá, Sergio; Coring, Eckhard

    2017-05-01

    In spite of being a widespread activity causing the salinization of rivers worldwide, the impact of potash mining on river ecosystems is poorly understood. Here we used a mesocosm approach to test the effects of a salt effluent coming from a potash mine on algal and aquatic invertebrate communities at different concentrations and release modes (i.e. press versus pulse releases). Algal biomass was higher in salt treatments than in control (i.e. river water), with an increase in salt-tolerant diatom species. Salt addition had an effect on invertebrate community composition that was mainly related with changes in the abundance of certain taxa. Short (i.e. 48 h long) salt pulses had no significant effect on the algal and invertebrate communities. The biotic indices showed a weak response to treatment, with only the treatment with the highest salt concentration causing a consistent (i.e. according to all indices) reduction in the ecological quality of the streams and only by the end of the study. Overall, the treatment's effects were time-dependent, being more clear by the end of the study. Our results suggest that potash mining has the potential to significantly alter biological communities of surrounding rivers and streams, and that specific biotic indices to detect salt pollution should be developed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. The natural sediment regime in rivers: broadening the foundation for ecosystem management

    Science.gov (United States)

    Wohl, Ellen E.; Bledsoe, Brian P.; Jacobson, Robert B.; Poff, N. LeRoy; Rathburn, Sara L.; Walters, David M.; Wilcox, Andrew C.

    2015-01-01

    Water and sediment inputs are fundamental drivers of river ecosystems, but river management tends to emphasize flow regime at the expense of sediment regime. In an effort to frame a more inclusive paradigm for river management, we discuss sediment inputs, transport, and storage within river systems; interactions among water, sediment, and valley context; and the need to broaden the natural flow regime concept. Explicitly incorporating sediment is challenging, because sediment is supplied, transported, and stored by nonlinear and episodic processes operating at different temporal and spatial scales than water and because sediment regimes have been highly altered by humans. Nevertheless, managing for a desired balance between sediment supply and transport capacity is not only tractable, given current geomorphic process knowledge, but also essential because of the importance of sediment regimes to aquatic and riparian ecosystems, the physical template of which depends on sediment-driven river structure and function.

  16. Aquatic Ecosystem Enhancement at Mountaintop Mining Sites Symposium

    Energy Technology Data Exchange (ETDEWEB)

    Black, D. Courtney; Lawson, Peter; Morgan, John; Maggard, Randy; Schor, Horst; Powell, Rocky; Kirk, Ed. J.

    2000-01-12

    Welcome to this symposium which is part of the ongoing effort to prepare an Environmental Impact Statement (EIS) regarding mountaintop mining and valley fills. The EIS is being prepared by the U.S. Environmental Protection Agency, U.S. Army Corps of Engineers, U.S. Office of Surface Mining, and U.S. Fish and Wildlife Service, in cooperation with the State of West Virginia. Aquatic Ecosystem Enhancement (AEE) at mountaintop mining sites is one of fourteen technical areas identified for study by the EIS Interagency Steering Committee. Three goals were identified in the AEE Work Plan: 1. Assess mining and reclamation practices to show how mining operations might be carried out in a way that minimizes adverse impacts to streams and other environmental resources and to local communities. Clarify economic and technical constraints and benefits. 2. Help citizens clarify choices by showing whether there are affordable ways to enhance existing mining, reclamation, mitigation processes and/or procedures. 3. Ide identify data needed to improve environmental evaluation and design of mining projects to protect the environment. Today’s symposium was proposed in the AEE Team Work Plans but coordinated planning for the event began September 15, 1999 when representatives from coal industry, environmental groups and government regulators met in Morgantown. The meeting participants worked with a facilitator from the Canaan Valley Institute to outline plans for the symposium. Several teams were formed to carry out the plans we outlined in the meeting.

  17. Bioavailability of radionuclides and dose rate in aquatic ecosystems within the Chernobyl accident exclusion zone

    International Nuclear Information System (INIS)

    Gudkov, Dmitri; Nazarov, Alexandr

    2008-01-01

    Full text: Our studies were carried out during 1997-2007 within Krasnensky flood-lands on the left bank of the Pripyat River, which is the most contaminated region of the Ukrainian part of the Chernobyl accident exclusion zone. During 1991-1993 the complex of hydraulic engineering structures as flood protection dams was constructed within the Krasnensky flood-lands, which preventing washing away of radioactive substances from soils and changing a hydrological mode of flood plain flows during a high water. In its turn it was by the reason of strengthening of over-moistening and swamping processes within embankment territories. As a result - on a background of the common tendencies of increase of the mobile forms of 90 Sr in soils of catchment territories and bottom sediments of the exclusion zone, there is an increase of humic acids concentrations in waterlogged soils of Krasnensky flood-lands. It is also raises the content of the water-soluble forms of 90 Sr forming with acids the soluble complexes. Thus the increase of concentrations of the mobile radionuclide forms and their inclusion into biotic circulation of aquatic ecosystems is observed. It confirms also an increase of 90 Sr specific activity in water of lakes within Krasnensky flood-lands, against a background of stabilisation of this parameter for 137 Cs last years. Such dynamics of 90 Sr and 137 Cs contents is significantly reflected on dose rate for hydrobionts due to incorporated radionuclides. However if in running water bodies the decrease of radionuclide contents defines, accordingly, and the decrease of dose rates, in lakes of the left-bank flood-lands of the Pripyat River the situation has an absolutely other character. At rather stable internal absorbed dose rate, caused by 137 Cs during 1993-2007, the dose, caused by the 90 Sr content, has grown more than in 20 times for some species of higher aquatic plants and fish in comparison with the beginning of 1990-s. As a result the total internal dose

  18. Experimental study and modelization of radium transfer in a simplified aquatic ecosystem

    International Nuclear Information System (INIS)

    Bruno, V.

    1990-11-01

    Radium transfer has been studied in an experimental aquatic ecosystem composed by four trophic levels. Water and sediment are the two abiotic units from which the other compartments could be contamined. Scenedesmus obliquus represents the primary producer. Daphnia magna, Gammarus pulex and Chironomus sp., the first order consumers; Cyprinius carpio, the second order consumer and Salmo gairdneri, the third order one. Each transfer is described by a mathematical equation, based on a theoretical analysis, which represents concentration evolution of each compartment as a function of time. From the experimental data, we suggest a mathematical model in order to simulate radium contamination of the ecosystem. This model takes into account the following parameters: the contamination mode (chronic or acute pollution), the type of ecosystem concerned by the contamination (pond or river), and the season during which the pollution occurred. Results obtained with the model agree with most of field data on contamination level of fish living in the mining complex environment; particularly, they put the emphasize on the trophic way for the fish radiocontamination [fr

  19. Expert evaluation and prediction of the radioecological state of the environment in the area of the radiation plume from the Chernobyl' nuclear power station (aquatic ecosystems)

    International Nuclear Information System (INIS)

    1986-01-01

    On the basis of experimental data on radionuclide distribution in the components of the aquatic ecosystems within and outside the 30 km zone around the Chernobyl power plant after the reactor accident the exposure doses for aquatic organisms in the area of the radiation plume have been estimated. In the Kiev reservoir the predicted exposure doses for most aquatic organisms do not exceed 0.1-1.0 mrad/h, in the river Pripyat' the exposure doses for fish are about 50 mrad/h and in the cooling pond of the Chernobyl power station the highest exposure doses, up to 5 rad/h in a number of locations were registered

  20. Effects of solar UV-B radiation on aquatic ecosystems

    Science.gov (United States)

    Häder, D.-P.

    Solar UV degrades dissolved organic carbon photolytically so that they can readily be taken up by bacterioplankton. On the other hand solar UV radiation inhibits bacterioplankton activity. Bacterioplankton productivity is far greater than previously thought and is comparable to phytoplankton primary productivity. According to the "microbial loop hypothesis," bacterioplankton is seen in the center of a food web, having a similar function to phytoplankton and protists. The penetration of UV and PAR into the water column can be measured. Marine waters show large temporal and regional differences in their concentrations of dissolved and particulate absorbing substances. A network of dosimeters (ELDONET) has been installed in Europe ranging from Abisko in Northern Sweden to Gran Canaria. Cyanobacteria are capable of fixing atmospheric nitrogen which is then made available to higher plants. The agricultural potential of cyanobacteria has been recognized as a biological fertilizer for wet soils such as in rice paddies. UV-B is known to impair processes such as growth, survival, pigmentation, motility, as well as the enzymes of nitrogen metabolism and CO 2 fixation. The marine phytoplankton represents the single most important ecosystem on our planet and produces about the same biomass as all terrestrial ecosystems taken together. It is the base of the aquatic food chain and any changes in the size and composition of phytoplankton communities will directly affect food production for humans from marine sources. Another important role of marine phytoplankton is to serve as a sink for atmospheric carbon dioxide. Recent investigations have shown a large sensitivity of most phytoplankton organisms toward solar short-wavelength ultraviolet radiation (UV-B); even at ambient levels of UV-B radiation many organisms seem to be under UV stress. Because of their requirement for solar energy, the phytoplankton dwell in the top layers of the water column. In this near-surface position

  1. Biotic Drivers of Spatial Heterogeneity and Implications for River Ecosystems

    Science.gov (United States)

    Wohl, Ellen

    2017-04-01

    Rivers throughout the northern hemisphere have been simplified and homogenized by the removal of beavers and instream wood, along with numerous forms of channel engineering and flow regulation. Loss of spatial heterogeneity in river corridors - channels and floodplains - affects downstream fluxes of water, sediment, organic matter, and nutrients, as well as stream metabolism, biomass, and biodiversity. Recent work in streams of the Colorado Rocky Mountains illustrates how the presence of beavers and instream wood can facilitate spatial heterogeneity by creating stable, persistent, multithread channel planform and high channel-floodplain and channel-hyporheic zone connectivity. This spatial heterogeneity facilitates retention of water in pools, floodplain wetlands, and hyporheic storage. Suspended sediment, particulate organic matter (POM), and solutes are also more likely to be retained in these stream segments than in more uniform stream segments with greater downstream conveyance. Retention of POM and solutes equates to greater volumes of organic carbon storage per unit valley length and greater rates of nitrogen uptake. Spatially heterogeneous stream segments also exhibit greater biomass and biodiversity of aquatic macroinvertebrates, salmonid fish, and riparian spiders than do more uniform stream segments. These significant differences in stream form and function are unlikely to be unique to this field area and can provide a conceptual model for understanding and restoring ecosystem functions in other rivers.

  2. Determining the Effectiveness of Aquatic Ecosystem Restoration, Conservation, and Management Practices.

    Science.gov (United States)

    The science of aquatic ecosystem restoration and management is still in its infancy, largely because most projects are inadequately tracked and monitored for assessing their success. Historically, evaluating the effectiveness of best management practices (BMPs) has relied heavily...

  3. Ecosystem services in the St. Louis River AOC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Dataset indicates the presence or absence of each ecosystems service at each coordinate Location. Also included are depth, fetch, and aquatic vegetation data. See...

  4. Aquatic ecosystems within the Chernobyl NPP exclusion zone: radioactive contamination, doses and effects

    International Nuclear Information System (INIS)

    Gudkov, D.I.; Kuzmenko, M.I.; Krot, Y.G.; Kipnis, L.S.; Mardarevich, M.G.; Ponomaryov, A.V.; Derevets, V.V.; Nazarov, A.B.

    2003-01-01

    For past 17 years after accident the character of radioactive contamination of water objects within the Chernobyl NPP exclusion zone has undergone essential changes. First of all it connected with realisation on a wide area of deactivation works, and also with transformation of radioactive substances in water-soil systems. Besides, during 1991-95 the complex of hydraulic engineering structures as protection dams, interfering washing away of radioactive substances from soils of the left-bank catchment basin and changed a hydrological regime of these territories during a high water, was constructed. The levels of radionuclide contamination of water objects within the Chernobyl NPP exclusion zone was rather stabilised. Due to high water change rate the river bottom sediments have undergone decontamination processes (especially during floods and periods of high water) and over the years have ceased to play the essential role as a secondary source of water contamination. On the other hand, the closed reservoirs have considerably higher levels of radioactive contamination caused by limited water change and by relatively high concentration of radionuclides deposited in the bottom sediments. Therefore, for the majority of standing reservoirs the level of radionuclide content is determined mainly by the rates of mobile radionuclide forms exchange between bottom sediment and water, as well as by the external washout from the catchment basin. In this paper will be considered: (1) the latest data on radionuclide content (Sr-90, Cs-137, Pu-238, Pu-239+240 and Am-241) and dynamics in water, seston, bottom sediments and hydrobionts of different trophic levels and ecological groups; (2) the peculiarities of formation of vegetative communities from lakes within embankment territory of Pripyat River flood-lands and its impact on radionuclide redistribution in aquatic ecosystems; (3) the major hydrochemical factors, which determine the behaviour of radionuclides in the aquatic

  5. The effects of a pesticide mixture on aquatic ecosystems differing in trophic status: responses of the macrophyte Myriophyllum spicatum and the periphytic algal community

    NARCIS (Netherlands)

    Wendt-Rasch, L.; Brink, van den P.J.; Crum, S.J.H.; Woin, P.

    2004-01-01

    The effects of a pesticide mixture (asulam, fluazinam, lambda-cyhalothrin, and metamitron) on aquatic ecosystems were investigated in 20 outdoor aquatic microcosms. Ten of the microcosms simulated mesotrophic aquatic ecosystems dominated by submerged macrophytes (Elodea). The others simulated

  6. Fishes and aquatic habitats of the Orinoco River Basin: diversity and conservation.

    Science.gov (United States)

    Lasso, C A; Machado-Allison, A; Taphorn, D C

    2016-07-01

    About 1000 freshwater fishes have been found so far in the Orinoco River Basin of Venezuela and Colombia. This high ichthyological diversity reflects the wide range of landscapes and aquatic ecosystems included in the basin. Mountain streams descend from the high Andes to become rapid-flowing foothill rivers that burst out upon vast savannah flatlands where they slowly make their way to the sea. These white-water rivers are heavily laden with sediments from the geologically young Andes. Because their sediment deposits have formed the richest soils of the basin, they have attracted the highest density of human populations, along with the greatest levels of deforestation, wildfires, agricultural biocides and fertilizers, sewage and all the other impacts associated with urban centres, agriculture and cattle ranching. In the southern portion of the basin, human populations are much smaller, where often the only inhabitants are indigenous peoples. The ancient rocks and sands of the Guiana Shield yield clear and black water streams of very different quality. Here, sediment loads are miniscule, pH is very acid and fish biomass is only a fraction of that observed in the rich Andean tributaries to the north. For each region of the basin, the current state of knowledge about fish diversity is assessed, fish sampling density evaluated, the presence of endemic species and economically important species (for human consumption or ornamental purposes) described and gaps in knowledge are pointed out. Current trends in the fishery for human consumption are analysed, noting that stocks of many species are in steep decline, and that current fishing practices are not sustainable. Finally, the major impacts and threats faced by the fishes and aquatic ecosystems of the Orinoco River Basin are summarized, and the creation of bi-national commissions to promote standardized fishing laws in both countries is recommended. © 2016 The Fisheries Society of the British Isles.

  7. Current levels and trends of radioactive contamination of aquatic ecosystem components in the Chernobyl exclusion zone

    Energy Technology Data Exchange (ETDEWEB)

    Gudkov, Dmitri I.; Kaglyan, Alexander Ye.; Ganzha, Kristina D.; Klenus, Vasiliy G. [Institute of Hydrobiology, Geroyev Stalingrada Ave. 12, UA-04210 Kiev (Ukraine); Kireev, Sergey I.; Nazarov, Alexander B. [Chernobyl Specialized Enterprise, Radyanska Str. 70, UA-07270 Chernobyl (Ukraine)

    2014-07-01

    The current radiation level and its composition in aquatic ecosystems within the Chernobyl exclusion zone (ChEZ) are conditioned, above all things, by the amount of radioactive matters released as aerosols on a water surface and adjacent territories during the period of the active phase of the accident from destroyed of the Chernobyl NPP in 1986, and also by intensity and duration of the second processes of radionuclides washout from the catchment areas and hydrodynamic processes of their transport outside of water bodies. During last 10-15 years in the soils of the ChEZ the tendency of increase of yield of the mobile bioavailable forms of radionuclides, which released into hydrological systems with surface and ground waters or localized in the closed water systems, where quickly involving in the biotic cycle is marked. On the example of lakes of the Krasnensky flood plain of the Pripyat River, which is one of the most contaminated by radionuclides territory of the ChEZ, was determined that the basic amount of radionuclides in lake ecosystem is deposited in the bottom sediments: {sup 90}Sr - 89-95%, {sup 137}Cs - 99%, transuranium elements (TUE) {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am - almost 100% of the total radionuclide amount in ecosystem. The increased migration activity of {sup 90}Sr determines its more high quantity in water (4-10%) on comparison with {sup 137}Cs (0.5-0.6%) and TUE (0.03-0.04%) and, opposite, less - in seston (0.15-0.16%) on comparison with {sup 137}Cs (0.25-0.30%). The value of {sup 90}Sr in biotic component amounts 0.25-0.61%, {sup 137}Cs - 0.14-0.47% and TUE - 0.07-0.16% of the total quantity in ecosystem. The gradual decline of radionuclide specific activity is a dominant tendency in the dynamics of {sup 137}Cs and {sup 90}Sr in water and aquatic biota of the majority of reservoirs and water flow in the ChEZ. The exception is water bodies, located on the dammed territories of the Krasnensky flood plain, where at the proceeding

  8. Productivity, Disturbance and Ecosystem Size Have No Influence on Food Chain Length in Seasonally Connected Rivers

    OpenAIRE

    Warfe, Danielle M.; Jardine, Timothy D.; Pettit, Neil E.; Hamilton, Stephen K.; Pusey, Bradley J.; Bunn, Stuart E.; Davies, Peter M.; Douglas, Michael M.

    2013-01-01

    The food web is one of the oldest and most central organising concepts in ecology and for decades, food chain length has been hypothesised to be controlled by productivity, disturbance, and/or ecosystem size; each of which may be mediated by the functional trophic role of the top predator. We characterised aquatic food webs using carbon and nitrogen stable isotopes from 66 river and floodplain sites across the wet-dry tropics of northern Australia to determine the relative importance of produ...

  9. Recent aquatic ecosystem response to environmental events revealed from 210Pb sediment profiles

    International Nuclear Information System (INIS)

    Mulsow, S.; Piovano, E.; Cordoba, F.

    2009-01-01

    The 210 Pb dating method was first introduced by , and since then has been applied to study sediment from lakes, estuaries and coastal marine environments. Hundreds of studies around the world have used 210 Pb as a geochronological tool in aquatic ecosystems. However little attention has been paid to the potential of this naturally occurring isotope as an environmental tracer of ecological events. Here we report three instances in which 210 Pb profiles measured on undisturbed sediment cores from lakes, rivers and fjords show us the potential of 210 Pb profile as a tracer of natural and anthropogenic processes. The methodology used here is a suite of techniques combining biogeochemistry (micro-electrodes), paleomagnetism (susceptibility), sediment characteristics (LOI) and visualization (SPI and X-ray) applied to the interpretation of 210 Pb profiles. We measured 210 Pb profiles on sediments from a river, Cruces River (Chile), which recorded a clear shift in the water chemistry caused by a pulp mill effluent to the river. Here metal mobilization and remobilization of the tracer may be the cause of the observed profile. We also measured 210 Pb profiles in sediment from two fjords of Southern Chile (Pillan and Renihue), the sudden deposition change of fresh 210 Pb with depth observed could very well be the result of bioturbation but it occurred in a seafloor area deprived of bioturbators. In this case, 210 Pb recorded the onset of aquaculture activities (fish farming) that took place two decades ago. Finally, 210 Pb profiles measured in two lakes in the 'pampa Argentina': Epecuen and Venado showed a particular shape with depth. These profiles apparently registered a sudden depositional event with recent 210 Pb material, probably related to strong shifts in precipitation and drought cycles in that part of the world. These three examples show that 210 Pb profiles provide valuable information not only on geochronology, but also related to natural and anthropogenic short

  10. Ecology of anuran populations inhabiting thermally stressed aquatic ecosystems, with emphasis on larval Rana pipiens and Bufo terrestris

    International Nuclear Information System (INIS)

    Nelson, D.H.

    1974-01-01

    Field and laboratory studies were conducted to determine the responses of anuran populations to thermally stressed aquatic ecosystems. Adult and larval amphibians were sampled in and around a cool arm of a 67 ha reservoir that receives high temperature effluent from a nuclear production reactor on the Savannah River Plant (SRP) in South Carolina. Patterns for some species were compared with data from nearby unheated areas and analyzed in terms of the thermal gradient (16-45 C) extending the length of the reservoir's cool arm. The adaptation to breeding during nocturnal rainfall fortuitously confers a double advantage especially to anurans breeding in thermally stressed waters. (U.S.)

  11. Stimulation of microbial nitrogen cycling in aquatic ecosystems by benthic macrofauna: mechanisms and environmental implications

    Science.gov (United States)

    Stief, P.

    2013-12-01

    Invertebrate animals that live at the bottom of aquatic ecosystems (i.e., benthic macrofauna) are important mediators between nutrients in the water column and microbes in the benthos. The presence of benthic macrofauna stimulates microbial nutrient dynamics through different types of animal-microbe interactions, which potentially affect the trophic status of aquatic ecosystems. This review contrasts three types of animal-microbe interactions in the benthos of aquatic ecosystems: (i) ecosystem engineering, (ii) grazing, and (iii) symbiosis. Their specific contributions to the turnover of fixed nitrogen (mainly nitrate and ammonium) and the emission of the greenhouse gas nitrous oxide are evaluated. Published data indicate that ecosystem engineering by sediment-burrowing macrofauna stimulates benthic nitrification and denitrification, which together allows fixed nitrogen removal. However, the release of ammonium from sediments is enhanced more strongly than the sedimentary uptake of nitrate. Ecosystem engineering by reef-building macrofauna increases nitrogen retention and ammonium concentrations in shallow aquatic ecosystems, but allows organic nitrogen removal through harvesting. Grazing by macrofauna on benthic microbes apparently has small or neutral effects on nitrogen cycling. Animal-microbe symbioses provide abundant and distinct benthic compartments for a multitude of nitrogen-cycle pathways. Recent studies reveal that ecosystem engineering, grazing, and symbioses of benthic macrofauna significantly enhance nitrous oxide emission from shallow aquatic ecosystems. The beneficial effect of benthic macrofauna on fixed nitrogen removal through coupled nitrification-denitrification can thus be offset by the concurrent release of (i) ammonium that stimulates aquatic primary production and (ii) nitrous oxide that contributes to global warming. Overall, benthic macrofauna intensifies the coupling between benthos, pelagial, and atmosphere through enhanced turnover and

  12. The effect of radioactive contamination of the Yenisei river on cytogenetic characteristics of aquatic plants

    Energy Technology Data Exchange (ETDEWEB)

    Bolsunovsky, A.; Medvedeva, M. [Institute of Biophysics SB Russian Academy of Sciences (Russian Federation); Muratova, E. [Institute of Forest SB Russian Academy of Sciences (Russian Federation)

    2014-07-01

    The Yenisei River, one of the world's largest rivers, is contaminated with artificial radionuclides released by one of the Russian facilities producing weapons-grade plutonium (the Mining-and-Chemical Combine, MCC), which has been in operation for many years. Aquatic plants are an important component of water ecosystems, which can accumulate high levels of radionuclides and, thus, can be used in bio-monitoring and bioremediation. The purpose of the study was to assess levels of radionuclides and to evaluate the frequency of chromosomal aberrations in samples of submerged plants collected in different parts of the Yenisei River. The following species were studied: Fontinalis antipyretica, Batrachium kauffmanii, Myriophyllum spicatum, Elodea canadensis, Ceratophyllum demersum and various Potamogeton species. Samples were collected at positions in the vicinity of the MCC discharge point, at a distance of 330 km downstream of Krasnoyarsk, and upstream of the MCC, during sampling campaigns in 2003-2012. Detailed analysis of radioactive contamination of aquatic plants of the Yenisei River revealed large-scale contamination of aquatic plants as far as 250 km downstream of the MCC. Before the last MCC reactor was shut down in 2010, about 30 radionuclides, including uranium and transuranium elements, were detected in the biomass of aquatic plants. The highest concentration factors of the major radionuclides were obtained for Fontinalis antipyretica and Potamogeton lucens. Samples of the plants collected after the shutdown of the reactor contained considerably lower activity levels of artificial radionuclides, and their diversity was significantly decreased. Results of cytogenetic investigations of aquatic plants collected when the reactor was still operating (2003-2009) suggest that at the MCC discharge site and downstream the occurrence of chromosomal aberrations in ana-telophase and metaphase cells of the plants was considerably higher (up to 30%) than in the control

  13. Bioaccumulation of 210Pb in the Kaveri River ecosystem, India

    International Nuclear Information System (INIS)

    Hameed, P.S.; Shaheed, K.; Somasundaram, S.S.N.; Iyengar, M.A.R.

    1997-01-01

    Data on the concentrations of 210 Pb in water, sediment and biota (plankton, weed, snail, bivalve, prawn and fish) of the Kaveri River ecosystem at Tiruchirappalli in South India are presented. The highest level of 210 Pb activity was observed in the sediment (15.5 Bq kg -1 dry) and the lowest activity in water (2.7 mBq l -1 ). The root of the aquatic weed, Eichhornia crassipes, showed a higher activity (1.17 Bq kg -1 wet) than its shoot (0.22 Bq kg -1 wet). Among the biotic components, the shells and bones of animals accumulated higher 210 Pb than their tissues and muscle. Among animals, the freshwater mussel, Lamellidens marginalis was identified to accumulate more 210 Pb in its soft tissues (0.79 Bq kg -1 wet) and shell (6.55 Bq kg -1 wet) than prawns (muscle 0.65 Bq kg -1 wet; exoskeleton: 1.06 Bq kg -1 ) wet and fish (muscle: 0.24 Bq kg -1 wet; bone: 1.37 Bq kg -1 wet). The concentration factors (CFs) of 210 Pb in biotic components ranged from ∼ 10 1 to ∼ 10 3 with higher CFs observed for shells and bones. It is shown that 210 Pb undergoes a seasonal variation in surface deposition with minimum values in summer and maximum values in winter. The significance of the results of 210 Pb in the abiotic and biotic environment of Kaveri River is discussed. (Author)

  14. Stimulation of microbial nitrogen cycling in aquatic ecosystems by benthic macrofauna: mechanisms and environmental implications

    DEFF Research Database (Denmark)

    Stief, P.

    2013-01-01

    (mainly nitrate and ammonium) and the emission of the greenhouse gas nitrous oxide are evaluated. Published data indicate that ecosystem engineering by sediment-burrowing macrofauna stimulates benthic nitrification and denitrification, which together allows fixed nitrogen removal. However, the release...... enhance nitrous oxide emission from shallow aquatic ecosystems. The beneficial effect of benthic macrofauna on fixed nitrogen removal through coupled nitrification-denitrification can thus be offset by the concurrent release of (i) ammonium that stimulates aquatic primary production and (ii) nitrous oxide...... of ammonium from sediments is enhanced more strongly than the sedimentary uptake of nitrate. Ecosystem engineering by reef-building macrofauna increases nitrogen retention and ammonium concentrations in shallow aquatic ecosystems, but allows organic nitrogen removal through harvesting. Grazing by macrofauna...

  15. Biogeochemical features of aquatic plants in the Selenga River delta

    Science.gov (United States)

    Shinkareva, Galina; Lychagin, Mikhail

    2014-05-01

    The Selenga River system provides more than a half of the Lake Baikal total inflow. The river collects a significant amount of pollutants (e.g. heavy metals) from the whole basin. These substances are partially deposited within the Selenga delta, and partially are transported further to the lake. A generous amount of aquatic plants grow in the delta area according to its favorable conditions. This vegetation works as a specific biofilter. It accumulates suspended particles and sorbs some heavy metals from the water. The study aimed to reveal the species of macrophytes which could be mostly important for biomonitoring according to their chemical composition. The field campaign took place in the Selenga River delta in July-August of 2011 (high water period) and in June of 2012 (low water period). 14 species of aquatic plants were collected: water starwort Callitriche hermaphroditica, small yellow pond lily Nuphar pumila, pondweeds Potamogeton crispus, P. pectinatus, P. friesii, broadleaf cattail Typha latifolia, hornwort or coontail Ceratophyllum demersum, arrowhead Sagittaria natans, flowering rush (or grass rush) Butomus umbellatus, reed Phragmites australis, parrot's feather Myriophyllum spicatum, the common mare's tail Hippuris vulgaris, Batrachium trichophyllum, canadian waterweed Elodea canadensis. The samples were dried, grinded up and digested in a mixture of HNO3 and H2O2. The chemical composition of the plant material was defined using ICP-MS and ICP-AES methods. Concentrations of Fe, Mn, Cr, Ni, Cu, B, Zn, V, Co, As, Mo, Pb, and U were considered. The study revealed that Potamogeton pectinatus and Myriophyllum spicatum concentrate elements during both high and low water periods. Conversely the Butomus umbellatus and Phragmites australis contain small amount of heavy metals. The reed as true grasses usually accumulates fewer amounts of elements than other macrophytes. To compare biogeochemical specialization of different species we suggest to use

  16. The impacts of past climate change on terrestrial and aquatic ecosystems

    International Nuclear Information System (INIS)

    Bradshaw, R.H.W.; Anderson, N.J.

    2001-01-01

    The last two million years of global history have been dominated by the impacts of rapid climate change. This influence is not immediately obvious to most biologists whose observations rarely extend beyond a period of a few years, but becomes apparent when interpreting long-term data sets whether they be population studies or palaeoecological data. It is appropriate therefore to consider how terrestrial and aquatic ecosystems have responded to climate change during the Quaternary when speculating about response to future climatic developments. In this chapter we discuss and illustrate the complex interactions between climate and anthropogenic influence on terrestrial and aquatic ecosystems during the Holocene. Climate influences ecosystems both directly (e.g. physiological responses or lake thermal stratification) and indirectly (e.g. via fire frequency or catchment hydrology). Lake sediments can be used to study both past climatic change directly and the effects of past climatic variability. In this chapter we present summary examples of the influence of past climate change on terrestrial and aquatic ecosystems as well showing how lake sediment records can provide proxy records of past climate change. The geological record from the last 18 000 years documents large changes in terrestrial and aquatic ecosystems that are primarily driven by climatic change, but are modified by internal ecosystem processes. These changes are comparable in magnitude and rapidity to those predicted for the near future. Species at their distributional limits are particularly sensitive to climate change and contractions of range can be sudden in response to extreme climatic events such as the storm of December 1999 that damaged Picea trees far more than tree species that lay within their natural range limits. Palaeoecological records provide compelling evidence for direct climate forcing of aquatic and terrestrial ecosystems but importantly also permit comparative analyses of impacts

  17. The feasibility of automated online flow cytometry for in-situ monitoring of microbial dynamics in aquatic ecosystems

    Science.gov (United States)

    Besmer, Michael D.; Weissbrodt, David G.; Kratochvil, Bradley E.; Sigrist, Jürg A.; Weyland, Mathias S.; Hammes, Frederik

    2014-01-01

    Fluorescent staining coupled with flow cytometry (FCM) is often used for the monitoring, quantification and characterization of bacteria in engineered and environmental aquatic ecosystems including seawater, freshwater, drinking water, wastewater, and industrial bioreactors. However, infrequent grab sampling hampers accurate characterization and subsequent understanding of microbial dynamics in all of these ecosystems. A logic technological progression is high throughput and full automation of the sampling, staining, measurement, and data analysis steps. Here we assess the feasibility and applicability of automated FCM by means of actual data sets produced with prototype instrumentation. As proof-of-concept we demonstrate examples of microbial dynamics in (i) flowing tap water from a municipal drinking water supply network and (ii) river water from a small creek subject to two rainfall events. In both cases, automated measurements were done at 15-min intervals during 12–14 consecutive days, yielding more than 1000 individual data points for each ecosystem. The extensive data sets derived from the automated measurements allowed for the establishment of baseline data for each ecosystem, as well as for the recognition of daily variations and specific events that would most likely be missed (or miss-characterized) by infrequent sampling. In addition, the online FCM data from the river water was combined and correlated with online measurements of abiotic parameters, showing considerable potential for a better understanding of cause-and-effect relationships in aquatic ecosystems. Although several challenges remain, the successful operation of an automated online FCM system and the basic interpretation of the resulting data sets represent a breakthrough toward the eventual establishment of fully automated online microbiological monitoring technologies. PMID:24917858

  18. Effects of water scarcity and chemical pollution in aquatic ecosystems: State of the art.

    Science.gov (United States)

    Arenas-Sánchez, Alba; Rico, Andreu; Vighi, Marco

    2016-12-01

    Water scarcity is an expanding climate and human related condition, which drives and interacts with other stressors in freshwater ecosystems such as chemical pollution. In this study we provide an overview of the existing knowledge regarding the chemical fate, biological dynamics and the ecological risks of chemicals under water scarcity conditions. We evaluated a total of 15 studies dealing with the combined effects of chemicals and water scarcity under laboratory conditions and in the field. The results of these studies have been elaborated in order to evaluate additive, synergistic or antagonistic responses of the studied endpoints. As a general rule, it can be concluded that, in situations of water scarcity, the impacts of extreme water fluctuations are much more relevant than those of an additional chemical stressor. Nevertheless, the presence of chemical pollution may result in exacerbated ecological risks in some particular cases. We conclude that further investigations on this topic would take advantage on the focus on some specific issues. Experimental (laboratory and model ecosystem) studies should be performed on different biota groups and life stages (diapausing eggs, immature stages), with particular attention to those including traits relevant for the adaptation to water scarcity. More knowledge on species adaptations and recovery capacity is essential to predict community responses to multiple stressors and to assess the community vulnerability. Field studies should be performed at different scales, particularly in lotic systems, in order to integrate different functional dynamics of the river ecosystem. Combining field monitoring and experimental studies would be the best option to reach more conclusive, causal relationships on the effects of co-occurring stressors. Contribution of these studies to develop ecological models and scenarios is also suggested as an improvement for the prospective aquatic risk assessment of chemicals in (semi-)arid areas

  19. Mercury bioaccumulation along food webs in temperate aquatic ecosystems colonized by aquatic macrophytes in south western France.

    Science.gov (United States)

    Gentès, Sophie; Maury-Brachet, Régine; Guyoneaud, Rémy; Monperrus, Mathilde; André, Jean-Marc; Davail, Stéphane; Legeay, Alexia

    2013-05-01

    Mercury (Hg) is considered as an important pollutant for aquatic systems as its organic form, methylmercury (MeHg), is easily bioaccumulated and bioamplified along food webs. In various ecosystems, aquatic periphyton associated with macrophyte was identified as an important place for Hg storage and methylation by microorganisms. Our study concerns temperate aquatic ecosystems (South Western France) colonized by invasive macrophytes and characterized by high mercury methylation potentials. This work establishes original data concerning Hg bioaccumulation in organisms (plants, crustaceans, molluscs and fish) from five contrasting ecosystems. For low trophic level species, total Hg (THg) concentrations were low (from 27±2ngTHgg(-1)dw in asiatic clam Corbicula fluminea to 418±114ngTHgg(-1)dw in crayfish Procambarus clarkii). THg concentrations in some carnivorous fish (high trophic level) were close to or exceeded the International Marketing Level (IML) with values ranging from 1049±220ngTHgg(-1)dw in pike perch muscle (Sander lucioperca) to 3910±1307ngTHgg(-1)dw in eel muscle (Anguilla Anguilla). Trophic levels for the individuals were also evaluated through stable isotope analysis, and linked to Hg concentrations of organisms. A significant Hg biomagnification (r(2)= 0.9) was observed in the Aureilhan lake, despite the absence of top predator fish. For this site, Ludwigia sp. periphyton, as an entry point of Hg into food webs, is a serious hypothesis which remains to be confirmed. This study provides a first investigation of Hg transfer in the ecosystems of south western France and allows the assessment of the risk associated with the presence of Hg in aquatic food webs. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Mapping ecosystem services in the St. Louis River Estuary

    Science.gov (United States)

    Sustainable management of ecosystems for the perpetual flow of services beneficial to human communities requires reliable data about from where in the ecosystem services flow. Our objective is to map ecosystem services in the St. Louis River with the overarching U.S. EPA goal of ...

  1. Mapping ecosystem services in the St. Louis River estuary (presentation)

    Science.gov (United States)

    Management of ecosystems for sustainable provision of services beneficial to human communities requires reliable data about from where in the ecosystem services flow. Our objective is to map ecosystem services in the St. Louis River with the overarching EPA goal of community sust...

  2. Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems

    Science.gov (United States)

    Vonk, J.E.; Tank, S.E.; Bowden, W.B.; Laurion, I.; Vincent, W.F.; Alekseychik, P.; Amyot, Y.; Billet, M.F.; Canario, J.; Cory, R.M.; Deshpande, B.N.; Helbig, M.; Jammet, M.; Karlsson, J.; Larouche, J.; MacMillan, G.; Rautio, Milla; Walter Anthony, K.M.; Wickland, Kimberly P.

    2015-01-01

    The Arctic is a water-rich region, with freshwater systems covering about 16 % of the northern permafrost landscape. Permafrost thaw creates new freshwater ecosystems, while at the same time modifying the existing lakes, streams, and rivers that are impacted by thaw. Here, we describe the current state of knowledge regarding how permafrost thaw affects lentic (still) and lotic (moving) systems, exploring the effects of both thermokarst (thawing and collapse of ice-rich permafrost) and deepening of the active layer (the surface soil layer that thaws and refreezes each year). Within thermokarst, we further differentiate between the effects of thermokarst in lowland areas vs. that on hillslopes. For almost all of the processes that we explore, the effects of thaw vary regionally, and between lake and stream systems. Much of this regional variation is caused by differences in ground ice content, topography, soil type, and permafrost coverage. Together, these modifying factors determine (i) the degree to which permafrost thaw manifests as thermokarst, (ii) whether thermokarst leads to slumping or the formation of thermokarst lakes, and (iii) the manner in which constituent delivery to freshwater systems is altered by thaw. Differences in thaw-enabled constituent delivery can be considerable, with these modifying factors determining, for example, the balance between delivery of particulate vs. dissolved constituents, and inorganic vs. organic materials. Changes in the composition of thaw-impacted waters, coupled with changes in lake morphology, can strongly affect the physical and optical properties of thermokarst lakes. The ecology of thaw-impacted lakes and streams is also likely to change; these systems have unique microbiological communities, and show differences in respiration, primary production, and food web structure that are largely driven by differences in sediment, dissolved organic matter, and nutrient delivery. The degree to which thaw enables the delivery

  3. Quantitative studies of Savannah River aquatic insects, 1959--1985

    Energy Technology Data Exchange (ETDEWEB)

    Soltis, R. [ed.; Hart, D.; Nagy, T.

    1986-10-30

    As part of a long-term study of water quality patterns, scientists from the Academy of Natural Sciences have collected aquatic insects from artificial substrates placed at several stations in Savannah River. This report presents the first detailed compilation and analysis of this substantial data base, and examines patterns of variations of insect distribution and abundance (both spatial and temporal) during the last quarter century. Data on the number of individuals of various taxa found in the insect traps were obtained from tables in the Academy`s cursory reports. Computer data files created from these records were subjected to extensive statistical analyses in order to examine variation among stations, seasons and years in the abundances of major taxa and various aggregate properties of the insect assemblage. Although a total of 83 taxa were collected over the 27-year study, 10 taxa accounted for nearly 80% of the individuals collected from the traps, hence there 10 taxa were analyzed more intensively.

  4. Quantitative studies of Savannah River aquatic insects, 1959--1985

    Energy Technology Data Exchange (ETDEWEB)

    Soltis, R. (ed.); Hart, D.; Nagy, T.

    1986-10-30

    As part of a long-term study of water quality patterns, scientists from the Academy of Natural Sciences have collected aquatic insects from artificial substrates placed at several stations in Savannah River. This report presents the first detailed compilation and analysis of this substantial data base, and examines patterns of variations of insect distribution and abundance (both spatial and temporal) during the last quarter century. Data on the number of individuals of various taxa found in the insect traps were obtained from tables in the Academy's cursory reports. Computer data files created from these records were subjected to extensive statistical analyses in order to examine variation among stations, seasons and years in the abundances of major taxa and various aggregate properties of the insect assemblage. Although a total of 83 taxa were collected over the 27-year study, 10 taxa accounted for nearly 80% of the individuals collected from the traps, hence there 10 taxa were analyzed more intensively.

  5. Environmental state of aquatic systems in the Selenga River basin

    Science.gov (United States)

    Shinkareva, Galina; Lychagin, Mikhail

    2013-04-01

    The transboundary river system of Selenga is the biggest tributary of Lake Baikal (about 50 % of the total inflow) which is the largest freshwater reservoir in the world. It originates in the mountainous part of Mongolia and then drains into Russia. There are numerous industries and agricultural activities within the Selenga drainage basin that affect the environmental state of the river aquatic system. The main source of industrial waste in the Republic of Buryatia (Russia) is mining and in Mongolia it is mainly gold mining. Our study aimed to determine the present pollutant levels and main features of their spatial distribution in water, suspended matter, bottom sediments and water plants in the Selenga basin. The results are based on materials of the 2011 (July-August) field campaign carried out both in Russian and Mongolian part of the basin. The study revealed rather high levels of dissolved Fe, Al, Mn, Zn, Cu and Mo in the Selenga River water which often are higher than maximum permissible concentrations for water fishery in Russia. In Russian part of the basin most contrast distribution is found for W and Mo, which is caused by mineral deposits in this area. The study showed that Mo and Zn migrate mainly in dissolved form, since more than 70% of Fe, Al, and Mn are bound to the suspended solids. Suspended sediments in general are enriched by As, Cd and Pb in relation to the lithosphere averages. Compared to the background values rather high contents of Mo, Cd, and Mn were found in suspended matter of Selenga lower Ulan-Ude town. Transboundary transport of heavy metals from Mongolia is going both in dissolved and suspended forms. From Mongolia in diluted form Selenga brings a significant amount of Al, Fe, Mn, Zn, Cu and Mo. Suspended solids are slightly enriched with Pb, Cu, and Mn, in higher concentration - Mo. The study of the Selenga River delta allowed determining biogeochemical specialization of the region: aquatic plants accumulate Mn, Fe, Cu, Cd, and to

  6. Balancing conservation needs with uses of river ecosystems

    International Nuclear Information System (INIS)

    Sabater, Sergi; Elosegui, Arturo

    2014-01-01

    Rivers are among the most diverse and threatened ecosystems on the earth, but their conservation are a requisite for sustainable development. Conservation must consider both the structure and the functioning of the elements (usually species), as well as of their ecosystem. Therefore, successful river conservation must go beyond protecting species to protecting entire ecosystems and the processes that give each ecosystem its special characteristics. River conservation has to meet the legitimate aspirations of human populations for clean, readily available supply of water, without compromising the water needs of ecosystems and nature. Therefore, it is essential to take a landscape perspective that incorporates processes occurring in the riverine riparian areas as well as on connectivity with the land and across the river network.

  7. Agrochemical mitigation of three aquatic macrophytes: implications for ecosystem services

    Science.gov (United States)

    Agricultural runoff containing nitrogen and phosphorus is a major contributor to eutrophication in aquatic systems. Vegetated drainage ditches lining agricultural fields have been investigated for their potential to mitigate runoff, acting similarly to a wetland as they filter contaminants. The ef...

  8. The influence of the physical environment on simulations of complex aquatic ecosystem dynamics

    DEFF Research Database (Denmark)

    Hu, Fenjuan

    hydrodynamics. To test the hypothesis that the physical environment may induce strong influence on ecosystem processes, we applied and compared PCLake applications, with the same standard ecosystem model parameterization, for three different physical environment representations of the same volume of water body......The field of aquatic ecosystem modelling has been active since the late 1970s, and in recent decades the models have grown in complexity in terms of ecosystem components and included processes. However, the complexity in ecosystem conceptualizations generally comes at the expense of simple...... or no hydrodynamic representation, in particular for ecosystem models where higher trophic levels, such as fish, are included. On the other hand, physically resolved hydrodynamic models often include none or only simple representations of ecosystem dynamics. To overcome this discrepancy in complexity between...

  9. Review of 130 years of research on cyanobacteria in aquatic ecosystems in Serbia presented in a Serbian Cyanobacterial Database

    Directory of Open Access Journals (Sweden)

    Zorica Svirčev

    2017-05-01

    Full Text Available The presence of toxic cyanobacteria in aquatic ecosystems in the territory of the Republic of Serbia was surveyed over a period of several decades. Increasing attention is being paid to some negative consequences that may be caused by these microorganisms. Information from available literary sources regarding the distribution and frequency of cyanobacteria and their toxins over a period of 130 years, together with the effects on humans and wildlife in aquatic ecosystems, were gathered and incorporated into a Serbian Cyanobacterial Database created for the CYANOCOST Action. This database encompasses information on 65 aquatic ecosystems, including rivers, lakes, ponds, canals, irrigation reservoirs, reservoirs used for drinking water supply and reservoirs used for other purposes. Cyanobacterial blooms were found in almost 80% of the investigated aquatic ecosystems. The analysis of the research showed the presence of more than 70 species, including blooms of 24 species from 13 genera. Five species of cyanobacteria: Microcystis aeruginosa, Aphanizomenon flos-aquae, Planktothrix agardhii, Microcystis flos-aquae and Planktothrix rubescens frequently formed blooms in the investigated waterbodies and cyanotoxins were also detected in some of them, which had certain negative effects. Here, we present an overview of data contained in the Serbian Cyanobacterial Database, concerning cyanobacterial distribution, cyanotoxin production and associated biological effects in different types of water bodies from the Republic of Serbia. Also, recent important and major cases of cyanobacterial blooming in reservoirs used for drinking water supply: at Vrutci and Ćelije, the Aleksandrovac irrigation reservoir, the Ponjavica River and Lake Palić, including systematic research on the Lake Ludoš and few fishponds are further described. It can be concluded that cyanobacteria and cyanotoxins are omnipresent in different water bodies throughout the Republic of Serbia

  10. Atmospheric transport of persistent organic pollutants to aquatic ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Agrell, Cecilia

    1999-04-01

    The load of persistent organic pollutants (POPs) is considered high in the Baltic ecosystem. The Baltic Sea spans over 12 latitudes and the regional differences in climate affect the behavior of POPs. Therefore spatial and temporal variability of the concentrations of POPs in air and precipitation within this area has been investigated at 16 (mostly rural) stations around the Baltic Sea between 1990-1993. In addition, the deposition of gaseous and particulate associated POPs to the Baltic Sea is estimated from empirical data. This atmospheric input of POPs is compared with the input from rivers. Additionally, data from Ross Island, Antarctica and Lake Kariba, Zimbabve, Africa is presented, and all results are discussed and explained using the `global fractionation hypothesis` as a framework. In the Baltic Sea, concentration of individual POPs in air were found to be influenced by their physical-chemical properties, ambient air temperature and location. A latitudinal gradient, with higher levels in the south was found for PCBs and the gradient was more pronounced for the low volatility congeners. As a result, the high volatility congeners in air increased in relative importance with latitude. Generally, PCB concentration increased with temperature, but slopes of the partial pressure in air versus reciprocal temperature were different between congeners and between stations. In general, the low volatility congeners were more temperature dependent than the high volatility PCB congeners. Steep slopes at a sampling location indicate that the concentration in air is largely determined by diffusive exchange with soils. Lack of a temperature dependence may be due to the influence of long-range transported air masses at remote sites and due to the episodic, or random nature of PCB sources at urban sites. The concentrations of individual congeners in precipitation were found to be influenced by atmospheric concentrations of PCBs, ambient temperature, precipitation volume and

  11. Initial Impacts of the Mount Polley Tailings Pond Breach on Adjacent Aquatic Ecosystems

    Science.gov (United States)

    Petticrew, Ellen; Gantner, Nikolaus; Albers, Sam; Owens, Philip

    2015-04-01

    On August 4th 2014, the Mount Polley Tailings pond breach near Likely, B.C., released approximately 24 million cubic metres of tailings material into Polley Lake, Hazeltine Creek and Quesnel Lake. The discharge scoured and eroded a swath of soil and sediment delivering an unknown amount of metals and sediment into this tributary ecosystem of the Fraser River. Subsequent efforts by the mine operator to remediate by pumping tailings water from Polley Lake into Hazeltine Creek, which flows into Quesnel Lake, resulted in additional and continuous release of unknown volumes of contaminated water and sediments into the watershed. Heavy metals (e.g., selenium, copper, or mercury) reported as stored in the tailings pond entered the downstream aquatic environment and have been monitored in the water column of Quesnel Lake since August. These contaminants are likely particle-bound and thus subject to transport over long distances without appreciable degradation, resulting in the potential for chronic exposures and associated toxicological effects in exposed biota. While significant dilution is expected during aquatic transport, and the resulting concentrations in the water will likely be low, concentrations in exposed biota may become of concern over time. Metals such as mercury and selenium undergo bioaccumulation and biomagnification, once incorporated into the food chain/web. Thus, even small concentrations of such contaminants in water can lead to greater concentrations (~100 fold) in top predators. Over time, our predictions are that food web transfer will lead to an increase in concentrations from water (1-2 years)->invertebrates (1-2 yrs) ->fishes (2-5 yrs). Pacific salmon travel great distances in this watershed and may be exposed to contaminated water during their migrations. Resident species will be exposed to the contaminated waters and sediments in the study lakes year round. Little or no background/baseline data for metals in biota from Quesnel Lake exists

  12. Effects of snails, submerged plants and their coexistence on eutrophication in aquatic ecosystems

    OpenAIRE

    Mo Shuqing; Zhang Xiufeng; Tang Yali; Liu Zhengwen; Kettridge Nicholas

    2017-01-01

    Eutrophication resulting from nutrient loading to freshwater habitats is a severe problem, leading to degradation of ecosystems, including deterioration of water quality, water clarity and loss of biodiversity. Measures enacted to restore degraded freshwater ecosystems often involve the reintroduction of submerged plants and aquatic animals with beneficial ecological functions. In a mesocosm experiment, three treatments (planting with Vallisneria natans, introduction of the snail Bellamya aer...

  13. Predicting the aquatic risk of realistic pesticide mixtures to species assemblages in Portuguese river basins.

    Science.gov (United States)

    Silva, Emília; Daam, Michiel A; Cerejeira, Maria José

    2015-05-01

    Although pesticide regulatory tools are mainly based on individual substances, aquatic ecosystems are usually exposed to multiple pesticides from their use on the variety of crops within the catchment of a river. This study estimated the impact of measured pesticide mixtures in surface waters from 2002 and 2008 within three important Portuguese river basins ('Mondego', 'Sado' and 'Tejo') on primary producers, arthropods and fish by toxic pressure calculation. Species sensitivity distributions (SSDs), in combination with mixture toxicity models, were applied. Considering the differences in the responses of the taxonomic groups as well as in the pesticide exposures that these organisms experience, variable acute multi-substance potentially affected fractions (msPAFs) were obtained. The median msPAF for primary producers and arthropods in surface waters of all river basins exceeded 5%, the cut-off value used in the prospective SSD approach for deriving individual environmental quality standards. A ranking procedure identified various photosystem II inhibiting herbicides, with oxadiazon having the relatively largest toxic effects on primary producers, while the organophosphorus insecticides, chlorfenvinphos and chlorpyrifos, and the organochloride endosulfan had the largest effects on arthropods and fish, respectively. These results ensure compliance with European legislation with regard to ecological risk assessment and management of pesticides in surface waters. Copyright © 2015. Published by Elsevier B.V.

  14. Bioavailability and distribution and of ceria nanoparticles in simulated aquatic ecosystems, quantification with a radiotracer technique

    International Nuclear Information System (INIS)

    Zhang Zhiyong; Zhang Peng; He Xiao; Ma Yuhui; Lu Kai; Zhao Yuliang

    2014-01-01

    Although the presence of manufactured nanoparticles in the aquatic environment is still largely undocumented, their release could certainly occur in the future, particularly via municipal treatment plant effluents of cities supporting nano-industries. To get an initial estimate of the environmental behavior of nanomaterials, we investigated the distribution and accumulation of ceria nanoparticles in simulated aquatic ecosystems which included aquatic plant, shellfish, fish, water, and sediment using a radiotracer technique. Radioactive ceria ( 141 CeO 2 ) nanoparticles with a diameter of ca. 7 nm were synthesized by a precipitation method and added to the simulated aquatic ecosystems. The results indicate that the concentration of ceria nanoparticles in water decreased to a steady-state value after 3 days; meanwhile, the concentrations of ceria nanoparticles in the aquatic plant and sediment increased to their highest values. The distribution and accumulation characteristics of ceria nanoparticles in various aquatic organisms were different. Ceratophyllum demersum showed a high ability of accumulation of ceria nanoparticles from water. (authors)

  15. Bioassay for aquatic ecosystems review and classification; Rassegna dei principali test di ecotossicologia acquatica

    Energy Technology Data Exchange (ETDEWEB)

    Sanci, Antonella; Rosa, Silvia [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente

    1997-09-01

    Bioassay play a crucial role in assessing the actual or potential impacts of anthropogenic agents on the natural environment. In this technical report, literature on bioassays for aquatic ecosystems has been reviewed and classified. Problems associated with the choice and application of bioassays are discussed.

  16. Beyond barriers: ecosystem functions of alien aquatic plants

    NARCIS (Netherlands)

    Grutters, Bart M.C.

    2017-01-01

    Human impacts have become a dominant force in shaping Earth’s biosphere. One major consequence is the global reshuffling of species, both through intentional introductions, but also unintentional because human infrastructure benefits the movement of certain species. Consequently, ecosystems are

  17. Flux of aquatic insect productivity to land: comparison of lentic and lotic ecosystems.

    Science.gov (United States)

    Gratton, Claudio; Vander Zanden, M Jake

    2009-10-01

    Recently, food web studies have started exploring how resources from one habitat or ecosystem influence trophic interactions in a recipient ecosystem. Benthic production in lakes and streams can be exported to terrestrial habitats via emerging aquatic insects and can therefore link aquatic and terrestrial ecosystems. In this study, we develop a general conceptual model that highlights zoobenthic production, insect emergence, and ecosystem geometry (driven principally by area-to-edge ratio) as important factors modulating the flux of aquatic production across the ecosystem boundary. Emerging insect flux, defined as total insect production emerging per meter of shoreline (g C x m(-1) x yr(-1)) is then distributed inland using decay functions and is used to estimate insect deposition rate to terrestrial habitats (g C x m(-2) x yr(-1)). Using empirical data from the literature, we simulate insect fluxes across the water-land ecosystem boundary to estimate the distribution of fluxes and insect deposition inland for lakes and streams. In general, zoobenthos in streams are more productive than in lakes (6.67 vs. 1.46 g C x m(-2) x yr(-1)) but have lower insect emergence to aquatic production ratios (0.19 vs. 0.30). However, as stream width is on average smaller than lake radius, this results in flux (F) estimates 2 1/2 times greater for lakes than for streams. Ultimately, insect deposition onto land (within 100 m of shore) adjacent to average-sized lakes (10-ha lakes, 0.021 g C x m(-2) x yr(-1)) is greater than for average-sized streams (4 m width, 0.002 g C x m(-2) x yr(-1)) used in our comparisons. For the average lake (both in size and productivity), insect deposition rate approaches estimates of terrestrial secondary production in low-productivity ecosystems (e.g., deserts and tundra, approximately 0.07 g C x m(-2) x yr(-1)). However, larger lakes (1300 ha) and streams (16 m) can have average insect deposition rates (approximately 0.01-2.4 g C x m(-2) x yr(-1

  18. Aquatic hyphomycetes as environmental quality bioindicators in the Chirgua River (Bejuma, Venezuela

    Directory of Open Access Journals (Sweden)

    Rafael Fernández

    2017-01-01

    Full Text Available At present, the evaluation of water resources uses bioindicators, such as additional diagnostic systems, because they indicate anthropogenic disturbances. Aquatic hyphomycetes,  part of the trophic chain of aquatic ecosystems, are indicators of water quality through their varying  presence and concentration of conidia based on environmental disturbance; therefore, this research assessed their bioindicator role for environmental quality in the Chirgua River in Venezuela. In 2011 in two areas: 1 Headwaters (unaffected and 2 downstream area (affected, physico-chemical parameters (O2, conductivity, pH, temperature and total solids and nutrients were determined weekly (SO4-2, PO4-3, NO2-2 and NO3-3, along with coliforms (total and fecal and water hyphomycetes (number of species and conidia/mL. We identified a total of 44 species, 42 (20 exclusive in zone 1 and 24 (2 exclusive in zone 2. In the affected sector, the number of species and conidia/mL of the coliforms (total and fecal decreased, as compared to the unaffected zone. Sensitive species to environmental disturbance for coliforms included Brachiosphaera tropicalis, Camposporium antenatum, Campylospora filicladia, Campylospora parvula, Clavatospora tentacula, Clavatospora stellata, Culicidospora gravida, Diplocladiella scalaroides, Flabellospora acuminata, Helicomyces colligatus, Helicomyces sp., Helicomyces torquatus, Phalangispora constricta, Tetracladium marchalianum and Triscelophorus monosporus, while tolerant species included Alatospora acuminata, Campylospora chaetocladia, Flabellospora crassa, Isthmotricladia gombakiensis, Tetraploa cf. Aristata and Triscelophorus acuminatus.

  19. Assessment of risk to aquatic biota from elevated salinity -- a case study from the Hunter River, Australia.

    Science.gov (United States)

    Muschal, Monika

    2006-05-01

    An ecological risk assessment was performed on salinity levels of the Hunter River and its tributaries to respond to concerns that high salinity may be damaging aquatic ecosystems. Probabilistic techniques were used to assess likelihood and consequence, and hence the risk to aquatic biota from salinity. Continuous electrical conductivity distributions were used to describe the likelihood that high salinity would occur (exposure dataset) and toxicity values were compiled from the limited literature sources available to describe the consequence of high salinity (effects dataset). The assessment was preliminary in the sense that it modelled risk on the basis of existing data and did not undertake site-specific toxicity testing. Some sections of the Hunter River catchment have geologies that are saline because of their marine origins. Catchment development has increased the liberation rates of salts into surface-waters. Such modifying activities include coal-mining, power generation and land clearing. The aquatic biota of tributaries had a greater risk of impairment from high salinity than that of the Hunter River. High salinities in the tributaries were attributed to the combined factors of naturally saline geologies, increased liberation of salts due to modification of the landscape, and reduced dilution by flushing flows. A salinity guideline trigger value of 1100 mg L(-1) was recommended.

  20. Fundamental study on magnetic separation of aquatic organisms for preservation of marine ecosystem

    International Nuclear Information System (INIS)

    Sakaguchi, F.; Akiyama, Y.; Izumi, Y.; Nishijima, S.

