WorldWideScience

Sample records for wadden sea

  1. Wadden Sea Mud

    DEFF Research Database (Denmark)

    Møller-Jensen, P.

    The present thesis deals with the transport phenomena of estuarine cohesive sediment from a laboratory and a numerical point of view. The cohesive sediment used throughout the whole process was natural mud from the Danish part of the Wadden sea, Ho Bay. In the laboratory, the work was concentrated...

  2. Wadden Sea Mud

    DEFF Research Database (Denmark)

    Møller-Jensen, P.

    The present thesis deals with the transport phenomena of estuarine cohesive sediment from a laboratory and a numerical point of view. The cohesive sediment used throughout the whole process was natural mud from the Danish part of the Wadden sea, Ho Bay. In the laboratory, the work was concentrated...

  3. Parasites in the Wadden Sea food web

    NARCIS (Netherlands)

    Thieltges, D.W.; Engelsma, M.Y.; Wendling, C.C.; Wegner, M.

    2013-01-01

    While the free-living fauna of the Wadden Sea has received much interest, little is known on the distribution and effects of parasites in the Wadden Sea food web. However, recent studies on this special type of trophic interaction indicate a high diversity of parasites in the Wadden Sea and suggest

  4. Parasites in the Wadden Sea food web

    NARCIS (Netherlands)

    Thieltges, D.W.; Engelsma, M.Y.; Wendling, C.C.; Wegner, K.M.

    2013-01-01

    While the free-living fauna of the Wadden Sea has received much interest, little is known on the distribution and effects of parasites in the Wadden Sea food web. However, recent studies on this special type of trophic interaction indicate a high diversity of parasites in the Wadden Sea and suggest

  5. Parasites in the Wadden Sea food web

    Science.gov (United States)

    Thieltges, David W.; Engelsma, Marc Y.; Wendling, Carolin C.; Wegner, K. Mathias

    2013-09-01

    While the free-living fauna of the Wadden Sea has received much interest, little is known on the distribution and effects of parasites in the Wadden Sea food web. However, recent studies on this special type of trophic interaction indicate a high diversity of parasites in the Wadden Sea and suggest a multitude of effects on the hosts. This also includes effects on specific predator-prey relationships and the general structure of the food web. Focussing on molluscs, a major group in the Wadden Sea in terms of biomass and abundance and an important link between primary producers and predators, we review existing studies and exemplify the ecological role of parasites in the Wadden Sea food web. First, we give a brief inventory of parasites occurring in the Wadden Sea, ranging from microparasites (e.g. protozoa, bacteria) to macroparasites (e.g. helminths, parasitic copepods) and discuss the effects of spatial scale on heterogeneities in infection levels. We then demonstrate how parasites can affect host population dynamics by acting as a strong mortality factor, causing mollusc mass mortalities. In addition, we will exemplify how parasites can mediate the interaction strength of predator-prey relationships and affect the topological structure of the Wadden Sea food web as a whole. Finally, we highlight some ongoing changes regarding parasitism in the Wadden Sea in the course of global change (e.g. species introduction, climate change) and identify important future research questions to entangle the role of parasites in the Wadden Sea food web.

  6. Consensus forecasting of intertidal seagrass habitat in the Wadden Sea

    NARCIS (Netherlands)

    Folmer, E.O.; van Beusekom, J.E.E.; Dolch, T; Gräwe, U.; van Katwijk, M.M.; Kolbe, K.; Philippart, C.J.M.

    2016-01-01

    1. After the dramatic eutrophication-induced decline of intertidal seagrasses in the 1970s, theWadden Sea has shown diverging developments. In the northern Wadden Sea, seagrass bedshave expanded and become denser, while in the southern Wadden Sea, only small beds withlow shoot densities are found. A

  7. The Wadden Sea Region: Towards a science for sustainable development

    NARCIS (Netherlands)

    Kabat, P.; Bazelmans, J.; Dijk, van J.; Hermans, P.; Oijen, van T.

    2012-01-01

    The Wadden Sea is one of the largest intertidal areas in the world and has been designated as a UNESCO World Heritage Site in recognition of its unique natural features. Major changes in the morphology and ecology of the Wadden Sea over the past millennium resulted from increasing anthropogenic infl

  8. The Wadden Sea Region : Towards a science for sustainable development

    NARCIS (Netherlands)

    Kabat, Pavel; Bazelmans, Jos; van Dijk, Jouke; Herman, Peter M. J.; van Oijen, Tim; Pejrup, Morten; Reise, Karsten; Speelman, Hessel; Wolff, Wim J.

    2012-01-01

    The Wadden Sea is one of the largest intertidal areas in the world and has been designated as a UNESCO World Heritage Site in recognition of its unique natural features. major changes in the morphology and ecology of the Wadden Sea over the past millennium resulted from increasing anthropogenic infl

  9. Trends in Wadden Sea Fish Fauna, Part I: Trilateral Cooperation

    NARCIS (Netherlands)

    Bolle, L.J.; Neudecker, T.; Vorberg, R.; Damm, U.; Diederichs, B.; Jager, Z.; Scholle, J.; Daenhardt, A.; Luerssen, G.; Marencic, H.

    2009-01-01

    The shallow waters of the Wadden Sea and the connected estuaries and coastal waters provide indispensable habitats for a whole range of fish species in the course of their life-cycle. These areas provide spawning, feeding and nursery grounds and serve as transit route for diadromous species migratin

  10. Trends in Wadden Sea Fish Fauna, Part I: Trilateral Cooperation

    NARCIS (Netherlands)

    Bolle, L.J.; Neudecker, T.; Vorberg, R.; Damm, U.; Diederichs, B.; Jager, Z.; Scholle, J.; Daenhardt, A.; Luerssen, G.; Marencic, H.

    2009-01-01

    The shallow waters of the Wadden Sea and the connected estuaries and coastal waters provide indispensable habitats for a whole range of fish species in the course of their life-cycle. These areas provide spawning, feeding and nursery grounds and serve as transit route for diadromous species

  11. Geological characterization of the Dutch Wadden Sea using shallow reflection seismics

    NARCIS (Netherlands)

    Paap, B.F.; Dubelaar, C.W.; Gunnink, J.L.

    2010-01-01

    Mapping of the Dutch Wadden Sea is a major challenge as it is an intertidal zone and therefore has limited accessibility by surveying vessels. Hence, the current subsurface model of the Dutch Wadden Sea is based on a sparse density of lithological information derived from core samples and seismic da

  12. Trilateral Wadden Sea World Heritage Foundation, Exploring added value, strategy and organisation

    NARCIS (Netherlands)

    During, R.; Coninx, I.; Simeonova, V.

    2014-01-01

    Once the Danish part of the Wadden Sea has been accepted for the UNESCO World Heritage List (expected in 2014), the whole of the Wadden Sea will then be enlisted and this offers new opportunities and obligations for integrative and integral management to safeguard its Outstanding Universal Value.

  13. Nature conservation and tourism development in the Dutch Wadden Sea region: a common future?

    NARCIS (Netherlands)

    Revier, Hans

    2013-01-01

    This chapter is about the development of tourism in the Dutch Wadden Sea Region in combination with nature conservation. The main question is whether they have a common future. There are some future points stated: - Nature and landscape of the Wadden Sea are the main pull factors for the tourism de

  14. Quantifying sediment dynamics within the Dutch Wadden Sea using bathymetric monitoring series

    NARCIS (Netherlands)

    Vonhögen-Peeters, L.M.; Heteren, S. van; Wiersma, A.P.; Kleine, M.P.E. de; Marges, V.C.

    2013-01-01

    During the last millennium, human intervention has had an increasing impact on the bathymetry of the Wadden Sea. The significance of these human-induced changes for the decadal-scale development of the Wadden Sea in light of natural sediment dynamics is still unknown. We compared a series of 20 th-c

  15. Nature conservation and tourism development in the Dutch Wadden Sea region: a common future?

    NARCIS (Netherlands)

    Hans Revier

    2013-01-01

    This chapter is about the development of tourism in the Dutch Wadden Sea Region in combination with nature conservation. The main question is whether they have a common future. There are some future points stated: - Nature and landscape of the Wadden Sea are the main pull factors for the tourism de

  16. Trilateral Wadden Sea World Heritage Foundation, Exploring added value, strategy and organisation

    NARCIS (Netherlands)

    During, R.; Coninx, I.; Simeonova, V.

    2014-01-01

    Once the Danish part of the Wadden Sea has been accepted for the UNESCO World Heritage List (expected in 2014), the whole of the Wadden Sea will then be enlisted and this offers new opportunities and obligations for integrative and integral management to safeguard its Outstanding Universal Value. Ac

  17. Macrobenthos of the subtidal Wadden Sea: revisited after 55 years

    Science.gov (United States)

    Riesen, W.; Reise, K.

    1982-12-01

    During the years 1923 1926 Hagmeier & Kändler (1927) sampled the macrofauna of subtidal shallows and channels of the Wadden Sea close to the Island of Sylt (German Bight, North Sea). Reinvestigating this study area in 1980, a substantially altered faunal composition was recorded. An approach is made to quantify the comparison in terms of abundance, species richness and diversity of invertebrate taxa. Human interference is assumed to be responsible for the major changes. Natural oyster beds have been overexploited and the local population of Ostrea edulis has been driven to extinction. Subsequently, mussels (Mytilus edulis) spread in the entire region, promoted by shell fishery. Particularly barnacles and many polychaetes took advantage of the expansion of mussel banks which is substantiated by correlation analysis. Reefs of the colonial polychaete Sabellaria spinulosa stood in the way of shrimp trawling and became destroyed together with the associated fauna. A subtidal Zostera marina bed was wiped out in 1934 by a natural epidemic disease but never succeeded in reestablishing itself. The associated fauna disappeared. Large epibenthic predators and scavengers (crabs, snails and starfish) survived all these changes. The total number of species remained approximately at the same level but molluscs experienced losses and polychaetes diversified. Overall abundance increased with a disproportionately large share of a few species (Mytilus edulis, Balanus crenatus, Cerastoderma edule, Scoloplos armiger). The subtidal fauna of the Wadden Sea proved to be vulnerable to human disturbance; thus, the present community can no longer be viewed as the outcome of entirely natural processes.

  18. Residual circulation and freshwater transport in the Dutch Wadden Sea: a numerical modelling study

    NARCIS (Netherlands)

    Duran-Matute, M.; Gerkema, T.; de Boer, G.J.; Nauw, J.; Grawe, U.

    2014-01-01

    The Dutch Wadden Sea is a region of intertidal flats located between the chain of Wadden Islands and the Dutch mainland. We present numerical model results on the tidal prisms and residual flows through the tidal inlets and across one of the main watersheds. The model also provides insight into the

  19. Dual nitrate isotopes in the Dutch and German Wadden Sea and its tributary rivers

    Science.gov (United States)

    Sanders, Tina; Wiese, Philipp; Dähnke, Kirstin

    2016-04-01

    The Dutch and German Wadden Sea is threatened by the river-induced eutrophication due to riverine nitrate. Despite reduction of nutrient inputs to rivers in the past decades, nitrate inputs remain problematic, also because the estuary of one of the main contributing rivers, the Elbe River, has now developed from a net nitrate sink to a nitrate source. During a sampling campaign in August 2014 we measured nitrate concentration and dual isotope signatures in the Wadden Sea and in two contributing rivers, the Ems and the Elbe River. Our goal was to assess individual riverine contributions and turnover mechanisms of nitrate in the estuaries and the Wadden Sea itself using dual nitrate isotopes as fingerprint signatures. Nitrate concentration in the Ems River and Estuary twice exceeded that of the Elbe River. δ15N and δ18O of nitrate nevertheless showed that denitrification was active in the Ems estuary, removing nitrate, whereas nitrification produced new nitrate in the Elbe Estuary. Surprisingly, Wadden Sea samples appeared not to be entirely dominated by these two riverine source signatures. This suggests that additional turnover mechanisms in the Wadden Sea itself or inputs of nitrate from the open North Sea additionally affect the isotope composition of nitrate in the Dutch and German Wadden Sea.

  20. Residence times in shallow waters help explain regional differences in Wadden Sea eutrophication

    Science.gov (United States)

    Schwichtenberg, Fabian; Callies, Ulrich; van Beusekom, Justus E. E.

    2016-11-01

    Regional variations in eutrophication levels of tidal basins in the Wadden Sea can be caused by external factors, like organic matter import, and internal factors like the morphology and hydrodynamics of the receiving tidal basin. For instance, benthic nutrients from remineralized organic matter may be more concentrated in shallow basins or diluted in basins with high exchange rates. In addition, the location of a monitoring station may determine which basin-specific water masses are actually observed. In the present paper a hydrodynamic intertidal imprint (IMP) is estimated for ten stations in various tidal basins of the Wadden Sea. The fraction of time water masses spent in intertidal areas prior to observation is calculated by linking the Lagrangian transport module PELETS to already existing hourly reconstructions of currents between 1959 and 2003. Irrespective of water depth, additional calculations of mean residence times (MRT) in the Wadden Sea indicate whether, in the case of low IMP values, water masses originate from coastal areas or tidal channels. Results show distinct regional differences, with highest values in the eastern part of the Dutch sector of the southern Wadden Sea (IMP=77%, MRT=99%) and lowest values in the German/Danish sector of the northern Wadden Sea (IMP=1.1%, MRT=21%). The IMP correlates positively with observed nutrient levels (R2=0.83). Evidently, this residence time-based intertidal signal is pivotal in explaining regional variations in eutrophication levels revealed by long-term comparative data from different monitoring stations.

  1. Rapid colonization of new habitats in the Wadden Sea by the ovoviviparous Littorina saxatilis (Olivi)

    Science.gov (United States)

    Wilhelmsen, U.

    1998-09-01

    The intertidal periwinkle Littorina saxatilis completely lacks larval dispersal and adult vagility is low. Although this suggests a low dispersal rate, L. saxatilis is frequently found in recently established habitats “exotic” to the Wadden Sea. Populations occur on man-made structures like dikes, breakwater and groynes, some of which are not older than several years. Furthermore, L. saxatilis is found on marsh grass Spartina anglica, introduced to the Wadden Sea in the 1920s and 1930s, as well as on mats of green macroalgae, which have become an abundant feature on the tidal flats since the late 1970s. Seagrass beds are likely to be the original habitat of L. saxatilis in the Wadden Sea. Since seagrass populations have dramatically declined over the last decades, colonization of new habitat types enabled L. saxatilis to maintain its Wadden Sea populations despite a changing environment. Colonizers can reach new habitats by means of passive transport, especially by rafting on macrophytes and by aerial dispersal attached to birds. In thew Wadden Sea, the ovoviviparously reproducing L. saxatilis has demonstrated its ability to successfully found new populations with only a few individuals. No reduction of genetic variablility (founder effect) was observed in recently established populations.

  2. The Netherlands' environmental policy for the North Sea and Wadden Sea.

    Science.gov (United States)

    Beukema, A A; Hekstra, G P; Venema, C

    1986-09-01

    The water quality management of The Netherlands' part of the North Sea (57 000 km(2) continental shelf of which 7600 km(2) is territorial sea to 12 miles) and the Wadden Sea (a wetland area behind the northern coastal islands), is described on the basis of recent scientific studies and governmental policy documents. The links with international conventions and treaties are mentioned. The overall water quality in these areas has significantly deteriorated over the last century, notably since the post-war industrial revival, due to a great number of emissions of heavy metals and organochlorine substances. A dramatic decline of seals and porpoises has occurred. However, over the last few years some emissions have been reduced. A national ecological research programme for the North Sea is developing. Monitoring is concentrated on levels of pollutants as well as on effects upon biota. Baseline standards are now being developed as references for further action against pollution. If the recent trend towards improvement is to continue, it requires that the increased economic activities (notably the mining of oil and gas, petrochemical production, and incineration and dumping of chemical wastes) be kept sufficiently under control. A need is felt for a continued rational harmonization and planning of all activities on the North Sea. An even more stringent planning is required for the Wadden Sea which is now an international nature reserve under the Wetland Convention and is eligible for designation as a Biosphere Reserve under the UNESCO-MAB-programme. The river Rhine as greatest polluter of the North Sea and Wadden Sea urgently needs a clean-up.

  3. How predictable is high bivalve recruitment in the Wadden Sea after a severe winter?

    Science.gov (United States)

    Strasser, Matthias; Dekker, Rob; Essink, Karel; Günther, Carmen-Pia; Jaklin, Sandra; Kröncke, Ingrid; Madsen, Poul Brinch; Michaelis, Hermann; Vedel, Grace

    2003-02-01

    Higher than average recruitment among bivalves on the intertidal flats of the Wadden Sea was often observed after severe winters in the period 1940-1995. The occurrence of another severe winter in 1995/96 prompted us to test the hypothesis of severe winters leading to universally high bivalve recruitment on a large geographic scale (500 km coastline) in temperate shallow waters. We analysed data sets on bivalve abundance from seven areas in the Dutch, German and Danish Wadden Sea. The longer data sets showed generally higher bivalve recruitment in the 1970s and 1980s than in the 1990s which may be related to the near absence of severe winters since 1987. Considering the period 1988 onwards (the longest possible period in which 1995/96 was the only severe winter), recruitment of Cerastoderma edule was in 1996 - in agreement with our hypothesis - above average in all seven areas investigated. In contrast, recruitment of Macoma balthica and Mya arenaria was for the same period above average only in the southern Wadden Sea (south-west of Jade Bay) but not in the northern Wadden Sea (north of Eiderstedt peninsula). These regional differences may be related to (i) the different topography of the northern Wadden Sea (with barrier islands west of the mainland) compared to the southern Wadden Sea (with barrier islands north of the mainland) and subsequent differential effects of wind-induced currents on bivalve recruitment, (ii) differences in biotic factors such as standing stocks, larval supply or epibenthic predation or (iii) changes in environmental conditions. Our results demonstrate that large-scale comparisons along coasts are an indispensable addition to insights derived from local studies alone.

  4. Understanding the cultural historical value of the Wadden Sea region : The co-evolution of environment and society in the Wadden Sea area in the Holocene up until early modern times (11,700 BC-1800 AD): An outline

    NARCIS (Netherlands)

    Bazelmans, J.; Meier, D.; Nieuwhof, A.; Spek, T.; Vos, P.

    2012-01-01

    The Wadden region is a cultural landscape of exceptional cultural historical value. The present article describes in qualitative terms how the cultural landscape of the Wadden Sea region came about through the complex interaction of people and nature. Human impact on this region has occurred in stag

  5. Holocene evolution of a drowned melt-water valley in the Danish Wadden Sea

    DEFF Research Database (Denmark)

    Pedersen, Jørn Bjarke Torp; Svinth, Steffen; Bartholdy, Jesper

    2009-01-01

    the total post-glacial transgression, and the reconstructed sea level curve represents the first unbroken curve of this kind from the Danish Wadden Sea, including all phases from the time where sea level first reached the Pleistocene substrate of the area. The sea level has been rising from - 12 m below...... the present level at c. 8400 cal yr BP, interrupted by two minor drops of sea level rise, and the Holocene sequence consists in most places of clay atop......Cores from the salt marshes along the drowned melt-water valley of river Varde Å in the Danish Wadden Sea have been dated and analysed (litho- and biostratigraphically) to reconstruct the Holocene geomorphologic evolution and relative sea level history of the area. The analysed cores cover...

  6. Seasonal occurrence of the invasive ctenophore Mnemiopsis leidyi in the western Dutch Wadden Sea

    Science.gov (United States)

    van Walraven, Lodewijk; Langenberg, Victor T.; van der Veer, Henk W.

    2013-09-01

    The ctenophore Mnemiopsis leidyi is an invasive species in northern European waters since 2006. This paper presents the first quantitative data for the western Dutch Wadden Sea based on weekly measurements year-round in 2009 of abundance and size distribution. Due to the short residence time of the water, the seasonal occurrence of this species in the western Dutch Wadden Sea is a reflection of its occurrence in the Dutch coastal zone of the North Sea. M. leidyi was present the whole year round with multiple peaks. Spawning started in May and was followed by an increase in density of 3 orders of magnitude, leading to the first peak in mid-June (highest mean density 360 ind m- 3). After a decrease in July numbers increased again and a second peak occurred in mid-August (highest mean density 342 ind m- 3) during which the highest density of 912 ind m- 3 in a single haul was observed. At peak densities the population consisted almost entirely of small (leidyi. Predatory impact of M. leidyi on fish larvae in the Wadden Sea is likely to be restricted because most fish species spawn early in the year before the first peak of M. leidyi. Nevertheless, through competition for food with other zooplanktivores, the species could have a major influence on the Wadden Sea ecosystem.

  7. Foreland development along the advanced seawall at Højer, the Danish Wadden Sea

    DEFF Research Database (Denmark)

    Vestergaard, Peter

    2006-01-01

    , but has also been influenced by sand accretion, 5) the vegetation of the outer part of the foreland is still open and characterized by beach and dune species, 6) the vegetation of the inner part of the foreland is slowly developing towards a typical Wadden Sea high marsh. In conclusion, the planned...

  8. Distinctly variable mudscapes : Distribution gradients of intertidal macrofauna across the Dutch Wadden Sea

    NARCIS (Netherlands)

    Compton, Tanya J.; Holthuijsen, Sander; Koolhaas, Anita; Dekinga, Anne; ten Horn, Job; Smith, Jeremy; Galama, Ysbrand; Brugge, Maarten; van der Wal, Daphne; van der Meer, Jaap; van der Veer, Henk W.; Piersma, Theunis

    2013-01-01

    The Wadden Sea is a shallow coastal region, with a large area of sedimentary tidal flats that extends from The Netherlands to Denmark and has been declared a site of international importance in the Dutch and German parts (Ramsar status and UNESCO World Heritage Site). Benthic macrofauna are central

  9. Distinctly variable mudscapes : Distribution gradients of intertidal macrofauna across the Dutch Wadden Sea

    NARCIS (Netherlands)

    Compton, Tanya J.; Holthuijsen, Sander; Koolhaas, Anita; Dekinga, Anne; ten Horn, Job; Smith, Jeremy; Galama, Ysbrand; Brugge, Maarten; van der Wal, Daphne; van der Meer, Jaap; van der Veer, Henk W.; Piersma, Theunis

    The Wadden Sea is a shallow coastal region, with a large area of sedimentary tidal flats that extends from The Netherlands to Denmark and has been declared a site of international importance in the Dutch and German parts (Ramsar status and UNESCO World Heritage Site). Benthic macrofauna are central

  10. Risk analysis on the import of seed mussels from Norway into the Wadden Sea

    NARCIS (Netherlands)

    Wijsman, J.W.M.; Tamis, J.E.; Kaag, N.H.B.M.; Karman, C.C.; Foekema, E.M.; Smaal, A.C.

    2007-01-01

    This report is the result of a risk analysis on the introduction of exotic nonCindigenous species with the import of rope culture mussels from Norway into the Wadden Sea. Based on available literature data and expert judgement, the target species are identified and the risks of these species are ass

  11. Some observations on tourism development in the Dutch Wadden Sea area

    NARCIS (Netherlands)

    Hans Revier; Akke Folmer; Albert Postma

    2012-01-01

    Tourism has become one of the important economic activities in the Dutch Wadden Sea area. The tranquillity, open space, the natural qualities and cultural inheritance of the area attract every year between 1 and 2 million visitors. Especially the islands are a popular holiday destination. Tourism de

  12. Human transformations of the Wadden Sea ecosystem through time : a synthesis

    NARCIS (Netherlands)

    Lotze, H.K.; Reise, K; Worm, B.; van Beusekom, J.; Busch, M.; Ehlers, A.; Heinrich, D.; Hoffman, R.C.; Holm, P.; Jensen, C.; Knottnerus, O.S.; Langhanki, N.; Prummel, W.; Vollmer, M.; Wolff, W.J.

    Todays Wadden Sea is a heavily human-altered ecosystem. Shaped by natural forces since its origin 7,500 years ago, humans gradually gained dominance in influencing ecosystem structure and functioning. Here, we reconstruct the timeline of human impacts and the history of ecological changes in the

  13. Effects of suction-dredging for cockles on non-target fauna in the Wadden Sea

    NARCIS (Netherlands)

    Hiddink, JG

    2003-01-01

    Suction dredging for cockles removes large cockles from tidal flats and may also cause mortality of non-target fauna and make the habitat less suitable for some species. This study examines whether suction dredging for cockles on tidal flats of the Dutch Wadden Sea had affected densities of non-targ

  14. High risk exotic species with respect to shellfish transports from the Oosterschelde to the Wadden Sea

    NARCIS (Netherlands)

    Brink, van den A.M.; Wijsman, J.W.M.

    2010-01-01

    This study presents the results of a literature review on 11 exotic marine species that are present in the Oosterschelde and could potentially be introduced into the Wadden Sea with shellfish transfers. Ten of the species result from a previous risk study, where they were identified as the species p

  15. Phosphorus limitation during a phytoplankton spring bloom in the western Dutch Wadden Sea

    NARCIS (Netherlands)

    Ly, J.; Philippart, C.J.M.; Kromkamp, J.C.

    2014-01-01

    Like many aquatic ecosystems, the western Dutch Wadden Sea has undergone eutrophication. Due to changes in management policy, nutrient loads, especially phosphorus decreased after the mid-80s. It is still under debate, however, whether nutrients or light is limiting phytoplankton production in the w

  16. Emic perspectives on quality of life: the case of the Danish Wadden Sea Festival

    NARCIS (Netherlands)

    Liburd, J.J.; Derkzen, P.H.M.

    2009-01-01

    This paper sets out to probe how a cultural festival can enhance quality of life (QoL) and identifies possible drivers in the process. The Wadden Sea Festival in Denmark is based on the idea of integrating the coastal environment in the presentation of contemporary art. Specifically, unique tidal

  17. Identities, Communities, and Practices in the Transition Towards Sustainable Mussel Fishery in the Dutch Wadden Sea

    NARCIS (Netherlands)

    Puente Rodriguez, D.; Swart, J.A.A.; Middag, M.; Windt, v.d. H.J.

    2015-01-01

    The Dutch mussel fishery in the Wadden Sea, a World Natural Heritage Site, is currently involved in a step-by-step transition from the traditional but controversial method of dredging mussel seed from natural beds using trawl nets to alternative sustainable practices. The main objectives of the tran

  18. Human transformations of the Wadden Sea ecosystem through time : a synthesis

    NARCIS (Netherlands)

    Lotze, HK; Reise, K; Worm, B; van Beusekom, J; Busch, M; Ehlers, A; Heinrich, D; Hoffmann, RC; Holm, P; Jensen, C; Knottnerus, OS; Langhanki, N; Prummel, W; Vollmer, M; Wolff, WJ

    2005-01-01

    Todays Wadden Sea is a heavily human-altered ecosystem. Shaped by natural forces since its origin 7,500 years ago, humans gradually gained dominance in influencing ecosystem structure and functioning. Here, we reconstruct the timeline of human impacts and the history of ecological changes in the Wad

  19. Net dispersal of harbour seals within the Wadden Sea before and after the 1988 epizootic

    Science.gov (United States)

    Ries, Edith H.; Traut, Ilona M.; Brinkman, Albertus G.; Reijnders, Peter J. H.

    1999-05-01

    Harbour seals in the Wadden Sea (The Netherlands, Germany and Denmark) have been monitored by aerial surveys since the 1980s. Annual maximum figures reported in the various regions (38 separate tidal basins) and the number of pups counted were used to estimate vital population parameters and to quantify the net migration of harbour seals within the Wadden Sea before (1980-1987) and after an epizootic (1990-1994). The total pre-whelping population increased at a mean annual rate of 9 and 14%, respectively, and varied considerably among the various regions of the Wadden Sea. The overall mean annual survival was found to increase from 0.88 during the pre-epizootic period to 0.93 during the post-epizootic period. The distribution of pups and of older seals over the 38 separate sub-areas was highly uneven. Based on between-year population changes and the number of pups reported, net dispersal fluxes among the four regions of the Wadden Sea were estimated for the two time intervals. During the pre-epizootic period, only Schleswig-Holstein, Germany, produced a surplus of animals which counter-balanced the low recruitment of the other regions. During the post-epizootic period, the net dispersal fluxes were at a much lower level. Nevertheless, in The Netherlands, a continuous influx of seals was required because the recruitment was insufficient to explain the observed numerical increase. At the level of the 38 separate tidal basins, the actual pattern of dispersal showed that the majority of sub-areas were not self-supporting with respect to the local pup production and thus dependent on the influx of animals. More than 65% of all immigrants originated from only 7 sub-areas, which are considered `key areas' of vital importance for the Wadden Sea harbour seal population.

  20. Public discussion on ground subsidence of the Wadden Sea, 8 September 1993; Openbare discussiedag `Bodemdaling Waddenzee`, 8 september 1993

    Energy Technology Data Exchange (ETDEWEB)

    Lindeboom, H.J. [ed.

    1996-12-31

    On the request of a number of members of the Dutch Parliament and the involved industries NAM (Dutch Oil Company) and Elf Petroland, NIOZ organized a workshop on ground subsidence in the Dutch part of the Wadden Sea as a result of gas exploration. In this report contributions of participants which served as the basis for the discussions, are presented. Also a summary is given of the discussions and impressions of the chairpersons. The contributions deal with the historical development of the Wadden Sea, the predicted ground subsidence, the question whether natural transport of sand can keep up with that subsidence, the possible effects on salt marshes and Wadden Sea birds, and the consequences for the total ecosystem of the Wadden Sea

  1. Ecosystem model of the western Wadden Sea: A bridge between science and management?

    Science.gov (United States)

    Lindeboom, H. J.; van Raaphorst, W.; Ridderinkhof, H.; van der Veer, H. W.

    1989-09-01

    This paper describes the construction, validation and application of a mathematical ecosystem model of the western Wadden Sea. This model is based upon the Ems-Dollard ecosystem model, but also includes a two-dimensional transport submodel, a benthic and epibenthic sublitoral submodel and nutrient regeneration. In 1986, an extensive field programme was executed to collect data for model validation. Apart from the subtidal processes the validation indicates that the model simulates the different state variables reasonably well. The applicability of the model for management purposes was tested in four case studies concerning: dredging activities, eutrophication, commercial mussel cultrue and oil spills and other calamities. It is concluded that the western Wadden Sea model in general is a useful tool in evaluating the impact of certain anthropogenic activities in the area.

  2. Distinctly variable mudscapes: Distribution gradients of intertidal macrofauna across the Dutch Wadden Sea

    Science.gov (United States)

    Compton, Tanya J.; Holthuijsen, Sander; Koolhaas, Anita; Dekinga, Anne; ten Horn, Job; Smith, Jeremy; Galama, Ysbrand; Brugge, Maarten; van der Wal, Daphne; van der Meer, Jaap; van der Veer, Henk W.; Piersma, Theunis

    2013-09-01

    The Wadden Sea is a shallow coastal region, with a large area of sedimentary tidal flats that extends from The Netherlands to Denmark and has been declared a site of international importance in the Dutch and German parts (Ramsar status and UNESCO World Heritage Site). Benthic macrofauna are central to the ecosystem functioning of this area, as they recycle nutrients, decompose organic matter and are an important food source for many secondary consumers, like fish and waterbirds. Due to the environmental gradients characteristic of estuarine systems, it is expected that changes in assemblage composition will be observed across the physical and environmental gradients of the Wadden Sea. First, we explored the spatial variation in assemblage composition of benthic macrofauna across the intertidal part of the Dutch Wadden Sea using 3 years of biomass data. Then, we identified the relative importance of six environmental variables for explaining and predicting changes in assemblage composition across the intertidal areas of the Wadden Sea using generalised dissimilarity modelling (GDM). In accordance with the environmental gradients across this system, the biomass contributed by a few common species differed from west to east and were distinct in the Dollard. In the west, bivalves Mya arenaria, Cerastoderma edule and Ensis directus contributed a relatively large and equal share of the total biomass, whereas C. edule contributed the sole largest share of the total biomass towards the east. The polychaete Alitta succinea became a large share of the total biomass in the upper Ems and in the Dollard estuary, but contributed little elsewhere. Similar to the observed differences in species composition, the spatial patterns in assemblage composition, as predicted by the GDM models, identified the Dollard as distinct and that the prevalence of assemblage types in the west differed to the east. Median grain size, followed by microphytobenthic biomass, and exposure time were the

  3. Alien parasitic copepods in mussels and oysters of the Wadden Sea

    Science.gov (United States)

    Elsner, Nikolaus O.; Jacobsen, Sabine; Thieltges, David W.; Reise, Karsten

    2011-09-01

    Molluscan intestinal parasites of the genus Mytilicola, specifically M. intestinalis, were initially introduced into bivalves in the North Sea in the 1930s. It was presumably introduced from the Mediterranean with ship-fouling mussels, then attained epidemic proportions in Mytilus edulis in the 1950s and is now widely established in the North Sea region. Mytilicola orientalis was co-introduced with Pacific oysters to France in the 1970s and in the southern North Sea in the early 1990s. Its main host Crassostrea gigas has massively invaded the Wadden Sea with a concomitant decline in mussels. To explore whether introduced mytilicolid parasites could play a role in the shifting dominance from native mussels to invasive oysters, we analysed 390 mussels and 174 oysters collected around the island of Sylt in the northern Wadden Sea. We show that M. intestinalis has a prevalence >90% and a mean intensity of 4 adult copepods in individual mussels with >50 mm shell length at all sheltered sites. By contrast, none were found in the oysters. However, at one site, we found M. orientalis in C. gigas with a prevalence of 10% and an intensity of 2 per host individual (August 2008). This constitutes the most northern record in Europe for this Pacific parasite until now. Alignments of partial sequences of the mitochondrial cytochrome oxidase I (COI) gene and the nuclear internal transcribed spacers (ITS) and 18S rDNA sequences each show a distinct difference between the two species, which confirms our morphological identification. We suggest that the high parasite load in mussels compared to oysters may benefit the continued expansion of C. gigas in the Wadden Sea.

  4. The impact of biological invasions on the Wadden Sea food web (INFOWEB)

    OpenAIRE

    de la Vega, Camille; Schückel, Ulrike; Jung, Sarina; Asmus, Harald; Asmus, Ragnhild; Kröncke, Ingrid; C. J. M. Philippart; van der Veer, Henk

    2012-01-01

    Invasive species are a general issue common of every seas in the world. Impacts of biological invasion on the food web of the Wadden Sea will be figure out through 3 related positions (Sarina Jung, PhD student ; Camille de la Vega, PhD student ; Ulrike Schueckel, Post doctoral student) included in the INFOWEB project. To investigate the impact of invasive species on the food web, a good comprehension of the trophic relation and energy fluxes between the different compartments of the food web ...

  5. Abundance and tidal behaviour of pelagic fish in the gateway to the Wadden Sea

    Science.gov (United States)

    Couperus, Bram; Gastauer, Sven; Fässler, Sascha M. M.; Tulp, Ingrid; van der Veer, Henk W.; Poos, Jan Jaap

    2016-03-01

    The shallow coast of The Netherlands is an important habitat for small pelagic fish. They form one of the major links between plankton and the higher trophic levels. Predatory fish, sea mammals and birds rely on small pelagic fish as a major food source. Currently, monitoring of fish in the Dutch coastal zone mainly focuses on demersal species, using bottom trawls and fykes. Four hydro-acoustic surveys were carried out in May and October 2010/2011 in the Marsdiep area, a relatively deep tidal inlet in the western Wadden Sea, to quantify abundances of pelagic fish. The aims of this study were to (1) describe temporal and vertical variations in fish distribution and school dimensions in relation to tide, and (2) estimate biomass of pelagic fish and their proportion to total fish biomass. The biomass of pelagic fish in the Marsdiep area ranged between 23 and 411 kg/ha. These were mainly sprat, but also young herring, anchovy and pilchard. The fish was scattered in small schools with volumes smaller than 5m3 and concentrated in the top 10 m below the surface. There was a clear effect of tidal cycle on school volume and fish abundance, with larger densities and larger schools at high tide compared to low tide. In May, sandeel contributed substantially to the pelagic assemblage, whereas in October sandeel was absent in the trawl catches, most likely because they stayed buried in the seabed from late summer to spring. The presence of pilchard and anchovy confirmed their re-establishment in the Southern North Sea and Wadden Sea. The abundance of pelagic fish exceeded the biomass of demersal fish in the western Wadden Sea by an order of magnitude. This finding is relevant for ecosystem studies. The fact that this study suggests that small pelagics outnumber demersal species to such a large extent calls for a rethinking of the allocation of monitoring effort in the Dutch coastal zone.

  6. Seasonal Variation of Harbor Seal's Diet from the Wadden Sea in Relation to Prey Availability

    Science.gov (United States)

    de la Vega, Camille; Lebreton, Benoit; Siebert, Ursula; Guillou, Gael; Das, Krishna; Asmus, Ragnhild; Asmus, Harald

    2016-01-01

    The Wadden Sea has an important role for marine mammals in terms of resting, nursing and foraging. Harbor seal is the most abundant marine mammal species in this area. The use of the food resources of the Wadden Sea by seals is not clear, and previous studies showed that this species can travel kilometers away from their haul-outs to forage in the North Sea. In this study, we analyzed the stable isotopes of vibrissae from 23 dead harbor seals found on the island of Sylt to investigate their diet. The predator´s carbon and nitrogen isotope compositions were compared to the compositions of different potential prey items from the Sylt-Rømø Bight and from the North Sea in order to study seasonal pattern in the diet and in the foraging location. In parallel, seasonal variation of abundance and biomass of the potential prey items from the Sylt-Rømø Bight were studied and compare to their contribution to the seal´s diet. The results revealed a change in the seal´s diet from pelagic sources in spring to a benthic based diet in summer, and an increasing use of the North Sea resources in fall and winter in accordance with the seasonal variation of the availability of prey in the Sylt-Rømø Bight. PMID:27176227

  7. Seasonal Variation of Harbor Seal's Diet from the Wadden Sea in Relation to Prey Availability.

    Directory of Open Access Journals (Sweden)

    Camille de la Vega

    Full Text Available The Wadden Sea has an important role for marine mammals in terms of resting, nursing and foraging. Harbor seal is the most abundant marine mammal species in this area. The use of the food resources of the Wadden Sea by seals is not clear, and previous studies showed that this species can travel kilometers away from their haul-outs to forage in the North Sea. In this study, we analyzed the stable isotopes of vibrissae from 23 dead harbor seals found on the island of Sylt to investigate their diet. The predator´s carbon and nitrogen isotope compositions were compared to the compositions of different potential prey items from the Sylt-Rømø Bight and from the North Sea in order to study seasonal pattern in the diet and in the foraging location. In parallel, seasonal variation of abundance and biomass of the potential prey items from the Sylt-Rømø Bight were studied and compare to their contribution to the seal´s diet. The results revealed a change in the seal´s diet from pelagic sources in spring to a benthic based diet in summer, and an increasing use of the North Sea resources in fall and winter in accordance with the seasonal variation of the availability of prey in the Sylt-Rømø Bight.

  8. On the dynamics of the stocks of blue mussels ( Mytilus edulis L.) in the Danish Wadden Sea

    DEFF Research Database (Denmark)

    Munch-Petersen, Sten; Kristensen, Per Sand

    2001-01-01

    As biological basis for the monitoring programme for the commercially exploited stock(s) of mussels (Mytilus edulis L.) in the Danish Wadden Sea, samples of mussels have been collected regularly since 1986, both from sub-tidal and inter- tidal mussel beds. These samples are the basis for the esti...... with figures from other investigations. These analyses have been the basis for annual assessments of the mussel stocks, which again are used in the current management of mussel fishery in the Danish Wadden Sea.......As biological basis for the monitoring programme for the commercially exploited stock(s) of mussels (Mytilus edulis L.) in the Danish Wadden Sea, samples of mussels have been collected regularly since 1986, both from sub-tidal and inter- tidal mussel beds. These samples are the basis...

  9. Subsidence due to gas production in the Wadden Sea: How to ensure no harm will be done to nature

    NARCIS (Netherlands)

    Thienen-Visser, K. van; Breunese, J.N.; Muntendam-Bos, A.G.

    2015-01-01

    The Wadden Sea is a shallow tidal sea in the north of the Netherlands where gas production is ongoing since 1986. Due to the sensitive nature of this area, gas extraction induced subsidence must remain within the "effective subsidence capacity" for the two tidal basins (Pinkegat and Zoutkamperlaag)

  10. Monitoring and change detection of Wadden Sea areas using Lidar data

    Science.gov (United States)

    Schmidt, A.; Soergel, U.

    2013-10-01

    In coastal areas morphological changes of various kinds are caused by tidal flows, storms, climate change, and human activities. For these reasons a recurrent monitoring becomes necessary in order to detect undesired changes at early stages enabling rapid countermeasures to mitigate or minimize potential harm or hazard. The morphology of the terrain can be represented by highly precise digital terrain models (DTM). Airborne lidar (light detection and ranging) has become a standard method for DTM generation in coastal zones like Wadden Sea areas. In comparison to echo sounding systems, lidar is feasible for data acquisition of large areas. However, only the eulittoral zone can be covered by standard laser because the near-infrared laser pulses are not able to penetrate water which remains, for example, in some tidal channels even during low tide. In the framework of a German research project, we analyse the spatial and temporal variability of Wadden Sea areas in the North Sea. For a systematic monitoring and the detection of morphological changes we compare terrain models of two different epochs in order to determine height differences which can be caused by natural influences or human activities. We focus especially on the analysis of morphological changes near to tidal channels. In order to detect changes we compare the location of edges derived from each DTM based on the gray values' gradients. Our results for a test site in the German Wadden Sea show height differences up to 1 m due to the shifting of tidal channels and relocations of the channels up to 55 m within a period of two years.

  11. Tidal and residual flows in the western Dutch Wadden Sea III: Vorticity balances

    Science.gov (United States)

    Ridderinkhof, H.

    A vorticity-dynamics approach is used to examine the origin of the small-scale residual current field in the western Dutch Wadden Sea. For a representative part of the Wadden Sea, the magnitude of vorticity and of terms in the balance equation for vorticity is determined on the basis of results from a two-dimensional numerical model. The torque from bottom friction along the side walls of the tidal channels appears to be the dominating mechanism in generating tidal relative vorticity, the magnitude of which is much larger than planetary vorticity. Especially near a tidal inlet, stretching and squeezing of fluid columns is of importance in increasing/decreasing relative vorticity. Averaging over a tidal period shows, compared to the tidal equations, an increased influence of the non-linear advective and streching/squeezing terms in the tidally-averaged balance. However, although the relative influence of these strong non-linear terms increases, the influence of the weak non-linear terms originating in bottom friction cannot be ignored. The mechanism responsible for the headland eddies near a tidal inlet and the topographical eddies in the channels of the Wadden Sea is essentially the same, viz. the transfer of vorticity from a source region where this vorticity is produced by differential bottom friction, to adjacent regions. This transfer of tidal vorticity, or advection, is most effective near a transition from straight to curved isobaths where a gradient in the production of tidal vorticity occurs. This is illustrated by showing the vorticity possessed by a particular fluid column during a tidal excursion. The dominant influence of the bathymetry on the small scale residual current pattern is used for a qualitative discussion of the residual flow field in other parts of our numerical model.

  12. Automated Waterline Detection in the Wadden Sea Using High-Resolution TerraSAR-X Images

    Directory of Open Access Journals (Sweden)

    Stefan Wiehle

    2015-01-01

    Full Text Available We present an algorithm for automatic detection of the land-water-line from TerraSAR-X images acquired over the Wadden Sea. In this coastal region of the southeastern North Sea, a strip of up to 20 km of seabed falls dry during low tide, revealing mudflats and tidal creeks. The tidal currents transport sediments and can change the coastal shape with erosion rates of several meters per month. This rate can be strongly increased by storm surges which also cause flooding of usually dry areas. Due to the high number of ships traveling through the Wadden Sea to the largest ports of Germany, frequent monitoring of the bathymetry is also an important task for maritime security. For such an extended area and the required short intervals of a few months, only remote sensing methods can perform this task efficiently. Automating the waterline detection in weather-independent radar images provides a fast and reliable way to spot changes in the coastal topography. The presented algorithm first performs smoothing, brightness thresholding, and edge detection. In the second step, edge drawing and flood filling are iteratively performed to determine optimal thresholds for the edge drawing. In the last step, small misdetections are removed.

  13. Species composition and predation pressure of the gelatinous zooplankton community in the western Dutch Wadden Sea before and after the invasion of the ctenophore

    NARCIS (Netherlands)

    van Walraven, L.; Daan, R.; Langenberg, V.T.; van der Veer, H.W.

    2017-01-01

    The ctenophore Mnemiopsis leidyi A. Agassiz, 1865 is a successful, recent, macroplanktonic invader in European coastal waters, including theDutch Wadden Sea. It occurs year-round in substantial numbers. The effect of M. leidyi on structure of the gelatinous zooplankton community inthe Dutch Wadden S

  14. Policy plans and management measures to restore eelgrass (Zostera marina L.) in the Dutch Wadden Sea

    Science.gov (United States)

    de Jonge, V. N.; de Jong, D. J.; van Katwijk, M. M.

    2000-07-01

    The Dutch Wadden Sea has been changed dramatically over the last centuries by human activities like land reclamation and different forms of fishery. This has, amongst other things, led to changes in the number of biological communities. One of the changes was the near extinction of eelgrass (Zostera marina L.) in the Dutch Wadden Sea. The deterioration of the area led to policy plans in the late 1980s that aimed at restoring the original natural communities of which the eelgrass community was one. This paper presents a restoration strategy which contains a selection procedure for suitable transplantation sites. The selection procedure is based on factors such as sediment composition, exposure time, current velocity and wave action. These were combined in a GIS-based map integrating these factors. One important action in the restoration process is to increase the number of freshwater discharge points to meet the requirements of the brackish water community in general and the growing conditions for eelgrass in particular.

  15. Residual currents and bedform migration in a natural tidal inlet (Knudedyb, Danish Wadden Sea)

    Science.gov (United States)

    Fraccascia, S.; Winter, C.; Ernstsen, V. B.; Hebbeln, D.

    2016-10-01

    The morphology and hydrodynamics of the natural tidal inlet Knudedyb in the Danish Wadden Sea were investigated by the analysis of high resolution bathymetric data and hydrodynamic numerical modeling. In contrast to the expected anticlockwise pattern similar to the other inlets in the Wadden Sea, a clockwise tidal residual current was found, which drives the sediment transport and results from the presence of a confluent meander bend. The channel is draped by bedforms of several hierarchical scales (on average, approximately 155 m long and 2.3 m high), with average sizes decreasing from south to north and seaward (i.e., westward). Primary bedforms in the area are mostly asymmetric ebb-directed and migrate in the ebb direction in the order of 3 m yr- 1. Bedform sections at the northern channel flank show more symmetrical profiles; crests migrate flood-ward, leading to crestal flexing in the central channel. Lateral recirculation cells develop during ebb tide on both sides of the channel seaward of a bend, before the tidal reversal occurs in the rest of the model domain. As a result of the longer flood phase, a main clockwise residual eddy exists in the middle reach of the channel. Bedform migration patterns and hydrodynamic simulations reveal that the pronounced tidal asymmetry in the channel is enhanced by the effects of the channel morphology on the confined flow (at low tide).

  16. Cyclic behavior of sandy shoals on the ebb-tidal deltas of the Wadden Sea

    Science.gov (United States)

    Ridderinkhof, W.; Hoekstra, P.; van der Vegt, M.; de Swart, H. E.

    2016-03-01

    Ebb-tidal deltas are bulges of sand that are located seaward of tidal inlets. Many of these deltas feature shoals that cyclically form and migrate towards the coast. The average period between successive shoals that attach to the coast varies among different inlets. In this study, a quantitative assessment of the cyclic behavior of shoals on the ebb-tidal deltas of the Wadden Sea is presented. Analysis of bathymetric data and Landsat satellite images revealed that at the majority of inlets along the Wadden Sea migrating shoals occur. The average period between succeeding shoals correlates to the tidal prism and has values ranging between 4 and 130 years. A larger tidal prism favors larger periods between successive shoal attachments. However, such a relationship was not found for wide inlets with multiple channels. There is a positive relationship between the frequency with which the shoals attach to the coast and their migration velocity, and a negative relationship between the migration velocity of the shoal and the tidal prism. Finally, the data were too sparse to assess whether the longshore sediment transport has a significant effect on the period between successive shoals that attach to the coasts downdrift of the observed tidal inlets.

  17. Influence of light quality and gassing on the vertical migration of diatoms inhabiting the Wadden Sea

    Science.gov (United States)

    Wenderoth, Klaus; Rhiel, Erhard

    2004-10-01

    Diatoms inhabiting the Wadden Sea show a rhythmic migration pattern, which is superimposed by the tidal rhythm. In addition to light intensity, light quality has a pronounced influence on the upward-directed migration, thus giving some information on the nature of the relevant photoreceptors. Maximum diatom migration occurred when sediment surfaces were illuminated with blue light. The cell densities in blue light exceeded those of white light control experiments 1.8-fold. Furthermore, we registered a minor peak in the red light region, which reached approximately 60% of the white light controls. Cryptochrome and/or phototropin may thus be involved and act as photoreceptors for the vertical migration pattern. Flushing sediment surfaces of freshly mixed Wadden Sea sediments with air, O2, CO2 or N2 did not show a significant influence of O2 on the upward migration. The disappearance of diatoms from sediment surfaces which were flushed with CO2 is most probably caused by the acidification of the sediment bed.

  18. Ground subsidence Wadden Sea 1977-2011. Precision and reliability of measurements; Bodemdaling Waddenzee 1977-2011. Precisie en betrouwbaarheid uit metingen

    Energy Technology Data Exchange (ETDEWEB)

    Houtenbos, A.P.E.M.

    2011-12-15

    What about the subsidence caused by gas exploitation around the Wadden Sea? Is subsidence on the Wadden Sea really manageable by extraction with the 'hand on the faucet'? These and other questions are examined in an analysis of the measurements around the Wadden Sea in the period 1977-2011 [Dutch] Hoe staat het met de bodemdaling door gaswinning rond de Waddenzee? Is bodemdaling op de Waddenzee werkelijk beheersbaar door winning met de 'Hand aan de kraan'? Deze en andere vragen zijn onderzocht in een analyse van de metingen rond de Waddenzee tot over de periode 1977-2011.

  19. Eutrophication as a possible cause of decline in the seagrass Zostera noltii of the dutch Wadden Sea.

    NARCIS (Netherlands)

    Philippart, C.J.M.

    1994-01-01

    The present thesis describes the results of research on the distribution and possible causes for the decrease of the seagrass Z. noltii in the Wadden Sea, carried out from 1986 to 1990. Chapter 2 examines the relation between the distribution of Zostera dominated ecosystems in the international Wadd

  20. Development and distribution of the non-indigenous Pacific oyster (Crassostrea gigas) in the Dutch Wadden Sea

    NARCIS (Netherlands)

    Fey-Hofstede, F.E.; Dankers, N.M.J.A.; Steenbergen, J.; Goudswaard, P.C.

    2010-01-01

    Pacific oysters (Crassostrea gigas) were first observed in the Dutch Wadden Sea near Texel in 1983. The population increased slowly in the beginning but grew exponentially from the mid-1990s onwards, although now some stabilisation seems to be occurring. They occur on a variety of substrates such as

  1. The co-production of power and knowledge around the mussel fisheries transition in the Dutch Wadden Sea

    NARCIS (Netherlands)

    van der Molen, Franke; Puente Rodriguez, Daniel

    2013-01-01

    Governance practices are places where knowledge and power interconnect. In this paper, the stabilization of a governance practice concerning mussel fisheries in the Dutch Wadden Sea is described and analyzed in terms of the co-production of knowledge and power. In this governance practice,

  2. Mytilus galloprovincialis-type foot-protein-1 alleles occur at low frequency among mussels in the Dutch Wadden Sea

    NARCIS (Netherlands)

    Luttikhuizen, PC; Koolhaas, A; Bol, A; Piersma, T

    2002-01-01

    The presence of M. galloprovincialis-type genes among the population of mussels in the Dutch Wadden Sea, historically described as M edulis, was assessed. We applied the molecular technique in which a fragment of the gene coding for an adhesive protein of the byssus of mussels is amplified by PCR an

  3. Growth and size-dependent loss of newly settled bivalves in two distant regions of the Wadden Sea

    NARCIS (Netherlands)

    Andresen, H.; Dorresteijn, I.; van der Meer, J.

    2013-01-01

    Individual growth and the timing of life history events determine the course of individual body sizes. Hence, these factors can influence size-dependent species interactions, such as predation. In the Wadden Sea, predation by crustaceans plays an important role in the survival of pre-recruit bivalve

  4. Effects of the North Atlantic Oscillation and wind waves on salt marsh dynamics in the Danish Wadden Sea

    DEFF Research Database (Denmark)

    Kim, Daehyun; Grant, William E.; Cairns, David M.

    2013-01-01

    this notion has been conceptually introduced for the Wadden Sea, no modeling attempts have been made yet. As a proof of concept, this study developed a simulation model using the commercially available STELLAA (R) software, based on long-term data on water level and sedimentation collected at a back...

  5. Risk analysis on the import of seed mussels from the west coast of Sweden into the Wadden Sea

    NARCIS (Netherlands)

    Wijsman, J.W.M.; Tamis, J.E.; Kaag, N.H.B.M.; Karman, C.C.; Foekema, E.M.; Smaal, A.C.

    2007-01-01

    This report is the result of a risk analysis on the introduction of exotic non-indigenous species with the import of rope culture mussels from Sweden into the Wadden Sea. Based on available literature data and expert judgement, the target species are identified and the risks of these species are ass

  6. A review of science-policy interactions in the Dutch Wadden Sea - The cockle fishery and gas exploitation controversies

    NARCIS (Netherlands)

    Floor, J.R.; Koppen, van C.S.A.; Lindeboom, H.J.

