Pre-spawning habitat selection of subarctic brown trout (Salmo trutta L.) in the river Vindelälven, Sweden

摘要: Habitat selection of migratory brown trout at the upper reaches River Vindelalven, was studied in September during pre-spawning period. The fish migrate from down- or upriver lakes for spawning river and data was collected by habitat mapping and radio-telemetry. analysed with preference curves and statistical modelling, using physical variables; depth, stream velocity streambed substrate. Preference were derived comparing use their nearby available environment while statistical modelling aimed to answer three main questions. 1) Do have a specific water streambed substrate? 2) Is there any difference between sexes? 3) shift habitat selection over time? indicated that favored depths 1-2 m, compositions characterized as glides (c. 0.2-0.4 m s-1), both fine (0.02-2 mm) and large (>200 mm) substrate compositions. overall was significantly influenced all investigated variables. Stream the only factor statistically segregating females males selection, where males used higher areas. No shifts one month study period were found. complexity streams correlations variables often results in difficulties evaluate preferences consequently future challenges lies in the development models accounting wider range abiotic biotic factors.