Evaluating Hydrologic Controls on Fish and Macroinvertebrate Communities in Ohio’s Western Allegheny Plateau

This research is part of a larger project to classify aquatic habitat in Ohio’s Western Allegheny Plateau (WAP). This study (1) correlates hydrologic predictor variables with biological response variables for sites on relatively undisturbed streams in Ohio’s WAP, (2) determines the dependency among 14 hydrologic variables to identify a least autocorrelated set, and (3) develops procedures for estimating hydrologic variables. These were determined via field measurement, linear regression with USGS gage data, basin-characteristics power equations, and GIS. Analysis showed high correlation among some of the variables, reducing the set to12. Aggregate fish (IBI) and macroinvertebrate (ICI) indices do not vary significantly with many hydrologic factors in undisturbed streams. In many cases, the component metrics of IBI and ICI do vary with hydrologic factors.