Ringed seal (Pusa hispida) population trends inferred from genetics

Abstract

Climate change is predicted to affect ringed seals negatively. The first objective of my thesis was to assess trends in abundance of ringed seals using genetics. I used genetic profiles to estimate the effective number of breeders (Nb) and assessed relationships with counts from aerial surveys (Ns). I did not detect a relationship between Nb and Ns or a temporal trend in either variable when the entire time series was assessed. However, Nb fluctuated over time, with a negative trend from 1983 to 1994 and becoming stable from 1995 to 2012. My second objective was to determine which variables predicted Nb. My analysis suggested that spring rainfall, snow depth, and the date of fall sea-ice freezeup had a greater influence on Nb than the timing of spring breakup. This research helps address the lack of long-term monitoring data for ringed seals, while improving our understanding of population dynamics.