The Everglades National Park (25°19' N-80°56' W) is a World Heritage Site in South Florida, USA. This unique marshland on the southern tip of Florida is known as the river of grass, a shallow sheet flowing imperceptibly across the land from south-central Florida. The exceptional variety of its water habitats has made it a sanctuary for great numbers of birds and reptiles, and for threatened species such as the manatee.
Threats to the Everglades National Park
The site was inscribed on the List of the World Heritage in Danger in 1993 after extensive damage to the Everglades' ecology by nearby urban growth, water pollution from fertilizer, mercury poisoning of fish and wildlife, a fall in water levels caused by flood protection measures and by the extensive alteration to much of Florida Bay and its ecological systems in August 1992 by hurricane Andrew which also destroyed the Park's visitor center.
The inscription on the List led to increased federal funding for the restoration of the site. An additional area of 44,370 hectares (ha) was authorized in the East Everglades Expansion Area in the north-east of the Park, 95% of which is being incorporated. Major rehabilitation is underway with a massive $US 31.4 million budget for land purchase and ecosystem research. Structural changes in the water management system have been made, to restore the water level in the area; legal negotiation and action have also begun to reduce pollution from fertilizers and farm wastes.
Legislation introduced in the US Congress would permanently retain the presence of the Miccosukee tribe on eastern Shark River Slough within the National Park, even though providing a site for the tribe's continued practice of its culture conflicts with the restoration of water flows through the slough, which flows are an essential measure for restoring the Everglades ecosystem.
On the southern tip of Florida, 40 kilometers (km) south west of Miami city, bounded on the west by the Gulf of Mexico, on the north by the Tamiami Canal and Big Cypress Nature Reserve, and on the south by the Florida keys across Florida Bay which is within the Park. The Biosphere Reserve includes Dry Tortugas National Park, 200 km to the southwest. The main park lies between 24°50’ - 25°55’N and 80°20’ - 81°30’W.
History of establishment
- 1947: Declared a National Park under the May 1934 Act of Congress
- 1976: Recognized as a Biosphere Reserve
- 1987: Designated a Ramsar site, a Wetland of International Significance
- 1989: The are of the park was to be increased by the Everglades Extension Act from 566,788 ha by an additional 44,112 ha, restoration of the natural water regimen was begun.
- 1992: Dry Tortugas National Park established (includes Fort Jefferson National Monument, designated 1935)
- 1993: Entered onto Montreux Record of Ramsar sites undergoing change.
- National Park: 609,681 ha (1,505,910 acres).
- World Heritage Site: 592,920 ha.
- Biosphere Reserve (with Dry Tortugas National Park): 636,411ha.
- Ramsar Site: 566,143ha.
The park is bordered by the following protected areas: Big Cypress National Preserve (21,198 hectares) to the north and Key Largo National Marine Sanctuary (32,388 hectares) to the southeast. Nearby are Biscayne National Park, ten additional National Wildlife Refuges and the Florida Keys National Marine Sanctuary.
USA Federal Government, Department of Interior. Administered by the National Park Service (NPS).
The Everglades National Park ranges in altitude from sea level to only two meters (m).
Everglades National Park is a shallow drainage basin comprised of two broad zones: wet freshwater prairies with forested islets, and coastal salt marshes, mangrove swamps, estuaries, beaches and dunes. The basin is tilted to the south-west draining south Florida in a slow-moving sheet of water 40 to 80 kilometers wide, depending on rainfall. It averages 150 millimeters (mm) deep, though the major drainage way, the Shark River Slough, can be up to a meter deep in the center. It flows to a coastline of estuaries along the Gulf of Mexico and into the shallow Florida Bay and is all that remains of the sheet of water which used to flow south annually from the Kissimee River and Lake Okeechobee 140 km north in the center of the state. The park is a vital recharge area for the Biscayne aquifer, a major source of freshwater for the city of Miami and southeast Florida. The area is underlain by extensive Pleistocene limestones with oolitic and bryozoan facies, overlaid by variable thicknesses of marl and peat, a thin porous crust which filters the surface water percolating to the aquifer.
