Abstract
Fish communities in the Peace River were assessed biannually via electrofishing from fall 2007 through spring 2010. Habitat characteristics were quantified for each electrofishing transect to allow comparison with fish community data. We determined fish population characteristics, calculated habitat suitability indices and curves, and compared fish communities across river section, season, year, and with physicochemical parameters. Fish communities differed in each section of the river (i.e., lower, middle, upper) but did not differ across seasons or years. The strongest correlations of changes in community structure with physicochemical variables and habitat metrics occurred for measures of habitat complexity, followed by water velocity and conductivity. Species-specific habitat affinities were found to overlap substantially, but some differences were apparent and could explain broad-scale distributional differences in habitat use among the species. In conclusion, the sections used to delineate the river in this study, based primarily on differences in geology and hydrology along the course of the river, were comprised of different fish communities. The habitat affinities of fishes identified in this study should be useful to resource managers for modeling biotic responses to changes in river water levels and habitat availability.