Some info on reefs in the Caribbean! Extracts from our summaries on ecosystems

In the Caribbean region, it is estimated that reefs cover approximately 26,000 km² (Miloslavich et al., 2010). The majority of Caribbean reefs are close to the coast and to the surface. The main reef formations in the region are:

■ fringing reefs, which are close to the coast and represent the majority of reefs in the region

■ the coral reefs, further from the coast. The largest is found in front of the Belize coast. It is also the second largest barrier in the world (1000 km long) after the Great Barrier Reef in Australia (2600 km).

■ there are also 4 atolls in the Caribbean, including 3 off Belize and the last off Mexico.

■ the so-called "mesophotic" reefs, which are found more in depth. They are found in the Bahamas, in the Gulf of Mexico, off the US Virgin Islands and Puerto Rico.

In the Caribbean, it is estimated that a total of about 30,000 species of all groups reside in coral reefs (Reaka-Kudla, 2005). They serve both as habitat, nursery, hiding place or shelter, pantry, resting place, breeding ground, etc. for many taxa, including fish, algae, sponges, crustaceans, molluscs, worms, turtles and a whole microfauna (fungi, bacteria etc.) ubiquitous but less known.

Although the biodiversity of Caribbean reefs is impressive, it remains relatively low compared to other reefs on the planet. Indeed, unlike the Red Sea, the Indian Ocean and the Pacific Ocean which are connected, the Caribbean and the Gulf of Mexico are isolated. This isolation has existed for more than 13 million years, when the Isthmus of Panama closed, which connected the two Americas (Montes et al., 2015). One of the consequences of this isolation is strong endemism. But also a lower diversity, probably because of the lack of genetic flows with the other oceans (Bouchon and Bouchon-Navaro, 2010). Their isolation also makes them particularly vulnerable to exotic diseases as they have not been in contact with these pathogens for millions of years (Jackson et al., 2014).

About 21% of the Caribbean coast is thought to be directly protected by reefs (Burke and Maidens, 2004). This is certainly the most important role of coral reefs through their ability to dissipate wave energy (Gracia et al., 2018). Indeed, they are very often the first defense against the swell. It is estimated that wave energy can be reduced by 97%.

You can consult the species sheets in the menu on the right.