Divergent trends in anadromous salmonid populations in Norwegian and Scottish rivers

The Atlantic salmon (Salmo salar) is a charismatic anadromous fish of high conservation and economic value. Concerns have been expressed regarding the long-term viability of fisheries throughout the species's distributional range because of abundance variations that cannot currently be explaine...

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Bibliographic Details
Published in:Proceedings of the Royal Society B: Biological Sciences
Main Authors: Vøllestad, Leif Asbjørn, Hirst, David, L'Abée-Lund, Jan Henning, Armstrong, John D., MacLean, Julian C., Youngson, Alan F., Stenseth, Nils Chr.
Format: Text
Language:English
Published: The Royal Society 2008
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Online Access:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2679082
http://www.ncbi.nlm.nih.gov/pubmed/19129101
https://doi.org/10.1098/rspb.2008.1600
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Summary:The Atlantic salmon (Salmo salar) is a charismatic anadromous fish of high conservation and economic value. Concerns have been expressed regarding the long-term viability of fisheries throughout the species's distributional range because of abundance variations that cannot currently be explained or predicted. Here, we analyse long-term catch data obtained over a wide geographical range and across a range of spatial subscales to understand more fully the factors that drive population abundance. We use rod catch data from 84 Norwegian rivers over 125 years (1876–2000) and 48 Scottish rivers over 51 years (1952–2002). The temporal correlation in catches is very long-term, with trends persisting over several decades. The spatial correlation is relatively short-range, indicating strong local-scale effects on catch. Furthermore, Scottish salmon populations exhibit recent negative trends in contrast to some more positive trends in Norway—especially in the north.