|Document Type:||Contract Report|
|Title:||Evaluation of subyearling fall chinook salmon passage in the McNary Dam juvenile fish bypass facility, 2000|
|Author/Editor:||Gordon A. Axel, Douglas B. Dey|
|Publisher:||National Marine Fisheries Service|
|Contracting Agency:||U.S. Army Corps of Engineers. Walla Walla, Washington|
In 2000, we completed the second year of a study to estimate post-detection bypass survival of juvenile subyearling fall chinook salmon at McNary Dam. The first year of study indicated a delay associated with passage through the juvenile fish bypass system. During 2000, radiotelemetry receivers were deployed to determine areas of delay within the gatewell, collection channel, and separator.
River-run subyearling chinook salmon were collected and radio tagged at the McNary Dam juvenile fish collection facility, released into a gatewell, and monitored as they passed through the bypass system.
Of the 114 radio-tagged fish released, 113 (99.1%) exited the separator. Median residence time in the gatewell was 2.8 hours, accounting for 96% of bypass delay. Median residence times in the collection channel and separator were 3.8 and 2.2 minutes, respectively.