Spatial variation in mercury concentrations in wild mink and river otter carcasses from the James Bay territory, Quebec, Canada

Mercury concentrations were analyzed in different organs/tissues of wild mi nks (Mustela vison) and river otters (Lutra canadensis) trapped during two seasons in the James Bay territory (49 degreesN to 55 degreesN, Quebec, Can ada). In 1993-94, mean total Hg concentration (mug/g, wet weight) in 39 wil d mink and 12 river otter carcasses was greatest in fur/hair samples (30.1 and 20.7 mug/g, respectively) and least in brain samples (0.96 and 0.8 mug/ g, respectively) with liver, kidney, and muscle samples showing intermediat e values. Pooling data from the 1993-94 and 1994-95 trapping seasons reveal ed mean (SD) liver total Hg concentrations of 3.71 mug/g (3.91) in 316 wild mink carcasses and 4.05 mug/g (3.41) in 153 river otter carcasses. Log liv er total Hg concentration increased with age in wild mink but not in river otter. Log liver total Hg concentration in each species was greatest in are as with moraine deposits and least in areas with rich clay deposits, but th e effect of soil deposits could be confounded by uneven deposition of anthr opogenic Hg. Controlling for type of soil deposits, log liver total Hg conc entration decreased with increasing distance from local industrial centers in each species but varied little with changes in distance from hydroelectr ic reservoirs. In a subsample of carcasses from the moraine sector, log liv er total Hg concentration was higher in wild mink than in river otter. Spat ial variation in log liver total Hg concentration in relation to soil depos it type and proximity to industrial centers suggests that the two wild furb earer species could be useful indicators of environmental contamination.