The RVCA's Benthic Macroinvertebrate Sampling Program started out in 1999 with sampling at only 15 sites, but has since evolved to more than 46 sites total. The area coverage has also grown from sampling in only 3 sub watersheds to now 6 sub watersheds.
Bugs are great barometers of pollution. Some can tolerate pollution while others are very sensitive to instream pollution. By sampling stream-bottom invertebrates (caddisflies, damselflies, crayfish, snails, aquatic worms, etc.) the program can determine changes in stream water conditions and levels of pollution over time.
The sampling method involves collecting the species by using a D-Net with a kick and sweep method. Aquatic invertebrates are sampled at 33 stream locations throughout the watershed in the spring and fall to account for all life stages of their development.
A total of three replicates of species are collected at each of the sites and are brought back to the lab for identification. Once identified the samples are run through various indices, which are then analyzed and observations can be made. Overtime trends and patterns of the data can be studied and water quality issues can be addressed by using best management practices in areas of concern.