Most scientists who study coral reefs generally recognize that there are three major types of coral reefs, i.e. the fringing reefs, Atolls and barrier reefs. The conventional way of recognizing and differentiating the three different types of coral reefs is through their morphology which involves study of the shape and size of the reef and how it relates the land nearby if any. While this helps in distinguishing between various types of coral reefs, it is however not sufficient. The different types of coral reefs do overlap from time to time particularly when it comes to the dominants animals and plants in the coral as well as ecological interactions among other similarities.
The fringing reefs are also referred to as shore reefs and grow from a shore directly. The main characteristic of the fringing reefs that differentiate it from other types of corals is the absence of a lagoon between the shore and the reef. This is however not to mean that you won’t find some areas of shallow sub-tidal or intertidal sand bottom that lies between the inshore edge and the beach as it does exist. Of the three major types of coral reefs, the fringing reef is actually the most common one. But due to the absence of a lagoon that effectively buffers pollution, sedimentation and freshwater runoff, fringing reefs are heavily exposed to many threats that could lead to their utmost destruction. Fringing reefs continue to be heavily decimated all over the world due to intensive agricultural activities and increased coastal development.
These are highly extensive linear coral reef complexes which lie parallel to the shore and a lagoon separates the reefs from the shore. A lagoon is a comparatively wide water band lying between the main coral reef development area and the shore. Barrier reefs are the rarest type of the three major types of coral reefs even though they exist in abundance in the Pacific and tropical Atlantic. The world’s largest barrier reef is the well known Great Barrier Reef that spreads over 1200 miles across the northern coast of Australia.
Atolls simply refer to a circular system of oceanic reef that surrounds a large central lagoon. These types of coral reefs are annular in nature and relatively more common than the barrier reefs but less common than the fringing reefs. The Indian Ocean for example is home to many atoll formations with most of them being concentrated in the Chagos and Maldive Island groups, the Cocos Island and the Seychelles. Very few atolls exist in the Caribbean and are easily distinguishable due to their unique geomorphology.
These three major types of coral reefs play a crucial role on the planet. Besides being home to a vast majority of marine life, they are source of income through tourism and source of food. Savingcorals.com is a program that works to protect and save coral reefs from their impeding threat through research, preservation programs and education.