Insights from Long-Term Monitoring: Asian Carp and Fish Communities within the Illinois River

Long-term monitoring can provide novel information regarding ecological patterns and processes. While long-term monitoring efforts have gained greater recognition in their impo11.ance in understanding ecological patterns, few have documented the influence of invasive species on ecosystem prope1ties and processes throughout the course of an invasion (introduction, establishment, and spread). The Long Tenn Resource Monitoring Program, an element of the Upper Mississippi River Restoration - Environmental Management Program, has been monitoring ecological patterns and aquatic resources throughout the upper Mississippi River system for over 20 years and provides a unique oppo1tunity to understand the influence of invasive species on the existing fish community. With the arrival and establishment of Asian carp in Illinois wate1ways, long-term monitoring has revealed that significant changes have occurred within the fish community of the La Grange reach of the Illinois River. In general, several sport fishes (e.g. largemouth bass, crappie, white bass, bluegill) and catastomids (i.e. suckers) have declined in terms of relative abundance since the establishment of Asian ca1p, whereas several non-sport fishes such as gar, grass ca1p, and emerald shiners have increased in abundance. Changes observed in fish community strncture may have potentially altered other aspects of ecosystem functioning ( e.g. primmy/secondary production, decomposition), and continued research and long-term monitoring will be necessary to further our understanding of existing impacts of invasive species while continuing to study and monitor future invasions occuffing within our ecosystems.