Survey of metal levels in common fish species from Greek waters.

This survey provided information for the background levels of metals in two common fish species of the Hellenic Seas. The concentration of Cu, Cr, Ni, Zn, Fe and Mn was monitored during the period 1987-1997 in the gills and flesh of the demersal Mullus barbatus (striped mullet) and the pelagic Boops boops (bogue) collected from a network of six sampling sites covering the Aegean and Ionian Seas. The effectiveness of the above fish as biomonitors for temporal evolution studies is also investigated. The results of more than 3400 analyses showed that the temporal evolution of each metal presented similar patterns in all the sampling stations. Copper, Ni and Zn seemed to increase with time, while Cr and Fe seemed to decrease. However, the metals were not evenly distributed in the fish of the Greek seas. The differences between the sampling stations could not be explained by known differences in the quality of the marine environment. Our results suggest that the fish species used, as well as the fish tissues selected, were good metal pollution indicators since similar temporal evolution patterns were obtained when using mindless the gills or the flesh of demersal (M. barbatus) or pelagic (B. boops) fish. Finally the determined levels in the studied fish from the Greek seas were low and similar to those from other non-polluted Mediterranean areas.