Florida Keys National Marine Sanctuary, Administered by NOAA
Designated on November 16, 1990, Florida Keys National Marine Sanctuary is one of 14 marine protected areas that make up the National Marine Sanctuary System. Administered by NOAA, a federal agency, and jointly managed with the State of Florida, Florida Keys National Marine Sanctuary protects 2,900 square nautical miles of waters surrounding the Florida Keys, from south of Miami westward to encompass the Dry Tortugas, excluding Dry Tortugas National Park. The shoreward boundary of the sanctuary is the mean high-water mark, essentially meaning that once you set foot in Keys waters, you have entered the sanctuary.
Within the boundaries of the sanctuary lie spectacular, unique, and nationally significant marine resources, from the world’s third largest barrier reef, extensive seagrass beds, mangrove-fringed islands, and more than 6,000 species of marine life. The sanctuary also protects pieces of our nation’s history such as shipwrecks and other archeological treasures.
Visitors to the sanctuary are encouraged to take advantage of the many recreational activities this amazing ecosystem has to offer, including world-class diving, swimming, snorkeling, and fishing. However, rules and regulations are in place to make sure that these activities only happen in ways–and at places–that reduce user conflict and are not harmful to the sanctuary’s natural and cultural resources.
Corals: With their hardened surfaces, corals are sometimes mistaken as being rocks. And, because they are attached, “taking root” to the seafloor, they are often mistaken for plants. However, unlike rocks, corals are alive. And unlike plants, corals do not make their own food. Corals are in fact animals.
The branch or mound that we often call “a coral” is actually made up of thousands of tiny animals called polyps. A coral polyp is an invertebrate that can be no bigger than a pinhead to up to a foot in diameter. Each polyp has a saclike body and a mouth that is encircled by stinging tentacles. The polyp uses calcium carbonate (limestone) from seawater to build a hard, cup-shaped skeleton. This skeleton protects the soft, delicate body of the polyp.
Mangroves: There are about 80 different species of mangrove trees. All of these trees grow in areas with low-oxygen soil, where slow-moving waters allow fine sediments to accumulate. Mangrove forests only grow at tropical and subtropical latitudes near the equator because they cannot withstand freezing temperatures.
Many mangrove forests can be recognized by their dense tangle of prop roots that make the trees appear to be standing on stilts above the water. This tangle of roots allows the trees to handle the daily rise and fall of tides, which means that most mangroves get flooded at least twice per day. The roots also slow the movement of tidal waters, causing sediments to settle out of the water and build up the muddy bottom.
Mangrove forests stabilize the coastline, reducing erosion from storm surges, currents, waves, and tides. The intricate root system of mangroves also makes these forests attractive to fishes and other organisms seeking food and shelter from predators.
Mangroves line more than 1,800 miles of shoreline within Florida Keys National Marine Sanctuary. In the Florida Keys, the red mangrove, black mangrove, and white mangrove tend to dominate wetland areas.
Manatees are mammals that live in the water: In the winter season, Keys residents and visitors may encounter West Indian manatees swimming leisurely along the shoreline. These large, air-breathing herbivores are found in shallow, slow-moving waters where seagrass beds or vegetation flourish. Eating up to 150 pounds of plants each day, manatees typically weigh between 800 and 1,200 pounds and reach about 10 feet in length.
Manatees are listed as a federally endangered species. Unfortunately, they are endangered largely due to human activity. Manatees are slow-moving and therefore unable to swim quickly away from boats; this often results in collisions that may cause injury or death to the creatures. In areas that are known manatee habitats, boaters should slow down and produce only minimal wake.
If you see a sick, injured, dead, or tagged manatee while in Florida, call the Florida Fish and Wildlife Conservation Commission’s Law Enforcement Hotline at 1-888-404-FWCC (3922) and give the location of the animal; whether it is alive, dead, or injured; and how long you have been observing it.
The Florida Keys are a chain of limestone islands that extend from the southern tip of the Florida mainland southwest to the Dry Tortugas, a distance of approximately 220 miles. They are island remnants of ancient coral reefs, Upper Keys, and sand bars, Lower Keys, that flourished during a period of higher sea levels approximately 125,000 years ago (a period of geologic time known as the Pleistocene Epoch).
During the last ice age (100,000 years ago) sea level dropped, exposing the ancient coral reefs and sand bars which became fossilized over time to form the rock that makes up the island chain today. The two dominate rock formations in the Keys are Key Largo Limestone and Miami Oolite.
During this time of lower sea levels, the Florida land mass was much larger than it is today and the area now referred to as Florida Bay was forested. As glaciers and polar ice caps started melting 15,000 years ago, flooding of land combined with tidal influence changed the geography of the Keys and their surrounding areas.
There are an estimated 1,000 shipwrecks off the Florida Keys: Shipwrecks lie scattered along the treacherous coral reefs and buried in the sandy shallows a few miles off the Florida Keys. Many of these wrecks have tales to tell. They can tell us about individuals who came before us, why they were here, and their difficulty in navigating these waters.
There are many reasons why these ships lie broken on the ocean floor, including an inability to accurately determine position, inaccurate nautical charts, lack of navigational aids such as lighthouses and buoys, unpredictable currents, lack of wind, storms, and human error.
And while we may tend to think of historic wrecks first, not all of the shipwrecks are old. Shipwrecks still occur in modern times despite dramatic improvements in propulsion and navigation. The City of Washington and Benwood are examples of modern vessels that came to grief in the Keys.
Fourteen of the sanctuary’s historic sites are listed in the Department of the Interior’s National Register of Historic Places. Sanctuary scientists and partners are continually documenting and researching ships that rest on the ocean floor.
If you happen upon a shipwreck site or an historical object, it is okay to look, but do not disturb anything. If you think the site has yet to be discovered, contact Florida Keys National Marine Sanctuary and let staff know where you found the site. This will allow the sanctuary to investigate further.
Artificial Reefs: Artificial reefs are only allowed in national marine sanctuaries after an extensive evaluation and permitting process to ensure that sanctuary resources will not be harmed by development of the reef. In general, development of artificial reefs is not allowed within national marine sanctuaries due to regulations that prohibit placing items or depositing materials on the seafloor. However, within Florida Keys National Marine Sanctuary, four ships have been permitted to sink since sanctuary regulations became effective in 1997.
Research suggests that artificial reefs may have a positive impact on the local economy by increasing diving, snorkeling, and fishing-related revenues. Artificial reefs may also draw divers from natural coral reefs, thereby reducing pressure on those sensitive habitats.
Despite the potential benefits of artificial reefs, creating a successful reef requires more than just placing random materials on the seafloor. Ensuring that the desired benefits of the reef are reached requires planning, long-term monitoring, and evaluation. Improperly planned, constructed, or managed artificial reefs may damage natural habitats, alter species composition, impede navigation, and cause conflict amongst users groups.
Establishment of artificial reefs within the sanctuary has happened only after an extensive review and permitting process conducted via Florida Keys National Marine Sanctuary in concert with other local, state, and federal agencies. This process was required to ensure that the reef is not detrimental to the resources that the sanctuary protects.