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Sample records for baltic sea

  1. Curonian Spit, Baltic Sea

    NASA Technical Reports Server (NTRS)

    2006-01-01

    On July 25, 2006, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), flying on NASA's Terra satellite, captured this image of the Curonian (or Courland)spit, the Curonian Lagoon (also known as the Courland Lagoon) it encloses, and part of the Baltic Sea. Just 3,800 meters (about 12,460 feet) at its widest point, the spit encloses a lagoon of some 1,620 square kilometers (625 square miles). In this image, dark blue indicates deep water, and lighter blue indicates shallow and/or sediment-laden water. Different shades of blue distinguish the deeper Baltic Sea and the shallower Curonian Lagoon. Vegetation appears in varying shades of green, paved surfaces and bare ground appear in shades of beige and gray, and sandy areas appear off-white. Obvious sandy areas appear along the length of the spit. On the Baltic Sea side, a thin off-white band of beach runs the length of the spit; on the Curonian Lagoon side, intermittent beaches carve their way into the narrow strip of land.

  2. Baltic Earth - Earth System Science for the Baltic Sea Region

    NASA Astrophysics Data System (ADS)

    Meier, Markus; Rutgersson, Anna; Lehmann, Andreas; Reckermann, Marcus

    2014-05-01

    The Baltic Sea region, defined as its river catchment basin, spans different climate and population zones, from a temperate, highly populated, industrialized south with intensive agriculture to a boreal, rural north. It encompasses most of the Scandinavian Peninsula in the west; most of Finland and parts of Russia, Belarus, and the Baltic states in the east; and Poland and small parts of Germany and Denmark in the south. The region represents an old cultural landscape, and the Baltic Sea itself is among the most studied sea areas of the world. Baltic Earth is the new Earth system research network for the Baltic Sea region. It is the successor to BALTEX, which was terminated in June 2013 after 20 years and two successful phases. Baltic Earth stands for the vision to achieve an improved Earth system understanding of the Baltic Sea region. This means that the research disciplines of BALTEX continue to be relevant, i.e. atmospheric and climate sciences, hydrology, oceanography and biogeochemistry, but a more holistic view of the Earth system encompassing processes in the atmosphere, on land and in the sea as well as in the anthroposphere shall gain in importance in Baltic Earth. Specific grand research challenges have been formulated, representing interdisciplinary research questions to be tackled in the coming years. A major means will be scientific assessments of particular research topics by expert groups, similar to the BACC approach, which shall help to identify knowledge gaps and develop research strategies. Preliminary grand challenges and topics for which Working Groups have been installed include: • Salinity dynamics in the Baltic Sea • Land-Sea biogeochemical feedbacks in the Baltic Sea region • Natural hazards and extreme events in the Baltic Sea region • Understanding sea level dynamics in the Baltic Sea • Understanding regional variability of water and energy exchange • Utility of Regional Climate Models • Assessment of Scenario Simulations

  3. Pollution in the Baltic Sea.

    PubMed

    Rheinheimer, G

    1998-07-01

    The Baltic Sea is almost totally surrounded by land and therefore more endangered by pollution than other marine areas. The sources of marine pollution are municipal and industrial waste inputs directly into the sea or via rivers, and atmospheric inputs mainly from traffic and agriculture. The increase of inorganic plant nutrients (NH3, NOx, PO4) caused eutrophication and consequent oxygen depletion in coastal bottom waters as well as in the depths of the open sea. In the anoxic sediments, hydrogen sulfide can be produced by protein-decomposing and sulfate-reducing bacteria. The bottom fauna will be destroyed and only H2S tolerant microorganisms can survive. Originating from cellulose manufacturing and from paper mills, large amounts of poisonous chlorinated compounds contaminated the coastal waters of Sweden and Finland until the 1980s. Most of this material is still present in sediments of the central Baltic Sea and can be resuspended by near bottom currents. To reduce pollution and improve the situation in the Baltic Sea, the surrounding countries organized the Helsinki Convention, which came into force on 3.5.1980. The Helsinki Commission (HELCOM) founded in 1974 acts as coordinator and is responsible for the enforcement of the Baltic monitoring program and international research projects. The activities of HELCOM have led to the reduction of dangerous pollutants which in turn has caused the regeneration of flora and fauna in some areas. Further improvements can be expected. PMID:9722964

  4. Status of Biodiversity in the Baltic Sea

    PubMed Central

    Ojaveer, Henn; Jaanus, Andres; MacKenzie, Brian R.; Martin, Georg; Olenin, Sergej; Radziejewska, Teresa; Telesh, Irena; Zettler, Michael L.; Zaiko, Anastasija

    2010-01-01

    The brackish Baltic Sea hosts species of various origins and environmental tolerances. These immigrated to the sea 10,000 to 15,000 years ago or have been introduced to the area over the relatively recent history of the system. The Baltic Sea has only one known endemic species. While information on some abiotic parameters extends back as long as five centuries and first quantitative snapshot data on biota (on exploited fish populations) originate generally from the same time, international coordination of research began in the early twentieth century. Continuous, annual Baltic Sea-wide long-term datasets on several organism groups (plankton, benthos, fish) are generally available since the mid-1950s. Based on a variety of available data sources (published papers, reports, grey literature, unpublished data), the Baltic Sea, incl. Kattegat, hosts altogether at least 6,065 species, including at least 1,700 phytoplankton, 442 phytobenthos, at least 1,199 zooplankton, at least 569 meiozoobenthos, 1,476 macrozoobenthos, at least 380 vertebrate parasites, about 200 fish, 3 seal, and 83 bird species. In general, but not in all organism groups, high sub-regional total species richness is associated with elevated salinity. Although in comparison with fully marine areas the Baltic Sea supports fewer species, several facets of the system's diversity remain underexplored to this day, such as micro-organisms, foraminiferans, meiobenthos and parasites. In the future, climate change and its interactions with multiple anthropogenic forcings are likely to have major impacts on the Baltic biodiversity. PMID:20824189

  5. Strontium-90 and cesium-137 distribution in Baltic Sea waters

    SciTech Connect

    Lazarev, L.N.; Gedeonov, L.I.; Ivanova, L.M.; Stepanov, A.V.

    1988-09-01

    The strontium-90 and cesium-137 concentrations determined in 1983 in the Baltic Sea proper and the Gulf of Finland and in the Soviet Baltic rivers are furnished. The cesium-137 content has been found to be directly proportional to the salinity of the water. Significant influx of technogenic radioactive contaminants from the North to the Baltic Sea was noted in 1983.

  6. Changes in extreme sea levels in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Dieterich, Christian; Gröger, Matthias; Andersson, Helén; Nerheim, Signild; Jönsson, Anette

    2016-04-01

    A newly developed shallow water model for the Baltic Sea and North Sea is presented. The model is validated by means of a comparison with hindcast simulations with observational data sets. The aim of the development is to provide and apply a modelling tool to model extreme sea levels in the Baltic Sea, Kattegat and Skagerrak. The model approach will support the direct analysis of extreme sea level observations in the past and provide the possibility to extend the statistical data base by producing very long time series or very large ensembles of coastal sea levels. This effort is intended to contribute to an assessment of risks due to storm surges and coastal flooding in the 21st century along the coast of Sweden. By using different RCP climate scenarios downscaled with a regional, coupled climate model atmospheric forcing is available to project possible changes in extreme sea levels into the future. Projected sea level rise, changes in dynamical sea level in the North East Atlantic and tidal forcing in the northern North Sea are applied as boundary condition which allows to investigate their impact on the dynamics of regional sea level variability. Initial experiments focus on the impact of model resolution, resolution in the atmospheric forcing and the amount of details necessary in the bathymetry to faithfully model coastal sea level in the Baltic Sea and North Sea.

  7. Pole tide in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Medvedev, I. P.; Rabinovich, A. B.; Kulikov, E. A.

    2014-03-01

    The pole tide, which is driven by the Chandler Wobble, has a period of about 14 months and typical amplitudes in the World Ocean of ˜0.5 cm. However, in the Baltic Sea the pole tide is anomalously high. To examine this effect we used long-term hourly sea level records from 23 tide gauges and monthly records from 64 stations. The lengths of the series were up to 123 years for hourly records and 211 years for monthly records. High-resolution spectra revealed a cluster of neighboring peaks with periods from 410 to 440 days. The results of spectral analysis were applied to estimate the integral amplitudes of pole tides from all available tide gauges along the coast of the Baltic Sea. The height of the pole tide was found to gradually increase from the entrance (Danish Straits, 1.5-2 cm) to the northeast end of the sea. The largest amplitudes—up to 4.5-7 cm—were observed in the heads of the Gulf of Finland and the Gulf of Bothnia. Significant temporal fluctuations in amplitudes and periods of the pole tide were observed during the 19th and 20th centuries.

  8. Astaxanthin dynamics in Baltic Sea mesozooplankton communities

    NASA Astrophysics Data System (ADS)

    Snoeijs, Pauline; Häubner, Norbert

    2014-01-01

    The red pigment astaxanthin is a powerful antioxidant, which occurs in eggs and body tissues of crustaceans and fish. It is produced by crustaceans from algal carotenoids. In a two-year field study we assessed natural concentrations and dynamics of astaxanthin in mesozooplankton communities in the brackish Baltic Sea area. Astaxanthin levels varied between 0.37 and 36 ng L- 1. They increased with salinity along the Baltic Sea gradient and were linked to zooplankton biomass and phytoplankton community composition. Astaxanthin concentrations showed typical seasonal patterns and varied from 0.2 to 5.1 ng ind- 1, 0.2 to 3.4 ng (μg C)- 1 and 6 to 100 ng mm- 3. These concentrations were inversely related to water temperature and strongly linked to zooplankton community composition. Communities dominated by the calanoid copepods Temora longicornis, Pseudocalanus acuspes and Eurytemora spp. generally held the highest concentrations. With increasing cladocerans:copepods biomass ratios community astaxanthin concentrations decreased and with higher relative biomass of Acartia spp. the proportion of astaxanthin diesters decreased. Diesters prevailed in the cold season and they are thought to improve the antioxidant protection of storage lipids during winter. Climate change causes higher temperature and lower salinity in the Baltic Sea proper. This modifies zooplankton community composition, but not necessarily into a community with lower concentrations of astaxanthin since T. longicornis (high concentrations) has been reported to increase with higher temperature. However, decreased astaxanthin production in the ecosystem is expected if a basin-wide increase in the cladocerans:copepods biomass ratios would occur with further climate change.

  9. An Earth System Science Program for the Baltic Sea Region

    NASA Astrophysics Data System (ADS)

    Meier, H. E. M.; Rutgersson, A.; Reckermann, M.

    2014-04-01

    From Russia in the east to Sweden, Denmark, and Germany in the west, reaching south to the tips of the Czech Republic, Slovakia, and Ukraine, the Baltic Sea watershed drains nearly 20% of Europe (see Figure 1). In the highly populated south, the temperate climate hosts intensive agriculture and industry. In the north, the landscape is boreal and rural. In the Baltic Sea itself, complex bathymetry and stratification patterns as well as extended hypoxic and anoxic deep waters add to the diversity. Yet in recent history, the differences across the Baltic Sea region have been more than physical: In the mid-20th century, the watershed was split in two.

  10. Changing seasonality of the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Kahru, M.; Elmgren, R.; Savchuk, O. P.

    2015-11-01

    Changes in the phenology of physical and ecological variables associated with climate change are likely to have significant effect on many aspects of the Baltic ecosystems. We apply a set of phenological indicators to multiple environmental variables measured by satellite sensors for 17-35 years to detect possible changes in the seasonality in the Baltic Sea environment. We detect significant temporal changes such as earlier start of the summer season and prolongation of the productive season in multiple variables ranging from basic physical drivers to ecological status indicators. While increasing trends in the absolute values of variables like sea-surface temperature (SST), diffuse attenuation of light (Ked490) and satellite-detected chlorophyll concentration (CHL) are detectable, the corresponding changes in their seasonal cycles are more dramatic. For example, the cumulative sum of 30 000 W m-2 of surface incoming shortwave irradiance (SIS) was reached 23 days earlier in 2014 compared to the beginning of the time series in 1983. The period of the year with SST of at least 17 °C has almost doubled (from 29 days in 1982 to 56 days in 2014), the period with Ked490 over 0.4 m-1 has increased from about 60 days in 1998 to 240 days in 2013, i.e. quadrupled. The period with satellite-detected CHL of at least 3 mg m-3 has doubled from approximately 110 days in 1998 to 220 days in 2013. While the timing of both the phytoplankton spring and summer blooms have advanced, the annual CHL maximum that in the 1980s corresponded to the spring diatom bloom in May has now switched to the summer cyanobacteria bloom in July.

  11. Changing seasonality of the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Kahru, Mati; Elmgren, Ragnar; Savchuk, Oleg P.

    2016-02-01

    Changes in the phenology of physical and ecological variables associated with climate change are likely to have significant effect on many aspects of the Baltic ecosystem. We apply a set of phenological indicators to multiple environmental variables measured by satellite sensors for 17-36 years to detect possible changes in the seasonality in the Baltic Sea environment. We detect significant temporal changes, such as earlier start of the summer season and prolongation of the productive season, in several variables ranging from basic physical drivers to ecological status indicators. While increasing trends in the absolute values of variables like sea-surface temperature (SST), diffuse attenuation of light (Ked490) and satellite-detected chlorophyll concentration (CHL) are detectable, the corresponding changes in their seasonal cycles are more dramatic. For example, the cumulative sum of 30 000 W m-2 of surface incoming shortwave irradiance (SIS) was reached 23 days earlier in 2014 compared to the beginning of the time series in 1983. The period of the year with SST of at least 17 °C has almost doubled (from 29 days in 1982 to 56 days in 2014), and the period with Ked490 over 0.4 m-1 has increased from about 60 days in 1998 to 240 days in 2013 - i.e., quadrupled. The period with satellite-estimated CHL of at least 3 mg m-3 has doubled from approximately 110 days in 1998 to 220 days in 2013. While the timing of both the phytoplankton spring and summer blooms have advanced, the annual CHL maximum that in the 1980s corresponded to the spring diatom bloom in May has now shifted to the summer cyanobacteria bloom in July.

  12. The regional geology and hydrocarbon potential of the Baltic Sea

    SciTech Connect

    Haselton, T.M. ); Brangulis, A.P.; Margulis, L.S. ); Kanev, S. )

    1991-08-01

    The Baltic Sea is roughly equivalent in size to the North Sea. Like the North Sea, is has an excellent oil prone source rock present over most of the area. In the entire Baltic Sea about 40 wells have been drilled. During the 1980s, exploration was carried out in the Soviet, Polish, and East German sectors of the Baltic Sea by Petrobaltic. Twenty-eight wells were drilled, 14 of which tested hydrocarbons. Two wells have been drilled in Danish waters and 11 in Swedish waters - all dry holes. Most of the Baltic Sea is included in the Baltic syneclise. In the deepest part of the basin a full Paleozoic and Mesozoic section is present. Major structural features are associated with reactivation of old basement faults. Most hydrocarbon discoveries are associated with structural arches. Exploration targets are Cambrian sandstones and Ordovician and Silurian reefs. The major discoveries are the B3 field in Poland and the D6 field offshore Lithuania and Kaliningrad, both of which have in-place reserves of around 100 million bbl. The Teisseyre-Tornquist line to the southwest represents the plate boundary between the East European platform and Europe. Repeated strike slip movements along this zone result in a complex pattern of extensional and compressional features in the Danish and German sectors. Primary exploration targets include Permian carbonates and sandstones as well as older zones. Gas has been tested in the German sector onshore.

  13. Influence of sea level rise on the dynamics of salt inflows in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Hordoir, Robinson; Axell, Lars; Löptien, Ulrike; Dietze, Heiner; Kuznetsov, Ivan

    2015-10-01

    The Baltic Sea is a marginal sea, located in a highly industrialized region in Central Northern Europe. Saltwater inflows from the North Sea and associated ventilation of the deep exert crucial control on the entire Baltic Sea ecosystem. This study explores the impact of anticipated sea level changes on the dynamics of those inflows. We use a numerical oceanic general circulation model covering both the Baltic and the North Sea. The model successfully retraces the essential ventilation dynamics throughout the period 1961-2007. A suite of idealized experiments suggests that rising sea level is associated with intensified ventilation as saltwater inflows become stronger, longer, and more frequent. Expressed quantitatively as a salinity increase in the deep central Baltic Sea, we find that a sea level rise of 1 m triggers a saltening of more than 1 PSU. This substantial increase in ventilation is the consequence of the increasing cross section in the Danish Straits amplified by a reduction of vertical mixing.

  14. The history of sturgeon in the Baltic Sea

    USGS Publications Warehouse

    Popovic, Danijela; Panagiotopoulou, Hanna; Baca, Mateusz; Stefaniak, Krzysztof; Mackiewicz, Pawel; Makowiecki, Daniel; King, Tim L.; Gruchota, Jakub; Weglenski, Piotr; Stankovic, Anna

    2014-01-01

    For the past 2000 years at least, A. o. oxyrinchus has been the dominant sturgeon in the Baltic Sea, indicating a much earlier origin than previously suggested. The most similar extant sturgeon populations to the extinct Baltic stock are those from the St John and St Lawrence rivers in Canada. These populations should be considered the best source of breeding material for the ongoing sturgeon restitution programmes in Poland and Germany.

  15. The Baltic Sea natural long-term variability of salinity

    NASA Astrophysics Data System (ADS)

    Schimanke, Semjon; Markus Meier, H. E.

    2015-04-01

    The Baltic Sea is one of the largest brackish sea areas of the world. The sensitive state of the Baltic Sea is sustained by a fresh-water surplus by river discharge and precipitation on one hand as well as inflows of highly saline and oxygen-rich water masses from the North Sea on the other. Major inflows which are crucial for the renewal of the deep water occur very intermittent with a mean frequency of approximately one per year. Stagnation periods (periods without major inflows) lead for instance to a reduction of oxygen concentration in the deep Baltic Sea spreading hypoxic conditions. Depending on the amount of salt water inflow and fresh-water supply the deep water salinity of the Baltic Sea varies between 11 to 14 PSU on the decadal scale. The goal of this study is to understand the contribution of different driving factors for the decadal to multi-decadal variability of salinity in the Baltic Sea. Continuous measurement series of salinity exist from the 1950 but are not sufficiently long for the investigation of long-term fluctuations. Therefore, a climate simulation of more than 800 years has been carried out with the Rossby Center Ocean model (RCO). RCO is a biogeochemical regional climate model which covers the entire Baltic Sea. It is driven with atmospheric data dynamical downscaled from a GCM mimicking natural climate variability. The analysis focus on the role of variations in river discharge and precipitation, changes in wind speed and direction, fluctuations in temperature and shifts in large scale pressure patterns (e.g. NAO). Hereby, the length of the simulation will allow to identify mechanisms working on decadal to multi-decadal time scales. Moreover, it will be discussed how likely long stagnation periods are under natural climate variability and if the observed exceptional long stagnation period between 1983-1993 might be related to beginning climate change.

  16. Postglacial paleoceanographic environments in the Barents and Baltic seas

    NASA Astrophysics Data System (ADS)

    Ivanova, E. V.; Murdmaa, I. O.; Emelyanov, E. M.; Seitkalieva, E. A.; Radionova, E. P.; Alekhina, G. N.; Sloistov, S. M.

    2016-01-01

    This paper presents reconstructions of ice sheet boundaries, lacustrine and marine paleobasins, as well as the connections of the Barents and Baltic seas with the North Atlantic from the Last Glacial Maximum to the Holocene. The reconstructions are based on original and published data obtained from the northern and western parts of the Barents Sea and Baltic depressions with account for the available regional schematic maps of deglaciation. The early deglaciation of the Scandinavian-Barents ice sheet culminated with the Bølling-Allerød interstadial (14.5-12.9 cal ka BP), which was characterized by a more vigorous Atlantic meridional overturning circulation (AMOC) and a corresponding increase in surface Atlantic water inflow into the Barents Sea through deep troughs. The Baltic Ice Lake (BIL) remained a dammed-up isolated basin during deglaciation from 16.0 to 11.7 cal ka BP. In the Younger Dryas (YD), the lake drained into the North Sea and was replaced by a brackish Yoldia Sea (YS) at the beginning of the Holocene (Preboreal, 11.7-10.7 cal ka BP), due to a limited connection between two basins through the Närke Strait. In the Barents Sea, the next increase in the Atlantic water influx into the deep basins corresponded to terminal YD and Preboreal events with a culmination in the Early Holocene. The Yoldia Sea became a lake again during the next stage, the Ancylus (~10.7-8.8 cal ka BP). Atlantic water inflow both into the Barents and Baltic seas varied during the Holocene, with a maximum contribution in the Early Holocene, when the Littorina Sea (LS, 8-4 cal ka BP) connection with the North Sea via the Danish Straits was formed to replace the Ancylus Lake. The recent, post-Littorina stage (PS, the last 4 cal ka) of the Baltic Sea evolution began in the Late Holocene.

  17. BALTEX - A science broker for the Baltic Sea Region

    NASA Astrophysics Data System (ADS)

    Reckermann, M.; von Storch, H.; Langner, J.; Omstedt, A. T.

    2010-12-01

    BALTEX (the Baltic Sea Experiment) is an interdisciplinary research network of scientists involved in environmental research dedicated to the Baltic Sea drainage basin (including disciplines such as meteorology, hydrology, oceanography, biogeochemistry and climate research). Originally founded in 1992 as a Continental Scale Experiment in GEWEX (the Global Energy and Water Cycle Experiment within the World Climate Research Programme (WCRP) of the World Meteorological Organization, WMO), it was intended to form a common science, communication and data platform with the overall goal to integrate efforts to gain a better understanding of the water and energy cycle in the Baltic Sea basin. BALTEX Phase II (since 2003) has extended the scope to research on regional climate change and variability, climate change impacts on biogeochemistry and water management, but also made first steps towards overarching social and political issues as cross-cutting activities in the context of the scientific objectives. An important aspect of BALTEX Phase II is a more holistic approach towards observing, understanding and modelling major environmental relevant for the entire Baltic Sea region. Parts of the BALTEX Phase II research activities thus contribute to the establishment of a high resolution integrated modelling system for Northern Europe, embedded in an Earth System Model. An outstanding product of BALTEX as a “knowledge broker” for regional political institutions is the BACC report. Following to a large extent the method of IPCC, a regional assessment report on climate change in the Baltic Sea basin was compiled, which summarizes the published scientifically legitimate knowledge on regional climate change in the Baltic Sea basin and its impacts. The assessment, known as the BACC report (BALTEX Assessment of Climate Change for the Baltic Sea Basin; BACC author team 2008, Reckermann et al., 2008) was published in 2008 as a book. A survey among climate researchers in the area

  18. Projected habitat loss for Atlantic herring in the Baltic Sea.

    PubMed

    Illing, Björn; Moyano, Marta; Hufnagl, Marc; Peck, Myron A

    2016-02-01

    Projected, climate-driven changes in rainfall patterns are expected to alter the salinity (S) of estuaries and larger brackish water bodies, such as the Baltic Sea. Some marine fish larvae are potentially more sensitive to low salinity than older stages, hence we compared the low salinity tolerance of Atlantic herring (Clupea harengus) larvae at the individual and population levels including four populations in the North and Baltic Seas. Acute low salinity tolerance was similar (S = 1.9-2.7) across populations and increased with increasing body size. Based on this physiological threshold and a regionally down-scaled climate model, spawning habitats in the northern and eastern Baltic Sea are projected to be largely unsuitable for herring by 2100. Although adaptive mechanisms may attenuate the effect in some species, the limited physiological tolerance of fish larvae will remain an important bottleneck for the persistence of marine fish populations in brackish waters undergoing climate-driven freshening. PMID:26724744

  19. Nitrogen surface water retention in the Baltic Sea drainage basin

    NASA Astrophysics Data System (ADS)

    Stålnacke, P.; Pengerud, A.; Vassiljev, A.; Smedberg, E.; Mörth, C.-M.; Hägg, H. E.; Humborg, C.; Andersen, H. E.

    2015-02-01

    In this paper, we estimate the surface water retention of nitrogen (N) in all the 117 drainage basins to the Baltic Sea with the use of a statistical model (MESAW) for source apportionment of riverine loads of pollutants. Our results show that the MESAW model was able to estimate the N load at the river mouth of 88 Baltic Sea rivers, for which we had observed data, with a sufficient degree of precision and accuracy. The estimated retention parameters were also statistically significant. Our results show that around 380 000 t of N are annually retained in surface waters draining to the Baltic Sea. The total annual riverine load from the 117 basins to the Baltic Sea was estimated at 570 000 t of N, giving a total surface water N retention of around 40%. In terms of absolute retention values, three major river basins account for 50% of the total retention in the 117 basins; i.e. around 104 000 t of N are retained in Neva, 55 000 t in Vistula and 32 000 t in Oder. The largest retention was found in river basins with a high percentage of lakes as indicated by a strong relationship between N retention (%) and share of lake area in the river drainage areas. For example in Göta älv, we estimated a total N retention of 72%, whereof 67% of the retention occurred in the lakes of that drainage area (Lake Vänern primarily). The obtained results will hopefully enable the Helsinki Commission (HELCOM) to refine the nutrient load targets in the Baltic Sea Action Plan (BSAP), as well as to better identify cost-efficient measures to reduce nutrient loadings to the Baltic Sea.

  20. The Baltic Klint beneath the central Baltic Sea and its comparison with the North Estonian Klint

    NASA Astrophysics Data System (ADS)

    Tuuling, Igor; Flodén, Tom

    2016-06-01

    Along its contact with the Baltic Shield, the margin of the East European Platform reveals a well-developed, flooded terraced relief. The most striking and consistent set of escarpments at the contact of the Lower Palaeozoic calcareous and terrigenous rocks, known as the Baltic Klint (BK), extends from northwest of Russia to the Swedish island of Öland. Marine seismic reflection profiling in 1990-2004 revealed the central Baltic Sea Klint (BSK) section in detail and enabled comparison of its geology/geomorphology with a classical klint-section onshore, namely the North Estonian Klint (NEK). The conception of the BK onshore, which is based on the land-sea separating terraced relief in northern Estonia, is not fully applicable beneath the sea. Therefore, we consider that the BSK includes the entire terraced Cambrian outcrop. We suggest the term "Baltic Klint Complex" to include the well-terraced margin of the Ordovician limestone outcrop, which is weakly developed in Estonia. Because of a steady lithological framework of the bedrock layers across the southern slope of the Fennoscandian Shield, the central BSK in the western and the NEK in the eastern part of the Baltic Homocline have largely identical morphologies. The North Estonian Ordovician limestone plateau with the calcareous crest of the BK extends across the central Baltic Sea, whereas morphological changes/variations along the Klint base occur due to the east-westerly lithostratigraphic/thickness changes in the siliciclastic Cambrian sequence. The verge of the NEK, located some 30-50 m above sea level, starts to drop in altitude as its east-westerly course turns to northeast-southwest in western Estonia. Further westwards, the BK shifts gradually into southerly deepening (0.1-0.2°) layers as its crest drops to c. 150 m below sea level (b.s.l.) near Gotska Sandön. This course change is accompanied by a considerable decrease in thickness of the platform sedimentary cover, as below the central Baltic Sea the

  1. Echoes from the past: a healthy Baltic Sea requires more effort.

    PubMed

    Kotilainen, Aarno T; Arppe, Laura; Dobosz, Slawomir; Jansen, Eystein; Kabel, Karoline; Karhu, Juha; Kotilainen, Mia M; Kuijpers, Antoon; Lougheed, Bryan C; Meier, H E Markus; Moros, Matthias; Neumann, Thomas; Porsche, Christian; Poulsen, Niels; Rasmussen, Peter; Ribeiro, Sofia; Risebrobakken, Bjørg; Ryabchuk, Daria; Schimanke, Semjon; Snowball, Ian; Spiridonov, Mikhail; Virtasalo, Joonas J; Weckström, Kaarina; Witkowski, Andrzej; Zhamoida, Vladimir

    2014-02-01

    Integrated sediment multiproxy studies and modeling were used to reconstruct past changes in the Baltic Sea ecosystem. Results of natural changes over the past 6000 years in the Baltic Sea ecosystem suggest that forecasted climate warming might enhance environmental problems of the Baltic Sea. Integrated modeling and sediment proxy studies reveal increased sea surface temperatures and expanded seafloor anoxia (in deep basins) during earlier natural warm climate phases, such as the Medieval Climate Anomaly. Under future IPCC scenarios of global warming, there is likely no improvement of bottom water conditions in the Baltic Sea. Thus, the measures already designed to produce a healthier Baltic Sea are insufficient in the long term. The interactions between climate change and anthropogenic impacts on the Baltic Sea should be considered in management, implementation of policy strategies in the Baltic Sea environmental issues, and adaptation to future climate change. PMID:24414805

  2. IODP expedition 347: Baltic Sea basin paleoenvironment and biosphere

    NASA Astrophysics Data System (ADS)

    Andrén, T.; Barker Jørgensen, B.; Cotterill, C.; Green, S.; IODP expedition 347 scientific party, the

    2015-12-01

    The Integrated Ocean Drilling Program (IODP) expedition 347 cored sediments from different settings of the Baltic Sea covering the last glacial-interglacial cycle. The main aim was to study the geological development of the Baltic Sea in relation to the extreme climate variability of the region with changing ice cover and major shifts in temperature, salinity, and biological communities. Using the Greatship Manisha as a European Consortium for Ocean Research Drilling (ECORD) mission-specific platform, we recovered 1.6 km of core from nine sites of which four were additionally cored for microbiology. The sites covered the gateway to the North Sea and Atlantic Ocean, several sub-basins in the southern Baltic Sea, a deep basin in the central Baltic Sea, and a river estuary in the north. The waxing and waning of the Scandinavian ice sheet has profoundly affected the Baltic Sea sediments. During the Weichselian, progressing glaciers reshaped the submarine landscape and displaced sedimentary deposits from earlier Quaternary time. As the glaciers retreated they left a complex pattern of till, sand, and lacustrine clay, which in the basins has since been covered by a thick deposit of Holocene, organic-rich clay. Due to the stratified water column of the brackish Baltic Sea and the recurrent and widespread anoxia, the deeper basins harbor laminated sediments that provide a unique opportunity for high-resolution chronological studies. The Baltic Sea is a eutrophic intra-continental sea that is strongly impacted by terrestrial runoff and nutrient fluxes. The Holocene deposits are recorded today to be up to 50 m deep and geochemically affected by diagenetic alterations driven by organic matter degradation. Many of the cored sequences were highly supersaturated with respect to methane, which caused strong degassing upon core recovery. The depth distributions of conservative sea water ions still reflected the transition at the end of the last glaciation from fresh-water clays to

  3. Parasitism at the ecosystem level in the Baltic Sea.

    PubMed

    Zander, C D; Reimer, L W

    2002-01-01

    The Baltic Sea is characterized by organisms that can tolerate brackish water. Because of the Sea's history during glacial times, its flora and fauna (and also their parasites) can be traced to marine, freshwater and genuine brackish elements beside glacial relics. Snails, planktonic copepods, benthic amphipods and isopods are important intermediate hosts of diverse helminths; in addition polychaetes, bivalves and fishes may also act as final hosts. The most important final hosts, beside fishes, were seals and birds; these were able to disperse the parasites over the whole of the Baltic. Decreasing salinity from west to east limits the distribution of many parasites. Several marine and genuine brackish water species have almost spread over the whole Baltic. Freshwater species, however, have a lower tolerance than marine species and are only rarely found in the western part. A serious problem in the Baltic is eutrophication which can lead to massive abundances of generalist parasites, in host populations as well as host individuals. The final stage of this influence can cause a general decrease of host abundance and, as a consequence, of all kinds of parasites, due to oxygen deficiency. In comparison with the species spectrum of other brackish waters in Europe, the Baltic presents some endemic parasites as well as sharing parasite species with the Mediterranean and even the Black Sea. PMID:12396220

  4. Climate change and the Baltic Sea action plan: Model simulations on the future of the western Baltic Sea

    NASA Astrophysics Data System (ADS)

    Friedland, René; Neumann, Thomas; Schernewski, Gerald

    2012-12-01

    In this study we apply the model ERGOM to simulate the consequences of Climate Change as well as the combination of Climate Change with nutrient load reductions according to the Baltic Sea Action Plan (BSAP) on the Baltic Sea ecosystem. According to the simulations, Climate Change will cause an increase of the water temperature up to 3 K and a salinity decrease of 1.5 PSU until 2100. However, the implementation of the BSAP will have much stronger effects on the ecosystem. The model suggests that the western Baltic Sea will shift from a nitrogen (N) towards a phosphorus (P) limited system. As a consequence, N-fixation will strongly decrease. The same applies to nutrient-concentrations in winter, denitrification as well as detritus and chlorophyll concentrations in summer. The availability of N in summer, the Secchi depth and the oxygen saturation will increase. Our simulations suggest that the full implementation of the BSAP will cause imbalances in the Baltic Sea over decades before a new system state will be reached. Our results indicate that the Secchi depth alone is not a suitable indicator for the state of eutrophication. Concerning the Water Framework Directive (WFD), Climate Change might alter gradients and concentrations, e.g. of salinity, and in return this might require a re-definition of the WFD typology or a spatial shift of the surface water types, e.g. in Germany. The western Baltic Sea is strongly controlled by regional nutrient loads. Climate Change has only a limited effect on loads in the western Baltic. A re-definition of reference conditions and a good status because of Climate Change seems not necessary.

  5. Sea level trends for all sections of the Baltic Sea coastline

    NASA Astrophysics Data System (ADS)

    Madsen, Kristine S.; Høyer, Jacob L.; Suursaar, Ülo; Knudsen, Per; She, Jun

    2016-04-01

    To better understand influence of sea level rise on societal vulnerability and coastal erosion processes, it is important to know the sea level trend. The coastline of the Baltic Sea is not uniformly exposed, and therefore we will determine the sea level trend of the last 10, 50 and 100 years for all sections of the coastline. The observational record of sea level in the Baltic Sea is quite unique with several records of more than 100 years of data. However, the information is confined to the tide gauge locations. Here, we utilize a statistical method based on least squares regression and originally developed for short term sea level variability (Madsen et al. 2015, JGR, doi:10.1002/2015JC011070) to spread out the sea level information from selected tide gauges to all sections of the Baltic Sea coast. Monthly mean tide gauge observations are retrieved from PSMSL and supplemented with Estonian observations. The spatial distribution of the sea level is obtained from model reanalysis from the Copernicus Marine Service and satellite altimetry observations and land rise information is taken into account. Results are validated against independent tide gauges, providing a consistent record of 20th century sea level trends and variability, including uncertainties, for the entire Baltic Sea coastline. This work is sponsored by the EMODnet project Baltic Checkpoint.

  6. Breaker zone aerosol dynamics in the southern Baltic Sea

    SciTech Connect

    Zielinski, T.; Zielinski, A.

    1994-12-31

    This paper presents the results of lidar based investigations of aerosol concentrations and their size distributions over the breaker zones. The measurements were carried out under various weather conditions over breaker zones of the Gulf of Gdansk (1992) and from a station on the open Baltic Sea (International Experiment BAEX in 1993).

  7. Past Occurrences of Hypoxia in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Zillen, L.; Conley, D. J.; Bjorck, S.

    2007-12-01

    The hypoxic zone in the Baltic Sea has increased in area by about four times since 1950. Widespread oxygen deficiency below the halocline has severely reduced macro benthic communities in the Baltic Proper and the Gulf of Finland over the past decades and negatively effected food chain dynamics, fish habitats and fisheries in the entire Baltic Sea. In addition, hypoxia alters nutrient biogeochemical cycles. The cause of the increased hypoxia is believed to be enhanced eutrophication through increased anthropogenic input of nutrients, such as phosphorous and nitrogen. Conditions prior to the 1950s are considered as the benchmark and some authors suggest that the earlier Baltic Sea was an oligothrophic, clear-water body with oxygenated deep waters. By contrast, studies of short sediment cores reveal that hypoxia has been present in some of the deepest basins for at least the last 100-200 years. In addition, long sediment cores suggest that hypoxia in the Baltic Sea has occurred intermittently in deep basins over the last c. 8500 years. Thus, the occurrence of present day hypoxia in the deeper basins need not necessarily be attributed to human activity but rather to natural oceanographic, geologic and climate conditions. We present a compilation of previous publications that reported the occurrence of laminated sediments (i.e. a palaeo-proxy for hypoxia) in the Baltic Sea. This review shows that the deeper parts of the Baltic Sea have experienced either intermittent or more regular hypoxia during most of the Holocene and that more continuous laminations started to form c. 7800-8500 cal. yr BP ago, in association with the establishment of a permanent halocline during the transition from the Ancylus Lake to the Littorina Sea. Laminated sediments were more common during the early and late Holocene and coincided with intervals of high organic productivity (high TOC content) and high salinity during the Holocene Thermal Maximum and the Medieval Climate Optimum. This study

  8. Evidence of chromosomal damage in common eiders (Somateria mollissima) from the Baltic Sea

    USGS Publications Warehouse

    Matson, C.W.; Franson, J.C.; Hollmén, Tuula E.; Kilpi, Mikael; Hario, Martti; Flint, P.L.; Bickham, J.W.

    2004-01-01

    Common eiders nesting in the Baltic Sea are exposed to generally high levels of contaminants including potentially genotoxic polycyclic aromatic hydrocarbons and organochlorines. Blood samples were collected from eiders at eight sites in the Baltic Sea and two sites in the Beaufort Sea. DNA content variation was estimated using the flow cytometric method, and subsequently utilized as a biomarker of genetic damage. We observed no significant differences in genetic damage among populations within either the Baltic or Beaufort Seas. However, eider populations from the Baltic Sea had significantly elevated estimates of genetic damage compared to populations from the Beaufort Sea.

  9. Evidence of chromosomal damage in common eiders (Somateria mollissima) from the Baltic Sea.

    PubMed

    Matson, Cole W; Franson, J Christian; Hollmén, Tuula; Kilpi, Mikael; Hario, Martti; Flint, Paul L; Bickham, John W

    2004-12-01

    Common eiders nesting in the Baltic Sea are exposed to generally high levels of contaminants including potentially genotoxic polycyclic aromatic hydrocarbons and organochlorines. Blood samples were collected from eiders at eight sites in the Baltic Sea and two sites in the Beaufort Sea. DNA content variation was estimated using the flow cytometric method, and subsequently utilized as a biomarker of genetic damage. We observed no significant differences in genetic damage among populations within either the Baltic or Beaufort Seas. However, eider populations from the Baltic Sea had significantly elevated estimates of genetic damage compared to populations from the Beaufort Sea. PMID:15556194

  10. Mass Balance of Perfluoroalkyl Acids in the Baltic Sea

    PubMed Central

    2013-01-01

    A mass balance was assembled for perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorodecanoic acid (PFDA), and perfluorooctanesulfonic acid (PFOS) in the Baltic Sea. Inputs (from riverine discharge, atmospheric deposition, coastal wastewater discharges, and the North Sea) and outputs (to sediment burial, transformation of the chemical, and the North Sea), as well as the inventory in the Baltic Sea, were estimated from recently published monitoring data. Formation of the chemicals in the water column from precursors was not considered. River inflow and atmospheric deposition were the dominant inputs, while wastewater treatment plant (WWTP) effluents made a minor contribution (<5%). A mass balance of the Oder River watershed was assembled to explore the sources of the perfluoroalkyl acids (PFAAs) in the river inflow. It indicated that WWTP effluents made only a moderate contribution to riverine discharge (21% for PFOA, 6% for PFOS), while atmospheric deposition to the watershed was 1–2 orders of magnitude greater than WWTP discharges. The input to the Baltic Sea exceeded the output for all four PFAAs, suggesting that inputs were higher during 2005–2010 than during the previous 20 years despite efforts to reduce emissions of PFAAs. One possible explanation is the retention and delayed release of PFAAs from atmospheric deposition in the soils and groundwater of the watershed. PMID:23528236

  11. Methane fluxes and their controlling processes in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Rehder, G. J.; Fossing, H.; Lapham, L.; Endler, R.; Spiess, V.; Bruchert, V.; Nguyen, T.; Gülzow, W.; Schneider von Deimling, J.; Conley, D. J.; Jorgensen, B.

    2010-12-01

    The Baltic Sea is an ideal natural laboratory to study the methane cycle in the framework of diagenetic processes. With its brackish character and a gradient from nearly marine to almost limnic conditions, a strong permanent haline stratification leading to large vertical redox gradients in the water column, and a sedimentation history which resulted in the deposition of organic-rich young post-glacial sediments over older glacial and post-glacial strata with very low organic content, the Baltic allows to study the role of a variety of key parameters for early diagenetic processes including the methane cycle. Within the BONUS + Project “Baltic Gas”, a 3.5 week scientific expedition of RV Maria S. Merian in August 2010 was dedicated to study the methane cycle in the various basins of the Baltic Sea, with strong emphasis on the metabolic reactions of early diagenesis and the occurrence of shallow gas deposits. Various subbottom profiling systems were used to map the thickness and structure of organic-rich deposits and build the base for a detailed coring program for biogeochemical analysis, including methane, sulfur compounds, iron, and other compounds. Methane gradients in connection with the information of the areal extend of organic-rich deposits are used to estimate the diffusive flux from the sediments into the water column and the rate of methane oxidation, with changing importance of sulfate as oxidant along the salinity gradient. On selected key stations, rate measurements of methanogenic and methanotrophic reactions were executed. The methane distribution in the water column was comprehensively assessed, revealing amongst other findings a drastic increase in bottom water methane concentration between the post bloom summer situation and the situation in the winter of 2009, in connection to the occurrence of a benthic nepheloid layer. Air-sea flux measurements were executed along the ship’s track comprising all major basins of the Baltic. The talk gives

  12. Intrusion of radioactive industrially polluted water from North Sea into central Baltic Sea

    SciTech Connect

    Vakulovskiy, S.M.; Nikitin, A.I.

    1985-02-01

    The problem of penetration of radioactive industrially polluted water into the central Baltic Sea was studied. The content of Cs-134 as determined in water near the bottom of deep water trenches along the path traveled by North Sea water entering the Baltic. Samples were taken at 5 locations, with Cs-134 concentrated from samples of several thousands of liters. It was found that radioactive pollution caused by the entry of water from the North Sea extends through the system of deep water depressions into the Baltic as far as the Gotland trench. The greatest degree of contamination is found in the Arkona depression adjacent to the straits. The concentration of Cs-134 in the Gdansk trench is one-half as great and in the Gotland trench one-third as great as in the Arkona depression. Radioactive contamination in the Baltic is attributed to discharge of radioactive wastes by plants at Windscale.

  13. Evaluation of Baltic Sea transport properties using particle tracking

    NASA Astrophysics Data System (ADS)

    Dargahi, Bijan; Cvetkovic, Vladimir

    2014-05-01

    Particle tracking model (PTM) is an effective tool for quantifying transport properties of large water bodies such as the Baltic Sea. We have applied PTM to our fully calibrated and validated Baltic Sea 3D hydrodynamic model for a 10-years period (2000-9). One hundred particles were released at a constant rate during an initial 10-days period from all the Baltic Sea sub-basins, the major rivers, and the open boundary in the Arkona Basin. In each basin, the particles were released at two different depths corresponding to the deep water and middle water layers. The objectives of the PTM simulations were to analyse the intra-exchange processes between the Baltic Sea basins and to estimate the arrival times and the paths of particles released from the rivers. The novel contribution of this study is determining the paths and arrival times of deeper water masses rather than the surface masses. Advective and diffusive transport processes in the Bornholm and Arkona basins are both driven by the interacting flows of the northern basins of the Baltic Sea and the North Sea. Particles released from Arkona basin flows northwards along the Stople Channel. The Gotland basins are the major contributors to the exchange process in the Baltic Sea. We find high values of the advection ratio, indicative of a forced advective transport process. The Bay of Gdansk is probably the most vulnerable region in the Baltic Sea. This is despite the fact that the main exchanging basins are the Bornholm Sea and the Easter Gotland Basin. The main reason is the intensive supply of the particles from the northern basins that normally take about 3000 days to reach the Bay of Gdansk. The process maintains a high level of particle concentration (90%) along its coastlines even after the 10-years period. Comparing the particle paths in the Western and Eastern Gotland basins two interesting features were found. Particles travelled in all four directions in the former basin and the middle layer particles

  14. A new radiation model for Baltic Sea ecosystem modelling

    NASA Astrophysics Data System (ADS)

    Neumann, Thomas; Siegel, Herbert; Gerth, Monika

    2015-12-01

    Photosynthetically available radiation (PAR) is one of the key requirements for primary production in the ocean. The ambient PAR is determined by incoming solar radiation and optical properties of sea water and the optically active water constituents along the radiation pathway. Especially in coastal waters, the optical properties are affected by terrigenous constituents like yellow substances as well as high primary production. Numerical models for marine ecosystems account for the optical attenuation process in different ways and details. For the consideration of coloured dissolved organic matter (CDOM) and shading effects of phytoplankton particles, we propose a dynamic parametrization for the Baltic Sea. Furthermore, products from biological turnover processes are implemented. Besides PAR and its attenuation coefficient, the model calculates the Secchi disk depth, a simple measurable parameter describing the transparency of the water column and a water quality parameter in the European Water Framework Directive. The components of the proposed optical model are partly implemented from other publications respectively derived from our own measurements for the area of investigation. The model allows a better representation of PAR with a more realistic spatial and temporal variability compared to former parametrizations. The effect is that regional changes of primary production, especially in the northern part of the Baltic Sea, show reduced productivity due to higher CDOM concentrations. The model estimates for Secchi disk depth are much more realistic now. In the northern Baltic Sea, simulated oxygen concentrations in deep water have improved considerably.

