Use of a fish transportation barge for increasing returns of steelhead imprinted for homing
transportation, steelhead, smolt, Columbia River, Bonneville Dam, adult, hatchery, releases, production, marking, dams, migration, survival, Lower Granite Dam, John Day Dam, juvenile
U.S. National Marine Fisheries Service, Northwest and Alaska Fisheries Centre
In 1982, the National Marine Fisheries Service, under contract to the Bonneville PowerAdministration, began a S-year study to determine if serially releasing steelhead, (Salmogairdneri), smolts over a 40-day period and transporting them by barge to a release site in theColumbia River below Bonneville Dam would result in increased returns of adults to DworshakNational Fish Hatchery.Over 252,000 smolts were marked for the study; about 30,000 fish for each of five test lots(transported) and three control lots (released into the Clearwater River at the hatchery). Serialreleases of test fish (barged to the Columbia River below Bonneville Dam) were made on 19April, 30 April, 19 May, and 31 May 1982. Paired control groups (fish released as normal hatcheryproduction into the Clearwater River) were released with the first three tests. In the interest ofmarking fewer fish, no control group was released with the last test.Recoveries of control releases at dams along the migration route indicated a high survival toLower Granite Dam and a low survival from there to John Day Dam. Approximately 57% of thecontrol releases were transported from collector dams (Lower Granite, Little Goose, and McNary),as part of the routine transportation program.The health and status of smoltification for the juvenile fish were monitored from mid-March to therelease date for each group. This phase of the study was conducted under subcontract to theUniversity of Idaho, Moscow, Idaho. The fish sampled were generally determined to be clinicallyhealthy.Final evaluation of the study will be based on the numbers of adults returning in ensuing years toColumbia River fisheries; adult collector points at Bonneville, McNary, and Lower Granite Dams;fisheries in Idaho; and the Dworshak National Fish Hatchery.