Despite their value, salt marshes are too often considered to be worthless. Salt marshes provide
nursery areas for fishes, shellfish, and crustaceans. These plants have extensive root systems
which enable them to withstand brief storm surges, buffering the impact on upland areas. Salt
marshes also act as filters. Tidal creeks meander through the marshes transporting valuable
nutrients as well as pollutants from upland development. Salt marshes can absorb, or trap, some
of these pollutants, reducing the pollutant load entering estuaries. Salt marshes also prevent
sediments from washing offshore, often creating more land on which salt marshes can grow.
Salt Marsh Losses in Florida
Salt marsh systems are dynamic, constantly changing. Society, however, emphasizes stability and
permanence. As a result, salt marshes have been drained or filled with silt, sand, or refuse to
an elevation at which they can no longer survive. It is estimated that in Florida at least 60,000
acres, or 8 percent, of estuarine habitat has been lost to permitted dredge and fill activities.
The Florida Marine Research Institute is studying changes in Florida's coastal habitats.
Scientists can evaluate changes by comparing aerial photographs of the coast in the 1940's,
1950's, and 1980's. Too frequently, the changes observed show loss of fisheries habitats.
Salt marsh loss has occurred in Florida's five northeast counties, which contain 11 percent of
the State's total salt marsh acreage. The primary loss in Nassau County occurred because of
dredging for the Intracoastal Waterway. Duval County has been impacted even more severely by
human activity. Extending 3.5 miles on either side of St. John's Inlet and 10 miles up the St.
John's River, analysis indicated a 36 percent loss of marsh habitat. The loss is primarily due
to dredge and fill of marsh habitat since 1943.
In Palm Beach County, a 51 percent decrease in salt marsh acreage occurred in Lake Worth between
1944 and 1982 due to major land developments. A network of canals draining low lying uplands
diverted the natural flow of freshwater away from salt marsh areas.
In southwest Florida, both salt marshes and mangroves occur along the Tampa Bay shore. Since 1940,
Tampa Bay has been one of the fastest growing metropolitan areas in Florida. Considerable
environmental damage has occurred in Tampa Bay along with this growth. Four major types of
dredging have impacted Tampa Bay during the last 100 years: channel deepening, maintenance
dredging, shell dredging, and dredging for land fill construction. Ship channel dredging and
port construction have brought Tampa Bay the economic benefits of being one of the largest ports
in the nation. Tampa Bay has lost more than 40 percent of its original mangrove and salt marsh
acreage over this time.
The elimination and alteration of Florida salt marshes have a negative effect on fishery
resources. Estuaries provide nursery areas for at least 70 percent of Florida's important
recreational and commercial fishes, shellfish, and crustaceans. Many of Florida's marine
fisheries will decline and may disappear without coastal wetlands.
State regulations have been enacted to protect Florida's salt marsh systems. Specifically,
the Warren B. Henderson Wetlands Act of 1984 established clear guidelines for defining wetland
areas that come under state jurisdiction. All dredging and filling activities in state waters
require permits unless specifically exempted. Local laws vary, so be sure to check with officials
in your area before taking any action.
Salt marshes are a part of our State heritage. It is up to us to ensure them a place in Florida's
future - your future.
This page was derived from a brochure developed by the Department of Environmental Protection,
Florida Marine Reseach institute with funds provided by a grant from the U.S. Office of Ocean and
Coastal Resource Management, NOAA.