Can Habitat Alteration and Spring Angling Explain Largemouth Bass Nest Success?

Abstract

AbstractLargemouth bass Micropterus salmoides nest in shallow littoral areas, making them vulnerable to negative effects of habitat alteration due to development of lake shorelines and fishing during the spring nesting period. For instance, alteration of shorelines may reduce the quality and abundance of nesting habitat, and the high visibility of nests and the aggressive guarding behavior of nesting males increase their vulnerability to fishing. In 2004, we monitored nest distribution and success and quantified local nest habitat features, lakewide angler effort, and lakeshore development patterns in five Michigan lakes to determine the extent to which habitat alteration and fishing limit the number of nests that produce swim‐up fry. Lakes spanned a range of lakeshore dwelling densities (8–22 dwellings/km), allowing us to determine the extent to which nest success varies within and among lakes due to local (e.g., substrate and cover) and lakewide (e.g., dwellings/km and fishing effort) factors. Surprisingly, local habitat characteristics were not important determinants of the probability that a nest would produce swim‐up fry (P > 0.05). At the whole‐lake scale, however, nest success was negatively related to dwelling density; the probability of producing swim‐up fry declined from 0.77 in the lake with the lowest dwelling density to 0.45 in the lake with the highest dwelling density (P = 0.018). Lakewide estimates of angling effort could not explain the difference among lakes, indicating the likely importance of quantifying angling at finer spatial scales. Knowledge of the magnitude of anthropogenic effects and the spatial scale at which they operate is integral for the management of black bass Micropterus spp.