Relations between Habitat Variables and Channel Catfish Populations in Prairie Streams

Abstract

Abstract Standing stocks (kg/hectare) of channel catfish Ictalurus punctatus were graphed against 19 abiotic variables measured for Kansas streams. The resulting habitat suitability curve for each variable allowed fish biomass to be normalized to index values (range, 0.0–1.0) that could be regressed linearly against the abiotic variables. Stepwise multiple-regression techniques isolated three variables (runoff, fraction of stream area consisting of runs, and water temperature) that accounted for nearly half the variability in channel catfish biomass. When the regression model derived from Kansas data was applied to an independent data set from Oklahoma, the correlation between predicted and observed standing stocks was highly significant, though low. Assigning suitability index values to the Oklahoma data set from the habitat suitability curves developed from Kansas data resulted in a significant model with more (often different) variables accounting for three-fourths of the biomass variability. The regre...