The response of a brown trout (Salmo trutta) population to reintroduced Eurasian beaver (Castor fiber) habitat modification
Robert James Needham, Martin Gaywood – NatureScot, AngusĀ Tree – NatureScot, Nick Sotherton – The Game and Wildlife Conservation Trust, DylanĀ Roberts – The Game and Wildlife Conservation Trust, ColinĀ Bean – NatureScot and Paul Kemp University of Southampton ICER
Ā Canadian Journal of Fisheries and Aquatic Sciences.Ā (In Press)
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Publication:Ā Canadian Journal of Fisheries and Aquatic SciencesĀ ā¢Ā 6 October 2021Ā ā¢Ā https://doi.org/10.1139/cjfas-2021-0023
Abstract
Globally, freshwaters are the most degraded and threatened of all ecosystems. In northern temperate regions, beaver reintroductions are increasingly used as a low-cost and self-sustaining means to restore river corridors. River modifications by beavers can increase availability of suitable habitat for fish, including salmonids. This study investigated the response of a population of brown trout to reintroduced beaver habitat modifications in northern Scotland. The field site comprised two streams entering a common loch; one modified by beavers, the other unaltered. Electrofishing and PIT telemetry surveys indicated abundance of post-young of the year (post-YOY) trout was higher in the modified stream. Considering juvenile year groups (YOY and post-YOY) combined, abundance and density varied with year and season. In the modified stream, fork length and mass were greater, there was a greater variety of age classes, and mean growth was positive during all seasons. Beavers had profound effects on the local brown trout population that promoted higher abundances of larger size classes. This study provides important insight into the possible future effect of beavers on freshwater ecosystems.
Our researchers @UoSEngineering @Paul_Kemp_Fish show beavers damming rivers in Scotland are helping fish in small upland streams. https://t.co/1nVybw7e9F Credit: R Needham pic.twitter.com/cUJdJjygdE
ā University of Southampton News (@UoSMedia) October 6, 2021