    2009-01-01

    Recently, destruction and disturbance of marine ecosystem have been caused by changes in global environment and transplants of farmed fishes and shellfishes. To solve the problems, water treatment techniques to kill or to remove aquatic organisms are necessary. In this study, application of magnetic separation for removal of the aquatic organisms was examined in order to establish the process with high-speed, compact device and low environmental load. Techniques of magnetic seeding and magnetic separation using superconducting magnet are important for high-speed processing of aquatic organisms. Magnetic seeding is to adhere separating object to the surface of ferromagnetic particles, and magnetic separation is to remove aquatic organisms with magnetic force. First, we confirmed the possibility of magnetic seeding of aquatic organisms, and then interaction between aquatic organisms and ferromagnetic particles was examined. Next, for practical application of magnetic separation system using superconducting magnet for removal of aquatic organisms, particle trajectories were simulated and magnetic separation experiment using superconducting magnet was performed in order to design magnetic separation system to achieve high separation efficiency.

  1. Prehistoric Human-environment Interactions and Their Impact on Aquatic Ecosystems

    Science.gov (United States)

    Mackay, H.; Henderson, A. C. G.; van Hardenbroek, M.; Cavers, G.; Crone, A.; Davies, K. L.; Fonville, T. R.; Head, K.; Langdon, P. G.; Matton, R.; McCormick, F.; Murray, E.; Whitehouse, N. J.; Brown, A. G.

    2017-12-01

    One of the first widespread human-environment interactions in Scotland and Ireland occurred 3000 years ago when communities first inhabited wetlands, building artificial islands in lakes called crannogs. The reason behind the development and intermittent occupation of crannogs is unclear. We don't know if they were a response to changes in environment or if they were driven by societal influences. Furthermore, the impact of the construction, settlement and human activities on lake ecosystems is unknown, but is a key example of early anthropogenic signatures on the environment. Our research characterises the prehistoric human-environment interactions associated with crannogs by analysing geochemical and biological signals preserved within the crannog and wetland sediments. Records of anthropogenic activities and environmental change have been produced using lipid biomarkers of faecal matter, sedimentary DNA, and the remains of beetles, aquatic invertebrates (chironomids), siliceous algae (diatoms) and pollen. Results of these analyses reveal settlement occupations occurred in phases from the Iron Age to the Medieval Period. The main effects of occupation on the wetland ecosystems are nutrient-driven increases in productivity and shifts in aquatic species from clear water taxa to those associated with more eutrophic conditions. Crannog abandonment reduces nutrient inputs and therefore levels of aquatic productivity, as evidenced by decreases in the abundance of siliceous algae. Despite returns to pre-settlement nutrient and productivity levels, the lake ecosystems do not recover to their previous ecological state: dominant aquatic invertebrate and siliceous algae taxa shift in response to elevated levels of macrophytes within the lakes. Whilst these phase changes in lake ecosystems highlight their adaptive capacity to environmental change, the temporary human interactions associated with crannogs had persisting environmental impacts that shaped the long

  2. Freshwater Ecosystem Services and Hydrologic Alteration in the Lower Mississippi River Basin

    Science.gov (United States)

    Yasarer, L.; Taylor, J.; Rigby, J.; Locke, M. A.

    2017-12-01

    Flowing freshwater ecosystems provide a variety of essential ecosystem services including: consumptive water for domestic, industrial, and agricultural use; transportation of goods; maintenance of aquatic biodiversity and water quality; and recreation. However, freshwater ecosystem services can oftentimes be at odds with each other. For example, the over-consumption of water for agricultural production or domestic use may alter hydrologic patterns and diminish the ability of flowing waters to sustain healthy aquatic ecosystems. In the Lower Mississippi River Basin there has been a substantial increase in groundwater-irrigated cropland acreage over the past several decades and subsequent declines in regional aquifer levels. Changes in aquifer levels potentially impact surface water hydrology throughout the region. This study tests the hypothesis that flowing water systems in lowland agricultural watersheds within the Lower Mississippi River Basin have greater hydrologic alteration compared to upland non-agricultural watersheds, particularly with declines in base flow and an increase in extreme low flows. Long-term streamflow records from USGS gauges located in predominantly agricultural and non-agricultural watersheds in Arkansas, Louisiana, Mississippi, and Tennessee were evaluated from 1969 -2016 using the Indicators of Hydrologic Alteration (IHA) software. Preliminary results from 8 non-agricultural and 5 agricultural watersheds demonstrate a substantial decline in base flow in the agricultural watersheds, which is not apparent in the non-agricultural watersheds. This exploratory study will analyze the trade-off between gains in agricultural productivity and changes in ecohydrological indicators over the last half century in diverse watersheds across the Lower Mississippi River Basin. By quantifying the changes in ecosystem services provided by flowing waters in the past, we can inform sustainable management pathways to better balance services in the future.

  3. Proceedings of the meeting on computational and experimental studies for modeling of radionuclide migration in complex aquatic ecosystems

    International Nuclear Information System (INIS)

    Matsunaga, Takeshi; Hakanson, Lars

    2010-09-01

    The Research Group for Environmental Science of JAEA held a meeting on computational and experimental studies for modeling of radionuclide migration in complex aquatic ecosystems during November 16-20 of 2009. The aim was to discuss the relevance of various computational and experimental approaches to that modeling. The meeting was attended by a Swedish researcher, Prof. Dr. Lars Hakanson of Uppsala University. It included a joint talk at the Institute for Environmental Sciences, in addition to a field and facility survey of the JNFL commercial reprocessing plant located in Rokkasho, Aomori. The meeting demonstrated that it is crucial 1) to make a model structure be strictly relevant to the target objectives of a study and 2) to account for inherent fluctuations in target values in nature in a manner of qualitative parameterization. Moreover, it was confirmed that there can be multiple different approaches of modeling (e.g. detailed or simplified) with relevance for the objectives of a study. These discussions should be considered in model integration for complex aquatic ecosystems consisting catchments, rivers, lakes and coastal oceans which can interact with the atmosphere. This report compiles research subjects and lectures presented at the meeting with associated discussions. The 10 of the presented papers indexed individually. (J.P.N.)

  4. Floods, fish, and people: Connecting biogeochemical fluxes to aquatic ecosystem functions and people (Invited)

    Science.gov (United States)

    Holtgrieve, G. W.; Arias, M. E.; Chheng, P.

    2013-12-01

    The Lower Mekong River basin, including Tonle Sap Lake (TSL), is the largest inland fishery in the world and a dominant source of protein and income for much of Southeast Asia. Maintaining ecosystem productivity in the face of large-scale environmental change from hydroelectric dams and climate change is critical for economic and social well-being in the region. Yet, we currently lack the most basic understanding of how hydrologic variation relates to fisheries production, nutritional quality, and ultimately livelihoods of people. We will describe past, present, and future research to establish mechanistic connections between the hydrology, ecology, and sustainability of the Mekong ecosystem. Past research includes application of a state-space oxygen mass balance model and continuous dissolved oxygen measurements from four locations to provide the first estimates of gross primary productivity (GPP) and ecosystem respiration (ER) for the Tonle Sap. GPP averaged 4.1 × 2.3 g O2 m-3 d-1 with minimal differences among sites, while ER averaged 24.9 × 20.0 g O2 m-3 d-1, but had greater than six-fold variation among sites. Using our measurements of GPP, we calibrated a hydrodynamic-productivity model and predicted aquatic net primary production of 2.0 × 0.2 g C m-2 d-1 (2.4 × 0.2 million tonnes C y-1). Present research is using stable isotope and fatty acid methyl ester biomarkers to investigate basal carbon sources to the fishery, focusing specifically on the role of biogenic methane oxidation in supporting the food web. Individuals a wide variety of taxa had tissue carbon isotope values (δ13C) ranging from -36 to -57 per mil. These extremely depleted values are best explained by utilization of biogenic methane by methane oxidizing bacteria (MOB) and subsequent grazing of these bacterial by benthic insects and ultimately fishes. The presence of MOB in the food web was confirmed by identifying 16:1ω8 and 18:1ω8 FAME biomarkers specific to these bacteria in fish

  5. Fire effects on aquatic ecosystems: an assessment of the current state of the science

    Science.gov (United States)

    Rebecca J. Bixby,; Scott D. Cooper,; Gresswell, Bob; Lee E. Brown,; Clifford N. Dahm,; Kathleen A. Dwire,

    2015-01-01

    Fire is a prevalent feature of many landscapes and has numerous and complex effects on geological, hydrological, ecological, and economic systems. In some regions, the frequency and intensity of wildfire have increased in recent years and are projected to escalate with predicted climatic and landuse changes. In addition, prescribed burns continue to be used in many parts of the world to clear vegetation for development projects, encourage desired vegetation, and reduce fuel loads. Given the prevalence of fire on the landscape, authors of papers in this special series examine the complexities of fire as a disturbance shaping freshwater ecosystems and highlight the state of the science. These papers cover key aspects of fire effects that range from vegetation loss and recovery in watersheds to effects on hydrology and water quality with consequences for communities (from algae to fish), food webs, and ecosystem processes (e.g., organic matter subsidies, nutrient cycling) across a range of scales. The results presented in this special series of articles expand our knowledge of fire effects in different biomes, water bodies, and geographic regions, encompassing aquatic population, community, and ecosystem responses. In this overview, we summarize each paper and emphasize its contributions to knowledge on fire ecology and freshwater ecosystems. This overview concludes with a list of 7 research foci that are needed to further our knowledge of fire effects on aquatic ecosystems, including research on: 1) additional biomes and geographic regions; 2) additional habitats, including wetlands and lacustrine ecosystems; 3) different fire severities, sizes, and spatial configurations; and 4) additional response variables (e.g., ecosystem processes) 5) over long (>5 y) time scales 6) with more rigorous study designs and data analyses, and 7) consideration of the effects of fire management practices and policies on aquatic ecosystems.

  6. The behavior of 89Sr and tritium water (HTO) in a model terrestrial-aquatic ecosystem

    International Nuclear Information System (INIS)

    Zhang Yongxi; Wang Shouxiang; Chen Chuangqun; Sun Zhiming; Huang Dan; Hu Bingmin

    1993-08-01

    The effect of land polluted by 89 Sr on water body and the immigration of HTO from water body to land were studied in a modelling terrestrial-aquatic ecosystem. The results are as follows: (1) The 89 Sr in soil quickly migrated to common bean plants and its concentration in common bean plants was increasing with the time, but the concentration of 89 Sr in soil was exponentially declining with the depth. About 5% of 89 Sr was migrated to water body by rainfall then distributed to other components, and it can be concentrated by aquatics in a certain degree. (2) when HTO entered into the water body, it would migrate to other components of the ecosystem. and the HTO in the pool was linearly decreasing with the time. However, the concentration of HTO in the sediments and aquatics would firstly increase then reached the peak and went down. The tritium of HTO was existed in two forms in the sediments and aquatics, free water (HTO) and bound tritium. HTO was also migrated to the adjacent land soil and absorbed by land crop plants, within one and half months the land system contained 24% of the total tritium in the aquatic system

  7. Interfaces in aquatic ecosystems: Implications for transport and impact of anthropogenic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Knulst, J.

    1996-11-01

    Mechanisms that govern transport, accumulation and toxicity of persistent pollutants at interfaces in aquatic ecosystems were the foci of this thesis. Specific attention was paid to humic substances, their occurrence, composition, and role in exchange processes across interfaces. It was concluded that: The composition of humic substances in aquatic surface microlayers is different from that of the subsurface water and terrestrial humic matter. Levels of dissolved organic carbon (DOC) in the aquatic surface microlayer reflect the DOC levels in the subsurface water. While the levels and enrichment of DOC in the microlayer generally show small variations, the levels and enrichment of particulate organic carbon (POC) vary to a great extent. Similarities exist between aquatic surface films, artificial semi-permeable and biological membranes regarding their structure and functioning. Acidification and liming of freshwater ecosystems affect DOC:POC ratio and humic composition of the surface film, thus influencing the partitioning of pollutants across aquatic interfaces. Properties of lake catchment areas extensively govern DOC:POC ratio both in the surface film and subsurface water. Increased UV-B irradiation changes the DOC:POC ratio in the surface film and thus affect transfer of matter across the interface. Transport of lipophilic, persistent organic pollutants across semi-permeable membranes is influenced by the solutes organic composition. 106 refs, 11 figs, 1 tab

  8. Review on Periphyton as Mediator of Nutrient Transfer in Aquatic Ecosystems

    Directory of Open Access Journals (Sweden)

    Surjya K. Saikia

    2011-12-01

    Full Text Available In the studies of aquatic ecology, periphyton has been uncared for despite its vital role in nutrient uptake and transfer to the upper trophic organisms. Being the component of food chain as attached organism it takes part in nutrient cycling in the ecosystem like that of suspended planktonic counterparts. The present review, with an aim to understand the role of periphyton in nutrient transfer from benthic environment to upper trophic level, focuses many aspects of periphyton-nutrient relationship based on available literatures. It also attempts to redefine periphyton, as a part of biofilm, harboring nutrient components like protein, fat and carbohydrate preferably in its extracellular polymeric substance (EPS, cyanobacteria, diatom and other algal communities. In addition to physical processes, nutrient uptake by periphyton is catalyzed by enzymes like Nitrogen Reductase and Alkaline Phosphatase from the environment. This uptake and transfer is further regulated by periphytic C: nutrient (N or P stoichiometry, colonization time, distribution of periphyton cover on sediments and macrophytes, macronutrient concentration, grazing, sloughing, temperature, and advective transport. The Carbon (C sources of periphyton are mainly dissolve organic matter and photosynthetic C that enters into higher trophic levels through predation and transfers as C-rich nutrient components. Despite of emerging interests on utilizing periphyton as nutrient transfer tool in aquatic ecosystem, the major challenges ahead for modern aquatic biologists lies on determining nutrient uptake and transfer rate of periphyton, periphytic growth and simulating nutrient models of periphyton to figure a complete energy cycle in aquatic ecosystem.

  9. The effects of PAT on the Savannah River ecosystem, particularly fisheries

    Energy Technology Data Exchange (ETDEWEB)

    Patrick, R.

    1994-03-01

    The main purpose of this study was to determine whether or not the pre-startup activities at K-Reactor, i.e., Power Ascension Testing (PAT), have caused damage because of temperature rises in the Savannah River. Therefore, the biological studies were mainly aimed at providing information as to changes that might cause the damage of the fish population, and to other important organisms in the ecosystem. To determine if deleterious effects had occurred, one had to review the past studies to determine the condition and diversity of aquatic life before these PAT studies started. Therefore old reports were reviewed and a current study made in 1992.

  10. Project AProWa: a national view on managing trade-offs between agricultural production and conservation of aquatic ecosystems

    Science.gov (United States)

    Dietzel, Anne; Rahn, Eric; Stamm, Christian

    2014-05-01

    Swiss agriculture is legally committed to fulfill several, partially conflicting goals such as agricultural production on the one hand and the conservation of natural resources on the other hand. In the context of the research project AProWa ("Agricultural Production and Water"), the relationships between the production aspect and the conservation of aquatic ecosystems is analyzed with a holistic approach. Agricultural production and the protection of water resources have high potential for conflicts: Farmers use ground and surface water to irrigate their fields. On the other hand, drainage systems enable the production on otherwise unfavorably wet soils. These in turn often affect ground water recharge and divert precipitation directly into surface waters, which changes their hydrological regime. Typically, drainage systems also elevate the input of nutrients and pesticides into the water bodies. In general, applied fertilizers, plant protection products, veterinary drugs and phytohormones of cultivated plants are introduced into the ground and surface waters through different processes such as drift, leaching, runoff, preferential flow or erosion. They influence the nutrient cycles and ecological health of aquatic systems. The nutrient and pesticide loss processes themselves can be altered by tillage operations and other agricultural practices. Furthermore, the competition for space can lead to additional conflicts between agriculture and the protection of aquatic ecosystems. For example, channelized or otherwise morphologically changed rivers do not have a natural discharge pattern and are often not suitable for the local flora and fauna; but naturally meandering rivers need space that cannot be used for agriculture. In a highly industrialized and densely populated country like Switzerland, all these potential conflicts are of importance. Although it is typically seen as a water-rich country, local and seasonal overexploitation of rivers through water extraction

  11. Impact of petroleum pollution on aquatic coastal ecosystems in Brazil

    International Nuclear Information System (INIS)

    Silva, E.M. da; Peso-Aguiar, M.C.; Navarro, M.F.T.; Chastinet, C.B.A.

    1997-01-01

    Although oil activities generate numerous forms of environmental impact on biological communities, studies of these impacts on Brazilian coastal ecosystems are rate. Results of tests for the content of oil in sediments and organisms indicate a substantially high rate of degradation. Results for uptake of polycyclic aromatic hydrocarbons in bivalves suggested the recent occurrence of oil spills and that these organisms differed in their capabilities to bioconcentrate oil. The mangrove community has suffered constant inputs of oil and has responded with increased numbers of aerial roots, generation of malformed leaves and fruits by plants, and a decrease in litter production. Studies of the impact of oil on rocky shore communities and the toxicity of oil and its by-products to marine organisms have confirmed the results reported in the literature. Presently most of the available studies deal with the macroscopic effects of oil on organisms and have indicated that the nature of oil, climate characteristics, the physical environment, and the structure of the community influence the symptoms of oil contamination in organisms of coastal waters. Long-term studies should be carried out to assess changes in community structure, sublethal effects in populations, and the resilience of contaminated ecosystems

  12. Elementary analyses in behalf of the project: Orientating investigation to Polonium-210 and other radionuclides in Dutch aquatic ecosystems

    International Nuclear Information System (INIS)

    Hart, M.J. 't; Breugem, P.M.; Koester, H.W.

    1989-11-01

    In this report, results of the determinations of total, organic and inorganic carbon analysis are reported for the project 'Orientating investigations of Polonium-210 and other natural radionuclides in Dutch aquatic ecosystems', projectnumber 248476. The method used is a modification of the method described by Froelich and is based on elemental analysis. Sediment samples from several locations of sea and river water show a large variation of the carbon content. The organic carbon concentration varies from 2.78 to 22.42 percent; the inorganic carbon varies from 1.25 to 5.66 percent. The analyses were run in duplicate with a mean standard deviation of 0.1 percent. (author). 4 refs.; 5 figs.; 7 tabs

  13. Global distribution of dissolved organic matter along the aquatic continuum: Across rivers, lakes and oceans

    DEFF Research Database (Denmark)

    Massicotte, Philippe; Asmala, Eero; Stedmon, Colin

    2017-01-01

    occurred more rapidly in freshwater ecosystems compared to marine water ecosystems, suggesting that the different degradation processes act preferentially on CDOM rather than carbon content. The observed change in the DOM characteristics along the aquatic continuum also suggests that the terrestrial DOM...

  14. Habitat mosaics and path analysis can improve biological conservation of aquatic biodiversity in ecosystems with low-head dams.

    Science.gov (United States)

    Hitchman, Sean M; Mather, Martha E; Smith, Joseph M; Fencl, Jane S

    2018-04-01

    Conserving native biodiversity depends on restoring functional habitats in the face of human-induced disturbances. Low-head dams are a ubiquitous human impact that degrades aquatic ecosystems worldwide. To improve our understanding of how low-head dams impact habitat and associated biodiversity, our research examined complex interactions among three spheres of the total environment. i.e., how low-head dams (anthroposphere) affect aquatic habitat (hydrosphere), and native biodiversity (biosphere) in streams and rivers. Creation of lake-like habitats upstream of low-head dams is a well-documented major impact of dams. Alterations downstream of low head dams also have important consequences, but these downstream dam effects are more challenging to detect. In a multidisciplinary field study at five dammed and five undammed sites within the Neosho River basin, KS, we tested hypotheses about two types of habitat sampling (transect and mosaic) and two types of statistical analyses (analysis of covariance and path analysis). We used fish as our example of biodiversity alteration. Our research provided three insights that can aid environmental professionals who seek to conserve and restore fish biodiversity in aquatic ecosystems threatened by human modifications. First, a mosaic approach identified habitat alterations below low-head dams (e.g. increased proportion of riffles) that were not detected using the more commonly-used transect sampling approach. Second, the habitat mosaic approach illustrated how low-head dams reduced natural variation in stream habitat. Third, path analysis, a statistical approach that tests indirect effects, showed how dams, habitat, and fish biodiversity interact. Specifically, path analysis revealed that low-head dams increased the proportion of riffle habitat below dams, and, as a result, indirectly increased fish species richness. Furthermore, the pool habitat that was created above low-head dams dramatically decreased fish species richness

  15. Habitat mosaics and path analysis can improve biological conservation of aquatic biodiversity in ecosystems with low-head dams

    Science.gov (United States)

    Hitchman, Sean M.; Mather, Martha E.; Smith, Joseph M.; Fencl, Jane S.

    2018-01-01

    Conserving native biodiversity depends on restoring functional habitats in the face of human-induced disturbances. Low-head dams are a ubiquitous human impact that degrades aquatic ecosystems worldwide. To improve our understanding of how low-head dams impact habitat and associated biodiversity, our research examined complex interactions among three spheres of the total environment. i.e., how low-head dams (anthroposphere) affect aquatic habitat (hydrosphere), and native biodiversity (biosphere) in streams and rivers. Creation of lake-like habitats upstream of low-head dams is a well-documented major impact of dams. Alterations downstream of low head dams also have important consequences, but these downstream dam effects are more challenging to detect. In a multidisciplinary field study at five dammed and five undammed sites within the Neosho River basin, KS, we tested hypotheses about two types of habitat sampling (transect and mosaic) and two types of statistical analyses (analysis of covariance and path analysis). We used fish as our example of biodiversity alteration. Our research provided three insights that can aid environmental professionals who seek to conserve and restore fish biodiversity in aquatic ecosystems threatened by human modifications. First, a mosaic approach identified habitat alterations below low-head dams (e.g. increased proportion of riffles) that were not detected using the more commonly-used transect sampling approach. Second, the habitat mosaic approach illustrated how low-head dams reduced natural variation in stream habitat. Third, path analysis, a statistical approach that tests indirect effects, showed how dams, habitat, and fish biodiversity interact. Specifically, path analysis revealed that low-head dams increased the proportion of riffle habitat below dams, and, as a result, indirectly increased fish species richness. Furthermore, the pool habitat that was created above low-head dams dramatically decreased fish species

  16. The role of wild and scenic rivers in the conservation of aquatic biodiversity

    Science.gov (United States)

    John D. Rothlisberger; Tamara Heartsill Scalley; Russell F. Thurow

    2017-01-01

    Formerly diverse and abundant freshwater species are highly imperiled, with higher extinction rates than many other taxonomic groups worldwide. In the 50 years since passage of the US Wild and Scenic Rivers Act, wild and scenic rivers (WSRs) have contributed significantly to the conservation of native aquatic biodiversity as well as to the conservation and restoration...

  17. Staunton 1 reclamation demonstration project. Aquatic ecosystems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Vinikour, W. S.

    1981-02-01

    To provide long-term indications of the potential water quality improvements following reclamation efforts at the Staunton 1 Reclamation Demonstration Project, macroinvertebrates were collected from three on-site ponds and from the receiving stream (Cahokia Creek) for site drainage. Implications for potential benthic community differences resulting from site runoff were disclosed, but macroinvertebrate diversity throughout Cahokia Creek was limited due to an unstable, sandy substrate. The three ponds sampled were the New Pond, which was created as part of the reclamation activities; the Shed Pond, which and the Old Pond, which, because it was an existing, nonimpacted pond free of site runoff, served as a control. Comparisons of macroinvertebrates from the ponds indicated the potential for the New Pond to develop into a productive ecosystem. Macroinvertebrates in the New Pond were generally species more tolerant of acid mine drainage conditions. However, due to the present limited faunal densities and the undesirable physical and chemical characteristics of the New Pond, the pond should not be stocked with fish at this time.

  18. The Dnieper River Aquatic System Radioactive Contamination; Long-tern Natural Attenuation And Remediation History

    Science.gov (United States)

    Voitsekhovych, Oleg; Laptev, Genadiy; Kanivets, Vladimir; Konoplev, Alexey

    2013-04-01

    Near 27 year passed after the Chernobyl Accident, and the experience gained to study radionuclide behavior in the aquatic systems and to mitigate water contamination are still pose of interest for scientists, society and regulatory austerities. There are different aspects of radionuclide transport in the environment were studied since the Chernobyl fallout in 1986 covered the river catchments, wetlands, river, lakes/reservoirs and reached the Black Sea. The monitoring time series data set and also data on the radionuclides behavior studies in the water bodies (river, lakes and the Black Sea) are available now in Ukraine and other affected countries. Its causation analyses, considering the main geochemical, physical and chemical and hydrological process, governing by radionuclide mobility and transport on the way from the initially contaminated catchments, through the river-reservoir hydrological system to the Black Sea can help in better understanding of the main factors governing be the radionuclide behavior in the environment. Radionuclide washout and its hydrological transport are determined speciation of radionuclides as well as soil types and hydrological mode and also geochemistry and landscape conditions at the affected areas. Mobility and bioavailability of radionuclides are determined by ratio of radionuclide chemical forms in fallout and site-specific environmental characteristics determining rates of leaching, fixation/remobilization as well as sorption-desorption of mobile fraction (its solid-liquid distribution). In many cases the natural attenuation processes governing by the above mentioned processes supported by water flow transportation and sedimentation played the key role in self-rehabilitation of the aquatic ecosystems. The models developed during post-Chernobyl decade and process parameters studies can help in monitoring and remediation programs planed for Fukusima Daichi affected watersheds areas as well. Some most important monitoring data

  19. Temporary streams in temperate zones: recognizing, monitoring and restoring transitional aquatic-terrestrial ecosystems

    OpenAIRE

    Stubbington, Rachel; England, Judy; Wood, Paul J.; Sefton, Catherine E.M.

    2017-01-01

    Temporary streams are defined by periodic flow cessation, and may experience partial or complete loss of surface water. The ecology and hydrology of these transitional aquatic-terrestrial ecosystems have received unprecedented attention in recent years. Research has focussed on the arid, semi-arid, and Mediterranean regions in which temporary systems are the dominant stream type, and those in cooler, wetter temperate regions with an oceanic climate influence are also receiving increasing atte...

  20. The use of biomarkers to assess the health of aquatic ecosystems in Brazil: a review

    Directory of Open Access Journals (Sweden)

    Thaís Dalzochio

    2016-11-01

    Full Text Available Abstract Organisms in polluted environments are typically exposed to a complex mixture of chemical contaminants. The great concern about the health of aquatic ecosystems has led to the increased use of biomarkers over the past years. The aim of this work was to review the papers published from 2000 to 2015, which used biomarkers to assess the health of aquatic ecosystems in Brazil. A research resulted in 99 eligible papers. More than 80% of studies were conducted in the states of São Paulo and Rio Grande do Sul. Approximately 63% of studies used fish as bioindicator, whereas the micronucleus test and biochemical analyses were the most used biomarkers. A multibiomarker approach was used by 60.6% of studies, while 39.4% used one single biomarker. Furthermore, 68% were field studies and more than 75% of these used control animals sampled at reference sites. A relationship between the biomarker responses and pollution was reported by 87% of studies; however, 43.4% of studies analyzed only one sampling period, limiting comparisons and comprehension about possible seasonal variations. This review evidenced some weak points in studies using biomarkers in Brazil, especially related to the lack of studies in two important biomes (the Pantanal and the Amazon Rainforest and experimental designs (small sample size, sampling in one single period, use of one single biomarker. Thus, future studies should consider mainly the use of multiple biomarkers, greater sample size, seasonal sampling and water physicochemical parameters to better diagnose the health of aquatic ecosystems.

  1. A REVIEW OF SINGLE SPECIES TOXICITY TESTS: ARE THE TESTS RELIABLE PREDICTORS OF AQUATIC ECOSYSTEM COMMUNITY RESPONSES?

    Science.gov (United States)

    This document provides a comprehensive review to evaluate the reliability of indicator species toxicity test results in predicting aquatic ecosystem impacts, also called the ecological relevance of laboratory single species toxicity tests.

  2. Impacts to ecosystem services from aquatic acidification: using FEGS-CS to understand the impacts of air pollution

    Science.gov (United States)

    Increases in anthropogenic emissions of sulfur (S) and nitrogen (N) have resulted in increases in the associated atmospheric deposition of acidic compounds. In sensitive watersheds, this deposition has initiated a cascade of negative environmental effects on aquatic ecosystems, ...

  3. Concerning human well-being and ecosystems sustainability on water resources management for Qishan River

    Science.gov (United States)

    Wang, C. Y.; Ho, C. C.; Chang, L. C.

    2016-12-01

    There are no large hydraulic structures in Qishan River cause the less human interference than other major river in Taiwan. However, the aquatic habitats still suffer disturbance from the discharge changes greatly between wet and drought season, and Jiaxian Weir and Yuemei Weir draw surplus water from Qishan River to Nanhua Reservoir and Agongdian Reservoir respectively. The weir operation rule doesn't clear define how much environmental flow should be preserved for maintaining downstream ecological environment. Hence, the study proposes a process for evaluating environmental flow under considering impact on human well-being and ecosystems sustainability. Empirical formula, hydrological, hydraulic and habitat methodologies were used to propose the environmental flow alternatives. Next, water allocation model and Habitat model were used to analysis the impact of environment flow alternatives on human well-being and ecosystems sustainability. The results show the suggested environmental flow in Qishan River is estimated by MAF10%. The environmental flow is between 8.03 10.83 cms during wet season and is between 1.07 1.44cms during wet season. The simulation results also provide the evidence from diverse aspect to help different authorities realized what they get and lose. The information can advance to reach a consensus during negotiations with different authorities and help decision maker make decisions.

  4. Exploring the Use of Participatory Information to Improve Monitoring, Mapping and Assessment of Aquatic Ecosystem Services at Landascape Scales

    Science.gov (United States)

    Traditionally, the EPA has monitored aquatic ecosystems using statistically rigorous sample designs and intensive field efforts which provide high quality datasets. But by their nature they leave many aquatic systems unsampled, follow a top down approach, have a long lag between ...

  5. Ecosystem differences in the trophic enrichment of 13C in aquatic food webs

    International Nuclear Information System (INIS)

    France, R.L.; Peters, R.H.

    1997-01-01

    Data from 35 published studies were collated to examine patterns in the trophic enrichment of 13 C of consumers. Because both δ 13 C and δ 14 N vary systematically across ecosystems, it was necessary to standardize for such differences before combining data from numerous sources. Relationships of these measures of ecosystem-standardized δ 13 C to ecosystem-standardized trophic position (Δδ 15 N) for freshwater, estuarine, coastal, and open-ocean and for all aquatic ecosystems yielded regression equations of low predictive capability (average of 20% explained variance in δ 13 C). However, differences were observed in the slopes between δ 13 C and standardized trophic position when data were examined study-specifically: the average trophic fractionation of 13 C was found to increase from +0.2micron for freshwater to +0.5micron for estuarine to +0.8micron for coastal, and to +1.1micron for open-ocean food webs. This ecosystem-specific gradient in 13 C enrichment for consumers supports previous findings of a similar continuum existing for zooplankton - particulate organic matter differences in δ 13 C. Possible mechanisms to explain these ecosystem-specific patterns in 13 C enrichment may be related to the relative importance of detritus, heterotrophic respiration, partial reliance on alternative food sources, and lipid influences in the different ecosystems. (author)

  6. Riparian swallows as integrators of landscape change in a multiuse river system: implications for aquatic-to-terrestrial transfers of contaminants.

    Science.gov (United States)

    Alberts, Jeremy M; Sullivan, S Mažeika P; Kautza, A

    2013-10-01

    Recent research has highlighted the transfer of contaminants from aquatic to terrestrial ecosystems via predation of aquatic emergent insects by riparian consumers. The influence of adjacent land use and land cover (LULC) on aquatic-to-terrestrial contaminant transfer, however, has received limited attention. From 2010 to 2012, at 11 river reaches in the Scioto River basin (OH, USA), we investigated the relationships between LULC and selenium (Se) and mercury (Hg) concentrations in four species of riparian swallows. Hg concentrations in swallows were significantly higher at rural reaches than at urban reaches (t=-3.58, Pemergent insects. For example, tree swallows (Tachycineta bicolor) at urban reaches exhibited a higher proportion of aquatic prey in their diet, fed at a higher trophic level, and exhibited elevated Se levels. We also found that both Se and Hg concentrations in adult swallows were significantly higher than those observed in nestlings at both urban and rural reaches (Se: t=-2.83, P=0.033, df=3; Hg: t=-3.22, P=0.024, df=3). Collectively, our results indicate that riparian swallows integrate contaminant exposure in linked aquatic-terrestrial systems and that LULC may strongly regulate aquatic contaminant flux to terrestrial consumers. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Adaptive Management Using Remote Sensing and Ecosystem Modeling in Response to Climate Variability and Invasive Aquatic Plants for the California Sacramento-San Joaquin Delta Water Resource

    Science.gov (United States)

    Bubenheim, David; Potter, Christopher; Zhang, Minghua; Madsen, John

    2017-01-01

    The California Sacramento-San Joaquin River Delta is the hub for California's water supply and supports important ecosystem services, agriculture, and communities in Northern to Southern California. Expansion of invasive aquatic plants in the Delta coupled with impacts of changing climate and long-term drought is detrimental to the San Francisco Bay/California Delta complex. NASA Ames Research Center and the USDA-ARS partnered with the State of California to develop science-based, adaptive-management strategies for invasive aquatic plant in the Sacramento-San Joaquin Delta. Specific mapping tools developed utilizing satellite and airborne platforms provide regular assessments of population dynamics on a landscape scale and support both strategic planning and operational decision making for resource managers. San Joaquin and Sacramento River watersheds water quality input to the Delta is modeled using the Soil-Water Assessment Tool (SWAT) and a modified SWAT tool has been customized to account for unique landscape and management of agricultural water supply and drainage within the Delta. Environmental response models for growth of invasive aquatic weeds are being parameterized and coupled with spatial distribution/biomass density mapping and water quality to study ecosystem response to climate and aquatic plant management practices. On the water validation and operational utilization of these tools by management agencies and how they are improving decision making, management effectiveness and efficiency will be discussed. The project combines science, operations, and economics related to integrated management scenarios for aquatic weeds to help land and water resource managers make science-informed decisions regarding management and outcomes.

  8. Adaptive Management Using Remote Sensing and Ecosystem Modeling in Response to Climate Variability and Invasive Aquatic Plants for the California Sacramento-San Joaquin Delta Water Resource

    Science.gov (United States)

    Bubenheim, D.; Potter, C. S.; Zhang, M.; Madsen, J.

    2017-12-01

    The California Sacramento-San Joaquin River Delta is the hub for California's water supply and supports important ecosystem services, agriculture, and communities in Northern and Southern California. Expansion of invasive aquatic plants in the Delta coupled with impacts of changing climate and long-term drought is detrimental to the San Francisco Bay/California Delta complex. NASA Ames Research Center and the USDA-ARS partnered with the State of California to develop science-based, adaptive-management strategies for invasive aquatic plant management in the California Sacramento-San Joaquin Delta. Specific mapping tools developed utilizing satellite and airborne platforms provide regular assessments of population dynamics on a landscape scale and support both strategic planning and operational decision making for resource managers. San Joaquin and Sacramento River watersheds water quality input to the Delta is modeled using the Soil-Water Assessment Tool (SWAT) and a modified SWAT tool has been customized to account for unique landscape and management of agricultural water supply and drainage within the Delta. Environmental response models for growth of invasive aquatic weeds are being parameterized and coupled with spatial distribution/biomass density mapping and water quality to study ecosystem response to climate and aquatic plant management practices. On the water validation and operational utilization of these tools by management agencies and how they improve decision making, management effectiveness and efficiency will be discussed. The project combines science, operations, and economics related to integrated management scenarios for aquatic weeds to help land and water resource managers make science-informed decisions regarding management and outcomes.

  9. Effects of snails, submerged plants and their coexistence on eutrophication in aquatic ecosystems

    Directory of Open Access Journals (Sweden)

    Mo Shuqing

    2017-01-01

    Full Text Available Eutrophication resulting from nutrient loading to freshwater habitats is a severe problem, leading to degradation of ecosystems, including deterioration of water quality, water clarity and loss of biodiversity. Measures enacted to restore degraded freshwater ecosystems often involve the reintroduction of submerged plants and aquatic animals with beneficial ecological functions. In a mesocosm experiment, three treatments (planting with Vallisneria natans, introduction of the snail Bellamya aeruginosa and a combined treatment with both plants and snails were compared with controls to evaluate their effects on trophic state. The total nitrogen (TN, total phosphorus (TP and chlorophyll a (Chl a concentrations of planktonic and benthic algal samples were determined every two weeks, along with light intensity at the sediment surface. The plant-only treatment significantly reduced the TN levels and planktonic and benthic algal biomass and increased the light intensity at the sediment surface. The snail-only treatment reduced the concentrations of TN and reduced planktonic and benthic algal biomass. The combined treatment decreased the concentrations of TN and TP, reduced planktonic algal biomass and increased the light intensity on the sediment surface. The results indicate that while submerged plants and snails can both improve water quality, the most pronounced effect in aquatic ecosystems is achieved by their presence in combination. A combined reintroduction approach may provide enhanced benefits in restoring the eutrophic ecosystems, following the reduction of external nutrient loading.

  10. Toxic potential of the emerging contaminant nicotine to the aquatic ecosystem.

    Science.gov (United States)

    Oropesa, Ana Lourdes; Floro, António Miguel; Palma, Patrícia

    2017-07-01

    Nicotine is a "life-style compound" widely consumed by human populations and, consequently, often found in surface waters. This fact presents a concern for possible effects in the aquatic ecosystems. The objective of this study was to assess the potential lethal and sublethal toxicity of nicotine in aquatic organisms from different trophic levels (Vibrio fischeri, Pseudokirchneriella subcapitata, Thamnocephalus platyurus, and Daphnia magna). The bioassays were performed by exposing the organisms to concentrations of nicotine in a range of 0.5-1000 μg/L. Results showed that nicotine, at tested concentration, was not acutely toxic to V. fischeri and T. platyurus. On the contrary, this substance exhibited toxicity to P. subcapitata and Daphnia magna. Thus, concentrations of nicotine of 100 and 200 μg/L promoted an inhibition in the growth of P. subcapitata. In addition, a concentration of 100 μg/L nicotine acted on the reproduction of the crustacean D. magna, by decreasing the number of juveniles produced by female. On the other hand, the results showed that concentrations equal to or greater than 10 μg/L induced the production of daphnids male offspring, which may indicate that nicotine is a weak juvenoid compound of the D. magna endocrine system. Furthermore, the result showed that concentrations tested of this chemical have the capacity to revert the effect of fenoxycarb, a strong juvenoid chemical insecticide. The results of the study revealed that nicotine can induce several changes in some of the most important key groups of the aquatic compartment, which can compromise, in a short time, the balance of aquatic ecosystem. Finally, a preliminary environmental risk assessment of this stimulant was performed from the highest measured concentration in surface water and the no observable effect concentration value in the most sensitive species, i.e., D. magna. This process revealed that nicotine can produce an important risk to aquatic organisms.

  11. Aquatic ecosystem response to timber harvesting for the purpose of restoring aspen.

    Directory of Open Access Journals (Sweden)

    Bobette E Jones

    Full Text Available The removal of conifers through commercial timber harvesting has been successful in restoring aspen, however many aspen stands are located near streams, and there are concerns about potential aquatic ecosystem impairment. We examined the effects of management-scale conifer removal from aspen stands located adjacent to streams on water quality, solar radiation, canopy cover, temperature, aquatic macroinvertebrates, and soil moisture. This 8-year study (2003-2010 involved two projects located in Lassen National Forest. The Pine-Bogard Project consisted of three treatments adjacent to Pine and Bogard Creeks: (i Phase 1 in January 2004, (ii Phase 2 in August 2005, and (iii Phase 3 in January 2008. The Bailey Project consisted of one treatment adjacent to Bailey Creek in September 2006. Treatments involved whole tree removal using track-laying harvesters and rubber tire skidders. More than 80% of all samples analyzed for NO₃-N, NH₄-N, and PO₄-P at Pine, Bogard, and Bailey Creeks were below the detection limit, with the exception of naturally elevated PO₄-P in Bogard Creek. All nutrient concentrations (NO₃-N, NH₄-N, PO₄-P, K, and SO₄-S showed little variation within streams and across years. Turbidity and TSS exhibited annual variation, but there was no significant increase in the difference between upstream and downstream turbidity and TSS levels. There was a significant decrease in stream canopy cover and increase in the potential fraction of solar radiation reaching the streams in response to the Pine-Bogard Phase 3 and Bailey treatments; however, there was no corresponding increase in stream temperatures. Macroinvertebrate metrics indicated healthy aquatic ecosystem conditions throughout the course of the study. Lastly, the removal of vegetation significantly increased soil moisture in treated stands relative to untreated stands. These results indicate that, with careful planning and implementation of site-specific best management

  12. Flow management for hydropower extirpates aquatic insects, undermining river food webs

    Science.gov (United States)

    Kennedy, Theodore A.; Muehlbauer, Jeffrey D.; Yackulic, Charles B.; Lytle, D.A.; Miller, S.A.; Dibble, Kimberly L.; Kortenhoeven, Eric W.; Metcalfe, Anya; Baxter, Colden V.

    2016-01-01

    Dams impound the majority of rivers and provide important societal benefits, especially daily water releases that enable on-peak hydroelectricity generation. Such “hydropeaking” is common worldwide, but its downstream impacts remain unclear. We evaluated the response of aquatic insects, a cornerstone of river food webs, to hydropeaking using a life history–hydrodynamic model. Our model predicts that aquatic-insect abundance will depend on a basic life-history trait—adult egg-laying behavior—such that open-water layers will be unaffected by hydropeaking, whereas ecologically important and widespread river-edge layers, such as mayflies, will be extirpated. These predictions are supported by a more-than-2500-sample, citizen-science data set of aquatic insects from the Colorado River in the Grand Canyon and by a survey of insect diversity and hydropeaking intensity across dammed rivers of the Western United States. Our study reveals a hydropeaking-related life history bottleneck that precludes viable populations of many aquatic insects from inhabiting regulated rivers.

  13. Reviews and syntheses : Effects of permafrost thaw on Arctic aquatic ecosystems

    NARCIS (Netherlands)

    Vonk, J. E.; Tank, S. E.; Bowden, W.B.; Laurion, I.; Vincent, W. F.; Alekseychik, P.; Amyot, M.; Billet, M. F.; Canário, J.; Cory, R. M.; Deshpande, B. N.; Helbig, M.; Jammet, M.; Karlsson, J.; Larouche, J.; Macmillan, G.; Rautio, M.; Walter Anthony, K. M.; Wickland, K.P.

    2015-01-01

    The Arctic is a water-rich region, with freshwater systems covering about 16 % of the northern permafrost landscape. Permafrost thaw creates new freshwater ecosystems, while at the same time modifying the existing lakes, streams, and rivers that are impacted by thaw. Here, we describe the current

  14. Parasites as drivers of key processes in aquatic ecosystems: Facts and future directions.

    Science.gov (United States)

    Sures, B; Nachev, M; Pahl, M; Grabner, D; Selbach, C

    2017-09-01

    Despite the advances in our understanding of the ecological importance of parasites that we have made in recent years, we are still far away from having a complete picture of the ecological implications connected to parasitism. In the present paper we highlight key issues that illustrate (1) important contributions of parasites to biodiversity, (2) their integral role in ecosystems, (3) as well as their ecological effects as keystone species (4) and in biological invasion processes. By using selected examples from aquatic ecosystems we want to provide an insight and generate interest into the topic, and want to show directions for future research in the field of ecological parasitology. This may help to convince more parasitologists and ecologists contributing and advancing our understanding of the complex and fascinating interplay of parasites, hosts and ecosystems. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Examining Ecological and Ecosystem Level Impacts of Aquatic Invasive Species in Lake Michigan Using An Ecosystem Productivity Model, LM-Eco

    Science.gov (United States)

    Ecological and ecosystem-level impacts of aquatic invasive species in Lake Michigan were examined using the Lake Michigan Ecosystem Model (LM-Eco). The LM-Eco model includes a detailed description of trophic levels and their interactions within the lower food web of Lake Michiga...

  16. Using Remotely Sensed Data and Hydrologic Models to Evaluate the Effects of Climate Change on Shallow Aquatic Ecosystems in the Mobile Bay, AL Estuary

    Science.gov (United States)

    Estes, M. G.; Al-Hamdan, M. Z.; Thom, R.; Judd, C.; Ellis, J.; Woodruff, D.; Quattrochi, D.; Rose, K.; Swann, R.

    2012-12-01

    Coastal systems in the northern Gulf of Mexico, including the Mobile Bay, AL estuary, are subject to increasing pressure from a variety of activities including climate change. Climate changes have a direct effect on the discharge of rivers that drain into Mobile Bay and adjacent coastal water bodies. The outflows change water quality (temperature, salinity, and sediment concentrations) in the shallow aquatic areas and affect ecosystem functioning. Mobile Bay is a vital ecosystem that provides habitat for many species of fauna and flora. Historically, submerged aquatic vegetation (SAV) and seagrasses were found in this area of the northern Gulf of Mexico; however the extent of vegetation has significantly decreased over the last 60 years. The objectives of this research are to determine: how climate changes affect runoff and water quality in the estuary and how these changes will affect habitat suitability for SAV and seagrasses. Our approach is to use watershed and hydrodynamic modeling to evaluate the impact of climate change on shallow water aquatic ecosystems in Mobile Bay and adjacent coastal areas. Remotely sensed Landsat data were used for current land cover land use (LCLU) model input and the data provided by Intergovernmental Panel on Climate Change (IPCC) of the future changes in temperature, precipitation, and sea level rise were used to create the climate scenarios for the 2025 and 2050 model simulations. Project results are being shared with Gulf coast stakeholders through the Gulf of Mexico Data Atlas to benefit coastal policy and climate change adaptation strategies.

  17. Using Remotely Sensed Data and Hydrologic Models to Evaluate the Effects of Climate Change on Shallow Aquatic Ecosystems in the Mobile Bay, AL Estuary

    Science.gov (United States)

    Estes, M. G.; Al-Hamdan, M. Z.; Thom, R.; Judd, C.; Woodruff, D.; Ellis, J. T.; Quattrochi, D.; Swann, R.

    2012-01-01

    Coastal systems in the northern Gulf of Mexico, including the Mobile Bay, AL estuary, are subject to increasing pressure from a variety of activities including climate change. Climate changes have a direct effect on the discharge of rivers that drain into Mobile Bay and adjacent coastal water bodies. The outflows change water quality (temperature, salinity, and sediment concentrations) in the shallow aquatic areas and affect ecosystem functioning. Mobile Bay is a vital ecosystem that provides habitat for many species of fauna and flora. Historically, submerged aquatic vegetation (SAV) and seagrasses were found in this area of the northern Gulf of Mexico; however the extent of vegetation has significantly decreased over the last 60 years. The objectives of this research are to determine: how climate changes affect runoff and water quality in the estuary and how these changes will affect habitat suitability for SAV and seagrasses. Our approach is to use watershed and hydrodynamic modeling to evaluate the impact of climate change on shallow water aquatic ecosystems in Mobile Bay and adjacent coastal areas. Remotely sensed Landsat data were used for current land cover land use (LCLU) model input and the data provided by Intergovernmental Panel on Climate Change (IPCC) of the future changes in temperature, precipitation, and sea level rise were used to create the climate scenarios for the 2025 and 2050 model simulations. Project results are being shared with Gulf coast stakeholders through the Gulf of Mexico Data Atlas to benefit coastal policy and climate change adaptation strategies.

  18. Impact Of Human Activities On Ecosystem In Rivers State, Nigeria ...

    African Journals Online (AJOL)

    This study was to assess the percent sample population size of people involved in selected human economic activities and the impact on ecosystem in Rivers State. The data for this study was obtained from a sample size of 1000 respondents who were purposively selected from the study area. Purposive sample was used ...

  19. The Human Threat to River Ecosystems at the Watershed Scale: An Ecological Security Assessment of the Songhua River Basin, Northeast China

    Directory of Open Access Journals (Sweden)

    Yuan Shen

    2017-03-01

    Full Text Available Human disturbances impact river basins by reducing the quality of, and services provided by, aquatic ecosystems. Conducting quantitative assessments of ecological security at the watershed scale is important for enhancing the water quality of river basins and promoting environmental management. In this study, China’s Songhua River Basin was divided into 204 assessment units by combining watershed and administrative boundaries. Ten human threat factors were identified based on their significant influence on the river ecosystem. A modified ecological threat index was used to synthetically evaluate the ecological security, where frequency was weighted by flow length from the grids to the main rivers, while severity was weighted by the potential hazard of the factors on variables of river ecosystem integrity. The results showed that individual factors related to urbanization, agricultural development and facility construction presented different spatial distribution characteristics. At the center of the plain area, the provincial capital cities posed the highest level of threat, as did the municipal districts of prefecture-level cities. The spatial relationships between hot spot locations of the ecological threat index and water quality, as well as the distribution areas of critically endangered species, were analyzed. The sensitivity analysis illustrated that alteration of agricultural development largely changed the ecological security level of the basin. By offering a reference for assessing ecological security, this study can enhance water environmental planning and management.

  20. Urgent and Compelling Need for Coastal and Inland Aquatic Ecosystem Research Using Space-Based Sensors

    Science.gov (United States)

    Otis, D. B.; Muller-Karger, F. E.; Hestir, E.; Turpie, K. R.; Roberts, D. A.; Frouin, R.; Goodman, J.; Schaeffer, B. A.; Franz, B. A.; Humm, D. C.

    2016-12-01

    Coastal and inland waters and associated aquatic habitats, including wetlands, mangroves, submerged grasses, and coral reefs, are some of the most productive and diverse ecosystems on the planet. They provide services critical to human health, safety, and prosperity. Yet, they are highly vulnerable to changes in climate and other anthropogenic pressures. With a global population of over seven billion people and climbing, and a warming atmosphere driven by carbon dioxide now in excess of 400 ppb, these services are at risk of rapidly diminishing globally. We know little about how these ecosystems function. We need to characterize short-term changes in the functional biodiversity and biogeochemical cycles of these coastal and wetland ecosystems, from canopy to benthos, and trace these changes to their underlying environmental influences. This requires an observation-based approach that covers coastal and inland aquatic ecosystems in a repeated, synoptic manner. Space-borne sensing systems can provide this capability, supported by coordinated in situ calibration and product validation activities. The design requires high temporal resolution (weekly or better), medium spatial resolution (30 m pixels at nadir to complement Landsat-class sensors), and highly sensitive, ocean-color radiometric quality, high resolution spectroscopy with Visible and Short-Wave IR bands (order of 10 nm or better) to assess both atmospheric correction parameters and land vegetation composition. The strategy needs to include sunglint avoidance schemes, and methods to maximize signal to noise ratios and temporal coverage of aquatic areas. We describe such a system, and urge the U.S. to implement such an observing strategy in the short-term and sustain it for the benefit of humankind.

  1. Aquatic habitat modifications in La Plata River basin, Patagonia and associated marine areas.

    Science.gov (United States)

    Mugetti, Ana Cristina; Calcagno, Alberto Tomás; Brieva, Carlos Alberto; Giangiobbe, María Silvia; Pagani, Andrea; Gonzalez, Silvia

    2004-02-01

    This paper describes the environmental characteristics and situation of aquatic habitats and communities in southern continental and maritime areas of southeastern South America (Patagonian Shelf GIWA Subregion), resulting from an overall assessment carried out within the framework of a GIWA project, mostly on the basis of publicly available data. The main focus of the analysis was on the current situation of transboundary water resources and anthropogenic impacts. In the inland waters, habitat and community modifications result, principally, from dams and reservoirs built in the main watercourses for hydroelectric power generation and other uses. The transformation of lotic environments into lentic ones have affected habitats and altered biotic communities. In the La Plata River basin, invasive exotic species have displaced native ones. Habitats in the ocean have been degraded, as their biodiversity becomes affected by overfishing and pollution. This article includes a discussion on the causal chain and the policy options elaborated for the Coastal Ecosystem of Buenos Aires province and the Argentinean-Uruguayan Common Fishing Zone, where fishing resources are shared by both countries.

  2. Heavy metal pollution in aquatic ecosystems and its phytoremediation using wetland plants: An ecosustainable approach

    Energy Technology Data Exchange (ETDEWEB)

    Rai, P.K. [Mizoram Central University, Tanhril (India). School for Earth Science & Natural Resource Management

    2008-07-01

    This review addresses the global problem of heavy metal pollution originating from increased industrialization and urbanization and its amelioration by using wetland plants both in a microcosm as well as natural/field condition. This review mentions salient features of wetland ecosystems, their vegetation component, and the pros and cons involved in heavy metal removal. Wetland plants are preferred over other bio-agents due to their low cost, frequent abundance in aquatic ecosystems, and easy handling. Constructed wetlands proved to be effective for the abatement of heavy metal pollution from acid mine drainage; landfill leachate; thermal power; and municipal, agricultural, refinery, and chlor-alkali effluent. the physicochemical properties of wetlands provide many positive attributes for remediating heavy metals. Typha, Phragmites, Eichhornia, Azolla, Lemna, and other aquatic macrophytes are some of the potent wetland plants for heavy metal removal. Biomass disposal problem and seasonal growth of aquatic macrophytes are some limitations in the transfer of phytoremediation technology from the laboratory to the field. However, the disposed biomass of macrophytes may be used for various fruitful applications. An ecosustainable model has been developed through the author's various works, which may ameliorate some of the limitations. The creation of more areas for phytoremediation may also aid in wetlands conservation. Genetic engineering and biodiversity prospecting of endangered wetland plants are important future prospects in this regard.

  3. Environmental Risk Assessment Caused by Selected Pollutants to Aquatic Environment on the Example of the Klodnica River

    Directory of Open Access Journals (Sweden)

    Marta Wiesner-Sękala

    2017-12-01

    Full Text Available The waterbody Kłodnica to Promna as was analysed an example of watercourse located in the densely populated and highly urbanized area of the Upper Silesian Industrial Region. The aim of the study was to assess the risk posed to the aquatic ecosystem by priority substances (Ni, Pb, Cd, Hg and specific non-synthetic pollutants (Cu, Zn, which are released to Kłodnica river. The analysis of the risk assessment was carried out by comparing the concentration of metals in the aquatic environment to the environmental quality standards and by using M-BAT and Pb Screening Tool which are user-friendly simplified BLM models (Biotic Ligand Model. These tools allowed to assess the potential risks posed by metals such as Cu, Ni, Zn, and Pb for the aquatic environment, taking into account the physicochemical parameters of water that affect the bioavailability of metals in the aquatic environment (DOC, Ca, pH. The results obtained by means of these tools showed that the risk caused by the toxicity of Cu, Ni and Pb has not occurred in any of the analyzed samples. On the other hand, high probability of risk due to the presence of Zn in surface water has been identified in all sampling points. The results of the analysis confirmed that the local conditions in terms of physicochemical water parameters have a significant impact on the risk assessment. The results of this study confirmed that the tools which are simplified version of complex BLM are an important element supporting the monitoring process in urbanized river catchment in the context of the Water Framework Directive requirements.

  4. A review of ecological effects and environmental fate of illicit drugs in aquatic ecosystems.

    Science.gov (United States)

    Rosi-Marshall, E J; Snow, D; Bartelt-Hunt, S L; Paspalof, A; Tank, J L

    2015-01-23

    Although illicit drugs are detected in surface waters throughout the world, their environmental fate and ecological effects are not well understood. Many illicit drugs and their breakdown products have been detected in surface waters and temporal and spatial variability in use translates into "hot spots and hot moments" of occurrence. Illicit drug occurrence in regions of production and use and areas with insufficient wastewater treatment are not well studied and should be targeted for further study. Evidence suggests that illicit drugs may not be persistent, as their half-lives are relatively short, but may exhibit "pseudo-persistence" wherein continual use results in persistent occurrence. We reviewed the literature on the ecological effects of these compounds on aquatic organisms and although research is limited, a wide array of aquatic organisms, including bacteria, algae, invertebrates, and fishes, have receptors that make them potentially sensitive to these compounds. In summary, illicit drugs occur in surface waters and aquatic organisms may be affected by these compounds; research is needed that focuses on concentrations of illicit drugs in areas of production and high use, environmental fate of these compounds, and effects of these compounds on aquatic ecosystems at the concentrations that typically occur in the environment. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Aquatic invertebrates of the Ribnica and Lepenica Rivers: Composition of the community and water quality

    Directory of Open Access Journals (Sweden)

    Jović Aleksandra

    2006-01-01

    Full Text Available Results of investigating the community of aquatic invertebrates in the Ribnica and Lepenica Rivers (Kolubara River drainage area are given in the present work. Forty-three taxa are recorded. In relation to other studied streams in Serbia, the investigated rivers are characterized by high diversity of macroinvertebrates. Cluster analysis indicates that the locality on the Lepenica stands apart from those on the Ribnica, which is a consequence of the difference of habitats found at them. Results of saprobiological analysis of the macrozoobenthos in the given rivers indicate that their waters belong to quality classes I and II.

  6. Terrestrial contributions to the aquatic food web in the middle Yangtze River.

    Directory of Open Access Journals (Sweden)

    Jianzhu Wang

    Full Text Available Understanding the carbon sources supporting aquatic consumers in large rivers is essential for the protection of ecological integrity and for wildlife management. The relative importance of terrestrial and algal carbon to the aquatic food webs is still under intensive debate. The Yangtze River is the largest river in China and the third longest river in the world. The completion of the Three Gorges Dam (TGD in 2003 has significantly altered the hydrological regime of the middle Yangtze River, but its immediate impact on carbon sources supporting the river food web is unknown. In this study, potential production sources from riparian and the main river channel, and selected aquatic consumers (invertebrates and fish at an upstream constricted-channel site (Luoqi, a midstream estuarine site (Huanghua and a near dam limnetic site (Maoping of the TGD were collected for stable isotope (δ13C and δ15N and IsoSource analyses. Model estimates indicated that terrestrial plants were the dominant carbon sources supporting the consumer taxa at the three study sites. Algal production appeared to play a supplemental role in supporting consumer production. The contribution from C4 plants was more important than that of C3 plants at the upstream site while C3 plants were the more important carbon source to the consumers at the two impacted sites (Huanghua and Maoping, particularly at the midstream site. There was no trend of increase in the contribution of autochthonous production from the upstream to the downstream sites as the flow rate decreased dramatically along the main river channel due to the construction of TGD. Our findings, along with recent studies in rivers and lakes, are contradictory to studies that demonstrate the importance of algal carbon in the aquatic food web. Differences in system geomorphology, hydrology, habitat heterogeneity, and land use may account for these contradictory findings reported in various studies.

