It is also in high demand from South Florida's growing population and agricultural interests. A healthy Everglades ecosystem, returned to its natural state, would retain more of this fresh water. The chemicals and nutrients which pollute the Everglades destroy a type of algae called periphyton, which lives on the water surface. These algae are a key link in the Everglades food chain and provide both food and oxygen for small aquatic organisms. In the dry season, this algae provides moisture to small organisms so they can survive the long months until rains come again.
Cattails love the chemicals and nutrients that destroy the periphyton.
Their rampant growth chokes the ecosystem and crowds out other native plants. Another Everglades pollutant is mercury. High levels of mercury have been detected in many species, including fish, alligators and the endangered Florida panther. Wetlands, such as the Everglades, normally have a natural filtering capacity. However, when the natural water flow is disrupted by canals and levees, the Everglades cannot supply this service.