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

• Published in: Journal of Fish Biology
• Main Authors: Bernthal, Fionn R., Seaman, Ben W., Rush, Edward, Armstrong, John D., McLennan, Darryl, Nislow, Keith H., Metcalfe, Neil B.
• Other Authors: H2020 European Research Council, Natural Environment Research Council
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2022
• Subjects: Aquatic Science; Ecology, Evolution, Behavior and Systematics; Atlantic salmon; Salmo salar
• Online Access: http://dx.doi.org/10.1111/jfb.15282; https://onlinelibrary.wiley.com/doi/pdf/10.1111/jfb.15282; https://onlinelibrary.wiley.com/doi/full-xml/10.1111/jfb.15282

Abstract 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.