Variation of juvenile Atlantic salmon (Salmo salar) body composition along sedimentary links

Abstract

Abstract - The objective of this study was to determine the proximate body composition of juvenile Atlantic salmon along the sequence of aquatic habitat types created by longitudinal changes in the riverbed substrate of two rivers (i.e., sedimentary links units). Interesting trends in the body composition were observed but our initial hypothesis, that fish of the upstream sections have higher energy content, was nevertheless not verified. No common longitudinal pattern was detected in the body composition (water, lipid, energy density) along the studied rivers. Trends in the body constituents were different between age-classes and rivers, whereas they were highly variable within- and among-samples. There was however a common trend in the pattern of variations, with the coefficient of variations increasing in the downstream direction for almost all constituents, age-classes and rivers. Potential abiotic and biotic factors that might have contributed to these observations are discussed. © 2010 John Wiley & Sons A/S.