Florida Reef
The Florida Reef (also known as the Great Florida Reef, Florida reefs, Florida Reef Tract and Florida Keys Reef Tract) is the only living coral barrier reef in the continental United States.[1] It lies a few miles seaward of the Florida Keys, is about 4 miles (6 to 7 km) wide and extends (along the 20 meter depth contour) 270 km (170 mi) from Fowey Rocks just east of Soldier Key to just south of the Marquesas Keys. The barrier reef tract forms a great arc, concentric with the Florida Keys, with the northern end, in Biscayne National Park, oriented north-south and the western end, south of the Marquesas Keys, oriented east-west. The rest of the reef outside Biscayne National Park lies within John Pennekamp Coral Reef State Park and the Florida Keys National Marine Sanctuary. Isolated coral patch reefs occur northward from Biscayne National Park as far north as Stuart, in Martin County. Coral reefs are also found in Dry Tortugas National Park west of the Marquesas Keys. There are more than 6,000 individual reefs in the system. The reefs are 5,000 to 7,000 years old, having developed since sea levels rose following the Wisconsinan glaciation.[2]
The densest and most spectacular reefs, along with the highest water clarity, are found to the seaward of Key Largo (in and beyond John Pennekamp Coral Reef State Park) and Elliott Key (the northernmost 'true' Florida Key) where the two long keys help protect the reefs from the effects of water exchange with Florida Bay, Biscayne Bay, Card Sound and Barnes Sound. The bays and sounds (all between the Florida Keys and the mainland) tend to have lower salinity, higher turbidity and wider temperature variations than the water in the open ocean. Channels between the Keys allow brackish water from the bays to flow onto the reefs (especially in the middle Keys), limiting their growth.[3]
Human use[edit]
Human use of the reefs has grown tremendously in the past century. One measure of the growth is that registrations for recreational boats in Monroe County increased by 1000% from 1964 to 2006.[18]
Recreational use of the Florida Reef and surrounding waters is popular and important to the economy of southern Florida, and in particular, of Monroe County. In 2000-2001 artificial and natural reefs in South Florida[19] and Monroe County had 28 million person-days of recreational use by residents and tourists, including scuba diving, fishing and viewing (as, for example, by snorkeling). These activities generated $4.4 million in sales, generated almost $2 million in local income and provided more than 70,000 full- and part-time jobs. The estimated asset value of the reefs was $8.5 billion. About two-thirds of the activity was related to natural reefs.[20]
In Monroe County for the period of June 2000 to May 2001 almost 5.5 million person-days of reef related activities resulted in $504 million in sales, which generated $140 million in income for 10,000 full- and part-time jobs. Almost two-thirds of the activity was by residents, and about half the activity involved fishing, with one-third involving snorkeling and one-sixth scuba diving.
[21]
In Dade County for the period from June 2000 to May 2001 a little over 6 million person-days of reef related activities resulted in $1,297 million in sales, which generated $614 million in income for 19,000 full- and part-time jobs. The activity was about evenly split between residents and tourists. As in Monroe County, about half the activity involved fishing, with one-third involving snorkeling and one-sixth scuba diving.[22]
In a more general sense, the reef acts as a layer of protection for human settlements against tropical storms, hurricanes, and erosion.[12]