Density and biomass of trout and char in western streams

Abstract

Density and biomass of resident salmonids in 313 streams in the W USA were analyzed for tendencies and significant differences. Trout density was less variable than trout biomass. Density ranged from 0-4.2 fish/m2 (average 0.25 fish/m2) while biomass varied between 0-81.9 g/m2 (averaged 5.4 g/m2). Generally, trout density was highest in the Rocky Mountain ecoregion, while trout biomass was greatest in the Sierra Nevada and Upper Gila Mountain ecoregions. The relationship between trout biomass and density was generally nonsignificant. Biomass data were used to develop a series of regional biomass-frequency curves for use in planning and management activities. -from Authors