Author: Shane R. RansburyPublisher:
ISBN:
Category : Escapement (Fisheries)
Languages : en
Pages : 0
Book Description
From 2016 to 2019, the Alaska Department of Fish and Game, Division of Commercial Fisheries, continued a stock assessment program that began in 1976 to estimate escapements and harvests of Chilkoot Lake sockeye salmon (Oncorhynchus nerka). Sockeye salmon were counted through a weir near the outlet of Chilkoot Lake, and age, length, and sex data were collected and analyzed each year. Sockeye salmon escapements at the weir were 86,721 fish in 2016, 43,098 fish in 2017, 85,463 fish in 2018, and 140,378 fish in 2019, all of which fell within or exceeded the sustainable escapement goal range of 38,000–86,000 fish. Ocean-age-3 sockeye salmon (ages 1.3 and 2.3 combined) of both sexes were the shortest in length since scale sampling began in 1982. The stock compositions of sockeye salmon harvested annually in the District 15 commercial drift gillnet fishery were estimated through scale pattern analysis (2016) and genetic stock identification (2017–2019). Estimated commercial harvests of Chilkoot Lake sockeye salmon were 119,843 fish in 2016, 1,933 fish in 2017, 33,969 fish in 2018, and 149,586 fish in 2019. Estimated harvest rates (including subsistence and sport harvests) were 59% in 2016, 9% in 2017, 31% in 2018, and 52% in 2019. Estimated fall sockeye salmon fry populations at Chilkoot Lake were 42% above average in 2016, 45% below average in 2017, and at or slightly below average in 2018 and 2019, respectively. Average May–September zooplankton density and biomass at Chilkoot Lake were nearly double the long-term average, and zooplankton density in 2019 and biomass in 2016 were the highest recorded since sampling began in 1987.