Types of Coral Reefs

Three types of Coral Reef

The different types of coral reefs include:

• Fringing reefs are reefs that form along a coastline. They grow on the continental shelf in shallow water. Fringing reefs are commonly found in the South Pacific Hawaiian Islands, and parts of the Caribbean.

• Barrier reefs grow parallel to shorelines, but farther out, usually separated from the land by a deep lagoon. Barrier reefs form when land masses sink, and fringing reefs become separated from shorelines by wide channels. Land masses sink as a result of erosion and shifting crustal plates of the earth (Crustal plates lift or sink the seafloor and adjacent land masses). Barrier reefs are common in the Caribbean and Indo-Pacific. The Great Barrier Reef off northern Australian in the Indo-Pacific is the largest barrier reef in the world. This reef stretches more than 1,240 miles (2,000 km).

• Coral Atolls are rings of coral that grow on top of old, sunken volcanoes in the ocean. They begin as fringe reefs surrounding a volcanic island; then, as the volcano sinks, the reef continues to grow, and eventually only the reef remains. The reef becomes an atoll. Atolls are reefs that surround a central lagoon. The result is several low coral islands around a lagoon. Atolls commonly occur in the Indo-Pacific. The largest atoll, named Kwajalein, surrounds a lagoon over 60 miles (97 km) long.