HABITAT UTILIZATION OF JUVENILE ATLANTIC SALMON (SALMO-SALAR L), BROWN TROUT (SALMO-TRUTTA L) AND ARCTIC CHARR (SALVELINUS-ALPINUS (L)) IN 2 LAKES IN NORTHERN NORWAY

Habitat utilization of juvenile Atlantic salmon, brown trout and Arcti c charr was investigated in two lakes in northern Norway during the ic e-free season. Both the vertical distribution and the distribution amo ng different habitat types were studied by gillnetting with small mesh sized gillnets (8-15 mm) in different habitats. Salmon and trout were predominantly caught in the littoral and sublittoral zones (0-6 m dep th). Access to shelter seemed to be the most important factor determin ing the horizontal distribution of small salmon and trout. Most of the se fish were caught in stony or vegetated habitats, while few salmon a nd trout were caught on sandy locations or in the pelagic zone. In one of the lakes, there were significantly higher catch races of salmon t han of trout in the stony littoral (0-3 m), while in the other lake th ere were no significant differences in spatial distribution between th ese two species. Charr were primarily found in the profundal, sublitto ral or pelagic zones of the lakes.