Bioaccumulation and temporal trends of trace elements in flounder from the southern Baltic Sea for the 1996-2003 period.

This study determined the concentrations of copper (Cu), zinc (Zn), cadmium (Cd), lead (Pb), mercury (Hg), and arsenic (As) in flounder from the southern Baltic for the 1996-2003 period. Analysis of more than 200 samples was used to determine the following: (1) concentrations of Hg and As in muscle tissue of flounder from different regions of the southern Baltic; (2) concentrations of Hg in the muscle tissue of flounder of different sizes; and (3) temporal trends in the concentrations of trace metals during the 1996-2003 period. A positive correlation between fish length and Hg concentration was noted. Further, the concentrations of Hg and As in flounder were correlated with sampling site. The most heavily polluted region of the Polish Baltic zone was the eastern region of the Baltic Sea. The temporal trend analyses showed significant downward trends in concentrations of Cd, Hg, and Pb in the flounder from the 1996-2003 period. Data suggest a decrease in the concentration of these elements in the environment of the Polish zone of the Baltic. It is noteworthy that no upward trends were noted in the concentrations of trace metals in the fish studied. If the flounder selected for the study are recognized as bioindicators of environmental pollution, then it is possible to conclude that the changes in trace metals concentrations in the Polish zone of the Baltic Sea are being reduced.