Chironomid (Diptera: Chironomidae) Larvae as Indicators of Water Quality in Irondequoit Creek, NY

Abstract

Chironomid community structure and mouthpart deformities were examined as indicators of pollution or degradation of water quality in the Irondequoit Creek watershed. Differences in Simpson's diversity, taxa richness, and chironomid abundance were assessed in upper, middle, and lower creek locations to determine changes as the creek passes through increasingly populated areas. Differences in the same measures also were assessed in vegetation, mud, and gravel habitats in order to assure that any changes observed were not due to differences in chironomid community structure in dissimilar substrates. Diversity and taxa richness were highest in the upper creek and lowest in the lower creek. Abundance was highest in the middle creek. All three measures were highest in the gravel habitats and lowest in the vegetation habitats. Slight organic pollution impacts on the creek were indicated by lower diversity and richness values in the lower locations of lrondequoit Creek and by community structure differences. Mouthpart deformity comparisons were inconclusive because affected taxa were not present at all sites. This study brings into question the feasibility of using chironomid communities and deformity rates as indicators of water quality changes in the Irondequoit Creek system. Due to the high variance in chironomid distributions, a larger number of samples is needed to detect changes in chironomid communities. Other changes in sampling methods may also be necessary.