title: Extensive feeding on sockeye salmon Oncorhynchus nerka smolts by bull trout Salvelinus confluentus during initial outmigration into a small, unregulated and inland British Columbia river.
abstract: Stomach contents were collected and analysed from 22 bull trout Salvelinus confluentus at the edge of the Chilko Lake and Chilko River in British Columbia, Canada, during spring outmigration of sockeye salmon Oncorhynchus nerka smolts. Twenty of the 22 (>90%) stomachs contained prey items, virtually all identifiable prey items were outmigrant O. nerka smolts and stomach contents represented a large portion (0·0-12·6%) of estimated S. confluentus mass. The results demonstrate nearly exclusive and intense feeding by S. confluentus on outmigrant smolts, and support recent telemetry observations of high disappearance rates of O. nerka smolts leaving large natural lake systems prior to entering high-order unregulated river systems.
authors.affiliation: Pacific Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, B.C, V6T 1Z4, Canada.
authors.forename: N B
authors.initials: NB
authors.lastname: Furey
authors.forename: S G
authors.initials: SG
authors.lastname: Hinch
authors.forename: A G
authors.initials: AG
authors.lastname: Lotto
authors.forename: D A
authors.initials: DA
authors.lastname: Beauchamp
mesh_terms: D025041:Animal Migration; D000818:Animals; D001955:British Columbia; D005247:Feeding Behavior; D005766:Gastrointestinal Contents; D011235:Predatory Behavior; D045483:Rivers; D012474:Salmon; D014337:Trout / Q000502:physiology*
keywords: charr; feeding ecology; migration; predation; prey pulse; stomach contents