Loudoun Wildlife Conservancy’s Stream Team conducted 12 stream health surveys around the county this spring. These surveys use a protocol developed by Virginia Save Our Streams to collect, identify and tally the benthic macroinvertebrates living in a riffle at the stream site. Benthic macroinvertebrates (“macros”) are aquatic organisms living on the stream bottom that vary in their sensitivity to pollution and are bioindicators of the ecological condition of a stream. Stream monitors use the type and frequency of these macros to compute a composite index score ranging from 1 (indicating unacceptable ecological conditions) to 12 (indicating acceptable ecological conditions).
As shown in the chart below, of the 12 streams surveyed, half received unhealthy ratings (indicating unacceptable ecological conditions), a third received healthy ratings (indicating acceptable ecological conditions), and the remaining 2 received indeterminate ratings (indicating that additional information is needed).
JK Black Oak Wildlife Sanctuary Stream Sites
To protect the environmentally sensitive habitat and rare species, JK Black Oak Wildlife Sanctuary is not open for general public access.
This spring we added two new stream monitoring sites, at the JK Black Oak Wildlife Sanctuary in Lucketts. Located at the northern and southern ends of the property on an unnamed tributary of Limestone Branch, these sites are located less than a quarter of a mile from each other but received drastically different health scores. The upstream site received a healthy rating of 10, while the downstream site received an unhealthy rating of 5. We are currently investigating various possible explanations for these differences.
Loudoun Wildlife’s Stream Team will continue to collect baseline data on the health of the Sanctuary’s stream by conducting macro surveys and chemical tests at both sites semiannually. In the future, we hope to expand these stream health surveys into educational outreach opportunities.
Other Stream Team Activities in Spring 2021
In the first five months of this year, 30 Stream Team volunteers contributed over 460 hours of their time! In addition to stream monitoring at one (or more) of our 12 sites, these folks also assisted with our “Splash into Citizen Science” educational outreach program at the Chapman DeMary Trail in Purcellville in April. Fifteen participants learned about how nonpoint and point pollution can enter a watershed, the pollution tolerance levels and feeding strategies of benthic macroinvertebrates, and how to collect and identify these macros from the South Fork of the Catoctin Creek.
Our volunteers also helped to create content for and edit our new monthly stream monitoring newsletter, The Monitor, which was initially issued in February. You can sign up for the newsletter here.
Three of our younger Stream Team volunteers also created video submissions relating to stream monitoring for area Student Environmental Action Showcase (SEAS) events this spring. The purpose of these SEAS events is to amplify youth voices in environmental problem-solving by showcasing to a real-world audience how students have meaningfully contributed to environmental stewardship. Aila McGregor, Tycho Svoboda, and Emma Lloyd developed videos for the Loudoun SEAS event that aired on Facebook and YouTube (you can see them here). Emma also submitted a video to the NoVa Outside SEAS event and contributed to a citizen science compilation video submitted by Loudoun Wildlife to the Loudoun SEAS event.