    2013-01-01

    The potential ecological effects of cockle fisheries and gas exploitation in the Dutch Wadden Sea and their implications for policy and management have been the topic of vigorous societal debates. Ecological science has played crucial but controversial roles in these debates. Several social science

  7. Experiments on Erosion of Mud from the Danish Wadden Sea

    DEFF Research Database (Denmark)

    Johansen, C.; Larsen, Torben; Petersen, O.

    1994-01-01

    Experiments on erosion and consolidation of natural cohesive sediments from the harbour of Esbjerg located in the Danish Watten Sea were conducted using a rotating annular flume. The objective of the paper is to describe the erosion rate of deposited beds and relate the erosion rate...

  8. Abundance, growth and food demand of the scyphomedusa Aurelia aurita in the western Wadden Sea

    Science.gov (United States)

    van der Veer, H. W.; Oorthuysen, W.

    Medusae of Aurelia aurita are found in the western Wadden Sea from the beginning of May till August with maximum numbers of 250 to 500 individuals per 10 3 m 3 during May-June. The existence of a continuous ebb surplus suggests an origin from polyps living in the inner parts of the estuary and a transport or migration of the released medusae towards the North Sea. Growth is fast; a bell size of 20 cm diameter is reached within 3 to 4 months. The species is important as a predator from May to July, reaching maximum carbon biomass values of 12 to 18 g C·10 3 m -3. Predation by A. aurita may affect the recruitment of one of its food sources, viz. fish larvae.

  9. Effects of Fucus vesiculosus covering intertidal mussel beds in the Wadden Sea

    Science.gov (United States)

    Albrecht, A.; Reise, K.

    1994-06-01

    The brown alga Fucus vesiculosus forma mytili (Nienburg) Nienhuis covered about 70% of mussel bed ( Mytilus edulis) surface area in the lower intertidal zone of Königshafen, a sheltered sandy bay near the island of Sylt in the North Sea. Mean biomass in dense patches was 584 g ash-free dry weight m-2 in summer. On experimental mussel beds, fucoid cover enhanced mud accumulation and decreased mussel density. The position of mussels underneath algal canopy was mainly endobenthic (87% of mussels with >1/3 of shell sunk into mud). In the absence of fucoids, mussels generated epibenthic garlands (81% of mussels with Fucus vesiculosus on mussel beds in the intertidal Wadden Sea affects mussels and their epibionts negatively, but supports various herbivores and increases overall benthic diversity.

  10. Meat content of cultured mussels (Mytilus edulis) in relation to food supply, eutrophication, and suspended matter concentration in the Dutch Wadden Sea

    National Research Council Canada - National Science Library

    Craeymeersch, J; van Stralen, M.l; Bult, T

    2001-01-01

    .... We analysed long-term data sets (from 1952 onwards) on the meat content of cultured mussels, primary production, chlorophyll concentrations, and suspended matter concentration in the dutch Wadden Sea...

  11. Chemical monitoring in the Dutch Wadden Sea by means of benthic invertebrates and fish

    Science.gov (United States)

    Essink, Karel

    1989-09-01

    In monitoring, it is of utmost importance to carefully define the purpose, the sampling strategy, as well as the analytical chemical and statistical requirements. Surveys are appropriate for describing the geographical variation in environmental contaminant levels. Repeated surveys and recurrentdata collection at permanent locations provide means of detecting temporal trends. Results are presented here of surveys on pollution by trace metals, polychlorinated biphenyls and organochlorine pesticides in the Ems Estuary and Dutch Wadden Sea using Mytilus edulis, Mya arenaria, Arenicoia marina, Nereis diversicolor and Crangon crangon as test organisms. Trends towards decreasing pollution by mercury are illustrated by monitoring data on Mytilus edulis and Zoarces viviparus. It is stressed that the results of chemical monitoring in organisms may be interpreted only in termser the biological effects on the basis of relevant toxicological knowledge and/or additional bio-assays.

  12. Mytilus galloprovincialis-type foot-protein-1 alleles occur at low frequency among mussels in the Dutch Wadden Sea

    Science.gov (United States)

    Luttikhuizen, Pieternella C.; Koolhaas, Anita; Bol, Anneke; Piersma, Theunis

    2002-11-01

    The presence of M. galloprovincialis-type genes among the population of mussels in the Dutch Wadden Sea, historically described as M. edulis, was assessed. We applied the molecular technique in which a fragment of the gene coding for an adhesive protein of the byssus of mussels is amplified by PCR and assayed for length using electrophoresis. Among 321 individual mussels collected in August-October 2001 at 14 sites (5 intertidal, 9 subtidal) widely dispersed over the Dutch Wadden Sea, 6 specimens (collected at 5 sites) were found that showed a heterozygote genotype with both the M. edulis- and the M. galloprovincialis-type alleles being amplified; all others were identified as homozygotes for the M. edulis-type allele. Differentiation in frequencies of heterozygotes among sites was not detected. The fact that the M. galloprovincialis-type allele was present at low frequency (0.0093) may be attributed to one of three possible, and not mutually exclusive, causes: incomplete diagnosticity of this marker, an historically stable introgression zone in the Wadden Sea, or a recent invasion.

  13. Distinction between sortable silts and aggregated particles in muddy intertidal sediments of the East Frisian Wadden Sea, southern North Sea

    Science.gov (United States)

    Chang, Tae Soo; Flemming, Burghard W.; Bartholomä, Alexander

    2007-12-01

    In muddy sediments, the distinction between sortable silt and aggregated silty clay is important for the understanding of fine particle dynamics because both have different hydraulic properties. The Wadden Sea of the southern North Sea is severely depleted in fine-grained sediments mainly due to high energy levels along the diked coastline. As a result, muddy sediments are restricted to a narrow belt along the diked mainland shore. In the present study, the mechanism by which this mud is deposited and how floc deposition and break-up are reflected in the size distribution, has been investigated. For this purpose, surficial sediments from four intertidal nearshore transects were monitored and repeatedly sampled in the course of two years. High-resolution grain-size analyses were performed by an automated settling tube and a Sedigraph particle analyser for the sand and mud fractions, respectively. The grain size frequency distributions of the fine fractions demonstrate that the Wadden Sea muds are composed of two subpopulations, a well-sorted coarse silt and an unsorted silty clay population. A depletion of grain size around 8 μm (7 phi) demarcates the grain-size boundary between the two populations, suggesting that the finer mud population (changing energy regimes lead to apparent seasonal sedimentation patterns in the back-barrier tidal basins. Furthermore, in the course of sample preparation, the flocs and aggregates are broken down into their constituent particles. This mechanical artefact in the size distributions produces an artificial seasonal fining/coarsening pattern. It was found that the comparison of clay/silt and effect of climate change further promotes depletion of fine-grained sediments in the basin.

  14. Age-dependent zonation of the periwinkle Littorina littorea (L.) in the Wadden Sea

    Science.gov (United States)

    Saier, Bettina

    2000-12-01

    On sedimentary tidal flats near the island of Sylt (German Bight, North Sea) abundance and size distribution of periwinkles, Littorina littorea L., were studied in low intertidal and in shallow and deep subtidal mussel beds ( Mytilus edulis L.). In low intertidal mussel beds, surveys revealed that high densities (1,369±571 m-2) of juvenile snails (≤13 mm) were positively correlated with strong barnacle epigrowth ( Semibalanus balanoides L. and Balanus crenatus Bruguière) on mussels. A subsequent field experiment showed that recruitment of L. littorea was restricted to the intertidal zone. Abundances of periwinkles (213±114 m-2) and barnacles abruptly decreased in the adjacent shallow subtidal zone, which served as a habitat for older snails (>13 mm). L. littorea was completely absent from disjunct deep (5 m) subtidal mussel beds. Snail abundance varied seasonally with maxima of >4,000 m-2 in low intertidal mussel beds in October and minima in July, just before the onset of new recruitment. I suggest that the presence of cracks and crevices among the dense barnacle overgrowth in intertidal mussel beds favoured recruitment and survival of juvenile snails. Larger (older) specimens are assumed to actively migrate to the less favourable adjacent subtidal. Therefore, intertidal mussel beds are considered as nurseries for the population of L. littorea in the Wadden Sea.

  15. Integrating ground-penetrating radar and borehole data from a Wadden Sea barrier island

    DEFF Research Database (Denmark)

    Nielsen, Lars; Møller, I.; Nielsen, L. H.

    2009-01-01

    Sea level rise may have large implications for low-gradient barrier coastal systems. This problem motivated an integrated ground-penetrating radar (GPR) and sedimentological study of the Rømø Wadden Sea barrier island. Crossing W-E and N-S-oriented 100 MHz GPR reflection profiles with a total...... signals varies between 7 and 15 m in the interior of the island where the shallow subsurface is not influenced by saltwater intrusion or fine-grained salt marsh sediments. Analysis of common midpoint reflection data constrains the radar wave velocity distribution in the subsurface and facilitates depth...

  16. Acoustic and optical methods to infer water transparency at Time Series Station Spiekeroog, Wadden Sea

    Science.gov (United States)

    Schulz, Anne-Christin; Badewien, Thomas H.; Garaba, Shungudzemwoyo P.; Zielinski, Oliver

    2016-11-01

    Water transparency is a primary indicator of optical water quality that is driven by suspended particulate and dissolved material. A data set from the operational Time Series Station Spiekeroog located at a tidal inlet of the Wadden Sea was used to perform (i) an inter-comparison of observations related to water transparency, (ii) correlation tests among these measured parameters, and (iii) to explore the utility of both acoustic and optical tools in monitoring water transparency. An Acoustic Doppler Current Profiler was used to derive the backscatter signal in the water column. Optical observations were collected using above-water hyperspectral radiometers and a submerged turbidity metre. Bio-fouling on the turbidity sensors optical windows resulted in measurement drift and abnormal values during quality control steps. We observed significant correlations between turbidity collected by the submerged metre and that derived from above-water radiometer observations. Turbidity from these sensors was also associated with the backscatter signal derived from the acoustic measurements. These findings suggest that both optical and acoustic measurements can be reasonable proxies of water transparency with the potential to mitigate gaps and increase data quality in long-time observation of marine environments.

  17. Grazing on green algae by the periwinkle Littorina littorea in the Wadden Sea

    Science.gov (United States)

    Wilhelmsen, U.; Reise, K.

    1994-06-01

    On sedimentary tidal flats in the Wadden Sea near the Island of Sylt, the periwinkle Littorina littorea occurred preferentially on clusters and beds of mussels and on shell beds (100 to 350 m-2), achieved moderate densities on green algal patches or mats (20 to 50 m-2), and remained rare on bare sediments (10% of sediment surface appeared in summer on approximately one third of the tidal zone, mainly in the upper and sheltered parts and almost never on mussel and shell beds. In feeding experiments, L. littorea ingested more of the dominant alge, Enteromorpha, than of Ulva, irrespective of whether or not algae were fresh or decaying. The tough thalli of Chaetomorpha were hardly consumed. Snails feeding on Enteromorpha produced fecal pellets from which new growth of Enteromorpha started. In the absence of periwinkles, Enteromorpha developed on mussels and the attached fucoids. Experimentally increased snail densities on sediments prevented green algal development, but the snails were unable to graze down established algal mats. It is concluded that natural densities of L. littorea hardly affect the ephemeral mass development of green algae on sediments. However, where the snails occur at high densities, i.e. on mussel beds, green algal development may be prevented.

  18. Disease prevalence in flounder (Platichthys flesus) from the Dutch Wadden Sea as indicator of environmental quality: A summary of 1988-2005 surveys

    Science.gov (United States)

    Vethaak, A. D.

    2013-09-01

    In 1988, epizootics of ulcer disease in the flatfish flounder in the Dutch Wadden Sea were reported near freshwater drainage sluices of IJsselmeer Lake, locally affecting up to 38.9% of fish. Other diseases such as fin rot and lymphocystis were less frequent, but followed a similar pattern. Results of follow-up surveys in the Wadden Sea in 1994-2005 confirm previous findings and also show significantly elevated ulcer prevalences at other smaller drainage works. The most likely stress factors that contributed to the development of the epizootics at these sites include osmotic stress, adverse water quality conditions including chemical contaminants, nutritional deficiencies, and obstruction to fish migration. It was shown that discharges of IJsselmeer Lake freshwater in 1988-96 had a wide effect on the prevalence and distribution of ulcers and lymphocystis in the western Wadden Sea. A general reduction in disease prevalence in flounder in the entire Dutch Wadden Sea was observed during 1988-2005, which was most likely due to a general improvement in water quality and locally improved habitat conditions for flounder near drainage sluices. Ulcer prevalences outside the two IJsselmeer Lake sluices (Den Oever and Kornwerderzand) declined in this period from approximately 30% to 10% for medium-sized fish. Other skin diseases have also displayed a downward trend at both sites in recent years, with prevalences falling sharply to below 1%. Elsewhere in the Wadden Sea and the Ems-Dollard estuary, disease prevalences have declined towards natural background levels (diseases, especially ulcers, are useful indicators of environmental quality in the Wadden Sea.

  19. Spatial variability in structural and functional aspects of macrofauna communities and their environmental parameters in the Jade Bay (Wadden Sea Lower Saxony, southern North Sea)

    Science.gov (United States)

    Schückel, Ulrike; Beck, Melanie; Kröncke, Ingrid

    2013-03-01

    Spatial distribution and functional structure of intertidal benthic macrofauna in relation to environmental variables in the Jade Bay (southern North Sea) were studied and compared with other intertidal areas of the Wadden Sea. A total of 128 stations covering the whole Jade Bay were sampled in summer 2009. A total of 114 taxa were found. Highest species numbers occurred in the subtidal areas, whereas highest mean abundances were found in the upper intertidal areas. Based on species abundance data, six significantly distinct macrofauna communities in the Jade Bay were identified and evaluated with multivariate statistics, univariate correlations and canonical correspondence analysis. Differences in these community patterns were caused by the response of the dominant species ( Hydrobia ulvae, Tubificoides benedii, Pygospio elegans, Caulleriella killariensis, Scoloplos armiger, Urothoe poseidonis, Microprotopus maculatus) to prevailing environmental conditions along the gradient from the lower and exposed sandy intertidal areas via intermediate mixed sediments to the upper mudflat areas. Distribution patterns in relation to tidal zonation were best explained by variability in submergence time, Chlorophyll a (chl a) content and sediment composition (mud content), which are proxies for hydrodynamic conditions and food availability. Species inventory and species richness were comparable with other intertidal areas of the Wadden Sea, but the Jade Bay differs from these areas regarding dominant species. Differences in sediment composition and morphological characteristics (macrotidal versus mesotidal Wadden Sea areas) are discussed for comparison of regional differences.

  20. Passive settlement of Macoma balthica spat on tidal flats of the Wadden Sea and subsequent migration of juveniles

    Science.gov (United States)

    Armonies, Werner; Hellwig-Armonies, Monika

    Spatfall of the tellinid bivalve Macoma balthica may occur in fine-grained sediments at different tidal elevations in the Wadden Sea. but it is not clear which mechanism (active habitat selection or passive sinking of larvae, or both) can explain the observed distribution pattern. Spatfall and the subsequent development of juvenile abundances and size distribution were studied along a transect in the northern Wadden Sea near the Island of Sylt. Initial spatfall was highest in the lower intertidal and correlated significantly with hydrographic parameters. The enhanced larval settlement observed in dense aggregates of the tube-building polychaete Lanice conchilega confirmed the prominent role of hydrographic factors in initial spatfall. Subsequently, abundance strongly decreased in the lower intertidal but increased in the upper intertidal due to immigration of newly settled spat from lower sites. By the end of October, abundance was higher in the upper intertidal. Growth of the juveniles was higher in the upper intertidal. It is suggested that (1) initial spatfall is mainly ruled by hydrographic factors without active sediment selection; (2) young Macoma remain highly mobile during the first weeks of their benthic life and by byssus drift may achieve a net transport into areas with weak initial spatfall; (3) at the end of their first winter a second period of high floating activity occurs, bringing them back towards the lower intertidal and shallow subtidal. Thus, by successive postlarval migrations Macoma may several times change the intertidal site occupied during their first year of life. The comparatively low interannual variability of recruitment success noted in this species in the Wadden Sea may be a result of these migrations.

  1. Exploring interactions among intertidal macrozoobenthos of the Dutch Wadden Sea using population growth models

    Science.gov (United States)

    Williams, I. D.; van der Meer, J.; Dekker, R.; Beukema, J. J.; Holmes, S. P.

    2004-11-01

    Using data taken from three long-term monitoring programs, we modelled the population dynamics of 13 common macrozoobenthic species of the Balgzand, an approximately 50 km 2 intertidal area in the Dutch part of the Wadden Sea. In order to identify likely interactions among species, while accounting as much as possible for other factors influencing population dynamics, models included both 'environmental' (water temperature, and phytoplankton concentration) and 'biological' (biomass of potentially interacting species) variables. This approach appeared to be effective at identifying certain types of interactions acting over relatively short time-frames, such as predation and competition for food. Among the species we considered, the strongest effects of this kind appeared to be from what we presume to be predation by Nephtys hombergii, and from competition for food among bivalves. Several of the strongest results of our analysis corroborated expectations derived from previous small-scale surveys or experimental studies, but there were also a number of highly significant results indicating possible interactions which were not immediately explicable, including the apparent positive effect of Macoma balthica on Arenicola marina, and the apparent negative effect of Nephtys hombergii on Mya arenaria. Our results also suggest that year to year changes in Cerastoderma edule and Arenicola marina populations did not have substantial and widespread influences on the population dynamics of the majority of other common infauna, which is not to deny the likely critical importance of recruitment effects and biogenic transformation of the intertidal environment by these species over longer time frames. Our modelling approach could be applied to other long-term data sets, and will become more useful as longer time series become available.

  2. Mapping species abundance by a spatial zero-inflated Poisson model: a case study in the Wadden Sea, the Netherlands

    NARCIS (Netherlands)

    Lyashevska, O.; Brus, D.J.; Van der Meer, J.

    2016-01-01

    The objective of the study was to provide a general procedure for mapping spe-cies abundance when data are zero-in?ated and spatially correlated counts. Thebivalve species Macoma balthica was observed on a 5009500 m grid in theDutch part of the Wadden Sea. In total, 66% of the 3451 counts were zeros

  3. Assessing adaptive capacity of institutions to climate change : a comparative case study of the Dutch Wadden Sea and the Venice Lagoon

    NARCIS (Netherlands)

    Munaretto, S.; Klostermann, J.E.M.

    2011-01-01

    In this study we assess the adaptive capacity of relevant institutions for ecosystems and environmental management in two complex systems: the Dutch Wadden Sea and the Venice Lagoon. A new tool called the Adaptive Capacity Wheel (ACW) is used to diagnose strengths and weaknesses in the institutional

  4. Flyway protection and the predicament of our migrant birds: A critical look at international conservation policies and the Dutch Wadden Sea

    NARCIS (Netherlands)

    Boere, G.C.; Piersma, T.

    2012-01-01

    The nomination of the Dutch and German parts of the Wadden Sea as a World Heritage Site within the framework of the World Heritage Convention (WHC) represents high-level recognition of the global importance of this area for millions of migratory birds. It was not the first accolade for the unique

  5. Flyway protection and the predicament of our migrant birds : A critical look at international conservation policies and the Dutch Wadden Sea

    NARCIS (Netherlands)

    Boere, Gerard C.; Piersma, Theunis

    2012-01-01

    The nomination of the Dutch and German parts of the Wadden Sea as a World Heritage Site within the framework of the World Heritage Convention (WHC) represents high-level recognition of the global importance of this area for millions of migratory birds. It was not the first accolade for the unique

  6. Quantifying the residual volume transport through a multiple-inlet system in response to wind forcing: The case of the western Dutch Wadden Sea

    NARCIS (Netherlands)

    Duran-Matute, M.; Gerkema, T.; Sassi, M.

    2016-01-01

    In multiple-inlet coastal systems like the western Dutch Wadden Sea, the tides (and their interaction with the bathymetry), the fresh water discharge, and the wind drive a residual flow through the system. In the current paper, we study the effect of the wind on the residual volume transport through

  7. Fishing over the sides or over the stern: does it matter : comparison of two fishing methodologies in the Wadden Sea Demersal Fish Survey

    NARCIS (Netherlands)

    Chen, C.; Bolle, L.J.; Boois I.J. de, Ingeborg

    2016-01-01

    Since 1972, the Demersal Fish Survey (DFS) in the Wadden Sea has been carried out with the RV Stern. Within a few years this vessel will be replaced by another vessel as a result of the current ship replacement policy of Rijkswaterstaat Rijksrederij. It is not yet clear which vessel will replace RV

  8. Variability in transport of fish eggs and larvae. IV. Interannual variability in larval stage duration of immigrating plaice in the Dutch Wadden Sea

    NARCIS (Netherlands)

    Veer, van der W.; Bolle, L.J.; Geffen, A.J.; Witte, J.IJ.

    2009-01-01

    Larval immigration of plaice Pleuronectes platessa L. into the western Wadden Sea in spring was followed biweekly from 1993 to 2002. For each year (1993 excluded), 150 settling individuals were selected and used for reconstruction of larval stage duration based on otolith daily ring counts. In addit

  9. Long-term patterns in 50 years of scyphomedusae catches in the western Dutch Wadden Sea in relation to climate change and eutrophication

    NARCIS (Netherlands)

    van Walraven, L.; Langenberg, V.T.; Dapper, R.; Witte, J.IJ.; Zuur, A.F.; van der Veer, H.W.

    2015-01-01

    Using a unique 50-year high-resolution time series of daily kom-fyke catches, long-term patterns of scyphomedusae in the western Dutch Wadden Sea were analysed and related to changes in environmental conditions [eutrophication in the 1980s–1990s and recent climate change (increased water temperature

  10. Identification of a domoic acid-producing pseudo-Nitzschia species (Bacillariophyceae) in the Dutch Wadden sea with electron microscopy and molecular probes

    NARCIS (Netherlands)

    Vrieling, Engel G.; Koeman, Reinoud P.T.; Scholin, Christopher A.; Scheerman, Paul; Peperzak, Louis; Veenhuis, Marten; Gieskes, Winfried W.C.

    1996-01-01

    Biological monitoring in the Dutch Wadden Sea between November 1993 and July 1994 revealed Pseudo-nitzschia-like pennate chain-forming diatom species with cell numbers ranging from 10^2 to 10^5 per litre. Cultured isolates and field samples were examined by electron microscopy, which revealed the

  11. Quantified and applied sea-bed dynamics of the Netherlands Continental Shelf and the Wadden Sea

    NARCIS (Netherlands)

    van Dijk, T.A.G.P.; Kleuskens, M.H.P.; Dorst, L.L.; Van der Tak, C.; Doornenbal, P.J.; Van der Spek, A.J.F.; Hoogendoorn, R.M.; Rodriguez Aguilera, D.; Menninga, P.J.; Noorlandt, R.P.

    2012-01-01

    Sedimentary coasts and shallow-sea beds may be dynamic. The large-scaled spatial variation in these dynamics and the smaller-scaled behaviour of individual marine bedforms are largely unknown. Sea-bed dynamics are relevant for the safety of shipping, and therefore for monitoring strategies, and for

  12. Population development and status of harbour seals (Phoca vitulina in the Wadden Sea

    Directory of Open Access Journals (Sweden)

    Peter JH Reijnders

    2010-09-01

    Full Text Available An index for the condition of a population should include a measure of the recuperative power or resilience of the population in question. This measure needs to cover both the demographic and physiological condition of the population. Applied to the harbour seal population in the Wadden Sea we therefore address respectively the population development and distribution, and its health condition, and relate these to environmental conditions. The harbour seal population has been severely depleted by hunting in the first half of the 20th century. After hunting was stopped in the mid-1970s the population recovered gradually. This recovery was twice interrupted by Phocine Distemper Virus (PDV outbreaks in 1988 and 2002. These PDV-epizootics reduced the population by 57% and 50% respectively. They also lead to changes in age and sex structure of the population, which gradually returned to a stable age-structure. Despite the reduction in population size by respectively 57% and 50%, the population showed a strong recovery with a growth rate close to the considered maximum possible for this species. The observed changes in the distribution of the population over the 4 sub-regions indicate that distribution is not a static phenomenon. Long term field and pathological investigations point out that the general health status of the population has improved, particularly that of newborn seals (0-6months old. The increasing prevalence of parasites in lungs and intestine warrants continued monitoring of the health status of seals. This is especially relevant in view of the exponential increase of the population, which may finally approach the carrying capacity of the area. Concluding, we canstate that the condition of the population in terms of demographic and health parameters is satisfactory. The best guarantee for maintaining such a favourable conservation status is to abstain from human interferences (e.g. rescue, rehabilitation and release with natural

  13. A review of science-policy interactions in the Dutch Wadden Sea - The cockle fishery and gas exploitation controversies

    Science.gov (United States)

    Floor, Judith R.; van Koppen, C. S. A. (Kris); Lindeboom, Han J.

    2013-09-01

    The potential ecological effects of cockle fisheries and gas exploitation in the Dutch Wadden Sea and their implications for policy and management have been the topic of vigorous societal debates. Ecological science has played crucial but controversial roles in these debates. Several social science studies have been dedicated to analysing these roles and making recommendations for the improvement of science-policy interactions. In reviewing these studies, this article aims to draw lessons for (ecological) scientists and policy makers on how to understand and guide the interactions of science and policy in Wadden Sea management. Studies addressing science-policy interactions in the Dutch Wadden Sea can be grouped into three main perspectives, emphasizing the social and economic dynamics of resource management, the role of nature views and discourses in controversies, and the influence of science dynamics in policy and management debates. The review demonstrates that ecological knowledge and ecological scientists have played important roles in the controversies on cockle fisheries and gas exploitation. However, scientific knowledge was not always the most important factor in the decision-making process, and scientific insights were not always used as expected by the scientists. How scientific knowledge is used and interpreted by stakeholders was dependent on their interests, their nature views and on the dominant policy discourses. Ecological knowledge and scientists themselves became part of the policy debates, e.g. in discussions on uncertainty and reliability. The position of scientists in policy debates was strongly influenced by the policy setting and by changes in this setting, e.g. by the operation of mediators or by new interpretations of legal rules. A lesson to be drawn for scientists is that they should reflect on the sort of position - e.g. independent outsider, or engaged stakeholder - they take in a debate. They should also be aware that this position

  14. Sulfur cycling of intertidal Wadden Sea sediments (Konigshafen, Island of Sylt, Germany): sulfate reduction and sulfur gas emission

    Science.gov (United States)

    Kristensen, E.; Bodenbender, J.; Jensen, M. H.; Rennenberg, H.; Jensen, K. M.

    2000-05-01

    Sulfate reduction rates (SRR t) and reduced inorganic sulfur pools (RIS) in Wadden Sea sediment as well as sulfur gas emissions directly to the atmosphere were measured at intervals of 2 to 12 months from 1991 to 1994. Three stations were chosen in the intertidal embayment, Königshafen, representing the range of sediments found in the Wadden Sea: Organic-poor coarse sand, organic-poor and Arenicola marina inhabited medium sand, and organic-rich muddy sand. Maximum SRR t were 2 to 5 times higher in muddy sand than in the sandy sediments. The depth-integrated SRR t varied 12 to 13-fold on a seasonal basis at the three stations. Although temperature controls biochemical processes, the overall control is more complex due to the simultaneous influence of other seasonal factors such as availability of organic matter and oxidation level of surface sediment. The sedimentary RIS pools were low due to iron limitation and contained only 30% acid volatile sulfur (AVS). Muddy sand had up to an order of magnitude more RIS than the two sandy sediments. The turnover of RIS was rapid (turnover time from ˜1 to 32 h), fastest during summer and at the sandy stations. The emission of S-gases was dominated by H 2S during summer (45-67% of the total), and was highest in muddy and lowest in coarse sand. H 2S was less important in early spring (3-49% of the total). Other sulfur gases, such as COS, DMS and CS 2, each accounted for less than 20% of the total sulfur emissions with no specific temporal and spatial pattern. Due to the low content of metals in the sediment, the reduced sulfur pools are cycled rapidly with chemical and biological reoxidation at oxic-anoxic boundaries as a major sink. Thus, the emissions of H 2S account for less than 1‰ of the sulfide produced.

  15. The importance of rivers as nursery grounds for 0- and 1-group flounder ( Platichthys flesus L.) in comparison to the Wadden sea

    Science.gov (United States)

    Kerstan, M.

    From May 1988 to June 1989 selected areas of the German Wadden Sea, the Ems, Weser, Elbe and Eider estuaries as well as in Elbe tributaries were sampled for 0- and 1-group flounder ( Platichthys flesus L.). Estuarine and Wadden Sea sampling was conducted on board commercial shrimp vessels equipped with beam trawls. The Elbe river system was sampled on board a research boat equipped with a similar 3-m beam trawl. Density indices were calculated for the various areas. To estimate the importance of rivers as nursery areas for flounder, river surface area was compared to the area of tidal flats in the Wadden Sea. In all surveys, there was no relationship between fish densities and tow directions with respect to tide. In the Elbe river system flounder densities were not correlated to substrate types but increased significantly with decreasing salinity. Abundances were always lowestt in polyhaline habitats and increased up to 10-fold in mesohaline estuarine areas. In the limnetic tidal sections of the Elbe river and its tributaries densities increased again by factors of 3 to 10. The succession of 1-group modal lengths from limnetic to polyhaline habitats demonstrated that smaller fish preferred less saline waters. 0-group specimens lagging behind in growth did not leave the limnetic river section in winter. The onset of the spawning migration in November was determined by monitoring the length-frequency distributions throughout the year. The possible sources of bias are discussed and gear efficiency is estimated from literature sources. The contribution of rivers to the 0- and 1-group flounder population on the tidal flats of the Wadden Sea is estimated at about 35.1%.

  16. Ground subsidence Wadden Sea 1977-2011. Precision and reliability of measurements. Annex; Bodemdaling Waddenzee 1977-2011. Precisie en betrouwbaarheid uit metingen. Appendix

    Energy Technology Data Exchange (ETDEWEB)

    Houtenbos, A.P.E.M.

    2011-12-15

    What about the subsidence caused by gas exploitation around the Wadden Sea? Is subsidence on the Wadden Sea really manageable by extraction with the 'hand on the faucet'? These and other questions are examined in an analysis of the measurements around the Wadden Sea in the period 1977-2011. After publication of the main report on the effects of ground subsidence at the island Ameland-Oost two more aspects were investigated: sedimentation and the speed of ground subsidence. This annex reports on those aspects [Dutch] Hoe staat het met de bodemdaling door gaswinning rond de Waddenzee? Is bodemdaling op de Waddenzee werkelijk beheersbaar door winning met de 'Hand aan de kraan'? Deze en andere vragen zijn onderzocht in een analyse van de metingen rond de Waddenzee tot over de periode 1977-2011. Na publicatie van het hoofdrapport over de effecten van bodemdaling op Ameland-Oost op 9 dec 2011 zijn nog twee aspecten met consequenties voor de bodemdaling op het Wad nader onderzocht: sedimentatie en bodemdalingsnelheid. Deze appendix geeft de resultaten weer.

  17. Organochlorine compounds in blue mussels, Mytilus edulis, and Pacific oysters, Crassostrea gigas, from seven sites in the Lower Saxonian Wadden Sea, Southern North Sea.

    Science.gov (United States)

    Dörr, Barbara; Liebezeit, Gerd

    2009-12-01

    Blue mussels (Mytilus edulis) and Pacific oysters (Crassostrea gigas) collected at seven locations in the Lower Saxonian Wadden Sea in January and February 2007 were analysed for organochlorine compounds. Contaminants were present in all samples, albeit with variable amounts and composition. The highest values were found in the Jade Bay. Congener PCB 153 was the contaminant which had the highest content of all organochlorines tested (475.75-937.39 ng/g lipid). DDT was detected in one sample only while DDD and DDE were found in all samples, the latter with contents up to 351.34 ng/g lipid. No clear differentiation could be made in terms of accumulation of organochlorines for M. edulis and C. gigas. Comparison with data from 2001 to 2006 showed an increase in 2007, which may be due to the different season the samples were taken.

  18. Mapping species abundance by a spatial zero-inflated Poisson model: a case study in the Wadden Sea, the Netherlands.

    Science.gov (United States)

    Lyashevska, Olga; Brus, Dick J; van der Meer, Jaap

    2016-01-01

    The objective of the study was to provide a general procedure for mapping species abundance when data are zero-inflated and spatially correlated counts. The bivalve species Macoma balthica was observed on a 500×500 m grid in the Dutch part of the Wadden Sea. In total, 66% of the 3451 counts were zeros. A zero-inflated Poisson mixture model was used to relate counts to environmental covariates. Two models were considered, one with relatively fewer covariates (model "small") than the other (model "large"). The models contained two processes: a Bernoulli (species prevalence) and a Poisson (species intensity, when the Bernoulli process predicts presence). The model was used to make predictions for sites where only environmental data are available. Predicted prevalences and intensities show that the model "small" predicts lower mean prevalence and higher mean intensity, than the model "large". Yet, the product of prevalence and intensity, which might be called the unconditional intensity, is very similar. Cross-validation showed that the model "small" performed slightly better, but the difference was small. The proposed methodology might be generally applicable, but is computer intensive.

  19. The Elbe flood 2002--toxic effects of transported contaminants in flatfish and mussels of the Wadden Sea.

    Science.gov (United States)

    Einsporn, S; Broeg, K; Koehler, A

    2005-04-01

    Cellular changes in livers from flounder (Platichthys flesus L.) and digestive glands of blue mussels (Mytilus edulis) were studied to analyze whether the Elbe flood catastrophe in August 2002 had any deleterious effects on animal health. Flatfish and mussels were sampled at different locations in the Elbe estuary and the Wadden Sea after the flood wave had reached the German Bight. Internationally used core biomarkers (lysosomal membrane stability, biotransformation enzymes) were applied to assess the toxic effects of putatively increased pollution levels. In comparison to earlier data from long-term studies at the same stations, we found a significant impairment in the function of cell organelles (lysosomes) involved in the detoxification and elimination of pollutants in fish liver. Concentrations of relevant contaminants (organochlorines, polychlorinated biphenyls) were analyzed in parallel with cellular biomarkers, and conspicuously raised concentrations of insecticides metabolites were detected. Cell recovery and a clear reduction in contaminant concentrations were observed in fish livers five months after the flood at all sampling sites except the Helgolander Tiefe Rinne.

  20. Determination of the Critical Erosion Threshold of Cohesive Sediments on Intertidal Mudflats Along the Dutch Wadden Sea Coast

    Science.gov (United States)

    Houwing, E.-J.

    1999-10-01

    The bed shear strength on an intertidal mudflat bordering salt marshes along the Dutch Wadden Sea coast was determined by means of an in situ erosion flume (ISEF). Characteristic erosion patterns (type I- and type II-erosion) were observed for most measurements. The critical erosion threshold varied between 0·11-0·18 (Pa) for all measurements and erosion rates varied between 5×10 -5and 3×10 -3(kg m -2 s -1). No clear relationship was found between distinct parameters like bed density, moisture content or biological activity and the critical erosion threshold. A more pronounced effect of the erodability of the mudflat was found when the erosion rate was taken into account. Basically two clusters were distinguished. High mean peak erosion rates of the substratum were found at locations which were characterized by a low mud content of the substratum (below 20% mud by weight). In these situations bed load transport is expected to be the most important process which determined erosion of the bed and erosion of predominantly the sand fraction was found. At higher rates of the mud content (over 20% mud by weight) mean peak erosion rates decreased substantially (an order 6 to 10 times lower) and both erosion of the mud and sand fraction was found.

  1. A 1D model for tides waves and fine sediment in short tidal basins—Application to the Wadden Sea

    Science.gov (United States)

    van Prooijen, Bram Christiaan; Wang, Zheng Bing

    2013-12-01

    In order to simulate the dynamics of fine sediments in short tidal basins, like the Wadden Sea basins, a 1D cross-sectional averaged model is constructed to simulate tidal flow, depth-limited waves, and fine sediment transport. The key for this 1D model lies in the definition of the geometry (width and depth as function of the streamwise coordinate). The geometry is computed by implementing the water level and flow data, from a 2D flow simulation, and the hypsometric curve in the continuity equation. By means of a finite volume method, the shallow-water equations and sediment transport equations are solved. The bed shear stress consists of the sum of shear stresses by waves and flow, in which the waves are computed with a depth-limited growth equation for wave height and wave frequency. A new formulation for erosion of fines from a sandy bed is proposed in the transport equation for fine sediment. It is shown by comparison with 2D simulations and field measurements that a 1D schematization gives a proper representation of the dynamics in short tidal basins.

  2. Spatial and temporal scales of shoreline morphodynamics derived from video camera observations for the island of Sylt, German Wadden Sea

    Science.gov (United States)

    Blossier, Brice; Bryan, Karin R.; Daly, Christopher J.; Winter, Christian

    2017-04-01

    Spatial and temporal scales of beach morphodynamics were assessed for the island of Sylt, German Wadden Sea, based on continuous video camera monitoring data from 2011 to 2014 along a 1.3 km stretch of sandy beach. They served to quantify, at this location, the amount of shoreline variability covered by beach monitoring schemes, depending on the time interval and alongshore resolution of the surveys. Correlation methods, used to quantify the alongshore spatial scales of shoreline undulations, were combined with semi-empirical modelling and spectral analyses of shoreline temporal fluctuations. The data demonstrate that an alongshore resolution of 150 m and a monthly survey time interval capture 70% of the kilometre-scale shoreline variability over the 2011-2014 study period. An alongshore spacing of 10 m and a survey time interval of 5 days would be required to monitor 95% variance of the shoreline temporal fluctuations with steps of 5% changes in variance over space. Although monitoring strategies such as land or airborne surveying are reliable methods of data collection, video camera deployment remains the cheapest technique providing the high spatiotemporal resolution required to monitor subkilometre-scale morphodynamic processes involving, for example, small- to middle-sized beach nourishment.

  3. Growth conditions of 0-group plaice Pleuronectes platessa in the western Wadden Sea as revealed by otolith microstructure analysis

    Science.gov (United States)

    Cardoso, Joana F. M. F.; Freitas, Vânia; de Paoli, Hélène; Witte, Johannes IJ.; van der Veer, Henk W.

    2016-05-01

    Growth studies based on population-based growth estimates are limited by the fact that they do not take into account differences in age/size structure within the population. To overcome these problems, otolith microstructure analysis is often used to estimate individual growth. Here, we analyse growth of 0-group plaice in the western Wadden Sea in two years: a year preceded by a mild winter (1995) and a year preceded by a severe winter (1996). Growth was analysed by combining information on individual growth based on otolith analysis with predictions of maximum growth (= under optimal food conditions) based on a Dynamic Energy Budget model. Otolith analysis revealed that settlement occurred earlier in 1995 than in 1996. In both years, one main cohort was found, followed by a group of late settlers. No differences in mean length-at-age were found between these groups. DEB modelling suggested that growth was not maximal during the whole growing season: realized growth (the fraction of maximum growth realized by 0-group plaice) declined in the summer, although this decline was relatively small. In addition, late settling individuals exhibited lower realized growth than individuals from the main cohort. This study confirms that growth conditions for 0-group plaice are not optimal and that a growth reduction occurs in summer, as suggested in previous studies.

  4. Spatial and temporal scales of shoreline morphodynamics derived from video camera observations for the island of Sylt, German Wadden Sea

    Science.gov (United States)

    Blossier, Brice; Bryan, Karin R.; Daly, Christopher J.; Winter, Christian

    2016-08-01

    Spatial and temporal scales of beach morphodynamics were assessed for the island of Sylt, German Wadden Sea, based on continuous video camera monitoring data from 2011 to 2014 along a 1.3 km stretch of sandy beach. They served to quantify, at this location, the amount of shoreline variability covered by beach monitoring schemes, depending on the time interval and alongshore resolution of the surveys. Correlation methods, used to quantify the alongshore spatial scales of shoreline undulations, were combined with semi-empirical modelling and spectral analyses of shoreline temporal fluctuations. The data demonstrate that an alongshore resolution of 150 m and a monthly survey time interval capture 70% of the kilometre-scale shoreline variability over the 2011-2014 study period. An alongshore spacing of 10 m and a survey time interval of 5 days would be required to monitor 95% variance of the shoreline temporal fluctuations with steps of 5% changes in variance over space. Although monitoring strategies such as land or airborne surveying are reliable methods of data collection, video camera deployment remains the cheapest technique providing the high spatiotemporal resolution required to monitor subkilometre-scale morphodynamic processes involving, for example, small- to middle-sized beach nourishment.

  5. How a barrier island may react on a sea-level rise: The Holocene to Recent Rømø barrier island, Danish Wadden Sea

    DEFF Research Database (Denmark)

    Johannessen, Peter N.; Nielsen, Lars H.; Møller, Ingelise

    The Rømø barrier island is situated in the northern part of the European Wadden Sea. It has been intensively studied on the basis of recent depositional systems and morphology, seven 25 m long sediment cores, 35 km ground penetrating radar (GPR) reflection profiles with a maximum signal penetration...... of c. 15 m and a resolution of c. 20–30 cm (Nielsen et al., 2009), and dating of 70 core samples using optically stimulated luminescence (OSL). The area has experienced a relative sea-level rise of c. 15 m during the last c. 8000 years. The Recent tidal amplitude reaches c. 1.8 m. During strong wind...... set up the water level increases considerably and the highest measured water level is 4.9 m above mean sea level. The barrier island is c. 14 km long and c. 4 km wide and is separated from the mainland by a c. 8 km wide lagoon. At the northern and southern parts of the island, tidal inlets occur...

  6. On the determination of net bedload transport patters in a natural tidal inlet system (Knudedyb in the Danish Wadden Sea)

    Science.gov (United States)

    Ernstsen, V. B.; Lefebvre, A.; Bartholdy, J.; Bartholomä, A.; Winter, C.

    2012-04-01

    An airborne swath topography survey using a LIDAR (Laser Induced Detection And Ranging or Light Detection And Ranging) system and a ship borne swath bathymetry survey using a multibeam echosounder (MBES) system were carried out within a 100 km2 quadratic section of the natural tidal inlet system Knudedyb in the Danish Wadden Sea. On the basis of the LIDAR data a detailed (0.5 m grid cell size) digital elevation model (DEM) of the dry-lying areas around low water (with the intertidal flats being of primary concern) was generated; whereas the MBES data were used to generate a detailed (also 0.5 m grid cell size) DEM of the tidal inlet main channel. The spatial distribution and characteristics of bedforms in a coastal system potentially yield information on the net bedload transport patterns in the system. The sandy main channel and intertidal flats of the Knudedyb tidal inlet are covered by bedforms. Bedform characterisation using a random field statistical approach (2D spectral analysis, cf. Lefebvre et al. 2011) as well as a discrete approach, in which the geometric variables of individual bedforms are determined (cf. Ernstsen et al. 2010), will be applied to the high-resolution DEMs. Based on these analyses net bedload transport patterns in the Knudedyb tidal inlet system will be determined. The findings will be used to investigate a potential exchange of sand between the main tidal channel and the adjacent intertidal flats. Acknowledgements This work is funded by the Danish Council for Independent Research | Natural Sciences (grant 10-081102) and the German Research Foundation DFG-Research Center / Excellence Cluster "The Ocean in the Earth System".

  7. The effects of shellfish fishery on the ecosystems of the Dutch Wadden Sea and Oosterschelde : final report on the second phase of the scientific evaluation of the Dutch shellfish fishery policy (EVA II)

    NARCIS (Netherlands)

    Ens, B.J.; Smaal, A.C.; Vlas, de J.

    2004-01-01

    This publication summarises the findings of the scientific research projects carried out as part of EVA II, the second phase in the evaluation of shellfish fisheries policy in the Zeeland Delta and the Wadden Sea, and relates these findings to other studies on the ecological effects of shellfish fis

  8. Resources for long-distance migration of knots Calidris canutus islandica and C. c. canutus : how broad is the temporal exploitation window of benthic prey in the western and eastern Wadden Sea?

    NARCIS (Netherlands)

    Piersma, Theunis; Verkuil, Yvonne; Tulp, Ingrid

    1994-01-01

    In the course of each spring, two subspecies of knots Calidris canutus (islandica wintering in Europe and breeding in the Nearctic, and canutus wintering in west Africa and breeding in Siberia), stage in the international Wadden Sea before their northward flights to the arctic breeding grounds. In M

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

    NARCIS (Netherlands)

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

    2013-01-01

    This paper describes and quantifies the effect of low stone dams on the extent and composition of salt-marsh habitats on two Dutch Wadden islands: Terschelling and Ameland. The stone dams were built to prevent erosion of the salt-marsh edge. Analyses of a series of aerial photographs taken between 1

  10. Impact on bird fauna of a non-native oyster expanding into blue mussel beds in the Dutch Wadden Sea

    NARCIS (Netherlands)

    Waser, Andreas M.; Deuzeman, Symen; Kangeri, Arno K.W.; Winden, van Erik; Postma, Jelle; Boer, de Peter; Meer, van der Jaap; Ens, Bruno J.

    2016-01-01

    Intertidal mussel beds are important for intertidal ecosystems, because they feature a high taxonomic diversity and abundance of benthic organisms and are important foraging grounds for many avian species. After the introduction of the Pacific oyster (Crassostrea gigas) into the European Wadden S

  11. Dendrochronology of Atriplex portulacoides and Artemisia maritima in Wadden Sea salt marshes

    NARCIS (Netherlands)

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

    2014-01-01

    The study uses a rather unusual method, dendrochronology, to investigate the growth and survival of Atriplex portulacoides L. and Artemisia maritima L. on salt marshes at two field sites on the Dutch North Sea barrier islands of Terschelling and Ameland. By providing information on longevity of thes

  12. Alien parasitic copepods in mussels and oysters of the Wadden Sea

    NARCIS (Netherlands)

    Elsner, N.O.; Jacobsen, S.; Thieltges, D.W.; Reise, K.

    2011-01-01

    Molluscan intestinal parasites of the genus Mytilicola, specifically M. intestinalis, were initially introduced into bivalves in the North Sea in the 1930s. It was presumably introduced from the Mediterranean with ship-fouling mussels, then attained epidemic proportions in Mytilus edulis in the 1950

  13. Dendrochronology of Atriplex portulacoides and Artemisia maritima in Wadden Sea salt marshes

    NARCIS (Netherlands)

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

    2014-01-01

    The study uses a rather unusual method, dendrochronology, to investigate the growth and survival of Atriplex portulacoides L. and Artemisia maritima L. on salt marshes at two field sites on the Dutch North Sea barrier islands of Terschelling and Ameland. By providing information on longevity of

  14. Trends in Wadden Sea Fish Fauna, Part II: Dutch Demersal Fish Survey (DFS)

    NARCIS (Netherlands)

    Tulp, I.Y.M.; Bolle, L.J.

    2009-01-01

    Shallow waters along the North Sea coast provide nursery areas for juveniles of several fish species, including commercially exploited species, and natural habitat for resident species and seasonal visitors. These areas have gone through major changes in the last decades due to climate change and hu

  15. Trends in Wadden Sea Fish Fauna, Part II: Dutch Demersal Fish Survey (DFS)

    OpenAIRE

    Tulp, I.Y.M.; Bolle, L.J.

    2009-01-01

    Shallow waters along the North Sea coast provide nursery areas for juveniles of several fish species, including commercially exploited species, and natural habitat for resident species and seasonal visitors. These areas have gone through major changes in the last decades due to climate change and human activities, which will likely result in changes in the abundance and species composition of the fish fauna in coastal waters.

  16. Long-term changes in species composition of demersal fish and epibenthic species in the Jade area (German Wadden Sea/Southern North Sea) since 1972

    Science.gov (United States)

    Meyer, Julia; Kröncke, Ingrid; Bartholomä, Alexander; Dippner, Joachim W.; Schückel, Ulrike

    2016-11-01

    Within this long-term study, the short- and long-term variability of demersal fish and epibenthic species in relation to temperature and climate-driven environmental changes in the inshore tidal bay system of the Jade area was investigated. Semiquantitative sampling took place once per spring and summer period from 1972 to 2014 by using a 2 m beam trawl at one station in the Jade area (German Wadden Sea/southern North Sea). Min/max autocorrelation analysis (MAFA) and Mann-Kendall analysis revealed significant increasing trends in total abundance and species number. Homogeneity analysis revealed shifts for abundance in spring and summer in the late 1980s and for species number in the late 1980s in spring and early 2000s in summer. Abundances of the estuarine crustacean species Carcinus maenas and Liocarcinus holsatus and of the estuarine fish species Pomatoschistus spp. showed significant increasing abundances since the late 1980s. The marine juvenile species Pleuronectes platessa and Limanda limanda showed significant decreasing abundances, while abundances of Solea solea showed significant increasing abundances since the early 2000s. Abundances of L.holsatus and C. maenas showed mass occurrences since the early 2000s. Spearman correlation analysis revealed significant correlations of temperature and abundance data of some characteristic species. Statistical downscaling analysis revealed significant correlations between observations and climate indicators such as the North Sea Environmental (NSE) Index for spring. Thus, it appears that climate effects influenced the long-term variability of species number and abundance of epibenthic and demersal fish species in the Jade area, resulting in community shifts in the late 1980s and early 2000s.

  17. Long-term population dynamics of breeding bird species in the German Wadden Sea area

    Science.gov (United States)

    Vauk, Gottfried; Prüter, Johannes; Hartwig, Eike

    1989-09-01

    For no other group of organisms in coastal areas are there so exact and long-term data available as there are for seabirds. Since the beginning of the 20th century, documentation of population size, especially for species breeding in colonies from the groups gulls, terns and auks, is almost complete. These species act as bio-indicators, and data on fluctuations in their population size are useful as they reflect changes in the state of the marine ecosystem. The population development of some of these seabird species (Herring Gull, Guillemot, Common, Arctic and Sandwich Tern) from the German North Sea coast, which primarily feed on fish, is given. Common to all these species is an exponential increase in numbers in recent years (1970 1985). Possible causes for this development, e.g. pressure from enemies or competitors, availability of breeding places, anthropogenic stress and mortality factors, as well as the direct and indirect anthropogenic-influenced changes in the trophic system due to the increasing eutrophication of coastal waters, are evaluated. Signs of a collapse in the stocks of seabrids resulting from environmental pollution are discussed. Consequences resulting from the ecosystem changes, such as reduction of nutrient discharge into the North Sea and the expansion of biological monitoring, are described.

  18. Turnover of postlarval bivalves in sediments of tidal flats in Königshafen (German Wadden sea)

    Science.gov (United States)

    Armonies, W.

    1994-06-01

    After larval settlement, juvenile bivalves may rapidly re-enter the water column and attain secondary dispersal by byssus-drifting. In order to estimate the quantitative importance of byssus-drifting, the abundance of drifters in the water column, their re-entry into the sediment, and their density in the ambient sediment were measured simultaneously over 3 months on a tidal flat in Königshafen near the Island of Sylt in the North Sea. Turnover of juvenile clams Macoma balthica and cockles Cerastoderma edule was more than once per week in summer, showing strong short-term variability because of semi-lunar rhythms of drifting activity. While there is currently no evidence for active habitat selection in settling M. balthica and C. edule larvae, it is suggested that habitat selection occurs following postlarval migrations.

  19. Effects of the North Atlantic Oscillation and wind waves on salt marsh dynamics in the Danish Wadden Sea: a quantitative model as proof of concept

    Science.gov (United States)

    Kim, Daehyun; Grant, William E.; Cairns, David M.; Bartholdy, Jesper

    2013-08-01

    Long-term eustatic sea-level variation has been recognized as a primary factor affecting the hydrological and geomorphic dynamics of salt marshes. However, recent studies suggest that wind waves influenced by atmospheric oscillations also may play an important role in many coastal areas. Although this notion has been conceptually introduced for the Wadden Sea, no modeling attempts have been made yet. As a proof of concept, this study developed a simulation model using the commercially available STELLA® software, based on long-term data on water level and sedimentation collected at a back-barrier marsh on the Skallingen peninsula in Denmark. In the model, the frequency (number year-1) of wind-driven extreme high water level (HWL) events (>130 cm Danish Ordnance Zero) was simulated in terms of the North Atlantic Oscillation (NAO) index. Then, surface accretion (cm year-1) and submergence duration (h year-1) were simulated for the period 1933-2007. The model showed good performances: simulated rates of surface accretion and simulated durations of submergence decreased from 1950 to 1980, the point at which the NAO shifted from its negative to its positive phase, and increased thereafter. Despite continuous increases in surface elevation, increases in simulated submergence duration were apparently due to wind-driven HWL events, which generally increased in frequency after 1980. These findings for the Danish Wadden Sea add to the growing body of evidence that the role of atmospheric oscillations—e.g., the NAO—as drivers of wind-generated water level variations merits more attention in assessing the impact of climate change on coastal marshes.

