An Estuary is part of a wetland system along with swamps and marshes. Estuaries differ from swamps and marshes because they are filled with water all year. The Caloosahatchee River in Ft. Myers, Fla. is an estuary. It has salt water from the sea traveling inland to meet fresh water from the land. The mixture of the salt and fresh water becomes brackish in color and provides a rich ecosystem for all kinds of wildlife including fish, birds, amphibians, reptiles, crustaceans and other kinds of wildlife. Mature fish often travel up estuaries to lay their eggs or reproduce and this inland and more protected environment provides a safe haven for young fish to feed and survive before they are large and strong enough to travel out to sea. The types of fish which inhabit estuaries include Tarpon, Redfish, Snook, Flounder, Snapper, Grouper, Sheepshead, Spotted Seatrout, Mullet and 13 species of shark. Dolphins, Manatees, Blue Crabs, Shrimp, Oysters, Clams, Scallops, wading birds, diving birds and raptors also use estuaries for their habitat. The largest estuary in the United States is the Chesapeake Bay in Maryland which covers 64,000 sq. miles. Large estuaries in Florida include Tampa Bay, Charlotte Harbor and the Caloosahatchee River. The U.S. Environmental protection Agency has a good website that explains what estuaries are and their importance to our environment. I also like the website at Oceanservice.noaa.gov which has an excellent picture of an estuary and explains it in more detail.