The U.S Environmental Protection Agency set goals in the Chesapeake Bay Watershed Agreement that Pennsylvania must cut 69% of nitrogen outputs, but this target has not yet been met. The Susquehanna River basin that flows to the Chesapeake is largely agricultural communities that have the potential for excess nutrient runoff and sediment pollution. Of the 69% of nitrogen production that Pennsylvania is responsible for, 80% are the byproducts of agriculture. Pennsylvania’s delisting stream initiatives are efforts to reduce the number of agricultural streams that are considered in poor health and thus impact the bay. For a stream to become listed as impaired, its Index of Biological Integrity (IBI) score must be less than 50. This score indicates the stream has a high level of disturbance with a predominance of benthic macroinvertebrate species that are tolerant to poor water quality. Using the PA Department of Environmental Protection’s IBI scores from 1991 to the present, along with the federal National Land Use/Land Cover Dataset (NLCD), we can predict which streams are likely to improve with restoration. We plan to use the state-wide DEP data to map trends in sub-watershed stream quality based on IBI scores. In addition, we have conducted case studies of specific stream reaches where the Freshwater Research Institute projects have given us a complete history of stream restoration efforts and timing. Using these case study results, we can make predictions about other watersheds that might be good candidates for new stream restoration projects. A choice-informed decision-making model will be utilized to reinforce rapid delisting strategies. We hope to provide some insight into trends associated with water quality and restoration in streams, contribute to efforts to delist streams in Pennsylvania, and accelerate the restoration of the Chesapeake Bay.
Using Index of Biotic Integrity (IBI) scores to predict potential stream restoration success in Pennsylvania
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Student Abstract Submission