- Research Article
- 10.1139/cjfas-2025-0161
High synchrony in size at maturity of Atlantic salmon over a large geographical scale
- Jan 01, 2025
- Canadian Journal of Fisheries and Aquatic Sciences
- Peder Fiske + 5 more +5
Size at maturity is an important demographic characteristic due to its effect on fecundity. Synchrony in size at maturity across populations suggests similar environmental conditions, mainly through shared feeding grounds. We study such synchrony over 30 years across 187 populations using data from about 200 000 individual Atlantic salmon belonging to four geographic regions in Norway. Synchrony was high among the three southern regions, while the northernmost region had more independent fluctuations. Synchrony among closely separated populations was high, declined with distance, but was still present more than 1000 km apart. In all regions, the general pattern was that size at age was largest in the late 1980s and around 2000 and smallest between 2005 and 2010. Fulton’s condition factor was consistently largest in the North region. Overall, our results are consistent with the known marine distribution, including that the northernmost populations have a reduced migration distance to feeding areas and forage more northeast than the southern populations. The observed synchrony in size at maturity is anticipated to have large-scale demographic consequences by generating synchrony in egg deposition.
Read more