Beaufort Sea Survey: Geographic and Historical Comparisons

During August 2008 the first survey of marine fishes in offshore waters of the Beaufort Sea since 1977 was conducted. The primary objective was to establish a baseline against which the effects of oil and gas development and climate change could be measured. The F/V Ocean Explorer was chartered for the survey. Benthic fish and invertebrate species composition, distribution and abundance were assessed with bottom trawls. Pelagic fish were surveyed with hydroacoustics and mid-water net tows. Physical oceanographic data were collected with conductivity-temperature-depth instruments. Fish made up 6% of the bottom trawl catch, and invertebrates made up the remaining 94%. A total of 38 species of fish and 174 species of invertebrates were identified at sea. The four most abundant benthic fish species were Arctic cod, eelpouts, Bering flounder and walleye pollock. The most abundant invertebrates were brittle stars, opilio snow crab, a mollusk (Musculus niger) and a seastar (Ctenodiscus crispatus). The pelagic community was dominated by age-0 and age-1+ Arctic cod, sculpin and eelblennies; these results will be described in a companion presentation by S. Parker-Stetter. The results of this survey will be put into the context of current surveys in the Bering and Chukchi Seas and past surveys of the Beaufort Sea. The results suggest that climate change may have resulted in northward expansion of some species ranges, including commercially valuable species such as walleye pollock and Pacific cod. Our survey was also the first to document commercial-sized opilio crab (Chionoecetes opilio) in the North American Arctic.