Florida Keys National Marine Sanctuary

January 27, 2011, 2:41 pm
Source: NMS::MPA
Content Cover Image

Foureye butterflyfish. Credit: Florida Keys National Marine Sanctuary. Photographer: Chris Huss.


caption Source: The National Oceanic and Atmospheric Administration (NOAA)

The Florida Keys National Marine Sanctuary is a marine protected area (MPA) in the United States, and is part of the National Marine Sanctuary System. The Sanctuary was designated in 1990 and encompasses 2,900 square nautical miles surrounding the Florida Keys archipelago. An island chain on the southern tip of the Florida peninsula, the Keys are surrounded by the Atlantic Ocean to the south, and Florida Bay and the Gulf of Mexico to the north. They stretch 202 miles (356 km) to the south and west, ending 90 miles north of Cuba.

The Florida coral reef tract is one of the world's most famous coral reefs. On the ocean side, adjacent to the island chain, lies North America’s only living coral barrier reef. This reef system is the most extensive living coral reef in the U.S. and is the third largest barrier reef in the world. It is part of a productive marine ecosystem that includes patch and bank reefs, seagrass meadows, soft- and hard-bottom communities, and coastal mangroves. This matrix of interconnected habitats supports one of the most biologically diverse assemblages of marine life in North America.

The region also sustains many other inter-dependent habitats including fringing mangroves, seagrass meadows, hard-bottom regions, patch reefs, and bank reefs. The Florida Keys are a partial barrier between the warm-temperate waters of the Gulf of Mexico and the tropical to subtropical waters of the Atlantic Ocean to their south. A corresponding distinction in marine flora and fauna between the two regimes is a result. This complex marine ecosystem is the foundation for the commercial fishing and tourism-based economies that are vital to south Florida.

Flora and Fauna

Marine Mammals

caption The West Indian or 'Florida' manatee (Trichechus manatus latirostris). Photo by Florida Park Service, District 5

Marine mammals in the Florida Keys include cetaceans (dolphins and whales) and sirenians (manatees). These marine mammals spend their entire lives in the water. Their front limbs have evolved into paddle shaped flippers and their tail is flattened laterally. They are generally social and can be found living alone or in large aggregations. Cetaceans have streamlined bodies, an external blowhole on the top of the head, and are basically hairless. They can dive for extended periods of time to great depths. Sirenians have massive bodies, unusually dense bones, and nostrils on top of a snout. Manatees are vegetarians and have large, mobile lips with stiff bristles that help them feed. Marine mammals can be seen throughout Florida Keys National Marine Sanctuary in both coastal and offshore waters.


caption The Spotted Eagle Ray (Aetobatus narinari). Photo by Mike White

This diverse group includes bony fishes, sharks, skates, rays, and eels. They live within a variety of habitats including seagrass beds, mangrove forests, coral or rocky reefs, sandy bottoms and the open ocean. Divers and snorkelers in the Florida Keys will easily see the variety of this group represented within the sanctuary. Many of these species are also commercially important for the south Florida economy.

Marine Birds

In the Florida Keys, seabirds can be divided generally into two groups: coastal/nearshore birds and offshore birds. Seabirds are often found feeding and nesting in wetlands, marshes and mangroves. Offshore seabirds spend more of their time feeding at sea, visiting islands or land only to breed.


caption Club-tipped Finger Coral (Porites porites). Photo by Paige Gill

Invertebrates in the Florida Keys include mollusks (snails, clams), echinoderms (sea stars, urchins, sea cucumbers), techtibranchs (sea hares), arthropods (lobster, crabs, shrimp), annelids (worms), porifera (sponges), and cnidarians (jellies, anemones, corals). Probably most notable to Florida Keys National Marine Sanctuary are the extensive coral reefs. These reefs are created by a community of coral polyps which are small animals that produce calcium carbonate (CaCO3). Colonies of tiny anemone-like polyps are the living coral tissue. Within the tissue of most reef-building corals live symbiotic small algae called zooxanthellae (pronounced zo-zan-thel-ee) that are capable of photosynthesis (changing sunlight energy into food). Although corals are carnivorous and feed on zooplankton, they receive much of their energy and oxygen as byproducts of photosynthesis by the zooxanthellae. The zooxanthellae also enhance the rate of calcium carbonate production by the coral colony, thus, promoting coral and reef growth. The majority of the other invertebrate species represented in the sanctuary use coral reefs as their habitat.