  15. The diet of whiting Merlangius merlangus in the western Baltic Sea.

    PubMed

    Ross, S D; Gislason, H; Andersen, N G; Lewy, P; Nielsen, J R

    2016-05-01

    The diet of whiting Merlangius merlangus in the western Baltic Sea was investigated and compared to the diet in the southern North Sea. Clupeids were important prey in both areas, but especially in the western Baltic Sea where they constituted up to 90% of the diet of larger individuals. Gobies, brown shrimps and polychaetes were the main prey of juveniles in the western Baltic Sea, while a wider range of species were consumed in the North Sea. The shift to piscivory occurred at smaller sizes in the western Baltic Sea and the fish prey consumed was proportionately larger than in the southern North Sea. Estimates of prey abundance and food intake of M. merlangus are required to evaluate its predatory significance in the western Baltic Sea, but its diet suggests that it could be just as significant a fish predator here as in the southern North Sea. PMID:27005681

  16. Projected future climate change and Baltic Sea ecosystem management

    NASA Astrophysics Data System (ADS)

    Andersson, Agneta

    2015-04-01

    Climate change is likely to have large effects on the Baltic Sea ecosystem. Simulations indicate 2-4oC warming and 50-80% decreasing ice cover by 2100. Precipitation may increase ~30% in the north, causing increased land runoff of allochthonous organic matter (AOM) and organic pollutants. Salinity will decrease by about 2 units. Coupled physical-biogeochemical models indicate that in the south, bottom-water anoxia may spread, reducing cod recruitment and increasing sediment phosphorus release, promoting cyanobacterial blooms. In the north, heterotrophic bacteria will be favoured by AOM while phytoplankton may become hampered. More trophic levels in the food web will increase energy losses and consequently reduce fish production. Future management of the Baltic Sea must consider effects of climate change on the ecosystem dynamics and functions, as well as effects of anthrophogenic nutrient and pollutant load. Monitoring should have a holistic approach and encompass both autotrophic (phytoplankton) and heterotrophic (e.g. bacterial) processes.

  17. Numerical investigations of future ice conditions in the Baltic Sea.

    PubMed

    Haapala, J; Meier, H E; Rinne, J

    2001-08-01

    Global climate changes is expected to have an effect on the physical and ecological characteristics of the Baltic Sea. Estimates of future climate on the regional scale can be obtained by using either statistical or dynamical downscaling methods of global AOGCM scenario results. In this paper, we use 2 different coupled ice-ocean models of the Baltic Sea to simulate present and future ice conditions around 100 years from present. Two 10-year time slice experiments have been performed using the results of atmospheric climate model simulations as forcing, one representing pre-industrial climate conditions (control simulation), and the other global warming with a 150% increase in CO2 greenhouse gas concentration (scenario simulation). Present-day climatological ice conditions and interannual variability are realistically reproduced by the models. The simulated range of the maximum annual ice extent in the Baltic in both models together is 180 to 420 x 10(3) km2 in the control simulation and 45 to 270 x 10(3) km2 in the scenario simulation. The range of the maximum annual ice thickness is from 32 to 96 cm and from 11 to 60 cm in the control and scenario simulations, respectively. In contrast to earlier estimates, sea ice is still formed every winter in the Northern Bothnian Bay and in the most Eastern parts of the Gulf of Finland. Overall, the simulated changes of quantities such as ice extent and ice thickness, as well as their interannual variations are relatively similar in both models, which is remarkable, because the 2 coupled ice-ocean model systems have been developed independently. This increases the reliability of future projections of ice conditions in the Baltic Sea. PMID:11697256

  18. Deoxygenation of the Baltic Sea during the last century

    PubMed Central

    Carstensen, Jacob; Andersen, Jesper H.; Gustafsson, Bo G.; Conley, Daniel J.

    2014-01-01

    Deoxygenation is a global problem in coastal and open regions of the ocean, and has led to expanding areas of oxygen minimum zones and coastal hypoxia. The recent expansion of hypoxia in coastal ecosystems has been primarily attributed to global warming and enhanced nutrient input from land and atmosphere. The largest anthropogenically induced hypoxic area in the world is the Baltic Sea, where the relative importance of physical forcing versus eutrophication is still debated. We have analyzed water column oxygen and salinity profiles to reconstruct oxygen and stratification conditions over the last 115 y and compare the influence of both climate and anthropogenic forcing on hypoxia. We report a 10-fold increase of hypoxia in the Baltic Sea and show that this is primarily linked to increased inputs of nutrients from land, although increased respiration from higher temperatures during the last two decades has contributed to worsening oxygen conditions. Although shifts in climate and physical circulation are important factors modulating the extent of hypoxia, further nutrient reductions in the Baltic Sea will be necessary to reduce the ecosystems impacts of deoxygenation. PMID:24706804

  19. Regional Ocean Colour Remote Sensing Algorithm for the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Hieronymi, Martin; Muller, Dagmar; Krasemann, Hajo; Schonfeld, Wolfgang; Rottgers, Rudiger; Doerffer, Roland

    2015-12-01

    The Baltic Sea is a challenging study site from an optically point of view. Its partly highly absorbing waters are mainly associated with the presence of coloured dissolved organic matter and often accompanied by non-algae absorbing particles. In addition, the Baltic Sea area is characterised by massive annual surface blooms of cyanobacteria. In Europe, the Baltic Sea is a very specific and important case study with intense user interest. In the framework of different research projects as the “Ocean Colour Climate Change Initiative”, the “SEOM OC Extreme Case 2 Waters”, and partly “MyOcean”, we aim to develop an optimised, error-characterised, regional ocean colour processor applicable to several satellite sensors, like MODIS, MERIS, VIIRS, and OLCI. The procedure, which is used to determine inherent optical properties and different water constituents’ concentrations from remote sensing reflectance, is an artificial Neural Network (NN). We provide first results of comparisons of in-situ data with different ocean colour products.

  20. Genetic structure of whitefish (Coregonus maraena) in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Olsson, Jens; Florin, Ann-Britt; Mo, Kerstin; Aho, Teija; Ryman, Nils

    2012-01-01

    Stocks of whitefish ( Coregonus maraena) in the northern part of the Baltic Sea have in many areas declined drastically during recent years. Causes for the decline are yet not fully understood, but knowledge on the genetic population structure of the species is pivotal for future conservation measures. In this study we analyse the genetic variation at seven microsatellite loci for whitefish from 18 different sites along the Swedish coast of the Baltic Sea. We found a strong dependence of isolation by distance ( R = 0.73), and a week but rather fine scaled genetic structure. In addition, there were differences between more northern and southern sites in the population genetic structure, where the degree of differentiation appears to be stronger in the north compared to the south. The results suggest that whitefish is a species suitable for local management with a regional context of the management strategy. In addition, the findings corroborate what is previously known for other coastal fish species in the Baltic Sea, such as perch and pike, suggesting that the majority of gene flow occurs between adjacent areas. Finally, our results highlight the potential for genetic subdivision even when the dependence of isolation by distance is strong.

  1. Response of the Baltic and North Seas to river runoff from the Baltic watershed - Physical and biological changes

    NASA Astrophysics Data System (ADS)

    Hänninen, Jari; Vuorinen, Ilppo; Rajasilta, Marjut; Reid, Philip C.

    2015-11-01

    Selected Baltic Sea watershed River Runoff (BSRR) events during 1970-2000 were used as predictor in Generalised Linear Mixed Models (GLIMMIX) for evidence of simultaneous changes/chain of events (including possible time lags) in some chemical, physical and biological variables in the Baltic and North Sea ecosystems. Our aim was to explore for climatic-based explanation for ecological regime shifts that were documented semi-simultaneously in both ecosystems. Certain similarities were identified in the North Sea and the Baltic Sea salinity, oxygen concentration, temperature and phyto- and zooplankton parameters. These findings suggest that BSRR events which originate in the Baltic Sea catchment area modify and contribute to large scale ecosystem changes not only in the Baltic Sea, but also in the adjacent parts of the North Sea. However, the Baltic Sea inter-annual and inter-decadal variabilities of physical and biological parameters are driven by direct atmospheric forcing, typically with a relatively short lag. In contrast, such changes in the North Sea are influenced by both local and direct atmospheric forcing, typically with a longer lag than in the Baltic, and a more regional, indirect forcing from changes in the North Atlantic. We suggest that this interactive system partially is behind large scale ecosystem regime shifts found in both Seas. During our study period two such shifts have been identified independently from us in a study earlier in the Southern and Central Baltic in 1980s and 1990s and a later one in 2001/2002 in the North Sea. As a post hoc test we compared the 0+ year class strength of the North Sea herring with BSRR intensity, and found evidence for higher herring production in high BSRR periods, which further corroborates the idea of a remote effect from the large watershed area of the Baltic. Regime shifts as well as their semi-synchronous appearance in two neighbouring sea areas could be identified. GLIMMIX models provide opportunities for

  2. Access to distributed marine databases on the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Sokolov, A.; Axe, P.; Bock, S.; Kaitala, S.; Manscher, O. H.; Rodriguez-Medina, M.; Olsonen, R.; Priha, I.; Tikka, K.

    2012-04-01

    Baltic Nest Institute, Stockholm University (Sweden) in cooperation with Department of Bioscience/DCE, National Centre for Environment and Energy, Aarhus University (Denmark), Leibniz Institute for Baltic Sea Research (Germany), Finnish Environment Institute, Finnish Meteorological Institute and Swedish Meteorological and Hydrological Institute developed a data assessment system, aimed at providing tools for online analysis of marine environmental data (temperature, salinity, chemical properties) from distributed collection of databases on the Baltic Sea. Such approach allows users to have fast access to the most recent data from all major data providers and providers remain in control of their data. The system contains a web data portal, which provides concurrent access to distributed marine databases and presents information in a unified way. Two client programs use the data portal and provide tools to analyse the data. The DAS - Data Assimilation System (http://nest.su.se/das/) accesses databases through the data portal and allow analysing the raw data and creating gridded data, which can be used as initial fields for 3D hydrodynamic models. A decision support system Nest (http://nest.su.se/nest/) developed and maintained at the Stockholm University as a tool to support decision-making at international negotiations regarding the Baltic Sea environment also uses the data portal to access marine data, provide access to the raw data and perform time-series analysis. The data portal designed to output data in a common format (CSV) for further post-processing using other software. It makes the system open to develop another client programs for data analysis.

  3. Geodetic observation of sea-level change and crustal deformation in the Baltic Sea region

    NASA Astrophysics Data System (ADS)

    Richter, A.; Groh, A.; Dietrich, R.

    Based on tide gauge observations spanning almost 200 years, homogeneous time series of the mean relative sea level were derived for nine sites at the southern coast of the Baltic Sea. Our regionally concentrated data were complemented by long-term relative sea-level records retrieved from the data base of the Permanent Service for Mean Sea Level (PSMSL). From these records relative sea-level change rates were derived at 51 tide gauge stations for the period between 1908 and 2007. A minimum observation time of 60 years is required for the determination of reliable sea-level rates. At present, no anthropogenic acceleration in sea-level rise is detected in the tide gauge observations in the southern Baltic. The spatial variation of the relative sea-level rates reflects the fingerprint of GIA-induced crustal uplift. Time series of extreme sea levels were also inferred from the tide gauge records. They were complemented by water level information from historic storm surge marks preserved along the German Baltic coast. Based on this combined dataset the incidence and spatial variation of extreme sea levels induced by storm surges were analysed yielding important information for hazard assessments. Permanent GPS observations were used to determine recent crustal deformation rates for 44 stations in the Baltic Sea region. The GPS derived height change rates were applied to reduce the relative sea-level changes observed by tide gauges yielding an estimate for the eustatic sea-level change. For 13 tide gauge-GPS colocation sites a mean eustatic sea-level trend of 1.3 mm/a was derived for the last 100 years.

  4. Paleogeographic sedimentation settings in the northern Baltic Sea

    NASA Astrophysics Data System (ADS)

    Trimonis, E. S.; Emelyanov, E. M.; Vaikutene, G.

    2008-10-01

    The grain-size and chemical composition of the bottom sediments and their diatom assemblages from the northern Baltic Sea is discussed. Characteristic layers are distinguished based on the lithostratgraphy and sediment core correlation, which reflect the transition from the lacustrine to marine sedimentation settings during the initial Holocene. Sediment cores demonstrate lateral variations in the sedimentation patterns during the marine (Yoldia Sea), the lacustrine (Ancylus Lake), and the subsequent marine (Littorina Sea) stages: first two stages were characterized by the clay deposition, while the latter one featured accumulation of silty-clayey and clayey muds in bottom depressions. Sea-level fluctuations and corresponding environmental changes are recorded in microlaminated sequences, in particular, sapropelic muds.

  5. Characterisation of juvenile flatfish habitats in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Florin, Ann-Britt; Sundblad, Göran; Bergström, Ulf

    2009-04-01

    Survival and growth of the earliest life-stages is considered a key factor in determining the abundance of many marine fish species. For flatfishes, the availability of high quality nursery areas is essential for successful recruitment. Regarding the Baltic Sea, there are large gaps in knowledge on factors that influence the distribution of flatfishes during this sensitive stage. To identify the characteristics of important nursery areas in the Baltic for flounder ( Platichthys flesus) and turbot ( Psetta maxima), a field survey with push net sampling was conducted in the northern Baltic proper during autumn 2006. The sampling stations were stratified to cover several different habitat types defined by substrate and wave exposure. Apart from density of young-of-the-year (YOY) flatfishes, a number of ecological characteristics of the habitat were recorded. Physical habitat variables included substrate type, salinity, depth, turbidity, vegetation and habitat structure. Variables describing biotic processes, such as prey availability and abundance of competitors, were also sampled. The relationships between the spatial distribution of species and these ecological characteristics were fitted to presence/absence data of juvenile flatfish using generalized additive models (GAM). The best habitat descriptors for flounder in order of contribution were: substrate, habitat structure, salinity, wave exposure and occurrence of filamentous algae. Positive effects of increasing wave exposure, salinity and structure were detected while a high cover of filamentous algae had a negative effect. Sand and gravel were preferred over soft and stony substrates. For turbot the best habitat descriptors in order of contribution were: occurrence of filamentous algae, substrate and turbidity. Turbot showed a preference for areas with a low cover of filamentous algae, high turbidity and sandy substrate. Prey availability and abundance of competitors were not included in the models, indicating

  6. Optically black waters in the northern Baltic Sea

    NASA Astrophysics Data System (ADS)

    Berthon, Jean-François; Zibordi, Giuseppe

    2010-05-01

    The peculiar bio-optical properties of the northernmost waters of the Baltic Sea (Bothnian Sea and Bothnian Bay) are illustrated by exploiting unique in situ measurements of apparent and inherent optical properties collected in 2007. Specifically, this study shows that the high values of absorption by colored dissolved organic matter (ays(412) around 1.4 m-1) resulting from the presence of humic matter brought by the numerous Swedish and Finnish rivers alimenting the basin are not correlated with high concentrations of particles as generally observed in the southern Baltic Sea. As a consequence, extremely low values (i.e., less than 0.5) of the ratio of scattering to absorption are observed in the blue spectral region. The corresponding spectra of normalized water leaving radiance are close to satisfy the “black pixel” assumption in the blue and even in the green part of the visible spectrum. Consequently, the Bothnian Sea and most of all the Bothnian Bay, appear ideal candidates for studies on atmospheric corrections and vicarious calibration of ocean color sensors in coastal waters.

  7. Ice-ocean-ecosystem operational model of the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Janecki, M.; Dzierzbicka-Glowacka, L.; Jakacki, J.; Nowicki, A.

    2012-04-01

    3D-CEMBS is a fully coupled model adopted for the Baltic Sea and have been developed within the grant, wchich is supported by the Polish State Committee of Scientific Reasearch. The model is based on CESM1.0 (Community Earth System Model), in our configuration it consists of two active components (ocean and ice) driven by central coupler (CPL7). Ocean (POP version 2.1) and ice models (CICE model, version 4.0) are forced by atmospheric and land data models. Atmospheric data sets are provided by ICM-UM model from University of Warsaw. Additionally land model provides runoff of the Baltic Sea (currently 78 rivers). Ecosystem model is based on an intermediate complexity marine ecosystem model for the global domain (J.K. Moore et. al., 2002) and consists of 11 main components: zooplankton, small phytoplankton, diatoms, cyanobacteria, two detrital classes, dissolved oxygen and the nutrients nitrate, ammonium, phosphate and silicate. The model is configured at two horizontal resolutions, approximately 9km and 2km (1/12° and 1/48° respectively). The model bathymetry is represented as 21 vertical levels and the thickness of the first four layers were chosen to be five metres. 3D-CEMBS model grid is based on stereographic coordinates, but equator of these coordinates is in the centre of the Baltic Sea (rotated stereographic coordinates) and we can assume that shape of the cells are square and they are identical. Currently model works in a operational state. The model creates 48-hour forecasts every 6 hours (or when new atmospheric dataset is available). Prognostic variables such as temperature, salinity, ice cover, currents, sea surface height and phytoplankton concentration are presented online on a the website and are available for registered users. Also time series for any location are accessible. This work was carried out in support of grant No NN305 111636 and No NN306 353239 - the Polish state Committee of Scientific Research. The partial support for this study was

  8. Radiational tides at the southeastern coast of the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Rabinovich, A. B.; Medvedev, I. P.

    2015-05-01

    The tides in the Baltic Sea are weak but unmistakably recognizable in sea-level spectra. Multiyear hourly tide gauge series enable us to examine specific tidal properties in detail and to identify some unexpected effects. Two nearby stations on the southeastern coast of the sea, namely Baltiysk, located in the strait connecting the Vistula Lagoon to the Baltic Sea, and Otkrytoe, on the coast of the Curonian Lagoon, are found to have very different character of tidal motions. Based on 13 years of simultaneous observations at these stations we constructed high-resolution spectra of sea level fluctuations that demonstrated that the tidal spectrum at Baltiysk is "classical" with sharp peaks corresponding to the major tidal constituents: M2, S2, N2, K1, O1, and P1. Unlike at Baltiysk, the main tidal peak at Otkrytoe is at the S1 frequency; the K1, P1, and S2 tidal harmonics also have significant peaks, while the other harmonics (including M2 and O1) are undistinguishable. Further analysis indicated that the tides at Baltiysk are generated by ordinary gravitational tidal forces, while at Otkrytoe they are induced by solar radiation, specifically by the breeze winds creating wind setups and setdowns in the Curonian Lagoon. Moreover, our findings demonstrate that the observed K1 and P1 peaks at Otkrytoe are related not to gravitational forces but to the seasonal modulation of the S1 radiational tidal constituent. The separate analysis of the "summer" and "winter" sea level spectra at Otkrytoe reveals prominent radiational tidal peaks (S1 and S2) in summer and the absence of these peaks in winter. The results of the analysis support the assumption that these motions are generated by the breeze winds associated with the sea/land temperature contrasts, which are substantial during the warm (ice-free) season but vague during the cold season when ice cover diminishes these contrasts.

  9. [Accumulation of polycyclic arenes in Baltic Sea algae].

    PubMed

    Veldre, I A; Itra, A R; Paal'me, L P; Kukk, Kh A

    1985-01-01

    The paper presents data on the level of benzo(a)pyrene (BP) and some other polycyclic arenes in alga and phanerogam specimens from different gulfs of the Baltic Sea. Algae were shown to absorb BP from sea water. The mean concentration of BP in sea water was under 0.004 microgram/1, while in algae it ranged 0.1-21.2 micrograms/kg dry weight. Algae accumulate BP to a higher degree than phanerogams. The highest concentrations of BP were found in algae Enteromorpha while the lowest ones in Furcellaria. In annual green algae, BP level was higher in autumn, i. e. at the end of vegetation period, than in spring. Brown algae Fucus vesiculosus is recommended for monitoring polycyclic arene pollution in the area from Vormsi Island to Käsmu and green algae Cladophora or Enteromorpha in the eastern part of the Finnish Gulf. PMID:4060672

  10. Variational data assimilation problem for the Baltic Sea thermodynamics

    NASA Astrophysics Data System (ADS)

    Zakharova, Natalia; Agoshkov, Valery; Parmuzin, Eugene

    2015-04-01

    The most versatile and promising technology for solving problems of monitoring and analysis of the natural environment is a four-dimensional variational data assimilation of observation data. In such problems not only the development and justification of algorithms for numerical solution of variational data assimilation problems but the properties of the optimal solution play an important role. In this work the variational data assimilation problems in the Baltic Sea water area were formulated and studied. Numerical experiments on restoring the ocean heat flux and obtaining solution of the system (temperature, salinity, velocity, and sea surface height) in the Baltic Sea primitive equation hydrodynamics model with assimilation procedure were carried out. In the calculations we used daily sea surface temperature observation from Danish meteorological Institute, prepared on the basis of measurements of the radiometer (AVHRR, AATSR and AMSRE) and spectroradiometer (SEVIRI and MODIS). The spatial resolution of the model grid with respect to the horizontal variables amounted to 0.0625x0.03125 degree. The results of the numerical experiments are presented. This study was supported by the Russian Foundation for Basic Research (project 13-01-00753, project 14-01-31195) and project 14-11-00609 by the Russian Science Foundation. References: 1 E.I. Parmuzin, V.I. Agoshkov, Numerical solution of the variational assimilation problem for sea surface temperature in the model of the Black Sea dynamics. Russ. J. Numer. Anal. Math. Modelling (2012) 27, No.1, 69-94 2 Zakharova N.B., Agoshkov V.I., Parmuzin E.I., The new method of ARGO buoys system observation data interpolation. Russian Journal of Numerical Analysis and Mathematical Modelling. Vol. 28, Issue 1, 2013. 3 Zalesny V.B., Gusev A.V., Chernobay S.Yu., Aps R., Tamsalu R., Kujala P., Rytkönen J. The Bal-tic Sea circulation modelling and assessment of marine pollution, Russ. J. Numer. Analysis and Math. Modelling, 2014, V 29

  11. Hypoxia Sustains Cyanobacteria Blooms in the Baltic Sea

    PubMed Central

    2014-01-01

    Nutrient over-enrichment is one of the classic triggering mechanisms for the occurrence of cyanobacteria blooms in aquatic ecosystems. In the Baltic Sea, cyanobacteria regularly occur in the late summer months and form nuisance accumulations in surface waters and their abundance has intensified significantly in the past 50 years attributed to human-induced eutrophication. However, the natural occurrence of cyanobacteria during the Holocene is debated. In this study, we present records of cyanobacteria pigments, water column redox proxies, and nitrogen isotopic signatures for the past ca. 8000 years from Baltic Sea sediment cores. Our results demonstrate that cyanobacteria abundance and nitrogen fixation are correlated with hypoxia occurring during three main intervals: (1) ca. 7000–4000 B.P. during the Littorina transgression, (2) ca. 1400–700 B.P. during the Medieval Climate Anomaly, and (3) from ca. 1950 A.D. to the present. Issues of preservation were investigated, and we show that organic matter and pigment profiles are not simply an artifact of preservation. These results suggest that cyanobacteria abundance is sustained during periods of hypoxia, most likely because of enhanced recycling of phosphorus in low oxygen conditions. PMID:24512281

  12. Hypoxia sustains cyanobacteria blooms in the Baltic sea.

    PubMed

    Funkey, Carolina P; Conley, Daniel J; Reuss, Nina S; Humborg, Christoph; Jilbert, Tom; Slomp, Caroline P

    2014-01-01

    Nutrient over-enrichment is one of the classic triggering mechanisms for the occurrence of cyanobacteria blooms in aquatic ecosystems. In the Baltic Sea, cyanobacteria regularly occur in the late summer months and form nuisance accumulations in surface waters and their abundance has intensified significantly in the past 50 years attributed to human-induced eutrophication. However, the natural occurrence of cyanobacteria during the Holocene is debated. In this study, we present records of cyanobacteria pigments, water column redox proxies, and nitrogen isotopic signatures for the past ca. 8000 years from Baltic Sea sediment cores. Our results demonstrate that cyanobacteria abundance and nitrogen fixation are correlated with hypoxia occurring during three main intervals: (1) ca. 7000-4000 B.P. during the Littorina transgression, (2) ca. 1400-700 B.P. during the Medieval Climate Anomaly, and (3) from ca. 1950 A.D. to the present. Issues of preservation were investigated, and we show that organic matter and pigment profiles are not simply an artifact of preservation. These results suggest that cyanobacteria abundance is sustained during periods of hypoxia, most likely because of enhanced recycling of phosphorus in low oxygen conditions. PMID:24512281

  13. Projected future climate change and Baltic Sea ecosystem management.

    PubMed

    Andersson, Agneta; Meier, H E Markus; Ripszam, Matyas; Rowe, Owen; Wikner, Johan; Haglund, Peter; Eilola, Kari; Legrand, Catherine; Figueroa, Daniela; Paczkowska, Joanna; Lindehoff, Elin; Tysklind, Mats; Elmgren, Ragnar

    2015-06-01

    Climate change is likely to have large effects on the Baltic Sea ecosystem. Simulations indicate 2-4 °C warming and 50-80 % decrease in ice cover by 2100. Precipitation may increase ~30 % in the north, causing increased land runoff of allochthonous organic matter (AOM) and organic pollutants and decreased salinity. Coupled physical-biogeochemical models indicate that, in the south, bottom-water anoxia may spread, reducing cod recruitment and increasing sediment phosphorus release, thus promoting cyanobacterial blooms. In the north, heterotrophic bacteria will be favored by AOM, while phytoplankton production may be reduced. Extra trophic levels in the food web may increase energy losses and consequently reduce fish production. Future management of the Baltic Sea must consider the effects of climate change on the ecosystem dynamics and functions, as well as the effects of anthropogenic nutrient and pollutant load. Monitoring should have a holistic approach, encompassing both autotrophic (phytoplankton) and heterotrophic (e.g., bacterial) processes. PMID:26022318

  14. Simulated sea surface temperature and heat fluxes in different climates of the Baltic Sea.

    PubMed

    Döscher, Ralf; Meier, H E Markus

    2004-06-01

    The physical state of the Baltic Sea in possible future climates is approached by numerical model experiments with a regional coupled ocean-atmosphere model driven by different global simulations. Scenarios and recent climate simulations are compared to estimate changes. The sea surface is clearly warmer by 2.9 degrees C in the ensemble mean. The horizontal pattern of average annual mean warming can largely be explained in terms of ice-cover reduction. The transfer of heat from the atmosphere to the Baltic Sea shows a changed seasonal cycle: a reduced heat loss in fall, increased heat uptake in spring, and reduced heat uptake in summer. The interannual variability of surface temperature is generally increased. This is associated with a smoothed frequency distribution in northern basins. The overall heat budget shows increased solar radiation to the sea surface, which is balanced by changes of the other heat flux components. PMID:15264603

  15. Atmospheric circulation and storm events in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Surkova, G. V.; Arkhipkin, Victor S.; Kislov, Alexander V.

    2015-09-01

    The storm events in the Baltic Sea are examined in connection with the main weather patterns grouped into the circulation types (CTs), and their changes in present climate. A calendar of storms was derived from results of wave model SWAN (Simulating WAves Nearshore) experiments for 1948-2011. Based on this calendar, a catalogue of atmospheric sea level pressure (SLP) fields was prepared for CTs from the NCEP/NCAR dataset. SLP fields were then analyzed using a pattern recognition algorithm which employed empirical orthogonal decomposition and cluster analysis. For every CT we conducted an analysis of their seasonal and interannual changes, along with their role in storm event formation. An increase of the storm CTs' frequency in the second part of the 20th century was shown to be in a close agreement with teleconnection circulation patterns such as the Arctic Oscillation, North Atlantic Oscillation and the Scandinavian blocking.

  16. Variability of atmospheric circulation patterns associated with large volume changes of the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Lehmann, A.; Post, P.

    2015-10-01

    Salinity and stratification in the deep basins of the Baltic Sea are linked to the occurrence of Major Baltic Inflows (MBIs) of higher saline water of North Sea origin, which occur sporadically and transport higher saline and oxygenated water to deeper layers. Since the mid-1970s, the frequency and intensity of MBIs have decreased. They were completely absent between February 1983 and January 1993. However, in spite of the decreasing frequency of MBIs, there was no obvious decrease of larger Baltic Sea volume changes (LVCs). A LVC is defined by a total volume change of at least 100 km3. LVCs can be identified from the sea level changes at Landsort which is known to represent the mean sea level of the Baltic Sea very well. Strong inflows leading to LVCs are associated to a special sequence of atmospheric circulation patterns. Our analysis based on Jenkinson-Collison circulation (JCC) types confirms that most effective inflows occur if about a month before the main inflow period, eastern air flow with anticyclonic vorticity over the western Baltic prevails. These conditions reduce the mean sea level of the Baltic Sea and lead to an increased saline stratification in the Belt Sea area. An immediate period of strong to very strong westerly winds trigger the inflow and force LVCs/MBIs. The lack of MBIs coincide with a negative trend of eastern types and a parallel increase of western type JCCs.

  17. Spatial sensitivity of inorganic carbon to model setup: North Sea and Baltic Sea with ECOSMO

    NASA Astrophysics Data System (ADS)

    Castano Primo, Rocio; Schrum, Corinna; Daewel, Ute

    2015-04-01

    In ocean biogeochemical models it is critical to capture the key processes adequately so they do not only reproduce the observations but that those processes are reproduced correctly. One key issue is the choice of parameters, which in most cases are estimates with large uncertainties. This can be the product of actual lack of detailed knowledge of the process, or the manner the processes are implemented, more or less complex. In addition, the model sensitivity is not necessarily homogenous across the spatial domain modelled, which adds another layer of complexity to biogeochemical modelling. In the particular case of the inorganic carbon cycle, there are several sets of carbonate constants that can be chosen. The calculated air-sea CO2 flux is largely dependent on the parametrization chosen. In addition, the different parametrizations all the underlying processes that in some way impact the carbon cycle beyond the carbonate dissociation and fluxes give results that can be significantly different. Examples of these processes are phytoplankton growth rates or remineralization rates. Despite their geographical proximity, the North and Baltic Seas exhibit very different dynamics. The North Sea receives important inflows of Atlantic waters, while the Baltic Sea is an almost enclosed system, with very little exchange from the North Sea. Wind, tides, and freshwater supply act very differently, but dominantly structure the ecosystem dynamics on spatial and temporal scales. The biological community is also different. Cyanobacteria, which are important due to their ability to fix atmospheric nitrogen, and they are only present in the Baltic Sea. These differentiating features have a strong impact in the biogeochemical cycles and ultimately shape the variations in the carbonate chemistry. Here the ECOSMO model was employed on the North Sea and Baltic Sea. The model is set so both are modelled at the same time, instead of having them run separately. ECOSMO is a 3-D coupled

  18. Radioactive pollution of the waters of the baltic sea during 1986

    SciTech Connect

    Lazarev, L.N.; Kuznetsov, Yu.V.; Gedeonov, L.I.; Gavrilov, V.M.; Gritchenko, Z.G.; Ivanova, L.M.; Orlova, T.E.; Tishkova, N.A.

    1989-01-01

    Results are presented from an investigation of radioactive pollution of the waters of the Baltic Sea during 1986. Inhomogeneities in the pollution of this area of water, due to varying density of atmospheric radioactive fallout, are detected. It is found that among the radionuclides entering the surface of the Baltic Sea in 1986 as a result of atmospheric transport, the main one in terms of radiation dose is cesium-137. Comparisons are made of the level of cesium-137 content in the waters of the Baltic Sea in 1986 and in preceding years. It is noted that even in the most polluted regions of the sea the cesium-137 content was 500 times less than the maximum allowable concentration (MAC) in the USSR for drinking water. The first results of the determination of plutonium-239 and 240 in the Baltic Sea are presented.

  19. Recent trends in Sea ice in the southern and western Baltic and the North Sea

    NASA Astrophysics Data System (ADS)

    Holfort, Jürgen; Schmelzer, Natalija; Schwegmann, Sandra

    2016-04-01

    We analyzed sea ice charts and observations of a 50 year long period starting in 1961 to produce two climatological ice atlases, one for the western and southern Baltic and one for the German Bight and Limfjord. As the year to year variability is large we subdivided the 50 year into three overlapping 30 year periods (1961-1990, 1971-2000 and 1981-2010) to look for trends in the sea ice. In the southern and western Baltic as well as in the North Sea there was a clear decrease in the total frequency of ice occurrence. Other parameters like begin and end of the ice season, ice thickness, etc. did not show such clear signal and also showed larger regional differences. The ice conditions mainly changed in accordance with the changes in air temperature in the same period, although some more regional changes in some parameters were most probably also influenced by other factors like the deepening of fairways.

  20. The radiological exposure of man from radioactivity in the Baltic Sea.

    PubMed

    Nielsen, S P; Bengtson, P; Bojanowsky, R; Hagel, P; Herrmann, J; Ilus, E; Jakobson, E; Motiejunas, S; Panteleev, Y; Skujina, A; Suplinska, M

    1999-09-30

    A radiological assessment has been carried out considering discharges of radioactivity to the Baltic Sea marine environment since 1950. The sources of radioactivity that have been evaluated are atmospheric nuclear-weapons fallout, fallout from the Chernobyl accident in 1986, discharges of radionuclides from Sellafield and La Hague transported into the Baltic Sea, and discharges of radionuclides from nuclear installations located in the Baltic Sea area. Dose rates from man-made radioactivity to individual members of the public (critical groups) have been calculated based on annual intake of seafood and beach occupancy time. The dose rates to individuals from the regions of the Bothnian Sea and Gulf of Finland are predicted to be larger than from any other area in the Baltic Sea due to the pattern of Chernobyl fallout. The dose rates are predicted to have peaked in 1986 at a value of 0.2 mSv year-1. Collective committed doses to members of the public have been calculated based on fishery statistics and predicted concentrations of radionuclides in biota and coastal sediments. The total collective dose from man-made radioactivity in the Baltic Sea is estimated at 2600 manSv, of which approximately two-thirds originate from Chernobyl fallout, approximately one-quarter from atmospheric nuclear-weapons fallout, approximately 8% from European reprocessing facilities, and approximately 0.04% from nuclear installations bordering the Baltic Sea area. An assessment of small-scale dumping of low-level radioactive waste in the Baltic Sea in the 1960s by Sweden and the Soviet Union has showed that doses to man from these activities are negligible. Dose rates and doses from natural radioactivity dominate except for the year 1986 where dose rates to individuals from Chernobyl fallout in some regions of the Baltic Sea approached those from natural radioactivity. PMID:10568271

  1. Bacterial methanogenesis in holocene sediments in the Baltic Sea

    SciTech Connect

    Lein, A.Y.; Namsaraev, B.B.; Trotsyuk, V.Y.; Ivanov, M.V.

    1981-01-01

    Soviet biologists have found evidence of viable methanogenic microorganisms in mud samples collected in 1978 from the Baltic Sea by the research ship Academician Kurchatov. Experiments with radioactive carbon and direct measurements of the samples' methane concentrations led to several conclusions: (1) the process of bacterial methanogenesis occurs mainly via carbon dioxide reduction, (2) the methanogenic intensity depends on the depth of the deposited sediment and its distance from land; shallow-water sediments found in gulfs produced more methane than deepwater ones taken from low spots, (3) organic-matter consumption during bacterial methane reduction makes up 0.14-7.9 mg of carbon/kg of wet mud per year; this is over 20 times less than during bacterial sulfate reduction, (4) The bulk of the methane generated migrates from the muds into the water and (5) marine sediments are undersaturated with methane, suggesting that the methane migrates via filtration of pore waters, not by diffusion.

  2. On Suspended matter grain size in Baltic sea

    NASA Astrophysics Data System (ADS)

    Bubnova, Ekaterina; Sivkov, Vadim; Zubarevich, Victor

    2016-04-01

    Suspended matter grain size data were gathered during the 25th research vessel "Akademik Mstislav Keldysh" cruise (1991, September-October). Initial quantitative data were obtained with a use of the Coulter counter and subsequently modified into volume concentrations (mm3/l) for size intervals. More than 80 samples from 15 stations were analyzed (depth range 0-355 m). The main goal of research was to illustrate the spatial variability of suspended matter concentration and dispersion in Baltic Sea. The mutual feature of suspended matter grain size distribution is the logical rise of particle number along with descending of particle's size. Vertical variability of grain size distribution was defined by Baltic Sea hydrological structure, including upper mixed layer - from the surface to the thermocline - with 35 m thick, cold intermediate layer - from the thermocline to the halocline- and bottom layer, which lied under the halocline. Upper layer showed a rise in total suspended matter concentration (up to 0.6 mm3/l), while cold intermediate level consisted of far more clear water (up to 0.1 mm3/l). Such a difference is caused by the thermocline boarding role. Meanwhile, deep bottom water experienced surges in suspended matter concentration owing to the nepheloid layer presence and "liquid bottom" effect. Coastal waters appeared to have the highest amount of particles (up to 5.0 mm3/l). Suspended matter grain size distribution in the upper mixed layer revealed a peak of concentration at 7 μ, which can be due to autumn plankton bloom. Another feature in suspended matter grain size distribution appeared at the deep layer below halocline, where both O2 and H2S were observed and red/ox barrier is. The simultaneous presence of Fe and Mn (in solutions below red/ox barrier) and O2 leads to precipitation of oxyhydrates Fe and Mn and grain size distribution graph peaking at 4.5 μ.

  3. Denitrification in the water column of the central Baltic Sea

    NASA Astrophysics Data System (ADS)

    Dalsgaard, Tage; De Brabandere, Loreto; Hall, Per O. J.

    2013-04-01

    Removal of fixed nitrogen in the water column of the eastern Gotland Basin, central Baltic Sea, was studied during two cruises in September 2008 and August 2010. The water column was stratified with anoxic sulfidic bottom water meeting oxic nitrate containing water at the oxic-anoxic interface. Anammox was never detected whereas denitrification was found in all incubations from anoxic depths and occurred immediately below the oxic-anoxic interface. Sulfide (H2S + HS- + S2-) was in most cases the only electron donor for denitrification but, in contrast to previous findings, denitrification was in some situations driven by organic matter alone. Nitrous oxide (N2O) became an increasingly important product of denitrification with increasing sulfide concentration and was >80% of the total N gas formation at 10 μM sulfide. The potential rates of denitrification measured in incubations at elevated NO3- or sulfide concentrations were converted to in situ rates using the measured water column concentrations of NO3- and sulfide and the actual measured relations between NO3- and sulfide concentrations and denitrification rates. In situ denitrification ranged from 0.24 to 15.9 nM N2 h-1. Assuming that these rates were valid throughout the anoxic NO3- containing zone, depth integrated in situ denitrification rates of 0.06-2.11 mmol N m-2 d-1 were estimated. The thickness of this zone was generally 3-6 m, which is probably what can be maintained through regular turbulent mixing induced by internal waves at the oxic-anoxic interface. However, layers of up to 55 m thickness with low O2 water (<10 μM) were observed which was probably the result of larger scale mixing. In such a layer nitrification may produce NO3- and once the O2 has been depleted denitrification will follow resulting in enormous rates per unit area. Even with an active denitrification layer of 3-6 m thickness the pelagic denitrification per unit area clearly exceeded sediment denitrification rates elsewhere in

  4. Magnetic enhancement of Baltic Sea sapropels by greigite magnetofossils

    NASA Astrophysics Data System (ADS)

    Reinholdsson, M.; Snowball, I.; Zillén, L.; Lenz, C.; Conley, D. J.

    2013-03-01

    Magnetotactic bacteria (MTB) are known to biosynthesise single-domain magnetite (Fe3O4) for geomagnetic navigation and their relict magnetosomes (called magnetofossils) can control the magnetic properties of lake and marine sediments. Magnetotactic bacteria also produce greigite (Fe3S4) magnetosomes but, compared to those made of magnetite, relatively little is known about the sedimentary environments where they are produced and the magnetic properties of the preserved particles. We studied the magnetic properties of sediment cores from two basins (the North Central Baltic Proper and eastern Gotland Basin) that currently experience hypoxia and we discovered the magnetic enhancement of older laminated sapropels, which are a signal of past occurrences of anoxia and hypoxia in the Baltic Sea. Magnetic concentrates extracted from the laminated sapropels were characterised by transmission electron microscopy and energy dispersive X-ray spectrometry and we identified only single-domain greigite (Fe3S4) particles with a mean size of 55×75 nm, which we interpret as magnetofossils due to diagnostic chains of individual particles separated by an intact dividing membrane. The degree of magnetic enhancement in the laminated sapropels has a positive relationship with loss-on-ignition data, which indicates a link between the production of greigite magnetosomes, organic matter supply and preservation and redox conditions. The coercive force of collections of non-interacting greigite magnetofossils is ∼13 mT, which is considerably lower than the magnetite counterparts (∼30 mT) and strictly non-bacterial and larger greigite single-domain grains (∼60 mT). The values of the interparametric ratios of SIRM/χ, χARM/SIRM and χARM/χ that we obtain for our greigite magnetofossils overlap with those previously considered to be diagnostic of magnetosomal magnetite. The presence of bacterial greigite, which is easily detected by magnetic measurements, forms a proxy for hypoxia and

  5. Stable isotope signals of eutrophication in Baltic Sea sediments

    NASA Astrophysics Data System (ADS)

    Voss, Maren; Larsen, Birger; Leivuori, Mirja; Vallius, Henry

    2000-07-01

    Increasing δ15N and δ13C values in coastal Baltic marine sediments are evaluated as indicator of changes in the trophic status of the ecosystem. The influence of eutrophication on the δ15N values was found to be so dominant that it even overprints the usually observed mixing gradient from terrestrial (low isotope values) to the marine environment (high isotope values). A distinct gradient in stable nitrogen isotope values from eutrophic coastal areas to open more oligotrophic waters in the central Baltic Sea and Gulf of Bothnia was found. Our data show high δ15N values in surface sediments: 13‰ in the Oder Lagoon and the Pomeranian Bight, over 9‰ in the Gulf of Riga (Daugava River), 7‰ in the inner Gulf of Finland (Neva River), 6.5‰ in the Curonian Lagoon (Nemunas River), and 5.7‰ in the Gdansk Deep (Vistula River). In the Baltic Sea Proper, significantly lower δ15N values of 3-5‰ are found. A decrease in δ15N values with depth/age of the sediment was indicated in some cores that were analyzed down to 15-40 cm depth in 1-cm steps. There is a great overall difference between pre-industrial δ15N values in coastal sediments and recent ones of 2.3-10‰. As explanations for this increase are suggested, elevated nutrient δ15N values of waste water in combination with fractionation processes like nutrient uptake by phytoplankton and denitrification and nitrification processes in rivers discharging into the coastal water. Delta 13C values in sediment surfaces off the river estuaries primarily indicate differences between the inorganic carbon signatures of the rivers. However, since the δ13C values also decrease downcore, we contribute this change to increased primary production caused by the enhanced nutrient load. Since both stable isotope values in sediments ( δ13C and δ15N) correlate downcore, this strongly suggests that the anthropogenic nutrient loads in the rivers might be the reason for the changes of stable isotope values.

  6. Tritium volume activity in the Baltic Sea in 1987-1989

    SciTech Connect

    Styro, D.B.; Korotkov, V.P.

    1994-11-01

    Tritium volume activities measured in the Baltic Sea are summarized in this paper. Activity levels were determined by the liquid scintillation method with a LS-1000 counter. The field investigations showed that the tritium volume activity in the Baltic Sea can change substantially in absolute magnitude. Therefore, average volume activity is used as an indicator of natural content. Correlations between calculated (averaged) tritium activity levels and the Chernobyl accident are very briefly discussed. 7 refs., 2 figs., 1 tab.

  7. Investigating the influence of sea level oscillations in the Danish Straits on the Baltic Sea dynamics

    NASA Astrophysics Data System (ADS)

    Tikhonova, Natalia; Gusev, Anatoly; Diansky, Nikolay; Zakharchuk, Evgeny

    2016-04-01

    In this research, we study the influence of dynamic processes in the Danish Straits on the sea surface height (SSH) oscillations in the Baltic Sea. For this purpose, we use the model of marine and oceanic circulation INMOM (Institute of Numerical Mathematics Ocean Model). The simulations were carried out for the period 2009-2010, and the coastal station data were used for verification of SSH modelling quality. Comparison of the simulated data with the ones measured in the coastal points showed us that the model does not describe SSH variability in different areas of the Baltic Sea well enough, so in the following simulation series the in situ SSH data of the coastal measurements were assimilated at the open boundary in the Danish Straits. The results of the new simulation showed us that this approach significantly increases the SSH simulation quality in all areas of the sea, where the comparison was made. In particular, the correlation coefficients between the simulated and measured SSH data increased from 0.21-0.73 to 0.81-0.90. On the basis of these results, it has been suggested that the Baltic Sea SSH variability is largely determined by the influence of the dynamic processes in the Danish Straits, which can be represented as a superposition of oscillations of different space-time scales. These oscillations can either be generated in the straits themselves, or propagate from the North Sea. For verification of this hypothesis and assessment of the oscillation propagation distance in the Baltic Sea, the following experiment was performed. At the open boundary in the Danish Straits, the six harmonics were set with the following parameters: the periods are 1.5, 3.0, 6.0, 13.5, 40.5, and 121.5 days, and the amplitude for all the harmonics is 50 cm. The results showed us that the prescribed harmonic oscillations at the open boundary propagate into all areas of the sea without changing the frequency, but with decreasing amplitude. The decrease in amplitude is not

  8. Physical processes in the transition zone between North Sea and Baltic Sea. Numerical simulations and observations

    NASA Astrophysics Data System (ADS)

    Stanev, Emil V.; Lu, Xi; Grashorn, Sebastian

    2015-09-01

    The dynamics in the transition zone between the North Sea and Baltic Sea are analyzed here using data from a 22-year-long climatic simulation with a focus on the periods 1992-1994 and 2001-2003 when two recent major inflow events occurred. Observations from gauges and in situ measurements are used to validate the model. Parameters, which cannot be easily measured, such as water and salt transports through straits, have been compared against similar previous estimates. The good performance of simulations is attributed to the finer resolution of the model compared to earlier set ups. The outflow in the Kattegat, which is an analogue of the tidal outflows, tends to propagate to the North over the shallows without showing a substantial deflection to the right due to the Earth's rotation. The inflow follows the topography. The different inflow and outflow pathways are explained as a consequence of the specific combination of bathymetry, axial and lateral processes. The circulation in Kattegat is persistently clockwise with an eastern intensification during inflow and a western one during outflow regimes. The tidal wave there propagates as Kelvin wave, keeping the coast on its right. The flows in the two main straits reveal very different responses to tides, which are also highly asymmetric during inflow and outflow conditions. The circulation has a typical two-layer structure, the correlation between salinity and velocity tends to increase the salt transport in the salinity conveyor belt. The transversal circulation in the entrance of the Sound enhances the vertical mixing of the saltier North Sea water. The long-term averaged ratio of the water transports through the Great Belt and the Sound is ∼2.6-2.7 but this number changes reaching lower values during the major inflow in 1993. The transports in the straits are asymmetric. During inflow events the repartition of water penetrating the Baltic Sea is strongly in favor of the pathway through the Sound, which provides

  9. Transferrin variants as markers of migrations and admixture between populations in the Baltic Sea region.

    PubMed

    Beckman, L; Sikström, C; Mikelsaar, A V; Krumina, A; Ambrasiene, D; Kucinskas, V; Beckman, G

    1998-01-01

    Transferrin (TF) types were examined by isoelectric focusing in an attempt to elucidate migrations and admixture between populations in the Baltic Sea region. A highly significant heterogeneity between populations was found with respect to TF*C subtypes as well as the rare TF variants B2, B0-1 and DCHI. With the exception for Estonia, increased frequencies of the TF*C3 allele were observed east of the Baltic Sea. The island of Gotland in the middle of the Baltic Sea also showed a high TF*C3 frequency indicating an eastern influence. The TF*DCHI allele, a marker of eastern (Finno-Ugric) influence, was found in Finland and Estonia and on the island of Gotland, but not in mainland Sweden and in the Baltic peoples (Latvians and Lithuanians). These results indicate the presence of a Finno-Ugric, most likely Estonian or Livonian, genetic influence in the Gotland population. PMID:9694249

  10. Iron cycling microbial communities in sediments of the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Reyes, Carolina; Delwig, Olaf; Noriega-Ortega, Beatriz; Dähnke, Kirstin; Böttcher, Michael E.; Friedrich, Michael W.

