Stable isotope analysis of marine feeding signatures of Atlantic salmon in the North Atlantic

• Published in: ICES journal of marine science Vol. 67; no. 1; pp. 52 - 61
• Main Authors: Dempson, J. Brian, Braithwaite, Victoria A., Doherty, Denis, Power, Michael
• Format: Journal Article
• Language: English
• Published: Oxford University Press 01-01-2010
• Subjects: Atlantic salmon; Brackish; C:N ratio; Feeding; Ireland; Isotopes; lipid reserves; Marine; marine feeding; Newfoundland; Northwest; Populations; Rivers; Salmon; Signatures; stable isotopes; Ungava Bay; C:N ratio; stable isotopes; marine feeding; Ireland; lipid reserves; Atlantic salmon; Newfoundland; Ungava Bay
• ISSN: 1054-3139; 1095-9289
• DOI: 10.1093/icesjms/fsp227

Dempson, J. B., Braithwaite, V. A., Doherty, D., and Power, M. 2010. Stable isotope analysis of marine feeding signatures of Atlantic salmon in the North Atlantic. – ICES Journal of Marine Science, 67: 52–61.Differences in the marine feeding of three geographically distinct populations of Atlantic salmon (Salmo salar) in the North Atlantic (Conne River, Newfoundland; Koksoak River, Ungava Bay, Québec; River Erne, northwest Ireland) were examined using analyses of stable isotopes of carbon and nitrogen (δ13C and δ15N) and contrasted with isotope signatures obtained from a sample of salmon of unknown origin captured in the Labrador Sea. Although the overall range of δ13C and δ15N values (δ13C: from −22.42 to −19.37; δ15N: from 10.70 to 13.38) was similar to that reported by others, significant differences were found among populations and between different sea-age life-history groups. Reported differences in marine feeding between populations from the Northeast and Northwest Atlantic corroborated the stable isotope results. A surrogate measure of lipid content, the C:N ratio, was also compared among 1-sea-winter salmon. The highest levels were associated with the Koksoak River, suggesting that Subarctic populations may require higher energy reserves to contend with their longer migrations and more-severe environmental conditions.