  20. Integration of TerraSAR-X, RapidEye and airborne lidar for remote sensing of intertidal bedforms on the upper flats of Norderney (German Wadden Sea)

    Science.gov (United States)

    Adolph, Winny; Jung, Richard; Schmidt, Alena; Ehlers, Manfred; Heipke, Christian; Bartholomä, Alexander; Farke, Hubert

    2017-04-01

    The Wadden Sea is a large coastal transition area adjoining the southern North Sea uniting ecological key functions with an important role in coastal protection. The region is strictly protected by EU directives and national law and is a UNESCO World Heritage Site, requiring frequent quality assessments and regular monitoring. In 2014 an intertidal bedform area characterised by alternating crests and water-covered troughs on the tidal flats of the island of Norderney (German Wadden Sea sector) was chosen to test different remote sensing methods for habitat mapping: airborne lidar, satellite-based radar (TerraSAR-X) and electro-optical sensors (RapidEye). The results revealed that, although sensitive to different surface qualities, all sensors were able to image the bedforms. A digital terrain model generated from the lidar data shows crests and slopes of the bedforms with high geometric accuracy in the centimetre range, but high costs limit the operation area. TerraSAR-X data enabled identifying the positions of the bedforms reflecting the residual water in the troughs also with a high resolution of up to 1.1 m, but with larger footprints and much higher temporal availability. RapidEye data are sensitive to differences in sediment moisture employed to identify crest areas, slopes and troughs, with high spatial coverage but the lowest resolution (6.5 m). Monitoring concepts may differ in their remote sensing requirements regarding areal coverage, spatial and temporal resolution, sensitivity and geometric accuracy. Also financial budgets limit the selection of sensors. Thus, combining differing assets into an integrated concept of remote sensing contributes to solving these issues.

  1. Integration of TerraSAR-X, RapidEye and airborne lidar for remote sensing of intertidal bedforms on the upper flats of Norderney (German Wadden Sea)

    Science.gov (United States)

    Adolph, Winny; Jung, Richard; Schmidt, Alena; Ehlers, Manfred; Heipke, Christian; Bartholomä, Alexander; Farke, Hubert

    2016-11-01

    The Wadden Sea is a large coastal transition area adjoining the southern North Sea uniting ecological key functions with an important role in coastal protection. The region is strictly protected by EU directives and national law and is a UNESCO World Heritage Site, requiring frequent quality assessments and regular monitoring. In 2014 an intertidal bedform area characterised by alternating crests and water-covered troughs on the tidal flats of the island of Norderney (German Wadden Sea sector) was chosen to test different remote sensing methods for habitat mapping: airborne lidar, satellite-based radar (TerraSAR-X) and electro-optical sensors (RapidEye). The results revealed that, although sensitive to different surface qualities, all sensors were able to image the bedforms. A digital terrain model generated from the lidar data shows crests and slopes of the bedforms with high geometric accuracy in the centimetre range, but high costs limit the operation area. TerraSAR-X data enabled identifying the positions of the bedforms reflecting the residual water in the troughs also with a high resolution of up to 1.1 m, but with larger footprints and much higher temporal availability. RapidEye data are sensitive to differences in sediment moisture employed to identify crest areas, slopes and troughs, with high spatial coverage but the lowest resolution (6.5 m). Monitoring concepts may differ in their remote sensing requirements regarding areal coverage, spatial and temporal resolution, sensitivity and geometric accuracy. Also financial budgets limit the selection of sensors. Thus, combining differing assets into an integrated concept of remote sensing contributes to solving these issues.

  2. Effects of herbivorous birds on intertidal seagrass beds in the northern Wadden Sea

    Science.gov (United States)

    Nacken, M.; Reise, K.

    2000-07-01

    During autumn migration (September to December), brent geese (Branta b. bernicla) and wigeon (Anas penelope) feed on the seagrass Zostera noltii in the nearshore, upper tidal zone leeward of the island of Sylt (eastern North Sea). To graze on leaves and shoots above the sediment and on rhizomes and roots below, these birds reworked the entire upper 1 cm layer of sediment eight times within this 3-month period. In addition, brent geese excavated pits 3-10 cm deep by trampling in order to feed on below-ground phytomass. About 12% of the seagrass beds became pitted to an average depth of 4.5 cm. Using net exclosures, it was estimated that birds removed 34 g dry weight m-2 of above-ground and 28 g of below-ground phytomass. This corresponds to 45% of the phytomass in September. Of the overall loss of phytomass from September to December, 63% was caused by birds. Roughly half of the leaves fell off anyway until December and the other half were taken by the birds. Below the ground, phytomass remained almost constant where birds were excluded, while with birds phytomass of rhizomes and roots was halved. In spite of this strong effect, in the next vegetation period the blade density was lower at former exclosure sites compared to the ambient seagrass bed. The underlying process seems to be a self-inhibition of dense overwintering seagrass by mud accretion. Assuming our experimental results can be scaled up to the entire seagrass bed, we hypothesize that in the sheltered upper intertidal zone, seasonal erosion caused by herbivorous geese and ducks is necessary for the persistence of Z. noltii.

  3. Clay mineralogy, grain size distribution and their correlations with trace metals in the salt marsh sediments of the Skallingen barrier spit, Danish Wadden Sea

    DEFF Research Database (Denmark)

    He, Changling; Bartholdy, Jesper; Christiansen, Christian

    2012-01-01

    metals. The clay assembly of the sediment consists of illite, kaolinite and much less chlorite and smectite. The major clay minerals of illite, kaolinite as well as chlorite correlate very poorly with all the trace metals investigated, due probably to the weak competing strength of these clays compared...... with the other adsorbents and to low availability of the mobile trace metals in the system. Correlation between trace metals and clay minerals may therefore be used as an indicator in environmental assessment. Fine grain fractions of the sediment increased markedly after salt marsh invasion in about 1931......To understand the behavior of trace metals in the salt marsh at Skallingen, Danish Wadden Sea, we investigated a profile from surface to 25 cm depth of the salt marsh sediment, focusing primarily on clay mineralogy and grain size distribution of the sediments and their relationship with trace...

  4. Distribution of total mercury in surface sediments of the western Jade Bay, Lower Saxonian Wadden Sea, southern North Sea.

    Science.gov (United States)

    Jin, Huafang; Liebezeit, Gerd; Ziehe, Daniel

    2012-04-01

    A total of 114 surface sediment samples was equidistantly collected in the western part of the Jade Bay, southern North Sea, to analyse total mercury contents as well as grain size distribution and total organic carbon (TOC) contents. Total mercury was determined by oxygen combustion-gold amalgamation. Validation, precision and accuracy of the method were evaluated and controlled with two certified reference materials (HISS-1 and MESS-3). Total mercury contents varied between 8 and 243 ng/g dry sediment with a mean value of 103 ng/g dw. The mercury levels in surface sediments showed an inhomogeneous spatial distribution with higher contents in near-dike areas. The values are mostly in the range of natural background values (50–100 ng/g dw) and positively related to TOC and clay/silt contents (Jade Bay are not mercury contaminated. These results also suggested that the current mercury contents of Jade Bay surficial sediments are mostly affected by atmospheric deposition and re-emission.

  5. Tidal cycles of total particulate mercury in the Jade Bay, lower Saxonian Wadden Sea, southern North Sea.

    Science.gov (United States)

    Jin, Huafang; Liebezeit, Gerd

    2013-01-01

    In this study, we evaluate the nature of the relationship between particulate matter and total mercury concentrations. For this purpose, we estimate both of the two values in water column over 12-h tidal cycles of the Jade Bay, southern North Sea. Total particulate mercury in 250 mL water samples was determined by oxygen combustion-gold amalgamation. Mercury contents varied from 63 to 259 ng/g suspended particulate matter (SPM) or 3.5-52.8 ng/L in surface waters. Total particulate mercury content (THg(p)) was positively correlated with (SPM), indicating that mercury in tidal waters is mostly associated with (SPM), and that tidal variations of total particulate mercury are mainly due to changes in (SPM) content throughout the tidal cycle. Maximum values for THg(p) were observed during mid-flood and mid-ebb, while the lowest values were determined at low tide and high tide. These data suggest that there are no mercury point sources in the Jade Bay. Moreover, the THg(p) content at low tide and high tide were significantly lower than the values recorded in the bottom sediment of the sampling site (>200 ng/g DW), while THg(p) content during the mid-flood and mid-ebb were comparable to the THg content in the surface bottom sediments. Therefore, changes in THg(p) content in the water column due to tidal forcing may have resulted from re-suspension of underlying surface sediments with relatively high mercury content.

  6. Options for socioeconomic developments in ICZM for the tri-national Wadden area

    NARCIS (Netherlands)

    Dijk, Jouke Van; Broersma, Lourens; Mehnen, Nora

    2016-01-01

    The Wadden Sea Forum has adopted integrated coastal zone management (ICZM) as a process for achieving the sustainable development of the Wadden Sea in a way that is environmentally sound, economically viable and socially beneficial. This requires, besides information about the ecosystem, also inform

  7. Options for socioeconomic developments in ICZM for the tri-national Wadden area

    NARCIS (Netherlands)

    Dijk, Jouke Van; Broersma, Lourens; Mehnen, Nora

    2016-01-01

    The Wadden Sea Forum has adopted integrated coastal zone management (ICZM) as a process for achieving the sustainable development of the Wadden Sea in a way that is environmentally sound, economically viable and socially beneficial. This requires, besides information about the ecosystem, also

  8. Options for socioeconomic developments in ICZM for the tri-national Wadden area

    NARCIS (Netherlands)

    Dijk, Jouke Van; Broersma, Lourens; Mehnen, Nora

    2016-01-01

    The Wadden Sea Forum has adopted integrated coastal zone management (ICZM) as a process for achieving the sustainable development of the Wadden Sea in a way that is environmentally sound, economically viable and socially beneficial. This requires, besides information about the ecosystem, also inform

  9. Ecologically least vulnerable sites for exploration drilling in the Wadden Sea and the North Sea coastal area; Ecologisch minst kwetsbare locaties voor exploratieboringen in de Waddenzee en Noordzee kustzone

    Energy Technology Data Exchange (ETDEWEB)

    Lindeboom, H.J.; Bergman, M.J.N.; De Gee, A. [eds.

    1996-12-31

    The Dutch Oil Company (NAM, abbreviated in Dutch) applied for a number of exploration drilling in the Dutch part of the Wadden Sea and the North Sea coastal area. NAM is obliged to draft a so-called MER (environmental impact report) to indicate the most environment-friendly alternative for the test drilling. By order of NAM, NIOZ and the IBN-DLO (Institute for Research on Forests and Nature) analyzed samples of the animal life in all the potential sites. Based on the results of the analyses, literature and expert knowledge the ecologically least vulnerable sites and the ecologically least vulnerable season were selected during a workshop. In this report the results are given of the workshop, the field sample analyses and a sailing trip along the sites

  10. On deriving transport pathways and morphodynamics in a tidal inlet from high-resolution MBES and LiDAR surveys: the Knudedyb tidal inlet in the Danish Wadden Sea

    DEFF Research Database (Denmark)

    Ernstsen, Verner Brandbyge; Lefebvre, Alice; Fraccascia, Serena

    and the different transport pathways shaping the system is needed to assess the impact of potentially changing environmental conditions, such as accelerating sea level rise, increasing storm intensities and frequencies, or shifting wind directions. The aim of this study is to investigate the sand transport pathways...... and morphodynamics in a natural tidal inlet system, the Knudedyb tidal inlet in the Danish Wadden Sea, by coupling investigations in the sub-tidal inlet channel and the adjacent inter-tidal and supra-tidal areas to encompass the complete system. More specifically, the objective is to develop a conceptual model...

  11. The impact of ocean acidification and warming on the elemental and stable isotope composition of Fucus vesiculosus in Wadden Sea mesocosm studies

    Science.gov (United States)

    Winde, Vera; Pansch, Andreas; Fenner, Anna-Kathrina; Voss, Maren; Schmiedinger, Iris; Schneider, Bernd; Asmus, Ragnhild; Asmus, Harald; Böttcher, Michael E.

    2015-04-01

    In the frame of the German BIOACID II project the separate and combined effects of different stress factors (acidification, warming, eutrophication) on the elemental and stable isotope composition of Fucus vesiculosus are investigated by means of benthic mesocosm experiments in coastal waters of the the North Sea. We aim for a calibration of the biogeochemical and stable isotope composition of Fucus in response to single and combined temperature, pCO2 (pH), and nutrient changes. Benthocosm experiments are carried out at the AWI Wadden Sea station in List (Sylt Island, North Sea) with application of different stressors: an increase in temperature and an increase in atmospheric CO2 partial pressure. The experiments run for almost several months per season. The aquatic biogeochemistry (e.g. TA, pH, 13C(DIC)) as well as the elemental and stable isotope composition of the grown Fucus vesiculosus organic tissue were followed. It was found, that the changes in daily biological activity caused by alternating phases of net respiration and photosynthesis created strong variations in the dissolved carbonate system and changes in the carbon isotope composition of DIC. The atmosphere of some experimental set-ups was enriched with gaseous carbon dioxide. This caused fast corresponding changes in the isotopic composition of DIC, thereby acting as a tracer for newly formed organic tissue. The chemical and isotopic parameters of the dissolved carbonate system showed differences between the set ups. The research is supported by BMBF during project BIOACID II, Helmholtz AWI Sylt, and Leibniz IOW

  12. Seasonal variation in parasite infection patterns of marine fish species from the Northern Wadden Sea in relation to interannual temperature fluctuations

    Science.gov (United States)

    Schade, Franziska M.; Raupach, Michael J.; Mathias Wegner, K.

    2016-07-01

    Marine environmental conditions are naturally changing throughout the year, affecting life cycles of hosts as well as parasites. In particular, water temperature is positively correlated with the development of many parasites and pathogenic bacteria, increasing the risk of infection and diseases during summer. Interannual temperature fluctuations are likely to alter host-parasite interactions, which may result in profound impacts on sensitive ecosystems. In this context we investigated the parasite and bacterial Vibrionaceae communities of four common small fish species (three-spined stickleback Gasterosteus aculeatus, Atlantic herring Clupea harengus, European sprat Sprattus sprattus and lesser sand eel Ammodytes tobianus) in the Northern Wadden Sea over a period of two years. Overall, we found significantly increased relative diversities of infectious species at higher temperature differentials. On the taxon-specific level some macroparasite species (trematodes, nematodes) showed a shift in infection peaks that followed the water temperatures of preceding months, whereas other parasite groups showed no effects of temperature differentials on infection parameters. Our results show that even subtle changes in seasonal temperatures may shift and modify the phenology of parasites as well as opportunistic pathogens that can have far reaching consequences for sensitive ecosystems.

  13. On the dynamics of compound bedforms in high-energy tidal channels: field observations in the German Bight and the Danish Wadden Sea

    Science.gov (United States)

    Ernstsen, Verner B.; Winter, Christian; Becker, Marius; Bartholdy, Jesper

    2010-05-01

    Tidal inlets are a common feature along much of the world's coastlines. They interrupt the alongshore continuity of shoreline processes, and by being exposed to both wave and current forcing, tidal inlets belong to the morphologically most dynamic and complex coastal systems on Earth. The tidal channels in these inlets are characterized by high flow velocities and, accordingly, the channel beds are typically sandy and covered with bedforms. The bedform fields in nature are often complex systems with larger primary-bedforms superimposed by smaller secondary-bedforms (cf. Bartholdy et al., 2002). There is a considerable amount of detailed field investigations on the dynamics of primary-bedforms at various temporal scales, ranging from short- to long-term tide-related cycles to flood hydrographs to seasonality. However, Julien et al. (2002) stated that a composite analysis of primary- and secondary-bedforms is recommended for future studies on resistance to flow. Such knowledge on the behaviour of compound bedforms is still deficient. In this study, we combine the findings on the dynamics of primary- and secondary-bedform height from detailed field investigations carried out in two high-energy tidal channels during 2007 and 2008: the Knudedyb tidal inlet channel in the Danish Wadden Sea and the Innenjade tidal channel in the Jade Bay, German Bight (both survey areas being ebb-dominated). We provide process-based explanations of the bedform behaviour and present a conceptual model of compound bedform dynamics. The conducted field investigations comprised repetitive, simultaneous measurements of high-resolution swath bathymetry (using a multibeam echosounder system) and flow velocity (using an acoustic Doppler current profiler) in combination with detailed spatial mapping of bed material characteristics (from grab sampling of bed material). For an objective and discrete analysis of primary- and secondary-bedforms a modified version of the bedform tracking tool

  14. Mapping of pollutants in sediments of the German Wadden Sea - June, 1989 to June, 1992. Final report January 1993; Schadstoffkartierung in Sedimenten des deutschen Wattenmeeres - Juni 1989 Juni 1992. Abschlussbericht Januar 1993

    Energy Technology Data Exchange (ETDEWEB)

    Koopmann, C. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Physik; Faller, J. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Chemie; Bernem, K.H. van [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Physik; Prange, A. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Physik; Mueller, A. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Physik

    1994-01-01

    From June 1989 to June 1992 a mapping of inorganic and organic pollutants in the sediments from the entire German Wadden Sea has been carried out. Following the guidelines of the national (Bund/Laender-Messprogramm) and international monitoring programmes for the North Sea (Joint Monitoring Programme) distribution patterns of pollutants according to their type and concentration have been determined in the course of this investigation and the main pollution areas have been established. Based on the results of the mapping of pollutants, as well as on the first findings of the biological mapping, a concept for the monitoring of pollutants in eulittoral sediments of the German Wadden Sea has been developed. (orig.) [Deutsch] Von Juni 1989 bis Juni 1992 wurde eine flaechendeckende Kartierung der anorganischen und organischen Schadstoffe in den Sedimenten des gesamten deutschen Wattenmeeres durchgefuehrt. Im Rahmen dieser Untersuchung wurden sowohl die Verteilungsmuster der Schadstoffe nach Art und Konzentration bestimmt als auch deren Belastungsschwerpunkte im Wattengebiet festgestellt. Dabei wurden die Vorgaben des nationalen (Bund/Laender-Messprogramm) und des internationalen Ueberwachungsprogramms fuer die Nordsee (Joint Monitoring Programme) beruecksichtigt. Auf der Grundlage der Ergebnisse der Schadstoffkartierung sowie ersten Erkenntnissen aus einer zeitgleich aufgenommenen biologischen Kartierung wurde ein Konzeptvorschlag fuer ein Schadstoffmonitoring in den eulitoralen Sedimenten des deutschen Wattenmeeres ausgearbeitet. (orig.)

  15. Coupled penetrometer, MBES and ADCP assessments of tidal variations in surface sediment layer characteristics along active subaqueous dunes, Danish Wadden Sea

    Science.gov (United States)

    Stark, Nina; Hanff, Hendrik; Svenson, Christian; Ernstsen, Verner B.; Lefebvre, Alice; Winter, Christian; Kopf, Achim

    2011-08-01

    In-situ geotechnical measurements of surface sediments were carried out along large subaqueous dunes in the Knudedyb tidal inlet channel in the Danish Wadden Sea using a small free-falling penetrometer. Vertical profiles showed a typical stratification pattern with a resolution of ˜1 cm depicting a thin surface layer of low sediment strength and a stiffer substratum below (quasi-static bearing capacity equivalent: 1-3 kPa in the top layer, 20-140 kPa in the underlying sediment; thickness of the top layer ca. 5-8 cm). Observed variations in the thickness and strength of the surface layer during a tidal cycle were compared to mean current velocities (measured using an acoustic Doppler current profiler, ADCP), high-resolution bathymetry (based on multibeam echo sounding, MBES) and qualitative estimates of suspended sediment distributions in the water column (estimated from ADCP backscatter intensity). The results revealed an ebb dominance in sediment remobilization, and a general accretion of the bed towards low water. A loose top layer occurred throughout the tidal cycle, likely influenced by bedload transport and small events of suspended sediment resettlement (thickness: 6 ± 2 cm). Furthermore, this layer showed a significant increase in thickness (e.g. from 8 cm to 16 cm) related to periods of overall deposition. These findings imply that dynamic penetrometers can conveniently serve to (1) quantify potentially mobile sediments by determining the thickness of a loose sediment surface layer, (2) unravel sediment strength development in potentially mobile sediments and (3) identify sediment accumulation. Such data are an important complement and add a new geotechnical perspective during investigations of sediment remobilization processes in highly dynamic coastal environments.

  16. Possible causes for growth variability and summer growth reduction in juvenile plaice Pleuronectes platessa L. in the western Dutch Wadden Sea

    Science.gov (United States)

    van der Veer, Henk W.; Jung, Alexa Sarina; Freitas, Vânia; Philippart, Catharina J. M.; Witte, Johannes IJ.

    2016-05-01

    Growth variability within individuals and among groups and locations and the phenomenon of summer growth reduction has been described for juvenile flatfish in a variety of European coastal areas whereby the underlying causes still remain elusive. Potential mechanisms were tested for juvenile plaice Pleuronectes platessa L. in the western Dutch Wadden Sea, by analysing published and unpublished information from long-term investigations (1986-present). Growth variability did occur and could be explained by differences induced by environmental variability (water temperature), and by non-genetic irreversible adaptation and sex. Dynamic Energy Budget analysis indicated that especially sexually-dimorphic growth in combination with variability in sex ratio could explain most of the variability in growth and the increase in the range of the size of individuals within the population over time. Summer growth reduction was not only observed among 0-group plaice in the intertidal, but also in the subtidal and tidal gullies as well as among I- and II-group plaice. Intraspecific competition for food was not detected but some support for interspecific competition with other predators was found. Also resource competition (due to crowding) with the other abundant epibenthic species (0-, I- and II-group flounder Platichthys flesus; the brown shrimp Crangon crangon; the shore crab Carcinus maenas; the goby species Pomatoschistus minutus and Pomatoschistus microps) could not explain the summer growth reduction. The observed growth reduction coincided with a decrease in stomach content, especially of regenerating body parts of benthic prey items. It is hypothesised that macrozoobenthos becomes less active after the spring phytoplankton bloom, reducing prey availability for juvenile plaice in summer, causing a reduction in food intake and hence in growth.

  17. Spatial and temporal variability of sediment accumulation rates on two tidal flats in Lister Dyb tidal basin, Wadden Sea, Denmark

    DEFF Research Database (Denmark)

    Madsen, A.T.; Murray, A.S.; Andersen, T.J.

    2010-01-01

    Depositional processes in intertidal areas are determined both by changes in sea-level and sediment supply. It is known on a millennial timescale that sedimentation normally keeps pace with sea-level rise in a subsiding tidal basin. However, little is known about whether the sedimentation can keep...

  18. Planktomarina temperata gen. nov., sp. nov., belonging to the globally distributed RCA cluster of the marine Roseobacter clade, isolated from the German Wadden Sea.

    Science.gov (United States)

    Giebel, Helge-Ansgar; Kalhoefer, Daniela; Gahl-Janssen, Renate; Choo, Yoe-Jin; Lee, Kiyoung; Cho, Jang-Cheon; Tindall, Brian J; Rhiel, Erhard; Beardsley, Christine; Aydogmus, Omer O; Voget, Sonja; Daniel, Rolf; Simon, Meinhard; Brinkhoff, Thorsten

    2013-11-01

    Four heterotrophic bacterial strains belonging to the globally distributed marine RCA (Roseobacter clade-affiliated) cluster (family Rhodobacteraceae, class Alphaproteobacteria) were obtained from coastal seawater samples. Strain RCA23(T) was isolated from a 10(-7) dilution culture inoculated with seawater from the German Wadden Sea (southern North Sea), reflecting the high abundance of RCA bacteria in this habitat. Strains IMCC1909, IMCC1923 and IMCC1933 were isolated from diluted seawater (10(-3)) of the Yellow Sea, South Korea. Based on 16S rRNA gene sequence comparison, Octadecabacter antarcticus 307(T) is the closest described relative of the RCA strains, with 95.4-95.5 % sequence similarity. Cells of RCA23(T), IMCC1909, IMCC1923 and IMCC1933 are small motile rods requiring sodium ions. Optimal growth of RCA23(T) occurs at 25 °C and within a very narrow pH range (pH 7-8, optimum pH 7.5). The DNA G+C base content of RCA23(T) is 53.67 mol%. The major respiratory lipoquinone is ubiquinone-10 (Q-10) and the dominant fatty acids (>1 %) are 12 : 1 3-OH, 16 : 1ω7c, 16 : 0, 18 : 1ω7c, 18 : 0 and 11-methyl 18 : 1ω7c. The polar lipid pattern indicated the presence of phosphatidylglycerol, two unidentified aminolipids and two unidentified phospholipids. On marine agar, RCA23(T) forms non-pigmented, transparent to light beige, small (colonies. Strain RCA23(T) harbours all genes for the production of bacteriochlorophyll a (BChl a). Genes encoding the light-harvesting reaction centre of BChl a (pufM) were identified in all RCA strains. No visible pigmentation was observed for any of the strains under laboratory conditions, but spectrophotometric analysis revealed weak production of BChl a by RCA23(T). Morphological, physiological and genotypic features of strain RCA23(T) suggest that it represents a novel species of a new genus within the Rhodobacteraceae, for which we propose the name Planktomarina temperata gen. nov., sp. nov., described

  19. Habitat management affects soil chemistry and allochthonous organic inputs mediating microbial structure and exo-enzyme activity in Wadden Sea salt-marsh soils

    Science.gov (United States)

    Mueller, Peter; Granse, Dirk; Thi Do, Hai; Weingartner, Magdalena; Nolte, Stefanie; Hoth, Stefan; Jensen, Kai

    2016-04-01

    The Wadden Sea (WS) region is Europe's largest wetland and home to approximately 20% of its salt marsh area. Mainland salt marshes of the WS are anthropogenically influenced systems and have traditionally been used for livestock grazing in wide parts. After foundation of WS National Parks in the late 1980s and early 1990s, artificial drainage has been abandoned; however, livestock grazing is still common in many areas of the National Parks and is under ongoing discussion as a habitat-management practice. While studies so far focused on effects of livestock grazing on biodiversity, little is known about how biogeochemical processes, element cycling, and particularly carbon sequestration are affected. Here, we present data from a recent field study focusing on grazing effects on soil properties, microbial exo-enzyme activity, microbial abundance and structure. Exo-enzyme activity was studied conducting digestive enzyme assays for various enzymes involved in C- and N cycling. Microbial abundance and structure was assessed measuring specific gene abundance of fungi and bacteria using quantitative PCR. Soil compaction induced by grazing led to higher bulk density and decreases in soil redox (∆ >100 mV). Soil pH was significantly lower in grazed parts. Further, the proportion of allochthonous organic matter (marine input) was significantly smaller in grazed vs. ungrazed sites, likely caused by a higher sediment trapping capacity of the taller vegetation in the ungrazed sites. Grazing induced changes in bulk density, pH and redox resulted in reduced activity of enzymes involved in microbial C acquisition; however, there was no grazing effect on enzymes involved in N acquisition. While changes in pH, bulk density or redox did not affect microbial abundance and structure, the relative amount of marine organic matter significantly reduced the relative abundance of fungi (F:B ratio). We conclude that livestock grazing directly affects microbial exo-enzyme activity, thus

  20. Changes in distribution patterns of 0-group bivalves in the Wadden Sea: Byssus-drifting releases juveniles from the constraints of hydrography

    Science.gov (United States)

    Armonies, W.

    1996-06-01

    grain size distribution and tidal level within the area studied. On a scale of hundreds of metres, there were no consistent correlations between juvenile abundance and sediment granulometry in any species. In summary, it seems that hydrography ruled the initial settlement of larvae to the sediment and strongly influenced the subsequent redistribution of juveniles caused by passive resuspension. The outcome of actively initiated migrations, on the other hand, was only weakly influenced by hydrography. Therefore it is suggested that hydrography plays a dominant role in the initial development of km-scale distributional patterns of just-settled bivalves in the Wadden Sea, while habitat selection is delayed to the byssus-drifting postlarvae phase.

  1. Comparison of two feature selection methods for the separability analysis of intertidal sediments with spectrometric datasets in the German Wadden Sea

    Science.gov (United States)

    Jung, Richard; Ehlers, Manfred

    2016-10-01

    The spectral features of intertidal sediments are all influenced by the same biophysical properties, such as water, salinity, grain size or vegetation and therefore they are hard to separate by using only multispectral sensors. This could be shown by a previous study of Jung et al. (2015). A more detailed analysis of their characteristic spectral feature has to be carried out to understand the differences and similarities. Spectrometry data (i.e., hyperspectral sensors), for instance, have the opportunity to measure the reflection of the landscape as a continuous spectral pattern for each pixel of an image built from dozen to hundreds of narrow spectral bands. This reveals a high potential to measure unique spectral responses of different ecological conditions (Hennig et al., 2007). In this context, this study uses spectrometric datasets to distinguish between 14 different sediment classes obtained from a study area in the German Wadden Sea. A new feature selection method is proposed (Jeffries-Matusita distance bases feature selection; JMDFS), which uses the Euclidean distance to eliminate the wavelengths with the most similar reflectance values in an iterative process. Subsequent to each iteration, the separation capability is estimated by the Jeffries-Matusita distance (JMD). Two classes can be separated if the JMD is greater than 1.9 and if less than four wavelengths remain, no separation can be assumed. The results of the JMDFS are compared with a state-of-the-art feature selection method called ReliefF. Both methods showed the ability to improve the separation by achieving overall accuracies greater than 82%. The accuracies are 4%-13% better than the results with all wavelengths applied. The number of remaining wavelengths is very diverse and ranges from 14 to 213 of 703. The advantage of JMDFS compared with ReliefF is clearly the processing time. ReliefF needs 30 min for one temporary result. It is necessary to repeat the process several times and to average

  2. Evolution of the Rømø barrier island in the Wadden Sea: Impacts of sea-level change on coastal morphodynamics

    DEFF Research Database (Denmark)

    Clemmensen, Lars B; Andersen, Thorbjørn Joest; Johannessen, Peter

    Sandy coastal barriers are abundant along most continents, and they are often intensively engineered to prevent erosion. Therefore, it is important to develop projections of the evolution of this coastal type in periods with changing climate and sea-level. We have used a multidisciplinary approach......, and falling sea-level, whereas wash-over sedimentation was promoted during periods of rapid sea-level rise when shoreface, beach and coastal dune deposits were reworked. In contrast, lagoonal sedimentation has been relatively continuous and kept pace with the long-term Holocene sea-level rise. Our findings...

  3. Evolution of the Rømø barrier island in the Wadden Sea: Impacts of sea-level change on coastal morphodynamics

    DEFF Research Database (Denmark)

    Clemmensen, Lars B; Andersen, Thorbjørn Joest; Johannessen, Peter

    Sandy coastal barriers are abundant along most continents, and they are often intensively engineered to prevent erosion. Therefore, it is important to develop projections of the evolution of this coastal type in periods with changing climate and sea-level. We have used a multidisciplinary approach...... of the barrier island system, and to interpret it in relation to sea-level changes. We found that the various subsystems constituting the barrier system responded differently to Holocene sea-level variations. Beach and shoreface deposition took place during periods of slowly rising sea-level, still stand...

  4. Spatial variation of bed material grain size over a large dune in the Jade Bay tidal channel, German Wadden Sea (preliminary results)

    Science.gov (United States)

    Thompson, J. A.; Ernstsen, V. B.

    2007-12-01

    High-resolution bathymetry of a large dune with a height of ~4 m, a length of ~70 m and a cross- channel width of ~400 m was measured in the Jade Bay tidal channel, German Wadden Sea, using a multibeam echosounder (MBES) system. A total of 34 bed material samples were collected along 5 transects (trough-crest-trough) across the dune using a ShipekTM grab sampler. High-resolution flow velocity measurements, by means of an acoustic Doppler current profiler (ADCP), were conducted along 3 of these transects during a tidal cycle. Along the channel, mean grain sizes increase from trough to crest along all 5 transects. This increase is most pronounced in the center of the channel (trough ~340 μm, crest ~610 μm) compared to near the channel sides (trough ~425 μm, crest ~500 μm). Across the channel, mean grain sizes decrease along the crest (center ~610 μm, sides ~500 μm), but increase along the trough (center ~340 μm, sides ~425 μm) from the channel center toward the channel sides. The along-channel increase in mean grain size from trough to crest is coherent with an increase in the maximum near-bed flow velocity (calculated as the average flow velocity in the interval from 1 to 2 m above the bed). Moreover, this increase in near-bed flow velocity from trough to crest is more pronounced in the center of the channel (trough ~0.7 m/s, crest ~1.1 m/s) than near the channel sides (trough ~0.9 m/s, crest ~1.1 m/s), which is in line with the larger gradients in mean grain size in the center than along the sides. The higher flow velocities recorded at the crest relative to the trough is due to flow continuity. The across-track increase in mean grain size in the trough from the channel center toward the channel sides is consistent with an increase in the maximum near-bed flow velocity (center ~0.7 m/s, sides ~0.9 m/s). The decrease in mean grain size on the crest from the channel center toward the channel sides cannot simply be explained by lower near-bed flow velocities

  5. Monitoring of the natural gas exploitation in the Wadden Sea from the locations Moddergat, Lauwersoog and Vierhuizen, Netherlands. Advice of the Audit Committee 2011; Monitoring van de aardgaswinning onder de Waddenzee vanaf de locaties Moddergat, Lauwersoog en Vierhuizen. Advies 2011 van de Auditcommissie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-04-15

    The Dutch governmental decree ('Rijksprojectenbesluit') on the project for natural gas exploitation in the Wadden Sea for the locations Moddergat, Lauwersoog and Vierhuizen gives the Dutch Petroleum Company (NAM) the possibility to produce natural gas under specific conditions in the Wadden Sea area from the six fields Moddergat, Nes, Lauwersoog C, Lauwersoog West, Lauwersoog East and Vierhuizen East. The precondition is that the (dynamic) nature in and around the Wadden Sea is not affected by subsidence as a result of the gas exploitation. For this, the NAM must monitor the subsidence and the nature values and report annually to the Dutch government. Also in the Rijksprojectbesluit it is determined that the Commission for Environmental Impact Assessment (EIA), as the independent auditor, will annually advise the responsible ministers on the EIA-report. This is the 2011 recommendation of the Audit Committee for exploitation of natural gas in the Wadden Sea [Dutch] Het Rijksprojectbesluit Gaswinning onder de Waddenzee vanaf de locaties Moddergat, Lauwersoog en Vierhuizen geeft de Nederlandse Aardolie Maatschappij (NAM) de mogelijkheid om onder randvoorwaarden aardgas te produceren in het Waddenzeegebied uit de zes velden Moddergat, Nes, Lauwersoog C, Lauwersoog West, Lauwersoog Oost en Vierhuizen Oost. De randvoorwaarde is dat de (dynamische) natuur in en rondom de Waddenzee niet wordt aangetast door bodemdaling als gevolg van de gaswinning. Daarvoor moet de NAM de bodemdaling en de natuurwaarden monitoren en jaarlijks rapporteren aan de Nederlandse overheid. Ook is in het Rijksprojectbesluit bepaald dat de Commissie voor de milieueffectrapportage (m.e.r.) als onafhankelijke auditor de verantwoordelijke ministers jaarlijks zal adviseren over deze Rapportage. Dit is het 2011 advies van de Auditcommissie gaswinning onder de Waddenzee.

  6. How a barrier island may react on a sea-level rise: The Holocene to Recent Rømø barrier island, Danish Wadden Sea

    DEFF Research Database (Denmark)

    Johannessen, Peter N.; Nielsen, Lars H.; Møller, Ingelise

    of c. 15 m and a resolution of c. 20–30 cm (Nielsen et al., 2009), and dating of 70 core samples using optically stimulated luminescence (OSL). The area has experienced a relative sea-level rise of c. 15 m during the last c. 8000 years. The Recent tidal amplitude reaches c. 1.8 m. During strong wind...... and related shoreface sand and lagoonal sediments are up to 20 m thick and overlie Weichselian fluvial sand. The first 5000 years the barrier island aggraded and the last 3000 years it prograded despite the relative rising sea level rise of c. 15 m during the last c. 8000 years. This shows......, that if there is a surplus of sand in a tidal area, barrier islands may aggrade even if there is a rise in sea level. If the rate of sea level rise decreases then the barrier island may prograded. With this unique dataset with extremely large amounts of OSL datings from core sediments it has been possible to construct...

  7. Transitions in sandflat biota since the 1930s: effects of sea-level rise, eutrophication and biological globalization in the tidal bay Königshafen, northern Wadden Sea

    Science.gov (United States)

    Schumacher, Juliane; Dolch, Tobias; Reise, Karsten

    2014-06-01

    Conspicuous macrozoobenthos and vegetation of intertidal sandflats in Königshafen (Island of Sylt, SE North Sea) were mapped in 1932, 1988 and 2008. Higher water levels since the 1930s with a concomitant increase in tidal dynamics are assumed to have weakened sediment stability. This dissolved the distinctly banded macrobenthic zonation of the 1930s. Near high water level, cyanobacterial mats with associated beetles, belts of the mudshrimp Corophium volutator and the seagrass Zostera noltii have vanished, while the range of the lugworm Arenicola marina has extended towards the shore. Near low water level, sandy elevations have become permanently submerged because a tidal creek has widened its bed. In 1988, extensive green algal mats and the almost complete absence of seagrass are attributed to peak eutrophication. This partially reversed until 2008. The mussel Mytilus edulis had strongly extended its beds along the creek in 1988. These were taken over by introduced Pacific oysters Crassostrea gigas in 2008. Also in 2008, the cordgrass Spartina anglica, another introduced species, grew into large tussocks where cyanobacterial mats and a Corophium-belt had been mapped in the 1930s. Former benthic patterns may have little chance of resurrection by conventional nature protection because these small-scale shifts represent responses to regional and global change.

  8. Punctuated sediment record resulting from channel migration in a shallow sand-dominated micro-tidal lagoon, Northern Wadden Sea, Denmark

    DEFF Research Database (Denmark)

    Fruergaard, Mikkel; Andersen, Thorbjørn Joest; Nielsen, Lars Henrik

    2011-01-01

    conclude that long-term (millennial timescale) sediment accumulation in the lagoon was controlled by rising sea-level, whereas short-term (centurial timescale) sediment accumulation was controlled by local erosion and depositional events caused by lateral migration of channels. Records of short-term sea...

  9. On the performance of topobathymetric LiDAR in shallow water environments: the Ribe Vesterå river and the Knudedyb tidal inlet in the Danish Wadden Sea

    DEFF Research Database (Denmark)

    Gergely, Aron; Andersen, Mikkel S.; Teglbrænder-Bjergkvist, Mathias

    Shallow water environments in the land-sea transition zone are challenging to map in high spatial resolution at large spatial scales. Historically this has led to gaps (white ribbons) between terrestrial and marine surveys. Topobathymetric LiDAR (Light Detection And Ranging), also referred...... to as green LiDAR which is able to penetrate through water, holds the potential to close this gap. However, water column turbidity poses limitations to the penetration of the green laser beam, and water column refraction of the laser beam poses limitations to the scale of features which can be resolved...... at the seabed. The aim of this study is to investigate the performance of topobathymetric LiDAR in shallow water environments in relation to resolving small-scale morphological features at landscape scale. More specifically, the objectives are: 1) to determine the spatial resolution as well as the horizontal...

  10. Survival of Spoonbills on Wadden Sea islands

    NARCIS (Netherlands)

    Bauchau, V.; Horn, H.; Overdijk, O.

    1998-01-01

    The Spoonbill populations in Europe are fragmented and threatened. The dynamics of the species is poorly known but ringing and observation programmes are under way. Here we estimated the local survival of two colour-ringed populations of Spoonbills in the Netherlands. Adult survival and sighting rat

  11. The Wadden area, a multiple landscape?

    NARCIS (Netherlands)

    Boomars, E.A.M.

    2004-01-01

    The concept ‘multiple landscapes’ implies that one particular landscape can entail different landscapes. Various social groups can ascribe different meanings to the same physical landscape. In this paper the Dutch Wadden area (Lancewad project) is analysed and described as a case of a multiple lands

  12. Evidence of cormorant-induced mortality, disparate migration strategies and repeatable circadian rhythm in the endangered North Sea houting (Coregonus oxyrinchus): A telemetry study mapping the postspawning migration

    DEFF Research Database (Denmark)

    Jensen, Lasse Fast; Rognon, Paul C.B.; Aarestrup, Kim

    2017-01-01

    , possibly indicating constrained navigation through the lakes. The migration into the Wadden Sea correlated with temperature indicating osmoregulatory constraints of sea entry. Unlike most salmonid species, migration occurred both day and night. Moreover, fish exhibited repeatable individual differences...

  13. Sediment accretion patterns in a salt marsh in relation to sea level rise.

    NARCIS (Netherlands)

    Both, Inge

    2011-01-01

    SUMMARY Sedimentation processes are determined by different factors, such as the amount of available sediment, hydrodynamic circumstances (wave length, wave flow), morphology (flood frequency, distance to the Wadden Sea, distance to the creek), and struc

  14. Seals at sea: modelling seal distribution in the German bight based on aerial survey data

    NARCIS (Netherlands)

    Herr, H.; Scheidat, M.; Lehnert, K.; Siebert, U.

    2009-01-01

    The Wadden Sea is an important habitat for harbour seals and grey seals. They regularly haul-out on sandbanks and islands along the coast. Comparably little is known about the time seals spend at sea and how they use the remainder of the North Sea. Yet, human activity in offshore waters is increasin

  15. Modelling Morphological Response of Large Tidal Inlet Systems to Sea Level Rise

    NARCIS (Netherlands)

    Dissanayake, P.K.

    2011-01-01

    This dissertation qualitatively investigates the morphodynamic response of a large inlet system to IPCC projected relative sea level rise (RSLR). Adopted numerical approach (Delft3D) used a highly schematised model domain analogous to the Ameland inlet in the Dutch Wadden Sea. Predicted inlet evolut

  16. The significance of radionuclides and trace elements in a back barrier tidal area: Results from the German Wadden

    Energy Technology Data Exchange (ETDEWEB)

    Schnetger, B.; Hinrichs, J.; Dellwig, O.; Brumsack, H.-J. [Institute of Biology and Chemistry of the Marine Enviroment (ICBM), University of Oldenburg, Oldenburg (Germany); Shaw, T. [Department of Chemistry and Biochemistry, University of South Carolina, Colombia (United States)

    2000-07-01

    Coastal areas like the German Wadden Sea are characterised by processes occurring on short (tides) seasonal (winter/summer), and long (sea level rise) timescales. This causes fluctuations in biological, chemical and physical parameters. In the geological past these parameters were driven by natural mechanisms whereas in the last centuries anthropogenic influences (coastal protection, agriculture) became important. It is more or less unknown how the different processes forming the German Wadden Sea interact together. We investigated the dissolved and particulate phase of the waters of the a back barrier tidal area of the East Frisian Islands. Intertidal and seasonal variations in radionuclides, alkalinity and redox-sensitive trace metals give us evidence to several important sources and processes going on in this area. In summer, spring and autumn, alkalinity as well as Mn concentrations in the dissolved phase are high during low tide and low during high tide. In winter, alkalinity and Mn concentration in the dissolved phase is lower. In the suspended particulate material a high and variable Mn/Al ratio during tidal cycles was found in summer and autumn. A low ratio close to average shale with minor variations during low and high tide was found in winter and spring. Stable sulphur isotopes measured in porewater draining the tidal flats during low tide indicate intense diagenesis by sulphate reducing bacteria. These observations point to a seasonal, microbially driven release of dissolved Mn and carbon species from the subsurface anoxic Wadden Sea sediments. Another source, adding dissolved components to the water of the back-barrier area, can be identified by short lived radium isotopes. {sup 223}Ra and {sup 224}Ra were found to vary by a factor of two during tidal cycles. Most possibly, the source for Ra are the subterranean sands, which are drained during low tide and replenished during high tide. The geochemical comparison between present day and Holocene tidal

  17. Planting the SEED : Towards a Spatial Economic Ecological Database for a shared understanding of the Dutch Wadden area

    NARCIS (Netherlands)

    Daams, Michiel N.; Sijtsma, Frans J.

    2013-01-01

    In this paper we address the characteristics of a publicly accessible Spatial Economic Ecological Database (SEED) and its ability to support a shared understanding among planners and experts of the economy and ecology of the Dutch Wadden area. Theoretical building blocks for a Wadden SEED are discus

  18. Carbon dioxide uptake by a temperate tidal sea

    NARCIS (Netherlands)

    Klaassen, Wim

    2007-01-01

    Carbon dioxide (CO2) exchange between the atmosphere and the Wadden Sea, a shallow coastal region along the northern Netherlands, has been measured from April 2006 onwards on a tidal flat and over open water. Tidal flat measurements were done using a flux chamber, and ship borne measurements using a

  19. Tourism Development in the Dutch Wadden Area : Spatial-Temporal Characteristics and Monitoring Needs

    NARCIS (Netherlands)

    Sijtsma, Frans J; Broersma, Lourens; Daams, Michiel N; Hoekstra, H; Werner, Gelijn

    2015-01-01

    The paper presents a spatial and temporal analysis of tourism in the Dutch Wadden area and identifies policy dilemmas and monitoring needs. The analysis is temporal because historical, current and future aspects of tourism development are addressed; it is spatial because the spatial differentiaton

  20. Deep feelings around a shallow coast. A spatial analysis of tourism jobs and the attractivity of nature in the Dutch Wadden area

    NARCIS (Netherlands)

    Sijtsma, Frans J.; Daams, Michiel N.; Farjon, Hans; Buijs, Arjen E.

    2012-01-01

    The Dutch Wadden area is an internationally renowned natural area with World Heritage status. Its ecological uniqueness can be attributed to its shallow coastal waters. However, the Wadden area is also a rural area in search of competitive economic activity so as to provide employment to its populat

  1. Deep feelings around a shallow coast. A spatial analysis of tourism jobs and the attractivity of nature in the Dutch Wadden area

    NARCIS (Netherlands)

    Sijtsma, Frans J.; Daams, Michiel N.; Farjon, Hans; Buijs, Arjen E.

    2012-01-01

    The Dutch Wadden area is an internationally renowned natural area with World Heritage status. Its ecological uniqueness can be attributed to its shallow coastal waters. However, the Wadden area is also a rural area in search of competitive economic activity so as to provide employment to its populat

  2. Decline of the North Sea houting: protective measures for an endangered anadromous fish

    DEFF Research Database (Denmark)

    Jepsen, Niels; Deacon, Michael; Koed, Anders

    2012-01-01

    Once an abundant fish species in the rivers of the Wadden Sea in northwest Europe, the North Sea houting Coregonus oxyrinchus (NSH) was at the brink of extinction 25 yr ago. The very last stronghold for this species was in the small Danish River Vidaa. In an attempt to preserve this anadromous...... whitefish species, juveniles were hatchery-reared and stocked in 6 Danish rivers flowing into the Wadden Sea. These stocking efforts were fairly successful, and the houting established populations in at least 2 of the rivers, but the underlying problem of habitat degradation and migration obstacles...... they were initially PIT-tagged, indicating some exchange/straying between adjacent rivers. Overall there is a good chance that this unique species was saved in the 11th hour by intervention from managers and the EU...

  3. Major changes in the ecology of the Wadden Sea : Human impacts, ecosystem engineering and sediment dynamics

    NARCIS (Netherlands)

    Eriksson, Britas Klemens; van der Heide, Tjisse; van de Koppel, Johan; Piersma, Theunis; van der Veer, Henk W.; Olff, Han

    Shallow soft-sediment systems are mostly dominated by species that, by strongly affecting sediment dynamics, modify their local environment. Such ecosystem engineering species can have either sediment-stabilizing or sediment-destabilizing effects on tidal flats. They interplay with abiotic forcing

  4. Cyclic behavior of sandy shoals on the ebb-tidal deltas of the Wadden Sea

    NARCIS (Netherlands)

    Ridderinkhof, W.; Hoekstra, P.; van der Vegt, M.; de Swart, H. E.

    2016-01-01

    Ebb-tidal deltas are bulges of sand that are located seaward of tidal inlets. Many of these deltas feature shoals that cyclically form and migrate towards the coast. The average period between successive shoals that attach to the coast varies among different inlets. In this study, a quantitative ass

  5. Major changes in the ecology of the Wadden Sea: human impacts, ecosystem engineering and sediment dynamics

    NARCIS (Netherlands)

    Eriksson, B.K.; van der Heide, T.; Van de Koppel, J.; Piersma, T.; Van der Veer, H.W.; Olff, H.

    2010-01-01

    Shallow soft-sediment systems are mostly dominated by species that, by strongly affecting sediment dynamics, modify their local environment. Such ecosystem engineering species can have either sediment-stabilizing or sediment-destabilizing effects on tidal flats. They interplay with abiotic forcing c

  6. Major changes in the ecology of the Wadden Sea : Human impacts, ecosystem engineering and sediment dynamics

    NARCIS (Netherlands)

    Eriksson, Britas Klemens; van der Heide, Tjisse; van de Koppel, Johan; Piersma, Theunis; van der Veer, Henk W.; Olff, Han

    2010-01-01

    Shallow soft-sediment systems are mostly dominated by species that, by strongly affecting sediment dynamics, modify their local environment. Such ecosystem engineering species can have either sediment-stabilizing or sediment-destabilizing effects on tidal flats. They interplay with abiotic forcing c

  7. Erodibility of a mixed mudflat dominated by microphytobenthos and Cerastoderma edule, East Frisian Wadden Sea, Germany

    DEFF Research Database (Denmark)

    Andersen, Thorbjørn Joest; Lanuru, Mahatma; van Bernem, Carlo

    2010-01-01

    ). The erodibility of the sediment showed strong temporal variation with high erosion thresholds in spring and late summer and significantly lower thresholds during the rest of the study period. The erosion thresholds were strongly dependent on the contents of chlorophyll a (chl a) and colloidal carbohydrates, both...

  8. Modelling the effects of seed mussel collectors on the western Dutch Wadden Sea ecosystem

    NARCIS (Netherlands)

    Brinkman, A.G.

    2013-01-01

    The bottom fishery for seed mussels is bound to be replaced by alternative methods of seed collection. This change is a result of an agreement between the Dutch Government, fishermen and nature protection organizations. Seed mussel collectors (abbreviated: MZI) are most promising as an alternative f

  9. Metapopulation structure in the lagoon cockle Cerastoderma lamarcki in the northern Wadden Sea

    Science.gov (United States)

    Reise, Karsten

    2003-01-01

    Benthic invertebrates in discontinuous inshore habitats and with short or no pelagic larval dispersal are likely to exhibit regional metapopulation dynamics with partially isolated local populations. Near the island of Sylt, the bivalve Cerastoderma (Cardium) lamarcki (Reeve, 1844, syn. in part with C. glaucum Bruguiére, 1789) was widespread in intertidal seagrass beds, coexisting with the sibling species C. edule (Linné, 1758). However, the last C. lamarcki in this habitat was found in 1980. At present the lagoon cockle is restricted to disjunct ditches, creeks and ponds within island salt marshes. There it differs in year-class structure between localities. Successful recruitment events did not coincide. At one locality, a period with regular recruitment was followed by 5 years of recruitment failure, resulting in an overaged population probably at the rim of extinction. In a nearby brackish pond, extinction was followed by recolonization 3 years later. Other lagoonal habitats which seem to be suitable are without cockles. It is speculated that small and isolated habitats occasionally receive colonizers by eggs and juveniles adhering to avian vectors.

  10. Strengthening coastal zone management in the Wadden Sea by applying ‘knowledge-practice interfaces’

    NARCIS (Netherlands)

    Puente Rodriguez, D.; Giebels, D.; Jonge, de V.N.

    2015-01-01

    Knowledge management (e.g., production, mobilization, integration) is key to achieve socio-ecological sustainability and to handle the many challenges that distress coastal zones – e.g. finding a balance between ecological conservation and economic development. Building on the concept of

  11. Visions of nature and environmental sustainability : Shellfish harvesting in the Dutch Wadden Sea

    NARCIS (Netherlands)

    Swart, JAA; van der Windt, HJ

    The concept of sustainability has several, sometimes contrasting, meanings that may generate confusion, misunderstanding, and conflict concerning conservation and restoration practices. It is therefore desirable to clarify the concept of sustainability, thereby potentially contributing to mutual

  12. Optical dating of young tidal sediments in the Danish Wadden Sea

    DEFF Research Database (Denmark)

    Madsen, Anni Tindahl; Murray, A. S.; Andersen, Thorbjørn Joest

    2007-01-01

    reliable and reproducible results in cores from sub-, inter- and supra-tidal sediments, ranging from only a few years up to ~1000 years old, confirming its value in the estimation of estuarine accretion rates. With OSL it is, for the first time, possible to date sediment cores from silty and sandy tidal...... We have tested the applicability of optically stimulated luminescence (OSL) to the dating of young estuarine sediments (dating. The degree of bleaching before deposition...... is investigated by examining the age trend in various sediment cores, and where possible, by comparison with independent age control provided by 210Pb dating. The consistency between optical ages and 210Pb ages is shown to be satisfactory on a time-scale down to only a few years. We conclude that OSL provides...

  13. Politiek door de staten: doel- of waarderationeel handelen in het besloten overleg over de Wadden en het openbaar beraad over de ecologische hoofdstructuur

    OpenAIRE

    2001-01-01

    POLITICS BY PROVINCE: Goal-oriented rational action or value-oriented rational action in closed debate on the Wadden region and public consultation on the ecological infrastructure General This thesis is a study of political conduct, and of provincial politics in particular. It is based on three research projects. The first two research projects are empirical studies that examine, respectively, the functioning of the discussion platform for government bodies relating to the Wadden Islands are...

  14. Comparative analysis of time series of marine litter surveyed on beaches and the seafloor in the southeastern North Sea.