Plants and Algae

caption Black Mangrove (Avicennia germinans) Photo by Nancy Diersing

Both vascular plants and algae are primary producers, forming the base of the food web in the ocean. Common plants found in the sanctuary include seagrasses and mangroves. Seagrasses are flowering plants that live underwater. They produce oxygen during photosynthesis, provide habitat for marine animals, stabilize sediments, and are a food source for several species. Mangroves are trees that thrive in salty environments because they are able to obtain freshwater from saltwater by secreting salt or blocking salt absorption. Mangroves are extremely important ecologically and serve many functions. They provide nursery habitat for young fish, crustaceans and shellfish, food for a multitude of marine species, and act as shelter, rookeries or feeding areas for many coastal bird species.

Marine reptiles

caption American Crocodile (Crocodylus Acutus) Photo by Photo by Everglades National Park

Reptiles in the Florida Keys include sea turtles, alligators and crocodiles. Worldwide, there are only seven species of sea turtles, and all but one are endangered. Five of these species of turtles (ridley, green, leatherback, loggerhead and hawksbill) can be found in Florida Keys National Marine Sanctuary.

History of Preservation Efforts

The Florida Keys have been a popular destination for explorers, scientists and tourists for centuries. However, their popularity has led to pollution of the marine ecosystem and overuse of resources. Signs of anthropogenic degradation in the Keys became apparent several decades ago. Corals were being damaged and water quality was suffering. Many began to recognize that the Keys’ environment and resources were fragile and needed protection before they were damaged beyond repair.

In 1957, a group of conservationists and scientists met to discuss the state of the coral reefs and other marine resources in the Keys. This conference resulted in the creation of the nation’s first underwater park in 1960—the John Pennekamp Coral Reef State Park. Despite the establishment of this park, pollution, over-harvesting of resources, physical impacts, and other conflicts continued to plague the Keys. Additional management efforts were initiated when the public began to call for more protection. Thus, the Key Largo National Marine Sanctuary, which is adjacent to Pennekamp Park, was established in 1975, and the Looe Key National Marine Sanctuary was established in 1981. Though these two marine sanctuaries encompassed only a small fraction of the Keys’ marine environment, they represented an important step in protection for the region.

Nevertheless, threats to the coral reef ecosystem continued. Proposed oil drilling in the mid- to late 1980s and reports of deteriorating water quality throughout the region surfaced as scientists were assessing rates of coral bleaching, seagrass die-offs, declines in reef fish populations and the spread of coral diseases. The final insult came in the fall of 1989 when three large ships ran aground on the coral reef within an 18-day period, destroying critical reef habitat. The cumulative impacts of these events prompted U.S. Rep. Dante Fascell and U.S. Sen. Bob Graham to introduce bills in November 1989, calling for more protection of the area. Congress passed the bi-partisan bill with little resistance, and on Nov. 16, 1990, President George Bush signed the Florida Keys National Marine Sanctuary and Protection Act into law. The act designated approximately 2,800 square nautical miles of state and federal waters in the Keys as the Florida Keys National Marine Sanctuary.

Managing the National Marine Sanctuary

Following the sanctuary designation, representatives of the newly formed Sanctuary Advisory Council, members of the public, and federal, state, and local agency officials worked to assemble a management plan for the sanctuary. Important issues addressed in the management plan came from several sources, including technical workshops, public meetings and surveys, and Sanctuary Advisory Council members.

During the six years it took to complete the management plan, participants encountered both support and opposition from the Florida Keys community. Those who opposed the sanctuary feared excessive regulations, economic losses, and possible displacement of traditional users and uses. The community was interested in improving water quality, but it also was concerned about possible restrictions placed on boating activities, commercial and recreational fishing, recreational use of cultural and historical resources, and general land use. Because the management design process included unprecedented public involvement, it was developed with all of these concerns in mind.

After conducting a thorough analysis of five different management alternatives and seeking extensive public comment, the preferred (and current) management plan was selected because it most closely met the resource protection goals of the National Marine Sanctuary Act and the Florida Keys National Marine Sanctuary and Protection Act. Yet, it still allowed public use of the sanctuary. It also recognized the role of federal, state and local management authorities in meeting sanctuary objectives.

One innovative component of the sanctuary management plan is the combination of sanctuary-wide regulations with a system of marine zoning. Approximately 6 percent of the sanctuary is set aside as fully protected zones known as ecological reserves, sanctuary preservation areas and special use areas. Stringent restrictions on harvesting marine life and harming natural resources govern these zones to ensure their long-term survival. Twenty-four fully protected zones exist within the sanctuary. They protect critical habitat, preserve species diversity and relieve pressure from some coral reef areas.

In 2001, the Tortugas Ecological Reserve was established to complete the sanctuary zoning scheme outlined in the management plan. This new reserve helps protect fish stocks in the Tortugas, ensuring the stability of commercial and recreational fisheries. Vessel discharges and anchoring activities are restricted in this zone to protect water quality and habitat. Scientists hope that the reserve’s geographical isolation will help them distinguish between natural and human-caused changes to the coral reef environment.

