AUTHORS: Ryan Skowronski, Eastern Illinois University; Eden Effert-Fanta, Eastern Illinois University; Dan Roth, Eastern Illinois University; Trent Thomas, Illinois Department of Natural Resources; Robert Colombo, Eastern Illinois University
ABSTRACT: The Midwestern landscape has been converted from forests and prairies into land used for urban development and agricultural practices over the past two centuries. This transformation in landscape composition has disrupted ecosystem function and reduced the stability of stream habitats by accelerating bank erosion, decreasing riparian buffers, and lowering water quality. These changes have led to the degradation of stream habitat heterogeneity, which is a key factor influencing the biotic integrity of fish assemblages. Habitat restoration is a common mitigation strategy for reversing stream degradation, though empirical research evaluating the effectiveness of habitat restoration is insufficient in the Midwestern United States. This study aims to investigate the temporal shifts in fish biotic integrity in four Illinois streams restored in the past 15 years using historical fish community data. We expect habitat enhancement to initially disrupt fish assemblages but show an overall increase in biotic integrity in restored sites over time with a rise in habitat specialist and intolerant fishes. Evaluating the outcomes of these restoration projects is critical to conserve fish communities in degraded streams and improve future restoration methods.
