|Document Type:||Contract Report|
|Title:||Evaluation of transportation of juvenile salmonids and related research on the Columbia and Snake Rivers, 1984|
|Author/Editor:||Gene M. Matthews, Donn L. Park, T. E. Ruehle, Jerrel R. Harmon|
|Publisher:||National Marine Fisheries Service|
|Contracting Agency:||U.S. Army Corps of Engineers. Walla Walla, Washington|
In 1984, the National Marine Fisheries Service continued to evaluate the effects of collecting and transporting juvenile salmonids from upriver dams on the Columbia and Snake Rivers to a release site downstream from Bonneville Dam on the Columbia River.
Returns of jack spring/summer Chinook salmon previously transported from Lower Granite Dam by barge in 1983 indicated the best return since the 1975 juvenile migration.
Fall Chinook salmon tagged as juveniles at McNary Dam between 1980 and 1983 and transported below Bonneville Dam continue to provide significantly more returning adults than corresponding controls released below McNary Dam. Returns of jacks tagged as juveniles at McNary Dam in 1983 indicate there is no significant difference between adult returns from juveniles transported by barge or truck.
In 1984, a total of 46,173 spring Chinook salmon smolts and 33,529 steelhead smolts were marked at Lower Granite Dam to provide an index of the success of the barge transportation program.
Standard seawater challenge tests conducted on spring Chinook salmon smolts at Lower Granite Dam indicated that no increase in stress occurred between the gatewells and the end of the bypass gallery, but a significant increase occurred between the end of the bypass gallery and the separator. We speculate that the majority of this increase occurred during passage through the downwell.
The extended seawater holding study conducted at Lower Granite Dam was terminated prematurely when a water valve was inexplicably closed. Limited information from the study demonstrated that bacterial kidney disease has some delayed effect on the spring Chinook salmon population transported from the Snake River. An estimate of the magnitude of the problem awaits future study.