The primary focus of our stream monitoring program is identifying the aquatic insects, called benthic macroinvertebrates, found in streams. The type and quantity of aquatic insects found in a stream tell a good story about the quality of water in the stream and its surrounding habitat.
You can see a map of our current stream monitoring sites here.
Stream monitoring is conducted three times per year, between April and November.
Monitoring is done in teams of three or four experienced and novice monitors who follow the Virginia Save Our Streams (SOS) monitoring protocol. Monitors use collecting nets, field tables, collecting pans, and microscopes that are provided by Loudoun Wildlife Conservancy.
Team members wade into the stream and use the collecting nets to capture live aquatic insects in the riffle and pool portions of the stream. Forceps, spoons and eye droppers are used to pick the live insects from the sample. The insects are then sorted, identified, counted, and recorded on a data sheet before they are released back into the stream.
The data are transcribed to a database maintained by Loudoun Wildlife Conservancy, and are used to prepare water quality reports. Because the same stream sites are sampled year after year, we are able to report on trends in the health of our streams and the aquatic life found in them. Read more about the data here. And see the data in action as it is aggregated with other Loudoun water quality monitoring efforts here through Loudoun Watershed Watch.
Three monitoring sessions per year. It takes the monitoring team approximately 3 to 4 hours to collect and identify the aquatic insects at stream-side.