Creel And Escapement Estimates For Chinook Salmon On The Gulkana River 1996 PDF Download

Counting tower techniques were used to estimate Chinook salmon Oncorhynchus tshawytscha escapement in the Gulkana River during 2019, 2020, and 2021. The counting tower was located on the mainstem Gulkana River about 3.25 river kilometers upstream of the West Fork Gulkana River confluence. The estimated escapement of Chinook salmon was 8,400 (SE = 436; 95% CI = 7,546–9,254) in 2019, 2,504 (SE = 216; 95% CI = 2,080–2,928) in 2020, and 3,402 (SE = 273; 95% CI = 2,867–3,937) in 2021. These numbers do not represent total inriver escapement, just escapement above the counting tower site. The 2019 estimated escapement of Chinook salmon was the highest on record since the inception of the project in 2002, whereas the 2020 and 2021 estimated escapements were below the average for the years 2002–2018. The dates of the 25th, 50th, and 75th percentile of cumulative passage of Chinook salmon past the Gulkana River counting tower have been getting later since the project’s inception in 2002. The estimated escapement of sockeye salmon O. nerka during the counting tower’s operational period was 20,850 (SE = 661; 95% CI = 19,555–22,145) in 2019, 13,500 (SE = 574; 95% CI = 12,375–14,625) in 2020, and 13,924 (SE = 711; 95% CI = 12,531–15,317) in 2021. Counting tower operations were extended during 2019–2021 to enumerate more of the sockeye salmon return.