Distribution and biological characteristics of Atlantic salmon (Salmo salar) at Greenland based on the analysis of historical tag recoveries

In this study, we examined 5481 records of tag recoveries at Greenland from a new tagging database held by ICES that contains information on salmon tagged in Canada, France, Faroes, Greenland, Iceland, Ireland, Norway, Spain, the UK (Northern Ireland, Scotland, England, and Wales), and the United States from the early 1960s to the present. For 4806 of the tag recoveries, latitude and longitude information were available, describing, to varying degrees of accuracy, the location of recovery of tagged fish. Release and recovery dates were variable, but no significant differences over time were noted. The information derived from tag recoveries was used to describe the distribution and growth of salmon of different origins. The proportion of recoveries from East Greenland suggested that potential multi-sea-winter salmon from northern Europe have a more easterly distribution than those from southern Europe. The location of recovery of salmon of North American origin differed from that of European salmon along the west coast of Greenland. Tag recoveries by country were not uniformly distributed across the respective NAFO Divisions. Tags from salmon originating in Canada and the United States were more commonly recovered in northern locations than tags from European-origin salmon. Analysis of rates of tag recovery suggested similar rates before and after the introduction of the NASCO Tag Return Incentive Scheme. The straight-line migration speed of both North American and European salmon changed very little over the time-series, but was ∼40% greater for North American salmon (0.43 m s−1) than for European salmon (0.29–0.32 m s−1).