Author: Michael J. McDougallPublisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 0
Book Description
Adaptive resolution imaging sonar (ARIS) and split-beam sonar equipment were used to estimate Chinook salmon Oncorhynchus tshawytscha and fall chum salmon O. keta passage in the Yukon River near Eagle, Alaska, from July 1 through October 6, 2020. A total of 33,550 (SE 219) Chinook salmon were estimated to have passed the sonar site from July 1 through August 27. The midpoint of the Chinook salmon migration occurred on July 29, which was 5 days later than the historical mean date. A total of 20,766 (SE 177) fall chum salmon were estimated to have passed the sonar site from August 28 through October 6. The fall chum salmon passage estimate was subsequently expanded to a total of 23,512 to include fish that may have passed after operations ceased. The midpoint of the fall chum salmon migration (based on the expanded estimate) occurred on September 24, which was 1 day later than the historical mean date. Drift gillnetting was conducted to collect age, sex, and length samples and tissue samples for genetic information. Species composition was analyzed to determine when the Chinook salmon migration ended and the fall chum salmon migration began.