Black bass reproduction and factors affecting individual nest success have been studied extensively, but the effects of these factors at the population level are poorly known. We monitored largemouth bass nests in four southern Michigan lakes with varying fishing pressures during spring 2008 and 2009 and sampled for young-of-year bass abundance and condition during the fall of 2009. We used Program MARK to determine the importance of factors affecting nest survival probabilities and whether a recent change in fishing regulations in Michigan (allowing a May catch-and-immediate release [CIR] season) affected nest survival. Differences in survival among lakes and between stages of offspring development varied between years, but between-year differences may have been due to sample size and method changes. Nest survival was higher during the CIR season than during the subsequent harvest season for both years. Nest survival probability estimates for 5- or 6-day intervals ranged 14-73% among years, lakes, fishing seasons, and stages of development. Differences in nest survival among lakes and between seasons and stages indicated the importance of the timing and development of nests to the observed percent of nests that were successful in each lake. The outcome of the nesting season was strongly linked to fall recruitment during 2009, but the population-level effects of fishing on recruitment appeared complex. We suggest that the CIR season can remain, with continued monitoring of bass populations for long-term effects.
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