There are many Types of coral reefs that the scientists have discovered along the years: patch reefs, barrier reefs, atolls and fringing reefs. The differences between Types of coral reefs are their geographical location, shape, size, color, etc. For example, one of the Types of coral reefs, the patch reefs are located near the shoreline, where various hill-like rock formations are close enough to the surface that will allow them to grow.
Another of the Types of coral reefs known to men, the fringing reefs extend from the outer shore towards the sea. This kind of coral reef only occurs on rocky coastline areas and forms their own ridge parallel to the shore. Being marine creatures, corals cannot exist above the water, thus the upper part of the reef becomes a sort of a plateau, called the reef flat. These Types of coral reef have a flat that reaches towards the shoreline. The part of the reef that reaches to the depths of the water is called the reef crest. This part offers the most favorable for the reefs to grow, so it extends both upwards and downwards, toward the depth.
One of the truly amazing and unusual of all the Types of coral reefs known to man is the atoll. The coral atolls present themselves to the eye as a big shallow bank, with a depression located in the middle, generally in the shape of a ring.
Charles Darwin, the British naturalist had a theory about how these Types of coral reefs came into being. The coral atolls usually evolve around volcanic islands; when the volcano erupts, over a long period of time the island slowly sinks into the ocean. However, the coral reef continues to grow along the shore of the ever-sinking island and so when the island is completely beyond sea level, what started of as a fringing coral reef is now an atoll of circular shape with a depression located in the middle of it.