Florida Bay is about 2240 square kilometers (km2) in area, has an average depth of one meter and a maximum depth of three meters and encloses hundreds of islands. Its substrate is composed of anastomosing mudbanks and unconsolidated calcareous sediments over limestones and is one of the most active areas of modern carbonate sedimentation. The park lies at the interface between temperate and subtropical America, between fresh and brackish water, shallow bays and deeper coastal waters, and protects a complex of habitats which support a high diversity of wildlife. The area of transition from freshwater glades to saltwater mangrove swamps is a highly productive zone that nurses great numbers of commercially valuable crustacea. The Dry Tortugas is an isolated cluster of coral reefs and shoals.
Temperatures are moderate, rarely freezing in winter, and reaching 23 to 35°C in summer, with annual precipitation often over 1470 millimeters, falling mostly between May and October. November to April is dry. Hurricane force storms can occur in summer and early autumn, as happened disastrously in August 1992 with hurricane Andrew, which felled many hammock trees and devastated and altered the ecology of Florida Bay where the hurricane destroyed a visitor center.
The Everglades is a unique, complex and fragile permanent 'floodplain ecosystem' with a great diversity of habitats and flora. The subtropical vegetation of southern Florida is unique in the United States although similar communities occur in the Caribbean and parts of tropical America. Taxonomic affinities show that many of its species migrated from tropical regions and are closer allied to tropical ecotypes than to temperate ones. Of approximately 1600 species of vascular plants in Dade, Monroe and Collier counties, 60 to 70% have tropical affinities. This fascinating vegetation was a primary reason for the establishment of the park. A total of about 950 vascular plant species has been recorded in the park, including 120 species of trees (60 of them endemic), many bryophytes, 25 species of orchid, about half of the species endemic to southern Florida and several rare plants. There is a rather high degree of local endemism. Approximately 65 taxa are south Florida endemics and of these about 25 are found only within the small area of slash pine forest in southeastern Florida.
There are five main terrestrial communities: hardwood hammocks (1.43% of the Park's area), pinelands (1.5%), bayheads (1.79%), sawgrass prairies (0.57%) and mangrove and cypress swamp forests (16.43%), and three main aquatic ecotypes: freshwater rivers, including flood savannas, ponds, brackish marshes (33%), coastal marshes (7.2%), and seagrass beds (38.1%). Hammocks, low tree islands, are dominated by hardwood species both tropical and temperate, such as West Indian mahogany (Swietenia mahagoni), and provide habitat for the larger mammals. Pinelands are dominated by slash pine Pinus elliotti var.densa and contain a large number of the endemics among the shrub and herbaceous species of the understorey. Mangrove forests contain red mangrove (Rhizophora mangle), black mangrove (Avicennia nitida) and white mangrove (Laguncularia racemosa). Their extent is surpassed in only a few parts of the world. Bayheads contain isolated stands of coastal plain willow (Salix caroliniana) on slight elevations or bald cypress (Taxodium distichum) in depressions filled with organic matter. Coastal prairies are often dominated by sawgrass (Cladium jamaicensis), a type of sedge, Gulf muhley grass (Muhlenbergia filipes), or cordgrass (Spartina spp.) in coastal areas. The sawgrass marshes may be the largest in the world, but with pollution by |nutrient-rich run-off especially from sugarcane farms, are being invaded by cat-tail, Typha spp. The dominant seagrasses are turtle grass (Thalassia testudinum), manatee grass (Syringodium filiforme) and shoal grass (Halodule wrightii); however, these taxa are being overrun by Codiaceae algae in the shallows and by pea-soup alga (Caulerpa taxifolia) in deeper water.
The terrestrial and aquatic plant and animal communities of the Everglades have over millennia adapted to the rhythm of wet summers and dry winters and to each other. The Park protects 800 species of land and water vertebrates including over 14 threatened species. Twenty-five native mammals occur including round-tailed muskrat Neofiber alleni struix, Everglades mink Mustela vison evergladensis, the native Florida panther Felis concolor coryi (E) of which there may be less than 30 individuals remaining in the entire state and less than ten in the Park, manatee Trichechus manatus latirostris (V) of which only about 1200 remain, mangrove fox squirrel Sciurus niger avicennia and Florida black bear Ursus americanus floridanus.
