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  • Studies of the spatial and temporal variations of hydrographic, hydrochemical and hydrobiological parameters in the frame of the COMBINE Programme of HELCOM as well as measurements for the IOW's long term data set

  • The cruise served the education of students in a combined Swedish/German course with the Institute of Environmental studies of Stockholm University. Whereas one part of the cruise was devoted to the study of the biogeochemistry in the different basin systems of the southern and central Baltic, the second part studied the anthropogenic effects on biology and chemistry in coastal Baltic fjord system of eastern Sweden. Base for shorter cruises of mixed Swedish/German student groups either to the deepest point of the Baltic, the Landsort Basin, or to the coastal fjords was the research station on the island of Askö. With a variety of instruments data on water column and sediment biology, chemistry and geochmistry were recorded and samples were taken, which were analyzed by the students on board or at the laboratory on Askö. The cruise lasted for 12 days and resulted in an extensive report assembled by the students. Both students and instructors consider the course and the cruise as a successful event.

  • Baltic Sea monitoring programme of IOW/BSH for the routinely assessment of the Baltic Sea with physical, chemical biological methods at standard positions. Mooring maintenance in the Gotland Basin. Hydrographic and biological and microbiological measurements in the course of the long term data acquisition programme of the IOW. Investigation of the redoxcline dynamics in the Gotland Basin.

  • The objectives of the cruise were 1) to test a profiling mooring in the Gotland Basin, 2) to measure elemental mercury and CO2 in surface waters along track, 3) to obtain samples for a method comparison for pH measurements, 4) to measure denitrification rates in anoxic waters, 5) to recover a sediment trap mooring from the Angermanälven (Sweden), 6) to isolate microorganisms from the Baltic Sea with the ability to degrade oil an pharmaceuticals. We left Rostock on the 18. July heading for the Gotland Basin. On arrival the winds and waves were too high for any station work so we continued the voyage north to Angermanaelven. We arrived at the mooring site on 21. July at 13:00 UTC. After recovery of the sediment trap mooring we made our way south back to the Gotland Basin. On the way it became clear that the weather conditions wouldn't allow work in the central Gotland Basin and we anchored close to land off Gotland to wait for improving weather (22. July at 21:00 UTC). On the 23. July at 21:00 UTC we lifted anchor and progressed to the GODESS mooring position, where we arrived on the 24. July at 04:00 UTC. After two CTD profiles the profiling mooring GODESS was deployed, followed by a series of CTD casts and one pump-CTD cast to provide water samples for incubations and lab analysis. Finally the GODESS mooring was recovered and we continued to the FINO2 station where an ADCP mooring was deployed (25. July 16:30 UTC). From the FINO2 we made our way back to Rostock where the vessel was moored at 06:00 UTC on the 26. July.

  • The Baltic Sea with its natural gradients and strong reactions to climate change and anthropogenic activity can be used in an ideal way to examine basic ecological processes and their variability in marine ecosystems. The most striking characteristics of the Baltic Sea are the extended gradients in primary (topography, energy, salinity) and secondary (organisms, matter flux, oxygen, nutrients, sediments) environmental properties as a result of different dynamical processes. Whereas leg M87/3a focussed on the role of the salinity gradients on degradation of terrestrial dissolved organic matter (tDOC), microbially mediated processes, and on the structure and function of pelagic microbial communities, leg M87b investigates the impact of the vertical oxygen gradients in the central Baltic Sea basins on these processes. This comprises the following aims: (1) Assessment of the physical structure and mixing processes within the oxic-anoxic transition zones and of the resulting impact on microbial activities and biogeochemical processes; (2) Characterisation of benthic and pelagic microbial communities along the transition from oxic to anoxic and sulfidic conditions, including protists, prokaryotes and viruses; (3) Analysis of the bottom topography and biogeochemical sediment properties along the deep basins. The overall aim of these studies is to gain insights into the physical-biological coupling and its effects on biogeochemical cycles within the vertical oxygen gradients of the water column as well as a comprehensive understanding of the structure and biogeochemistry of the deep, anoxic basins of the central Baltic Sea. For this purpose, high-resolution sampling of the oxic-anoxic transition zones, assessment of the physical structure and turbulence of the water column, Parasound subbottom profiling and high resolution multi-beam echosounding, and sediment sampling were performed mainly within the Gotland and Landsort basins, along transects from the center to the edges.

