Trout are raised at large hatcheries in various parts of the state, one of which is located near Sweet Briar in the Blue Ridge Mountains, at Montebello. All three species are raised in a cascading trough system where they are separated by size, class and species. They are released once they have reached legal catchable size. The effects of the actual trout farms on the environment have been researched to some extent. The decrease in richness downstream of the effluent outlet shows that the trout farm decreases the health of the stream, and makes it difficult for organisms to live in.
Mayflies are aquatic insects that coexist with trout and other fishes in Virginia's streams.
Mayflies have a unique life history, throughout which they are preyed upon by trout. They hatch out of eggs at the bottom of streams, where they live as aquatic nymphs for six months, breathing underwater using gills. They then emerge into the air, where they hang onto trees, rocks, or other stable structures. During this phase they are called subimagos. After molting one more time, the mayflies are sexually mature adults, and mating ensues.