Under-ice distribution of polar cod Boreogadus saida in the Central Arctic Ocean and its association with sea ice habitats properties

In the Arctic Ocean, sea ice habitats are undergoing rapid environmental change. Because sea ice constitutes an important habitat for numerous species, these changes have a significant impact on ecosystem functioning, species distribution, and population sizes. In the Arctic Ocean, polar cod is an ecological key species known to be associated with the underside of pack-ice. In spite of numerous studies in coastal shelf habitats, the under-ice distribution of polar cod in the Central Arctic Ocean has received little attention in the past. During 2012, we sampled polar cod and other under-ice fauna with a novel under-ice trawl for the first time, covering large parts of the Eurasian deep-sea basins of the Arctic Ocean. To model the relationship of polar cod with sea ice habitat properties, we used a bio-environmental sensor array during under-ice fishing. The parameters measured included sea ice thickness, roughness and spectral light transmission of sea ice. The sensors enabled a real-time characterization of sea ice habitat properties over large (1-5km) distances. Statistical modeling techniques (GLMs, GAMs) were used to model the association of polar cod with these habitat properties. We will present the progress of our group in linking biological and physical sea ice data as a tool to understand, and ultimately predict, ecological responses to a rapidly changing Arctic Ocean