  7. Terrestrial contributions to the aquatic food web in the middle Yangtze River.

    Science.gov (United States)

    Wang, Jianzhu; Gu, Binhe; Huang, Jianhui; Han, Xingguo; Lin, Guanghui; Zheng, Fawen; Li, Yuncong

    2014-01-01

    Understanding the carbon sources supporting aquatic consumers in large rivers is essential for the protection of ecological integrity and for wildlife management. The relative importance of terrestrial and algal carbon to the aquatic food webs is still under intensive debate. The Yangtze River is the largest river in China and the third longest river in the world. The completion of the Three Gorges Dam (TGD) in 2003 has significantly altered the hydrological regime of the middle Yangtze River, but its immediate impact on carbon sources supporting the river food web is unknown. In this study, potential production sources from riparian and the main river channel, and selected aquatic consumers (invertebrates and fish) at an upstream constricted-channel site (Luoqi), a midstream estuarine site (Huanghua) and a near dam limnetic site (Maoping) of the TGD were collected for stable isotope (δ13C and δ15N) and IsoSource analyses. Model estimates indicated that terrestrial plants were the dominant carbon sources supporting the consumer taxa at the three study sites. Algal production appeared to play a supplemental role in supporting consumer production. The contribution from C4 plants was more important than that of C3 plants at the upstream site while C3 plants were the more important carbon source to the consumers at the two impacted sites (Huanghua and Maoping), particularly at the midstream site. There was no trend of increase in the contribution of autochthonous production from the upstream to the downstream sites as the flow rate decreased dramatically along the main river channel due to the construction of TGD. Our findings, along with recent studies in rivers and lakes, are contradictory to studies that demonstrate the importance of algal carbon in the aquatic food web. Differences in system geomorphology, hydrology, habitat heterogeneity, and land use may account for these contradictory findings reported in various studies.

  8. Widespread occurrence of estrogenic UV-filters in aquatic ecosystems in Switzerland

    International Nuclear Information System (INIS)

    Fent, Karl; Zenker, Armin; Rapp, Maja

    2010-01-01

    We performed a trace analytical study covering nine hormonally active UV-filters by LC-MS/MS and GC-MS in river water and biota. Water was analysed at 10 sites above and below wastewater treatment plants in the river Glatt using polar organic chemical integrative samplers (POCIS). Four UV-filters occurred in the following order of decreasing concentrations; benzophenone-4 (BP-4) > benzophenone-3 (BP-3) > 3-(4-methyl)benzylidene-camphor (4-MBC) > 2-ethyl-hexyl-4-trimethoxycinnamate (EHMC). BP-4 ranged from 0.27 to 24.0 μg/POCIS, BP-3, 4-MBC and EHMC up to 0.1 μg/POCIS. Wastewater was the most important source. Levels decreased with higher river water flow. No significant in-stream removal occurred. BP-3, 4-MBC and EHMC were between 6 and 68 ng/L in river water. EHMC was accumulated in biota. In all 48 macroinvertebrate and fish samples from six rivers lipid-weighted EHMC occurred up to 337 ng/g, and up to 701 ng/g in 5 cormorants, suggesting food-chain accumulation. UV-filters are found to be ubiquitous in aquatic systems. - Several UV-filters from cosmetics and materials protection occur in rivers and EHMC accumulates in biota.

  9. Widespread occurrence of estrogenic UV-filters in aquatic ecosystems in Switzerland

    Energy Technology Data Exchange (ETDEWEB)

    Fent, Karl, E-mail: karl.fent@bluewin.c [University of Applied Sciences (FHNW), School of Life Sciences, Gruendenstrasse 40, CH-4132 Muttenz (Switzerland); Swiss Federal Institute of Technology (ETH Zurich), Department of Environmental Sciences, CH-8092 Zuerich (Switzerland); Zenker, Armin [University of Applied Sciences (FHNW), School of Life Sciences, Gruendenstrasse 40, CH-4132 Muttenz (Switzerland); Rapp, Maja [Swiss Federal Institute of Technology (ETH Zurich), Institute of Environmental Engineering, Wolfgang-Pauli-Strasse 15, CH-8093 Zuerich (Switzerland)

    2010-05-15

    We performed a trace analytical study covering nine hormonally active UV-filters by LC-MS/MS and GC-MS in river water and biota. Water was analysed at 10 sites above and below wastewater treatment plants in the river Glatt using polar organic chemical integrative samplers (POCIS). Four UV-filters occurred in the following order of decreasing concentrations; benzophenone-4 (BP-4) > benzophenone-3 (BP-3) > 3-(4-methyl)benzylidene-camphor (4-MBC) > 2-ethyl-hexyl-4-trimethoxycinnamate (EHMC). BP-4 ranged from 0.27 to 24.0 mug/POCIS, BP-3, 4-MBC and EHMC up to 0.1 mug/POCIS. Wastewater was the most important source. Levels decreased with higher river water flow. No significant in-stream removal occurred. BP-3, 4-MBC and EHMC were between 6 and 68 ng/L in river water. EHMC was accumulated in biota. In all 48 macroinvertebrate and fish samples from six rivers lipid-weighted EHMC occurred up to 337 ng/g, and up to 701 ng/g in 5 cormorants, suggesting food-chain accumulation. UV-filters are found to be ubiquitous in aquatic systems. - Several UV-filters from cosmetics and materials protection occur in rivers and EHMC accumulates in biota.

  10. Aquatic emergency response model at the Savannah River Plant

    International Nuclear Information System (INIS)

    Hayes, D.W.

    1987-01-01

    The Savannah River Plant emergency response plans include a stream/river emergency response model to predict travel times, maximum concentrations, and concentration distributions as a function of time at selected downstream/river locations from each of the major SRP installations. The menu driven model can be operated from any of the terminals that are linked to the real-time computer monitoring system for emergency response

  11. Impacts of aquatic nonindigenous invasive species on the Lake Erie ecosystem

    Science.gov (United States)

    Austen, Madeline J.W.; Ciborowski, Jan J.H.; Corkum, Lynda D.; Johnson, Tim B.; MacIsaac, Hugh J.; Metcalfe-Smith, Janice L.; Schloesser, Donald W.; George, Sandra E.

    2002-01-01

    Lake Erie is particularly vulnerable to the introduction and establishment of aquatic nonindigenous invasive species (NIS) populations. A minimum of 144 aquatic NIS have been recorded in the Lake Erie basin including several species [e.g., Eurasian watermilfoil (Myriophyllum spicatum); zebra mussel (Dreissena polymorpha); quagga mussel (Dreissena bugensis); an amphipod (Echinogammarus ischnus); round goby (Neogobius melanostomus); and sea lamprey (Petromyzon marinus)] that have had discernible impacts on the lake's ecology. NIS pose threats to the Lake Erie ecosystem for a variety of reasons including their ability to proliferate quickly, compete with native species, and transfer contaminants (e.g., PCBs) and disease through the food web. Six of the 14 beneficial use impairments listed in Annex 2 of the Great Lakes Water Quality Agreement are impaired in Lake Erie, in part as a result of the introduction of NIS. The Lake Erie Lakewide Management Plan (LaMP) has adopted an ecosystem approach to restore beneficial use impairments in the lake. Furthermore, a research consortium, known as the Lake Erie Millennium Network, is working alongside the LaMP, to address research problems regarding NIS, the loss of habitat, and the role of contaminants in the Lake Erie ecosystem.

  12. Polychlorinated biphenyls (PCBs) in a river ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Bremle, G

    1997-03-01

    In the Emaan River, in southeast Sweden, contaminated sediment was a source of PCB, the largest deposits of it being found in a small lake connected to the river: lake Jaernsjoen, the sediment of which contained about 400 kg of PCB. The concentration of PCB in the water and in the fish was more elevated downstream from the lake than at upstream sites. Lake Jaernsjoen was cleaned up by dredging during 1993 and 1994. The dredged sediment, estimated to contain over 95% of the PCB in the lake, was deposited in a landfill. During the cleanup action, the concentration of PCB downstream from the lake did not become higher than before. The PCB concentration in the air around the landfill increased in the vicinity and during construction of the landfill. After closure of the landfill by a layer placed on top of it, the PCB concentration in the air fell to background levels. No increase in the PCB concentration in the ground water around the landfill as a result of the remedial action could be detected. In the summer of 1996, nearly two years after remediation had been completed, an investigation of the PCB concentration in the fish of the river system was conducted. This investigation was a repetition of one made in 1991, prior to remediation. It showed that after remediation the concentration of PCB in one-year old fish in Lake Jaernsjoen was halved. The concentration of PCB in fish upstream was also lower, probably because of the decrease in overall background contamination. 155 refs, 13 figs

  13. Nitrogen and phosphorus in the Upper Mississippi River: Transport, processing, and effects on the river ecosystem

    Science.gov (United States)

    Houser, J.N.; Richardson, W.B.

    2010-01-01

    Existing research on nutrients (nitrogen and phosphorus) in the Upper Mississippi River (UMR) can be organized into the following categories: (1) Long-term changes in nutrient concentrations and export, and their causes; (2) Nutrient cycling within the river; (3) Spatial and temporal patterns of river nutrient concentrations; (4) Effects of elevated nutrient concentrations on the river; and (5) Actions to reduce river nutrient concentrations and flux. Nutrient concentration and flux in the Mississippi River have increased substantially over the last century because of changes in land use, climate, hydrology, and river management and engineering. As in other large floodplain rivers, rates of processes that cycle nitrogen and phosphorus in the UMR exhibit pronounced spatial and temporal heterogeneity because of the complex morphology of the river. This spatial variability in nutrient processing creates clear spatial patterns in nutrient concentrations. For example, nitrate concentrations generally are much lower in off-channel areas than in the main channel. The specifics of in-river nutrient cycling and the effects of high rates of nutrient input on UMR have been less studied than the factors affecting nutrient input to the river and transport to the Gulf of Mexico, and important questions concerning nutrient cycling in the UMR remain. Eutrophication and resulting changes in river productivity have only recently been investigated the UMR. These recent studies indicate that the high nutrient concentrations in the river may affect community composition of aquatic vegetation (e. g., the abundance of filamentous algae and duckweeds), dissolved oxygen concentrations in off-channel areas, and the abundance of cyanobacteria. Actions to reduce nutrient input to the river include changes in land-use practices, wetland restoration, and hydrological modifications to the river. Evidence suggests that most of the above methods can contribute to reducing nutrient concentration in

  14. Aquatic life protection index of an urban river Bacanga basin in northern Brazil, São Luís - MA

    Directory of Open Access Journals (Sweden)

    A. K. Duarte-dos-Santos

    Full Text Available Abstract Bacanga River Basin faces environmental problems related to urbanization and discharge of untreated domestic sewage, which compromise its ecosystem health. Due to the small number of studies that assessed its water quality, the present study aimed to assess the current status of this ecosystem based on the aquatic life protection index. Samples were carried out every two months, in a total of six events, in six sites along the basin, where the water samples were collected to assess physicochemical parameters and calculate the trophic state index and the index of minimum parameters for the protection of aquatic communities. The data were also compared with values determined by the resolution National Environment Council - CONAMA 357/05. Our results reveal significant changes in the water quality of Bacanga River Basin. An increase in nutrients and chlorophyll-a concentration led it to eutrophication. The surfactant values were high and put in danger the aquatic biota. Dissolved oxygen rates were below the values allowed by the resolution in most sites sampled. The current water quality is terrible for the protection of aquatic life in 61.92% of the sites sampled.

  15. Mining in the Alligator Rivers Region, northern Australia: Assessing potential and actual effects on ecosystem and human health

    International Nuclear Information System (INIS)

    Dam, R.A. van; Humphrey, C.L.; Martin, P.

    2002-01-01

    This paper presents an overview of issues related to surface water contamination arising from uranium mining activities in the Alligator Rivers Region (ARR) of northern Australia, and a program of research and monitoring that must assess the potential and actual effects on ecosystem and human health. The program of assessing effects on aquatic ecosystems involves a four-tiered approach including the derivation of local water quality guideline trigger values, direct toxicity assessment of mine waters prior to their release, creekside or in situ monitoring for early warning of adverse effects during mine water release, and longer-term monitoring of macroinvertebrate and fish communities. Bioaccumulation in aquatic biota is also assessed, and is an issue of importance not only to ecosystem health, but also to the health of local Aboriginal people. The aquatic animals they consume represent potential sources of radiological dose, and as a result, a major component of the program to assess potential effects on human health is the prediction of doses to Aboriginal people living downstream of mining activities. Acknowledging the assumptions and uncertainties, the calculation of concentration factors for local aquatic (and other) food sources allows the prediction of potential radiological exposure to people following hypothetical mine water releases. The approaches described form the basis of best-practice protocols that are relevant at both regional and national levels

  16. Managing the effects of multiple stressors on aquatic ecosystems under water scarcity. The GLOBAQUA project.

    Science.gov (United States)

    Navarro-Ortega, Alícia; Acuña, Vicenç; Bellin, Alberto; Burek, Peter; Cassiani, Giorgio; Choukr-Allah, Redouane; Dolédec, Sylvain; Elosegi, Arturo; Ferrari, Federico; Ginebreda, Antoni; Grathwohl, Peter; Jones, Colin; Rault, Philippe Ker; Kok, Kasper; Koundouri, Phoebe; Ludwig, Ralf Peter; Merz, Ralf; Milacic, Radmila; Muñoz, Isabel; Nikulin, Grigory; Paniconi, Claudio; Paunović, Momir; Petrovic, Mira; Sabater, Laia; Sabaterb, Sergi; Skoulikidis, Nikolaos Th; Slob, Adriaan; Teutsch, Georg; Voulvoulis, Nikolaos; Barceló, Damià

    2015-01-15

    Water scarcity is a serious environmental problem in many European regions, and will likely increase in the near future as a consequence of increased abstraction and climate change. Water scarcity exacerbates the effects of multiple stressors, and thus results in decreased water quality. It impacts river ecosystems, threatens the services they provide, and it will force managers and policy-makers to change their current practices. The EU-FP7 project GLOBAQUA aims at identifying the prevalence, interaction and linkages between stressors, and to assess their effects on the chemical and ecological status of freshwater ecosystems in order to improve water management practice and policies. GLOBAQUA assembles a multidisciplinary team of 21 European plus 2 non-European scientific institutions, as well as water authorities and river basin managers. The project includes experts in hydrology, chemistry, biology, geomorphology, modelling, socio-economics, governance science, knowledge brokerage, and policy advocacy. GLOBAQUA studies six river basins (Ebro, Adige, Sava, Evrotas, Anglian and Souss Massa) affected by water scarcity, and aims to answer the following questions: how does water scarcity interact with other existing stressors in the study river basins? How will these interactions change according to the different scenarios of future global change? Which will be the foreseeable consequences for river ecosystems? How will these in turn affect the services the ecosystems provide? How should management and policies be adapted to minimise the ecological, economic and societal consequences? These questions will be approached by combining data-mining, field- and laboratory-based research, and modelling. Here, we outline the general structure of the project and the activities to be conducted within the fourteen work-packages of GLOBAQUA. Copyright © 2014. Published by Elsevier B.V.

  17. Managing the effects of multiple stressors on aquatic ecosystems under water scarcity. The GLOBAQUA project

    Science.gov (United States)

    Navarro-Ortega, Alícia; Acuña, Vicenç; Bellin, Alberto; Burek, Peter; Cassiani, Giorgio; Choukr-Allah, Redouane; Dolédec, Sylvain; Elosegi, Arturo; Ferrari, Federico; Ginebreda, Antoni; Grathwohl, Peter; Jones, Colin; Rault, Philippe Ker; Kok, Kasper; Koundouri, Phoebe; Ludwig, Ralf Peter; Merz, Ralf; Milacic, Radmila; Muñoz, Isabel; Nikulin, Grigory; Paniconi, Claudio; Paunović, Momir; Petrovic, Mira; Sabater, Laia; Sabaterb, Sergi; Skoulikidis, Nikolaos Th.; Slob, Adriaan; Teutsch, Georg; Voulvoulis, Nikolaos; Barceló, Damià

    2015-01-01

    Water scarcity is a serious environmental problem in many European regions, and will likely increase in the near future as a consequence of increased abstraction and climate change. Water scarcity exacerbates the effects of multiple stressors, and thus results in decreased water quality. It impacts river ecosystems, threatens the services they provide, and it will force managers and policy-makers to change their current practices. The EU-FP7 project GLOBAQUA aims at identifying the prevalence, interaction and linkages between stressors, and to assess their effects on the chemical and ecological status of freshwater ecosystems in order to improve water management practice and policies. GLOBAQUA assembles a multidisciplinary team of 21 European plus 2 non-European scientific institutions, as well as water authorities and river basin managers. The project includes experts in hydrology, chemistry, biology, geomorphology, modelling, socio-economics, governance science, knowledge brokerage, and policy advocacy. GLOBAQUA studies six river basins (Ebro, Adige, Sava, Evrotas, Anglian and Souss Massa) affected by water scarcity, and aims to answer the following questions: how does water scarcity interact with other existing stressors in the study river basins? How will these interactions change according to the different scenarios of future global change? Which will be the foreseeable consequences for river ecosystems? How will these in turn affect the services the ecosystems provide? How should management and policies be adapted to minimise the ecological, economic and societal consequences? These questions will be approached by combining data-mining, field- and laboratory-based research, and modelling. Here, we outline the general structure of the project and the activities to be conducted within the fourteen work-packages of GLOBAQUA. PMID:25005236

  18. Modeling techniques for predicting long-term consequences of the effects of radiation on natural aquatic populations and ecosystems

    International Nuclear Information System (INIS)

    Van Winkle, W.

    1977-01-01

    Appropriate modeling techniques already exist for investigating some long-term consequences of the effects of radiation on natural aquatic populations and ecosystems, even if to date these techniques have not been used for this purpose. At the low levels of irradiation estimated to occur in natural aquatic systems, effects are difficult to detect at even the individual level much less the population or ecosystem level where the subtle effects of radiation are likely to be completely overshadowed by the effects of other environmental factors and stresses and the natural variability of the system. The claim that population and ecosystem models can be accurate and reliable predictive tools in assessing any stress has been oversold. Nonetheless, the use of these tools can be useful for learning more about the effects of radioactive releases on aquatic populations and ecosystems

  19. Patterning and predicting aquatic insect richness in four West-African coastal rivers using artificial neural networks

    OpenAIRE

    Edia E.O.; Gevrey M.; Ouattara A.; Brosse S.; Gourène G.; Lek S.

    2010-01-01

    Despite their importance in stream management, the aquatic insect assemblages are still little known in West Africa. This is particularly true in South-Eastern Ivory Coast, where aquatic insect assemblages were hardly studied. We therefore aimed at characterising aquatic insect assemblages on four coastal rivers in South-Eastern Ivory Coast. Patterning aquatic insect assemblages was achieved using a Self-Organizing Map (SOM), an unsupervised Artificial Neural Networks (ANN) method. This metho...

  20. Aquatic ecosystem responses to Holocene climate change and biome development in boreal, central Asia

    Science.gov (United States)

    Mackay, Anson W.; Bezrukova, Elena V.; Leng, Melanie J.; Meaney, Miriam; Nunes, Ana; Piotrowska, Natalia; Self, Angela; Shchetnikov, Alexander; Shilland, Ewan; Tarasov, Pavel; Wang, Luo; White, Dustin

    2012-05-01

    Boreal ecosystems are highly vulnerable to climate change, and severe ecological impacts in the near future are virtually certain to occur. We undertook a multiproxy study on an alpine lake (ESM-1) at the modern tree-line in boreal, southern Siberia. Steppe and tundra biomes were extensive in eastern Sayan landscapes during the early Holocene. Boreal forest quickly expanded by 9.1 ka BP, and dominated the landscape until c 0.7 ka BP, when the greatest period of compositional turnover occurred. At this time, alpine meadow landscape expanded and Picea obovata colonised new habitats along river valleys and lake shorelines, because of prevailing cool, moist conditions. During the early Holocene, chironomid assemblages were dominated by cold stenotherms. Diatoms for much of the Holocene were dominated by alkaliphilous, fragilarioid taxa, up until 0.2 ka BP, when epiphytic species expanded, indicative of increased habitat availability. C/N mass ratios ranged between 9.5 and 13.5 (11.1-15.8 C/N atomic ratios), indicative of algal communities dominating organic matter contributions to bottom sediments with small, persistent contributions from vascular plants. However, δ13C values increased steadily from -34.9‰ during the early Holocene (9.3 ka BP) to -24.8‰ by 0.6 ka BP. This large shift in magnitude may be due to a number of factors, including increasing within-lake productivity, increasing disequilibrium between the isotopic balance of the lake with the atmosphere as the lake became isotopically ‘mature’, and declining soil respiration linked to small, but distinct retreat in forest biomes. The influence of climatic variables on landscape vegetation was assessed using redundancy analysis (RDA), a linear, direct ordination technique. Changes in July insolation at 60 °N significantly explained over one-fifth of the variation in species composition, while changes in estimates of northern hemisphere temperature and ice-rafted debris events in the North Atlantic

  1. Hydrologic alteration affects aquatic plant assemblages in an arid-land river

    Science.gov (United States)

    Vinson, Mark; Hestmark, Bennett; Barkworth, Mary E.

    2014-01-01

    We evaluated the effects of long-term flow alteration on primary-producer assemblages. In 1962, Flaming Gorge Dam was constructed on the Green River. The Yampa River has remained an unregulated hydrologically variable river that joins the Green River 100 km downstream from Flaming Gorge Dam. In the 1960s before dam construction only sparse occurrences of two macroalgae, Cladophora and Chara, and no submerged vascular plants were recorded in the Green and Yampa rivers. In 2009–2010, aquatic plants were abundant and widespread in the Green River from the dam downstream to the confluence with the Yampa River. The assemblage consisted of six vascular species, Elodea canadensis, Myriophyllum sibiricum, Nasturtium officinale,Potamogeton crispus, Potamogeton pectinatus, and Ranunculus aquatilis, the macroalgae Chara and Cladophora, and the bryophyte, Amblystegium riparium. In the Green River downstream from the Yampa River, and in the Yampa River, only sparse patches of Chara and Cladophora growing in the splash zone on boulders were collected. We attribute the observed changes in the Green River to an increase in water transparency and a reduction in suspended and bed-load sediment and high flow disturbances. The lack of hydrophyte colonization downstream from the confluence with the Yampa River has implications for understanding tributary amelioration of dam effects and for designing more natural flow-regime schedules downstream from large dams.

  2. DISTRIBUTION OF AQUATIC OFF-CHANNEL HABITATS AND ASSOCIATED RIPARIAN VEGETATION, WILLAMETTE RIVER, OREGON, USA

    Science.gov (United States)

    The extent of aquatic off-channel habitats such as secondary and side channels, sloughs, and alcoves, have been reduced more than 50% since the 1850s along the upper main stem of the Willamette River, Oregon, USA. Concurrently, the hydrogeomorphic potential, and associated flood...

  3. Biodiversity of microcrustaceans (Cladocera, Copepoda in a lowland river ecosystem

    Directory of Open Access Journals (Sweden)

    Maciej Karpowicz

    2016-06-01

    Full Text Available This study presents comprehensive research on microcrustacean diversity in different types of aquatic environments in the Upper Narew Valley over five years. A total of 559 samples were analyzed, and 74 species of crustacean zooplankton were identified. Metacyclops planus (Gurney, 1909 is a new species for the fauna of Poland and was found in oxbow lakes and tributary streams. The results of the study suggest that oxbow lakes, with more than 80% of all recorded species, may significantly contribute to the regional biodiversity of floodplain rivers. The highest crustacean community diversity was observed in the semi-lotic oxbow lakes, which emphasizes the role of intermediate disturbance in enhancing biodiversity of water bodies in river valleys. Generally, more “heterogeneous” habitats, such as small oxbow lakes and tributary streams, had higher crustacean species richness. However, a sampling station that was quite “homogeneous”, the Narew River upstream the Siemianówka Reservoir, had high crustacean species richness. The species accumulation curves revealed that approximately 50 - 100 zooplankton samples taken from different environments of river valley are required to establish crustacean species richness. These data could be important for river catchment management and could act as pilot survey data for monitoring plans.

  4. Ecosystem change and the Olifants River crocodile mass mortality events

    CSIR Research Space (South Africa)

    Woodborne, S

    2012-10-01

    Full Text Available ) and the Crocodile River (25823057.100 S, 31857029.900 E) (site CR). Sharptooth catfish and tiger fish were caught on baited hooks or artificial lures, while other species were sampled using an electrofisher (Samus). The fish that were subject to isotopic... analysis comprise a subsample of the June 2011 collection from the OL, LR and CR sites. Invertebrates, diatoms, riparian and aquatic vegetation, sediments and organic detritus were also sampled for isotopic analysis. On 4?7 September 2011 tiger fish...

  5. Spatial patterns of aquatic habitat richness in the Upper Mississippi River floodplain, USA

    Science.gov (United States)

    De Jager, Nathan R.; Rohweder, Jason J.

    2012-01-01

    Interactions among hydrology and geomorphology create shifting mosaics of aquatic habitat patches in large river floodplains (e.g., main and side channels, floodplain lakes, and shallow backwater areas) and the connectivity among these habitat patches underpins high levels of biotic diversity and productivity. However, the diversity and connectivity among the habitats of most floodplain rivers have been negatively impacted by hydrologic and structural modifications that support commercial navigation and control flooding. We therefore tested the hypothesis that the rate of increase in patch richness (# of types) with increasing scale reflects anthropogenic modifications to habitat diversity and connectivity in a large floodplain river, the Upper Mississippi River (UMR). To do this, we calculated the number of aquatic habitat patch types within neighborhoods surrounding each of the ≈19 million 5-m aquatic pixels of the UMR for multiple neighborhood sizes (1–100 ha). For all of the 87 river-reach focal areas we examined, changes in habitat richness (R) with increasing neighborhood length (L, # pixels) were characterized by a fractal-like power function R = Lz (R2 > 0.92 (P z) measures the rate of increase in habitat richness with neighborhood size and is related to a fractal dimension. Variation in z reflected fundamental changes to spatial patterns of aquatic habitat richness in this river system. With only a few exceptions, z exceeded the river-wide average of 0.18 in focal areas where side channels, contiguous floodplain lakes, and contiguous shallow-water areas exceeded 5%, 5%, and 10% of the floodplain respectively. In contrast, z was always less than 0.18 for focal areas where impounded water exceeded 40% of floodplain area. Our results suggest that rehabilitation efforts that target areas with <5% of the floodplain in side channels, <5% in floodplain lakes, and/or <10% in shallow-water areas could improve habitat diversity across multiple scales in the UMR.

  6. Program GICC - AQUABIO. Possible consequences of the climatic change on the aquatic and river french biocenoses. Final report; Programme GICC - AQUABIO. Consequences potentielles du changement climatique sur les biocenoses aquatiques et riveraines francaises. Rapport final

    Energy Technology Data Exchange (ETDEWEB)

    Pont, D [Lyon-1 Univ., CNRS UMR 5023, Ecologie des Hydrosystemes Fluviaux, 69 - Villeurbanne (France)

    2003-11-15

    The consequences of the climatic change can modify the ecosystems. The aim of this research program is to analyze the impacts of the climatic change on the propagation of the exotic species in France in aquatic and river environment, the population of macro invertebrates and fishes in the french rivers and the socio economic challenges. The methodology is based on the simulation from the exploitation of great data bases and the combination of many approaches at different scales. (A.L.B.)

  7. National Aquatic Resource Survey Rivers and Streams Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Data are from 1,000 river and stream sites across the conterminous US where consistent biological, chemical, physical and watershed data were gathered. The sites...

  8. Radiological impact evaluation on the aquatic ecosystems surrounding IPEN-CNEN/SP

    International Nuclear Information System (INIS)

    Jacomino, Vanusa F.; Maduar, Marcelo F.; Bellintani, Sandra A.; Mazzilli, Barbara P.

    1996-01-01

    In order to control the discharge of radioactive materials into the aquatic system surrounding IPEN-CNEN/SP, an monitoring program has been carried out on a routine basis. All the liquid effluent generated by the IPEN facilities are released into the Pinheiros river at two different discharge points located 2 km apart. In the present paper the source term measured during the period 1985 to 1984 is presented, as well as the effective equivalent dose received by public individuals for each critical pathway. These results showed that the total activity released into the Pinheiros river is just a small fraction of the receiving capacity of the environment. The estimated annual doses during the period of study were always below 1/10 of the primary limit for the public individual as established by the International Commission of Radiological Protection, which is 1 mSv/year. (author)

  9. Evaluation of zebra mussels (Dreissena polymorpha) as biomonitors of mercury contamination in aquatic ecosystems.

    Science.gov (United States)

    Blackwell, Bradley D; Driscoll, Charles T; Spada, Michael E; Todorova, Svetoslava G; Montesdeoca, Mario R

    2013-03-01

    Zebra mussels have invaded many lakes in the United States and could be a useful tool for monitoring responses of aquatic biota to changes in mercury loading. The goal of the present study was to evaluate zebra mussels for use as a biomonitor of mercury contamination by comparing zebra mussel mercury concentrations between a lake with only indirect atmospheric mercury contamination (Otisco Lake, NY, USA) and a lake that was directly contaminated by mercury discharges (Onondaga Lake, NY, USA). Zebra mussels were sampled in both the spring and fall of 2004 and 2005. Total mercury (THg) concentrations in zebra mussels were approximately seven times greater in Onondaga Lake than in Otisco Lake, and water column mercury concentrations differed by an order of magnitude between the two lakes. Seasonal differences resulted in significantly higher zebra mussel THg concentrations during the fall for both lakes. There was also significant variation among different sampling sites in Onondaga Lake. Mussel methylmercury concentrations averaged 53% of THg concentrations but were highly variable. Strong relationships between water column THg and zebra mussel THg suggest that zebra mussels are a good indicator of aquatic mercury concentrations and could be used as an effective biomonitor of mercury contamination in aquatic ecosystems. Copyright © 2013 SETAC.

  10. Presence of the Neurotoxin BMAA in Aquatic Ecosystems: What Do We Really Know?

    Science.gov (United States)

    Faassen, Elisabeth J.

    2014-01-01

    The neurotoxin β-N-methylamino-l-alanine (BMAA) is suspected to play a role in the neurological diseases amyotrophic lateral sclerosis, Alzheimer’s disease, and Parkinson’s disease. BMAA production by cyanobacteria has been reported and contact with cyanobacteria infested waters or consumption of aquatic organisms are possible pathways to human exposure. However, there is little consensus regarding whether BMAA is present in cyanobacteria or not, and if so, at what concentrations. The aim of this review is to indicate the current state of knowledge on the presence of BMAA in aquatic ecosystems. Some studies have convincingly shown that BMAA can be present in aquatic samples at the µg/g dry weight level, which is around the detection limit of some equally credible studies in which no BMAA was detected. However, for the majority of the reviewed articles, it was unclear whether BMAA was correctly identified, either because inadequate analytical methods were used, or because poor reporting of analyses made it impossible to verify the results. Poor analysis, reporting and prolific errors have shaken the foundations of BMAA research. First steps towards estimation of human BMAA exposure are to develop and use selective, inter-laboratory validated methods and to correctly report the analytical work. PMID:24662480

  11. Bioindication in natural-like aquatic ecosystems: endocrine disruptors in outdoor microcosms. Status-report

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, K.W.; Severin, G.F.

    2002-07-01

    Over the past few decades scientists have shown that the hormone system of a wide range of organisms can be affected by numerous environmental chemicals. Society strongly demands studies about the fate and effects of such endocrine disruptors on the aquatic environment. It has been scientifically accepted that risk assessment studies done in aquatic microcosms can be used to extrapolate the potential impact of the tested compound on natural ecosystems. Realistic exposure situations were simulated and screening methods as well as analytical methods with high accuracy were applied on water and sediment. For the comprehensive risk assessment as many trophic levels as possible have to be investigated. Changes in the population dynamics and the community structure serve as ecotoxicological endpoints. Modelling the concentrations of the chemicals in the different aquatic compartments complements and confirms the analytical diagnostics. A directed design of the analytical procedures according to amount of sample and limits of determination becomes possible. Bridging acute and chronic time scales in effect diagnostics the 'area under the curve' - approach has been followed in combination with multivariate statistics. Haber's rule have been applied to the results about complex effect- and exposure-conditions. In some cases the interpretation of results becomes more easy and clear by this approach. (orig.)

  12. Vegetation development following stream/river restoration: more natural fluvial dynamics and morphology, return of aquatic and riparian plant species?

    Science.gov (United States)

    Soons, M. B.

    2012-04-01

    After centuries of human interventions in stream/river dynamics and morphology aimed at optimizing landscapes for agricultural and industrial purposes, new insights have inspired water managers to try and combine stream and river ecosystem functions with the conservation of biodiversity. Around the world, aquatic and riparian species have declined strongly due to pollution, destruction and fragmentation of their habitat, so that biodiversity conservation initiatives primarily focus on habitat restoration. In the past decades many stream and river restoration projects have been carried out and often hydrological dynamics and morphology have been restored to a more natural state. However, the successful restoration of aquatic and riparian habitats very often failed to result in restoration of their biodiversity. This lack of success from a biodiversity conservation perspective is usually attributed to 'dispersal limitation', meaning that the habitat may be restored, but species fail to reach the site and re-colonize it. Especially re-colonization by aquatic and riparian plant species is important, as such species function as ecosystem engineers: their presence alters fluvial dynamics and morphology, generates additional habitat heterogeneity and provides habitat and food for animal species. Following minor disturbances, re-colonization is often possible through locally remaining populations, by seeds in the seed bank or by surviving plant fragments. However, following major disturbances, colonization and establishment from other source populations are necessary. This usually occurs through dispersal of seeds (and in more aquatic species also by dispersal of vegetative fragments) into the restored wetland area. As dispersal occurs predominantly over short distances and source populations of aquatic and riparian species may be lacking in the surroundings, dispersal may be a limiting factor in the development of aquatic and riparian vegetation at a restored site. But

  13. Revisiting restored river reaches - Assessing change of aquatic and riparian communities after five years.

    Science.gov (United States)

    Lorenz, Armin W; Haase, Peter; Januschke, Kathrin; Sundermann, Andrea; Hering, Daniel

    2018-02-01

    Hydromorphological restructuring of river sections, i.e. river restoration measures, often has little effects on aquatic biota, even in case of strong habitat alterations. It is often supposed that the biotic response is simply delayed as species require additional time to recolonize the newly generated habitats and to establish populations. To identify and specify the supposed lag time between restoration and biotic response, we investigated 19 restored river reaches twice in a five-year interval. The sites were restored one to ten years prior to the first sampling. We sampled three aquatic (fish, benthic invertebrates, macrophytes) and two riparian organism groups (ground beetles and riparian vegetation) and analyzed changes in assemblage composition and biotic metrics. With the exception of ground beetle assemblages, we observed no significant changes in richness and abundance metrics or metrics used for biological assessment. However, indicator taxa for near-natural habitat conditions in the riparian zone (indicators for regular inundation in plants and river bank specialists in beetles) improved significantly in the five-year interval. Contrary to general expectations in river restoration planning, we neither observed a distinct succession of aquatic communities nor a general trend towards "good ecological status" over time. Furthermore, multiple linear regression models revealed that neither the time since restoration nor the morphological status had a significant effect on the biological metrics and the assessment results. Thus, the stability of aquatic assemblages is strong, slowing down restoration effects in the aquatic zone, while riparian assemblages improve more rapidly. When defining restoration targets, the different timelines for ecological recovery after restoration should be taken into account. Furthermore, restoration measures should not solely focus on local habitat conditions but also target stressors acting on larger spatial scales and take

  14. Characteristics of terrestrial and aquatic ecosystems of two locations in Deaf Smith and Swisher Counties, Texas

    International Nuclear Information System (INIS)

    1984-11-01

    According to the Civilian Radioactive Waste Management Program and the Nuclear Waste Policy Act of 1982 (P.L. 97-425), a potential nuclear waste repository site must be chosen with consideration of potential impacts on terrestrial and aquatic ecosystems. This report is a preliminary environmental characterization of two locations in the Texas Panhandle, one in Deaf Smith County and the other in Swisher County, that have been recommended for further study. A description of important natural areas is offered as a basis for comparative studies of the two locations and for the identification and screening of potential repository sites. Information on current land uses, potential habitats, and expected plant and wildlife species is provided to assist field investigators in the collection of baseline data in support of further siting activities. The results of limited field surveys are also included. The report is in two parts. Part I contains a characterization of terrestrial ecological resources based upon limited field surveys aimed at verifying the presence of plant communities and wildlife habitats. It also presents inventories of species with special status, species with recreational and economic importance, and species of ecological value to important or special-status species. Part II presents information on aquatic ecosystems and resources derived primarily from a review of the literature, interviews, and limited field surveys. 21 figures, 18 tables

  15. A carbon budget for the aquatic ecosystem above SFR in Oeregrundsgrepen

    International Nuclear Information System (INIS)

    Kumblad, L

    1999-07-01

    The potential hazards of radionuclide release to humans and the environment is regularly evaluated in safety assessments of SFR, the final repository for radioactive operational waste. SFR handles, since 1988, low and intermediate level nuclear waste from Swedish nuclear power plants, medical care attendance, industries and research laboratories and is located in the bedrock 50 meters under the seabed of Oeregrundsgrepen in the southern Bothnian Sea. This report presents a description of the aquatic ecosystem and a carbon budget for the area above SFR with the aim to include ecosystem dynamics in the present safety assessment of the repository (SAFE). The carbon budget will support SAFE by facilitating evaluations of transport and fate of radionuclides, primarily 14 C, in case of a release from the repository and describe the ecosystem structure and function. Furthermore, 14 C is the dose-dominant radionuclide in the repository which most likely will follow the general carbon flow in the ecosystem if there should be a release. The carbon budget was based on biomass and flow of carbon between thirteen functional groups (including POC and DOC) in the ecosystem above SFR and the results indicates that the organisms are self-sufficient on carbon and that the area exports carbon corresponding to approximately 50% of the annual primary production. The largest organic carbon pool is DOC (one and a half time larger than the total biomass) and the major functional organism groups are the macrophytes (37% of the total biomass), benthic macrofauna (36%), and the microphytes (11%). The soft bottom and phytobenthic communities seem to have important roles in the ecosystem since these communities comprise the main part of the living carbon in the studied area

  16. A carbon budget for the aquatic ecosystem above SFR in Oeregrundsgrepen

    Energy Technology Data Exchange (ETDEWEB)

    Kumblad, L [Stockholm Univ. (Sweden). Dept. of Systems Ecology

    1999-07-01

    The potential hazards of radionuclide release to humans and the environment is regularly evaluated in safety assessments of SFR, the final repository for radioactive operational waste. SFR handles, since 1988, low and intermediate level nuclear waste from Swedish nuclear power plants, medical care attendance, industries and research laboratories and is located in the bedrock 50 meters under the seabed of Oeregrundsgrepen in the southern Bothnian Sea. This report presents a description of the aquatic ecosystem and a carbon budget for the area above SFR with the aim to include ecosystem dynamics in the present safety assessment of the repository (SAFE). The carbon budget will support SAFE by facilitating evaluations of transport and fate of radionuclides, primarily {sup 14}C, in case of a release from the repository and describe the ecosystem structure and function. Furthermore, {sup 14}C is the dose-dominant radionuclide in the repository which most likely will follow the general carbon flow in the ecosystem if there should be a release. The carbon budget was based on biomass and flow of carbon between thirteen functional groups (including POC and DOC) in the ecosystem above SFR and the results indicates that the organisms are self-sufficient on carbon and that the area exports carbon corresponding to approximately 50% of the annual primary production. The largest organic carbon pool is DOC (one and a half time larger than the total biomass) and the major functional organism groups are the macrophytes (37% of the total biomass), benthic macrofauna (36%), and the microphytes (11%). The soft bottom and phytobenthic communities seem to have important roles in the ecosystem since these communities comprise the main part of the living carbon in the studied area.

  17. Use of aquatic mosses for monitoring artificial radionuclides downstream of the nuclear power plant of Bugey (River Rhone, France)

    International Nuclear Information System (INIS)

    Beaugelin-Seiller, K.; Brottet, D.

    1994-01-01

    The detection of radionuclides in water, downstream of nuclear installations located on river banks, is often very difficult notably because of their low concentrations. Thus the use of biological indicators is an interesting process to detect radioactive contamination of an aquatic ecosystem. From 1986 to 1990, artificial radionuclides were measured in freshwater mosses sampled downstream of the nuclear power station of Bugey. These field data on the whole, have shown a comparatively good qualitative and quantitative relationship between radioactive composition of liquid waste and radionuclides detected in mosses. In other respects, the results showed up a relatively clear hierarchical structure in the affinity of the different radionuclides for the mosses. To specify these relations, mesh bags containing allochtonous mosses were immersed at four stations downstream of the power plant and regularly sampled during a 10-h waste discharge period. (author)

  18. Toxicity of methanol to fish, crustacean, oligochaete worm, and aquatic ecosystem.

    Science.gov (United States)

    Kaviraj, A; Bhunia, F; Saha, N C

    2004-01-01

    Static renewal bioassays were conducted in the laboratory and in outdoor artificial enclosures to evaluate toxic effects of methanol to one teleost fish and two aquatic invertebrates and to limnological variables of aquatic ecosystem. Ninety-six-hour acute toxicity tests revealed cladoceran crustacea Moina micrura as the most sensitive to methanol (LC50, 4.82 g/L), followed by freshwater teleost Oreochromis mossambicus (LC50, 15.32 g/L) and oligochaete worm Branchiura sowerbyi (LC50, 54.89 g/L). The fish, when exposed to lethal concentrations of methanol, showed difficulties in respiration and swimming. The oligochaete body wrinkled and fragmented under lethal exposure of methanol. Effects of five sublethal concentrations of methanol (0, 23.75, 47.49, 736.10, and 1527.60 mg/L) on the feeding rate of the fish and on its growth and reproduction were evaluated by separate bioassays. Ninety-six-hour bioassays in the laboratory showed significant reduction in the appetite of fish when exposed to 736.10 mg/L or higher concentrations of methanol. Chronic toxicity bioassays (90 days) in outdoor enclosures showed a reduction in growth, maturity index and fecundity of fish at 47.49 mg/L or higher concentrations of methanol. Primary productivity, phytoplankton population, and alkalinity of water were also reduced at these concentrations. Chronic exposure to 1527.60 mg/L methanol resulted in damages of the epithelium of primary and secondary gill lamellae of the fish. The results revealed 23.75 mg/L as the no-observed-effect concentration (NOEC) of methanol to freshwater aquatic ecosystem.

  19. Aquatic bird disease and mortality as an indicator of changing ecosystem health

    Science.gov (United States)

    Newman, Scott H.; Chmura, Aleksei; Converse, Kathy; Kilpatrick, A. Marm; Patel, Nikkita; Lammers, Emily; Daszak, Peter

    2007-01-01

    We analyzed data from pathologic investigations in the United States, collected by the USGS National Wildlife Health Center between 1971 and 2005, into aquatic bird mortality events. A total of 3619 mortality events was documented for aquatic birds, involving at least 633 708 dead birds from 158 species belonging to 23 families. Environmental causes accounted for the largest proportion of mortality events (1737 or 48%) and dead birds (437 258 or 69%); these numbers increased between 1971 and 2000, with biotoxin mortalities due to botulinum intoxication (Types C and E) being the leading cause of death. Infectious diseases were the second leading cause of mortality events (20%) and dead birds (20%), with both viral diseases, including duck plague (Herpes virus), paramyxovirus of cormorants (Paramyxovirus PMV1) and West Nile virus (Flavivirus), and bacterial diseases, including avian cholera (Pasteurella multocida), chlamydiosis (Chalmydia psittici), and salmonellosis (Salmonella sp.), contributing. Pelagic, coastal marine birds and species that use marine and freshwater habitats were impacted most frequently by environmental causes of death, with biotoxin exposure, primarily botulinum toxin, resulting in mortalities of both coastal and freshwater species. Pelagic birds were impacted most severely by emaciation and starvation, which may reflect increased anthropogenic pressure on the marine habitat from over-fishing, pollution, and other factors. Our study provides important information on broad trends in aquatic bird mortality and highlights how long-term wildlife disease studies can be used to identify anthropogenic threats to wildlife conservation and ecosystem health. In particular, mortality data for the past 30 yr suggest that biotoxins, viral, and bacterial diseases could have impacted >5 million aquatic birds.

  20. Science to Support Management of Receiving Waters in an Event-Driven Ecosystem: From Land to River to Sea

    Directory of Open Access Journals (Sweden)

    Stuart E. Bunn

    2013-06-01

    Full Text Available Managing receiving-water quality, ecosystem health and ecosystem service delivery is challenging in regions where extreme rainfall and runoff events occur episodically, confounding and often intensifying land-degradation impacts. We synthesize the approaches used in river, reservoir and coastal water management in the event-driven subtropics of Australia, and the scientific research underpinning them. Land-use change has placed the receiving waters of Moreton Bay, an internationally-significant coastal wetland, at risk of ecological degradation through increased nutrient and sediment loads. The event-driven climate exacerbates this issue, as the waterways and ultimately Moreton Bay receive large inputs of nutrients and sediment during events, well above those received throughout stable climatic periods. Research on the water quality and ecology of the region’s rivers and coastal waters has underpinned the development of a world-renowned monitoring program and, in combination with catchment-source tracing methods and modeling, has revealed the key mechanisms and management strategies by which receiving-water quality, ecosystem health and ecosystem services can be maintained and improved. These approaches provide a useful framework for management of water bodies in other regions driven by episodic events, or where novel stressors are involved (e.g., climate change, urbanization, to support sustained ecosystem service delivery and restoration of aquatic ecosystems.

  1. A Synthesis of the Effects of Pesticides on Microbial Persistence in Aquatic Ecosystems

    Science.gov (United States)

    Staley, Zachery R.; Harwood, Valerie J.; Rohr, Jason R.

    2016-01-01

    Pesticides are a pervasive presence in aquatic ecosystems throughout the world. While pesticides are intended to control fungi, insects, and other pests, their mechanisms of action are often not specific enough to prevent unintended effects, such as on non-target microbial populations. Microorganisms, including algae and cyanobacteria, protozoa, aquatic fungi, and bacteria, form the basis of many food webs and are responsible for crucial aspects of biogeochemical cycling; therefore, the potential for pesticides to alter microbial community structures must be understood to preserve ecosystem services. This review examines studies that focused on direct population-level effects and indirect community-level effects of pesticides on microorganisms. Generally, insecticides, herbicides, and fungicides were found to have adverse direct effects on algal and fungal species. Insecticides and fungicides also had deleterious direct effects in the majority of studies examining protozoa species, although herbicides were found to have inconsistent direct effects on protozoans. Our synthesis revealed mixed or no direct effects on bacterial species among all pesticide categories, with results highly dependent on the target species, chemical, and concentration used in the study. Examination of community-level, indirect effects revealed that all pesticide categories had a tendency to reduce higher trophic levels, thereby diminishing top-down pressures and favoring lower trophic levels. Often, indirect effects exerted greater influence than direct effects. However, few studies have been conducted to specifically address community-level effects of pesticides on microorganisms and further research is necessary to better understand and predict the net effects of pesticides on ecosystem health. PMID:26565685

  2. In situ and laboratory bioassays to evaluate the impact of effluent discharges on receiving aquatic ecosystems

    International Nuclear Information System (INIS)

    Smolders, R.; Bervoets, L.; Blust, R.

    2004-01-01

    Effluents are a main source of direct and often continuous input of pollutants into aquatic ecosystems with long-term implications on ecosystem functioning. Therefore, the study of the effects of effluent exposure on organisms, populations or communities within the framework of impact assessment has a high ecological relevance. The aim of this study was to assess the toxicological impact of two effluents, one household wastewater treatment effluent (Effluent 1) and one industrial effluent (Effluent 2), on the receiving aquatic ecosystem using two test species under both in situ and laboratory conditions. Zebra mussel (Dreissena polymorpha) and common carp (Cyprinus carpio) were exposed under laboratory conditions in an online monitoring flow-through system (receiving different concentrations of Effluent 2) and under in situ conditions along the pollution gradient established by these two effluent discharges. Bioassays focussed on growth and condition related endpoints (i.e. condition, growth, lipid budget), since these are key functional processes within organisms and populations. Under laboratory conditions, increasing concentrations of the industrial effluent (Effluent 2) had a negative effect on both zebra mussel and carp energy reserves and condition. Under in situ conditions, the same negative impact of Effluent 2 was observed for zebra mussels, while Effluent 1 had no apparent effect on exposed zebra mussels. Carp growth and condition, on the other hand, were significantly increased at the discharge sites of both effluents when compared to the reference site, probably due to differences in food availability. The results indicate that a combination of in situ and laboratory exposures can illustrate how ecological processes influence bioassay studies. The incorporation of indirect, ecological effects, like changes in food availability, provides considerable benefit in understanding and predicting effects of effluents on selected species under realistic exposure

  3. In situ and laboratory bioassays to evaluate the impact of effluent discharges on receiving aquatic ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Smolders, R. [Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp (RUCA), Groenenborgerlaan 171, B-2020 Antwerp (Belgium)]. E-mail: roel.smolders@ua.ac.be; Bervoets, L. [Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp (RUCA), Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Blust, R. [Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp (RUCA), Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2004-11-01

    Effluents are a main source of direct and often continuous input of pollutants into aquatic ecosystems with long-term implications on ecosystem functioning. Therefore, the study of the effects of effluent exposure on organisms, populations or communities within the framework of impact assessment has a high ecological relevance. The aim of this study was to assess the toxicological impact of two effluents, one household wastewater treatment effluent (Effluent 1) and one industrial effluent (Effluent 2), on the receiving aquatic ecosystem using two test species under both in situ and laboratory conditions. Zebra mussel (Dreissena polymorpha) and common carp (Cyprinus carpio) were exposed under laboratory conditions in an online monitoring flow-through system (receiving different concentrations of Effluent 2) and under in situ conditions along the pollution gradient established by these two effluent discharges. Bioassays focussed on growth and condition related endpoints (i.e. condition, growth, lipid budget), since these are key functional processes within organisms and populations. Under laboratory conditions, increasing concentrations of the industrial effluent (Effluent 2) had a negative effect on both zebra mussel and carp energy reserves and condition. Under in situ conditions, the same negative impact of Effluent 2 was observed for zebra mussels, while Effluent 1 had no apparent effect on exposed zebra mussels. Carp growth and condition, on the other hand, were significantly increased at the discharge sites of both effluents when compared to the reference site, probably due to differences in food availability. The results indicate that a combination of in situ and laboratory exposures can illustrate how ecological processes influence bioassay studies. The incorporation of indirect, ecological effects, like changes in food availability, provides considerable benefit in understanding and predicting effects of effluents on selected species under realistic exposure

  4. Kootenai River Floodplain Ecosystem Operational Loss Assessment, Protection, Mitigation and Rehabilitation, 2007-2008 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Merz, Norm [Kootenai Tribe of Idaho

    2009-02-18

    The overarching goals of the 'Kootenai River Floodplain Ecosystem Operational Loss Assessment, Protection, Mitigation and Rehabilitation' Project (BPA Project No.2002-011-00) are to: (1) assess abiotic and biotic factors (i.e., geomorphologic, hydrological, aquatic and riparian/floodplain communities) in determining a definitive composition of ecological integrity, (2) develop strategies to assess and mitigate losses of ecosystem functions, and (3) produce a regional operational loss assessment framework. To produce a scientifically defensible, repeatable, and complete assessment tool, KTOI assembled a team of top scientists in the fields of hydrology, hydraulics, ornithology, entomology, statistics, and river ecology, among other expertise. This advisory team is known as the Research Design and Review Team (RDRT). The RDRT scientists drive the review, selection, and adaptive management of the research designs to evaluate the ecologic functions lost due to the operation of federal hydropower facilities. The unique nature of this project (scientific team, newest/best science, adaptive management, assessment of ecological functions, etc.) has been to work in a dynamic RDRT process. In addition to being multidisciplinary, this model KTOI project provides a stark contrast to the sometimes inflexible process (review, re-review, budgets, etc.) of the Columbia River Basin Fish and Wildlife Program. The project RDRT is assembled annually, with subgroups meeting as needed throughout the year to address project issues, analyses, review, and interpretation. Activities of RDRT coordinated and directed the selection of research and assessment methodologies appropriate for the Kootenai River Watershed and potential for regional application in the Columbia River Basin. The entire RDRT continues to meet annually to update and discuss project progress. RDRT Subcontractors work in smaller groups throughout the year to meet project objectives. Determining the extent to

  5. Biodiversity of Aquatic Insects of Zayandeh Roud River and Its Branches, Isfahan Province, Iran.

    Directory of Open Access Journals (Sweden)

    Mansoreh Shayeghi

    2014-12-01

    Full Text Available Aquatic insects are the major groups of arthropods that spend some parts of their life cycle in the water. These insects play an important role for transmission of some human and animal diseases. There is few information about the aquatic insects fauna of Iran.To study the aquatic insects fauna, adult, nymphal and larval collections were carried out from different habitats using the standard technique in Zayandeh Roud River, Isfahan Province,central Iran, during summer 2011.In total, 741 speimens of aquatic insects were collected and morphologically identified. They include 7 families and 12 genera representing 2 Orders. The order of Diptera (92.31% and Coleoptera (7.69%. The families Culicidae, Syrphidae and Chironomidae from Diptera order, Gyrinidae, Dytiscidae, Haliplidae, Hydrophilidae from Coleoptera order were identified.Some aquatic insects play an important role for transmission of human and animal diseases. These insects also are important for biological control. Therefore ecological study on aquatic insects can provide information about ecology of insects in an area for any decision making.

  6. Responses of aquatic ecosystems to environmental changes in Finland and China

    Directory of Open Access Journals (Sweden)

    Jan eWeckström

    2015-11-01

    Full Text Available The concern for the state of global freshwater reservoirs has increased due to deterioration of the water quality during the last decades. This has prompted monitoring and restoration efforts such as the European Water Framework Directive and the national-scale 2nd-investigation and monitoring of the water quality, water volume and biota resources in China. The challenge so far has been the determination of the natural state (reference conditions of freshwater ecosystems. We used the sediment archives of five lakes and one brackish water embayment in Finland and China to assess the impact of selected variables of climatology, hydrology, nutrients, and changes in human population on these ecosystems during the last few centuries. The study sites represent catchment areas with varying land use. Despite the long distance between the sites and their different land-use characteristics, the direction and timing of changes during the last few centuries are well comparable between the high latitudes of Finland and the mid-low latitudes of China. This study reinforces the sensitivity of aquatic ecosystems to environmental change and underlines the usefulness of the palaeolimnological approach as a tool for determining reference conditions.

  7. Productivity, disturbance and ecosystem size have no influence on food chain length in seasonally connected rivers.

    Science.gov (United States)

    Warfe, Danielle M; Jardine, Timothy D; Pettit, Neil E; Hamilton, Stephen K; Pusey, Bradley J; Bunn, Stuart E; Davies, Peter M; Douglas, Michael M

    2013-01-01

    The food web is one of the oldest and most central organising concepts in ecology and for decades, food chain length has been hypothesised to be controlled by productivity, disturbance, and/or ecosystem size; each of which may be mediated by the functional trophic role of the top predator. We characterised aquatic food webs using carbon and nitrogen stable isotopes from 66 river and floodplain sites across the wet-dry tropics of northern Australia to determine the relative importance of productivity (indicated by nutrient concentrations), disturbance (indicated by hydrological isolation) and ecosystem size, and how they may be affected by food web architecture. We show that variation in food chain length was unrelated to these classic environmental determinants, and unrelated to the trophic role of the top predator. This finding is a striking exception to the literature and is the first published example of food chain length being unaffected by any of these determinants. We suggest the distinctive seasonal hydrology of northern Australia allows the movement of fish predators, linking isolated food webs and potentially creating a regional food web that overrides local effects of productivity, disturbance and ecosystem size. This finding supports ecological theory suggesting that mobile consumers promote more stable food webs. It also illustrates how food webs, and energy transfer, may function in the absence of the human modifications to landscape hydrological connectivity that are ubiquitous in more populated regions.

  8. Productivity, disturbance and ecosystem size have no influence on food chain length in seasonally connected rivers.

    Directory of Open Access Journals (Sweden)

    Danielle M Warfe

    Full Text Available The food web is one of the oldest and most central organising concepts in ecology and for decades, food chain length has been hypothesised to be controlled by productivity, disturbance, and/or ecosystem size; each of which may be mediated by the functional trophic role of the top predator. We characterised aquatic food webs using carbon and nitrogen stable isotopes from 66 river and floodplain sites across the wet-dry tropics of northern Australia to determine the relative importance of productivity (indicated by nutrient concentrations, disturbance (indicated by hydrological isolation and ecosystem size, and how they may be affected by food web architecture. We show that variation in food chain length was unrelated to these classic environmental determinants, and unrelated to the trophic role of the top predator. This finding is a striking exception to the literature and is the first published example of food chain length being unaffected by any of these determinants. We suggest the distinctive seasonal hydrology of northern Australia allows the movement of fish predators, linking isolated food webs and potentially creating a regional food web that overrides local effects of productivity, disturbance and ecosystem size. This finding supports ecological theory suggesting that mobile consumers promote more stable food webs. It also illustrates how food webs, and energy transfer, may function in the absence of the human modifications to landscape hydrological connectivity that are ubiquitous in more populated regions.

  9. The energetic contributions of aquatic primary producers to terrestrial food webs in a mid-size river system.

    Science.gov (United States)

    Kautza, Adam; Mazeika, S; Sullivan, P

    2016-03-01

    Rivers are increasingly recognized as providing nutritional subsidies (i.e., energy and nutrients) to adjacent terrestrial food webs via depredation of aquatic organisms (e.g., emergent aquatic insects, crayfish, fish) by terrestrial consumers. However, because these prey organisms assimilate energy from both aquatic (e.g., benthic algae, phytoplankton, aquatic macrophytes) and terrestrial (e.g., riparian leaf detritus) primary producers, river subsidies to terrestrial consumers represent a combination of aquatically and terrestrially derived energy. To date, the explicit contribution of energy derived from aquatic primary producers to terrestrial consumers has not been fully explored yet might be expected to be quantitatively important to terrestrial food webs. At 12 reaches along a 185-km segment of the sixth-order Scioto River system (Ohio, USA), we quantified the relative contribution of energy derived from aquatic primary producers to a suite of terrestrial riparian consumers that integrate the adjacent landscape across multiple spatial scales through their foraging activities (tetragnathid spiders, rove beetles, adult coenagrionid damselflies, riparian swallows, and raccoons). We used naturally abundant stable isotopes (13C and 15N) of periphyton, phytoplankton, macrophytes, and terrestrial vegetation to evaluate the energetic contribution of aquatic primary producers to terrestrial food webs. Shoreline tetragnathid spiders were most reliant on aquatic primary producers (50%), followed by wider-ranging raccoons (48%), damselflies (44%), and riparian swallows (41%). Of the primary producers, phytoplankton (19%) provisioned the greatest nutritional contribution to terrestrial consumers (considered collectively), followed by periphyton (14%) and macrophytes (11%). Our findings provide empirical evidence that aquatic primary producers of large streams and rivers can be a critical nutritional resource for terrestrial food webs. We also show that aquatically

  10. A mathematical model of algae growth in a pelagic-benthic coupled shallow aquatic ecosystem.

    Science.gov (United States)

    Zhang, Jimin; Shi, Junping; Chang, Xiaoyuan

    2018-04-01

    A coupled system of ordinary differential equations and partial differential equations is proposed to describe the interaction of pelagic algae, benthic algae and one essential nutrient in an oligotrophic shallow aquatic ecosystem with ample supply of light. The existence and uniqueness of non-negative steady states are completely determined for all possible parameter range, and these results characterize sharp threshold conditions for the regime shift from extinction to coexistence of pelagic and benthic algae. The influence of environmental parameters on algal biomass density is also considered, which is an important indicator of algal blooms. Our studies suggest that the nutrient recycling from loss of algal biomass may be an important factor in the algal blooms process; and the presence of benthic algae may limit the pelagic algal biomass density as they consume common resources even if the sediment nutrient level is high.