    Science.gov (United States)

    Schulz, Marcus; Krone, Roland; Dederer, Gabriele; Wätjen, Kai; Matthies, Michael

    2015-05-01

    The comparative analysis of marine litter in different marine compartments has rarely been attempted. In this study, long-term time series of marine litter abundance on the seafloor and on the coast, both from the southeastern North Sea, were analyzed for temporal trends and correlations. On four beach sections of 100 m length, mean abundances of total beach litter collected four times a year from 2002 to 2008 varied between 105 and 435 items. Mean densities of total inorganic litter on the seafloor amounted to 10.6 ± 9.7 kg km(-2) in the offshore region (2001-2010) and 13.7 ± 12.6 kg km(-2) in the Wadden Sea (1998-2007), respectively. In the offshore region, there was no significant long-term trend, while in the Wadden Sea, densities of marine litter declined significantly. Correlations between time series were weak, indicating different sources and transport processes responsible for compositions of beach litter and litter on the seafloor. Decreases in inputs from fisheries and substantial export due to resuspension are discussed as reasons for the decrease in litter on the seafloor in the Wadden Sea. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Politiek door de staten : doel- of waarderationeel handelen in het besloten overleg over de Wadden en het openbaar beraad over de ecologische hoofdstructuur

    NARCIS (Netherlands)

    Tromp, Gerbrig Heleen Maria

    2001-01-01

    POLITICS BY PROVINCE: Goal-oriented rational action or value-oriented rational action in closed debate on the Wadden region and public consultation on the ecological infrastructure General This thesis is a study of political conduct, and of provincial politics in particular. It is based on three

  16. Politiek door de staten : doel- of waarderationeel handelen in het besloten overleg over de Wadden en het openbaar beraad over de ecologische hoofdstructuur

    NARCIS (Netherlands)

    Tromp, Gerbrig Heleen Maria

    2001-01-01

    POLITICS BY PROVINCE: Goal-oriented rational action or value-oriented rational action in closed debate on the Wadden region and public consultation on the ecological infrastructure General This thesis is a study of political conduct, and of provincial politics in particular. It is based on three res

  17. MOD2SEA: A Coupled Atmosphere-Hydro-Optical Model for the Retrieval of Chlorophyll-a from Remote Sensing Observations in Complex Turbid Waters

    Directory of Open Access Journals (Sweden)

    Behnaz Arabi

    2016-09-01

    Full Text Available An accurate estimation of the chlorophyll-a (Chla concentration is crucial for water quality monitoring and is highly desired by various government agencies and environmental groups. However, using satellite observations for Chla estimation remains problematic over coastal waters due to their optical complexity and the critical atmospheric correction. In this study, we coupled an atmospheric and a water optical model for the simultaneous atmospheric correction and retrieval of Chla in the complex waters of the Wadden Sea. This coupled model called MOD2SEA combines simulations from the MODerate resolution atmospheric TRANsmission model (MODTRAN and the two-stream radiative transfer hydro-optical model 2SeaColor. The accuracy of the coupled MOD2SEA model was validated using a matchup data set of MERIS (MEdium Resolution Imaging SpectRometer observations and four years of concurrent ground truth measurements (2007–2010 at the NIOZ jetty location in the Dutch part of the Wadden Sea. The results showed that MERIS-derived Chla from MOD2SEA explained the variations of measured Chla with a determination coefficient of R2 = 0.88 and a RMSE of 3.32 mg·m−3, which means a significant improvement in comparison with the standard MERIS Case 2 regional (C2R processor. The proposed coupled model might be used to generate a time series of reliable Chla maps, which is of profound importance for the assessment of causes and consequences of long-term phenological changes of Chla in the turbid Wadden Sea area.

  18. Optimising the lighting equipment on the Mittelplate drilling and production island in the German Wadden sea tidelands

    Energy Technology Data Exchange (ETDEWEB)

    Mattfeld, Heiner [RWE Dea AG, Hamburg (Germany); Ehlers, Fabian [RWE Dea AG, Friedrichskoog (Germany); Reichenbach, Marc [ARSU GmbH, Oldenburg (Germany)

    2012-06-15

    Since October 1987, RWE Dea (operator) and Wintershall Holding GmbH (partner) have developed the most significant German oil reservoir in the field Mittelplate. The production of more than 25 million t of crude oil to date has chiefly been carried out via the artificial island Mittelplate located 7 km off the coast near the southern border of the national park known as ''Schleswig-Holsteinisches Wattenmeer'', which also has the status of a world natural heritage site since 2009. The lighting facilities on the Mittelplate drilling and production island were optimised against the backdrop of this sensitive environment. Birds migrating by night are attracted by large-scale artificial light sources, especially when visibility is poor. This leads to impairments for bird life in the form of disorientation, dissipation of energy, collisions and increased decimation by predators. This phenomenon is particularly problematic in offshore regions. As regards the impact of green, blue and red spectral ranges of light, there are contradictory statements in specialist literature. While van de Laar and Poot et al. describe that nocturnally migrating birds are attracted by red light rather than by blue and green light, Evans et al. discovered exactly the opposite. Against this backdrop, RWE Dea AG has abstained from using e. g. green light for the time being, opting for a reduction of the light being emitted into the environment instead. To this end, various measures have been implemented on Mittelplate island to date. All lighting facilities potentially emitting light externally on Mittelplate island were recorded, classified and examined with regard to their optimisation potential. A description of the de-commissioning, switching and optimum alignment of light sources, the installation of light guidance shields as well as control of light sources via the process steering system is given. Moreover, compliance with safety at work rules and regulations is dealt with. In order to document the success of the relevant measures, photographs were taken in darkness subject to identical conditions before and after implementation of the optimisation measures. In strict compliance with safety at work rules and regulations, by implementing these measures it was possible to bring about a mitigation of the impacts of Mittelplate particularly on nocturnally migrating birds. (orig.)

  19. Parasites in harbour seals ( Phoca vitulina) from the German Wadden Sea between two Phocine Distemper Virus epidemics

    Science.gov (United States)

    Lehnert, K.; Raga, J. A.; Siebert, U.

    2007-12-01

    Parasites were collected from 107 harbour seals ( Phoca vitulina) found on the coasts of Schleswig-Holstein, Germany, between 1997 and 2000. The prevalence of the parasites and their associated pathology were investigated. Eight species of parasites, primarily nematodes, were identified from the examined organs: two anisakid nematodes ( Pseudoterranova decipiens (sensu lato) , Contracaecum osculatum (sensu lato)) from the stomach, Otostrongylus circumlitus (Crenosomatidae) and Parafilaroides gymnurus (Filaroididae) from the respiratory tract, one filarioid nematode ( Acanthocheilonema spirocauda) from the heart, two acanthocephalans, Corynosoma strumosum and C. semerme (Polymorphidae), from the intestine and an ectoparasite, Echinophthirius horridus (Anoplura, Insecta). Lungworm infection was the most prominent parasitological finding and secondary bacterial bronchopneumonia the most pathogenic lesion correlated with the parasites. Heavy nematode burdens in the respiratory tract were highly age-related and more frequent in young seals. A positive correlation was observed between high levels of pulmonary infection and severity of bronchopneumonia. The prevalence of lungworms in this study was higher than in seals that died during the 1988/1989 Phocine Distemper Virus epidemic, and the prevalence of acanthocephalans and heartworms had decreased compared to findings from the first die-off.

  20. On the dynamics of the stocks of blue mussels ( Mytilus edulis L.) in the Danish Wadden Sea

    DEFF Research Database (Denmark)

    Munch-Petersen, Sten; Kristensen, Per Sand

    2001-01-01

    for the estimation of total biomass. They also provide data on size frequency distributions, which have been analysed for cohort identification resulting in length at age data, which again have been used for estimating parameters (L-infinity and K) for the von Bertalanffy growth equation (VBGE) as well as mortality...

  1. Moderate livestock grazing of salt, and brackish marshes benefits breeding birds along the mainland coast of the Wadden Sea

    NARCIS (Netherlands)

    Mandema, F.S.; Tinbergen, J.M.; Ens, B.J.; Koffijberg, K.; Dijkema, K.S.; Bakker, J.P.

    2015-01-01

    Our study investigated how bird species richness and abundance was related to livestock grazing on salt, and brackish marshes, with an emphasis on songbirds, and shorebirds. Survey areas with a high percentage cover of tall vegetation were assumed to have experienced lower livestock grazing

  2. The Influence of Benthic Diatoms and Invertebrates on the Erodibility of an Intertidal Mudflat, the Danish Wadden Sea

    Science.gov (United States)

    Austen, I.; Andersen, T. J.; Edelvang, K.

    1999-07-01

    The erodibility of mudflat surfaces has been investigated in the Lister Dyb tidal area. A description is given of the short-term erosional, depositional history and the main biological factors governing the stability of the sediment surface. The erosion threshold seems mainly to be controlled by the relationship between algal biomass, expressed as chlorophylla content and the abundance of deposit feeders. Benthic microalgae are important for the sediment stabilization due to their production of extracellular polymeric substances (EPS) during locomotion. The deposit feeder Hydrobia ulvae on the other hand limits the influence of microalgae because diatoms are the main part of their diet. Additionally, H. ulvae produces fecal pellets which can be more easily eroded than the cohesive bed since they seem to behave as individual units losing cohesive properties. Freshly deposited material was more stable than eroded areas, explained by the occurrence of benthic microalgae, which stabilize the sediment surface in areas of accretion. There was a positive correlation between the water content of the surface material and erosion threshold, interpreted as a result of the dominance of biological stabilizing and destabilizing factors at the site. The variation in algal mass and species abundance causes a marked cross-shore variation in erosion threshold with an increase of stability towards the salt marsh line. The reason for this is argued to be the cross-shore variation of exposure time, which governs the growth of microphytobenthos since light exposure declines towards the low-water line. The cross-shore variation of the erosion threshold is discussed in relation to the suspended sediment transport and it is argued that the result of this variation is a tendency for net landward transport of suspended sediment.

  3. The impact of tourism upon some breeding wader species on the isle of Vlieland in the Netherlands' Wadden Sea

    NARCIS (Netherlands)

    Roos, de G.Th.

    1981-01-01

    Birds and man are of importance to eachother, directly and indirectly, positively or negatively.Populations of wild birds may decrease or even become extinct due to human activities because they are threatened directly or because theire characteristic habitats are destroyed. On the other hand, human

  4. Rethinking the interface between ecology and society. The case of the cockle controversy in the Dutch Wadden Sea

    NARCIS (Netherlands)

    Swart, Jac. A. A.; van Andel, Jelte

    1. Applied ecology, like conservation research, may deal with societal issues if its scientifically based interventions have societal consequences. Human utilization plays a significant role in many ecosystems, so conservation ecologists often have to act on the interface between science and

  5. Luminescence dating of Holocene sedimentary deposits on Rømø, a barrier island in the Wadden Sea, Denmark

    DEFF Research Database (Denmark)

    Madsen, Anni Tindahl; Murray, Andrew S.; Andersen, Thorbjørn Joest

    2010-01-01

    (SAR) protocol; samples were retrieved from seven sediment cores, each up to 25 m long, taken from locations on the island and within the back-barrier lagoon. The reliability of the OSL results is assessed using preheat plateaus, thermal transfer tests, and dose recovery measurements, and by comparison...... the west, north and south as a result of an abundant sediment supply. Luminescence dating is concluded to be well-suited for establishing precise and accurate chronologies for barrier island deposits, and the technique has provided an excellent basis for the reconstruction of barrier island evolution....

  6. Uncertainties in the assessment of ‘‘significant effect’’ on the Dutch Natura 2000 Wadden Sea site

    NARCIS (Netherlands)

    Floor, J.R.; Koppen, van C.S.A.; Tatenhove, van J.P.M.

    2016-01-01

    Natura 2000, the nature network based on the European Bird and Habitat Directives, is explicitly grounded on ecological science. To acquire a permit under the Dutch Nature Conservation Act, an appropriate assessment of significant effects must be conducted based on the best available scientific know

  7. Beached bird surveys indicate decline in chronic oil pollution in the North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Camphuysen, K.C.J. [Netherlands Institute for Sea Research, Texel (Netherlands)

    1998-12-31

    Strandings of oiled seabirds have been a signal of the ongoing problem of chronic oil pollution in the North Sea since the beginning of the twentieth century. Overall numbers of beached birds are subject to enormous fluctuations, being the result, for example, of changes in the amount of oil spilled in the marine environment, currents, the frequency of onshore winds and variations in the numbers of seabirds in a given region. In contrast, oil rates, being the fraction of oiled birds of the total stranded, appeared to be relatively constant while specific for different species and regions. A power analysis of the results of beached bird surveys demonstrated the sensitivity of these data as a tool to monitor trends in oil rates of stranded birds. Rather subtle changes in oil rates could be demonstrated, indicating positive results of attempts to protect certain sea areas (e.g. the Wadden Sea) and a decline in oil rates over time. (author)

  8. Modelling transport and reproduction of the invasive comb jelly Mnemiopsis leidyi in the North Sea

    Science.gov (United States)

    van der Molen, Johan

    2014-05-01

    Mnemiopsis leidyi is an invasive comb jelly fish species that originates from the Gulf of Mexico and the US east coast. It has high bloom potential, and can survive in a wide variety of environmental conditions. It was first introduced in Europe through ballast water discharges in the Black Sea, where it was associated with the anchovis stock collapse in the 1990's. From there, it has spread through the Mediterranean Sea. Since the mid 2000's it has been observed in ports and estuaries along the English Channel, the North Sea and the Baltic Sea. In the North Sea, M. leidyi blooms occur in the Scheldt estuaries, the Wadden Sea, and in ports and canals. In winter, M. Leidyi has been observed at sea in the German Bight. A particle tracking model was modified to include a simple reproduction mechanism, using food fields from the coupled hydrodynamics-ecosystem model GETM-ERSEM. The model was used to study the potential spreading and bloom potential of M. Leidyi in the southern North Sea under present and increased temperature conditions. Under present conditions, the model suggested that M. Leidyi can survive in the North Sea, and can be transported over distances of several hundreds of km, enabling connectivity between estuarine populations. It could not, however, bloom at open sea because of temperature constraints. These constraints were lifted for increased temperature scenarios, suggesting increased bloom potential under climate change conditions.

  9. Groundwater salinisation in the Wadden Sea area of the Netherlands: quantifying the effects of climate change, sea level rise and anthropogenic interferences

    NARCIS (Netherlands)

    Pauw, P.S.; Louw, de P.G.B.; Oude Essink, G.H.P.

    2012-01-01

    Hydrogeological research in coastal areas has gained considerable attention over the last decades due to increasing stresses on fresh groundwater resources. Fundamental groundwater flow and solute transport analyses remain essential for a concise understanding of the governing processes that lead to

  10. Efficiency of blue mussel (Mytilus edulis) spat collectors in highly dynamic tidal environments of the Lower Saxonian coast (southern North Sea).

    Science.gov (United States)

    Walter, Uwe; Liebezeit, Gerd

    2003-07-01

    Traditional mussel culture in the Wadden Sea, southern North Sea, is carried out by taking seed mussels of about 1-4 cm shell length from natural beds and transplanting them to permanently water covered sites. Besides the damage done to the natural beds, the ratio of seeded to harvested mussels is only about 1:1-1.3, i.e. about the same tonnage of mussels seeded is recovered. In addition, this technique relies exclusively on natural spat falls, which do not occur regularly. In order to overcome these difficulties spat collectors have been deployed in the Jade Bay, southern North Sea. These provided suitable settlement grounds for mussel larvae. Blue mussel weights reached weights of about 8-9 kg/m collector rope with maximum shell lengths of 4-5 cm within one growing season.

  11. Development of a Dynamic Barrier Island (Sylt, Eastern North Sea) Based on High-Resolution Aerial Photographs and GIS

    Science.gov (United States)

    Dolch, T.; Hass, H. C.

    2004-12-01

    Wind and currents are the driving forces for the morphological development of coastlines and islands by giving them their shape, run and structure. This is especially true in highly dynamic areas such as the Wadden Sea in North-Western Europe. In this unique environment changes are continuous and distinct developments can be noticed within decades. The Island of Sylt, located in the Wadden Sea near the German-Danish border, is a sandy barrier island that protects the mainland against storm floods and waves. Thus, it experiences strong erosion (about 1 m coastal retreat per year). The North Atlantic Oscillation (NAO), that controls the atmospheric circulation over the North Sea, and northerly currents are the driving forces for the morphological development. Rising sea-level due to global change amplifies the erosion processes and forces people to protect the coastline (in this case beach nourishment). The Koenigshafen, a protected, semi-enclosed bay in the north of the Island of Sylt, can be regarded as representative for the study of many coastal processes that affect the island. In this case study, a long-term series of high resolution aerial photographs of the Koenigshafen (starting in 1936) shows the development of the survey area. Wind and currents affect not only the run of the coastline but also sediment composition and biodynamics in the bay. Looking at the hydrodynamics governing the bay, it should have mostly muddy sediments. Strong westerly winds, however, supply the bay with large amounts of sand from inland dunes and create sandy tidal flats. The long-term development of seagrass and mussel beds can also be retrieved from aerial photographs. In both cases a distinct decline in size can be noticed. Remote sensing and GIS techniques allow monitoring the conditions as well as to reconstruct the past development and to predict future developments.

  12. Annual mean sea level and its sensitivity to wind climate

    Science.gov (United States)

    Gerkema, Theo; Duran Matute, Matias

    2017-04-01

    Changes in relative mean sea level affect coastal areas in various ways, such as the risk of flooding, the evolution of barrier island systems, or the development of salt marshes. Long-term trends in these changes are partly masked by variability on shorter time scales. Some of this variability, for instance due to wind waves and tides (with the exception of long-period tides), is easily averaged out. In contrast, inter-annual variability is found to be irregular and large, of the order of several decimeters, as is evident from tide gauge records. This is why the climatic trend, typically of a few millimeters per year, can only be reliably identified by examining a record that is long enough to outweigh the inter-annual and decadal variabilities. In this presentation we examine the relation between the annual wind conditions from meteorological records and annual mean sea level along the Dutch coast. To do this, we need reliable and consistent long-term wind records. Some wind records from weather stations in the Netherlands date back to the 19th century, but they are unsuitable for trend analysis because of changes in location, height, surroundings, instrument type or protocol. For this reason, we will use only more recent, homogeneous wind records, from the past two decades. The question then is whether such a relatively short record is sufficient to find a convincing relation with annual mean sea level. It is the purpose of this work to demonstrate that the answer is positive and to suggest methods to find and exploit such a relation. We find that at the Dutch coast, southwesterly winds are dominant in the wind climate, but the west-east direction stands out as having the highest correlation with annual mean sea level. For different stations in the Dutch Wadden Sea and along the coast, we find a qualitatively similar pattern, although the precise values of the correlations vary. The inter-annual variability of mean sea level can already be largely explained by

  13. Spatial patterns and trends in abundance of larval sandeels in the North Sea: 1950–2005

    DEFF Research Database (Denmark)

    Lynam, Christopher P.; Halliday, Nicholas C.; Höffle, Hannes

    2013-01-01

    with catches by dedicated larval samplers (Gulf and bongo nets) during ICES coordinated surveys in 2004 and 2009. ICES data are also used to explore environmental influences on sandeel distributions. Temporally, CPR data correlate with larval data from plankton surveys off Stonehaven (1999–2005), with sandeel...... 0-group trawl data at the east Fair Isle ground (since 1984), and with recruitment data (since 1983) for the Dogger Banks stock assessment area. Therefore, CPR data may provide an early recruit index of relative abundance for the Dogger Banks assessment area, where the majority of the commercial...... catch of A. marinus is taken, and the Wee Bankie area that is particularly important for seabird foraging. While warm conditions may stimulate the production of sandeel larvae, their natural mortality is typically greater, in the Dogger Banks and Wadden Sea areas, when the larvae are hatched in warm...

  14. Coupled penetrometer, MBES and ADCP assessments of tidal variations of the surface sediment layer along active subaqueous dunes, Danish Wadden Sea

    DEFF Research Database (Denmark)

    Stark, Nina; Hanff, Henrik; Svenson, Christian

    2011-01-01

    a tidal cycle were compared to mean current velocities (measured using an acoustic Doppler current profiler, ADCP), high-resolution bathymetry (based on multibeam echo sounding, MBES) and qualitative estimates of suspended sediment distributions in the water column (estimated from ADCP backscatter......). Furthermore, this layer showed a significant increase in thickness (e.g. from 8 cm to 16 cm) related to periods of overall deposition. These findings imply that dynamic penetrometers can conveniently serve to (1) quantify potentially mobile sediments by determining the thickness of a loose sediment surface...

  15. Risk assessment on the possible introduction of three predatory snails (Ocinebrellus inornatus, Urosalpinx cinerea, Rapana venosa in the Dutch Wadden Sea

    NARCIS (Netherlands)

    Fey-Hofstede, F.E.; Brink, van den A.M.; Wijsman, J.W.M.; Bos, O.G.

    2010-01-01

    Recently three alien invasive predatory snails have been found in the Dutch marine waters, which are identified by the Ministry of Agriculture, Nature and Food Quality as potential high risk species due to their possible impact on bivalve species (TRCPD/2009/3587). These are: Japanese oyster drill

  16. Field measurements on seasonal variation of the activity of primary producers on a sandy tidal flat in the northern Wadden sea

    Science.gov (United States)

    Asmus, R.

    In 1980 chlorophyll a and biomass of phytoplankton showed two distinct peaks in spring and late summer. Thalassiosira nordenskiöldii dominated the spring bloom, whereas in late summer Thalassiosira eccentrica and Biddulphia rhombus reached a maximum. Microphytobenthos biomass was dominated by the small species Achnanthes hauckiana. Highest biomass of microphytobenthos was attained in late winter. Gross primary productivity of the community amounted to 100 g C · m -2 · a 1 during time of submersion, 68% of which produced by microphytobenthos, 32% by phytoplankton. In spite of increasing production in summer, microphytobenthos did not increase in biomass. This is assumed to be due to grazing by the snail Hydrobia ulvae.

  17. Nature excursions in the Dutch Wadden Sea: tools to integrate tourism, outdoor recreation and nature protection in a natural World Heritage site.

    NARCIS (Netherlands)

    Revier, Hans; Folmer, Akke

    2014-01-01

    Proceedings of the 7th International Conference on Monitoring and Management of Visitors in Recreational and Protected Areas (MMV) Local Community and Outdoor Recreation August 20 - 23, 2014 Tallinn, Estonia

  18. Coupled penetrometer, MBES and ADCP assessments of tidal variations of the surface sediment layer along active subaqueous dunes, Danish Wadden Sea

    DEFF Research Database (Denmark)

    Stark, Nina; Hanff, Henrik; Svenson, Christian;

    2011-01-01

    a tidal cycle were compared to mean current velocities (measured using an acoustic Doppler current profiler, ADCP), high-resolution bathymetry (based on multibeam echo sounding, MBES) and qualitative estimates of suspended sediment distributions in the water column (estimated from ADCP backscatter...

  19. On the dynamics of compound bedforms in high-energy tidal channels: field observations in the German Bight and the Danish Wadden Sea

    DEFF Research Database (Denmark)

    Ernstsen, Verner; Christian, Winter; Becker, Marius

    2010-01-01

    Tidal inlets are a common feature along much of the world’s coastlines. They interrupt the alongshore continuity of shoreline processes, and by being exposed to both wave and current forcing, tidal inlets belong to the morphologically most dynamic and complex coastal systems on Earth. The tidal......). There is a considerable amount of detailed field investigations on the dynamics of primary-bedforms at various temporal scales, ranging from short- to long-term tide-related cycles to flood hydrographs to seasonality. However, Julien et al. (2002) stated that a composite analysis of primary- and secondary...... decreased during ebb tide and increased during flood tide. This was due to erosion and deposition of the crest, as the trough remained practically constant. The erosion of the crest occurred at high energy stages during ebb tide, while the overall deposition on the crest occurred during flood tide. The low...

  20. Nature excursions in the Dutch Wadden Sea: tools to integrate tourism, outdoor recreation and nature protection in a natural World Heritage site.

    NARCIS (Netherlands)

    Akke Folmer; Hans Revier

    2014-01-01

    Proceedings of the 7th International Conference on Monitoring and Management of Visitors in Recreational and Protected Areas (MMV) Local Community and Outdoor Recreation August 20 - 23, 2014 Tallinn, Estonia

  1. Nature excursions in the Dutch Wadden Sea: tools to integrate tourism, outdoor recreation and nature protection in a natural World Heritage site

    NARCIS (Netherlands)

    Akke Folmer; Hans Revier

    2014-01-01

    Presentation at the 7th International Conference on Monitoring and Management of Visitors in Recreational and Protected Areas (MMV) Local Community and Outdoor Recreation August 20 - 23, 2014 Tallinn, Estonia

  2. Exploitation of a new staging area in the Dutch Wadden Sea by Greylag Geese Anser anser : the importance of food-plant dynamics

    NARCIS (Netherlands)

    Bakker, L; van der Wal, R; Esselink, Peter; Siepel, A

    1999-01-01

    The colonisation by Greylag Geese Anser anser of a new autumn migration staging area was studied on the island of Schiermonnikoog, The Netherlands. Over 500 Greylag Geese first visited the island in 1991. During subsequent years, peak numbers rose to 700-900 birds. The geese most likely originated f

  3. New evidence for habitat-specific selection in Wadden Sea Zostera marina populations revealed by genome scanning using SNP and microsatellite markers

    NARCIS (Netherlands)

    Oetjen, Katharina; Ferber, Steven; Dankert, Ilka; Reusch, Thorsten B. H.

    2010-01-01

    Eelgrass Zostera marina is an ecosystem-engineering species of outstanding importance for coastal soft sediment habitats that lives in widely diverging habitats. Our first goal was to detect divergent selection and habitat adaptation at the molecular genetic level; hence, we compared three pairs of

  4. What determines the densities of feeding birds on tidal flats? A case study on dunlin, Calidris alpina, in the Wadden Sea

    Science.gov (United States)

    Nehls, Georg; Tiedemann, Ralph

    The tidal and seasonal pattern of habitat utilization by dunlin was studied in a tidal-flat area in a shallow bay called Königshafen, island of Sylt, by counting the number of dunlins on marked plots at 10-min intervals over whole tidal cycles. Sediment type, tidal elevation, and seasonal changes in food choice were found to influence the feeding densities of dunlin irrespective of total numbers present in the area. Densities of dunlin were generally highest on low muddy substrates. A preference for high sandy substrates was found in late summer. The tidal pattern of habitat utilization differed between areas. In preferred areas dunlin stayed during the whole emersion period. Other areas were only used by following the moving tide line. Seasonal changes in habitat utilization were apparently triggered by changes in food choice. In spring dunlin fed almost exclusively on polychaetes. In late summer a relatively high proportion of shrimps, Crangon crangon, was found in the diet of dunlins. The preference for shrimps may force the birds to stay away from the tide line, where the shrimps can escape into deeper waters. It is recommended that studies on habitat utilization on tidal flats should consider the tidal behaviour of the target species, as single low-tide counts may not give valid results.

  5. Increasing species richness of the macrozoobenthic fauna on tidal flats of the Wadden Sea by local range expansion and invasion of exotic species

    NARCIS (Netherlands)

    Beukema, J.; Dekker, R.

    2011-01-01

    A 40-y series of consistently collected samples (15 fixed sampling sites, constant sampled area of 15 × 0.95 m2, annual sampling only in late-winter/early-spring seasons, and consistent sieving and sorting procedures; restriction to 50 easily recognizable species) of macrozoobenthos on Balgzand, a

  6. On the dynamics of compound bedforms in high-energy tidal channels: field observations in the German Bight and the Danish Wadden Sea

    DEFF Research Database (Denmark)

    Ernstsen, Verner; Christian, Winter; Becker, Marius

    2010-01-01

    Tidal inlets are a common feature along much of the world’s coastlines. They interrupt the alongshore continuity of shoreline processes, and by being exposed to both wave and current forcing, tidal inlets belong to the morphologically most dynamic and complex coastal systems on Earth. The tidal...

  7. On the performance of topobathymetric LiDAR in shallow water environments: the Ribe Vesterå river and the Knudedyb tidal inlet in the Danish Wadden Sea

    DEFF Research Database (Denmark)

    Gergely, Aron; Andersen, Mikkel S.; Teglbrænder-Bjergkvist, Mathias;

    2015-01-01

    to as green LiDAR which is able to penetrate through water, holds the potential to close this gap. However, water column turbidity poses limitations to the penetration of the green laser beam, and water column refraction of the laser beam poses limitations to the scale of features which can be resolved...... is a function of water depth and water column refraction. The horizontal and vertical precision of the LiDAR system is at sub-decimetre scale at a 95% confidence level. This suggests that topobathymetric LiDAR is capable of resolving relatively small-scale morphological features in challenging shallow water...

  8. Essential and Toxic Elements in Blood Samples of Harbor Seals (Phoca vitulina) from the Islands Helgoland (North Sea) and Anholt (Baltic Sea): A Comparison Study with Urbanized Areas.

    Science.gov (United States)

    Kakuschke, Antje; Griesel, Simone

    2016-01-01

    The harbor seals (Phoca vitulina) from Helgoland (North Sea) and Anholt (Kattegat, Baltic Sea) are top predators within the marine food web and an indicator species of the environmental contamination. Furthermore, they are a main tourist attraction. Despite these important roles, little is known about the health and pollutant contamination of these seals. The objective of this study was therefore to investigate 18 essential and nonessential/toxic elements (Al, As, Be, Ca, Cr, Cu, Fe, K, Mn, Mo, Ni, P, Pb, Rb, S, Se, Sr, and Zn) in blood samples using inductively coupled plasma mass spectrometry and total X-ray-fluorescence spectrometry. Blood concentrations of mineral nutrients, such as Ca, K, P, and S, were within the reference ranges described for harbor seals. Likewise, for the trace elements, As, Be, Rb, Se, and Sr, no significant differences were observed compared with previous studies. Interestingly, blood concentrations of nine nonessential as well as essential trace metals (Al, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Zn) measured significantly lower in the offshore living seals from Helgoland and Anholt compared with results obtained from animals living close to urbanized areas, such as the Wadden Sea and Elbe estuary. This suggests that industrial emissions, sewage deposition, shipping traffic and dredging tasks might be the cause of increased metal concentrations of inshore harbor seals.

  9. Grain-size based sea-level reconstruction in the south Bohai Sea during the past 135 kyr

    Science.gov (United States)

    Yi, Liang; Chen, Yanping

    2013-04-01

    and sea level. Nature 324, 137-140. Charman, D.J., Roe, H.M., Roland Gehrels, W., 2002. Modern distribution of saltmarsh testate amoebae: regional variability of zonation and response to environmental variables. Journal of Quaternary Science 17, 387-409. Horton, B.P., 1997. Quantification of the indicative meaning of a range of Holocene sea-level index points from the western North Sea, Department of Geography. University of Durham, Durham City, UK, p. 509. Horton, B.P., Corbett, R., Culver, S.J., Edwards, R.J., Hillier, C., 2006. Modern saltmarsh diatom distributions of the Outer Banks, North Carolina, and the development of a transfer function for high resolution reconstructions of sea level. Estuarine, Coastal and Shelf Science 69, 381-394. IOCAS (Institute of Oceanology, Chinese Academy of Sciences), 1985. Bohai Sea Geology. Science Press, Beijing, China. Madsen, A.T., Murray, A.S., Andersen, T.J., Pejrup, M., 2007. Temporal changes of accretion rates on an estuarine salt marsh during the late Holocene -Reflection of local sea level changes? The Wadden Sea, Denmark. Marine Geology 242, 221-233. Mauz, B., Hassler, U., 2000. Luminescence chronology of Late Pleistocene raised beaches in southern Italy: new data of relative sea-level changes. Marine Geology 170, 187-203. Yi, L., Yu, H.J., Ortiz, J.D., Xu, X.Y., Qiang, X.K., Huang, H.J., Shi, X., Deng, C.L., 2012. A reconstruction of late Pleistocene relative sea level in the south Bohai Sea, China, based on sediment grain-size analysis. Sedimentary Geology 281, 88-100. Zong, Y., Shennan, I., Combellick, R.A., Hamilton, S.L., Rutherford, M.M., 2003. Microfossil evidence for land movements associated with the AD 1964 Alaska earthquake. The Holocene 13, 7-20.

  10. Sea Legs

    Science.gov (United States)

    Macdonald, Kenneth C.

    Forty-foot, storm-swept seas, Spitzbergen polar bears roaming vast expanses of Arctic ice, furtive exchanges of forbidden manuscripts in Cold War Moscow, the New York city fashion scene, diving in mini-subs to the sea floor hot srings, life with the astronauts, romance and heartbreak, and invading the last bastions of male exclusivity: all are present in this fast-moving, non-fiction account of one woman' fascinating adventures in the world of marine geology and oceanography.

  11. Satellite tracking of harbour seals on Horns Reef - Use of the Horns Reef wind farm area and the North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Tougaard, J.; Tougaard, S.; Jensen, Thyge [Fisheries and Maritime Museum Esbjerg (Denmark); Ebbesen, I. [Univ. of Sourthern Denmark, Inst. of Biology, Odense (Denmark); Teilmann, J. [NationL Environmental Res. Inst., Roskidle (Denmark)

    2003-03-15

    Ten harbour seals (Phoca vitulina) caught on the Danish Wadden Sea island Roemoe were equipped with satellite linked time depth recorders. The animals were caught on three separate occasions (Jan. 4th, Feb. 18th and May 6th, 2002). The transmitters worked between 49 and 100 days, relaying positional and dive information back via the ARGOS satellite service until beginning of July. Background for the studies is the construction of the Worlds largest off shore wind farm on Horns Reef. Based on previous studies using VHF-transmitters, it was expected that the seals would spend considerable time on Horns Reef. The VHF-telemetry studies showed that the preferred direction for seals leaving the Danish Wadden Sea is NW from Graedyb tidal area outside Esbjerg, the direction directly towards the wind farm area. The previously used VHF-transmitters had a limited detection range and it was decided to equip a number of seals from the same area as before with satellite transmitters. This allows for positioning of the seals in the entire North Sea as well as providing dive summary information, as a transmitter with a depth transducer was chosen for the study. Positional information revealed that animals move about more extensively than previously believed. Substantial variation between animals was observed and each seal seemed to have adopted its own foraging strategy. Some animals travelled to the centre of the North Sea on foraging trips and spent considerable time close to the bottom at 30-70 meters depth. Other seals remained in the German Bight and yet others spent considerable time on and around Horns Reef. The area of Horns reef wind farm constitutes a negligible fraction of the total area visited by the tagged seals. The reef as a whole however, appears to be important to the seals both for foraging and as transit area to other feeding grounds further off shore. The resolution in positional information is not sufficiently high to allow for a detailed study of the effects

  12. Sea Ice

    Science.gov (United States)

    Perovich, D.; Gerland, S.; Hendricks, S.; Meier, Walter N.; Nicolaus, M.; Richter-Menge, J.; Tschudi, M.

    2013-01-01

    During 2013, Arctic sea ice extent remained well below normal, but the September 2013 minimum extent was substantially higher than the record-breaking minimum in 2012. Nonetheless, the minimum was still much lower than normal and the long-term trend Arctic September extent is -13.7 per decade relative to the 1981-2010 average. The less extreme conditions this year compared to 2012 were due to cooler temperatures and wind patterns that favored retention of ice through the summer. Sea ice thickness and volume remained near record-low levels, though indications are of slightly thicker ice compared to the record low of 2012.

  13. Sea level change

    Digital Repository Service at National Institute of Oceanography (India)

    Church, J.A.; Clark, P.U.; Cazenave, A.; Gregory, J.M.; Jevrejeva, S.; Levermann, A.; Merrifield, M.A.; Milne, G.A.; Nerem, R.S.; Nunn, P.D.; Payne, A.J.; Pfeffer, W.T.; Stammer, D.; Unnikrishnan, A.S.

    This chapter considers changes in global mean sea level, regional sea level, sea level extremes, and waves. Confidence in projections of global mean sea level rise has increased since the Fourth Assessment Report (AR4) because of the improved...

  14. Mammals of the Sea.

    Science.gov (United States)

    Naturescope, 1986

    1986-01-01

    Presents information on sea mammals, including definitions and characteristics of cetaceans, pinnipeds, and sirenians. Contains descriptions of the teaching activities "Whale Music,""Draw A Whale to Scale,""Adopt a Sea Mammal," and "Sea Mammal Sleuths." (TW)

  15. Mammals of the Sea.

    Science.gov (United States)

    Naturescope, 1986

    1986-01-01

    Presents information on sea mammals, including definitions and characteristics of cetaceans, pinnipeds, and sirenians. Contains descriptions of the teaching activities "Whale Music,""Draw A Whale to Scale,""Adopt a Sea Mammal," and "Sea Mammal Sleuths." (TW)

  16. White sea radioactivity assessment

    Energy Technology Data Exchange (ETDEWEB)

    Aliev, R.A. [Lomonosov Moscow State Univ. (Russian Federation). Skobeltsyn Inst. of Nuclear Physics]|[Lomonosov Moscow State Univ. (Russian Federation). Chemistry Dept.]|[Russian Academy of Sciences, Moscow (Russian Federation). Shirshov Inst. of Oceanology; Kalmykov, S.N.; Lisitzin, A.P. [Lomonosov Moscow State Univ. (Russian Federation). Chemistry Dept.

    2004-07-01

    The aim of the present work is to estimate potential sources and chronology of pollution of the White Sea (Russia) by artificial radionuclides. White Sea is semi-closed water body connected with Barents Sea by a narrow strait. Thus, pollution of White Sea may be caused by highly polluted Barents waters and river (mainly Northern Dvina) run-off. This is the first detailed investigation of radioactivity of White Sea sediment records. (orig.)

  17. Wave-current interactions in the southern North Sea: The impact on salinity

    Science.gov (United States)

    Schloen, Julia; Stanev, Emil V.; Grashorn, Sebastian

    2017-03-01

    The interplay between wind waves and currents in the coastal zone of the southern North Sea along with the resulting changes in the salinity distribution are quantified using simulations with the unstructured-grid ocean model SCHISM coupled with the wind wave model WWM III. Several sensitivity runs, which are carried out to estimate the individual contributions of different physical mechanisms and forcing, demonstrated that the density gradients in the coastal zone reduce tidal current by 18%, whereas the wind waves enhance the circulation in some cases. The latter happens when along-shore wind speed approaches ∼10 m s-1 resulting in long-shore currents following the western Dutch coast and the German Wadden Sea islands. The wave-induced transport of salt leads to changes in the horizontal salinity distribution. These are most pronounced in front of barrier islands where coherent patterns caused by the coupling between tides, surface drift, and wind waves reveal salinity changes up to 0.5. The weak stratification of salinity in the coastal zone is mostly destroyed by wind waves. Thus, effects created by wind waves tend to substantially modify the estuarine circulation. An explanation of these important processes in the coastal zone has been given based on an analysis of the ratio between significant wave height and tidal range. This control-parameter, which is relatively small under mild weather conditions, can exceed unity under strong wind conditions in the coastal zone, thus mixing due to waves becomes dominant. The effect of fresh water fluxes from subterranean estuaries is relatively small and confined only in the vicinity of corresponding sources.

  18. 7 CFR 1437.310 - Sea grass and sea oats.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT... Determining Coverage Using Value § 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value...

  19. Sea Turtle Interaction Report

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Sea Turtle Interaction Report is a report sent out in pdf format to authorized individuals that summarizes sea turtle interactions in the longline fishery. The...

  20. Sea Turtle Interaction Report

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Sea Turtle Interaction Report is a report sent out in pdf format to authorized individuals that summarizes sea turtle interactions in the longline fishery. The...

  1. Sea Lion Diet Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — California sea lions pup and breed at four of the nine Channel Islands in southern California. Since 1981, SWFSC MMTD has been conducting a diet study of sea lions...

  2. All hands on deck : an interactive perspective on complex common-pool resource management based on case studies in the coastal waters of the Isle of Wight (UK), Connemara (Ireland) and the Dutch Wadden Sea

    NARCIS (Netherlands)

    Steins, N.A.

    1999-01-01

    In 1996, the new fish cages of an Irish salmon farm were sabotaged and juvenile salmon with a value of IR£ 250,000 were released, nearly putting the farm out of business. This deed was an act of protest against the growth of the salmon farming industry. The loss of fishing grounds,

  3. All hands on deck : An interactive perspective on complex common-pool resource management based on case studies in the coastal waters of the Isle of Wight (UK), Connemara (Ireland) and the Dutch Wadden Sea

    NARCIS (Netherlands)

    Steins, N.A.

    1999-01-01

    In 1996, the new fish cages of an Irish salmon farm were sabotaged and juvenile salmon with a value of IR£ 250,000 were released, nearly putting the farm out of business. This deed was an act of protest against the growth of the salmon farming industry. The loss of fishing grounds, ecological and en

  4. All That Unplowed Sea

    Science.gov (United States)

    MOSAIC, 1975

    1975-01-01

    Hunting and gathering at sea may fast be approaching their productive limits. Aquaculture - farming at sea - linked to conservation represents the sea's promise. If the system works, it might prove to be the key to supplying large amounts of food and fresh water at no cost in nonrenewable energy resources. (BT)

  5. The Caspian Sea Environment

    Science.gov (United States)

    Kostianoy, Andrey; Kosarev, A.

    The systematic description of the knowledge accumulated on the physical oceanography, marine chemistry and pollution, and marine biology of the Caspian Sea forms the basis of this book. It presents the principal characteristic features of the environmental conditions of the sea and their changes in the second half of the 20th century. At present, the principal problems of the Caspian Sea are related to the interannual sea level changes and their forecast and to the estimation of the intensity of the chemical pollution of the sea and its impact upon the biota.

  6. SEA and planning

    DEFF Research Database (Denmark)

    Stoeglehner, G.; Brown, A.L.; Kørnøv, Lone

    2009-01-01

    As the field of strategic environmental assessment (SEA) has matured, the focus has moved from the development of legislation, guidelines and methodologies towards improving the effectiveness of SEA. Measuring and of course achieving effectiveness is both complex and challenging. This paper...... suggests that SEA professionals need to consider 'democratic effectiveness' as well as 'environmental effectiveness' in both 'direct' and 'indirect' outputs. The effectiveness of SEA depends critically on the context within which SEA legislation and guidelines are understood and implemented......, and the relationship of the SEA to the planning activity itself. This paper focuses on the influence that planners have in these implementation processes, postulating the hypothesis that these are key players in achieving effectiveness in SEA. Based upon implementation theory and empirical experience, the paper...

  7. Baltic Sea: Radionuclides

    DEFF Research Database (Denmark)

    Nielsen, Sven Poul; Lüning, Maria; Ilus, Erkki

    2011-01-01

    about 14%. For 90Sr in the Baltic Sea, input from atmospheric fallout from nuclear weapons tests has contributed about 81%, while the contribution from Chernobyl fallout was about 13%. Cesium-137 is the main indicator of Baltic seawater with respect to anthropogenic radioactivity. The highest....... Radioactivity inputs into the Baltic Sea from nuclear reprocessing plants in Western Europe have become of minor importance due to significant reduction of discharges in recent years. In terms of input of 137Cs into the Baltic Sea, Chernobyl fallout has contributed about 82% and nuclear weapons test fallout...... 137Cs values due to their higher concentration factors (CFs). The larger 137Cs values of pike were observed at the coast of the Bothnian Sea. The Baltic Sea is the regional sea in the world with the highest concentrations of 137Cs. The Baltic Sea ranks third in the world with respect to 90Sr...

  8. Baltic Sea: Radionuclides

    DEFF Research Database (Denmark)

    Nielsen, Sven Poul; Lüning, Maria; Ilus, Erkki

    2010-01-01

    about 14%. For 90Sr in the Baltic Sea, input from atmospheric fallout from nuclear weapons tests has contributed about 81%, while the contribution from Chernobyl fallout was about 13%. Cesium-137 is the main indicator of Baltic seawater with respect to anthropogenic radioactivity. The highest....... Radioactivity inputs into the Baltic Sea from nuclear reprocessing plants in Western Europe have become of minor importance due to significant reduction of discharges in recent years. In terms of input of 137Cs into the Baltic Sea, Chernobyl fallout has contributed about 82% and nuclear weapons test fallout...... 137Cs values due to their higher concentration factors (CFs). The larger 137Cs values of pike were observed at the coast of the Bothnian Sea. The Baltic Sea is the regional sea in the world with the highest concentrations of 137Cs. The Baltic Sea ranks third in the world with respect to 90Sr...

  9. Sea piracy and law of the sea

    OpenAIRE

    Hanif, Muhammad Tahir

    2010-01-01

    As the sea become world’s largest source to trade between the nations during the last few decades. Of course there are lots of problems in this regards when we are using the sea on such a large scale. The problem of piracy is most dangerous problems, among the all problems of the sea at the same time. Nations are trying to control this crime individually and collectively but the problem is still on its peak. Lots of international and national laws and conventions are held in this ...

  10. The impact of future sea-level rise on the European Shelf tides

    Science.gov (United States)

    Pickering, M. D.; Wells, N. C.; Horsburgh, K. J.; Green, J. A. M.

    2012-03-01

    This paper investigates the effect of future sea-level rise (SLR) on the tides of the northwest European Continental Shelf. The European shelf tide is dominated by semidiurnal constituents. This study therefore focuses primarily on the changes in the M2 tidal constituent and the spring and neap tidal conditions. The validated operational Dutch Continental Shelf Model is run for the present day sea-level as well as 2 and 10 m SLR scenarios. The M2 tidal amplitude responds to SLR in a spatially non-uniform manner, with substantial amplitude increases and decreases in both scenarios. The M2 tidal response is non-linear between 2 and 10 m with respect to SLR, particularly in the North Sea. Under the 2 m SLR scenario the M2 constituent is particularly responsive in the resonant areas of the Bristol Channel and Gulf of St. Malo (with large amplitude decreases) and in the southeastern German Bight and Dutch Wadden Sea (with large amplitude increases). Changes in the spring tide are generally greater still than those in the M2 or neap tides. With 2 m SLR the spring tidal range increases up to 35 cm at Cuxhaven and decreases up to -49 cm at St. Malo. Additionally the changes in the shallow water tides are larger than expected. With SLR the depth, wave speed and wave length (tidal resonance characteristics) are increased causing changes in near resonant areas. In expansive shallow areas SLR causes reduced energy dissipation by bottom friction. Combined these mechanisms result in the migration of the amphidromes and complex patterns of non-linear change in the tide with SLR. Despite the significant uncertainty associated with the rate of SLR over the next century, substantial alterations to tidal characteristics can be expected under a high end SLR scenario. Contrary to existing studies this paper highlights the importance of considering the modification of the tides by future SLR. These substantial future changes in the tides could have wide reaching implications; including

  11. Salish Sea Genetics - Salish Sea genetic inventory

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Salish Sea comprises most of the Puget Sound water area. Marine species are generally assemblages of discrete populations occupying various ecological niches....

  12. Summer Arctic sea fog

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Synchronous or quasi-synchronous sea-land-air observations were conducted using advanced sea ice, atmospheric and marine instruments during China' s First Arctic Expedition. Based on the Precious data from the expedition, it was found that in the Arctic Ocean, most part of which is covered with ice or is mixed with ice, various kinds of sea fog formed such as advection fog, radiation fog and vapor fog. Each kind has its own characteristic and mechanics of creation. In the southern part of the Arctic Ocean, due to the sufficient warm and wet flow there, it is favorable for advection fog to form,which is dense and lasts a long time. On ice cap or vast floating ice, due to the strong radiation cooling effect, stable radiating fog is likely to form. In floating ice area there forms vapor fog with the appearance of masses of vapor from a boiling pot, which is different from short-lasting land fog. The study indicates that the reason why there are many kinds of sea fog form in the Arctic Ocean is because of the complicated cushion and the consequent sea-air interaction caused by the sea ice distribution and its unique physical characteristics. Sea fog is the atmospheric phenomenon of sea-air heat exchange. Especially, due to the high albedo of ice and snow surface, it is diffcult to absorb great amount of solar radiation during the polar days. Besides, ice is a poor conductor of heat; it blocks the sea-air heat exchange.The sea-air exchange is active in floating ice area where the ice is broken. The sea sends heat to the atmosphere in form of latent heat; vapor fog is a way of sea-air heat exchange influencing the climate and an indicator of the extent of the exchange. The study also indicates that the sea also transports heat to the atmosphere in form of sensible heat when vapor fog occurs.

  13. Arctic Sea Level Reconstruction

    DEFF Research Database (Denmark)

    Svendsen, Peter Limkilde

    Reconstruction of historical Arctic sea level is very difficult due to the limited coverage and quality of tide gauge and altimetry data in the area. This thesis addresses many of these issues, and discusses strategies to help achieve a stable and plausible reconstruction of Arctic sea level from...... 1950 to today.The primary record of historical sea level, on the order of several decades to a few centuries, is tide gauges. Tide gauge records from around the world are collected in the Permanent Service for Mean Sea Level (PSMSL) database, and includes data along the Arctic coasts. A reasonable...... amount of data is available along the Norwegian and Russian coasts since 1950, and most published research on Arctic sea level extends cautiously from these areas. Very little tide gauge data is available elsewhere in the Arctic, and records of a length of several decades,as generally recommended for sea...

  14. South China Sea Challenge

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    China's attempts to solve disputes with ASEAN over the South China Sea help regional peace China's marine economy and security are currently faced with new challenges, requiring careful handling, especially in disputes with ASEAN countries and in promoting common development of the South China Sea. The outcome of how this is dealt with could undoubtedly pave the way for solutions to other oceanic disputes. The South China Sea is located south of

  15. Dilemmas in SEA application

    DEFF Research Database (Denmark)

    Lyhne, Ivar

    Dilemmas in SEA Application: The DK Energy SectorIvar Lyhne - lyhne@plan.aau.dk. Based on three years of collaborative research, this paper outlines dilemmas in the application of SEA in the strategic development of the Danish energy sector. The dilemmas are based on concrete examples from practice...... the Danish energy sector) are starting to get it right. Lessons for SEA implementation in similar contexts are proposed....

  16. Pelagic sea snakes dehydrate at sea

    Science.gov (United States)

    Lillywhite, Harvey B.; Sheehy, Coleman M.; Brischoux, François; Grech, Alana

    2014-01-01

    Secondarily marine vertebrates are thought to live independently of fresh water. Here, we demonstrate a paradigm shift for the widely distributed pelagic sea snake, Hydrophis (Pelamis) platurus, which dehydrates at sea and spends a significant part of its life in a dehydrated state corresponding to seasonal drought. Snakes that are captured following prolonged periods without rainfall have lower body water content, lower body condition and increased tendencies to drink fresh water than do snakes that are captured following seasonal periods of high rainfall. These animals do not drink seawater and must rehydrate by drinking from a freshwater lens that forms on the ocean surface during heavy precipitation. The new data based on field studies indicate unequivocally that this marine vertebrate dehydrates at sea where individuals may live in a dehydrated state for possibly six to seven months at a time. This information provides new insights for understanding water requirements of sea snakes, reasons for recent declines and extinctions of sea snakes and more accurate prediction for how changing patterns of precipitation might affect these and other secondarily marine vertebrates living in tropical oceans. PMID:24648228

  17. Pelagic sea snakes dehydrate at sea.

    Science.gov (United States)

    Lillywhite, Harvey B; Sheehy, Coleman M; Brischoux, François; Grech, Alana

    2014-05-07

    Secondarily marine vertebrates are thought to live independently of fresh water. Here, we demonstrate a paradigm shift for the widely distributed pelagic sea snake, Hydrophis (Pelamis) platurus, which dehydrates at sea and spends a significant part of its life in a dehydrated state corresponding to seasonal drought. Snakes that are captured following prolonged periods without rainfall have lower body water content, lower body condition and increased tendencies to drink fresh water than do snakes that are captured following seasonal periods of high rainfall. These animals do not drink seawater and must rehydrate by drinking from a freshwater lens that forms on the ocean surface during heavy precipitation. The new data based on field studies indicate unequivocally that this marine vertebrate dehydrates at sea where individuals may live in a dehydrated state for possibly six to seven months at a time. This information provides new insights for understanding water requirements of sea snakes, reasons for recent declines and extinctions of sea snakes and more accurate prediction for how changing patterns of precipitation might affect these and other secondarily marine vertebrates living in tropical oceans.

  18. Numerical modelling of climate change impacts on freshwater lenses on the North Sea Island of Borkum using hydrological and geophysical methods

    Directory of Open Access Journals (Sweden)

    H. Sulzbacher

    2012-10-01

    Full Text Available A numerical, density dependent groundwater model is set up for the North Sea Island of Borkum to estimate climate change impacts on coastal aquifers and especially the situation of barrier islands in the Wadden Sea. The database includes information from boreholes, a seismic survey, a helicopter-borne electromagnetic (HEM survey, monitoring of the freshwater-saltwater boundary by vertical electrode chains in two boreholes, measurements of groundwater table, pumping and slug tests, as well as water samples. Based on a statistical analysis of borehole columns, seismic sections and HEM, a hydrogeological model is set up. The groundwater model is developed using the finite-element programme FEFLOW. The density dependent groundwater model is calibrated on the basis of hydraulic, hydrological and geophysical data, in particular spatial HEM and local monitoring data. Verification runs with the calibrated model show good agreement between measured and computed hydraulic heads. A good agreement is also obtained between measured and computed density or total dissolved solids data for both the entire freshwater lens on a large scale and in the area of the well fields on a small scale.

    For simulating future changes in this coastal groundwater system until the end of the current century, we use the climate scenario A2, specified by the Intergovernmental Panel on Climate Change and, in particular, the data for the German North Sea coast. Simulation runs show proceeding salinisation with time beneath the well fields of the two waterworks Waterdelle and Ostland.

    The modelling study shows that the spreading of well fields is an appropriate protection measure against excessive salinisation of the water supply until the end of the current century.

