The water is clear and cold and becomes rich with oxygen.
Few plants can survive the violent water in the brook.
Those that can are usually small and form tight mats on rocks. There are many small insects which choose to live in these fast turbulent waters. The flat stonefly nymph clings to the undersides of rocks. The black fly larva holds on by means of a tiny grappling hook The caddis fly larva builds living quarters from pebbles or sticks and cements this protective case to a stationary rock. Each stream dweller has its own unique adaptation for life in fast water.