Over 400 bird species, many of limited distribution in the USA, have been recorded, notably great blue heron Ardea occidentalis, roseate spoonbill Platalea ajaja, Rothschild's magnificent frigatebird Fregata magnificens rothschildi, reddish egret Hydranassa rufescens, wood stork Mycteria americana (E), osprey Pandion haliaetus, snail kite Rostrahamus sociabilis (R), short-tailed hawk Buteo brachyurus, southern bald eagle Haliaeetus leucocephalus (V), peregrine falcon Falco peregrinus, crested caracara Polyborus plancus, Florida sandhill crane Grus canadensis pratensis, American oystercatcher Haematopus palliatus, Cuban snowy plover Charadrius alexandrinus tenuirostris, roseate tern Sterna dougallii, least tern Sterna albifrons, white-crowned pigeon Columba leucocephala, mangrove cuckoo Coccyzus minor, red-cockaded woodpecker Picoides borealis, ivory-billed woodpecker Campephilus principalis, Florida scrub jay Aphelocoma coerulescens coerulescens Cape Sable seaside sparrow Ammospiza maritima mirabilis, Florida grasshopper sparrow Ammodramus savannarum floridanus, and many species typical of the Caribbean region.
There are 60 known species of reptiles and amphibians, including American alligator Alligator mississippiensis, American crocodile Crocodylus acutus (E), hawksbill turtle Eretmochelys imbricata (E), green turtle Chelonia mydas (V) and loggerhead turtle Caretta caretta (E). 23 species of snake have been recorded, including the threatened indigo snake Drymarchon corais souperi. Alligator wallows become dry season oases for many freshwater species.
More than 275 species of fishes are known from the Everglades, most inhabiting the marine and estuarine waters. Several are important game fish that attract thousands of anglers to the park. Smaller species both inland and in estuaries are prey for the many wading birds. Bahama swallowtail butterfly Papilio ardraemon bonhotei and Schaus swallowtail butterfly P. aristodemus ponceanus are threatened insects. Seabirds nesting at Dry Tortugas National Park in the Gulf include sooty terns Sterna fuscata, noddy tern Anous stolidus, roseate tern and frigate birds. During autumn a continuous procession of songbirds and other migrants flies over or rests on these islands.
Everglades National Park is rich in both prehistoric and historic heritage. The park contains some 200 known archaeological sites, and two archaeological districts with 62 and 70 sites have been submitted to the National Register of Historic Places. In addition, five separate sites have been nominated for their individual significance. Historic use of the park has left a rich record of native American use, settlement, farming and fishing. A native American group, the Miccosukee tribe, has a permit to use an area inside the park for its tribal headquarters, visitor center, housing and businesses. Fort Jefferson, built between 1846 and 1876 on an island in Dry Tortugas National Park, but now abandoned, is the largest brick fortification in the western hemisphere.
Local human population
Most staff members commute from local communities. However, 30-50 park personnel and 50-100 concession personnel live in the park. A 50 ha site along the park's northern boundary is retained by the Miccosukee tribe of Indians under a special use permit for community development. In 1996, the population of the Florida Bay region was approximately six million people, and double the population is forecast during the next 20 years.
Visitors and visitor facilities
The development of visitor facilities follows the original aim of preserving the park's wilderness. Nevertheless there were 1,002,109 visitors to the Everglades in 2001. Facilities include five visitor centers, nature trails and boardwalks, four camping areas, one motel, restaurant, marina, small stores, a 24 kilometer long paved loop road for tram and bicycle tours, canoing trails, and primitive backcountry camping areas. Use of the Everglades is devoted to natural and cultural resource interpretation, environmental education, recreational fishing, boating, hiking and wilderness exploration. Boat dock camping facilities are available in Dry Tortugas National Park.
