Energetic costs of migration through the Fraser River Canyon, British Columbia, in adult pink ( Oncorhynchus gorbuscha) and sockeye ( Oncorhynchus nerka) salmon as assessed by EMG telemetry

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Authors: Standen, Emily M, Hinch, Scott G, Healey, Michael C, Farrell, Anthony P
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 2002
• Subjects: Fraser River; Pacific; Sockeye; Oncorhynchus gorbuscha; Pink salmon
• Online Access: http://dx.doi.org/10.1139/f02-151; http://www.nrcresearchpress.com/doi/pdf/10.1139/f02-151

Adult Pacific salmon (Oncorhynchus spp.) depend on energy reserves to complete their upriver spawning migration. Little is known about how flow patterns and bank characteristics affect energetics or how species differ in reach-specific energy use. In 1999, electromyogram (EMG) radiotelemetry was used to describe activity levels and estimate energy use of 12 adult pink salmon (Oncorhynchus gorbuscha) during their upstream migration in a 7-km section of the Fraser River Canyon. Data collected previously on sockeye salmon (Oncorhynchus nerka) in the same study area provided a species comparison. We could not identify any strong differences in energetics between species. Although sex had some influence, reach characteristics were the primary factors affecting migration activity and energetics. Fish increased their activity levels when they migrated through reaches constricted by islands or gravel bars compared with nonconstricted reaches. The former contained higher velocity currents and more complex hydraulic conditions than the latter. Two behavioural responses, with similar energetic consequences, occurred in constricted reaches. Either fish swam slowly and took more time, presumably searching for lower velocity areas for migration thus increasing passage time, or they swam quickly through higher velocity flow fields.