    2014-05-01

    The biogeochemical cycling of iron is a key early diagenetic process. However, limited information exists about the diversity and metabolic pathways of microorganisms linked to iron cycling in marine sediments. The goal of this study was to determine the bacterial community diversity in sediments showing ongoing dissimilatory iron reduction using 454-pyrosequencing as a first step in characterizing microorganisms potentially involved in iron reduction. For this purpose, two 35 cm cores were sampled from ferruginous sediments in the Skagerrak (SK) and the Bothnian Bay (BB) from the North-Sea Baltic Sea and the northern Baltic Sea respectively. Pore water profiles showed Fe2+ and Mn2+ levels of ~140-150 µM throughout the core below a 6 cm thick oxidized surface layer in SK sediments and ~300 µM below a 2 cm thick surface layer in BB sediments. Dissolved sulphide levels were below detection in both sediments. No significant depletion of SO42- occurred at both sites, further supported by stable S and O isotope analyses of dissolved sulfate at SK site. Only very minor net sulfate reduction is suggested here from the trend in sulphur isotope signatures, in agreement with previously reported gross microbial sulphate rate measurements (Canfield et al., 1993;GCA). Based on these biogeochemical constraints, Fe reduction in the studied sediments is therefore dominated by microbial dissimilatory iron reduction, while cryptic Fe-S-cycling can be largely excluded. 16S rRNA gene sequences indicate Proteobacteria as the dominating microbial group in these sediments. Potential iron and manganese reducing bacteria included Geobacteraceae, Pelobacteraceae, Shewanellaceae, and Oceanospirillales. Additionally, Actinobacteria and Bacteroidetes were present. Also, Fe-oxidizers were present and their occurrence correlated in depth with a Fe-oxide-rich layer, most likely a former buried Fe-oxidation front. Gene sequences point to the presence of Mariprofundus in SK sediments and

  11. Fresh oxygen for the Baltic Sea — An exceptional saline inflow after a decade of stagnation

    NASA Astrophysics Data System (ADS)

    Mohrholz, V.; Naumann, M.; Nausch, G.; Krüger, S.; Gräwe, U.

    2015-08-01

    The ecological state of the Baltic Sea depends crucially on sufficiently frequent, strong deep water renewal on the periodic deep water renewal events by inflow of oxygen rich saline water from the North Sea. Due to the strong density stratification these inflows are the only source for deep water ventilation. Since the early eighties of the last century the frequency of inflow events has dropped drastically from 5 to 7 major inflows per decade to only one inflow per decade. Wide spread anoxic conditions became the usual state in the central Baltic. The rare major Baltic inflow (MBI) events in 1993 and 2003 could interrupt the anoxic bottom conditions only temporarily. After more than 10 years without a major Baltic inflow events, in December 2014 a strong MBI brought large amounts of saline and well oxygenated water into the Baltic Sea. Based on observations and numerical modeling, the inflow was classified as one of the rare very strong events. The inflow volume and the amount of salt transported into the Baltic were estimated to be with 198 km3 and 4 Gt, respectively. The strength of the MBI exceeded considerably the previous 2003 event. In the list of the MBIs since 1880, the 2014 inflow is the third strongest event together with the MBI in 1913. This inflow event will most probably turn the entire Baltic deep water from anoxic to oxic conditions, with substantial spread consequences for marine life and biogeochemical cycles.

  12. Horizontal Variation of Bacterioplankton in the Baltic Sea

    PubMed Central

    Heinänen, Anne; Kuparinen, Jorma

    1991-01-01

    Variations in the thymidine incorporation rate, bacterial abundance, and mean cell volumes in the surface water (0.5 m) of the Baltic Sea in spring and summer were compared in studies with different spatial scales (570 nautical miles [nmi] [ca. 1056 km], 220 nmi [ca. 407 km], 24 nmi [ca. 44 km], 12 nmi [ca. 22 km], and 200 m). The objective of the comparison was to investigate whether a single sample taken at one sampling point is representative enough for researchers to make generalizations about a larger water area. Bacterioplankton variation was connected more to seasonal characteristics than to the spatial scale of sampling. Variation was greater and more random in spring than in summer. The state variables (bacterial abundance and mean cell volume) varied less than the rate variable (thymidine incorporation). The results suggest that the sampling design for bacterioplankton studies in northern temperate seas should be planned primarily according to the season and that more stress should be put on rate variable measurements than on those of state variables. PMID:16348580

  13. Non-tidal loading by the Baltic Sea: comparison of modelled deformation with GNSS time series

    NASA Astrophysics Data System (ADS)

    Nordman, Maaria; Virtanen, Heikki; Nyberg, Sonja; Mäkinen, Jaakko; Virtanen, Jenni

    2013-04-01

    The Baltic Sea is a well-monitored semi-enclosed sea in northern Europe. The mass variations of the Baltic Sea are mostly due to atmospheric pressure changes and wind, which redistribute the water within the basin and also govern the so-called fill level, the amount of water exchange with the North Sea. The variations in the sea level can be abrupt and and large, for example during storms. The variable load may cause significant effects in geodetic measurements, especially near the coastline. We have computed the time series of non-tidal loading due to Baltic Sea for 193 stations in northern Europe. These stations are used for GNSS, absolute and relative gravity measurements and other geodetic observations.. We have used hourly observations of the sea level at the tide gauges of the Baltic Operational Oceanographic Service (BOOS, http://boos.org) to estimate the momentary sea level over the whole basin of the Baltic Sea. These sea level models are then convolved with Green's functions for the Gutenberg-Bullen Earth model using program SPOTL (Agnew, 2012, http://escholarship.org/uc/item/954322pg) to obtain gravity change, deformation in three dimensions and change in tilt and strain. The time period is four years, February 2008 to February 2012. The time series could be used for several purposes, e.g. for the studies of other error sources, to create stable time series and also to correct campaign measurements, which take place in varying conditions. In this study we have compared the computed deformation to coordinate changes measured by GNSS at selected stations around the Baltic Sea. We use two different daily time series of GNSS positions: the PPP (Precise Point Positioning) time series provided by Jet Propulsion Laboratory (JPL, http://sideshow.jpl.nasa.gov/post/series.html) and a double difference solution computed at our institute.

  14. Geological Storage od CO2 in the Southern Baltic Sea

    NASA Astrophysics Data System (ADS)

    Vernon, Richard; O'Neill, Nick; Pasquali, Riccardo; Niemi, Auli

    2014-05-01

    Geological Storage of CO2 in the Southern Baltic Sea Region The BASTOR project identifies and characterises the potential CO2 storage sites in the southern Baltic Sea. A regional theoretical storage capacity of 16Gt of CO2 in the Middle Cambrian sandstone beneath 900 metres of cap rock was estimated. 1.9Gt of this storage potential is estimated in the Dalders Monocline with some 743Mt CO2 in individual hydrocarbon and saline aquifer structures located mainly offshore Latvia and 128Mt in the Dalders Structure. Although the study has established a relatively large theoretical storage capacity, there is no effective capacity proven within these totals. Dynamic modelling undertaken in the Southern Swedish sector suggests that the relatively poor permeability and porosity characteristics would limit the injection rate to 0.5Mt per well per annum and restrict the reservoir pressure increase to 50% above the hydrostatic pressure for an injection period of 50 years. The dynamic modelling for this area suggests that an injection strategy for this sector would be limited to 5 injection wells giving a total injection capacity of 2.5 Mt per annum. Based on these results, the potential of the Southern Swedish offshore sector to sustain injection rates of CO2 required for regional industrial capture, even when using horizontal wells, brine extraction and hydraulic fracturing, would appear to be very low. Areas to the north east of the Monocline, such as offshore Latvia have been identified as having better reservoir quality despite limited data being available. These areas could sustain higher rates of injection and prove suitable areas for commercial storage. Furthermore, the regional storage capacity assessment demonstrated that there are sweet spots in the Cambrian reservoir such as onshore Latvia, where there is commercial gas storage, and both onshore and offshore Kaliningrad, where there is ongoing hydrocarbon production. The potential for seal failure was investigated as

  15. Long-term variability of extreme waves in the Caspian, Black, Azov and Baltic Seas

    NASA Astrophysics Data System (ADS)

    Arkhipkin, Victor; Dobroliubov, Sergey

    2013-04-01

    In order to study extreme storm waves in the Caspian, Black, Azov and Baltic Sea we used the spectral wave model SWAN. Significant wave height, swell and sea height, direction of propagation, their length and period were calculated with the NCEP/NCAR (1,9°x1,9°, 4-daily) reanalysis wind forcing from 1948 to 2010 in the Caspian, Black and Baltic Seas and with the NCEP/CFSR (0,3°x0,3°, 1 hour) for the period from 1979 to 2010 in the Azov Sea. The calculations were performed on supercomputers of Lomonosov Moscow State University (MSU). The spatial resolution of the numerical grid was of order 5 km for the Caspian, Baltic and Black Seas, 2 km for the Azov Sea. These model wave hindcasts were used to calculate interannual and seasonal variability of the storm frequency, location and duration. The Initial Distribution Method and Annual Maxima Series Methods were used to study probable waves of a century reoccurrence. The long-term variability of extreme waves revealed different trends in the investigated seas. The Caspian and Azov seas decreased the storm activity, while in the Baltic Sea the number of storm cases increased and the Black Sea showed no significant trend. The of more than 12 m were observed in two centers in the middle part of the Caspian Sea and in the center of the Baltic Sea. In the Black Sea the extreme waves of the same probability of more than 14 m were found in the region to the south of the Crimean peninsula. In the Azov Sea the highest waves of a century reoccurrence do not exceed 5 m. The work was done in Natural Risk Assessment Laboratory, MSU under contract G.34.31.0007.

  16. Foraminiferal stable isotope constraints on salinity changes in the deglacial and early Holocene Baltic Sea region

    NASA Astrophysics Data System (ADS)

    Quintana Krupinski, Nadine; Filipsson, Helena; Bokhari-Friberg, Yasmin; Knudsen, Karen-Luise; Mackensen, Andreas; Groeneveld, Jeroen; Austin, William

    2015-04-01

    The northern European Baltic Sea shows evidence of strong coupling with North Atlantic climate over recent glacial-interglacial cycles, but existing climate proxy evidence from regional sediment records suggest that the coupling may occur through non-linear processes. High-resolution regional climate records in Europe and from the Baltic Sea are critical for evaluating this coupling and the regional sensitivity to North Atlantic and global climate signals. However, evaluating the drivers and mechanisms of proposed links between the North Atlantic and Baltic Sea climate has often been hampered by a lack of long, continuous, high-resolution climate records from this area. New high-resolution sediment cores collected by IODP/ECORD Expedition 347 (Baltic Sea Paleoenvironment) allow such records to be generated, including foraminiferal geochemistry records of Baltic Sea hydrographic conditions during the most recent deglaciation and early Holocene (~19-7 cal. ka). The dramatic changes in salinity, sea level, circulation, temperature, and oxygenation during this period, e.g. through massive meltwater release from proglacial lakes and the early Holocene inundation of the Baltic by seawater highlight these non-linear links between the Baltic and North Atlantic. This work uses benthic foraminiferal stable isotope records (δ18O and δ13C) from sites in the western Baltic (M0059, Lillebælt, early Holocene marine stage (Littorina Sea)) and Kattegat (M0060, Anholt, deglaciation) to constrain salinity changes during these intervals. Because of the dramatic changes in salinity this region experiences today and during the study periods, oxygen isotope records (δ18O) here primarily reflect a signal of changing salinity, with a reduced temperature effect. Early δ18O results from the western Baltic (M0059) show a trend of declining δ18O/salinity during the first several kyr of the Littorina Sea stage, in agreement with previous work indicating declining salinity due to gradual

  17. Using satellite data to estimate partial pressure of CO2 in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Parard, Gaëlle; Charantonis, Anastase Alexandre; Rutgersson, Anna

    2016-03-01

    In this study we focused on estimating the pressure partial of CO2 (pCO2) in the entire Baltic Sea which can be considered a coastal area in its entirety. We used the self-organizing multiple linear output (SOMLO) method to estimate the ocean surface pCO2 in the Baltic Sea from the remotely sensed sea surface temperature, chlorophyll a, colored dissolved organic matter, net primary production, and mixed-layer depth. Uncertainties in the estimates include sparsity of in situ data used to train the algorithms, in particular, for some sectors and seasons. For this application we divided the Baltic Sea in four basins. When comparing the results obtained with this division to those obtained in previous studies, we notice a decrease in the root-mean-square error (<40 μatm) between the reconstruction of the pCO2 and their corresponding in situ measurements, as well as an increase of the correlation coefficient (> 0.96) between them. The outputs of this research have a horizontal resolution of 4 km and cover the 1998-2011 period. For the first time, a climatological mean distribution of surface water pCO2 over the Baltic Sea was calculated based on the SOMLO method with a mean pCO2 of 368.3 ± 100 μatm, and a range of 234-514 μatm. The seasonal variability is similar throughout the Baltic Sea, being high in winter and low in summer.

  18. Microsatellite variation in ringed seals (Phoca hispida): genetic structure and history of the Baltic Sea population.

    PubMed

    Palo, J U; Mäkinen, H S; Helle, E; Stenman, O; Väinölä, R

    2001-05-01

    Genetic variability and population structure of Baltic ringed seals and an Arctic reference population were assessed using eight microsatellite loci. Ringed seals colonized the Baltic Sea basin soon after deglaciation 11 500 years ago and are supposed to have remained largely isolated from the main Arctic stock since then, approximately 1000 generations. In the 1900s the Baltic population declined rapidly, and is now confined to three distinct breeding areas, with N < 6000 seals altogether. Microsatellite heterozygosity in ringed seals was higher than that in the closely related, boreal harbour seal and grey seal, for which the markers were initially developed. This is plausibly attributed to an overall greater population (species) size of ringed seals during the Quaternary. Allele frequency differentiation between the Baltic and Arctic ringed seals, conventionally treated as different subspecies, was weak. Assuming complete isolation, the divergence (FST=0.023) would imply a notably high postglacial effective population size, approximately 20 000 for the Baltic population. The isolation assumption however, seems unrealistic in the light of the data: a coalescent-based simulation approach to the likelihood of alternative demographic histories clearly favoured a scenario with recurrent gene flow to the Baltic, over one of complete isolation (drift only). Within the Baltic Sea, no differentiation was found between the Gulf of Finland and the Gulf of Bothnia breeding areas; the recent population decline and split have not yet affected the inbreeding levels of the disjunct breeding stocks. PMID:11554977

  19. Sea-surface altimetry airborne observations using synoptic GNSS reflectometry at the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Ribó, Serni; Fabra, Fran; Cardellach, Estel; Li, Weiqiang; Rius, Antonio; Praks, Jaan; Rouhe, Erkka; Seppänen, Jaakko; Martín-Neira, Manuel

    2016-04-01

    Recent GNSS-R (Global Navigation Satellite System-Reflections) observations over the Baltic Sea have been taken using the SPIR (Software PARIS Interferometric Receiver) from an airborne platform at 3 km altitude. This newly developed instrument is capable of acquiring GNSS signals transmitted by multiple satellites simultaneously that have been reflected of the sea-surface. Reflections are usually gathered in off-nadir configuration using the instrument's beam-forming capabilities, which results in an increase of the instrument's swath. In this way, this technique opens the door to densify in space and time sea-altimetry observations to enhance future mesoscale and sub-mesoscale ocean altimetry. The altimetric observations collected during the Baltic Sea campaign have been analysed in terms of their power spectral densities. We consider the sequence of observations as an ergodic process that has contributions from the actual true altimetry as well as the observation noise. In this way it is possible to relate the expected ground resolution of the observations with the obtainable altimetric uncertainty. Results will be presented.

  20. Inactivated phosphorus by added aluminum in Baltic Sea sediment

    NASA Astrophysics Data System (ADS)

    Rydin, Emil

    2014-12-01

    Decreased phosphorus (P) retention in aquatic sediments during hypoxic periods results in increased P recycling to the water column. To revert to less productive conditions in the enclosed bays of the Baltic Sea archipelago, increased sediment P burial capacity is needed. Aluminum (Al) addition is considered to be a cost-effective lake restoration method, as it improves sediment P burial capacity. However, little is known about its ability to permanently bind P in brackish systems. In summer 2000, Al sulfate granules were added to a hypoxic bottom area in the Östhammar bay, Sweden. Sediment core samples from the area were collected 10 years later. A peak in Al and P was detected at 20 cm sediment depth, reflecting the added Al and P trapped to it. Only part of the added Al was recovered, but the recovered Al (8 g Al/m2) trapped P at a ratio of 5:1 (molar). Chemical fractionation showed that P extracted as 'Al-P' constituted 55% of the trapped P, indicating that Al added also trapped P extracted as other P forms.

  1. Assessment of Marine Mammal Impact Zones for Use of Military Sonar in the Baltic Sea.

    PubMed

    Andersson, Mathias H; Johansson, Torbjörn

    2016-01-01

    Military sonars are known to have caused cetaceans to strand. Navies in shallow seas use different frequencies and sonar pulses, commonly frequencies between 25 and 100 kHz, compared with most studied NATO sonar systems that have been evaluated for their environmental impact. These frequencies match the frequencies of best hearing in the harbor porpoises and seals resident in the Baltic Sea. This study uses published temporary and permanent threshold shifts, measured behavioral response thresholds, technical specifications of a sonar system, and environmental parameters affecting sound propagation common for the Baltic Sea to estimate the impact zones for harbor porpoises and seals. PMID:26610942

  2. Metazoan parasites from herring (Clupea harengus L.) as biological indicators in the Baltic Sea.

    PubMed

    Unger, Patrick; Klimpel, Sven; Lang, Thomas; Palm, Harry Wilhelm

    2014-09-01

    Zoographical distribution of metazoan fish parasites in herring, Clupea harengus, from the Baltic Sea was analysed in order to use them as potential biological indicators. A total of 210 herring from six different sampling sites were investigated, harbouring 12 different parasite species [five digeneans (D), one cestode (C), three nematodes (N) and three acanthocephalans (A)]. The distribution of the parasite species differed according to region, with a distinct gradient of decreasing species richness towards the east of the Baltic Sea. The western localities at Kiel Bay, Rügen and Poland had the highest parasite diversity, including the marine parasite species Anisakis simplex (s.s.) (N), Brachyphallus crenatus and Hemiurus luehei (both D). The eastern localities had low parasite species richness, predominated by the freshwater digenean Diplostomum spathaceum. We could identify three different Baltic herring stocks, the spring-spawning herring of the western Baltic reaching from the Kattegat to the German and Polish coast, the stock of the central Baltic proper and the northern stock of C. harengus var. membras of the Gulf of Finland. The limited distribution of the herring parasites within the Baltic Sea enables their use as biological indicators for migration patterns and stock separation. The acanthocephalan Pomphorhynchus laevis that has already been used as an accumulation bioindicator for heavy metals was only recorded for the western herring stocks. However, the presence of mainly generalistic parasites and their uneven distribution patterns make their use as indicators for regional environmental and global change more difficult. PMID:25119368

  3. Sources of sedimentary biomarkers and proxies with potential paleoenvironmental significance for the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Kaiser, Jérôme; Arz, Helge W.

    2016-07-01

    The Baltic Sea is a shallow, semi-enclosed and intra-continental shelf sea characterized by anoxic bottom waters in the deepest basins, allowing for the preservation of sedimentary organic matter. In the present study, the most abundant, naturally-occurring lipids in surface sediments from the entire Baltic Sea and the Skagerrak area were identified and their potential sources were assigned. Together with long-chain n-alkanes derived from land plant leaf waxes, diploptene and branched glycerol dialkyl glycerol tetraethers (GDGTs) are of allochthonous origin, while isoprenoid GDGTs, hydroxylated isoprenoid GDGTs (OH-GDGTs), n-C25:1, n-C27:1 and n-C29:1 alkenes are autochthonous lipids. The isoprenoid and OH-GDGTs are probably derived from Thaumarchaeota and the long-chain n-alkenes from phototrophic organisms. Significant correlations were found between indexes based on isoprenoid and OH-GDGTs and Baltic Sea surface and bottom temperatures. The calibrations obtained for surface temperature have statistically similar slopes, but different intercepts than calibrations established for the Nordic Seas. The branched and isoprenoid tetraether index can be used to estimate the percentage of soil (terrestrial) organic matter in the sediments of the Baltic Sea. High values of the Paq' ratio (defined here as the ratio of odd numbered n-C23 and n-C25 over n-C23 to n-C29 alkanes) in the northern Baltic Sea originate from the presence of both Sphagnum mosses in the drainage basin and submerged macrophytes, such as Potamogeton sp. and Myriophyllum sp., in the freshwater to brackish water of the coastal areas. The Paq' ratio may thus reflect fluctuations in the regional expansion of freshwater to brackish coastal environments in the Baltic Sea.

  4. Long-chain alkenone patterns in the Baltic Sea - An ocean-freshwater transition

    NASA Astrophysics Data System (ADS)

    Schulz, Hans-Martin; Schöner, Anne; Emeis, Kay-Christian

    2000-02-01

    Two different patterns of long-chain alkenones are found in surficial sediments of the Baltic Sea, which is the largest brackish water body on Earth. One pattern occurs in surficial sediments from the Western Baltic Sea where surface-water salinitiy is in excess of 7.7 PSU. It corresponds to the pattern produced by the marine coccolithophorid Emiliania huxleyi with a suite of C 37 di- to tetra-unsaturated methyl ketones and C 38 di- and tri-unsaturated methyl and ethyl ketones. A second pattern, resembling that found in lake sediments in lacking C 38 methyl ketones and having distinctly higher C 37:4 methyl ketone concentrations, dominates in surficial sediments of the eastern and northern Baltic Sea, where salinities are lower than 7.7 PSU. Correspondence of sea-surface temperature (SST) estimates from the U37K and U37K' indices (using marine calibrations) with mean SST in the euphotic zone from July-August (the main haptophyte growth season) is poor. Thus, these indices are not applicable as sedimentary thermometers in surficial sediments of the Baltic Sea. The different patterns may either reflect the salinity-dependent occurrence of specific alkenone producers or changes in the alkenone biosynthesis due to physiological stress caused by salinity variations. Furthermore, advection of saline and oxygenated North Sea water may transport marine algal material characterized by a marine E. huxleyi-like alkenone pattern into the western Baltic Sea, thus covering the signature of the local alkenone producers with a Baltic Sea pattern.

  5. Biodiversity gradient in the Baltic Sea: a comprehensive inventory of macrozoobenthos data

    NASA Astrophysics Data System (ADS)

    Zettler, Michael L.; Karlsson, Anna; Kontula, Tytti; Gruszka, Piotr; Laine, Ari O.; Herkül, Kristjan; Schiele, Kerstin S.; Maximov, Alexey; Haldin, Jannica

    2014-03-01

    In the Helsinki Commission Red List project 2009-2012, taxonomic and distributional data of benthic (macro) invertebrates were compiled by the present authors in a comprehensive checklist of the Baltic Sea fauna. Based on the most recent and comprehensive data, this paper presents the diversity patterns observed among benthic invertebrates in the Baltic Sea. As expected, the total number of species per sub-region generally declined along the salinity gradient from the Danish Straits to the northern Baltic Sea. This relationship is well known from the Baltic Sea and has resulted in a general assumption of an exponentially positive relationship between species richness and salinity for marine species, and a negative relationship for freshwater species. In 1934, Remane produced a diagram to describe the hypothetical distribution of benthic invertebrate diversity along a marine-freshwater salinity gradient. Our results clearly indicated the validity of this theory for the macrozoobenthic diversity pattern within the Baltic Sea. Categorisation of sub-regions according to species composition showed both separation and grouping of some sub-regions and a strong alignment of similarity patterns of zoobenthic species composition along the salinity gradient.

  6. Mean and extreme sea level changes in the southwestern Baltic Sea

    NASA Astrophysics Data System (ADS)

    Schmidt, Jessica; Patzke, Justus; Dangendorf, Sönke; Arns, Arne; Jensen, Jürgen; Fröhle, Peter

    2016-04-01

    In this contribution an overview over the BMBF project AMSeL_Ostsee (2015-2018) for the assessment of mean and extreme sea level changes over the past 150 years in the southwestern Baltic Sea is presented. We compile several high resolution tide gauge records provided by the Water and Shipping Administration (WSV) along the German Baltic Sea coastline and merge them in internationally available data bases (UHSLC, PSMSL, and data officially available at national authorities). In addition, we make efforts in digitizing historical records to expand the number of available data sets in this complex and vulnerable coastal region. To separate absolute from relative long-term changes in sea level the vertical land motion (VLM) at specific sites is assessed. Possible sources of VLM are independently assessed by using different state-of-the-art approaches, that is: Glacial Isostatic Adjustment (GIA) modelled by viscoelastic Earth models, GPS derived VLM, and the difference between tide gauge and nearby satellite altimetry. The VLM corrected tide gauge records are further assessed for linear and non-linear trends as well as possible acceleration/deceleration patterns by applying advanced time series models such as Singular System Analysis (SSA) combined with a Monte-Carlo-Autoregressive-Padding approach (Wahl et al., 2010). These trend assessments are applied to mean and extreme sea levels independently to prove whether observed changes in extremes are either due to an underlying trend on mean sea levels or changes in storminess. References: Wahl, T., Jensen, J., Frank, T. (2011): On analysing sea level rise in the German Bight since 1844, NHESS, 10, 171-179.

  7. Quantifying the importance of sediment resuspension for the North Sea and Baltic Sea ecosystem

    NASA Astrophysics Data System (ADS)

    Nissen, Cara; Schrum, Corinna; Daewel, Ute; Fennel, Katja; Castaño Primo, Rocío

    2014-05-01

    Including sedimentary processes such as resuspension in marine coupled bio-physical models is crucial to realistically simulate the dynamics of biologically important chemical variables (e.g oxygen and the macro-nutrients nitrate, phosphate and silicate). These comprise diffusive release of dissolved nutrients and resuspension of particulate organic material, which occurs when a critical bottom shear stress (τcrit) acting on the sediment particles is exceeded. In global and regional modelling approaches sediment-water exchange is often parametrized by sedimentation and constant release rates and dynamic resuspension resolving the tidal cycle is often neglected in coupled physical-biological ecosystem models. During resuspension, sediment particles get transported back into the water column. Thereby, both the turbidity of the water and nutrient availability by releasing dissolved nutrients from the pore-water are changed. Since both light and nutrients are limiting factors in primary production, it is near by hand to suspect resuspension to play an important role in the growth of phytoplankton. Here, we assess the role of resuspension and its dynamic consideration for the modelled productivity and CO2 air-sea exchange in the North Sea and Baltic Sea using the coupled 3D physical-biological model ECOSMO. ECOSMO is a coupled hydrodynamic-sea ice-NPZD-carbonate-system model and is implemented for the North Sea and Baltic Sea. Its ecosystem module includes interactions between three functional groups of phytoplankton, two of zooplankton, detritus, oxygen, three nutrient cycles (nitrogen, phosphorus, silicate) and sediment pools. In the North Sea, wind forcing and strong tides lead to a frequent exceedance of the critical bottom shear stress and therefore, resuspension events take place regularly, especially in the shallow coastal areas where the tidal range is largest. Here, the model results indicate a clear increase in estimated primary production when dynamical

  8. Anthropogenic and naturally produced brominated substances in Baltic herring (Clupea harengus membras) from two sites in the Baltic Sea.

    PubMed

    Dahlberg, Anna-Karin; Bignert, Anders; Legradi, Jessica; Legler, Juliette; Asplund, Lillemor

    2016-02-01

    In the eutrophicated Baltic Sea, several naturally produced hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have been found in marine biota. OH-PBDEs are toxic to adult and developing zebrafish and shown to be potent disruptors of oxidative phosphorylation (OXPHOS). Disturbed OXPHOS can result in altered energy metabolism and weight loss. In herring, the concentration of OH-PBDEs (i.e. 2'-OH-BDE68 and 6-OH-BDE47) has increased during the period 1980-2010 in the Baltic Proper. Over the same time period, the condition and fat content in Baltic herring have decreased. Given the toxicity and increasing trends of OH-PBDEs in Baltic herring it is important to further assess the exposure to OH-PBDEs in Baltic herring. In this study, the concentrations of OH-PBDEs and related brominated substances i.e. polybrominated phenols (PBPs), polybrominated anisoles (PBAs), methoxylated polybrominated diphenyl ethers (MeO-PBDEs) and polybrominated diphenyl ethers (PBDEs) were measured in herring sampled in the northern Baltic Proper (Askö, n = 12) and the southern Bothnian Sea (Ängskärsklubb, n = 12). The geometric mean (GM) concentrations (ng/g l.w.) at Askö and Ängskärsklubb were; Σ2PBPs: 4.3 and 9.6, Σ(2)PBAs: 34 and 20, Σ(6)OH-PBDEs: 9.4 and 10, Σ(7)MeO-PBDEs: 42 and 150, Σ(6)PBDEs: 54 and 27, respectively. 6-OH-BDE47 dominated the OH-PBDE profile and comprised 87% (Askö) and 91% (Ängskärsklubb) of the ΣOH-PBDEs. At Ängskärsklubb the mean concentration of ΣMeO-PBDEs (150 ng/g l.w.) was 15 times higher than ΣOH-PBDEs. As other fish species are known to metabolically transform MeO-PBDEs to OH-PBDEs, high levels of MeO-PBDEs can be of concern as a precursor for more toxic OH-PBDEs in herring and their roe. PMID:26613358

  9. Influence of the arrival of radioactive industrially contaminated North Sea water upon the radiation conditions in the Baltic Sea

    SciTech Connect

    Vakulovskii, S.M.; Nikitin, A.I.; Chumichev, V.B.

    1987-08-01

    The authors present and evaluate data from a four-year period of monitoring the movement of radioactive effluents from the radiochemical plants of Western Europe from the North Sea to the Baltic Sea and determine the concentrations at various regions along this pathway for cesium 134 and 137 and strontium 90 isotopes.

  10. Unstructured-grid model for the North Sea and Baltic Sea: Validation against observations

    NASA Astrophysics Data System (ADS)

    Zhang, Yinglong J.; Stanev, E. V.; Grashorn, S.

    2016-01-01

    A new unstructured-grid model and its application to the North Sea and Baltic Sea are described. The research focus is on the dynamics in the two basins and in the multiple straits connecting them and more specifically on how the model replicates the temporal and spatial variability of physical processes. The comparison against observed data indicates the realism in the simulations of the exchange flows. The simulations demonstrated that in contrast to the tidal variability which decreases in the strait, the role of the barotropic forcing due to weather systems increases. In this zone reversal of transport is well manifested by the increased difference between the surface and bottom salinity values. Small sub-basins like Arkona and Bornholm play the role of reservoirs for denser water which under specific conditions cascades on its way to the Gotland Deep. Unlike the intermediate and deep water salinity in the Baltic Sea, which is strongly affected by fluxes in the straits, the simulated winter-refill and evolution of cold intermediate water are rather driven by surface cooling and processes in the upper mixed layer.

  11. Transplant experiments uncover Baltic Sea basin-specific responses in bacterioplankton community composition and metabolic activities.

    PubMed

    Lindh, Markus V; Figueroa, Daniela; Sjöstedt, Johanna; Baltar, Federico; Lundin, Daniel; Andersson, Agneta; Legrand, Catherine; Pinhassi, Jarone

    2015-01-01

    Anthropogenically induced changes in precipitation are projected to generate increased river runoff to semi-enclosed seas, increasing loads of terrestrial dissolved organic matter and decreasing salinity. To determine how bacterial community structure and functioning adjust to such changes, we designed microcosm transplant experiments with Baltic Proper (salinity 7.2) and Bothnian Sea (salinity 3.6) water. Baltic Proper bacteria generally reached higher abundances than Bothnian Sea bacteria in both Baltic Proper and Bothnian Sea water, indicating higher adaptability. Moreover, Baltic Proper bacteria growing in Bothnian Sea water consistently showed highest bacterial production and beta-glucosidase activity. These metabolic responses were accompanied by basin-specific changes in bacterial community structure. For example, Baltic Proper Pseudomonas and Limnobacter populations increased markedly in relative abundance in Bothnian Sea water, indicating a replacement effect. In contrast, Roseobacter and Rheinheimera populations were stable or increased in abundance when challenged by either of the waters, indicating an adjustment effect. Transplants to Bothnian Sea water triggered the initial emergence of particular Burkholderiaceae populations, and transplants to Baltic Proper water triggered Alteromonadaceae populations. Notably, in the subsequent re-transplant experiment, a priming effect resulted in further increases to dominance of these populations. Correlated changes in community composition and metabolic activity were observed only in the transplant experiment and only at relatively high phylogenetic resolution. This suggested an importance of successional progression for interpreting relationships between bacterial community composition and functioning. We infer that priming effects on bacterial community structure by natural episodic events or climate change induced forcing could translate into long-term changes in bacterial ecosystem process rates. PMID

  12. Comparison of nematode communities in Baltic and North Sea sublittoral, permeable sands Diversity and environmental control

    NASA Astrophysics Data System (ADS)

    Urban-Malinga, Barbara; Hedtkamp, Stefanie I. C.; van Beusekom, Justus E. E.; Wiktor, Józef; Węsławski, Jan Marcin

    2006-10-01

    The structure of free-living nematode communities was investigated seasonally at two sandy locations representing typical shallow sublittoral, permeable environments of the North Sea and the Baltic Sea. At the Baltic study site the chlorophyll and organic carbon concentrations in the sediment were, on average, four times lower than at the North Sea. Highest nematode densities (1674-4100 ind. 10 cm -2) and a higher number of free-living nematode genera (66) were recorded in the North Sea (Baltic: 206-1227 ind. 10 cm -2, 30 genera). Despite lower salinity and lower food availability the less dense and less diverse Baltic nematode community was similar in generic composition to the North Sea community. At the North Sea site, all trophic groups according to Wieser's classification were present with omnivores/predators, dominated by Viscosia, prevailing and followed by epistrate-feeders. In the food-limited Baltic community, non-selective deposit feeders (mainly Ascolaimus, Axonolaimus and Daptonema) and omnivores/predators dominated by Enoplolaimus were the most abundant trophic groups while selective deposit feeders were absent or their contribution was negligible. An analysis of the vertical generic distribution revealed highest diversity of the Baltic community in deeper sediment layers, below the sediment surface affected by ripple migration and near the interface of oxic and anoxic conditions. The diversity pattern in the North Sea sediment was more variable but generally showed high diversity in the upper centimetre of the sediment. These observations suggest that food supply and sediment oxygenation are the most important factors influencing the vertical pattern of nematode generic diversity in sublittoral, permeable sands.

  13. Transplant experiments uncover Baltic Sea basin-specific responses in bacterioplankton community composition and metabolic activities

    PubMed Central

    Lindh, Markus V.; Figueroa, Daniela; Sjöstedt, Johanna; Baltar, Federico; Lundin, Daniel; Andersson, Agneta; Legrand, Catherine; Pinhassi, Jarone

    2015-01-01

    Anthropogenically induced changes in precipitation are projected to generate increased river runoff to semi-enclosed seas, increasing loads of terrestrial dissolved organic matter and decreasing salinity. To determine how bacterial community structure and functioning adjust to such changes, we designed microcosm transplant experiments with Baltic Proper (salinity 7.2) and Bothnian Sea (salinity 3.6) water. Baltic Proper bacteria generally reached higher abundances than Bothnian Sea bacteria in both Baltic Proper and Bothnian Sea water, indicating higher adaptability. Moreover, Baltic Proper bacteria growing in Bothnian Sea water consistently showed highest bacterial production and beta-glucosidase activity. These metabolic responses were accompanied by basin-specific changes in bacterial community structure. For example, Baltic Proper Pseudomonas and Limnobacter populations increased markedly in relative abundance in Bothnian Sea water, indicating a replacement effect. In contrast, Roseobacter and Rheinheimera populations were stable or increased in abundance when challenged by either of the waters, indicating an adjustment effect. Transplants to Bothnian Sea water triggered the initial emergence of particular Burkholderiaceae populations, and transplants to Baltic Proper water triggered Alteromonadaceae populations. Notably, in the subsequent re-transplant experiment, a priming effect resulted in further increases to dominance of these populations. Correlated changes in community composition and metabolic activity were observed only in the transplant experiment and only at relatively high phylogenetic resolution. This suggested an importance of successional progression for interpreting relationships between bacterial community composition and functioning. We infer that priming effects on bacterial community structure by natural episodic events or climate change induced forcing could translate into long-term changes in bacterial ecosystem process rates. PMID

  14. Oceanographic connectivity and environmental correlates of genetic structuring in Atlantic herring in the Baltic Sea

    PubMed Central

    Teacher, Amber GF; André, Carl; Jonsson, Per R; Merilä, Juha

    2013-01-01

    Marine fish often show little genetic structuring in neutral marker genes, and Atlantic herring (Clupea harengus) in the Baltic Sea are no exception; historically, very low levels of population differentiation (FST ≍ 0.002) have been found, despite a high degree of interpopulation environmental heterogeneity in salinity and temperature. Recent exome sequencing and SNP studies have however shown that many loci are under selection in this system. Here, we combined population genetic analyses of a large number of transcriptome-derived microsatellite markers with oceanographic modelling to investigate genetic differentiation and connectivity in Atlantic herring at a relatively fine scale within the Baltic Sea. We found evidence for weak but robust and significant genetic structuring (FST = 0.008) explainable by oceanographic connectivity. Genetic differentiation was also associated with site differences in temperature and salinity, with the result driven by the locus Her14 which appears to be under directional selection (FST = 0.08). The results show that Baltic herring are genetically structured within the Baltic Sea, and highlight the role of oceanography and environmental factors in explaining this structuring. The results also have implications for the management of herring fisheries, the most economically important fishery in the Baltic Sea, suggesting that the current fisheries management units may be in need of revision. PMID:23745145

  15. alpha1-antitrypsin (PI) alleles as markers of Westeuropean influence in the Baltic Sea region.

    PubMed

    Beckman, L; Sikström, C; Mikelsaar, A; Krumina, A; Kucinskas, V; Beckman, G

    1999-01-01

    The distribution of alpha1-antitrypsin (PI) alleles was studied in an attempt to elucidate migrations and admixture between populations in the Baltic Sea region. The frequency of the PI Z allele, a typically Northwesteuropean marker gene, showed a highly significant regional variation in the Baltic Sea region. The highest frequency (4.5%) was found in the western part of Latvia (Courland). The PI S allele, another marker of Westeuropean influence, also showed an increased frequency in the Courland population. These results indicate that among the populations east of the Baltic Sea the Curonian population has the most pronounced Westeuropean influence. Archaeological data have shown that from the 7th century and for several hundreds of years Courland received immigrations from mainland Sweden and the island of Gotland. We speculate that the increased frequencies of the PI Z alleles and S alleles in Courland may have been caused by these migrations. PMID:9858859

  16. The nutrient load from food waste generated onboard ships in the Baltic Sea.

    PubMed

    Wilewska-Bien, Magda; Granhag, Lena; Andersson, Karin

    2016-04-15

    The combination of the sensitive characteristics of the Baltic Sea and the intense maritime traffic makes the marine environment vulnerable to anthropogenic influences. The theoretical scenario calculated in this study shows that the annually generated food waste onboard ships in traffic in the Baltic Sea contains about 182tonnes of nitrogen and 34tonnes of phosphorus. Today, all food waste generated onboard can be legally discharged into the marine environment at a distance of 12NM from the nearest land. The annual load of nitrogen contained in the food waste corresponds to 52% of load of nitrogen from the ship-generated sewage. Future regulations for sewage discharge in the Baltic Sea will require significant reduction of total nitrogen and phosphorus released. The contribution of nutrients from food waste compared to sewage will therefore be relatively larger in the future, if food waste still can be legally discharged. PMID:26992746

  17. Mass variations of the Baltic Sea compared to superconducting gravimeter and GRACE

    NASA Astrophysics Data System (ADS)

    Virtanen, H.; Virtanen, J.; Nordman, M.; Bilker-Koivula, M.; Mäkinen, J.

    2009-04-01

    We study the gravity effect of Baltic Sea mass variations observed using different methods and time resolutions. We compare data from tide gauges, from superconductive gravimeter (SG) at Metsähovi, Finland and from the GRACE gravity satellite. The mass variation in the semi-enclosed Baltic Sea is due to both internal redistribution of the water mass and due to changes in the so-called fill level caused by water exchange with the North Sea. The monthly variation in the water mass is about 60 Gt over an area of 390000 km-2. Due to a dense network of tide gauges, the Baltic Sea is one of best monitored mass variations in this size in the world. For modeling the observed water mass, we have used both monthly PSMSL tide gauge records and hourly values from several sources. In addition, we have hydrodynamic models for comparisons. To calculate gravity effect, we have used Green's function formalism for modeled sea surface. We have previously used temporal gravity field data from GRACE satellite to show that GRACE can recover the total mass variation in the Baltic Sea on monthly scales. In addition to monthly GRACE solutions with different filters, we now also use 10-day mascon block solutions from Goddard Space Flight Center. As the GRACE solutions are already corrected for gravity changes due to oceans, we have restored the contribution due to the Baltic Sea. We have also corrected for an effect due to leakage of continental water storage using the GLDAS hydrology model. The fundamental station Metsähovi is located 10 km from the nearest bay of the Baltic Sea and 15 km from the open sea. Using a single tide gauge at the distance of 30 km from SG at Metsähovi, very clear correlation is found between gravity and sea level. Superconducting gravity data has been corrected by tides and polar motion, atmospheric mass redistribution, local groundwater and drift. Hourly mass variations of sea are clearly separable. Theoretically one-meter even-layer water cause 30 nms-2

  18. Seabird guano fertilizes Baltic Sea littoral food webs.

    PubMed

    Gagnon, Karine; Rothäusler, Eva; Syrjänen, Anneli; Yli-Renko, Maria; Jormalainen, Veijo

    2013-01-01

    Nutrient enrichment in coastal marine systems can have profound impacts on trophic networks. In the Baltic Sea, the population of Great Cormorant (Phalacrocorax carbo sinensis) has increased nearly exponentially since the mid-1990 s, and colonies of these seabirds can be important sources of nitrogen enrichment for nearby benthic communities due to guano runoff. In this study we used stable isotope analyses and diet mixing models to determine the extent of nitrogen enrichment from cormorant colonies, as well as to examine any possible changes in herbivore diet preferences due to enrichment. We found significantly higher levels of δ(15)N in samples from colony islands than control islands for producers (the dominant macroalga Fucus vesiculosus, filamentous algae, and periphyton) and herbivores, as well as a positive correlation between enrichment and nest density in colony sites. We also found that enrichment increased over the breeding season of the cormorants, with higher enrichment in late summer than early summer. While the amount of total nitrogen did not differ between colony and control sites, the amount of guano-based nitrogen in algae was >50% in most sites, indicating high nitrogen enrichment from colonies. Herbivores (the isopod Idotea balthica and the gastropod Theodoxus fluviatilis) preferred feeding upon the dominant macroalga Fucus vesiculosus rather than on filamentous algae or periphyton in both control and colony, and there was a significant increase in periphyton consumption near colony sites. Overall, guano from cormorant colonies seems to have effects on both producers and herbivores, as well as the potential to modify algae-herbivore interactions. PMID:23593452

  19. Egg production of turbot, Scophthalmus maximus, in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Nissling, Anders; Florin, Ann-Britt; Thorsen, Anders; Bergström, Ulf

    2013-11-01

    In the brackish water Baltic Sea turbot spawn at ~ 6-9 psu along the coast and on offshore banks in ICES SD 24-29, with salinity influencing the reproductive success. The potential fecundity (the stock of vitellogenic oocytes in the pre-spawning ovary), egg size (diameter and dry weight of artificially fertilized 1-day-old eggs) and gonad dry weight were assessed for fish sampled in SD 25 and SD 28. Multiple regression analysis identified somatic weight, or total length in combination with Fulton's condition factor, as main predictors of fecundity and gonad dry weight with stage of maturity (oocyte packing density or leading cohort) as an additional predictor. For egg size, somatic weight was identified as main predictor while otolith weight (proxy for age) was an additional predictor. Univariate analysis using GLM revealed significantly higher fecundity and gonad dry weight for turbot from SD 28 (3378-3474 oocytes/g somatic weight) compared to those from SD 25 (2343 oocytes/g somatic weight), with no difference in egg size (1.05 ± 0.03 mm diameter and 46.8 ± 6.5 μg dry weight; mean ± sd). The difference in egg production matched egg survival probabilities in relation to salinity conditions suggesting selection for higher fecundity as a consequence of poorer reproductive success at lower salinities. This supports the hypothesis of higher size-specific fecundity towards the limit of the distribution of a species as an adaptation to harsher environmental conditions and lower offspring survival probabilities. Within SD 28 comparisons were made between two major fishing areas targeting spawning aggregations and a marine protected area without fishing. The outcome was inconclusive and is discussed with respect to potential fishery induced effects, effects of the salinity gradient, effects of specific year-classes, and effects of maturation status of sampled fish.

