A comparison of organochlorine and heavy metal contamination and effects in freshwater fish from the U.S. and Russian Arctic

Liver and muscle from grayling (Thymallus arcticus) and lake trout (Salvelinus namaycush) from four US Arctic lakes, and Arctic charr (Salvelinus alpinus), whitefish (Coregonus sp.) and burbot (Lola lota) from five lakes in the Taimyr Peninsula of the Russian Arctic were analyzed for heavy metal (As, Cu, Cd, Hg, Ni, Pb and Zn) and organochlorine content (DDTs, PCBs, HCHs, chlordanes). Although the Russian Arctic is home to two of the largest metal smelters in the world (Nickel and Norilsk), and is often considered a source for atmospheric pollutants to the North American Arctic, heavy metal burdens in fish collected along a transact northeast of the Norilsk smelter in Russia were not elevated relative to US Arctic fish. Sediment records from these lakes indicate that metal flux to the lakes has not increased in the post industrial era. Thus, metal concentrations in fish likely represent natural background concentrations for these areas. Likewise, levels of PCBs and DDTs were similar in US and Russian fish. Burbot collected south of the Norilsk smelter showed elevated levels of Hg, p,p{prime}-DDE, and PCBs 138 and 153 relative to other species collected in Russia and the US. The authors believe this is attributable to species differencesmore » in trophic positioning, rather than differences in total contaminant flux. There were no indications of reproductive impairment, as indicated by circulating sex steroid levels, in Russian fish. By contrast, a negative correlation was observed between both 17{beta}-estradiol and testosterone and liver Pb concentrations (R{sup 2} = 0.51--0.82) in Arctic graving from the US Arctic. These data suggest that long range atmospheric transport and deposition of anthropogenically-derived contaminants are probably not a significant stressor affecting aquatic food webs in these two Arctic regions.« less