Reached the Tipping Point
Nutrients that Kill
These excess "nutrients" feed unhealthy algal blooms that deplete oxygen levels within the stream (remember: these nutrients are good for plants but bad for aquatic life)
When oxygen levels are depleted, animals that can't move die. Floyds Fork has a mollusk population (fresh water clams, muscles, snails, etc) that depend upon a healthy stream. These mollusks are the natural filtration process that keep the water clean for the fish. If they die, the fish will not live much longer after them. Two thirds (2/3) of the Floyds Fork mussel species have already died.