Growth of Atlantic salmon parr in fluvial and lacustrine habitats

The growth of naturally recruited Atlantic salmon Salmo salar parr in fluvi al and lacustrine habitats was investigated in three northern Norwegian wat ercourses. Salmon parr were sampled in autumn with small mesh gillnets in l akes, and by electrofishing in streams. In three northern Norwegian waterco urses, lacustrine Atlantic salmon Salmo salar parr were larger in length an d weight at age than fluvial parr. Back-calculated lengths indicated that l acustrine salmon parr were recruited from the fastest growing part of the p opulations and they had larger growth (length) increments between age inter vals than fluvial parr. There was no consistent pattern in growth compariso ns between parr from the inlet and outlet streams. Temperature regime alone could not explain the growth difference observed between parr from the dif ferent habitats. (C) 2000 The Fisheries Society of the British Isles.