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The Use of a Habitat Assessment Method in the Derivation and Assessment of Tiered Aquatic Life Uses in Midwest Streams
Edward T. Rankin
Center for Applied Bioassessment and Biocriteria
P.O. Box 21541
Columbus, Ohio 43221-0541
There is a gradient of anthropogenic physical conditions within most ecoregions that has profound influences on the aquatic communities that inhabit these systems. Current and historic monitoring has been used to identify these patterns in many states. In this paper we summarize the use of a habitat assessment tool, the Qualitative Habitat Evaluation Index (QHEI), in the derivation and designation of a tiered series of aquatic life uses in Ohio for warmwater streams. The concept and initiation of tiered aquatic life uses in Ohio predated the systematic collection of QHEI data, but was based on a good historical record of the fauna of Ohio streams, especially fish species distribution data from Trautman's Fishes of Ohio (1981). Trautman described associations he observed between species distributions and natural factors (e.g., gradient) and anthropogenic stressors (e.g., siltation, habitat loss) he identified over a long period of changing land uses. We use biological and QHEI habitat data collected in Ohio over the past 25 years to quantify similar associations between habitat variables at local and watershed scales with measures of community condition in Ohio (IBI, ICI). These indices comprise the biocriteria associated with specific tiered aquatic life uses formalized in Ohio's Water Quality Standards and are based on an extensive monitoring program. We also describe how habitat data is used in watershed-based assessments to: 1.) perform use attainability analyses to identify the appropriate tiered aquatic life use, 2.) determine aquatic life attainment status for streams, and 3.) determine likely causes and sources of impairment.
Keywords: Habitat, QHEI, IBI, ICI, use attainment, aquatic life use, biocriteria, streams, siltation, watershed