  20. Prospects of the New Science and Outreach Network Baltic Earth with Results of the Second Climate Change Assessment for the Baltic Sea Region (BACC II)

    NASA Astrophysics Data System (ADS)

    Reckermann, M.; Von Storch, H.; Omstedt, A. T.; Meier, M.; Rutgersson, A.

    2014-12-01

    The Baltic Sea region in Northern Europe spans different climate and population zones, from a temperate, highly populated, industrialized south with intensive agriculture to a boreal, rural north. It represents an old cultural landscape, and the Baltic Sea itself is among the most intensively studied sea areas of the world. Baltic Earth is the new Earth system research network for the Baltic Sea region. It is the successor to BALTEX, which was terminated in June 2013 after 20 years and two successful phases. Baltic Earth stands for the vision to achieve an improved Earth system understanding of the Baltic Sea region. This means that the research disciplines of BALTEX continue to be relevant, i.e. atmospheric and climate sciences, hydrology, oceanography and biogeochemistry, but a more holistic view of the Earth system encompassing processes in the atmosphere, on land and in the sea as well as in the anthroposphere shall gain in importance in Baltic Earth. Specific grand research challenges have been formulated, representing interdisciplinary research questions to be tackled in the coming years. A major means will be scientific assessments of particular research topics by expert groups, similar to the BACC approach, which shall help to identify knowledge gaps and develop research strategies. A major outcome of Baltic Earth will be the update of the BALTEX Assessment of Climate Change for the Baltic Sea Basin (BACC II). This new study after 5 years finds the results of BACC I still valid. Climate change can be detected at the regional scale but attribution is still weak. The effect of changing atmospheric aerosol loads and land use change is largely unknown so far and needs further attention in the coming years. For the observed changes in biogeochemical and ecological systems, multiple drivers are at work of which climate change is one. Their relative importance still needs to be evaluated. When addressing climate change impacts on e.g. forestry, agriculture, urban

  1. Artificial radionuclides in the surface waters of the Baltic Sea and the North Sea in the fall of 1984

    SciTech Connect

    Kadzhene, G.I.; Kleiza, I.V.; Korotkov, V.P.; Lukinskene, M.V.; Mironov, V.K.; Styro, D.B.

    1987-10-01

    The authors compare data from the literature with data taken in the fall of 1984 on the concentrations of cesium 137, strontium 90, cesium 144, and tritium in the waters of the Baltic and North seas. Sampling was conducted along the coastal regions as well as offshore and the consequent concentration and distribution profiles are mapped. They attempt to assess the weight of meteorological and water current as well as seasonal factors on the determined levels and also point to possible sources of the isotopes, including nuclear power plants situated along Baltic and North Sea shorelines and an atmospheric test of a thermonuclear bomb carried out by China.

  2. Population genomic evidence for adaptive differentiation in the Baltic Sea herring.

    PubMed

    Guo, Baocheng; Li, Zitong; Merilä, Juha

    2016-06-01

    Detecting and estimating the degree of genetic differentiation among populations of highly mobile marine fish having pelagic larval stages is challenging because their effective population sizes can be large, and thus, little genetic drift and differentiation is expected in neutral genomic sites. However, genomic sites subject to directional selection stemming from variation in local environmental conditions can still show substantial genetic differentiation, yet these signatures can be hard to detect with low-throughput approaches. Using a pooled RAD-seq approach, we investigated genomewide patterns of genetic variability and differentiation within and among 20 populations of Atlantic herring in the Baltic Sea (and adjacent Atlantic sites), where previous low-throughput studies and/or studies based on few populations have found limited evidence for genetic differentiation. Stringent quality control was applied in the filtering of 1 791 254 SNPs, resulting in a final data set of 68 182 polymorphic loci. Clear differentiation was identified between Atlantic and Baltic populations in many genomic sites, while differentiation within the Baltic Sea area was weaker and geographically less structured. However, outlier analyses - whether including all populations or only those within the Baltic Sea - uncovered hundreds of directionally selected loci in which variability was associated with either salinity, temperature or both. Hence, our results support the view that although the degree of genetic differentiation among Baltic Sea herring populations is low, there are many genomic regions showing elevated divergence, apparently as a response to temperature- and salinity-related natural selection. As such, the results add to the increasing evidence of local adaptation in highly mobile marine organisms, and those in the young Baltic Sea in particular. PMID:27093194

  3. Temporal variatiions of Sea ice cover in the Baltic Sea derived from operational sea ice products used in NWP.

    NASA Astrophysics Data System (ADS)

    Lange, Martin; Paul, Gerhard; Potthast, Roland

    2014-05-01

    Sea ice cover is a crucial parameter for surface fluxes of heat and moisture over water areas. The isolating effect and the much higher albedo strongly reduces the turbulent exchange of heat and moisture from the surface to the atmosphere and allows for cold and dry air mass flow with strong impact on the stability of the whole boundary layer and consequently cloud formation as well as precipitation in the downstream regions. Numerical weather centers as, ECMWF, MetoFrance or DWD use external products to initialize SST and sea ice cover in their NWP models. To the knowledge of the author there are mainly two global sea ice products well established with operational availability, one from NOAA NCEP that combines measurements with satellite data, and the other from OSI-SAF derived from SSMI/S sensors. The latter one is used in the Ostia product. DWD additionally uses a regional product for the Baltic Sea provided by the national center for shipping and hydrografie which combines observations from ships (and icebreakers) for the German part of the Baltic Sea and model analysis from the hydrodynamic HIROMB model of the Swedish meteorological service for the rest of the domain. The temporal evolution of the three different products are compared for a cold period in Februar 2012. Goods and bads will be presented and suggestions for a harmonization of strong day to day jumps over large areas are suggested.

  4. Activation of the marine ecosystem model 3D CEMBS for the Baltic Sea in operational mode

    NASA Astrophysics Data System (ADS)

    Dzierzbicka-Glowacka, Lidia; Jakacki, Jaromir; Janecki, Maciej; Nowicki, Artur

    2013-04-01

    The paper presents a new marine ecosystem model 3D CEMBS designed for the Baltic Sea. The ecosystem model is incorporated into the 3D POPCICE ocean-ice model. The Current Baltic Sea model is based on the Community Earth System Model (CESM from the National Center for Atmospheric Research) which was adapted for the Baltic Sea as a coupled sea-ice model. It consists of the Community Ice Code (CICE model, version 4.0) and the Parallel Ocean Program (version 2.1). The ecosystem model is a biological submodel of the 3D CEMBS. It consists of eleven mass conservation equations. There are eleven partial second-order differential equations of the diffusion type with the advective term for phytoplankton, zooplankton, nutrients, dissolved oxygen, and dissolved and particulate organic matter. This model is an effective tool for solving the problem of ecosystem bioproductivity. The model is forced by 48-hour atmospheric forecasts provided by the UM model from the Interdisciplinary Centre for Mathematical and Computational Modelling of Warsaw University (ICM). The study was financially supported by the Polish State Committee of Scientific Research (grants: No N N305 111636, N N306 353239). The partial support for this study was also provided by the project Satellite Monitoring of the Baltic Sea Environment - SatBaltyk founded by European Union through European Regional Development Fund contract no. POIG 01.01.02-22-011/09. Calculations were carried out at the Academy Computer Centre in Gdańsk.

  5. BIAS: A Regional Management of Underwater Sound in the Baltic Sea.

    PubMed

    Sigray, Peter; Andersson, Mathias; Pajala, Jukka; Laanearu, Janek; Klauson, Aleksander; Tegowski, Jaroslaw; Boethling, Maria; Fischer, Jens; Tougaard, Jakob; Wahlberg, Magnus; Nikolopoulos, Anna; Folegot, Thomas; Matuschek, Rainer; Verfuss, Ursula

    2016-01-01

    Management of the impact of underwater sound is an emerging concern worldwide. Several countries are in the process of implementing regulatory legislations. In Europe, the Marine Strategy Framework Directive was launched in 2008. This framework addresses noise impacts and the recommendation is to deal with it on a regional level. The Baltic Sea is a semienclosed area with nine states bordering the sea. The number of ships is one of the highest in Europe. Furthermore, the number of ships is estimated to double by 2030. Undoubtedly, due to the unbound character of noise, an efficient management of sound in the Baltic Sea must be done on a regional scale. In line with the European Union directive, the Baltic Sea Information on the Acoustic Soundscape (BIAS) project was established to implement Descriptor 11 of the Marine Strategy Framework Directive in the Baltic Sea region. BIAS will develop tools, standards, and methodologies that will allow for cross-border handling of data and results, measure sound in 40 locations for 1 year, establish a seasonal soundscape map by combining measured sound with advanced three-dimensional modeling, and, finally, establish standards for measuring continuous sound. Results from the first phase of BIAS are presented here, with an emphasis on standards and soundscape mapping as well as the challenges related to regional handling. PMID:26611063

  6. Density and Absolute Salinity of the Baltic Sea 2006-2009

    NASA Astrophysics Data System (ADS)

    Feistel, R.; Weinreben, S.; Wolf, H.; Seitz, S.; Spitzer, P.; Adel, B.; Nausch, G.; Schneider, B.; Wright, D. G.

    2010-01-01

    The brackish water of the Baltic Sea is a mixture of ocean water from the Atlantic/North Sea with fresh water from various rivers draining a large area of lowlands and mountain ranges. The evaporation-precipitation balance results in an additional but minor excess of fresh water. The rivers carry different loads of salts washed out of the ground, in particular calcium carbonate, which cause a composition anomaly of the salt dissolved in the Baltic Sea in comparison to Standard Seawater. Directly measured seawater density shows a related anomaly when compared to the density computed from the equation of state as a function of Practical Salinity, temperature and pressure. Samples collected from different regions of the Baltic Sea during 2006-2009 were analysed for their density anomaly. The results obtained for the river load deviate significantly from similar measurements carried out forty years ago; the reasons for this decadal variability are not yet fully understood. An empirical formula is derived which estimates Absolute from Practical Salinity of Baltic Sea water, to be used in conjunction with the new Thermodynamic Equation of Seawater 2010 (TEOS-10), endorsed by IOC/UNESCO in June 2009 as the substitute for the 1980 International Equation of State, EOS-80. Our routine measurements of the samples were accompanied by studies of additional selected properties which are reported here: conductivity, density, chloride, bromide and sulphate content, total CO2 and alkalinity.

  7. Density and Absolute Salinity of the Baltic Sea 2006-2009

    NASA Astrophysics Data System (ADS)

    Feistel, R.; Weinreben, S.; Wolf, H.; Seitz, S.; Spitzer, P.; Adel, B.; Nausch, G.; Schneider, B.; Wright, D. G.

    2009-08-01

    The brackish water of the Baltic Sea is a mixture of ocean water from the Atlantic/North Sea with fresh water from various rivers draining a large area of lowlands and mountain ranges. The evaporation-precipitation balance results in an additional but minor excess of fresh water. The rivers carry different loads of salts washed out of the ground, in particular calcium carbonate, which cause a composition anomaly of the salt dissolved in the Baltic Sea in comparison to Standard Seawater. Directly measured seawater density shows a related anomaly when compared to the density computed from the equation of state as a function of Practical Salinity, temperature and pressure. Samples collected from different regions of the Baltic Sea during 2006-2009 were analysed for their density anomaly. The results obtained for the river load deviate significantly from similar measurements carried out forty years ago; the reasons for this decadal variability are not yet fully understood. An empirical formula is derived which estimates Absolute from Practical Salinity of Baltic Sea water, to be used in conjunction with the new Thermodynamic Equation of Seawater 2010 (TEOS-10), endorsed by IOC/UNESCO in June 2009 as the substitute for the 1980 International Equation of State, EOS-80. Our routine measurements of the samples were accompanied by studies of additional selected properties which are reported here: conductivity, density, chloride, bromide and sulphate content, total CO2 and alkalinity.

  8. Projected climate change impacts on North Sea and Baltic Sea: CMIP3 and CMIP5 model based scenarios

    NASA Astrophysics Data System (ADS)

    Pushpadas, D.; Schrum, C.; Daewel, U.

    2015-08-01

    Climate change impacts on the marine biogeochemistry and lower trophic level dynamics in the North Sea and Baltic Sea have been assessed using regional downscaling in a number of recent studies. However, most of these where only forced by physical conditions from Global Climate Models (GCMs) and regional downscaling considering the climate change impact on oceanic nutrient conditions from Global Earth System Models (ESMs) are rare and so far solely based on CMIP3-generation climate models. The few studies published show a large range in projected future primary production and hydrodynamic condition. With the addition of CMIP5 models and scenarios, the demand to explore the uncertainty in regional climate change projections increased. Moreover, the question arises how projections based on CMIP5-generation models compare to earlier projections and multi-model ensembles comprising both AR4 and AR5 generation forcing models. Here, we investigated the potential future climate change impacts to the North Sea and the Baltic Sea ecosystem using a coherent regional downscaling strategy based on the regional coupled bio-physical model ECOSMO. ECOSMO was forced by output from different ESMs from both CMIP3 and CMIP5 models. Multi-model ensembles using CMIP3/A1B and CMIP5/RCP4.5 scenarios are examined, where the selected CMIP5 models are the successors of the chosen CMIP3 models. Comparing projected changes with the present day reference condition, all these simulations predicted an increase in Sea Surface Temperature (SST) in both North Sea and Baltic Sea, reduction in sea ice in the Baltic, decrease in primary production in the North Sea and an increase in primary production in the Baltic Sea. Despite these largely consistent results on the direction of the projected changes, our results revealed a broad range in the amplitude of projected climate change impacts. Our study strengthens the claim that the choice of the ESM is a major factor for regional climate projections

  9. Meteorological conditions influencing the formation of level ice within the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Mazur, A. K.; Krezel, A.

    2012-12-01

    The Baltic Sea is covered by ice every winter and on average, the ice-covered area is 45% of the total area of the Baltic Sea. The beginning of ice season usually starts in the end of November, ice extent is the largest between mid-February and mid-March and sea ice disappears completely in May. The ice covered areas during a typical winter are the Gulf of Bothnia, the Gulf of Finland and the Gulf of Riga. The studies of sea ice in the Baltic Sea are related to two aspects: climate and marine transport. Depending on the local weather conditions during the winter different types of sea ice can be formed. From the point of winter shipping it is important to locate level and deformed ice areas (rafted ice, ridged ice, and hummocked ice). Because of cloud and daylight independency as well as good spatial resolution, SAR data seems to be the most suitable source of data for sea ice observation in the comparatively small area of the Baltic Sea. We used ASAR Wide Swath Mode data with spatial resolution 150 m. We analyzed data from the three winter seasons which were examples of severe, typical and mild winters. To remove the speckle effect the data were resampled to 250 m pixel size and filtred using Frost filter 5x5. To detect edges we used Sobel filter. The data were also converted into grayscale. Sea ice classification was based on Object-Based Image Analysis (OBIA). Object-based methods are not a common tool in sea ice studies but they seem to accurately separate level ice within the ice pack. The data were segmented and classified using eCognition Developer software. Level ice were classified based on texture features defined by Haralick (Grey Level Co-Occurrence Matrix homogeneity, GLCM contrast, GLCM entropy and GLCM correlation). The long-term changes of the Baltic Sea ice conditions have been already studied. They include date of freezing, date of break-up, sea ice extent and some of work also ice thickness. There is a little knowledge about the relationship of

  10. Parasite diversity of sticklebacks from the Baltic Sea.

    PubMed

    Zander, C Dieter

    2007-01-01

    In the brackish Baltic Sea, the species richness and diversity of parasite communities of three- (Gasterosteus aculeatus) and nine-spined sticklebacks (Pungitius pungitius) were investigated. The studies regarded four localities at the Schleswig-Holstein and Mecklenburg coasts, northern Germany, where salinities were between 10 and 18 per thousand. Species richness was relatively high, attaining 15 parasite species in G. aculeatus and 16 in P. pungitius, which are only surpassed by former investigations that lasted a year or more. An analysis of parasite species identity revealed clear differences in diverse localities referring to different supracommunities. The infracommunity comprised maximally of eight species in G. aculeatus and seven in P. pungitius, which corresponds to former investigations. The mean value of infracommunity with 5.3 parasites is the highest value ever found in small-sized fish. An infracommunity index revealed that the digenean Podocotyle atomon and Magnibursatus caudofilamentosa and the copepod Thersitina gasterostei were the most abundant parasites. The relationship of component community to mean infracommunity can judge about the threshold level, which allows parasite to settle successfully. An important factor to form parasite communities is the season of their appearance, which depends also on their reproduction and on the presence of intermediate hosts. In addition, the choice of prey (for passive infection) and quality of habitats (for active infection) influences the constitution of the parasite communities. The diversity values of parasites were low in all hosts, which is due to the brackish milieu and by different levels of eutrophication, which both create extreme environments. These do not mirror in every case the biodiversity of the respective habitats. The parasite community was in a level of early heterotrophic succession where low diversity is combined with high population density, which is characteristic for extreme

  11. Assessing Secchi and photic zone depth in the Baltic Sea from satellite data.

    PubMed

    Kratzer, Susanne; Håkansson, Bertil; Sahlin, Charlotte

    2003-12-01

    Long-term trends in the Secchi depth of the Baltic Sea have been interpreted in terms of eutrophication. The spectral attenuation coefficient Kd (490) can be estimated from remote sensing data. Given the empirical and theoretical relationships between diffuse attenuation and Secchi depth, it is therefore possible to estimate the trophic state from remote sensing data. This paper considers relationships among remotely sensed and in-water measured K (490), and Secchi depth data obtained during dedicated sea-truthing campaigns in the eastern Baltic Proper in 1999 (4) and in the western Baltic Proper/Himmerfjärden area during 2001 and 2002. In-water measurements are used to establish the relationship between the PAR and the spectral attenuation coefficient in the Baltic Sea via regression analysis. The analysis showed that in the area of investigation Kd(490) is about 1.48 times higher than Kd (PAR). This relationship is then used to define the link between the photic zone depth and the remote sensing optical depth, Kd (490)-1. The results show that the depth of the euphotic zone is about 6.8 times Kd (490)-1. The regression analysis between Kd (PAR) and Secchi depth confirmed previous work that Kd (PAR) is about 1.7 of the inverse Secchi depth. Furthermore, an in-water algorithm between Secchi depth and Kd (490) is used to simulate a Secchi depth map of the Baltic Sea from SeaWiFS Kd(490) data. This map is verified against sea-truthing data. Kd (490) data derived from satellite is compared to in situ Kd (490), and the sources of error are discussed. PMID:15049356

  12. Assessment of PCDD/F source contributions in Baltic Sea sediment core records.

    PubMed

    Assefa, Anteneh T; Tysklind, Mats; Sobek, Anna; Sundqvist, Kristina L; Geladi, Paul; Wiberg, Karin

    2014-08-19

    Spatial and temporal trends of sources of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the Baltic Sea were evaluated by positive matrix factorization (PMF) and principal component analysis (PCA). Sediment cores were sampled at eight coastal, one coastal reference, and six offshore sites covering the northern to the southern Baltic Sea. The cores, which covered the period 1919-2010, were sliced into 2-3 cm disks among which 8-11 disks per core (in total 141 disks) were analyzed for all tetra- through octa-CDD/Fs. Identification and apportionment of PCDD/F sources was carried out using PMF. Five stable model PCDD/F congener patterns were identified, which could be associated with six historically important source types: (i) atmospheric background deposition (ABD), (ii) use and production of penta-chlorophenol (PCP), (iii) use and production of tetra-chlorophenol (TeCP), (iv) high temperature processes (Thermal), (v) hexa-CDD-related sources (HxCDD), and (vi) chlorine-related sources (Chl), all of which were still represented in the surface layers. Overall, the last four decades of the period 1920-2010 have had a substantial influence on the Baltic Sea PCDD/F pollution, with 88 ± 7% of the total amount accumulated during this time. The 1990s was the peak decade for all source types except TeCP, which peaked in the 1980s in the northern Baltic Sea and has still not peaked in the southern part. The combined impact of atmospheric-related emissions (ABD and Thermal) was dominant in the open sea system throughout the study period (1919-2010) and showed a decreasing south to north trend (always >80% in the south and >50% in the north). Accordingly, to further reduce levels of PCDD/Fs in the open Baltic Sea ecosystem, future actions should focus on reducing atmospheric emissions. PMID:25103626

  13. PHOTOCHEMICAL MINERALIZATION OF DISSOLVED ORGANIC NITROGEN TO AMMONIUM IN THE BALTIC SEA

    EPA Science Inventory

    Solar radiation-induced photochemistry can be considered as a new source of nutrients when photochemical reactions release bioavailable nitrogen from biologically non-reactive dissolved organic nitrogen (DON). Pretreatments of Baltic Sea waters in the dark indicated that >72% of ...

  14. Diversity of Pico- to Mesoplankton along the 2000 km Salinity Gradient of the Baltic Sea.

    PubMed

    Hu, Yue O O; Karlson, Bengt; Charvet, Sophie; Andersson, Anders F

    2016-01-01

    Microbial plankton form the productive base of both marine and freshwater ecosystems and are key drivers of global biogeochemical cycles of carbon and nutrients. Plankton diversity is immense with representations from all major phyla within the three domains of life. So far, plankton monitoring has mainly been based on microscopic identification, which has limited sensitivity and reproducibility, not least because of the numerical majority of plankton being unidentifiable under the light microscope. High-throughput sequencing of taxonomic marker genes offers a means to identify taxa inaccessible by traditional methods; thus, recent studies have unveiled an extensive previously unknown diversity of plankton. Here, we conducted ultra-deep Illumina sequencing (average 10(5) sequences/sample) of rRNA gene amplicons of surface water eukaryotic and bacterial plankton communities sampled in summer along a 2000 km transect following the salinity gradient of the Baltic Sea. Community composition was strongly correlated with salinity for both bacterial and eukaryotic plankton assemblages, highlighting the importance of salinity for structuring the biodiversity within this ecosystem. In contrast, no clear trends in alpha-diversity for bacterial or eukaryotic communities could be detected along the transect. The distribution of major planktonic taxa followed expected patterns as observed in monitoring programs, but groups novel to the Baltic Sea were also identified, such as relatives to the coccolithophore Emiliana huxleyi detected in the northern Baltic Sea. This study provides the first ultra-deep sequencing-based survey on eukaryotic and bacterial plankton biogeography in the Baltic Sea. PMID:27242706

  15. Valuing the commons: An international study on the recreational benefits of the Baltic Sea.

    PubMed

    Czajkowski, Mikołaj; Ahtiainen, Heini; Artell, Janne; Budziński, Wiktor; Hasler, Berit; Hasselström, Linus; Meyerhoff, Jürgen; Nõmmann, Tea; Semeniene, Daiva; Söderqvist, Tore; Tuhkanen, Heidi; Lankia, Tuija; Vanags, Alf; Zandersen, Marianne; Żylicz, Tomasz; Hanley, Nick

    2015-06-01

    The Baltic Sea provides benefits to all of the nine nations along its coastline, with some 85 million people living within the catchment area. Achieving improvements in water quality requires international cooperation. The likelihood of effective cooperation is known to depend on the distribution across countries of the benefits and costs of actions needed to improve water quality. In this paper, we estimate the benefits associated with recreational use of the Baltic Sea in current environmental conditions using a travel cost approach, based on data from a large, standardized survey of households in each of the 9 Baltic Sea states. Both the probability of engaging in recreation (participation) and the number of visits people make are modeled. A large variation in the number of trips and the extent of participation is found, along with large differences in current annual economic benefits from Baltic Sea recreation. The total annual recreation benefits are close to 15 billion EUR. Under a water quality improvement scenario, the proportional increases in benefits range from 7 to 18% of the current annual benefits across countries. Depending on how the costs of actions are distributed, this could imply difficulties in achieving more international cooperation to achieve such improvements. PMID:25846001

  16. Diversity of Pico- to Mesoplankton along the 2000 km Salinity Gradient of the Baltic Sea

    PubMed Central

    Hu, Yue O. O.; Karlson, Bengt; Charvet, Sophie; Andersson, Anders F.

    2016-01-01

    Microbial plankton form the productive base of both marine and freshwater ecosystems and are key drivers of global biogeochemical cycles of carbon and nutrients. Plankton diversity is immense with representations from all major phyla within the three domains of life. So far, plankton monitoring has mainly been based on microscopic identification, which has limited sensitivity and reproducibility, not least because of the numerical majority of plankton being unidentifiable under the light microscope. High-throughput sequencing of taxonomic marker genes offers a means to identify taxa inaccessible by traditional methods; thus, recent studies have unveiled an extensive previously unknown diversity of plankton. Here, we conducted ultra-deep Illumina sequencing (average 105 sequences/sample) of rRNA gene amplicons of surface water eukaryotic and bacterial plankton communities sampled in summer along a 2000 km transect following the salinity gradient of the Baltic Sea. Community composition was strongly correlated with salinity for both bacterial and eukaryotic plankton assemblages, highlighting the importance of salinity for structuring the biodiversity within this ecosystem. In contrast, no clear trends in alpha-diversity for bacterial or eukaryotic communities could be detected along the transect. The distribution of major planktonic taxa followed expected patterns as observed in monitoring programs, but groups novel to the Baltic Sea were also identified, such as relatives to the coccolithophore Emiliana huxleyi detected in the northern Baltic Sea. This study provides the first ultra-deep sequencing-based survey on eukaryotic and bacterial plankton biogeography in the Baltic Sea. PMID:27242706

  17. Dynamical downscaling of warming scenarios with NEMO-Nordic setup for the North Sea and Baltic Sea

    NASA Astrophysics Data System (ADS)

    Gröger, Matthias; Almroth Rosell, Elin; Anderson, Helén; Axell, Lars; Dieterich, Christain; Edman, Moa; Eilola, Kari; Höglund, Anders; Hordoir, Robinson; Hieronymus, Jenny; Karlsson, Bengt; Liu, Ye; Meier, Markus; Pemberton, Per; Saraiva, Sofia

    2016-04-01

    The North Sea and Baltic Sea constitute one of the most complex and challenging areas in the world. The oceanographic setting ranges from quasi open ocean conditions in the northern North Sea to more brackish conditions in the Baltic Sea which is also affected by sea ice in winter. The two seas are connected by narrow straits which sporadically allow the important inflow of salt and oxygen rich bottom waters into the Baltic Sea. For this, the high resolution regional model NEMO-Nordic has recently been developed. Here, the model is applied on hindcast simulations and used to downscale several climate warming scenarios. The model can be interactively coupled to the regional atmosphere model RCA4 by exchanging air sea fluxes of mass and energy (Wang et al., 2015). Comparison with well established models and newly compiled observational data sets (Bersch et al., 2013) indicates NEMO-Nordic performs well on climate relevant time scales. Emphasis is laid on thermal dynamics. Hindcast simulations demonstrate that simulated winter temperatures in the Baltic Sea can benefit from interactive air sea coupling by allowing interactive feedback loops to take place between the ocean and the atmosphere (Gröger et al. 2015). Likewise, a more realistic dynamical behaviour makes the interactive coupled model suitable for dynamic downscaling of climate warming scenarios. Depending on the driving global climate model and IPCC representative concentration pathway scenario NEMO-Nordic shows an average warming of the North Sea between 2 and 4 K at the end of the 21st century. However the warming pattern is spatially inhomogeneous showing strong east west gradients. Involved processes such as circulation changes and changes in radiative forcing will be discussed. Bersch, M., Gouretski, V., Sadikni, R., Hinrichs, I., 2013. Hydrographic climatology of the North Sea and surrounding regions. Centre for Earth System Research and Sustainability, University of Hamburg, www

  18. Trend Analysis of Nitrogen Deposition to Baltic Sea and its sub basins

    NASA Astrophysics Data System (ADS)

    Semeena, V. S.; Jerzy, Bartnicki

    2009-04-01

    Since the beginning of last century, Baltic Sea has changed from a clear-water sea into a eutrophic marine environment. Eutrophication is the major problem in the Baltic Sea. Excessive nitrogen and phosphorus loads coming from land-based sources within and outside the catchment area of the bordering countries of the Baltic Sea are the main cause of the eutrophication in the sea. Even though a major part of nitrogen(75%) and phosphorus load(95%) enter the sea via rivers or as water-born discharges, 25% of the nitrogen load comes as atmospheric deposition. Numerical models are the best tools to measure atmospheric deposition into sea waters. We have used the latest version of the Unified EMEP model - which has been developed at the EMEP/MSC-W (Meteorological Synthesizing Centre - West of EMEP) for simulating atmospheric transport and deposition of acidifying and eutrophying compounds as well as photo-oxidants in Europe- to study the trends in atmospheric deposition of nitrogen into Baltic Sea for the period 1995-2006. The model domain covers Europe and the Atlantic Ocean. The model grid (of the size 170×133) has a horizontal resolution of 50 km at 60o N, which is consistent with the resolution of emission data reported to CLRTAP. Approximately 10 of these layers are placed below 2 km to obtain high resolution of the boundary layer which is of special importance to the long range transport of air pollution. EMEP model has been thouroughly validated (Fagerli et.al.[1], Simpson et.al.[2], Simpson et.al.[3] ) The contribution of deposition of nitrogen into Baltic Sea from each of the bordering countries of the Baltic Sea and the deposition trends for the period 1995-2006 has been analysed and the results will be presented. References: [1]. Fagerli H., Simpson D. and Aas W.: Model performance for sulphur and nitrogen compounds for the period 1980 to 2000. [In:] L. Tarraśon, (editor), Transboundary Acidification, Eutrophication and Ground Level Ozone in Europe. EMEP

  19. Attributing causes of regional climate change in the Baltic Sea area

    NASA Astrophysics Data System (ADS)

    Bhend, Jonas; Gaillard-Lemdahl, Marie-José; Hansson, Hans-Christen

    2015-04-01

    Here we assess to what extent the effect of forcing mechanisms on the observed climate change in the Baltic Sea area can be detected. In particular, we assess the effect of factors causing large-scale warming (mainly anthropogenic greenhouse gases) and the regional effect of atmospheric aerosols and land-cover and land-use changes. Unfortunately, only very few targeted analyses for the Baltic catchment area are available at the moment, but findings at the regional scale are generally qualitatively consistent with global or hemispheric analyses. The observed warming in summer cannot be explained without human influence (in particular the warming effect of increasing atmospheric greenhouse gas concentrations). In other seasons and for other aspects of regional warming, findings are mixed or not significant as of yet. In addition, large-scale circulation and rainfall changes in the northern hemisphere and the Arctic have been detected to exceed natural internal variability. Other aspects of regional climate change including changes in storminess, snow properties, runoff and the changing physical properties of the Baltic Sea have not been formally attributed to human influence yet. Scientific understanding of the effect of aerosols on regional climate is still accumulating. It is likely that the major emission changes in Europe have had an effect on the climate in the Baltic region, the magnitude of which, however, is still unknown. Development of the modelling capability and targeted analyses are urgently needed to reduce the uncertainties related to the effect of aerosol changes on regional observed climate change. Historic deforestation and recent reforestation are the major anthropogenic land-cover changes affecting the Baltic Sea area. From all studies at hand it can be concluded that there is no evidence that anthropogenic land-cover change would be one of the forcings behind the recent warming in the Baltic region. However, past anthropogenic land-cover change

  20. BALTEX—an interdisciplinary research network for the Baltic Sea region

    NASA Astrophysics Data System (ADS)

    Reckermann, Marcus; Langner, Joakim; Omstedt, Anders; von Storch, Hans; Keevallik, Sirje; Schneider, Bernd; Arheimer, Berit; Markus Meier, H. E.; Hünicke, Birgit

    2011-10-01

    BALTEX is an environmental research network dealing with the Earth system of the entire Baltic Sea drainage basin. Important elements include the water and energy cycle, climate variability and change, water management and extreme events, and related impacts on biogeochemical cycles. BALTEX was founded in 1993 as a GEWEX continental-scale experiment and is currently in its second 10 yr phase. Phase I (1993-2002) was primarily dedicated to hydrological, meteorological and oceanographic processes in the Baltic Sea drainage basin, hence mostly dealt with the physical aspects of the system. Scientific focus was on the hydrological cycle and the exchange of energy between the atmosphere, the Baltic Sea and the surface of its catchment. The BALTEX study area was hydrologically defined as the Baltic Sea drainage basin. The second 10 yr phase of BALTEX (Phase II: 2003-12) has strengthened regional climate research, water management issues, biogeochemical cycles and overarching efforts to reach out to stakeholders and decision makers, as well as to foster communication and education. Achievements of BALTEX Phase II have been the establishment of an assessment report of regional climate change and its impacts on the Baltic Sea basin (from hydrological to biological and socio-economic), the further development of regional physical climate models and the integration of biogeochemical and ecosystem models. BALTEX features a strong infrastructure, with an international secretariat and a publication series, and organizes various workshops and conferences. This article gives an overview of the BALTEX programme, with an emphasis on Phase II, with some examples from BALTEX-related research.

  1. Significance of archaeal nitrification in hypoxic waters of the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Berg, C.; Vandieken, V.; Thamdrup, B.; Jürgens, K.

    2012-04-01

    Marine oxygen deficient areas are sites of important microbially mediated transformations within the nitrogen cycle. In the Baltic Sea, suboxic waters (oxygen below 5 μmol L-1) are considered to be a major nitrification zone within the water column. Recent evidence indicates that Archaea and not Bacteria are here the major ammonium oxidizers. In a Baltic Sea pelagic redoxcline, the crenarchaeotal subcluster GD2 which is related to the first cultivated ammonia-oxidizing crenarchaeote Candidatus Nitrosopumilus maritimus occurs in high abundance. However, little is known about its function and importance for the nitrogen and carbon cycles in oxygen minimum zones of the Baltic Sea. To approach this question, we sampled pelagic redoxclines in the Baltic Sea and determined the rates of nitrification and light-independent, inorganic carbon fixation via 15N and 14C isotope incubations, and quantified the abundance of putative ammonia-oxidizing Crenarchaeota by catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH). Nitrification was detectable throughout the suboxic zone with maxima of 122-131 nmol L-1 d-1 in layers with 1.8-7.1 μmol oxygen L-1 and ammonium below 0.2 μmol L-1. However, a nitrification potential was detected even in the upper anoxic, sulfidic zone. Crenarchaeotal abundance correlated strongly with nitrification rates and accounted for up to 24% of total prokaryotic cells. In contrast, the CO2 fixation in the suboxic zone was with 1.6-19.6 nmol L-1 d-1 rather low when compared to the subjacent anoxic, sulfidic waters. Our study indicates that ammonia oxidation in the suboxic zone of the Baltic Sea is mainly driven by Crenarchaeota. Their occurrence also in the anoxic, sulfidic water masses and the maintained nitrification potential point to special adaptations in this habitat with a potentially reduced sensitivity against hydrogen sulfide.

  2. The general circulation of the Baltic Sea in the context of climate variability

    NASA Astrophysics Data System (ADS)

    Getzlaff, K.; Lehmann, A.

    2012-04-01

    A detailed assessment of climate variability of the Baltic Sea area for the period 1958-2009 revealed that the recent changes in the warming trend since the mid-1980s are associated with changes in the large-scale atmospheric circulation over the North Atlantic. The analysis of winter sea level pressure (SLP) data highlighted considerable changes in the number and pathways of deep cyclones (<980 hPa) in parallel with the eastward shift of the North Atlantic Oscillation (NAO) centres of action. Additionally, a seasonal shift of strong wind events from autumn to winter and early spring exists for the Baltic area. Earlier studies showed that different atmospheric climate regimes force different circulation regimes in the Baltic Sea. The analysis of the winter (DJFM) circulation patterns for the period 1970-2008 reveals changes in the general circulation of the Baltic Sea. While it is difficult to clearly link individual winter circulation patterns to one of the four dominant atmospheric climate regimes for the North Atlantic domain, the comparison of mean winter circulation patterns for 20-year periods (1970-1989 and 1990-2009) highlights that for the later 20-year period an intensified cyclonic circulation exists in the central Baltic Sea. This intensified circulation results from stronger westerly and north-westerly winds and is most likely connected to changes in the large-scale atmospheric circulation. As climate, to a large extent, controls patterns of water circulation and biophysical aspects relevant for biological production, such as the vertical distribution of temperature, salinity and oxygen, alterations in climate may severely impact the trophic structure and functioning of marine food webs.

  3. To what extent does the salinity flux influence phytoplankton blooms? - Baltic Sea modeling study

    NASA Astrophysics Data System (ADS)

    Cieszyńska, Agata; Stramska, Małgorzata

    2016-04-01

    This work is focused on numerical modeling of biological-physical interactions and their influence on phytoplankton production and vertical distribution of biomass and its variability in the surface waters of the Baltic Sea. The area of interest is an inland sea with water salinity much smaller than observed in the global ocean (about one fifth of the open ocean value). Vertical distribution of the salinity has a significant influence on water column density stratification, and therefore influences intensity of mixing and the depth of mixed layer. This, in turn, defines environmental conditions for phytoplankton growth. Vertical distribution of water salinity in the basin is controlled by processes such as evaporation/precipitation, freezing/melting of sea ice and runoff of freshwater from land. There are a lot of different phytoplankton species in the area of the Baltic Sea. Every single one has its own characteristics and is sensitive to distinct complex environmental conditions. Biological-physical interactions controlling these microorganisms' life cycles are multiplicitous and because of their complexity difficult to quantify. The best and probably only way to study presented issue is the usage of numerical modeling tool. The results presented here are based on 1D numerical simulations carried out with Princeton Ocean Model (POM, http://www.ccpo.odu.edu/POMWEB/) merged with the Ecological Regional Ecosystem Model (ERGOM, http://ergom.net/) developed for the Baltic Sea research by German scientists from the Leibniz Institute for Baltic Sea Research in Warnemünde. In model simulations surface salinity flux was determined from the difference between the precipitation and evaporation rate at the air-sea interface. Data for parameterization of atmospheric forcing were defined based on data sets from National Centers of Environmental Prediction (NCEP). We carried out systematic calculations using different values of surface fluxes encompassing the range of

  4. Ctenophore population recruits entirely through larval reproduction in the central Baltic Sea.

    PubMed

    Jaspers, Cornelia; Haraldsson, Matilda; Bolte, Sören; Reusch, Thorsten B H; Thygesen, Uffe H; Kiørboe, Thomas

    2012-10-23

    The comb jelly Mertensia ovum, widely distributed in Arctic regions, has recently been discovered in the northern Baltic Sea. We show that M. ovum also exists in the central Baltic but that the population consists solely of small-sized larvae (less than 1.6 mm). Despite the absence of adults, eggs were abundant. Experiments revealed that the larvae were reproductively active. Egg production and anticipated mortality rates suggest a self-sustaining population. This is the first account of a ctenophore population entirely recruiting through larval reproduction (paedogenesis). We hypothesize that early reproduction is favoured over growth to compensate for high predation pressure. PMID:22535640

  5. Plastic ingestion by pelagic and demersal fish from the North Sea and Baltic Sea.

    PubMed

    Rummel, Christoph D; Löder, Martin G J; Fricke, Nicolai F; Lang, Thomas; Griebeler, Eva-Maria; Janke, Michael; Gerdts, Gunnar

    2016-01-15

    Plastic ingestion by marine biota has been reported for a variety of different taxa. In this study, we investigated 290 gastrointestinal tracts of demersal (cod, dab and flounder) and pelagic fish species (herring and mackerel) from the North and Baltic Sea for the occurrence of plastic ingestion. In 5.5% of all investigated fishes, plastic particles were detected, with 74% of all particles being in the microplastic (<5mm) size range. The polymer types of all found particles were analysed by means of Fourier transform infrared (FT-IR) spectroscopy. Almost 40% of the particles consisted of polyethylene (PE). In 3.4% of the demersal and 10.7% of the pelagic individuals, plastic ingestion was recorded, showing a significantly higher ingestion frequency in the pelagic feeders. The condition factor K was calculated to test differences in the fitness status between individuals with and without ingested plastic, but no direct effect was detected. PMID:26621577

  6. Legacy phosphorus in the Baltic Sea and implications for reversing eutrophication

    NASA Astrophysics Data System (ADS)

    McCrackin, M. L.; Gustafsson, B.; Humborg, C.; Hong, B.; Svanbäck, A.; Swaney, D. P.; Viktorsson, L.

    2015-12-01

    Eutrophication has depleted concentrations of dissolved oxygen in bottom waters of the Baltic Sea, resulting in the world's largest "dead" zone. A number of measures have been implemented to reduce nutrient inputs and, indeed, between 1995 and 2012 phosphorus (P) loads to the sea deceased 19%. The long-term accumulation and subsequent release of P from both the catchment and marine sediments combined with 30-year water residence times could significantly delay recovery from eutrophication. We estimated net P accumulation (legacy P) for the Baltic Sea using the Net Anthropogenic Phosphorus Inputs (NAPI) approach and historical records of food and feed trade and riverine fluxes. Net P inputs to the catchment peaked at 0.7 million tons per year during the 1970's and since the political and economical changes in Eastern Europe during the 1990's, decreased to 0.2-0.3 million tons per year. P accumulation on land is ten times greater than accumulation in the sea (20 million and 2 million tons, respectively). Of the P retained on land, the majority (18-19 million tons) is in agricultural lands, with the balance in lake sediments. Of the 2 million tons in the sea, two-thirds are in sediments and one-third in the water column. The success of nutrient management actions in reducing river nutrient fluxes will lead to improvement in the Baltic Sea environment, but the massive accumulation of P on land will complicate efforts to achieve complete recovery.

  7. Anomalous secular sea-level acceleration in the Baltic Sea caused by glacial isostatic adjustment

    NASA Astrophysics Data System (ADS)

    Spada, Giorgio; Galassi, Gaia; Olivieri, Marco

    2014-05-01

    Observations from the global array of tide gauges show that global sea-level has been rising at an average rate of 1.5-2 mm/yr during the last ˜ 150 years (Spada & Galassi, 2012). Although a global sea-level acceleration was initially ruled out, subsequent studies have coherently proposed values of ˜1 mm/year/century (Olivieri & Spada, 2012). More complex non-linear trends and abrupt sea-level variations have now also been recognized. Globally, they could manifest a regime shift between the late Holocene and the current rhythms of sea-level rise, while locally they result from ocean circulation anomalies, steric effects and wind stress (Bromirski et al. 2011). Although isostatic readjustment affects the local rates of secular sea-level change, a possible impact on regional acceleration have been so far discounted (Woodworth et al., 2009) since the process evolves on a millennium scale. Here we report a previously unnoticed anomaly in the long-term sea-level acceleration of the Baltic Sea tide gauge records, and we explain it by the classical post-glacial rebound theory and numerical modeling of glacial isostasy. Contrary to previous assumptions, our findings demonstrate that isostatic compensation plays a role in the regional secular sea-level acceleration. In response to glacial isostatic adjustment (GIA), tide gauge records located along the coasts of the Baltic Sea exhibit a small - but significant - long-term sea-level acceleration in excess to those in the far field of previously glaciated regions. The sign and the amplitude of the anomaly is consistent with the post-glacial rebound theory and with realistic numerical predictions of GIA models routinely employed to decontaminate the tide gauges observations from the GIA effects (Peltier, 2004). Model computations predict the existence of anomalies of similar amplitude in other regions of the globe where GIA is still particularly vigorous at present, but no long-term instrumental observations are available to

  8. Anatomizing one of the largest saltwater inflows into the Baltic Sea in December 2014

    NASA Astrophysics Data System (ADS)

    Gräwe, Ulf; Naumann, Michael; Mohrholz, Volker; Burchard, Hans

    2015-11-01

    In December 2014, an exceptional inflow event into the Baltic Sea was observed, a so-called Major Baltic Inflow (MBI). Such inflow events are important for the deep water ventilation in the Baltic Sea and typically occur every 3-10 years. Based on first observational data sets, this inflow had been ranked as the third largest since 100 years. With the help of a multinested modeling system, reaching from the North Atlantic (8 km resolution) to the Western Baltic Sea (600 m resolution, which is baroclinic eddy resolving), this event is reproduced in detail. The model gave a slightly lower salt transport of 3.8 Gt, compared to the observational estimate of four Gt. Moreover, by using passive tracers to mark the different inflowing water masses, including an age tracer, the inflowing water masses could be tracked and their paths and timing through the different basins could be reproduced and investigated. The analysis is supported by the recently developed Total Exchange Flow (TEF) to quantify the volume transport in different salinity classes. To account for uncertainties in the modeled velocity and tracer fields, a Monte Carlo Analysis (MCA) is applied to correct possible biases and errors. With the help of the MCA, 95% confidence intervals are computed for the transport estimates. Based on the MCA, the "best guess" of the volume transport is 291.0 ± 13.65 km3 and 3.89 ± 0.18 Gt for the total salt transport.

  9. N/P ratio of nutrient uptake in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Wan, Z.; Jonasson, L.; Bi, H.

    2011-06-01

    The N/P ratio of nutrient uptake, i.e., the ratio of dissolved inorganic nitrogen (DIN) to dissolved inorganic phosphorus (DIP) taken by primary producers, varies in different basins and in different seasons in the Baltic Sea. The N/P ratio of nutrient alteration fore and after spring blooms is not same as the N/P ratio of nutrient uptake, but the former can be regarded as an indicator for the later in the Baltic Sea. Based on the observed N/P ratio of nutrient alteration, we hypothesize a non-Redfield N/P ratio of nutrient uptake. The 3D-ecosystem model ERGOM coupled with the circulation model DMI-BSHcmod was used to test the hypothesis. When the Redfield ratio was used in the model, the DIP surplus after spring blooms was too high and resulted in the overly growth of cyanobacteria and too much nitrogen fixation. When the non-Redfield ratio was used in the model, the corresponding problem tended to disappear. In summary, we show that: (1) the Redfield N/P ratio of nutrient uptake in the Baltic Sea tends to be too high; (2) a lower N/P ratio 10:1 appears to work better than the Redfield value; and (3) the N/P ratio of nutrient uptake in the Baltic Proper during spring blooms is around 6:1.

