Comparison of Three Methods for Studies of Stream Habitat Use by Young Brown Trout and Atlantic Salmon

Abstract

Surface observation, diving, and electrofishing were compared as methods to study habitat use by young brown trout Salmo trutta and Atlantic salmon S. salar in a Norwegian river. These three methods often gave widely disparate information about habitat use by young of these two species. The probability of encountering individual fish varied when the same method was used in different habitats. Surface observation and diving produced similar results in habitats with low mean water velocities (<20 cm/s) and fine substrate (mean diameter, ≤64 mm), whereas electrofishing was more effective than the sighting methods in shallow areas with greater water velocities and larger substrate.