Genetic stock identification of Atlantic salmon (Salmo salar) populations in the southern part of the European range

• Published in: BMC Genetics
• Main Authors: Griffiths, Andrew M., Machado-Schiaffino, Gonzalo, Dillane, Eileen, Coughlan, Jamie P., Horreo, Jose L., Bowkett, Andrew E., Minting, Peter, Toms, Simon, Roche, Willie, Gargan, Paddy, McGinnity, Philip, Cross, Thomas F., Bright, Dylan, Garcia-Vazquez, Eva, Stevens, Jamie R.
• Format: Article in Journal/Newspaper
• Language: English
• Published: BioMed Central 2010
• Subjects: Monte Carlo Markov chain; Atlantic salmon; River catchment; Baseline sample; Reporting region; Pacific; North Atlantic; Salmo salar
• Online Access: http://hdl.handle.net/10468/5698; https://doi.org/10.1186/1471-2156-11-31

Background: Anadromous migratory fish species such as Atlantic salmon (Salmo salar) have significant economic, cultural and ecological importance, but present a complex case for management and conservation due to the range of their migration. Atlantic salmon exist in rivers across the North Atlantic, returning to their river of birth with a high degree of accuracy; however, despite continuing efforts and improvements in in-river conservation, they are in steep decline across their range. Salmon from rivers across Europe migrate along similar routes, where they have, historically, been subject to commercial netting. This mixed stock exploitation has the potential to devastate weak and declining populations where they are exploited indiscriminately. Despite various tagging and marking studies, the effect of marine exploitation and the marine element of the salmon lifecycle in general, remain the "black-box" of salmon management. In a number of Pacific salmonid species and in several regions within the range of the Atlantic salmon, genetic stock identification and mixed stock analysis have been used successfully to quantify exploitation rates and identify the natal origins of fish outside their home waters - to date this has not been attempted for Atlantic salmon in the south of their European range. Results: To facilitate mixed stock analysis (MSA) of Atlantic salmon, we have produced a baseline of genetic data for salmon populations originating from the largest rivers from Spain to northern Scotland, a region in which declines have been particularly marked. Using 12 microsatellites, 3,730 individual fish from 57 river catchments have been genotyped. Detailed patterns of population genetic diversity of Atlantic salmon at a sub-continent-wide level have been evaluated, demonstrating the existence of regional genetic signatures. Critically, these appear to be independent of more commonly recognised terrestrial biogeographical and political boundaries, allowing reporting regions to be defined. The implications of ...