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

Authored by Richard D Hedger, Line E Sundt-Hansen, Torbjorn Forseth, Ola Ugedal, Ola H Diserud, Anund S Kvambekk, Anders G Finstad

Date Published: 2013

DOI: 10.1139/cjfas-2012-0205

Sponsors: Norwegian Research Council (NRF) Norwegian Institute for Nature Research Directorate for Nature Management

Platforms: No platforms listed

Model Documentation: Other Narrative Mathematical description

Model Code URLs: Model code not found

Abstract

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 (similar to 59 degrees N), western Norway (similar to 62 degrees N), and northern Norway (similar to 70 degrees 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.

Tags

Individual-based model growth Impacts Temperature River Life Flow Trout Fishes Winter