  11. Temporal changes in the distribution, methylation, and bioaccumulation of newly deposited mercury in an aquatic ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Orihel, Diane M. [Clayton H. Riddell Faculty of Environment, Earth, and Resources, University of Manitoba, Winnipeg, Manitoba, R3T 2N2 (Canada); Freshwater Institute, Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, Manitoba, R3T 2N6 (Canada)], E-mail: orihel@ualberta.ca; Paterson, Michael J.; Blanchfield, Paul J.; Bodaly, R.A. [Freshwater Institute, Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, Manitoba, R3T 2N6 (Canada); Gilmour, Cynthia C. [Smithsonian Environmental Research Center, 647 Contees Wharf Road, Edgewater, MD 21037 (United States); Hintelmann, Holger [Department of Chemistry, Trent University, 1600 West Bank Drive, Peterborough, Ontario, K9J 7B8 (Canada)

    2008-07-15

    Our objective was to examine how the behavior of atmospheric mercury (Hg) deposited to boreal lake mesocosms changed over time. We added inorganic Hg enriched in a different stable isotope in each of two years, which allowed us to differentiate between Hg added in the first and second year. Although inorganic Hg and methylmercury (MeHg) continued to accumulate in sediments throughout the experiment, the availability of MeHg to the food web declined within one year. This decrease was detected in periphyton, zooplankton, and water mites, but not in gomphid larvae, amphipods, or fish. We suggest that reductions in atmospheric Hg deposition should lead to decreases in MeHg concentrations in biota, but that changes will be more easily detected in short-lived pelagic species than long-lived species associated with benthic food webs. - Mercury deposited to aquatic ecosystems becomes less available for uptake by biota over time.

  12. Impacts of lawn-care pesticides on aquatic ecosystems in relation to property value

    International Nuclear Information System (INIS)

    Overmyer, Jay P.; Noblet, Raymond; Armbrust, Kevin L.

    2005-01-01

    To determine the potential impacts of lawn-care pesticides on aquatic ecosystems, the macroinvertebrate communities of six streams were assessed using a multimetric approach. Four streams flowed through residential neighborhoods of Peachtree City, GA, USA, with differing mean property values and two reference streams were outside the city limits. A series of correlation analyses were conducted comparing stream rank from water quality and physical stream parameters, habitat assessments, benthic macroinvertebrate metric, pesticide toxicity and metal toxicity data to determine relationships among these parameters. Significant correlations were detected between individual analyses of stream rank for pesticide toxicity, specific conductance, turbidity, temperature and dissolved oxygen with benthic macroinvertebrate metrics. - The macroinvertebrate communities of suburban streams may be influenced by the toxicity of the pesticides present in the water and sediment as well as select water quality parameters

  13. Mapping critical loads of nitrogen deposition for aquatic ecosystems in the Rocky Mountains, USA

    Science.gov (United States)

    Nanus, Leora; Clow, David W.; Saros, Jasmine E.; Stephens, Verlin C.; Campbell, Donald H.

    2012-01-01

    Spatially explicit estimates of critical loads of nitrogen (N) deposition (CLNdep) for nutrient enrichment in aquatic ecosystems were developed for the Rocky Mountains, USA, using a geostatistical approach. The lowest CLNdep estimates (-1 yr-1) occurred in high-elevation basins with steep slopes, sparse vegetation, and abundance of exposed bedrock and talus. These areas often correspond with areas of high N deposition (>3 kg N ha-1 yr-1), resulting in CLNdep exceedances ≥1.5 ± 1 kg N ha-1 yr-1. CLNdep and CLNdep exceedances exhibit substantial spatial variability related to basin characteristics and are highly sensitive to the NO3- threshold at which ecological effects are thought to occur. Based on an NO3- threshold of 0.5 μmol L-1, N deposition exceeds CLNdep in 21 ± 8% of the study area; thus, broad areas of the Rocky Mountains may be impacted by excess N deposition, with greatest impacts at high elevations.

  14. Unifying concepts linking dissolved organic matter composition to persistence in aquatic ecosystems

    Science.gov (United States)

    Kellerman, Anne M.; Guillemette, François; Podgorski, David C.; Aiken, George R.; Butler, Kenna D.; Spencer, Robert G. M.

    2018-01-01

    The link between composition and reactivity of dissolved organic matter (DOM) is central to understanding the role aquatic systems play in the global carbon cycle; yet, unifying concepts driving molecular composition have yet to be established. We characterized 37 DOM isolates from diverse aquatic ecosystems, including their stable and radiocarbon isotopes (δ13C-dissolved organic carbon (DOC) and Δ14C-DOC), optical properties (absorbance and fluorescence), and molecular composition (ultrahigh resolution mass spectrometry). Isolates encompassed end-members of allochthonous and autochthonous DOM from sites across the United States, the Pacific Ocean, and Antarctic lakes. Modern Δ14C-DOC and optical properties reflecting increased aromaticity, such as carbon specific UV absorbance at 254 nm (SUVA254), were directly related to polyphenolic and polycyclic aromatic compounds, whereas enriched δ13C-DOC and optical properties reflecting autochthonous end-members were positively correlated to more aliphatic compounds. Furthermore, the two sets of autochthonous end-members (Pacific Ocean and Antarctic lakes) exhibited distinct molecular composition due to differences in extent of degradation. Across all sites and end-members studied, we find a consistent shift in composition with aging, highlighting the persistence of certain biomolecules concurrent with degradation time.

  15. DNAqua-Net: Developing new genetic tools for bioassessment and monitoring of aquatic ecosystems in Europe

    Directory of Open Access Journals (Sweden)

    Florian Leese

    2016-11-01

    Full Text Available The protection, preservation and restoration of aquatic ecosystems and their functions are of global importance. For European states it became legally binding mainly through the EU-Water Framework Directive (WFD. In order to assess the ecological status of a given water body, aquatic biodiversity data are obtained and compared to a reference water body. The quantified mismatch obtained determines the extent of potential management actions. The current approach to biodiversity assessment is based on morpho-taxonomy. This approach has many drawbacks such as being time consuming, limited in temporal and spatial resolution, and error-prone due to the varying individual taxonomic expertise of the analysts. Novel genomic tools can overcome many of the aforementioned problems and could complement or even replace traditional bioassessment. Yet, a plethora of approaches are independently developed in different institutions, thereby hampering any concerted routine application. The goal of this Action is to nucleate a group of researchers across disciplines with the task to identify gold-standard genomic tools and novel eco-genomic indices for routine application in biodiversity assessments of European fresh- and marine water bodies. Furthermore, DNAqua-Net will provide a platform for training of the next generation of European researchers preparing them for the new technologies. Jointly with water managers, politicians, and other stakeholders, the group will develop a conceptual framework for the standard application of eco-genomic tools as part of legally binding assessments.

  16. Effects of acidic deposition on forest and aquatic ecosystems in New York State

    Energy Technology Data Exchange (ETDEWEB)

    Driscoll, Charles T.; Driscoll, Kimberley M.; Mitchell, Myron J.; Raynal, Dudley J

    2003-06-01

    Elevated inputs of acidic deposition have deleterious effects on forest and aquatic ecosystems in New York. - Acidic deposition is comprised of sulfuric and nitric acids and ammonium derived from atmospheric emissions of sulfur dioxide, nitrogen oxides, and ammonia, respectively. Acidic deposition has altered soil through depletion of labile pools of nutrient cations (i.e. calcium, magnesium), accumulation of sulfur and nitrogen, and the mobilization of elevated concentrations of inorganic monomeric aluminum to soil solutions in acid-sensitive areas. Acidic deposition leaches essential calcium from needles of red spruce, making this species more susceptible to freezing injury. Mortality among sugar maples appears to result from deficiencies of nutrient cations, coupled with other stresses such as insect defoliation or drought. Acidic deposition has impaired surface water quality in the Adirondack and Catskill regions of New York by lowering pH levels, decreasing acid-neutralizing capacity, and increasing aluminum concentrations. Acidification has reduced the diversity and abundance of aquatic species in lakes and streams. There are also linkages between acidic deposition and fish mercury contamination and eutrophication of estuaries.

  17. Ecotoxic heavy metals transformation by bacteria and fungi in aquatic ecosystem.

    Science.gov (United States)

    Chaturvedi, Amiy Dutt; Pal, Dharm; Penta, Santhosh; Kumar, Awanish

    2015-10-01

    Water is the most important and vital molecule of our planet and covers 75% of earth surface. But it is getting polluted due to high industrial growth. The heavy metals produced by industrial activities are recurrently added to it and considered as dangerous pollutants. Increasing concentration of toxic heavy metals (Pb(2+), Cd(2+), Hg(2+), Ni(2+)) in water is a severe threat for human. Heavy metal contaminated water is highly carcinogenic and poisonous at even relatively low concentrations. When they discharged in water bodies, they dissolve in the water and are distributed in the food chain. Bacteria and fungi are efficient microbes that frequently transform heavy metals and remove toxicity. The application of bacteria and fungi may offer cost benefit in water treatment plants for heavy metal transformation and directly related to public health and environmental safety issues. The heavy metals transformation rate in water is also dependent on the enzymatic capability of microorganisms. By transforming toxic heavy metals microbes sustain aquatic and terrestrial life. Therefore the application of microbiological biomass for heavy metal transformation and removal from aquatic ecosystem is highly significant and striking. This paper reviews the microbial transformation of heavy metal, microbe metal interaction and different approaches for microbial heavy metal remediation from water bodies.

  18. Characterizing the oxygen isotopic composition of phosphate sources to aquatic ecosystems

    Science.gov (United States)

    Young, M.B.; McLaughlin, K.; Kendall, C.; Stringfellow, W.; Rollog, M.; Elsbury, K.; Donald, E.; Paytan, A.

    2009-01-01

    The oxygen isotopic composition of dissolved inorganic phosphate (δ18Op) in many aquatic ecosystems is not in isotopic equilibrium with ambient water and, therefore, may reflect the source δ18Op. Identification of phosphate sources to water bodies is critical for designing best management practices for phosphate load reduction to control eutrophication. In order for δ18O p to be a useful tool for source tracking, the δ18Op of phosphate sources must be distinguishable from one another; however, the δ18Op of potential sources has not been well characterized. We measured the δ18O p of a variety of known phosphate sources, including fertilizers, semiprocessed phosphorite ore, particulate aerosols, detergents, leachates of vegetation, soil, animal feces, and wastewater treatment plant effluent. We found a considerable range of δ18Op values (from +8.4 to +24.9‰) for the various sources, and statistically significant differences were found between several of the source types. δ18Op measured in three different fresh water systems was generally not in equilibrium with ambient water. Although there is overlap in δ18Op values among the groups of samples, our results indicate that some sources are isotopically distinct and δ18Op can be used for identifying phosphate sources to aquatic systems.

  19. PCB Food Web Dynamics Quantify Nutrient and Energy Flow in Aquatic Ecosystems.

    Science.gov (United States)

    McLeod, Anne M; Paterson, Gordon; Drouillard, Ken G; Haffner, G Douglas

    2015-11-03

    Measuring in situ nutrient and energy flows in spatially and temporally complex aquatic ecosystems represents a major ecological challenge. Food web structure, energy and nutrient budgets are difficult to measure, and it is becoming more important to quantify both energy and nutrient flow to determine how food web processes and structure are being modified by multiple stressors. We propose that polychlorinated biphenyl (PCB) congeners represent an ideal tracer to quantify in situ energy and nutrient flow between trophic levels. Here, we demonstrate how an understanding of PCB congener bioaccumulation dynamics provides multiple direct measurements of energy and nutrient flow in aquatic food webs. To demonstrate this novel approach, we quantified nitrogen (N), phosphorus (P) and caloric turnover rates for Lake Huron lake trout, and reveal how these processes are regulated by both growth rate and fish life history. Although minimal nutrient recycling was observed in young growing fish, slow growing, older lake trout (>5 yr) recycled an average of 482 Tonnes·yr(-1) of N, 45 Tonnes·yr(-1) of P and assimilated 22 TJ yr(-1) of energy. Compared to total P loading rates of 590 Tonnes·yr(-1), the recycling of primarily bioavailable nutrients by fish plays an important role regulating the nutrient states of oligotrophic lakes.

  20. Cyanobacterial effects in Lake Ludoš, Serbia - Is preservation of a degraded aquatic ecosystem justified?

    Science.gov (United States)

    Tokodi, Nada; Drobac, Damjana; Meriluoto, Jussi; Lujić, Jelena; Marinović, Zoran; Važić, Tamara; Nybom, Sonja; Simeunović, Jelica; Dulić, Tamara; Lazić, Gospava; Petrović, Tamaš; Vuković-Gačić, Branka; Sunjog, Karolina; Kolarević, Stoimir; Kračun-Kolarević, Margareta; Subakov-Simić, Gordana; Miljanović, Branko; Codd, Geoffrey A; Svirčev, Zorica

    2018-04-20

    Cyanobacteria are present in many aquatic ecosystems in Serbia. Lake Ludoš, a wetland area of international significance and an important habitat for waterbirds, has become the subject of intense research interest because of practically continuous blooming of cyanobacteria. Analyses of water samples indicated a deterioration of ecological condition and water quality, and the presence of toxin-producing cyanobacteria (the most abundant Limnothrix redekei, Pseudanabaena limnetica, Planktothrix agardhii and Microcystis spp.). Furthermore, microcystins were detected in plants and animals from the lake: in macrophyte rhizomes (Phragmites communis, Typha latifolia and Nymphaea elegans), and in the muscle, intestines, kidneys, gonads and gills of fish (Carassius gibelio). Moreover, histopathological deleterious effects (liver, kidney, gills and intestines) and DNA damage (liver and gills) were observed in fish. A potential treatment for the reduction of cyanobacterial populations employing hydrogen peroxide was tested during this study. The treatment was not effective in laboratory tests although further in-lake trials are needed to make final conclusions about the applicability of the method. Based on our observations of the cyanobacterial populations and cyanotoxins in the water, as well as other aquatic organisms and, a survey of historical data on Lake Ludoš, it can be concluded that the lake is continuously in a poor ecological state. Conservation of the lake in order to protect the waterbirds (without urgent control of eutrophication) actually endangers them and the rest of the biota in this wetland habitat, and possibly other ecosystems. Thus, urgent measures for restoration are required, so that the preservation of this Ramsar site would be meaningful. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Aquatic vegetation were photographed from aircraft from Florida Bay, Indian River (Florida), and the Coast of Massachusetts (NODC Accession 0000411)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Aerial photographs were taken of the aquatic vegetation of Florida Bay, Indian River (Florida), and the Coast of Massachusetts. Photographs were scanned and...

  2. Patterns of occurrence of semi-aquatic reptiles in highly invaded Mediterranean rivers

    Directory of Open Access Journals (Sweden)

    Daniel Escoriza

    2018-05-01

    Full Text Available The fluvial systems in the north-east of the Iberian Peninsula are highly disturbed habitats, with widespread occurrence of alien species. Previous studies have shown that alien species have a major impact on native freshwater fauna, but it is not known what effect they have on semi-aquatic reptiles. Here the author investigated the factors that influence the occurrence of three species of semi-aquatic reptiles, one turtle (Mauremys leprosa and two snakes (Natrix astreptophora and Natrix maura, at 261 sites in seven rivers/streams in Girona (north-eastern Spain. The studied semi-aquatic reptiles are habitat generalists which can occupy sections of rivers with altered regimes. The relationships of reptile presence to abiotic niche parameters and the presence of alien species were evaluated, as well as the patterns of pairwise co-occurrence between the reptiles. The presence of alien species did impact one out of three reptiles in this community. The association between both species of natricines was weakly negative, suggesting that interspecific competition does not structure their co-occurrences. The removal of alien species is the most appropriate strategy to preserve the complete diversity of native semi-aquatic reptiles.

  3. Solar energy development and aquatic ecosystems in the southwestern United States: potential impacts, mitigation, and research needs.

    Science.gov (United States)

    Grippo, Mark; Hayse, John W; O'Connor, Ben L

    2015-01-01

    The cumulative impacts of utility-scale solar energy facilities on aquatic ecosystems in the Southwestern United States are of concern, considering the many existing regional anthropogenic stressors. We review the potential impacts of solar energy development on aquatic habitat and biota. The greatest potential for impacts is related to the loss, fragmentation, or prolonged drying of ephemeral water bodies and drainage networks resulting from the loss of desert washes within the construction footprint of the facility. Groundwater-dependent aquatic habitat may also be affected by operational groundwater withdrawal in the case of water-intensive solar technologies. Solar panels have also been found to attract aquatic insects and waterbirds, potentially resulting in mortality. Avoiding construction activity near perennial and intermittent surface waters is the primary means of reducing impacts on aquatic habitats, followed by measures to minimize erosion, sedimentation, and contaminant inputs into waterways. Currently, significant data gaps make solar facility impact assessment and mitigation more difficult. Examples include the need for more regional and site-specific studies of surface-groundwater connectivity, more detailed maps of regional stream networks and riparian vegetation corridors, as well as surveys of the aquatic communities inhabiting ephemeral streams. In addition, because they often lack regulatory protection, there is also a need to develop valuation criteria for ephemeral waters based on their ecological and hydrologic function within the landscape. By addressing these research needs, we can achieve the goal of greater reliance on solar energy, while at the same time minimizing impacts on desert ecosystems.

  4. An eDNA assay for river otter detection: A tool for surveying a semi-aquatic mammal

    Science.gov (United States)

    Ticha M. Padgett-Stewart; Taylor M. Wilcox; Kellie J. Carim; Kevin S. McKelvey; Michael K. Young; Michael K. Schwartz

    2016-01-01

    Environmental DNA (eDNA) is an effective tool for the detection of elusive or low-density aquatic organisms. However, it has infrequently been applied to mammalian species. North American river otters (Lontra canadensis) are both broad ranging and semi-aquatic, making them an ideal candidate for examining the uses of eDNA for detection of mammals. We developed...

  5. Community structure of aquatic insects in the karstic Jadro River in Croatia.

    Science.gov (United States)

    Rađa, Biljana; Santić, Mate

    2014-04-19

    This study focused on the aquatic insect community in the longitudinal gradient and temporal scales of the Jadro River. The river was sampled for a period of ten years (2000- 2010), four times per year through the various seasons, along the river course. Sampling stations were selected in the upper, middle, and downstream parts of the river. A total of 21,852 specimens of aquatic insects belonging to six orders were obtained. The species determination confirmed 27 different species in the river. The data were analyzed by the multivariate methodologies of correspondence analysis and cluster analysis (unweighted pair group method with arithmetic mean) using the similarity index of Morosita for all ten years. Canonical correspondence analysis was applied to the data to check which of the mesured physicochemical variables significantly explained community variation. According to those data, significant variables for the upper station were water temperature and dissolved oxygen, and chlorides was the significant variable for the lower stations. This is an open access paper. We use the Creative Commons Attribution 3.0 license that permits unrestricted use, provided that the paper is properly attributed.

  6. Ecological effects of the Hayman Fire - Part 3: Soil properties, erosion, and implications for rehabilitation and aquatic ecosystems

    Science.gov (United States)

    Jan E. Cipra; Eugene F. Kelly; Lee MacDonald; John Norman

    2003-01-01

    This team was asked to address three questions regarding soil properties, erosion and sedimentation, and how aquatic and terrestrial ecosystems have responded or could respond to various land management options. We have used soil survey maps, burn severity maps, and digital elevation model (DEM) maps as primary map data. We used our own field measurements and...

  7. Towards Mapping the Provision of Ecosystem Services from Headwater Wetlands in the Susquehanna River Basin

    Science.gov (United States)

    Headwater wetlands provide a range of ecosystem services including habitat provisioning and flood retention. Following the River Ecosystem Synthesis framework we identified and assessed not only headwater wetlands, but unconstrained reaches with the potential to support diverse s...

  8. Chemical fractionation of radionuclides and stable elements in aquatic plants of the Yenisei River.

    Science.gov (United States)

    Bolsunovsky, Alexander

    2011-09-01

    The Yenisei River is contaminated with artificial radionuclides released by one of the Russian nuclear plants. The aquatic plants growing in the radioactively contaminated parts of the river contain artificial radionuclides. The aim of the study was to investigate accumulation of artificial radionuclides and stable elements by submerged plants of the Yenisei River and estimate the strength of their binding to plant biomass by using a new sequential extraction scheme. The aquatic plants sampled were: Potamogeton lucens, Fontinalis antipyretica, and Batrachium kauffmanii. Gamma-spectrometric analysis of the samples of aquatic plants has revealed more than 20 radionuclides. We also investigated the chemical fractionation of radionuclides and stable elements in the biomass and rated radionuclides and stable elements based on their distribution in biomass. The greatest number of radionuclides strongly bound to biomass cell structures was found for Potamogeton lucens and the smallest for Batrachium kauffmanii. For Fontinalis antipyretica, the number of distribution patterns that were similar for both radioactive isotopes and their stable counterparts was greater than for the other studied species. The transuranic elements (239)Np and (241)Am were found in the intracellular fraction of the biomass, and this suggested their active accumulation by the plants.

  9. Valuing trade-offs of river ecosystem services in large hydropower development in Tibet, China

    Science.gov (United States)

    Yu, B.; Xu, L.

    2015-12-01

    Hydropower development can be considered as a kind of trade-offs of ecosystem services generated by human activity for their economic and energy demand, because it can increase some river ecosystem services but decrease others. In this context, an ecosystem service trade-off framework in hydropower development was proposed in this paper. It aims to identify the ecological cost of river ecosystem and serve for the ecological compensation during hydropower development, for the hydropower services cannot completely replace the regulating services of river ecosystem. The valuing trade-offs framework was integrated by the influenced ecosystem services identification and ecosystem services valuation, through ecological monitoring and ecological economic methods, respectively. With a case study of Pondo hydropower project in Tibet, China, the valuing trade-offs of river ecosystem services in large hydropower development was illustrated. The typical ecological factors including water, sediment and soil were analyzed in this study to identify the altered river ecosystem services by Pondo hydropower project. Through the field monitoring and valuation, the results showed that the Lhasa River ecosystem services value could be changed annually by Pondo hydropower project with the increment of 5.7E+8CNY, and decrement of 5.1E+7CNY. The ecological compensation for river ecosystem should be focus on water and soil conservation, reservoir dredging and tributaries habitat protection.

  10. Isotope Investigations of Nitrogen Compounds in Different Aquatic Ecosystems in Cyprus, Russia and Ukraine

    Energy Technology Data Exchange (ETDEWEB)

    Voropaev, A.; Voerkelius, S.; Eichinger, L. [Hydroisotop GmbH, Schweitenkirchen (Germany); Grinenko, V. [Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow (Russian Federation)

    2013-07-15

    The isotope analyses of nitrogen compounds is a powerful tool for the investigation of anrthropogenic influence on the nitrogen cycle in terrestrial and aquatic ecosystems. The isotopic composition of nitrogen and oxygen in nitrates from different groundwater aquifers in Cyprus reflects anthropogenic inputs of nitrogen mainly from industrial fertilizer application in agriculture. Significant denitrification as identified at many sampling sites is an important process, which reduces nitrate concentrations in groundwater. In surface water ecosystems anthropogenic influences and natural environmental changes are detected by the isotopic composition of nitrogen in suspended organic material and in bottom sediments. In the oligotrophic fresh water of Lake Galich in Russia the waste water outflow is a reason for the local increase of {delta}{sup 15}N values in bottom sediments, where the nitrogen and carbon isotopic compositions of unpolluted sediments are very homogeneous. In the Neva estuary in russia the lateral destribution of {delta}{sup 15}N values in upper layers of bottom sediments reflects changes in the mixing pattern of marine and continental organic matter caused by a flood protection dam building in the Dneprovsko-Bugsky estuary in Ukraine - probably the increasing influence of anthropogenic {sup 15}N enriched nutrient load. (author)

  11. Climate regulates alpine lake ice cover phenology and aquatic ecosystem structure

    Science.gov (United States)

    Preston, Daniel L.; Caine, Nel; McKnight, Diane M.; Williams, Mark W.; Hell, Katherina; Miller, Matthew P.; Hart, Sarah J.; Johnson, Pieter T.J.

    2016-01-01

    High-elevation aquatic ecosystems are highly vulnerable to climate change, yet relatively few records are available to characterize shifts in ecosystem structure or their underlying mechanisms. Using a long-term dataset on seven alpine lakes (3126 to 3620 m) in Colorado, USA, we show that ice-off dates have shifted seven days earlier over the past 33 years and that spring weather conditions – especially snowfall – drive yearly variation in ice-off timing. In the most well-studied lake, earlier ice-off associated with increases in water residence times, thermal stratification, ion concentrations, dissolved nitrogen, pH, and chlorophyll-a. Mechanistically, low spring snowfall and warm temperatures reduce summer stream flow (increasing lake residence times) but enhance melting of glacial and permafrost ice (increasing lake solute inputs). The observed links among hydrological, chemical, and biological responses to climate factors highlight the potential for major shifts in the functioning of alpine lakes due to forecasted climate change.

  12. Project SHARE Sustainable Hydropower in Alpine Rivers Ecosystems

    Science.gov (United States)

    Mammoliti Mochet, Andrea

    2010-05-01

    SHARE - Sustainable Hydropower in Alpine Rivers Ecosystems is a running project early approved and co funded by the European regional development fund in the context of the European Territorial Cooperation Alpine Space programme 2007 - 2013: the project is formally ongoing from August 2009 and it will end July 2012. Hydropower is the most important renewable resource for electricity production in alpine areas: it has advantages for the global CO2 balance but creates serious environmental impacts. RES-e Directives require renewable electricity enhance but, at the same time, the Water Framework Directive obliges member States to reach or maintain a water bodies "good" ecological status, intrinsically limiting the hydropower exploitation. Administrators daily face an increasing demand of water abstraction but lack reliable tools to rigorously evaluate their effects on mountain rivers and the social and economical outputs on longer time scale. The project intends to develop, test and promote a decision support system to merge on an unprejudiced base, river ecosystems and hydropower requirements. This approach will be led using existing scientific tools, adjustable to transnational, national and local normative and carried on by permanent panel of administrators and stakeholders. Scientific knowledge related to HP & river management will be "translated" by the communication tools and spent as a concrete added value to build a decision support system. In particular, the Multicriteria Analysis (MCA) will be applied to assess different management alternatives where a single-criterion approach (such as cost-benefit analysis) falls short, especially where environmental, technical, economic and social criteria can't be quantified by monetary values. All the existing monitoring databases will be used and harmonized with new information collected during the Pilot case studies. At the same time, all information collected will be available to end users and actors of related

  13. A universal method to assess the potential of phosphorus loss from soil to aquatic ecosystems.

    Science.gov (United States)

    Pöthig, Rosemarie; Behrendt, Horst; Opitz, Dieter; Furrer, Gerhard

    2010-02-01

    Phosphorus loss from terrestrial to the aquatic ecosystems contributes to eutrophication of surface waters. To maintain the world's vital freshwater ecosystems, the reduction of eutrophication is crucial. This needs the prevention of overfertilization of agricultural soils with phosphorus. However, the methods of risk assessment for the P loss potential from soils lack uniformity and are difficult for routine analysis. Therefore, the efficient detection of areas with a high risk of P loss requires a simple and universal soil test method that is cost effective and applicable in both industrialized and developing countries. Soils from areas which varied highly in land use and soil type were investigated regarding the degree of P saturation (DPS) as well as the equilibrium P concentration (EPC(0)) and water-soluble P (WSP) as indicators for the potential of P loss. The parameters DPS and EPC(0) were determined from P sorption isotherms. Our investigation of more than 400 soil samples revealed coherent relationships between DPS and EPC(0) as well as WSP. The complex parameter DPS, characterizing the actual P status of soil, is accessible from a simple standard measurement of WSP based on the equation [Formula: see text]. The parameter WSP in this equation is a function of remaining phosphorous sorption capacity/total accumulated phosphorous (SP/TP). This quotient is independent of soil type due to the mutual compensation of the factors SP and TP. Thus, the relationship between DPS and WSP is also independent of soil type. The degree of P saturation, which reflects the actual state of P fertilization of soil, can be calculated from the easily accessible parameter WSP. Due to the independence from soil type and land use, the relation is valid for all soils. Values of WSP, which exceed 5 mg P/kg soil, signalize a P saturation between 70% and 80% and thus a high risk of P loss from soil. These results reveal a new approach of risk assessment for P loss from soils to

  14. Changing seasonality of Arctic hydrology disrupts key biotic linkages in Arctic aquatic ecosystems.

    Science.gov (United States)

    Deegan, L.; MacKenzie, C.; Peterson, B. J.; Fishscape Project

    2011-12-01

    Arctic grayling (Thymallus arcticus) is an important circumpolar species that provide a model system for understanding the impacts of changing seasonality on arctic ecosystem function. Grayling serve as food for other biota, including lake trout, birds and humans, and act as top-down controls in stream ecosystems. In Arctic tundra streams, grayling spend their summers in streams but are obligated to move back into deep overwintering lakes in the fall. Climatic change that affects the seasonality of river hydrology could have a significant impact on grayling populations: grayling may leave overwintering lakes sooner in the spring and return later in the fall due to a longer open water season, but the migration could be disrupted by drought due to increased variability in discharge. In turn, a shorter overwintering season may impact lake trout dynamics in the lakes, which may rely on the seasonal inputs of stream nutrients in the form of migrating grayling into these oligotrophic lakes. To assess how shifting seasonality of Arctic river hydrology may disrupt key trophic linkages within and between lake and stream components of watersheds on the North Slope of the Brooks Mountain Range, Alaska, we have undertaken new work on grayling and lake trout population and food web dynamics. We use Passive Integrated Transponder (PIT) tags coupled with stream-width antenna units to monitor grayling movement across Arctic tundra watersheds during the summer, and into overwintering habitat in the fall. Results indicate that day length may prime grayling migration readiness, but that flooding events are likely the cue grayling use to initiate migration in to overwintering lakes. Many fish used high discharge events in the stream as an opportunity to move into lakes. Stream and lake derived stable isotopes also indicate that lake trout rely on these seasonally transported inputs of stream nutrients for growth. Thus, changes in the seasonality of river hydrology may have broader

  15. Downstream effects of hydropower production on aquatic macroinvertebrate assemblages in two rivers in Costa Rica.

    Science.gov (United States)

    Chaves-Ulloa, Ramsa; Umaña-Villalobos, Gerardo; Springer, Monika

    2014-04-01

    Despite the fact that little is known about the consequences of hydropower production in tropical areas, many large dams (> 15 m high) are currently under construction or consideration in the tropics. We researched the effects of large hydroelectric dams on aquatic macroinvertebrate assemblages in two Costa Rican rivers. We measured physicochemical characteristics and sampled aquatic macroinvertebrates from March 2003 to March 2004 in two dammed rivers, Peñas Blancas and San Lorenzo, as well as in the undammed Chachagua River. Sites above and below the dam had differences in their physicochemical variables, with wide variation and extreme values in variables measured below the dam in the San Lorenzo River. Sites below the dams had reduced water discharges, velocities, and depths when compared with sites above the dams, as well as higher temperatures and conductivity. Sites above dams were dominated by collector-gatherer-scrapers and habitat groups dominated by swimmer-clingers, while sites below dams had a more even representation of groups. In contrast, a comparison between two sites at different elevation in the undammed river maintained a similar assemblage composition. Tributaries might facilitate macroinvertebrate recovery above the turbine house, but the assemblage below the turbine house resembled the one below the dam. A massive sediment release event from the dam decreased the abundance per sample and macroinvertebrate taxa below the dam in the Peñas Blancas River. Our study illustrates the effects of hydropower production on neotropical rivers, highlighting the importance of using multiple measures of macroinvertebrate assemblage structure for assessing this type of environmental impact.

  16. Are the streams of the Sinos River basin of good water quality? Aquatic macroinvertebrates may answer the question

    Directory of Open Access Journals (Sweden)

    L. Bieger

    Full Text Available Macroinvertebrate communities are one of the most used groups in assessments of water quality, since they respond directly to the level of contamination of aquatic ecosystems. The main objective of this study was the assessment of the water quality of the Sinos River basin (Rio Grande do Sul state, Brazil through biotic indices based on the macroinvertebrate community ("Family Biotic Index - FBI", and "Biological Monitoring Working Party Score System - BMWP". Three lower order streams (2nd order were selected in each one of three main regions of the basin. In each stream, the samplings were performed in three reaches (upper, middle, and lower, totalling 27 reaches. Two samplings were carried in each reach over one year (winter and summer. A total of 6,847 macroinvertebrates distributed among 54 families were sampled. The streams from the upper region were of better water quality than the lower region. The water quality did not change between the upper, middle and lower reaches of the streams. However, the upper reaches of the streams were of better water quality in all the regions of the basin. The water quality of the streams did not vary between the summer and the winter. This result demonstrated that water quality may be analysed in both studied seasons (summer and winter using biotic indices. The analysis of the results allows us to conclude that the biotic indices used reflected the changes related to the water quality along the longitudinal gradient of the basin. Thus, aquatic macroinvertebrates were important bioindicators of the water and environmental quality of the streams of the Sinos River basin.

  17. Ecosystem Services and Related Sustainable Management of River Oases along the Tarim River in Northwest China

    Science.gov (United States)

    Disse, M.; Keilholz, P.; Rumbaur, C.; Thevs, N.

    2011-12-01

    Within the Taklimakan Desert of Northwestern China, an area renowned for its extreme climate and vulnerable ecosystems, lies one of the largest inland rivers in the world, the Tarim River. Because the Tarim River is located in a remote area from the oceans, rainfall is extremely rare (less than 50 mm per year) but potential evaporation is high (3000 mm). Thus, the major source of water discharge comes from snowmelt and glacier-melt in the mountains. Though the water discharge into the Tarim River has experienced an increase over the past ten years, global climate change forecasts predict this water supply to decline within the century. The Tarim River is the major source of water in Northwestern China, and has become the hub of many economic activities related to agriculture and urban life. Over the past 50 years increased activity in the area has led to a severe decline in river flow. Both human and natural ecosystems have been impacted by water diversions. Since rainfall is rare, the majority of vegetation in this area depends solely on groundwater for survival, and plants are experiencing stress caused by decreasing groundwater levels. Recently nearby cities have experienced severe dust storms caused by the shrinking of the vegetative region along the river. SuMaRiO (Sustainable Management of River Oases) is a bundle project between Germany and China working to contribute to a sustainable land management which explicitly takes into account ecosystem functions (ESF) and ecosystem services (ESS). In a transdisciplinary research process, SuMaRiO will identify realizable management strategies, considering social, economic and ecological criteria. SuMaRiO is developing tools to work with Chinese decision makers to implement sustainable land management strategies. In addition, research is being conducted to estimate climate change impacts, floodplain biodiversity, and water runoff characteristics. The overarching goal of SuMaRiO is to support oasis management along

  18. Combined sewer overflows impact on water quality and environmental ecosystem in the Harlem River

    Science.gov (United States)

    Wang, J.

    2017-12-01

    Combined sewer overflows (CSOs) discharge untreated sewage into the Harlem River during wet weather conditions, and it elevated nutrients and pathogen levels. It is not safe for swimming, fishing or boating especially in rainstorms. The Harlem River, a 9.3 mile long natural straight, connects the Hudson and East Rivers in New York City. It had been historically used for swimming, fishing, boating. Anthropogenic impacts have degraded water quality, limiting current aquatic activity in the river. CSOs water samples were collected during rainstorms, and analyzed in the laboratories of the Chemistry and Biology Department, Bronx Community College, City University of New York. Results showed elevated bacteria/pathogen and nutrient levels. Most recent data showed an ammonia concentration of 2.6 mg/L on July 30, 2015 during a heavy afternoon thunderstorm, and an ammonia level 2.7mg/L during tropical storm Arthur on July 2, 2014. Both significantly exceeded the EPA regulation level for NYC waters of 0.23mg/L. Phosphate levels peaked at 0.197 mg/L during a heavy thunderstorm on Apr 28, 2011, which was much higher than regulated level of 0.033 mg/L. Turbidity was 319 FAU during the July 30 2015 heavy thunderstorm, and was 882 FAU during tropical storm Arthur; which was significantly higher than regulation level of 5.25 FAU. CSOs collected during a recent heavy rainstorm on Oct 28, 2015, showed fecal coliform of 1 million MPN/100ml, E.Coli. of 60,000 MPN/100ml, and enterococcus of 65,000 MPN/100ml; which exceeded regulated levels of fecal coliform-200 MPN/100ml, E.Coli.-126 MPN/100ml, enterococcus-104 MPN/100ml. It is critical to reduce CSOs, restore ecosystem and improve water quality of the Harlem River. Green wall, green roof, and wetland had been used to reduce stormwater runoff & CSOs in the Bronx River; these green infrastructures are going to be used along the Harlem River waterfront as well. The goal of this research is to make the Harlem River swimmable and fishable

  19. The impact of the Chernobyl accident on continental aquatic ecosystems. A literature review

    International Nuclear Information System (INIS)

    Foulquier, L.; Baudin-Jaulent, Y.

    1991-01-01

    This synthesis has been produced by contract with the Commission of the European Communities (DG XI) and the International Union of Radioecologists. 117 reports from 19 countries have been studied. Collecting information on water, sediments, aquatic vegetation and fish provides data concerning transfers in rivers and lakes which must be identified. There is a direct relation between radioactivity and the deposit level which is mainly in wet form. Beyond the areas near the accident, it is particularly noticeable in Scandinavia, Central Europe, northern Italy and in the north-west of the United Kingdom. Wide variations occur from one station to another in a same region. The radioecology of each site must be taken into consideration. Seven radionuclides have been detected in significant amounts: 132 Te, 131 I, 103+106 Ru, 134+137 Cs, 110m Ag. 137 Cs predominated very quickly. The main characteristic lies in the acute nature of the contamination in comparison with the more chronic one brought about by nuclear testing between 1959 and 1963. The results show the speed of the radionuclide transfer and fixation process and the rapid return to former levels, except for 137 Cs. Fish provide the best means of comparing radionuclide concentrations through time and space. In rivers, the values are less than or equal to 400 Bq kg -1 w. w. of 137 Cs. In the lakes of the regions which were affected the most by the fall-out, we find 1000 Bq kg -1 w. w., and up to 131,000. The effective half-life in situ is approximately 200 days in rivers and 500 in lakes. Some elements will also be given for comparing the impact of Chernobyl to that of fall-out from nuclear tests. (author)

  20. Comparative analysis of the mobility of uranium and artificial radionuclides in the ecosystem of the Yenisei River

    Energy Technology Data Exchange (ETDEWEB)

    Bolsunovsky, Alexander; Medvedeva, Marina [Institute of Biophysics SB Russian Academy of Sciences, 660036, Krasnoyarsk (Russian Federation)

    2014-07-01

    The Yenisei River is one of the largest rivers in the world, which had been subjected to radioactive contamination for over 50 years, due to operation of the Mining-and-Chemical Combine (MCC) of Rosatom at Zheleznogorsk, which had been producing weapons-grade plutonium. Bottom sediments and flood plain of the Yenisei River are contaminated by artificial radionuclides, including transuranium ones, both close to the MCC and at a considerable distance downstream. The MCC is also a source of uranium isotopes in the Yenisei. Thus, the Yenisei River basin is a unique environment for studying the mobility of both uranium isotopes and artificial radionuclides in all components of the aquatic ecosystem. The purpose of this study was to compare the mobility of uranium and artificial radionuclides in the ecosystem of the Yenisei River. Samples of water, sediments, and aquatic organisms were used as study material. Aquatic organisms were represented by submerged plants, benthic-feeding fish, and zoo-benthos. The submerged plants (macrophytes) analyzed were of five species: Fontinalis antipyretica, Potamogeton lucens, Ceratophyllum demersum, Myriophyllum spicatum, and Elodea canadensis. Grayling (Timalus arcticus) represented benthic-feeding fish, and zoo-benthos species were represented by Philolimnogammarus viridis, which forms the major part of the grayling's diet. Samples were collected at positions in the vicinity of the MCC discharge point, at a distance of 110 km downstream of Krasnoyarsk, and upstream of the MCC, during sampling campaigns in 2008-2012. Radionuclide measurements were performed using a wide range of instrumental methods: gamma-spectrometry with a 'Canberra' spectrometer (U.S.), mass spectrometry with an 'Agilent' spectrometer (U.S.), neutron activation analysis, and beta-alpha radiometry. The results obtained in this study suggest that the part of the Yenisei River ecosystem contaminated due to MCC radioactive discharges contains

  1. Bottom-up nutrient and top-down fish impacts on insect-mediated mercury flux from aquatic ecosystems.

    Science.gov (United States)

    Jones, Taylor A; Chumchal, Matthew M; Drenner, Ray W; Timmins, Gabrielle N; Nowlin, Weston H

    2013-03-01

    Methyl mercury (MeHg) is one of the most hazardous contaminants in the environment, adversely affecting the health of wildlife and humans. Recent studies have demonstrated that aquatic insects biotransport MeHg and other contaminants to terrestrial consumers, but the factors that regulate the flux of MeHg out of aquatic ecosystems via emergent insects have not been studied. The authors used experimental mesocosms to test the hypothesis that insect emergence and the associated flux of MeHg from aquatic to terrestrial ecosystems is affected by both bottom-up nutrient effects and top-down fish consumer effects. In the present study, nutrient addition led to an increase in MeHg flux primarily by enhancing the biomass of emerging insects whose tissues were contaminated with MeHg, whereas fish decreased MeHg flux primarily by reducing the biomass of emerging insects. Furthermore, the authors found that these factors are interdependent such that the effects of nutrients are more pronounced when fish are absent, and the effects of fish are more pronounced when nutrient concentrations are high. The present study is the first to demonstrate that the flux of MeHg from aquatic to terrestrial ecosystems is strongly enhanced by bottom-up nutrient effects and diminished by top-down consumer effects. Copyright © 2012 SETAC.

  2. Marcellus and mercury: Assessing potential impacts of unconventional natural gas extraction on aquatic ecosystems in northwestern Pennsylvania.

    Science.gov (United States)

    Grant, Christopher J; Weimer, Alexander B; Marks, Nicole K; Perow, Elliott S; Oster, Jacob M; Brubaker, Kristen M; Trexler, Ryan V; Solomon, Caroline M; Lamendella, Regina

    2015-01-01

    Mercury (Hg) is a persistent element in the environment that has the ability to bioaccumulate and biomagnify up the food chain with potentially harmful effects on ecosystems and human health. Twenty-four streams remotely located in forested watersheds in northwestern PA containing naturally reproducing Salvelinus fontinalis (brook trout), were targeted to gain a better understanding of how Marcellus shale natural gas exploration may be impacting water quality, aquatic biodiversity, and Hg bioaccumulation in aquatic ecosystems. During the summer of 2012, stream water, stream bed sediments, aquatic mosses, macroinvertebrates, crayfish, brook trout, and microbial samples were collected. All streams either had experienced hydraulic fracturing (fracked, n = 14) or not yet experienced hydraulic fracturing (non-fracked, n = 10) within their watersheds at the time of sampling. Analysis of watershed characteristics (GIS) for fracked vs non-fracked sites showed no significant differences (P > 0.05), justifying comparisons between groups. Results showed significantly higher dissolved total mercury (FTHg) in stream water (P = 0.007), lower pH (P = 0.033), and higher dissolved organic matter (P = 0.001) at fracked sites. Total mercury (THg) concentrations in crayfish (P = 0.01), macroinvertebrates (P = 0.089), and predatory macroinvertebrates (P = 0.039) were observed to be higher for fracked sites. A number of positive correlations between amount of well pads within a watershed and THg in crayfish (r = 0.76, P shale natural gas exploration is having an effect on aquatic ecosystems.

  3. Assessing Sources of Stress to Aquatic Ecosystems: Using Biomarkers and Bioindicators to Characterize Exodure-Response Profiles of Anthropogenic Activities

    Energy Technology Data Exchange (ETDEWEB)

    Adams, S.M.

    1999-03-29

    Establishing causal relationships between sources of environmental stressors and aquatic ecosystem health if difficult because of the many biotic and abiotic factors which can influence or modify responses of biological systems to stress, the orders of magnitude involved in extrapolation over both spatial and temporal scales, and compensatory mechanisms such as density-dependent responses that operate in populations. To address the problem of establishing causality between stressors and effects on aquatic systems, a diagnostic approach, based on exposure-response profiles for various anthropogenic activities, was developed to help identify sources of stress responsible for effects on aquatic systems at ecological significant levels of biological organization (individual, population, community). To generate these exposure-effects profiles, biomarkers of exposure were plotted against bioindicators of corresponding effects for several major anthropogenic activities including petrochemical , pulp and paper, domestic sewage, mining operations, land-development activities, and agricultural activities. Biomarkers of exposure to environmental stressors varied depending on the type of anthropogenic activity involved. Bioindicator effects, however, including histopathological lesions, bioenergetic status, individual growth, reproductive impairment, and community-level responses were similar among many of the major anthropogenic activities. This approach is valuable to help identify and diagnose sources of stressors in environments impacted by multiple stressors. By identifying the types and sources of environmental stressors, aquatic ecosystems can be more effectively protected and managed to maintain acceptable levels of environmental quality and ecosystem fitness.

  4. Predicting wading bird and aquatic faunal responses to ecosystem restoration scenarios

    Science.gov (United States)

    Beerens, James M.; Trexler, Joel C.; Catano, Christopher P.

    2017-01-01

    In large-scale conservation decisions, scenario planning identifies key uncertainties of ecosystem function linked to ecological drivers affected by management, incorporates ecological feedbacks, and scales up to answer questions robust to alternative futures. Wetland restoration planning requires an understanding of how proposed changes in surface hydrology, water storage, and landscape connectivity affect aquatic animal composition, productivity, and food-web function. In the Florida Everglades, reintroduction of historical hydrologic patterns is expected to increase productivity of all trophic levels. Highly mobile indicator species such as wading birds integrate secondary productivity from aquatic prey (small fishes and crayfish) over the landscape. To evaluate how fish, crayfish, and wading birds may respond to alternative hydrologic restoration plans, we compared predicted small fish density, crayfish density and biomass, and wading bird occurrence for existing conditions to four restoration scenarios that varied water storage and removal of levees and canals (i.e. decompartmentalization). Densities of small fish and occurrence of wading birds are predicted to increase throughout most of the Everglades under all restoration options because of increased flows and connectivity. Full decompartmentalization goes furthest toward recreating hypothesized historical patterns of fish density by draining excess water ponded by levees and hydrating areas that are currently drier than in the past. In contrast, crayfish density declined and species composition shifted under all restoration options because of lengthened hydroperiods (i.e. time of inundation). Under full decompartmentalization, the distribution of increased prey available for wading birds shifted south, closer to historical locations of nesting activity in Everglades National Park.

  5. Subcatchment deltas and upland features influence multiscale aquatic ecosystem recovery in damaged landscapes.

    Science.gov (United States)

    Kielstra, Brian W; Arnott, Shelley E; Gunn, John M

    2017-12-01

    Assessing biological recovery in damaged aquatic environments requires the consideration of multiple spatial and temporal scales. Past research has focused on assessing lake recovery from atmospheric or catchment disturbance at regional or catchment levels. Studies have also rarely considered the influences of adjacent terrestrial characteristics on within-lake habitats, such as subcatchment delta confluences. We used Hyalella azteca, a ubiquitous freshwater amphipod, as a sensitive indicator to assess the importance of local subcatchment scale factors in the context of multiscale lake recovery within the metal mining region of Sudbury, Canada following a period of major reductions in atmospheric pollution. At the regional scale, data from repeated surveys of 40 lakes showed higher probabilities of H. azteca occurrence with higher lake water conductivity, alkalinity, and pH and lower metal concentrations. The importance of metals decreased through time and the importance of higher conductivity, alkalinity, and pH increased. At the subcatchment scale, a subset of six lakes sampled across a colonization gradient revealed higher H. azteca abundances at subcatchment delta sites than non-delta sites in early colonization stages, and that abundance at delta sites was correlated with both within-lake habitat and terrestrial subcatchment characteristics. For example, wetland cover reduced the strength of positive associations between H. azteca abundance and macrophyte density. A single lake from this subset also revealed higher abundances at delta sites associated with higher concentrations of terrestrial organic matter and larger subcatchments. Our results demonstrate that factors affecting recovery can change with the scale of study, and that managing terrestrial-aquatic linkages is important for facilitating recovery processes within damaged lake ecosystems. © 2017 by the Ecological Society of America.

  6. Science for Managing Riverine Ecosystems: Actions for the USGS Identified in the Workshop "Analysis of Flow and Habitat for Instream Aquatic Communities"

    Science.gov (United States)

    Bencala, Kenneth E.; Hamilton, David B.; Petersen, James H.

    2006-01-01

    Federal and state agencies need improved scientific analysis to support riverine ecosystem management. The ability of the USGS to integrate geologic, hydrologic, chemical, geographic, and biological data into new tools and models provides unparalleled opportunities to translate the best riverine science into useful approaches and usable information to address issues faced by river managers. In addition to this capability to provide integrated science, the USGS has a long history of providing long-term and nationwide information about natural resources. The USGS is now in a position to advance its ability to provide the scientific support for the management of riverine ecosystems. To address this need, the USGS held a listening session in Fort Collins, Colorado in April 2006. Goals of the workshop were to: 1) learn about the key resource issues facing DOI, other Federal, and state resource management agencies; 2) discuss new approaches and information needs for addressing these issues; and 3) outline a strategy for the USGS role in supporting riverine ecosystem management. Workshop discussions focused on key components of a USGS strategy: Communications, Synthesis, and Research. The workshop identified 3 priority actions the USGS can initiate now to advance its capabilities to support integrated science for resource managers in partner government agencies and non-governmental organizations: 1) Synthesize the existing science of riverine ecosystem processes to produce broadly applicable conceptual models, 2) Enhance selected ongoing instream flow projects with complementary interdisciplinary studies, and 3) Design a long-term, watershed-scale research program that will substantively reinvent riverine ecosystem science. In addition, topical discussion groups on hydrology, geomorphology, aquatic habitat and populations, and socio-economic analysis and negotiation identified eleven important complementary actions required to advance the state of the science and to

  7. Longitudinal patterns of fish assemblages, aquatic habitat, and water temperature in the Lower Crooked River, Oregon

    Science.gov (United States)

    Torgersen, Christian E.; Hockman-Wert, David P.; Bateman, Douglas S.; Leer, David W.; Gresswell, Robert E.

    2007-01-01

    The Lower Crooked River is a remarkable groundwater-fed stream flowing through vertical basalt canyons in the Deschutes River Valley ecoregion in central Oregon (Pater and others, 1998). The 9-mile section of the river between the Crooked River National Grasslands boundary near Ogden Wayside and river mile (RM) 8 is protected under the National Wild and Scenic Rivers Act (16 U.S.C. 1271-1287) for its outstandingly remarkable scenic, recreational, geologic, hydrologic, wildlife, and botanical values (ORVs), and significant fishery and cultural values. Groundwater springs flow directly out of the canyon walls into the Lower Crooked River and create a unique hydrologic setting for native coldwater fish, such as inland Columbia Basin redband trout (Oncorhynchus mykiss gairdneri). To protect and enhance the ORVs that are the basis for the wild and scenic designation, the Bureau of Land Management (BLM) has identified the need to evaluate, among other conditions, fish presence and habitat use of the Lower Crooked River. The results of this and other studies will provide a scientific basis for communication and cooperation between the BLM, Oregon Water Resources Department, Oregon Department of Fish and Wildlife (ODFW) and all water users within the basin. These biological studies initiated by the BLM in the region reflect a growing national awareness of the impacts of agricultural and municipal water use on the integrity of freshwater ecosystems.

  8. The Paradox of Restoring Native River Landscapes and Restoring Native Ecosystems in the Colorado River System

    Science.gov (United States)

    Schmidt, J. C.

    2014-12-01

    Throughout the Colorado River basin (CRb), scientists and river managers collaborate to improve native ecosystems. Native ecosystems have deteriorated due to construction of dams and diversions that alter natural flow, sediment supply, and temperature regimes, trans-basin diversions that extract large amounts of water from some segments of the channel network, and invasion of non-native animals and plants. These scientist/manager collaborations occur in large, multi-stakeholder, adaptive management programs that include the Lower Colorado River Multi-Species Conservation Program, the Glen Canyon Dam Adaptive Management Program, and the Upper Colorado River Endangered Species Recovery Program. Although a fundamental premise of native species recovery is that restoration of predam flow regimes inevitably leads to native species recovery, such is not the case in many parts of the CRb. For example, populations of the endangered humpback chub (Gila cypha) are largest in the sediment deficit, thermally altered conditions of the Colorado River downstream from Glen Canyon Dam, but these species occur in much smaller numbers in the upper CRb even though the flow regime, sediment supply, and sediment mass balance are less perturbed. Similar contrasts in the physical and biological response of restoration of predam flow regimes occurs in floodplains dominated by nonnative tamarisk (Tamarix spp.) where reestablishment of floods has the potential to exacerbate vertical accretion processes that disconnect the floodplain from the modern flow regime. A significant challenge in restoring segments of the CRb is to describe this paradox of physical and biological response to reestablishment of pre-dam flow regimes, and to clearly identify objectives of environmentally oriented river management. In many cases, understanding the nature of the perturbation to sediment mass balance caused by dams and diversions and understanding the constraints imposed by societal commitments to provide

  9. A new framework for assessing river ecosystem health with consideration of human service demand.

    Science.gov (United States)

    Luo, Zengliang; Zuo, Qiting; Shao, Quanxi

    2018-06-01

    In order to study river health status from harmonic relationship between human and natural environment, a river health evaluation method was proposed from the aspects of ecosystem integrity and human service demand, and the understanding of river health connotation. The proposed method is based on the harmony theory and two types of river health assessment methods (the forecasting model and index evaluation). A new framework for assessing river water health was then formed from the perspective of harmony and dynamic evolution between human service demand and river ecosystem integrity. As a case study, the method and framework were applied to the Shaying River Basin, a tributary of the most polluted Huaihe River Basin in China. The health status of the river's ecosystem and its effect on the mainstream of Huaihe River were evaluated based on water ecological experiment. The results indicated that: (1) the water ecological environment in Shaying River was generally poor and showed a gradual changing pattern along the river. The river health levels were generally "medium" in the upstream but mostly "sub-disease" in the midstream and downstream, indicating that the water pollution in Shaying River were mainly concentrated in the midstream and downstream; (2) the water pollution of Shaying River had great influence on the ecosystem of Huaihe River, and the main influencing factors were TN, followed by TP and COD Mn ; (3) the natural attribute of river was transferring toward to the direction of socialization due to the increasing human activities. The stronger the human activity intervention is, the faster the transfer will be and the more river's attributes will match with human service demand. The proposed framework contributes to the research in water ecology and environment management, and the research results can serve as an important reference for basin management in Shaying River and Huaihe River. Copyright © 2018. Published by Elsevier B.V.

  10. Application of Bayesian Network modeling on the stability and toxicity of engineered nanomaterials in aquatic ecosystems

    CSIR Research Space (South Africa)

    Ondiaka, M

    2013-08-01

    Full Text Available The stability of engineered nanomaterials (ENMs) in the aquatic systems influences their eventual interactions with aquatic biota – and subsequently the observed toxic effects. Increasing data suggests that physicochemical properties of ENMs...

  11. Characterization of the interactions between endocrine disruptors and aquatic humic substances from tropical rivers

    International Nuclear Information System (INIS)

    Botero, Wander G.; Oliveira, Luciana C. de; Cunha, Bruno B.; Oliveira, Lilian K. de; Goveia, Danielle; Fraceto, Leonardo F.; Rosa, Andre Henrique; Rocha, Julio Cesar

    2011-01-01

    Interactions between two endocrine disruptors (ED) and aquatic humic substances (AHS) from tropical rivers were studied using an ultrafiltration system equipped with a 1 kDa cut-off cellulose membrane to separate free ED from the fraction bound in the AHS. Quantification of 17α-ethynylestradiol and bisphenol A was performed using gas chromatography-mass spectrometry (GC-MS). The times required for establishment of equilibrium between the AHS and the ED were ca. 30 min, and complexation capacities for 17α-ethynylestradiol and bisphenol A were 18.53 and 2.07 mg g -1 TOC, respectively. The greater interaction of AHS with 17α-ethynylestradiol, compared to bisphenol A, was due to the presence of hydrogen in the structure of 17α-ethynylestradiol, which could interact with ionized oxygenated groups of the AHS. The results indicate that AHS can strongly influence the transport and reactivity of endocrine disruptors in aquatic systems. (author)

  12. Transgenic Bacillus thuringiensis (Bt rice is safer to aquatic ecosystems than its non-transgenic counterpart.

    Directory of Open Access Journals (Sweden)

    Guangsheng Li

    Full Text Available Rice lines genetically modified with the crystal toxin genes from Bacillus thuringiensis (Bt have experienced rapid development, with biosafety certificates for two Bt rice lines issued in 2009. There has still been no commercial release of these lines yet due to public concerns about human health and environmental risks. Some studies confirmed that Bt rice was as safe as conventional rice to non-target organisms when pesticides were not applied, however, pesticides are still required in Bt rice to control non-lepidopteran pests. In this study, we assessed the environmental effects of two Bt rice lines expressing either the cry1Ab/1Ac or cry2A genes, respectively, by using zooplanktons as indicator species under normal field management practices using pesticides when required. In the whole rice growing season, non-Bt rice was sprayed 5 times while Bt rice was sprayed 2 times, which ensured both rice achieved a normal yield. Field investigations showed that rice type (Bt and non-Bt significantly influenced zooplankton abundance and diversity, which were up to 95% and 80% lower in non-Bt rice fields than Bt rice fields. Laboratory rearing showed that water from non-Bt rice fields was significantly less suitable for the survival and reproduction of Daphnia magna and Paramecium caudatum in comparison with water from Bt rice fields. Higher pesticide residues were detected in the water from non-Bt than Bt rice fields, accounting for the bad performance of zooplankton in non-Bt field water. Our results demonstrate that Bt rice is safer to aquatic ecosystems than non-Bt rice, and its commercialization will be beneficial for biodiversity restoration in rice-based ecosystems.

  13. [A process of aquatic ecological function regionalization: The dual tree framework and conceptual model].

