Research article - Peer-reviewed, 2007
Nonnative brook trout (Salvelinus fontinalis) and the demise of native brown trout (Salmo trutta) in northern boreal lakes: stealthy, long-term patterns?
Spens J, Alanara A, Eriksson LOAbstract
This study of 193 boreal lakes of northern Sweden suggests a long-term detrimental impact of introduced brook trout (Salvelinus fontinalis) on brown trout (Salmo trutta) populations. Thirteen of 65 (20%) brown trout populations in lakes exposed to brook trout went extinct, whereas the extinction rate in unexposed lakes was significantly lower (2%). We verified other studies that indicate that altitude strongly affects the distribution of the two species; brown trout populations in our higher altitude lakes were more sensitive to impact from brook trout. In 28 lakes above 285 m, 12 trout populations exposed to brook trout went extinct, while only one population became extinct in 37 lakes below 285 m. No effects of other environmental factors were detected (e.g., water chemistry, stocking of rainbow trout (Oncorhynchus mykiss), fish species community assembly, migration barriers, or lake morphometry on brown trout extinction). The time lag between the first record of brook trout introduction and subsequent extinction of brown trout was two decades on average (maximum 70 years). Even though further stocking of brook trout has been stopped, our analysis suggest that existing sympatric populations may continue to pose an extinction threat to brown troutPublished in
Canadian Journal of Fisheries and Aquatic Sciences2007, volume: 64, number: 4, pages: 654-664
Publisher: NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS
Authors' information
Spens, Johan
Swedish University of Agricultural Sciences, Department of Wildlife, Fish and Environmental Studies
Swedish University of Agricultural Sciences, Department of Wildlife, Fish and Environmental Studies
Eriksson, Lars-Ove
Swedish University of Agricultural Sciences, Department of Wildlife, Fish and Environmental Studies
UKÄ Subject classification
Environmental Sciences related to Agriculture and Land-use
Publication Identifiers
DOI: https://doi.org/10.1139/F07-040
URI (permanent link to this page)
https://res.slu.se/id/publ/16422