The effects of dam dredging on aquatic macroinvertebrate communities located in Sharon Woods, Cincinnati, Ohio
Start Date
April 2025
Location
3rd floor - Library
Abstract
Dams provide many beneficial services for humans, including drinking water, hydroelectric power, and recreational sites. However, dams can create negative impacts on waterways, such as altering the flow of water, decreasing stream discharge, and changing the surrounding environment. Disturbances such as these create ideal conditions for sedimentation and eutrophication. Sedimentation occurs when reduced water flow causes benthic material to build-up, creating a shallower environment. As a result, eutrophication can occur. Eutrophication is the buildup of nutrients, followed by increased plant growth and oxygen depletion. Through the process of dredging, benthic sediments are removed from the dam to improve ecosystem health. The objective of this study was to assess the impacts that the dredging process has on aquatic macroinvertebrate communities within Sharon Woods Creek. Macroinvertebrates serve as effective indicators of water quality due to their range of tolerances to different types of disturbances. Three sites were sampled in Sharon Creek, with one site upstream of the dam, and two sites downstream of the dam. Each site was sampled once during the pre-dredging phase in Fall 2022 and again during dredging in Fall 2024. Quantitative macroinvertebrate samples were collected in benthic riffle samples (n=5) with a Surber sampler and D-framed kick net. Qualitative macroinvertebrate samples were collected from all sub-habitat types (e.g. riffle, run, pool, margin) in a 15-minute timed search. Macroinvertebrates were preserved in 70% ethanol and identified to family level in the laboratory. Different indices were measured spatially and temporally to determine stream health from Fall 2022 and Fall 2024. Our results show that both the %EPT and %Chironomidae vary significantly from each site and from each year. This suggests that dam dredging could play a role in the reduction of sensitive taxa (represented by %EPT) and the increase in insensitive taxa (represented by %Chironomidae). As the dredging process is completed in 2025, this will be important data to have to examine the changes in macroinvertebrate communities because of the dredging process.
The effects of dam dredging on aquatic macroinvertebrate communities located in Sharon Woods, Cincinnati, Ohio
3rd floor - Library
Dams provide many beneficial services for humans, including drinking water, hydroelectric power, and recreational sites. However, dams can create negative impacts on waterways, such as altering the flow of water, decreasing stream discharge, and changing the surrounding environment. Disturbances such as these create ideal conditions for sedimentation and eutrophication. Sedimentation occurs when reduced water flow causes benthic material to build-up, creating a shallower environment. As a result, eutrophication can occur. Eutrophication is the buildup of nutrients, followed by increased plant growth and oxygen depletion. Through the process of dredging, benthic sediments are removed from the dam to improve ecosystem health. The objective of this study was to assess the impacts that the dredging process has on aquatic macroinvertebrate communities within Sharon Woods Creek. Macroinvertebrates serve as effective indicators of water quality due to their range of tolerances to different types of disturbances. Three sites were sampled in Sharon Creek, with one site upstream of the dam, and two sites downstream of the dam. Each site was sampled once during the pre-dredging phase in Fall 2022 and again during dredging in Fall 2024. Quantitative macroinvertebrate samples were collected in benthic riffle samples (n=5) with a Surber sampler and D-framed kick net. Qualitative macroinvertebrate samples were collected from all sub-habitat types (e.g. riffle, run, pool, margin) in a 15-minute timed search. Macroinvertebrates were preserved in 70% ethanol and identified to family level in the laboratory. Different indices were measured spatially and temporally to determine stream health from Fall 2022 and Fall 2024. Our results show that both the %EPT and %Chironomidae vary significantly from each site and from each year. This suggests that dam dredging could play a role in the reduction of sensitive taxa (represented by %EPT) and the increase in insensitive taxa (represented by %Chironomidae). As the dredging process is completed in 2025, this will be important data to have to examine the changes in macroinvertebrate communities because of the dredging process.
