Feasibility of using an Index of Biotic Integrity (IBI) approach for synthesizing data from a Maryland biological stream survey

A state-wide survey is currently being designed to assess the status of Maryland biological stream resources. The report provides an assessment of the feasibility of using an approach similar to Karr's Index of Biotic Integrity (IBI) for reduction and interpretation of data obtained from the survey. Relationships among instream physical habitat, landuse, water quality characteristics and biological communities were examined in western Maryland, and the Piedmont region. Additionally, a trial biotic index for western Maryland fish was tested using available data. Biologically based metrics were found to have some ability to discriminate sites with respect to anthropogenic influences; thus, it appears feasible to devise an aggregated measure of biological integrity for detecting anthropogenic stress in streams of the Appalachian Plateau and Piedmont regions of Maryland. Two remaining challenges are to improve the sensitivity of the metrics and to develop a sufficient understanding of land use effects on biological communities in acid sensitive regions of the state to discriminate their effects from those associated with acidic deposition.