The sanctuary also includes 27 wildlife management areas that protect sensitive wildlife habitats by restricting public access. Finally, the sanctuary encompasses 20 existing management areas, which are managed by other agencies. Such areas include national parks, national wildlife refuges, state parks and aquatic preserves. In the remaining unzoned portions of the sanctuary, management activities focus on improving water quality and protecting habitat.

The sanctuary also enforces specific regulations that protect and preserve ecological, recreational, research, educational, historical and aesthetic resources, and aim to minimize conflicts among users. These regulations pertain to boating, fishing, submerged land use, submerged cultural resource use and recreational activities. The sanctuary implements several techniques to ensure that these regulations are followed. For example, frequently used channels, no-wake areas and shallow reefs are marked with highly visible buoys that warn boaters of critical areas and help them avoid groundings, propeller damage, or other injury to corals, seagrasses and the seabed. The buoys help to reduce boat wakes in sensitive habitats, areas vulnerable to erosion, and high-density areas like marinas.

caption Scuba diving in the Florida keys.

In addition, the sanctuary employs mooring buoys in areas of high recreational use. Instead of dropping anchors that can potentially damage reefs or the seabed, boats can tie up to these buoys to let passengers snorkel or SCUBA dive. Techniques for managing water quality include establishing no-discharge zones—areas where vessels are not allowed to discharge wastes—and establishing mobile pump-out services that remove wastewater from vessels located outside of marina facilities.

The sanctuary relies on an extensive education program to ensure protection of the Keys’ resources. Education and outreach efforts are aimed primarily at tourists, recreational users, residents and students. Education campaigns focus primarily on managing boating, fishing, SCUBA diving and snorkeling because these activities have the potential to seriously damage coral reefs and seagrasses if they are conducted carelessly.

Finally, research and monitoring activities are critical components of the sanctuary’s primary goal of resource protection. Research and monitoring activities have helped scientists establish baseline information for various components of the ecosystem. Using this information, scientists can study cause and effect linkages and direct research to determine the reasons for reef decline. Among other studies, scientists are conducting a zone monitoring program, which tracks and compares ecological changes inside and outside of the fully protected zones. They also are monitoring the health status and trends of corals, seagrasses and water quality under the Water Quality Protection Program.

Ongoing Resource Management Issues

Despite active management, the sanctuary continues to face declines of healthy coral. Rates of coral disease and coral bleaching are increasing, and algae is increasingly invading seagrass beds and coral reefs. Overfishing, reduced freshwater inflow from Florida Bay, inadequate wastewater and stormwater management, damage to coral from careless boaters and divers, and occasional large ship groundings all continue to challenge managers.

Further reading

  • The Florida Keys National Marine Sanctuary's Web site
  • Barley, G. 1993. The Florida Keys Example From An Activist Citizen’s Point of View. Oceanus. 36(3).
  • National Marine Sanctuaries (NMS). 2001. The National Marine Sanctuary Program’s Web site. www.sanctuaries.nos.noaa.gov.
  • Suman, D., M. Shivlani and J. Milon. 1999. Perceptions and Attitudes Regarding Marine Reserves: A Comparison of Stakeholder Groups in the Florida Keys National Marine Sanctuary. Ocean & Coastal Management: 42.
  • U.S. Department of Commerce (DOC). 1996. Strategy for Stewardship: Florida Keys National Marine Sanctuary Final Management Plan/Environmental Impact Statement. 3 volumes.
  • U.S. Department of Commerce (DOC). 2000. Strategy for Stewardship: Tortugas Ecological Reserve Final Supplemental Environmental Impact Statement/Final Supplemental Management Plan. 310 pp.



Disclaimer: This article is taken wholly from, or contains information that was originally published by, the National Marine Sanctuary and National Marine Protected Areas Center. Topic editors and authors for the Encyclopedia of Earth may have edited its content or added new information. The use of information from the National Marine Sanctuary and National Marine Protected Areas Center should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.



(2011). Florida Keys National Marine Sanctuary. Retrieved from http://www.eoearth.org/view/article/51cbedcc7896bb431f693fd7

1 Comment

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Kainen Unser wrote: 05-05-2011 21:37:31

The Florida Keys are known for their coral reefs as well as other interdependent habits including mangroves and sea grass beds. The Florida Reef Tract is home to over 6,000 species of plants, fishes, and invertebrates, including the only coral reef system in U.S. waters. This complex ecosystem is the foundation for the commercial and recreational fishing industries & it is also suitable place for Crocodile. http://www.wildlifeworld360.com/amazing-american-crocodile.html