Justyna Kopecka

Environmental Mutagenesis in different zones of the Baltic Sea

Environmental mutagenesis was assessed in fish from the selected coastal areas of the Baltic SeanKvadofjarden and the Stockholm archipelago (Sweden), the KlaipodanBstingo zone (Lithua- nia), the Gulf of Gdansk (Poland) and the Wismar Bay (Germany). The frequency of micronuclei, as markers of cytogenetic damage, was evaluated in erythrocytes of 911 flounder (Platichthys flesus), 332 perch (Perca fluviatilis) and 458 eelpout (Zoarces viviparus) specimens. Fish was collected du- ring bi-annual sampling campaigns performed in 2001 and 2002. Statistically significant differences (p < 0.0001) regarding season and sampling location were recorded. The highest values of cytogenetic damage were registered in flounder from the Lithuanian coast near Palanga (autumn 2001) and from the Wismar Bay (spring 2001), in perch from the Lithuanian coast near Nemirseta (autumn 2001) and in eelpout from the Wismar Bay (autumn 2001). These values are 5n10-fold higher than the baseline level of micronucleus incidence. In general, the decrease in environmental mutagenesis was observed in 2002. Nevertheless a significant increase in micronucleus levels was determined in fish after the oil spill in the Bstingo oil terminal.

Toxicants accumulation rates and effects in Mytilus trossulus and Nereis diversicolor exposed separately or together to cadmium and PAHs.

Two invertebrates, Mytilus trossulus and Nereis diversicolor, were exposed in aquaria to cadmium (50 μ g L− 1) and a mixture of three- to six-ring PAHs (2 μ g L− 1 each) for 2 weeks. Organisms of two species were reared in separate tanks or together in the same one. Concentrations of Cd, PAHs and activities of selected biomarkers: catalase (CAT), glutathione S-transferase (GST) and acetylcholinesterase (AChE) were measured within 2 weeks of exposure. When reared separately, higher accumulation rates for cadmium were measured in mussels (16.4 μ g day− 1 g− 1 d.w. lipid-free tissue) than in polychaeta (0.7 μ g Cd g− 1 d.w day− 1). When co-exposed, a difference in bioaccumulation was maintained but the accumulation rate in N. diversicolor increased to 1.0 μ g Cd g− 1 d.w. day− 1 and decreased to 9.6 μ g Cd g− 1 d.w. day− 1 in M. trossulus. On the contrary, faster bioaccumulation rates of PAHs were seen in polychaeta than in mussels when exposed separately (19.3 vs 4.5 μ g PAHs day− 1 g− 1 lipid weight) than together (12.0 vs 3.1 μ g PAHs g− 1 l.w. day− 1). Substantial changes in the bioaccumulation patterns of the different M. trossulus organs were observed when both species were reared together. Biochemical responses indicated no effect of the accumulated contaminants on AChE, enhancement of CAT in both species and depletion of GST in Mytilus. The observed differences are discussed in terms of different bioavailability of contaminants, route of uptake and detoxification mechanism, under the two modes of exposure.