    Science.gov (United States)

    Guo, Shu Hai; Wu, Bo

    2017-12-01

    Aquatic ecological regionalization and aquatic ecological function regionalization are the basis of water environmental management of a river basin and rational utilization of an aquatic ecosystem, and have been studied in China for more than ten years. Regarding the common problems in this field, the relationship between aquatic ecological regionalization and aquatic ecological function regionalization was discussed in this study by systematic analysis of the aquatic ecological zoning and the types of aquatic ecological function. Based on the dual tree structure, we put forward the RFCH process and the diamond conceptual model. Taking Liaohe River basin as an example and referring to the results of existing regionalization studies, we classified the aquatic ecological function regions based on three-class aquatic ecological regionalization. This study provided a process framework for aquatic ecological function regionalization of a river basin.

  14. Epizootic ulcerative syndrome: Exotic fish disease threatens Africa’s aquatic ecosystems

    Directory of Open Access Journals (Sweden)

    Karl D.A. Huchzermeyer

    2012-09-01

    Full Text Available In late 2006 an unusual ulcerative condition in wild fish was reported for the first time in Africa from the Chobe and upper Zambezi Rivers in Botswana and Namibia. Concern increased with subsistence fishermen reporting large numbers of ulcerated fish in their catches. In April 2007 the condition was confirmed as an outbreak of epizootic ulcerative syndrome (EUS. The causative agent, Aphanomyces invadans, is a pathogenic water mould of fish that shows little host specificity. Ulcers follow infection of tissues by oomycete zoospores, resulting in a granulomatous inflammation associated with invading oomycete hyphae. Granulomatous tracts surrounding oomycete hyphae within the necrotic tissues characterise the diagnostic histological picture. The upper Zambezi floodplain at the confluence with the Chobe River spans the four countries of Botswana, Namibia, Zambia and Zimbabwe, making disease control a challenge. The floodplain ecosystem supports a high fish diversity of around 80 species, and is an important breeding and nursery ground. The annual cycle of flooding brings about changes in water quality that are thought to favour the infectivity of A. invadans, with diseased fish appearing soon after the plains become flooded. Since 2006 the disease has spread rapidly upstream along the upper Zambezi and its tributaries. By 2010 the disease was reported from the Okavango Delta in Botswana and in 2011 from the Western Cape Province of South Africa. EUS has the potential to disrupt floodplain ecosystems elsewhere in Africa where high fish diversity forms the basis of subsistence fisheries and local economies, and is a direct threat to freshwater fish culture.

  15. Deposition of chromium in aquatic ecosystem from effluents of handloom textile industries in Ranaghat–Fulia region of West Bengal, India

    Directory of Open Access Journals (Sweden)

    Tanmay Sanyal

    2015-11-01

    Full Text Available Accumulation of chromium (Cr was determined in water, sediment, aquatic plants, invertebrates and fish in aquatic ecosystems receiving effluents from handloom textile industries in Ranaghat–Fulia region of West Bengal in India. Cr was determined in the samples by atomic absorption spectrophotometer and data were analyzed functionally by Genetic Algorithm to determine trend of depositions of Cr in the sediment and water. Area plot curve was used to represent accumulation of Cr in biota. The results indicate that the aquatic ecosystems receiving the effluents from handloom textile factories are heavily contaminated by Cr. The contamination is hardly reflected in the concentration of Cr in water, but sediment exhibits seasonal fluctuation in deposition of Cr, concentration reaching to as high as 451.0 μg g−1 during the peak production period. There is a clear trend of gradual increase in the deposition of Cr in the sediment. Aquatic weed, insect and mollusk specimens collected from both closed water bodies (S1 & S2 and riverine resources (S3 & S4 showed high rate of accumulation of Cr. Maximum concentration of Cr was detected in roots of aquatic weeds (877.5 μg g−1. Fish specimens collected from the polluted sites (S3 & S4 of river Churni showed moderate to high concentration of Cr in different tissues. Maximum concentration was detected in the liver of Glossogobius giuris (679.7 μg g−1 during monsoon followed by gill of Mystus bleekeri (190.0 μg g−1 and gut of G. giuris (123.7 μg g−1 during summer. Eutropiichthys vacha showed moderately high concentration of Cr in different tissues (65–99 μg g−1 while Puntius sarana showed relatively low concentration of Cr (below detection limit to 18.0 μg g−1 in different tissues except in gill (64.4 μg g−1.

  16. A methodology for assessing the impact of mutagens on aquatic ecosystems. Final report

    International Nuclear Information System (INIS)

    Knezovich, J.P.; Martinelli, R.E.

    1995-03-01

    Assessments of impacts of hazardous agents (i.e., chemical and physical mutagens) on human health have focused on defining the effects of chronic exposure on individuals, with cancer being the main effect of concern. In contrast, impacts on ecosystems have traditionally been gauged by the assessment of near-term organism mortality, which is clearly not a useful endpoint for assessing the long-term effects of chronic exposures. Impacts on individual organisms that affect the long-term survival of populations are much more important but are also more difficult to define. Therefore, methods that provide accurate measures of sub-lethal effects that are linked to population survival are required so that accurate assessments of environmental damage can be made and remediation efforts, if required, can be initiated. Radioactive substances have entered aquatic environments as a result of research and production activities, intentional disposal, and accidental discharges. At several DOE sites, surface waters and sediments are contaminated with radioactive and mutagenic materials. The accident at the Chernobyl power station in the former Soviet Union (FSU) has resulted in the contamination of biota present in the Kiev Reservoir. This documents presents a methodology which addresses the effects of a direct-acting mutagen (radiation) on aquantic organisms by applying sensitive techniques for assessing damage to genetic material

  17. Scaling relationships among drivers of aquatic respiration from the smallest to the largest freshwater ecosystems

    Science.gov (United States)

    Hall, Ed K; Schoolmaster, Donald; Amado, A.M; Stets, Edward G.; Lennon, J.T.; Domaine, L.; Cotner, J.B.

    2016-01-01

    To address how various environmental parameters control or constrain planktonic respiration (PR), we used geometric scaling relationships and established biological scaling laws to derive quantitative predictions for the relationships among key drivers of PR. We then used empirical measurements of PR and environmental (soluble reactive phosphate [SRP], carbon [DOC], chlorophyll a [Chl-a)], and temperature) and landscape parameters (lake area [LA] and watershed area [WA]) from a set of 44 lakes that varied in size and trophic status to test our hypotheses. We found that landscape-level processes affected PR through direct effects on DOC and temperature and indirectly via SRP. In accordance with predictions made from known relationships and scaling laws, scale coefficients (the parameter that describes the shape of a relationship between 2 variables) were found to be negative and have an absolute value 1, others respiration from small pond catchments to the largest body of freshwater on the planet, Lake Superior, these findings should be applicable to controls of PR for the great majority of temperate aquatic ecosystems.

  18. Aging infrastructure creates opportunities for cost-efficient restoration of aquatic ecosystem connectivity.

    Science.gov (United States)

    Neeson, Thomas M; Moody, Allison T; O'Hanley, Jesse R; Diebel, Matthew; Doran, Patrick J; Ferris, Michael C; Colling, Timothy; McIntyre, Peter B

    2018-06-09

    A hallmark of industrialization is the construction of dams for water management and roads for transportation, leading to fragmentation of aquatic ecosystems. Many nations are striving to address both maintenance backlogs and mitigation of environmental impacts as their infrastructure ages. Here, we test whether accounting for road repair needs could offer opportunities to boost conservation efficiency by piggybacking connectivity restoration projects on infrastructure maintenance. Using optimization models to align fish passage restoration sites with likely road repair priorities, we find potential increases in conservation return-on-investment ranging from 17% to 25%. Importantly, these gains occur without compromising infrastructure or conservation priorities; simply communicating openly about objectives and candidate sites enables greater accomplishment at current funding levels. Society embraces both reliable roads and thriving fisheries, so overcoming this coordination challenge should be feasible. Given deferred maintenance crises for many types of infrastructure, there could be widespread opportunities to enhance the cost effectiveness of conservation investments by coordinating with infrastructure renewal efforts. © 2018 by the Ecological Society of America.

  19. Intercalibrating classifications of ecological status: Europe's quest for common management objectives for aquatic ecosystems.

    Science.gov (United States)

    Birk, S; Willby, N J; Kelly, M G; Bonne, W; Borja, A; Poikane, S; van de Bund, W

    2013-06-01

    Halting and reversing the deterioration of aquatic ecosystems requires concerted action across state boundaries and administrative barriers. However, the achievement of common management objectives is jeopardised by different national quality targets and ambitions. The European Water Framework Directive requires that quality classifications are harmonised via an intercalibration exercise, ensuring a consistent level of ambition in the protection and restoration of surface water bodies across the Member States of the European Union. We outline the key principles of the intercalibration methodology, review the achievements of intercalibration and discuss its benefits and drawbacks. Less than half of the required intercalibration has been completed, mostly due to a lack of national assessment methods. The process has fostered a scientific debate on ecological classification with important implications for environmental management. Despite a significant level of statistical abstraction, intercalibration yielded a fundamental and unified vision of what constitutes good ecology across Europe, in principle ensuring greater parity in the funds invested to achieve good ecological status. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Operation of an enclosed aquatic ecosystem in the Shenzhou-8 mission

    Science.gov (United States)

    Li, Xiaoyan; Richter, Peter R.; Hao, Zongjie; An, Yanjun; Wang, Gaohong; Li, Dunhai; Liu, Yongding; Strauch, Sebastian M.; Schuster, Martin; Haag, Ferdinand W.; Lebert, Michael

    2017-05-01

    Long- term spaceflight needs reliable Biological life support systems (BLSS) to supply astronauts with enough food, fresh air and recycle wasters, but the knowledge about the operation pattern and controlling strategy is rear. For this purpose, a miniaturized enclosed aquatic ecosystem was developed and flown on the Chinese spaceship Shenzhou-8. The system with a total volume of about 60 mL was separated into two chambers by means of a gas transparent membrane. The lower chamber was inoculated with Euglena gracilis cells, and the upper chamber was cultured with Chlorella cells and three snails. After 17.5 days flight, the samples were analyzed. It was found that all snails in the ground module (GM) were alive, while in the flight module (FM) only one snail survived. The total cell numbers, assimilation of nutrients like nitrogen and phosphorus, soluble proteins and carbohydrate contents showed a decrease in FM than in GM. The correlation analysis showed upper chambers of both FM and GM had the same positive and negative correlation factors, while differential correlation was found in lower chambers. These results suggested primary productivity in the enclosed system decreased in microgravity, accompanied with nutrients assimilation. The FM chamber endured lacking of domination species to sustain the system development and GM chamber endured richness in population abundance. These results implied photosynthesis intensity should be reduced to keep the system healthy. More Chlorella but less Euglena might be a useful strategy to sustain system stability. It is the first systematic analysis of enclosed systems in microgravity.

  1. Ecological responses of epilithic diatoms and aquatic macrophytes to fish farm pollution in a Spanish river

    Directory of Open Access Journals (Sweden)

    Camargo, Julio A.

    2007-12-01

    Full Text Available We examined the ecological responses of epilithic diatoms and aquatic macrophytes to organic pollution and nutrient enrichment caused by a trout farm effluent in the upper Tajuña River (Guadalajara, Spain. Four sampling sites were selected over the study area: one site (S-1 placed upstream from the trout farm was used as a reference station; sampling sites S-2, S-3 and S-4 were set, respectively, about 10, 100 and 1000 metres downriver of the trout farm outlet. The river bottom was mainly stony with cobbles and pebbles at S-1, S-3 and S-4, but at S-2 it was covered by a thick layer of organic sediment. Although some macrophyte species (Apium nodiflorum, Groenlandia densa were either absent or fewer downstream of the farm, abundance (% coverage and diversity (number of species for the aquatic macrophyte community as a whole increased. In contrast, epilithic diatoms were completely absent at S-2, and some species (Diploneis parma, Fragilaria ulna, Gomphonema angustatum, Nitzschia dissipata were also absent at S-3 and S-4. Indeed, diatom diversity (number of species was lower at S-3 and S-4 than at S-1. However, diatom abundance (cells/cm2 was higher at S-3 and S-4 than at S-1. Biological indices for diatoms (IBD, TDI indicated a better water quality at S-1 than at S-3 and S-4, with a clear tendency to improve with distance from the fish farm. In contrast, biological indices of macrophytes (IM, IVAMG indicated a similar water quality at S-1, S-3 and S-4, but with bad water quality at S-2. We conclude that epilithic diatoms may be more useful than aquatic macrophytes for biological monitoring of fish farm pollution in fluvial ecosystems. However, as historical and seasonal factors may be relevant to understanding the distribution, abundance and diversity of primary producers in running waters, further studies on long-term seasonal changes are needed to improve the use of macrophyte and diatom indices in assessing fish farm pollution.En este trabajo

  2. Parasites and pollution: the effectiveness of tiny organisms in assessing the quality of aquatic ecosystems, with a focus on Africa.

    Science.gov (United States)

    Gilbert, Beric Michael; Avenant-Oldewage, Annemariè

    2017-08-01

    The aquatic environment represents the final repository for many human-generated pollutants associated with anthropogenic activities. The quality of natural freshwater systems is easily disrupted by the introduction of pollutants from urban, industrial and agricultural processes. To assess the extent of chemical perturbation and associated environmental degradation, physico-chemical parameters have been monitored in conjunction with biota in numerous biological monitoring protocols. Most studies incorporating organisms into such approaches have focussed on fish and macroinvertebrates. More recently, interest in the ecology of parasites in relation to environmental monitoring has indicated that these organisms are sensitive towards the quality of the macroenvironment. Variable responses towards exposure to pollution have been identified at the population and component community level of a number of parasites. Furthermore, such responses have been found to differ with the type of pollutant and the lifestyle of the parasite. Generally, endoparasite infection levels have been shown to become elevated in relation to poorer water quality conditions, while ectoparasites are more sensitive, and exposure to contaminated environments resulted in a decline in ectoparasite infections. Furthermore, endoparasites have been found to be suitable accumulation indicators for monitoring levels of several trace elements and metals in the environment. The ability of these organisms to accumulate metals has further been observed to be of benefit to the host, resulting in decreased somatic metal levels in infected hosts. These trends have similarly been found for host-parasite models in African freshwater environments, but such analyses are comparatively sparse compared to other countries. Recently, studies on diplozoids from two freshwater systems have indicated that exposure to poorer water quality resulted in decreased infections. In the Vaal River, the poor water quality resulted in

  3. Water-sensitivity assessment of regional spatial plan based on the relation between watershed imperviousness and aquatic ecosystem health

    Science.gov (United States)

    Sutjiningsih, D.; Soeryantono, H.; Anggraheni, E.

    2018-04-01

    Upper Ciliwung watershed in the JABODETABEKPUNJUR area experiencing rapid population growth, which in turn promotes the pace of infrastructure development especially increasing impervious land cover. This will trigger various stressors to the abiotic and biotic elements in the aquatic ecosystem. This study aims to examine whether the relationship between imperviousness in the subwatersheds in Upper Ciliwung and abiotic/biotic elements of its aquatic ecosystems can be used to assess the degree of water-sensitivity of the related regional spatial plan. Two scenarios of impervious cover changes have been assessed, scenario 1 using constant growth of 7.56% per annum, while scenario 2 refers to regional spatial plan of Bogor Regency. Although there are inconsistencies in four (out of 13) subwatersheds, the tests proved that the procedure is succesful to be applied in Upper Ciliwung.

  4. Degradation and damages from utilizing ecosystem services in a river basin

    Science.gov (United States)

    Travis W. Warziniack

    2012-01-01

    We examine the tradeoffs between utilizing multiple ecosystem services in an economic model of the Lower Mississippi-Atchafalaya River Basin. We show how economic development in the basin degraded the ecosystem, but diversified the economy. A degraded ecosystem and more employment opportunities elsewhere reduced the region's reliance on agriculture and other...

  5. The interactive effects of excess reactive nitrogen and climate change on aquatic ecosystems and water resources of the United States

    Science.gov (United States)

    Baron, Jill S.; Hall, E.K.; Nolan, B.T.; Finlay, J.C.; Bernhardt, E.S.; Harrison, J.A.; Chan, F.; Boyer, E.W.

    2012-01-01

    Nearly all freshwaters and coastal zones of the US are degraded from inputs of excess reactive nitrogen (Nr), sources of which are runoff, atmospheric N deposition, and imported food and feed. Some major adverse effects include harmful algal blooms, hypoxia of fresh and coastal waters, ocean acidification, long-term harm to human health, and increased emissions of greenhouse gases. Nitrogen fluxes to coastal areas and emissions of nitrous oxide from waters have increased in response to N inputs. Denitrification and sedimentation of organic N to sediments are important processes that divert N from downstream transport. Aquatic ecosystems are particularly important denitrification hotspots. Carbon storage in sediments is enhanced by Nr, but whether carbon is permanently buried is unknown. The effect of climate change on N transport and processing in fresh and coastal waters will be felt most strongly through changes to the hydrologic cycle, whereas N loading is mostly climate-independent. Alterations in precipitation amount and dynamics will alter runoff, thereby influencing both rates of Nr inputs to aquatic ecosystems and groundwater and the water residence times that affect Nr removal within aquatic systems. Both infrastructure and climate change alter the landscape connectivity and hydrologic residence time that are essential to denitrification. While Nr inputs to and removal rates from aquatic systems are influenced by climate and management, reduction of N inputs from their source will be the most effective means to prevent or to minimize environmental and economic impacts of excess Nr to the nation’s water resources.

  6. The use of Salvinia auriculata as a bioindicator in aquatic ecosystems: biomass and structure dependent on the cadmium concentration

    OpenAIRE

    Wolff,G.; Pereira,GC; Castro,EM; Louzada,J; Coelho,FF

    2012-01-01

    This study shows, in a multiple-level approach, the responses of Salvinia auriculata to Cd pollution in aquatic ecosystems. S. auriculata ramets were cultivated in nutrient solution and subjected to five treatments with Cd for ten days. At the end of the experiment, the number of new ramets and the dry biomass were determined. For ultrastructural observations, the leaves of S. auriculata were analyzed using a scanning electron microscope and transmission electron microscope. At the end of the...

  7. Valued ecosystem components for watershed cumulative effects: an analysis of environmental impact assessments in the South Saskatchewan River watershed, Canada.

    Science.gov (United States)

    Ball, Murray A; Noble, Bram F; Dubé, Monique G

    2013-07-01

    The accumulating effects of human development are threatening water quality and availability. In recognition of the constraints to cumulative effects assessment (CEA) under traditional environmental impact assessment (EIA), there is an emerging body of research dedicated to watershed-based cumulative effects assessment (WCEA). To advance the science of WCEA, however, a standard set of ecosystem components and indicators is required that can be used at the watershed scale, to inform effects-based understanding of cumulative change, and at the project scale, to inform regulatory-based project based impact assessment and mitigation. A major challenge, however, is that it is not clear how such ecosystem components and indicators for WCEA can or should be developed. This study examined the use of aquatic ecosystem components and indicators in EIA practice in the South Saskatchewan River watershed, Canada, to determine whether current practice at the project scale could be "scaled up" to support ecosystem component and indicator development for WCEA. The hierarchy of assessment components and indicators used in a sample of 35 environmental impact assessments was examined and the factors affecting aquatic ecosystem component selection and indicator use were identified. Results showed that public environmental impact statements are not necessarily publically accessible, thus limiting opportunities for data and information sharing from the project to the watershed scale. We also found no consistent terminology across the sample of impact statements, thus making comparison of assessment processes and results difficult. Regulatory compliance was found to be the dominant factor influencing the selection of ecosystem components and indicators for use in project assessment, rather than scientific reasoning, followed by the mandate of the responsible government agency for the assessment, public input to the assessment process, and preexisting water licensing arrangements external

  8. Hazardous materials in aquatic environments of the Mississippi River Basin. Quarterly project status report, July 1, 1994--September 30, 1994

    International Nuclear Information System (INIS)

    1994-01-01

    This document references information pertaining to the presence of hazardous materials in the Mississippi River Basin. Topics discussed include: The biological fate, transport, and ecotoxicity of toxic and hazardous wastes; biological uptake and metabolism; sentinels of aquatic contamination; bioremediation; microorganisms; biomarkers of exposure and ecotoxicity; expert geographical information systems for assessing hazardous wastes in aquatic environments; and enhancement of environmental education at Tulane and Xavier

  9. Radioactive contamination of the Shagan river ecosystem components with artificial radionuclides

    International Nuclear Information System (INIS)

    Subbotin, S.B.; Lukashenko, S.N.; Larionova, N.V.; Yakovenko, Yu.Yu.

    2008-01-01

    Full text: The Shagan river is the only surface waterway on the Semipalatinsk Nuclear Test Site territory. It flows along the eastern boundary of the SNTS and is a left-bank tributary of the Irtysh river. The length of the Shagan riverbed is 275 km with an average slope 0.003, which changes considerably from one part of the riverbed to the other. Within the Balapan testing ground the length of the riverbed is about 50 km, and the slope angle is, on average, 0.002. The watershed area of the left-bank part of the testing ground, where testing wells are located, is about 900 km 2 . In 2006 during radio-ecological investigations of the SNTS aquatic environment, scientists determined contamination of the Shagan river with radioactive products of nuclear explosions. The main radioactive pollutant is tritium. Maximal tritium concentration in the river waters (40*10 4 Bq/l) was registered 4.7 km away from the Atomic lake at levels of more than 50 times higher than the maximal permissible level for drinking water. As the distance from the Atomic lake increases, tritium concentration in the Shagan waters considerably decreases, and in the place of its confluence with the Irtysh rivertritium concentration in water becomes 10 Bq/l, which is equal to MPL (maximal permissible level) used for equipment. A complex of scientific investigations including hydrogeological, hydrological and geophysical investigation showed that tritium contamination of the Shagan waters is caused by the discharge of contaminated ground waters from the testing ground Balapan. In 2007 additional investigations of the river ecosystem showed that surface waters of the river in addition to tritium contained 90 Sr, and bottom sedimentations were contaminated with 60 Co, 152 Eu, 154 Eu and 137 Cs. It should be noted that concentration of 90 Sr in water reaches the level comparable with intervention level established by NRB-99 (Radiation Safety Norms) for water and food intake. By the character of tritium and

  10. The aquatic annelid fauna of the San Marcos River headsprings, Hays County, Texas

    Directory of Open Access Journals (Sweden)

    McLean L.D. Worsham

    2016-09-01

    Full Text Available The San Marcos River in Central Texas has been well studied and has been demonstrated to be remarkably specious. Prior to the present study, research on free-living invertebrates in the San Marcos River only dealt with hard bodied taxa with the exception of the report of one gastrotrich, and one subterranean platyhelminth that only incidentally occurs in the head spring outflows. The remainder of the soft-bodied metazoan fauna that inhabit the San Marcos River had never been studied. Our study surveyed the annelid fauna and some other soft-bodied invertebrates of the San Marcos River headsprings. At least four species of Hirudinida, two species of Aphanoneura, one species of Branchiobdellida, and 11 (possibly 13 species of oligochaetous clitellates were collected. Other vermiform taxa collected included at least three species of Turbellaria and one species of Nemertea. We provide the results of the first survey of the aquatic annelid fauna of the San Marcos Springs, along with a dichotomous key to these annelids that includes photos of some representative specimens, and line drawings to elucidate potentially confusing diagnostic structures.

  11. The aquatic annelid fauna of the San Marcos River headsprings, Hays County, Texas

    Science.gov (United States)

    Worsham, McLean L. D.; Gibson, Randy; Huffman, David G.

    2016-01-01

    Abstract The San Marcos River in Central Texas has been well studied and has been demonstrated to be remarkably specious. Prior to the present study, research on free-living invertebrates in the San Marcos River only dealt with hard bodied taxa with the exception of the report of one gastrotrich, and one subterranean platyhelminth that only incidentally occurs in the head spring outflows. The remainder of the soft-bodied metazoan fauna that inhabit the San Marcos River had never been studied. Our study surveyed the annelid fauna and some other soft-bodied invertebrates of the San Marcos River headsprings. At least four species of Hirudinida, two species of Aphanoneura, one species of Branchiobdellida, and 11 (possibly 13) species of oligochaetous clitellates were collected. Other vermiform taxa collected included at least three species of Turbellaria and one species of Nemertea. We provide the results of the first survey of the aquatic annelid fauna of the San Marcos Springs, along with a dichotomous key to these annelids that includes photos of some representative specimens, and line drawings to elucidate potentially confusing diagnostic structures. PMID:27853397

  12. The influence of ecological processes on the accumulation of persistent organochlorines in aquatic ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Berglund, Olof

    1999-09-01

    Several ecological problems influences the fate, transport, and accumulation of persistent organochlorines (OCs) in aquatic ecosystems. In this thesis, I have focused on two processes, namely (i) the food chain bioaccumulation of OCs, and (ii) the trophic status of the aquatic system. To test the biomagnification theory, I investigated PCB concentrations in planktonic food chains in lakes. The concentrations of PCB on a lipid basis did not increase with increasing trophic level. Hence, I could give no support to the theory of biomagnification. Instead, lipid content explained most of the variation in PCB accumulation in these food chains. PCBs were differentially fractionated in the food chains, the relative amount of high molecular weight PCBs increased with increasing trophic level, indicating congener specific differences in either the accumulation or the elimination of PCBs at the different trophic levels. In another study, I investigated the relationship between OC concentrations and trophic level, measured as {delta}{sup 15}N, in a specific predatory fish population. The dry weight OC concentrations and {delta}{sup 15}N were related, indicating effects of prey choice on the OC accumulation. However, here also, lipid content explained the major part of the variation in OC concentrations, independent of trophic level (e. g. {delta}{sup 15}N). I investigated the effects of trophic status, measured as Tot-P concentration in water, on the concentrations of OCs in water, planktonic food chains and sediment in lakes. The dry weight concentrations of PCBs in phytoplankton were negatively related to the trophic status of the lakes. However, this relationship was explained by the decreasing lipid content of phytoplankton with lake trophic status. The phytoplankton in eutrophic lakes had lower lipid content than phytoplankton in oligotrophic lakes, possibly due to inter- and intraspecific differences in lipid content due to nutrient stress. The sediment accumulation and

  13. Propagation and Establishment of Native Plants for Vegetative Restoration of Aquatic Ecosystems

    Science.gov (United States)

    2013-06-01

    ERDC/EL TR-13-9 ii Abstract Aquatic plants are a vital, but often missing, component of shallow, freshwater systems. Manmade systems, such as... water quality problems; development of noxious algal blooms; and, often, susceptibility to invasion by harmful, non-native, aquatic weeds. If...emergent aquatic plants that we have successfully used in founder colony establishment in US water bodies. ............................................. 7

  14. REVIEW: Citanduy river diversion, advantages and disadvantages plan to conserve mangrove ecosystem in Segara Anakan

    Directory of Open Access Journals (Sweden)

    AHMAD DWI SETYAWAN

    2003-01-01

    Full Text Available Mangrove ecosystem at Segara Anakan lagoon, Cilacap having specific characteristics so that in developing this area should consider the conservation aspect. This area is the widest conserved-mangrove ecosystem at Java, and the place for breeding of many species of fish, crustacean and others. Thousand families of fisheries were supported both direct and indirectly from this ecosystem. However, along with the development activities in the watershed of Citanduy, Cimeneng/Cikonde and other rivers connected to the area has brought about the increase of sediment, and threaten the existence of the lagoon and surrounding mangrove ecosystem. Diversion of Citanduy river, dredging sediment, and reboisation of the watershed river was a preference of conserving the ecosystem, however, the diversion could be forming a new ecosystem, that actually threat the fisheries and tourism activities at Pangandaran, Ciamis.

  15. Mapping critical loads of nitrogen deposition for aquatic ecosystems in the Rocky Mountains, USA

    International Nuclear Information System (INIS)

    Nanus, Leora; Clow, David W.; Saros, Jasmine E.; Stephens, Verlin C.; Campbell, Donald H.

    2012-01-01

    Spatially explicit estimates of critical loads of nitrogen (N) deposition (CL Ndep ) for nutrient enrichment in aquatic ecosystems were developed for the Rocky Mountains, USA, using a geostatistical approach. The lowest CL Ndep estimates ( −1 yr −1 ) occurred in high-elevation basins with steep slopes, sparse vegetation, and abundance of exposed bedrock and talus. These areas often correspond with areas of high N deposition (>3 kg N ha −1 yr −1 ), resulting in CL Ndep exceedances ≥1.5 ± 1 kg N ha −1 yr −1 . CL Ndep and CL Ndep exceedances exhibit substantial spatial variability related to basin characteristics and are highly sensitive to the NO 3 − threshold at which ecological effects are thought to occur. Based on an NO 3 − threshold of 0.5 μmol L −1 , N deposition exceeds CL Ndep in 21 ± 8% of the study area; thus, broad areas of the Rocky Mountains may be impacted by excess N deposition, with greatest impacts at high elevations. - Highlights: ► Critical loads maps for nutrient enrichment effects of nitrogen deposition. ► Critical load estimates show spatial variability related to basin characteristics. ► Critical loads are sensitive to the nitrate threshold value for ecological effects. ► Broad areas of the Rocky Mountains may be impacted by excess nitrogen deposition. - Critical loads maps for nutrient enrichment effects of nitrogen deposition show that broad areas of the Rocky Mountains may be impacted by excess nitrogen deposition.

  16. Can Runoff Responses be Used to Predict Aquatic Biogeochemical Fluxes from Boreal Forest Ecosystems?

    Science.gov (United States)

    Prestegaard, K. L.; Ziegler, S. E.; Billings, S. A.; Edwards, K. A.

    2017-12-01

    Climate change has direct effects on precipitation and temperature, which contribute to indirect changes in ecosystem productivity, runoff, biogeochemical processes, and species composition. In this research, we examine water balances in boreal forest watersheds to determine spatial and inter-annual variations in their responses to changes in precipitation. Our research indicates that Central and Western N. American boreal watersheds with mean annual precipitation (MAP) of less than 1000 mm exhibit positive relationships between annual precipitation and annual evapotranspiration, suggesting an increase in forest productivity during wet years often without increased runoff. In Maritime boreal watersheds in Eastern N. America and N. Europe, runoff is a significantly larger portion of the water balance and runoff increases with precipitation This regionalism in the water balance may have significant consequences for biogeochemical fluxes; for example, where MAP >1000 mm, a future wetter climate may result in increases in the terrestrial-to-aquatic transport of solutes. To test this idea, we examined inter-annual variations in hydrologic and dissolved organic carbon fluxes in watersheds in Newfoundland and Labrador along a longitudinal transect. Mean annual temperature varies from 0-5.2oC along the transect, and MAP varies from 1050 to 1500 mm. Data indicate an increase in evapotranspiration, runoff, and soil DOC fluxes with the increasing mean annual precipitation among watersheds along the transect. During the 2011-2015 period of study there was significant overlap in annual precipitation among the sites. Although wet water years also produced higher amounts of runoff from most watersheds, the annual soil DOC flux within each region was not significantly affected by these inter-annual changes in precipitation. Stream and groundwater monitoring data from the catchments reveal seasonal variations in evapotranspiration and runoff and their role in solute fluxes, and

  17. Critical Loads of Atmospheric Nitrogen Deposition for Aquatic Ecosystems in Yosemite and Sequoia and Kings Canyon National Parks

    Science.gov (United States)

    Nanus, L.; Clow, D. W.; Sickman, J. O.

    2016-12-01

    High-elevation aquatic ecosystems in Yosemite (YOSE) and Sequoia and Kings Canyon (SEKI) National Parks are impacted by atmospheric nitrogen (N) deposition associated with local and regional air pollution. Documented effects include elevated surface water nitrate concentrations, increased algal productivity, and changes in diatom species assemblages. Annual wet inorganic N deposition maps, developed at 1-km resolution for YOSE and SEKI to quantify N deposition to sensitive high-elevation ecosystems, range from 1.0 to over 5.0 kg N ha-1 yr-1. Critical loads of N deposition for nutrient enrichment of aquatic ecosystems were quantified and mapped using a geostatistical approach, with N deposition, topography, vegetation, geology, and climate as potential explanatory variables. Multiple predictive models were created using various combinations of explanatory variables; this approach allowed us to better quantify uncertainty and more accurately identify the areas most sensitive to atmospherically deposited N. The lowest critical loads estimates and highest exceedances identified within YOSE and SEKI occurred in high-elevation basins with steep slopes, sparse vegetation, and areas of neoglacial till and talus. These results are consistent with previous analyses in the Rocky Mountains, and highlight the sensitivity of alpine ecosystems to atmospheric N deposition.

  18. Heavy metal and Pb isotopic compositions of aquatic organisms in the Pearl River Estuary, South China

    International Nuclear Information System (INIS)

    Ip, C.C.M.; Li, X.D.; Zhang, G.; Wong, C.S.C.; Zhang, W.L.

    2005-01-01

    The accumulation of trace metals in aquatic organisms may lead to serious health problems through the food chain. The present research project aims to study the accumulation and potential sources of trace metals in aquatic organisms of the Pearl River Estuary (PRE). Four groups of aquatic organisms, including fish, crab, shrimp, and shellfish, were collected in the PRE for trace metal and Pb isotopic analyses. The trace metal concentrations in the aquatic organism samples ranged from 0.01 to 2.10 mg/kg Cd, 0.02 to 4.33 mg/kg Co, 0.08 to 4.27 mg/kg Cr, 0.15 to 77.8 mg/kg Cu, 0.17 to 31.0 mg/kg Ni, 0.04 to 30.7 mg/kg Pb, and 8.78 to 86.3 mg/kg Zn (wet weight). High concentrations of Cd were found in crab, shrimp and shellfish samples, while high concentration of Pb was found in fish. In comparison with the baseline reference values in other parts of the world, fish in the PRE had the highest elevated trace metals. The results of Pb isotopic compositions indicated that the bioaccumulation of Pb in fish come from a wide variety of food sources and/or exposure pathways, particularly the anthropogenic inputs. - Relative high concentrations of Cd were found in crab, shrimp and shellfish samples while high concentration of Pb was found in fish, particularly from the anthropogenic inputs

  19. Trace element accumulation and trophic relationships in aquatic organisms of the Sundarbans mangrove ecosystem (Bangladesh)

    International Nuclear Information System (INIS)

    Borrell, Asunción; Tornero, Victoria; Bhattacharjee, Dola; Aguilar, Alex

    2016-01-01

    The Sundarbans forest is the largest and one of the most diverse and productive mangrove ecosystems in the world. Located at the northern shoreline of the Bay of Bengal in the Indian Ocean and straddling India and Bangladesh, the mangrove forest is the result of three primary river systems that originate further north and northwest. During recent decades, the Sundarbans have been subject to increasing pollution by trace elements caused by the progressive industrialization and urbanization of the basins of these three rivers. As a consequence, animals and plants dwelling downstream in the mangroves are exposed to these pollutants in varying degrees, and may potentially affect human health when consumed. The aim of the present study was to analyse the concentrations of seven trace elements (Zn, Cu, Cr, Hg, Pb, Cd and As) in 14 different animal and plant species collected in the Sundarbans in Bangladesh to study their transfer through the food web and to determine whether their levels in edible species are acceptable for human consumption. δ"1"5N values were used as a proxy of the trophic level. A decrease in Zn, Cu, Pb and Cd levels was observed with increasing trophic position. Trace element concentrations measured in all organisms were, in general, lower than the concentrations obtained in other field studies conducted in the same region. When examined with respect to accepted international standards, the concentrations observed in fish and crustaceans were generally found to be safe for human consumption. However, the levels of Zn in Scylla serrata and Cr and Cd in Harpadon nehereus exceeded the proposed health advisory levels and may be of concern for human health. - Highlights: • Trace elements were determined in organisms from the Sundarbans mangrove. • The levels found were similar to those determined in wildlife from other mangroves. • Levels in three edible species were close to threshold limits for human consumption. • Except for Cr, As and Hg

  20. Trace element accumulation and trophic relationships in aquatic organisms of the Sundarbans mangrove ecosystem (Bangladesh)

    Energy Technology Data Exchange (ETDEWEB)

    Borrell, Asunción, E-mail: xonborrell@ub.edu [Department of Animal Biology, Institute of Biodiversity (IRBIO), University of Barcelona, Av. Diagonal, 643, Barcelona (Spain); Tornero, Victoria [Department of Animal Biology, Institute of Biodiversity (IRBIO), University of Barcelona, Av. Diagonal, 643, Barcelona (Spain); Bhattacharjee, Dola [Indian Institute of Science Education & Research — Kolkata, Department of Biological Sciences, Mohanpur Campus, Nadia, West Bengal (India); Aguilar, Alex [Department of Animal Biology, Institute of Biodiversity (IRBIO), University of Barcelona, Av. Diagonal, 643, Barcelona (Spain)

    2016-03-01

    The Sundarbans forest is the largest and one of the most diverse and productive mangrove ecosystems in the world. Located at the northern shoreline of the Bay of Bengal in the Indian Ocean and straddling India and Bangladesh, the mangrove forest is the result of three primary river systems that originate further north and northwest. During recent decades, the Sundarbans have been subject to increasing pollution by trace elements caused by the progressive industrialization and urbanization of the basins of these three rivers. As a consequence, animals and plants dwelling downstream in the mangroves are exposed to these pollutants in varying degrees, and may potentially affect human health when consumed. The aim of the present study was to analyse the concentrations of seven trace elements (Zn, Cu, Cr, Hg, Pb, Cd and As) in 14 different animal and plant species collected in the Sundarbans in Bangladesh to study their transfer through the food web and to determine whether their levels in edible species are acceptable for human consumption. δ{sup 15}N values were used as a proxy of the trophic level. A decrease in Zn, Cu, Pb and Cd levels was observed with increasing trophic position. Trace element concentrations measured in all organisms were, in general, lower than the concentrations obtained in other field studies conducted in the same region. When examined with respect to accepted international standards, the concentrations observed in fish and crustaceans were generally found to be safe for human consumption. However, the levels of Zn in Scylla serrata and Cr and Cd in Harpadon nehereus exceeded the proposed health advisory levels and may be of concern for human health. - Highlights: • Trace elements were determined in organisms from the Sundarbans mangrove. • The levels found were similar to those determined in wildlife from other mangroves. • Levels in three edible species were close to threshold limits for human consumption. • Except for Cr, As and Hg

  1. Desertification, salinization, and biotic homogenization in a dryland river ecosystem.

    Science.gov (United States)

    Miyazono, Seiji; Patiño, Reynaldo; Taylor, Christopher M

    2015-04-01

    This study determined long-term changes in fish assemblages, river discharge, salinity, and local precipitation, and examined hydrological drivers of biotic homogenization in a dryland river ecosystem, the Trans-Pecos region of the Rio Grande/Rio Bravo del Norte (USA/Mexico). Historical (1977-1989) and current (2010-2011) fish assemblages were analyzed by rarefaction analysis (species richness), nonmetric multidimensional scaling (composition/variability), multiresponse permutation procedures (composition), and paired t-test (variability). Trends in hydrological conditions (1970s-2010s) were examined by Kendall tau and quantile regression, and associations between streamflow and specific conductance (salinity) by generalized linear models. Since the 1970s, species richness and variability of fish assemblages decreased in the Rio Grande below the confluence with the Rio Conchos (Mexico), a major tributary, but not above it. There was increased representation of lower-flow/higher-salinity tolerant species, thus making fish communities below the confluence taxonomically and functionally more homogeneous to those above it. Unlike findings elsewhere, this biotic homogenization was due primarily to changes in the relative abundances of native species. While Rio Conchos discharge was>2-fold higher than Rio Grande discharge above their confluence, Rio Conchos discharge decreased during the study period causing Rio Grande discharge below the confluence to also decrease. Rio Conchos salinity is lower than Rio Grande salinity above their confluence and, as Rio Conchos discharge decreased, it caused Rio Grande salinity below the confluence to increase (reduced dilution). Trends in discharge did not correspond to trends in precipitation except at extreme-high (90th quantile) levels. In conclusion, decreasing discharge from the Rio Conchos has led to decreasing flow and increasing salinity in the Rio Grande below the confluence. This spatially uneven desertification and

  2. Desertification, salinization, and biotic homogenization in a dryland river ecosystem

    Science.gov (United States)

    Miyazono, S.; Patino, Reynaldo; Taylor, C.M.

    2015-01-01

    This study determined long-term changes in fish assemblages, river discharge, salinity, and local precipitation, and examined hydrological drivers of biotic homogenization in a dryland river ecosystem, the Trans-Pecos region of the Rio Grande/Rio Bravo del Norte (USA/Mexico). Historical (1977-1989) and current (2010-2011) fish assemblages were analyzed by rarefaction analysis (species richness), nonmetric multidimensional scaling (composition/variability), multiresponse permutation procedures (composition), and paired t-test (variability). Trends in hydrological conditions (1970s-2010s) were examined by Kendall tau and quantile regression, and associations between streamfiow and specific conductance (salinity) by generalized linear models. Since the 1970s, species richness and variability of fish assemblages decreased in the Rio Grande below the confluence with the Rio Conchos (Mexico), a major tributary, but not above it. There was increased representation of lower-flow/higher-salinity tolerant species, thus making fish communities below the confluence taxonomically and functionally more homogeneous to those above it. Unlike findings elsewhere, this biotic homogenization was due primarily to changes in the relative abundances of native species. While Rio Conchos discharge was > 2-fold higher than Rio Grande discharge above their confluence, Rio Conchos discharge decreased during the study period causing Rio Grande discharge below the confluence to also decrease. Rio Conchos salinity is lower than Rio Grande salinity above their confluence and, as Rio Conchos discharge decreased, it caused Rio Grande salinity below the confluence to increase (reduced dilution). Trends in discharge did not correspond to trends in precipitation except at extreme-high (90th quantile) levels. In conclusion, decreasing discharge from the Rio Conchos has led to decreasing flow and increasing salinity in the Rio Grande below the confluence. This spatially uneven desertification and

  3. Hydrologic cycle and dynamics of aquatic macrophytes in two intermittent rivers of the semi-arid region of Brazil

    Directory of Open Access Journals (Sweden)

    F. Pedro

    Full Text Available The dynamics of aquatic macrophytes in intermittent rivers is generally related to the characteristics of the resistance and resilience of plants to hydrologic disturbances of flood and drought. In the semi-arid region of Brazil, intermittent rivers and streams are affected by disturbances with variable intensity, frequency, and duration throughout their hydrologic cycles. The aim of the present study is to determine the occurrence and variation of biomass of aquatic macrophyte species in two intermittent rivers of distinct hydrologic regimes. Their dynamics were determined with respect to resistance and resilience responses of macrophytes to flood and drought events by estimating the variation of biomass and productivity throughout two hydrologic cycles. Twenty-one visits were undertaken in the rewetting, drying, and drought phases in a permanent puddle in the Avelós stream and two temporary puddles in the Taperoá river, state of Paraíba, Northeast Brazil. The sampling was carried out by using the square method. Floods of different magnitudes occurred during the present study in the river and in the stream. The results showed that floods and droughts are determining factors in the occurrence of macrophytes and in the structure of their aquatic communities. The species richness of the aquatic macrophyte communities was lower in the puddles of the river and stream subject to flood events, when compared to areas where the run-off water is retained. At the beginning of the recolonization process, the intensity of the floods was decisive in the productivity and biomass of the aquatic macrophytes in the Taperoá river and the Avelós stream. In intermediate levels of disturbance, the largest values of productivity and biomass and the shortest time for starting the recolonization process occurred.

  4. Aquatic studies

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    Thermal stress to microorganisms was measured by the production of dissolved organic matter by algal communities and the mineralization of glucose by heterotrophic populations. Mutagenic activity as measured by the Ames/Salmonella/microsome assay indicate that such activity does not occur in Par Pond, although limited mutagenic activity does occur in a nearby canal system due to chlorination of cooling water. Sodium hypochlorite, used as an algicide in the reactor fuel storage basins, caused increased pitting corrosion to reactor fuel targets. Five other compounds selected for testing proved to be superior to sodium hypochlorite. Legionella pneumophila, the pathogen which causes Legionnaire's disease, was found to be a natural part of aquatic ecosystems. It occurs over a wide range of environments and is able to utilize nutrients provided by primary producers. Phytoplankton size classes of less than 3 μm (less than 5% of the total phytoplankton biomass) accounted for 15 to 40% of the total primary productivity in Par Pond, Pond C, and Clark Hill Reservoir. Three major biological data sets were compiled and are available in the SRL computer system for analysis: the SRP deer herd data; 20 years of Par Pond data; and 25 years of biological data on the Savannah River. Results of marine studies indicated that nearly all plutonium in the Savannah River and its estuary resulted from nuclear weapons fallout. The plutonium concentration in the Savannah River is about one fourth the concentration in the Newport River which has no nuclear operations associated with it

  5. Bioavailability of Polycyclic Aromatic Hydrocarbons in aquatic ecosystems : influence of natural and anthropic organic matter; Biodisponibilite des hydrocarbures aromatiques polycycliques dans les ecosystemes aquatiques: influence de la matiere organique naturelle et anthropique

    Energy Technology Data Exchange (ETDEWEB)

    Gourlay, C

    2004-11-01

    Aquatic ecosystems receive micro-pollutants. They also contain organic matter (OM) of natural and anthropogenic origins. The contaminant bioavailability in aquatic media is determined by the interactions between contaminants and OM. This work deals with the influence of organic matter from anthropogenic media on the bioavailability of hydrophobic organic pollutants. Polycyclic Aromatic Hydrocarbons (PAHs) have been used as model contaminants, since they are widely spread in urban media. In anthropogenic media, some OM may be bio-degraded. Up to now, most researches focused on the interactions between contaminants and humic OM that are mostly non-degradable, using physico-chemical characterizations of OM. On the contrary, in this work, the biodegradability of OM was deliberately taken into account. Indeed, we assume that the contaminant affinity for OM evolves during OM biodegradation, so that pollutants may be released in a bio-available form and then may be bond again by biodegradation sub-products. In laboratory evaluation, PAH bioavailability was assessed through the measurements of the bioaccumulation in Daphnia magna. The influence of organic matter on the bioavailability of PAHs and the evolution of this influence along OM bacterial mineralization were proved, as well as the strong binding efficiency of degradation by-products. A model of observed phenomena was elaborated. These observations about urban and natural OM effect were compared to in situ PAH bioavailability measurements in the river Seine basin. In this case, the bioavailability was estimated using Semi-Permeable Membrane Device (SPMD) sampling technique. (author)

  6. Models for transport and fate of carbon, nutrients and point source released radionuclides to an aquatic ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Kumblad, Linda [Stockholm Univ. (Sweden). Dept. of Systems Ecology; Kautsky, Ulrik [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2004-09-01

    In this report three ecosystem models are described in terms of structure, initial data, and results. All models are dynamic, mass-balanced and describe the transport and fate of elements in an open aquatic ecosystem. The models are based on ecologically sound principles, provide model results with high resolution and transparency, and are constrained by the nutrient dynamics of the ecosystem itself. The processes driving the transport in all the models are both the biological processes such as primary production, consumption, respiration and excretion, and abiotic e.g. water exchange and air-sea exchange. The first model, the CNP-model, describes the distribution and fluxes of carbon and nutrients for the coastal ecosystem off Forsmark. The second model, the C-14 model, is an extension of the CNP-model and describes the transport and distribution of hypothetically released C-14 from the underground repository SFR-1 to the ecosystem above. The third model, the RN-model, is a generic radionuclide flow model that models the transport and distribution of radionuclides other than C-14 hypothetically discharged to the ecosystem. The model also analyses the importance of some radionuclide specific mechanisms for the radionuclide flow. The generic radionuclide model is also based on the CNP-model, but has radionuclide specific mechanisms connected to each compartment.

  7. Models for transport and fate of carbon, nutrients and point source released radionuclides to an aquatic ecosystem

    International Nuclear Information System (INIS)

    Kumblad, Linda

    2004-09-01

    In this report three ecosystem models are described in terms of structure, initial data, and results. All models are dynamic, mass-balanced and describe the transport and fate of elements in an open aquatic ecosystem. The models are based on ecologically sound principles, provide model results with high resolution and transparency, and are constrained by the nutrient dynamics of the ecosystem itself. The processes driving the transport in all the models are both the biological processes such as primary production, consumption, respiration and excretion, and abiotic e.g. water exchange and air-sea exchange. The first model, the CNP-model, describes the distribution and fluxes of carbon and nutrients for the coastal ecosystem off Forsmark. The second model, the C-14 model, is an extension of the CNP-model and describes the transport and distribution of hypothetically released C-14 from the underground repository SFR-1 to the ecosystem above. The third model, the RN-model, is a generic radionuclide flow model that models the transport and distribution of radionuclides other than C-14 hypothetically discharged to the ecosystem. The model also analyses the importance of some radionuclide specific mechanisms for the radionuclide flow. The generic radionuclide model is also based on the CNP-model, but has radionuclide specific mechanisms connected to each compartment

  8. A Dreissena Risk Assessment for the Colorado River Ecosystem

    Science.gov (United States)

    Kennedy, Theodore A.

    2007-01-01

    Executive Summary Nonnative zebra and quagga mussels (Dreissena polymorpha and Dreissena bugensis, respectively; see photo above) were accidentally introduced to the Great Lakes in the 1980s and subsequently spread to watersheds of the Eastern United States (Strayer and others, 1999). The introduction of Dreissena mussels has been economically costly and has had large and far-reaching ecological impacts on these systems. Quagga mussels were found in Lakes Mead and Havasu in January 2007. Given the likelihood that quagga mussels and, eventually, zebra mussels will be introduced to Lake Powell and the Colorado River at Lees Ferry, it is important to assess the risks that introduction of Dreissena mussels pose to the Colorado River ecosystem (here defined as the segment of river from just below Glen Canyon Dam to Diamond Creek; hereafter CRE). In this report, I assess three different types of risks associated with Dreissena and the CRE: (1) the risk that Dreissena will establish at high densities in the CRE, (2) the risk of ecological impacts should Dreissena establish at high densities in the CRE or in Lake Powell, and (3) the risk that Dreissena will be introduced to tributaries of the CRE. The risk of Dreissena establishing within the CRE is low, except for the Lees Ferry tailwater reach where the risk appears high. Dreissena are unlikely to establish at high densities within the CRE or its tributaries because of high suspended sediment, high ratios of suspended inorganic:organic material, and high water velocities, all of which interfere with the ability of Dreissena to effectively filter feed. The rapids of Grand Canyon may represent a large source of mortality to larval Dreissena, which would limit their ability to disperse and colonize downstream reaches of the CRE. In contrast, conditions within the Lees Ferry tailwater generally appear suitable for Dreissena establishment, with the exception of high average water velocity. If Dreissena establish within the

  9. Proceedings of the Columbia River Estuary Conference on Ecosystem Restoration.

    Energy Technology Data Exchange (ETDEWEB)

    U.S. Bonneville Power Administration

    2008-08-01

    The 2008 Columbia River Estuary Conference was held at the Liberty Theater in Astoria, Oregon, on April 19-20. The conference theme was ecosystem restoration. The purpose of the conference was to exchange data and information among researchers, policy-makers, and the public, i.e., interrelate science with management. Conference organizers invited presentations synthesizing material on Restoration Planning and Implementation (Session 1), Research to Reduce Restoration Uncertainties (Session 2), Wetlands and Flood Management (Session 3), Action Effectiveness Monitoring (Session 4), and Management Perspectives (Session 5). A series of three plenary talks opened the conference. Facilitated speaker and audience discussion periods were held at the end of each session. Contributed posters conveyed additional data and information. These proceedings include abstracts and notes documenting questions from the audience and clarifying answers from the presenter for each talk. The proceedings also document key points from the discussion periods at the end of each session. The conference program is outlined in the agenda section. Speaker biographies are presented in Appendix A. Poster titles and authors are listed in Appendix B. A list of conference attendees is contained in Appendix C.

  10. Bioaccumulation of {sup 210}Pb in the Kaveri River ecosystem, India

    Energy Technology Data Exchange (ETDEWEB)

    Hameed, P.S.; Shaheed, K.; Somasundaram, S.S.N. [Jamal Mohamed Coll., Post-Graduate Dept. of Zoology, Tiruchirappalli (India); Iyengar, M.A.R. [Bhabha Atomic Research Centre, Health Physics Div., Kalpakkam (India)

    1997-12-31

    Data on the concentrations of {sup 210}Pb in water, sediment and biota (plankton, weed, snail, bivalve, prawn and fish) of the Kaveri River ecosystem at Tiruchirappalli in South India are presented. The highest level of {sup 210}Pb activity was observed in the sediment (15.5 Bq kg{sup -1} dry) and the lowest activity in water (2.7 mBq l{sup -1}). The root of the aquatic weed, Eichhornia crassipes, showed a higher activity (1.17 Bq kg{sup -1} wet) than its shoot (0.22 Bq kg{sup -1} wet). Among the biotic components, the shells and bones of animals accumulated higher {sup 210}Pb than their tissues and muscle. Among animals, the freshwater mussel, Lamellidens marginalis was identified to accumulate more {sup 210}Pb in its soft tissues (0.79 Bq kg{sup -1} wet) and shell (6.55 Bq kg{sup -1} wet) than prawns (muscle 0.65 Bq kg{sup -1} wet; exoskeleton: 1.06 Bq kg{sup -1}) wet and fish (muscle: 0.24 Bq kg{sup -1} wet; bone: 1.37 Bq kg{sup -1} wet). The concentration factors (CFs) of {sup 210}Pb in biotic components ranged from {approx} 10{sup 1} to {approx} 10{sup 3} with higher CFs observed for shells and bones. It is shown that {sup 210}Pb undergoes a seasonal variation in surface deposition with minimum values in summer and maximum values in winter. The significance of the results of {sup 210}Pb in the abiotic and biotic environment of Kaveri River is discussed. (Author).

  11. Review of the effects of in-stream pipeline crossing construction on aquatic ecosystems and examination of Canadian methodologies for impact assessment.

    Science.gov (United States)

    Lévesque, Lucie M; Dubé, Monique G

    2007-09-01

    Pipeline crossing construction alters river and stream channels, hence may have detrimental effects on aquatic ecosystems. This review examines the effects of crossing construction on fish and fish habitat in rivers and streams, and recommends an approach to monitoring and assessment of impacts associated with these activities. Pipeline crossing construction is shown to not only compromise the integrity of the physical and chemical nature of fish habitat, but also to affect biological habitat (e.g., benthic invertebrates and invertebrate drift), and fish behavior and physiology. Indicators of effect include: water quality (total suspended solids TSS), physical habitat (substrate particle size, channel morphology), benthic invertebrate community structure and drift (abundance, species composition, diversity, standing crop), and fish behavior and physiology (hierarchy, feeding, respiration rate, loss of equilibrium, blood hematocrit and leukocrit levels, heart rate and stroke volume). The Before-After-Control-Impact (BACI) approach, which is often applied in Environmental Effects Monitoring (EEM), is recommended as a basis for impact assessment, as is consideration of site-specific sensitivities, assessment of significance, and cumulative effects.

  12. Catchment2Coast: A systems approach to coupled river-coastal ecosystem science and management

    CSIR Research Space (South Africa)

    Monteiro, PMS

    2009-07-01

    Full Text Available Catchment2Coast was an interdisciplinary research and modelling project that aimed to improve understanding of the linkages between coastal ecosystems and the adjacent river catchments. The project involved nine partner organizations from three...

  13. Assessing the societal benefits of river restoration using the ecosystem services approach

    NARCIS (Netherlands)

    Vermaat, Jan; Ansink, Erik

    2016-01-01

    The success of river restoration was estimated using the ecosystem services approach. In eight pairs of restored–unrestored reaches and floodplains across Europe, we quantified provisioning (agricultural products, wood, reed for thatching, infiltrated drinking water), regulating (flooding and

  14. Environmental effect of resort centres on the distribution of aquatic insect fauna in Ethiope River, Delta State, Nigeria

    Directory of Open Access Journals (Sweden)

    Edore Edwin Ito

    2017-11-01

    Full Text Available Objective: To assess water quality and diversity of aquatic insects relative to effluents discharge from resort centres in Ethiope River. Methods: Water samples collected from three study stations were analyzed using APHA methods while the kick sampling techniques were used for collection of aquatic insects. The obtained data were subjected to statistical analysis at significance level of 0.05. Results: Among the study stations, water temperature varied from 20 °C to 34 °C with a mean temperature of (26.17 ± 2.37 °C, while pH was recorded from 5.57 ± 0.18 to 5.94 ± 0.21. Statistically, water temperature, pH, dissolved oxygen and conductivity were significantly different (P 0.05 in the stations. Conclusions: Significant relationships were recorded between water quality parameters and occurrence of Neoperla spio, Caenis horaria, Baetis and Chironomus species. The observed changes in aquatic insect composition were principally due to alteration in water quality. The weak correlation between aquatic insects and water quality can be attributed to functional adaptations to environmental changes. Aquatic insects have been proved to be good bioindicator of pollution and long-term monitoring of the aquatic insects is necessary for water quality evaluation in Ethiope River.

  15. Structural and functional effects of herbicides on non-target organisms in aquatic ecosystems with an emphasis on atrazine

    Science.gov (United States)

    Fairchild, James; Kortekamp, Andreas

    2011-01-01

    for controlling nuisance aquatic vegetation. Although aquatic herbicide exposure has been widely documented, these exposures are not necessarily related to adverse non-target ecological effects on natural communities in aquatic environments. This chapter evaluates the potential for effects of herbicides on the structure and function of aquatic envrionments at the population, community, and ecosystem levels of biological organization. In this manuscript I examine several critical aspects of the subject matter area: primary herbicides in use and chemical modes of action; the regulatory process used for registration and risk assessment of herbicides; data regarding non-target risks and the relative sensitivity of aquatic plants, inveretebrates, and fish to herbicides; and emerging areas of science regarding the potential for endocrine-disrupting effects of herbicides on aquatic vertebrates. Much of the focus of this paper is on atrazine due to the extensive database which exists regarding its fate and effects. 

  16. Community structure of aquatic insects in the Esparza River, Costa Rica

    Directory of Open Access Journals (Sweden)

    Jonathan Herrera-Vásquez

    2009-06-01

    Full Text Available Community structure of aquatic insects in the Esparza River, Costa Rica. This study focused on the structure of the aquatic insect community in spatial and temporal scales in the Esparza River. The river was sampled for one full year throughout 2007. During the dry season low flow months, five sampling points were selected in two different habitats (currents and pools, with five replicates per sample site. During the wet season with peak rain, only the data in the "current habitat" were sampled at each site. Specimens present in the different substrates were collected and preserved in situ. A nested ANOVA was then applied to the data to determine richness and density as the response variables. The variations in temporal and spatial scales were analyzed using width, depth and discharge of the river, and then analyzed using a nested ANOVA. Only a correlation of 51% similarity in richness was found, while in spatial scale, richness showed significant variation between sampling sites, but not between habitats. However, the temporal scale showed significant differences between habitats. Density showed differences between sites and habitats during the dry season in the spatial scale, while in the temporal scale significant variation was found between sampling sites. Width varied between habitats during the dry season, but not between sampling points. Depth showed differences between sampling sites and season. This work studies the importance of community structure of aquatic insects in rivers, and its relevance for the quality of water in rivers and streams. Rev. Biol. Trop. 57 (1-2: 133-139. Epub 2009 June 30.Se estudió la estructura de la comunidad de insectos acuáticos en el río Esparza, Costa Rica, en escalas espacial y temporal. Los muestreos se realizaron durante 2007 en 5 estaciones. En mayor sequía se recolectaron cinco réplicas en cada estación en dos tipos de hábitat: corriente y pozas. En mayor precipitación se utilizó este

  17. The distribution of submersed aquatic vegetation and water lettuce in the fresh and oligohaline tidal Potomac River, 2007

    Science.gov (United States)

    Campbell, Sarah Hunter; Rybicki, Nancy B.; Schenk, Edward R.

