Exploring the Impacts of Methylmercury‐Induced Behavioral Alterations in Larval Yellow Perch in Lake Michigan Using an Individual‐Based Model

Abstract

AbstractThe inclusion of sublethal behavioral effects in population models has predicted lower estimates of cohort abundance and survival. Methylmercury, a persistent contaminant in the Great Lakes, has been shown to alter foraging and predator avoidance behaviors of larval Yellow Perch Perca flavescens, which may have indirect effects on recruitment. Poor recruitment of Yellow Perch in Lake Michigan has been associated with changes in trophic structure and adverse habitat conditions, but the potential effects of contaminants have not been fully explored. To test this, we adapted existing larval fish individual‐based models to incorporate laboratory‐derived methylmercury behavioral impairments on a larval Yellow Perch cohort in Lake Michigan. Overall, swimming speed reductions following methylmercury exposure did not drastically affect cohort survival. In contrast, the impairment to prey capture success resulted in an additional 8, 45, and 28% starvation of the cohort in simulations with tissue concentrations of 0.21, 0.95, and 3.14 μg/g total mercury whole‐embryo wet weight, respectively. While our experimental methylmercury concentrations were higher than those typically found in Lake Michigan, our findings suggest that contaminants could be an additional factor impacting recruitment of Yellow Perch in systems highly contaminated with mercury.