Using aquatic macroinvertebrates to assess human impacts in local streams
Start Date
7-8-2026 10:15 AM
End Date
7-8-2026 10:30 AM
Location
ALT 206
Abstract
Local streams throughout the Mill Creek Watershed have been impacted by growing urbanization, industrial pollution, and physical alterations through dams and cement channelization. This summer we conducted two projects to evaluate these impacts on stream health: (1) the Biomonitoring Project, focused on comparing multiple sites across streams throughout the watershed and (2) the Dam Project, focused on assessing dam/dredging impacts on one stream. To determine stream health, we used aquatic macroinvertebrates as biological indicators due to their ability to respond to environmental change and ease of collection. For both projects, we collected standardized macroinvertebrate kick samples (n= 3-5 depending on the project), by scrubbing all benthic organisms in a 12 inch by 12-inch area of riffle for 2 minutes into a net. These samples allowed us to estimate the structure of the aquatic macroinvertebrate community (e.g., density, diversity, % sensitive taxa) at each site. Then, we collected one composite sample at each site, which consisted of a 30-minute timed search in all possible habitats (e.g., riffles, runs, pools) to determine the diversity of all habitats. In the laboratory, organisms were sorted and identified using a dichotomous key. Fieldwork was completed in July, and sample processing will continue throughout the school year. These data will contribute to ongoing long-term data sets that have been collected for 5-10 years, allowing for spatial comparisons overtime. Biomonitoring using aquatic macroinvertebrates has been proven to be a reliable way to evaluate stream health and can help to determine future management decisions in the watershed.
Using aquatic macroinvertebrates to assess human impacts in local streams
ALT 206
Local streams throughout the Mill Creek Watershed have been impacted by growing urbanization, industrial pollution, and physical alterations through dams and cement channelization. This summer we conducted two projects to evaluate these impacts on stream health: (1) the Biomonitoring Project, focused on comparing multiple sites across streams throughout the watershed and (2) the Dam Project, focused on assessing dam/dredging impacts on one stream. To determine stream health, we used aquatic macroinvertebrates as biological indicators due to their ability to respond to environmental change and ease of collection. For both projects, we collected standardized macroinvertebrate kick samples (n= 3-5 depending on the project), by scrubbing all benthic organisms in a 12 inch by 12-inch area of riffle for 2 minutes into a net. These samples allowed us to estimate the structure of the aquatic macroinvertebrate community (e.g., density, diversity, % sensitive taxa) at each site. Then, we collected one composite sample at each site, which consisted of a 30-minute timed search in all possible habitats (e.g., riffles, runs, pools) to determine the diversity of all habitats. In the laboratory, organisms were sorted and identified using a dichotomous key. Fieldwork was completed in July, and sample processing will continue throughout the school year. These data will contribute to ongoing long-term data sets that have been collected for 5-10 years, allowing for spatial comparisons overtime. Biomonitoring using aquatic macroinvertebrates has been proven to be a reliable way to evaluate stream health and can help to determine future management decisions in the watershed.