Scientific research and facilities
Extensive research has been carried out in the Park, especially since 1976. Its size, complexity, and the number of ways it is impacted require continual work. There is a research and resource management staff of about 60 scientists, technicians, resource specialists and administrative assistants. The effects of water on wildlife, estuarine fisheries and monitoring vegetation communities have been subjects of major research; also marine ecology, the effects of fire and exotics on native plants, and cultural resources. The federally financed Critical Ecosystem Studies Initiative has also made much useful scientific input. The Everglades Regional Collection Centre houses some 50,000 biological and cultural museum artifacts and archives, and a library with 10,000 volumes. Dry Tortugas National Park has excellent research possibilities on coral reef ecology, subtropical islands, bird migrations and fisheries; a Carnegie Institute marine research laboratory on Loggerhead Key in the Dry Tortugas provided substantial research from 1904 to 1964.
The Everglades National Park is a wilderness of exceptional conservation value, which preserves a fifth of the original extent of the biome which is over half of what remains of the Everglades ecosystem. Resources include the only subtropical reserve in North America and the largest continuous stand of sawgrass prairie in the country, the largest mangrove ecosystem in the western hemisphere, the most significant breeding grounds for tropical wading birds in North America and the habitat of some 14 endangered species.
The park's boundaries enclose the southern end of a 150 km drainage system, from Lake Okeechobee in central Florida, southwards. The construction of the Central and Southern Florida Flood Control Project by the Army Corps of Engineers has over many years created major changes in water flow patterns across the southern end of the state. Half the original Everglades was diverted and drained, and water to the National Park segment controlled through canals and floodgates. Three separate watershed sources essential to the system lie outside the park boundaries, and are in varying stages of preservation and control: Big Cypress National Preserve on the northern boundary, (93% Federal property); Shark River Slough watershed which is supplied by a large number of water conservation areas managed by the state plus, to the north of them, a large agricultural area formed from the northern Everglades; and the small Taylor Slough watershed which originates on private lands, passes through the park where it supports exceptional seasonal wildlife displays on the Anhinga Trail, and empties into north-east Florida Bay.
The Everglades National Park protects the region's major source of freshwater and fosters environmentally based tourism. 93% of the park is federally designated as wilderness within which strict natural, managed natural, and developed zones have been defined. A series of preservation zones by Metropolitan Dade County and the State of Florida help to protect the park's north and east boundaries from encroaching urbanization. Development and encroachments are kept to a minimum: at present only about 0.1% of the park is developed. Visitor facilities are adequate, and only upgrading and replacement of aging facilities is planned. In 1990 an Act of Congress authorized the purchase of 44,112 ha in the East Everglades Expansion Area along the northeast boundary of the park to increase the protection of Shark River Slough. Control of this area along with infrastructural changes in the water management system will allow the park to restore natural hydro-patterns without flooding private land. 95% of this area was ready to be incorporated in 2001. In a separate issue, prescribed burning was successfully pioneered as a National Park Service management tool in the Everglades to perpetuate the native ecosystem. The Fire Management Plan (1990) and Statement for Management (1989) state current management goals and objectives.
Official restoration of the region's natural water regimen started from concern with the impact of the Flood Control Project on the Park. In 1989 Congress stated in the Everglades Expansion Act that the ecosystem had suffered major adverse effects and should be restored; in 1992, the Corps of Engineers was directed to review the Project in order to restore and enhance the water flow. In 1993, the Department of the Interior established an interagency task force of 22 federal, state, tribal and local government agencies to co-ordinate restoration. In 1994, the Governor of Florida established the Governor's Commission for a Sustainable South Florida . These forces converged in a plan to restore the whole of southern Florida ecosystem. This includes developing a federal, state and private sector cost-sharing partnership for environmental and water quality improvements (the Everglades Forever Act of 1994); new federal legislation to authorize and guide the Army Corps of Engineers' restoration work (the Water Resource Development Act of 1996); funding for accelerated land acquisition to purchase and protect key parcels of land not in public ownership (the Farm Bill of 1996) and increased scientific research into adaptive environmental management (the Department of the Interior's South Florida Science Initiative, 1997). The target year for restoration to begin is 2006, and the task is expected to cost $250 million. This is one of the world's largest ever ecosystem reconstruction projects. Major rehabilitation has begun with a $US31.4 million budget for land purchase and ecosystem research. Research into the flow of water and its biological effects on wild plants and animals has been done to design, modify and revise hydrological management of the park. Already, the structural changes in the water management system have begun to restore water levels in the area and legal action has been started to reduce fertilizer pollution. In recognition of its seriously threatened status, Everglades National Park was added to the list of World Heritage in Danger in 1993.
