Comparisons and temporal trends of organochlorines and heavy metals in fish from the gulf of Bothnia

Concentrations of organochlorines and heavy metals were determined in herring (Clupea harengus), whitefish (Coregonus sp.), vendace (Coregonus albula), pike (Esox lucius), sea trout and salmon from the Bothnia gulf during 1979-1992. Concentrations of organochlorines, hexachlorobenzene (HCB), lindane, total DDT and PCB were generally higher in pike and sea trout than in herring, whitefish or vendace from the same sites. Total DDT concentrations were lowest in the northernmost sampling area. Levels of total DDT, PCB and mercury decreased with time. Zinc and copper concentrations varied with species and did not show any areal differences. Lead concentrations were low in all samples. Concentrations of all the organochlorines and heavy metals in the fish studied were much lower than maximal allowable concentrations for human consumption.