Live coral reefs surround the Florida Keys in southwestern Florida. Hardbottom habitats in this area feature rock colonized by calcifying algae, octocorals, stony corals and sponges. Patch reefs dominated by stony corals are found near Key Largo, Key West and Elliott Key. Bank reefs, also know as forereefs, extend seaward from other reef types.
Located immediately west of the Florida, the Tortugas Banks are extensive coral reefs growing on a foundation of Pleistocene-era limestone. These reefs have a high degree of coral cover but low coral diversity.
More reef areas are found on the West Florida Shelf in the Gulf of Mexico, extending west and north of the Florida Keys and the peninsula. Pulley Ridge is a rocky underwater feature located west of the Keys that is colonized by a vibrant reef ecosystem. Farther north are the Florida Middle Grounds, which comprise carbonate ledges westward of the bend in Florida's coastline. The Florida Middle Grounds are the northernmost coral reefs in the continental U.S. They support algae, sponges, urchins and many species of coral and fish.