An aquatic community assessment relative to a whole-lake herbicide treatment in Perch Lake, Michigan

Aquatic plant density, diversity, and biomass were evaluated with respect to a whole-lake fluridone treatment in Perch Lake, Michigan to evaluate indirect effects of exotic vegetation removal on foraging juvenile centrarchids. Prey abundance, diversity and taxa composition were evaluated with respect to five aquatic plant density levels and with respect to native and exotic vegetated sites. Predator distribution, forage selectivity, and energy gain of juvenile centrarchids were evaluated among different levels and composition of aquatic vegetation. Significant changes were noted in the aquatic plant community after the herbicide treatment. No significant correlations were found between prey availability, forager abundance, and type and density of aquatic vegetation. However, prey selectivity was enhanced at intermediate levels of aquatic vegetation and energy gain by juvenile centrarchids was greatest at low aquatic plant density sites and at native plant density sites.