Kayla Trempe-Kay

Master’s Student (Université de Sherbrooke)

Project description:

Comparison of the birth phenology of harbour seals (Phoca vitulina) and grey seals (Halichoerus grypus) in response to climate change in the Estuary and Gulf of St. Lawrence.

Phenological responses to climate change vary enormously between species. It is imperative to understand these responses, as they can have major consequences for the survival of youngs. This can result in a time lag between births and the abundance of resources, leading to a lack of resources at the time when they are needed by the young.

Harbour seals (Phoca vitulina concolor) and grey seals (Halichoerus grypus) are sympatric species in the Estuary and Gulf of St. Lawrence. Both species are therefore subject to similar environmental conditions. However, they have very different life cycles. Harbour seals whelp from mid-May to the end of June, whereas grey seals whelp in December and January.

The aim of my project, which will be carried out in collaboration with Fisheries and Oceans Canada, is to characterize the distribution of births for both species over the last 20 years. This information will then enable us to observe the variance in the distribution of births, and to assess whether the average date of birth has changed over time for each species. I will then be able to verify whether the mean date of birth is associated with environmental variables such as water temperature and ice characteristics in the Estuary and Gulf of St. Lawrence, in order to understand the relative influence of these changes on phenology in grey and harbour seals. The study of these two species will enable us to better explain their phenological responses to climate change, taking into account their distinct strategies.