    2015-01-01

    Surveys documenting the composition of species of submersed aquatic vegetation (SAV) have been conducted in the Potomac River for decades. These surveys can help managers assess the proportion of native and exotic plants in the river or can be used to determine relationships between native and exotic plants, environmental conditions, and wildlife. SAV coverage increased from 2005 to 2007 throughout the fresh and oligohaline study area. The 2007 survey documented here determined that eleven species of SAV were present. The abundance of the exotic species Hydrilla verticillata (hydrilla) was relatively low, and species diversity was relatively high compared to previous years. The survey also revealed a new population of the invasive, floating aquatic plant Pistia stratiotes (water lettuce). In 2007, water lettuce, the latest exotic aquatic plant to be found in the fresh to oligohaline portion of the Potomac River, was most abundant in Mattawoman Creek, Charles County, Maryland. However, it was not observed in the fresh to oligohaline portion of the Potomac River in the summer of 2008. An understanding of the distribution of SAV species and factors governing the abundance of native and invasive aquatic species is enhanced by long-term surveys.

  18. Impacts of mute swans (Cygnus olor) on submerged aquatic vegetation in Illinois River Valley backwaters

    Science.gov (United States)

    Stafford, Joshua D.; Michael W. Eichholz,; Adam C. Phillips,

    2012-01-01

    Wetland loss in North America has been considerable and well documented, and the establishment of exotic species in remaining wetlands can further reduce their ability to support native flora and fauna. In the Chesapeake Bay and Great Lakes ecosystems, exotic mute swans (Cygnus olor) have been found to negatively impact wetlands through degradation of submerged aquatic vegetation (SAV) communities. Mute swan populations have expanded into many areas of mid-continental North America outside the Great Lakes ecosystem, but the environmental impact of these populations is not well known. Mid-continental wetlands in North America differ in physical characteristics (e.g., size, depth, and permanency) and aquatic vegetation species composition compared to wetlands in other areas where mute swans have been studied and, thus, may be more or less susceptible to degradation from swan herbivory. To investigate the impact of mute swan herbivory on SAV communities in mid-continent wetlands, we used exclosures to prevent swans from foraging in 2 wetland complexes in central Illinois. Above-ground biomass of vegetation did not differ between exclosures and controls; however, mean below-ground biomass was greater in exclosures (52.0 g/m2, SE = 6.0) than in controls (34.4 g/m2 SE = 4.0). Thus, although swan densities were lower in our study region compared to that of previous studies, we observed potentially detrimental impacts of swan herbivory on below-ground biomass of SAV. Our results indicate that both above-ground and below-ground impacts of herbivory should be monitored, and below-ground biomass may be most sensitive to swan foraging.

  19. Characterization of the interactions between endocrine disruptors and aquatic humic substances from tropical rivers

    Energy Technology Data Exchange (ETDEWEB)

    Botero, Wander G. [Universidade Federal de Alagoas (UFAL), Arapiraca, AL (Brazil); Oliveira, Luciana C. de [Universidade Federal de Sao Carlos (UFSCar), Sorocaba, SP (Brazil); Cunha, Bruno B.; Oliveira, Lilian K. de; Goveia, Danielle; Fraceto, Leonardo F.; Rosa, Andre Henrique, E-mail: ahrosa@sorocaba.unesp.b [UNESP, Sorocaba, SP (Brazil). Dept. de Engenharia do Meio Ambiente; Rocha, Julio Cesar [UNESP, Araraquara, SP (Brazil). Inst. de Quimica. Dept. de Quimica Analitica

    2011-07-01

    Interactions between two endocrine disruptors (ED) and aquatic humic substances (AHS) from tropical rivers were studied using an ultrafiltration system equipped with a 1 kDa cut-off cellulose membrane to separate free ED from the fraction bound in the AHS. Quantification of 17{alpha}-ethynylestradiol and bisphenol A was performed using gas chromatography-mass spectrometry (GC-MS). The times required for establishment of equilibrium between the AHS and the ED were ca. 30 min, and complexation capacities for 17{alpha}-ethynylestradiol and bisphenol A were 18.53 and 2.07 mg g{sup -1} TOC, respectively. The greater interaction of AHS with 17{alpha}-ethynylestradiol, compared to bisphenol A, was due to the presence of hydrogen in the structure of 17{alpha}-ethynylestradiol, which could interact with ionized oxygenated groups of the AHS. The results indicate that AHS can strongly influence the transport and reactivity of endocrine disruptors in aquatic systems. (author)

  20. Inelastic hyperspectral lidar for aquatic ecosystems monitoring and landscape plant scanning test

    Science.gov (United States)

    Zhao, Guangyu; Malmqvist, Elin; Rydhmer, Klas; Strand, Alfred; Bianco, Giuseppe; Hansson, Lars-Anders; Svanberg, Sune; Brydegaard, Mikkel

    2018-04-01

    We have developed an aquatic inelastic hyperspectral lidar with unrestricted focal-depth and enough sensitivity and spatio-temporal resolution to detect and resolve position and behavior of individual sub-millimeter aquatic organisms. We demonstrate ranging with monitoring of elastic echoes, water Raman signals and fluorescence from chlorophyllbearing phytoplankton and dye tagged organisms. The system is based on a blue CW diode laser and a Scheimpflug optical arrangement.

  1. Inelastic hyperspectral lidar for aquatic ecosystems monitoring and landscape plant scanning test

    Directory of Open Access Journals (Sweden)

    Zhao Guangyu

    2018-01-01

    Full Text Available We have developed an aquatic inelastic hyperspectral lidar with unrestricted focal-depth and enough sensitivity and spatio-temporal resolution to detect and resolve position and behavior of individual sub-millimeter aquatic organisms. We demonstrate ranging with monitoring of elastic echoes, water Raman signals and fluorescence from chlorophyllbearing phytoplankton and dye tagged organisms. The system is based on a blue CW diode laser and a Scheimpflug optical arrangement.

  2. [Study on contamimation of endocrine disrupting chemicals in aquatic environment of Qiantang River].

    Science.gov (United States)

    Cai, Delei; Chen, Jiang; Fu, Jianyun; Zheng, Yunyan; Song, Yanhua; Yan, Jun; Ding, Gangqiang

    2011-07-01

    To study contamination of endocrine disrupting chemicals (EDCs) in aquatic environment of Qiantang River. Carp vitellogenin (VTG) content in serum and ethoxyresorufin-o-deethylase (EROD) activity in liver of wild crucian, pesticide content including organic cholorine, organic phosphorus and pyrethroid in its muscle from 7 monitoring sites including Zhangtan (ZT), Jiekou (JK), Jiangjunyan (JJY), Yandongguan (YDG), Tonglu (TL), Fuyang (FY) and Yuanpu (YP) in Qiantang river were detected. And chemical analysis of water quality was carried on in four sites. EROD activity in crucian from ZT, JJY, FY and YP [(23.51 +/- 4.17), (16.79 +/- 7.39), (18.74 +/- 5.16), (18.65 +/- 8.86) nmol x g(-1) pro x min(-1), respectively] was significantly higher than that of control ((7.84 +/- 2.42) nmol x g(-1) pro x min(-1)), and VTG content in wild crucian from ZT, TL, FY and YP [(1.536 +/- 0.521), (16.404 +/- 13.579), (19.672 +/- 16.354) and (17.079 +/- 18.397)] microg/ml, respectively) was significantly higher than that of control [(0.400 +/- 0.099) (microg/ ml]. No significantly difference in biomarkers was observed between other site and control. From high to low, in total organophosphorus, it was followed as: TL, YDG, YP, FY, QZ, JK, JJY (EPN was up to 2695.64, 611.96 microg/kg in TL and YDG, respectively). In total organochlorine: TL, YP, YDG, FY, QZ, JK and JJY (tetradifon content in muscle of wild crucian from TL was up to 3962.17 microg/kg). For pyrethroid pesticides: TL, YDG, YP, ZT, JK, FY and JJY (alpha-tetramethrin and alpha-phenothrin was comparatively high in TL and YDG, up to 371.54, 239.62 microg/kg in the former, 416.23, 189.15 microg/kg in the latter, respectively). Aquatic environment of these sites including ZT, TL, FY and YP in Qiantang river received comparatively high EDCs, whose effects may be mainly due to pesticide pollution. Obvious organic contamination occurred in these sites including ZT, JJY, FY and YP. Changes of chemicals in water and EROD activity in

  3. The Kings River Sustainable Forest Ecosystems Project: inception, objectives, and progress

    Science.gov (United States)

    Jared Verner; Mark T. Smith

    2002-01-01

    The Kings River Sustainable Forest Ecosystems Project, a formal administrative study involving extensive and intensive collaboration between Forest Service managers and researchers, is a response to changes in the agency’s orientation in favor of ecosystem approaches and to recent concern over issues associated with maintenance of late successional forest attributes...

  4. River basins as social-ecological systems: linking levels of societal and ecosystem water metabolism in a semiarid watershed

    Directory of Open Access Journals (Sweden)

    Violeta Cabello

    2015-09-01

    Full Text Available River basin modeling under complexity requires analytical frameworks capable of dealing with the multiple scales and dimensions of environmental problems as well as uncertainty in the evolution of social systems. Conceptual and methodological developments can now be framed using the wide socio-eco-hydrological approach. We add hierarchy theory into the mix to discuss the conceptualization of river basins as complex, holarchic social-ecological systems. We operationalize the social-ecological systems water metabolism framework in a semiarid watershed in Spain, and add the governance dimension that shapes human-environment reciprocity. To this purpose, we integrate an eco-hydrological model with the societal metabolism accounting scheme for land use, human activity, and water use. We explore four types of interactions: between societal organization and water uses/demands, between ecosystem organization and their water requirements/supplies, between societal metabolism and aquatic ecosystem health, and between water demand and availability. Our results reveal a metabolic pattern of a high mountain rural system striving to face exodus and agricultural land abandonment with a multifunctional economy. Centuries of social-ecological evolution shaping waterscapes through traditional water management practices have influenced the eco-hydrological functioning of the basin, enabling adaptation to aridity. We found a marked spatial gradient on water supply, use pattern, and impact on water bodies from the head to the mouth of the basin. Management challenges posed by the European water regulatory framework as a new driver of social-ecological change are highlighted.

  5. The unionid (Bivalvia) fauna of the Sipsey River in northwestern Alabama, an aquatic hotspot

    Science.gov (United States)

    McCullagh, W. Henry; Williams, James D.; McGregor, Stuart W.; Pierson, J. Malcom; Lydeard, Charles

    2002-01-01

    Recent surveys for unionid bivalves were conducted in the mainstem of the Sipsey River and headwater tributaries (Tombigbee River drainage) during the summer and autumn of 1996-1999. A total of 35 species and 22 genera were found. Museum records from the upper Sipsey, based largely on the efforts of H. H. Smith during 1910-11, raised the total number of recorded unionids in the Sipsey to 42. Smith documented 25 species in the river; however, most of his collections were made in the mid- to upper-Sipsey, which has lower diversity. The three most common recently observed species in descending order of abundance were Quadrula asperata (I. Lea, 1861), Pleurobema decisum (I. Lea, 1831), and Tritogonia verrucosa (Rafinesque, 1820). Federally listed species observed recently include Lampsilis perovalis (Conrad, 1834) (threatened), Medionidus acutissimus (I. Lea, 1831) (threatened), P. decisum (endangered), P. perovatum (Conrad, 1834) (endangered), and Potamilus inflatus (I. Lea, 1831) (threatened). Species not observed recently but recorded in prior surveys include Anodontoides radiatus (Conrad, 1834), Arcidens confragosus (Say, 1829), Plectomerus dombeyanus (Valenciennes, 1827), Q. metanevra (Rafinesque, 1820), Q. stapes (I. Lea, 1831) (federally endangered), P. taitianum (I. Lea, 1834) (federally endangered), and Toxolasma parvus (Barnes, 1823). Many, species are known recently or historically by only five or fewer recorded specimens including: A. radiatus, Elliptio arctata (Conrad, 1834), Ligumia recta (Lamarck, 1819), P. taitianum, P. inflatus, Q. aspera (Lea, 1831), Q. metanevra, Q. stapes, T. parvus, Truncilla donaciformis (I. Lea, 1828), Uniomerus tetralasmus (Say, 1831), Utterbackia imbecillis (Say, 1829), A. confragosus, and P. dombeyanus. Unlike the mussel fauna of most Alabama streams, that of the Sipsey River is still relatively intact in terms of species richness despite impacts from mining, silvicultural, and agricultural activities. A concerted effort

  6. Fisher research and the Kings River Sustainable Forest Ecosystem Project: current results and future efforts

    Science.gov (United States)

    Brian B. Boroski; Richard T. Golightly; Amie K. Mazzoni; Kimberly A. Sager

    2002-01-01

    The Kings River Sustainable Forest Ecosystems Project was initiated on the Kings River Ranger District of the Sierra National Forest, California, in 1993, with fieldwork beginning in 1994. Knowledge of the ecology of the fisher (Martes pennanti) in the Project area, and in the Sierra Nevada of California in general, is insufficient to develop...

  7. Stream classification of the Apalachicola-Chattahoochee-Flint River System to support modeling of aquatic habitat response to climate change

    Science.gov (United States)

    Elliott, Caroline M.; Jacobson, Robert B.; Freeman, Mary C.

    2014-01-01

    A stream classification and associated datasets were developed for the Apalachicola-Chattahoochee-Flint River Basin to support biological modeling of species response to climate change in the southeastern United States. The U.S. Geological Survey and the Department of the Interior’s National Climate Change and Wildlife Science Center established the Southeast Regional Assessment Project (SERAP) which used downscaled general circulation models to develop landscape-scale assessments of climate change and subsequent effects on land cover, ecosystems, and priority species in the southeastern United States. The SERAP aquatic and hydrologic dynamics modeling efforts involve multiscale watershed hydrology, stream-temperature, and fish-occupancy models, which all are based on the same stream network. Models were developed for the Apalachicola-Chattahoochee-Flint River Basin and subbasins in Alabama, Florida, and Georgia, and for the Upper Roanoke River Basin in Virginia. The stream network was used as the spatial scheme through which information was shared across the various models within SERAP. Because these models operate at different scales, coordinated pair versions of the network were delineated, characterized, and parameterized for coarse- and fine-scale hydrologic and biologic modeling. The stream network used for the SERAP aquatic models was extracted from a 30-meter (m) scale digital elevation model (DEM) using standard topographic analysis of flow accumulation. At the finer scale, reaches were delineated to represent lengths of stream channel with fairly homogenous physical characteristics (mean reach length = 350 m). Every reach in the network is designated with geomorphic attributes including upstream drainage basin area, channel gradient, channel width, valley width, Strahler and Shreve stream order, stream power, and measures of stream confinement. The reach network was aggregated from tributary junction to tributary junction to define segments for the

  8. Two prototype tools for assessing good environmental/ecological status (GES) in aquatic ecosystems – DEVOTES and WATERS

    DEFF Research Database (Denmark)

    Murray, Ciarán; Carstensen, Jacob; Andersen, Jesper

    2015-01-01

    -based tools, which classify ecological/environmental status in two classes (good or not good) and five classes (High, Good, Moderate, Poor or Bad) by comparing observed indicator values with specified status classification boundaries. Assessments are made for geographical entities (“sectors” in DEVOTES......We present two prototype tools for assessment of GES (good ecological status and good environmental status) in aquatic ecosystems: the DEVOTES biodiversity assessment tool (for the MSFD) and the WATERS ecological status assessment tool (for the WFD). Both tools are multi-metric indicator...... for sub-division of sectors and habitat types into hierarchical structures. The DEVOTES tool weights indicator results from different sectors according to their geographical extent and/or assigned quantitative value scores. The DEVOTES tool allows the assessment to be targeted to a particular ecosystem...

  9. Use of the aquatic plant Elodea canadensis to assess toxicity and genotoxicity of Yenisei River sediments.

    Science.gov (United States)

    Zotina, Tatiana A; Trofimova, Elena A; Medvedeva, Marina Yu; Dementyev, Dmitry V; Bolsunovsky, Alexander Ya

    2015-10-01

    The toxicity, cytotoxicity, and genotoxicity of bulk sediments from the Yenisei River (Siberia, Russia) were estimated in laboratory bioassays based on several endpoints in the aquatic plant Elodea canadensis. The bottom sediment samples were collected in the Yenisei River upstream and downstream of the sources of chemical and radioactive contamination. The testing revealed different sensitivities of Elodea endpoints to the quality of the bottom sediment: weight of shoots Elodea) was the highest in sediments with chemical pollution, whereas the highest inhibition of toxicity endpoints (shoot and root length) occurred in sediments with the highest level of radioactive pollution. The extreme response of Elodea endpoints to the quality of certain sediment samples may be regarded as related to the possible presence of unknown toxicants. The results show that E. canadensis can be used as an indicator species in laboratory contact testing of bottom sediment. The responses of shoot and root length growth endpoints of Elodea can be recommended as basic sensitivity indicators of bottom sediment toxicity. Analysis of cells carrying abnormal chromosomes in the apical root meristem of Elodea can be performed optionally in the same test to assess the genotoxicity of sediments. © 2015 SETAC.

  10. Accumulation of {sup 241}Am by suspended matter, diatoms and aquatic weeds of the Yenisei River

    Energy Technology Data Exchange (ETDEWEB)

    Zotina, T.A., E-mail: t_zotina@ibp.r [Institute of Biophysics SB RAS, Akademgorodok, Krasnoyarsk 660036 (Russian Federation); Bolsunovsky, A.Ya.; Bondareva, L.G. [Institute of Biophysics SB RAS, Akademgorodok, Krasnoyarsk 660036 (Russian Federation)

    2010-02-15

    In this work we experimentally estimated the capacities of the key components of the Yenisei River (Russia): particulate suspended matter (seston), diatom microalgae, and submerged macrophytes for accumulating {sup 241}Am from water. In our experiments large particles of seston (>8 mum), comparable in size with diatoms, took up most of americium from water. The accumulation of americium by isolated diatom algae (Asterionella formosa and Diatoma vulgare) was lower than by total seston. The concentration factors (CFs) of {sup 241}Am for seston of the Yenisei River in our experiments were (2.8-6.9).10{sup 5}; for diatoms - (1.5-4.2).10{sup 4}. The CFs for aquatic plant Elodea canadensis were within the same order of magnitude as those for diatoms. Activity concentration and CFs of {sup 241}Am were nearly the same in experiments under dark and light conditions. This is indicative of an energy independent mechanism of americium uptake from the water by diatoms and submerged macrophytes.

  11. Use of stable nitrogen isotope signatures of riparian macrophytes as an indicator of anthropogenic N inputs to river ecosystems.

    Science.gov (United States)

    Kohzu, Ayato; Miyajima, Toshihiro; Tayasu, Ichiro; Yoshimizu, Chikage; Hyodo, Fujio; Matsui, Kiyoshi; Nakano, Takanori; Wada, Eitaro; Fujita, Noboru; Nagata, Toshi

    2008-11-01

    Deterioration of aquatic ecosystems resulting from enhanced anthropogenic N loading has become an issue of increasing concern worldwide, and methods are needed to trace sources of N in rivers. Because nitrate from sewage is enriched in 15N relative to nitrate from natural soils, delta(15)N values of stream nitrate (delta(15)Nnitrate) should be an appropriate index of anthropogenic N loading to rivers, as should the delta(15)N values of riparian plants (delta(15)Nplant) because they are consumers of nitrate. We determined the delta(15)N values of stream nitrate and six species of riparian macrophytes in 31 rivers in the Lake Biwa Basin in Japan. We then tested the correlation between these values and various land-use parameters, including the percentage of land used for residential and agricultural purposes as well as for natural areas. These delta(15)N values were significantly positively correlated with land use (%) that had a high N load (i.e., residential or agricultural use) and significantly negatively correlated with forest (%). These findings indicate that delta(15)N values of stream nitrate and riparian plants might be good indicators of anthropogenic inputs of nitrogen.

  12. The use of Salvinia auriculata as a bioindicator in aquatic ecosystems: biomass and structure dependent on the cadmium concentration.

    Science.gov (United States)

    Wolff, G; Pereira, G C; Castro, E M; Louzada, J; Coelho, F F

    2012-02-01

    This study shows, in a multiple-level approach, the responses of Salvinia auriculata to Cd pollution in aquatic ecosystems. S. auriculata ramets were cultivated in nutrient solution and subjected to five treatments with Cd for ten days. At the end of the experiment, the number of new ramets and the dry biomass were determined. For ultrastructural observations, the leaves of S. auriculata were analyzed using a scanning electron microscope and transmission electron microscope. At the end of the experiment, the plants exposed to Cd showed damage in the leaves including necrosis and chlorosis, stomate deformations and damaged trichomes. We observed a decrease in the number of new ramets and dry biomass of S. auriculata following the increase in Cd concentration in the solution. At the ultrastructural level, leaves exposed to Cd presented chloroplast deformations and deterioration in the cell wall. All the symptoms of toxicity were directly proportionate to the concentration of Cd in the solution. The results suggests that S. auriculata shows good potential for use as a bioindicator and it can be used in the biomonitoring of aquatic ecosystems contaminated by Cd.

  13. The use of Salvinia auriculata as a bioindicator in aquatic ecosystems: biomass and structure dependent on the cadmium concentration

    Directory of Open Access Journals (Sweden)

    G. Wolff

    Full Text Available This study shows, in a multiple-level approach, the responses of Salvinia auriculata to Cd pollution in aquatic ecosystems. S. auriculata ramets were cultivated in nutrient solution and subjected to five treatments with Cd for ten days. At the end of the experiment, the number of new ramets and the dry biomass were determined. For ultrastructural observations, the leaves of S. auriculata were analyzed using a scanning electron microscope and transmission electron microscope. At the end of the experiment, the plants exposed to Cd showed damage in the leaves including necrosis and chlorosis, stomate deformations and damaged trichomes. We observed a decrease in the number of new ramets and dry biomass of S. auriculata following the increase in Cd concentration in the solution. At the ultrastructural level, leaves exposed to Cd presented chloroplast deformations and deterioration in the cell wall. All the symptoms of toxicity were directly proportionate to the concentration of Cd in the solution. The results suggests that S. auriculata shows good potential for use as a bioindicator and it can be used in the biomonitoring of aquatic ecosystems contaminated by Cd.

  14. Riparian vegetation interacting with river morphology : modelling long-term ecosystem responses to invasive species, climate change, dams and river restoration

    NARCIS (Netherlands)

    van Oorschot, M.

    2017-01-01

    River systems are amongst the most dynamic and productive ecosystems in the world and provide habitats for numerous fluvial species. River flow and river shape determine the conditions that affect plant growth and survival. In turn, riparian plants can actively influence river flow and sedimentation

  15. Effects of the global changes on the aquatic ecosystems in West Europe - role of the plankton communities

    International Nuclear Information System (INIS)

    Souissi, S.

    2007-01-01

    Examination of long-term records of aquatic ecosystems has provided useful information to find out their major driving forces. Understanding the impact of climate change on these ecosystems, the management of their resources and the extrapolation between sites are the main scopes of actual and emerging studies. Such goals can be achieved by inter-site and inter-ecosystem comparisons. This approach was undertaken during our project which has the originality to tackle with marine and freshwater ecosystems. It allowed us to compile and validate several multi-decadal time series of planktonic and other physical driving forces at local and regional scales. Then, the same methodology based on the analysis of the variability of climate indices and biological data across several spatial scales was used. The different ecosystems analyzed here showed clear response to the North Atlantic climate variability. Although the local differences abrupt changes in community composition occurred in all ecosystems in the middle of the years 80. During this period there was also a major shift in climatic conditions during winter and early spring, suggesting an impact of climatic factors. Phenological changes were also observed in plankton communities in all sites. The consequences of the modifications of plankton dynamics on higher trophic levels were also showed. Fluctuations in plankton have resulted in long-term changes in cod recruitment in the North Sea (bottom-up control). On the other hand, both climate change and the improvement of trophic status in Geneva Lake favored the outbreak of whitefish during the years 90. Lower larval mortality and better recruitment are supposed to be linked to faster growth associated with warmer temperatures and better food conditions induced by better temporal overlap between larvae hatching and zooplankton development. (author)

  16. Assessment of chevron dikes for the enhancement of physical-aquatic habitat within the Middle Mississippi River, USA

    Science.gov (United States)

    Remo, Jonathan W. F.; Khanal, Anish; Pinter, Nicholas

    2013-09-01

    Blunt-nosed chevron dikes, a new invention now being widely constructed on the Middle Mississippi River (MMR), have been justified as a tool for enhancing physical-aquatic habitat. Chevron dikes were initially designed to concentrate flow, induce channel scour, and thus facilitate river navigation. More recently, these structures have been justified, in part, for promoting habitat heterogeneity. The ability of chevrons to create and diversify physical-aquatic habitat, however, has not been empirically evaluated. To assess the ability of chevrons to create and diversify physical-aquatic habitat, we compiled hydrologic and geospatial data for three channel reference conditions along a 2.0 km (∼140 ha) reach of the MMR where three chevrons were constructed in late 2007. We used the hydrologic and hydraulic data to construct detailed 2-D hydrodynamic models for three reference condition: historic (circa 1890), pre-chevron, and post-chevron channel conditions. These models documented changes in depths and flow dynamics for a wide range of in-channel discharges. Depth-velocity habitat classes were used to assess change in physical-aquatic habitat patches and spatial statistical tools in order to evaluate the reach-scale habitat patch diversity. Comparisons of pre- and post-chevron conditions revealed increases in deep to very deep (>3.0 m) areas of slow moving (3.0 m], low velocity [<0.6 m/s]). Chevron construction also created some (0.8-3.8 ha) shallow-water habitat (0-1.5 m depth with a 0-0.6 m/s velocity) for flows ⩽2.0 × MAF and contributed to an 8-35% increase in physical-aquatic-habitat diversity compared to pre-chevron channel conditions. However, modeling of the historic reference condition (less engineered channel, circa 1890) revealed that the historical physical-aquatic-habitat mosaic consisted of a wider and shallower channel with: 45-390% more shallow-water habitat (2.4-11.0 ha) and 22-83% more physical-aquatic-habitat diversity, but little over

  17. From a microcosm to the catchment scale: studying the fate of organic runoff pollutants in aquatic ecosystems

    Science.gov (United States)

    Böttcher, T.; Schroll, R.

    2009-04-01

    Spray-drift, drainage, erosion and runoff events are the major causes responsible for deportation of agrochemicals as micropollutants to aquatic non-target sites. These processes can lead to the contamination of nearby freshwater ecosystems with considerably high concentrations of xenobiotics. Thus, it is important to unravel the fate of these pollutants and to evaluate their ecological effects. A novel approach to address this goal was established by the development of a microcosm with multiple sampling abilities enabling quantitative assessment of organic volatilisation, mineralization, metabolization and distribution within the aquatic ecosystem. This microcosm system was designed to support modelling approaches of the catchment scale and gain insights into the fate of pesticides simulating a large scale water body. The potential of this microcosm was exemplified for Isoproturon (IPU), a phenylurea derived systemic herbicide, which is frequently found as contaminant in water samples and with the free-floating macrophyte Lemna minor as non-target species, that is common to occur in rural water bodies. During 21 days exposure time, only a small amount of 14C labeled IPU was removed from the aquatic medium. The major portion (about 5%) was accumulated by Lemna minor resulting in a BCF of 15.8. IPU-volatilisation was very low with 0.13% of the initially applied herbicide. Only a minor amount of IPU was completely metabolized, presumably by rhizosphere microorganisms and released as 14CO2. The novel experimental system allowed to quantitatively investigate the fate of IPU and showed a high reproducibility with a mean average 14C-recovery rate of 97.1

  18. [Responses of functional diversity of aquatic insect community to land use change in middle reach of Qiantang River, East China].

    Science.gov (United States)

    Zhang, Lian-Bo; Liu, Dong-Xiao; Liu, Shuo-Ru; Zhang, Yong; Tong, Xiao-Li; Wang, Bei-Xin

    2013-10-01

    Based on the biological traits such as life history, resistance ability against environmental disturbance, and physiological characteristics of aquatic insects, and by using the fourth-corner statistical method, this paper studied the responses of the functional diversity of aquatic insect community to land use change in the middle reach of Qiantang River, Zhejiang Province of East China. For the test aquatic insect community, some of its biological traits were sensitive to land use change, and altered along human disturbance gradients as expected. With the increasing intensity of human disturbance, the maximal insect body length decreased gradually, the dominant respiration pattern evolved from gill respiration to tegument respiration, and the abundance of burrowers increased significantly. At the same time, the functional diversity measured as Rao's quadratic entropy was significantly higher in reference sites than in disturbed sites (P aquatic community were mainly induced by the land use change caused by human activities, which resulted in the decline of stream water quality and habitat quality and the variations of aquatic insect community composition and biological traits. The aquatic insect biological traits and functional diversity could be the potentially effective indicators in the stream health assessment in the future.

  19. Mycobacterium ulcerans ecological dynamics and its association with freshwater ecosystems and aquatic communities : results from a 12-month environmental survey in Cameroon

    OpenAIRE

    Garchitorena, Andres; Roche, Benjamin; Kamgang, R.; Ossomba, J.; Babonneau, J.; Landier, J.; Fontanet, A.; Flahault, A.; Eyangoh, S.; Guégan, Jean-François; Marsollier, L.

    2014-01-01

    International audience; Background: Mycobacterium ulcerans (MU) is the agent responsible for Buruli Ulcer (BU), an emerging skin disease with dramatic socioeconomic and health outcomes, especially in rural settings. BU emergence and distribution is linked to aquatic ecosystems in tropical and subtropical countries, especially to swampy and flooded areas. Aquatic animal organisms are likely to play a role either as host reservoirs or vectors of the bacilli. However, information on MU ecologica...

  20. Organization of vegetation cover of aquatic ecosystems at Borodinskiy opencast coal mine dumps (Kansk forest-steppe, Eastern Siberia

    Directory of Open Access Journals (Sweden)

    D. Yu. Efimov

    2016-04-01

    Full Text Available The paper present the results of study of the floristic composition and importance of species of aquatic ecosystems on different types of technogenic surfaces of the Borodino coal mine and assessment of the impact of local factors on the structure and the dynamics of vegetation. The list of plant taxa containing 91 species of higher plants and 3 cha-rophytes. The largest amount of macrophytes species are Elodea canadensis Michx., Eleocharis palustris (L. Roem. & Schult., Hydrocharis morsus-ranae L., Potamogeton alpinus Balb., P. perfoliatus L., Sparganium emersum Rehm., Spirodela polyrhiza (L. Schleid., Typha latifolia L., Warnstorfia fluitans (Hedw. Loeske, Chara contraria A. Braun ex Kutz., the basis (up to 67.6‒70.9 % of vegetation mosaic of aquatic systems and differentiate its structure post-technogenic landscape. Sorensen index (QS = 0.63‒0.71 and Spearman rank correlation coefficient (rs = 0.29‒0.62, p < 0.01 values showed the greatest similarity between the species composition of the aquatic complexes arising on mineral surfaces planned dumps. The low level of similarity (QS = 0.13‒0.45; rs = 0.25‒0.34, p < 0.05 in spe-cies composition is typical fir ponds and wetlands formed around the perimeter of the heaps along the erosion of slopes. Non-parametric analysis of variance showed a statistically significant (p < 0.001 differentiation of the species composition of the variables values of the analyzed environmental factors: the direction of reclamation, type and age of geomorphic surfaces dumps. Aquatic complexes significantly complement and enrich the mosaic of man-made landscape of the Borodino coal mine, the potential of their diversity should be taken into account when developing plans and strategies for reclamation of disturbed areas.

  1. An integrated ecological modeling system for assessing impacts of multiple stressors on stream and riverine ecosystem services within river basins

    Data.gov (United States)

    U.S. Environmental Protection Agency — We demonstrate a novel, spatially explicit assessment of the current condition of aquatic ecosystem services, with limited sensitivity analysis for the atmospheric...

  2. Metacommunity theory as a multispecies, multiscale framework for studying the influence of river network structure on riverine communities and ecosystems

    Science.gov (United States)

    Brown, B.L.; Swan, C.M.; Auerbach, D.A.; Campbell, Grant E.H.; Hitt, N.P.; Maloney, K.O.; Patrick, C.

    2011-01-01

    Explaining the mechanisms underlying patterns of species diversity and composition in riverine networks is challenging. Historically, community ecologists have conceived of communities as largely isolated entities and have focused on local environmental factors and interspecific interactions as the major forces determining species composition. However, stream ecologists have long embraced a multiscale approach to studying riverine ecosystems and have studied both local factors and larger-scale regional factors, such as dispersal and disturbance. River networks exhibit a dendritic spatial structure that can constrain aquatic organisms when their dispersal is influenced by or confined to the river network. We contend that the principles of metacommunity theory would help stream ecologists to understand how the complex spatial structure of river networks mediates the relative influences of local and regional control on species composition. From a basic ecological perspective, the concept is attractive because new evidence suggests that the importance of regional processes (dispersal) depends on spatial structure of habitat and on connection to the regional species pool. The role of local factors relative to regional factors will vary with spatial position in a river network. From an applied perspective, the long-standing view in ecology that local community composition is an indicator of habitat quality may not be uniformly applicable across a river network, but the strength of such bioassessment approaches probably will depend on spatial position in the network. The principles of metacommunity theory are broadly applicable across taxa and systems but seem of particular consequence to stream ecology given the unique spatial structure of riverine systems. By explicitly embracing processes at multiple spatial scales, metacommunity theory provides a foundation on which to build a richer understanding of stream communities.

  3. Hazardous materials in aquatic environments of the Mississippi River Basin. Annual technical report, 30 December 1992--29 December 1993

    International Nuclear Information System (INIS)

    1993-01-01

    Tulane and Xavier Universities have singled out the environment as a major strategic focus for research and training for now and beyond the year 2000. In 1989, the Tulane/Xavier Center for Bioenvironmental Research (CBR) was established as the umbrella organization which coordinates environmental research at both universities. In December, 1992, the Tulane/Xavier DBR was awarded a five year grant to study pollution in the Mississippi River system. The ''Hazardous Materials in Aquatic Environments of the Mississippi River Basin'' project is a broad research and education program aimed at elucidating the nature and magnitude of toxic materials that contaminate aquatic environments of the Mississippi River Basin. Studies include defining the complex interactions that occur during the transport of contaminants, the actual and potential impact on ecological systems and health, and the mechanisms through which these impacts might be remediated. The Mississippi River Basin represents a model system for analyzing and solving contamination problems that are found in aquatic systems world-wide. Individual papers have been processed separately for inclusion in the appropriate data bases

  4. Pollution by Nonylphenol in river, tap water, and aquatic in an acid rain-plagued city in southwest China.

    Science.gov (United States)

    Jie, Yu; Jie, Zhou; Ya, Luo; Xuesong, Yang; Jing, Yang; Yu, Yang; Jiaqi, Yang; Jie, Xu

    2017-06-01

    Nonylphenol (NP) has provoked much environmental concern because of their weak estrogenic activities; however, few data are available on the environmental levels of the chemical in China. Environmental or river samples were assayed for NP by high-performance liquid chromatography (HPLC) technique. The concentration for NP measured in Xiangjiang River, ranging from 0.174 to 3.411 μg/L with a mean value of 1.73 μg/L, was lower than the Water Quality Criteria for NP of the US (6.6 μg/L); however, the NP concentration was maintained at a higher level compare to the developed countries and other civil cities. NP concentration in downstream water was markedly higher than that both in midstream and upstream water. Tissue accumulation of NP was observed in aquatics. A ratio of mean concentration of NP in aquatic (chlamys farreri and hemiculter leucisculus) to that in river water was 241 and 1087, respectively. The presence of NP in tap water in two urban districts of Zunyi was common with a detectable rate reached 100.0%. Mean NP concentration in terminal tap water in Huichuan district was six times as high as Honghuagang district, which was above Standards for the Drinking Water Quality for Phenols of China (2 μg/L). The pollution of NP in Xiangjiang River, tap water, and aquatic in Zunyi belongs to moderate or severe level in the world.

  5. Hazardous materials in aquatic environments of the Mississippi River Basin. Annual technical report, 30 December 1992--29 December 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-31

    Tulane and Xavier Universities have singled out the environment as a major strategic focus for research and training for now and beyond the year 2000. In 1989, the Tulane/Xavier Center for Bioenvironmental Research (CBR) was established as the umbrella organization which coordinates environmental research at both universities. In December, 1992, the Tulane/Xavier DBR was awarded a five year grant to study pollution in the Mississippi River system. The ``Hazardous Materials in Aquatic Environments of the Mississippi River Basin`` project is a broad research and education program aimed at elucidating the nature and magnitude of toxic materials that contaminate aquatic environments of the Mississippi River Basin. Studies include defining the complex interactions that occur during the transport of contaminants, the actual and potential impact on ecological systems and health, and the mechanisms through which these impacts might be remediated. The Mississippi River Basin represents a model system for analyzing and solving contamination problems that are found in aquatic systems world-wide. Individual papers have been processed separately for inclusion in the appropriate data bases.

  6. Potential for biotic resistance from herbivores to tropical and subtropical plant invasions in aquatic ecosystems

    NARCIS (Netherlands)

    Petruzella, A.; Grutters, B.M.C.; Thomaz, S.M.; Bakker, E.S.

    2017-01-01

    Invasions of tropical and subtropical aquatic plants threaten biodiversity and cause ecological and economic impacts worldwide. An urgent question is whether native herbivores are able to inhibit the spread of these alien species thus providing biotic resistance. The potential for biotic resistance

  7. The remote sensing of aquatic macrophytes Part 1: Color-infrared aerial photography as a tool for identification and mapping of littoral vegetation. Part 2: Aerial photography as a quantitative tool for the investigation of aquatic ecosystems. [Lake Wingra, Wisconsin

    Science.gov (United States)

    Gustafson, T. D.; Adams, M. S.

    1973-01-01

    Research was initiated to use aerial photography as an investigative tool in studies that are part of an intensive aquatic ecosystem research effort at Lake Wingra, Madison, Wisconsin. It is anticipated that photographic techniques would supply information about the growth and distribution of littoral macrophytes with efficiency and accuracy greater than conventional methods.

  8. 2010-2015 Juvenile fish ecology in the Nisqually River Delta and Nisqually Reach Aquatic Reserve

    Science.gov (United States)

    Hodgson, Sayre; Ellings, Christopher S.; Rubin, Steve P.; Hayes, Michael C.; Duval, Walker; Grossman, Eric E.

    2017-01-01

    The return of tidal inundation to over 750 acres of the U. S. Fish and Wildlife Service Billy Frank Jr. Nisqually National Wildlife Refuge (NNWR) in fall of 2009 was the crowning moment in the effort to protect and restore the Nisqually Delta. The Nisqually NWR project complemented three earlier restoration projects completed by the Nisqually Indian Tribe (Tribe) on tribal property to restore over 900 acres of the estuary, representing the largest estuary restoration project in the Pacific Northwest and one of the most significant advances to date towards the recovery of Puget Sound (USFWS 2005). In 2011 the Washington Department of Natural Resources (WADNR established the over 14000 acre Nisqually Reach Aquatic Reserve (Reserve), complementing the protection and restoration successes in the Nisqually Delta. The Reserve includes all state-owned aquatic lands around Anderson, Ketron and Eagle islands and part of McNeil Island (Figure 1, WDNR 2011). The Reserve also includes a diverse assemblage of nearshore and offshore habitats important to resident and migratory fish including federal endangered species act listed fish like Chinook salmon (Oncorynchus tshawytscha) and steelhead (O. mykiss). Studies in the Nisqually Estuary (Ellings and Hodgson 2007, David et al. 2014, Ellings et al. 2016) and South Puget Sound (Duffy 2003) have summarized fish use of the area. However, the fish ecology of the reserve had not been systematically surveyed. The Tribe, U.S. Geological Survey (USGS), NNWR, Nisqually River Foundation (NRF), and others are currently conducting a multi-year, interdisciplinary, hypothesis-based research and monitoring study investigating the impact of delta restoration on estuarine processes, habitat structures, and functions. Our interdisciplinary monitoring framework enables us to link key estuarine processes with habitat development and biological response at multiple scales across the restored footprint, reference marshes, and throughout the Nisqually

  9. Investigating the need for complex vs. simple scenarios to improve predictions of aquatic ecosystem exposure with the SoilPlus model

    International Nuclear Information System (INIS)

    Ghirardello, Davide; Morselli, Melissa; Otto, Stefan; Zanin, Giuseppe; Di Guardo, Antonio

    2014-01-01

    A spatially-explicit version of the recent multimedia fate model SoilPlus was developed and applied to predict the runoff of three pesticides in a small agricultural watershed in north-eastern Italy. In order to evaluate model response to increasing spatial resolution, a tiered simulation approach was adopted, also using a dynamic model for surface water (DynA model), to predict the fate of pesticides in runoff water and sediment, and concentrations in river water. Simulation outputs were compared to water concentrations measured in the basin. Results showed that a high spatial resolution and scenario complexity improved model predictions of metolachlor and terbuthylazine in runoff to an acceptable performance (R 2 = 0.64–0.70). The importance was also shown of a field-based database of properties (i.e. soil texture and organic carbon, rainfall and water flow, pesticides half-life in soil) in reducing the distance between predicted and measured surface water concentrations and its relevance for risk assessment. Highlights: • A GIS based model was developed to predict pesticide fate in soil and water. • Spatial scenario was obtained at field level for a small agricultural basin. • A tiered strategy was applied to test the performance gain with complexity. • Increased details of scenario as well as the role of surface water are relevant. -- In order to obtain more ecologically realistic predictions of pulse exposure in aquatic ecosystems detailed information about the scenario is required

  10. Valuing tradeoffs between agricultural production and ecosystem services in the Heihe River Basin

    Science.gov (United States)

    Li, Z.; Deng, X.; Wu, F.

    2017-12-01

    Ecosystem services are faced with multiple stress from complex driving factors, such as climate change and human interventions. The Heihe River Basin (HRB), as the second largest inland river basin in China, is a typical semi-arid and arid region with fragile and sensitive ecological environment. For the past decades, agricultural production activities in the basin has affected ecosystem services in different degrees, leading to complex relations among "water-land-climate-ecology-human", in which hydrological process and water resource management is the key. In this context, managing trade-offs among water uses in the river basin to sustain multiple ecosystem services is crucial for healthy ecosystem and sustainable socioeconomic development. In this study, we analyze the trade-offs between different water uses in agricultural production and key ecosystem services in the HRB by applying production frontier analysis, with the aim to explore the potential for managing them. This method traces out joint production frontiers showing the combinations of ecosystem services and agricultural production that can be generated in a given area, and it deals with the economic problem of the allocation of scarce water resources under presumed objective, which aims to highlight synergies and reduce trade-offs between alternative water uses. Thus, management schemes that targets to both sustain agricultural production and increase the provision of key ecosystem services have to consider not only the technological or biological nature of interrelationships, but also the economic interdependencies among them.

  11. Assessment of land use impact on water-related ecosystem services capturing the integrated terrestrial-aquatic system.

    Science.gov (United States)

    Maes, Wouter H; Heuvelmans, Griet; Muys, Bart

    2009-10-01

    Although the importance of green (evaporative) water flows in delivering ecosystem services has been recognized, most operational impact assessment methods still focus only on blue water flows. In this paper, we present a new model to evaluate the effect of land use occupation and transformation on water quantity. Conceptually based on the supply of ecosystem services by terrestrial and aquatic ecosystems, the model is developed for, but not limited to, land use impact assessment in life cycle assessment (LCA) and requires a minimum amount of input data. Impact is minimal when evapotranspiration is equal to that of the potential natural vegetation, and maximal when evapotranspiration is zero or when it exceeds a threshold value derived from the concept of environmental water requirement. Three refinements to the model, requiring more input data, are proposed. The first refinement considers a minimal impact over a certain range based on the boundary evapotranspiration of the potential natural vegetation. In the second refinement the effects of evaporation and transpiration are accounted for separately, and in the third refinement a more correct estimate of evaporation from a fully sealed surface is incorporated. The simplicity and user friendliness of the proposed impact assessment method are illustrated with two examples.

  12. Cyanobacterial toxins: modes of actions, fate in aquatic and soil ecosystems, phytotoxicity and bioaccumulation in agricultural crops.

    Science.gov (United States)

    Corbel, Sylvain; Mougin, Christian; Bouaïcha, Noureddine

    2014-02-01

    The occurrence of harmful cyanobacterial blooms in surface waters is often accompanied by the production of a variety of cyanotoxins. These toxins are designed to target in humans and animals specific organs on which they act: hepatotoxins (liver), neurotoxins (nervous system), cytotoxic alkaloids, and dermatotoxins (skin), but they often have important side effects too. When introduced into the soil ecosystem by spray irrigation of crops they may affect the same molecular pathways in plants having identical or similar target organs, tissues, cells or biomolecules. There are also several indications that terrestrial plants, including food crop plants, can bioaccumulate cyanotoxins and present, therefore, potential health hazards for human and animals. The number of publications concerned with phytotoxic effects of cyanotoxins on agricultural plants has increased recently. In this review, we first examine different cyanotoxins and their modes of actions in humans and mammals and occurrence of target biomolecules in vegetable organisms. Then we present environmental concentrations of cyanotoxins in freshwaters and their fate in aquatic and soil ecosystems. Finally, we highlight bioaccumulation of cyanotoxins in plants used for feed and food and its consequences on animals and human health. Overall, our review shows that the information on the effects of cyanotoxins on non-target organisms in the terrestrial environment is particularly scarce, and that there are still serious gaps in the knowledge about the fate in the soil ecosystems and phytotoxicity of these toxins. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Hazardous materials in Aquatic environments of the Mississippi River basin. Quarterly project status report, 1 January 1994--30 March 1994

    Energy Technology Data Exchange (ETDEWEB)

    Abdelghani, A.

    1994-06-01

    Projects associated with this grant for studying hazardous materials in aquatic environments of the Mississippi River Basin are reviewed and goals, progress and research results are discussed. New, one-year initiation projects are described briefly.

  14. Bioindicators of climate and trophic state in lowland and highland aquatic ecosystems of the Northern Neotropics

    Directory of Open Access Journals (Sweden)

    Liseth Pérez

    2013-06-01

    Full Text Available Chironomids, diatoms and microcrustaceans that inhabit aquatic ecosystems of the Northern Neotropics are abundant and diverse. Some species are highly sensitive to changes in water chemical composition and trophic state. This study was undertaken as a first step in developing transfer functions to infer past environmental conditions in the Northern lowland Neotropics. Bioindicator species abundances were related to multiple environmental variables to exploit their use as environmental and paleoenvironmental indicators. We collected and analyzed water and surface sediment samples from 63 waterbodies located along a broad trophic state gradient and steep gradients of altitude (~0-1 560m.a.s.l. and precipitation (~400-3 200mm/y, from NW Yucatán Peninsula (Mexico to southern Guatemala. We related 14 limnological variables to relative abundances of 282 diatom species, 66 chironomid morphospecies, 51 species of cladocerans, 29 non-marine ostracode species and six freshwater calanoid copepods. Multivariate statistics indicated that bicarbonate is the strongest driver of chironomid and copepod distribution. Trophic state is the second most important factor that determines chironomid distribution. Conductivity, which is related to the precipitation gradient and marine influence on the Yucatán Peninsula, is the main variable that shapes diatom, ostracode and cladoceran communities. Diatoms, chironomids and cladocerans displayed higher diversities (H=2.4-2.6 than ostracodes and copepods (H=0.7- 1.8. Species richness and diversity were greater at lower elevations (Los quironómidos, diatomeas y microcrustaceos que habitan ecosistemas acuáticos en el norte de los Neotrópicos son abundantes y diversos. Algunas especies son altamente sensibles a cambios en la composición química del agua y en el estado trófico. Este estudio se realizó como el primer paso para desarrollar funciones de transferencia para inferir condiciones ambientales en el norte de las

  15. Development of integrated scenarios to assess future conditions of aquatic ecosystems under water scarcity in the Mediterranean - perspectives from the GLOBAQUA project

    Science.gov (United States)

    Huber-Garcia, Verena; Akinsete, Ebun; Gampe, David; Ker Rault, Philippe; Kok, Kasper; Koundouri, Phoebe; Luttik, Joke; Nikulin, Grigory; Pistocchi, Alberto; Souliotis, Ioannis; Ludwig, Ralf

    2017-04-01

    Water and water-related services are major components of the human wellbeing, and as such are major factors of socio-economic development; yet freshwater systems are under threat by a variety of stressors (organic and inorganic pollution, geomorphological alterations, land cover change, water abstraction, invasive species and pathogens). Water scarcity is most commonly associated with inappropriate water management and resulting river flow reductions. It has become one of the most important drivers of change in freshwater ecosystems. Conjoint occurrence of a myriad of stressors (chemical, geomorphological, biological) under water scarcity will produce novel and unfamiliar synergies and most likely very pronounced effects. Stressors are hierarchically arranged in terms of intensity, frequency and scale, and their effects can be predicted to be from transient to irreversible. Most ecosystems are simulta¬neously exposed to multiple-stress situations. Within the scope of the GLOBAQUA project the effects of multiple stressors on aquatic ecosystems in selected river basins across Europe with a focus on areas suffering from water scarcity are analyzed. In addition, management strategies are improved and adapted with the aim of inhibiting adverse effects on aquatic ecosystems and ensuring the supply with water for all purposes in the study areas also in the future. Policy relevant implications will be given to ensure a best possible status of these aquatic ecosystems also under future conditions. In this context, land use and land cover as well as the meteorological conditions can be seen as two main stressors for the quality and quantity of surface and subsurface water. These factors considerably affect the use and availability of water, especially in regions which already experience water scarcity. If the problem is not addressed correctly, negative effects on biodiversity, water supply as well as important economic consequences may arise. In Europe, many fresh water

  16. Tulane/Xavier University Hazardous Materials in Aquatic Environments of the Mississippi River Basin. Quarterly progress report, January 1, 1995--March 31, 1995

    International Nuclear Information System (INIS)

    1995-01-01

    This progress report covers activities for the period January 1 - March 31, 1995 on project concerning 'Hazardous Materials in Aquatic Environments of the Mississippi River Basin.' The following activities are each summarized by bullets denoting significant experiments/findings: biotic and abiotic studies on the biological fate, transport and ecotoxicity of toxic and hazardous waste in the Mississippi River Basin; assessment of mechanisms of metal-induced reproductive toxicity in quatic species as a biomarker of exposure; hazardous wastes in aquatic environments: biological uptake and metabolism studies; ecological sentinels of aquatic contamination in the lower Mississippi River system; bioremediation of selected contaminants in aquatic environments of the Mississippi River Basin; a sensitive rapid on-sit immunoassay for heavy metal contamination; pore-level flow, transport, agglomeration and reaction kinetics of microorganism; biomarkers of exposure and ecotoxicity in the Mississippi River Basin; natural and active chemical remediation of toxic metals, organics and radionuclides in the aquatic environment; expert geographical information systems for assessing hazardous wastes in aquatic environments; enhancement of environmental education; and a number of just initiated projects including fate and transport of contaminants in aquatic environments; photocatalytic remediation; radionuclide fate and modeling from Chernobyl

  17. Cumulative effect assessment in Canada: a regional framework for aquatic ecosystems

    International Nuclear Information System (INIS)

    Dube, Monique G.

    2003-01-01

    Sustainable development of the aquatic environment depends upon routine and defensible cumulative effects assessment (CEA). CEA is the process of predicting the consequences of development relative to an assessment of existing environmental quality. Theoretically, it provides an on-going mechanism to evaluate if levels of development exceed the environment's assimilative capacity; i.e., its ability to sustain itself. In practice, the link between CEA and sustainable development has not been realized because CEA concepts and methods have developed along two dichotomous tracks. One track views CEA as an extension of the environmental assessment (EA) process for project developments. Under this track, stressor-based (S-B) methods have been developed where the emphasis is on local, project-related stressors, their link with aquatic indicators, and the potential for environmental effects through stressor-indicator interactions. S-B methods focus on the proposed development and prediction of project-related effects. They lack a mechanism to quantify existing aquatic quality especially at scales broader than an isolated development. This limitation results in the prediction of potential effects relative to a poorly defined baseline state. The other track views CEA as a broader, regional assessment tool where effects-based (E-B) methods specialize in quantification of existing aquatic effects over broad spatial scales. However, the predictive capabilities of E-B methods are limited because they are retrospective, i.e., the stressor causing the effect is identified after the effect has been measured. When used in isolation, S-B and E-B methods do not address CEA in the context necessary for sustainable development. However, if the strengths of these approaches were integrated into a holistic framework for CEA, an operational mechanism would exist to better monitor and assess sustainable development of our aquatic resources. This paper reviews the existing conceptual basis

  18. LCREP genetic stock ID - Lower Columbia River Ecosystem Monitoring Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — 1) The purpose of this project is to document juvenile salmon habitat occurrence in the Lower Columbia River and estuary, and examine how habitat conditions...

  19. LCREP catch records - Lower Columbia River Ecosystem Monitoring Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — 1) The purpose of this project is to document juvenile salmon habitat occurrence in the Lower Columbia River and estuary, and examine how habitat conditions...

  20. LCREP prey data - Lower Columbia River Ecosystem Monitoring Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — 1) The purpose of this project is to document juvenile salmon habitat occurrence in the Lower Columbia River and estuary, and examine how habitat conditions...

  1. LCREP chemistry and lipids - Lower Columbia River Ecosystem Monitoring Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — 1) The purpose of this project is to document juvenile salmon habitat occurrence in the Lower Columbia River and estuary, and examine how habitat conditions...

  2. LCREP growth rates - Lower Columbia River Ecosystem Monitoring Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — 1) The purpose of this project is to document juvenile salmon habitat occurrence in the Lower Columbia River and estuary, and examine how habitat conditions...

  3. Climate Change and River Ecosystems: Protection and Adaptation Options

    Science.gov (United States)

    Palmer, Margaret A.; Lettenmaier, Dennis P.; Poff, N. Leroy; Postel, Sandra L.; Richter, Brian; Warner, Richard

    2009-12-01

    Rivers provide a special suite of goods and services valued highly by the public that are inextricably linked to their flow dynamics and the interaction of flow with the landscape. Yet most rivers are within watersheds that are stressed to some extent by human activities including development, dams, or extractive uses. Climate change will add to and magnify risks that are already present through its potential to alter rainfall, temperature, runoff patterns, and to disrupt biological communities and sever ecological linkages. We provide an overview of the predicted impacts based on published studies to date, discuss both reactive and proactive management responses, and outline six categories of management actions that will contribute substantially to the protection of valuable river assets. To be effective, management must be place-based focusing on local watershed scales that are most relevant to management scales. The first priority should be enhancing environmental monitoring of changes and river responses coupled with the development of local scenario-building exercises that take land use and water use into account. Protection of a greater number of rivers and riparian corridors is essential, as is conjunctive groundwater/surface water management. This will require collaborations among multiple partners in the respective river basins and wise land use planning to minimize additional development in watersheds with valued rivers. Ensuring environmental flows by purchasing or leasing water rights and/or altering reservoir release patterns will be needed for many rivers. Implementing restoration projects proactively can be used to protect existing resources so that expensive reactive restoration to repair damage associated with a changing climate is minimized. Special attention should be given to diversifying and replicating habitats of special importance and to monitoring populations at high risk or of special value so that management interventions can occur if the

  4. Patterning and predicting aquatic insect richness in four West-African coastal rivers using artificial neural networks

    Directory of Open Access Journals (Sweden)

    Edia E.O.

    2010-10-01

    Full Text Available Despite their importance in stream management, the aquatic insect assemblages are still little known in West Africa. This is particularly true in South-Eastern Ivory Coast, where aquatic insect assemblages were hardly studied. We therefore aimed at characterising aquatic insect assemblages on four coastal rivers in South-Eastern Ivory Coast. Patterning aquatic insect assemblages was achieved using a Self-Organizing Map (SOM, an unsupervised Artificial Neural Networks (ANN method. This method was applied to pattern the samples based on the richness of five major orders of aquatic insects (Diptera, Ephemeroptera, Coleoptera, Trichoptera and Odonata. This permitted to identify three clusters that were mainly related to the local environmental status of sampling sites. Then, we used the environmental characteristics of the sites to predict, using a multilayer perceptron neural network (MLP, trained by BackPropagation algorithm (BP, a supervised ANN, the richness of the five insect orders. The BP showed high predictability (0.90 for both Diptera and Trichoptera, 0.84 for both Coleoptera and Odonata, 0.69 for Ephemeroptera. The most contributing variables in predicting the five insect order richness were pH, conductivity, total dissolved solids, water temperature, percentage of rock and the canopy. This underlines the crucial influence of both instream characteristics and riparian context.

  5. Merits and Limits of Ecosystem Protection for Conserving Wild Salmon in a Northern Coastal British Columbia River

    Directory of Open Access Journals (Sweden)

    Aaron C. Hill

    2010-06-01

    Full Text Available Loss and degradation of freshwater habitat reduces the ability of wild salmon populations to endure other anthropogenic stressors such as climate change, harvest, and interactions with artificially propagated fishes. Preservation of pristine salmon rivers has thus been advocated as a cost-effective way of sustaining wild Pacific salmon populations. We examine the value of freshwater habitat protection in conserving salmon and fostering resilience in the Kitlope watershed in northern coastal British Columbia - a large (3186 km2 and undeveloped temperate rainforest ecosystem with legislated protected status. In comparison with other pristine Pacific Rim salmon rivers we studied, the Kitlope is characterized by abundant and complex habitats for salmon that should contribute to high resilience. However, biological productivity in this system is constrained by naturally cold, light limited, ultra-oligotrophic growing conditions; and the mean (± SD density of river-rearing salmonids is currently low (0.32 ± 0.27 fish per square meter; n = 36 compared to our other four study rivers (grand mean = 2.55 ± 2.98 fish per square meter; n = 224. Existing data and traditional ecological knowledge suggest that current returns of adult salmon to the Kitlope, particularly sockeye, are declining or depressed relative to historic levels. This poor stock status - presumably owing to unfavorable conditions in the marine environment and ongoing harvest in coastal mixed-stock fisheries - reduces the salmon-mediated transfer of marine-derived nutrients and energy to the system's nutrient-poor aquatic and terrestrial food webs. In fact, Kitlope Lake sediments and riparian tree leaves had marine nitrogen signatures (δ15N among the lowest recorded in a salmon ecosystem. The protection of the Kitlope watershed is undoubtedly a conservation success story. However, "salmon strongholds" of pristine watersheds may not adequately sustain salmon populations and foster

  6. Variability of Ecosystem State in Rivers Containing Natural Dams: A Chemical Analysis

    Science.gov (United States)

    Reynolds, Z. A.

