Influence of the marine feeding area on the muscle and egg fatty‐acid composition of Atlantic salmon Salmo salarspawners estimated from the scale stable isotopes

• Published in: Journal of Fish Biology
• Main Authors: Torniainen, J., Kainz, M. J., Jones, R. I., Keinänen, M., Vuorinen, P. J., Kiljunen, M.
• Other Authors: Maj ja Tor Nesslingin Säätiö, Suomen Akatemia
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2017
• Subjects: Atlantic salmon; Salmo salar
• Online Access: http://dx.doi.org/10.1111/jfb.13258; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fjfb.13258; https://onlinelibrary.wiley.com/doi/pdf/10.1111/jfb.13258

Fatty acids in muscle tissue and eggs of female Atlantic salmon Salmo salar spawners were analysed to evaluate the dietary quality of their final feeding areas in the Baltic Sea. The final likely feeding area was identified by comparing stable carbon and nitrogen isotope composition of the outermost growth region (final annulus) of scales of returned S. salar with that of reference S. salar caught from different feeding areas. Some overlap of stable‐isotope reference values among the three areas, in addition to prespawning fasting, decreased the ability of muscle tri‐acylglycerols to discriminate the final likely feeding area and the area's dietary quality. Among three long‐chained polyunsaturated fatty acids, docosahexaenoic acid ( DHA 22:6 n ‐3), eicosapentaenoic acid ( EPA 20:5 n ‐3) and arachidonic acid ( ARA 20:4 n ‐6), the proportions of ARA in total lipids of spawning S. salar muscle and eggs showed a significant negative correlation with increasing probability of S. salar having returned from the Baltic Sea main basin ( i.e. the Baltic Sea proper). The results suggest that ARA in muscle and eggs is the best dietary indicator for dietary characteristics of final marine feeding area dietary characteristics among S. salar in the Baltic Sea.