Sonar estimation of summer chum and pink salmon in the Anvik River, Alaska, 2019

Dual-frequency identification sonar (DIDSON) was used to estimate adult summer chum salmon Oncorhynchus keta and pink salmon O. gorbuscha passage in the Anvik River from June 16 to July 26, 2019. Apportionment to species was determined from data collected from tower counts. A total of 249,014 (SE 2,034) summer chum and 241 (SE 81) pink salmon were estimated to have passed the sonar site. A beach seine sample fishery was conducted to collect age, sex, and length information. Both sonar systems functioned well with minimal interruptions to operation. Range of ensonification was considered adequate for most fish that migrated upstream.