Bonanza River Chum Salmon Escapement Assessment

The Bonanza River weir enumerated chum salmon for three seasons from 2018 to 2020. Chum salmon escapements were 7,903 in 2018; 8,824 in 2019; and 2,471 in 2020. In 2018 and 2019, high water delayed installation of the weir and therefore the beginning of the run may have been missed. Additionally, in 2019 high water forced weir operations to stop before the proposed end date, so it likely the end of the chum salmon run was missed. In 2020, the weir went in according to schedule and counted the beginning of the run, but personnel issues, exacerbated by COVID-19 protocols, resulted in early termination of the project, and likely caused missed counting at the end of the run. High water that hindered counting on Bonanza River in 2018 and 2019 also hindered counting operations on other Subdistrict 1 rivers. Age, sex, and length data were collected from chum salmon passing through the weir in all three years. Minimum sample size requirements to evaluate Objective 3 were met in 2018 and 2020, but not in 2019. In 2018, chum salmon were predominantly 4 years old and in 2020 chum salmon were predominantly 5 years old. This project indicated that using existing methods, such as weirs and aerial surveys, to estimate Bonanza River’s contribution to chum salmon abundance in Subdistrict 1 provide a reasonable approximation of chum salmon escapement in the absence of an enumeration project on Bonanza River.

Chum salmon are an important subsistence resource in the Norton Sound area. Data provided by this project will improve management precision of the Norton Sound Subdistrict 1 chum salmon, resulting in: 1) maintenance of population sustainability via achievement of escapement objectives, and 2) limiting restriction to subsistence harvest by allowing targeted harvest of the most abundant stocks.