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High summer temperatures are associated with poorer performance of underyearling Atlantic salmon (Salmo salar) in upland streams


Fionn Bernthal

Benjamin Seaman

Edward Rush

John Armstrong

Darryl McLennan

Keith Nislow

Neil Metcalfe

+2 more
Publication Type:
Journal Article
Year of Publication:
Secondary Title:
Journal of Fish Biology


Future warming scenarios are predicted to result in an increased frequency of high, and potentially stressful, temperatures in aquatic ecosystems. Here we examined whether the performance of wild underyearling Atlantic salmon (Salmo salar) in Scottish streams stocked with identical egg densities was influenced by thermal stress. Biomass and density declined with degree hours exceeding 23°C, indicating apparent mortality or emigration as a possible result of exposure to high temperatures. These results strengthen the need for further action such as riparian tree planting to reduce stream summer temperatures.