Habitat, Growth, and Food of Young Lake Sturgeons in the Lake Winnebago System, Wisconsin

Abstract

Abstract Populations of lake sturgeon Acipenser fulvescens have declined throughout most of the species' North American range. The flourishing population in the Lake Winnebago system, Wisconsin, provided an opportunity to study the habitat, growth, and food of young lake sturgeon from 1981–1987. In all, 297 age-0 lake sturgeons 29–281 mm total length (TL) and 27–186 d old were captured over seven summers by seining, electrofishing, diving, and trawling. Age-0 fish were captured in areas with a detectable current, a flat substrate composed of pea-sized gravel and coarse sand, and an absence of rooted vegetation. When disturbed by divers they moved slowly and appeared unwary. Lake sturgeons were solitary; they stayed in close contact with the sand substrate, oriented upstream, and appeared to be feeding on drifting benthic organisms. Species of Baetidae nymphs and Diptera larvae found in relatively clean water were the two principal organisms consumed by lake sturgeons during their first summer of life. The...