Organochlorine and mercury residues in wild mink and otter: Comparison with fish

Organochlorine and mercury levels in wild mink (Mustela vison) and otter (Lutra canadensis) from eight areas of New York State were measured in adipose and liver tissues. Polychlorinated biphenyl (PCB) compounds, quantified as Aroclor 1254/1260 and p,p'-DDE, were detected in all animals. Significantly greater concentrations of organochlorines in both species were associated with habitat known to be contaminated with PCB (Hudson Valley and within 5 mi of Lake Ontario). Wet-weight PCB concentrations in adipose tissue of mink and otter from the more contaminated areas ranged as high as 67 and 114 μg/g, respectively. PCB levels in wild mink are similar to those that caused reproductive problems in other controlled feeding studies. Mercury concentrations in liver tissue were similar in both species (mean, 2.2 and 1.8 μg/g wet weight in mink and otter, respectively). Comparisons of the mink and otter body burdens with data for fish from New York's statewide Toxic Substance Monitoring Program were made. To test the hypothesis that organochlorine contaminant concentrations in mink and otter are related to environmental levels, collection locations of fish were paired with those of mink or otter on the basis of the size of the home range of the respective mammal. Correlations between fish and both mammalian species were significant for PCB and p,p'-DDE when fish and mustelid collection stations were between 10 and 20 km apart. Correlations for mercury in fish and mustelids were significant only on the basis of major watershed.