Application of Mixed-Stock Analysis for Yukon River Fall Chum Salmon, 2008. Annual Report for Study 06-205 Blair

摘要

Here we report interim results for genetic mixed-stock analysis (MSA) of Yukon River chum salmon harvested from the Pilot Station sonar and Mountain Village test fisheries in 2008; this is a continuation of previous work by Flannery et al. (2007). Fall chum salmon did not outnumber summer chum salmon until the July 28 to August 5 time period, well after the start of the fall management season. Overall, the largest contribution to the 2008 fall chum salmon return came from the U.S. border region (38.6%). Contributions of fall chum salmon from other regions were: Tanana 25.4%, Canada mainstem 14.4%, Canada Porcupine 4.4%, White 16.4%, and Teslin 0.8%. The abundance estimates derived from combining the results from genetic and sonar estimates continued to be less than those from the escapement and harvest estimates. The level of agreement between the methods appears to be related to the run timing in a given year, with better agreement when the fall run is not late. For 2008, the comparison was hampered by the discontinuation of the Tanana River mark and recapture project. Nevertheless, while the 2008 fall run was nine days late as in 2006, the disparity between genetic/sonar and escapement/harvest was slightly less.