Coral Reefs
Florida's coral reefs came into existence 10,000 years ago when sea levels rose. Reef growth is relatively slow, with individual colonies growing approximately one-half inch to 7 inches per year, depending on the species. Coral reefs are in a constant state of flux. New polyps, the living tissue of corals, grow on the outer surface while their skeleton erodes, contributing to help make the white sand found on Florida’s beaches. During long periods of favorable conditions, reefs can develop into complex structures that support tremendous biodiversity.
For information about DEP’s coral reef management efforts, visit: Florida's Coral Reef
What Are Corals?
Corals are animals that have a symbiotic relationship with microscopic algae. The corals benefit from the nutrients and oxygen that the symbionts provide through photosynthesis, and the symbionts receive nutrients and protection from the corals. The symbionts also give the corals their beautiful spectrum of colors.
Coral reef development occurs primarily in areas with specific environmental characteristics: a solid structure for attachment, warm water temperatures, clear waters low in phosphate and nitrogen nutrients and moderate wave action to disperse waste and bring oxygen and plankton to the reef. Many of Florida's sport fish species and other marine animals spend significant parts of their lives, particularly during early development, on or around Florida's Coral Reef and its associated ecosystems.
Types of Reefs and Corals
The three major types of coral reefs around the world are atolls, fringing reefs and barrier reefs. Florida's Coral Reef most closely resembles a barrier reef; however, the reef is closer to shore and lacks the shallow in-shore lagoons found on most barrier reefs. For this reason, Florida's Coral Reef is more aptly referred to as a barrier bank reef. Florida also has patch reefs, which grow in shallow water between the reef and land. Patch reefs are typically small, often the size of a backyard or a small home.
Corals can generally be divided into two main categories: stony corals and octocorals, which include sea fans, sea whips and other soft corals. More than 45 species of stony corals and 35 species of octocorals are found along Florida's Coral Reef. Each species forms colonies with distinct shapes and structures. Marine sponges are also very important within the coral reef community, with more than 70 species found along the reef.
Stony corals are the major reef architects. Polyps, the living portion of corals, extract calcium from seawater and combine it with carbon dioxide to construct the elaborate limestone skeletons that form the reef backbone.
Historically, Florida's reef-building corals were brain and star. Brain coral is dome-shaped and has waves, folds and ridges that resemble those of a human brain.
Star coral can also be dome-shaped but has a distinctive star pattern on its surface that is caused by the accordion-like folds within its polyp cups.
In recent years, corals have experienced declines due to a combination of global and local factors. These include high ocean temperatures resulting in more frequent coral bleaching events, coral disease, poor water quality associated with land-based sources of pollution, planned and unplanned impacts resulting in direct physical injury and other human impacts. In 2006, elkhorn and staghorn coral were listed as threatened species under the Endangered Species Act, and in 2014 the boulder star coral, mountainous star coral, lobed star coral, rough cactus coral and pillar coral were also added.
Florida’s Coral Reef recently experienced a coral disease outbreak termed stony coral tissue loss disease. First reported in 2014 off the coast of Miami-Dade County, this outbreak has spread to the northern and southernmost extent of the reef, affecting more than half of Florida’s reef-building corals. The Florida Department of Environmental Protection, Florida Fish and Wildlife Conservation Commission, National Oceanic and Atmospheric Administration and National Park Service led a collaborative, multi-faceted response effort. Learn more about stony coral tissue loss disease.
To help restore the health and abundance of these corals throughout the reef, coral nurseries have been established along Florida's coast and in the Florida Keys. Land-based and in-water nurseries have been growing new colonies for relocation to reef sites where corals had once flourished.
Learn more about Florida's Coral Reef.