  10. Iceberg ploughmark features on bottom surface of the South-Eastern Baltic Sea

    NASA Astrophysics Data System (ADS)

    Dorokhov, Dmitry; Sivkov, Vadim; Dorokhova, Evgenia; Krechik, Viktor

    2016-04-01

    A detail swath bathymetry, side-scan sonar and acoustic profiling combined with sediment sampling during the 64th cruise of RV "Academic Mstislav Keldysh" (October 2015) allowed to identify new geomorphological features of the South-Eastern Baltic Sea bottom surface. The extended chaotic ploughmarks (furrows) in most cases filled with thin layer of mud were discovered on surface of the Gdansk-Gotland sill glacial deposits. They are observed on the depth of more than 70 m and have depth and width from 1 to 10 m. Most of them are v- or u-shaped stepped depressions. The side-scan records of similar geomorpholoical features are extensively reported from Northern Hemisphere and Antarctica (Goodwin et al., 1985; Dowdeswell et al., 1993). Ploughmarks are attributed to the action of icebergs scouring into the sediment as they touch bottom. We are suggest that furrows discovered in the South-Eastern Baltic Sea are also the result of iceberg scouring during the Baltic Ice Lake stage (more than 11 600 cal yr BP (Bjorck, 2008)). This assumption confirmed by occurrence of fragmental stones and boulders on the sea bottom surface which are good indicators of iceberg rafting (Lisitzin, 2003). Ice ploughmarks at sea bottom surface were not occurred before in the South-Eastern Baltic Sea. The study was financed by Russian Scientific Fund, grant number 14-37-00047. References Bjorck S. The late Quaternary development of the Baltic Sea Basin. In: The BACC Author Team (eds) Assessment of climate change for the Baltic Sea Basin. Springer, Berlin, Heidelberg. 2008. Dowdeswell J. A., Villinger H., Whittington R. J., Marienfeld P. Iceberg scouring in Scoresby Sund and on the East Greenland continental shelf // Marine Geology. V. 111. N. 1-2. 1993. P. 37-53. Goodwin C. R., Finley J. C., Howard L. M. Ice scour bibliography. Environmental Studies Revolving Funds Report No. 010. Ottawa. 1985. 99 pp. Lisitzin A. P. Sea-Ice and Iceberg Sedimentation in the Ocean: Recent and Past. Springer

  11. What can ARGO's tell us on the processes in Baltic Sea?

    NASA Astrophysics Data System (ADS)

    Roiha, Petra; Siiriä, Simo-Matti; Nummelin, Aleksi; Aro, Eemeli; Purokoski, Tero

    2014-05-01

    Finnish Meteorological Institute has been testing ARGO floats in the Baltic Sea as a mean for collecting data from the sea areas that are not easily reachable by research vessels or remote sensing. The observational data for Baltic Sea off-shore areas is very sparse and new observational methods are needed to fill the gaps in our knowledge and collect new data for different purposes, such as, operational activities, modelling and ocean science. The ARGO floats have been used successfully in the deep oceans. However, applying the ARGO floats in Baltic Sea is not straight forward, as the conditions differ greatly: the water is brackish, some areas are heavily trafficked and the northern parts freeze during the winter. In addition, the mean depth is only 54 metres, which is only a fraction of depths where ARGO floats have commonly been used. FMI has deployed three ARGO floats in Baltic Sea for different missions. The first ARGO was deployed in 2012 with normal diving algorithm, which checks the pressure hourly. The second float was modified by Aalto University so that the algorithm checks the pressure every 15 minutes. The first float was deployed in the Bothnian Sea in May 2013 and it measured over 200 profiles during its half year mission. The float with faster pressure detection was deployed in the Bothnian Sea in May 2013, and during it's 4 month mission it measured succesfully over 120 profiles. Another, longer test is ongoing on Eastern Gotland basin, where another ARGO float was deployed at Aug 2013, and still measures at Jan 2014. This one differs from earlier experiments as it has additional oxygen and scattering meters, also the area of measurements is deeper (200+ meters). The missions so far indicate, that with proper control and monitoring, ARGO's can be operated, and can measure long series of profiles. In addition to the actual measurements, the movement of ARGO floats gives possibilities to analyse currents in deeper areas of Baltic, and help

  12. Sensitivity of modeled atmospheric nitrogen species to variations in sea salt emissions in the North and Baltic Sea regions

    NASA Astrophysics Data System (ADS)

    Neumann, D.; Matthias, V.; Bieser, J.; Aulinger, A.; Quante, M.

    2015-10-01

    Coarse sea salt particles are emitted ubiquitously from the oceans' surfaces by wave breaking and bubble bursting processes. These particles impact atmospheric chemistry by affecting condensation of gas-phase species and nucleation of new fine particles, particularly in regions with high air pollution. In this study, atmospheric particle concentrations are modeled for the North and Baltic Sea regions, Northwestern Europe, using the Community Multiscale Air Quality (CMAQ) modeling system and evaluated against European Monitoring and Evaluation Programme (EMEP) measurement data. As model extension, sea salt emissions are scaled by water salinity because of low salinity in large parts of the Baltic Sea and in certain river estuaries. The resulting improvement in predicted sea salt concentrations is assessed. The contribution of surf zone emissions is separately considered. Additionally, the impact of sea salt particles on atmospheric nitrate, ammonium and sulfate concentrations is evaluated. The comparisons show that sea salt concentrations are commonly overestimated at coastal stations and partly underestimated when going inland. The introduced salinity scaling improves predicted Baltic Sea sea salt concentrations considerably. Dates of measured peak concentrations are appropriately reproduced by the model. The impact of surf zone emissions is negligible in both seas. Nevertheless, they might be relevant because surf zone emissions were cut at an upper threshold in this study. Deactivating sea salt leads to a minor increase of NH4+ and NO3- and a minor decrease of SO42- concentrations. However, the overall effect is very low and lower than the deviation from measurements. Size resolved measurements of Na+, NH4+, NO3-, and SO42- are needed for a more detailed analysis on the impact of sea salt particles.

  13. Effects of an extensive Prymnesium polylepis bloom on breeding eiders in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Larsson, K.; Hajdu, S.; Kilpi, M.; Larsson, R.; Leito, A.; Lyngs, P.

    2014-04-01

    The effects of an extensive bloom of the potentially toxic Prymnesium polylepis (Haptophyta) on breeding eiders (Somateria mollissima) in the Baltic Sea were analysed. Increasing abundances of the alternate stage P. polylepis was detected by a marine monitoring programme in the autumn 2007. The bloom peaked between March and May 2008 in the southern, central and northwestern Baltic Proper and abundances of up to 5 × 106 cells l- 1 were recorded. At several sites P. polylepis constituted between 30 and 90% of the total phytoplankton biovolume. The flagellate was only recorded in low numbers in the northeastern Baltic Proper and Gulf of Finland. The abundances were low in 2007, 2009 and 2010. In 28 eider colonies situated in the southern and central Baltic Proper, sharp and synchronous declines in the number of nesting eiders were observed from 2007 to 2008. In colonies on Gotland in the central Baltic Proper, a 76% decrease, from 6650 nests to 1620 nests, was followed by increases in 2009 and 2010, although not up to numbers observed in 2007. At Utklippan and Ertholmene in the southern Baltic Proper, the observed decreases of 55%, from 144 to 65 nests, and 36%, from 1660 to 1060 nests, respectively, between 2007 and 2008, were followed by increases in 2009 and 2010 up to the level observed in 2007. By contrast, no general decline of the number of nesting eiders was observed from 2007 to 2008 in 75 colonies in the northeastern Baltic Proper and Gulf of Finland. Hence, the spatial distribution of the P. polylepis bloom in 2008 closely matched the observed distribution of extensive non-breeding of female eiders. We suggest that the intensive spring bloom of P. polylepis, either through a toxic or non-toxic pathway, affected the main benthic food of eiders, i.e. blue mussels (Mytilus trossulus × Mytilus edulis), at pre-breeding foraging sites close to the breeding sites, and, subsequently, the body condition of adult female eiders and their breeding propensity.

  14. Factors influencing variability of mercury input to the southern Baltic Sea.

    PubMed

    Bełdowska, Magdalena; Saniewska, Dominika; Falkowska, Lucyna

    2014-09-15

    The southern Baltic countries have been identified as significant sources of Hg into the sea. Are anthropogenic activities the sole source? How do meteorological parameters influence the deposition? Studies on input of Hg to the Baltic were conducted in 2008-2012 in the Polish coastal stations. The riverine load was found to depend directly or indirectly on the amount of precipitation and catchment type. Input of atmospheric Hg increased along with the number of precipitation episodes from remote maritime air masses, as well as with the number of days when continental air masses from regional (when domestic heating prevailed) and remote sources moved over the Baltic, during the heating season. During the non-heating season metal input was found to be proportional to episodes of rain from continental regional air masses and to the number of days under influence of continental and maritime air masses from regional sources. PMID:25066454

  15. Processes relevant for decadal changes in primary production of the North Sea and Baltic Sea: hindcast and scenario modelling

    NASA Astrophysics Data System (ADS)

    Daewel, Ute; Schrum, Corinna; Pushpadas, Dhanya

    2016-04-01

    Despite their geographical vicinity, the North Sea and the Baltic Sea ecosystems exhibit very different characteristics in both physical and biological parameters. Nonetheless, since both ecosystems are characterized by the same general functional groups in phytoplankton and zooplankton and, their geographical distribution indicates comparable thermal adaptation of the plankton groups, we propose that the same ecosystem parameterization can be utilized to simulate the dynamics in both ecosystems simultaneously. Here we present results from an updated version of the 3d coupled ecosystem model ECOSMO valid for both areas. The model allows both multi-decadal hind cast simulation of primary production and specific process studies under controlled environmental conditions. Our results from a long-term hind-cast (1948-2008) indicate incoherent "regime shifts" in the primary productivity (PP) between the North Sea and Baltic Sea. Correlation analysis between atmospheric forcing and PP indicates significant correlations for both solar radiation and wind but cannot serve to identify causal relationship. Therefore additional scenario tests with perturbations in individual atmospheric condition where accomplished emphasizing specifically the role of solar radiation, wind and eutrophication. The results revealed that, although all parameters are relevant for the PP in North Sea and Baltic Sea, the dominant impact on long term variability was introduced by modulations of the wind fields.

  16. Actors and arenas in hybrid networks: implications for environmental policymaking in the Baltic Sea region.

    PubMed

    Joas, Marko; Kern, Kristine; Sandberg, Siv

    2007-04-01

    Policymaking within and among states is under pressure for change. One feature of this change is empirically observed as an activation of different network structures in the Baltic Sea Region, especially since the collapse of the Iron Curtain, the initiation of the Rio process, and the enlargement of the European Union. The contemporary theoretical debates about governance highlight the changing conditions for policymaking and implementation on all societal levels. This process of change, especially evident concerning environmental policies, includes new types of networks crossing state borders both at the supranational and the subnational levels. This article illuminates this process of change with empirical data from the project "Governing a Common Sea" (GOVCOM) within the Baltic Sea Research Program (BIREME). PMID:17520939

  17. The use of bathymetric data in society and science: a review from the Baltic Sea.

    PubMed

    Hell, Benjamin; Broman, Barry; Jakobsson, Lars; Jakobsson, Martin; Magnusson, Ake; Wiberg, Patrik

    2012-03-01

    Bathymetry, the underwater topography, is a fundamental property of oceans, seas, and lakes. As such it is important for a wide range of applications, like physical oceanography, marine geology, geophysics and biology or the administration of marine resources. The exact requirements users may have regarding bathymetric data are, however, unclear. Here, the results of a questionnaire survey and a literature review are presented, concerning the use of Baltic Sea bathymetric data in research and for societal needs. It is demonstrated that there is a great need for detailed bathymetric data. Despite the abundance of high-quality bathymetric data that are produced for safety of navigation purposes, the digital bathymetric models publicly available to date cannot satisfy this need. Our study shows that DBMs based on data collected for safety of navigation could substantially improve the base data for administrative decision making as well as the possibilities for marine research in the Baltic Sea. PMID:22396094

  18. Infusorians as a component of the planktonic community in the Baltic Sea

    SciTech Connect

    Mamaeva, N.V.

    1985-09-01

    The authors' investigations of infusorians as a component of the planktonic community in the Baltic Sea coincided with the heterotrophic stage of seasonal succession, and as a result the infusorians were numerous. In the deep troughs of the Sea at a depth of more than 150 m, the water is saturated with hydrogen sulfide. A community of infusorians relating to the saprobionts and capable of living with the minimal amount of oxygen was discovered for the first time--in the upper boundary of the hydrogen sulfide zone. In its level of infusorian abundance, the Baltic Sea must be considered a eutrophic body of water where infusorians serve as one of the leading agents in its self-purification.

  19. Salinity dependence of recruitment success of the sea star Asterias rubens in the brackish western Baltic Sea

    NASA Astrophysics Data System (ADS)

    Casties, Isabel; Clemmesen, Catriona; Melzner, Frank; Thomsen, Jörn

    2015-06-01

    Salinity strongly influences development and distribution of the sea star Asterias rubens. In Kiel Fjord, located in the western Baltic Sea, A. rubens is the only echinoderm species and one of the main benthic predators controlling blue mussel ( Mytilus edulis) abundance. However, Kiel Fjord with an average salinity of about 15 is located close to the eastern distribution boundary of A. rubens in the Baltic Sea. In this study, we combined field and laboratory investigations to test whether the salinity of Kiel Fjord is high enough to enable successful development of A. rubens. Sea star eggs were fertilized in vitro, and development was monitored in the laboratory at four salinities (9, 12, 15 and 18) for 10 weeks. At a salinity of 9, development ceased prior to the blastula stage. At a salinity of 12, no larvae reached metamorphosis. At higher salinities, larvae developed normally and metamorphosed into juvenile sea stars. Abundances of A. rubens larvae and settled juveniles were also observed in Kiel Fjord and correlated to salinity values measured from March until June during 6 years (2005-2010). Results revealed high A. rubens settlement rates only in 2009, the year when salinity was the highest and least variable during the period of spawning and larval development. It appears that only years with high and stable salinities permit recruitment of A. rubens in Kiel Fjord. Projected desalination of the Baltic Sea could shift the distribution of A. rubens in the western Baltic Sea north-westwards and may lead to local extinction of a keystone species of the benthic ecosystem.

  20. Chemical characterization of dissolved organic compounds from coastal sea surface microlayers (Baltic Sea, Germany).

    PubMed

    van Pinxteren, Manuela; Müller, Conny; Iinuma, Yoshiteru; Stolle, Christian; Herrmann, Hartmut

    2012-10-01

    The physicochemical properties of the sea surface microlayer (SML), i.e. the boundary layer between the air and the sea, and its impact on air-sea exchange processes have been investigated for decades. However, a detailed description about these processes remains incomplete. In order to obtain a better chemical characterization of the SML, in a case study three pairs of SML and corresponding bulk water samples were taken in the southern Baltic Sea. The samples were analyzed for dissolved organic carbon and dissolved total nitrogen, as well as for several organic nitrogen containing compounds and carbohydrates, namely aliphatic amines, dissolved free amino acids, dissolved free monosaccharides, sugar alcohols, and monosaccharide anhydrates. Therefore, reasonable analytical procedures with respect to desalting and enrichment were established. All aliphatic amines and the majority of the investigated amino acids (11 out of 18) were found in the samples with average concentrations between 53 ng L(-1) and 1574 ng L(-1). The concentrations of carbohydrates were slightly higher, averaging 2900 ng L(-1). Calculation of the enrichment factor (EF) between the sea surface microlayer and the bulk water showed that dissolved total nitrogen was more enriched (EF: 1.1 and 1.2) in the SML than dissolved organic carbon (EF: 1.0 and 1.1). The nitrogen containing organic compounds were generally found to be enriched in the SML (EF: 1.9-9.2), whereas dissolved carbohydrates were not enriched or even depleted (EF: 0.7-1.2). Although the investigated compounds contributed on average only 0.3% to the dissolved organic carbon and 0.4% to the total dissolved nitrogen fraction, these results underline the importance of single compound analysis to determine SML structure, function, and its potential for a transfer of compounds into the atmosphere. PMID:22475414

  1. The Ancylus Lake stage of the Baltic Sea in Fehmarn Belt: Indications of a new threshold?

    NASA Astrophysics Data System (ADS)

    Feldens, Peter; Schwarzer, Klaus

    2012-03-01

    The Baltic Ice Lake, Yoldia Sea, Ancylus Lake and Littorina Sea stages of regression and transgression controlled the history of the Baltic Sea since the last glacial period. Many details regarding their development remain unknown, including the question whether the regression of the Ancylus Lake (between 10,700 and 10,200 cal yr BP) took place west of the Darss Sill, or elsewhere. This study addresses whether a drowned river system in Fehmarn Belt (SW Baltic Sea) can be related to the drainage of the Ancylus Lake. The river channel is cut into glacial till in the western part of Fehmarn Belt. Here, the channel reaches an incision depth of up to 12 m at a base level of 40 m b.s.l. (below sea level). Near Mecklenburg Bay, the buried channel is incised down to 60 m b.s.l. and widens rapidly from several hundred meters to more than 1 km, fading towards east. It was mainly shaped as part of a glacial meltwater system at a maximum water level of 30 m b.s.l., and is therefore not related to the Ancylus Lake drainage. During the lowstand of the Baltic Ice Lake, local shallow water bodies covered the study area. A previously reported westward directed drainage of a lake in the eastern Fehmarn Belt could be restricted to a time interval between the highstand of the Ancylus Lake and prior to the Littorina Transgression. Timing, water level and potential water discharge of this event suggest a connection to a partial drainage of the Ancylus Lake. It is concluded that the threshold separating the Ancylus Lake from the North Sea needs to be located west of Fehmarn Belt.

  2. On temporal wind variations forcing salt water inflows into the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Lass, H. U.; Matthäus, W.

    1996-10-01

    Salt water inflows into the Baltic Sea are important processes for maintaining the general stratification and the ventilation of the bottom water in deep basins of the central Baltic. These events occur randomly during the winter season at intervals from one to several years. This pattern changed in the mid-seventies when only weak or no major inflows were observed. During that period a steady loss of salt together with a steady increase in hydrogen sulphide concentrations was observed in the central Baltic deep water.It is generally assumed that strong westerly winds force a salt water inflow. Long time series of daily wind records at the meteorological station Arkona and sea level observations at Landsort between 1951 and 1990 have been analyzed in order to find characteristic sequences being associated with inflow events. A necessary condition for a salt water inflow is for the wind to blow from west for several tens of days. The weighted mean of the yearly cycle of the wind components for years without and with salt water inflows revealed that this condition happens usually in November and December. However, in years with inflows, a long-lasting easterly wind occurs in October and early November just before the strengthening of westerly winds. A similar sequence is observed in the yearly cycle of the mean sea level of the Baltic Sea, i.e., in years with inflows a lowering of the mean sea level precedes the increase of the sea level in November to December. Hence, major salt water inflows are very likely forced by a sequence of easterly winds in late autumn lasting for 20 30days followed by strong to very strong westerly winds of similar duration.

  3. Recent trends and variations in Baltic Sea temperature, salinity, stratification and circulation

    NASA Astrophysics Data System (ADS)

    Elken, Jüri; Lehmann, Andreas; Myrberg, Kai

    2015-04-01

    The presentation highlights the results of physical oceanography from BACC II (Second BALTEX Assessment of Climate Change for the Baltic Sea basin) book based on the review of recent literature published until 2013. We include also information from some more recent publications. A recent warming trend in sea surface waters has been clearly demonstrated by all available methods: in-situ measurements, remote sensing data and modelling tools. In particular, remote sensing data for the period 1990-2008 indicate that the annual mean SST has increased even by 1°C per decade, with the greatest increase in the northern Bothnian Bay and also with large increases in the Gulf of Finland, the Gulf of Riga, and the northern Baltic Proper. Although the increase in the northern areas is affected by the recent decline in the extent and duration of sea ice, and corresponding changes in surface albedo, warming is still evident during all seasons and with the greatest increase occurring in summer. The least warming of surface waters (0.3-0.5°C per decade) occurred northeast of Bornholm Island up to and along the Swedish coast, probably owing to an increase in the frequency of coastal upwelling forced by the westerly wind events. Comparing observations with the results of centennial-scale modelling, recent changes in sea water temperature appear to be within the range of the variability observed during the past 500 years. Overall salinity pattern and stratification conditions are controlled by river runoff, wind conditions, and salt water inflows through the Danish straits. The mean top-layer salinity is mainly influenced by the accumulated river runoff, with higher salinity during dry periods and lower salinity during wet periods. Observations reveal a low-salinity period above the halocline starting in the 1980s. The strength of stratification and deep salinity are reduced when the mean zonal wind stress increases, as it occurred since 1987. Major Baltic Inflows of highly saline

  4. Content of strontium-90 and cesium-137 in a number of regions of the Baltic Sea in 1982

    SciTech Connect

    Lazarev, L.N.; Flegontov, V.M.; Gedenov, L.I.; Ivanova, L.M.; Orlova, T.B.; Stepanov, A.V.

    1985-07-01

    The authors present the data gathered from the samples of water and bed deposits taken at various sites in the Baltic Sea, the Gulf of Riga, and the Gulf of Finland. By means of the radiochemical method using ferrocyanide-carbonate concentration, they determine strotium-90 and cesium-137 content. The authors conclude by noting an increase in the cesium-137 content in the deep waters of the Baltic Sea and in bed deposits, and by cautioning that this development commands close attention.

  5. Large spatial variations in coastal 14C reservoir age - a case study from the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Lougheed, B. C.; Filipsson, H. L.; Snowball, I.

    2013-05-01

    Coastal locations are highly influenced by input from freshwater river runoff, including sources of terrestrial carbon, which can be expected to modify the 14C reservoir age, or R (t), associated with marine water. In this Baltic Sea case study, pre-bomb museum collection mollusc shells of known calendar age, from 30 locations across a strategic salinity transect of the Baltic Sea, were analysed for 14C, δ13C and δ18O. R (t) was calculated for all 30 locations. Seven locations, of which six are within close proximity of the coast, were found to have relatively higher R (t) values, indicative of hard-water effects. Whenever possible, the Macoma genus of mollusc was selected from the museum collections, in order to exclude species specific reservoir age effects as much as possible. When the Macoma samples are exclusively considered, and samples from hard-water locations excluded, a statistically significant correlation between Macoma R (t) and average salinity is found, indicating a two end-member linear mixing model between 14Cmarine and 14Crunoff. A map of Baltic Sea Macoma aragonite R (t) for the late 19th and early 20th centuries is produced. Such a map can provide an estimate for contemporary Baltic Sea Macoma R (t), although one must exercise caution when applying such estimates back in time or to 14C dates obtained from different sample material. A statistically significant correlation is found between δ18Oaragonite and Macoma R (t), suggesting that δ18Oaragonite can be used to estimate Macoma palaeo-R (t), due to the δ18Oaragonite signal being dominated by the salinity gradient of the Baltic Sea. A slightly increased correlation can be expected when δ18Oaragonite is corrected for temperature fractionation effects. The results of this Baltic Sea case study, which show that R (t) is affected by hydrographic conditions and local carbon inputs, have important consequences for other coastal and estuarine locations, where R (t) is also likely to significantly

  6. Divergence within and among Seaweed Siblings (Fucus vesiculosus and F. radicans) in the Baltic Sea.

    PubMed

    Ardehed, Angelica; Johansson, Daniel; Sundqvist, Lisa; Schagerström, Ellen; Zagrodzka, Zuzanna; Kovaltchouk, Nikolaj A; Bergström, Lena; Kautsky, Lena; Rafajlovic, Marina; Pereyra, Ricardo T; Johannesson, Kerstin

    2016-01-01

    Closely related taxa provide significant case studies for understanding evolution of new species but may simultaneously challenge species identification and definition. In the Baltic Sea, two dominant and perennial brown algae share a very recent ancestry. Fucus vesiculosus invaded this recently formed postglacial sea 8000 years ago and shortly thereafter Fucus radicans diverged from this lineage as an endemic species. In the Baltic Sea both species reproduce sexually but also recruit fully fertile new individuals by asexual fragmentation. Earlier studies have shown local differences in morphology and genetics between the two taxa in the northern and western Bothnian Sea, and around the island of Saaremaa in Estonia, but geographic patterns seem in conflict with a single origin of F. radicans. To investigate the relationship between northern and Estonian distributions, we analysed the genetic variation using 9 microsatellite loci in populations from eastern Bothnian Sea, Archipelago Sea and the Gulf of Finland. These populations are located in between earlier studied populations. However, instead of bridging the disparate genetic gap between N-W Bothnian Sea and Estonia, as expected from a simple isolation-by-distance model, the new populations substantially increased overall genetic diversity and showed to be strongly divergent from the two earlier analysed regions, showing signs of additional distinct populations. Contrasting earlier findings of increased asexual recruitment in low salinity in the Bothnian Sea, we found high levels of sexual reproduction in some of the Gulf of Finland populations that inhabit extremely low salinity. The new data generated in this study supports the earlier conclusion of two reproductively isolated but very closely related species. However, the new results also add considerable genetic and morphological complexity within species. This makes species separation at geographic scales more demanding and suggests a need for more

  7. Divergence within and among Seaweed Siblings (Fucus vesiculosus and F. radicans) in the Baltic Sea

    PubMed Central

    Ardehed, Angelica; Johansson, Daniel; Sundqvist, Lisa; Schagerström, Ellen; Zagrodzka, Zuzanna; Kovaltchouk, Nikolaj A.; Bergström, Lena; Kautsky, Lena; Rafajlovic, Marina; Pereyra, Ricardo T.

    2016-01-01

    Closely related taxa provide significant case studies for understanding evolution of new species but may simultaneously challenge species identification and definition. In the Baltic Sea, two dominant and perennial brown algae share a very recent ancestry. Fucus vesiculosus invaded this recently formed postglacial sea 8000 years ago and shortly thereafter Fucus radicans diverged from this lineage as an endemic species. In the Baltic Sea both species reproduce sexually but also recruit fully fertile new individuals by asexual fragmentation. Earlier studies have shown local differences in morphology and genetics between the two taxa in the northern and western Bothnian Sea, and around the island of Saaremaa in Estonia, but geographic patterns seem in conflict with a single origin of F. radicans. To investigate the relationship between northern and Estonian distributions, we analysed the genetic variation using 9 microsatellite loci in populations from eastern Bothnian Sea, Archipelago Sea and the Gulf of Finland. These populations are located in between earlier studied populations. However, instead of bridging the disparate genetic gap between N-W Bothnian Sea and Estonia, as expected from a simple isolation-by-distance model, the new populations substantially increased overall genetic diversity and showed to be strongly divergent from the two earlier analysed regions, showing signs of additional distinct populations. Contrasting earlier findings of increased asexual recruitment in low salinity in the Bothnian Sea, we found high levels of sexual reproduction in some of the Gulf of Finland populations that inhabit extremely low salinity. The new data generated in this study supports the earlier conclusion of two reproductively isolated but very closely related species. However, the new results also add considerable genetic and morphological complexity within species. This makes species separation at geographic scales more demanding and suggests a need for more

  8. A 35-year hindcast for the Baltic Sea (1980-2014) - a statistical analysis

    NASA Astrophysics Data System (ADS)

    Gräwe, Ulf; Holtermann, Peter

    2015-04-01

    The Baltic Sea is a semi-enclosed sea with limited water exchange. The most important process that leads to deep water renewal of the Baltic Sea are inflows of dense, saline North Sea water. These water masses have to pass narrow channels and sills in the Danish Straits and three basins with increasing depth. Along this path, the inflowing gravity currents are subject to entrainment, vertical and horizontal mixing. Thus, physical and numerical mixing are crucial for the proper propagation of these inflows. Additionally, a permanent halocline and a summer thermocline are challenging for state of the art ocean models. Moreover, Holtermann et al (2014) could show, that boundary mixing in the deep basins dominates the vertical mixing of tracers. To tackle these challenges, we used the General Estuarine Transport Model (GETM) to give a state estimate for the Baltic Sea for the period 1980-2014. The setup has a horizontal resolution of 1 nm. In the vertical, terain following coordinates are used. A special feature of GETM is that it can run with vertical adaptive coordinates. Here we use an adaptation towards stratification. The minimum layer thickness is limited to 30 cm. We also include the effects of wind waves (by radiation stresses, and changes in the bottom stresses) into our simulations. The atmospheric forcing is taken from the global reanalysis of the NCEP-CFSR (Saha et al 2011) with a spatial resolution of 30 km and hourly values. The model validation at selected stations in the Baltic Sea shows an average Bias of ±0.15 psu and a RMSE of 0.4 psu. These values are similar to the data assimilation runs of Fu et al (2011) or Liu et al (2013). However, one has to note that our simulations are free runs without any nudging or data assimilation. Driven by the good performance of the model, we use the model output to provide a state estimate of the actual climate period (1980-2010). The analysis includes a quantification and estimation of: surge levels with a 30-year

  9. Fine spatial structure of flows on satellite radar image of the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Lavrova, O. Yu.; Sabinin, K. D.

    2016-04-01

    Satellite images of the sea surface demonstrate different dynamic processes at the water-air boundary and in the water layer. The objective of this investigation is to identify the fine structure of flows in the mesoscale vortex with the help of a specially developed method for flow estimation by ship wakes in the sea. The method described in this work made it possible to identify the jet nature and surges of flows in the mesoscale cyclonic vortex in the southern part of the Baltic Sea after long western and southwestern winds.

  10. Baltic Sea Gastrotricha--one new species and one new record of Chaetonotida from Poland.

    PubMed

    Kolicka, Małgorzata; Jankowska, Emilia; Kotwicki, Lech

    2015-01-01

    Gastrotricha is a cosmopolitan phylum of aquatic and semi-aquatic invertebrates that comprise about 820 described species, which are divided into two orders: Chaetonotida Remane, 1925 [Rao & Clausen, 1970] and Macrodasyida Remane, 1925 [Rao & Clausen, 1970]. They inhabit natural as well as artificial habitats in diverse marine, freshwater, and semi-aquatic ecosystems (e.g. peatbogs, alder woods, riparian forests). Until now, 29 species of gastrotrichs from the Polish Baltic Sea region (including three freshwater species which were found in estuaries) were known. Sixteen species belong to Chaetonotida and thirteen to Macrodasyida. During this study we found two species, Heterolepidoderma sinus spec. nov., and Aspidiophorus lamellophorus Balsamo, Hummon, Todaro et Tongiorgi, 1997 which is new to the Baltic Sea fauna. H. sinus spec. nov. has distinct cuticular reinforcements in the anterior dilatation of the pharynx. Moreover, it is characterized by two kinds of lamellae: one type is represented by small triangular lamellae which aris from lateral scales, the second type is large and clearly visible and arises from ventral scales. None of the Heterolepidoderma species known so far has two types of lamellae. A. lamellophorus was previously known only from the Mediterranean Sea. The finding of two new gastrotrich species in the Baltic Sea shows that the knowledge of these small invertebrates in the area is still far from complete. PMID:26624193

  11. The hydrodynamic part of the 3D CEMBS model for the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Dzierzbicka-Glowacka, Lidia; Jakacki, Jaromir; Janecki, Maciej; Nowicki, Artur

    2013-04-01

    The paper presents a hydrodynamic part of the coupled ice-ocean model 3D CEMBS designed for the Baltic Sea. It is based on the Community Earth System Model (CESM from the National Center for Atmospheric Research). It was adopted for the Baltic Sea as a coupled sea-ice model. It consists of the Community Ice Code (CICE model, version 4.0) and the Parallel Ocean Program (version 2.1). The models are linked through the coupler (CPL7) based on the Model Coupling Toolkit library. The ocean model has 21 vertical levels and horizontal grid of 600x640 cells. Horizontal resolution is approximately 2km. It is forced by atmospheric fields from European Centre for Medium-Range Weather Forecasts and in operational mode from 48-hour atmospheric forecasts provided by the UM model from the Interdisciplinary Centre for Mathematical and Computational Modelling of Warsaw University (ICM). The study was financially supported by the Polish State Committee of Scientific Research (grants: No N N305 111636, N N306 353239). The partial support for this study was also provided by the project Satellite Monitoring of the Baltic Sea Environment - SatBaltyk founded by European Union through European Regional Development Fund contract no. POIG 01.01.02-22-011/09. Calculations were carried out at the Academy Computer Centre in Gdansk.

  12. Turbulence structure of the marine stable boundary layer over the Baltic Sea

    SciTech Connect

    Smedman, A.S.; Hoegstroem, U.

    1994-12-31

    For more than half of the year the land surfaces surrounding the Baltic Sea is warmer than the sea surface, and the marine boundary layer over the Baltic is stable. Observations, at various sites in the Baltic Sea area during the last decade. also indicate frequent occurrence of low-level jets at the top of the stable boundary layer. In many cases the marine jet can be considered as an analogy in space to the evolution of the nocturnal jet with time. The frictional decoupling occurs when warm air over the land is flowing out over the sea. Data from two areas together with model simulations are used in this study to characterize turbulence structure in the marine boundary layer. The measurements include profiles of wind and temperature on towers situated at two isolated islands, together with turbulence recordings and aircraft measurements. Also wave height and water surface temperature have been measured. The model simulations are performed with a second-order closure model.

  13. Morphological abnormalities in gonads of the Baltic herring (Clupea harengus membras): Description of types and prevalence in the northern Baltic Sea.

    PubMed

    Rajasilta, Marjut; Elfving, Mikael; Hänninen, Jari; Laine, Päivi; Vuorinen, Ilppo; Paranko, Jorma

    2016-03-01

    Due to heavy anthropogenic influence and variation of the environmental conditions in the Baltic Sea, reproductive disorders are becoming a major environmental concern. We show here an increasing prevalence of gonadal malformations in the Baltic herring (Clupea harengus membras), a key species of the Baltic ecosystem and important in commercial fishery. During 1987-2014, the spawning herring population in the Archipelago Sea (AS) (North Baltic Sea, Finland) was monitored annually and analyzed for gross morphology of the gonads [total number (n) of analyzed fish = 38 284]. Four different types of malformations were repeatedly found and named as asymmetric, rudimentary, segmented, and branched gonads, but also hermaphroditic gonads and miscellaneous (unidentified) disorders were recorded. In 2013, additional samplings (n of fish analyzed = 541) showed similar malformations in herring from the Bothnian Sea. In some gonad types, histological examination revealed disintegration of seminiferous tubules and hyperplasia of the interstitial tissue. In 2014, the overall prevalence of malformations was still relatively low in the AS (frequency = 0-3.4 %; n = 750) and had apparently minimal effect on population recruitment. However, an increasing trend in the time-series (GLM; F = 32.65; p < 0.001) and a significantly higher prevalence in the Bothnian Sea (frequency = 0.7-5.0 %; n = 541; χ (2) = 6.24; p < 0.05) suggest that gonadal malformations may become a new threat for fish in the Baltic Sea. The observed gonad atrophies may be due to environmental endocrine disruption; however, also other explanations may exist and potential explanations are discussed. PMID:26446509

  14. Model estimates of the eutrophication of the Baltic Sea in the contemporary and future climate

    NASA Astrophysics Data System (ADS)

    Ryabchenko, V. A.; Karlin, L. N.; Isaev, A. V.; Vankevich, R. E.; Eremina, T. R.; Molchanov, M. S.; Savchuk, O. P.

    2016-01-01

    The St. Petersburg Baltic eutrophication model (SPBEM) is used to assess the ecological condition of the sea under possible changes in climate and nutrient loads in the 21st century. According to model estimates, in the future climate water quality will worsen, compared to modern conditions. This deterioration is stronger in the climate warming scenario with a stronger change in future near-surface air temperature. In the considered scenarios of climate change, climate warming will lead to an increase in the area of anoxic and hypoxic zones. Reduction of nutrient loading, estimated in accordance with the Baltic Sea Action Plan, will only be able to partially compensate for the negative effects of global warming.

  15. The potential of current- and wind-driven transport for environmental management of the Baltic Sea.

    PubMed

    Soomere, Tarmo; Döös, Kristofer; Lehmann, Andreas; Meier, H E Markus; Murawski, Jens; Myrberg, Kai; Stanev, Emil

    2014-02-01

    The ever increasing impact of the marine industry and transport on vulnerable sea areas puts the marine environment under exceptional pressure and calls for inspired methods for mitigating the impact of the related risks. We describe a method for preventive reduction of remote environmental risks caused by the shipping and maritime industry that are transported by surface currents and wind impact to the coasts. This method is based on characterizing systematically the damaging potential of the offshore areas in terms of potential transport to vulnerable regions of an oil spill or other pollution that has occurred in a particular area. The resulting maps of probabilities of pollution to be transported to the nearshore and the time it takes for the pollution to reach the nearshore are used to design environmentally optimized fairways for the Gulf of Finland, Baltic Proper, and south-western Baltic Sea. PMID:24414808

  16. No observed effect of ocean acidification on nitrogen biogeochemistry in a summer Baltic Sea plankton community

    NASA Astrophysics Data System (ADS)

    Paul, A. J.; Achterberg, E. P.; Bach, L. T.; Boxhammer, T.; Czerny, J.; Haunost, M.; Schulz, K.-G.; Stuhr, A.; Riebesell, U.

    2015-10-01

    Nitrogen fixation by filamentous cyanobacteria supplies significant amounts of new nitrogen (N) to the Baltic Sea. This balances N loss processes such as denitrification and anammox and forms an important N source supporting primary and secondary production in N-limited post-spring bloom plankton communities. Laboratory studies suggest that filamentous diazotrophic cyanobacteria growth and N2-fixation rates are sensitive to ocean acidification with potential implications for new N supply to the Baltic Sea. In this study, our aim was to assess the effect of ocean acidification on diazotroph growth and activity as well as the contribution of diazotrophically-fixed N to N supply in a natural plankton assemblage. We enclosed a natural plankton community in a summer season in the Baltic Sea near the entrance to the Gulf of Finland in six large-scale mesocosms (volume ~ 55 m3) and manipulated fCO2 over a range relevant for projected ocean acidification by the end of this century (average treatment fCO2: 365-1231 μatm). The direct response of diazotroph growth and activity was followed in the mesocosms over a 47 day study period during N-limited growth in the summer plankton community. Diazotrophic filamentous cyanobacteria abundance throughout the study period and N2-fixation rates (determined only until day 21 due to subsequent use of contaminated commercial 15N-N2 gas stocks) remained low. Thus estimated new N inputs from diazotrophy were too low to relieve N limitation and stimulate a summer phytoplankton bloom. Instead regeneration of organic N sources likely sustained growth in the plankton community. We could not detect significant CO2-related differences in inorganic or organic N pools sizes, or particulate matter N : P stoichiometry. Additionally, no significant effect of elevated CO2 on diazotroph activity was observed. Therefore, ocean acidification had no observable impact on N cycling or biogeochemistry in this N-limited, post-spring bloom plankton

  17. Precision and accuracy of spectrophotometric pH measurements at environmental conditions in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Hammer, Karoline; Schneider, Bernd; Kuliński, Karol; Schulz-Bull, Detlef E.

    2014-06-01

    The increasing uptake of anthropogenic CO2 by the oceans has raised an interest in precise and accurate pH measurement in order to assess the impact on the marine CO2-system. Spectrophotometric pH measurements were refined during the last decade yielding a precision and accuracy that cannot be achieved with the conventional potentiometric method. However, until now the method was only tested in oceanic systems with a relative stable and high salinity and a small pH range. This paper describes the first application of such a pH measurement system at conditions in the Baltic Sea which is characterized by a wide salinity and pH range. The performance of the spectrophotometric system at pH values as low as 7.0 (“total” scale) and salinities between 0 and 35 was examined using TRIS-buffer solutions, certified reference materials, and tests of consistency with measurements of other parameters of the marine CO2 system. Using m-cresol purple as indicator dye and a spectrophotometric measurement system designed at Scripps Institution of Oceanography (B. Carter, A. Dickson), a precision better than ±0.001 and an accuracy between ±0.01 and ±0.02 was achieved within the observed pH and salinity ranges in the Baltic Sea. The influence of the indicator dye on the pH of the sample was determined theoretically and is presented as a pH correction term for the different alkalinity regimes in the Baltic Sea. Because of the encouraging tests, the ease of operation and the fact that the measurements refer to the internationally accepted “total” pH scale, it is recommended to use the spectrophotometric method also for pH monitoring and trend detection in the Baltic Sea.

  18. Satellite mapping of Baltic Sea Secchi depth with multiple regression models

    NASA Astrophysics Data System (ADS)

    Stock, Andy

    2015-08-01

    Secchi depth is a measure of water transparency. In the Baltic Sea region, Secchi depth maps are used to assess eutrophication and as input for habitat models. Due to their spatial and temporal coverage, satellite data would be the most suitable data source for such maps. But the Baltic Sea's optical properties are so different from the open ocean that globally calibrated standard models suffer from large errors. Regional predictive models that take the Baltic Sea's special optical properties into account are thus needed. This paper tests how accurately generalized linear models (GLMs) and generalized additive models (GAMs) with MODIS/Aqua and auxiliary data as inputs can predict Secchi depth at a regional scale. It uses cross-validation to test the prediction accuracy of hundreds of GAMs and GLMs with up to 5 input variables. A GAM with 3 input variables (chlorophyll a, remote sensing reflectance at 678 nm, and long-term mean salinity) made the most accurate predictions. Tested against field observations not used for model selection and calibration, the best model's mean absolute error (MAE) for daily predictions was 1.07 m (22%), more than 50% lower than for other publicly available Baltic Sea Secchi depth maps. The MAE for predicting monthly averages was 0.86 m (15%). Thus, the proposed model selection process was able to find a regional model with good prediction accuracy. It could be useful to find predictive models for environmental variables other than Secchi depth, using data from other satellite sensors, and for other regions where non-standard remote sensing models are needed for prediction and mapping. Annual and monthly mean Secchi depth maps for 2003-2012 come with this paper as Supplementary materials.

  19. No observed effect of ocean acidification on nitrogen biogeochemistry in a summer Baltic Sea plankton community

    NASA Astrophysics Data System (ADS)

    Paul, Allanah J.; Achterberg, Eric P.; Bach, Lennart T.; Boxhammer, Tim; Czerny, Jan; Haunost, Mathias; Schulz, Kai-Georg; Stuhr, Annegret; Riebesell, Ulf

    2016-07-01

    Nitrogen fixation by filamentous cyanobacteria supplies significant amounts of new nitrogen (N) to the Baltic Sea. This balances N loss processes such as denitrification and anammox, and forms an important N source supporting primary and secondary production in N-limited post-spring bloom plankton communities. Laboratory studies suggest that filamentous diazotrophic cyanobacteria growth and N2-fixation rates are sensitive to ocean acidification, with potential implications for new N supply to the Baltic Sea. In this study, our aim was to assess the effect of ocean acidification on diazotroph growth and activity as well as the contribution of diazotrophically fixed N to N supply in a natural plankton assemblage. We enclosed a natural plankton community in a summer season in the Baltic Sea near the entrance to the Gulf of Finland in six large-scale mesocosms (volume ˜ 55 m3) and manipulated fCO2 over a range relevant for projected ocean acidification by the end of this century (average treatment fCO2: 365-1231 µatm). The direct response of diazotroph growth and activity was followed in the mesocosms over a 47 day study period during N-limited growth in the summer plankton community. Diazotrophic filamentous cyanobacteria abundance throughout the study period and N2-fixation rates (determined only until day 21 due to subsequent use of contaminated commercial 15N-N2 gas stocks) remained low. Thus estimated new N inputs from diazotrophy were too low to relieve N limitation and stimulate a summer phytoplankton bloom. Instead, regeneration of organic N sources likely sustained growth in the plankton community. We could not detect significant CO2-related differences in neither inorganic nor organic N pool sizes, or particulate matter N : P stoichiometry. Additionally, no significant effect of elevated CO2 on diazotroph activity was observed. Therefore, ocean acidification had no observable impact on N cycling or biogeochemistry in this N-limited, post-spring bloom

  20. Shelf-to-basin iron shuttling enhances vivianite formation in deep Baltic Sea sediments

    NASA Astrophysics Data System (ADS)

    Reed, Daniel C.; Gustafsson, Bo G.; Slomp, Caroline P.

    2016-01-01

    Coastal hypoxia is a growing and persistent problem largely attributable to enhanced terrestrial nutrient (i.e., nitrogen and phosphorus) loading. Recent studies suggest phosphorus removal through burial of iron (II) phosphates, putatively vivianite, plays an important role in nutrient cycling in the Baltic Sea - the world's largest anthropogenic dead zone - yet the dynamics of iron (II) phosphate formation are poorly constrained. To address this, a reactive-transport model was used to reconstruct the diagenetic and depositional history of sediments in the Fårö basin, a deep anoxic and sulphidic region of the Baltic Sea where iron (II) phosphates have been observed. Simulations demonstrate that transport of iron from shelf sediments to deep basins enhances vivianite formation while sulphide concentrations are low, but that pyrite forms preferentially over vivianite when sulphate reduction intensifies due to elevated organic loading. Episodic reoxygenation events, associated with major inflows of oxic waters, encourage the retention of iron oxyhydroxides and iron-bound phosphorus in sediments, increasing vivianite precipitation as a result. Results suggest that artificial reoxygenation of the Baltic Sea bottom waters could sequester up to 3% of the annual external phosphorus loads as iron (II) phosphates, but this is negligible when compared to potential internal phosphorus loads due to dissolution of iron oxyhydroxides when low oxygen conditions prevail. Thus, enhancing vivianite formation through artificial reoxygenation of deep waters is not a viable engineering solution to eutrophication in the Baltic Sea. Finally, simulations suggest that regions with limited sulphate reduction and hypoxic intervals, such as eutrophic estuaries, could act as important phosphorus sinks by sequestering vivianite. This could potentially alleviate eutrophication in shelf and slope environments.