  19. Hindcasting and forecasting macrofauna species distribution for the Jade Bay tidal basin (North Sea, Germany) in response to climatic and environmental changes

    Science.gov (United States)

    Singer, Anja; Schückel, Ulrike; Beck, Melanie; Bleich, Oliver; Brumsack, Hans-J.; Freund, Holger; Geimecke, Christina; Lettmann, Karsten; Millat, Gerald; Staneva, Joanna; Vanselow, Anna; Westphal, Heiko; Wolff, Jörg-O.; Wurpts, Andreas; Kröncke, Ingrid

    2016-04-01

    During the last decades severe climatic and environmental changes have been monitored for the Jade Bay (German Wadden Sea), causing pronounced changes in the abundance and spatial distribution of characteristic benthic species. Due to their relatively sessile habit, benthic species are ideal organisms for small-scale species distribution modelling (SDM) and important indicators for environmental changes and disturbances. In a first step, the present distribution (representing 2009) was modelled for 10 characteristic macrofauna (> 0.5 mm) species, built on statistical relations between species presences and 11 high-resolution environmental grids. Here, five different presence-absence modelling algorithms were merged (GLM, GBM, RF, MARS, ANN) within the ensemble forecasting platform 'biomod2'. In a second step, the past distribution scenario was reconstructed for the 1970s in order to evaluate the hindcast model results with independent macrofauna data from the 1970s. In a third step, the future macrofauna distribution (representing 2050) was forecasted under potential future habitat conditions, i.e. ongoing sea-level rise and changing biogenic structures (seagrass and mussel beds). Submergence time and sediment characteristics correlated most significantly with the modelled macrofauna distribution at the study site, followed by nutrient supply and topography. The historical macrofauna data evaluated the past distribution scenario model results. Climate change induced sea-level rise and its local implications on the Jade Bay (increased sediment load, rise in the tidal height) explained the changes in the macrofauna distribution patterns since the last four decades. The forecast scenario revealed clear species distribution shifts, range size changes and niche overlap changes.

  20. Phytoplankton of the North Sea and its dynamics: A review

    Science.gov (United States)

    Reid, P. C.; Lancelot, C.; Gieskes, W. W. C.; Hagmeier, E.; Weichart, G.

    Phytoplankton is the major contributor to algal biomass and primary production of the North Sea, although crops of macroalgae can locally be up to 2000 g C.m -2 along the coast of the U.K. and Norway, and microphytobenthos dominates production in the shallow tidal flat areas bordering the coasts of England, the Netherlands, Germany and Denmark. Data collected since 1932 during the Continuous Plankton Recorder Survey show consistent patterns of geographical, seasonal and annual variation in the distribution of phytoplankton and its major taxonomic components. There is a trend of increased colouration in Recorder silks in the southern North Sea until approximately 1975 since when Colour levels (assumed to be indicative of algal biomass) have declined. In the eutrophic Dutch Wadden Sea the algal crop continued to increase; in Dutch coastal North Sea waters a trend of biomass increase reversed since 1984, apparently due to a reduction in Rhine river outflow. Long-term observations made at Helgoland since the 60's also show trends of increasing nutrients and phytoplankton biomass only to 1984. Adverse effects such as deoxygenation, foam formation and toxin production have been linked to mass concentrations of algae known as blooms. There is no evidence from existing reports for an increase in their frequency, although some years stand out with larger numbers. Occurrence of blooms can partly be explained by hydrographic conditions. More than 30 taxa are recognised as occurring in bloom proportions in the North Sea, approximately one third of which can be toxic. The crop of Bacillariophyceae (diatoms) is not likely to increase with eutrophication due to silicate limitation. An extensive subsurface maximum of armoured dinoflagellates, its abundance gouverned by hydrographic conditions, is the most characteristic feature of the central and northern North Sea in the summer months. Abundance, sometimes dominance, of picoplankton and of species that are not readily detected by

  1. Sea surface temperatures and salinities from platforms in the Barents Sea, Sea of Japan, North Atlantic Ocean, Philippine Sea, Red Sea, and the South China Sea (Nan Hai) from 1896-1950 (NODC Accession 0000506)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface temperatures and salinities were collected in the Barents Sea, Sea of Japan, North Atlantic Ocean, Philippine Sea, Red Sea, and South China Sea (Nan Hai)...

  2. Somalia ... From the Sea

    Science.gov (United States)

    2009-07-01

    from the Sea, p. 7. 65. Robert D. Heinl, Jr., “Inchon, 1950,” in As- sault from the Sea: Essays on the History of Amphibious Warfare, ed. Merrill L...Mohamed Haji. Historical Dictionary of Somalia. New ed. Lanham, Md.: Scare- crow , 2003. Natsios, Andrew S. U.S. Foreign Policy and the Four Horsemen of

  3. SEA in Southern Africa

    CSIR Research Space (South Africa)

    Audouin, M

    2011-01-01

    Full Text Available in a number of them. Despite these trends, however, the opportunities that SEA can offer to facilitate sustainable development are not being realized. In this chapter, the authors describe the emergence of SEA in the post-colonial, democratic context...

  4. Oceanography of marginal seas

    Digital Repository Service at National Institute of Oceanography (India)

    DileepKumar, M.

    dioxide in intermediate layers falls from approx. 1000 mu atm in the southern end to approx. 500 mu atm in the northern Red Sea. Temperature in Atlantis II deep and brine level in Discovery deep in the Red Sea seem to be increasing in recent years...

  5. Dilemmas in SEA application

    DEFF Research Database (Denmark)

    Lyhne, Ivar

    Dilemmas in SEA Application: The DK Energy SectorIvar Lyhne - lyhne@plan.aau.dk. Based on three years of collaborative research, this paper outlines dilemmas in the application of SEA in the strategic development of the Danish energy sector. The dilemmas are based on concrete examples from practice...... in the implementation of SEA in the sector, and they concern, e.g., strategic choices in transmission network development and ministerial choices on location of energy production units. The paper outlines the roots of the dilemmas as well as their implications for timing and content of SEA. The verdict is that we (in...... the Danish energy sector) are starting to get it right. Lessons for SEA implementation in similar contexts are proposed....

  6. IOMASA SEA ICE DEVELOPMENTS

    DEFF Research Database (Denmark)

    Andersen, Søren; Tonboe, Rasmus; Heygster, Georg

    2005-01-01

    Sensitivity studies show that the radiometer ice concentration estimate can be biased by +10% by anomalous atmospheric emissivity and -20% by anomalous ice surface emissivity. The aim of the sea ice activities in EU 5th FP project IOMASA is to improve sea ice concentration estimates at higher...... spatial resolution. The project is in the process of facilitating an ice concentration observing system through validation and a better understanding of the microwave radiative transfer of the sea ice and overlying snow layers. By use of a novel modelling approach, it is possible to better detect...... and determine the circumstances that may lead to anomalous sea ice concentration retrieval as well as to assess and possibly minimize the sensitivities of the retrieval system. Through an active partnership with the SAF on Ocean and Sea Ice, a prototype system will be implemented as an experimental product...

  7. Indicators and SEA

    DEFF Research Database (Denmark)

    Gao, Jingjing; Kørnøv, Lone; Christensen, Per

    Abstract: Indicators are widely used in SEA to measure, communicate and monitor impacts from a proposed policy, plan or programme, and can improve the effectiveness for the SEA by simplifying the complexity of both assessment and presentation. Indicators can be seen as part of the implementation...... process helping to understand, communicate and, integrate important environmental issues in planning and decision-making. On the other hand, use of indicators can also limit SEA effectiveness, if the ones chosen are biased or limited, if the aggregation gives incorrect interpretation...... and if the information requirement for different target groups is not addressed. Indicators are widely used in SEA to measure, communicate and monitor impacts from a proposed policy, plan or programme, and can improve the effectiveness for the SEA by simplifying the complexity of both assessment and presentation...

  8. IOMASA SEA ICE DEVELOPMENTS

    DEFF Research Database (Denmark)

    Andersen, Søren; Tonboe, Rasmus; Heygster, Georg

    2005-01-01

    Sensitivity studies show that the radiometer ice concentration estimate can be biased by +10% by anomalous atmospheric emissivity and -20% by anomalous ice surface emissivity. The aim of the sea ice activities in EU 5th FP project IOMASA is to improve sea ice concentration estimates at higher...... spatial resolution. The project is in the process of facilitating an ice concentration observing system through validation and a better understanding of the microwave radiative transfer of the sea ice and overlying snow layers. By use of a novel modelling approach, it is possible to better detect...... and determine the circumstances that may lead to anomalous sea ice concentration retrieval as well as to assess and possibly minimize the sensitivities of the retrieval system. Through an active partnership with the SAF on Ocean and Sea Ice, a prototype system will be implemented as an experimental product...

  9. Gracilaria vermiculophylla (Ohmi) Papenfuss, 1967 (Rhodophyta, Gracilariaceae) in northern Europe, with emphasis on Danish conditions, and what to expect in the future

    DEFF Research Database (Denmark)

    Thomsen, Mads S.; Stæhr, Peter Anton; Nyberg, Cecilia D.

    2007-01-01

    Gracilaria vermiculophylla, a red macroalga from the West Pacific, was discovered in western Germany (the Wadden Sea) in 2002 and has since also been observed in Sweden (from about 70 km south to about 80 km north of Göteborg), Denmark (Wadden Sea, Horsens Fjord, Limfjorden, Vejle Fjord, Holckenh...

  10. Dead sea water intoxication.

    Science.gov (United States)

    Levy-Khademi, Floris; Brooks, Rebecca; Maayan, Channa; Tenenbaum, Ariel; Wexler, Isaiah D

    2012-08-01

    Near drowning in the Dead Sea is associated with both respiratory manifestations and severe electrolyte abnormalities. It is often difficult to distinguish between the contributions of sea water aspiration or ingestion to clinical manifestations. We present a unique case of accidental ingestion of a large amount of Dead Sea water through a gastrostomy tube in which a patient with familial dysautonomia presented with severe electrolyte disturbances. Forced diuresis with large amounts of intravenous fluids resulted in clinical and biochemical improvement. Full recovery was achieved after 2 days of treatment.

  11. The north Sulu Sea productivity

    Science.gov (United States)

    Xiao, Z.

    2009-12-01

    The Sulu Sea is a part of the western North Pacific. It is a closed sea for its deep water and a semi-closed sea for its upper layer. The Sulu Sea exchanges mainly surface waters with the South China Sea and the Celebes Sea. The Sulu Sea is more productive than the adjacent South China Sea (Jones, 2002). On the basis of MERIS satellite observations from 2002 to 2008, we focus on the high-chlorophyll area as an indicator of the abundance of primary productivity in the Sulu Sea. Strong chlorophyll concentration in the north Sulu Sea close to the Mindoro Strait mainly occurs from December to March and low chlorophyll concentration happens in April to November. The adjacent South China Sea on the other side of Mindoro Strait has shown persistent signs of low chlorophyll concentration. Based on 1/8° Global Navy Coastal Ocean Model, the intrusion of the South China Sea waters through the Mindoro Strait to the Sulu Sea from April to November is the main reason for the low chlorophyll concentration observed in the north Sulu Sea. During April to November, the South China Sea waters flow through the Mindoro Strait and stay on the surface of the north Sulu Sea because of their low density. The north Sulu Sea waters mix with fresher waters coming from the South China Sea without new nutrients supply. When the inflow from South China Sea to Sulu Sea ceases in December to March, the upwelling due to the summer monsoon wind becomes an important mechanism supplying deep nutrients to the surface water which lead to high chlorophyll concentration. Jones, I.S.F., 2002. Primary production in the Sulu Sea. Proceedings of the Indian Academy of Sciences-Earth and Planetary Sciences 111, 209-213.

  12. Sea Scallop Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Sea Scallop Survey began in 1980 and has covered an area from Cape Hatteras to Georges Bank. The survey aims to determine the distribution and...

  13. Pollution of coastal seas

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.

    cities. Various types of wastes, if not properly treated, would cause serious pollution of these shallow seas endangering marine life and spoiling recreational facilities. Different polluting agents like sewage, chemicals, industrial coolants etc...

  14. A Sea Floor Penetrometer.

    Science.gov (United States)

    processed through an analog-to-digital (A/D) converter, and stored in the memory of a mini-computer. Computer algorithms are applied to the deceleration data to provide real-time sea floor classification.

  15. Baltic Sea: Radionuclides

    DEFF Research Database (Denmark)

    Nielsen, Sven Poul; Lüning, Maria; Ilus, Erkki

    2011-01-01

    The most significant source of anthropogenic radioactivity in the Baltic Sea is fallout from the accident at the Chernobyl nuclear power plant in 1986. The second most important source is global fallout from atmospheric nuclear weapons tests carried out during the late 1950s and early 1960s....... Radioactivity inputs into the Baltic Sea from nuclear reprocessing plants in Western Europe have become of minor importance due to significant reduction of discharges in recent years. In terms of input of 137Cs into the Baltic Sea, Chernobyl fallout has contributed about 82% and nuclear weapons test fallout...... about 14%. For 90Sr in the Baltic Sea, input from atmospheric fallout from nuclear weapons tests has contributed about 81%, while the contribution from Chernobyl fallout was about 13%. Cesium-137 is the main indicator of Baltic seawater with respect to anthropogenic radioactivity. The highest...

  16. South China Sea.

    Science.gov (United States)

    Morton, B; Blackmore, G

    2001-12-01

    The South China Sea is poorly understood in terms of its marine biota, ecology and the human impacts upon it. What is known is most often contained in reports and workshop and conference documents that are not available to the wider scientific community. The South China Sea has an area of some 3.3 million km2 and depths range from the shallowest coastal fringe to 5377 m in the Manila Trench. It is also studded with numerous islets, atolls and reefs many of which are just awash at low tide. It is largely confined within the Tropic of Cancer and, therefore, experiences a monsoonal climate being influenced by the Southwest Monsoon in summer and the Northeast Monsoon in winter. The South China Sea is a marginal sea and, therefore, largely surrounded by land. Countries that have a major influence on and claims to the sea include China, Malaysia, the Philippines and Vietnam, although Thailand, Indonesia and Taiwan have some too. The coastal fringes of the South China Sea are home to about 270 million people that have had some of the fastest developing and most vibrant economies on the globe. Consequently, anthropogenic impacts, such as over-exploitation of resources and pollution, are anticipated to be huge although, in reality, relatively little is known about them. The Indo-West Pacific biogeographic province, at the centre of which the South China Sea lies, is probably the world's most diverse shallow-water marine area. Of three major nearshore habitat types, i.e., coral reefs, mangroves and seagrasses, 45 mangrove species out of a global total of 51, most of the currently recognised 70 coral genera and 20 of 50 known seagrass species have been recorded from the South China Sea. The island groups of the South China Sea are all disputed and sovereignty is claimed over them by a number of countries. Conflicts have in recent decades arisen over them because of perceived national rights. It is perhaps because of this that so little research has been undertaken on the

  17. South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Morton, Brian [Hong Kong Univ., Swire Inst. of Marine Science, Hong Kong (China); Hong Kong Univ., Dept. of Ecology and Biodiversity, Hong Kong (China); Blackmore, Graham [Hong Kong Univ. of Science and Technology, Dept. of Biology, Hong Kong (China)

    2001-07-01

    The South China Sea is poorly understood in terms of its marine biota, ecology and the human impacts upon it. What is known is most often contained in reports and workshops and conference documents that are not available to the wider scientific community. The South China Sea has an area of some 3.3 million km{sup 2} and depths range from the shallowest coastal fringe to 5377m in the Manila Trench. It is also studded with numerous islets, atolls and reefs many of which are just awash at low tide. It is largely confined within the Tropic of Cancer and, therefore, experiences a monsoonal climate being influenced by the Southwest Monsoon in summer and the Northeast Monsoon in winter. The South China Sea is a marginal sea and, therefore, largely surrounded by land. Countries that have a major influence on and claims to the sea include China, Malaysia, the Philippines and Vietnam, although Thailand, Indonesia and Taiwan have some too. The coastal fringes of the South China Sea are home to about 270 million people that have had some of the fastest developing and most vibrant economics on the globe. Consequently, anthropogenic impacts, such as over-exploitation of resources and pollution, are anticipated to be huge although, in reality, relatively little is known about them. The Indo-West Pacific biogeographic province, at the centre of which the South China Sea lies, is probably the world's most diverse shallow-water marine area. Of three major nearshore habitat types, i.e., coral reefs, mangroves and seagrasses, 45 mangrove species out of a global total of 51, most of the currently recognised 70 coral genera and 20 of 50 known seagrass species have been recorded from the South China Sea. The island groups of the South China Sea are all disputed and sovereignty is claimed over them by a number of countries. Conflicts have in recent decades arisen over them because of perceived national rights. It is perhaps because of this that so little research has been undertaken

  18. South China Sea

    Science.gov (United States)

    Morton, Brian; Blackmore, Graham

    2001-01-01

    The South China Sea is poorly understood in terms of its marine biota, ecology and the human impacts upon it. What is known is most often contained in reports and workshop and conference documents that are not available to the wider scientific community. The South China Sea has an area of some 3.3 million km2 and depths range from the shallowest coastal fringe to 5377 m in the Manila Trench. It is also studded with numerous islets, atolls and reefs many of which are just awash at low tide. It is largely confined within the Tropic of Cancer and, therefore, experiences a monsoonal climate being influenced by the Southwest Monsoon in summer and the Northeast Monsoon in winter. The South China Sea is a marginal sea and, therefore, largely surrounded by land. Countries that have a major influence on and claims to the sea include China, Malaysia, the Philippines and Vietnam, although Thailand, Indonesia and Taiwan have some too. The coastal fringes of the South China Sea are home to about 270 million people that have had some of the fastest developing and most vibrant economies on the globe. Consequently, anthropogenic impacts, such as over-exploitation of resources and pollution, are anticipated to be huge although, in reality, relatively little is known about them. The Indo-West Pacific biogeographic province, at the centre of which the South China Sea lies, is probably the world's most diverse shallow-water marine area. Of the three major nearshore habitat types, i.e., coral reefs, mangroves and seagrasses, 45 mangrove species out of a global of 51, most of the currently recognised 70 coral genera and 20 of 50 known seagrass species have been recorded from the South China Sea. The island groups of the South China Sea are all disputed and sovereignty is claimed over them by a number of countries. Conflicts have in recent decades arisen over them because of perceived national rights. It is perhaps because of this that so little research has been undertaken on the South

  19. Contemporary sea level rise.

    Science.gov (United States)

    Cazenave, Anny; Llovel, William

    2010-01-01

    Measuring sea level change and understanding its causes has considerably improved in the recent years, essentially because new in situ and remote sensing observations have become available. Here we report on most recent results on contemporary sea level rise. We first present sea level observations from tide gauges over the twentieth century and from satellite altimetry since the early 1990s. We next discuss the most recent progress made in quantifying the processes causing sea level change on timescales ranging from years to decades, i.e., thermal expansion of the oceans, land ice mass loss, and land water-storage change. We show that for the 1993-2007 time span, the sum of climate-related contributions (2.85 +/- 0.35 mm year(-1)) is only slightly less than altimetry-based sea level rise (3.3 +/- 0.4 mm year(-1)): approximately 30% of the observed rate of rise is due to ocean thermal expansion and approximately 55% results from land ice melt. Recent acceleration in glacier melting and ice mass loss from the ice sheets increases the latter contribution up to 80% for the past five years. We also review the main causes of regional variability in sea level trends: The dominant contribution results from nonuniform changes in ocean thermal expansion.

  20. Projecting future sea level

    Science.gov (United States)

    Cayan, Daniel R.; Bromirski, Peter; Hayhoe, Katharine; Tyree, Mary; Dettinger, Mike; Flick, Reinhard

    2006-01-01

    California’s coastal observations and global model projections indicate that California’s open coast and estuaries will experience increasing sea levels over the next century. Sea level rise has affected much of the coast of California, including the Southern California coast, the Central California open coast, and the San Francisco Bay and upper estuary. These trends, quantified from a small set of California tide gages, have ranged from 10–20 centimeters (cm) (3.9–7.9 inches) per century, quite similar to that estimated for global mean sea level. So far, there is little evidence that the rate of rise has accelerated, and the rate of rise at California tide gages has actually flattened since 1980, but projections suggest substantial sea level rise may occur over the next century. Climate change simulations project a substantial rate of global sea level rise over the next century due to thermal expansion as the oceans warm and runoff from melting land-based snow and ice accelerates. Sea level rise projected from the models increases with the amount of warming. Relative to sea levels in 2000, by the 2070–2099 period, sea level rise projections range from 11–54 cm (4.3–21 in) for simulations following the lower (B1) greenhouse gas (GHG) emissions scenario, from 14–61 cm (5.5–24 in) for the middle-upper (A2) emission scenario, and from 17–72 cm (6.7–28 in) for the highest (A1fi) scenario. In addition to relatively steady secular trends, sea levels along the California coast undergo shorter period variability above or below predicted tide levels and changes associated with long-term trends. These variations are caused by weather events and by seasonal to decadal climate fluctuations over the Pacific Ocean that in turn affect the Pacific coast. Highest coastal sea levels have occurred when winter storms and Pacific climate disturbances, such as El Niño, have coincided with high astronomical tides. This study considers a range of projected future

  1. Pelagic molybdenum concentration anomalies and the impact of sediment resuspension on the molybdenum budget in two tidal systems of the North Sea

    Science.gov (United States)

    Kowalski, Nicole; Dellwig, Olaf; Beck, Melanie; Gräwe, Ulf; Neubert, Nadja; Nägler, Thomas F.; Badewien, Thomas H.; Brumsack, Hans-Jürgen; van Beusekom, Justus E. E.; Böttcher, Michael E.

    2013-10-01

    The seasonal dynamics of molybdenum (Mo) were studied in the water column of two tidal basins of the German Wadden Sea (Sylt-Rømø and Spiekeroog) between 2007 and 2011. In contrast to its conservative behaviour in the open ocean, both, losses of more than 50% of the usual concentration level of Mo in seawater and enrichments up to 20% were observed repeatedly in the water column of the study areas. During early summer, Mo removal by adsorption on algae-derived organic matter (e.g. after Phaeocystis blooms) is postulated to be a possible mechanism. Mo bound to organic aggregates is likely transferred to the surface sediment where microbial decomposition enriches Mo in the pore water. First δ98/95Mo data of the study area disclose residual Mo in the open water column being isotopically heavier than MOMo (Mean Ocean Molybdenum) during a negative Mo concentration anomaly, whereas suspended particulate matter shows distinctly lighter values. Based on field observations a Mo isotope enrichment factor of ε = -0.3‰ has been determined which was used to argue against sorption on metal oxide surfaces. It is suggested here that isotope fractionation is caused by biological activity and association to organic matter. Pelagic Mo concentration anomalies exceeding the theoretical salinity-based concentration level, on the other hand, cannot be explained by replenishment via North Sea waters alone and require a supply of excess Mo. Laboratory experiments with natural anoxic tidal flat sediments and modelled sediment displacement during storm events suggest fast and effective Mo release during the resuspension of anoxic sediments in oxic seawater as an important process for a recycling of sedimentary sulphide bound Mo into the water column.

  2. Initialization and state updating utilizing the OpenDA platform and Sentinel Satellite Series data for ecological modeling in the North Sea*

    Science.gov (United States)

    Ziemba, Alexander; El Serafy, Ghada

    2017-04-01

    Ecological modeling relies on the mathematical reconstruction of natural processes which results in a simplification of interactions between a vast number of ecological functions and variables. Despite this simplification, models are able to provide an approximation of the future states of environmental systems, however, inherit therein is a degree of uncertainty due to the simplifications. In order to compensate for these uncertainties and resulting errors, it is possible to anneal real world measurements from both Remote Sensing and In-Situ observations into the model space utilizing data assimilation. Given this, the OpenDA platform and related algorithms are employed in order to initialize the model space and update the model states during hindcasting simulations in order to provide an optimal departure state from which forecasts can be made. Through such a method, future model states have a reduced uncertainty band and provide deterministic results with higher accuracy. This methodology is applied to the prediction of chlorophyll-a concentrations within the southern coastal zone of the North Sea, focusing primarily on the Dutch coastal zone and the Wadden Sea. By utilizing data assimilation with the Sentinel Satellite Series data, an improved forecast is obtained as seen through a comparison of both purely deterministic runs as well as ensemble results which do not implement DA. Various combination of Sentinel data re used in order to evaluate the efficacy and benefit of introducing multiple data sets in the DA process for Coastal and Estuarine Ecological modeling. *This work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 641762

  3. The Dead Sea

    Science.gov (United States)

    2006-01-01

    The Dead Sea is the lowest point on Earth at 418 meters below sea level, and also one of the saltiest bodies of water on Earth with a salinity of about 300 parts-per-thousand (nine times greater than ocean salinity). It is located on the border between Jordan and Israel, and is fed by the Jordan River. The Dead Sea is located in the Dead Sea Rift, formed as a result of the Arabian tectonic plate moving northward away from the African Plate. The mineral content of the Dead Sea is significantly different from that of ocean water, consisting of approximately 53% magnesium chloride, 37% potassium chloride and 8% sodium chloride. In the early part of the 20th century, the Dead Sea began to attract interest from chemists who deduced that the Sea was a natural deposit of potash and bromine. From the Dead Sea brine, Israel and Jordan produce 3.8 million tons potash, 200,000 tons elemental bromine, 45,000 tons caustic soda, 25, 000 tons magnesium metal, and sodium chloride. Both countries use extensive salt evaporation pans that have essentially diked the entire southern end of the Dead Sea. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining

  4. The Dead Sea

    Science.gov (United States)

    2006-01-01

    The Dead Sea is the lowest point on Earth at 418 meters below sea level, and also one of the saltiest bodies of water on Earth with a salinity of about 300 parts-per-thousand (nine times greater than ocean salinity). It is located on the border between Jordan and Israel, and is fed by the Jordan River. The Dead Sea is located in the Dead Sea Rift, formed as a result of the Arabian tectonic plate moving northward away from the African Plate. The mineral content of the Dead Sea is significantly different from that of ocean water, consisting of approximately 53% magnesium chloride, 37% potassium chloride and 8% sodium chloride. In the early part of the 20th century, the Dead Sea began to attract interest from chemists who deduced that the Sea was a natural deposit of potash and bromine. From the Dead Sea brine, Israel and Jordan produce 3.8 million tons potash, 200,000 tons elemental bromine, 45,000 tons caustic soda, 25, 000 tons magnesium metal, and sodium chloride. Both countries use extensive salt evaporation pans that have essentially diked the entire southern end of the Dead Sea. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining

  5. Kara Sea radioactivity assessment

    Energy Technology Data Exchange (ETDEWEB)

    Osvath, I.; Povinec, P.P.; Baxter, M.S. [Marine Environment Laboratory, International Atomic Energy Agency, B.P. 800 MC (Monaco)

    1999-09-30

    Investigations following five international expeditions to the Kara Sea have shown that no radiologically significant contamination has occurred outside of the dumping sites in Novaya Zemlya bays. Increased levels of radionuclides in sediment have only been observed in Abrosimov and Stepovoy Bays very close to dumped containers. Evaluations of radionuclide inventories in water and sediment of the open Kara Sea and Novaya Zemlya bays as well as soil from the shore of Abrosimov bay have shown that radionuclide contamination of the open Kara Sea is mainly due to global fallout, with smaller contributions from the Sellafield reprocessing plant, the Chernobyl accident run-off from the Ob and Yenisey rivers and local fallout. Computer modelling results have shown that maximum annual doses of approximately 1 mSv are expected for a hypothetical critical group subsisting on fish caught in the Novaya Zemlya bays whereas populations living on the mainland can be expected to receive doses at least three orders of magnitude lower.

  6. Sea Spray Aerosols

    DEFF Research Database (Denmark)

    Butcher, Andrew Charles

    emissions produced directly from bubble bursting as the result of air entrainment from breaking waves and particles generated from secondary emissions of volatile organic compounds. In the first paper, we study the chemical properties of particles produced from several sea water proxies with the use...... of a cloud condensation nuclei ounter. Proxy solutions with high inorganic salt concentrations and some organics produce sea spray aerosol particles with little change in cloud condensation activity relative to pure salts. Comparison is made between a frit based method for bubble production and a plunging...... a relationship between plunging jet particle ux, oceanic particle ux, and energy dissipation rate in both systems. Previous sea spray aerosol studies dissipate an order of magnitude more energy for the same particle ux production as the open ocean. A scaling factor related to the energy expended in air...

  7. Sea Spray Aerosols

    DEFF Research Database (Denmark)

    Butcher, Andrew Charles

    emissions produced directly from bubble bursting as the result of air entrainment from breaking waves and particles generated from secondary emissions of volatile organic compounds. In the first paper, we study the chemical properties of particles produced from several sea water proxies with the use...... of a cloud condensation nuclei ounter. Proxy solutions with high inorganic salt concentrations and some organics produce sea spray aerosol particles with little change in cloud condensation activity relative to pure salts. Comparison is made between a frit based method for bubble production and a plunging...... a relationship between plunging jet particle ux, oceanic particle ux, and energy dissipation rate in both systems. Previous sea spray aerosol studies dissipate an order of magnitude more energy for the same particle ux production as the open ocean. A scaling factor related to the energy expended in air...

  8. Dynamics of sea level variations in the coastal Red Sea

    Science.gov (United States)

    Churchill, James; Abulnaja, Yasser; Nellayaputhenpeedika, Mohammedali; Limeburner, Richard; Lentz, Steven

    2016-04-01

    Sea level variations in the central Red Sea coastal zone span a range of roughly 1.2 m. Though relatively small, these water level changes can significantly impact the environment over the shallow reef tops prevalent in the central Red Sea, altering the water depth by a factor or two or more. While considerable scientific work has been directed at tidal and seasonal variations of Red Sea water level, very little attention has been given to elevation changes in an 'intermediate' frequency band, with periods of 2-30 d, even though motions in this band account for roughly half of the sea level variance in central Red Sea. We examined the sea level signal in this band using AVISO sea level anomaly (SLA) data, COARDAS wind data and measurements from pressure sensors maintained for more than five years at a number of locations in Saudi Arabian coastal waters. Empirical orthogonal function analysis of the SLA data indicates that longer-period (10-30 d) sea level variations in the intermediate band are dominated by coherent motions in a single mode that extends over most of the Red Sea axis. Idealized model results indicate that this large-scale mode of sea level motion is principally due to variations in the large-scale gradient of the along-axis wind. Our analysis indicates that coastal sea level motions at shorter periods (2-10 d) are principally generated by a combination of direct forcing by the local wind stress and forcing associated with large-scale wind stress gradients. However, also contributing to coastal sea level variations in the intermediate frequency band are mesoscale eddies, which are prevalent throughout the Red Sea basin, have a sea level signal of 10's of cm and produce relatively small-scale (order 50 km) changes in coastal sea level.

  9. Mediterranean, our sea

    Science.gov (United States)

    Markaki, Foteini

    2017-04-01

    My school (1o EPAL Ymittos -Athens, Greece) is a technical school of secondary education and throughout this school year being drafted a program of environmental education. The main theme is the Mediterranean Sea, the biggest closed sea extending between three continents. Topics studied: 1. Biodiversity and the risks threat. 2. The geophysics that characterize (earthquakes, volcanoes explosions, etc). 3. The Mediterranean Sea as environment anthropogenesis, a mosaic of other cultures and even place current notions of social phenomena (refugees). Pedagogical Objectives: Cognitive/Enviromental: 1. To investigate and understand the biodiversity of the Mediterranean Sea and the risks to threaten and phenomena that characterize. 2. To understand the position of the Mediterranean Sea in the land and the role of the historical, cultural and social human environment. 3. To come in contact with texts literary, social, articles on the Mediterranean. Psychomotor: 1. To work together and collect information for the Mediterranean Sea. 2. Experiential approach to the natural environment. 3. Develop critical thinking. 4. Undertake responsibilities for the presentation of the program. Emotional: 1. To feel joy from participation in the program. 2. Being sensitized and configure attitudes and actions of respect towards the environment. Methodology implementation: Teamwork. Interdisciplinary - holistic to dissemination of program recordings to courses curriculum. Study in the field. Gathering information from newspapers, magazines, internet, maps, and photographs. Experiential method- Project. Assessment methods and self-assessment. Fields of courses: Greek language- History- Biology- Chemistry- Technology Dissemination of results: Make a page of social media (facebook), a blog, enhancing environmental awareness via video, make an electronic poster.

  10. Seasonal Change of Steric Sea Level in the GIN Seas

    Institute of Scientific and Technical Information of China (English)

    LI Lei; WANG Huijuan; SUN Ruili

    2011-01-01

    The Greenland Sea, Iceland Sea, and Norwegian Sea (GIN seas) form the main channel connecting the Arctic Ocean with other Oceans, where significant water and energy exchange take place, and play an important role in global climate change. In this study steric sea level, associated with temperature and salinity, in the GIN seas is examined based on analysis of the monthly temperature and salinity fields from Polar science center Hydrographic Climatology (PHC3.0). A method proposed by Tabata et al. is used to calculate steric sea level, in which, steric sea level change due to thermal expansion and haline contraction is termed as the thermosteric component (TC) and the halosteric component (SC), recpectively. Total steric sea level (TSSL) change is the sum of TC and SC. The study shows that SC is making more contributions than TC to the seasonal change of TSSL in the Greenland Sea, whereas TC contributes more in the Norwegian and the Iceland Seas. Annual variation of TSSL is larger than 50ram over most regions of the GIN Seas, and can be larger than 200mm at some locations such as 308mm at 76.5°N, 12.5°E and 246mm at 77.50N, 17.5°W.

  11. Analysis of Sea Spikes in Radar Sea Clutter Data

    NARCIS (Netherlands)

    Melief, H.W.; Greidanus, H.; Genderen, P. van; Hoogeboom, P.

    2006-01-01

    Abstract—In this paper three sets of high-resolution, coherent, and polarimetric radar sea clutter data are analyzed and compared with radar sea clutter models. The nature of the data allows a thorough analysis of the power, polarization and velocity of the sea clutter. It is shown that these

  12. Analysis of Sea Spikes in Radar Sea Clutter Data

    NARCIS (Netherlands)

    Melief, H.W.; Greidanus, H.; Genderen, P. van; Hoogeboom, P.

    2006-01-01

    Abstract—In this paper three sets of high-resolution, coherent, and polarimetric radar sea clutter data are analyzed and compared with radar sea clutter models. The nature of the data allows a thorough analysis of the power, polarization and velocity of the sea clutter. It is shown that these quanti

  13. Air-sea exchange studies at the North Sea

    NARCIS (Netherlands)

    Leeuw, G. de; Eijk, A.M.J. van; Kunz, G.J.; Veefkind, P.J.

    1996-01-01

    The North Sea can be considered as a local 'inner' sea in which many processes are quite different from these over the open ocean. The surrounding land has a major influence, being the source for man-made aerosols and gases, whereas the North Sea acts as a sink for these. At the same time the North

  14. SEA LEVEL (TOPEX/POSEIDON)

    Data.gov (United States)

    National Aeronautics and Space Administration — Sea level rise is caused by the thermal expansion of sea water due to climate warming and widespread melting of land ice. The TOPEX/POSEIDON mission a joint...

  15. Atlantic Flyway Sea Duck Survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Atlantic Flyway Sea Duck Survey, conducted from 1991 to 2002 by the U.S. Fish and Wildlife Service, was established to record sea duck numbers using near shore...

  16. Seafloor Control on Sea Ice

    Science.gov (United States)

    Nghiem, S. V.; Clemente-Colon, P.; Rigor, I. G.; Hall, D. K.; Neumann, G.

    2011-01-01

    The seafloor has a profound role in Arctic sea ice formation and seasonal evolution. Ocean bathymetry controls the distribution and mixing of warm and cold waters, which may originate from different sources, thereby dictating the pattern of sea ice on the ocean surface. Sea ice dynamics, forced by surface winds, are also guided by seafloor features in preferential directions. Here, satellite mapping of sea ice together with buoy measurements are used to reveal the bathymetric control on sea ice growth and dynamics. Bathymetric effects on sea ice formation are clearly observed in the conformation between sea ice patterns and bathymetric characteristics in the peripheral seas. Beyond local features, bathymetric control appears over extensive ice-prone regions across the Arctic Ocean. The large-scale conformation between bathymetry and patterns of different synoptic sea ice classes, including seasonal and perennial sea ice, is identified. An implication of the bathymetric influence is that the maximum extent of the total sea ice cover is relatively stable, as observed by scatterometer data in the decade of the 2000s, while the minimum ice extent has decreased drastically. Because of the geologic control, the sea ice cover can expand only as far as it reaches the seashore, the continental shelf break, or other pronounced bathymetric features in the peripheral seas. Since the seafloor does not change significantly for decades or centuries, sea ice patterns can be recurrent around certain bathymetric features, which, once identified, may help improve short-term forecast and seasonal outlook of the sea ice cover. Moreover, the seafloor can indirectly influence cloud cover by its control on sea ice distribution, which differentially modulates the latent heat flux through ice covered and open water areas.

  17. Pollution around Malta's sea

    OpenAIRE

    Formosa, Nicolette; Duca, Edward

    2014-01-01

    Marine littering is a global concern and every single year tons of litter end up in the ocean all around the globe. It has become such a problem that the waste has amalgamated into huge ‘islands’ floating in the world’s oceans. http://www.um.edu.mt/think/pollution-around-maltas-sea/

  18. Sailing the Cyber Sea

    Science.gov (United States)

    2012-04-01

    years, the Internet 4 years, and the iPod 3 years, while Facebook added 200 million users in less than 1 year. And finally, if Facebook were a... Apple ] gets an iPhone. It’s not an acceptable trade.” New Thinking In the context of security, unleashing the power of the Cyber Sea has changed

  19. Pollution around Malta's sea

    OpenAIRE

    Formosa, Nicolette

    2014-01-01

    Marine littering is a global concern and every single year tons of litter end up in the ocean all around the globe. It has become such a problem that the waste has amalgamated into huge ‘islands’ floating in the world’s oceans. http://www.um.edu.mt/think/pollution-around-maltas-sea/

  20. Solar Sea Power

    Science.gov (United States)

    Zener, Clarence

    1976-01-01

    In their preoccupation with highly complex new energy systems, scientists and statesmen may be overlooking the possibilities of Ocean Thermal Energy Conversion (OTEC). That is the view of a Carnegie-Mellon University physicist who is in the forefront of solar sea power investigation. (Author/BT)

  1. Baltic Sea: Radionuclides

    DEFF Research Database (Denmark)

    Nielsen, Sven Poul; Lüning, Maria; Ilus, Erkki

    2010-01-01

    The most significant source of anthropogenic radioactivity in the Baltic Sea is fallout from the accident at the Chernobyl nuclear power plant in 1986. The second most important source is global fallout from atmospheric nuclear weapons tests carried out during the late 1950s and early 1960s. Radi...

  2. Solomon's Sea and [Pi

    Science.gov (United States)

    Simoson, Andrew J.

    2009-01-01

    This paper is a whimsical survey of the various explanations which might account for the biblical passage in I Kings 7:23 that describes a round object--a bronze basin called Solomon's Sea--as having diameter ten cubits and circumference thirty cubits. Can the biblical pi be any number other than 3? We offer seven different perspectives on this…

  3. Deep-sea fungi

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; Damare, S.

    The deep-sea environment, despite being rich in mineral nutrients and near-saturation levels of oxygen, because of its darkness is not conducive to photosynthesis, the process that sustains life on earth. If a liigh abundance and diversity of life...

  4. Sensitivity mapping of the German North Sea Coast II. Data update and development of an operational model for precaution measures of oil spill response; Sensititivaetsraster Deutsche Nordseekueste II. Aktualisierung und Erstellung eines operationellen Modells zur Vorsorgeplanung bei der Oelbekaempfung

    Energy Technology Data Exchange (ETDEWEB)

    Bernem, K.H. van; Doerffer, R.; Heymann, K.; Kleeberg, U.; Krasemann, H.; Schiller, H. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Kuestenforschung; Grohnert, A.; Reichert, J. [IfaB - Institut fuer Angewandte Biologie Freiburg/Niederelbe (Germany); Reichert, M. [ARCADIS, Rostock (Germany)

    2007-07-01

    The Wadden Sea is an area of tidal flats and salt marshes extending between the North Sea coasts of Denmark, Germany and the Netherlands. It has enormous value as a cleansing site for North Sea water, as a nursery for young fish and as a feeding ground for many bird species. Due to the proximity of important shipping routes and harbours, this region is especially threatened by oil spills. Thus, for oil spill response and precaution measures, a sensitivity study of the entire intertidal area was badly needed in order to assess and minimize the potential ecological and economical damage. Based on comprehensive field surveys and in close cooperation with the Central Command for Maritime Emergencies, an automated expert-model for the german part of Wadden Sea areas was developed at the Institute for Coastal Research (GKSS-Research Centre). As an operational model it will serve as important instrument for decision making processes, precautionary measures and the further design of oil spill response strategies. Since it is not possible to protect the entire German North Sea coast equally at all levels, oil spill contingency planning requires a more detailed classification. For this reason, individual soft bottom habitats, communities and stocks of saltmarshes, macrofauna, waterfowl and estuarine biotop types were evaluated and classified according to their vulnerability to oil pollution. Hence, the fieldwork for habitat mapping during 2003-2006 was a central part of the study. For this part, the experiences and results obtained from the previous GKSS-project ''Thematic mapping and sensitivity study of Intertidal flats'' during the years 1987-1992 served as an valuable basis. For example, the documentation of changes during these periods of observation provides information on stability features of the ecosystems. During the first project nearly 5000 locations were processed and characterised using about 70 parameters for each site. The in-situ mapping

  5. Boundary organisations and their strategies

    NARCIS (Netherlands)

    Enst, van Wynanda I.; Runhaar, Hens A.C.; Driessen, P.P.J.

    2016-01-01

    This article discusses three empirical cases of boundary organisations, within the context of the Wadden Sea: the Wadden Academy, IMSA Amsterdam and the NCEA. The research aims to provide further insights into how boundary organisations work in practice. The research shows that the role of a boun

  6. The North Sea - A shelf sea in the Anthropocene

    Science.gov (United States)

    Emeis, Kay-Christian; van Beusekom, Justus; Callies, Ulrich; Ebinghaus, Ralf; Kannen, Andreas; Kraus, Gerd; Kröncke, Ingrid; Lenhart, Hermann; Lorkowski, Ina; Matthias, Volker; Möllmann, Christian; Pätsch, Johannes; Scharfe, Mirco; Thomas, Helmuth; Weisse, Ralf; Zorita, Eduardo

    2015-01-01

    Global and regional change clearly affects the structure and functioning of ecosystems in shelf seas. However, complex interactions within the shelf seas hinder the identification and unambiguous attribution of observed changes to drivers. These include variability in the climate system, in ocean dynamics, in biogeochemistry, and in shelf sea resource exploitation in the widest sense by societies. Observational time series are commonly too short, and resolution, integration time, and complexity of models are often insufficient to unravel natural variability from anthropogenic perturbation. The North Sea is a shelf sea of the North Atlantic and is impacted by virtually all global and regional developments. Natural variability (from interannual to multidecadal time scales) as response to forcing in the North Atlantic is overlain by global trends (sea level, temperature, acidification) and alternating phases of direct human impacts and attempts to remedy those. Human intervention started some 1000 years ago (diking and associated loss of wetlands), expanded to near-coastal parts in the industrial revolution of the mid-19th century (river management, waste disposal in rivers), and greatly accelerated in the mid-1950s (eutrophication, pollution, fisheries). The North Sea is now a heavily regulated shelf sea, yet societal goals (good environmental status versus increased uses), demands for benefits and policies diverge increasingly. Likely, the southern North Sea will be re-zoned as riparian countries dedicate increasing sea space for offshore wind energy generation - with uncertain consequences for the system's environmental status. We review available observational and model data (predominantly from the southeastern North Sea region) to identify and describe effects of natural variability, of secular changes, and of human impacts on the North Sea ecosystem, and outline developments in the next decades in response to environmental legislation, and in response to

  7. Possible sea sediments due to glaciofluvial activity in Elysium Planitia, Mars

    Science.gov (United States)

    Nussbaumer, J.

    Observations of fluvial morphologies in southern Elysium Planitia strongly supports the hypothesis that water substantially affected this region during the relatively recent geologic past. As of yet, however, the extent of a standing body of water has been speculative. The observation of zig-zag features potentially analogous to those observed near the Wadden Sea on Earth [see 1] may help show in more detail the origin, activity, and fate of water in this region of Mars. These terrestrial analogs could constrain environmental scenarios concerning the formation of these features. We present a geomorphologic map of central Elysium Planitia, that aids in our interpretation of potentially site-specific depositional/erosional morphologies. Positive relief zig-zag features within the Medusae Fossae Formation (Themis Image V05875001) resemble similar structures on Earth observed at shorelines of flat regions. Glaciofluvial activity is indicated by linear features resembling straight glacial flutings, which could form aeolian yardangs subsequently. The flutings are associated with branches of inverted fluvial channels (Images Themis V05588002, MOC e1800307). Their excavated positive relief (height ~40 m) indicates, that the adjacent material was eroded by sublimation or aeolian activity. The channels possibly resemble ice marginal channels. A high resolution Digital Terrain Model of one of the channels suggests, that one channel is possibly running upslope. Fluvial processes could have operated at one location at one time, and glacial processes at another location at another time [2]. A glacial drainage system [see 3] is a possible terrestrial analog for one inverted fluvial channel on Mars (Themis Image V05875001). Flutings occur on the foreland of many glaciers and their length may provide important evidence for rapid advance over substantial distances. Flutings are the product of subglacial erosion and transport processes [4]. By assigning the different environmental

  8. SEA/WOMAN

    OpenAIRE

    Furse, Anna F. D.

    2011-01-01

    A new laboratory research performance by Anna Furse, Athletes of the Heart, UK) in collaboration with Maja Mitic (DAH Teatar, Serbia) and Antonella Diana (Teatret OM, Denmark) based on Henrik Ibsen's 'The lady from the sea' (1888). The project is an AHRC/ACE funded project as part of the Pinter Centre for Performance and Creative Writing's Fractured Narratives project. It has been touring in the UK and to Beirut, Lebanon.

  9. SEA/WOMAN

    OpenAIRE

    Furse, Anna F. D.

    2011-01-01

    A new laboratory research performance by Anna Furse, Athletes of the Heart, UK) in collaboration with Maja Mitic (DAH Teatar, Serbia) and Antonella Diana (Teatret OM, Denmark) based on Henrik Ibsen's 'The lady from the sea' (1888).\\ud \\ud The project is an AHRC/ACE funded project as part of the Pinter Centre for Performance and Creative Writing's Fractured Narratives project. It has been touring in the UK and to Beirut, Lebanon.

  10. Sea Basing Logistiek

    Science.gov (United States)

    2007-11-01

    iets wat nu voor zware goederen niet mogeljk is met de middelen binnen de Nederlandse krijgsmachit. Nederland heeft bijvoorbeeld (nog) geen specifieke...weer gevechtsklaar zijn. Nederlandse troepen voeren de reconstitute fase in het algemeen uit in Nederland . [Kang&Gue] A special concern in sea based...besluit Nederland zelf in te grijpen. De Nederlandse vredesmissie bevindt zich nabij de kust. maar ver van de grens met buurlanden. De operatie kan niet

  11. Armada puts to sea

    Energy Technology Data Exchange (ETDEWEB)

    Esau, I.

    1995-04-01

    This article describes the operational success of British Gas in exploiting the Armada gas field. Armada consists of three separate reservoirs (Fleming, Drake and Hawkins) and lies in the central North Sea. British Gas has successfully exploited this field on behalf of a group of co-venturers. This article describes the economic, technical and political difficulties faced by the company in operating this innovative method of management. (UK)

  12. Dead Sea rhodopsins revisited.

    Science.gov (United States)

    Bodaker, Idan; Suzuki, Marcelino T; Oren, Aharon; Béjà, Oded

    2012-12-01

    The Dead Sea is a unique hypersaline ecosystem with near toxic magnesium levels (∼2 M), dominance of divalent cations and a slightly acidic pH. Previously, we reported a haloarchaeon related to Halobacterium salinarum to dominate in a microbial bloom that developed in 1992 in the upper water layers of the lake following massive freshwater runoff. Whether this clade also dominated an earlier bloom in 1980-1982 cannot be ascertained as no samples for cultivation-independent analysis were preserved. The presence of the light-driven proton pump bacteriorhodopsin was reported in the 1980-1982 bloom of prokaryotes that had developed in the Dead Sea. To test the hypothesis that bacteriorhodopsin proton pumping may play a major role in determining what type of haloarchaea may dominate in specific bloom conditions, we compared rhodopsin genes recovered from Dead Sea biomass collected in different periods with genes coding for retinal proteins in isolated haloarchaea. Novel bacteriorhodopsin and sensory rhodopsin genes were found in samples collected in 2007 and 2010. The fact that no rhodopsin genes were recovered from samples collected during the 1992 bloom, which was dominated by a single species, suggests that different clades were present in the 1980-1982 and 1992 blooms, and that bacteriorhodopsin proton pumping did not necessarily play a determinative role in the dominance of specific halophiles in the blooms.

  13. Arctic Sea Ice

    Science.gov (United States)

    Stroeve, J. C.; Fetterer, F.; Knowles, K.; Meier, W.; Serreze, M.; Arbetter, T.

    2004-12-01

    Of all the recent observed changes in the Arctic environment, the reduction of sea ice cover stands out most prominantly. Several independent analysis have established a trend in Arctic ice extent of -3% per decade from the late 1970s to the late 1990s, with a more pronounced trend in summer. The overall downward trend in ice cover is characterized by strong interannual variability, with a low September ice extent in one year typically followed by recovery the next September. Having two extreme minimum years, such as what was observed in 2002 and 2003 is unusual. 2004 marks the third year in a row of substantially below normal sea ice cover in the Arctic. Early summer 2004 appeared unusual in terms of ice extent, with May a record low for the satellite period (1979-present) and June also exhibiting below normal ice extent. August 2004 extent is below that of 2003 and large reductions in ice cover are observed once again off the coasts of Siberia and Alaska and the Greenland Sea. Neither the 2002 or 2003 anomaly appeared to be strongly linked to the positive phase of the Arctic Oscillation (AO) during the preceding winter. Similarly, the AO was negative during winter 2003/2004. In the previous AO framework of Rigor et al (2002), a positive winter AO implied preconditioning of the ice cover to extensive summer decay. In this hypothesis, the AO does not explain all aspects of the recent decline in Arctic ice cover, such as the extreme minima of 2002, 2003 and 2004. New analysis by Rigor and Wallace (2004) suggest that the very positive AO state from 1989-1995 can explain the recent sea ice minima in terms of changes in the Arctic surface wind field associated with the previous high AO state. However, it is also reasonable to expect that a general decrease in ice thickness accompanying warming would manifest itself as greater sensitivity of the ice pack to wind forcings and albedo feedbacks. The decrease in multiyear ice and attendant changes in ice thickness

  14. Highly variable Pliocene sea surface conditions in the Norwegian Sea

    Science.gov (United States)

    Bachem, Paul E.; Risebrobakken, Bjørg; De Schepper, Stijn; McClymont, Erin L.

    2017-09-01

    The Pliocene was a time of global warmth with small sporadic glaciations, which transitioned towards the larger-scale Pleistocene glacial-interglacial variability. Here, we present high-resolution records of sea surface temperature (SST) and ice-rafted debris (IRD) in the Norwegian Sea from 5.32 to 3.14 Ma, providing evidence that the Pliocene surface conditions of the Norwegian Sea underwent a series of transitions in response to orbital forcing and gateway changes. Average SSTs are 2 °C above the regional Holocene mean, with notable variability on millennial to orbital timescales. Both gradual changes and threshold effects are proposed for the progression of regional climate towards the Late Pliocene intensification of Northern Hemisphere glaciation. Cooling from 4.5 to 4.3 Ma may be linked to the onset of poleward flow through the Bering Strait. This cooling was further intensified by a period of cool summers due to weak obliquity forcing. A 7 °C warming of the Norwegian Sea at 4.0 Ma suggests a major increase in northward heat transport from the North Atlantic, leading to an enhanced zonal SST gradient in the Nordic Seas, which may be linked to the expansion of sea ice in the Arctic and Nordic Seas. A warm Norwegian Sea and enhanced zonal temperature gradient between 4.0 and 3.6 Ma may have been a priming factor for increased glaciation around the Nordic Seas due to enhanced evaporation and precipitation at high northern latitudes.

  15. Bindin from a sea star

    OpenAIRE

    Patiño, Susana; Jan E. Aagaard; MacCoss, Michael J.; Swanson, Willie J.; Hart, Michael W

    2009-01-01

    The genetic basis for the evolution of development includes genes that encode proteins expressed on the surfaces of sperm and eggs. Previous studies of the sperm acrosomal protein bindin have helped to characterize the adaptive evolution of gamete compatibility and speciation in sea urchins. The absence of evidence for bindin expression in taxa other than the Echinoidea has limited such studies to sea urchins, and led to the suggestion that bindin might be a sea urchin-specific molecule. Here...

  16. Sea Salt Source Function over the Baltic Sea

    Science.gov (United States)

    Petelski, Tomasz; Makuch, Przemyslaw; Markuszewski, Piotr; Jankowski, Andrzej; Zieliński, Tymon

    2013-04-01

    Studies of production and transport of aerosol over the sea are very important for many areas of knowledge. Marine aerosol emitted from the sea surface helps to clean the boundary layer from other aerosol particles. The emitted droplets do not dry out in the highly humid surface layer air and because of their sizes most of them are deposited quickly at the sea surface. Therefore, marine aerosol has many features of rain i.e. the deposition in the marine boundary layer in high wind events is controlled not only by the "dry" processes but also by the "wet" scavenging. While many cruises conducted on board S/Y Oceania, we collected many data which were used to calculate sea salt source function over the Baltic Sea. Our cruises held between 2009 and 2012. Measurements were carried out using gradient method. For this method we used Laser Particle Counter (PMS model CSASP-100_HV) placed on one oft the mast of S/Y Oceania. Measurements were performed on five different levels around sea level: 8, 11, 14, 17 and 20 meters. Based on the averaged vertical concentration, profiles were calculated, using Monin-Obuchow theory, vertical sea spray fluxes in the near water layer. Based on fluxes calculated from vertical concentration profiles was calculated sea salt source function over the Baltic Sea. This function gives emission for different particle size, depending on environmental parameters. Emission of sea spray depends of the size of energy lost by the wind waves in process of collapse. Acknowledgements: The support for this study was provided by the project Satellite Monitoring of the Baltic Sea Environment - SatBałtyk founded by European Union through European Regional Development Fund contract No. POIG 01.01.02-22-011/09.

