Organochlorine and Heavy Metal Residues in Standard Fillets of Coho and Chinook Salmo
By Thomas K. Rohrer, James C. Forney, John H. Hartig
Journal of Great Lakes Research, Volume 8, Issue 4, 1982, Pages 623-634, ISSN 0380-1330, DOI: 10.1016/S0380-1330(82)72002-7.
Coho (Oncorhynchus kisutch) and chinook (O. tshawytscha) salmon were collected from seven Michigan tributaries to the Great Lakes and analyzed for chlorinated hydrocarbon pesticides, polychlorinated biphenyls (PCB), and metals. Analyses of standard skin-on fillets of these salmon revealed the presence of PCBs, DDT, dieldrin, zinc (found in one chinook), and mercury, but no detectable residues of aldrin, chlordane, heptachlor, heptachlor epoxide, toxaphene, arsenic, cadmium, chromium, copper, or lead. Chlorinated hydrocarbon contaminants were present at significantly lower levels than were found in salmon samples collected in 1971. No sample of either species exceeded FDA action levels for DDT, dieldrin, or mercury; however, 6 of 63 coho and 29 of 50 chinook salmon exceeded the FDA action level for PCBs. In general, chinook salmon had higher contaminant levels than did coho salmon collected at the same time and location. Salmon collected from the southernmost Lake Michigan tributary had highest contaminant levels (especially PCBs) while salmon from the Lake Erie tributaries had lowest contaminant levels. Samples analyzed as skinless fillets showed dramatically reduced levels of PCBs and DDT analogs compared to standard, skin-fillets from the same fish. A strong linear correlation was observed between residues of DDT and PCBs in samples analyzed
Keywords: PCBs; DDT; dieldrin; mercury; heavy metals; bioconcentration