Assessment of water quality, benthic community structure and microbial indicators in Cattaraugus Creek, Zoar Valley, N.Y.

Abstract

Assessing the ecological health of rivers has become one of the most important environmental goals worldwide. This study of Cattaraugus Creek in Zoar Valley, western New York State, aims to identify spatial and temporal trends in physical and chemical characteristics and benthic community structure, and to establish unified baseline data for this previously little-studied site. Sampling was conducted during 2003-2004 in the two main branches of Cattaraugus Creek, and in the combined reach below their confluence. Water quality parameters (temperature, conductivity, pH, dissolved oxygen, turbidity, chlorophyll a, fecal coliform count) were measured either by YSI6600 Multiparameter probe, or by standard wet chemistry methods. Macroinvertebrates were sampled with either a 0.3 x 0.3-m Surber sampler, or 5-cm diameter core tubes, depending on the substratum. Principal Components Analysis (PCA) of water quality variables suggested a greater influence of sampling season than of river branch/reach on water quality. Turbidity and fecal coliforms were especially strongly associated with spring 2004 samples. Benthic macroinvertebrate community structure (density, richness, diversity, EPT richness, and FBI) appeared to be more influenced by substratum type (riffle-cobble, bedrock, pool-oft sediment)than by river reach. Benthic community metrics generally suggested moderate water quality. All of the microbial indicators evaluated (heterotrophic bacteria, fecal coliforms, and E. coli) were highly correlated with suspended solids. Fecal coliforms and E. coli numbers in Cattaraugus Creek met the US EPA standards dictated for recreational purposes. Long-term monitoring of this system will further assess possible stresses on ecosystem health, and should guide watershed management practices.