I often tout the idea of getting the kids down to the swimming hole. Let them splash in the creek, and watch the fish and turtles that live in the water and on the shores. Let them flip over rocks and identify some of the larva.
One of the ways biologists determine the quality of water is to check for macroinvertebrates such as May and Stone fly larvae. If the water is too polluted for human consumption, it also will not support the bugs – or the fish that feed on them.