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Upstream Movement of Residual Hatchery Steelhead into Areas Containing Bull Trout and Cutthroat Trout
Author(s) -
McMichael Geoffrey A.,
Pearsons Todd N.
Publication year - 2001
Publication title -
north american journal of fisheries management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.587
H-Index - 72
eISSN - 1548-8675
pISSN - 0275-5947
DOI - 10.1577/1548-8675(2001)021<0943:umorhs>2.0.co;2
Subject(s) - hatchery , trout , rainbow trout , fishery , oncorhynchus , catch and release , population , biology , threatened species , habitat , ecology , fish <actinopterygii> , recreational fishing , demography , sociology
Abstract Hatchery‐reared steelhead Oncorhynchus mykiss that do not emigrate as smolts shortly after release may harm wild fish communities through ecological interactions. We used systematic, stratified snorkeling surveys to document the relative abundance of wild rainbow trout (nonanadromous O. mykiss ), bull trout Salvelinus confluentus , and westslope cutthroat trout O. clarki lewisi as well as the upstream limit of residual hatchery steelhead (hatchery‐reared steelhead that had failed to emigrate by June 1). Our objective was to determine whether residual hatchery steelhead had migrated upstream from their release point into an area containing westslope cutthroat trout and a threatened population of bull trout. Hatchery steelhead made up a larger proportion of the salmonid community in the sites near their release location and constituted a lower proportion as distance upstream from the release location increased. However, residual hatchery steelhead had migrated over 12 km upstream into an area containing westslope cutthroat trout and a threatened stock of bull trout.