Middleburg, VA — On Thursday, October 2, Goose Creek Association (GCA) partnered with George Mason University’s Potomac Environmental Research and Education Center (PEREC) to conduct fish count testing along Goose Creek. The fieldwork was led by Dr. T. Reid Nelson, Assistant Professor and Faculty Fellow at PEREC, with support from fellow faculty, graduate students, and undergraduates studying aquatic and fisheries ecology.
This work is part of GCA’s ongoing efforts to monitor and protect Goose Creek, a State Scenic River and a vital source of drinking water for Loudoun and Northern Fauquier Counties.
“Fish counts tell us a lot about the condition of Goose Creek,” said Dr. T. Reid Nelson, Assistant Professor and Faculty Fellow at George Mason University’s PEREC. “In just one small 100-meter stretch of stream, we found more than 700 individual fish and over 20 different species—an incredible snapshot of biodiversity that speaks to a healthy ecosystem. For folks who haven’t seen it firsthand, it’s almost unbelievable how much life can be found in such a short section of creek. By combining traditional methods with newer tools like eDNA, we can continue to track these changes and make informed decisions about conservation.”
A Closer Look at the Day’s Work
The research team spent the day studying stream health through several methods:
· Electrofishing fish counts to measure the diversity and abundance of fish in the creek.
· Benthic sampling to gather aquatic insects and invertebrates that indicate long-term water quality.
· Environmental DNA (eDNA) testing to detect traces of genetic material from species that may not appear in nets.
Together, these approaches help build a detailed picture of the creek’s ecosystem.
How Electrofishing Works
One of the main activities was electrofishing, a safe and effective way to study fish populations without harming them. Using specialized equipment, researchers briefly send a controlled electrical current into the water. The current momentarily stuns fish, allowing them to be gently netted and placed in holding tanks. Each fish is then identified, measured, and recorded before being released back into the creek.
This process helps scientists understand which species are thriving, which are struggling, and how the overall fish community reflects the health of the watershed.
Looking Ahead: Pilot Program and Report Card
This fish count and related sampling are part of a Goose Creek Association’s one-year water quality monitoring pilot program with George Mason University, funded by Loudoun County. The PEREC team is performing a comprehensive water quality investigation of Goose Creek and the Broad Run watershed (Loudoun and Fauquier Counties, VA), which includes:
· Monthly analysis of water samples collected at 8 sites in the Goose Creek watershed and 4 sites in the Broad Run watershed. Testing will include parameters measured on-site with a portable sonde and laboratory analysis for bacteria, nutrients, and suspended solids.
· Biannual benthic macroinvertebrate (BMI) analysis at the same 12 sites, providing a long-term biological measure of stream health.
· Data analysis and report preparation to summarize findings.
· Bimonthly meetings with GCA to review results and guide monitoring efforts.
The results of their sampling can be viewed on our Creek Watch page.
At the end of the pilot, Goose Creek Association will publish a revised Goose Creek Report Card to help communicate the health of the creek and encourage informed conservation practices.
“Our work with George Mason University strengthens what volunteers have been doing for decades,” added Karl Kelley, GCA Board Member and Chair of the Water Quality Committee. “By pairing rigorous science with grassroots stewardship, we can give the public the information they need to understand the state of Goose Creek and why protecting it matters.”