  17. Experiencing the Full Research Process at Sea Education Association (SEA)

    Science.gov (United States)

    Harris, S. E.; Joyce, P.; Jaroslow, G.; Graziano, L.; Lea, C.; Witting, J.; Bower, A.

    2003-12-01

    While some undergraduate research experiences include only a small piece of the research process, students attending Sea Education Association's SEA Semester complete all aspects of oceanographic research in an intensive 12 week program that earns a full semester's credit. In the first half of the program, students read and discuss background literature on a subject, ask questions, pose hypotheses, and develop a written research proposal, which they defend orally. The second half of the course takes place at sea on one of SEA's state-of-the-art oceanographic research vessels where students carry out their sampling plans, analyze samples and data, write a final paper and present their results before the vessel reaches port, completing the course. At sea, students participate in sample collection and analysis for all student projects in addition to learning the general oceanography along their cruise track. This structure exposes students to the realities of research from start to finish and allows them to take full ownership of their projects. In addition to honing writing, public speaking, and problem-solving skills, students learn that research requires dedication, flexibility, and creativity, particularly when their results are unexpected or negate their hypothesis. SEA's undergraduate research program has been developing since 1971. Over that time, SEA has collected an extensive historical oceanographic database in the western Atlantic and Caribbean, plus Pacific data since 2001. This database is available to both students and outside research scientists. Collaborations with scientists outside SEA enhance the student experience and help facilitate oceanographic research by providing "ship-of-opportunity" sampling in remote locations. SEA Semester provides an excellent model for undergraduate research experiences with over 5000 alumni, about 30% of whom enter graduate school. About half the students in SEA's undergraduate programs are non-science majors. Although

  18. Waves in the seas

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.

    or change. If ini- tially, only a thin layer of air close to the water surface matters in the mo- mentum transfer from wind to water, afterwards with strong winds, a layer of air upto say 15 to 30 metres comes Small sand waves formed on a seashore due... it breaks with a heading wind or on a beach). Consider an open sea of say 1000 square kilometres wherein billions of 'pushes' and 'pulls' happen over tens of hours, causing uncountable number of waves and wave groups of various types moving in different...

  19. Polarimetric signatures of sea ice in the Greenland Sea

    DEFF Research Database (Denmark)

    Skriver, Henning; Pedersen, Leif Toudal

    1995-01-01

    Polarimetric SAR data of sea ice have been acquired by the Danish polarimetric SAR (EMISAR) during a mission at the Greenland Sea in August 1994. Video recordings from a low-altitude acquisition have been used for interpretation of the SAR data. Also, ERS-1 SAR data and NOAA AVHRR-data have been...

  20. NOAA NDBC SOS - sea_floor_depth_below_sea_surface

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA NDBC SOS server is part of the IOOS DIF SOS Project. The stations in this dataset have sea_floor_depth_below_sea_surface data. Because of the nature of SOS...

  1. EASE-Grid Sea Ice Age

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides weekly estimates of sea ice age for the Arctic Ocean from remotely sensed sea ice motion and sea ice extent. The ice age data are derived from...

  2. Sea modeling and rendering

    Science.gov (United States)

    Cathala, Thierry; Latger, Jean

    2010-10-01

    More and more defence and civil applications require simulation of marine synthetic environment. Currently, the "Future Anti-Surface-Guided-Weapon" (FASGW) or "anti-navire léger" (ANL) missile needs this kind of modelling. This paper presents a set of technical enhancement of the SE-Workbench that aim at better representing the sea profile and the interaction with targets. The operational scenario variability is a key criterion: the generic geographical area (e.g. Persian Gulf, coast of Somalia,...), the type of situation (e.g. peace keeping, peace enforcement, anti-piracy, drug interdiction,...)., the objectives (political, strategic, or military objectives), the description of the mission(s) (e.g. antipiracy) and operation(s) (e.g. surveillance and reconnaissance, escort, convoying) to achieve the objectives, the type of environment (Weather, Time of day, Geography [coastlines, islands, hills/mountains]). The paper insists on several points such as the dual rendering using either ray tracing [and the GP GPU optimization] or rasterization [and GPU shaders optimization], the modelling of sea-surface based on hypertextures and shaders, the wakes modelling, the buoyancy models for targets, the interaction of coast and littoral, the dielectric infrared modelling of water material.

  3. Modelling sea ice dynamics

    Science.gov (United States)

    Murawski, Jens; Kleine, Eckhard

    2017-04-01

    Sea ice remains one of the frontiers of ocean modelling and is of vital importance for the correct forecasts of the northern oceans. At large scale, it is commonly considered a continuous medium whose dynamics is modelled in terms of continuum mechanics. Its specifics are a matter of constitutive behaviour which may be characterised as rigid-plastic. The new developed sea ice dynamic module bases on general principles and follows a systematic approach to the problem. Both drift field and stress field are modelled by a variational property. Rigidity is treated by Lagrangian relaxation. Thus one is led to a sensible numerical method. Modelling fast ice remains to be a challenge. It is understood that ridging and the formation of grounded ice keels plays a role in the process. The ice dynamic model includes a parameterisation of the stress associated with grounded ice keels. Shear against the grounded bottom contact might lead to plastic deformation and the loss of integrity. The numerical scheme involves a potentially large system of linear equations which is solved by pre-conditioned iteration. The entire algorithm consists of several components which result from decomposing the problem. The algorithm has been implemented and tested in practice.

  4. SeaPort-e Workshop

    Science.gov (United States)

    2014-08-01

    aquilent.com 22 QUESTIONS?? 23 Back-up 24 Program Evolution Category SeaPort Original (2001 – 2004) SeaPort-Enhanced (2004...Function = Industry User Function External System Interfaces: Create Purchase Request (Navy ERP ) Receive CAR Data (FPDS-NG) Receive Award Documents (EDA) Receive Award Data (SPS)

  5. Her Husband Is at Sea

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    Out in the sea of China are Chinese offshore oil workers. They battle against wind, waves, loneliness and monotony. Their profession requires not only bravery and endurance from the employees themselves, but also from their spouses. It is because of the wives’support that the husbands can work at sea. This,for women, means double family responsibilities, loneliness, worries and endless waiting.

  6. The Law of the Sea

    Science.gov (United States)

    Levy, Jean-Pierre

    1978-01-01

    Recounts problems related to the law of the sea and suggests that these problems could be dealt with in the classroom in an interdisciplinary manner. Problems include pollution control, fishing rights, development of deep sea mineral deposits, and shore access. (Author/DB)

  7. Plastic in North Sea Fish

    NARCIS (Netherlands)

    Foekema, E.M.; Gruijter, de C.; Mergia, M.T.; Franeker, van J.A.; Murk, A.J.; Koelmans, A.A.

    2013-01-01

    To quantify the occurrence of ingested plastic in fish species caught at different geographical positions in the North Sea, and to test whether the fish condition is affected by ingestion of plastics, 1203 individual fish of seven common North Sea species were investigated: herring, gray gurnard, wh

  8. Sea level and climate variations

    NARCIS (Netherlands)

    Oerlemans, J.

    1985-01-01

    Review paper, ESA Symposium on Application of Satellite Data to Climate Modelling. Alpbach (Austria) Sea level is an essential component of the climate system, on which many human activities in the coastal zone depend. Climate variations leading to changes in relative sea level are

  9. The environmental state at sea

    NARCIS (Netherlands)

    Tatenhove, van J.P.M.

    2016-01-01

    Seas and oceans are confronted with a plethora of environmental problems, caused by land-based activities (agriculture, industries, and ports) and by maritime activities (such as shipping, fishing, oil and gas drilling, tourism, and navigational dredging). Environmental problems at sea challenge the

  10. Sea Level Rise Data Discovery

    Science.gov (United States)

    Quach, N.; Huang, T.; Boening, C.; Gill, K. M.

    2016-12-01

    Research related to sea level rise crosses multiple disciplines from sea ice to land hydrology. The NASA Sea Level Change Portal (SLCP) is a one-stop source for current sea level change information and data, including interactive tools for accessing and viewing regional data, a virtual dashboard of sea level indicators, and ongoing updates through a suite of editorial products that include content articles, graphics, videos, and animations. The architecture behind the SLCP makes it possible to integrate web content and data relevant to sea level change that are archived across various data centers as well as new data generated by sea level change principal investigators. The Extensible Data Gateway Environment (EDGE) is incorporated into the SLCP architecture to provide a unified platform for web content and science data discovery. EDGE is a data integration platform designed to facilitate high-performance geospatial data discovery and access with the ability to support multi-metadata standard specifications. EDGE has the capability to retrieve data from one or more sources and package the resulting sets into a single response to the requestor. With this unified endpoint, the Data Analysis Tool that is available on the SLCP can retrieve dataset and granule level metadata as well as perform geospatial search on the data. This talk focuses on the architecture that makes it possible to seamlessly integrate and enable discovery of disparate data relevant to sea level rise.

  11. Scaling the Baltic Sea environment

    DEFF Research Database (Denmark)

    Larsen, Henrik Gutzon

    2008-01-01

    The Baltic Sea environment has since the early 1970s passed through several phases of spatial objectification in which the ostensibly well-defined semi-enclosed sea has been framed and reframed as a geographical object for intergovernmental environmental politics. Based on a historical analysis...

  12. Highly variable Pliocene sea surface conditions in the Norwegian Sea

    Directory of Open Access Journals (Sweden)

    P. E. Bachem

    2017-09-01

    Full Text Available The Pliocene was a time of global warmth with small sporadic glaciations, which transitioned towards the larger-scale Pleistocene glacial–interglacial variability. Here, we present high-resolution records of sea surface temperature (SST and ice-rafted debris (IRD in the Norwegian Sea from 5.32 to 3.14 Ma, providing evidence that the Pliocene surface conditions of the Norwegian Sea underwent a series of transitions in response to orbital forcing and gateway changes. Average SSTs are 2 °C above the regional Holocene mean, with notable variability on millennial to orbital timescales. Both gradual changes and threshold effects are proposed for the progression of regional climate towards the Late Pliocene intensification of Northern Hemisphere glaciation. Cooling from 4.5 to 4.3 Ma may be linked to the onset of poleward flow through the Bering Strait. This cooling was further intensified by a period of cool summers due to weak obliquity forcing. A 7 °C warming of the Norwegian Sea at 4.0 Ma suggests a major increase in northward heat transport from the North Atlantic, leading to an enhanced zonal SST gradient in the Nordic Seas, which may be linked to the expansion of sea ice in the Arctic and Nordic Seas. A warm Norwegian Sea and enhanced zonal temperature gradient between 4.0 and 3.6 Ma may have been a priming factor for increased glaciation around the Nordic Seas due to enhanced evaporation and precipitation at high northern latitudes.

  13. Chartering the high seas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Far from being a standard exercise, the transportation of coal by sea involves different players and procedures depending on the buyers and the sellers own strategy. This article, extracted from a new report by Drewry Shipping Consultants, identifies the strategies of the main players in the seaborne coal trade. In the coking coal market there is a long established preference for direct producer consumer purchase contracts, with the buyer undertaking the trading function, rather than purchasing through third parties. However, trading companies play a more important role in the steam coal market, acting either as principals or agents - or in some cases both. Both steam and coking coal are contracted mainly on a long-term basis. This guarantees supplies form sources which offer the optimum grades of coal for their plant. Diversity of supply is also an issue in case there are problems in obtaining the chosen coal. Shipping practices in Japan, Europe and elsewhere are examined. 2 figs., 3 tabs.

  14. Arctic Sea Ice Predictability and the Sea Ice Prediction Network

    Science.gov (United States)

    Wiggins, H. V.; Stroeve, J. C.

    2014-12-01

    Drastic reductions in Arctic sea ice cover have increased the demand for Arctic sea ice predictions by a range of stakeholders, including local communities, resource managers, industry and the public. The science of sea-ice prediction has been challenged to keep up with these developments. Efforts such as the SEARCH Sea Ice Outlook (SIO; http://www.arcus.org/sipn/sea-ice-outlook) and the Sea Ice for Walrus Outlook have provided a forum for the international sea-ice prediction and observing community to explore and compare different approaches. The SIO, originally organized by the Study of Environmental Change (SEARCH), is now managed by the new Sea Ice Prediction Network (SIPN), which is building a collaborative network of scientists and stakeholders to improve arctic sea ice prediction. The SIO synthesizes predictions from a variety of methods, including heuristic and from a statistical and/or dynamical model. In a recent study, SIO data from 2008 to 2013 were analyzed. The analysis revealed that in some years the predictions were very successful, in other years they were not. Years that were anomalous compared to the long-term trend have proven more difficult to predict, regardless of which method was employed. This year, in response to feedback from users and contributors to the SIO, several enhancements have been made to the SIO reports. One is to encourage contributors to provide spatial probability maps of sea ice cover in September and the first day each location becomes ice-free; these are an example of subseasonal to seasonal, local-scale predictions. Another enhancement is a separate analysis of the modeling contributions. In the June 2014 SIO report, 10 of 28 outlooks were produced from models that explicitly simulate sea ice from dynamic-thermodynamic sea ice models. Half of the models included fully-coupled (atmosphere, ice, and ocean) models that additionally employ data assimilation. Both of these subsets (models and coupled models with data

  15. Sea Surface Temperature Climate Data Record for the North Sea and Baltic Sea

    DEFF Research Database (Denmark)

    Høyer, Jacob L.; Karagali, Ioanna

    2016-01-01

    A 30-yr climate data record (CDR) of sea surface temperature (SST) has been produced with daily gap-free analysis fields for the North Sea and the Baltic Sea region from 1982 to 2012 by combining the Pathfinder AVHRR satellite data record with the Along-Track Scanning Radiometer (ATSR) Reprocessing...... observations on average. Validation against independent in situ observations shows a very stable performance of the data record, with a mean difference of -0.06 °C compared to moored buoys and a 0.46 °C standard deviation of the differences. The mean annual biases of the SST CDR are small for all years......, with a negligible temporal trend when compared against drifting and moored buoys. Analysis of the SST CDR reveals that the monthly anomalies for the North Sea, the Danish straits, and the central Baltic Sea regions show a high degree of correlation for interannual and decadal time scales, whereas the monthly...

  16. Role of sea ice in air-sea exchange and its relation to sea fog

    Institute of Scientific and Technical Information of China (English)

    解思梅; 包澄澜; 姜德中; 邹斌

    2001-01-01

    Synchronous or quasi-synchronous stereoscopic sea-ice-air comprehensive observation was conducted during the First China Arctic Expedition in summer of 1999. Based on these data, the role of sea ice in sea-air exchange was studied. The study shows that the kinds, distribution and thickness of sea ice and their variation significantly influence the air-sea heat exchange. In floating ice area, the heat momentum transferred from ocean to atmosphere is in form of latent heat; latent heat flux is closely related to floating ice concentration; if floating ice is less, the heat flux would be larger. Latent heat flux is about 21 23.6 W*m-2, which is greater than sensible heat flux. On ice field or giant floating ice, heat momentum transferred from atmosphere to sea ice or snow surface is in form of sensible heat. In the floating ice area or polynya, sea-air exchange is the most active, and also the most sensible for climate. Also this area is the most important condition for the creation of Arctic vapor fog. The heat exchange of a large-scale vapor fog process of about 500000 km2 on Aug. 21 22,1999 was calculated; the heat momentum transferred from ocean to air was about 14.8×109 kW. There are various kinds of sea fog, radiation fog, vapor fog and advection fog, forming in the Arctic Ocean in summer. One important cause is the existence of sea ice and its resultant complexity of both underlying surface and sea-air exchange.

  17. Sea surface temperature anomalies in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R.

    . Further analysis has shown that the sea surface anomalies are well correlated to the anomalies of air temperature and latent heat flux values; whereas they are least correlated to the anomalies of wind stress and net radiation values, except over...

  18. Sea otters and Alaska's developing sea farming industry

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The objectives of this paper are to give an overview of the current status of the industry in Alaska, identify potential problems between mariculture and sea otters...

  19. Chemical oceanography of the Arabian Sea Part iv Laccadive sea

    Digital Repository Service at National Institute of Oceanography (India)

    SenGupta, R.; Moraes, C.; Kureishy, T.W.; Sankaranarayanan, V.N.; Jana, T.K.; Naqvi, S.W.A.; Rajagopal, M.D.

    Patterns of distribution of nutrients and nutrients-oxygen relationships are similar to those observed in other parts of the Arabian Sea High magnesium and low fluoride concentrations in the water indicate probable loss of the latter as insoluble ion...

  20. Iridium in sea-water.

    Science.gov (United States)

    Fresco, J; Weiss, H V; Phillips, R B; Askeland, R A

    1985-08-01

    Iridium in sea-water has been measured (after isolation from the saline matrix by reduction with magnesium) by neutron bombardment, radiochemical purification and high-resolution gamma-ray spectroscopy. The concentration obtained in a Pacific coastal water was 1.02 +/- 0.26 x 10(-14) g per g of sea-water. At such extremely low concentrations, seawater is an extremely unlikely source for anomalously high iridium concentrations measured in the Cretaceous-Tertiary boundary layer of deep-sea sediments.

  1. Iridium in sea-water

    Energy Technology Data Exchange (ETDEWEB)

    Fresco, J.; Weiss, H.V.; Phillips, R.B.; Askeland, R.A.

    1985-08-01

    Iridium in sea-water has been measured (after isolation from the saline matrix by reduction with magnesium) by neutron bombardment, radiochemical purification and high resolution ..gamma..-ray spectroscopy. The concentration obtained in a Pacific coastal water was 1.02 +- 0.26 x 10/sup 14/ g per g of sea-water. At such extremely low concentrations, seawater is an extremely unlikely source for anomalously high iridium concentrations measured in the Cretaceous-Tertiary boundary layer of deep-sea sediments.

  2. How SEA can inform lenders

    DEFF Research Database (Denmark)

    Banhalmi-Zakar, Zsuzsa; Larsen, Sanne Vammen

    SEA can be a powerful tool to improve decision-making for plans, policies and programmes, but it can also be a useful for banks. SEA can help lenders address the reputational risks they are exposed to through financing projects that may have a negative impact on the environment and it can also help......, such as in the credit policies. It was also found that in some cases lenders become involved in project planning at a very early stage, when projects are conceptualized, and certainly before formal approval is sought from relevant authorities and an EIA is conducted. This suggests that SEA can be a useful tool...

  3. The politics of SEA indicators

    DEFF Research Database (Denmark)

    Gao, Jingjing; Kørnøv, Lone; Christensen, Per

    2013-01-01

    The use of indicators is not only technical and science-led, but also a value-laden social process, and thus concerns public participation, political judgment and decision-making. This article approaches the Chinese SEA indicator system from a science-policy interface and aims at: 1) contributing...... to the general recognition of indicators functioning at science-policy interfaces in SEA, and 2) analysing, through a Chinese case-study, to what extent national guidelines mediate the science-policy interaction. The overall finding is a strong emphasis on technical/science aspects found in the Chinese SEA...

  4. Summer sea ice characteristics of the Chukchi Sea

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    During August 1999, we investigated sea ice characteristics; its distribution, surface feature, thickness, ice floe movement, and the temperature field around inter-borders of air/ice/seawater in the Chukchi Sea. Thirteen ice cores were drilled at 11 floe stations in the area of 72°24′ 77°18′N, 153°34′ 163°28′W and the ice core structure was observed. From field observation, three melting processes of ice were observed; surface layer melting, surface and bottom layers melting, and all of ice melting. The observation of temperature fields around sea ice floes showed that the bottom melting under the ice floes were important process. As ice floes and open water areas were alternately distributed in summer Arctic Ocean; the water under ice was colder than the open water by 0.4 2.8℃. The sun radiation heated seawater in open sea areas so that the warmer water went to the bottom when the ice floes move to those areas. This causes ice melting to start at the bottom of the ice floes. This process can balance effectively the temperature fluctuating in the sea in summer. From the crystalline structure of sea ice observed from the cores, it was concluded that the ice was composed of ice crystals and brine-ice films. During the sea ice melting, the brine-ice films between ice crystals melted firstly; then the ice crystals were encircled by brine films; the sea ice became the mixture of ice and liquid brine. At the end of melting, the ice crystals would be separated each other, the bond between ice crystals weakens and this leads to the collapse of the ice sheet.

  5. SMOS Sea Surface Salinity Validation in the South China Sea

    Science.gov (United States)

    Ren, Yongzheng; Li, Xiaoming; Dong, Qing

    2013-01-01

    In November 2009, the European Space Agency (ESA) launched the first soil moisture and ocean salinity (SMOS) satellite, which represented the first use of spaceborne remote sensing tools to probe global sea surface salinity (SSS). The SMOS satellite carries a microwave imaging radiometer with aperture synthesis (MIRAS) for detection in the microwave L-band as the only payload. The MIRAS instrument is expected to provide a global SSS distribution with a spatial resolution of approximately 100 km and an accuracy of 0.1-0.2 practical salinity units (psu). The South China Sea is semi-enclosed, and the sea conditions are relatively complex. The suitability of ESA SMOS salinity products for the South China Sea has not been validated. Therefore, using SSS data measured during an expedition in the South China Sea, which was sponsored by China Natural Science Foundation and conducted in the fall of 2011, this paper validated the SSS products released by ESA, which were retrieved using three sea surface roughness models. To analyze the effect of the spatial resolution on the weekly average SMOS SSS distribution, the weekly average salinity data were averaged to reduce the spatial resolution to 0.25 ° x 0.25°. These average data were then compared to the measured data, followed by an analysis of the error variation. In addition, the effects of the orbital track (ascending or descending) on the SSS retrieval were analyzed.

  6. Microscale spatial distributions of microbes and viruses in intertidal photosynthetic microbial mats

    NARCIS (Netherlands)

    Carreira, C; Piel, T; Staal, M.; Stuut, J.-B; Middelboe, M.; Brussaard, C.P.D.

    2015-01-01

    Intertidal photosynthetic microbial mats from the Wadden Sea island Schiermonnikoog were examined for microscale (millimetre) spatial distributions of viruses, prokaryotes and oxygenic photoautotrophs (filamentous cyanobacteria and benthic diatoms) at different times of the year. Abundances of virus

  7. Microscale spatial distributions of microbes and viruses in intertidal photosynthetic microbial mats

    NARCIS (Netherlands)

    Carreira, C; Piel, T; Staal, M.; Stuut, J.-B; Middelboe, M.; Brussaard, C.P.D.

    2015-01-01

    Intertidal photosynthetic microbial mats from the Wadden Sea island Schiermonnikoog were examined for microscale (millimetre) spatial distributions of viruses, prokaryotes and oxygenic photoautotrophs (filamentous cyanobacteria and benthic diatoms) at different times of the year. Abundances of

  8. Key environmental variables determining the occurrence and life span of basiphilous dune slack vegetation

    NARCIS (Netherlands)

    Lammerts, EJ; Grootjans, AP

    Environmental processes controlling the occurrence of basiphilous pioneer vegetation were identified in seven representative dune slacks on the Dutch Wadden Sea Islands. The variation in vegetation and relations with soil and groundwater composition were established first. Cluster analysis of the

  9. Towards Good Order at Sea

    DEFF Research Database (Denmark)

    Mandrup, Thomas; Vreÿ, Francois

    . The problems originating from the resultant “bad order at sea” can be directly felt on land, when smuggling, terrorism and related criminal activities operate more or less unhindered. The book provides an important mapping of the challenges preventing good order at sea off the African coast and East Africa......This book addresses a timely and important theme in the debate on how to create good governance at sea in general, but specifically in the Western Indian Ocean. In a security milieu where the number of piracy attacks originating from Somalia has decreased, there is an urgent need to address...... structural problems facing attempts to create and maintain good order at sea off East Africa. As mentioned in one of the chapters, the most secure place for a criminal in East Africa to be is at sea, because most African littoral states have only limited capacity to police their territorial waters...

  10. USGS Sea Ice Email Script

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Daily sea ice imagery and charting benefits logistics and navigational planning in the Alaskan Arctic waters, yet access to these data often requires high bandwidth...

  11. Doppler characteristics of sea clutter.

    Energy Technology Data Exchange (ETDEWEB)

    Raynal, Ann Marie; Doerry, Armin Walter

    2010-06-01

    Doppler radars can distinguish targets from clutter if the target's velocity along the radar line of sight is beyond that of the clutter. Some targets of interest may have a Doppler shift similar to that of clutter. The nature of sea clutter is different in the clutter and exo-clutter regions. This behavior requires special consideration regarding where a radar can expect to find sea-clutter returns in Doppler space and what detection algorithms are most appropriate to help mitigate false alarms and increase probability of detection of a target. This paper studies the existing state-of-the-art in the understanding of Doppler characteristics of sea clutter and scattering from the ocean to better understand the design and performance choices of a radar in differentiating targets from clutter under prevailing sea conditions.

  12. A Can of Sea Worms

    Science.gov (United States)

    Zinn, Donald J.

    1977-01-01

    A comprehensive discussion of the free-living worms that inhabit the beaches and subtidal bottoms of the Cape Cod shoreline is presented. Methods for the location, collection, preservation, and identification of sea worms are identified. (BT)

  13. Temperature measurement in the sea

    Digital Repository Service at National Institute of Oceanography (India)

    Krishnamacharyulu, R.J.; Rao, L.V.G.

    ), their advantages and limitations are also touched upon. Calibration of various instruments used for temperature measurement in the sea and the special setup/facilities needed for this purpose are also discussed...

  14. Sea otter studies in Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The final objective of the present Fish and Wildlife sea otter program is to learn enough of the ecology, population, reproductive potential, and requirements in...

  15. Spirulina culture in sea water

    Energy Technology Data Exchange (ETDEWEB)

    Materassi, R.; Tredici, M.; Waldemaro, B.

    1984-01-01

    Laboratory experiments using small raceway ponds have shown that Spirulina maxima can be adapted easily to grow in sea-water supplemented with nitrate, phosphate, bicarbonate, and Fe-EDTA. To prevent precipitate formation, phosphate was supplied by diffusion through a dialysis membrane; the amount of Na-bicarbonate added was low (100 ppm) and the pH was kept in the range 8.6 - 8.8 by bubbling CO/sub 2/ into the culture. No significant differences have been noticed in productivity or in the chemical composition of the biomass between cultures in sea-water and in the standard bicarbonate medium. Cultures subjected to light/dark cycles of 12/12 hours showed a higher respiration rate in sea-water than in the bicarbonate medium. The higher weight loss in the sea-water medium in the dark was counterbalanced by an increased synthesis of carbohydrates during the light period. 9 references.

  16. Black Sea Bass genetic connectivity

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Microsatellite analysis of black sea bass was undertaken to determine magnitude and direction of mixing of black seabass across the Hatteras boundary, as well as...

  17. Sea Turtle Acoustic Telemetry Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Acoustic tags were attached to sea turtles captured in various fishing gear and the animals are either actively or passively tracked

  18. Sea bed mapping and inspection

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    The conference has 24 presentations on the topics: Sea bed mapping, inspection, positioning, hydrography, marine archaeology, remote operation vehicles and computerized simulation technologies, oil field activities and plans, technological experiences and problems. (tk)

  19. Dynamic Topography of the Bering Sea

    Science.gov (United States)

    2011-01-01

    Bering Sea. Comparisons also indicate that MDT estimates derived from the latest Gravity Recovery and Climate Experiment geoid model have more in common...with the presented sea surface topography than with the MDTs based on earlier versions of the geoid . The presented MDT will increase the accuracy of...estimating the geoid in the Bering Sea. 15. SUBJECT TERMS dynamic topography, sea surface height, Bering Sea, 4DVar 16. SECURITY CLASSIFICATION OF: a

  20. Alien seas oceans in space

    CERN Document Server

    Lopes, Rosaly

    2013-01-01

    In the early days of planetary observation, oceans were thought to exist in all corners of the Solar System. Carbonated seas percolated beneath the clouds of Venus. Features on the Moon's surface were given names such as "the Bay of Rainbows” and the "Ocean of Storms." With the advent of modern telescopes and spacecraft exploration these ancient concepts of planetary seas have been replaced by the reality of something even more exotic. Alien Seas serves up the current research, past beliefs, and new theories to offer a rich array of the "seas" on other worlds. It is organized by location and by the material composing the oceans under discussion, with expert authors penning chapters on their  specialty. Each chapter features new original art depicting alien seas, as well as the latest ground-based and spacecraft images. With the contributors as guides, readers can explore the wild seas of Jupiter's watery satellite Europa, believed similar in composition to battery acid. Saturn's planet-sized moon Titan see...

  1. Sea otter investigation, Amchitka Island, 1954, and proposed plan of research for sea otters

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report describes a sea otter investigation on Amchitka Island during 1954 and a proposed plan of research for sea otters. The report covers capturing wild sea...

  2. Deep-sea Hexactinellida (Porifera) of the Weddell Sea

    Science.gov (United States)

    Janussen, Dorte; Tabachnick, Konstantin R.; Tendal, Ole S.

    2004-07-01

    New Hexactinellida from the deep Weddel Sea are described. This moderately diverse hexactinellid fauna includes 14 species belonging to 12 genera, of which five species and one subgenus are new to science: Periphragella antarctica n. sp., Holascus pseudostellatus n. sp., Caulophacus (Caulophacus) discohexactinus n. sp., C. ( Caulodiscus) brandti n. sp., C. ( Oxydiscus) weddelli n. sp., and C. ( Oxydiscus) n. subgen. So far, 20 hexactinellid species have been reported from the deep Weddell Sea, 15 are known from the northern part and 10 only from here, while 10 came from the southern area, and five of these only from there. However, this apparent high "endemism" of Antarctic hexactinellid sponges is most likely the result of severe undersampling of the deep-sea fauna. We find no reason to believe that a division between an oceanic and a more continental group of species exists. The current poor database indicates that a substantial part of the deep hexactinellid fauna of the Weddell Sea is shared with other deep-sea regions, but it does not indicate a special biogeographic relationship with any other ocean.

  3. Toxic Algae and Early Warning Management in Yellow Sea and Bohai Sea of China

    Institute of Scientific and Technical Information of China (English)

    Song; Lun; Song; Guangjun; Song; Yonggang; Xu; Xiaohong

    2014-01-01

    The research status of toxic algae in Yellow Sea and Bohai Sea are reviewed from the aspects of toxicity characteristics,toxic mechanism and early warning management,and the existing toxic algae and their toxicity in Yellow Sea and Bohai Sea are analyzed in the paper. The early warning level of toxic algae in Yellow Sea and Bohai Sea of China is put forward,and the research direction of shellfish poisoning in future is summarized.

  4. Magnetohydrodynamic sea water propulsion

    Energy Technology Data Exchange (ETDEWEB)

    Petrick, M.; Thomas, A.; Genens, L.; Libera, J.; Nietert, R.; Bouillard, J.; Pierson, E.; Hill, D.; Picologlou, B.; Ohlsson, O.; Kasprzyk, T.; Berry, G.

    1991-01-01

    An experimental and theoretical investigation of a large scale MHD propulsor has been undertaken whose objectives are to (1) investigate the transient and steady state performance of the thruster over operating parameter ranges that are compatible with achievement of high efficiency, (2) to quantify the principal loss mechanisms within the thruster and (3) to obtain preliminary hydroacoustic data. The performance of the thruster was first investigated theoretically with a 3-D code to quantify the loss mechanisms and identify experimental parameter ranges of interest. The loss mechanisms of interest are ohmic losses within the channel and those resulting from electrical currents at the entrance and exit of the thruster, and enhanced frictional losses. The analysis indicated that the relative importance of the loss mechanisms was a function of the thruster design and operating parameters. The experimental investigation of the large scale propulsor is being conducted on a sea water test facility that was designed to match the capabilities of a large 6-T superconducting magnet. The facility design was such that {approximately}90{degrees} of all losses occurred within the propulsion test train (inlet nozzle, propulsor and diffuser) thus facilitating isolation of the loss mechanisms. The test thruster itself is heavily instrumented to provide local measurements of velocity, pressure, and electric fields. The predicted overall thruster performance and value of the loss mechanisms will be compared with measured values. Comparisons will also be presented of the voltage gradients between electrodes, overall thruster efficiency, axial pressure gradients across the propulsor, change in velocity profiles, axial and vertical current distributions and exit distribution of the electrolytic gases.

  5. Magnetohydrodynamic sea water propulsion

    Energy Technology Data Exchange (ETDEWEB)

    Petrick, M.; Thomas, A.; Genens, L.; Libera, J.; Nietert, R.; Bouillard, J.; Pierson, E.; Hill, D.; Picologlou, B.; Ohlsson, O.; Kasprzyk, T.; Berry, G.

    1991-12-31

    An experimental and theoretical investigation of a large scale MHD propulsor has been undertaken whose objectives are to (1) investigate the transient and steady state performance of the thruster over operating parameter ranges that are compatible with achievement of high efficiency, (2) to quantify the principal loss mechanisms within the thruster and (3) to obtain preliminary hydroacoustic data. The performance of the thruster was first investigated theoretically with a 3-D code to quantify the loss mechanisms and identify experimental parameter ranges of interest. The loss mechanisms of interest are ohmic losses within the channel and those resulting from electrical currents at the entrance and exit of the thruster, and enhanced frictional losses. The analysis indicated that the relative importance of the loss mechanisms was a function of the thruster design and operating parameters. The experimental investigation of the large scale propulsor is being conducted on a sea water test facility that was designed to match the capabilities of a large 6-T superconducting magnet. The facility design was such that {approximately}90{degrees} of all losses occurred within the propulsion test train (inlet nozzle, propulsor and diffuser) thus facilitating isolation of the loss mechanisms. The test thruster itself is heavily instrumented to provide local measurements of velocity, pressure, and electric fields. The predicted overall thruster performance and value of the loss mechanisms will be compared with measured values. Comparisons will also be presented of the voltage gradients between electrodes, overall thruster efficiency, axial pressure gradients across the propulsor, change in velocity profiles, axial and vertical current distributions and exit distribution of the electrolytic gases.

  6. Dead sea asphalts: historical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Nissenbaum, A.

    1978-05-01

    Asphalts are present in the Dead Sea basin in three forms: (1) huge blocks, up to 100 tons in weight, composed of extremely pure (>99.99%) solid asphalt occasionally found floating on the lake, (2) veins, seepages, and cavity and fissure fillings in Lower Cretaceous to Holocene rocks, and (3) ozocerite veins on the eastern shore of the lake. Dead Sea asphalts probably have been documented over a longer period of time than any other hydrocarbon deposit--from antiquity to the 19th century. Major uses of asphalt from the Dead Sea have been as an ingredient in the embalming process, for medicinal purposes, for fumigation, and for agriculture. The first known war for control of a hydrocarbon deposit was in the Dead Sea area in 312 B.C. between the Seleucid Syrians and the Nabatean Arabs who lived around the lake. Surface manifestations of asphalt are linked closely to tectonic activity. In the lake itself, the asphalt is associated with diapirs During certain historic periods, tectonic and diapiric activity caused frequent liberation to the Dead Sea surface of semiliquid asphalt associated with large amounts of hydrogen sulfide gas. When the tectonic activity was attenuated, as in the 19th and 20th centuries, the rate of asphalt seepage to the bottom sediments of the Dead Sea was much slower and the asphalt solidified on the lake bottom. The release of asphalt to the surface became much more sporadic, and may have resulted in part from earthquakes. Thus, future asphalt prospecting in the Dead Sea area should be conducted along the boundaries of diapirs or their associated faults.

  7. Integrating out the Dirac sea

    Energy Technology Data Exchange (ETDEWEB)

    Karbstein, Felix

    2009-07-08

    We introduce a new method for dealing with fermionic quantum field theories amenable to a mean-field-type approximation. In this work we focus on the relativistic Hartree approximation. Our aim is to integrate out the Dirac sea and derive a no-sea effective theory'' with positive energy single particle states only. As the derivation of the no-sea effective theory involves only standard Feynman diagrams, our approach is quite general and not restricted to particular space-time dimensions. We develop and illustrate the approach in the ''large N'' limit of the Gross-Neveu model family in 1+1 dimensions. As the Gross-Neveu model has been intensely studied and several analytical solutions are known for this model, it is an ideal testing ground for our no-sea effective theory approach. The chiral Gross-Neveu model, also referred to as 1+1 dimensional Nambu-Jona-Lasinio model, turns out to be of particular interest. In this case, we explicitly derive a consistent effective theory featuring both elementary ''{pi} meson'' fields and (positive energy) ''quark'' fields, starting from a purely fermionic quantum field theory. In the second part of this work, we apply our approach to the Walecka model in 1+1 and 3+1 dimensions. As the Dirac sea caused considerable difficulties in attempts to base nuclear physics on field theoretic models like the Walecka model, mean-field calculations were typically done without the sea. We confront several of these mean-field theory results with our no-sea effective theory approach. The potential of our approach is twofold. While the no-sea effective theory can be utilized to provide new analytical insights in particular parameter regimes, it also sheds new light on more fundamental issues as the explicit emergence of effective, Dirac-sea induced multi-fermion interactions in an effective theory with positive energy states only. (orig.)

  8. Understanding the Amundsen Sea Low

    Science.gov (United States)

    McDonald, Adrian

    2016-04-01

    The Amundsen Sea Low (ASL) is a climatological low pressure system located between 170-300 ° E and 60-75°S and is a key component of the non-zonal climatological circulation at high southern latitudes. With reanalysis output identifying that climatologically the low in the Amundsen Sea is the deepest of three mean sea level pressure (MSLP) centres observed around Antarctica. The ASL strongly modulates West Antarctic climate with impacts on sea ice extent, temperature and precipitation, via its controlling influence on the variability of the meridional wind field. It has also been shown to have a significant influence on the atmospheric circulation in the Ross Sea region and to strongly modulate temperature and moisture advection over the Antarctic Peninsula. Previous work has demonstrated strong relationships between the depth of the ASL and cyclone densities in the region. However, interestingly a recent review identified that it is not easy to relate the storm density and depths of the cyclones to the climatological ASL, since the climatological location of the ASL does not occur at a clear maximum of storm activity. This study examines output from the ERA-interim reanalyses around Antarctica to further understand the contributors to the climatological pattern, partially in an effort to identify whether a more physically meaningful ASL depth index (normally simply defined as the monthly minimum MSLP) can be created. In this effort, storm track data derived from the ERA-Interim reanalysis and mean sea level pressure data bandpass filtered to accentuate synoptic scale variability are first examined. The contribution of persistent positive anomalies in the mean sea level pressure (defined as 8hPa positive anomalies from the climatological mean for a period of 5 days) in the region surrounding the Amundsen sea is also examined to identify whether blocking plays a role. Finally, the frequency of persistent negative anomalies (defined as a negative 8hPa occurring for

  9. Sea Ice Concentration and Extent

    Science.gov (United States)

    Comiso, Josefino C.

    2014-01-01

    Among the most seasonal and most dynamic parameters on the surface of the Earth is sea ice which at any one time covers about 3-6% of the planet. In the Northern Hemisphere, sea ice grows in extent from about 6 x 10(exp 6) sq km to 16 x 10(exp 6) sq km, while in the Southern Hemisphere, it grows from about 3 x 10(exp 6) sq km to about 19 x 10(exp 6) sq km (Comiso, 2010; Gloersen et al., 1992). Sea ice is up to about 2-3 m thick in the Northern Hemisphere and about 1 m thick in the Southern Hemisphere (Wadhams, 2002), and compared to the average ocean depth of about 3 km, it is a relatively thin, fragile sheet that can break due to waves and winds or melt due to upwelling of warm water. Being constantly advected by winds, waves, and currents, sea ice is very dynamic and usually follows the directions of the many gyres in the polar regions. Despite its vast expanse, the sea ice cover was previously left largely unstudied and it was only in recent years that we have understood its true impact and significance as related to the Earths climate, the oceans, and marine life.

  10. Sea Ice Concentration and Extent

    Science.gov (United States)

    Comiso, Josefino C.

    2014-01-01

    Among the most seasonal and most dynamic parameters on the surface of the Earth is sea ice which at any one time covers about 3-6% of the planet. In the Northern Hemisphere, sea ice grows in extent from about 6 x 10(exp 6) sq km to 16 x 10(exp 6) sq km, while in the Southern Hemisphere, it grows from about 3 x 10(exp 6) sq km to about 19 x 10(exp 6) sq km (Comiso, 2010; Gloersen et al., 1992). Sea ice is up to about 2-3 m thick in the Northern Hemisphere and about 1 m thick in the Southern Hemisphere (Wadhams, 2002), and compared to the average ocean depth of about 3 km, it is a relatively thin, fragile sheet that can break due to waves and winds or melt due to upwelling of warm water. Being constantly advected by winds, waves, and currents, sea ice is very dynamic and usually follows the directions of the many gyres in the polar regions. Despite its vast expanse, the sea ice cover was previously left largely unstudied and it was only in recent years that we have understood its true impact and significance as related to the Earths climate, the oceans, and marine life.

  11. Iodine emissions from the sea ice of the Weddell Sea

    Directory of Open Access Journals (Sweden)

    H. M. Atkinson

    2012-05-01

    Full Text Available Iodine compounds were measured above, below and within the sea ice of the Weddell Sea during a cruise in 2009, to elucidate the mechanism of local enhancement and volatilisation of iodine. I2 mixing ratios of up to 12.4 pptv were measured 10 m above the sea ice, and up to 31 pptv was observed above surface snow on the nearby Brunt Ice Shelf – large amounts. Atmospheric IO of up to 7 pptv was measured from the ship, and the average sum of HOI and ICl was 1.9 pptv. These measurements confirm the Weddell Sea as an iodine hotspot. Average atmospheric concentrations of CH3I, C2H5I, CH2ICl, 2-C3H7I, CH2IBr and 1-C3H7I were each 0.2 pptv or less. On the Brunt Ice Shelf, enhanced concentrations of CH3I and C2H5I (up to 0.5 and 1 pptv, respectively were observed in firn air, with a diurnal profile that suggests the snow may be a source. In the sea ice brine, iodocarbons concentrations were over 10 times those of the sea water below. The sum of iodide + iodate was depleted in sea ice samples, suggesting some missing iodine chemistry. Flux calculations suggest I2 dominates the iodine atom flux to the atmosphere, but models cannot reconcile the observations and suggest either a missing iodine source or other deficiencies in our understanding of iodine chemistry. The observation of new particle formation, consistent with the model predictions, strongly suggests an iodine source. This combined study of iodine compounds is the first of its kind in this unique region of sea ice rich in biology and rich in iodine chemistry.

  12. Iodine emissions from the sea ice of the Weddell Sea

    Directory of Open Access Journals (Sweden)

    H. M. Atkinson

    2012-11-01

    Full Text Available Iodine compounds were measured above, below and within the sea ice of the Weddell Sea during a cruise in 2009, to make progress in elucidating the mechanism of local enhancement and volatilisation of iodine. I2 mixing ratios of up to 12.4 pptv were measured 10 m above the sea ice, and up to 31 pptv was observed above surface snow on the nearby Brunt Ice Shelf – large amounts. Atmospheric IO of up to 7 pptv was measured from the ship, and the average sum of HOI and ICl was 1.9 pptv. These measurements confirm the Weddell Sea as an iodine hotspot. Average atmospheric concentrations of CH3I, C2H5I, CH2ICl, 2-C3H7I, CH2IBr and 1-C3H7I were each 0.2 pptv or less. On the Brunt Ice Shelf, enhanced concentrations of CH3I and C2H5I (up to 0.5 and 1 pptv respectively were observed in firn air, with a diurnal profile that suggests the snow may be a source. In the sea ice brine, iodocarbons concentrations were over 10 times those of the sea water below. The sum of iodide + iodate was depleted in sea ice samples, suggesting some missing iodine chemistry. Flux calculations suggest I2 dominates the iodine atom flux to the atmosphere, but models cannot reconcile the observations and suggest either a missing iodine source or other deficiencies in our understanding of iodine chemistry. The observation of new particle formation, consistent with the model predictions, strongly suggests an iodine source. This combined study of iodine compounds is the first of its kind in this unique region of sea ice rich in biology and rich in iodine chemistry.

  13. Alone by the Sea

    Directory of Open Access Journals (Sweden)

    Zoran Ferić

    2015-06-01

    Full Text Available 1.At first the island is just a sign on a yellow board with a drawing of a vessel and the letters saying “Car Ferry,” then it is a grayish silhouette in the blue of the sea, and then, later still, an acquaintance working on the ferry, who just nods briefly in greeting. Jablanac, ferry port, its pleasant lobby, and then, from the upper deck, a giant rock approaching. That is the object of a year-long desire: the moment of stepping off the boat and smelling the rosemary, diesel and sheep droppings, seeing the sharp rocks looking at the Strait of Senj, coarse limestone in sharp opposition to the signs that say: Benvenuti, Welcome, Willkommen!At home, on the terrace, in the shade of the oleander, there’s no wish to eat. Only swimming trunks are put on and then, barefoot, without a towel or sun-tanning lotion, off to the beach.“Why won’t you eat something?” grandma asks.She knows that there’s an exciting world waiting out there, but she knows nothing of the details. All friends went on a boat trip. And suddenly one step from the shade of a path covered with oleanders and acacias leads into the burning sun of the afternoon. The light screams, just like children in the water, just like white objects that radiate as if there are some powerful light bulbs within. The feeling of freedom of someone who has just arrived in a foreign place and can now do anything. There’s no one familiar on the beach, they all got in the boat and left. The seafront leading to the camp is full of people, naked children with dirty faces licking ice cream, young families pushing strollers, groups of teenagers who have just woken up from their last night’s party. But there’s no one that must be greeted. The feeling of freedom that’s at the same time close to death. Suddenly, all paths are open. That there are no obligations or friends waiting, this afternoon, until they come back, is a complete boon.

  14. On The Black Sea Surozhian

    Science.gov (United States)

    Caraivan, Glicherie; Corneliu, Cerchia

    2016-04-01

    Some Black Sea researchers still support the idea of no other connection to the Mediterranean Sea between LGM and Karangatian Stage (Riss - Wurm). We try to clarify the source of these disagreements. C14 AMS age data (HERAS Project) made on undisturbed samples from a new Mamaia drilling hole where compared with the classical Black Sea stratigraphic schemes. A first transgressive event (Zone D) is found between 38.00 - 20.20 m depth. Zone D4 shows a fairly rapid rise of sea level, about 10 m below the present one indicating an inner shelf marine polyhaline environment. AMS age data show 14C ages between 53690 - 47359 y (MIS 1), corresponding to the "Surozhian Beds" of Popov. The "beach rock" from Zone E marks the decrease of the sea level after the maximum reached in Zone D4. Zone E mollusc shells AMS data, indicate 14C ages of 48724 - 44604 y, suggesting a long-time reworked material from the previous D4 zone sediments, and represents the beginning of the "regressive Tarkankutian" sequence.The Last Glacial Maximum (LGM) led to the retreat of the sea level down to about 100 m below the current one (27-17 ky BP), followed by an retreat of the shoreline to the present position. At the beginning of the Holocene - MIS 1 (8408-8132 cal. y BP), Black Sea brackish water level grew rapidly, up to -14 m below the present one (Zone F: 22, 57-20, 20 m). Zone F deposits could be correlated with the Bugazian strata. Then, a continuous rising of the Black Sea level is recorded up to a maximum of -2 m under the present one, about 6789 - 7063 cal. y BP, when a transgressive spurt ("Neolithic transgression") may have taken place. After that, given a weak Danubian sedimentary input, coastal erosion intensified. The coarse sandy sediments were reworked and pushed over the previous peat deposits, and suggest a classical "sedimentary regression", not a sea-level decrease. During the last 1.5 ky, sea level has risen towards the current one. Previous C14 dates from "Karangatian

  15. Vulnerability of marginal seas to sea level rise

    Science.gov (United States)

    Gomis, Damia; Jordà, Gabriel

    2017-04-01

    Sea level rise (SLR) is a serious thread for coastal areas and has a potential negative impact on society and economy. SLR can lead for instance to land loss, beach reduction, increase of the damage of marine storms on coastal infrastructures and to the salinization of underground water streams. It is well acknowledged that future SLR will be inhomogeneous across the globe, with regional differences of up to 100% with respect to global mean sea level (GMSL). Several studies have addressed the projections of SLR at regional scale, but most of them are based on global climate models (GCMs) that have a relatively coarse spatial resolution (>1°). In marginal seas this has proven to be a strong limitation, as their particular configurations require spatial resolutions that are not reachable by present GCMs. A paradigmatic case is the Mediterranean Sea, connected to the global ocean through the Strait of Gibraltar, a narrow passage of 14 km width. The functioning of the Mediterranean Sea involves a variety of processes including an overturning circulation, small-scale convection and a rich mesoscale field. Moreover, the long-term evolution of Mediterranean sea level has been significantly different from the global mean during the last decades. The observations of present climate and the projections for the next decades have lead some authors to hypothesize that the particular characteristics of the basin could allow Mediterranean mean sea level to evolve differently from the global mean. Assessing this point is essential to undertake proper adaptation strategies for the largely populated Mediterranean coastal areas. In this work we apply a new approach that combines regional and global projections to analyse future SLR. In a first step we focus on the quantification of the expected departures of future Mediterranean sea level from GMSL evolution and on the contribution of different processes to these departures. As a result we find that, in spite of its particularities

  16. GHRSST Level 4 DMI_OI North Sea and Baltic Sea Regional Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis by the Danish...

  17. How SEA can inform lenders

    DEFF Research Database (Denmark)

    Banhalmi-Zakar, Zsuzsa; Larsen, Sanne Vammen

    SEA can be a powerful tool to improve decision-making for plans, policies and programmes, but it can also be a useful for banks. SEA can help lenders address the reputational risks they are exposed to through financing projects that may have a negative impact on the environment and it can also help...... with identifying the financial incentives that ‘green’ projects attract. Although bank lending decisions apply to projects, examination of the lending practices of an Australian and a Hungarian bank have shown that decisions about the type of projects to target or avoid are also made at strategic level......, such as in the credit policies. It was also found that in some cases lenders become involved in project planning at a very early stage, when projects are conceptualized, and certainly before formal approval is sought from relevant authorities and an EIA is conducted. This suggests that SEA can be a useful tool...

  18. Coccidioidomycosis in southern sea otters

    Science.gov (United States)

    Thomas, Nancy J.; Pappagianis, Demosthenes; Creekmore, Lynn H.; Duncan, Ruth M.

    1994-01-01

    Disseminated coccidioidomycosis was diagnosed postmortem in six southern sea otters (Enhydra lutris nereis) found dying or dead along the Pacific Coast of California at San Luis Obispo County.  These otters were found during winter or summer 1992, 1993, and 1994.  Coccidioides immitis was identified by its morphology in tissue impression smears and by histopathology, and was confirmed by culture.  Positive serologic results were obtained from four of five sea otters tested.  The lungs, pleura, tracheobronchial lymph nodes, liver, and spleen were involved in each case.  There was meningeal involvement in half of the affected animals.  Coccidioidomycosis has been reported in a wild sea otter only once previously, in 1976, and that otter was also found on the coast of San Luis Obispo County.

  19. Mapping the deep sea floor

    DEFF Research Database (Denmark)

    Nielsen, Kristian Hvidtfelt

    By the early 20th century, oceanographers intensified their efforts to map the deep sea. The great depth of the Philippine Trench was first observed by the German Planet Expedition in 1912. During World War II, the US naval vessel Cape Johnson used directional echo-sounding to obtain a depth of 10......,497 m. In 1951, the Danish Galathea Deep Sea Expedition from 1950 to 1952 verified the result of the Cape Johnson sounding. Today, the greatest depth in the Philippine Trench is the Galathea Depth of 10,540 m. The Galathea Expedition produced several echograms of the deepest parts of the Philippine...... Trench in order to map its bathymetric features. The resulting maps are presented in this poster. Unlike many other contemporary developments in deep sea topography and cartography that were shaped by the Cold War, the Galathea maps of the Philippine Trench were intimately connected with the expedition...

  20. EXPERIMENTS OF SEA ICE SIMULATION

    Institute of Scientific and Technical Information of China (English)

    LIU Xi-ying; ZHANG Xue-hong; YU Ru-cong; LIU Hai-long; YU Yong-qiang

    2005-01-01

    As a substitute for the original displaced pole grids, a simple rotated spherical coordinate system was introduced into the Community Sea Ice Model version 4(CSIM4), which is a component of the Community Climate System Model(CCSM) of the American National Center of Atmospheric Research(NCAR), to deal with the "pole problems".In the new coordinates, both the geographical North Pole and South Pole lie in the model equator and grid sizes near the polar region are more uniform.With reanalysis dataset of American National Centers for Environment Prediction(NCEP) and Levitus dataset without considering sub-mixed layer heat flux, the model was integrated for 100 years with thermodynamics process involved only in the former 49 years and both dynamic and thermodynamic processes involved in the left time.Inner consistency of model results was checked with no contradiction found.The results of last 10 years' model output were analyzed and it is shown that the simulated sea ice seasonal variation is rational whereas sea ice extent in the Barents Sea in winter is larger than that of observation.Numerical experiment on influence of sub-mixed layer heat flux was also carried out and it is shown that the sub-mixed layer heat flux can modulate seasonal variation of sea ice greatly.As a model component, the sea ice model with rotated spherical coordinates was coupled with other models (the oceanic general circulation model is the LASG/IAP Climate System Ocean Model(LICOM) with reduced grid, other models are components of NCAR CCSM2) forming a climate system model and its preliminary results were also given briefly.

