These organisms are an important part of the food chain. Toxic chemicals can and do hurt these animals. The transfer of food energy from plants to animals to people. You are and important part of the food chain. I can absorb harmful chemicals found in the fish.
Some harmful pollutants can build up through the food chain and get into people.
For example pollutants can increase up to 6 million times from the level found in water to the level found in water to the level found in lake trout, which may then be eaten by people. All of these. Even though some areas may not look like fish habitat, they can be, sometimes even just for a short while. For example, pike can use flooded fields to spawning. Beaver, fox and coyotes.