The Three Types of Coral Reefs

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Types of Coral Reefs

Identifying major reef types is not an absolute science as many reef formations are intermediate versions of the three major reef formations we'll discuss in this article. Keep that in mind as we walk you through the three main reef formations.

The Caribbean area (and Roatan in particular) is especially tricky in that it has many examples of these intermediate reef formations which are in fact fringing reefs that generate open water between the shoreline and the reef formation. The open water created by these reefs can extend a mile or so off the shoreline. Are these barrier reefs, fringing reefs, or something else? Let's explore the alternatives.

There are three major types of Coral Reefs:

  • Fringing Reefs
  • Barrier Reefs
  • Atolls

1) Fringing Reefs

Fringing reefs grow directly from the shoreline. This type of reef formation does not create a lagoon between the edge of the reef and the shoreline. Fringing reefs can create shallow sub-tidal or intertidal areas with sandy bottoms, but these areas are not large enough to be considered lagoons. Fringing Reefs require the most protection through Marine Parks because they are the most susceptible to human activity as they don't have lagoon buffers. 

WHAT IS A LAGOON?

A Lagoon, as it relates to coral reef formations, is a wide band of water that is created from a barrier reef (or any reef type) and the shoreline and forms a deep or semi-deep body of water. Barrier reefs are not as common as atolls or fringing reefs. But they can be easily found in the waters of Roatan.

2) Barrier Reefs

Barrier reefs usually run parallel to the shoreline. They are extensive, and they are usually separated from the shoreline by a lagoon. They are a barrier between open waters and the shoreline, and because of their formation, the barrier reef wall is the divide between deep blue waters and clear shallow waters in a lagoon. 

3) Atolls

An atoll is an annular (circular) oceanic reef. Atolls often surround a large, and often deep, lagoon known as a "central lagoon."

BONUS: PATCH REEFS

Patch reefs are isolated outcrops of coral reefs which are surrounded by sand and or by seagrass. Patch reefs exist in a variety of sizes and formations, and for this reason, they don't warrant their category type but rather are an extension of the three reef category types described above.