For the Virginia Save Our Streams protocol, monitors collect macroinvertebrates from a stream and then count and identify them. Based on the numbers of pollution-tolerant and pollution-intolerant macroinvertebrates found, a stream health score can be calculated. The scores range from 0-12. Scores between 0 and 7 are in the “unacceptable” range, meaning the stream is unacceptably unhealthy. Scores between 9 and 12 are “acceptable”, meaning the stream shows an acceptable level of health. A score of 8 is considered “grayzone” – more information is needed to determine the health of the stream.
For more information on the Virginia Save Our Streams protocol, visit vasos.org.