  1. Reconstructing ecosystem functions of the active microbial community of the Baltic Sea oxygen depleted sediments

    PubMed Central

    Franzetti, Andrea; Lundin, Daniel; Sjöling, Sara

    2016-01-01

    Baltic Sea deep water and sediments hold one of the largest anthropogenically induced hypoxic areas in the world. High nutrient input and low water exchange result in eutrophication and oxygen depletion below the halocline. As a consequence at Landsort Deep, the deepest point of the Baltic Sea, anoxia in the sediments has been a persistent condition over the past decades. Given that microbial communities are drivers of essential ecosystem functions we investigated the microbial community metabolisms and functions of oxygen depleted Landsort Deep sediments by metatranscriptomics. Results show substantial expression of genes involved in protein metabolism demonstrating that the Landsort Deep sediment microbial community is active. Identified expressed gene suites of metabolic pathways with importance for carbon transformation including fermentation, dissimilatory sulphate reduction and methanogenesis were identified. The presence of transcripts for these metabolic processes suggests a potential for heterotrophic-autotrophic community synergism and indicates active mineralisation of the organic matter deposited at the sediment as a consequence of the eutrophication process. Furthermore, cyanobacteria, probably deposited from the water column, are transcriptionally active in the anoxic sediment at this depth. Results also reveal high abundance of transcripts encoding integron integrases. These results provide insight into the activity of the microbial community of the anoxic sediment at the deepest point of the Baltic Sea and its possible role in ecosystem functioning. PMID:26823996

  2. Reconstructing ecosystem functions of the active microbial community of the Baltic Sea oxygen depleted sediments.

    PubMed

    Thureborn, Petter; Franzetti, Andrea; Lundin, Daniel; Sjöling, Sara

    2016-01-01

    Baltic Sea deep water and sediments hold one of the largest anthropogenically induced hypoxic areas in the world. High nutrient input and low water exchange result in eutrophication and oxygen depletion below the halocline. As a consequence at Landsort Deep, the deepest point of the Baltic Sea, anoxia in the sediments has been a persistent condition over the past decades. Given that microbial communities are drivers of essential ecosystem functions we investigated the microbial community metabolisms and functions of oxygen depleted Landsort Deep sediments by metatranscriptomics. Results show substantial expression of genes involved in protein metabolism demonstrating that the Landsort Deep sediment microbial community is active. Identified expressed gene suites of metabolic pathways with importance for carbon transformation including fermentation, dissimilatory sulphate reduction and methanogenesis were identified. The presence of transcripts for these metabolic processes suggests a potential for heterotrophic-autotrophic community synergism and indicates active mineralisation of the organic matter deposited at the sediment as a consequence of the eutrophication process. Furthermore, cyanobacteria, probably deposited from the water column, are transcriptionally active in the anoxic sediment at this depth. Results also reveal high abundance of transcripts encoding integron integrases. These results provide insight into the activity of the microbial community of the anoxic sediment at the deepest point of the Baltic Sea and its possible role in ecosystem functioning. PMID:26823996

  3. Microbial metagenomics in the Baltic Sea: Recent advancements and prospects for environmental monitoring.

    PubMed

    Ininbergs, Karolina; Bergman, Birgitta; Larsson, John; Ekman, Martin

    2015-06-01

    Metagenomics refers to the analysis of DNA from a whole community. Metagenomic sequencing of environmental DNA has greatly improved our knowledge of the identity and function of microorganisms in aquatic, terrestrial, and human biomes. Although open oceans have been the primary focus of studies on aquatic microbes, coastal and brackish ecosystems are now being surveyed. Here, we review so far published studies on microbes in the Baltic Sea, one of the world's largest brackish water bodies, using high throughput sequencing of environmental DNA and RNA. Collectively the data illustrate that Baltic Sea microbes are unique and highly diverse, and well adapted to this brackish-water ecosystem, findings that represent a novel base-line knowledge necessary for monitoring purposes and a sustainable management. More specifically, the data relate to environmental drivers for microbial community composition and function, assessments of the microbial biodiversity, adaptations and role of microbes in the nitrogen cycle, and microbial genome assembly from metagenomic sequences. With these discoveries as background, prospects of using metagenomics for Baltic Sea environmental monitoring are discussed. PMID:26022326

  4. Sustainable Phosphorus Loadings from Effective and Cost-Effective Phosphorus Management Around the Baltic Sea

    PubMed Central

    Bryhn, Andreas C.

    2009-01-01

    Nutrient over-enrichment of the Baltic Sea, accompanied by intensified algal blooms and decreasing water clarity, has aroused widespread concern in the surrounding countries during the last four decades. This work has used a well-tested dynamic mass-balance model to investigate which decrease in total phosphorus loading would be required to meet the environmental goal to restore the trophic state in the Baltic Sea to pre-1960s levels. Furthermore, the extent to which various abatement options may decrease the phosphorus loading in a cost-effective manner has been studied. Upgrading urban sewage treatment in the catchment could, alone or in combination with banning phosphates in detergents, be sufficient to meet the set environmental goal, at an estimated annual basin-wide cost of 0.21–0.43 billion euro. Such a plan would potentially decrease the total phosphorus loading to the Baltic Sea with 6,650–10,200 tonnes per year. PMID:19412551

  5. Distribution and sources of organic matter in sediments of the south-eastern Baltic Sea

    NASA Astrophysics Data System (ADS)

    Remeikaitė-Nikienė, Nijolė; Lujanienė, Galina; Malejevas, Vitalijus; Barisevičiūtė, Rūta; Žilius, Mindaugas; Garnaga-Budrė, Galina; Stankevičius, Algirdas

    2016-05-01

    Temporal and spatial distribution of sedimentary organic matter (SOM) as well as its sources in the south-eastern Baltic Sea were investigated. Organic matter was characterized by the organic carbon content, δ13C and δ15N signatures and C/N ratios. The sampling was performed in the coastal, offshore areas and in the Curonian Lagoon in the period from May 2012 to September 2014. The average elemental (C/N ~ 6.4) and isotopic composition (δ13C from - 29.6‰ to - 24.9‰) of SOM suggested that during most of the year it was composed of both freshwater and marine phytoplanktonic material. Elevated δ15N values (average ranging from 5.6‰ to 6.7‰) were detected in SOM from the Curonian Lagoon. This most likely reflected the increased isotopic signal of the Nemunas River (δ15N ~ 8‰) derived from the anthropogenic input in the basin area. At the Baltic Sea offshore sites, SOM had lower δ15N values (δ15N ~ 3.5‰ on average), indicating phytoplankton blooms. A two-end member mixing model based on the carbon stable isotopic composition showed that a large proportion (~ 90%) of SOM in the northern part of the Curonian Lagoon was of the freshwater origin. The allochthonous organic matter accounted for about 47% of SOM in the studied Baltic Sea area with the highest contribution (about 75%) within the Curonian Lagoon plume zone in the coastal waters.

  6. A new approach to model oxygen dependent benthic phosphate fluxes in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Almroth-Rosell, Elin; Eilola, Kari; Kuznetsov, Ivan; Hall, Per O. J.; Meier, H. E. Markus

    2015-04-01

    The new approach to model the oxygen dependent phosphate release by implementing formulations of the oxygen penetration depths (OPD) and mineral bound inorganic phosphorus pools to the Swedish Coastal and Ocean Biogeochemical model (SCOBI) is described. The phosphorus dynamics and the oxygen concentrations in the Baltic proper sediment are studied during the period 1980-2008 using SCOBI coupled to the 3D-Rossby Centre Ocean model. Model data are compared to observations from monitoring stations and experiments. The impact from oxygen consumption on the determination of the OPD is found to be largest in the coastal zones where also the largest OPD are found. In the deep water the low oxygen concentrations mainly determine the OPD. Highest modelled release rate of phosphate from the sediment is about 59 × 103 t P year- 1 and is found on anoxic sediment at depths between 60-150 m, corresponding to 17% of the Baltic proper total area. The deposition of organic and inorganic phosphorus on sediments with oxic bottom water is larger than the release of phosphorus, about 43 × 103 t P year- 1. For anoxic bottoms the release of total phosphorus during the investigated period is larger than the deposition, about 19 × 103 t P year- 1. In total the net Baltic proper sediment sink is about 23.7 × 103 t P year- 1. The estimated phosphorus sink efficiency of the entire Baltic Sea is on average about 83% during the period.

  7. Towards an improved understanding of Baltic Sea hypoxia during the Holocene: preliminary results from IODP Expedition 347

    NASA Astrophysics Data System (ADS)

    Slomp, Caroline; Dijkstra, Nikki; Egger, Matthias; Gustafsson, Bo; Ash, Jeanine; Bauersachs, Thorsten; Hardisty, Dalton; Martin, Ellen; Riedinger, Natascha; Andren, Thomas; Barker Jorgensen, Bo

    2015-04-01

    The Baltic Sea is a restricted brackish-marine basin that is highly sensitive to changes in climate and anthropogenic activity. Due to its salinity stratification, the Baltic Sea is particularly vulnerable to hypoxia (oxygen concentrations < 2 ml/L). Besides the modern, human-induced period of hypoxia (since A.D. 1960), there is evidence for two earlier major intervals of hypoxia since the transition of the Baltic Sea from the Ancylus freshwater phase to the Littorina brackish-marine phase. These are the Holocene Thermal Maximum (HTM), ca. 8-4 ka, and the Medieval Climate Anomaly (MCA), ca. 1-0.7 ka (Zillen et al., 2008; Jilbert and Slomp, 2013). While changes in salinity, temperature and the input and recycling of nutrients all may contribute to the development of hypoxia in the Baltic Sea, their relative importance in driving the hypoxia during the MCA and HTM is still incompletely understood. Here, we use porewater and sediment geochemical data obtained during the IODP Expedition 347: Baltic Sea Paleoenvironment (September 13 - November 1, 2013) to obtain further insight into the role of changes in salinity and phosphorus recycling during the HTM. We focus on three sites along the modern salinity gradient in the Baltic Sea, Sites M0059, M0063 and M0065. Our results indicate that bottom water salinity in the Baltic Proper was higher during the HTM than at present, confirming previous studies that increased salinity stratification may have contributed to the development of hypoxia during the HTM. We also discuss evidence for temporal changes and spatial differences in primary productivity and phosphorus burial and recycling in the Baltic Sea and their potential role in contributing to the development of hypoxia during the HTM and MCA. References: Jilbert, T., and Slomp, C.P. (2013). Rapid high-amplitude variability in Baltic Sea hypoxia during the Holocene. Geology 41, 1183-1186. doi: 10.1130/g34804.1. Zillén, L., Conley, D.J., Andrén, T., Andrén, E., and Bj

  8. Model simulations of dense bottom currents in the Western Baltic Sea

    NASA Astrophysics Data System (ADS)

    Burchard, Hans; Janssen, Frank; Bolding, Karsten; Umlauf, Lars; Rennau, Hannes

    2009-01-01

    Only recently, medium intensity inflow events into the Baltic Sea have gained more awareness because of their potential to ventilate intermediate layers in the Southern Baltic Sea basins. With the present high-resolution model study of the Western Baltic Sea a first attempt is made to obtain model based realistic estimates of turbulent mixing in this area where dense bottom currents resulting from medium intensity inflow events are weakened by turbulent entrainment. The numerical model simulation which is carried out using the General Estuarine Transport Model (GETM) during nine months in 2003 and 2004 is first validated by means of three automatic stations at the Drogden and Darss Sills and in the Arkona Sea. In order to obtain good agreement between observations and model results, the 0.5×0.5 nautical mile bathymetry had to be adjusted in order to account for the fact that even at that scale many relevant topographic features are not resolved. Current velocity, salinity and turbulence observations during a medium intensity inflow event through the Øresund are then compared to the model results. Given the general problems of point to point comparisons between observations and model simulations, the agreement is fairly good with the characteristic features of the inflow event well represented by the model simulations. Two different bulk measures for mixing activity are then introduced, the vertically integrated decay of salinity variance, which is equal to the production of micro-scale salinity variance, and the vertically integrated turbulent salt flux, which is related to an increase of potential energy due to vertical mixing of stably stratified flow. Both measures give qualitatively similar results and identify the Drogden and Darss Sills as well as the Bornholm Channel as mixing hot spots. Further regions of strong mixing are the dense bottom current pathways from these sills into the Arkona Sea, areas around Kriegers Flak (a shoal in the western Arkona Sea

  9. Evaluation of the operational SAR based Baltic sea ice concentration products

    NASA Astrophysics Data System (ADS)

    Karvonen, Juha

    Sea ice concentration is an important ice parameter both for weather and climate modeling and sea ice navigation. We have developed an fully automated algorithm for sea ice concentration retrieval using dual-polarized ScanSAR wide mode RADARSAT-2 data. RADARSAT-2 is a C-band SAR instrument enabling dual-polarized acquisition in ScanSAR mode. The swath width for the RADARSAT-2 ScanSAR mode is about 500 km, making it very suitable for operational sea ice monitoring. The polarization combination used in our concentration estimation is HH/HV. The SAR data is first preprocessed, the preprocessing consists of geo-rectification to Mercator projection, incidence angle correction fro both the polarization channels. and SAR mosaicking. After preprocessing a segmentation is performed for the SAR mosaics, and some single-channel and dual-channel features are computed for each SAR segment. Finally the SAR concentration is estimated based on these segment-wise features. The algorithm is similar as introduced in Karvonen 2014. The ice concentration is computed daily using a daily RADARSAT-2 SAR mosaic as its input, and it thus gives the concentration estimated at each Baltic Sea location based on the most recent SAR data at the location. The algorithm has been run in an operational test mode since January 2014. We present evaluation of the SAR-based concentration estimates for the Baltic ice season 2014 by comparing the SAR results with gridded the Finnish Ice Service ice charts and ice concentration estimates from a radiometer algorithm (AMSR-2 Bootstrap algorithm results). References: J. Karvonen, Baltic Sea Ice Concentration Estimation Based on C-Band Dual-Polarized SAR Data, IEEE Transactions on Geoscience and Remote Sensing, in press, DOI: 10.1109/TGRS.2013.2290331, 2014.

  10. Sea level rise of semi-enclosed basins: deviation of Adriatic and Baltic sea level from the mean global value.

    NASA Astrophysics Data System (ADS)

    Scarascia, Luca; Lionello, Piero

    2015-04-01

    Future sea level rise (SL), which represents today one of the major threats that are caused by climate change, will not be uniform. Regional differences are crucial for 40% of the world population, which is located in the coastal zone. To explore the mechanisms linking regional SL to climate variables is very important in order to provide reliable future projections. This study focuses on two semi-enclosed basins, the Adriatic and Baltic Sea and investigates the deviation of their SL from the mean global value. In fact, past deviations of the SL of these two basins from the global value have been observed and can be attributed to large scale factors (such as teleconnections) and regional factors, such as the inverse barometric effect, the wind stress, the thermosteric and halosteric effects. The final goal of this work is to assess to which extent the Adriatic and Baltic SL will depart from the mean global value in the next decades and at the end of 21st century. This is achieved by analyzing deviations of the mean SL of the Baltic and Adriatic Sea from the global mean SL during the 20th century and investigating which factors can explain such deviations. A multivariate linear regression model is built and used to describe the link between three large scale climate variables which are used as predictors (mean sea level pressure, surface air temperature and precipitation), and the regional SL deviation (the predictand), computed as the difference between the regional and the global SL. At monthly scale this linear regression model provides a good reconstruction of the past variability in the cold season during which it explains 60%-70% of the variance. Summer reconstruction is substantially less successful and it represents presently the main limit of the model skill. This linear regression model, forced by predictors extracted from CMIP5 multi-model simulations, is used to provide projections of SL in the Adriatic and Baltic Sea. On the basis of the projections

  11. The ecophysiology of Sprattus sprattus in the Baltic and North Seas

    NASA Astrophysics Data System (ADS)

    Peck, Myron A.; Baumann, Hannes; Bernreuther, Matthias; Clemmesen, Catriona; Herrmann, Jens-Peter; Haslob, Holger; Huwer, Bastian; Kanstinger, Philipp; Köster, Fritz W.; Petereit, Christoph; Temming, Axel; Voss, Rudi

    2012-09-01

    The European sprat (Sprattus sprattus) was a main target species of the German GLOBEC program that investigated the trophodynamic structure and function of the Baltic and North Seas under the influence of physical forcing. This review summarizes literature on the ecophysiology of sprat with an emphasis on describing how environmental factors influence the life-history strategy of this small pelagic fish. Ontogenetic changes in feeding and growth, and the impacts of abiotic and biotic factors on vital rates are discussed with particular emphasis on the role of temperature as a constraint to life-history scheduling of this species in the Baltic Sea. A combination of field and laboratory data suggests that optimal thermal windows for growth and survival change during early life and are wider for eggs (5-17 °C) than in young (8- to 12-mm) early feeding larvae (5-12 °C). As larvae become able to successfully capture larger prey, thermal windows expand to include warmer waters. For example, 12- to 16-mm larvae can grow well at 16 °C and larger, transitional-larvae and early juveniles display the highest rates of feeding and growth at ∼18-22 °C. Gaps in knowledge are identified including the need for additional laboratory studies on the physiology and behavior of larvae (studies that will be particularly critical for biophysical modeling activities) and research addressing the role of overwinter survival as a factor shaping phenology and setting limits on the productivity of this species in areas located at the northern limits of its latitudinal range (such as the Baltic Sea). Based on stage- and temperature-specific mortality and growth potential of early life stages, our analysis suggests that young-of-the year sprat would benefit from inhabiting warmer, near-shore environments rather than the deeper-water spawning grounds such as the Bornholm Basin (central Baltic Sea). Utilization of warmer, nearshore waters (or a general increase in Baltic Sea temperatures) is

  12. Reprint of: The ecophysiology of Sprattus sprattus in the Baltic and North Seas

    NASA Astrophysics Data System (ADS)

    Peck, Myron A.; Baumann, Hannes; Bernreuther, Matthias; Clemmesen, Catriona; Herrmann, Jens-Peter; Haslob, Holger; Huwer, Bastian; Kanstinger, Philipp; Köster, Fritz W.; Petereit, Christoph; Temming, Axel; Voss, Rudi

    2012-12-01

    The European sprat (Sprattus sprattus) was a main target species of the German GLOBEC program that investigated the trophodynamic structure and function of the Baltic and North Seas under the influence of physical forcing. This review summarizes literature on the ecophysiology of sprat with an emphasis on describing how environmental factors influence the life-history strategy of this small pelagic fish. Ontogenetic changes in feeding and growth, and the impacts of abiotic and biotic factors on vital rates are discussed with particular emphasis on the role of temperature as a constraint to life-history scheduling of this species in the Baltic Sea. A combination of field and laboratory data suggests that optimal thermal windows for growth and survival change during early life and are wider for eggs (5-17 °C) than in young (8- to 12-mm) early feeding larvae (5-12 °C). As larvae become able to successfully capture larger prey, thermal windows expand to include warmer waters. For example, 12- to 16-mm larvae can grow well at 16 °C and larger, transitional-larvae and early juveniles display the highest rates of feeding and growth at ∼18-22 °C. Gaps in knowledge are identified including the need for additional laboratory studies on the physiology and behavior of larvae (studies that will be particularly critical for biophysical modeling activities) and research addressing the role of overwinter survival as a factor shaping phenology and setting limits on the productivity of this species in areas located at the northern limits of its latitudinal range (such as the Baltic Sea). Based on stage- and temperature-specific mortality and growth potential of early life stages, our analysis suggests that young-of-the year sprat would benefit from inhabiting warmer, near-shore environments rather than the deeper-water spawning grounds such as the Bornholm Basin (central Baltic Sea). Utilization of warmer, nearshore waters (or a general increase in Baltic Sea temperatures) is

  13. Large spatial variations in coastal 14C reservoir age - a case study from the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Lougheed, B. C.; Filipsson, H. L.; Snowball, I.

    2013-02-01

    Coastal locations are highly influenced by input from freshwater river runoff, including sources of terrestrial carbon, which can be expected to modify the 14C reservoir age, or R(t), associated with marine water. In this Baltic Sea case study, pre-bomb museum collection mollusc shells of known calendar age, from 30 locations across a strategic salinity transect of the Baltic Sea, were analysed for 14C, δ13C and δ18O. R(t) was calculated for all 30 locations. Seven locations, of which six are within close proximity of the coast, were found to have relatively higher R(t) values, indicative of hard-water effects. δ13Caragonite values were found to be indicative of hard-water influence only for certain locations, suggesting the possibility of different sources of old carbon in different locations. Whenever possible, the Macoma genus of mollusc was selected from the museum collections, in order to exclude species specific reservoir age effects as much as possible. When the Macoma samples are exclusively considered, and samples from hard-water locations excluded, a statistically significant correlation between Macoma R(t) and average salinity is found, indicating a two end-member linear mixing model between 14Cmarine and 14Crunoff. A map of Baltic Sea Macoma aragonite R(t) for the late 19th and early 20th centuries is produced. Such a map can provide an estimate for contemporary Baltic Sea Macoma R(t), although one must exercise caution when applying such estimates back in time or to 14C dates obtained from different sample material. A statistically significant correlation is also found between δ18Oaragonite and Macoma R(t), suggesting that δ18Oaragonite can be used to estimate Macoma palaeo-R(t). The results of this Baltic Sea case study, which show that R(t) is affected by hydrographic conditions and local carbon inputs, have important consequences for other coastal and estuarine locations, where R(t) is also likely to significantly vary on spatial and temporal

  14. Analysing water level trends and extremes in the Baltic Sea for the period 1950-2015

    NASA Astrophysics Data System (ADS)

    Gräwe, Ulf; Klingbeil, Knut

    2016-04-01

    The General Estuarine Transport Model (GETM) was applied to create a state estimate of the Baltic Sea for the period 1950-2015 with a horizontal resolution of 1 nautical mile . In the vertical 60 terrain-following layers were used, which during runtime automatically adapt to the highly variable stratification. This is associated with sporadicly inflowing bottom gravity currents of saline North Sea water, the seasonal thermocline and internal wave motions at the permanent halocline. These challenges need to be tackled by a model to correctly reproduce the mixing and entrainment of water masses in the Baltic Sea. The atmospheric forcing was taken from a regional reanalysis with a spatial resolution of less than 20 km and hourly values. The analysis of the sea surface height (SSH) revealed a non-uniform absolute mean sea level (MSL) rise in the Baltic Sea. Lowest values are found in the western part with 1.4mm/year and highest values in the Gulf of Finland with values of 2.2 mm/year. This spatial heterogeneity is partially explained by an increase in the mean zonal winds but also by changes in air pressure. The warming trend of the sea surface temperature adds to the regional increase in SSH. Analysing water level extremes, the simulations indicate a much faster rise in annual maximum SSH compared to MSL rise. This is well correlated with an increase in the annual maximum wind speed. The linear trends in annual maximum SSH are 2 mm/year in the western Baltic Sea and reach peak values of 6 mm/year in the Gulf of Finland. For the trends in annual minimum SSH we do not see any trend different from MSL rise. As a further measure to quantify changes in extreme water levels, we computed the duration and intensity (duration times excess water height over 99 percentile). Whereas the mean duration does not change significantly, the model results indicate a significant increase in intensity. To estimate the robustness of the results, their sensitivity to the atmospheric forcing

  15. The Baltic Sea: Geophysical and geochemical properties of Holocene sediment sequences as indicators of past environmental variability

    NASA Astrophysics Data System (ADS)

    Lenz, Conny; Reinholdsson, Maja; Zillén, Lovisa; Conley, Daniel J.; Snowball, Ian

    2010-05-01

    The Baltic Sea has undergone large environmental changes since the retreat of the Weischselian Ice-sheet. In the Late Glacial Period and the early Holocene these changes were most likely caused by natural environmental changes (i.e. changes in the morphology and depths of the Baltic basin and the sills). In more recent time anthropogenic impacts have become more important as a possible and likely cause for changes. During the whole Holocene period climate variability played an important role. However, the relative importance between humans and nature is largely unknown. Here we present the results of a combined geophysical and geochemical study on selected sediment sequences from the Baltic Sea within the two BONUS (Baltic Organisations Network For Funding Science) funded projects HYPER (HYPoxia mitigation for Baltic Sea Ecosystem Restoration) and Baltic GAS (GAS storage and effects of climate change and eutrophication). The over-all aim of these projects is to understand large-scale Baltic Sea ecosystem responses to environmental, climate and anthropogenic forcing. During two Baltic Sea research cruises in 2009 long sediment cores from 8 different locations were recovered. We present preliminary results from one site (LL19) located in the north central Baltic Proper at 169 m water depth. The Littorina Sea sediment record (i.e. the last c. 8000 years) is characterised by alternating periods of homogenised sediments (indicative of oxic conditions) and laminated sediments (indicative of hypoxic/anoxic conditions). Mineral magnetic properties illustrate clear changes between laminated and non-laminated sections of the core. The concentration of ferrimagnetic minerals, as revealed by initial magnetic susceptibility (χ) and saturation isothermal remanent magnetization (SIRM) is variable. The laminated sections in particular show high concentrations and to reveal the origin of the ferrimagnetic signal additional magnetic properties were measured, specifically the

  16. Parasitation of sea trout (Salmo trutta trutta L.) from the spawning ground and German coastal waters off Mecklenburg-Western Pomerania, Baltic Sea.

    PubMed

    Unger, Patrick; Palm, Harry W

    2016-01-01

    A total of 52 sea trouts, Salmo trutta trutta, were studied for parasites, originating from German freshwater streams and coastal waters of the Baltic Sea. While 35 specimens were caught mainly close to the shoreline in the Baltic Sea, 17 were sampled during their spawning migration in Warnow River and other neighboring rivers in Mecklenburg-Western Pomerania. A total of 12 different metazoan parasite species were found in sea trout originating from the Baltic Sea, including five digeneans, two cestodes, three nematodes, and two acanthocephalans. Marine and freshwater species were found. In the migratory trout, seven different parasite species were recorded (one digenean, two cestodes, one nematode, and one acanthocephalan), demonstrating lower parasite diversity and load during the spawning migration compared with the fish from the Baltic Sea. The anisakid nematodes Anisakis simplex (sensu stricto), Contraceacum rudolphii, and Hysterothylacium aduncum were identified by molecular analyses of the ITS-1, 5.8S, ITS-2, and flanking sequences of the rDNA. Together with the digenean Derogenes varicus, Hemiurus communis and H. luehei, and the cestode Diphyllobothrium dendriticum seven new host records for sea trout from the German part of the Baltic Sea are made. PMID:26374539

  17. Sensitivity of modeled atmospheric nitrogen species and nitrogen deposition to variations in sea salt emissions in the North Sea and Baltic Sea regions

    NASA Astrophysics Data System (ADS)

    Neumann, Daniel; Matthias, Volker; Bieser, Johannes; Aulinger, Armin; Quante, Markus

    2016-03-01

    Coarse sea salt particles are emitted ubiquitously from the ocean surface by wave-breaking and bubble-bursting processes. These particles impact the atmospheric chemistry by affecting the condensation of gas-phase species and, thus, indirectly the nucleation of new fine particles, particularly in regions with significant air pollution. In this study, atmospheric particle concentrations are modeled for the North Sea and Baltic Sea regions in northwestern Europe using the Community Multiscale Air Quality (CMAQ) modeling system and are compared to European Monitoring and Evaluation Programme (EMEP) measurement data. The sea salt emission module is extended by a salinity-dependent scaling of the sea salt emissions because the salinity in large parts of the Baltic Sea is very low, which leads to considerably lower sea salt mass emissions compared to other oceanic regions. The resulting improvement in predicted sea salt concentrations is assessed. The contribution of surf zone emissions is considered separately. Additionally, the impacts of sea salt particles on atmospheric nitrate and ammonium concentrations and on nitrogen deposition are evaluated. The comparisons with observational data show that sea salt concentrations are commonly overestimated at coastal stations and partly underestimated farther inland. The introduced salinity scaling improves the predicted Baltic Sea sea salt concentrations considerably. The dates of measured peak concentrations are appropriately reproduced by the model. The impact of surf zone emissions is negligible in both seas. Nevertheless, they might be relevant because surf zone emissions were cut at an upper threshold in this study. Deactivating sea salt leads to minor increases in NH3 + NH4+ and HNO3 + NO3- and a decrease in NO3- concentrations. However, the overall effect on NH3 + NH4+ and HNO3 + NO3- concentrations is smaller than the deviation from the measurements. Nitrogen wet deposition is underestimated by the model at most

  18. (137)Cs, (40)K and (210)Po in marine mammals from the southern Baltic Sea.

    PubMed

    Ciesielski, Tomasz; Góral, Marta; Szefer, Piotr; Jenssen, Bjørn Munro; Bojanowski, Ryszard

    2015-12-15

    This study provides information on baseline concentrations of the radionuclides Cesium-137, Potassium-40 and Polonium-210 in sea mammals from the Baltic Sea. The radionuclides were analyzed in the liver, kidney and muscle of harbor porpoises, striped dolphins, and gray and ringed seals from the Polish coast by γ- and α-spectrometry. Median (137)Cs activities were 14.8, 13.2 and 23.2 Bq kg(-1) w.w. in the liver, kidney and muscles, respectively. Activities of (40)K and (210)Po in the respective tissues were found to be 79.1, 79.8 and 111 Bq kg(-1) for (40)K and 58.1, 59.2 and 32.9 Bq kg(-1) for (210)Po. The measured (137)Cs concentrations were extraordinarily high in comparison to those reported in sea mammals from other locations. However, dose assessments did not imply health effects from (137)Cs exposure in Baltic Sea mammals. Correlations between (137)Cs tissue activities and reported sea water concentrations highlight the potential use of marine mammals for biomonitoring purposes. PMID:26456908

  19. Nitrate source identification in the Baltic Sea using its isotopic ratios in combination with a Bayesian isotope mixing model

    NASA Astrophysics Data System (ADS)

    Korth, F.; Deutsch, B.; Frey, C.; Moros, C.; Voss, M.

    2014-09-01

    Nitrate (NO3-) is the major nutrient responsible for coastal eutrophication worldwide and its production is related to intensive food production and fossil-fuel combustion. In the Baltic Sea NO3- inputs have increased 4-fold over recent decades and now remain constantly high. NO3- source identification is therefore an important consideration in environmental management strategies. In this study focusing on the Baltic Sea, we used a method to estimate the proportional contributions of NO3- from atmospheric deposition, N2 fixation, and runoff from pristine soils as well as from agricultural land. Our approach combines data on the dual isotopes of NO3- (δ15N-NO3- and δ18O-NO3-) in winter surface waters with a Bayesian isotope mixing model (Stable Isotope Analysis in R, SIAR). Based on data gathered from 47 sampling locations over the entire Baltic Sea, the majority of the NO3- in the southern Baltic was shown to derive from runoff from agricultural land (33-100%), whereas in the northern Baltic, i.e. the Gulf of Bothnia, NO3- originates from nitrification in pristine soils (34-100%). Atmospheric deposition accounts for only a small percentage of NO3- levels in the Baltic Sea, except for contributions from northern rivers, where the levels of atmospheric NO3- are higher. An additional important source in the central Baltic Sea is N2 fixation by diazotrophs, which contributes 49-65% of the overall NO3- pool at this site. The results obtained with this method are in good agreement with source estimates based upon δ15N values in sediments and a three-dimensional ecosystem model, ERGOM. We suggest that this approach can be easily modified to determine NO3- sources in other marginal seas or larger near-coastal areas where NO3- is abundant in winter surface waters when fractionation processes are minor.

  20. Nitrate source identification using its isotopic ratios in combination with a Bayesian isotope mixing model in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Korth, F.; Deutsch, B.; Frey, C.; Moros, C.; Voss, M.

    2014-04-01

    Nitrate (NO3-) is the major nutrient responsible for coastal eutrophication worldwide and its production is related to intensive food production and fossil-fuel combustion. In the Baltic Sea NO3-inputs have increased four-fold over the last decades and now remain constantly high. NO3- source identification is therefore an important consideration in environmental management strategies. In this study focusing on the Baltic Sea, we used a method to estimate the proportional contributions of NO3- from atmospheric deposition, N2 fixation, and runoff from pristine soils as well as from agricultural land. Our approach combines data on the dual isotopes of NO3- (δ15N-NO3- and δ18O-NO3-) in winter surface waters with a Bayesian isotope mixing model (Stable Isotope Analysis in R, SIAR). Based on data gathered from 46 sampling locations over the entire Baltic Sea, the majority of the NO3- in the southern Baltic was shown to derive from runoff from agricultural land (30-70%), whereas in the northern Baltic, i.e., the Gulf of Bothnia, NO3- originates from nitrification in pristine soils (47-100%). Atmospheric deposition accounts for only a small percentage of NO3- levels in the Baltic Sea, except for contributions from northern rivers, where the levels of atmospheric NO3- are higher. An additional important source in the central Baltic Sea is N2 fixation by diazotrophs, which contributes 31-62% of the overall NO3- pool at this site. The results obtained with this method are in good agreement with source estimates based upon δ15N values in sediments and a three-dimensional ecosystem model, ERGOM. We suggest that this approach can be easily modified to determine NO3- sources in other marginal seas or larger near-coastal areas where NO3- is abundant in winter surface waters when fractionation processes are minor.

  1. Eye function of Mysidacea (Crustacea) in the northern Baltic Sea.

    PubMed

    Lindström

    2000-03-30

    Eye spectral sensitivity, [S(lambda)], was measured in seven northern Baltic mysid species using an electroretinogram technique. Their S(lambda) curves were compared with the spectral distribution of underwater light at their normal habitats. In the littoral species Neomysis integer, Praunus flexuosus and Praunus inermis, the S(lambda) maxima, [S(lambda)(max)], were in the wavelength-bands of 525-535, 505-515 and 520-530 nm respectively. The neoimmigrant species Hemimysis anomala had a S(lambda)(max) around 500 nm and high sensitivity at 393 nm, possibly indicating UV-sensitivity. S(lambda) of the pelagic species Mysis mixta and Mysis relicta sp. II was at about 505-520 nm. M. relicta sp. I from Pojoviken Bay and fresh water humic Lake Pääjärvi had S(lambda)(max) at approximately 550 nm and 570 nm respectively. This is in accordance with a similar long-wavelength shift in light transmittance of the respective waters. The eyes of the latter population were also damaged by strong light. The pontocaspian neoimmigrant H. anomala is clearly adapted to waters transmitting more blue light. PMID:10699220

  2. Helmintofauna of turbot Scophthalmus maximus (Linnaeus, 1758) from the southern Baltic Sea including new data.

    PubMed

    Skrzypczak, M; Rolbiecki, L

    2015-01-01

    Turbot Scophthalmus maximus (Linnaeus, 1758) is a fish belonging to the Pleuronectiformes order. It is commonly observed in waters of the northern Atlantic, and also in the Baltic Sea. As an economically significant species, it is fished on an industrial scale, and also farmed in some European countries. Seventy-two turbots from the Gulf of Gdańsk (26th ICES zone) were examined for parasite presence in the years 2010-2012. The study revealed the presence of the tapeworm Bothriocephalus scorpii (Müller, 1776) and acanthocephalan Corynosoma semerme (Forssell, 1904). The overall (both parasites) prevalence of turbot infection was 100% with a mean intensity of 18.7. C. semerme is a parasite which has not been noted so far in turbot from the southern Baltic. The presence of C. semerme in turbot was emphasized in the context of possible infection of terrestrial mammals, including humans. PMID:26618593

  3. Virulence Profiles of Vibrio vulnificus in German Coastal Waters, a Comparison of North Sea and Baltic Sea Isolates.

    PubMed

    Bier, Nadja; Jäckel, Claudia; Dieckmann, Ralf; Brennholt, Nicole; Böer, Simone I; Strauch, Eckhard

    2015-12-01

    Vibrio vulnificus is a halophilic bacterium of coastal environments known for sporadically causing severe foodborne or wound infections. Global warming is expected to lead to a rising occurrence of V. vulnificus and an increasing incidence of human infections in Northern Europe. So far, infections in Germany were exclusively documented for the Baltic Sea coast, while no cases from the North Sea region have been reported. Regional variations in the prevalence of infections may be influenced by differences in the pathogenicity of V. vulnificus populations in both areas. This study aimed to compare the distribution of virulence-associated traits and genotypes among 101 V. vulnificus isolates from the Baltic Sea and North Sea in order to assess their pathogenicity potential. Furthermore, genetic relationships were examined by multilocus sequence typing (MLST). A high diversity of MLST sequences (74 sequence types) and differences regarding the presence of six potential pathogenicity markers were observed in the V. vulnificus populations of both areas. Strains with genotypes and markers associated with pathogenicity are not restricted to a particular geographic region. This indicates that lack of reported cases in the North Sea region is not caused by the absence of potentially pathogenic strains. PMID:26694432

  4. Virulence Profiles of Vibrio vulnificus in German Coastal Waters, a Comparison of North Sea and Baltic Sea Isolates

    PubMed Central

    Bier, Nadja; Jäckel, Claudia; Dieckmann, Ralf; Brennholt, Nicole; Böer, Simone I.; Strauch, Eckhard

    2015-01-01

    Vibrio vulnificus is a halophilic bacterium of coastal environments known for sporadically causing severe foodborne or wound infections. Global warming is expected to lead to a rising occurrence of V. vulnificus and an increasing incidence of human infections in Northern Europe. So far, infections in Germany were exclusively documented for the Baltic Sea coast, while no cases from the North Sea region have been reported. Regional variations in the prevalence of infections may be influenced by differences in the pathogenicity of V. vulnificus populations in both areas. This study aimed to compare the distribution of virulence-associated traits and genotypes among 101 V. vulnificus isolates from the Baltic Sea and North Sea in order to assess their pathogenicity potential. Furthermore, genetic relationships were examined by multilocus sequence typing (MLST). A high diversity of MLST sequences (74 sequence types) and differences regarding the presence of six potential pathogenicity markers were observed in the V. vulnificus populations of both areas. Strains with genotypes and markers associated with pathogenicity are not restricted to a particular geographic region. This indicates that lack of reported cases in the North Sea region is not caused by the absence of potentially pathogenic strains. PMID:26694432

  5. Assimilating NOAA SST data into BSH operational circulation model for North and Baltic Seas

    NASA Astrophysics Data System (ADS)

    Losa, Svetlana; Schroeter, Jens; Nerger, Lars; Janjic, Tijana; Danilov, Sergey; Janssen, Frank

    A data assimilation (DA) system is developed for BSH operational circulation model in order to improve forecast of current velocities, sea surface height, temperature and salinity in the North and Baltic Seas. Assimilated data are NOAA sea surface temperature (SST) data for the following period: 01.10.07 -30.09.08. All data assimilation experiments are based on im-plementation of one of the so-called statistical DA methods -Singular Evolutive Interpolated Kalman (SEIK) filter, -with different ways of prescribing assumed model and data errors statis-tics. Results of the experiments will be shown and compared against each other. Hydrographic data from MARNET stations and sea level at series of tide gauges are used as independent information to validate the data assimilation system. Keywords: Operational Oceanography and forecasting

  6. NEMO-Nordic : A NEMO based ocean modelling configuration for Baltic & North Seas

    NASA Astrophysics Data System (ADS)

    Hordoir, Robinson; Schimanke, Semjon; Axell, Lars; Gröger, Matthias; Dieterich, Christian; Liu, Ye; Höglund, Anders; Kuznetsov, Ivan; Ljungemyr, Patrik; Nygren, Petter; Jönsson, Anette; Meier, Markus

    2015-04-01

    Based on the NEMO ocean engine, three regional setups for the North Sea and Baltic Sea domain have been developed : the NEMO-Nordic configuration is declined in an operational setup, a stand-alone version used for climate and process studies, and a NEMO-Nordic-RCA4 atmosphere/ocean coupled configuration used for downscalling climate scenarios. We give a brief overview of the options chosen within the NEMO engine to design the configurations. Based on the results provided by each of the three configurations, we also provide an assessment of the strengths and weaknesses of NEMO-Nordic. Finally, a validation of the configurations is provided based on an extensive comparison between in-situ measurements and model results for temperature, salinity, sea-ice extent, sea level and mean circulation.

  7. Baroclinic internal wave energy distribution in the Baltic Sea derived from 45 years of circulation simulations

    NASA Astrophysics Data System (ADS)

    Rybin, Artem; Soomere, Tarmo; Kurkina, Oxana; Kurkin, Andrey; Rouvinskaya, Ekaterina; Markus Meier, H. E.

    2016-04-01

    Internal waves and internal tides are an essential component of the functioning of stratified shelf seas. They carry substantial amounts of energy through the water masses, drive key hydrophysical processes such as mixing and overturning and support the functioning of marine ecosystem in many ways. Their particular impact becomes evident near and at the bottom where they often create substantial loads to engineering structures and exert a wide range of impacts on the bottom sediments and evolution of the seabed. We analyse several properties of spatio-temporal distributions of energy of relatively long-period large-scale internal wave motions in the Baltic Sea. The analysis is based on numerically simulated pycnocline variations that are extracted from the hydrographic data calculated by the Rossby Centre Ocean circulation model (RCO) for the entire Baltic Sea for 1961-2005. This model has a horizontal resolution of 2 nautical miles and uses 41 vertical layers with a thickness between 3 m close to the surface and 12 m in 250 m depth. The model is forced with atmospheric data derived from the ERA-40 re-analysis using a regional atmosphere model with a horizontal resolution of 25 km. It also accounts for river inflow and water exchange through the Danish Straits. See (Meier, H.E.M., Höglund, A., 2013. Studying the Baltic Sea circulation with Eulerian tracers, in Soomere, T., Quak, E., eds., Preventive Methods for Coastal Protection, Springer, Cham, Heidelberg, 101-130) for a detailed description of the model and its forcing. The resolution of the model output used in this study (once in 6 hours) is sufficient for estimates of spectral amplitudes of the displacements of isopycnal surfaces with a typical period of 2-12 days. We provide the analysis of kinetic and potential energy of motions with these periods. The resulting maps of the maxima of energy and spatial distributions of near-bottom velocities have been evaluated for the entire simulation interval of 45

  8. Does the zooplankton prey availability limit the larval habitats of pike in the Baltic Sea?

    NASA Astrophysics Data System (ADS)

    Kallasvuo, Meri; Salonen, Maiju; Lappalainen, Antti

    2010-01-01

    The objectives of this study were to (1) investigate whether the availability of suitable zooplankton prey limits the distribution of the coastal larval areas of pike ( Esox lucius) in two archipelago areas of the northern Baltic Sea and (2) compare the availability of zooplankton prey in spring between different types of coastal littoral habitat. According to the results, reed belt habitats formed by Phragmites australis constitute hot spots for zooplankton prey in the coastal ecosystem. During the spring, reed-covered shores of the inner archipelago maintained more than 10 times higher densities of copepods and cladocerans, the preferred prey for larval pike, compared to the other studied shores. Temperature conditions were also most favourable in the reed belt habitat. Thus, the reed belts of the inner and middle archipelago were shown to form the best habitat for larval pike in the coastal area of the northern Baltic Sea, and this was also the only habitat where pike larvae were found. Our results suggest that the poor survival and recruitment of pike in the outer archipelago, however, cannot exclusively be explained by sub-optimal feeding conditions of the larvae. There are also other important factors, presumably connected to the exposure to the open sea, that affect the distribution of the pike larvae. Our results, however, highlight the importance of sheltered coastal reed belt shores as reproduction habitat for spring-spawning fish in the northern Baltic Sea. Further, this study disproves the assumption that the seaweed bladder wrack ( Fucus vesiculosus) forms a reproduction habitat for pike in the coastal area.

  9. Benthic marine landscapes of the Eastern Gulf of Finland, the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Kaskela, Anu; Kotilainen, Aarno; Orlova, Marina; Ronkainen, Minna; Rousi, Heta; Ryabchuk, Daria

    2014-05-01

    Benthic marine landscapes are a combination of ecologically relevant hydrographical and geological datasets that characterize potential broad scale habitat distribution patterns with the overall aim to allocate conservation efforts on biodiversity and spaces instead of single species. At the best the benthic marine landscapes describe both the habitat distribution as well as the characteristics of the physical environment. This kind of spatial knowledge that informs both about geology and biology at the regional scale is very usable in ecosystem based management (ESBM) of marine areas. Here we will present the benthic marine landscapes of the Eastern Gulf of Finland at the scale of 1:500 000 and explain the analysis methods behind. The study area in the Eastern Gulf of Finland, the Baltic Sea, is a transboundary marine area shared by Finland and Russia. The HELCOM Baltic Sea Action Plan along with EU, Finnish and Russian legislation requires both countries to identify and assess the state of the marine environment in the Gulf of Finland. These appoint the need for shared knowledge on the marine environment, its state, physical characteristics and distribution of habitats among others. In order to produce ecologically relevant marine landscapes we have collected geological, hydrographical and biological data from the transboundary study area and studied their correlation. The statistical analyses have been run with Primer -software (BEST and LINKTREE). The study is a part of ENPI CBC funded Finnish-Russian co-operation project, the TOPCONS (http://www.merikotka.fi/topcons/). Project aims to develop innovative spatial tools for the regional planning of the sea areas in the Gulf of Finland, the Baltic Sea. The objective is to create methodology and tools to map the locations of the most diverse and sensitive marine landscapes. These will help the society when striving for the sustainable consolidation of human activities and the marine nature values. The TOPCONS is

  10. Draft Genome Sequence of Flavobacterium sp. 316, a Baltic Sea Isolate Exhibiting a High Level of Resistance to Marine Stress Conditions.

    PubMed

    Karczewska-Golec, Joanna; Kochanowska-Łyżen, Maja; Olszewski, Paweł; Bałut, Magdalena; Moskot, Marta; Piotrowski, Arkadiusz; Golec, Piotr; Szalewska-Pałasz, Agnieszka

    2016-01-01

    Here, we present the draft genome sequence ofFlavobacteriumsp. 316, isolated from brackish water of the Gulf of Gdańsk, southern Baltic Sea. The assembly contains 3,971,755 bp in 17 scaffolds. The sequence will facilitate postgenomic studies on bacterial stress responses in the challenging habitat of the Baltic Sea. PMID:27034490

  11. Draft Genome Sequence of Flavobacterium sp. 316, a Baltic Sea Isolate Exhibiting a High Level of Resistance to Marine Stress Conditions

    PubMed Central

    Kochanowska-Łyżen, Maja; Olszewski, Paweł; Bałut, Magdalena; Moskot, Marta; Piotrowski, Arkadiusz; Golec, Piotr; Szalewska-Pałasz, Agnieszka

    2016-01-01

    Here, we present the draft genome sequence of Flavobacterium sp. 316, isolated from brackish water of the Gulf of Gdańsk, southern Baltic Sea. The assembly contains 3,971,755 bp in 17 scaffolds. The sequence will facilitate postgenomic studies on bacterial stress responses in the challenging habitat of the Baltic Sea. PMID:27034490

  12. Sources of polyfluoroalkyl compounds in the North Sea, Baltic Sea and Norwegian Sea: Evidence from their spatial distribution in surface water.