More than most parks, the Everglades depends on the larger ecosystem of which it is part. Although the area was settled relatively late, changes occurred very rapidly in the early decades of the 20th century. During the past fifty years it has been under continual stress from the rapid urbanization of south Florida the population of which has grown from under 500,000 in 1945 to more than six million today. The impacts on the Park have been massive: 93% decline in the number of wading birds, 14 threatened or [[IUCN Red List Criteria for Endangered|endangered species (out of 63 in the region), the spread of invasive exotic species, mercury contamination in fish and predator species, seawater infiltration of aquifers from excessive freshwater drawdown and the decline of the productiveness of Florida Bay, now covered by pea-soup alga. Increased salinity in the Bay due to reduced freshwater inflow may be one factor in the decline of fish species and shrimps and the spread of algal blooms. The forecast doubling of the area's population in the next 20 years could lead to destruction of the Park and ensures the attention of conservationists to the activities of the Army Corps of Engineers and the South Florida Water Management District. The local chapter of the Sierra Club has voiced opposition to the $8 billion Comprehensive Everglades Restoration Plan for planning to divert water from wildlife habitats into new reservoirs, quarry pits within the Everglades worked under the plan, and for affecting the quality of the local drinking water.
Water manipulations are the second largest environmental threat to the ecosystem. Congressional action ensured a minimum annual supply, but the timing and manner of delivery were not specified. Irregular releases over many years disrupted the wildlife which is dependent on a predictable regime of alternating wet and dry seasons. The quality, timing, amounts, and distribution of canal releases affect the natural system that controls the vegetation and wildlife populations. The plant communities of southern Florida proved extremely vulnerable to disturbance from human activities. During droughts in the early 1960s and late 1980s the lack of sheet run-off from the north noticeably reduced the breeding of wading bird populations. Exotic fish species, including walking catfish Clarias batrachus, are competing with native species for habitat. This deterioration has continued, through agriculture, urbanization, drainage, deliberate and accidental burning, and pollution from oil developments, pesticides and other run-off.
Invasion by exotic plant species is a third great threat to Everglades ecosystems. There are at least 221 species of introduced plants in the park. These can be categorized by their distribution, their potential to spread and invade native vegetation, and the corresponding management approach for each group of species. The most significant category is of species such as Brazilian Pepper tree Schinus terebithifolius that are widespread in the Park or southern Florida that invade undisturbed native plant communities. A second category is of species like cat-tail that can naturalize and spread locally into undisturbed native vegetation and form dense stands once they have been introduced. A third category is of species such as Cajeput tree Melaleuca quinqenervia that are widespread in the park or southern Florida which form dense monospecific populations, primarily on disturbed sites such as roadsides, canal embankments and agricultural lands. Extraordinary financial and political investments have been committed. There is no assurance of success but a start has been made.
Everglades National Park employs approximately 230 full time permanent employees.
The Everglades National Park has a budget of US$13,000,000 for administration, protection, resource management, research, interpretation and maintenance. The budget was made available in 1996. For 2002, US$ 31,400,000 of increased appropriations for land purchases were made and $4.1million was allocated to improve wastewater management.
IUCN management category
- II National Park. Biosphere Reserve. Ramsar Site
- Natural World Heritage Site, inscribed in 1979. Natural Criteria i, ii, iv.
- Listed as 'World Heritage in Danger' in 1993 because of urban encroachment, pollution, lowered water levels, declining waterbird populations, invasion by exotic species and hurricane damage.
