Divergent habitat use and the influence of sea ice concentration on the movement behaviour of ringed seals Pusa hispida in Labrador, Canada

Abstract

Climate change and industrial activities are leading to significant ecological changes in the Eastern Canadian Arctic, with consequences for top predators, including ringed seals Pusa hispida. However, there remains a limited understanding of habitat use, constraining an understanding of the impacts of change on this culturally valued pinniped. A total of 20 ringed seals from 2 areas in Labrador with different geomorphic attributes (Saglek Fjord in the North, and Lake Melville, an estuarine ‘fjard’ in the South) were equipped with satellite-linked transmitters to characterize behaviour states, home ranges, core use areas and environmental variables. Lake Melville-tagged seals had a smaller home range than Saglek Fjord seals (84968 vs. 196886 km2). There was little spatial overlap in the home ranges (10%) and core use areas (0%) between the 2 areas, which were separated by 572 km. Lake Melville seals spent more time in a transiting state during open water conditions (26%) than during ice-covered periods (9%), probably due to an influence of sea ice concentration; they also spent more time in the area in which they were tagged (72%) than did Saglek Fjord seals (36%), increasing the risk of exposure to local contaminants associated with hydroelectric developments. Our results suggest that ringed seals in Lake Melville have better feeding opportunities but may be more vulnerable to changing ice conditions and contaminants compared to seals in Saglek. These results will support the development of a planned culturally based Marine Protected Area in Nunatsiavut and can inform efforts to remediate contaminant sources in the region.