An Evaluation of Fresh Water Recoveries of Fish Released from National Fish Hatcheries in the Columbia River Basin, and Observations of Straying
Stephen M. Pastor
Abstract.—Approximately 80 million anadromous salmonids with coded-wire tags have been released from national fish hatcheries in the Columbia River basin. The U.S. Fish and Wildlife Service operates fish hatcheries throughout the basin, many of which are located hundreds of miles from the ocean. Spring Chinook salmon Oncorhynchus tshawytscha is the most widely raised species. Coho salmon O. kisutch, steelhead O. mykiss, and both tule and upriver bright fall Chinook are raised at fewer locations, with fall Chinook being raised only in the lower basin. Releases have produced over one hundred thousand observed recoveries, seventy-five thousand of which were in the Columbia River basin. Although tagging was initially inconsistent, practically all groups of fish released since brood year 1989 have been coded-wire tagged. In spite of uncertainties in the coding of recovery locations, and inconsistencies in the sampling and reporting of returning coded-wire tagged fish, recovery patterns can be distinguished.