How to Identify Types of Coral Reefs

What are the three main types of coral reefs?

A. Fringing reefs, barrier reefs, and atolls

B. Patch reefs, platform reefs, and cays

C. Shelf reefs, lagoon reefs, and pinnacle reefs

Answer:

A. Fringing reefs, barrier reefs, and atolls

Coral reefs are underwater structures made from calcium carbonate secreted by corals. There are three main types of coral reefs: fringing reefs, barrier reefs, and atolls.

Fringing reefs:

Fringing reefs are the most common type of reef. They grow directly from the shoreline outwards, forming a border along the coastline. Fringing reefs are often found in shallow waters.

Barrier reefs:

Barrier reefs are separated from the shoreline by a lagoon. They are usually farther offshore and larger than fringing reefs. The Great Barrier Reef in Australia is an example of a barrier reef.

Atolls:

Atolls are circular or horseshoe-shaped reefs that surround a central lagoon. They are usually found in the open ocean and are formed from the growth of coral around a sinking volcanic island.