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In Ohio, the Ohio EPA monitors and assesses surface water resources using an "ecosystem" approach. This includes the use of an array of tools including water chemistry, physical and habitat assessment and the direct sampling of the resident biota. This approach, in turn, necessitates a similar approach in the design and success criteria of stream ecosystem restoration projects. This means that all components of a restoration project should support increasing the integrity of the water resource as defined in Ohio Water Quality Standards.
Ohio EPA first proposed biological criteria as part of its water quality standards regulations in November 1987 and reproposed them in October 1989. Following extensive interaction with interested parties the revised WQS (Water Quality Standards) were adopted in February 1990 and became effective in May 1990. A three volume set entitled Biological Criteria for the Protection of Aquatic Life contains the rationale, development, and field methods for deriving and using biocriteria in Ohio (Ohio EPA 1987a,b; 1989a,b). In addition, a detailed rationale for the development and application of the Qualitative Habitat Evaluation Index (QHEI) was produced (Rankin 1989).
This issue has received national attention as evidenced by the first national workshop on biocriteria held December 1987. Since that initial effort U.S. EPA has produced guidance on Rapid Bioassessment (U.S. EPA 1989), national biocriteria program guidance (U.S. EPA 1990b), and a policy statement on biocriteria in April 1990.
Based on analyses presented in the 1990 Ohio Water Resource Inventory (Ohio EPA 1990a) and elsewhere (Yoder 1991a, 1991b), there is little doubt that the addition of biological criteria and ambient biological monitoring significantly adds to the capability to detect and manage water resource impairments. For example, Ohio EPA (1987a) illustrates several examples of problem discovery and problem amplification, none of which would have been possible without an integrated chemical, physical, and biological approach to surface water monitoring. Aquatic life use impairments that we have identified and characterized during the past 12 years simply would not have been detected using chemical criteria and assessment tools alone.
It is evident from the data summarized in Year 2000 Water Resource Inventory (OEPA 2000) that the Ohio EPA year 2000 goal of restoring water resource quality cannot be achieved by controlling point sources alone. While nonpoint sources and causes of impairment are often complex there is a physical 'infrastructure' of streams and rivers that is basic and essential for the proper ecological functioning of these ecosystems.
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IBI (Index of Biological Integrity) responds strongly to habitat quality, and so follows the ability for a stream or river to attain a specified aquatic life use designation. An obvious consequence of this conclusion is that habitat data must be considered as an integral part of any attempt to restore aquatic life in a stream or river if such efforts are to succeed. 
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