A future for ice-associated top tropic Arctic animals in a changing climate?

This project aims to explore the effects of climate change, specifically reductions in sea ice extent, on three ice-associated arctic animals -- the ringed seal (Pusa hispida), polar bear (Ursus maritimus) and ivory gull (Pagophila eburnea). All three species are endemic to the Arctic ecosystem and are dependent on sea ice for various aspects of their life cycle. They are also connected, as ringed seals are one of the primary food sources for polar bears and ivory gulls scavenge at polar bear kill sites, where ringed seals are often the prey. This project will explore changes that have occurred across the last decade in Svalbard, Norway. In the early 2000's, the summer sea ice extent was over Svalbard's northern continental shelf, similar to the conditions that have prevailed in this region for decades. A shift in sea ice conditions began in 2006, when large declines in sea ice suddenly occurred in fjords on the western coast of Svalbard, and a marked northward retreat of the summer sea ice extent commenced, leading to the current situation in which the southern edge of the arctic ice sits over the deep waters of the Arctic Ocean in the summer.

We will explore the possible impacts of the environmental changes that have occurred using biotelemetry instruments (satellite-linked devices that record and relay information related to the animal's position, behaviour and environment) deployed on these species. Our main research questions are to 1) investigate changes in the behaviour, movement patterns and key habitats of ringed seals in relation to declining sea ice; 2) evaluate changes in habitat use by polar bears, in relation to changes in ringed seal habitat use and climate change; 3) investigate spatial-temporal trophic relationships among these three ice-associated target species and; 4) develop future risk scenarios for this species assemblage based on forward-looking sea-ice models.

From field work in Svalbard, 2014

Publications:

1.     Hamilton CD, Lydersen C, Ims RA, Kovacs KM. 2015. Predictions replaced by facts: a keystone species’ behavioural responses to declining arctic sea-ice. Biol. Lett. 11, 20150803, doi:10.1098/rsbl.2015.0803

2.     Hamilton CD, Lydersen C, Ims RA, Kovacs KM. 2016. Coastal habitat use by ringed seals Pusa hispida following a regional sea-ice collapse: importance of glacial refugia in a changing Arctic. Mar. Ecol. Prog. Ser. 545, 261-277

3.     Hamilton CD, Kovacs KM, Ims RA, Aars J, Lydersen, C. XXXX. An Arctic predator-prey system in flux: climate change impacts on coastal space use by polar bears and ringed seals. In revision – Journal of Animal Ecology.

4.     Hamilton CD, Kovacs KM, Ims RA, Aars J, Strøm H, Lydersen C. XXXX. An Arctic predator, prey and scavenger system in a changing climate. In revision – Marine Ecology Progress Series.