Influence of Winter Starvation on the Distribution of Smallmouth Bass among Wisconsin Streams: A Bioenergetics Modeling Assessment

Abstract

Abstract I used a bioenergetics model to test whether overwinter starvation of age-0 smallmouth bass Micropterus dolomieu, a representative warmwater species, could account for their scarcity in coldwater streams of Wisconsin. I modeled 84 combinations of food consumption rate, maximum daily mean summer temperature, and winter duration that encompassed the range of conditions likely to be encountered in Wisconsin streams, and ran simulations for the specific thermal regimes in four coldwater, one coolwater, and two warmwater Wisconsin streams where smallmouth bass population status was known. The model predicted that starvation mortality was unlikely at the highest food consumption rates, the warmest summer temperatures, and the shortest winters. Mortality increased with decreasing food consumption rates, decreasing maximum summer temperatures, and increasing winter duration. Starvation mortality was predicted to be negligible in the two Wisconsin warmwater streams, which had self-sustaining smallmouth ba...