Predicting climate change effects on subarctic–Arctic populations of Atlantic salmon ( Salmo salar )

• Published in: Canadian journal of fisheries and aquatic sciences Vol. 70; no. 2; pp. 159 - 168
• Main Authors: Hedger, Richard D., Sundt-Hansen, Line E., Forseth, Torbjørn, Ugedal, Ola, Diserud, Ola H., Kvambekk, Ånund S., Finstad, Anders G.
• Format: Journal Article
• Language: English
• Published: Ottawa, ON National Research Council of Canada 01.02.2013; NRC Research Press; Canadian Science Publishing NRC Research Press
• Subjects: anadromous fish; Animal populations; Animal, plant and microbial ecology; Applied ecology; Aquatic sciences; Arctic region; Atlantic salmon; Biological and medical sciences; climate; Climate change; Climate models; Climatic changes; Climatology. Bioclimatology. Climate change; Earth, ocean, space; eggs; Environmental aspects; Exact sciences and technology; Exploitation and management of natural biological resources (hunting, fishing and exploited populations survey, etc.); External geophysics; Freshwater; Fundamental and applied biological sciences. Psychology; Global climate; Growth; Meteorology; mortality; Norway; Ocean temperature; parr; prediction; Salmo salar; Salmon; smoltification; summer; Survival analysis; water temperature; Arctic Region; Norway; Norway, Nausta R; Arctic region; Dynamical climatology; Salmonidae; Climate change; Aquatic environment; Vertebrata; Pisces; Salmo salar; Polar region; Subpolar zone
• ISSN: 0706-652X; 1205-7533; 1205-7533
• DOI: 10.1139/cjfas-2012-0205

We predict an increase in parr recruitment and smolt production of Atlantic salmon (Salmo salar) populations along a climate gradient from the subarctic to the Arctic in western and northern Norway in response to future climate change. Firstly, we predicted local stream temperature and discharge from downscaled data obtained from Global Climate Models. Then, we developed a spatially explicit individual-based model (IBM) parameterized for the freshwater stage, with combinations of three different postsmolt survival probabilities reflecting different marine survival regimes. The IBM was run for three locations: southern Norway (∼59°N), western Norway (∼62°N), and northern Norway (∼70°N). Increased temperatures under the future climate regimes resulted in faster parr growth, earlier smolting, and elevated smolt production in the western and northern locations, in turn leading to increased egg deposition and elevated recruitment into parr. In the southern location, density-dependent mortality of parr resulting from low summer wetted-areas reduced predicted future smolt production in comparison to the other locations. It can be inferred, therefore, that climate change may have both positive and negative effects on anadromous fish abundance within the subarctic–Arctic according to geographical region.