Spatial Variation in Mercury Concentrations in Wild Mink and River Otter Carcasses from the James Bay Territory, Québec, Canada

Abstract

Mercury concentrations were analyzed in different organs/tissues of wild minks (Mustela vison) and river otters (Lutra canadensis) trapped during two seasons in the James Bay territory (49 degrees N to 55 degrees N, Québec, Canada). In 1993-94, mean total Hg concentration (microg/g, wet weight) in 39 wild mink and 12 river otter carcasses was greatest in fur/hair samples (30.1 and 20.7 microg/g, respectively) and least in brain samples (0.96 and 0.8 microg/g, respectively) with liver, kidney, and muscle samples showing intermediate values. Pooling data from the 1993-94 and 1994-95 trapping seasons revealed mean (SD) liver total Hg concentrations of 3.71 microg/g (3.91) in 316 wild mink carcasses and 4.05 microg/g (3.41) in 153 river otter carcasses. Log liver 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 areas with moraine deposits and least in areas with rich clay deposits, but the effect of soil deposits could be confounded by uneven deposition of anthropogenic Hg. Controlling for type of soil deposits, log liver total Hg concentration decreased with increasing distance from local industrial centers in each species but varied little with changes in distance from hydroelectric reservoirs. In a subsample of carcasses from the moraine sector, log liver total Hg concentration was higher in wild mink than in river otter. Spatial variation in log liver total Hg concentration in relation to soil deposit type and proximity to industrial centers suggests that the two wild furbearer species could be useful indicators of environmental contamination.

Global DNA methylation loss associated with mercury contamination and aging in the American alligator (Alligator mississippiensis)

“…Pilsner et al (2010) examined global DNA methylation and THg in the brains of polar bears ( Ursus maritimus ), and found no correlation between the two. In addition, mean THg concentrations in bear brains were lower those observed in the studies of other wildlife (Bastos et al, 2015; Fortin et al, 2001; Heaton-Jones et al, 1997). However, the size class of bears sampled was heavily skewed toward sub-adults.…”

Mercury Levels in Raccoons (Procyon Lotor) from the Warta Mouth National Park, Northwestern Poland

“…High inorganic Hg in the liver and kidney relative to other tissues has also been reported for the river otter and the wild mink [33, 34]. Based on publications, kidney Hg concentrations in the North American raccoons range from 1.2 to 6.8 mg/kg dw.…”

Trapped river otters (Lontra canadensis) from central Saskatchewan differ in total and organic mercury concentrations by sex and geographic location

“…Due to biomagnification, otters may be exposed to greater concentrations of Hg than species feeding at lower trophic levels or those foraging on terrestrial prey. This, along with their wide distribution, makes otters ideal for studying Hg variation and impacts, both individually and at the landscape level (Kucera 1983;Mierle et al 2000;Fortin et al 2001;Yates et al 2005;Strom 2008;Stansley et al 2010;Spencer et al 2011). Moreover, there are studies showing adverse biochemical and organismal effects, and potentially population-level impacts on otters related to MeHg exposure (Wren 1991;Basu et al 2005;Sleeman et al 2010).…”