Chum salmon escapement on Bonanza River in Norton Sound, Alaska

Bonanza River flows 40 rkm south from the Kigluaik Mountains and drains into Safety Sound approximately 39 km northeast of Nome, Alaska. Chum, pink, and coho salmon are the predominant species that return to the Bonanza River. A fixed-picket weir was installed  approximately 11 rkm above the Bonanza Bridge on the Nome-Council Highway (GPS coordinates 64°32.964ʹN, 164°35.812ʹW). 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 is 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, and as a result aspects of Objectives 1 and 2 could not be completed for all project years. 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.