Use of a Fish Transportation Barge for Increasing Returns of Steelhead Imprinted for Homing

摘要

In 1982, the National Marine Fisheries Service began a 6-year study to determine if transporting steelhead, Salmo gairdneri, smolts by barge from Dworshak National Fish Hatchery (NFH) to a release site on the Columbia River below Bonneville Dam would result in increased returns of adults to the various fisheries and to the hatchery homing site. During 1982 and 1983, over 500,000 juveniles were marked and serially released as controls from the hatchery or barged as test fish to below Bonneville Dam. As of July 1986, returns of adults to various recovery sites from juveniles released in 1982 are virtually complete. Returns of one- and two-ocean fish from the 1983 release are nearly complete. The 1983 test releases showed much less homing impairment and delay in upstream migration than 1982 releases. Most adults from both control and test releases in 1983 and control releases in 1982 migrated a considerable distance upstream and overwintered in the Snake and Clearwater Rivers - behavior similar to Clearwater River fish previously transported from Lower Granite Dam. In contrast, many of the adults from test releases in 1982 failed to migrate upstream very far in the fall and overwintered in the Columbia River. (ERA citation 12:044141)