MACROINVERTEBRATES USED AS BIOINDICATORS OF RESTORED STREAM HEALTH IN THE MILL CREEK
Start Date
April 2024
Location
2nd floor - Library
Abstract
Stream restoration is a valuable tool in maintaining ecosystem health in degraded urban watersheds. Monitoring the effectiveness of completed restoration projects is critical to project success, future management decisions and funding opportunities. Macroinvertebrates are often used as biological indicators of stream condition because they are responsive to physical, chemical and biological stressors and reflect overall water quality. The main objective of this study was to assess macroinvertebrate community structure within restored sites of different age (2-years and 5-years post-restoration) within an urban stream. This study was conducted in two restored riffle installations within the Mill Creek Watershed of Cincinnati, Ohio in September 2023. Benthic macroinvertebrates (n=5) were collected from riffles using a Surber sampler. Samples were identified to the family level using dissecting microscopes. Macroinvertebrate community structure, including density, percent Diptera, %EPT (Ephemeroptera, Plecoptera, and Trichoptera), and Hilsenhoff Biotic Index (HBI), were analyzed. While macroinvertebrate density did not statistically differ among sites, higher densities were observed for all the major taxa at the 5-year site. The 2-year site, however, had less tolerant macroinvertebrates (% Diptera) and more sensitive macroinvertebrates (% EPT) compared to the older site. The 2-year site also had better water quality (HBI=3.87, very good) compared to the 5-year site (HBI=4.29, good). According to the macroinvertebrate community, the older restored site may have lower water quality due to a longer period of exposure to possible urban degradation, like pollution build-up and sedimentation, or allowed more time for competition to alter the macroinvertebrate composition.
MACROINVERTEBRATES USED AS BIOINDICATORS OF RESTORED STREAM HEALTH IN THE MILL CREEK
2nd floor - Library
Stream restoration is a valuable tool in maintaining ecosystem health in degraded urban watersheds. Monitoring the effectiveness of completed restoration projects is critical to project success, future management decisions and funding opportunities. Macroinvertebrates are often used as biological indicators of stream condition because they are responsive to physical, chemical and biological stressors and reflect overall water quality. The main objective of this study was to assess macroinvertebrate community structure within restored sites of different age (2-years and 5-years post-restoration) within an urban stream. This study was conducted in two restored riffle installations within the Mill Creek Watershed of Cincinnati, Ohio in September 2023. Benthic macroinvertebrates (n=5) were collected from riffles using a Surber sampler. Samples were identified to the family level using dissecting microscopes. Macroinvertebrate community structure, including density, percent Diptera, %EPT (Ephemeroptera, Plecoptera, and Trichoptera), and Hilsenhoff Biotic Index (HBI), were analyzed. While macroinvertebrate density did not statistically differ among sites, higher densities were observed for all the major taxa at the 5-year site. The 2-year site, however, had less tolerant macroinvertebrates (% Diptera) and more sensitive macroinvertebrates (% EPT) compared to the older site. The 2-year site also had better water quality (HBI=3.87, very good) compared to the 5-year site (HBI=4.29, good). According to the macroinvertebrate community, the older restored site may have lower water quality due to a longer period of exposure to possible urban degradation, like pollution build-up and sedimentation, or allowed more time for competition to alter the macroinvertebrate composition.
