“Stoneflies (Order Plecoptera), Mayflies (Order Ephemeroptera) and Caddisfly (Order Tricoptera) are as suitable swimming pals as dolphins. Trout fishermen have been using these species as an indicator of good fishing for ages. These insects need healthy water to survive, so just by finding some of them in your recreational site, chances are high that the water quality is good.”
Unsure about a swimming hole’s water quality? Just follow the flies!