    PubMed

    Ahrens, Lutz; Gerwinski, Wolfgang; Theobald, Norbert; Ebinghaus, Ralf

    2010-02-01

    The spatial distribution of 15 polyfluoroalkyl compounds (PFCs) in surface water was investigated in the North Sea, Baltic Sea and Norwegian Sea. In addition, an interlaboratory comparison of the sampling techniques and analysis was conducted. Highest concentration in the North Sea was found near the coast, whereas the summation operatorPFC concentration decreased rapidly from 18.4 to 0.07 ng l(-1) towards the open North Sea. The river Elbe could identify as a local input source for PFCs into the North Sea, whereas perfluorobutanoic acid (PFBA) was transported into the sampling area with the easterly current. In contrast to the North Sea, the distribution of PFCs in the Baltic Sea was relatively homogenous, where diffuse sources dominated. In general, the composition profile was influenced from local sources caused by human activities, whereas atmospheric depositions of here analysed PFCs were negligible, but it could have possibly an influence on low contaminated sites like the open North Sea or Norwegian Sea. PMID:19818459

  13. Holocene Sedimentation in the Ångermanälven River Estuary, the northern Baltic Sea

    NASA Astrophysics Data System (ADS)

    Kotilainen, Aarno; Hyttinen, Outi; Obrochta, Stephen; Andrén, Thomas; Ryabchuk, Daria; Snowball, Ian; IODP Expedition 347 Science Party, The

    2015-04-01

    In the IODP Expedition 347 - "Baltic Sea Paleoenvironment" - two sites in the Ångermanälven River estuary were drilled. Sites M0061 and M0062 are located at about 62°47'N, in an area which was deglaciated ca. 10 ka ago. It has long been known that varve deposition is an ongoing process in Ångermanälven estuary, and that it has continued so several thousand years back in time. It has also been shown that a correlation exists between maximum daily discharge and mean varve thickness at least AD 1901-1971 in the Ångermanälven River (Sander et al. 2002). Studying varve thickness and sediment geochemistry potentially yield estimations on past changes in precipitation and sedimentation processes in the estuary. In this presentation, the preliminary results from site M0062 are shown. The core recovery was approximately 36 m and the sediment sequence was divided into two lithological units (Expedition 347 Scientists, 2014). The lowest Unit 2 (17.09-35.9 mbsf) consists of well-sorted sand, deposited by a (glacio)fluvial system. Unit 1 (0-17.09 mbsf) showed transition from glacial lake varves to brackish marine couplets. The uppermost 18 metres were analysed for grain-size and elemental geochemistry every 0.3-0.5 m. From selected intervals, a 1mm-resolution XRF-scanning of the split core surface was done to compare changes in the relative abundance of light elements. Results from Ångermanälven were compared with measurements from glacial varved sediments, retrieved from the eastern Gulf of Finland. This work is also part of "Climate - ice sheet - sea interactions - evolution of the Baltic Sea Basin over the past 60000 years (CISU)" which is a new joint research project with The Academy of Finland and The Russian Foundation for Basic Research. The CISU project is coordinated by Geological Survey of Finland and the other partners are Helsinki University and A.P. Karpinsky Russian Geological Research Institute (VSEGEI), Russia. The project bases on the IODP Expedition

  14. The science and management of the North Sea and the Baltic Sea: natural history, present threats and future challenges.

    PubMed

    Ducrotoy, Jean-Paul; Elliott, Michael

    2008-01-01

    The review provides an overview of the features of the North Sea and the Baltic Sea in their European geographical and socio-political context. To reach sustainability in the wider sense the common society has to meet the 7 tenets - that management actions have to be environmentally sustainable, economically viable, technologically feasible, socially desirable (or at least tolerable), legally permissible, administratively achievable and politically expedient. Each of these are explained and discussed using examples from the two seas including pollution control, physical resource exploitation (such as aggregates, habitat loss, renewable energy and oil and gas), and biological resources exploitation (fisheries and aquaculture). This paper discusses the similarities between the areas in terms of their management regimes, population in the catchment, history of anthropogenic changes, derivation of objectives against a wealth of information and understanding, and the history of management and control. In contrast, the differences between the areas centre on their differing hydrographic regimes, including residence and flushing times, biological features, nature of the pollutants discharged, dominant types of fishing and type of control indicated by a predominant Eastern Bloc for the Baltic as opposed to European Union control in the North Sea. The review ends with an assessment of future challenges and examples of the way in which environmental problems have been addressed in the two areas. In particular, it sets the features against a background of management designed to achieve the Ecosystem Approach within the prevailing European marine management framework. PMID:18533194

  15. Eutrophication status of the North Sea, Skagerrak, Kattegat and the Baltic Sea in present and future climates: A model study

    NASA Astrophysics Data System (ADS)

    Skogen, Morten D.; Eilola, Kari; Hansen, Jørgen L. S.; Meier, H. E. Markus; Molchanov, Mikhail S.; Ryabchenko, Vladimir A.

    2014-04-01

    A method to combine observations and an ensemble of ecological models has been used to assess eutrophication. Using downscaled forcing from two GCMs under the A1B emission scenario, an assessment of the eutrophication status was made for a control (1970-2000) and a future climate (2070-2100) period. By using validation results from a hindcast to compute individual weights between the models, an assessment of eutrophication is done using a set of threshold values. The final classification distinguishes between three categories: problem area, potential problem area, and non-problem area, in accordance with current management practice as suggested by the Oslo and Paris Commissions (OSPAR) and the Helsinki Commission (HELCOM). For the control run the assessment indicates that the Kattegat, the Danish Straits, the Gulf of Finland, the Gotland Basin as well as main parts of the Arkona Basin, the Bornholm Basin, and the Baltic proper may be classified as problem areas. The main part of the North Sea and also the Skagerrak are non-problem areas while the main parts of the Gulf of Bothnia, Gulf of Riga and the entire southeastern continental coast of the North Sea may be classified as potential problem areas. In the future climate scenarios most of the previous potential problem areas in the Baltic Sea have become problem areas, except for the Bothnian Bay where the situation remain fairly unchanged. In the North Sea there seems to be no obvious changes in eutrophication status in the projected future climate.

  16. Sea-level changes and the Middle-Upper Devonian sequence in the Baltic basin

    NASA Astrophysics Data System (ADS)

    Lukševičs, E.; Stinkulis, Ä.¢.

    2012-04-01

    Lithostratigraphic succession of the Middle-Upper Devonian of Baltic, represented by siliciclastic and carbonate deposits of the wide shallow epeiric sea, is well-established. The sequence of biotic and sea-level changes has been studied in detail for about half a century. However, it was rarely tried to compare the sea-level curve for the Baltic with the curve of the global sea-level changes and correlate the succession with the sequence of the Devonian global events well established mainly in the marine record. New facies analysis and biostratigraphical and taphonomical studies together with the re-evaluation of signatures of the world-wide events using sedimentological and palaeontological data enables better understanding of the development of the Middle-Late Devonian basins of the Baltic area. Indications of such events as eustatic fall of the sea-level close to the Givetian-Frasnian and Frasnian-Famennian boundaries, several small-scale transgressions during Famennian interglacials are rather clearly traceable within the sequence. Distribution of deposits, biotas and facies suggests diminishing of the depositional area since the maximum transgression in the earliest Frasnian thus demonstrating good coincidence with the global sea level curve (Haq & Schutter 2008). The retreat of depocentre of the palaeobasin in westerly direction during the late Frasnian and the Famennian likely was caused by tectonic subsidence at the western part of the east Baltics. The most significant event levels identified within the section are the extended Taghanic onlap (middle Givetian) evidenced by dolocretes in the upper part of the Burtnieki Fm; significant drop of the sea level during the earliest Frasnian indicated by widely distributed dolocretes in the top of the Amata Fm that points to the possible position of the Givetian/Frasnian boundary below the Amata; level of the Dubnik RS with extensive gypsum deposits and non-oxidised organic matter of the Salaspils Fm evidencing

  17. Mercury in particulate matter over Polish zone of the southern Baltic Sea

    NASA Astrophysics Data System (ADS)

    Beldowska, M.; Saniewska, D.; Falkowska, L.; Lewandowska, A.

    2012-01-01

    Important Hg transformations can occur at the air-water interface where polluted terrestrial air masses meet humid, halogen-rich marine air masses over the southern Baltic Sea. These chemical and physical processes include gas-to-particle conversion that led to an increase of Hg associated with coarse particles, which due to higher dry deposition rates, enhanced local scale deposition and limited the transport of this toxic trace metal. Daily (24 h) sampling of size-segregated atmospheric particles revealed the sea to be a sink for Hg during winter months and as a source of Hg during summer months. Poland is one of the major Hg emitters among the Baltic States according to International HELCOM Reports. Thus, important measurements in this region were conducted over a one-year period from December 18, 2007 to December 15, 2008. The range in concentrations of Hg in particulate matter (2-142 pg m -3) at the Polish site are comparable to other measurements at sites along the coastal areas of the Baltic Sea. Annual Hg(p) represents 1% of the total atmospheric Hg (Hg TOT) under unpolluted or background ambient conditions. A major source of atmospheric Hg in this area is the combustion of fossil fuels, especially coal burning used for home heating. This was clearly seen in the statistically higher mean concentration of 24 pg m -3 observed during the heating season compared to the 15 pg m -3 measured during the non-heating season. Construction activities e.g., cement manufacturing, gravel extraction, and waste incineration during the warm season strongly influenced Hg concentrations and led to an increase in Hg(p) on working days compared to weekend days.

  18. Scyphozoa in the Bornholm Basin (central Baltic Sea) The role of advection

    NASA Astrophysics Data System (ADS)

    Barz, Kristina; Hinrichsen, Hans-Harald; Hirche, Hans-Jürgen

    2006-04-01

    The usual absence of ephyrae and late appearance of medusae of the Scyphozoa Aurelia aurita and Cyanea capillata in the Bornholm Basin (BB; central Baltic Sea) indicate that these species are not strobilating in the region and their presence depends on advection. To study their potential origin we compared drift from historically known strobilation areas derived from a circulation model with spatial distributions observed during 19 cruises in the BB during 2002 and 2003. The model results are in good accordance with the field observations. According to the model results inter-annual differences in the timing of first appearance and life stage at appearance of A. aurita were clearly related to differences in the hydrodynamic regime during the investigation periods. During the stagnation regime in 2002 young medusae occurred first in June in the BB. In contrast, in 2003 fast transport due to several inflow events advected ephyrae released between January and March in the western Baltic already in April to the BB. Although the Gullmar Fjord (western Sweden) is the nearest known strobilation area for C. capillata, the model did not support advection from there in numbers explaining the occurrence of this species in the BB in 2002 and 2003. If the model works adequately in this regions we have to assume that the Gullmar Fjord is not a main source region of C. capillata in the BB, but other strobilation areas in the Kattegat or the North Sea appear more important. Our results imply that advection and inflow events are critical for the occurrence and distribution of early stages of jellyfish in the central Baltic Sea. They demonstrate the potential of circulation models as tools to study the effect of long-range transport on the spatial composition of these organisms.

  19. Active nitrogen-fixing heterotrophic bacteria at and below the chemocline of the central Baltic Sea.

    PubMed

    Farnelid, Hanna; Bentzon-Tilia, Mikkel; Andersson, Anders F; Bertilsson, Stefan; Jost, Günter; Labrenz, Matthias; Jürgens, Klaus; Riemann, Lasse

    2013-07-01

    The Baltic Sea receives large nitrogen inputs by diazotrophic (N2-fixing) heterocystous cyanobacteria but the significance of heterotrophic N2 fixation has not been studied. Here, the diversity, abundance and transcription of the nifH fragment of the nitrogenase enzyme in two basins of the Baltic Sea proper was examined. N2 fixation was measured at the surface (5 m) and in anoxic water (200 m). Vertical sampling profiles of >10 and <10 μm size fractions were collected in 2007, 2008 and 2011 at the Gotland Deep and in 2011 in the Bornholm Basin. Both of these stations are characterized by permanently anoxic bottom water. The 454-pyrosequencing nifH analysis revealed a diverse assemblage of nifH genes related to alpha-, beta- and gammaproteobacteria (nifH cluster I) and anaerobic bacteria (nifH cluster III) at and below the chemocline. Abundances of genes and transcripts of seven diazotrophic phylotypes were investigated using quantitative polymerase chain reaction revealing abundances of heterotrophic nifH phylotypes of up to 2.1 × 10(7) nifH copies l(-1). Abundant nifH transcripts (up to 3.2 × 10(4) transcripts l(-1)) within nifH cluster III and co-occurring N2 fixation (0.44±0.26 nmol l(-1) day(-1)) in deep water suggests that heterotrophic diazotrophs are fixing N2 in anoxic ammonium-rich waters. Our results reveal that N2 fixation in the Baltic Sea is not limited to illuminated N-deplete surface waters and suggest that N2 fixation could also be of importance in other suboxic regions of the world's oceans. PMID:23446833

  20. Biomarkers in the stratified water column of the Landsort Deep (Baltic Sea)

    NASA Astrophysics Data System (ADS)

    Berndmeyer, C.; Thiel, V.; Schmale, O.; Wasmund, N.; Blumenberg, M.

    2014-06-01

    The water column of the Landsort Deep, central Baltic Sea, is stratified into an oxic, suboxic and anoxic zone. This stratification controls the distributions of individual microbial communities and biogeochemical processes. In summer 2011, particulate organic matter was filtered from these zones using an in~situ pump. Lipid biomarkers were extracted from the filters to establish water column profiles of individual hydrocarbons, alcohols, phospholipid fatty acids, and bacteriohopanepolyols (BHPs). As a reference, a cyanobacterial bloom sampled in summer 2012 in the central Baltic Sea Gotland Deep was analyzed for BHPs. The biomarker data from the surface layer of the oxic zone showed major inputs from different cyanobacteria and eukaryotes such as dinoflagellates and ciliates, while the underlying cold winter water layer was characterized by a low diversity and abundance of organisms, with copepods as a major group. The suboxic zone supported bacterivorous ciliates, type I aerobic methanotrophic bacteria, sulfate reducing bacteria, and, most likely, methanogenic archaea. In the anoxic zone, sulfate reducers and archaea were the dominating microorganisms as indicated by the presence of distinctive branched fatty acids, archaeol and PMI derivatives, respectively. Our study of in situ biomarkers in the Landsort Deep thus provided an integrated insight into the distribution of relevant players and the related biogeochemical processes in stratified water columns of marginal seas.

  1. Atmospheric pathways of chlorinated pesticides and natural bromoanisoles in the northern Baltic Sea and its catchment.

    PubMed

    Bidleman, Terry; Agosta, Kathleen; Andersson, Agneta; Brorström-Lundén, Eva; Haglund, Peter; Hansson, Katarina; Laudon, Hjalmar; Newton, Seth; Nygren, Olle; Ripszam, Matyas; Tysklind, Mats; Wiberg, Karin

    2015-06-01

    Long-range atmospheric transport is a major pathway for delivering persistent organic pollutants to the oceans. Atmospheric deposition and volatilization of chlorinated pesticides and algae-produced bromoanisoles (BAs) were estimated for Bothnian Bay, northern Baltic Sea, based on air and water concentrations measured in 2011-2012. Pesticide fluxes were estimated using monthly air and water temperatures and assuming 4 months ice cover when no exchange occurs. Fluxes were predicted to increase by about 50 % under a 2069-2099 prediction scenario of higher temperatures and no ice. Total atmospheric loadings to Bothnian Bay and its catchment were derived from air-sea gas exchange and "bulk" (precipitation + dry particle) deposition, resulting in net gains of 53 and 46 kg year(-1) for endosulfans and hexachlorocyclohexanes, respectively, and net loss of 10 kg year(-1) for chlordanes. Volatilization of BAs releases bromine to the atmosphere and may limit their residence time in Bothnian Bay. This initial study provides baseline information for future investigations of climate change on biogeochemical cycles in the northern Baltic Sea and its catchment. PMID:26022329

  2. The influence of dissolved organic matter on the acid-base system of the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Kuliński, Karol; Schneider, Bernd; Hammer, Karoline; Machulik, Ulrike; Schulz-Bull, Detlef

    2014-04-01

    To assess the influence of dissolved organic matter (DOM) on the acid-base system of the Baltic Sea, 19 stations along the salinity gradient from Mecklenburg Bight to the Bothnian Bay were sampled in November 2011 for total alkalinity (AT), total inorganic carbon concentration (CT), partial pressure of CO2 (pCO2), and pH. Based on these data, an organic alkalinity contribution (Aorg) was determined, defined as the difference between measured AT and the inorganic alkalinity calculated from CT and pH and/or CT and pCO2. Aorg was in the range of 22-58 μmol kg- 1, corresponding to 1.5-3.5% of AT. The method to determine Aorg was validated in an experiment performed on DOM-enriched river water samples collected from the mouths of the Vistula and Oder Rivers in May 2012. The Aorg increase determined in that experiment correlated directly with the increased DOC concentration caused by enrichment of the > 1 kDa DOM fraction. To examine the effect of Aorg on calculations of the marine CO2 system, the pCO2 and pH values measured in Baltic Sea water were compared with calculated values that were based on the measured alkalinity and another variable of the CO2 system, but ignored the existence of Aorg. Large differences between measured and calculated pCO2 and pH were obtained when the computations were based on AT and CT. The calculated pCO2 was 27-56% lower than the measured value whereas the calculated pH was overestimated by more than 0.4 pH units. Since biogeochemical models are based on the transport and transformations of AT and CT, the acid-base properties of DOM should be included in calculations of the CO2 system in DOM-rich basins like the Baltic Sea. In view of our limited knowledge about the composition and acid/base properties of DOM, this is best achieved using a bulk dissociation constant, KDOM, that represents all weakly acidic functional groups present in DOM. Our preliminary results indicated that the bulk KDOM in the Baltic Sea is 2.94 · 10- 8 mol kg- 1

  3. Sulfidization of lacustrine glacial clay upon Holocene marine transgression (Arkona Basin, Baltic Sea)

    NASA Astrophysics Data System (ADS)

    Holmkvist, Lars; Kamyshny, Alexey; Brüchert, Volker; Ferdelman, Timothy G.; Jørgensen, Bo Barker

    2014-10-01

    Towards the end of the last deglaciation more than 13,500 years ago the southern Baltic Sea was a freshwater lake, the Baltic Ice Lake, for several thousand years during which iron-rich, organic-poor clay was deposited. The modern brackish-marine stage started about 8600 years ago with the deposition of organic-rich mud, which is today characterized by high rates of sulfate reduction and high concentrations of free sulfide. We studied the iron-sulfur diagenesis in gravity cores from the Arkona Basin, SW Baltic Sea, to track the progressing sulfidization front in the buried Ice Lake sediment. The geochemical zonation was unusual as the sulfate concentration dropped steeply by two thirds below which it increased again due to a deep sulfate reservoir. The reservoir had been established during the early Holocene marine period as sulfate and other seawater ions diffused down into the lake sediment for several thousand years. Sulfur isotope analyses confirmed its origin as seawater sulfate, while its oxygen isotope composition indicated a microbially catalyzed equilibration with ambient interstitial water, decoupled from net sulfate reduction. Today, hydrogen sulfide diffuses from the marine mud down into the lake sediment where a black band with high magnetic susceptibility and high iron monosulfide, greigite and elemental sulfur content shows progressing sulfidization of the large pool of solid-phase reactive iron. Dissolved iron from the deep Ice Lake sediment diffuses up to the sulfide front and provides a small supplement to the solid Fe(III) pool as a sulfide sink. Pyrite formation at the sulfidization front may involve surface-bound zero-valent sulfur while, above the front, polysulfides are in equilibrium with the system hydrogen sulfide - polysulfide - rhombic sulfur and may not be important for further pyrite formation. The Holocene iron-sulfur diagenesis observed in the Arkona Basin represents an important transitional state for post-glacial transgressions

  4. CO2 Storage Capacity of Saline Aquifers in the Swedish Sector of the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Sopher, Daniel; Juhlin, Christopher

    2014-05-01

    Carbon Capture and Storage (CCS) is one of a range of options to reduce CO2 emissions in order to mitigate climate change in the future. The Intra-cratonic Baltic Sea Basin contains several saline aquifers which could be suitable for CO2 storage. In this study the CO2 storage capacity of the Cambrian När and Faludden sandstone members is evaluated within the Swedish sector of the Baltic Sea Basin. A probabilistic approach is adopted to characterise both the most likely storage capacity estimate as well as the associated uncertainty. The storage capacity within structural closures and stratigraphic traps is considered. Depth structure maps generated using a dense grid of vintage 2D marine seismic data are used to assess the storage potential in structural traps for both potential reservoirs. A regional scale stratigraphic trap is also considered for the Faludden reservoir. Key input properties for the CO2 storage capacity calculations such as porosity, CO2 density and storage efficiency factor are characterised based on available well log and core data. CO2 storage capacities for the structural and stratigraphic traps are then calculated using a Monte Carlo type approach where the input parameters are randomly perturbed within a set range. A statistical analysis of the input parameters is used to define the range within which these properties are allowed to vary, both spatially and at a given point. Finally these results are compared to others for the greater Baltic Sea region. This approach allows a most likely CO2 storage capacity estimate as well as low and high estimates to be obtained for the Swedish sector of the Baltic Sea in the investigated formations. Based on these results it appears that the largest storage capacity lies within the regional stratigraphic trap of the Faludden reservoir. The structural traps provide significantly smaller volumes when compared to the Faludden stratigraphic trap. The majority of the structural traps are also less certain

  5. Structures and Activity of New Anabaenopeptins Produced by Baltic Sea Cyanobacteria

    PubMed Central

    Spoof, Lisa; Błaszczyk, Agata; Meriluoto, Jussi; Cegłowska, Marta; Mazur-Marzec, Hanna

    2015-01-01

    Anabaenopeptins, bioactive cyclic hexapeptides, were isolated by preparative reversed-phase high performance liquid chromatography from an extract of Baltic Sea cyanobacterial bloom material composed of Nodularia spumigena (50%), Aphanizomenon flos-aquae (40%) and Dolichospermum spp. (10%). Five new anabaenopeptins and nine previously known anabaenopeptins were isolated, and their putative structures were determined by tandem mass spectrometry. The activity of the peptides against carboxypeptidase A and protein phosphatase 1 as well as chymotrypsin, trypsin and thrombin was tested. All anabaenopeptins inhibited carboxypeptidase A (apart from one anabaenopeptin variant) and protein phosphatase 1 with varying potency, but no inhibition against chymotrypsin, trypsin and thrombin was observed. PMID:26729139

  6. Phosphorus recycling and burial in Baltic Sea sediments with contrasting redox conditions

    NASA Astrophysics Data System (ADS)

    Slomp, Caroline P.; Mort, Haydon P.; Reed, Dan C.; Jilbert, Tom; Gustafsson, Bo G.

    2010-05-01

    The Baltic Sea is a classical example of a coastal system that is subject to an increased intensity and spatial extent of hypoxia due to human activities. The expansion of hypoxia since the 1960s is the result of increased inputs of nutrients from land (both from fertilizer and wastewater) and is negatively affecting living conditions for benthic organisms. In addition, the biogeochemical cycling of carbon and nutrients has been significantly altered. Water column studies have shown that the availability of dissolved inorganic phosphorus (DIP) is positively correlated with hypoxia due to release of phosphorus from sediment Fe-oxides and from organic matter upon the transition from oxic to hypoxic conditions. Thus, a large internal source of phosphorus exists in the sediment that largely controls short-term variability in water column DIP concentrations. In this presentation, we focus on results of recent field and modeling work for various parts of the Baltic Sea that confirm the role of Fe-bound P from seasonally hypoxic sediments at intermediate water depths as a major source of DIP. We also show that extended hypoxia and anoxia leads to depletion of sediment Fe-bound P and, ultimately, lower rates of sediment-water exchange of P. Authigenic Ca-P minerals appear to be only a relatively minor burial sink for P. The lack of major inorganic P burial makes the Baltic Sea sensitive to the feedback loop between increased hypoxia, enhanced regeneration of P and increased primary productivity. Historical records of bottom water oxygen at two sites (Bornholm, Northern Gotland) show a decline over the past century which is accompanied by a rise in values of typical sediment proxies for anoxia (total sulfur, molybdenum and organic C/P ratios). While sediment reactive P concentrations in anoxic basins are equal to or higher than at oxic sites, burial rates of P at hypoxic and anoxic sites are up to 20 times lower because of lower sedimentation rates. Nevertheless, burial of

  7. Vertical distribution of (241)Pu in the southern Baltic Sea sediments.

    PubMed

    Strumińska-Parulska, Dagmara I

    2014-12-15

    The vertical distribution of plutonium (241)Pu in marine sediments can assist in determining the deposition history and sedimentation process of analyzed regions. In addition, (241)Pu/(239+240)Pu activity ratio could be used as a sensitive fingerprint for radioactive source identification. The present preliminary studies on vertical distribution of (241)Pu in sediments from four regions of the southern Baltic Sea are presented. The distribution of (241)Pu was not uniform and depended on sediment geomorphology and depth as well as location. The highest concentrations of plutonium were found in the surface layers of all analyzed sediments and originated from the Chernobyl accident. PMID:25455816

  8. Bacteriohopanepolyols record stratification, nitrogen fixation and other biogeochemical perturbations in Holocene sediments of the Central Baltic Sea

    NASA Astrophysics Data System (ADS)

    Blumenberg, M.; Berndmeyer, C.; Moros, M.; Muschalla, M.; Schmale, O.; Thiel, V.

    2012-12-01

    The Baltic Sea, one of the world's largest brackish-marine basins, established after deglaciation of Scandinavia about 17 000 to 15 000 yr ago. In the changeable history of the Baltic Sea, the initial freshwater system was connected to the North Sea about 8000 yr ago and the modern brackish-marine setting (Littorina Sea) was established. Today, a relatively stable stratification developed in the water column of the deep basins due to salinity differences. Stratification is only occasionally interrupted by mixing events, and controls nutrient availability and growth of specifically adapted microorganisms and algae. We studied bacteriohopanepolyols (BHPs), lipids of specific bacterial groups, in a sediment core from the Central Baltic Sea (Gotland Deep) and found considerable differences between the distinct stages of the Baltic Sea's history. Individual BHP structures indicate contributions from as yet unknown redoxcline-specific bacteria (bacteriohopanetetrol isomer), methanotrophic bacteria (35-aminobacteriohopanetetrol), cyanobacteria (bacteriohopanetetrol cyclitol ether isomer) and, through allochthonous input after the Littorina transgression, from soil bacteria (adenosylhopane), whereas the origin of other BHPs in the core has still to be identified. Notably high BHP abundances were observed in the deposits of the brackish-marine Littorina phase, particularly in laminated sediment layers. Because these sediments record periods of stable water column stratification, bacteria specifically adapted to these conditions may account for the high portions of BHPs. An additional and/or accompanying source may be nitrogen-fixing (cyano)bacteria, which is indicated by a good correlation of BHP abundances with Corg and δ15N.

  9. Spatial variation of statistical properties of extreme water levels along the eastern Baltic Sea

    NASA Astrophysics Data System (ADS)

    Pindsoo, Katri; Soomere, Tarmo; Rocha, Eugénio

    2016-04-01

    Most of existing projections of future extreme water levels rely on the use of classic generalised extreme value distributions. The choice to use a particular distribution is often made based on the absolute value of the shape parameter of the Generalise Extreme Value distribution. If this parameter is small, the Gumbel distribution is most appropriate while in the opposite case the Weibull or Frechet distribution could be used. We demonstrate that the alongshore variation in the statistical properties of numerically simulated high water levels along the eastern coast of the Baltic Sea is so large that the use of a single distribution for projections of extreme water levels is highly questionable. The analysis is based on two simulated data sets produced in the Swedish Meteorological and Hydrological Institute. The output of the Rossby Centre Ocean model is sampled with a resolution of 6 h and the output of the circulation model NEMO with a resolution of 1 h. As the maxima of water levels of subsequent years may be correlated in the Baltic Sea, we also employ maxima for stormy seasons. We provide a detailed analysis of spatial variation of the parameters of the family of extreme value distributions along an approximately 600 km long coastal section from the north-western shore of Latvia in the Baltic Proper until the eastern Gulf of Finland. The parameters are evaluated using maximum likelihood method and method of moments. The analysis also covers the entire Gulf of Riga. The core parameter of this family of distributions, the shape parameter of the Generalised Extreme Value distribution, exhibits extensive variation in the study area. Its values evaluated using the Hydrognomon software and maximum likelihood method, vary from about -0.1 near the north-western coast of Latvia in the Baltic Proper up to about 0.05 in the eastern Gulf of Finland. This parameter is very close to zero near Tallinn in the western Gulf of Finland. Thus, it is natural that the Gumbel

  10. Genetic diversity of Saccharina latissima (Phaeophyceae) along a salinity gradient in the North Sea-Baltic Sea transition zone.

    PubMed

    Møller Nielsen, Mette; Paulino, Cristina; Neiva, João; Krause-Jensen, Dorte; Bruhn, Annette; Serrão, Ester A

    2016-08-01

    The North Sea-Baltic Sea transition zone constitutes a boundary area for the kelp species Saccharina latissima due to a strong salinity gradient operating in the area. Furthermore, the existence of S. latissima there, along Danish waters, is fairly patchy as hard bottom is scarce. In this study, patterns of genetic diversity of S. latissima populations were evaluated along the salinity gradient area of Danish waters (here designated brackish) and were compared to reference sites (here designated marine) outside the gradient area, using microsatellite markers. The results showed that the S. latissima populations were structured into two clusters corresponding to brackish versus marine sites, and that gene flow was reduced both between clusters and between populations within clusters. In addition, results provided empirical evidence that marginal populations of S. latissima in the salinity gradient area exhibited a distinct genetic structure when compared to marine ones. Brackish populations were less diverse, more related, and showed increased differentiation over distance compared to marine populations. The isolation of the brackish S. latissima populations within the salinity gradient area of Danish waters in conjunction with their general low genetic diversity makes these populations vulnerable to ongoing environmental and climate change, predicted to result in declining salinity in the Baltic Sea area that may alter the future distribution and performance of S. latissima in the area. PMID:27151230

  11. GIS analysis of effects of future Baltic sea level rise on the island of Gotland, Sweden

    NASA Astrophysics Data System (ADS)

    Ebert, Karin; Ekstedt, Karin; Jarsjö, Jerker

    2016-07-01

    Future sea level rise as a consequence of global warming will affect the world's coastal regions. Even though the pace of sea level rise is not clear, the consequences will be severe and global. Commonly the effects of future sea level rise are investigated for relatively vulnerable development countries; however, a whole range of varying regions needs to be considered in order to improve the understanding of global consequences. In this paper we investigate consequences of future sea level rise along the coast of the Baltic Sea island of Gotland, Sweden, with the aim to fill knowledge gaps regarding comparatively well-suited areas in developed countries. We study both the quantity of the loss of features of infrastructure, cultural, and natural value in the case of a 2 m sea level rise of the Baltic Sea and the effects of climate change on seawater intrusion in coastal aquifers, which indirectly cause saltwater intrusion in wells. We conduct a multi-criteria risk analysis by using lidar data on land elevation and GIS-vulnerability mapping, which gives the application of distance and elevation parameters formerly unimaginable precision. We find that in case of a 2 m sea level rise, 3 % of the land area of Gotland, corresponding to 99 km2, will be inundated. The features most strongly affected are items of touristic or nature value, including camping places, shore meadows, sea stack areas, and endangered plants and species habitats. In total, 231 out of 7354 wells will be directly inundated, and the number of wells in the high-risk zone for saltwater intrusion in wells will increase considerably. Some valuable features will be irreversibly lost due to, for example, inundation of sea stacks and the passing of tipping points for seawater intrusion into coastal aquifers; others might simply be moved further inland, but this requires considerable economic means and prioritization. With nature tourism being one of the main income sources of Gotland, monitoring and

  12. Characterization of OMI tropospheric NO2 over the Baltic Sea region

    NASA Astrophysics Data System (ADS)

    Ialongo, I.; Hakkarainen, J.; Hyttinen, N.; Jalkanen, J.-P.; Johansson, L.; Boersma, K. F.; Krotkov, N.; Tamminen, J.

    2014-08-01

    Satellite-based data are very important for air-quality applications in the Baltic Sea region, because they provide information on air pollution over the sea and where ground-based and aircraft measurements are not available. Both the emissions from urban sites over land and ships over sea, contribute to tropospheric NO2 levels. Tropospheric NO2 monitoring at high latitudes using satellite data is challenging because of the reduced light hours in winter and the weak signal due to the low Sun, which make the retrieval complex. This work presents a characterization of tropospheric NO2 columns based on case-study analysis in the Baltic Sea region, using the Ozone Monitoring Instrument (OMI) tropospheric NO2 standard product. Previous works have focused on larger seas and lower latitudes. The results of this paper showed that, despite the regional area of interest, it is possible to distinguish the signal from the main coastal cities and from the ships by averaging the data over a~seasonal time range. The summertime NO2 emission and lifetime values (E' = (1.5 ± 0.6) mol s-1 and τ = (3 ± 1) h, respectively) in Helsinki were estimated from the decay of the signal with distance from the city center. These results agree within the uncertainties with the emissions from the existing database. For comparison, the results for the cities of Saint Petersburg and Stockholm are also shown. The method developed for megacities was successfully applied to smaller-scale sources, in both size and intensity, which are located at high latitudes (~60° N). The same methodology could be applied to similar-scale cities elsewhere, as long as they are relatively isolated from other sources. Transport by the wind plays an important role in the Baltic Sea region. The NO2 spatial distribution is mainly determined by the contribution of westerly winds, which dominate the wind patterns during summer. The comparison between the ship emissions from model calculations and OMI NO2 tropospheric

  13. Characterization of OMI tropospheric NO2 over the Baltic Sea region

    NASA Astrophysics Data System (ADS)

    Ialongo, I.; Hakkarainen, J.; Hyttinen, N.; Jalkanen, J.-P.; Johansson, L.; Boersma, F.; Krotkov, N.; Tamminen, J.

    2014-01-01

    Satellite-based data are very important for air quality applications in the Baltic Sea area, because they provide information on air pollution over sea and there where ground-based network and aircraft measurements are not available. Both the emissions from urban sites over land and ships over sea, contribute to the tropospheric NO2 levels. The tropospheric NO2 monitoring at high latitudes using satellite data is challenging because of the reduced light hours in winter and the snow-covered surface, which make the retrieval complex, and because of the reduced signal due to low Sun. This work presents a detailed characterization of the tropospheric NO2 columns focused on part of the Baltic Sea region using the Ozone Monitoring Instrument (OMI) tropospheric NO2 standard product. Previous works have focused on larger seas and lower latitudes. The results showed that, despite the regional area of interest, it is possible to distinguish the signal from the main coastal cities and from the ships by averaging the data over a seasonal time range. The summertime NO2 emission and lifetime values (E = (1.0 ± 0.1) × 1028 molec. and τ = (3.0 ± 0.5) h, respectively) in Helsinki were estimated from the decay of the signal with distance from the city center. The method developed for megacities was successfully applied to a smaller scale source, in both size and intensity (i.e., the city of Helsinki), which is located at high latitudes (∼60° N). The same methodology could be applied to similar scale cities elsewhere, as far as they are relatively isolated from other sources. The transport by the wind plays an important role in the Baltic Sea area. The NO2 spatial distribution is mainly determined by the contribution of strong westerly winds, which dominate the wind patterns during summer. The comparison between the emissions from model calculations and OMI NO2 tropospheric columns confirmed the applicability of satellite data for ship emission monitoring. In particular

  14. Fate of excess phosphorus in the Baltic Sea: A real driving force for cyanobacterial blooms?

    NASA Astrophysics Data System (ADS)

    Raateoja, M.; Kuosa, H.; Hällfors, S.

    2011-02-01

    The wintertime ratio of inorganic dissolved nitrogen to phosphorus (DIN/DIP) in the surface waters of the Baltic Sea is typically below the molar Redfield ratio of 16, which expresses the presence of an excess inorganic dissolved phosphorus (eDIP) reserve compared to DIN. We assessed the role of the vernal phytoplankton bloom period (VPBP) in the consumption of the potential wintertime eDIP reserve, and the role of eDIP after the VPBP as a nutritional agent for the summertime growth of the cyanobacteria in the Baltic Sea. We employed a high-frequency dataset collected by the unattended monitoring systems on board merchant ships. The dataset encompasses the Baltic basins from the Arkona Basin to the Western Gulf of Finland and the time period from 1993 to 2009. All the observed values of the wintertime DIN/DIP ratio were below the molar Redfield ratio; the ratio showed a declining trend during the study, suggesting that there is a pronounced wintertime stock of the potential eDIP in the waters of the Baltic Sea, and that this stock has lately increased in magnitude. The VPBP took up excessively DIP to DIN than calculated according to the uptake in the molar Redfield ratio, thus reducing the potential eDIP reserve. On average, 59% of the potential eDIP reserve was left in the water after the VPBP as eDIP. eDIP was typically exhausted in the time frame early June-early July, matching well the timing of the appearance of cyanobacteria in substantial numbers in the water-column. eDIP clearly fueled the cyanobacterial growth in every instance in which it was possible to clarify their relationship. The cyanobacteria must still have another DIP source than eDIP to form extensive late-summer blooms, except in the western Gulf of Finland, where eDIP remained detectable up to early August. The annual role of eDIP for cyanobacterial growth depends greatly on the weather of late spring and early summer: this may sometimes launch the cyanobacterial growth much earlier than is

  15. Fishing cod in the Baltic Sea - Gambling with the ecosystem services

    NASA Astrophysics Data System (ADS)

    Björkman, Sven; Nordlöf, Anders

    2014-05-01

    The population of cod in the Baltic sea has over the last decades decreased due to overfishing. To make the students aware of this problem and also to find a solution they are introduced to a game. The purpose of the game is to let the students know how to use renewable natural resources in these aspects; 1 Fishing cod without using it up 2 That solidarity is needed if you are sharing a resource 3 That cooperation is the key to keeping a natural resource healthy. The students are fishermen in group of four and are equipped with a boat. The playing board is a map over the Baltic sea. The rules of the game include the carrying capacity of the sea, how much fish one fishing boat is allowed to pick up, how much it costs to have a boat, and possibilities to buy a bigger boat. The game has two rounds: In round one the students in the group are competing against each other, they are not allowed to talk to each other and they are supposed to get as much fish as they can. As a consequence after round one the sea will become empty. In round two the groups compete with each other and they are coworking within the group. After this round the result is different from the first round. The catches are bigger than in round one and still there are cod left in the sea, which will generate a good fishing in the future.. The discussions after the game can be about why the two rounds ended so different, general discussion about "tragedy of the commons", sustainable use of ecosystem services and discussions about resources in common.

  16. Understanding salt dynamics for a restored coastal wetland at the Baltic Sea in Germany

    NASA Astrophysics Data System (ADS)

    Selle, Benny; Gräff, Thomas; Salzmann, Thomas; Oswald, Sascha; Walther, Marc; Miegel, Konrad

    2016-04-01

    Coastal fens like the nature reserve „Hütelmoor und Heiligensee"(north-eastern Germany) are important landscape elements along the southern Baltic coast, which exchange fresh water and brackish water with the Baltic Sea. These exchange processes can be understood as experiments with a natural tracer, which may be used to investigate the hydrologic behaviour of these fen systems. With the establishment of coastal protection measures such as dunes and dikes, the installation of surface drainage and, more recently, also nature conservation measures, the hydrologic regime of these coastal wetlands constantly altered over the last centuries. The rehabilitated wetland „Hütelmoor und Heiligensee" is suitable for an analysis of hydrologic change as it was monitored over the time period since nature conservation measures started in the 1990s. Collected data sets include observation of groundwater levels and electrical conductivities, weather data as well as discharge at the outlet of the drainage catchment. In this study, we identifed processes and quantify process magnitudes that govern the salt balance of the study area including its variability in space and time. We found that - over the period of rehabilitation - salt water entered the catchment with episodic storm surges by wave overtopping of dunes. The intruded brackish water was then diluted, which is a slow process occurring over decades. It is governed by local groundwater recharge from precipitation and the inflow of relatively fresh groundwater from the hinterland. It is concluded that salt inputs from the Baltic Sea provide a natural tracer of hydrological processes, which can be readily monitored via electrical conductivity measurements.

  17. Seasonal variations of hydroxylated and methoxylated brominated diphenyl ethers in blue mussels from the Baltic Sea.

    PubMed

    Löfstrand, Karin; Liu, Xitao; Lindqvist, Dennis; Jensen, Sören; Asplund, Lillemor

    2011-07-01

    Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) and methoxylated polybrominated diphenyl ethers (MeO-PBDEs) found at high levels in the Baltic biota are mainly natural products, but can also be formed through metabolism or abiotic oxidation of polybrominated diphenyl ethers (PBDEs). The formation of OH-PBDEs is of concern since there is growing evidence of phenolic toxicity. This study investigates seasonal variations in levels of OH-PBDEs and MeO-PBDEs, focusing on an exposed species, the blue mussel (Mytilus edulis), sampled in the Baltic Sea in May, June, August and October of 2008. Both the OH-PBDE and MeO-PBDE levels in the mussels showed seasonal variations from May to October, the highest concentration of each congener appearing in June. The seasonal variation was more marked for OH-PBDEs than in MeO-PBDEs, but all congeners showed the same trends, except 6-MeO-BDE47 and 2'-MeO-BDE68, which did not significantly decline in concentrations after June. Biotic or abiotic debromination is suggested as a possible reason for the rapid decrease in methoxylated penta- and hexa-BDE concentrations observed in blue mussels from June to August, while the tetraBDE concentrations were stable. In addition, 1,3,7/1,3,8-tribrominated dibenzo-p-dioxins showed the same seasonal variation. The seasonal variations indicates natural formation and are unlikely to be due to transformation of anthropogenic precursors. The levels of PBDEs were fairly constant over time and considerably lower than those of the OH-PBDEs and MeO-PBDEs. The timing of the peaks in concentrations suggests that filamentous macro-algae may be important sources of these compounds found in the blue mussels from this Baltic Sea location. PMID:21288551

  18. A Eulerian nutrient to fish model of the Baltic Sea — A feasibility-study

    NASA Astrophysics Data System (ADS)

    Radtke, Hagen; Neumann, Thomas; Fennel, Wolfgang

    2013-09-01

    A nutrient-to-fish-model with an explicit two-way interaction between a biogeochemical model of the lower food web and a fish model component is presented for the example of the Baltic Sea, demonstrating the feasibility of a consistent coupling of the upper and lower parts of the food web in a Eulerian model system. In the Baltic Sea, the fish stock is dominated by two prey species (sprat and herring) and one predator (cod). The dynamics of the fish model is driven by size (mass-class) dependent predator-prey interactions while the interaction between the biogeochemical and Fish model component is established through feeding of prey fish on zooplankton and recycling of fish biomass to nutrients and detritus. The fish model component is coupled to an advanced three dimensional biogeochemical model (ERGOM, Neumann et al., 2002). A horizontally explicit representation of fish requires the implementation of fish behavior. As a first step, we propose an algorithm to stimulate fish migration by letting the fish follow the food. Moreover, fish species are guided to their respective spawning areas. Results of first three-dimensional simulations are presented with emphasis on the transport of matter by moving fish. The spawning areas of cod and sprat are in the deep basins, which are not well reached by advective transport. Hence the deposition of matter in these areas by spawning fish could play some role in the distribution of matter. The approach is not limited to applications for the Baltic and the model can be transferred also to other systems.

  19. Fecundity of flounder, Pleuronectes flesus, in the Baltic Sea — Reproductive strategies in two sympatric populations

    NASA Astrophysics Data System (ADS)

    Nissling, Anders; Dahlman, Gry

    2010-10-01

    Two sympatric flounder populations with different reproductive strategies, offshore spawning at 10-20 psu producing pelagic eggs and coastal spawning at 5-7 psu with demersal eggs respectively, inhabit the brackish water Baltic Sea. Salinity governs the reproductive success by irregular saline water inflows and hence stock abundance and distribution. The potential fecundity (the standing stock of vitellogenic oocytes in the pre-spawning ovary) was assessed for fish sampled at five locations (two for offshore spawners and three for coastal spawners) along the salinity gradient (ICES SD 25, 27/28, 28 and 29). Multiple linear regression analysis resulted in r2-values of 0.698-0.894 for the respective sampling location with somatic weight or total fish length as the main predictor, and otolith weight (proxy for age) and oocyte density (by gravimetric counting) as additional predictors. Analysis by univariate regressions using GLM revealed significantly higher fecundity for coastal spawning- than offshore spawning flounder (˜ 69% more oocytes for an intermediate sized fish) but no intra-population differences. Similarly, gonad dry weight was significantly higher for coastal spawning flounder. Further, growth estimations indicated higher growth in offshore spawning- than in coastal spawning flounder suggesting that the coastal spawning population allocate relatively more resources into reproductive growth than somatic, potentially a result of strong selection for high fecundity of flounder producing demersal eggs due to poor egg survival for this spawning strategy. Earlier studies on fecundity of Baltic flounder are reviewed and discussed with consideration of inter-population differences questioning the idea of in general higher fecundity of flounder in the Baltic Sea.

  20. Redox processes as revealed by voltammetry in the surface sediments of the Gotland Basin, Baltic Sea

    NASA Astrophysics Data System (ADS)

    Yücel, Mustafa; Dale, Andy; Sommer, Stefan; Pfannkuche, Olaf

    2014-05-01

    Sulfur cycling in marine sediments undergoes dramatic changes with changing redox conditions of the overlying waters. The upper sediments of the anoxic Gotland Basin, central Baltic Sea represent a dynamic redox environment with extensive mats of sulfide oxidizing bacteria covering the seafloor beneath the chemocline. In order to investigate sulfur redox cycling at the sediment-water interface, sediment cores were sampled over a transect covering 65 - 174 m water depth in August-September 2013. High resolution (0.25 mm minimum) vertical microprofiles of electroactive redox species including dissolved sulfide and iron were obtained with solid state Au-Hg voltammetric microelectrodes. This approach enabled a fine-scale comparison of porewater profiles across the basin. The steepest sulfide gradients (i.e. the highest sulfide consumption) occurred within the upper 10 mm in sediments covered by surficial mats (2.10 to 3.08 mmol m-2 day-1). In sediments under permanently anoxic waters (>140m), voltammetric signals for Fe(II) and aqueous FeS were detected below a subsurface maximum in dissolved sulfide, indicating a Fe flux originating from older, deeper sedimentary layers. Our results point to a unique sulfur cycling in the Gotland basin seafloor where sulfide accumulation is moderated by sulfide oxidation at the sediment surface and by FeS precipitation in deeper sediment layers. These processes may play an important role in minimizing benthic sulfide fluxes to bottom waters around the major basins of the Baltic Sea.