  • Study of spatial and temporal variations of hydrographic, hydrochemical and biological parameters in the frame of the COMBINE Programme of HELCOM, combined with long term observations of IOW.

  • HELCOM Monitoring and IOW long-term observation of hydrophysical, marine chemical and marine biological conditions in the central and western Baltic Sea

  • Main objective of this cruise was the evaluation of recent transport processes and mixing of dissolved organic constituents between Baltic and North Sea and the reconstruction of deep water inflow events from the North into the Baltic Sea during the Holocene.\n On a transect into the Baltic Sea including Skagerrak, Kattegat , the Belt Sea and the major Baltic Basins \n( Arkona, Bornholm, Gotland, Landsort , Bothnian Sea and Bay ) CTD-Profiles were obtained and samples collected for the analyses of oxygen, plant nutrients, gases and different organic dissolved and particulate constituents.Geological samples were collected employing multicorer and gravity corer. In two areas (off Anholt and in the Hanö-bight off Bornholm) surface sediment mapping for proposed IODP-sites was performed employing multibeam and parasound echosounding devices. Two sediment trap moorings were deployed. The research vessel Maria S.Merian left Bremerhaven on the 25th of August and reached the first station off Helgoland after a few hours, where several CTD-Profiles were obtained and samples collected for the analyses of oxygen, plant nutrients and different organic dissolved and particulate constituents.Geological samples were collected employing Multicorer and gravity corer and sediment cores of 6 m length were retrieved without problems. This program was continued on a transect into the Baltic Sea sampling Skagerrak, Kattegat , the Belt Sea and the major Baltic Basins ( Arkona, Bornholm, Gotland, Landsort , Bothnian Sea,Bothnian Bay. In the Kattegat the first surface sediment mapping for one proposed IODP-site was performed off the isle of Anholt .In the Danish sector of the Hanö-bight off Bornholm a second larger area was mapped for the joint Baltic deep drilling programme employing multibeam and parasound echosounding devices. In the central Baltic intense sampling of the oxic and anoxic water masses of the Gotland- and Landsort-deep was performed including profiling measurements of CO2- und N2 concentrations. In the frame of a long-term study on vertical particle flux a sediment trap mooring was deployed in the Lithuanian sector of the central Gotland sea. The retrieval of a sediment trap in the Bothnian Sea provided time resolved samples of vertical particle flux for the period of one year. Maria S. Merian reached Stockholm harbour early in the morning on the 9th of September for the exchange of the scientists.

  • Monitoring Cruise in the frame of the Combine programme of HELCOM

  • The Baltic Sea with its still ongoing postglacial changes, its natural gradients and strong reactions to climate change and anthropogenic activity can be used in an ideal way to examine basic ecological processes and their variability in marine ecosystems. The most striking characteristics of the Baltic Sea are the extended gradients in primary (topography, energy, salinity) and secondary (organisms, matter flux, oxygen, nutrients, sediments) environmental properties as a result of different dynamical processes. This cruise investigated, besides geomarine tasks, the impacts of salinity and redox gradients on degradation of tDOC, microbially mediated processes (e.g., methane consumption, nitrification), and on the structure and function of pelagic microbial communities. We expect, that heterotrophic microorganisms adapt to this situation by changes in diversity and specific decomposition rates. \nDuring the cruise, the following aims are related to the study of microbial diversity and function in the lateral Baltic gradient between Skagerrak and Bothnian Bay: \n1. Assessment of structure and (selected) functions of pelagic prokaryotic communities (Bacteria, Archaea) along the salinity gradient. \n2. Quantification, chemical characterization and decomposition dynamics of discharged terrestrial DOC from Northern (arctic) soils in relation to microbial diversity in different Baltic Sea basins.\n3. Quantification of methane fluxes and consumption along the horizontal and vertical gradients.\n3. The identification of microbial key organisms and the relation to activities and functional characteristics (e.g., nitrification) in the vertical pelagic oxygen gradients of the central Baltic Sea.\n4. The historic, climate-driven regime shifts of e.g. decomposition dynamics in the central basins recorded in sediments, which is highly dependent e.g. on the temporal variability of bottom water inflow events.