The Florida Middle Grounds are a reefs in the northeastern

Gulf of Mexico The Gulf of Mexico () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...

, approximately west northwest of the West coast of

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

Geography

These reefs consist of a series of both high and low relief

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

ledges and pinnacles that exceed in some areas. The roughly 348 NM² of this hardbottom region lies south of the

panhandle A salient, panhandle, or bootheel is an elongated protrusion of a geopolitical entity, such as a subnational entity or a sovereign state. While similar to a peninsula in shape, a salient is most often not surrounded by water on three sides. Ins ...

coast and northwest of

Tampa Bay Tampa Bay is a large natural harbor and shallow estuary connected to the Gulf of Mexico on the west-central coast of Florida, comprising Hillsborough Bay, McKay Bay, Old Tampa Bay, Middle Tampa Bay, and Lower Tampa Bay. The largest freshwater i ...

between 28° 10' and 28° 45' N and 084°00' and 084°25' W

Geology

The ridges consist of unconsolidated marine calcareous muddy sand, about 12 meters (40 feet) thick, overlying a weathered, fossiliferous limestone of

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

age (between 5 and 22 million years old) and capped by a carbonate rock composed primarily of the sessile vermetid gastropod Petaloconchus sp. (a marine snail that cements its tubular shell to a hard surface, such as a rock or another shell). Previous to core sample studies in 2010 and 2011, the Florida Middle grounds were thought to have been formed by coral. However, new research indicates that the ridges likely formed as a series of shore-parallel sediment bars eventually capped and preserved by vermetid gastropods, or "worm snails."

Flora and fauna

Today's middle ground reef

ecosystem An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...

represents the northernmost scope of mid-shelf

octocoral Octocorallia, along with Hexacorallia, is one of the two extant classes of Anthozoa. It comprises over 3,000 species of marine and brackish animals consisting of colonial polyps with 8-fold symmetry, commonly referred informally as "soft cora ...

communities in

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

. It is a

prehistoric Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins million years ago and the beginning of recorded history with the invention of writing systems. The use o ...

coral-reef complex that has bio-similarities to modern patch-reefs, and a species distribution that includes both Carolinian and Caribbean components. The fish species are markedly tropical, with

stony coral Scleractinia, also called stony corals or hard corals, are marine animals in the phylum Cnidaria that build themselves a hard skeleton. The individual animals are known as polyps and have a cylindrical body crowned by an oral disc in which a mo ...

gorgonians Alcyonacea is the old scientific Order (biology), order name for the informal group known as "soft corals". It is now an unaccepted name for Class (biology), class Octocorallia. It became deprecated . The following text should be considered a hi ...

, and

sponge Sponges or sea sponges are primarily marine invertebrates of the animal phylum Porifera (; meaning 'pore bearer'), a basal clade and a sister taxon of the diploblasts. They are sessile filter feeders that are bound to the seabed, and a ...

dominating the community that relies upon the existence of the

Loop Current Mesh analysis (or the mesh current method) is a circuit analysis method for planar circuits; planar circuits are circuits that can be drawn on a plane surface with no wires crossing each other. A more general technique, called loop analysis ...

. Currently, there are 170 species of

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

, 103 species of

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

, approximately 40

s, 75

mollusks Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The num ...

, 56

decapod crustaceans The Decapoda or decapods, from Ancient Greek δεκάς (''dekás''), meaning "ten", and πούς (''poús''), meaning "foot", is a large order of crustaceans within the class Malacostraca, and includes crabs, lobsters, crayfish, shrimp, and pr ...

, 41

polychaete Polychaeta () is a paraphyletic class of generally marine Annelid, annelid worms, common name, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called c ...

s, 23

echinoderm An echinoderm () is any animal of the phylum Echinodermata (), which includes starfish, brittle stars, sea urchins, sand dollars and sea cucumbers, as well as the sessile sea lilies or "stone lilies". While bilaterally symmetrical as ...

s and 23 species of

Research

In 2000, a research project was funded by the

National Oceanic and Atmospheric Administration The National Oceanic and Atmospheric Administration (NOAA ) is an American scientific and regulatory agency charged with Weather forecasting, forecasting weather, monitoring oceanic and atmospheric conditions, Hydrography, charting the seas, ...

to evaluate the status of the reef. This research was conducted utilizing the DeepWorker 2000 one person

submersible A submersible is an underwater vehicle which needs to be transported and supported by a larger ship, watercraft or dock, platform. This distinguishes submersibles from submarines, which are self-supporting and capable of prolonged independent ope ...

Recreation

The "Middle grounds shipwreck" is a popular

scuba diving Scuba diving is a Diving mode, mode of underwater diving whereby divers use Scuba set, breathing equipment that is completely independent of a surface breathing gas supply, and therefore has a limited but variable endurance. The word ''scub ...

and

fishing Fishing is the activity of trying to catch fish. Fish are often caught as wildlife from the natural environment (Freshwater ecosystem, freshwater or Marine ecosystem, marine), but may also be caught from Fish stocking, stocked Body of water, ...

location. In 2004, the wreck was identified by a team of divers led by Michael C. Barnette as the

tugboat A tugboat or tug is a marine vessel that manoeuvres other vessels by pushing or pulling them, with direct contact or a tow line. These boats typically tug ships in circumstances where they cannot or should not move under their own power, suc ...

''Gwalia''.

References

{{Reflist Reefs of Florida