The influence of habitat and environment on smallmouth bass (Micropterus dolomieu) nest sites and nest success in northern Lake Michigan

Information on smallmouth bass nesting ecology is lacking in northern Lake Michigan, despite available information for other Great Lakes ecosystems. Our objectives were to identify factors that influenced nesting sites and nest success in a smallmouth bass population in northern Lake Michigan. Temperature, substrate firmness, and lake bottom rugosity were measured and related to the number of smallmouth bass nests in four bays. We also investigated the role of temperature, effective fetch, and storms to explain nest success. Temperature appeared to be most important in explaining the number of nests and nest success; transects that experienced the greatest number of cumulative degree days above 15 °C during nesting contained more nests and increased nest success. Our results suggest that warmer areas during spawning in northern latitude lentic systems should be protected from anthropogenic disturbances because these areas may be important for future recruitment of smallmouth bass.

Research highlights
► Among the variables measured, temperature best explained variability in nest site location and nest success.
► Warmer areas, such as bays, may contain higher densities of smallmouth bass nests and exhibit higher nest success.
► Warmer areas should be protected from anthropogenic disturbances due to their importance for smallmouth bass recruitment.