Physiological seawater adaptation in juvenile Atlantic salmon (Salmo salar) autumn migrants
Article first published online: 8 JAN 2008
© 2007 Crown Copyright
Volume 53, Issue 4, pages 745–755, April 2008
How to Cite
RILEY, W. D., IBBOTSON, A. T., LOWER, N., COOK, A. C., MOORE, A., MIZUNO, S., PINDER, A. C., BEAUMONT, W. R. C. and PRIVITERA, L. (2008), Physiological seawater adaptation in juvenile Atlantic salmon (Salmo salar) autumn migrants. Freshwater Biology, 53: 745–755. doi: 10.1111/j.1365-2427.2007.01933.x
- Issue published online: 18 JAN 2008
- Article first published online: 8 JAN 2008
- (Manuscript accepted 19 November 2007)
- autumn migration;
- gill Na+K+ ATPase;
- juvenile salmon;
- seawater adaptation;
- thyroid hormones
- 1About 25 % of juvenile Atlantic salmon (Salmo salar) migrating downstream in the River Frome in southern England do so in the autumn rather than in the spring. Here, we examine the physiological status of these fish with regard to those features that adapt them to sea water during the parr–smolt transformation (i.e. gill Na+K+ ATPase activity; the number, size and type of chloride cells on the gill lamellae; salinity tolerance and relative plasma thyroid levels).
- 2Autumn migrants, and those fish which subsequently reside in the tidal reaches during the winter, are not sufficiently physiologically adapted to permit permanent or early, entry into the marine environment.
- 3It is not known what proportion of autumn migrating fish survive and return to spawn as adults. If significant numbers do return, however, the production from tidal reach habitats must be taken into account in the development of salmon stock management strategies, especially monitoring and assessment programmes, and in the evaluation of factors affecting stocks.