    2015-12-01

    Flooding, and the resulting economic damage to roads and property, is associated with natural dams such as beaver dams or log jams. For this reason, humans often remove natural dams; however, river reaches with natural dams provide very different ecosystem services in comparison with free-flowing river reaches. Therefore, the goal of this project is to assess the differences in ecosystem state between these different river reach types in the northeastern United States. We focused on differences in basic chemistry (e.g., dissolved oxygen, pH, temperature, and organic carbon) to assess the impact of natural dams on river ecosystem state. Study sites include rivers in the White Mountains and southeastern New Hampshire at locations with beaver dams, beaver ponds, beaver meadows, log jams, and free-flowing reaches. Dissolved oxygen, ORP, pH, temperature, and conductivity were measured in the field with a YSI Professional Plus meter. Water samples were collected for subsequent laboratory analysis of total organic carbon with a Shimadzu TOC-L. Preliminary results show that the chemistry of river water varies with feature type. Most significantly, dissolved oxygen concentrations are highest in free-flowing reaches and lowest in beaver ponds. Although beaver ponds are often associated with lower pH, due the increased concentration of organic acids, some beaver ponds can increase pH when compared to free-flowing reaches on the same river. Early results also show that water chemistry returns quickly to the chemistry typical of the free-flowing river reaches after being altered by a natural dam. Overall, natural dams create a river system that has more heterogeneity, and therefore has opportunities to provide more ecosystem functions, than a purely free-flowing river; this can increase the number of supported instream and riparian species. By increasing the understanding of how natural dams affect the chemistry of river water, river engineers can improve their decisions on how

  7. The Patoka River, Indiana: An ecosystem at risk

    International Nuclear Information System (INIS)

    Morales, N.E.; Sobiech, S.

    1993-01-01

    An ecological assessment of the Patoka River was conducted during the summer of 1992. The purpose of the study was to determine the status of the fish population along 68 sampling stations in the mainstream of the river and the watershed. The river system was subjected to various forms of man-made alterations including acid mine drainage, agricultural runoff, oil film drainage from oil drilling operations, feed lot runoff, domestic sewage disposal, illegal solid waste dumping, and partial channelization. The observed effects of these alterations to the fish community depended on the dominant environmental alterations to the studied sites. In sites impacted by heavy mine drainage, the fish were absent, probably due to the high toxicity observed at the sites. Oil film drainage effects were overshadowed by the effects of the nutrient enrichment from farm and feed lot runoff. Water eutrophication effects caused higher abundance of juvenile fish at selected sites. Within the channelized portion of the river, larger individuals were collected. This was probably due to the loss of habitat for young and for small individuals along the banks of the river. The extreme effects of these environmental alterations could be decreased by initiating a series of restoration efforts in the river and the watershed

  8. Radioecological monitoring of the Tom' river ecosystem within zone of nuclear fuel cycle plants influence

    International Nuclear Information System (INIS)

    Leonova, G.A.; Bobrov, V.A.; Malikov, Yu.I.; Mel'gunov, M.S.; Makarova, I.V.; Toropov, A.V.

    2005-01-01

    According to the results of 2000-2002 expeditions the estimation of radioactive contamination scales in water ecosystems within zone of Siberian Chemical Industrial Complex (SCC) influence was performed. The accumulation levels of short-lived artificial radionuclides in biota components of SCC technological channel (Romashka river), and spatial radionuclide distribution in biota of ecosystem of the Tom' and Ob' rivers at different distances from the local source have been determined using biochemical indication method. The most frequently occurring species of plants, filamentous green algae and fish were selected as indicator bioobjects for the monitoring. In spectrum of radioisotopes revealed in water plants, fish and water of the Romashka river there were determined twelve short-living isotopes that denoted continuing river burial. (author)

  9. Models for transport and fate of carbon, nutrients and radionuclides in the aquatic ecosystem at Oeregrundsgrepen

    International Nuclear Information System (INIS)

    Erichsen, Anders Christian; Moehlenberg, Flemming; Closter, Rikke Margrethe; Sandberg, Johannes

    2010-06-01

    The aim of the work was to provide supplementary input to the risk assessment of a planned final nuclear waste repository at Forsmark. The main deliverable was a computed water exchange between basins in the Forsmark marine area for the period 6500 BC to 9000 AD - based on the hydrodynamic modelling - to be used as input to the landscape dose model. In addition and what is described in this report, a second deliverable was development and application of high-resolution models for the marine ecosystem and radionuclide processes. The purpose of this deliverable was to illustrate the spatial and temporal variation in important processes and parameters, while constituting a complement to previous modelling approaches and providing supporting information to discussions of the marine ecosystem, parameters and variation (see Chapter 4 and 6).To this end, a hydrodynamic model of high temporal and spatial resolution was constructed and calibrated for the Forsmark area. An ecosystem model was then developed and coupled to the hydrodynamic model. In turn, a detailed radionuclide model was coupled to the ecosystem model to provide detailed predictions of radionuclide transport and accumulation in the coastal ecosystem. The ecosystem and radionuclide models were developed in the equation solver MIKE ECOLab that links seamless to the MIKE3 FM hydrodynamic model. The 'standard' ECOLab ecosystem model was extended with six biological state variables, perennial macroalgae, benthic herbivors, detritus feeders, planktivorus fish and, benthic predators representing the relict isopod Saduria and cod. In contrast to the ecosystem model, the radionuclide model was developed from scratch but building on the structure of the ecosystem model and using the output (process rates linking state variables) from the ecosystem model as input to the radionuclide model. Both the ecosystem model and the radionuclide model were run for several years (5-8 years) to bring state variables into quasi

  10. Models for transport and fate of carbon, nutrients and radionuclides in the aquatic ecosystem at Oeregrundsgrepen

    Energy Technology Data Exchange (ETDEWEB)

    Erichsen, Anders Christian; Moehlenberg, Flemming; Closter, Rikke Margrethe; Sandberg, Johannes [DHI, Hoersholm (Denmark)

    2010-06-15

    The aim of the work was to provide supplementary input to the risk assessment of a planned final nuclear waste repository at Forsmark. The main deliverable was a computed water exchange between basins in the Forsmark marine area for the period 6500 BC to 9000 AD - based on the hydrodynamic modelling - to be used as input to the landscape dose model. In addition and what is described in this report, a second deliverable was development and application of high-resolution models for the marine ecosystem and radionuclide processes. The purpose of this deliverable was to illustrate the spatial and temporal variation in important processes and parameters, while constituting a complement to previous modelling approaches and providing supporting information to discussions of the marine ecosystem, parameters and variation (see Chapter 4 and 6).To this end, a hydrodynamic model of high temporal and spatial resolution was constructed and calibrated for the Forsmark area. An ecosystem model was then developed and coupled to the hydrodynamic model. In turn, a detailed radionuclide model was coupled to the ecosystem model to provide detailed predictions of radionuclide transport and accumulation in the coastal ecosystem. The ecosystem and radionuclide models were developed in the equation solver MIKE ECOLab that links seamless to the MIKE3 FM hydrodynamic model. The 'standard' ECOLab ecosystem model was extended with six biological state variables, perennial macroalgae, benthic herbivors, detritus feeders, planktivorus fish and, benthic predators representing the relict isopod Saduria and cod. In contrast to the ecosystem model, the radionuclide model was developed from scratch but building on the structure of the ecosystem model and using the output (process rates linking state variables) from the ecosystem model as input to the radionuclide model. Both the ecosystem model and the radionuclide model were run for several years (5-8 years) to bring state variables into quasi

  11. Uptake of uranium by aquatic plants growing in fresh water ecosystem around uranium mill tailings pond at Jaduguda, India.

    Science.gov (United States)

    Jha, V N; Tripathi, R M; Sethy, N K; Sahoo, S K

    2016-01-01

    Concentration of uranium was determined in aquatic plants and substrate (sediment or water) of fresh water ecosystem on and around uranium mill tailings pond at Jaduguda, India. Aquatic plant/substrate concentration ratios (CRs) of uranium were estimated for different sites on and around the uranium mill tailings disposal area. These sites include upstream and downstream side of surface water sources carrying the treated tailings effluent, a small pond inside tailings disposal area and residual water of this area. Three types of plant groups were investigated namely algae (filamentous and non-filamentous), other free floating & water submerged and sediment rooted plants. Wide variability in concentration ratio was observed for different groups of plants studied. The filamentous algae uranium concentration was significantly correlated with that of water (r=0.86, puranium concentration in plant and the substrate (r=0.88, puranium concentration was significantly correlated with Mn, Fe, and Ni concentration of plants (puranium accumulation and concentration ratio can be useful for prospecting phytoremediation of stream carrying treated or untreated uranium mill tailings effluent. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Total mercury and mercury species in birds and fish in an aquatic ecosystem in the Czech Republic

    International Nuclear Information System (INIS)

    Houserova, Pavlina; Kuban, Vlastimil; Kracmar, Stanislav; Sitko, Jilji

    2007-01-01

    Total mercury and mercury species (methylmercury-MeHg, inorganic mercury - Hg 2+ ) were determined in the aquatic ecosystem Zahlinice (Czech Republic). Four tissues (muscle, intestines, liver and kidney) of three bird species - cormorant, great crested grebe and Eurasian buzzard, muscle tissues of common carp, grass carp, northern pike, goldfish, common tench, perch and rudd, aquatic plants (reed mace and common reed), sediments and water were analysed. Relative contents of MeHg (of total Hg) were in the range from 71% to 94% and from 15% up to 62% in the muscle and intestines and in liver, respectively, for all birds. Statistically significant differences were found between contents of MeHg in liver tissues of young and adult cormorant populations (F 4.6 = 56.71, P -5 ). Relative contents of MeHg in muscle tissues of fishes were in the range from 65.1% to 87.9% of total Hg. - The distribution of the mercury species among the organs of the individual birds is discussed

  13. Total mercury and mercury species in birds and fish in an aquatic ecosystem in the Czech Republic

    Energy Technology Data Exchange (ETDEWEB)

    Houserova, Pavlina [Department of Chemistry and Biochemistry, Mendel University of Agriculture and Forestry, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Kuban, Vlastimil [Department of Chemistry and Biochemistry, Mendel University of Agriculture and Forestry, Zemedelska 1, CZ-613 00 Brno (Czech Republic)]. E-mail: kuban@mendelu.cz; Kracmar, Stanislav [Department of Animal Nutrition, Mendel University of Agriculture and Forestry, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Sitko, Jilji [Commenius Museum, Moravian Ornithological Station, Horni nam. 1, Prerov CZ-751 52 (Czech Republic)

    2007-01-15

    Total mercury and mercury species (methylmercury-MeHg, inorganic mercury - Hg{sup 2+}) were determined in the aquatic ecosystem Zahlinice (Czech Republic). Four tissues (muscle, intestines, liver and kidney) of three bird species - cormorant, great crested grebe and Eurasian buzzard, muscle tissues of common carp, grass carp, northern pike, goldfish, common tench, perch and rudd, aquatic plants (reed mace and common reed), sediments and water were analysed. Relative contents of MeHg (of total Hg) were in the range from 71% to 94% and from 15% up to 62% in the muscle and intestines and in liver, respectively, for all birds. Statistically significant differences were found between contents of MeHg in liver tissues of young and adult cormorant populations (F {sub 4.6} = 56.71, P < 10{sup -5}). Relative contents of MeHg in muscle tissues of fishes were in the range from 65.1% to 87.9% of total Hg. - The distribution of the mercury species among the organs of the individual birds is discussed.

  14. Genetically modified crops and aquatic ecosystems: considerations for environmental risk assessment and non-target organism testing.

    Science.gov (United States)

    Carstens, Keri; Anderson, Jennifer; Bachman, Pamela; De Schrijver, Adinda; Dively, Galen; Federici, Brian; Hamer, Mick; Gielkens, Marco; Jensen, Peter; Lamp, William; Rauschen, Stefan; Ridley, Geoff; Romeis, Jörg; Waggoner, Annabel

    2012-08-01

    Environmental risk assessments (ERA) support regulatory decisions for the commercial cultivation of genetically modified (GM) crops. The ERA for terrestrial agroecosystems is well-developed, whereas guidance for ERA of GM crops in aquatic ecosystems is not as well-defined. The purpose of this document is to demonstrate how comprehensive problem formulation can be used to develop a conceptual model and to identify potential exposure pathways, using Bacillus thuringiensis (Bt) maize as a case study. Within problem formulation, the insecticidal trait, the crop, the receiving environment, and protection goals were characterized, and a conceptual model was developed to identify routes through which aquatic organisms may be exposed to insecticidal proteins in maize tissue. Following a tiered approach for exposure assessment, worst-case exposures were estimated using standardized models, and factors mitigating exposure were described. Based on exposure estimates, shredders were identified as the functional group most likely to be exposed to insecticidal proteins. However, even using worst-case assumptions, the exposure of shredders to Bt maize was low and studies supporting the current risk assessments were deemed adequate. Determining if early tier toxicity studies are necessary to inform the risk assessment for a specific GM crop should be done on a case by case basis, and should be guided by thorough problem formulation and exposure assessment. The processes used to develop the Bt maize case study are intended to serve as a model for performing risk assessments on future traits and crops.

  15. Uptake of uranium by aquatic plants growing in fresh water ecosystem around uranium mill tailings pond at Jaduguda, India

    Energy Technology Data Exchange (ETDEWEB)

    Jha, V.N., E-mail: jhavn1971@gmail.com; Tripathi, R.M., E-mail: tripathirm@yahoo.com; Sethy, N.K., E-mail: sethybarc@rediffmail.com; Sahoo, S.K., E-mail: sksbarc@gmail.com

    2016-01-01

    Concentration of uranium was determined in aquatic plants and substrate (sediment or water) of fresh water ecosystem on and around uranium mill tailings pond at Jaduguda, India. Aquatic plant/substrate concentration ratios (CRs) of uranium were estimated for different sites on and around the uranium mill tailings disposal area. These sites include upstream and downstream side of surface water sources carrying the treated tailings effluent, a small pond inside tailings disposal area and residual water of this area. Three types of plant groups were investigated namely algae (filamentous and non-filamentous), other free floating & water submerged and sediment rooted plants. Wide variability in concentration ratio was observed for different groups of plants studied. The filamentous algae uranium concentration was significantly correlated with that of water (r = 0.86, p < 0.003). For sediment rooted plants significant correlation was found between uranium concentration in plant and the substrate (r = 0.88, p < 0.001). Both for other free floating species and sediment rooted plants, uranium concentration was significantly correlated with Mn, Fe, and Ni concentration of plants (p < 0.01). Filamentous algae, Jussiaea and Pistia owing to their high bioproductivity, biomass, uranium accumulation and concentration ratio can be useful for prospecting phytoremediation of stream carrying treated or untreated uranium mill tailings effluent. - Highlights: • Uranium mill tailings pond. • Jaduguda, India. • Fresh water plants. • Uranium uptake. • Relationship of uranium with stable elements.

  16. Effects on parathion on the ecology of a eutrophic aquatic ecosystem: limnocorral experiment

    International Nuclear Information System (INIS)

    Gasith, A.; Perry, A.S.; Mozel, Y.; Albright, J.L.

    1983-01-01

    Repetitive exposure of a eutrophic fish pond ecosystem, enclosed in limnocorrals, to 30 ppb parathion resulted in elimination of the potentially dominant zooplankton species, Moina micrura. Consequently, the populations of the rotifers Brachionus and Asplanchna markedly increased. Changes in the zooplankton composition and abundance were followed by increased fluctuations in phytoplankton biomass, phytoplankton photosynthesis, plankton respiration and community metabolism. Similar responses to parathion treatment were observed in previous studies under fish pond conditions. In the presence of fish the effect of parathion on the ecosystem was generally less pronounced and not uniform. The collapse of the zooplankton community and the rapid changes in limnological conditions in the control (untreated) limnocorrals severely limited the duration of the experiment. The results suggest that under eutrophic conditions, small enclosures may be useful for evaluation of the effect of toxicants on the ecosystem only in short term experiments with short lived chemicals. (author)

  17. The fate of mercury in Arctic terrestrial and aquatic ecosystems, a review

    DEFF Research Database (Denmark)

    Douglas, Thomas A.; Loseto, Lisa L.; MacDonald, Robie W.

    2012-01-01

    the fate of Hg in most ecosystems, and the role of trophic processes in controlling Hg in higher order animals are also included. Case studies on Eastern Beaufort Sea beluga (Delphinapterus leucas) and landlocked Arctic char (Salvelinus alpinus) are presented as examples of the relationship between...... into non-biological archives is also addressed. The review concludes by identifying major knowledge gaps in our understanding, including: (1) the rates of Hg entry into marine and terrestrial ecosystems and the rates of inorganic and MeHg uptake by Arctic microbial and algal communities; (2...

  18. SUSTAINABLE MANAGEMENT OF RIVER OASES ALONG THE TARIM RIVER (P.R. CHINA AND THE ECOSYSTEM SERVICES APPROACH

    Directory of Open Access Journals (Sweden)

    Bernd Cyffka

    2013-01-01

    Full Text Available In north-western China, the endorheic Tarim River is running along the northern rim of the Taklamakan desert. It is the solely water source for the oases in the region as precipitation is low. The river is mainly fed from water of snow and glacier melt, causing floods in the summer months. Due to global climate change the annual water discharge is increasing. However, not sufficient water flows downstream, as the region is the main production area of cotton in China, and much water is needed for irrigation. A conflict arises between water users of the upper reaches and water users of the lower reaches of the Tarim River as well as with the natural vegetation. The central question of the Sino-German SuMaRiO project (Sustainable Management of River Oases is how to manage land use, i.e. irrigation agriculture and utilization of the natural ecosystems, and water use in a very water-scarce region, with changing water availability due to climate change, such that ecosystem services and economic benefits are maintained in the best balance for a sustainable development. The overall goal of the project is to support oasis management along the Tarim River under conditions of climatic and societal changes by: i developing methods for analyzing ecosystem functions/ecosystem services, and integrating them into land and water management of oases and riparian forests; ii Involving stakeholders in the research process to integrate their knowledge and problem perceptions into the scientific process; iii Developing tools (Decision support system with Chinese decision makers that demonstrate the ecological and socio-economic consequences of their decisions in a changing world.

  19. Congruence and the Biomonitoring of Aquatic Ecosystems: Are Odonate Larvae or Adults the Most Effective for the Evaluation of Impacts.

    Science.gov (United States)

    Mendes, T P; Oliveira-Junior, J M B; Cabette, H S R; Batista, J D; Juen, L

    2017-12-01

    Odonata have been widely used as indicators for the biomonitoring of terrestrial and aquatic habitats due to their sensitivity to environmental impacts. We aimed to determine whether the larval or adult phases of these insects were the best predictors of variation in habitat parameters and the loss of environmental integrity. Specimens were collected during three seasons (dry, rainy, and ebb) from 12 points in the Suiá-missu River basin, at the headwaters of the Xingu River in Mato Grosso, Brazil. The Protest analysis indicated a high degree of congruence between the assemblages of larvae and adults in streams with varying degrees of habitat integrity (R = 0.832, p congruence with environmental factors was analyzed, a significant association was found only for the larval phase (R = 0.318, p = 0.03, m 2  = 0.888). When the suborders were analyzed separately, congruence was confirmed for anisopteran adults (R = 0.338, p = 0.031, m 2  = 0.885) and larvae (R = 0.417, p = 0.003, m 2  = 0.826) and for the zygopteran adults (R = 0.345, p = 0.027, m 2  = 0.881) and larvae (R = 0.405, p = 0.011, m 2  = 0.836). These results indicate that both larvae and adults respond systematically to environmental impacts. We suggest that either life phase can be used for biomonitoring, given their effectiveness for the interpretation of disturbance in terrestrial and aquatic habitats. These findings further reinforce the effectiveness of this insect order for the detection of modifications to the environment, showing that they are good indicators of environmental conditions.

  20. Alien invasions in aquatic ecosystems: toward an understanding of brook trout invasions and potential impacts on inland cutthroat trout in western North America

    Science.gov (United States)

    Jason B. Dunham; Susan B. Adams; Robert E. Schroeter; Douglas C. Novinger

    2002-01-01

    Experience from case studies of biological invasions in aquatic ecosystems has motivated a set of proposed empirical “rules” for understanding patterns of invasion and impacts on native species. Further evidence is needed to better understand these patterns, and perhaps contribute to a useful predictive theory of invasions. We reviewed the case of brook trout (

  1. Review of available data for a South African Inventory of Inland Aquatic Ecosystems (SAIIAE)

    NARCIS (Netherlands)

    van Deventer, Heidi; Smith-Adao, Lindie; Petersen, Chantel; Mbona, Namhla; Skowno, Andrew; Nel, J.L.

    2018-01-01

    The National Biodiversity Assessment of 2011 found freshwater ecosystems to be highly threatened and poorly protected. However, a number of studies have shown that the National Wetland Map (NWM) Version 4 represents less than 54% of wetlands mapped at a fine scale. A more comprehensive South African

  2. Applications of the First Law to Ecological Systems. Physical Processes in Terrestrial and Aquatic Ecosystems, Thermodynamics.

    Science.gov (United States)

    Stevenson, R. D.

    These materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. This report describes concepts presented in another module called "The First Law of…

  3. Climate-driven changes in the ecological stoichiometry of aquatic ecosystems

    NARCIS (Netherlands)

    van de Waal, D.B.; Verschoor, A.M.; Verspagen, J.M.H.; van Donk, E.; Huisman, J.

    2010-01-01

    Advances in ecological stoichiometry, a rapidly expanding research field investigating the elemental composition of organisms and their environment, have shed new light on the impacts of climate change on freshwater and marine ecosystems. Current changes in the Earth's climate alter the availability

  4. Soil Heat Flow. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Processes.

    Science.gov (United States)

    Simpson, James R.

    These materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. Soil heat flow and the resulting soil temperature distributions have ecological consequences…

  5. Factors influencing aquatic-to-terrestrial contaminant transport to terrestrial arthropod consumers in a multiuse river system.

    Science.gov (United States)

    Alberts, Jeremy M; Sullivan, S Mažeika P

    2016-06-01

    Emerging aquatic insects are important vectors of contaminant transfer from aquatic to terrestrial food webs. However, the environmental factors that regulate contaminant body burdens in nearshore terrestrial consumers remain largely unexplored. We investigated the relative influences of riparian landscape composition (i.e., land use and nearshore vegetation structure) and contaminant flux via the emergent aquatic insect subsidy on selenium (Se) and mercury (Hg) body burdens of riparian ants (Formica subsericea) and spiders of the family Tetragnathidae along 11 river reaches spanning an urban-rural land-use gradient in Ohio, USA. Model-selection results indicated that fine-scale land cover (e.g., riparian zone width, shrub cover) in the riparian zone was positively associated with reach-wide body burdens of Se and Hg in both riparian F. subsericea and tetragnathid spiders (i.e., total magnitude of Hg and Se concentrations in ant and spider populations, respectively, for each reach). River distance downstream of Columbus, Ohio - where study reaches were impounded and flow through a large urban center - was also implicated as an important factor. Although stable-isotope analysis suggested that emergent aquatic insects were likely vectors of Se and Hg to tetragnathid spiders (but not to F. subsericea), emergent insect contaminant flux did not emerge as a significant predictor for either reach-wide body burdens of spider Hg or Se. Improved understanding of the pathways and influences that control aquatic-to-terrestrial contaminant transport will be critical for effective risk management and remediation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Characterization of the Kootenai River Aquatic Macroinvertebrate Community before and after Experimental Nutrient Addition, 2003-2006. [Chapter 3

    Energy Technology Data Exchange (ETDEWEB)

    Holderman, Charlie [Kootenai Tribe of Idaho Bonners

    2009-02-19

    The Kootenai River ecosystem has experienced numerous ecological changes since the early 1900s. Some of the largest impacts to habitat, biological communities, and ecological function resulted from levee construction along the 120 km of river upstream from Kootenay Lake, completed by the 1950s, and the construction and operation of Libby Dam, completed in 1972 on the river near Libby Montana. Levee construction isolated tens of thousands of hectares of historic functioning floodplain habitat from the river channel, eliminating nutrient production and habitat diversity crucial to the functioning of a large river-floodplain ecosystem. Libby Dam continues to create large changes in the timing, duration, and magnitude of river flows, and greatly reduces sediment and nutrient transport to downstream river reaches. These changes have contributed to the ecological collapse of the post-development Kootenai River ecosystem and its native biological communities. In response to this artificial loss of nutrients, experimental nutrient addition was initiated in the Kootenay Lake's North Arm in 1992, the South Arm in 2004, and in the Kootenai River at the Idaho-Montana border during 2005. This report characterizes the macroinvertebrate community in the Kootenai River and its response to experimental nutrient addition during 2005 and 2006. This report also provides an initial evaluation of cascading trophic interactions in response to nutrient addition. Macroinvertebrates were sampled at 12 sites along a 325 km section of the Kootenai River, representing an upriver unimpounded reference reach, treatment and control canyon reach sites, and braided and meandering reach sites, all downstream from Libby Dam. Principle component analysis revealed that richness explained the greatest amount of variability in response to nutrient addition as did taxa from Acari, Coleoptera, Ephemeroptera, Plecoptera, and Trichoptera. Analysis of variance revealed that nutrient addition had a

  7. Copper, cadmium, and zinc concentrations in aquatic food chains from the Upper Sacramento River (California) and selected tributaries

    Science.gov (United States)

    Saiki, M.K.; Castleberry, D. T.; May, T. W.; Martin, B.A.; Bullard, F. N.

    1995-01-01

    Metals enter the Upper Sacramento River above Redding, California, primarily through Spring Creek, a tributary that receives acid-mine drainage from a US EPA Superfund site known locally as Iron Mountain Mine. Waterweed (Elodea canadensis) and aquatic insects (midge larvae, Chironomidae; and mayfly nymphs, Ephemeroptera) from the Sacramento River downstream from Spring Creek contained much higher concentrations of copper (Cu), cadmium (Cd), and zinc (Zn) than did similar taxa from nearby reference tributaries not exposed to acid-mine drainage. Aquatic insects from the Sacramento River contained especially high maximum concentrations of Cu (200 mg/kg dry weight in midge larvae), Cd (23 mg/kg dry weight in mayfly nymphs), and Zn (1,700 mg/kg dry weight in mayfly nymphs). Although not always statistically significant, whole-body concentrations of Cu, Cd, and Zn in fishes (threespine stickleback, Gasterosteus aculeatus; Sacramento sucker, Catostomus occidentalis; Sacramento squawfish, Ptychocheilus grandis; and chinook salmon, Oncorhynchus tshawytasch) from the Sacramento River were generally higher than in fishes from the reference tributaries.

  8. Impact of treated effluents released from processing of radioactive mineral on the aquatic environment of Periyar river

    International Nuclear Information System (INIS)

    Radhakrishnan, Sujata; Haridasan, P.P.; Radhakrishna Pillai, K.; Pillai, P.M.B.; Khan, A.H.

    2005-01-01

    The chemical processing of monazite/ thorium concentrate for the separation of thorium, uranium and rare earths results in the generation of effluents, both acidic and alkaline. Indian Rare Earths Ltd (IREL), Udyogamandal was carrying out processing of monazite for nearly 50 years. Presently (since 2004) Indian Rare Earths Ltd, Udyogamandal is processing earlier stocked thorium hydroxide concentrate retrieved from Silos to produce Thorium Oxalate (along with a small percentage of Rare Earth elements), Nuclear Grade Ammonium Di-Uranate (NGADU), and small quantities of Nuclear Grade Thorium Oxide ('THRUST' Project). The treated effluents after monitoring are discharged to river Periyar. River Periyar is the recipient water body for treated effluents from IREL as well as a host of other chemical industries. Indian Rare Earths Ltd, Udyogamandal had been carrying out chemical processing of monazite for the past 50 years. Recently, from 2004, the plant has shifted from monazite processing to processing of thorium concentrate (THRUST Project). The present paper discusses the characteristics of the effluents generated as per this project, their treatment, monitoring methodology, discharge and impact on the aquatic environment of river Periyar. It has been noted that the impact on the aquatic environment by way of enhancing the natural background radioactivity in the river had been insignificant. (author)

  9. Identifying hotspots and management of critical ecosystem services in rapidly urbanizing Yangtze River Delta Region, China.

    Science.gov (United States)

    Cai, Wenbo; Gibbs, David; Zhang, Lang; Ferrier, Graham; Cai, Yongli

    2017-04-15

    Rapid urbanization has altered many ecosystems, causing a decline in many ecosystem services, generating serious ecological crisis. To cope with these challenges, we presented a comprehensive framework comprising five core steps for identifying and managing hotspots of critical ecosystem services in a rapid urbanizing region. This framework was applied in the case study of the Yangtze River Delta (YRD) Region. The study showed that there was large spatial heterogeneity in the hotspots of ecosystem services in the region, hotspots of supporting services and regulating services aggregately distributing in the southwest mountainous areas while hotspots of provisioning services mainly in the northeast plain, and hotspots of cultural services widespread in the waterbodies and southwest mountainous areas. The regionalization of the critical ecosystem services was made through the hotspot analysis. This study provided valuable information for environmental planning and management in a rapid urbanizing region and helped improve China's ecological redlines policy at regional scale. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Parameterization of aquatic ecosystem functioning and its natural variation: Hierarchical Bayesian modelling of plankton food web dynamics

    Science.gov (United States)

    Norros, Veera; Laine, Marko; Lignell, Risto; Thingstad, Frede

    2017-10-01

    Methods for extracting empirically and theoretically sound parameter values are urgently needed in aquatic ecosystem modelling to describe key flows and their variation in the system. Here, we compare three Bayesian formulations for mechanistic model parameterization that differ in their assumptions about the variation in parameter values between various datasets: 1) global analysis - no variation, 2) separate analysis - independent variation and 3) hierarchical analysis - variation arising from a shared distribution defined by hyperparameters. We tested these methods, using computer-generated and empirical data, coupled with simplified and reasonably realistic plankton food web models, respectively. While all methods were adequate, the simulated example demonstrated that a well-designed hierarchical analysis can result in the most accurate and precise parameter estimates and predictions, due to its ability to combine information across datasets. However, our results also highlighted sensitivity to hyperparameter prior distributions as an important caveat of hierarchical analysis. In the more complex empirical example, hierarchical analysis was able to combine precise identification of parameter values with reasonably good predictive performance, although the ranking of the methods was less straightforward. We conclude that hierarchical Bayesian analysis is a promising tool for identifying key ecosystem-functioning parameters and their variation from empirical datasets.

  11. Flow intermittence and ecosystem services in rivers of the Anthropocene

    Science.gov (United States)

    Intermittent rivers and ephemeral streams (IRES) are watercourses that cease flow at some point in time and space. Arguably Earth's most widespread type of flowing water, IRES are expanding where Anthropocenic climates grow drier and human demands for water escalate. However, IRE...

  12. [Health assessment of Qi'ao Island mangrove wetland ecosystem in Pearl River Estuary].

    Science.gov (United States)

    Wang, Shu-Gong; Zheng, Yao-Hui; Peng, Yi-Sheng; Chen, Gui-Zhu

    2010-02-01

    Based on the theories of wetland ecosystem health and by using "Pressure-State-Response" model, a health assessment indicator system for Qi' ao Island mangrove wetland ecosystem in Pearl River Estuary was built, and the assessment indices, assessment criteria, indices weighted values, assessment grades, and assessment methods were established to assess the health state of this ecosystem. In 2008, the overall health index of this ecosystem was 0.6580, health level was of grade II (healthy), and the pressure, state, and response indices were 0.3469, 0.8718, and 0.7754, respectively, suggesting that this ecosystem was good in state and response, but still had definite pressure. As a provincial nature reserve, this ecosystem was to be further improved in its health level. However, the research on the health assessment of mangrove wetland ecosystem was still young. Further studies should be made on the selection of assessment indices, long-term oriented monitoring of these indices, and quantification of the relations between ecosystem health level and ecosystem services.

  13. Models for transport and fate of carbon, nutrients and radionuclides in the aquatic ecosystem at Oeregrundsgrepen

    Energy Technology Data Exchange (ETDEWEB)

    Erichsen, Anders Christian; Moehlenberg, Flemming; Closter, Rikke Margrethe; Sandberg, Johannes (DHI, Hoersholm (Denmark))

    2010-06-15

    The aim of the work was to provide supplementary input to the risk assessment of a planned final nuclear waste repository at Forsmark. The main deliverable was a computed water exchange between basins in the Forsmark marine area for the period 6500 BC to 9000 AD - based on the hydrodynamic modelling - to be used as input to the landscape dose model. In addition and what is described in this report, a second deliverable was development and application of high-resolution models for the marine ecosystem and radionuclide processes. The purpose of this deliverable was to illustrate the spatial and temporal variation in important processes and parameters, while constituting a complement to previous modelling approaches and providing supporting information to discussions of the marine ecosystem, parameters and variation (see Chapter 4 and 6).To this end, a hydrodynamic model of high temporal and spatial resolution was constructed and calibrated for the Forsmark area. An ecosystem model was then developed and coupled to the hydrodynamic model. In turn, a detailed radionuclide model was coupled to the ecosystem model to provide detailed predictions of radionuclide transport and accumulation in the coastal ecosystem. The ecosystem and radionuclide models were developed in the equation solver MIKE ECOLab that links seamless to the MIKE3 FM hydrodynamic model. The 'standard' ECOLab ecosystem model was extended with six biological state variables, perennial macroalgae, benthic herbivors, detritus feeders, planktivorus fish and, benthic predators representing the relict isopod Saduria and cod. In contrast to the ecosystem model, the radionuclide model was developed from scratch but building on the structure of the ecosystem model and using the output (process rates linking state variables) from the ecosystem model as input to the radionuclide model. Both the ecosystem model and the radionuclide model were run for several years (5-8 years) to bring state variables into

  14. Ecological effects assessment of anionic surfactant on aquatic ecosystem using microcosm system; Microcosm wo mochiita in ion kaimen kasseizai no suiken seitaikei ni oyobosu eikyo hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Takamatsu, Y. [University of Tsukuba, Tsukuba (Japan); Inamori, Y. [National Institute for Environmental Studies, Tsukuba (Japan); Sudo, R. [Tohoku University, Sendai (Japan). Faculty of Engineering; Kurihara, Y. [Ou Univ., Fukushima (Japan). Faculty of Engineering; Matsumura, M. [University of Tsukuba, Tsukuba (Japan). Institute of Applied Biochemical

    1997-11-10

    Microcosm system was applied to assess effect of anionic surfactant (LAS) on aquatic ecosystem. Anionic surfactant such as LAS was added to an flask microcosm consisting of four species of bacteria as decomposer, one species of ciliate protozoa (Cyclidium glaucoma), two rotifers (Philodina sp. and Lepadella sp.) and one aquatic oligochaete (Aeolosoma hemprichi) as predator, and a green alga (Chlorella sp.) and a filamentous blue-green alga (Tolypothrix sp.) as producer, comparing with that of an natural lake model ecosystem derived from natural lake water. In the flask microcosm system and the natural lake model ecosystem, biodegradation rates of LAS were almost same and NOECs (no observed effect concentration) of LAS were also below 1.5 mg{center_dot} l{sup -1}. It was found that flask microcosm test could provide precise ecological effect assessment of LAS on number of microorganisms because the system showed higher reproducibility and stability than natural take model ecosystem. It was suggested that flask microcosm test was useful ecological effect assessment method which can reflect natural aquatic ecosystem. 10 refs., 4 figs., 2 tabs.

  15. Prescribed burning in the Kings River Ecosystem Project Area: lessons learned

    Science.gov (United States)

    David S. McCandliss

    2002-01-01

    The prescribed fire program on the Sierra National Forest is in its infancy. Prescription burning was initiated in 1994 in two 32,000-acre watersheds in the Kings River District of the Sierra National Forest. Primary objectives are to return fire to a more historical role in forest ecosystems and to provide opportunities for scientists from the Pacific Southwest...

  16. Variable selection for modelling effects of eutrophication on stream and river ecosystems

    NARCIS (Netherlands)

    Nijboer, R.C.; Verdonschot, P.F.M.

    2004-01-01

    Models are needed for forecasting the effects of eutrophication on stream and river ecosystems. Most of the current models do not include differences in local stream characteristics and effects on the biota. To define the most important variables that should be used in a stream eutrophication model,

  17. Responses of aquatic ecosystems to environmental changes in Finland and China

    OpenAIRE

    Jan eWeckström; Mengna eLiao; Ge eYu; Susanne eAmsinck; Tommi eKauppila; Boqjang eQin; Guangwei eZhu; Jouko eSarvala; Kaarina eWeckström; Marjo eTarvainen; Teija eKirkkala; Leena eNurminen; Anne-Mari eVentelä

    2015-01-01

    The concern for the state of global freshwater reservoirs has increased due to deterioration of the water quality during the last decades. This has prompted monitoring and restoration efforts such as the European Water Framework Directive and the national-scale 2nd-investigation and monitoring of the water quality, water volume and biota resources in China. The challenge so far has been the determination of the “natural” state (reference conditions) of freshwater ecosystems. We used the sedim...

  18. Radial oxygen loss from roots of Vallisneria spiralis L.: biogeochemical implications in eutrophic aquatic ecosystems

    OpenAIRE

    Soana, Elisa

    2013-01-01

    Eutrophication and the accumulation of organic matter have been addressed as the major factors determining the decline of benthic vegetation in impacted water bodies and the consequent loss of key ecosystemic functions. In freshwater environments the literature reports submersed macrophyte die-back events and the switch to free-floating and floating-leaved plants dominated states. Species-specific differences in macrophyte response along organic gradients are evident. Some species have develo...

  19. Cyanobacteria and Cyanotoxins: From Impacts on Aquatic Ecosystems and Human Health to Anticarcinogenic Effects

    Directory of Open Access Journals (Sweden)

    Giliane Zanchett

    2013-10-01

    Full Text Available Cyanobacteria or blue-green algae are among the pioneer organisms of planet Earth. They developed an efficient photosynthetic capacity and played a significant role in the evolution of the early atmosphere. Essential for the development and evolution of species, they proliferate easily in aquatic environments, primarily due to human activities. Eutrophic environments are conducive to the appearance of cyanobacterial blooms that not only affect water quality, but also produce highly toxic metabolites. Poisoning and serious chronic effects in humans, such as cancer, have been described. On the other hand, many cyanobacterial genera have been studied for their toxins with anticancer potential in human cell lines, generating promising results for future research toward controlling human adenocarcinomas. This review presents the knowledge that has evolved on the topic of toxins produced by cyanobacteria, ranging from their negative impacts to their benefits.

  20. Cyanobacteria and cyanotoxins: from impacts on aquatic ecosystems and human health to anticarcinogenic effects.

    Science.gov (United States)

    Zanchett, Giliane; Oliveira-Filho, Eduardo C

    2013-10-23

    Cyanobacteria or blue-green algae are among the pioneer organisms of planet Earth. They developed an efficient photosynthetic capacity and played a significant role in the evolution of the early atmosphere. Essential for the development and evolution of species, they proliferate easily in aquatic environments, primarily due to human activities. Eutrophic environments are conducive to the appearance of cyanobacterial blooms that not only affect water quality, but also produce highly toxic metabolites. Poisoning and serious chronic effects in humans, such as cancer, have been described. On the other hand, many cyanobacterial genera have been studied for their toxins with anticancer potential in human cell lines, generating promising results for future research toward controlling human adenocarcinomas. This review presents the knowledge that has evolved on the topic of toxins produced by cyanobacteria, ranging from their negative impacts to their benefits.

  1. Cyanobacteria and Cyanotoxins: From Impacts on Aquatic Ecosystems and Human Health to Anticarcinogenic Effects

    Science.gov (United States)

    Zanchett, Giliane; Oliveira-Filho, Eduardo C.

    2013-01-01

    Cyanobacteria or blue-green algae are among the pioneer organisms of planet Earth. They developed an efficient photosynthetic capacity and played a significant role in the evolution of the early atmosphere. Essential for the development and evolution of species, they proliferate easily in aquatic environments, primarily due to human activities. Eutrophic environments are conducive to the appearance of cyanobacterial blooms that not only affect water quality, but also produce highly toxic metabolites. Poisoning and serious chronic effects in humans, such as cancer, have been described. On the other hand, many cyanobacterial genera have been studied for their toxins with anticancer potential in human cell lines, generating promising results for future research toward controlling human adenocarcinomas. This review presents the knowledge that has evolved on the topic of toxins produced by cyanobacteria, ranging from their negative impacts to their benefits. PMID:24152991

  2. Assessing the impacts of water abstractions on river ecosystem services: an eco-hydraulic modelling approach

    Energy Technology Data Exchange (ETDEWEB)

    Carolli, Mauro, E-mail: mauro.carolli@unitn.it; Geneletti, Davide, E-mail: davide.geneletti@unitn.it; Zolezzi, Guido, E-mail: guido.zolezzi@unitn.it

    2017-03-15

    The provision of important river ecosystem services (ES) is dependent on the flow regime. This requires methods to assess the impacts on ES caused by interventions on rivers that affect flow regime, such as water abstractions. This study proposes a method to i) quantify the provision of a set of river ES, ii) simulate the effects of water abstraction alternatives that differ in location and abstracted flow, and iii) assess the impact of water abstraction alternatives on the selected ES. The method is based on river modelling science, and integrates spatially distributed hydrological, hydraulic and habitat models at different spatial and temporal scales. The method is applied to the hydropeaked upper Noce River (Northern Italy), which is regulated by hydropower operations. We selected locally relevant river ES: habitat suitability for the adult marble trout, white-water rafting suitability, hydroelectricity production from run-of-river (RoR) plants. Our results quantify the seasonality of river ES response variables and their intrinsic non-linearity, which explains why the same abstracted flow can produce different effects on trout habitat and rafting suitability depending on the morphology of the abstracted reach. An economic valuation of the examined river ES suggests that incomes from RoR hydropower plants are of comparable magnitude to touristic revenue losses related to the decrease in rafting suitability.

  3. Assessing the impacts of water abstractions on river ecosystem services: an eco-hydraulic modelling approach

    International Nuclear Information System (INIS)

    Carolli, Mauro; Geneletti, Davide; Zolezzi, Guido

    2017-01-01

    The provision of important river ecosystem services (ES) is dependent on the flow regime. This requires methods to assess the impacts on ES caused by interventions on rivers that affect flow regime, such as water abstractions. This study proposes a method to i) quantify the provision of a set of river ES, ii) simulate the effects of water abstraction alternatives that differ in location and abstracted flow, and iii) assess the impact of water abstraction alternatives on the selected ES. The method is based on river modelling science, and integrates spatially distributed hydrological, hydraulic and habitat models at different spatial and temporal scales. The method is applied to the hydropeaked upper Noce River (Northern Italy), which is regulated by hydropower operations. We selected locally relevant river ES: habitat suitability for the adult marble trout, white-water rafting suitability, hydroelectricity production from run-of-river (RoR) plants. Our results quantify the seasonality of river ES response variables and their intrinsic non-linearity, which explains why the same abstracted flow can produce different effects on trout habitat and rafting suitability depending on the morphology of the abstracted reach. An economic valuation of the examined river ES suggests that incomes from RoR hydropower plants are of comparable magnitude to touristic revenue losses related to the decrease in rafting suitability.

  4. How sulfate-rich mine drainage affected aquatic ecosystem degradation in northeastern China, and potential ecological risk.

    Science.gov (United States)

    Zhao, Qian; Guo, Fen; Zhang, Yuan; Ma, Shuqin; Jia, Xiaobo; Meng, Wei

    2017-12-31

    Mining activity is an increasingly important stressor for freshwater ecosystems. However, the mechanism on how sulfate-rich mine drainage affects freshwater ecosystems is largely unknown, and its potential ecological risk has not been assessed so far. During 2009-2016, water and macroinvertebrate samples from 405 sample sites were collected along the mine drainage gradient from circum-neutral to alkaline waters in Hun-Tai River, Northeastern China. Results of linear regressions showed that sulfate-rich mine drainage was significantly positively correlated with the constituents typically derived from rock weathering (Ca 2+ , Mg 2+ and HCO 3 - +CO 3 2- ); the diversity of intolerant stream macroinvertebrates exhibited a steep decline along the gradient of sulfate-rich mine drainage. Meanwhile, stressor-response relationships between sulfate-rich mine drainage and macroinvertebrate communities were explored by two complementary statistical approaches in tandem (Threshold Indicator Taxa Analysis and the field-based method developed by USEPA). Results revealed that once stream sulfate concentrations in mine drainage exceeded 35mg/L, significant decline in the abundance of intolerant macroinvertebrate taxa occurred. An assessment of ecological risk posed by sulfate-rich mine drainage was conducted based on a tiered approach consisting of simple deterministic method (Hazard Quotient, HQ) to probabilistic method (Joint Probability Curve, JPC). Results indicated that sulfate-rich mine drainage posed a potential risk, and 64.62-84.88% of surface waters in Hun-Tai River exist serious risk while 5% threshold (HC 05 ) and 1% threshold (HC 01 ) were set up to protect macroinvertebrates, respectively. This study provided us a better understanding on the impacts of sulfate-rich mine drainage on freshwater ecosystems, and it would be helpful for future catchment management to protect streams from mining activity. Copyright © 2017. Published by Elsevier B.V.

  5. Nitrogen metabolism of the eutrophic Delaware River ecosystem

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    A comprehensive investigation of the nitrogen cycle in the Delaware River was carried out using 13 N tracers to measure rates for important transformations of nitrogen. Daily, depth-averaged 15 N rates for the principal inorganic nitrogen species were consistent with rates derived from longitudinal profiles of concentration in the river. The data indicated that nitrification was a rapid, irreversible sink for NH 4 + , with export of the product NO 3 - from the study area. Utilization of NO 3 - by primary producers was negligible, owing to low irradiance levels and to high NH 4 + concentrations. The oxygen sag near Philadelphia was found to result from oxygen demand in the water column, with only minor benthic influence. Reaeration provided the major oxygen input. Nitrification accounted for about 1% of the net oxygen demand near Philadelphia but as much as 25% farther downstream

  6. Another unique river: a consideration of some of the characteristics of the trunk tributaries of the Nile River in northwestern Ethiopia in relationship to their aquatic food resources.

    Science.gov (United States)

    Kappelman, John; Tewabe, Dereje; Todd, Lawrence; Feseha, Mulugeta; Kay, Marvin; Kocurek, Gary; Nachman, Brett; Tabor, Neil; Yadeta, Meklit

    2014-12-01

    Aquatic food resources are important components of many modern human hunter-gatherer diets and yet evidence attesting to the widespread exploitation of this food type appears rather late in the archaeological record. While there are times when, for example, the capture of fish and shellfish requires sophisticated technology, there are other cases when the exact ecological attributes of an individual species and the particulars of its environment make it possible for these foods to be incorporated into the human diet with little or no tool use and only a minimal time investment. In order to better understand the full set of variables that are considered in these sorts of foraging decisions, it is necessary to detail the attributes of each particular aquatic environment. We discuss here some of the characteristics of the trunk tributaries of the Nile and Blue Rivers in the Horn of Africa. Unlike typical perennial rivers, these 'temporary' rivers flow only during a brief but intense wet season; during the much longer dry season, the rivers are reduced to a series of increasingly disconnected waterholes, and the abundant and diverse fish and mollusk populations are trapped in ever smaller evaporating pools. The local human population today utilizes a number of diverse capture methods that range from simple to complex, and vary according to the size and depth of the waterhole and the time of the year. When we view the particular characteristics of an individual river system, we find that each river is 'unique' in its individual attributes. The Horn of Africa is believed to be along the route that modern humans followed on their migration out of Africa, and it is likely that the riverine-based foraging behaviors of these populations accompanied our species on its movement into the rest of the Old World. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Aquatic pathway 2

    International Nuclear Information System (INIS)

    1977-01-01

    This third part of the investigation discusses the preliminary results of sub-investigations concerning problems of the release of radioactive substances into the environment via the water pathway. On the basis of papers on the emission into the draining ditch and the exchange processes there, investigations of a possible incorporation via different exposure pathways are reported. Special regard is paid to drinking water supply aquatic foodstuffs, the river sediment, the utilisation of the agricultural surfaces and the draining ditch including its pre-pollution. The dynamics of contamination processes is reported on with regard to the problem of accidents. The colloquium will give an outline of the progress made so far and admit participants' suggestions for further work on the sub-investigations. The following colloquia will report further findings, in particular effects on aquatic ecosystems. (orig.) [de

  8. Impact of river basin management on coastal water quality and ecosystem services: A southern Baltic estuary

    Science.gov (United States)

    Schernewski, Gerald; Hürdler, Jens; Neumann, Thomas; Stybel, Nardine; Venohr, Markus

    2010-05-01

    Eutrophication management is still a major challenge in the Baltic Sea region. Estuaries or coastal waters linked to large rivers cannot be managed independently. Nutrient loads into these coastal ecosystems depend on processes, utilisation, structure and management in the river basin. In practise this means that we need a large scale approach and integrated models and tools to analyse, assess and evaluate the effects of nutrient loads on coastal water quality as well as the efficiency of river basin management measures on surface waters and especially lagoons and estuaries. The Odra river basin, the Szczecin Lagoon and its coastal waters cover an area of about 150,000 km² and are an eutrophication hot-spot in the Baltic region. To be able to carry out large scale, spatially integrative analyses, we linked the river basin nutrient flux model MONERIS to the coastal 3D-hydrodynamic and ecosystem model ERGOM. Objectives were a) to analyse the eutrophication history in the river basin and the resulting functional changes in the coastal waters between early 1960's and today and b) to analyse the effects of an optimal nitrogen and phosphorus management scenario in the Oder/Odra river basin on coastal water quality. The models show that an optimal river basin management with reduced nutrient loads (e.g. N-load reduction of 35 %) would have positive effects on coastal water quality and algae biomass. The availability of nutrients, N/P ratios and processes like denitrification and nitrogen-fixation would show spatial and temporal changes. It would have positive consequences for ecosystems functions, like the nutrient retention capacity, as well. However, this optimal scenario is by far not sufficient to ensure a good coastal water quality according to the European Water Framework Directive. A "good" water quality in the river will not be sufficient to ensure a "good" water quality in the coastal waters. Further, nitrogen load reductions bear the risk of increased

  9. Toxicological assessment of aquatic ecosystems: application to watercraft contaminants in shallow water environments

    Science.gov (United States)

    Winger, P.V.; Kemmish, Michael J.

    2002-01-01

    Recreational boating and personal watercraft use have the potential to adversely impact shallow water systems through contaminant release and physical disturbance of bottom sediments. These nearshore areas are often already degraded by surface runoff, municipal and industrial effluents, and other anthropogenic activities. For proper management, information is needed on the level of contamination and environmental quality of these systems. A number of field and laboratory procedures can be used to provide this much needed information. Contaminants, such as metals, pesticides, polychlorinated biphenyls and polycyclic aromatic hydrocarbons, entering aquatic environments generally attach to particulate matter that eventually settles and becomes incorporated into the bottom sediments. Because bottom sediments serve as a sink and as a source for contaminants, environmental assessments generally focus on this matrix. While contaminant residues in sediments and sediment pore waters can reflect environmental quality, characteristics of sediment (redox potential, sediment/pore-water chemistry, acid volatile sulfides, percent organic matter, and sediment particle size) influence their bioavailability and make interpretation of environmental significance difficult. Comparisons of contaminant concentrations in pore water (interstitial water) and sediment with water quality criteria and sediment quality guidelines, respectively, can provide insight into potential biological effects. Laboratory bioaccumulation studies and residue concentrations in resident or caged biota also yield information on potential biological impacts. The usefulness of these measurements may increase as data are developed relating in-situ concentrations, tissue residue levels, and biological responses. Exposure of test organisms in situ or to field-collected sediment and pore water are additional procedures that can be used to assess the biological effects of contaminants. A battery of tests using multi

  10. Preliminary assessment of the aquatic impacts of a proposed defense waste processing facility at the Savannah River Plant

    Energy Technology Data Exchange (ETDEWEB)

    Mackey, H.E. Jr.

    1979-01-01

    A review of the literature indicates that a significant body of descriptive information exists concerning the aquatic ecology of Upper Three Runs Creek and Four Mile Creek of the Savannah River Plant south of Aiken, South Carolina. This information is adequate for preparation of an environmental document evaluating these streams. These streams will be impacted by construction and operation of a proposed Defense Waste Processing Facility for solidification of high level defense waste. Potential impacts include (1) construction runoff, erosion, and siltation, (2) effluents from a chemical and industrial waste treatment facility, and (3) radionuclide releases. In order to better evaluate potential impacts, recommend mitigation methods, and comply with NEPA requirements, additional quantitative biological information should be obtained through implementation of an aquatic baseline program.

  11. Preliminary assessment of the aquatic impacts of a proposed defense waste processing facility at the Savannah River Plant

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.

    1979-01-01

    A review of the literature indicates that a significant body of descriptive information exists concerning the aquatic ecology of Upper Three Runs Creek and Four Mile Creek of the Savannah River Plant south of Aiken, South Carolina. This information is adequate for preparation of an environmental document evaluating these streams. These streams will be impacted by construction and operation of a proposed Defense Waste Processing Facility for solidification of high level defense waste. Potential impacts include (1) construction runoff, erosion, and siltation, (2) effluents from a chemical and industrial waste treatment facility, and (3) radionuclide releases. In order to better evaluate potential impacts, recommend mitigation methods, and comply with NEPA requirements, additional quantitative biological information should be obtained through implementation of an aquatic baseline program

  12. Distribution of C, N, P in aquatic plants of some lakes in the middle of Yangtze river

    International Nuclear Information System (INIS)

    Huang Liang; Wu Ying; Zhou Juzhen; Zhang Jing; Li Wei

    2003-01-01

    By analyzing three elements (C, N, P, 13 C) in the ten aquatic plants of nine lakes in the middle of Yangtze River, the concentrations of C, N and δ 13 C in leaves of aquatic macrophytes depend on the environment where they live in. The concentration of C and N in leaves of submerged macrophytes is significantly lower than that of leaves of floating and emergent macrophytes because of limitation of inorganic carbon; And at the same time, because δ 13 C of inorganic carbon in water is higher than that of CO 2 in air, δ 13 C of leaves of submerged macrophytes is higher than that of leaves of floating and emergent macrophytes. (authors)

  13. Flow regime alterations under changing climate in two river basins: Implications for freshwater ecosystems

    Science.gov (United States)

    Gibson, C.A.; Meyer, J.L.; Poff, N.L.; Hay, L.E.; Georgakakos, A.

    2005-01-01

    We examined impacts of future climate scenarios on flow regimes and how predicted changes might affect river ecosystems. We examined two case studies: Cle Elum River, Washington, and Chattahoochee-Apalachicola River Basin, Georgia and Florida. These rivers had available downscaled global circulation model (GCM) data and allowed us to analyse the effects of future climate scenarios on rivers with (1) different hydrographs, (2) high future water demands, and (3) a river-floodplain system. We compared observed flow regimes to those predicted under future climate scenarios to describe the extent and type of changes predicted to occur. Daily stream flow under future climate scenarios was created by either statistically downscaling GCMs (Cle Elum) or creating a regression model between climatological parameters predicted from GCMs and stream flow (Chattahoochee-Apalachicola). Flow regimes were examined for changes from current conditions with respect to ecologically relevant features including the magnitude and timing of minimum and maximum flows. The Cle Elum's hydrograph under future climate scenarios showed a dramatic shift in the timing of peak flows and lower low flow of a longer duration. These changes could mean higher summer water temperatures, lower summer dissolved oxygen, and reduced survival of larval fishes. The Chattahoochee-Apalachicola basin is heavily impacted by dams and water withdrawals for human consumption; therefore, we made comparisons between pre-large dam conditions, current conditions, current conditions with future demand, and future climate scenarios with future demand to separate climate change effects and other anthropogenic impacts. Dam construction, future climate, and future demand decreased the flow variability of the river. In addition, minimum flows were lower under future climate scenarios. These changes could decrease the connectivity of the channel and the floodplain, decrease habitat availability, and potentially lower the ability

  14. Radionuclide distribution and transport in terrestrial and aquatic ecosystems. A critical review of data

    International Nuclear Information System (INIS)

    Coughtrey, P.J.; Jackson, D.; Jones, C.H.; Thorne, M.C.

    1984-01-01

    These volumes present the results of a study undertaken for the Commission of the European Communities. The aim was to review available data concerning the movement of radionuclides through the environment and to recommend values of parameters for use in environmental transport models. The elements reviewed all have radioactive isotopes which could contribute significantly to the radiological impact of chronic releases of radioactivity from nuclear installations within the countries of the European community, i.e. the major activation and fission products. In dividing these elements between volumes an effort has been made to take account of the method of production of their major radioisotopes, together with their chemical similarities and environmental interactions. This volume covers the radionuclide distribution of americium and curium. The main areas which are covered include the deposition of radionuclides on plants and soils, transport in soils, uptake and translocation in plants via the roots and foliage, metabolism in domestic animals and radionuclide transfers through the main physical and biotic components of the aquatic environment. In reviewing these subject areas, account has been taken not only of the literature relating to specific radionuclides, but also of the literature relating to the stable element of which they are radioisotopes. (Auth.)

  15. CEDEX research activities in Antarctica. Aquatic ecosystems in Byers Peninsula (Livingston Island, maritime Antarctica)

    International Nuclear Information System (INIS)

    Toro, M.; Quesada, A.; Camacho, A.; Oliva, M.; Alcami, A.; Antoniades, D.; Banon, M.; Fassnacht, S.; Fernandez-Valiente, E.; Galan, L.; Giralt, S.; Granados, I.; Justel, A.; Liu, E. J.; Lopez-Bravo, A.; Martinez-Cortizas, A.; Pla-Rabes, S.; Rastrojo, A.; Rico, E.; Rochera, C.; Van de Vijver, B.; Velazquez, D.; Villaescusa, J. A.; Vicent, W. F.