  1. Black Sea coastal forecasting system

    Directory of Open Access Journals (Sweden)

    A. I. Kubryakov

    2012-03-01

    Full Text Available The Black Sea coastal nowcasting and forecasting system was built within the framework of EU FP6 ECOOP (European COastalshelf sea OPerational observing and forecasting system project for five regions: the south-western basin along the coasts of Bulgaria and Turkey, the north-western shelf along the Romanian and Ukrainian coasts, coastal zone around of the Crimea peninsula, the north-eastern Russian coastal zone and the coastal zone of Georgia. The system operates in the real-time mode during the ECOOP project and afterwards. The forecasts include temperature, salinity and current velocity fields. Ecosystem model operates in the off-line mode near the Crimea coast.

  2. Sailing In Sea of Commerce

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The law of big fish swallowing little fish has expired when it comes to the era of new economy.What prevails nowadays in the sea of commerce is quick fish swallowing slow fish.In the Internet economy,small companies are not destined to lose to giants,but slow ones are doomed to become prey of their quick counterparts. The swiftly rising Yongkang Group has made a breakthrough in dental treatment by translating the law into practice.It is called"Law of the Sea."‘Law of the Sea’

  3. Temperature, salinity, and nutrients data collected from North Atlantic Ocean, White Sea, Mediterranean Sea, Black Sea, and Sea of Azov from 1924-03-19 to 1989-11-19 by multiple Soviet Union institutes (NODC Accession 0077413)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, and nutrients data collected from North Atlantic Ocean, White Sea, Mediterranean Sea, Black Sea, and Sea of Azov from 1924-03-19 to 1989-11-19...

  4. 2010 USGS Lidar: Salton Sea (CA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The USGS Salton Sea project encompasses a 5-kilometer buffer around the Salton Sea, California. Dewberry classified LiDAR for a project boundary that touches 623...

  5. Extended Reconstructed Sea Surface Temperature (ERSST)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Extended Reconstructed Sea Surface Temperature (ERSST) dataset is a global monthly sea surface temperature analysis derived from the International Comprehensive...

  6. Erective Sea Embankment with PCC Piles

    Institute of Scientific and Technical Information of China (English)

    LIU Han-long; FEI Kang; DENG An; ZHANG Ting

    2005-01-01

    The sea embankment is a critical civil works in marine and coastal engineering. In this study, an innovative technique is proposed for constructing erective sea embankments. In the construction of sea embankments, this technique integrates PCC pile installation, PVDs drainage systems, and geotextile reinforcements, resulting in sea embankments with PCC piles. In the application of a sea embankment with PCC piles, PCC piles are employed as the retaining structures;the soft sea ground inside PCC piles is drained and improved by PVDs and vacuum-surcharge combined preloading; geotextile-reinforced backfills lying over the improved soft ground form the embankment body. Brief descrptions of the fundamentals, design and construction of the sea embankment with PCC piles are presented. A case study on the stability of sea embankment with PCC piles is presented as well.

  7. Range Extent for southern sea otters 2016

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The GIS shapefile "Range extent of southern sea otters 2016" is a simple polyline representing the geographic distribution of the southern sea otter (Enhydra lutris...

  8. Biogeochemistry of iron in the Arabian sea

    Digital Repository Service at National Institute of Oceanography (India)

    Moffett, J.W.; Vedamati, J.; Goepfert, T.J.; Pratihary, A.K.; Gauns, M.; Naqvi, S.W.A.

    The Arabian Sea is a productive basin where seasonal upwelling and convective mixing result in high surface nutrient concentrations and widespread algal blooms. The factors controlling primary productivity in the Arabian Sea are of interest because...

  9. Quarterly Fishery Surveys - Salton Sea [ds428

    Data.gov (United States)

    California Department of Resources — In the spring of 2003, California Department of Fish and Game (CDFG) personnel began quarterly sampling of Salton Sea fish at fourteen stations around the sea, as...

  10. Implementing the European SEA Directive in planning

    DEFF Research Database (Denmark)

    Kørnøv, Lone

    The paper describes how the European SEA Directive can complement the existing planning practice in Denmark.......The paper describes how the European SEA Directive can complement the existing planning practice in Denmark....

  11. Sea turtles sightings in North Carolina

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sea turtles sightings are reported to the NMFS Beaufort Laboratory sea turtle program by the general public as they are fishing, boating, etc. These sightings...

  12. Levels of hexabromocyclododecane in harbor porpoises and common dolphins from western European seas, with evidence for stereoisomer-specific biotransformation by cytochrome p450.

    Science.gov (United States)

    Zegers, Bart N; Mets, Anchelique; Van Bommel, Ronald; Minkenberg, Chris; Hamers, Timo; Kamstra, Jorke H; Pierce, Graham J; Boon, Jan P

    2005-04-01

    Commercial hexabromocyclododecane (HBCD) is a high-production-volume flame-retardant applied in polystyrene foams. It contains three stereoisomers, of which gamma-HBCD always dominates. Here we report on the levels of HBCD in blubber of harbor porpoise and common dolphin from different European seas. The highest total (sigma)-HBCD levels were measured in harbor porpoises stranded on the Irish and Scottish coasts of the Irish Sea (median concentration 2.9 microg (g of lipid)(-1)) and the northwest coast of Scotland (median concentration 5.1 microg (g of lipid)(-1)). The median levels in other areas were, for the harbor porpoise south coast of Ireland, 1.2 microg (g of lipid)(-1), for the coasts of The Netherlands, Belgium, and France north of Calais (southern North Sea), 1.1 microg (g of lipid)(-1), for the east coast of Scotland (northern North Sea), 0.77 microg (g of lipid)(-1), and, for Galicia (Spain), 0.1 microg (g of lipid)(-1). The median levels for the common dolphin were, for west coast of Ireland, 0.9 microg (g of lipid)(-1), for the French coast of the English Channel between Normandy and Brest, 0.4 microg (g of lipid)(-1), and, for Galicia, 0.2 microg (g of lipid)(-1). A subset of 10 harbor porpoise and 9 common dolphin blubber samples representing all areas were analyzed by LC/MS to determine the diastereomeric composition of their HBCD residues. All samples showed exclusively the peak of alpha-HBCD. To test if biotransformation by the cytochrome P450 system could explain the observed compositional difference with technical HBCD mixtures, a number of in vitro assays with microsomal preparations of liver were carried out. We had to revert to material stored at -80 degrees C from laboratory rats and a fresh harbor seal found dead in the Dutch Wadden Sea, since such liver samples of cetaceans were not in our possession. The in vitro assays showed that beta- and gamma-HBCDs were indeed significantly metabolized when incubated in the presence of NADPH as

  13. 50 CFR 697.12 - At-sea sea sampler/observer coverage.

    Science.gov (United States)

    2010-10-01

    ... ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) ATLANTIC COASTAL FISHERIES COOPERATIVE... must: (1) Notify the sea sampler/observer of any sea turtles, marine mammals, or other specimens taken by the vessel. (2) Provide the sea sampler/observer with sea turtles, marine mammals, or...

  14. Estimating sea floor dynamics in the Southern North Sea to improve bathymetric survey planning

    NARCIS (Netherlands)

    Dorst, Leendert Louis

    2009-01-01

    Safe nautical charts require a carefully designed bathymetric survey policy, especially in shallow sandy seas that potentially have dynamic sea floor patterns. Bathymetric resurveying at sea is a costly process with limited resources, though. A pattern on the sea floor known as tidal sand waves is c

  15. Multiscale Models of Melting Arctic Sea Ice

    Science.gov (United States)

    2014-09-30

    1 Multiscale Models of Melting Arctic Sea Ice Kenneth M. Golden University of Utah, Department of Mathematics phone: (801) 581-6851...feedback has played a major role in the recent declines of the summer Arctic sea ice pack. However, understanding the evolution of melt ponds and sea...Models of Melting Arctic Sea Ice 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER

  16. [Multiple scattering of visible and infrared light by sea fog over wind driving rough sea surface].

    Science.gov (United States)

    Sun, Xian-Ming; Wang, Hai-Hua; Lei, Cheng-Xin; Shen, Jin

    2013-08-01

    The present paper is concerned with computing the multiple scattering characteristics of a sea fog-sea surface couple system within this context. The single scattering characteristics of sea fog were studied by Mie theory, and the multiple scattering of sunlight by single sea fog layer was studied by radiative transfer theory. The reflection function of a statistically rough ocean surface was obtained using the standard Kirchhoff formulation, with shadowing effects taken into account. The reflection properties of the combined sea fog and ocean surface were obtained employing the adding method, and the results indicated that the reflected light intensity of sea fog increased with the sea background.

  17. Increased CO2 uptake due to sea ice growth and decay in the Nordic Seas

    DEFF Research Database (Denmark)

    Rysgaard, Søren; Bendtsen, Jørgen; Petersen, L.T.

    2009-01-01

    uptake in the Nordic Seas is currently unknown. We present evidence from 50 localities in the Arctic Ocean that dissolved inorganic carbon is rejected together with brine from growing sea ice and that sea ice melting during summer is rich in carbonates. Model calculations show that melting of sea ice......The uptake rates of atmospheric CO2 in the Nordic Seas are among the highest in the world's oceans. This has been ascribed mainly to a strong biological drawdown, but chemical processes within the sea ice itself have also been suggested to play a role. The importance of sea ice for the carbon...

  18. India and the South China Sea Dispute

    Institute of Scientific and Technical Information of China (English)

    Ma Jiali

    2012-01-01

    South China Sea is a sea area of great significance. It lies between the Pacific and Indian Oceans, a crucial waterway bridging East Asia, Southeast Asia and South Asia. In general, South China Sea is a rich deposit of oil and fishing resources, a transportation hub of strategic importance, and an important buffer zone to safeguard China's maritime rights and interests.

  19. Messinian events in the Black Sea

    NARCIS (Netherlands)

    van Baak, Christiaan G C; Radionova, Eleanora P.; Golovina, Larisa A.; Raffi, Isabella; Kuiper, Klaudia F.; Vasiliev, Iuliana; Krijgsman, Wout

    2015-01-01

    Past hydrological interactions between the Mediterranean Sea and Black Sea are poorly resolved due to complications in establishing a high-resolution time frame for the Black Sea. We present a new greigite-based magnetostratigraphic age model for the Mio-Pliocene deposits of DSDP Hole 380/380A,

  20. 33 CFR 2.22 - Territorial sea.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Territorial sea. 2.22 Section 2... Jurisdictional Terms § 2.22 Territorial sea. (a) With respect to the United States, the following apply— (1) Territorial sea means the waters, 12 nautical miles wide, adjacent to the coast of the United States...

  1. Biogeographic classification of the Caspian Sea

    DEFF Research Database (Denmark)

    Fendereski, F.; Vogt, M.; Payne, Mark

    2014-01-01

    using the Hierarchical Agglomerative Clustering (HAC) method. From an initial set of 12 potential physical variables, 6 independent variables were selected for the classification algorithm, i.e., sea surface temperature (SST), bathymetry, sea ice, seasonal variation of sea surface salinity (DSSS), total...... confirms the relevance of the ecoregions as proxies for habitats with common biological characteristics....

  2. 50 CFR 223.205 - Sea turtles.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Sea turtles. 223.205 Section 223.205... Threatened Marine and Anadromous Species § 223.205 Sea turtles. (a) The prohibitions of section 9 of the Act (16 U.S.C. 1538) relating to endangered species apply to threatened species of sea turtle, except...

  3. Redescription of the sea anemone Bunodeopsis Pelagica

    NARCIS (Netherlands)

    Fisher, Elaine

    1976-01-01

    There are two species of sea anemone occurring on the floating sea weed Sargassum natans in the Caribbean sea: Bunodeopsis pelagica (Quoy & Gaimard) and Anemonia sargassensis Hargitt. The anemones are readily distinguished from one another by their colour and the nature of their tentacles. B.

  4. OW NASA SeaWIFS Ocean Color

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The dataset contains satellite-derived sea-surface ocean color (chlorophyll-a) measurements collected by means of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS)...

  5. [Comparative analysis of sea-ice diatom species composition in the seas of Russian Arctic].

    Science.gov (United States)

    Il'iash, L V; Zhitina, L S

    2009-01-01

    Comparative analysis of species composition of ice diatom algae (IDA) of the White, Barents, Kara, Laptev, East Siberian, Chukchi Seas and the Basin of the Arctic Ocean was conducted on the basis of both original and published data. Species composition of IDA counts 567 taxa including 122 centric and 446 pennate diatoms. The freshwater algae composed about 18% of the total species number. In the White Sea, IDA were the most numerous (272 taxa), in the Kara Sea they are the least numerous (57 taxa). The species compositions in different seas differ significantly from each other. Similarity of IDA was consistent with the Arctic Ocean circulation and ice drift. IDA of Chukchi, East Siberian and Laptev Seas are the most similar, as are IDA of White and Kara Seas. Similarity of IDA of Chukchi Sea to those of other seas decrease in the west direction. IDA species differences between regions within one sea could be greater than those between different seas.

  6. Radar for Mapping Sea Ice

    Science.gov (United States)

    Barath, F. T.; Jordan, R. L.

    1983-01-01

    X-band system has 100-m2 resolution. Wide swath imaging radar of synthetic aperature type transmits signal to ground station for subsequent processing into imagery. Concept meets functional requirements for continuously mapping sea ice in north and south polar regions.

  7. Performance and sickness at sea

    NARCIS (Netherlands)

    Bos, J.E.; Bles, W.

    2000-01-01

    Human performance at sea generally decreases with increasing severity of seasickness. Seasickness predictions can be made, be it that motions are assumed to be translational along a vertical axis only and sinusoidal. Here, a deterministic model is presented based on physiological knowledge of the ve

  8. Chicken Porridge with Sea Cucumber

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    Main ingredients: 50 grams of chicken breast, 200 grams of gray sea cucumbers Supplementary ingredients: 100 grams of water chestnut, the whites of four eggs, MSG, salt, wine, meat soup, starch, sugar, scallions, ginger, soy sauce Directions: Chop up the chicken breast and water chestnut into small

  9. IAHR List of Sea Parameters

    DEFF Research Database (Denmark)

    Frigaard, Peter; Helm-Petersen, J; Klopman, G.

    1997-01-01

    A Working Group on multidirectional waves formed by the International Association for Hydraulic Research has proposed an update of the IAHR List of Sea State Parameters from 1986 in the part concerning directional. Especially wave structure interaction with reflection of the waves have been treated....

  10. The Sea Ice Board Game

    Science.gov (United States)

    Bertram, Kathryn Berry

    2008-01-01

    The National Science Foundation-funded Arctic Climate Modeling Program (ACMP) provides "curriculum resource-based professional development" materials that combine current science information with practical classroom instruction embedded with "best practice" techniques for teaching science to diverse students. The Sea Ice Board…

  11. Climate change challenges for SEA

    DEFF Research Database (Denmark)

    Larsen, Sanne Vammen

    This paper takes a theoretical perspective on the challenges that climate changes pose for SEA. The theoretical framework used is the sociologist Ulrich Beck’s theory of risk society and the aspects that characterise this society. Climate change is viewed as a risk, and the theory is used to derive...

  12. The Sea Ice Board Game

    Science.gov (United States)

    Bertram, Kathryn Berry

    2008-01-01

    The National Science Foundation-funded Arctic Climate Modeling Program (ACMP) provides "curriculum resource-based professional development" materials that combine current science information with practical classroom instruction embedded with "best practice" techniques for teaching science to diverse students. The Sea Ice Board…

  13. Chaetognatha of the Andaman Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, V.R.; Achuthankutty, C.T.; Nair, S.R.S.; Madhupratap, M.

    Chaetognatha of the Andaman Sea were studied during 51 and 52 cruises of R.V Gaveshani (Jan to Feb 1979) The area between southeast of Andaman island and north of Nicobar island had relatively higher density Total population of chaetognaths ranged...

  14. Generic Hurricane Extreme Seas State

    DEFF Research Database (Denmark)

    Wehmeyer, Christof; Skourup, Jesper; Frigaard, Peter

    2012-01-01

    the US east coast and the Gulf of Mexico (1851 - 2009) and Japanese east coast (1951 -2009) form the basis for Weibull extreme value analyses to determine return period respective maximum wind speeds. Unidirectional generic sea state spectra are obtained by application of the empirical models...

  15. Meiofauna of the Andaman Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Ansari, Z.A.; Parulekar, A.H.

    Total meiofauna of the Andaman Sea, in the depth range 30-2150m was between 68 and 438/10cm2 (X-bar = 247.8). The biomass was within the range 3.57 and 32.8mg/10cm 2 (X-bar = 14.46). faunal components were maximum in sandy sediments which contained...

  16. Past and present Aral Sea

    Science.gov (United States)

    Dukhovniy, Viktor; Stulina, Galina; Eshchanov, Odylbek

    2013-04-01

    The tragedy of disappearing of Aral Sea is well known to the World. Before and after collapse of Soviet Union, a huge quantity of scientific and popular editions described with grief the situation around the Aral Sea. After the NIS states became independent, World Bank, UNDP, UNEP in proper competition with each other had provided some assessment of the situation through presentation of some small and medium grants, but after 2000, the local population remained alone with own problems. Although on the eyes of the present generation a unique transformation of great water body into deserts took place, the global scientific community did not find forces and financing for real and detail investigation of the processes accompanying the Sea shrinking and land formation. We should acknowledge and give big respect to NATO, later to German Government that through GTZ (now GIZ) - German International Collaboration Agency - and GFZ (Potzdam) paid attention to this area of environment crisis and organized scientific and protective design in the so-called Priaralie - the territory around the drying Sea and delta of the two rivers - Amudarya and Syrdarya. Thank to this assistance, the local specialists in collaboration with limited a number of foreign scientists (N.Aladin, P.Zavialov, Joop de Schutter, Hans Wilps, Hedi Oberhansli) organized significant works for detail socioeconomic, ecological and hydrological assessment situation in Priaralie and on the Aral sea coast. On this base, Ministry of Agriculture and Water resources of Uzbekistan and State Committee of Water resources of Kazakhstan developed a plan of rehabilitation of Amudarya and Syrdarya deltas and started implementation of these projects. If Kazakh water authority moved ahead in wetland restoration faster, a forestation of delta and drying bed of Aral Sea got big success in Uzbek territory. 244 thousands hectares of saxsaul and tamarix were planted for protection of the Priaralie. By request of GTZ SIC, ICWC

  17. Salton Sea Ecosystem Monitoring Project

    Science.gov (United States)

    Miles, A. Keith; Ricca, Mark A.; Meckstroth, Anne; Spring, Sarah E.

    2009-01-01

    The Salton Sea is critically important for wintering and breeding waterbirds, but faces an uncertain future due to water delivery reductions imposed by the Interstate and Federal Quantification Settlement Agreement of 2003. The current preferred alternative for wetland restoration at the Salton Sea is saline habitat impoundments created to mitigate the anticipated loss of wetland habitat. In 2006, a 50-hectare experimental complex that consisted of four inter-connected, shallow water saline habitat ponds (SHP) was constructed at the southeastern shoreline of the Salton Sea and flooded with blended waters from the Alamo River and Salton Sea. The present study evaluated ecological risks and benefits of the SHP concept prior to widespread restoration actions. This study was designed to evaluate (1) baseline chemical, nutrient, and contaminant measures from physical and biological constituents, (2) aquatic invertebrate community structure and colonization patterns, and (3) productivity of and contaminant risks to nesting waterbirds at the SHP. These factors were evaluated and compared with those of nearby waterbird habitat, that is, reference sites.

  18. Climate change challenges for SEA

    DEFF Research Database (Denmark)

    Larsen, Sanne Vammen

    This paper takes a theoretical perspective on the challenges that climate changes pose for SEA. The theoretical framework used is the sociologist Ulrich Beck’s theory of risk society and the aspects that characterise this society. Climate change is viewed as a risk, and the theory is used to derive...

  19. Sunlight, Sea Ice, and the Ice Albedo Feedback in a Changing Arctic Sea Ice Cover

    Science.gov (United States)

    2015-09-30

    the Arctic Ocean and surrounding seas, with particular emphasis on the Chukchi and Beaufort Seas. Some of the largest changes to the sea ice cover are...Changing Arctic Sea Ice Cover Don Perovich ERDC – CRREL 72 Lyme Road Hanover, NH 03755 Phone: 603-646-4255 Email: donald.k.perovich...quantitative understanding of the partitioning of solar radiation by the Arctic sea ice cover and its impact on the heat and mass balance of the ice and upper

  20. Facing up to sea rise.

    Science.gov (United States)

    Pernetta, J

    1994-01-01

    A milder and less extreme climate, abundance of fish and mollusks, transport and communication, and fertile land at low altitudes have drawn humans to coastal areas and river valleys for centuries. More than 60% of the world's population occupy the 150 km closest to the coast. Millions of tourists come to coastlines and small tropical islands for recreation. About 80% of the global fish supply originates from the 19 km closest to the shore. Fish are the only protein source for the rapidly growing populations in many developing countries. Global climate change is increasing the sea level so much that by 2050, the mean increase will be about 38 cm (24-52 cm). The Intergovernmental Panel on Climate Change (IPCC) notes that the effects of sea level rise will differ from place to place. Direct effects are flooding of low-lying coastal areas and increased erosion rates. An indirect effect includes higher water tables and intrusion of saline water into aquifers, resulting in loss of fresh ground water resources. These effects may make coastal areas less suitable for settlement and agriculture. Coral sand settled on top of coral reefs makes up the unstable, small atoll islands of the Pacific and Indian Oceans. People on these islands depend almost entirely on the sea for their livelihood and on the small amount of fresh water with which they grow root crops and drink. Rising sea levels also threaten low lying countries, e.g., Bangladesh, and densely populated deltas, e.g., the Nile. Changes in the frequency and severity of flooding will increase Bangladesh's dependence on foreign aid. IPCC sees 3 possible responses to the rising sea level: defense, retreat, and accommodation. Accommodation is the only practical choice for many developing countries. A switch from rice cultivation to mariculture of prawns and fish is an example of accommodation. We need to more completely understand the natural processes in coastal environments to be better prepared for climate change.

  1. Temperature, Salinity, Oxygen, Phosphate, pH and Alkalinity data collected in the North Atlantic Ocean, Baltic Sea, Barents Sea, Greenland Sea, North Sea, Norwegian Sea and White Sea from R/Vs Artemovsk, Atlantida, Okeanograf, Professor Rudovits, and ice observations, 1957 - 1995 (NODC Accession 0073674)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, Salinity, Oxygen, Phosphate, pH and Alkalinity data collected in the North Atlantic Ocean, Baltic Sea, Barents Sea, Greenland Sea, North Sea, Norwegian...

  2. Thermal biology of sea snakes and sea kraits.

    Science.gov (United States)

    Heatwole, Harold; Grech, Alana; Monahan, John F; King, Susan; Marsh, Helene

    2012-08-01

    Temperature probably had no direct effect on the evolution of sea kraits within their center of origin, a geologically stable thermal zone straddling the equator, but may have indirectly affected expansions and contractions in distributions beyond that zone through global fluctuations that caused alternation of higher and lower sea levels. The northern limit of the Laticauda colubrina complex seems to be the 20°C isotherm; in the south, the range does not reach that isotherm because there is no land (also a habitat requirement of sea kraits) within the zone of suitable temperature. The relationship of temperature to the pattern of geographic variation in morphology supports either the hypothesis of peripheral convergence or the developmental hypothesis but does not distinguish between them. Quadratic surfaces relating cumulative scores for coloration and morphological characters to global position showed a strong latitudinal component and an even stronger longitudinal one in which the direction of the latitudinal effect was reversed between east and west. A multivariate analysis revealed that while morphological characters vary significantly by location and climate when tested separately, when the influence of location on morphology is taken into account, no residual relationship between climate and morphology remains. Most marine snakes have mean upper temperature tolerances between 39°C and 40°C and operate at temperatures much nearer their upper thermal limits than their lower limits but still avoid deleterious extremes by diving from excessively hot water to deeper, cooler strata, and by surfacing when water is cold. At the surface in still water in sunlight, Pelamis can maintain its body temperature slightly above that of the water, but whether this is significant in nature is questionable. As temperature falls below 18-20°C, survival time is progressively reduced, accompanied by the successive occurrence of cessation of feeding, cessation of swimming, and

  3. Jet formation at the sea ice edge

    Science.gov (United States)

    Feltham, D. L.; Heorton, H. D.

    2014-12-01

    The sea ice edge presents a region of many feedback processes between the atmosphere, ocean and sea ice, which are inadequately represented in current climate models. Here we focus on on-ice atmospheric and oceanic flows at the sea ice edge. Mesoscale jet formation due to the Coriolis effect is well understood over sharp changes in surface roughness such as coastlines. This sharp change in surface roughness is experienced by the atmosphere flowing over, and ocean flowing under, a compacted sea ice edge. We have studied a dynamic sea ice edge responding to atmospheric and oceanic jet formation. The shape and strength of atmospheric and oceanic jets during on-ice flows is calculated from existing studies of the sea ice edge and prescribed to idealised models of the sea ice edge. An idealised analytical model of sea ice drift is developed and compared to a sea ice climate model (the CICE model) run on an idealised domain. The response of the CICE model to jet formation is tested at various resolutions. We find that the formation of atmospheric jets during on-ice winds at the sea ice edge increases the wind speed parallel to the sea ice edge and results in the formation of a sea ice edge jet. The modelled sea ice edge jet is in agreement with an observed jet although more observations are needed for validation. The increase in ice drift speed is dependent upon the angle between the ice edge and wind and can result in a 40% increase in ice transport along the sea ice edge. The possibility of oceanic jet formation during on-ice currents and the resultant effect upon the sea ice edge is less conclusive. Observations and climate model data of the polar oceans has been analysed to show areas of likely atmospheric jet formation, with the Fram Strait being of particular interest.

  4. Global Warming and Caspian Sea Level Fluctuations

    CERN Document Server

    Ardakanian, Reza

    2013-01-01

    Coastal regions have a high social, economical and environmental importance. Due to this importance the sea level fluctuations can have many bad consequences. In this research the correlation between the increasing trend of temperature in coastal stations due to Global Warming and the Caspian Sea level has been established. The Caspian Sea level data has been received from the Jason-1 satellite. It was resulted that the monthly correlation between the temperature and sea level is high and also positive and almost the same for all the stations. But the yearly correlation was negative. It means that the sea level has decreased by the increase in temperature.

  5. Deep-sea fungi: Occurrence and adaptations

    Digital Repository Service at National Institute of Oceanography (India)

    Damare, S.

    in it being the least understood environments on the earth. The understanding of deep sea will unravel a lot of exciting information about the history of life existing on earth. The deep sea was thought to be a very difficult environment for life forms.... Danovaro R, Fabiano M, Della Croce N (1995) Labile organic matter and microbial biomasses in deep-sea sediments (Eastern Mediterranean Sea). Deep-Sea Research I, 40: 953-65. DasSarma S, Arora P (2001) Halophiles. Encyclopedia of Life Sciences. Macmillan...

  6. Ecological consequences of sea-ice decline.

    Science.gov (United States)

    Post, Eric; Bhatt, Uma S; Bitz, Cecilia M; Brodie, Jedediah F; Fulton, Tara L; Hebblewhite, Mark; Kerby, Jeffrey; Kutz, Susan J; Stirling, Ian; Walker, Donald A

    2013-08-02

    After a decade with nine of the lowest arctic sea-ice minima on record, including the historically low minimum in 2012, we synthesize recent developments in the study of ecological responses to sea-ice decline. Sea-ice loss emerges as an important driver of marine and terrestrial ecological dynamics, influencing productivity, species interactions, population mixing, gene flow, and pathogen and disease transmission. Major challenges in the near future include assigning clearer attribution to sea ice as a primary driver of such dynamics, especially in terrestrial systems, and addressing pressures arising from human use of arctic coastal and near-shore areas as sea ice diminishes.

  7. On the Sea, From the Sea, Of the Sea: The Physics of maritime Governance

    Science.gov (United States)

    James, Royce; Page, Eric

    2014-03-01

    The United States Coast Guard Academy Physics Section is proud to present our initial conceptions of ``On the Sea, From the Sea, Of the Sea: The Physics of Maritime Governance,'' a program funded by an APS Outreach Grant in 2013. In our classes, the Physics Section has focused on active student engagement for the past ten years. Recently, we have refined our program to make heavy use of Interactive Lecture Demonstrations (ILDs) and our own highly interactive adaptation which we call Interactive Lecture Labs (ILLs). ``On the Sea'' is a unique opportunity to investigate their use in a different learning modality from our standard college level military academic use. Multigenerational science, technology, engineering, and mathematics (STEM) projects are a prolific source of academic discourse, while learning through play has been touted as an effective learning tool. We plan to investigate group and individual participation, intragroup communication, demographics, and prior skill (or education) in comparison to outcomes in learning objectives through projects designed to educate the Coast Guard Academy and surrounding community on the physics of the Coast Guard's missions. Progress on the lab and demonstration designs, community participation, and our emerging ILL and ILD pedagogical methods, will be reported.

  8. Deglacial sea level history of the East Siberian Sea and Chukchi Sea margins

    Science.gov (United States)

    Cronin, Thomas M.; O'Regan, Matt; Pearce, Christof; Gemery, Laura; Toomey, Michael; Semiletov, Igor; Jakobsson, Martin

    2017-09-01

    Deglacial (12.8-10.7 ka) sea level history on the East Siberian continental shelf and upper continental slope was reconstructed using new geophysical records and sediment cores taken during Leg 2 of the 2014 SWERUS-C3 expedition. The focus of this study is two cores from Herald Canyon, piston core SWERUS-L2-4-PC1 (4-PC1) and multicore SWERUS-L2-4-MC1 (4-MC1), and a gravity core from an East Siberian Sea transect, SWERUS-L2-20-GC1 (20-GC1). Cores 4-PC1 and 20-GC were taken at 120 and 115 m of modern water depth, respectively, only a few meters above the global last glacial maximum (LGM; ˜ 24 kiloannum or ka) minimum sea level of ˜ 125-130 meters below sea level (m b.s.l.). Using calibrated radiocarbon ages mainly on molluscs for chronology and the ecology of benthic foraminifera and ostracode species to estimate paleodepths, the data reveal a dominance of river-proximal species during the early part of the Younger Dryas event (YD, Greenland Stadial GS-1) followed by a rise in river-intermediate species in the late Younger Dryas or the early Holocene (Preboreal) period. A rapid relative sea level rise beginning at roughly 11.4 to 10.8 ka ( ˜ 400 cm of core depth) is indicated by a sharp faunal change and unconformity or condensed zone of sedimentation. Regional sea level at this time was about 108 m b.s.l. at the 4-PC1 site and 102 m b.s.l. at 20-GC1. Regional sea level near the end of the YD was up to 42-47 m lower than predicted by geophysical models corrected for glacio-isostatic adjustment. This discrepancy could be explained by delayed isostatic adjustment caused by a greater volume and/or geographical extent of glacial-age land ice and/or ice shelves in the western Arctic Ocean and adjacent Siberian land areas.

  9. Sea ice thickness and recent Arctic warming

    Science.gov (United States)

    Lang, Andreas; Yang, Shuting; Kaas, Eigil

    2017-01-01

    The climatic impact of increased Arctic sea ice loss has received growing attention in the last years. However, little focus has been set on the role of sea ice thickness, although it strongly determines surface heat fluxes. Here ensembles of simulations using the EC-Earth atmospheric model (Integrated Forecast System) are performed and analyzed to quantify the atmospheric impacts of Arctic sea ice thickness change since 1982 as revealed by the sea ice model assimilation Global Ice-Ocean Modeling and Assimilation System. Results show that the recent sea ice thinning has significantly affected the Arctic climate, while remote atmospheric responses are less pronounced owing to a high internal atmospheric variability. Locally, the sea ice thinning results in enhancement of near-surface warming of about 1°C per decade in winter, which is most pronounced over marginal sea ice areas with thin ice. This leads to an increase of the Arctic amplification factor by 37%.

  10. Episodic sea-floor spreading in the Southern Red Sea

    Science.gov (United States)

    Almalki, Khalid A.; Betts, Peter G.; Ailleres, Laurent

    2014-03-01

    The Red Sea represents the most spectacular example of a juvenile ocean basin on the modern Earth. Synthesis of regional aeromagnetic data, gravity data, seismic refraction data coupled with structural mapping from the Farasan Islands suggest that the opening of the Red Sea is complex and episodic. Modeling of magnetic and gravity data constrained by seismic refraction data reveals the Arabian Shelf is underlain by oceanic and transitional crust and that mafic diking and intrusions are focused at the continental-transitional crust boundary. This relationship is interpreted to indicate that early Miocene diking along the Arabian Escarpment heralded termination of oceanic basin formation and a shift in the locus of extension focused from a central mid-ocean ridge spreading center to the continental-transitional crust zone. Uplift along the Arabian Escarpment caused erosion and Middle to Late Miocene sedimentation of the Farasan Bank onto existing oceanic crust, suggesting that the extensive sedimentary banks of the southern Red Sea are not passive margins. Re-initiation of spreading occurred at ca 5 Ma. Pliocene to Pleistocene Shelf reef systems (Farasan Islands), developed on the flanks of the spreading ridge, are extensively overprinted by normal faults, suggesting that not all crustal extension is accommodated by active spreading.

  11. Variability and Trends in Sea Ice Extent and Ice Production in the Ross Sea

    Science.gov (United States)

    Comiso, Josefino; Kwok, Ronald; Martin, Seelye; Gordon, Arnold L.

    2011-01-01

    Salt release during sea ice formation in the Ross Sea coastal regions is regarded as a primary forcing for the regional generation of Antarctic Bottom Water. Passive microwave data from November 1978 through 2008 are used to examine the detailed seasonal and interannual characteristics of the sea ice cover of the Ross Sea and the adjacent Bellingshausen and Amundsen seas. For this period the sea ice extent in the Ross Sea shows the greatest increase of all the Antarctic seas. Variability in the ice cover in these regions is linked to changes in the Southern Annular Mode and secondarily to the Antarctic Circumpolar Wave. Over the Ross Sea shelf, analysis of sea ice drift data from 1992 to 2008 yields a positive rate of increase in the net ice export of about 30,000 sq km/yr. For a characteristic ice thickness of 0.6 m, this yields a volume transport of about 20 cu km/yr, which is almost identical, within error bars, to our estimate of the trend in ice production. The increase in brine rejection in the Ross Shelf Polynya associated with the estimated increase with the ice production, however, is not consistent with the reported Ross Sea salinity decrease. The locally generated sea ice enhancement of Ross Sea salinity may be offset by an increase of relatively low salinity of the water advected into the region from the Amundsen Sea, a consequence of increased precipitation and regional glacial ice melt.

  12. Relationship between Hadley circulation and sea ice extent in the Bering Sea

    Institute of Scientific and Technical Information of China (English)

    ZHOU BoTao; WANG HuiJun

    2008-01-01

    The linkage between Hadley circulation (HC) and sea ice extent in the Bering Sea during March-April is investigated through an analysis of observed data in this research. It is found that HC is negatively correlated to the sea ice extent in the Bering Sea, namely, strong (weak) HC is corresponding to less (more) sea ice in the Bering Sea. The present study also addresses the large-scale atmospheric general circulation changes underlying the relationship between HC and sea ice in the Bering Sea. It follows that a positive phase of HC corresponds to westward located Aleutian low, anomalous southerlies over the eastern North Pacific and higher temperature in the Bering Sea, providing unfavorable atmospheric and thermal conditions for the sea ice forming, and thus sea ice extent in the Bering Sea is decreased, and vice versa. In addition, it is further identified that East Asian-North Pacific-North America telecon-nection may play an important role in linking HC and changes of atmospheric circulations as well as sea ice in the Bering Sea.

  13. Micromechanics of Sea Urchin spines.

    Directory of Open Access Journals (Sweden)

    Naomi Tsafnat

    Full Text Available The endoskeletal structure of the Sea Urchin, Centrostephanus rodgersii, has numerous long spines whose known functions include locomotion, sensing, and protection against predators. These spines have a remarkable internal microstructure and are made of single-crystal calcite. A finite-element model of the spine's unique porous structure, based on micro-computed tomography (microCT and incorporating anisotropic material properties, was developed to study its response to mechanical loading. Simulations show that high stress concentrations occur at certain points in the spine's architecture; brittle cracking would likely initiate in these regions. These analyses demonstrate that the organization of single-crystal calcite in the unique, intricate morphology of the sea urchin spine results in a strong, stiff and lightweight structure that enhances its strength despite the brittleness of its constituent material.

  14. Sea Power. Quickscan; Zeekracht. Quickscan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-08-15

    The Dutch Stichting Natuur en Milieu (The Netherlands Foundation for Nature and Environment - SNM) takes the view that the long time span between application for a permit and the realization of offshore wind parks in the North Sea is the result of unnecessary bureaucracy. Therefore SNM has asked the Kafka Brigade to list the procedures for construction of offshore wind parks in the North Sea that might be causing these delays. [mk]. [Dutch] de Stichting Natuur en Milieu (SNM) is van mening dat de oorzaak van de lange doorlooptijd die ligt tussen het aanvragen van een vergunning en de realisatie van offshore windparken in de Noordzee ligt in de onnodige bureaucratie. SNM heeft daarom de Kafkabrigade gevraagd een inventarisatie te maken van procedures rond het bouwen van offshore windmolenparken in de Noordzee die mogelijk vertragend kunnen werken.

  15. Generic Hurricane Extreme Seas State

    DEFF Research Database (Denmark)

    Wehmeyer, Christof; Skourup, Jesper; Frigaard, Peter

    2012-01-01

    Extreme sea states, which the IEC 61400-3 (2008) standard requires for the ultimate limit state (ULS) analysis of offshore wind turbines are derived to establish the design basis for the conceptual layout of deep water floating offshore wind turbine foundations in hurricane affected areas...... data is required for a type specific conceptual design. ULS conditions for different return periods are developed, which can subsequently be applied in siteindependent analysis and conceptual design. Recordings provided by National Oceanic and Atmospheric Administration (NOAA), of hurricanes along...... for hurricane generates seas by Young (1998, 2003, and 2006), requiring maximum wind speeds, forward velocity and radius to maximum wind speed. An averaged radius to maximum sustained wind speeds, according to Hsu et al. (1998) and averaged forward speed of cyclonic storms are applied in the initial state...

  16. Mind the gap in SEA

    DEFF Research Database (Denmark)

    Larsen, Sanne Vammen; Kørnøv, Lone; Wejs, Anja

    2012-01-01

    and discussed, mainly based on Scott's theory of institutions. The institutional analysis highlights a regulatory element, since the assessment of climate change synergies is underpinned by legislation, but not by guidance. This means that great focus is on normative elements such as the local interpretation...... of legislation and of climate change mitigation and adaptation. The analysis also focuses on how the fragmentation of the organisation in which climate change and SEA are embedded has bearings on both normative and cultural–cognitive elements. This makes the assessment of synergies challenging. The evidence......This article takes its point of departure in two approaches to integrating climate change into Strategic Environmental Assessment (SEA): Mitigation and adaptation, and in the fact that these, as well as the synergies between them and other policy areas, are needed as part of an integrated...

  17. Open Ocean Bilging, Arabian Sea

    Science.gov (United States)

    1989-01-01

    These dual oil slicks on the ocean surface are the result of tanker ships flushing their tanks (bilging) in the Arabian Sea (18.5N, 62.5E). These two ships flushed out their bilges, apparently contaminated with bunker oil, leaving oily residues on the ocean's surface. One wake, believed to have been done earlier than the other, has been broadened by the effects of surface winds and current.

  18. Chicken Porridge with Sea Cucumber

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    Chicken Porridge with Sea Cucumber is a dish created according to a well-known story about Jia Chang, who raised cocks during the Tang Dynasty. Cockfighting was popular among commonfolk during the Tang Dynasty. Emperor Xuanzong selected 5,000 cocks in Chang’an, and 500 children to feed them and train them to fight. Jia Chang was one of the children. Sent to the

  19. Coastal and Semi Enclosed Seas

    Science.gov (United States)

    2016-06-07

    Numerical model process and sensitivity studies are conducted to better understand the dynamics and thermodynamics of shallow and deep semi-enclosed seas...provision of law , no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently...Navy Coastal Ocean Model (NCOM) code being developed in the ONR Ocean Model Development for COAMPS project. This model was first set up on the NPAC

  20. Chemical munitions dumped at sea

    Science.gov (United States)

    Edwards, Margo; Bełdowski, Jacek

    2016-06-01

    Modern chemical warfare is a byproduct of the industrial revolution, which created factories capable of rapidly producing artillery shells that could be filled with toxic chemicals such as chlorine, phosgene and mustard agent. The trench warfare of World War I inaugurated extensive deployments of modern chemical weapons in 1915. Concomitantly, the need arose to dispose of damaged, captured or excess chemical munitions and their constituents. Whereas today chemical warfare agents (CWA) are destroyed via chemical neutralization processes or high-temperature incineration in tandem with environmental monitoring, in the early to middle 20th century the options for CWA disposal were limited to open-air burning, burial and disposal at sea. The latter option was identified as the least likely of the three to impact mankind, and sea dumping of chemical munitions commenced. Eventually, the potential impacts of sea dumping human waste were recognized, and in 1972 an international treaty, the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter, was developed to protect the marine environment from pollution caused by the dumping of wastes and other matter into the ocean. By the time this treaty, referred to as the London Convention, was signed by a majority of nations, millions of tons of munitions were known to have been disposed throughout the world's oceans.

  1. Fracture Networks in Sea Ice

    Directory of Open Access Journals (Sweden)

    Jonas Nesland Vevatne

    2014-04-01

    Full Text Available Fracturing and refreezing of sea ice in the Kara sea are investigated using complex networkanalysis. By going to the dual network, where the fractures are nodes and their intersectionslinks, we gain access to topological features which are easy to measure and hence comparewith modeled networks. Resulting network reveal statistical properties of the fracturing process.The dual networks have a broad degree distribution, with a scale-free tail, high clusteringand efficiency. The degree-degree correlation profile shows disassortative behavior, indicatingpreferential growth. This implies that long, dominating fractures appear earlier than shorterfractures, and that the short fractures which are created later tend to connect to the longfractures.The knowledge of the fracturing process is used to construct growing fracture network (GFNmodel which provides insight into the generation of fracture networks. The GFN model isprimarily based on the observation that fractures in sea ice are likely to end when hitting existingfractures. Based on an investigation of which fractures survive over time, a simple model forrefreezing is also added to the GFN model, and the model is analyzed and compared to the realnetworks.

  2. Long-term changes in nutrients and mussel stocks are related to numbers of breeding eiders Somateria mollissima at a large Baltic colony.

    Directory of Open Access Journals (Sweden)

    Karsten Laursen

    Full Text Available BACKGROUND: The Baltic/Wadden Sea eider Somateria mollissima flyway population is decreasing, and this trend is also reflected in the large eider colony at Christiansø situated in the Baltic Sea. This colony showed a 15-fold increase from 1925 until the mid-1990's, followed by a rapid decline in recent years, although the causes of this trend remain unknown. Most birds from the colony winter in the Wadden Sea, from which environmental data and information on the size of the main diet, the mussel Mytilus edulis stock exists. We hypothesised that changes in nutrients and water temperature in the Wadden Sea had an effect on the ecosystem affecting the size of mussel stocks, the principal food item for eiders, thereby influencing the number of breeding eider in the Christiansø colony. METHODOLOGY/PRINCIPAL FINDING: A positive relationship between the amount of fertilizer used by farmers and the concentration of phosphorus in the Wadden Sea (with a time lag of one year allowed analysis of the predictions concerning effects of nutrients for the period 1925-2010. There was (1 increasing amounts of fertilizer used in agriculture and this increased the amount of nutrients in the marine environment thereby increasing the mussel stocks in the Wadden Sea. (2 The number of eiders at Christiansø increased when the amount of fertilizer increased. Finally (3 the number of eiders in the colony at Christiansø increased with the amount of mussel stocks in the Wadden Sea. CONCLUSIONS/SIGNIFICANCE: The trend in the number of eiders at Christiansø is representative for the entire flyway population, and since nutrient reduction in the marine environment occurs in most parts of Northwest Europe, we hypothesize that this environmental candidate parameter is involved in the overall regulation of the Baltic/Wadden Sea eider population during recent decades.

  3. Distributions of dimethylsulfide in the Bohai Sea and Yellow Sea of China

    Institute of Scientific and Technical Information of China (English)

    HU Min; TANG Xiao-yan; LI Jin-long; MA Qi-ju

    2003-01-01

    Dimethylsulfide(DMS) measurements in the surface seawater of China eastern coastline were conducted during March 9-10, 1993 in Bohai Sea along the cruise from Dalian to Tianjin and during September 24-25, 1994 in Yellow Sea along the cruise from Shanghai to Qingdao. On the cruise in Bohai Sea DMS concentrations varied from 0. 11 to 2.63 nmol/L with an average of 1.31 nmol/L, while DMS flux Bohai Sea. DMS concentrations and fluxes had a similar spatial trend both in Bohai Sea and Yellow Sea with the correlation coefficients of 0.75 and 0.64, respectively.

  4. Sea-level variation/change and thermal contribution in the Bering Sea

    Institute of Scientific and Technical Information of China (English)

    ZUO Juncheng; ZHANG Jianli; DU Ling; LI Peiliang; LI Lei

    2005-01-01

    The long-term sea-level trend in the Bering Sea is obtained by the analysis of TOPEX/Poseidon altimeter data, including the data of two tide gauges. The averaged sea-level in the Bering Sea rises at a rate of 2.47 mm/a from 1992 to 2002. The mean sea-level is falling in the most part of the Bering Sea, especially in its central basin, and it is rising in the northeastern part of the Bering Sea. During the 1998/99 change, the sea-level anomaly differences exhibit a significant sea-level anomaly fall in the deep basin of the Bering Sea,which is roughly in the same position where a prominent SST fall exists. The maximal fall of sea-level is about 10 cm in the southwestern part of the Bering Sea, and the maximal fall of about 2℃ in the SST also appeared in the same region as the sea level did.The steric sea-level change due to temperature variations is discussed. The results are compared with the TOPEX/Poseidon altimeter data at the different spatial scales. It is indicated that the seasonal amplitude of the steric height is about 35% of the observed TOPEX/Poseidon amplitude, which is much smaller than the 83% in the mid-latitudes area. The systematic difference between the TOPEX/Poseidon data with the range of about 7.5 cm and the thermal contribution with the range of about 2.5 cm is about 5 cm. This indicates that the thermal effect on the sea level is not as important as the case in the mid-latitudes area. In the Bering Sea, the phase of the steric height leads the observed sea level by about three months.

  5. The Suspended Sediment Concentration Distribution in the Bohai Sea, Yellow Sea and East China Sea

    Institute of Scientific and Technical Information of China (English)

    BIAN Changwei; JIANG Wensheng; Richard J.Greatbatch; DING Hui

    2013-01-01

    The distribution of the suspended sediment eoncentration (SSC) in the Bohai Sea,Yellow Sea and East China Sea (BYECS) is studied based on the observed turbidity data and model simulation results.The observed turbidity results show that (i)the highest SSC is found in the coastal areas while in the outer shelf sea areas turbid water is much more difficult to observe,(ii) the surface layer SSC is much lower than the bottom layer SSC and (iii) the winter SSC is higher than the summer SSC.The Regional Ocean Modeling System (ROMS) is used to simulate the SSC distribution in the BYECS.A comparison between the modeled SSC and the observed SSC in the BYECS shows that the modeled SSC can reproduce the principal features of the SSC distribution in the BYECS.The dynamic mechanisms of the sediment erosion and transport processes are studied based on the modeled results.The horizontal distribution of the SSC in the BYECS is mainly determined by the current-wave induced bottom stress and the fine-grain sediment distribution.The current-induced bottom stress is much higher than the wave-induced bottom stress,which means the tidal currents play a more significant role in the sediment resuspension than the wind waves.The vertical mixing strength is studied based on the mixed layer depth and the turbulent kinetic energy distribution in the BYECS.The strong winter time vertical mixing,which is mainly caused by the strong wind stress and surface cooling,leads to high surface layer SSC in winter.High surface layer SSC in summer is restricted in the coastal areas.

  6. Aerial Surveys of Endangered Whales in the Beaufort Sea, Chukchi Sea, and Northern Bering Sea.

    Science.gov (United States)

    1981-06-01

    16 Surveys of St Lawrence Island Nome to Point Barrow . . . 16 I Surveys of Barrow Area . . 18 Point Barrow to Deadhorse . . . 20 Surveys from...lease area, the Norton Basin - St . Lawrence Island area, the Hope Basin, and coastal portions of the Chukchi Sea. DESIGN The areas of study are listed...Bowhead Whale 314 857 Balaena mysticetus Beluga Whale** 284 3404 Delphinapterus leucas Gray Whale 2 6 Eschrichtius robustus Ring Seal 250 765 Phoca

  7. [Distribution and air-sea fluxes of methane in the Yellow Sea and the East China Sea in the spring].

    Science.gov (United States)

    Cao, Xing-Peng; Zhang, Gui-Ling; Ma, Xiao; Zhang, Guo-Ling; Liu, Su-Mei

    2013-07-01

    A survey was carried out in the Yellow Sea and the East China Sea from March 17 to April 06 of 2011. Dissolved CH4 in various depths were measured and sea-to-air fluxes were estimated. Methane concentrations in surface and bottom waters ranged between 2.39-29.67 nmol x L(-1) and 2.63-30.63 nmol x L(-1), respectively. Methane concentrations in bottom waters were slightly higher than those in surface waters, suggesting the existence of methane source in bottom waters or sediments. The horizontal distribution of dissolved CH4 showed a decrease from the river mouth to the open sea, and was influenced by the freshwater discharge and the Kuroshio intrusion. Surface methane saturations ranged from 93%-1 038%. Sea to air CH4 fluxes were (2.85 +/- 5.11) micromol x (m2 x d)(-1) (5.18 +/- 9.99) micromol x (m2 x d)(-1) respectively, calculated using the Liss and Merlivat (LM86), the Wanninkhof (W92) relationships and in situ wind speeds, and estimated emission rates of methane from the East China Sea and the Yellow Sea range from 7.05 x 10(-2) - 12.0 x 10(-2) Tg x a(-1) and 1.17 x 10(-2) - 2.20 x 10(-2) Tg x a(-1), respectively. The Yellow Sea and East China Sea are the net sources of atmospheric methane in the spring.

  8. Physics of the nucleon sea quark distributions

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, R.

    2000-03-10

    Sea quark distributions in the nucleon have naively been expected to be generated perturbatively by gluon splitting. In this case, there is no reason for the light quark and anti-quark sea distributions to be different. No asymmetries in the strange or heavy quark sea distributions are predicted in the improved parton model. However,recent experiments have called these naive expectations into question. A violation of the Gottfried sum rule has been measured in several experiments, suggesting that (bar u) < (bar d) in the proton. Additionally, other measurements, while not definitive, show that there may be an asymmetry in the strange and anti-strange quark sea distributions. These effects may require nonperturbative explanations. In this review we first discuss the perturbative aspects of the sea quark distributions. We then describe the experiments that could point to nonperturbative contributions to the nucleon sea. Current phenomenological models that could explain some of these effects are reviewed.

  9. Sea ice, climate, and multiscale composites

    Science.gov (United States)

    Golden, Kenneth

    2014-03-01

    In September of 2012, the area of the Arctic Ocean covered by sea ice reached its lowest level ever recorded in more than three decades of satellite measurements. In fact, compared to the 1980's and 1990's, this represents a loss of more than half of the summer Arctic sea ice pack. While global climate models generally predict sea ice declines over the 21st century, the precipitous losses observed so far have significantly outpaced most projections. I will discuss how mathematical models of composite materials and statistical physics are being used to study key sea ice processes and advance how sea ice is represented in climate models. This work is helping to improve projections of the fate of Earth's ice packs, and the response of polar ecosystems. A brief video of a recent Antarctic expedition where sea ice properties were measured will be shown. Supported by NSF and ONR.

  10. Microplastic pollution in deep-sea sediments.

    Science.gov (United States)

    Van Cauwenberghe, Lisbeth; Vanreusel, Ann; Mees, Jan; Janssen, Colin R

    2013-11-01

    Microplastics are small plastic particles (microplastics have been accumulating in the marine environment for decades and have been detected throughout the water column and in sublittoral and beach sediments worldwide. However, up to now, it has never been established whether microplastic presence in sediments is limited to accumulation hot spots such as the continental shelf, or whether they are also present in deep-sea sediments. Here we show, for the first time ever, that microplastics have indeed reached the most remote of marine environments: the deep sea. We found plastic particles sized in the micrometre range in deep-sea sediments collected at four locations representing different deep-sea habitats ranging in depth from 1100 to 5000 m. Our results demonstrate that microplastic pollution has spread throughout the world's seas and oceans, into the remote and largely unknown deep sea.

  11. Observed variability of sea surface salinity and thermal inversions in the Lakshadweep Sea during contrast monsoons

    Digital Repository Service at National Institute of Oceanography (India)

    Gopalakrishna, V.V.; Johnson, Z.; Salgaonkar, G.; Nisha, K.; Rajan, C.K.; Rao, R.R.

    The sea surface salinity (SSS) of the Lakshadweep Sea (LS) shows large seasonal variability due to horizontal advection of low (high) salinity waters from south (north) during winter (summer) monsoon. The measurements made in the LS during...

  12. Oceanographic cruise: Coral Sea, Arafura Sea, and Java Trench, April - May 1969 (NODC Accession 7100914)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This report contains oceanographic data which was obtained aboard HMAS DIAMANTINA during an oceanographic cruise in the Coral Sea, Arafura Sea, and Java Trench...

