Comparing Habitat Use and Mercury Accumulation in Arctic Grayling (Thymallus Arcticus) from Two Northern Ecosystems

Résumé du livre

An improved understanding of the distribution and habitat requirements for mountain stream populations of Arctic Grayling (Thymallus arcticus) is necessary to assess their vulnerability to environmental stressors, establish thresholds for development activities, and evaluate population distribution trends over time. Life stage-specific habitat use may be a particularly sensitive indicator of environmental change, but baseline data is lacking, especially for young-of year (YOY) Arctic Grayling. Occupancy-based survey methods were used in the Little Nahanni River watershed in 2015 to quantify Arctic Grayling occupancy across the landscape. Data on a suite of associated habitat variables were also collected to explain YOY occupancy, and to relate to detection efficiency during field surveys, as detection efficiency is an often-neglected aspect of field sampling that affects our understanding of species-habitat relationships. Occupancy modelling has revealed that stream temperature (>8ʻC) and elevation (