    2015-01-01

    Since 2001 CEDEX has taken part in many Antarctic joint research projects with different institutions from Spain and other countries, developing scientific activities in the International Camp of Byers Peninsular (Livingston Island, South Shetland Islands, Antarctica). This place was designed as an Antarctic Specially Protected Area (No.126) because the importance and value of its terrestrial and aquatic habitats. It is one of the largest ice-free areas of maritime Antarctica, with the highest diversity of environments and geological, hydrological and biological processes in the whole region, all of them in a pristine state. Byers Peninsula is considered the most significant limnological area in the Antarctic Peninsula region because it hosts a high number of lakes, ponds and streams, with an exceptional fauna and flora diversity, including the most singular, representative or endemic Antarctic species. Furthermore, the lakes sedimentary record is one of the widest and complete archives in Antarctic Peninsula region for the palaeocological and climatic study of the Holocene. Because Byers Peninsula is an Antarctic biodiversity hotspot, and it is located in one of the areas in the Earth where global warming is being more significant, it must be considered as a suitable international reference site for limnetic, terrestrial and coastal studies, and long term monitoring programmes. (Author)

  16. The impact of systematic landscape conservation planning on ecosystem: Chen Youlan river watershed

    Science.gov (United States)

    Chen, Chi-ju

    2017-04-01

    Heraclitus said that "no man ever steps in the same river twice." Everything continues to change. Land use change will keep redefine itself and subject the Earth and humankind to collateral changes. Humankind benefits from ecosystem in many ways. The ecosystem provides people with nutrients, enriches soil with sediment, and sustains all living organisms with water; these benefits are known as ecosystem services. In Taiwan, land use change has impacted ecosystem and biodiversity on various levels. Thus, we took six land use scenarios from 1999 to 2005 in Chen Youlan river watershed as our case study, intending to observe the course of ecosystem and biodiversity changes and the cause of it. Systematic Landscape conservation planning (SLCP) framework can be adopted when designing land use policy to safeguard human interests and ecosystem. This study use SLCP to develop ecosystem services and biodiversity protection strategies. Several strategies were designed by using 1999 to 2005 data as provision to protect the intactness of future ecosystem services and biodiversity. This research explores the potential and possible impacts of different land use protection strategies in the future. It is possible to identify the conservation priority of a certain region by using the Zonation meta-algorithm. This study selects the zonation critical protection area (Joint set of Yushan National Park) as strategy A, B and C. Strategy D takes Yushan National Park as a protected area; unstable hot spots in 1999/03 (Joint set of Yushan National Park) are selected as strategy E. Next, we used Kappa statistical method to find the minimal ecosystem services change and biodiversity hotspots change of the five aforementioned strategies and compared with those from 1999/03. By the Kappa statistical method, we further prioritized the important conservation areas by strategy A, B, C, E in the future. The results can not only serve as management reference for government agencies, but also develop

  17. Development of criteria for an ecotoxicological examination procedure by differentially high integrated parts of aquatic model ecosystems and mathematical models. Final report

    International Nuclear Information System (INIS)

    Huber, W.; Zieris, F.J.; Lay, J.P.; Weiss, K.; Brueggemann, R.; Benz, J.

    1994-01-01

    It is difficult to assess the risks of environmental toxicants, especially when they have to be extrapolated from laboratory datas. Therefore efforts are made to determine the potential hazards of chemicals with the help of artificial ecosystems or parts of them. These kinds of test systems are similar to the structure and function of natural ecosystems and therefore allow to make representative extrapolations to real nature. As a disadvantage they are expensive and not yet standardized. To be accepted for the risk assessment of chemicals it was attempted to standardize artificial aquatic ecosystems in this project. It was tried to minimize the costs of the testing procedures by using a mathematical model simulating artificial littoral ecosystems. With increasing complexity of the system a better description of expected effects caused by a substance in environment can be given. With the help of outdoor ecosystems the threshold concentration of a chemical could be determined that is not likely to affect an aquatic ecosystem. Further we succeeded in providing a prototype modeling the effects in the microcosms used in our experiments. This model is able to approximately describe the behavior of macrophytes, algae, and secondary consumers in uncontaminated and contaminated systems (with the test chemical atrazine). (orig.) [de

  18. The effects of a pesticide mixture on aquatic ecosystems differing in trophic status: responses of the macrophyte Myriophyllum spicatum and the periphytic algal community.

    Science.gov (United States)

    Wendt-Rasch, L; Van den Brink, P J; Crum, S J H; Woin, P

    2004-03-01

    The effects of a pesticide mixture (asulam, fluazinam, lambda-cyhalothrin, and metamitron) on aquatic ecosystems were investigated in 20 outdoor aquatic microcosms. Ten of the microcosms simulated mesotrophic aquatic ecosystems dominated by submerged macrophytes (Elodea). The others simulated eutrophic ecosystems with a high Lemna surface coverage (Lemna). This paper describes the fate of the chemicals as well as their effects on the growth of Myriophyllum spicatum and the periphytic algal community. In the Elodea-dominated microcosms significant increase in the biomass and alterations of species composition of the periphytic algae were observed, but no effect on M. spicatum growth could be recorded in response to the treatment. The opposite was found in the Lemna-dominated microcosms, in which decreased growth of M. spicatum was observed but no alterations could be found in the periphytic community. In the Elodea-dominated microcosms the species composition of the periphytic algae diverged from that of the control following treatment with 0.5% spray drift emission of the label-recommended rate (5% for lambda-cyhalothrin), while reduced growth of M. spicatum in the Lemna-dominated microcosms was recorded at 2% drift (20% for lambda-cyhalothrin). This study shows that the structure of the ecosystem influences the final effect of pesticide exposure.

  19. The Economic Value of the Greater Montreal Blue Network (Quebec, Canada: A Contingent Choice Study Using Real Projects to Estimate Non-Market Aquatic Ecosystem Services Benefits.

    Directory of Open Access Journals (Sweden)

    Thomas G Poder

    Full Text Available This study used a contingent choice method to determine the economic value of improving various ecosystem services (ESs of the Blue Network of Greater Montreal (Quebec, Canada. Three real projects were used and the evaluation focused on six ESs that are related to freshwater aquatic ecosystems: biodiversity, water quality, carbon sequestration, recreational activities, landscape aesthetics and education services. We also estimated the value associated with the superficies of restored sites. We calculated the monetary value that a household would be willing to pay for each additional qualitative or quantitative unit of different ESs, and these marginal values range from $0.11 to $15.39 per household per unit. Thus, under certain assumptions, we determined the monetary values that all Quebec households would allocate to improve each ES in Greater Montreal by one unit. The most valued ES was water quality ($13.5 million, followed by education services ($10.7 million, recreational activities ($8.9 million, landscape aesthetics ($4.1 million, biodiversity ($1.2 million, and carbon sequestration ($0.1 million. Our results ascribe monetary values to improved (or degraded aquatic ecosystems in the Blue Network of Greater Montreal, but can also enhance economic analyses of various aquatic ecosystem restoration and management projects.

  20. The Economic Value of the Greater Montreal Blue Network (Quebec, Canada): A Contingent Choice Study Using Real Projects to Estimate Non-Market Aquatic Ecosystem Services Benefits.

    Science.gov (United States)

    Poder, Thomas G; Dupras, Jérôme; Fetue Ndefo, Franck; He, Jie

    2016-01-01

    This study used a contingent choice method to determine the economic value of improving various ecosystem services (ESs) of the Blue Network of Greater Montreal (Quebec, Canada). Three real projects were used and the evaluation focused on six ESs that are related to freshwater aquatic ecosystems: biodiversity, water quality, carbon sequestration, recreational activities, landscape aesthetics and education services. We also estimated the value associated with the superficies of restored sites. We calculated the monetary value that a household would be willing to pay for each additional qualitative or quantitative unit of different ESs, and these marginal values range from $0.11 to $15.39 per household per unit. Thus, under certain assumptions, we determined the monetary values that all Quebec households would allocate to improve each ES in Greater Montreal by one unit. The most valued ES was water quality ($13.5 million), followed by education services ($10.7 million), recreational activities ($8.9 million), landscape aesthetics ($4.1 million), biodiversity ($1.2 million), and carbon sequestration ($0.1 million). Our results ascribe monetary values to improved (or degraded) aquatic ecosystems in the Blue Network of Greater Montreal, but can also enhance economic analyses of various aquatic ecosystem restoration and management projects.

  1. Mapping ecosystem service dynamic in Wuyuer River watershed, Northeast China from 1954 to 2000

    Science.gov (United States)

    Huang, Fang; Wang, Ping; Li, Yanqing

    2007-06-01

    Wuyuer River watershed is one of concentrative and extensive distribution area of inland wetlands in China. Wetland ecosystem plays an important role in maintain the ecological functions in the region. Integrating topographic maps in 1954, Landsat MSS, TM/ETM imagery in 2000 and GIS, spatial-temporal pattern in land-use and ecosystem services in middle and lower Wuyuer River were analyzed in this paper. Results showed that area of marsh decreased from 56.04 ×10 4 ha to 32.04×10 4 ha, while the area of cropland increase 24.94×10 4 ha from 1954 to 2000. The annual loss rate of marsh was -1.48% (from 1954 to 1976) and -0.76% (from 1976 to 2000) respectively. Marsh land were turned into dry grassland and degraded to saline-alkalined land. The grassland decreased 40.26×104 ha dramatically for having been opened up to cropland and degraded into hardly-used land. Due to the negative effect of the decline in wetlands and grassland, total values of Middle and Lower Wuyur River's ecosystem services lost 66.10×10 8 RMB ¥ with an extent of 14.67% between 1954 and 2000. The highest ecosystem service value centralized in the middle area, and decreased gradually to surrounding regions.

  2. Orientating investigation to Polonium-210 and other radionuclides in Dutch aquatic ecosystems

    International Nuclear Information System (INIS)

    Koester, H.W.; Marwitz, P.A.; Berger, G.W.; Weers, A.W. van; Hagel, P.; Nieuwenhuize, J.

    1990-08-01

    In 1985/86 reconnaissance investigations were carried out of Po-210, Pb-210, Ra-226, Th-230 of the U-238 series, and of Th-232 and its daughter Th-228. In the lower reaches of the Rhine, Westerschelde, and Hoogoven(furnace)-channel concentrations were markedly elevated. The average Po-210 concentrations of these waters were between 3-4 Bq.m -3 dissolved in water, between 200-500 Bq.kg -1 in dry suspended matter, between 300-400 Bq.kg -1 in mussels dry matter. These elevated levels could be ascribed to emissions on these waters by the phosphate rock and iron-ore-processing industries. In bottom sediment of waterways or of docks close to these industries Pb-210 and Po-210 concentrations varied from 150 to 750 Bq.kg -1 dry sediment. The lowest average Po-210 concentrations were found in the Oosterschelde: 0.8 Bq.m -3 dissolved in water, 70 Bq.kg -1 in dry suspended matter, 100 Bq.kg -1 in mussels dry matter. It was found that several organisms incorporate Po-210 more strongly than the other natural radionuclides. Po-210 also contributes most to the radiation burden caused by the consumption of fish products, in particular mussels and shrimps. Consumption of 1 kg. a -1 of shrimps from the Oosterschelde or from the coastal area causes respectively a radiation exposure of 10 μSv.a -1 or 30 μSv.a -1 . This study points out the necessity for further studies of the emissions of Po-210 and other U-238 daughters and their dispersal and/or accumulation in the aquatic environment. Furthermore it is important to identify critical groups with respect to the radiation exposure caused by the consumption of mussels and other fish products, and the contribution to this radiation exposure by the industries. (author). 43 refs.; 58 figs.; 52 tabs

  3. Aquatic ecosystems of the lower Pecos drainage, October-December, 1980

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    Emphasis of work completed in 1980 was placed on analysis of macrobenthos and preparation of the dominant component, the Chironomidae (Diptera) for further study. One series of chironomid larvae was examined by scanning electron microscopy. The limnological survey techniques used during this study are the same as those described in earlier reports of work at the Los Medanos site by Sublette and Sublette. The Pecos River below Carlsbad is a severely perturbed stream. Human activity has resulted in the regulation of stream flow and nutrient enrichment from sewage effluents and return flow from fields adjacent to the river. Stream flow regulation is most noticeable below 10 Mile Dam near Loving where virtually all flow is diverted into irrigation ditches. Flow regulation minimizes the effects of spates (periods of high flow) resulting in reduced attachment sites for macrobenthos. A protracted period of no spates preceded the January 1978 sampling period and, as would be expected, numbers of taxa were reduced. After a period of heavy local flooding, a colonizer effect was observed in the composition of the January 1979 samples. By January of 1980, the fauna had returned essentially to the 1978 condition. A heavy saline inflow at Malaga Bend results in impoverished macrobenthos in terms of numbers of species and individuals. This is believed to result from both elevated salinity and heavy metals concentrations; a synergistic effect may exist. Slight variations in fish composition occur between up-stream, lower salinity stations and down-stream, higher salinity stations. Up-stream stations show greater diversity in fish populations

  4. Hazardous materials in aquatic environments of the Mississippi River Basin. Quarterly project status report, October 1, 1993--December 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-31

    This quarterly project status report discusses research projects being conducted on hazardous materials in aquatic environments of the Mississippi River basin. We continued to seek improvement in our methods of communication and interactions to support the inter-disciplinary, inter-university collaborators within this program. In addition to the defined collaborative research teams, there is increasing interaction among investigators across projects. Planning for the second year of the project has included the development of our internal request for proposals, and refining the review process for selection of proposals for funding.

  5. Aquatic macroinvertebrates of Batalha river reservoir for water captation and supply of the city of Bauru, SP, Brazil

    Directory of Open Access Journals (Sweden)

    Diana Calcidoni Moreira

    2009-08-01

    Full Text Available In this study the composition and diversity of aquatic macroinvertebrates were evaluated in the reservoir of water captation of Batalha river for treatment and supplying of the city of Bauru. The samples were collected in dry (from June to August, 2005 and rainy (from December, 2005 to February, 2006 seasons. We analyzed and identified 840 organisms belonging to 8 taxa in dry season and 4 taxa in rainy season. The system presented low abundance and diversity of macroinvertebrates probably due to the water quality and its physical and chemical variations associated with rain events.

  6. Evaluation of Daphnia ambigua for Routine Aquatic Toxicity Testing at the Savannah River Site

    International Nuclear Information System (INIS)

    Specht, W.L.; Harmon, S.M.

    1997-09-01

    Short-term whole effluent toxicity testing, which is currently a requirement of the U.S. EPA's National Pollution Discharge Elimination System (NPDES), commonly uses the cladoceran species Ceriodaphnia dubia. Despite the advantages to using a common test species to model the toxic effects of effluents, it could be argued that toxicity test results would be more meaningful if a wider variety of test organisms were commonly used. One particular argument against C. dubia is that tests conducted with this species do not always reflect local, site-specific conditions. The careful selection and use of an indigenous test species would produce a more realistic model of local instream effects and would account for regional differences in water quality. Permitted effluent discharges from Savannah River Site (SRS), a government weapons facility operated by the U.S. Department of Energy, require toxicity testing with C. dubia. However, water quality in these receiving streams is markedly different (lower pH and hardness) from standard laboratory water used for the culturing and testing of C. dubia, and it has been shown that this receiving water presents varying degrees of toxicity to C. dubia. Based on these results, it is possible that toxic effects observed during an effluent study could be the result of test organism stress from the dilution water and not the effects of SRS effluents. Therefore, this study addressed the substitution of C. dubia with an indigenous cladoceran species, Daphnia ambigua for routine regulatory testing at SRS. Given the indigenous nature of this species, combined with the fact that it has been successfully cultured by other investigators, D. ambigua was ideal for consideration as a replacement for C. dubia, but further study of the overall success and sensitivity of laboratory-reared D. ambigua was required. This investigation determined that D. ambigua could be laboratory cultured with only minimal changes to established regulatory protocol and

  7. Mercury in aquatic forage of large herbivores: impact of environmental conditions, assessment of health threats, and implications for transfer across ecosystem compartments.

    Science.gov (United States)

    Bergman, Brenda Gail; Bump, Joseph K

    2014-05-01

    Mercury (Hg) is a leading contaminant across U.S. water bodies, warranting concern for wildlife species that depend upon food from aquatic systems. The risk of Hg toxicity to large herbivores is little understood, even though some large herbivores consume aquatic vascular plants (macrophytes) that may hyper-accumulate Hg. We investigated whether total Hg and methylmercury (MeHg) in aquatic forage may be of concern to moose (Alces alces) and beaver (Castor canadensis) by measuring total Hg and MeHg concentrations, calculating sediment-water bioconcentration factors for macrophyte species these herbivores consume, and estimating herbivore daily Hg consumption. Abiotic factors impacting macrophyte Hg were assessed, as was the difference in Hg concentrations of macrophytes from glacial lakes and those created or expanded by beaver damming. The amount of aquatic-derived Hg that moose move from aquatic to terrestrial systems was calculated, in order to investigate the potential for movement of Hg across ecosystem compartments by large herbivores. Results indicate that the Hg exposure of generalist herbivores may be affected by macrophyte community composition more so than by many abiotic factors in the aquatic environment. Mercury concentrations varied greatly between macrophyte species, with relatively high concentrations in Utricularia vulgaris (>80 ng g(-1) in some sites), and negligible concentrations in Nuphar variegata (~6 ng g(-1)). Macrophyte total Hg concentration was correlated with water pH in predictable ways, but not with other variables generally associated with aquatic Hg concentrations, such as dissolved organic carbon. Moose estimated daily consumption of MeHg is equivalent to or below human reference levels, and far below wildlife reference levels. However, estimated beaver Hg consumption exceeds reference doses for humans, indicating the potential for sub-lethal nervous impairment. In regions of high moose density, moose may be ecologically important

  8. [Terrain gradient effect of ecosystem service value in middle reach of Yangtze River, China].

    Science.gov (United States)

    Yang, Suo Hua; Hu, Shou Geng; Qu, Shi Jin

    2018-03-01

    Using land use data in the year 1995, 2005 and 2014, this study estimated the ecosystem service value (ESV) in each county located in the middle reach of Yangtze River and analyzed its spatiotemporal variation features and terrain gradient effects based on "the equivalent value per unit area of ecosystem services in China". The results showed that ESV in the middle reach of Yangtze River was generally higher in mountainous area but lower in plain region, with an obvious terrain gradient effect. Specifically, the relationship of the relief degree of land surface (RDLS) and the ESV showed significant logarithm function at county scale with a high curve fitting degree of 0.53. The ESV increased from 400.35×10 4 yuan·km -2 to 554.57×10 4 yuan·km -2 with the increasing RDLS (grade 1-5) in 2014. During 1995-2004, the ecosystem service value variation changed from decreasing to stable with the increases of the RDLS. With a perspective of ecosystem service values, the value of food production and waste treatment service value decreased with the increase of the RDLS, while the others increased in general, such as the production of raw materials and gas regulation service value, because of the influences of dynamic land use structure in varied topography and distinct dominant ecosystem services from different land types.

  9. Hazardous materials in aquatic environments of the Mississippi River Basin Project management. Technical quarterly progress report, April 1, 1996--June 30, 1996

    Energy Technology Data Exchange (ETDEWEB)

    McLachlan, J.; Ide, C.F.; O`Connor, S.

    1996-08-01

    This quarterly report summarizes accomplishments for the Project examining hazardous materials in aquatic environments of the Mississippi River Basin. Among the many research areas summarized are the following: assessment of mechanisms of metal-induced reproductive toxicity in aquatic species as a biomarker of exposure; hazardous wastes in aquatic environment;ecological sentinels of aquatic contamination in the lower Mississippi River System; remediation of selected contaminants; rapid on-site immunassay for heavy metal contamination; molecular mechanisms of developmental toxicity induced by retinoids and retinoid-like molecules; resuseable synthetic membranes for the removal of aromatic and halogenated organic pollutants from waste water; Effects of steroid receptor activation in neurendocrine cell of the mammalian hypothalamus; modeling and assessment of environmental quality of louisiana bayous and swamps; enhancement of environmental education. The report also contains a summary of publications resulting from this project and an appendix with analytical core protocals and target compounds and metals.

  10. Continental-Scale Effects of Nutrient Pollution on Stream Ecosystem Functioning

    OpenAIRE

    Woodward , Guy; Gessner , Mark O.; Giller , Paul S.; Gulis , Vladislav; Hladyz , Sally; Lecerf , Antoine; Malmqvist , Björn; McKie , Brendan G.; Tiegs , Scott D.; Cariss , Helen; Dobson , Mike; Elosegi , Arturo; Ferreira , Veronica; Graça , Manuel A. S.; Fleituch , Tadeusz

    2012-01-01

    International audience; Excessive nutrient loading is a major threat to aquatic ecosystems worldwide that leads to profound changes in aquatic biodiversity and biogeochemical processes. Systematic quantitative assessment of functional ecosystem measures for river networks is, however, lacking, especially at continental scales. Here, we narrow this gap by means of a pan-European field experiment on a fundamental ecosystem process--leaf-litter breakdown--in 100 streams across a greater than 100...

  11. Diversity and abundance of aquatics macroinvertebrates and water quality from high and low watersheds of Gariche River, Chiriqui province, Republic of Panama

    International Nuclear Information System (INIS)

    Guinard, Johana del C; Rios, Tomas; Bernal Vega, Juan A

    2013-01-01

    Diversity and abundance of aquatic microinvertebrate and quality of water in four sampling stations located in Gariche river high and low watersheds, during the dry season (January to April) and the rainy season (July to October) of 2010, were determined using methods described by Pino and Bernal (2009). A total of 4 964 individuals, belonging to 50 genera, 30 families and nine orders of class Insecta were identified. The average of the Shannon-Weaver Diversity Index in the dry season was 2.36 and 1.95 in rainy season, representing a middle diversity in this ecosystem. In dry season, the abundance of individuals was higher in the order Hemiptera, family Veliidae, and genus Rhagovelia followed by Trichoptera, family Hydroptilidae, and genus Atanatolica. In rainy season, the most representative orders were Ephemeroptera, family Leptophlebiidae and genus Thraulodes, followed by Hemiptera, family Veliidae and genus Rhagovelia. The Jaccard Index indicated that the stations with the greatest similarity were 1 and 2, with a 65.2 % (dry season) and 76.9 % (rainy season), while the similarity was low between stations 1 and 3, with 33.3 % (dry season) and 41.7 % (rainy season). The Biotic Index BMWP/PAN for the dry and rainy seasons, indicated a regular water quality for stations 1 and 2, but with acceptable quality at stations 3 and 4. The physic and chemical variables showed values within acceptable limits during the dry season, while in the rainy season the levels were low, according to the values established by the primary environmental quality standards and quality levels for freshwater recreational use without direct contact, influencing in the heterogeneity of aquatic macroinvertebrates in each sampling station.

  12. USGS River Ecosystem Modeling: Where Are We, How Did We Get Here, and Where Are We Going?

    Science.gov (United States)

    Hanson, Leanne; Schrock, Robin; Waddle, Terry; Duda, Jeffrey J.; Lellis, Bill

    2009-01-01

    This report developed as an outcome of the USGS River Ecosystem Modeling Work Group, convened on February 11, 2008 as a preconference session to the second USGS Modeling Conference in Orange Beach, Ala. Work Group participants gained an understanding of the types of models currently being applied to river ecosystem studies within the USGS, learned how model outputs are being used by a Federal land management agency, and developed recommendations for advancing the state of the art in river ecosystem modeling within the USGS. During a break-out session, participants restated many of the recommendations developed at the first USGS Modeling Conference in 2006 and in previous USGS needs assessments. All Work Group recommendations require organization and coordination across USGS disciplines and regions, and include (1) enhancing communications, (2) increasing efficiency through better use of current human and technologic resources, and (3) providing a national infrastructure for river ecosystem modeling resources, making it easier to integrate modeling efforts. By implementing these recommendations, the USGS will benefit from enhanced multi-disciplinary, integrated models for river ecosystems that provide valuable risk assessment and decision support tools for adaptive management of natural and managed riverine ecosystems. These tools generate key information that resource managers need and can use in making decisions about river ecosystem resources.

  13. Aquatic insects associated to Eichhornia azurea (Schwartz Kunth in wetlands of Atrato River, Chocó - Colombia

    Directory of Open Access Journals (Sweden)

    Zuleyma Mosquera Murillo

    2018-03-01

    Full Text Available The objective of this study was to characterize the aquatic insect community associated with Eichhornia azurea (Schwartz Kunth in four swamp of the middle and lower basin of the Atrato river (Chocó-Colombia during high and low water periods; the influence of environmental and physicochemical variables on this community was also evaluated. For two months, aquatic insects associated with the roots of E. azurea were collected, using a quadrant of one m2, provided with a mesh of 0.5 mm, with three replicates per swamp and simultaneously measured some physical and chemical variables of the water. The community consisted of 6 orders, 21 families and 28 genera. The highest number of organisms (55.39% and of taxa (23 were recorded in the low water period. The most abundant orders were Ephemeroptera (37.55% and Coleoptera (26.77%, standing out the families Baetidae and Noteridae respectively; while the greatest taxonomic richness was for Coleoptera, Diptera and Hemiptera. There were no significant differences in diversity and dominance between hydrological periods (p> 0.05, but in the specific richness (p <0.05. The most abundant functional groups were predators (54.81% and collectors (43.70%. The physicochemical variables did not show significant differences between hydrological periods and there were associations between the aquatic entomofauna and the abiotic variables analyzed, mainly with dissolved oxygen, conductivity and total dissolved solids.

  14. Preservation of natural aquatic ecosystems by application of bottom coal ash based bioreactor for in situ treatment of anthropogenic effluents

    Science.gov (United States)

    Anker, Y.; Nisnevitch, M.; Tal, M.; Cahan, R.; Michael, E.

    2012-12-01

    One consequence of global climate change is recharge decrease at sub tropical and Mediterranean regions to both the surface and the ground fresh water resources. As a general rule, when water source quantity is reduced, the level of salination, as well as chemical and biological pollutants, tends to increase. The situation is more severe whenever the drainage basin is (a) heavily populated from urban, industrial and agricultural areas, (b) has wide areas of thin or non soil cover and (c) has a karstic structure and morphology. These latter conditions are typical to many regions around the Middle East; whereas pollution hazard to Mid Eastern streams is greater than to those in more humid regions owing to their relative small size and poor dilution capacity. The consequence of this ongoing and increasing anthropogenic pollution is endangerment of natural aquatic habitats and due to decrease in fresh water supply availability also to human sustainability. The ecological impact may involve transition of ephemeral (Wadi) streams into intermittent ones with the accompanied biodiversity change or extinction once the pollution is extreme. The impact on indigenous human communities might be as severe owing to drinking water quality decrease and the consequent decrease id quantity as well as damage to dryland farming. In setting of operations applied to the Yarkon Taninim watershed (central Israel) management, a pilot biofilter facility for sustainable preservation and rehabilitation of natural fluvial ecosystems was tested. This biofilter is planned to operate through low impact concept assimilating natural treatment processes occurring during runoff recharge through a porous flow media. The facility is constructed out of several grain sizes of bottom coal ash aggregate, which was found to be a better microbial mats growing stratum, compared to common natural aggregates such as tuff and lime pebbles (and also has an EPA directive for wastewater treatment). The biofilter is

  15. Nejayote produced at household level by Mayan women in Guatemala : is it a threat to aquatic ecosystems or a resource for food security?

    OpenAIRE

    Cifuentes de Gramajo, Luisa

    2011-01-01

    The aim of this study was to find out if nejayote produced at household level in Guatemala represents a threat to aquatic ecosystems and, if so, propose sustainable processing, reuse and disposal methods. First, all aspects related to nejayote production were explored. This study presents combined results from literature study on corn consumption and Guatemalan demography, a survey to Guatemalan women of all ethnical groups, nixtamalization replica and solids removal experiments and laborator...

  16. Comparing the Influence of Wildfire and Prescribed Burns on Watershed Nitrogen Biogeochemistry Using 15N Natural Abundance in Terrestrial and Aquatic Ecosystem Components

    Science.gov (United States)

    Stephan, Kirsten; Kavanagh, Kathleen L.; Koyama, Akihiro

    2015-01-01

    We evaluated differences in the effects of three low-severity spring prescribed burns and four wildfires on nitrogen (N) biogeochemistry in Rocky Mountain headwater watersheds. We compared paired (burned/unburned) watersheds of four wildfires and three spring prescribed burns for three growing seasons post-fire. To better understand fire effects on the entire watershed ecosystem, we measured N concentrations and δ15N in both the terrestrial and aquatic ecosystems components, i.e., soil, understory plants in upland and riparian areas, streamwater, and in-stream moss. In addition, we measured nitrate reductase activity in foliage of Spiraea betulifolia, a dominant understory species. We found increases of δ15N and N concentrations in both terrestrial and aquatic ecosystem N pools after wildfire, but responses were limited to terrestrial N pools after prescribed burns indicating that N transfer from terrestrial to aquatic ecosystem components did not occur in low-severity prescribed burns. Foliar δ15N differed between wildfire and prescribed burn sites; the δ15N of foliage of upland plants was enriched by 2.9 ‰ (difference between burned and unburned watersheds) in the first two years after wildfire, but only 1.3 ‰ after prescribed burns. In-stream moss δ15N in wildfire-burned watersheds was enriched by 1.3 ‰, but there was no response by moss in prescription-burned watersheds, mirroring patterns of streamwater nitrate concentrations. S. betulifolia showed significantly higher nitrate reductase activity two years after wildfires relative to corresponding unburned watersheds, but no such difference was found after prescribed burns. These responses are consistent with less altered N biogeochemistry after prescribed burns relative to wildfire. We concluded that δ15N values in terrestrial and aquatic plants and streamwater nitrate concentrations after fire can be useful indicators of the magnitude and duration of fire effects and the fate of post

  17. Radioactive contamination of aquatic organisms of the Yenisei river in the area affected by the activity of a Russian plutonium complex

    International Nuclear Information System (INIS)

    Bolsunovsky, A.; Sukovaty, A.

    2005-01-01

    The Yenisei River, one of the world's largest rivers, is contaminated with artificial radionuclides released by a Russian facility producing weapons-grade plutonium, which has been in operation for many years. The aim of the study conducted between 1997 and 2003 was to investigate accumulation of artificial radionuclides by aquatic organisms of the Yenisei River and to estimate the exposure dose rates to organisms from various sources. The aquatic plants sampled were of three species: Potamogeton lucens, Fontinalis antipyretica, and Ceratophyllum demersum. The gamma-spectrometric and radiochemical analysis of the samples of aquatic plants for artificial radionuclides has revealed more than 20 long-lived and short-lived radionuclides, including plutonium isotopes. The aquatic animal Phylolimnogammarus viridis and diatoms also contain artificial radionuclides. For most aquatic organisms under study, the dose received from the artificial irradiation is an order of magnitude higher than the dose received from natural irradiation. As Fontinalis antipyretica features the highest capacity to accumulate artificial radionuclides, it accumulates the largest artificial exposure does among the study aquatic organisms (up to 39 μGy/day)

  18. Additions to the aquatic diptera (Chaoboridae, Chironomidae, Culicidae, Tabanidae, Tipulidae) fauna of the White River National Wildlife Refuge, Arkansas

    Science.gov (United States)

    Chordas, Stephen W.; Hudson, Patrick L.; Chapman, Eric G.

    2004-01-01

    The dipteran fauna of Arkansas is generally poorly known. A previous study of the Aquatic macroinvertebrates of the White River National Wildlife Refuge, the largest refuge in Arkansas, reported only 12 diptera taxa out of 219 taxa collected (Chordas et al., 1996). Most of the dipterans from this study were identified only to the family level. The family Chironomidae is a large, diverse group and was predicted to be much more diverse in the refuge than indicated by previous studies. In this study, Chironomidae were targeted, with other aquatic or semiaquatic dipterans also retained, in collections designed to better define the dipteran fauna of the White River National Wildlife Refuge. Adult dipterans were collected from 22 sites within the refuge using sweep-nets, two types of blacklight traps, and lighted fan traps in June of 2001. Specimens from previous studies were retrieved and identified to the lowest possible taxonomic level. A total of 4,917 specimens representing 122 taxa was collected. The 122 taxa were comprised of the following: two chaoborids, 83 chironomids, 15 culicids, nine tabanids, and 13 tipulids. Of these, 46 species are new state records for Arkansas. Nine undescribed species of chironomids were collected, and eight species records represent significant range extensions.

  19. Ecosystem based river basin management planning in critical water catchment in Mongolia

    Science.gov (United States)

    Tugjamba, Navchaa; Sereeter, Erdenetuul; Gonchigjav, Sarantuya

    2014-05-01

    Developing the ecosystem based adaptation strategies to maintain water security in critical water catchments in Mongolia would be very significant. It will be base by reducing the vulnerability. "Ecosystem Based adaptation" is quite a new term in Mongolia and the ecosystem approach is a strategy for the integrated management of land, water and living resources that promotes conservation and sustainable use in an equitable way. To strengthen equitable economic development, food security, climate resilience and protection of the environment, the implementation of sustainable river basin management in critical water catchments is challenging in Mongolia. The Ulz river basin is considered one of the critical water catchments due to the temperature has increased by in average 1.30Ñ over the period 1976 to 2011. It is more intense than the global warming rate (0.740C/100 years) and a bit higher than the warming rate over whole Mongolia as well. From long-term observations and measurements it is clear that Ulz River has low water in a period of 1970-1980 and since the end of 1980s and middle of 1990s there were dominated years of the flood. However, under the influence of the global warming, climate changes of Mongolia and continuation of drought years with low water since the end of 1990s until today river water was sharply fallen and dried up. For the last ten years rivers are dried up and annual mean run-off is less by 3-5 times from long term mean value. The Ulz is the transboundary river basin and taking its origin from Ikh and Baga Burd springs on territory of Norovlin soum of Khentii province that flows through Khentii and Dornod provinces to the northeast, crossing the state border it flows in Baruun Tari located in Tari Lake concavity in Russia. Based on the integrative baseline study on the 'The Ulz River Basin Environmental and Socioeconomic condition', ecosystem based river basin management was planned. 'Water demand Calculator 3' (WDC) software was used to

  20. Successes, Failures and Suggested Future Directions for Ecosystem Restoration of the Middle Sacramento River, California

    OpenAIRE

    Gregory H. Golet; David L. Brown; Melinda Carlson; Thomas Gardali; Adam Henderson; Karen D. Holl; Christine A. Howell; Marcel Holyoak; John W. Hunt; G. Mathias Kondolf; Eric W. Larsen; Ryan A. Luster; Charles McClain; Charles Nelson; Seth Paine

    2013-01-01

    Large-scale ecosystem restoration projects seldom undergo comprehensive evaluation to determine project effectiveness. Consequently, there are missed opportunities for learning and strategy refinement. Before our study, monitoring information from California’s middle Sacramento River had not been synthesized, despite restoration having been ongoing since 1989. Our assessment was based on the development and application of 36 quantitative ecological indicators. These indicators were used to ch...

  1. Flow intermittence and ecosystem services in rivers of the Anthropocene_Figure 4_Journal of Applied Ecology

    Data.gov (United States)

    U.S. Environmental Protection Agency — Counts of ecosystem service status (provided, altered, and lost/absent) during three hydrological phases (flowing, pool, dry) typically seen in intermittent rivers...

  2. CDOM Distribution and Dynamics in a Mangrove Ecosystem along the Shark River, Florida Everglades

    Science.gov (United States)

    Andrew, A. A.; del Castillo, C. E.

    2016-02-01

    Mangrove forests, a fraction of tropical forest, are in general a disproportionately important component in the global carbon cycle. Mangroves are highly productive, sequestering CO2 at rates higher than many other ecosystems, however more than half of this fixed carbon cannot be accounted for. Additionally, as they sit at the intersection of land and ocean, it's hypothesized that a large fraction of DOC transformations occur in these ecosystems and represent a major sink of terrigenous DOM. These factors highlight the importance of understanding mangrove environments in terms of DOM optical signals as well as reactivity upon light absorption. Here, we present the CDOM dynamics and distribution for a mangrove ecosystem in the Shark River, along the Southwest coast of Florida, part of the largest contiguous mangrove forest in North America. Station sampling of the study area occurred over 4 cruises, approximately one week in length: October 2014, March 2015, July 2015 and September 2015. Most of the stations were along the Shark River, with a smaller number in the vicinity of Tarpon bay and Harney River. Optical measurements of CDOM absorption and fluorescence, fluorescence quantum yields, DOC and spectral slope were obtained for over 70 stations in the study area. The spatial distribution of these optical properties are presented including their relation to salinity and tidal patterns in the study area. Additionally, we present the wavelength dependent quantum photoproduction efficiencies of DIC obtained via irradiation experiments of selective samples in the study area.

  3. Species and biogeochemical cycles of organic phosphorus in sediments from a river with different aquatic plants located in Huaihe River Watershed, China.

    Science.gov (United States)

    Yuan, He Zhong; Pan, Wei; Ren, Li Jun; Liu, Eeng Feng; Shen, Ji; Geng, Qi Fang; An, Shu Qing

    2015-01-01

    The results of phosphorus fractionation in the sediments from a contaminated river containing different aquatic plants, analyzed by solution 31P-NMR for Organic Phosphorus, showed that the concentration of Inorganic Phosphorus dominated in all species and Organic Phosphorus accounted for over 20% of Total Phosphorus. In general, orthophosphate was dominant in all the sampling sites. The proportion of Organic Phosphorus accounting for the Total Phosphorus in the sediments with different plant decreased in the following order: Paspalum distichum>Typha orientalis>Hydrilla verticillata. Phosphorus-accumulation ability of Paspalum distichum was obviously stronger than Typha orientalis and Hydrilla verticillata. The Organic Phosphorus was in aquatic plants dominated by humic-associated P (Hu-P), which converted to Inorganic Ohosphorus more significantly in submerged plants than in emerged plants. The sediment dominated by Paspalum distichum abundantly accumulated Organic Phosphorus in the orthophosphate monoester fraction. The degradation and mineralization of orthophosphate monoester was the important source of high Inorganic Phosphorus concentration and net primary productivity in Suoxu River. The Organic Phosphorus derived from Typha orientalis and Hydrilla verticillata was dramatically converted to Inorganic Phosphorus when the environmental factors varied.

  4. Ecosystem Design Principles for Restoring Deltaic Floodplains: Examples from Mississippi River Delta

    Science.gov (United States)

    Twilley, R.

    2017-12-01

    The Mississippi River Deltaic Plain (MRDP) provides examples for many of the functions and feedbacks regarding how human river management has impacted source-sink processes in coastal deltaic basins, resulting in human settlements more at risk to flooding from coastal storms. The Atchafalaya Basin, with continued sediment delivery, compared to Terrebonne Basin, with reduced river inputs, allow us to test assumptions of how landward migration of fringe wetlands of coastal basins as result of river management over the last 75 years can provide insights to these complex issues. The average landward migration for Terrebonne Basin was nearly 17,000 m (17 km) compared to only 22 m in Atchafalaya Basin over the last 78 yrs (pmanagement decisions in deltaic coast. Restoration features focused on living shorelines may contribute to solutions to these non-linear feedbacks; but certain ecosystem design features have to be considered so such shorelines can adapt to relative sea level rise. Shorelines must have adaptive strategies compared to fixed hard structures - resulting on sediment management and redistribution as critical process to shoreline stabilization. Policies in US to encourage sediment placement associated with national dredge activities must be integrated to ecosystems services of fringe wetland restoration.

  5. Occurrence of perfluorinated compounds in the aquatic environment as found in science park effluent, river water, rainwater, sediments, and biotissues.

    Science.gov (United States)

    Lin, Angela Yu-Chen; Panchangam, Sri Chandana; Tsai, Yu-Ting; Yu, Tsung-Hsien

    2014-05-01

    The current article maps perfluoroalkyl acids (PFAAs) contamination in the largest Science Park of Taiwan. The occurrence of ten target PFAAs in the effluent of an industrial wastewater treatment plant (IWWTP), its receiving rivers, rainwater, sediment, and the muscles and livers of fish was investigated. All target PFAAs were found in effluent of IWWTP, in which perfluorooctane sulfonate (PFOS) (6,930 ng/L), perfluorohexyl sulfonate (PFHxS) (2,662 ng/L) and perfluorooctanoic acid (PFOA) (3,298 ng/L) were the major constituents. Concentrations of PFBS and PFOS in the IWWTP downstream areas have exceeded safe concentration levels of avian and aquatic life, indicating a potential risk to wildlife in those areas. In sediment samples, predominant contaminants were PFOS (1.5-78 ng/g), PFOA (0.5-5.6 ng/g), and perfluorododecanoic acid (PFDoA) (nd-5.4 ng/g). In biological tissue samples, concentrations as high as 28,933 ng/g of PFOS were detected in tilapia and catfish liver samples. A positive correlation for log (C sediment/C water) and log (C tissue/C water) was found. The concentration and proportion (percentage of all PFAAs) of PFOS found in biotissue samples from the Keya River (which receives industrial wastewater) were found to be much greater (200 times) than those of samples from the Keelung River (which receives mainly domestic wastewater). These findings suggest that the receiving aquatic environments and, in turn, the human food chain can be significantly influenced by industrial discharges.

  6. Exposure of coastal ecosystems to river plume spreading across a near-equatorial continental shelf

    Science.gov (United States)

    Tarya, A.; Hoitink, A. J. F.; Vegt, M. Van der; van Katwijk, M. M.; Hoeksema, B. W.; Bouma, T. J.; Lamers, L. P. M.; Christianen, M. J. A.

    2018-02-01

    The Berau Continental Shelf (BCS) in East Kalimantan, Indonesia, harbours various tropical marine ecosystems, including mangroves, seagrass meadows and coral reefs. These ecosystem are located partly within reach of the Berau River plume, which may affect ecosystem health through exposure to land-derived sediments, nutrients and pollutants carried by the plume. This study aims (1) to assess the exposure risk of the BCS coastal ecosystems to river plume water, measured as exposure time to three different salinity levels, (2) to identify the relationships between these salinity levels and the abundance and diversity of coral and seagrass ecosystems, and (3) to determine a suitable indicator for the impacts of salinity on coral reef and seagrass health. We analysed hydrodynamic models, classified salinity levels, and quantified the correlations between the salinity model parameters and ecological metrics for the BCS systems. An Empirical Orthogonal Functions (EOF) analysis revealed three modes of river plume dispersal patterns, which strongly reflect monsoon seasonality. The first mode, explaining 39% of the variability, was associated with the southward movement of the plume due to northerly winds, while the second and third modes (explaining 29% and 26% of the variability, respectively) were associated with the northeastward migration of the plume related to southwesterly and southerly winds. Exposure to low salinity showed higher correlations with biological indicators than mean salinity, indicating that low salinity is a more suitable indicator for coastal ecosystem health. Significant correlations (R2) were found between exposure time to low salinity (days with salinity values below 25 PSU) with coral cover, coral species richness, seagrass cover, the number of seagrass species, seagrass leaf phosphorus, nitrogen, C:N ratio and iron content. By comparing the correlation coefficients and the slopes of the regression lines, our study suggests that coral reefs are

  7. Pipe dream? Envisioning a grassroots Python ecosystem of open, common software tools and data access in support of river and coastal biogeochemical research (Invited)

    Science.gov (United States)

    Mayorga, E.

    2013-12-01

    Practical, problem oriented software developed by scientists and graduate students in domains lacking a strong software development tradition is often balkanized into the scripting environments provided by dominant, typically proprietary tools. In environmental fields, these tools include ArcGIS, Matlab, SAS, Excel and others, and are often constrained to specific operating systems. While this situation is the outcome of rational choices, it limits the dissemination of useful tools and their integration into loosely coupled frameworks that can meet wider needs and be developed organically by groups addressing their own needs. Open-source dynamic languages offer the advantages of an accessible programming syntax, a wealth of pre-existing libraries, multi-platform access, linkage to community libraries developed in lower level languages such as C or FORTRAN, and access to web service infrastructure. Python in particular has seen a large and increasing uptake in scientific communities, as evidenced by the continued growth of the annual SciPy conference. Ecosystems with distinctive physical structures and organization, and mechanistic processes that are well characterized, are both factors that have often led to the grass-roots development of useful code meeting the needs of a range of communities. In aquatic applications, examples include river and watershed analysis tools (River Tools, Taudem, etc), and geochemical modules such as CO2SYS, PHREEQ and LOADEST. I will review the state of affairs and explore the potential offered by a Python tool ecosystem in supporting aquatic biogeochemistry and water quality research. This potential is multi-faceted and broadly involves accessibility to lone grad students, access to a wide community of programmers and problem solvers via online resources such as StackExchange, and opportunities to leverage broader cyberinfrastructure efforts and tools, including those from widely different domains. Collaborative development of such

  8. An ecosystem services framework for multidisciplinary research in the Colorado River headwaters

    Science.gov (United States)

    Semmens, D.J.; Briggs, J.S.; Martin, D.A.

    2009-01-01

    A rapidly spreading Mountain Pine Beetle epidemic is killing lodgepole pine forest in the Rocky Mountains, causing landscape change on a massive scale. Approximately 1.5 million acres of lodgepoledominated forest is already dead or dying in Colorado, the infestation is still spreading rapidly, and it is expected that in excess of 90 percent of all lodgepole forest will ultimately be killed. Drought conditions combined with dramatically reduced foliar moisture content due to stress or mortality from Mountain Pine Beetle have combined to elevate the probability of large fires throughout the Colorado River headwaters. Large numbers of homes in the wildland-urban interface, an extensive water supply infrastructure, and a local economy driven largely by recreational tourism make the potential costs associated with such a fire very large. Any assessment of fire risk for strategic planning of pre-fire management actions must consider these and a host of other important socioeconomic benefits derived from the Rocky Mountain Lodgepole Pine Forest ecosystem. This paper presents a plan to focus U.S. Geological Survey (USGS) multidisciplinary fire/beetle-related research in the Colorado River headwaters within a framework that integrates a wide variety of discipline-specific research to assess and value the full range of ecosystem services provided by the Rocky Mountain Lodgepole Pine Forest ecosystem. Baseline, unburned conditions will be compared with a hypothetical, fully burned scenario to (a) identify where services would be most severely impacted, and (b) quantify potential economic losses. Collaboration with the U.S. Forest Service will further yield a distributed model of fire probability that can be used in combination with the ecosystem service valuation to develop comprehensive, distributed maps of fire risk in the Upper Colorado River Basin. These maps will be intended for use by stakeholders as a strategic planning tool for pre-fire management activities and can

  9. Relating metal bioavailability to risk assessment for aquatic species: Daliao River watershed, China

    International Nuclear Information System (INIS)

    Han, Shuping; Zhang, Ying; Masunaga, Shigeki; Zhou, Siyun; Naito, Wataru

    2014-01-01

    The spatial distribution of metal bioavailability (Ni, Cu, Zn, and Pb) was first evaluated within the waters of Daliao River watershed, using the diffusive gradient in thin films (DGT) and chemical equilibrium models. To assess potential risks associated with metal bioavailability, site-specific 95% protection levels (HC5), risk characterizations ratios (RCR) and ratios of DGT-labile/HC5 were derived, using species sensitivity distribution (SSD). The highest bioavailability values for metals were recorded in the main channel of the Daliao River, followed by the Taizi River. Dynamic concentrations predicted by WHAM 7.0 and NICA-Donnan for Cu and Zn agreed well with DGT results. The estuary of the Daliao River was found to have the highest risks related to Ni, Cu, and Zn. The number of sites at risk increased when considering the total toxicity of Ni, Cu, and Zn. - Highlights: • Spatial variation in metal bioavailability within Daliao River watershed was studied. • WHAM 7.0 and NICA-Donnan examined the differences in predicting metal speciation. • Bioavailability values of metals were highest in main channel of the Daliao River. • Site-specific 95% protection levels (HC5)/risk variations were assessed using SSD. • Maximum risks from Ni, Cu, and Zn occurred in the estuary of the Daliao River. - The highest bioavailability values and the highest risks of metals were found in the estuary of the Daliao River

  10. Linking benthic biodiversity to the functioning of coastal ecosystems subjected to river runoff (NW Mediterranean

    Directory of Open Access Journals (Sweden)

    Harmelin–Vivien, M. L.

    2009-12-01

    Full Text Available Continental particulate organic matter (POM plays a major role in the functioning of coastal marine ecosystems as a disturbance as well as an input of nutrients. Relationships linking continental inputs from the Rhone River to biodiversity of the coastal benthic ecosystem and fishery production were investigated in the Golfe du Lion (NW Mediterranean Sea. Macrobenthic community diversity decreased when continen¬tal inputs of organic matter increased, whereas ecosystem production, measured by common sole (Solea solea fishery yields in the area, increased. Decreases in macrobenthic diversity were mainly related to an increasing abundance of species with specific functional traits, particularly deposit-feeding polychaetes. The decrease in macrobenthic diversity did not result in a decrease, but an increase in ecosystem production, as it enhanced the transfer of continental POM into marine food webs. The present study showed that it is necessary to consider functional traits of species, direct and indirect links between species, and feedback loops to understand the effects of biodiversity on ecosystem functioning and productivity.

  11. Survey of patterns, levels, and trends of perfluorinated compounds in aquatic organisms and bird eggs from representative German ecosystems.

    Science.gov (United States)

    Rüdel, Heinz; Müller, Josef; Jürling, Heinrich; Bartel-Steinbach, Martina; Koschorreck, Jan

    2011-11-01

    Samples from the German Environmental Specimen Bank (ESB) covering particularly the years 1994-1996, 2000-2002, and 2006-2009 were analyzed for perfluorinated compounds (PFC; mainly C4-C13 carboxylic and sulfonic acids) to gain an overview on current PFC levels and patterns in marine, limnetic, and terrestrial biota; to assess their concentrations in different trophic levels; and to investigate whether risk management measures for PFC are successful. Specimens, either standardized annual pooled samples (blue mussels, eelpout liver, bream liver, pigeon eggs) or individual single samples (cormorant eggs, rook eggs), were collected for the German ESB program from representative sampling sites according to documented guidelines. After appropriate extraction, PFC were quantified under ISO/IEC 17025 accreditation by HPLC/MS-MS with isotopically labeled internal standards. Limits of quantification (LOQs) were 0.2-0.5 ng/g. Data are reported on a wet weight basis. In most samples the predominant PFC was perfluorooctane sulfonic acid (PFOS). However, in marine mussels from North and Baltic Seas, PFOS levels were mostly below the LOQ, but low residues of PFOS amide were found which declined in recent years. Livers of eelpout showed maximum concentrations of 15-25 ng/g PFOS in the period 2000-2002 and low amounts of perfluoropentanoate in all years. Beside PFOS (median 48 ng/g) several PFC could be determined in cormorant eggs sampled in 2009 from a Baltic Sea site. For a freshwater ecosystem, current PFC burdens for cormorant eggs were even higher (median 400 ng/g PFOS). Livers of bream from rivers showed concentrations of 130-260 ng/g PFOS, but for bream from a reference lake levels were only about 6 ng/g. In contrast to cormorants, eggs of rook and feral pigeon from terrestrial ecosystems displayed only low PFC burdens (up to 6 ng/g PFOS). Generally, PFC levels were lower in marine than in freshwater biota. PFC burdens were higher in biota from the ESB-North Sea sites than

  12. Multiproxy evidence for terrestrial and aquatic ecosystem responses during the 8.2 ka cold event as recorded at Højby Sø, Denmark

    DEFF Research Database (Denmark)

    Hede, Mikkel Ulfeldt; Rasmussen, Peter; Noe-Nygaard, Nanna

    2010-01-01

    ecosystems to the 8.2 ka cold event. A reduced pollen production by thermophilous deciduous tree taxa in the period c. 8250–8000 cal yr BP reveal that the forest ecosystem was affected by low temperatures during the summer and winter/early-spring seasons. This finding is consistent with the timing of the 8.......2 ka cold event as registered in the Greenland ice cores. At Højby Sø, the climate anomaly appears to have started 200–250 yr earlier than the 8.2 ka cold event as the lake proxy data provide strong evidence for a precipitation-induced distinct increase in catchment soil erosion beginning around 8500...... cal yr BP. Alteration of the terrestrial environment then resulted in a major aquatic ecosystem change with nutrient enrichment of the lake and enhanced productivity, which lasted until c. 7900 cal yr BP. Keywords: 8.2 ka cold event; Lake sediments; Palaeoclimate; Pollen; Macrofossils; Geochemistry...

  13. Integrated assessment of river health based on the conditions of water quality,aquatic life and physical habitat

    Institute of Scientific and Technical Information of China (English)

    MENG Wei; ZHANG Nan; ZHANG Yuan; ZHENG Binghui

    2009-01-01

    The health conditions of Liao River were assessed using 25 sampling sites in April 2005, with water quality index, biotic index and physical habitat quality index.Based on the method of cluster analysis (CA) for water quality indices, it reveals that heavily polluted sites of Liao River are located at estuary and mainstream.The aquatic species surveyed were attached algae and benthic invertebrates.The result shows that the diversity and biomass of attached algae and benthic index of biotic integrity (B-IBI) are degrading as the chemical and physical quality of water bodies deteriorating.Physiochemical parameters, BOD5, CODCr, TN, TP, NH3-N, DO, petroleum hydrocarbon and conductivity, were statistically analyzed with principal component analysis and correlation analysis.The statistical results were incorporated into the integrated assessing water quality index, combining fecal coliform count, attached algae diversity, B-IBI and physical habitat quality score, a comprehensive integrated assessing system of river ecological health was established.Based on the systimetic assesment, the assessed sites are categorized into 9 "healthy" and "sub-healthy" sites and 8 "sub-sick" and "sick" sites.

  14. Modeling of hydroecological feedbacks predicts distinct classes of landscape pattern, process, and restoration potential in shallow aquatic ecosystems

    Science.gov (United States)

    Larsen, Laurel G.; Harvey, Judson W.

    2011-01-01

    It is widely recognized that interactions between vegetation and flow cause the emergence of channel patterns that are distinct from the standard Schumm classification of river channels. Although landscape pattern is known to be linked to ecosystem services such as habitat provision, pollutant removal, and sustaining biodiversity, the mechanisms responsible for the development and stability of different landscape patterns in shallow, vegetated flows have remained poorly understood. Fortunately, recent advances have made possible large-scale models of flow through vegetated environments that can be run over a range of environmental variables and over timescales of millennia. We describe a new, quasi-3D cellular automata model that couples simulations of shallow-water flow, bed shear stresses, sediment transport, and vegetation dynamics in an efficient manner. That efficiency allowed us to apply the model widely in order to determine how different hydroecological feedbacks control landscape pattern and process in various types of wetlands and floodplains. Distinct classes of landscape pattern were uniquely associated with specific types of allogenic and autogenic drivers in wetland flows. Regular, anisotropically patterned wetlands were dominated by allogenic processes (i.e., processes driven by periodic high water levels and flow velocities that redistribute sediment), relative to autogenic processes (e.g., vegetation production, peat accretion, and gravitational erosion). These anistropically patterned wetlands are therefore particularly prone to hydrologic disturbance. Other classes of wetlands that emerged from simulated interactions included maze-patterned, amorphous, and topographically noisy marshes, open marsh with islands, banded string-pool sequences perpendicular to flow, parallel deep and narrow channels flanked by marsh, and ridge-and-slough patterned marsh oriented parallel to flow. Because vegetation both affects and responds to the balance between the

  15. Functional redundancy and sensitivity of fish assemblages in European rivers, lakes and estuarine ecosystems.

    Science.gov (United States)

    Teichert, Nils; Lepage, Mario; Sagouis, Alban; Borja, Angel; Chust, Guillem; Ferreira, Maria Teresa; Pasquaud, Stéphanie; Schinegger, Rafaela; Segurado, Pedro; Argillier, Christine

    2017-12-14

    The impact of species loss on ecosystems functioning depends on the amount of trait similarity between species, i.e. functional redundancy, but it is also influenced by the order in which species are lost. Here we investigated redundancy and sensitivity patterns across fish assemblages in lakes, rivers and estuaries. Several scenarios of species extinction were simulated to determine whether the loss of vulnerable species (with high propensity of extinction when facing threats) causes a greater functional alteration than random extinction. Our results indicate that the functional redundancy tended to increase with species richness in lakes and rivers, but not in estuaries. We demonstrated that i) in the three systems, some combinations of functional traits are supported by non-redundant species, ii) rare species in rivers and estuaries support singular functions not shared by dominant species, iii) the loss of vulnerable species can induce greater functional alteration in rivers than in lakes and estuaries. Overall, the functional structure of fish assemblages in rivers is weakly buffered against species extinction because vulnerable species support singular functions. More specifically, a hotspot of functional sensitivity was highlighted in the Iberian Peninsula, which emphasizes the usefulness of quantitative criteria to determine conservation priorities.

  16. Rivers and streams in the media: a content analysis of ecosystem services

    Directory of Open Access Journals (Sweden)

    Matthew A. Weber

    2017-09-01

    Full Text Available Although ecosystem services research has become common, few efforts are directed toward in-depth understanding of the specific ecological quantities people value. The theoretical framework of final ecosystem services focuses attention on such measurable attributes, as a common currency for social-ecological systems research. Environmental communications as well as ecological monitoring and analysis efforts could be enhanced through increased documentation of final ecosystem services. For example, small changes in the way ecosystems are described could strongly influence relevance to the public and improve the foundation for environmental decision making. Focusing on rivers and streams, we conducted a content analysis of existing publications to document the breadth and frequency with which various measurable attributes, such as flooding, water quality characteristics, and wildlife appeared in different news sources over a multiyear timeline. In addition to attributes, motivations for human interest in river-related resources were also coded, such as recreation or preservation for future generations. To allow testing of differences between materials written for different audiences, three sources were sampled: a blog hosted by National Geographic, New York Times articles, and Wall Street Journal articles. The coding approach was rigorously tested in a pilot phase, with measures developed to ensure high data quality, including use of two independent coders. Results show numerous similarities across sources with some notable differences in emphasis. Significant relationships between groups of attribute and motivation codes were also found, one outcome of which is further support for the importance of nonuse values for fish and wildlife. Besides offering insight on ecosystem services, the project demonstrates an in-depth quantitative approach to analyzing preexisting qualitative data.

  17. Reed beds may facilitate transfer of tributyltin from aquatic to terrestrial ecosystems through insect vectors in the Archipelago Sea, SW Finland.

    Science.gov (United States)

    Lilley, Thomas M; Meierjohann, Axel; Ruokolainen, Lasse; Peltonen, Jani; Vesterinen, Eero; Kronberg, Leif; Nikinmaa, Mikko

    2012-08-01

    Due to their adsorptive behavior, organotin compounds (OTCs), such as tributyltin (TBT), are accumulated in aquatic sediments. They resist biodegradation and, despite a ban in 2008, are a potential source for future exposure. Sediment OTCs have mostly been measured from sites of known high concentrations such as ports, shipping lanes, and marine dredging waste sites. The possible flow of OTCs from marine to terrestrial ecosystems, however, has not been studied. In the present study, the authors assessed whether sediments in common reed beds (Phragmites australis) accumulate TBT and whether chironomid (Diptera: Chironomidae) communities developing in reed-bed sediments act as vectors in the transfer of TBT from aquatic to terrestrial ecosystems in the Airisto channel, Archipelago Sea. The authors also investigated whether distance from the only known source and depth and TBT concentration of the adjacent shipping lane affect reed-bed concentrations. Thirty-six sites along the Airisto channel were sampled at 2-km intervals with triplicate samples from reed beds and the adjacent shipping lane for sediment and seven reed-bed sites for chironomids, and these were analyzed with an solid phase extraction liquid chromatography tamdem mass spectrometry method. The closer to the source the sample site was, the higher the measured TBT concentrations were; and the deeper the shipping lane, the lower the concentration of TBT in reed-bed sediments. The chironomid TBT concentrations correlated with reed-bed sediment TBT concentrations and showed evidence of accumulation. Therefore, TBT may