References and further reading
- Over 200 reference works have been published, but there is no single comprehensive account of the natural history.
- Anon (1994). South Florida Ecosystem Restoration Working Group 1994 Annual Report (Draft). Interagency Working Group. 127 pp.
- Alexander, T. & Crook, A. (1975). Recent and Long-term Vegetation Changes and Patterns in South Florida: Part II. Final Report. South Florida Ecological Study. University of Miami, Coral Gables, Florida. 827 pp.
- Avery, G. & Loope, L. (1980). Endemic Taxa in the Flora of South Florida. South Florida Research Centre Report T-558.
- Carr, A. & the Editors of Time-Life Books (1973). The Everglades. Time Life Books, New York, NY.
- Carter, L. (1974). The Florida Experience. Resources for the Future, Inc. John Hopkins University Press, Baltimore, MD.
- Caufield, P. (1970). Everglades. Sierra Club, San Francisco, California.
- Cook, R. (1996) Everglades National Park World Heritage Site, Two Anniversaries The World Heritage Newsletter No. 12, October 1996.
- Craighead, F. (1963). Orchids and Other Air Plants of the Everglades National Park. University of Miami Press, Coral Gables, Florida. (Paperback: ISBN: B000PGQQ5C)
- Craighead, F. (1971). The Trees of South Florida, Vol. I: The Natural Environments and Their Succession. University of Miami Press, Coral Gables, Florida.
- Dasman, R. (1971). No Further Retreat - The Fight to Save Florida, Macmillan Company.
- Douglas, M. (1947). The Everglades: River of Grass. Mockingbird Books, Inc. Covington, Georgia. ISBN: B0006W21MW
- DeGolia, J. (1978). Everglades: The Story Behind the Scenery. K.C. Publication, Las Vegas, Nevada.
- Everhart, W. (1972). The National Park Service. Praeger Publishers, New York, NY.
- George, J. (1972). Everglades Wildguide. Office of Publications, US Department of the Interior, Washington, DC.
- Gore, R. (1976). Florida, Noah's Ark for Exotic Newcomers. National Geographic, Washington, DC.
- Hendrix, G. & Morehead, J. (1983). Everglades National Park. An imperiled wetland. Ambio 12: 153-157.
- Hoffmeister, J. (1974). Land From the Sea. University of Miami Press, Coral Gables, Florida. (Hardcover: ISBN: 0870242687)
- Long, R. & Lakela, O. (1976). A Flora of Tropical Florida. Banyan Books, Miami. Second edition. 962 pp.
- Loope, L. & Avery, G. (1979). A Preliminary Report on Rare Plant Species in the Flora of National Park Service Areas of South Florida. South Florida Research Centre Report M-548.
- Loope, L., Black, D., Black, S. & Avery, G. (1979). Distribution and Abundance of Flora in Limestone Rockland Pine Forests of Southeastern Florida. South Florida Research Centre Report T-547.
- Morehead, J. (1982). A Case Study of Everglades National Park, U.S.A. World Parks Congress, Bali.
- Robertson, W. (1959). Everglades - The Park Story. University of Miami Press, Coral Gables, Florida. (Paperback: ISBN: B000V2UJ6M)
- Strong, A. & Bancroft, G. (1994). Postfledging dispersal of white-crowned pigeons: Implications for conservation of deciduous seasonal forests in the Florida keys. Conservation Biology 8(3): 770-779.
- Tebeau, C. (1968). Man in the Everglades. University of Miami Press, Coral Gables, Florida. ISBN: B0006BUTN6
- Tilden, F. (1978). The National Parks, Alfred A. Knopf, Inc. New York, NY.
- Todd, K. (2003). Who Gets the Water?. Sierra Club Florida Chapter.
- UNESCO World Heritage Committee (2002). Report on the 26th Session of the World Heritage Committee, Paris.
- Whiteaker, L. & Doren, R. (1989). Exotic Plant Species Management Strategies and List of Exotic Species in Prioritized Categories for Everglades National Park. US Department of the Interior, National Park Service,
- Research/Resource Management Report SER-89/04. 21 pp.
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