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Heavy metal Concentrations in the Baltic Sea in 2005 (Summary)

  Leibniz-Institut für Ostseeforschung, Warnemünde
(IOW) (Baltic Sea Research Institute, Warnemünde)
commissioned by
Bundesamtes für Seeschifffahrt und Hydrographie, Hamburg, Rostock
(Federal Maritime and Hydrographic Agency of Germany, Hamburg, Rostock)

In general the 2005 results of heavy metal concentrations in the Baltic Sea revealed no pronounced changes compared to previous years. Regional and temporal limited variations of trace metal concentrations, which have been observed periodically in the western Baltic, have been attributed to the changing enrichment of suspended matter in the water column, released by wind induced mixing up to the ground level. During sample filtration only particles <0.4 µm were restrained, while particles >0.4 µm passed the filter.

Changes induced during the main saltwater inflow event in February 2003 were observed in the vertical trace metal distribution in the Bornholm- and Gotland Basin with nearly homogeneous concentrations for Cddiss, Cudiss and Zndiss in surface waters. Stagnant conditions with anoxia and decreasing dissolved trace metal conditions below the oxic-anoxic interface were noticed in the near bottom layer of the Bornholm Basin at 80 m depth, below 200 m in the Gotland Deep and below 100 m in the Landsort Deep.
For the contents of CdSPM, CuSPM and ZnSPM a slight increase was observed with depth in the central Baltic, a possible hint for the beginning of a new stagnation period. Altogether the saltwater inflow event in 2003 had influenced the trace metal long term trends in the deepwater of the central Baltic Sea. Now there is another chance to study changes in trace metal concentrations during the stabilisation of an anoxic deep water body as well as the "feedback mechanism” on the trace metal concentrations in the surface water body.

Heavy metal concentrations in surface sediments of the western Baltic Sea (BLMP-stations) still not show a significant temporal trend (1998 to 2005). In the western Arkona-Basin (Station K7), a sediment core was taken, dated, and analyzed for temporal reconstruction of heavy metal pollution history. The results show that especially for Hg, at the end of the 50th of the past century, an exceptional contamination was found which causes still remain unknown.

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 © 2016 Bundesamt für Seeschifffahrt und Hydrographie Last Update: 19.04.2013 18:00:22  
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