Spatial Patterns of Mercury Accumulation in Wolverine (Gulo gulo) Across the Western Canadian Arctic: Landscape, Climate and Dietary Factors

Abstract

Mercury contamination in Arctic aquatic biota has been monitored for decades. Little information exists on mercury concentrations and drivers in terrestrial Arctic carnivores. I assessed spatial patterns of mercury concentrations in wolverine (Gulo gulo) and the relationship with environmental and dietary factors across the western Canadian Arctic. Environmental variables were measured at two scales: collection location and around a 150 km buffer. This buffer size was selected from correlation analysis between hydrogen stable isotopes in precipitation and hair from 80 individuals. Mean mercury concentrations in wolverines varied geographically in decreasing order Northwest Territories > Nunavut > Yukon. Regression models illustrated that nitrogen stable isotope ratios (diet), soil organic carbon, % cover of wet area, % of perennial snow-ice, and distance to the Arctic coast explained best this variation. Diet was the main driver of mercury concentrations in wolverines with contributions from landscape characteristics near Arctic coastal areas.