Field studies of eelpout (.Zoarces viviparus L.) from Polish coastal waters (southern Baltic Sea)

The aim of the presented studies was to detect the possible effects of contaminants on the physiological and biochemical parameters of eelpout females from the southern Baltic. Eeelpout was sampled in Polish coastal waters during November 2001, 2002 and 2003. The integrated studies included measurements of selected biomarkers in fish as well as the analysis of female reproductive capacity and fry malformation frequencies in relation to environmental conditions in examined areas. The mean values of relative fecundity (RF) and embryo somatic (ESI) indexes were the highest at the reference site. The frequency of females carrying dead and malformed fry was the highest at selected sites from the outer and inner part of the Gulf of Gdansk. The highest mean activity levels of muscular AChE were noted in fish sampled at the reference site and one site from the outer part of the gulf, whereas liver GST activity was the highest in samples from other site from the outer part of the gulf and the reference site. The results of trace metals analyses in fish muscle and liver did not indicate any substantial differences in the mean tissue concentrations between samples from contaminated sites and the reference site. The concentrations of PCBs, HCHs and DDTs in liver were markedly higher at three contaminated sites in comparison with the other sites. A similar pattern was observed in muscle tissue. Based on the preceding evidence, it cannot be concluded unequivocally that these studies on the physiology, biochemistry and contaminant concentrations of eelpout females provide evidence that the contaminants present in the coastal areas of the Polish part of the southern Baltic Sea have a harmful impact on this species.