Life History of 186 Atlantic Salmons

The origin and life history of 186 Atlantic salmon caught at sea within Icelandic waters were investigated using microsatellites to assess the origin and scales and otoliths to assess freshwater and sea age. The investigation was performed by Matís in collaboration with the Institute of Freshwater Fisheries, the Marine Research Institute, and the Directorate of Fisheries.

Most of the samples were from individuals in their first year at sea (72.8%). The freshwater age varied from 1 to 5 years with an average of 2.6 years. The most common freshwater age was 2 years (42%), with a further substantial proportion of 3-year-old fish (28%).

The origin of individual salmon was identified using a database of genetic information from 284 salmon rivers across Europe. A total of 68% were from the Southern Group, i.e. from mainland Europe, the UK, and Ireland, 30% were from the Northern Group, i.e. Scandinavia and Northern Russia, and 4 individuals were from Iceland 2%.

These results indicate that the seas south and east of Iceland are important as feeding areas for migrating Atlantic salmon, particularly for salmon originating in the UK, Ireland, and southern Europe. Furthermore, the lack of adult Icelandic fish so close to Iceland is remarkable and suggests that Atlantic salmon from Icelandic stocks are using different feeding grounds.

For more information please visit the ICES Journal of Marine Science.