By Darcy McNicholl – MSc. Candidate (University of Manitoba, Fisheries and Oceans Canada)
Currently there is little known about Capelin in the Canadian Arctic and their role in the Beaufort Sea ecosystem. Like Capelin, Arctic Cod are a pelagic, planktivorous forage fish species, which serve as an important prey source for piscivorous fishes, sea birds and marine mammals in circumpolar waters. Both species (Capelin and Arctic Cod) were collected in high numbers in Darnley Bay, NWT, during the 2013 survey of the Amundsen Gulf in the Western Canadian Arctic. It is unknown whether Capelin can overwinter in the Canadian Arctic or if they migrate seasonally from Hudson Bay or the Northern Pacific Ocean. My study aims to investigate the dietary overlap of Arctic Cod and Capelin and the environmental factors influencing the persistence of Capelin in the Canadian Beaufort Sea.
The objectives of my master’s thesis are to describe the life history characteristics of Beaufort Sea Capelin and how they differ from sub-Arctic populations, to determine the extent of overlap between Capelin and co-occurring Arctic cod with respect to their stomach contents and isotopic niches and to examine the implications of Capelin as a prey source for predators such as Arctic Char.
During the July and August of this summer, in collaboration with ongoing projects conducted by Fisheries and Oceans Canada, I collected Capelin at three locations on the Cape Parry peninsula. Capelin were captured using trapnets set in the nearshore habitat and frozen on site for analysis at a later date. The Capelin captured in the nearshore habitat of Darnley Bay were mature and showed evidence of spawning, unlike immature individuals collected in the centre of the bay using a benthic trawl during a summer survey in 2013. Individuals from both surveys are currently being processed for stable isotopes, stomach contents and basic life history characteristics including age. The individuals captured during this year’s field season provide further support that Capelin in the Beaufort Sea are part of a self-sustaining population and an integral component of the nearshore ecosystem in the Canadian Beaufort Sea.
Dr. James Reist (Adjunct Prof. Biological Sciences, Fisheries and Oceans Canada)
Dr. Gail Davoren (Associate Professor, Biological Sciences, University of Manitoba)