The age structure and distribution of Atlantic salmon parr, Salmo salar L., in small tributaries and main stems of the subarctic River Teno, northern Finland

• Published in: Ecology of Freshwater Fish
• Main Author: Erkinaro, J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1995
• Subjects: Ecology; Aquatic Science; Ecology, Evolution, Behavior and Systematics; Teno; Atlantic salmon; Northern Finland; Salmo salar; Subarctic
• Online Access: http://dx.doi.org/10.1111/j.1600-0633.1995.tb00117.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1600-0633.1995.tb00117.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1600-0633.1995.tb00117.x

Abstract Parr of the Atlantic salmon in subarctic River Teno, northern Finland (70°N, 28°E), are found to migrate to small tributaries that are not spawning areas for the adult salmon. The age distribution of the salmon differs significantly between these brooks and the natal rivers, the parr in the brooks being typically 2–4 years old, whereas those in the main rivers were mostly of age 0–2 years. The older fish were found in the uppermost regions of the brooks. The ratio of salmon to brown trout decreases towards the upper reaches of the brooks. At least some of the young salmon overwinter in the brooks. However, the number of fish and the area inhabited diminished towards the autumn in some occasions. It is suggested that this migratory behavior may be an adaptational phenomenon that could cause variation in survival among young salmon in the River Teno.