The estuary zones include the mangrove swamp, the coastal prairie, the freshwater slough, the cypress swamp, the hardwood hammocks, and the pinelands. Along the shore, seagrass provides habitat for shellfish, fish and sponges. The nutrient for this zone is acquired by water as it drains off land.
Behind the estuary are the Mangrove forests. During winter, wading shore birds nest in the mangrove trees and feed on the abundance shrimp supply. Drought-resistant grasses and cacti hold the costal sand dune in place, except when hurricanes blow ashore. Then vegetation will have to start its growing process again since the dunes have become heavily eroded.
Fresh water fen composes the main part of the Everglades. Along its edges, limestone sediments restrict the flow of water, while in the center of the wetlands; a broad marshy slough shields the land. Fresh water plants and animals in the Everglades can be killed by the increase of salinity of the water in their habitats.
Approximately nine hundred people take up permanent residence in Florida each day. During its dry winter season, an additional 12 millions tourists arrive to visit each year. The fresh water supplies in the park are severely disrupted by municipal water need and increased coastal development. Furthermore, sewage and agricultural wastes are reducing water quality. Insects that are essential to the food web are being killed off by pesticides and fertilizers are disrupting the growth of microscopic plants on Lake Okeechobee. Salinity of the water also increases when too much water is taken from aquifers for municipal water needs. Fresh water plants and animals are being killed by seawater and waste water that have flown into the sloughs. .
If the proper preventative measures and cleanup project targeted at the recovery of the Everglade ecosystem are implemented. The eventual destruction of Everglades can be prevented.