Your Online Guide to the World of the Coral Reef

Caribbean Coral Reefs

Caribbean coral reefs comprise only about 8% (by surface area) of the world's coral reefs.

This comes as no surprise considering the overall size of the wider Caribbean compared with that of the vast Indo-Pacific region.

Still, these reefs provide critical habitat to thousands of species - some of which are of very high commercial value.

Caribbean reefs also provide numerous other benefits to nearby human communities, not the least of which is a measure of shoreline protection from the hurricanes that regularly ravage these waters.

Caribbean coral reefs also serve as premier vacation attractions, affording excellent opportunities for visitors to explore the undersea wonders of the coral reef environment through snorkeling or scuba diving excursions.

Distinctive Characteristics of Caribbean Reefs

The term "Caribbean coral reefs" (as used herein) is not used in the strict sense of the Caribbean Sea proper.

Greater caribbean map
Greater Caribbean region

Rather, we use the term to denote a much broader region often referred to as the Greater Caribbean region, (formally known as the tropical western Atlantic).

This region includes the coral reefs of Florida, The Bahamas, Bermuda, and the northeastern coast of South America as well as those of the Caribbean Sea proper.

Caribbean Reef Types

Most of the coral reefs of the Greater Caribbean region are fringing reef systems. In many cases these are quite extensive and well developed, such as those that parallel much of the coast of Cuba, and the east coasts of Andros Island and Eleuthera in The Bahamas.

Caribbean fringing reef
A shallow fringing reef is seen as a light green band along the shore. Courtesy NASA

Fringing reefs also encircle most of the smaller islands of the Caribbean region such as Aruba, Bonaire, Antigua, and the Cayman Islands, providing some of the best Caribbean snorkeling opportunities to be had.

The entire Caribbean region is home to only two true barrier reefs. The largest (Belize Barrier Reef) is about 220 km in length and runs from the Yucatan (southern Mexico) to the Gulf of Honduras. A smaller barrier reef lies north of Providencia Island (Colombia) in the southwest Caribbean.

There are also only a few true atolls (between about 10-20) in the Caribbean region. Most of these lie offshore Central America from the Yucatan to Nicaragua, and most (if not all) appear to have developed in ways other than volcanic island subsidence as is typical of Indo-Pacific atolls.

The best developed Caribbean atoll is Glover's Reef, which lies about 50 miles off shore the coast of southern Belize.

Caribbean Reef Structure

Along with the overwhelming predominance of fringing reefs as the major reef type, Caribbean coral reefs tend to differ structurally from those of the Indo-Pacific region in a number of other ways.

One such marked difference is the rarity of a prominent algal ridge on Caribbean reef crests, a feature far more prevalent on Indo-Pacific reefs.

A Caribbeaan coral reef with abundant octocorals
Numerous octocorals adorn a Caribbean coral reef. ©

Another distinguishing structural feature of many shallow Caribbean reefs is that they often support an abundant mixture of sponges and octocorals that grow from the hard coral base of the reef (see photo; left).

These additions afford Caribbean coral reef surfaces substantial added biodiversity and topographic complexity.

Well developed reef systems of the Caribbean region also generally contain numerous patch reefs. Usually, the dominate corals of Caribbean patch reefs are Porites porites, Montastrea annularis, and other species of Diploria and Porites.

Biodiversity Of Caribbean Reefs

The Greater Caribbean became completely isolated from the Pacific Ocean some 3-4 million years ago by the closing of the Isthmus of Panama, and has since developed its own unique coral reef biota.

The diversity of Caribbean coral reef life is considerably poorer than that of the Indo-Pacific region. Here, "only" about 65 species of hard corals are recognized and perhaps 500-700 reef-associated fish species.

The center of marine biodiversity for the region lies in the west-central Caribbean Sea, in the neighborhood of the Jamaica - Belize Barrier Reef area. Reef biodiversity generally decreases with distance from this center.

For example, of the estimated 60-65 hard coral species recorded from the Greater Caribbean region as a whole, estimates ranging from 40-50 species have been recorded from The Bahamas. Likewise, the number of reef-associated fish species recorded from all of The Bahamas is "only" about 480, or about 80% of the total reef fish species recorded in the entire Greater Caribbean.

In contrast, as many as 62 species of hard corals were recorded at a single reef complex in Jamaica back in the 1960's - when reef health there was exceptional.

Current Status of Caribbean Coral Reefs

For many nations within the Caribbean Sea, coral reefs provide vital protection from the rages of frequent summer hurricanes.

Many island and coastal residents are also highly dependent on coral reef fisheries for both their food supplies and livelihoods. Coral reef related tourism (particularly scuba diving and snorkeling) also represent a major source of revenue.

Over the last 30 years, Caribbean coral reefs have suffered enormous declines both in terms of overall coral reef ecosystem "health" and the productivity of reef fisheries.

Caribbean reef overgrown with algae
Caribbean reef with heavy algal growth. Credit: NOAA

Overdevelopment of coastal areas, overfishing, direct tourism impacts such as overuse of particular reefs for recreational diving and snorkeling, and declines in water quality have in many cases led to dire consequences for coral reefs, leaving devastated underwater seascapes where thriving hard coral colonies once stood (see photo, above).

In recognition of the intrinsic value and vulnerability of their coral reef ecosystems, many Caribbean nations are developing more Marine Protected Areas (MPAs) and increasingly stringent regulations aimed at better protecting these resources.

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