  13. First biological measurements of deep-sea corals from the Red Sea.

    KAUST Repository

    Roder, Cornelia

    2013-10-03

    It is usually assumed that metabolic constraints restrict deep-sea corals to cold-water habitats, with \\'deep-sea\\' and \\'cold-water\\' corals often used as synonymous. Here we report on the first measurements of biological characters of deep-sea corals from the central Red Sea, where they occur at temperatures exceeding 20°C in highly oligotrophic and oxygen-limited waters. Low respiration rates, low calcification rates, and minimized tissue cover indicate that a reduced metabolism is one of the key adaptations to prevailing environmental conditions. We investigated four sites and encountered six species of which at least two appear to be undescribed. One species is previously reported from the Red Sea but occurs in deep cold waters outside the Red Sea raising interesting questions about presumed environmental constraints for other deep-sea corals. Our findings suggest that the present understanding of deep-sea coral persistence and resilience needs to be revisited.

  14. Retrieval of chlorphyll from the sea-leaving radiance in the Arbaian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Sathe, P.V.; Jadhav, N.

    Error estimates in chlorophyll retrieval in the sea from satellite data have always been higher compared to the errors in retrieval of sea surface temperature or wind speed from satellite data. This is due to the higher percentage of noise...

  15. GHRSST Level 4 ODYSSEA Mediterranean Sea Regional Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at Ifremer/CERSAT...

  16. First biological measurements of deep-sea corals from the Red Sea.

    Science.gov (United States)

    Roder, C; Berumen, M L; Bouwmeester, J; Papathanassiou, E; Al-Suwailem, A; Voolstra, C R

    2013-10-03

    It is usually assumed that metabolic constraints restrict deep-sea corals to cold-water habitats, with 'deep-sea' and 'cold-water' corals often used as synonymous. Here we report on the first measurements of biological characters of deep-sea corals from the central Red Sea, where they occur at temperatures exceeding 20°C in highly oligotrophic and oxygen-limited waters. Low respiration rates, low calcification rates, and minimized tissue cover indicate that a reduced metabolism is one of the key adaptations to prevailing environmental conditions. We investigated four sites and encountered six species of which at least two appear to be undescribed. One species is previously reported from the Red Sea but occurs in deep cold waters outside the Red Sea raising interesting questions about presumed environmental constraints for other deep-sea corals. Our findings suggest that the present understanding of deep-sea coral persistence and resilience needs to be revisited.

  17. The lowering of sea surface temperature in the east central Arabian sea associated with a cyclone

    Digital Repository Service at National Institute of Oceanography (India)

    Murty, V.S.N.; Rao, D.P.; Sastry, J.S.

    An analysis of thermal Structure in the East Central Arabian Sea associated with a moderate cyclone is presented. The heat storage and the heat budget components have been computed. Under the influence of the cyclone the Sea Surface Temperature (SST...

  18. GHRSST Level 4 EUR Mediterranean Sea Regional Foundation Sea Surface Temperature Analysis (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily by Ifremer/CERSAT (France) using optimal...

  19. Impact of sea ice initialization on sea ice and atmosphere prediction skill on seasonal timescales

    Science.gov (United States)

    Guemas, V.; Chevallier, M.; Déqué, M.; Bellprat, O.; Doblas-Reyes, F.

    2016-04-01

    We present a robust assessment of the impact of sea ice initialization from reconstructions of the real state on the sea ice and atmosphere prediction skill. We ran two ensemble seasonal prediction experiments from 1979 to 2012 : one using realistic sea ice initial conditions and another where sea ice is initialized from a climatology, with two forecast systems. During the melting season in the Arctic Ocean, sea ice forecasts become skilful with sea ice initialization until 3-5 months ahead, thanks to the memory held by sea ice thickness. During the freezing season in both the Arctic and Antarctic Oceans, sea ice forecasts are skilful for 7 and 2 months, respectively, with negligible differences between the two experiments, the memory being held by the ocean heat content. A weak impact on the atmosphere prediction skill is obtained.

  20. Sea otter health: challenging a pet hypothesis

    Science.gov (United States)

    Lafferty, Kevin D.

    2015-01-01

    A recent series of studies on tagged sea otters (Enhydra lutris nereis) challenges the hypothesis that sea otters are sentinels of a dirty ocean, in particular, that pet cats are the main source of exposure to Toxoplasma gondii in central California. Counter to expectations, sea otters from unpopulated stretches of coastline are less healthy and more exposed to parasites than city-associated otters. Ironically, now it seems that spillover from wildlife, not pets, dominates spatial patterns of disease transmission.

  1. Sea Surface Salinity : Research Challenges and Opportunities

    Science.gov (United States)

    Halpern, David; Lagerloef, Gary; Font, Jordi

    2012-01-01

    Sea surface salinity (SSS) can be important in regulating sea surface temperature (SST). Two technological breakthrough satellite SSS missions, Aquarius and Soil Moisture and Ocean Salinity (SMOS), are currently producing high-quality SSS data. This paper provides an overview of the importance of SSS for weather and climate applications and describes the Aquarius and SMOS missions. The newness of adequately sampled SSS data prompted a first-time at-sea field campaign devoted to improved understanding of SSS variations.

  2. Navigation Issues in the South China Sea

    OpenAIRE

    2005-01-01

    The South China Sea is one of the most important sea lanes with numerous competing sovereignty disputes. The freedom of navigation in this region is critical to all major trading States in the world. After an introduction to the navigational regimes of UNCLOS, this article describes the whole navigation situation in this region, by separately introducing the navigation issues in the territorial sea, straits, archipelagic waters and the Spratly area. Meanwhile, since the legal status of the ma...

  3. Physical oceanography of the Baltic Sea

    Energy Technology Data Exchange (ETDEWEB)

    Leppaeranta, Matti [Helsinki Univ. (Finland). Dept. of Physics; Myrberg, Kai [Finnish Institute of Marine Research, Helsinki (Finland)

    2009-07-01

    The Baltic Sea oceanographic research community is wide and the research history is over 100 years old. Nevertheless, there is still no single, coherent book on the physical oceanography of the Baltic Sea as a whole. There is a strong need for such a book, coming from working oceanographers as well as the university teaching programmes in advanced undergraduate to graduate levels. In the regional conference series in physical oceanography (Baltic Sea Science Conference, Baltic Sea Oceanographers' conference, Baltex-conferences) about 500 scientists take part regularly. Even more scientists work in the fields of marine biology, chemistry and the environment, and they need information on the physics of the Baltic Sea as well. There are nine countries bordering on the Baltic Sea and five more in the runoff area. The Baltic Sea as a source of fish, means of transportation and leisure activities is highly important to the regional society. In the runoff area there are a total of 85 million people. Research and protection strategies need to be developed, as the Baltic Sea is probably the most polluted sea in the world. Since the Baltic Sea has become an inner sea of the EU (apart from small shore parts of Russia in Petersburg and Kaliningrad), it is anticipated that the importance of the region will consequently rise. The book will arouse interest among students, scientists and decision makers involved with the Baltic problems. It will also give important background information for those working with biogeochemical processes in the Baltic Sea, because the physical forcing for those processes is of vital importance. (orig.)

  4. Sunlight, Sea Ice, and the Ice Albedo Feedback in a Changing Artic Sea Ice Cover

    Science.gov (United States)

    2015-11-30

    Arctic sea ice cover and its impact on the heat and mass balance of the ice and upper ocean ... Arctic Ocean and surrounding seas, with particular emphasis on the Chukchi and Beaufort Seas. Some of the largest changes to the sea ice cover are...other parts of the Arctic ice cover appear to now be accelerating. Figure 6. Maps of the linear trend of annual solar heat input to the ocean

  5. Comparison among four kinds of data of sea surface wind stress in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    谢强; 王卫强; 毛庆文

    2002-01-01

    By using remote sensing (ERS) data, FSU data, GOADS data and Hellerman & Rcsenstein objective analysis data to analyze the sea surface wind stress in the South China Sea, it is found that the remote sensing data have higher resolution and more reasonable values. Therefore we suggest that remote sensing data be chosen in the study of climatological features of sea surface wind stress and its seasonal variability in the South China Sea, especially in the study of small and middle scale eddies.

  6. Arctic tides from GPS on sea ice

    DEFF Research Database (Denmark)

    Kildegaard Rose, Stine; Skourup, Henriette; Forsberg, René

    The presence of sea-ice in the Arctic Ocean plays a significant role in the Arctic climate. Sea ice dampens the ocean tide amplitude with the result that global tidal models which use only astronomical data perform less accurately in the polar regions. This study presents a kinematic processing...... of Global Positioning System (GPS) buoys placed on sea-ice at five different sites north of Greenland for the study of sea level height and tidal analysis to improve tidal models in the Central Arctic. The GPS measurements are compared with the Arctic tidal model AOTIM-5, which assimilates tide...

  7. Dynamic Singularity Spectrum Distribution of Sea Clutter

    Science.gov (United States)

    Xiong, Gang; Yu, Wenxian; Zhang, Shuning

    2015-12-01

    The fractal and multifractal theory have provided new approaches for radar signal processing and target-detecting under the background of ocean. However, the related research mainly focuses on fractal dimension or multifractal spectrum (MFS) of sea clutter. In this paper, a new dynamic singularity analysis method of sea clutter using MFS distribution is developed, based on moving detrending analysis (DMA-MFSD). Theoretically, we introduce the time information by using cyclic auto-correlation of sea clutter. For transient correlation series, the instantaneous singularity spectrum based on multifractal detrending moving analysis (MF-DMA) algorithm is calculated, and the dynamic singularity spectrum distribution of sea clutter is acquired. In addition, we analyze the time-varying singularity exponent ranges and maximum position function in DMA-MFSD of sea clutter. For the real sea clutter data, we analyze the dynamic singularity spectrum distribution of real sea clutter in level III sea state, and conclude that the radar sea clutter has the non-stationary and time-varying scale characteristic and represents the time-varying singularity spectrum distribution based on the proposed DMA-MFSD method. The DMA-MFSD will also provide reference for nonlinear dynamics and multifractal signal processing.

  8. Quantification of ikaite in Antarctic sea ice

    Directory of Open Access Journals (Sweden)

    M. Fischer

    2012-02-01

    Full Text Available Calcium carbonate precipitation in sea ice can increase pCO2 during precipitation in winter and decrease pCO2 during dissolution in spring. CaCO3 precipitation in sea ice is thought to potentially drive significant CO2 uptake by the ocean. However, little is known about the quantitative spatial and temporal distribution of CaCO3 within sea ice. This is the first quantitative study of hydrous calcium carbonate, as ikaite, in sea ice and discusses its potential significance for the carbon cycle in polar oceans. Ice cores and brine samples were collected from pack and land fast sea ice between September and December 2007 during an expedition in the East Antarctic and another off Terre Adélie, Antarctica. Samples were analysed for CaCO3, Salinity, DOC, DON, Phosphate, and total alkalinity. A relationship between the measured parameters and CaCO3 precipitation could not be observed. We found calcium carbonate, as ikaite, mostly in the top layer of sea ice with values up to 126 mg ikaite per liter melted sea ice. This potentially represents a contribution between 0.12 and 9 Tg C to the annual carbon flux in polar oceans. The horizontal distribution of ikaite in sea ice was heterogenous. We also found the precipitate in the snow on top of the sea ice.

  9. Physicochemical Studies of the Sea Surface Microlayer.

    Science.gov (United States)

    Zhengbin; Liansheng; Zhijian; Jun; Haibing

    1998-08-15

    The sea surface microlayer and its thickness are theoretically analyzed. A multiple-layer model of the sea surface microlayer is proposed. Through in situ and laboratory imitation experiments using glass plate, rotating drum, screen, and funnel samplers, the relationships between pH, surface tension, the concentrations of dissolved trace metals Cu and Pb, phosphate, and particulate and sampling thicknesses are carefully investigated. The apparent sampling thickness of the sea surface microlayer is determined to be 50 +/- 10 µm, which is basically consistent with the mean thickness of the liquid boundary film in the models of gas exchange across the sea surface. Copyright 1998 Academic Press.

  10. On sea level - ice sheet interactions

    Science.gov (United States)

    Gomez, Natalya Alissa

    This thesis focuses on the physics of static sea-level changes following variations in the distribution of grounded ice and the influence of these changes on the stability and dynamics of marine ice sheets. Gravitational, deformational and rotational effects associated with changes in grounded ice mass lead to markedly non-uniform spatial patterns of sea-level change. I outline a revised theory for computing post-glacial sea-level predictions and discuss the dominant physical effects that contribute to the patterns of sea-level change associated with surface loading on different timescales. I show, in particular, that a large sea-level fall (rise) occurs in the vicinity of a retreating (advancing) ice sheet on both short and long timescales. I also present an application of the sea-level theory in which I predict the sea-level changes associated with a new model of North American ice sheet evolution and consider the implications of the results for efforts to establish the sources of Meltwater Pulse 1A. These results demonstrate that viscous deformational effects can influence the amplitude of sea-level changes observed at far-field sea-level sites, even when the time window being considered is relatively short (≤ 500 years). Subsequently, I investigate the feedback of sea-level changes on marine ice-sheet stability and dynamics by coupling a global sea-level model to ice-sheet models of increasing complexity. To begin, I incorporate gravitationally self-consistent sea-level changes into an equilibrium marine ice-sheet stability theory to show that the sea-level changes have a stabilizing influence on ice-sheet retreat. Next, I consider the impact of the stabilizing mechanism on the timescale of ice-sheet retreat using a 1D dynamic coupled ice sheet - sea level model. Simulations with the coupled model, which incorporate viscoelastic deformation of the solid Earth, show that local sea-level changes at the grounding line act to slow, and in some cases, halt

  11. Seasonal variability of the Caspian Sea three-dimensional circulation, sea level and air-sea interaction

    Directory of Open Access Journals (Sweden)

    R. A. Ibrayev

    2010-03-01

    Full Text Available A three-dimensional primitive equation model including sea ice thermodynamics and air-sea interaction is used to study seasonal circulation and water mass variability in the Caspian Sea under the influence of realistic mass, momentum and heat fluxes. River discharges, precipitation, radiation and wind stress are seasonally specified in the model, based on available data sets. The evaporation rate, sensible and latent heat fluxes at the sea surface are computed interactively through an atmospheric boundary layer sub-model, using the ECMWF-ERA15 re-analysis atmospheric data and model generated sea surface temperature. The model successfully simulates sea-level changes and baroclinic circulation/mixing features with forcing specified for a selected year. The results suggest that the seasonal cycle of wind stress is crucial in producing basin circulation. Seasonal cycle of sea surface currents presents three types: cyclonic gyres in December–January; Eckman south-, south-westward drift in February–July embedded by western and eastern southward coastal currents and transition type in August–November. Western and eastern northward sub-surface coastal currents being a result of coastal local dynamics at the same time play an important role in meridional redistribution of water masses. An important part of the work is the simulation of sea surface topography, yielding verifiable results in terms of sea level. The model successfully reproduces sea level variability for four coastal points, where the observed data are available. Analyses of heat and water budgets confirm climatologic estimates of heat and moisture fluxes at the sea surface. Experiments performed with variations in external forcing suggest a sensitive response of the circulation and the water budget to atmospheric and river forcing.

  12. Seasonal variability of the Caspian Sea three-dimensional circulation, sea level and air-sea interaction

    Directory of Open Access Journals (Sweden)

    R. A. Ibrayev

    2009-09-01

    Full Text Available A three-dimensional primitive equation model including sea ice thermodynamics and air-sea interaction is used to study seasonal circulation and water mass variability in the Caspian Sea under the influence of realistic mass, momentum and heat fluxes. River discharges, precipitation, radiation and wind stress are seasonally specified in the model, based on available data sets. The evaporation rate, sensible and latent heat fluxes at the sea surface are computed interactively through an atmospheric boundary layer sub-model, using the ECMWF-ERA15 re-analysis atmospheric data and model generated sea surface temperature. The model successfully simulates sea-level changes and baroclinic circulation/mixing features with forcing specified for a selected year. The results suggest that the seasonal cycle of wind stress is crucial in producing basin circulation. Seasonal cycle of sea surface currents presents three types: cyclonic gyres in December–January; Eckman south-, south-westward drift in February–July embedded by western and eastern southward coastal currents and transition type in August–November. Western and eastern northward sub-surface coastal currents being a result of coastal local dynamics at the same time play an important role in meridional redistribution of water masses. An important part of the work is the simulation of sea surface topography, yielding verifiable results in terms of sea level. Model successfully reproduces sea level variability for four coastal points, where the observed data are available. Analyses of heat and water budgets confirm climatologic estimates of heat and moisture fluxes at the sea surface. Experiments performed with variations in external forcing suggest a sensitive response of the circulation and the water budget to atmospheric and river forcing.

  13. Sea Turtle Conservation on Bonaire. Sea Turtle Club Bonaire 1997. Project Report

    NARCIS (Netherlands)

    Schuit, M.; Put, van A.L.L.M.; Valkering, N.P.; Eijck, van T.J.W.

    1998-01-01

    The Sea Turtle Club Bonaire (STCB) is a non-governmental, non-profit organization. Its main goal is the conservation of the sea turtles that occur on Bonaire. To reach this goal, annual projects are undertaken, such as research and the promotion of public awareness on sea turtle conservation. The ST

  14. Long Term Sea Level Change and Water Mass Balance in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    RONG Zengrui; LIU Yuguang; ZONG Haibo; XIU Peng

    2009-01-01

    Sea level anomalies observed by altimeter during the 1993-2006 period, thermosterie sea level anomalies estimated by using subsurface temperature data produced by Ishii and SODA reanalysis data, tide gauge records and HOAPS freshwater flux data were analyzed to investigate the long term sea level change and the water mass balance in the South China Sea. The altimeter-observed sea level showed a rising rate of (3.5±0.9)mm yr-1 during the period 1993-2006, but this figure was considered to have been highly distorted by the relatively short time interval and the large inter-decadal variability, which apparently exists in both the thermosteric sea level and the observed sea level. Long term thermosteric sea level from 1945 to 2004 gave a rising rate of 0.15±0.06 mmyr-1. Tide gauge data revealed this discrepancy and the regional distributions of the sea-level trends. Both the 'real' and the thermosteric sea level showed a good correspondence to ENSO: decreasing during E1 Nifio years and increasing during La Nina years. Amplitude and phase differences between the 'real' sea level and the thermosteic sea level were substantially revealed on both seasonal and interannual time scales. As one of the possible factors, the freshwater flux might play an important role in balancing the water mass.

  15. Sensitivity of Red Sea circulation to sea level and insolation forcing during the last interglacial

    NARCIS (Netherlands)

    Trommer, G.; Siccha, M.; Rohling, E.J.; Grant, K.; van der Meer, M.T.J.; Schouten, S.; Baranowski, U.; Kucera, M.

    2011-01-01

    This study investigates the response of Red Sea circulation to sea level and insolation changes during termination II and across the last interglacial, in comparison with termination I and the Holocene. Sediment cores from the central and northern part of the Red Sea were investigated by

  16. Authigenic gypsum in a deep sea core from Southeastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Guptha, M.V.S.

    Authigenic gypsum has been encountered in a deep sea core RC9-157 from the southeastern Arabian Sea at a depth of 4111 m which is a zone of lysocline. The formation of gypsum in the deep sea region is attributed to the prevailing sulphate rich...

  17. Sea Turtle Conservation on Bonaire. Sea Turtle Club Bonaire 1997. Project Report

    NARCIS (Netherlands)

    Schuit, M.; Put, van A.L.L.M.; Valkering, N.P.; Eijck, van T.J.W.

    1998-01-01

    The Sea Turtle Club Bonaire (STCB) is a non-governmental, non-profit organization. Its main goal is the conservation of the sea turtles that occur on Bonaire. To reach this goal, annual projects are undertaken, such as research and the promotion of public awareness on sea turtle conservation. The

  18. Morphotype patterns of Norwegian Sea deep-sea benthic foraminifera and ecological implications

    Science.gov (United States)

    Corliss, Bruce H.; Chen, Christina

    1988-08-01

    Deep-sea benthic foraminifera from Norwegian Sea surface sediments are classified into morphotypes on the basis of test shape and nature of test coiling and show distinct patterns with water depth. The morphotype data are used to determine microhabitat patterns of the foraminifera, which are suggested to be related to the organic-carbon content of the surficial deep-sea sediments.

  19. Long-term sea level change in the Malaysian seas from multi-mission altimetry data

    NARCIS (Netherlands)

    Din, A.H.; Omar, K.M.; Naeije, M.C.; Ses, S.

    2012-01-01

    The long-term sea level change during 1993 to 2008 was investigated in the Malaysian seas from satellite altimetry data of the TOPEX, JASON-1, ERS-1, ERS-2 and ENVISAT missions. Sea level data retrieval and reduction were carried out using the radar altimeter database system (RADS). In RADS data pro

  20. Sea Turtle Conservation on Bonaire. Sea Turtle Club Bonaire 1997. Project Report

    NARCIS (Netherlands)

    Schuit, M.; Put, van A.L.L.M.; Valkering, N.P.; Eijck, van T.J.W.

    1998-01-01

    The Sea Turtle Club Bonaire (STCB) is a non-governmental, non-profit organization. Its main goal is the conservation of the sea turtles that occur on Bonaire. To reach this goal, annual projects are undertaken, such as research and the promotion of public awareness on sea turtle conservation. The ST

  1. Ordenisaajate seas seisab arvukalt riigiteenistujaid

    Index Scriptorium Estoniae

    2004-01-01

    Riikliku autasu saajate nimekiri. Teenetemärgi saajate seas muusikud: Valgetähe III klass Henn Tiivel. Valgetähe IV klass Johannes Jürisson, Valeri Petrov, Aadu Regi, Helga Surva, Kalle Tamra. Valgetähe V klass Kalev Kuljus, Jaan Mikkel, Heidi Mägi, Heino Mähar, Sigrid Orusaar, Aarne Saluveer, Heli Lääts, Ludmilla Toon. Valgetähe medal Endla Jaanus, Ralf Kaup, Aadu Kukk, Tiit Köster, Heino Pehk, Tiiu Schüts

  2. Filling regulatory gaps in high seas fisheries: discrete high seas fish stocks, deep-sea fisheries and vulnerable marine ecosystems

    NARCIS (Netherlands)

    Takei, Y.

    2008-01-01

    The present study examines the legal regime of high seas fisheries with a view to identifying regulatory gaps. The main research questions are as follows: 1. What general principles are applicable to high seas fisheries?; 2. What implications do these general principles have for new challenges in th

  3. Deep-sea pollen research in China

    Institute of Scientific and Technical Information of China (English)

    SUN Xiangjun; LUO Yunli; CHEN Huaicheng

    2003-01-01

    This paper briefly presents the progress of deep-sea pollen research in China since the beginning ofninetieths of the last Century. All the deep-sea pollen contri-butions mainly come from the South China Sea (SCS) andthe East China Sea (ECS). The German-Chinese joint cruise(Sonne 95) and ODP 184 cruise initiated by Chinese scientistsin the SCS provided excellent material for the deep-sea pol-len research. So far a number of pollen results of 20-30 kaand million years from the SCS have been published. A couple of deep-sea pollen records from Okinawa Through of the ECS also came out. The high resolution pollen records obtained from the continuous deposits with high sedimentation rates and reliable age control of the deep-sea sediments provided a high time resolution history (hundred to millennial scales) of vegetation, environment and monsoon evolution of the pollen source areas (southern China and Japan). Spectral analysis of deep-sea pollen records from the SCS discovered orbital (100, 41, 23, 10 ka) and suborbital cyclicities (Heinrich and Dansgaard/Oscheger-O/D events) in the vege-tation changes. Moreover, cross spectral analysis showed that the trend of vegetation changes in northern SCS was regulated mainly by changes of the ice volume in the Northern Hemisphere. The pollen record of the last 20 ka from the Okinawa Through of the ECS indicates that the marine environmental change lagged that on the terrestrail by about 1000 year. The asynchronous environmental changes between land and sea were probably caused by the time difference in thermohaline circulation. This study underscored the role of the deep-sea plant fossils as a bridge across the land and sea.

  4. Biogeochemical Coupling between Ocean and Sea Ice

    Science.gov (United States)

    Wang, S.; Jeffery, N.; Maltrud, M. E.; Elliott, S.; Wolfe, J.

    2016-12-01

    Biogeochemical processes in ocean and sea ice are tightly coupled at high latitudes. Ongoing changes in Arctic and Antarctic sea ice domain likely influence the coupled system, not only through physical fields but also biogeochemical properties. Investigating the system and its changes requires representation of ocean and sea ice biogeochemical cycles, as well as their coupling in Earth System Models. Our work is based on ACME-HiLAT, a new offshoot of the Community Earth System Model (CESM), including a comprehensive representation of marine ecosystems in the form of the Biogeochemical Elemental Cycling Module (BEC). A full vertical column sea ice biogeochemical module has recently been incorporated into the sea ice component. We have further introduced code modifications to couple key growth-limiting nutrients (N, Si, Fe), dissolved and particulate organic matter, and phytoplankton classes that are important in polar regions between ocean and sea ice. The coupling of ocean and sea ice biology-chemistry will enable representation of key processes such as the release of important climate active constituents or seeding algae from melting sea ice into surface waters. Sensitivity tests suggest sea ice and ocean biogeochemical coupling influences phytoplankton competition, biological production, and the CO2 flux. Sea ice algal seeding plays an important role in determining phytoplankton composition of Arctic early spring blooms, since different groups show various responses to the seeding biomass. Iron coupling leads to increased phytoplankton biomass in the Southern Ocean, which also affects carbon uptake via the biological pump. The coupling of macronutrients and organic matter may have weaker influences on the marine ecosystem. Our developments will allow climate scientists to investigate the fully coupled responses of the sea ice-ocean BGC system to physical changes in polar climate.

  5. A Heavy Sea Fog Event over the Yellow Sea in March 2005:Analysis and Numerical Modeling

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, a heavy sea fog episode that occurred over the Yellow Sea on 9 March 2005 is investigated.The sea fog patch, with a spatial scale of several hundred kilometers at its mature stage, reduced visibility along the Shandong Peninsula coast to 100 m or much less at some sites. Satellite images, surface observations and soundings at islands and coasts, and analyses from the Japan Meteorology Agency (JMA) are used to describe and analyze this event. The analysis indicates that this sea fog can be categorized as advection cooling fog. The main features of this sea fog including fog area and its movement are reasonably reproduced by the Fifth-generation Pennsylvania State University/National Center for Atmospheric Research Mesoscale Model (MM5). Model results suggest that the formation and evolution of this event can be outlined as:(1) southerly warm/moist advection of low-level air resulted in a strong sea-surface-based inversion with a thickness of about 600 m; (2) when the inversion moved from the warmer East Sea to the colder Yellow Sea, a thermal internal boundary layer (TIBL) gradually formed at the base of the inversion while the sea fog grew in response to cooling and moistening by turbulence mixing; (3) the sea fog developed as the TIBL moved northward and (4) strong northerly cold and dry wind destroyed the TIBL and dissipated the sea fog. The principal findings of this study are that sea fog forms in response to relatively persistent southerly warm/moist wind and a cold sea surface, and that turbulence mixing by wind shear is the primary mechanism for the cooling and moistening the marine layer. In addition, the study of sensitivity experiments indicates that deterministic numerical modeling offers a promising approach to the prediction of sea fog over the Yellow Sea but it may be more efficient to consider ensemble numerical modeling because of the extreme sensitivity to model input.

  6. Air-sea CO2 fluxes on the Bering Sea shelf

    Directory of Open Access Journals (Sweden)

    M. A. Jeffries

    2011-05-01

    Full Text Available There have been few previous studies of surface seawater CO2 partial pressure (pCO2 variability and air-sea CO2 gas exchange rates for the Bering Sea shelf. In 2008, spring and summertime observations were collected in the Bering Sea shelf as part of the Bering Sea Ecological Study (BEST. Our results indicate that the Bering Sea shelf was close to neutral in terms of CO2 sink-source status in springtime due to relatively small air-sea CO2 gradients (i.e., ΔpCO2 and sea-ice cover. However, by summertime, very low seawater pCO2 values were observed and much of the Bering Sea shelf became strongly undersaturated with respect to atmospheric CO2 concentrations. Thus the Bering Sea shelf transitions seasonally from mostly neutral conditions to a strong oceanic sink for atmospheric CO2 particularly in the "green belt" region of the Bering Sea where there are high rates of phytoplankton primary production (PPand net community production (NCP. Ocean biological processes dominate the seasonal drawdown of seawater pCO2 for large areas of the Bering Sea shelf, with the effect partly countered by seasonal warming. In small areas of the Bering Sea shelf south of the Pribilof Islands and in the SE Bering Sea, seasonal warming is the dominant influence on seawater pCO2, shifting localized areas of the shelf from minor/neutral CO2 sink status to neutral/minor CO2 source status, in contrast to much of the Bering Sea shelf. Overall, we compute that the Bering Sea shelf CO2 sink in 2008 was 157 ± 35 Tg C yr−1 (Tg = 1012 g C and thus a strong sink for CO2.

  7. Albinistic common seals (Phoca vitulina) and melanistic grey seals (Halichoerus grypus) rehabilitated in the Netherlands

    NARCIS (Netherlands)

    Osinga, Nynke; 't Hart, Pieter; Vader, Pieter C. van Voorst

    2010-01-01

    The Seal Rehabilitation and Research Centre (SRRC) in Pieterburen, The Netherlands, rehabilitates seals from the waters of the Wadden Sea, North Sea and Southwest Delta area. Incidental observations of albinism and melanism in common and grey seals are known from countries surrounding the North Sea.

  8. A morbillivirus causing mass mortality in seals.

    NARCIS (Netherlands)

    A.D.M.E. Osterhaus (Albert)

    1989-01-01

    textabstractDuring an outbreak of a serious apparently infectious disease among harbour seals (Phoca vitulina), which started in the Kattegat area in April 1988 and rapidly spread to the North sea, the Wadden sea and the Baltic sea, greater than 17,000 animals died within a period of eight months. I

  9. A morbillivirus causing mass mortality in seals.

    NARCIS (Netherlands)

    A.D.M.E. Osterhaus (Albert)

    1989-01-01

    textabstractDuring an outbreak of a serious apparently infectious disease among harbour seals (Phoca vitulina), which started in the Kattegat area in April 1988 and rapidly spread to the North sea, the Wadden sea and the Baltic sea, greater than 17,000 animals died within a period of eight months.

  10. Variability of surface meteorological parameters over the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R.; Fernandes, A.A.

    The trends and periodicities of surface meteorological parameters (sea surface temperature, air temperature, cloudiness, wind speed and sea level pressure) over the western, central, eastern and southern Arabian Sea regions are studied...

  11. Multisensor Analyzed Sea Ice Extent - Northern Hemisphere (MASIE-NH)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Multisensor Analyzed Sea Ice Extent Northern Hemisphere (MASIE-NH) products provide measurements of daily sea ice extent and sea ice edge boundary for the...

  12. Mapping of sea bottom topography

    Science.gov (United States)

    Calkoen, C. J.; Wensink, G. J.; Hesselmans, G. H. F. M.

    1992-01-01

    Under suitable conditions the bottom topography of shallow seas is visible in remote sensing radar imagery. Two experiments were performed to establish which remote sensing technique or combination yields optimal imaging of bottom topography and which hydro-meteorological conditions are favorable. A further goal is to gain experience with these techniques. Two experiments were performed over an area in the North Sea near the measuring platform Meetpost Noordwijk (MPN). The bottom topography in the test area is dominated by sand waves. The crests of the sand waves are perpendicular to the coast line and the dominating (tidal-)current direction. A 4x4 sq km wide section of the test area was studied in more detail. The first experiment was undertaken on 16 Aug. 1989. During the experiment the following remote sensing instruments were used: Landsat-Thematic Mapper, and NASA/JPL Airborne Imaging Radar (AIR). The hydro-meteorological conditions; current, wind, wave, and air and water temperature were monitored by MPN, a ship of Rijkswaterstaat (the OCTANS), and a pitch-and-roll WAVEC-buoy. The second experiment took place on 12 July 1992. During this experiment data were collected with the NASA/JPL polarimetric synthetic aperture radar (SAR), and a five-band helicopter-borne scatterometer. Again the hydro-meteorological conditions were monitored at MPN and the OCTANS. Furthermore, interferometric radar data were collected.

  13. BACTERIAL DESEASES IN SEA FISH

    Directory of Open Access Journals (Sweden)

    Ivančica Strunjak-Perović

    1997-10-01

    Full Text Available With development of the fish culturing in the sea, the interest in their health also increased. The reason for this are diseases or rather mortality that occur in such controlled cultures and cause great economic losses. By growing large quantities of fish in rather small species, natural conditions are changed, so fish is more sensitive and prone to infection agents (viruses, bacteria, parasites. Besides, a large fish density in the cultural process accelerates spreading if the diseases, but also enables a better perception of them. In wild populations sick specimen very quickly become predator’s prey, witch makes it difficult to note any pathological changes in such fish. There are lots of articles on viral, bacterial and parasitic diseases nowdays, but this work deals exclusively with bacterial deseases that occur in the controlled sea cultures (vibriosis, furunculosis, pastherelosis, nocardiosis, mycobaceriosis, edwardsielosis, yersiniosis, deseases caused by bacteria of genera Flexibacter, Pseudomonas, Aeromonas, Streptococus and bacteria nephryithis. Yet, the knowledge of these deseases vary, depending on wether a fish species is being cultured for a longer period of time or is only being introduced in the controlled culture.

  14. CO2 and sea level

    Science.gov (United States)

    Bell, Peter M.

    There is considerable discussion currently about the potential effects of carbon dioxide build-up in the atmosphere over the next several decades. The sources of information are two Government funded reports, one by the National Research Council (NRC), the other by the Environment Protection Agency (EPA), both were released within the last five months. The reports were described recently as being conservative, although the consequences of the resulting greenhouse effects are deemed inevitable. Atmospheric warming on a global scale of as much as 5°C cannot be avoided, only perhaps delayed by a few years at best (Environ. Sci. Technol, 18, 45A-46A, 1984). The cause is the burning of fossil fuels. Oil will not be too important because its supplies are predictably exhausted on the time scale of 50-100 years. Coal burning is considered as the main source of carbon dioxide. Among the more spectacular results of a global temperature rise over the next 100 years is the expected rise in sea level of a minimum of 70 cm (Oceanus, Winter, 1983/84). If the West Antarctic Ice Sheet breaks up and melts, the rise could be in the several meter range. Sea level rose only 15 cm in the past century.

  15. Snow on Antarctic sea ice

    Science.gov (United States)

    Massom, Robert A.; Eicken, Hajo; Hass, Christian; Jeffries, Martin O.; Drinkwater, Mark R.; Sturm, Matthew; Worby, Anthony P.; Wu, Xingren; Lytle, Victoria I.; Ushio, Shuki; Morris, Kim; Reid, Phillip A.; Warren, Stephen G.; Allison, Ian

    2001-08-01

    Snow on Antarctic sea ice plays a complex and highly variable role in air-sea-ice interaction processes and the Earth's climate system. Using data collected mostly during the past 10 years, this paper reviews the following topics: snow thickness and snow type and their geographical and seasonal variations; snow grain size, density, and salinity; frequency of occurrence of slush; thermal conductivity, snow surface temperature, and temperature gradients within snow; and the effect of snow thickness on albedo. Major findings include large regional and seasonal differences in snow properties and thicknesses; the consequences of thicker snow and thinner ice in the Antarctic relative to the Arctic (e.g., the importance of flooding and snow-ice formation); the potential impact of increasing snowfall resulting from global climate change; lower observed values of snow thermal conductivity than those typically used in models; periodic large-scale melt in winter; and the contrast in summer melt processes between the Arctic and the Antarctic. Both climate modeling and remote sensing would benefit by taking account of the differences between the two polar regions.

  16. Interpretation and Implications of Previous Sea Pay Estimates

    Science.gov (United States)

    2015-04-01

    amount of sea duty that can be gained from a rise in Career Sea Pay and Career Sea Pay Premium . The second was how to separate multiple effects of sea...linear pricing scheme that would induce personnel to reveal important information about their willingness to reenlist and their willingness to...undertake sea duty. Under this pricing mechanism, the Navy could fashion combinations of Selective Reenlistment Bonuses and sea pays that would achieve

  17. The application of ERTS imagery to monitoring Arctic sea ice. [mapping ice in Bering Sea, Beaufort Sea, Canadian Archipelago, and Greenland Sea

    Science.gov (United States)

    Barnes, J. C. (Principal Investigator); Bowley, C. J.

    1974-01-01

    The author has identified the following significant results. Because of the effect of sea ice on the heat balance of the Arctic and because of the expanding economic interest in arctic oil and minerals, extensive monitoring and further study of sea ice is required. The application of ERTS data for mapping ice is evaluated for several arctic areas, including the Bering Sea, the eastern Beaufort Sea, parts of the Canadian Archipelago, and the Greenland Sea. Interpretive techniques are discussed, and the scales and types of ice features that can be detected are described. For the Bering Sea, a sample of ERTS-1 imagery is compared with visual ice reports and aerial photography from the NASA CV-990 aircraft. The results of the investigation demonstrate that ERTS-1 imagery has substantial practical application for monitoring arctic sea ice. Ice features as small as 80-100 m in width can be detected, and the combined use of the visible and near-IR imagery is a powerful tool for identifying ice types. Sequential ERTS-1 observations at high latitudes enable ice deformations and movements to be mapped. Ice conditions in the Bering Sea during early March depicted in ERTS-1 images are in close agreement with aerial ice observations and photographs.

  18. Teaching Wide Sargasso Sea in New Jersey

    Science.gov (United States)

    Jolley, Susan Arpajian

    2005-01-01

    High school teacher Susan Arpajian Jolley emphasizes experience and understanding by using the related novels "Wide Sargasso Sea" and "Jane Eyre" to help her students travel into unfamiliar cultural territory. "Wide Sargasso Sea" relates to Caribbean history and culture, feminism, race relations, colonialism, and personal identity.

  19. Teaching Wide Sargasso Sea in New Jersey

    Science.gov (United States)

    Jolley, Susan Arpajian

    2005-01-01

    High school teacher Susan Arpajian Jolley emphasizes experience and understanding by using the related novels "Wide Sargasso Sea" and "Jane Eyre" to help her students travel into unfamiliar cultural territory. "Wide Sargasso Sea" relates to Caribbean history and culture, feminism, race relations, colonialism, and…

  20. Seasonal variability in the Baltic Sea level

    Directory of Open Access Journals (Sweden)

    Marek Świrgoń

    2013-11-01

    Full Text Available Sea level is subject to spatial and temporal variability on different scales. In this paper we investigate seasonal variability in the open Baltic Sea level using daily satellite altimetry data for the period 1 January 1993-31 December 2010. Our results indicate that there is a well-pronounced seasonal cycle in the 18-year average sea level and in its standard deviation. The average annual SLA amplitude in the open Baltic Sea is about 18 cm. The seasonal cycle of the SLA in the Baltic Sea is asymmetric in shape. In the autumn and winter (about 240-260 days per year, the 18-year average daily SLA are higher than the 18-year annual average SLA. In the spring and summer (about 100-120 days per year, the 18-year average daily SLA are lower than the 18-year annual average SLA. A similar asymmetry of the seasonal cycle is not observed in the North Sea and North Atlantic SLA data. The annual pattern of the sea level variability in the Baltic Sea is evident if one considers multi-year average time series, but the cycle can be obscured in some years.

  1. History of sea ice in the Arctic

    DEFF Research Database (Denmark)

    Polyak, Leonid; Alley, Richard B.; Andrews, John T.

    2010-01-01

    Arctic sea-ice extent and volume are declining rapidly. Several studies project that the Arctic Ocean may become seasonally ice-free by the year 2040 or even earlier. Putting this into perspective requires information on the history of Arctic sea-ice conditions through the geologic past. This inf...

  2. Tritium level along Romanian Black Sea Coast

    Energy Technology Data Exchange (ETDEWEB)

    Varlam, C.; Stefanescu, I.; Popescu, I.; Faurescu, I. [National Inst. for Cryogenic and Isotopic Technologies, PO Box 10, Rm. Valcea, 24050 (Romania)

    2008-07-15

    Establishing the tritium level along the Romanian Black Sea Coast, after 10 years of exploitation of the nuclear power plant from Cernavoda, is a first step in evaluating its impact on the Black Sea ecosystem. The monitoring program consists of tritium activity concentration measurement in sea water and precipitation from Black Sea Coast between April 2005 and April 2006. The sampling points were spread over the Danube-Black Sea Canal - before the locks Agigea and Navodari, and Black Sea along the coast to the Bulgarian border. The average tritium concentration in sea water collected from the sampling locations had the value of 11.1 {+-} 2.1 TU, close to tritium concentration in precipitation. Although an operating nuclear power plant exists in the monitored area, the values of tritium concentration in two locations are slightly higher than those recorded elsewhere. To conclude, it could be emphasized that until now, Cernavoda NPP did not had any influence on the tritium concentration of the Black Sea Shore. (authors)

  3. Sea energy; Energie de la mer

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2004-07-01

    The tidal and wave power of the sea could offer electric power for many towns and villages of seashore. This document presents the possibilities of electric power production from the sea energy (submarine wind turbines, tidal energy and wave energy) and the research programs in the world. (A.L.B.)

  4. Microplastic sampling in the Mediterranean Sea

    DEFF Research Database (Denmark)

    Biginagwa, Fares; Sosthenes, Bahati; Syberg, Kristian

    The extent of microplastic pollution in the Southwestern Mediterranean Sea is not yet known, although on Northwestern part has been previously studied. Plastic samples were collected at 7 transects during a 10 day expedition from Sicily (Italy) to Malaga (Spain) in September 2014. A 330 µM mesh....... This is the first study to assess plastic pollution levels in SW Mediterranean Sea....

  5. Nitrite maxima in the Northern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Sankaranarayanan, V.N.; DeSousa, S.N.; Fondekar, S.P.

    There are 2 nitrite maxima in the Northern Arabian Sea, one at the thermocline depth and the other at depths between 300 and 500 m. The 2nd maximum is more prominent in the northeastern part of the Arabian Sea. The 1st maximum is associated...

  6. The South Pole and the Ross Sea

    Science.gov (United States)

    2002-01-01

    This image shows a rare clear view of the South Pole (lower right) and the Ross Sea, Antarctica. The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) acquired the scene on December 26, 2001. The geographic South Pole is located in the center of Antarctica, at an altitude of 2,900 meters (9,300 feet). It rests on a continent-wide ice sheet that is 2,870 m thick, with the underlying bedrock only 30 m (98 feet) above sea level. The ice underlying the South Pole is as much as 140,000 years old, and is currently accumulating at about 82 cm (32 inches) per year. Roughly 2,500 km (1,550 miles) away is the green water of the Ross Sea, which indicates the presence of large numbers of phytoplankton. This is a highly productive part of the world's oceans. Also note the ice gathered around McMurdo Sound, seen toward the lefthand shoreline of the Ross Sea, at the edge of the Ross Ice Shelf. According to National Science Foundation researchers, this ice is making it difficult for penguins to reach their food supply. Separating the continental Antarctic ice sheet from the Ross Sea are the Queen Maud Mountains and the Ross Ice Shelf. Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  7. Sea level rise: A literature survey

    NARCIS (Netherlands)

    Oude Essink, G.H.P.

    1992-01-01

    In order to assess the impact of sea level rise on Water Management, it is useful to understand the mechanisrns that determine the level of the sea. In this study, a literature survey is executed to analyze these mechanisms. Climate plays a centra! role in these mechanisms, Climate mainly changes du

  8. Greenhouse warming and changes in sea level

    NARCIS (Netherlands)

    Oerlemans, J.

    1989-01-01

    It is likely that the anticipated warming due to the effect of increasing concentration of carbon dioxide and other greenhouse gases will lead to a further and faster rise in world mean sea level. There are many processes in the climate system controlling sea level, but the most important factors in

  9. Greenhouse warming and changes in sea level

    NARCIS (Netherlands)

    Oerlemans, J.

    1989-01-01

    It is likely that the anticipated warming due to the effect of increasing concentration of carbon dioxide and other greenhouse gases will lead to a further and faster rise in world mean sea level. There are many processes in the climate system controlling sea level, but the most important

  10. Mapping of the air-sea CO

    NARCIS (Netherlands)

    Yasunaka, S.; Murata, A.; Watanabe, E.; Chierici, M.; Fransson, A.; van Heuven, S.; Hoppema, M.; Ishii, M.; Johannessen, T.; Kosugi, N.; Lauvset, S.K.; Mathis, J.T.; Nishino, S.; Omar, A.M.; Olsen, A.; Sasano, D.; Takahashi, T.; Wanninkhof, R.

    2016-01-01

    We produced 204 monthly maps of the air–sea CO2 flux in the Arctic north of 60°N, including the Arctic Ocean and its adjacent seas, from January 1997 to December 2013 by using a self-organizing map technique. The partial pressure of CO2 (pCO2) in surface water data were obtained by shipboard underwa

  11. Sea Ice Mapping using Unmanned Aerial Systems

    Science.gov (United States)

    Solbø, S.; Storvold, R.

    2011-12-01

    Mapping of sea ice extent and sea ice features is an important task in climate research. Since the arctic coastal and oceanic areas have a high probability of cloud coverage, aerial platforms are superior to satellite measurements for high-resolution optical measurements. However, routine observations of sea ice conditions present a variety of problems using conventional piloted aircrafts. Specially, the availability of suitable aircrafts for lease does not cover the demand in major parts of the arctic. With the recent advances in unmanned aerial systems (UAS), there is a high possibility of establishing routine, cost effective aerial observations of sea ice conditions in the near future. Unmanned aerial systems can carry a wide variety of sensors useful for characterizing sea-ice features. For instance, the CryoWing UAS, a system initially designed for measurements of the cryosphere, can be equipped with digital cameras, surface thermometers and laser altimeters for measuring freeboard of ice flows. In this work we will present results from recent CryoWing sea ice flights on Svalbard, Norway. The emphasis will be on data processing for stitching together images acquired with the non-stabilized camera payload, to form high-resolution mosaics covering large spatial areas. These data are being employed to map ice conditions; including ice and lead features and melt ponds. These high-resolution mosaics are also well suited for sea-ice mechanics, classification studies and for validation of satellite sea-ice products.

  12. Source of Aegean Sea harbour porpoises

    DEFF Research Database (Denmark)

    Lockyer, Christina; Rosel, P. E.; Frantzis, A.

    2003-01-01

    Documented sightings of harbour porpoises in the Mediterranean are rare, although the species is common in the neighbouring North Atlantic and Black Sea. However, in the past 2 decades, 4 harbour porpoises Phocoena phocoena have been recorded in the northern Aegean Sea in the eastern Mediterranean...

  13. Causes for contemporary regional sea level changes.

    Science.gov (United States)

    Stammer, Detlef; Cazenave, Anny; Ponte, Rui M; Tamisiea, Mark E

    2013-01-01

    Regional sea level changes can deviate substantially from those of the global mean, can vary on a broad range of timescales, and in some regions can even lead to a reversal of long-term global mean sea level trends. The underlying causes are associated with dynamic variations in the ocean circulation as part of climate modes of variability and with an isostatic adjustment of Earth's crust to past and ongoing changes in polar ice masses and continental water storage. Relative to the coastline, sea level is also affected by processes such as earthquakes and anthropogenically induced subsidence. Present-day regional sea level changes appear to be caused primarily by natural climate variability. However, the imprint of anthropogenic effects on regional sea level-whether due to changes in the atmospheric forcing or to mass variations in the system-will grow with time as climate change progresses, and toward the end of the twenty-first century, regional sea level patterns will be a superposition of climate variability modes and natural and anthropogenically induced static sea level patterns. Attribution and predictions of ongoing and future sea level changes require an expanded and sustained climate observing system.

  14. Sea ice thickness estimation in the Bohai Sea using geostationary ocean color imager data

    Institute of Scientific and Technical Information of China (English)

    LIU Wensong; SHENG Hui; ZHANG Xi

    2016-01-01

    A method to estimate the thickness of the sea ice of the Bohai Sea is proposed using geostationary ocean color imager (GOCI) data and then applied to the dynamic monitoring of the sea ice thickness in the Bohai Sea during the winter of 2014 to 2015. First of all, a model is given between the GOCI shortwave broadband albedo and the reflectance of each band with high temporal resolution GOCI data. Then, the relationship model between the sea ice thickness and the GOCI shortwave broadband albedo is established and applied to the thickness extraction of the sea ice in the Bohai Sea. Finally, the sea ice thickness extraction method is tested by the results based on the MODIS data, thermodynamic empirical models (Lebedev and Zubov), and thein situ ice thickness data. The test results not only indicated that the sea ice thickness retrieval method based on the GOCI data was a good correlation (r2>0.86) with the sea ice thickness retrieved by the MODIS and thermodynamic empirical models, but also that the RMS is only 6.82 cm different from the thickness of the sea ice based on the GOCI andin situ data.

  15. The wind sea and swell waves climate in the Nordic seas

    Science.gov (United States)

    Semedo, Alvaro; Vettor, Roberto; Breivik, Øyvind; Sterl, Andreas; Reistad, Magnar; Soares, Carlos Guedes; Lima, Daniela

    2015-02-01

    A detailed climatology of wind sea and swell waves in the Nordic Seas (North Sea, Norwegian Sea, and Barents Sea), based on the high-resolution reanalysis NORA10, developed by the Norwegian Meteorological Institute, is presented. The higher resolution of the wind forcing fields, and the wave model (10 km in both cases), along with the inclusion of the bottom effect, allowed a better description of the wind sea and swell features, compared to previous global studies. The spatial patterns of the swell-dominated regional wave fields are shown to be different from the open ocean, due to coastal geometry, fetch dimensions, and island sheltering. Nevertheless, swell waves are still more prevalent and carry more energy in the Nordic Seas, with the exception of the North Sea. The influence of the North Atlantic Oscillation on the winter regional wind sea and swell patterns is also presented. The analysis of the decadal trends of wind sea and swell heights during the NORA10 period (1958-2001) shows that the long-term trends of the total significant wave height (SWH) in the Nordic Seas are mostly due to swell and to the wave propagation effect.

  16. Quantifying the influence of sea ice on ocean microseism using observations from the Bering Sea, Alaska

    Science.gov (United States)

    Tsai, Victor C.; McNamara, Daniel E.

    2011-01-01

    Microseism is potentially affected by all processes that alter ocean wave heights. Because strong sea ice prevents large ocean waves from forming, sea ice can therefore significantly affect microseism amplitudes. Here we show that this link between sea ice and microseism is not only a robust one but can be quantified. In particular, we show that 75–90% of the variability in microseism power in the Bering Sea can be predicted using a fairly crude model of microseism damping by sea ice. The success of this simple parameterization suggests that an even stronger link can be established between the mechanical strength of sea ice and microseism power, and that microseism can eventually be used to monitor the strength of sea ice, a quantity that is not as easily observed through other means.

  17. The cooling and moistening effect on the formation of sea fog in the Huanghai Sea

    Institute of Scientific and Technical Information of China (English)

    HUANG Jian; ZHOU Faxiu

    2006-01-01

    With the sea surface observations from ICOADS for the years 1960~2002, the conditions of cooling, evaporation and water vapor transportation are analyzed and compared for the formation of seasonal sea fog in April-July in the Huanghai Sea. It is found that sea surface cooling is always existent during the fog seasons while sea surface evaporation only appears in April-June in the Huanghai Sea. Local evaporation alone is not sufficient to form fogs though it may lead to light ones. Water vapor transported from the low-latitudes accomplished by specific synoptic systems is the most important condition for sea fog formation. In general, the moistening effect is more important than the cooling one.

  18. A sea temperature data assimilation system for the China Seas and adjacent areas

    Institute of Scientific and Technical Information of China (English)

    YOU Xiaobao; ZHOU Guangqing; ZHU Jiang; LI Rongfeng

    2003-01-01

    A sea temperature data assimilation system for the China Seas and adjacent areas is developed based on a nested regional ocean circulation model and variational optimal interpolation assimilation method. A 12-year assimilation experiment is performed by using the observational temperature profiles from World Ocean Database 1998 (WOD98) and ECMWF reanalysis surface wind stress. Experimental results indicate that the variational scheme shows good skill in assimilating the observed sea temperature into a regional ocean circulation model. Compared with simulation alone, the sea temperature data assimilation significantly improves the performance of a regional ocean model and obtains comprehensive description of the circulations in the China Seas and adjacent areas. Assimilation results, such as the strength and flowing axis of the Kuroshio, Yellow Sea Cold Water Mass and its corresponding horizontal circulation in summer and dipole eddies in the South China Sea in the late summer/early autumn and the eastward jet between them, are well consistent with the observed evidences.

  19. On the measure of sea ice area from sea ice concentration data sets

    Science.gov (United States)

    Boccolari, Mauro; Parmiggiani, Flavio

    2015-10-01

    The measure of sea ice surface variability provides a fundamental information on the climatology of the Arctic region. Sea ice extension is conventionally measured by two parameters, i.e. Sea Ice Extent (SIE) and Sea Ice Area (SIA), both parameters being derived from Sea Ice Concentration (SIC) data sets. In this work a new parameter (CSIA) is introduced, which takes into account only the compact sea-ice, which is defined as the sea-ice having concentration at least equal the 70%. Aim of this study is to compare the performances of the two parameters, SIA and CSIA, in analyzing the trends of three monthly time-series of the whole Arctic region. The SIC data set used in this study was produced by the Institute of Environmental Physics of the University of Bremen and covers the period January 2003 - December 2014, i.e. the period in which the data set is built using the new AMSR passive microwave sensor.

  20. Captive sea turtle rearing inventory, feeding, and water chemistry in sea turtle rearing tanks at NOAA Galveston 1995-present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The database contains daily records of sea turtle inventories by species feeding rates type of food fed sick sea turtles sea turtles that have died log of tanks...