Stock origins of Dolly Varden collected from Beaufort Sea coastal sites of Arctic Alaska and Canada

Anadromous northern Dolly Varden Salvelinus malma support a summer subsistence fishery in Beaufort Sea coastal waters. These same waters coincide with areas of oil and gas exploration and development. The purpose of this study was to assess variation in stock origins of Dolly Varden collected from sites along 400 km of Beaufort Sea coast. Mixed-stock analyses (MSA) of allozyme data were used to compare collections from four sites (Endicolt near Prudhoe Bay, Mikkelsen Bay, and Kaktovik in Alaska and Phillips Bay in Canada) and to assess variation in stock contributions among summer months and between 1987 and 1988. The MSA estimates for individual stocks were summed into estimates for three stock groups: western stocks from the area near Sagavarnirktok River and Prudhoe Bay (SAG), Arctic National Wildlife Refuge stocks (Arctic Refuge), and Canadian stocks. The MSA of Endicott samples taken in 1987 and 1988 did not differ among months in terms of contributions from local SAG stocks (range, 71-95%). Contributions from nonlocal (>100 km distant) Canadian and Arctic Refuge stocks were not different from zero in 1987, but contributions from Canadian stocks were so in July (17%) and August (20%) but not in September of 1988. Thus, stock contributions to Endicott collections were different between 1987 and 1988. Samples from the Kaktovik area in 1988 were different between months in terms of contributions from nonlocal SAG stocks (July, 7%; August, 27%). Significant contributions to these samples were made both months by Canadian (25% and 17%) and local Arctic Refuge stocks (68% and 56%). Among the four coastal sites, local stocks typically contributed most to collections; however, every site had collections that contained significant contributions from nonlocal stocks. The MSA estimates clearly revealed the movement of Dolly Varden between U.S. and Canada coastal waters. If local stocks are affected by oil and gas development activities, distant subsistence fisheries along the coast could also be affected. ?? Copyright by the American Fisheries Society 1999.