  1. Arsenic concentrations in Baltic Sea sediments close to chemical munitions dumpsites

    NASA Astrophysics Data System (ADS)

    Bełdowski, Jacek; Szubska, Marta; Emelyanov, Emelyan; Garnaga, Galina; Drzewińska, Anna; Bełdowska, Magdalena; Vanninen, Paula; Östin, Anders; Fabisiak, Jacek

    2016-06-01

    In addition to natural sources and land-originated pollution, the Baltic Sea has another anthropogenic source of arsenic in bottom sediments-arsenic-based Chemical Warfare Agents (CWA). To examine the potential usage of arsenic contents results for monitoring the leakage from chemical weapons, sediment samples were collected from officially reported and potential chemical weapon dumpsites located in the Baltic Sea, and total and inorganic arsenic concentrations were analyzed. Results showed an elevated arsenic content in dumpsite areas compared to reference areas. Correlations of arsenic with other metals and organic matter were studied to elucidate any unusual behavior of arsenic in the dumpsites. In the area of the Bornholm Deep, such behavior was observed for inorganic arsenic. It appears that in close vicinity of dumped munitions, the inorganic arsenic concentration of sediments is not correlated with either organic matter content or authigenic minerals formation, as is commonly observed elsewhere. Investigations on CWA concentrations, performed within the CHEMSEA (Chemical Munition Search and Assesment) project, allowed us to compare the results of arsenic concentrations with the occurrence of arsenic-containing CWA.

  2. Champacyclin, a New Cyclic Octapeptide from Streptomyces Strain C42 Isolated from the Baltic Sea

    PubMed Central

    Pesic, Alexander; Baumann, Heike I.; Kleinschmidt, Katrin; Ensle, Paul; Wiese, Jutta; Süssmuth, Roderich D.; Imhoff, Johannes F.

    2013-01-01

    New isolates of Streptomyces champavatii were isolated from marine sediments of the Gotland Deep (Baltic Sea), from the Urania Basin (Eastern Mediterranean), and from the Kiel Bight (Baltic Sea). The isolates produced several oligopeptidic secondary metabolites, including the new octapeptide champacyclin (1a) present in all three strains. Herein, we report on the isolation, structure elucidation and determination of the absolute stereochemistry of this isoleucine/leucine (Ile/Leu = Xle) rich cyclic octapeptide champacyclin (1a). As 2D nuclear magnetic resonance (NMR) spectroscopy could not fully resolve the structure of (1a), additional information on sequence and configuration of stereocenters were obtained by a combination of multi stage mass spectrometry (MSn) studies, amino acid analysis, partial hydrolysis and subsequent enantiomer analytics with gas chromatography positive chmical ionization/electron impact mass spectrometry (GC-PCI/EI-MS) supported by comparison to reference dipeptides. Proof of the head-to-tail cyclization of (1a) was accomplished by solid phase peptide synthesis (SPPS) compared to an alternatively side chain cyclized derivative (2). Champacyclin (1a) is likely synthesized by a non-ribosomal peptide synthetase (NRPS), because of its high content of (d)-amino acids. The compound (1a) showed antimicrobial activity against the phytopathogen Erwinia amylovora causing the fire blight disease of certain plants. PMID:24317473

  3. Environmental response of living benthic foraminifera in Kiel Fjord, SW Baltic Sea

    NASA Astrophysics Data System (ADS)

    Nikulina, A.; Polovodova, I.; Schönfeld, J.

    2007-12-01

    The living benthic foraminiferal assemblages in the Kiel Fjord (SW Baltic Sea) were investigated in the years 2005 and 2006. The faunal studies were accomplished by geochemical analyses of surface sediments. In general, sediment pollution by copper, zinc, tin and lead was assessed as moderate in comparison with levels reported from other areas of the Baltic Sea. However, the inner Kiel fjord is still exposed to a high load of metals and organic matter due to enhanced accumulation of fine-grained sediments in conjunction with a concentration of pollution sources as shipyards, harbours and intensive traffic. The results of our survey showed that the dominant environmental forcing of benthic foraminifera is nutrients availability coupled with human impact. A comparison with data from the 1960s revealed apparent changes in species composition and population densities over the past decades. The stress-tolerant species Ammonia beccarii invaded Kiel Fjord whereas Ammotium cassis disappeared, possibly due to low salinity that prevailed 10 years ago. These changes in foraminiferal community and a significant increase of test abnormalities indicate enforced environmental stress since the 1960s.

  4. Foraminiferal response to environmental changes in Kiel Fjord, SW Baltic Sea

    NASA Astrophysics Data System (ADS)

    Nikulina, A.; Polovodova, I.; Schönfeld, J.

    2008-08-01

    The living benthic foraminiferal assemblages in Kiel Fjord (SW Baltic Sea) were investigated in the years 2005 and 2006. The faunal studies were accomplished by geochemical analyses of surface sediments. In general, sediment pollution by copper, zinc, tin and lead is assessed as moderate in comparison with levels reported from other areas of the Baltic Sea. However, the inner Kiel Fjord is still exposed to a high load of metals and organic matter due to enhanced accumulation of fine-grained sediments in conjunction with potential pollution sources as shipyards, harbours and intensive traffic. The results of our survey show that the dominant environmental forcing of benthic foraminifera is nutrients availability coupled with human impact. A comparison with faunal data from the 1960s reveals apparent changes in species composition and population densities. The stress-tolerant species Ammonia beccarii invaded Kiel Fjord. Ammotium cassis had disappeared that reflects apparently the changes in salinity over the last 10 years. These changes in foraminiferal community and a significant increase of test abnormalities indicate an intensified environmental stress since the 1960s.

  5. Picocyanobacteria containing a novel pigment gene cluster dominate the brackish water Baltic Sea

    PubMed Central

    Larsson, John; Celepli, Narin; Ininbergs, Karolina; Dupont, Christopher L; Yooseph, Shibu; Bergman, Bigitta; Ekman, Martin

    2014-01-01

    Photoautotrophic picocyanobacteria harvest light via phycobilisomes (PBS) consisting of the pigments phycocyanin (PC) and phycoerythrin (PE), encoded by genes in conserved gene clusters. The presence and arrangement of these gene clusters give picocyanobacteria characteristic light absorption properties and allow the colonization of specific ecological niches. To date, a full understanding of the evolution and distribution of the PBS gene cluster in picocyanobacteria has been hampered by the scarcity of genome sequences from fresh- and brackish water-adapted strains. To remediate this, we analysed genomes assembled from metagenomic samples collected along a natural salinity gradient, and over the course of a growth season, in the Baltic Sea. We found that while PBS gene clusters in picocyanobacteria sampled in marine habitats were highly similar to known references, brackish-adapted genotypes harboured a novel type not seen in previously sequenced genomes. Phylogenetic analyses showed that the novel gene cluster belonged to a clade of uncultivated picocyanobacteria that dominate the brackish Baltic Sea throughout the summer season, but are uncommon in other examined aquatic ecosystems. Further, our data suggest that the PE genes were lost in the ancestor of PC-containing coastal picocyanobacteria and that multiple horizontal gene transfer events have re-introduced PE genes into brackish-adapted strains, including the novel clade discovered here. PMID:24621524

  6. Picocyanobacteria containing a novel pigment gene cluster dominate the brackish water Baltic Sea.

    PubMed

    Larsson, John; Celepli, Narin; Ininbergs, Karolina; Dupont, Christopher L; Yooseph, Shibu; Bergman, Bigitta; Ekman, Martin

    2014-09-01

    Photoautotrophic picocyanobacteria harvest light via phycobilisomes (PBS) consisting of the pigments phycocyanin (PC) and phycoerythrin (PE), encoded by genes in conserved gene clusters. The presence and arrangement of these gene clusters give picocyanobacteria characteristic light absorption properties and allow the colonization of specific ecological niches. To date, a full understanding of the evolution and distribution of the PBS gene cluster in picocyanobacteria has been hampered by the scarcity of genome sequences from fresh- and brackish water-adapted strains. To remediate this, we analysed genomes assembled from metagenomic samples collected along a natural salinity gradient, and over the course of a growth season, in the Baltic Sea. We found that while PBS gene clusters in picocyanobacteria sampled in marine habitats were highly similar to known references, brackish-adapted genotypes harboured a novel type not seen in previously sequenced genomes. Phylogenetic analyses showed that the novel gene cluster belonged to a clade of uncultivated picocyanobacteria that dominate the brackish Baltic Sea throughout the summer season, but are uncommon in other examined aquatic ecosystems. Further, our data suggest that the PE genes were lost in the ancestor of PC-containing coastal picocyanobacteria and that multiple horizontal gene transfer events have re-introduced PE genes into brackish-adapted strains, including the novel clade discovered here. PMID:24621524

  7. Determination of /sup 239,240/Pu in bottom sediments of the Baltic Sea

    SciTech Connect

    Kuznetsov, Yu.V.; Legin, V.K.; Pospelov, Yu.N.; Simonyak, Z.N.

    1988-11-01

    We present a technique for determining the /sup 239,240/Pu content, using /sup 236/Pu as the monitor of chemical yield, in samples of soils and bottom sediments - objects of the external environment. Plutonium is extracted from the matrix material by leaching with a mixture of concentrated acids HCl-HNO/sub 3/, after which it is separated by ion-exchange methods. After electrodeposition onto stainless steel discs the activity of the nuclides of plutonium is measured by the method of alpha-spectrometry. The average chemical yields during the analysis of the samples was 40-60%, the relative standard deviation was 10%, and the lower limit of detectability was 0.3 Bq. We present results of the determination of the /sup 239,240/Pu content in surface samples of bottom sediments from the Gulf of Finland and that past of the Baltic Sea which adjoins the territory of the USSR. It is found that the unit activity of /sup 239,240/Pu in the bottom sediments varies within the limits of 0.4-1.2 Bq/kg and lies at the global level. Global genesis of /sup 239,240/Pu in the bottom sediments of the Gulf of Finland and the open parts of the Baltic Sea is also confirmed by the values which are found for the ratios /sup 238/Pu//sup 239,240/Pu and /sup 239,240/Pu//sup 137/Cs.

  8. Immunosuppression in harbour seals fed fish from the contaminated Baltic Sea

    SciTech Connect

    Ross, P.S. |; Swart, R.L. de |; Timmerman, H.H.; Loveren, H. van; Vos, J.G.; Vedder, L.J.; Reijnders, P.J.H.; Osterhaus, A.D.M.E.

    1994-12-31

    Environmental contaminants including dioxins and polychlorinated biphenyls have been shown to be immunotoxic in laboratory animals, but little information exists as to their possible effect on mammals in the natural environment. Recent virus-induced mass mortalities among marine mammals occupying high trophic levels have led to much speculation regarding a possible contributory role of pollutants in these events. The authors undertook a two-year captive feeding experiment with harbor seals, Phoca vitulina, where one group was fed herring from the contaminated Baltic Sea and a second group was fed relatively uncontaminated herring from the Atlantic Ocean. During the course of the experiment, they regularly sampled blood and undertook a series of immune function tests. They observed a significant impairment of natural killer cell activity and T-lymphocyte function, in vitro, in the group of seals fed the Baltic Sea fish. In addition, seals of this group were less able to mount a specific humoral and delayed type hypersensitivity response to a protein antigen, ovalbumin, upon immunization. Increased numbers of granulocytes in this group may have reflected periodic bacterial infections as a consequence of impaired immune function. Their results suggest that pollutants accumulated through the food chain in contaminated marine waters may suppress normal immune responses in marine mammals and lead to an increased susceptibility to opportunistic infection.

  9. Champacyclin, a new cyclic octapeptide from Streptomyces strain C42 isolated from the Baltic Sea.

    PubMed

    Pesic, Alexander; Baumann, Heike I; Kleinschmidt, Katrin; Ensle, Paul; Wiese, Jutta; Süssmuth, Roderich D; Imhoff, Johannes F

    2013-12-01

    New isolates of Streptomyces champavatii were isolated from marine sediments of the Gotland Deep (Baltic Sea), from the Urania Basin (Eastern Mediterranean), and from the Kiel Bight (Baltic Sea). The isolates produced several oligopeptidic secondary metabolites, including the new octapeptide champacyclin (1a) present in all three strains. Herein, we report on the isolation, structure elucidation and determination of the absolute stereochemistry of this isoleucine/leucine (Ile/Leu = Xle) rich cyclic octapeptide champacyclin (1a). As 2D nuclear magnetic resonance (NMR) spectroscopy could not fully resolve the structure of (1a), additional information on sequence and configuration of stereocenters were obtained by a combination of multi stage mass spectrometry (MSn) studies, amino acid analysis, partial hydrolysis and subsequent enantiomer analytics with gas chromatography positive chmical ionization/electron impact mass spectrometry (GC-PCI/EI-MS) supported by comparison to reference dipeptides. Proof of the head-to-tail cyclization of (1a) was accomplished by solid phase peptide synthesis (SPPS) compared to an alternatively side chain cyclized derivative (2). Champacyclin (1a) is likely synthesized by a non-ribosomal peptide synthetase (NRPS), because of its high content of (D)-amino acids. The compound (1a) showed antimicrobial activity against the phytopathogen Erwinia amylovora causing the fire blight disease of certain plants. PMID:24317473

  10. Integrated ecological assessment of Danish Baltic Sea coastal areas by means of phytoplankton and macrophytobenthos

    NASA Astrophysics Data System (ADS)

    Sagert, Sigrid; Krause Jensen, Dorte; Henriksen, Peter; Rieling, Thorsten; Schubert, Hendrik

    2005-04-01

    The Water Framework Directive (WFD) demands an integrated assessment of ecological quality based on biological parameters. In this context combined macrophytobenthos and phytoplankton data sets along the Danish Baltic Sea coast were analysed for similarities and differences in their response to abiotic variables. Zostera marina's depth limits showed a significantly negative correlation with concentrations of total-nitrogen, total phosphorus and chlorophyll a as well as with Myrionecta rubra biomass and a strongly positive correlation with Secchi depth. The results documented that selected phytobenthos and phytoplankton indicators show correlated responses to water quality. All biotic and abiotic parameters clustered in two groups, indicating two trophic states but, at the same time, also two distinct salinity classes. One class was characterised by low nutrient levels and low salinity while the other class was characterised by high nutrient levels and high salinity, indicating that the mixing of relatively nutrient poor brackish Baltic water with more nutrient rich North Sea water overruled traditional estuarine gradients in the investigated area. The results therefore allow an analysis of the eutrophication state regarding the additional influence of decreased salinity on euryhaline marine species. The consequences of the results are discussed in relation to classification systems for brackish water ecosystems.

  11. Newly Digitized Historical Climate Data of the German Bight and the Southern Baltic Sea Coasts

    NASA Astrophysics Data System (ADS)

    Röhrbein, Dörte; Tinz, Birger; von Storch, Hans

    2015-04-01

    The detection of historical climate information plays an important role with regard to the discussion on climate change, particularly on storminess. The German Meteorological Service houses huge archives of historical handwritten journals of weather observations. A considerable number of original observation sheets from stations along the coast of the German Bight and the southern Baltic Sea exists which has been until recently almost unnoticed. These stations are called signal stations and are positioned close to the shore. However, for this region meteorological observation data of 128 stations exist from 1877 to 1999 and are partly digitized. In this study we show an analysis of firstly newly digitized wind and surface air pressure data of 15 stations from 1877 to 1939 and we also present a case study of the storm surge at the coast of the southern Baltic Sea in December 1913. The data are quality controlled by formal, climatological, temporal and consistency checks. It is shown that these historical climate data are usable in consistency and quality for further investigations on climate change, e.g. as input for regional and global reanalysis.

  12. Active bacterial community structure along vertical redox gradients in Baltic Sea sediment

    SciTech Connect

    Jansson, Janet; Edlund, Anna; Hardeman, Fredrik; Jansson, Janet K.; Sjoling, Sara

    2008-05-15

    Community structures of active bacterial populations were investigated along a vertical redox profile in coastal Baltic Sea sediments by terminal-restriction fragment length polymorphism (T-RFLP) and clone library analysis. According to correspondence analysis of T-RFLP results and sequencing of cloned 16S rRNA genes, the microbial community structures at three redox depths (179 mV, -64 mV and -337 mV) differed significantly. The bacterial communities in the community DNA differed from those in bromodeoxyuridine (BrdU)-labeled DNA, indicating that the growing members of the community that incorporated BrdU were not necessarily the most dominant members. The structures of the actively growing bacterial communities were most strongly correlated to organic carbon followed by total nitrogen and redox potentials. Bacterial identification by sequencing of 16S rRNA genes from clones of BrdU-labeled DNA and DNA from reverse transcription PCR (rt-PCR) showed that bacterial taxa involved in nitrogen and sulfur cycling were metabolically active along the redox profiles. Several sequences had low similarities to previously detected sequences indicating that novel lineages of bacteria are present in Baltic Sea sediments. Also, a high number of different 16S rRNA gene sequences representing different phyla were detected at all sampling depths.

  13. Biomarkers in the stratified water column of the Landsort Deep (Baltic Sea)

    NASA Astrophysics Data System (ADS)

    Berndmeyer, C.; Thiel, V.; Schmale, O.; Wasmund, N.; Blumenberg, M.

    2014-12-01

    The water column of the Landsort Deep, central Baltic Sea, is stratified into an oxic, suboxic, and anoxic zone. This stratification controls the distributions of individual microbial communities and biogeochemical processes. In summer 2011, particulate organic matter was filtered from these zones using an in situ pump. Lipid biomarkers were extracted from the filters to establish water-column profiles of individual hydrocarbons, alcohols, phospholipid fatty acids, and bacteriohopanepolyols (BHPs). As a reference, a cyanobacterial bloom sampled in summer 2012 in the central Baltic Sea Gotland Deep was analyzed for BHPs. The biomarker data from the surface layer of the oxic zone showed major inputs from cyanobacteria, dinoflagellates, and ciliates, while the underlying cold winter water layer was characterized by a low diversity and abundance of organisms, with copepods as a major group. The suboxic zone supported bacterivorous ciliates, type I aerobic methanotrophic bacteria, sulfate-reducing bacteria, and, most likely, methanogenic archaea. In the anoxic zone, sulfate reducers and archaea were the dominating microorganisms as indicated by the presence of distinctive branched fatty acids: archaeol and pentamethylicosane (PMI) derivatives, respectively. Our study of in situ biomarkers in the Landsort Deep thus provided an integrated insight into the distribution of relevant compounds and describes useful tracers to reconstruct stratified water columns in the geological record.

  14. Application of Empirical Wave Run-Up Formulas to the Polish Baltic Sea Coast

    PubMed Central

    Paprotny, Dominik; Andrzejewski, Paweł; Terefenko, Paweł; Furmańczyk, Kazimierz

    2014-01-01

    Advanced, multidimensional models are typically applied when researching processes occurring in the nearshore. Relatively simple, empirical equations are commonly used in coastal engineering practice in order to estimate extreme wave run-up on beaches and coastal structures. However, they were mostly calibrated to the characteristics of oceanic coasts, which have different wave regime than a semi-enclosed basin like the Baltic Sea. In this paper we apply the formulas to the Polish Baltic Sea coast. The equations were adjusted to match local conditions in two test sites in Międzyzdroje and Dziwnówek, where beaches are under continuous video surveillance. Data from WAM wave model and coastal gauge stations were used, as well as precise measurements of the beaches' cross-sections. More than 600 run-up events spanning from June to December 2013 were analysed, including surges causing dune erosion. Extreme wave run-up R2% was calculated and presented as a percentage value indicating what part of the beach was inundated. The method had a root-mean-square error of 6.1 and 6.5 percentage points depending on the test site. We consider it is a fast and computationally undemanding alternative to morphodynamic models. It will constitute a part of the SatBałtyk Operating System-Shores, delivering forecasts of wave run-up on the beaches for the entire Polish coastline. PMID:25137155

  15. Aerosol-cloud interaction determined by satellite data over the Baltic Sea countries

    NASA Astrophysics Data System (ADS)

    Saponaro, Giulia; Kolmonen, Pekka; Sogacheva, Larisa; de Leeuw, Gerrit

    2015-04-01

    The present study investigates the use of long-term satellite data to assess the influence of aerosols upon cloud parameters over the Baltic Sea region. This particular area offers the contrast of a very clean environment (Fennoscandia) against a more polluted one (Germany, Poland). The datasets consists of Collection 6 Level 3 daily observations from 2002 to 2014 collected by the NASA's Moderate-Resolution Imaging Spectrometer (MODIS) instrument on-board the Aqua platform. The MODIS aerosol optical depth (AOD) product is used as a proxy for the number concentration of aerosol particles while the cloud effective radius (CER) and cloud optical thickness (COT) describe cloud microphysical and optical properties respectively. Satellite data have certain limitations, such as the restriction to summer season due to solar zenith angle restrictions and the known problem of the ambiguity of the aerosol-cloud interface, for instance. Through the analysis of a 12-years dataset, distribution maps provide information on a regional scale about the first aerosol indirect effect (AIE) by determining the aerosol-cloud interaction (ACI). The ACI is defined as the change in cloud optical depth or effective radius as a function of aerosol load for a fixed liquid water path (LWP). The focusing point of the current study is the evaluation of regional trends of ACI over the observed area of the Baltic Sea.

  16. Mapping present and future potential distribution patterns for a meso-grazer guild in the Baltic Sea

    PubMed Central

    Leidenberger, Sonja; De Giovanni, Renato; Kulawik, Robert; Williams, Alan R; Bourlat, Sarah J; Maggs, Christine

    2015-01-01

    Aim The Baltic Sea is one of the world's largest semi-enclosed brackish water bodies characterized by many special features, including endemic species that may be particularly threatened by climate change. We mapped potential distribution patterns under present and future conditions for a community with three trophic levels. We analysed climate-induced changes in the species' distribution patterns and examined possible consequences for the chosen food web. Location Baltic Sea and northern Europe. Methods We developed two open-source workflow-based analytical tools: one for ecological niche modelling and another for raster layer comparison to compute the extent and intensity of change in species' potential distributions. Individual ecological niche models were generated under present conditions and then projected into a future climate change scenario (2050) for a food web consisting of a guild of meso-grazers (Idotea spp.), their host algae (Fucus vesiculosus and Fucus radicans) and their fish predator (Gasterosteus aculeatus). We used occurrence data from the Global Biodiversity Information Facility (GBIF), literature and museum collections, together with five environmental layers at a resolution of 5 and 30 arc-minutes. Results Habitat suitability for Idotea balthica and Idotea chelipes in the Baltic Sea seems to be mostly determined by temperature and ice cover rather than by salinity. 2050 predictions for all modelled species show a northern/north-eastern shift in the Baltic Sea. The distribution ranges for Idotea granulosa and G. aculeatus are predicted to become patchier in the Baltic than in the rest of northern Europe, where the species will gain more suitable habitats. Main conclusions For the Baltic Sea, climate-induced changes resulted in a gain of suitable habitats for F. vesiculosus,I. chelipes and I. balthica, whereas lower habitat suitability was predicted for I. granulosa,F. radicans and G. aculeatus. The predicted north-eastern shift of I. balthica

  17. Submerged terrestrial landscapes in the Baltic Sea: Evidence from multiproxy analyses of sediment cores from Fehmarnbelt

    NASA Astrophysics Data System (ADS)

    Enters, Dirk; Wolters, Steffen; Blume, Katharina; Segschneider, Martin; Lücke, Andreas; Theuerkauf, Martin; Hübener, Thomas

    2016-04-01

    Five sediment cores were taken from the southern part of the Fehmarn Belt (Baltic Sea) in the context of an environmental impact study for the intended fixed traverse between Germany and Denmark. The lithologies of the 8m long cores reveal dramatic changes in sedimentary environments which reflect the early Holocene history of the southern Baltic Sea. A succession of terrestrial, semiterrestrial and limnic facies from glacial sediments to peat, lacustrine/estuarine deposits and finally marine sediments document the interplay of eustatic sea level rise and isostatic rebound, which finally lead to the establishment of marine conditions during the Littorina transgression. An age control of the observed changes was established by dating over 50 C-14 samples of different fractions. During the Lateglacial minerogenic varves with thicknesses of several centimeters verify the existence of a proglacial lake in the Fehmarnbelt. Peat development started around 11.250 cal. BP and terminated ca. 10.600 cal. BP which is roughly contemporaneous with the end of the Yoldia Phase in the central Baltic Sea. The oldest peat layers consist of undecomposed sedges and reed. Woody remains of willows appear not before 10.700 cal BP and indicate a stagnant or slowly decreasing water table. This semi-terrestrial phase is followed by a shallow inland lake which existed until the Littorina transgression around 8.300 cal. BP. Initially the lacustrine sediments exhibit high C/N ratios, low low δ13Corg values and contain numerous wood fragments as well as other botanical macro remains. This indicates shallow conditions close to the lake shore. Later, the occurrence of planktonic diatom species such as Aulacoseira ambigua suggest greater water depths. We did not find any indications of the often postulated catastrophic outburst of the Ancylus Lake via Fehmarnbelt and the Great Belt into the North Sea. Likewise, XRF scanning does not show conspicuous peaks in Ti or K which would have been

  18. Water protection in the Baltic Sea and the Chesapeake Bay: institutions, policies and efficiency.

    PubMed

    Iho, Antti; Ribaudo, Marc; Hyytiäinen, Kari

    2015-04-15

    The Baltic Sea and the Chesapeake Bay share many characteristics. Both are shallow, brackish marine areas that suffer from eutrophication. Successful policies targeting point source pollution have lowered nutrient loads in both areas, but achieving the desired marine quality will require further abatement: efforts may be extended to more complicated and expensive pollution sources, notably agricultural nonpoint loads. Despite their ecological similarities, the two watersheds have different histories and institutional settings and have thus adopted different policies. Comparing and contrasting the policies reveal ways to improve the efficiency of each and ways to avoid the path of trial and error. No comparison of the parallel protection efforts, which involve expenditures of hundreds of millions of dollars annually, has been carried out to date. The present paper analyzes the policies applied in the two regions, distilling the results into six recommendations for future steps in preserving what are valuable sea areas. PMID:25752532

  19. Local adaptation and oceanographic connectivity patterns explain genetic differentiation of a marine diatom across the North Sea–Baltic Sea salinity gradient

    PubMed Central

    Sjöqvist, C; Godhe, A; Jonsson, P R; Sundqvist, L; Kremp, A

    2015-01-01

    Drivers of population genetic structure are still poorly understood in marine micro-organisms. We exploited the North Sea–Baltic Sea transition for investigating the seascape genetics of a marine diatom, Skeletonema marinoi. Eight polymorphic microsatellite loci were analysed in 354 individuals from ten locations to analyse population structure of the species along a 1500-km-long salinity gradient ranging from 3 to 30 psu. To test for salinity adaptation, salinity reaction norms were determined for sets of strains originating from three different salinity regimes of the gradient. Modelled oceanographic connectivity was compared to directional relative migration by correlation analyses to examine oceanographic drivers. Population genetic analyses showed distinct genetic divergence of a low-salinity Baltic Sea population and a high-salinity North Sea population, coinciding with the most evident physical dispersal barrier in the area, the Danish Straits. Baltic Sea populations displayed reduced genetic diversity compared to North Sea populations. Growth optima of low salinity isolates were significantly lower than those of strains from higher native salinities, indicating local salinity adaptation. Although the North Sea–Baltic Sea transition was identified as a barrier to gene flow, migration between Baltic Sea and North Sea populations occurred. However, the presence of differentiated neutral markers on each side of the transition zone suggests that migrants are maladapted. It is concluded that local salinity adaptation, supported by oceanographic connectivity patterns creating an asymmetric migration pattern between the Baltic Sea and the North Sea, determines genetic differentiation patterns in the transition zone. PMID:25892181

  20. Past occurrences of hypoxia in the Baltic Sea and the role of climate variability, environmental change and human impact

    NASA Astrophysics Data System (ADS)

    Zillén, Lovisa; Conley, Daniel J.; Andrén, Thomas; Andrén, Elinor; Björck, Svante

    2008-12-01

    The hypoxic zone in the Baltic Sea has increased in area about four times since 1960 and widespread oxygen deficiency has severely reduced macro benthic communities below the halocline in the Baltic Proper and the Gulf of Finland, which in turn has affected food chain dynamics, fish habitats and fisheries in the entire Baltic Sea. The cause of increased hypoxia is believed to be enhanced eutrophication through increased anthropogenic input of nutrients, such as nitrogen and phosphorus. However, the spatial variability of hypoxia on long time-scales is poorly known: and so are the driving mechanisms. We review the occurrence of hypoxia in modern time (last c. 50 years), modern historical time (AD 1950-1800) and during the more distant past (the last c. 10 000 years) and explore the role of climate variability, environmental change and human impact. We present a compilation of proxy records of hypoxia (laminated sediments) based on long sediment cores from the Baltic Sea. The cumulated results show that the deeper depressions of the Baltic Sea have experienced intermittent hypoxia during most of the Holocene and that regular laminations started to form c. 8500-7800 cal. yr BP ago, in association with the formation of a permanent halocline at the transition between the Early Littorina Sea and the Littorina Sea s. str. Laminated sediments were deposited during three main periods (i.e. between c. 8000-4000, 2000-800 cal. yr BP and subsequent to AD 1800) which overlap the Holocene Thermal Maximum (c. 9000-5000 cal. yr BP), the Medieval Warm Period (c. AD 750-1200) and the modern historical period (AD 1800 to present) and coincide with intervals of high surface salinity (at least during the Littorina s. str.) and high total organic carbon content. This study implies that there may be a correlation between climate variability in the past and the state of the marine environment, where milder and dryer periods with less freshwater run-off correspond to increased salinities

  1. Model studies of the flux of CO{sub 2} over the air-sea interface in the Baltic Sea

    SciTech Connect

    Ohlson, M.

    1994-12-31

    In the discussion about the green house effect generated by the burning of fossil fuels, carbon dioxide (CO{sub 2}) has a key role. A major part of the surplus CO{sub 2} has been suggested, by the scientific community, to be withdrawn from the atmosphere and to be taken up by the growth in continental shelf areas with high primary production, and in terrestrial forests. The exact quantity and reaction ways and mechanisms of those processes are not known today. The Baltic Sea is, for several reasons, a well chosen area to study this phenomenon. It is a shallow continental Mediterranean sea, in this area almost the first measurements of the carbonate system were carried out in the end of the last century. This has resulted in long time series of measurements of the carbonate system available for use in, e.g. modelling work, a working numerical carbonate model.

  2. Discovery of bacterial polyhydroxyalkanoate synthase (PhaC)-encoding genes from seasonal Baltic Sea ice and cold estuarine waters.

    PubMed

    Pärnänen, Katariina; Karkman, Antti; Virta, Marko; Eronen-Rasimus, Eeva; Kaartokallio, Hermanni

    2015-01-01

    Polyhydroxyalkanoates (PHAs) are macromolecules produced by bacteria as means for storing carbon and energy in intracellular granules. PHAs have physical properties similar to those of plastics and have become of interest to industry as materials for environmentally friendly bioplastic production. There is an ongoing search for new PHA-producing bacterial strains and PHA-synthesizing enzymes tolerating extreme conditions to find ways of producing PHAs at cold temperatures and high solute concentrations. Moreover, the study of PHA producers in the sea-ice biome can aid in understanding the microbial ecology of carbon cycling in ice-associated ecosystems. In this study, PHA producers and PHA synthase genes were examined under the extreme environmental conditions of sea ice and cold seawater to find evidence of PHA production in an environment requiring adaptation to high salinity and cold temperatures. Sea ice and cold estuarine water samples were collected from the northern Baltic Sea and evidence of PHA production was gathered, using microscopy with Nile Blue A staining of PHA-granules and PCR assays detecting PHA-synthesis genes. The PHA granules and PHA synthases were found at all sampling locations, in both sea ice and water, and throughout the sampling period spanning over 10 years. Our study shows, for the first time, that PHA synthesis occurs in Baltic Sea cold-adapted bacteria in their natural environment, which makes the Baltic Sea and its cold environments an interesting choice in the quest for PHA-synthesizing bacteria and synthesis genes. PMID:25280551

  3. Development of interdisciplinary model of microplastics transport and transformation in the Baltic sea

    NASA Astrophysics Data System (ADS)

    Bagaev, Andrei; Chubarenko, Irina; Mizyuk, Artem; Zobkov, Mikhail; Esiukova, Elena; Isachenko, Igor; Stepanova, Natalya

    2016-04-01

    Nowadays, anthropogenic pressure from the coastal areas comes up in many aspects of marine environment changes, decreasing the aesthetics of the underwater world, threatening the sustainability of marine ecosystems and influencing the quality of human life. Microplastics are pervasive throughout the marine environment, are ingested by many marine organisms, and enter a food chain that includes humans. A certain fraction of microplastics in marine environment results from breakdown of larger items in numerous tiny fragments due to mechanical forces and photochemical processes, as well as from other degradation sources. Microplastics can absorb high levels of Persistent Organic Pollutants (POPs) and other toxins. Deep-sea sediments are a likely, but yet unquantified, sink for microplastics (Cole et al., 2011). Since the MARBLE ('MicroplAstics Research in the BaLtic Environment') project started, three expeditions and multiple on-shore field experiments have been conducted in the South-Eastern Baltic. The samples were collected from the surface, deep water layers and bottom sediments. The samples were processed and physical parameters of the microparticles were established. In parallel, laboratory experiments under controllable conditions over the particles of regular shapes were conducted in order to test the empirical formulas for the sinking velocity. PLEX ('PLastics EXplorer') -- a device for efficiently collecting microparticles in marine environment -- was developed, built and tested. An attempt was made to quantify some geometrical properties of particles, to compare their surface areas, fouling rates, sinking velocities, and finally provide some estimates for the main spatial and temporal scales, describing the behaviour of the particles of different densities and shapes in the Baltic Sea (Chubarenko et al., 2016). An original 3D model of Microplastics dynamics is under development now. Its aim is to provide a robust numerical predictive tool to study pathways

  4. Sea ice in the Baltic Sea - revisiting BASIS ice, a~historical data set covering the period 1960/1961-1978/1979

    NASA Astrophysics Data System (ADS)

    Löptien, U.; Dietze, H.

    2014-06-01

    The Baltic Sea is a seasonally ice-covered, marginal sea, situated in central northern Europe. It is an essential waterway connecting highly industrialised countries. Because ship traffic is intermittently hindered by sea ice, the local weather services have been monitoring sea ice conditions for decades. In the present study we revisit a historical monitoring data set, covering the winters 1960/1961. This data set, dubbed Data Bank for Baltic Sea Ice and Sea Surface Temperatures (BASIS) ice, is based on hand-drawn maps that were collected and then digitised 1981 in a joint project of the Finnish Institute of Marine Research (today Finish Meteorological Institute (FMI)) and the Swedish Meteorological and Hydrological Institute (SMHI). BASIS ice was designed for storage on punch cards and all ice information is encoded by five digits. This makes the data hard to access. Here we present a post-processed product based on the original five-digit code. Specifically, we convert to standard ice quantities (including information on ice types), which we distribute in the current and free Network Common Data Format (NetCDF). Our post-processed data set will help to assess numerical ice models and provide easy-to-access unique historical reference material for sea ice in the Baltic Sea. In addition we provide statistics showcasing the data quality. The website baltic-ocean.org"target="_blank">www.baltic-ocean.org hosts the post-prossed data and the conversion code. The data are also archived at the Data Publisher for Earth & Environmental Science PANGEA (doi:10.1594/PANGEA.832353).

  5. Significance of archaeal nitrification in hypoxic waters of the Baltic Sea

    PubMed Central

    Berg, Carlo; Vandieken, Verona; Thamdrup, Bo; Jürgens, Klaus

    2015-01-01

    Ammonia-oxidizing archaea (AOA) of the phylum Thaumarchaeota are widespread, and their abundance in many terrestrial and aquatic ecosystems suggests a prominent role in nitrification. AOA also occur in high numbers in oxygen-deficient marine environments, such as the pelagic redox gradients of the central Baltic Sea; however, data on archaeal nitrification rates are scarce and little is known about the factors, for example sulfide, that regulate nitrification in this system. In the present work, we assessed the contribution of AOA to ammonia oxidation rates in Baltic deep basins and elucidated the impact of sulfide on this process. Rate measurements with 15N-labeled ammonium, CO2 dark fixation measurements and quantification of AOA by catalyzed reporter deposition–fluorescence in situ hybridization revealed that among the three investigated sites the highest potential nitrification rates (122–884 nmol l−1per day) were measured within gradients of decreasing oxygen, where thaumarchaeotal abundance was maximal (2.5–6.9 × 105 cells per ml) and CO2 fixation elevated. In the presence of the archaeal-specific inhibitor GC7, nitrification was reduced by 86–100%, confirming the assumed dominance of AOA in this process. In samples spiked with sulfide at concentrations similar to those of in situ conditions, nitrification activity was inhibited but persisted at reduced rates. This result together with the substantial nitrification potential detected in sulfidic waters suggests the tolerance of AOA to periodic mixing of anoxic and sulfidic waters. It begs the question of whether the globally distributed Thaumarchaeota respond similarly in other stratified water columns or whether the observed robustness against sulfide is a specific feature of the thaumarchaeotal subcluster present in the Baltic Deeps. PMID:25423026

  6. Significance of archaeal nitrification in hypoxic waters of the Baltic Sea.

    PubMed

    Berg, Carlo; Vandieken, Verona; Thamdrup, Bo; Jürgens, Klaus

    2015-06-01

    Ammonia-oxidizing archaea (AOA) of the phylum Thaumarchaeota are widespread, and their abundance in many terrestrial and aquatic ecosystems suggests a prominent role in nitrification. AOA also occur in high numbers in oxygen-deficient marine environments, such as the pelagic redox gradients of the central Baltic Sea; however, data on archaeal nitrification rates are scarce and little is known about the factors, for example sulfide, that regulate nitrification in this system. In the present work, we assessed the contribution of AOA to ammonia oxidation rates in Baltic deep basins and elucidated the impact of sulfide on this process. Rate measurements with (15)N-labeled ammonium, CO(2) dark fixation measurements and quantification of AOA by catalyzed reporter deposition-fluorescence in situ hybridization revealed that among the three investigated sites the highest potential nitrification rates (122-884 nmol l(-1)per day) were measured within gradients of decreasing oxygen, where thaumarchaeotal abundance was maximal (2.5-6.9 × 10(5) cells per ml) and CO(2) fixation elevated. In the presence of the archaeal-specific inhibitor GC(7), nitrification was reduced by 86-100%, confirming the assumed dominance of AOA in this process. In samples spiked with sulfide at concentrations similar to those of in situ conditions, nitrification activity was inhibited but persisted at reduced rates. This result together with the substantial nitrification potential detected in sulfidic waters suggests the tolerance of AOA to periodic mixing of anoxic and sulfidic waters. It begs the question of whether the globally distributed Thaumarchaeota respond similarly in other stratified water columns or whether the observed robustness against sulfide is a specific feature of the thaumarchaeotal subcluster present in the Baltic Deeps. PMID:25423026

  7. Modelling the contributions to marine acidification from deposited SOx, NOx, and NHx in the Baltic Sea: Past and present situations

    NASA Astrophysics Data System (ADS)

    Omstedt, Anders; Edman, Moa; Claremar, Björn; Rutgersson, Anna

    2015-12-01

    We have examined the effects of historical atmospheric depositions of sulphate, nitrate, and ammonium from land and shipping on the acid-base balance in the Baltic Sea. The modelling considers the 1750-2014 period, when land and ship emissions changed greatly, with increasing carbon dioxide concentrations, SOx, NOx, and NHx emissions, and nutrient loads. The present results indicate that Baltic Sea acidification due to the atmospheric deposition of acids peaked around 1980, with a pH cumulative decrease of approximately 10-2 in surface waters. This is one order of magnitude less than the cumulative acidification due to increased atmospheric CO2. The acidification contribution of shipping is one order of magnitude less than that of land emissions. However, the pH trend due to atmospheric acids has started to reverse due to reduced land emissions, though the effect of shipping is ongoing. The effect of strong atmospheric acids on Baltic Sea water depends on the region and period studied. The largest total alkalinity sink per surface area is in the south-western Baltic Sea where shipping is intense. Considering the entire Baltic Sea over the 2001-2010 period, the pH changes are approximately -3×10-3 to -11×10-3 and -4×10-4 to -16×10-4 pH units attributable to all emissions and ship emissions only, respectively. The corresponding changes in total alkalinity are approximately -10 to -30 μmol kg-1 and -1 to -4 μmol kg-1 attributable to all emissions and ship emissions only, respectively.

  8. Transformation of the Lake Ladoga-Baltic Sea water connection during the Holocene

    NASA Astrophysics Data System (ADS)

    Subetto, D.; Kuznetsov, D.; Ludikova, A.; Sapelko, T.; Averichkin, O.

    2009-04-01

    1. In this presentation we will present results of complex paleolimnological and archeological studies several lakes in the Karelian Isthmus, NW Russia, located along the former Ladoga-Baltic water-system connection. Complementary field expeditions were organized in 2007 and 2008 in order to core lakes Volojarvi, Makarovskoye, Lamskoye, Uzlovoye and a lake on the Isl.Puutsaari, Northern Ladoga. 2. The ancient water connection between Lake Ladoga and the Baltic in the northern lowland of the Karelian Isthmus has been originated after the ice retreating ca 14,000-12,000 cal BP. At that time, until the catastrophic dropping of the Baltic Ice Lake (BIL) water-level happened ca 11,500 cal BP, Lake Ladoga was a deep easternmost bay of the BIL. During the BIL stage the highest shoreline reached c. 50-60 m a.s.l. in the northern part of the Karelian Isthmus. All studied lakes were flooded the BIL waters. Varved-type clay sediments were formed at that time 3. Arctic climatic and environmental conditions with stagnant ice/permafrost and sparse shrub, herb and grass vegetation on barren soils characterized the central highland of the Karelian Isthmus prior to 12,650 cal yrs BP. Steppe-tundra and cold, dry conditions are inferred between 12,650-11,200/11,000 cal yrs BP. 4. After 11,500 cal BP a straight/river existed in the northern part of the Karelian Isthmus during ca 7000 years. 5. During the Yoldia Sea regression of the Baltic (11500-11 000 cal. BP) Lake Ladoga was re-connected with the Baltic. Water level of Lake Ladoga and lakes in its basin was dropped. The vegetation was arctic tundra with sparse vegetation, which made the soils susceptible to erosion as reflected by the silty clayey sediments in Lake Ladoga. Most of the studied lakes were isolated. 6. The earliest evidence of human settlement in north-eastern Baltic Area is attested at Antrea-Korpilahti (11,200-10,250 cal BP) where artifacts were found in the deposits of a channel between the Baltic and the Ladoga

  9. Quantifying the heterogeneity of hypoxic and anoxic areas in the Baltic Sea by a simplified coupled hydrodynamic-oxygen consumption model approach

    NASA Astrophysics Data System (ADS)

    Lehmann, Andreas; Hinrichsen, Hans-Harald; Getzlaff, Klaus; Myrberg, Kai

    2014-06-01

    The Baltic Sea deep waters suffer from extended areas of hypoxia and anoxia. Their intra- and inter-annual variability is mainly determined by saline inflows which transport oxygenated water to deeper layers. During the last decades, oxygen conditions in the Baltic Sea have generally worsened and thus, the extent of hypoxic as well as anoxic bottom water has increased considerably. Climate change may further increase hypoxia due to changes in the atmospheric forcing conditions resulting in less deep water renewal Baltic inflows, decreased oxygen solubility and increased respiration rates. Feedback from climate change can amplify effects from eutrophication. A decline in oxygen conditions has generally a negative impact on marine life in the Baltic Sea. Thus, a detailed description of the evolution of oxygenated, hypoxic and anoxic areas is particularly required when studying oxygen-related processes such as habitat utilization of spawning fish, survival rates of their eggs as well as settlement probability of juveniles. One of today's major challenges is still the modeling of deep water dissolved oxygen, especially for the Baltic Sea with its seasonal and quasi-permanent extended areas of oxygen deficiency. The detailed spatial and temporal evolution of the oxygen concentrations in the entire Baltic Sea have been simulated for the period 1970-2010 by utilizing a hydrodynamic Baltic Sea model coupled to a simple pelagic and benthic oxygen consumption model. Model results are in very good agreement with CTD/O2-profiles taken in different areas of the Baltic Sea. The model proved to be a useful tool to describe the detailed evolution of oxygenated, hypoxic and anoxic areas in the entire Baltic Sea. Model results are further applied to determine frequencies of the occurrence of areas of oxygen deficiency and cod reproduction volumes.

  10. Mercury in precipitation over the coastal zone of the southern Baltic Sea, Poland.

    PubMed

    Siudek, Patrycja; Falkowska, Lucyna; Brodecka, Aleksandra; Kowalski, Artur; Frankowski, Marcin; Siepak, Jerzy

    2015-02-01

    An investigation of atmospheric mercury was conducted in the urban coastal zone of the Gulf of Gdansk (Baltic Sea, Poland) in 2008. Rainwater samples were collected in bulk samplers and Hg concentration was determined using AAS method. Total mercury concentration ranged from 1.9 to 14.8 ng l(-1) (the mean was 8.3 ng l(-1) with standard deviation ±3.7), out of which about 34 % were water-soluble Hg(II) forms. Distribution of Hg species in rainwater was related to both the emission source and the atmospheric processes. During the sampling period, two maxima of Hg concentration in precipitation were observed: the first in the cold season and the second one in the warm season. Elevated concentrations of Hg in wintertime precipitation were generally the result of local urban atmospheric emission connected with the following anthropogenic sources: intensive combustion of fossil fuels in domestic furnaces, individual power/heat generating plants, and motor vehicles. During summertime, Hg° re-emitted from contaminated land and sea surfaces was photochemically oxidized by active atmospheric substances (e.g., hydroxyl radicals, hydrogen peroxide, halogens) and could be an additional source of atmospherically deposited Hg. The results presented in this work indicate that rainwater Hg concentration and deposition values are not much higher in comparison with other urban locations along the Baltic Sea basin and other coastal cities. However, the elevated mercury concentration in rainwater and, consequently, higher deposition ratio could appear occasionally as an effect of intensive anthropogenic emissions (domestic heating) and/or photochemical reactions. PMID:25189806