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Abstract: 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 10,200calyr 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 12m at a base level of 40m b.s.l. (below sea level). Near Mecklenburg Bay, the buried channel is incised down to 60m b.s.l. and widens rapidly from several hundred meters to more than 1km, fading towards east. It was mainly shaped as part of a glacial meltwater system at a maximum water level of 30m 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. [Copyright &y& Elsevier]

Intersex in snails (Littorina littorea) and DNA damage in blue mussels (Mytilus edulis) were analysed to assess how these bio-indicators reflected the level of chemical contamination at two sites in a highly contaminated harbour in Denmark. The comet assay using mussel gill cells was an indicator of exposure to genotoxic chemicals, and the intersex index (ISI) observed in snails was an indicator of exposure to butyltin (BT) compounds. Biota and sediments were analysed for heavy metals (Cd, Cu, Pb and Zn), butyltin compounds (TBT, DBT and MBT), nine PCB congeners and 19 PAH compounds. The biological effects were found to reflect the levels of the chemicals, and it was concluded that intersex in L. littorea and DNA damage in M. edulis can be used as bio-indicators of harbour pollution. [Copyright &y& Elsevier]

Recent geomorphological and sedimentological investigation of the raised beach ridge plain on Anholt in the Kattegat Sea, Denmark, has demonstrated how these deposits, when combined with Optically Stimulated Luminescence (OSL) dating, can provide information about past changes in relative sea level. The southwest–northeast trending plain is divided into three topographic levels, one of which has been surveyed using Ground-Penetrating Radar (GPR). Samples retrieved from the survey line indicate that the initial part of the beach ridge plain formed about 7700 years ago in response to a mid-Holocene Littorina transgression. The raised marine deposits document a subsequent rise in relative sea level of about 9 m, and OSL dates indicate that this transgression took place about 6650 years ago. The flooding of the Kattegat Sea 7700 years ago might possibly be related to a rapid global sea-level rise peaking around 7500 years ago. [ABSTRACT FROM AUTHOR]

Shells of the common intertidal gastropod Littorina littorea both of recent and mid-Holocene origin were analysed along their growth spirals for seasonally induced variations in stable oxygen and carbon isotope compositions. The subfossil specimens are from the Stone Age kitchen midden in Ertebølle, northern Denmark, dated between 5970±95 and 5070±90 BP. The recent specimens were collected along a west–east salinity gradient within the Limfjord. A Limfjord mixing line of 0.25‰ change in δ18O (V-SMOW) for each salinity unit was determined. The recent Littorina periwinkles display a calcite relationship of (-0.22‰ change in shell δ18O per °C change in temperature, as derived from the Littorina equilibrium equation (versus V-PDB): δ18O(Littorina) (-δ18O(water) = 5.250 (-0.224T (°C). By using this linearity together with maximum ('winter') isotopic results, we extracted a Littorina growth stop isotherm equivalent to a temperature of 3.7±1°C. In order to constrain the climate and salinity in the Limfjord region during the mid-Holocene, we used this regression-derived growth stop isotherm as a boundary condition. The subfossil shells indicate a summer surface-water temperature close to 22±1°C together with a salinity of 31±1 PSU. These results suggest a more pronounced water exchange between the central Limfjord and the North Sea during the late Atlantic time, and in terms of temperature they indicate 2–4°C warmer conditions than today. [ABSTRACT FROM AUTHOR]

Accumulation of waterborne cadmium in Littorina littorea, Mytilus edulis and Carcinus maenas (collected in 1988 and 1989 around the island of Funen, Denmark) was investigated in a matrix of salinities (10 to 30‰) and calcium concentrations (2.9 to 8.9 m M Ca). Cadmium accumulation rates in soft parts of L. littorina, soft parts and shells of M. edulis and whole bodies and exoskeletons of C. maenas decreased with increasing salinity. Changes in the calcium concentrations accounted for 72% of the 'salinity effect' on cadmium accumulation rates in L. littorina, whereas calcium concentrations had little or no effect on cadmium accumulation in M. edulis. Cadmium accumulation in the whole body of C. maenas was affected equally by calcium concentrations and total salinity, whereas accumulation in the exoskeleton was mainly affected by changes in total salinity. Individual variability in cadmium accumulation in the organs of C. maenas was greater than the variation attributable either to changes in ambient calcium concentrations or total salinity. An appreciable amount of the inter-individual variability in the cadmium accumulation in all three species was correlated with wet:dry weight ratios of the tissues and size of the organisms. [ABSTRACT FROM AUTHOR]