Types of Coral Reefs
Reef types are differentiated in large-scale along the reef's morphology. This is to say the size and the same of the reef itself in relation to any nearby land. Reef types and reef formations can be easily categorized along these lines. 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. That said, reef types do overlap with one another. Not only is that a common thing, but it is also usually the case.
Three Reef Types
The Caribbean 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
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.
FRINGING REEFS (Also known as Shore 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 can be found all around Roatan. In fact, fringing reefs can be found around the Bay Islands. Fringing reefs are by far and away the most common of the three major reef types. Fringing reefs can be found in all major coral growing regions of the globe.
Fringing reefs are more susceptible to human activity and land-based activity and benefit most from Marine Parks. They lack the lagoons which buffer freshwater, pollutions, runoff, and sedimentation. Fringing reefs have been the most affected in coastal areas because of their proximity to human activity and urban development.
- Great Barrier Reef
- IndoPacific Barrier Reef
- Mesoamerican Barrier Reef
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. Barrier Reefs are big magnets for Scuba Diving.
THE GREAT BARRIER REEF
The Great Barrier Reef in Austrailia is 1200 miles in length. Barrier Reef is a chain of many reef formations, among which barrier reefs exist.
THE INDOPACIFIC BARRIER REEF
The second largest barrier reef is the Indopacific Barrier Reef which exists off the coast of New Caledonia. It measures some 400 miles. This reef is 1 to 8 miles wide. There are other large barrier reefs in Fiji and Vanua Levu which measures 170 miles in length.
MESOAMERICAN BARRIER REEF
The Caribbean has very few barrier reefs. In fact, there are only two. The largest of these is the Mesoamerican Barrier Reef, which runs from Belize to the Bay Islands of Honduras (Roatan, Guanaja, Utila). The second largest reef in this area is found in east Nicaragua of the coast of Providencia.
An atoll is an annular (circular) oceanic reef. Atolls often surround a large, and often deep, lagoon known as a "central lagoon."
The South Pacific is home to many atolls. Some of the more noteworthy formations are in French Polynesia, the Marshall Islands, Micronesia, and in the Cook Islands.
There are atoll formations in the Indian Ocean as well. Look no further than the Maldive & Chagos Islands, Cocos Islands, and the Seychelles Islands. Atolls are relatively rare in the Caribbean with less than 27 known atolls in this area. The IndoPacific has far more atolls than the Caribbean. The reason for this is that volcanic island formations and subsidence is more prevalent in the IndoPacific area and the IndoPacific area is many times the size of the Caribbean.
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.