Associate Professor of Biology and Environmental Science St. Norbert College De Pere, Wisconsin, United States
Abstract: We implemented a short-term, two-year project to measure the water quality of an urban creek undergoing restoration. We hypothesized that restoring the creek would positively impact the health of the stream by improving the macroinvertebrate abundance, water column characteristics, nutrients, and chlorophyll a.
The study contained three sites along Kelly Creek in South Beloit, IL. Site 1 and site 2 were within the restoration area of the creek. In these areas, efforts were made throughout the duration of the study to pick up trash, clean out muck, plant riparian vegetation, and install limestone outcroppings to increase public accessibility. Site 3 remained untreated. Data were collected in 2021 and 2022 from early May to late August approximately every two weeks. Macroinvertebrate abundance, temperature, dissolved oxygen, total phosphorus (TP), and chlorophyll a were collected during each sampling period. Macroinvertebrate richness and diversity, and the Hilsenhoff Biotic Index (HBI) were calculated.
Preliminary results suggest that amphipod (Gammaridae), dragonfly (Anisoptera), and leech (Hirudinea) abundances differ significantly by site. Dragonflies have a higher abundance in site 2 than in sites 1 and 3. Dragonflies have a mid-range HBI index value indicating better water quality in site 2. Leeches have a higher abundance in site 3 than in sites 1 and 2. Leeches have a high HBI index value, which indicates that they can survive well in polluted waters, such as the water in the untreated non-restoration area. Amphipods have a lower abundance in site 2 than in sites 1 and 3, likely due to the lack of their preferred rocky substrate in site 2. TP in the water column did not vary significantly between the sites. Although HBI did not differ significantly between sites, it appears that the restoration efforts may be improving water quality in site 2 of Kelly Creek. The results of this study will help to promote further research and improvement of Kelly Creek, and gain insight into short-term impacts of ecological restoration in polluted urban areas.