Sonar Estimation of Chinook and Fall Chum Salmon Passage in the Yukon River near Eagle, Alaska, 2010

摘要

Dual-Frequency Identification Sonar and split-beam sonar equipment were used to estimate Chinook salmon Oncorhynchus tshawytscha and fall chum salmon Oncorhynchus keta passage in the Yukon River near Eagle, Alaska from July 3 to October 6, 2010. A total of 35,074 Chinook salmon were estimated to have passed the sonar site between July 3 and August 19, and an estimated 125,547 chum salmon passed between August 20 and October 6. The sonar-estimated passage of chum salmon was subsequently expanded to a total passage estimate of 132,930 to include fish that may have passed after operations ceased. Subtracting the preliminary subsistence catch upstream of the sonar site results in an estimated border passage of 34,465 Chinook salmon, and 121,580 chum salmon. A drift gillnet sample fishery was conducted to collect age, sex, length, and genetic information. Species composition was also recorded to determine when the Chinook salmon run ended and the fall chum salmon run began. Both sonar systems functioned well with minimal interruptions to operation. Range of ensonification was considered adequate for most fish that migrated upstream. A continued long-term hydroacoustic enumeration project for Chinook and chum salmon near the United States/Canada border will help fishery managers meet conservation and management commitments made by both countries under the Yukon River Salmon Agreement.