Distribution and diet of the bottom dwelling Arctic cod in the Canadian Beaufort Sea

Abstract

Distribution and diet of bottom-dwelling Arctic cod were studied in the nearshore Canadian Beaufort Sea in summer of 2006–2009 using a 3m benthic beam trawl. In total, 82 stations were visited ranging in depth from 8 to 128m. Fish densities were generally low for benthic habitats; pelagic fish occurrence was not assessed. We observed a gradual increase in both the biomass of daily food rations and their energetic content over fish age. Overall, fish were able to obtain high food rations indicating that the Beaufort Sea Shelf has sufficient food resources for them. Demersal Arctic cod fed mainly on copepods (Pseudocalanus spp., Calanus glacialis, Calanus hyperboreus, Limnocalanus macrurus and Jaschnovia tolli), amphipods (Apherusa glacialis and Themisto libellula) and mysids (Mysis oculata). Further studies, particularly focused on combined pelagic/benthic sampling, are needed to fully assess ecology of the Arctic cod population in the Canadian Beaufort Sea.