Coral Reefs

As well as observing fish when we go snorkelling and diving, the coral reefs in which they live are just as stunning and a vital part of ocean life. Known as the “rainforests of the sea”, coral reefs are the greatest expression of ocean life and the largest living structure on the planet. Coral reefs are the most diverse and beautiful of all marine habitats.
What is a coral reef? Coral reefs are like underwater cities built from living animals (coral polyps) which usually live together in colonies. Hard corals, which are the only types of corals to form coral reefs, produce limestone skeletons. Amazingly, they do this with the help of tiny microscopic plants that actually live inside them. These plants give the corals their colours and capture energy from the sun by photosynthesis - just like plants in your garden!
Although they cover only 0.2 percent of the ocean environment, they are home to 25 - 30 percent of all fish species and are a home for oysters, sea urchins, sea anemones, jellyfish, crabs, shrimp, sponges, lobsters, octopus, clams and sea turtles, amongst many others.
Over 3,000 species can live on one reef.
Coral reefs worldwide are under intense pressure. The continued development of coastal regions has caused silt water to run into the seas, smothering these delicate systems, and, coupled with the damage caused by destructive fishing methods, it is thought that up to 90 percent of reefs have been impacted by humankind.
There is also evidence that rising water temperatures are causing a phenomenon known as bleaching, which is fatal to reefs. Coral reefs only thrive in warm, clear water with few nutrients (which is why water pollution kills corals) so they generally only grow in the subtropics and tropics.
There are three major types of coral reefs that exist, firstly fringing reefs they are directly attached to a shore and are the most common kind of reefs found in the Caribbean.
Secondly barrier reefs that run parallel to the shore line, like the Mesoamerican Barrier Reef along the east coast of Mexico.
Lastly there are atolls which are a roughly circular reef surrounding a lagoon. Some of these coral reefs that are present today have been alive for over 50 million years.
Diving a reef can be the highlight of a diver’s life, but we have a huge responsibility when exploring reefs not to harm or disrupt them in any way. A considerate approach is vital if we are to preserve these wonderfully vibrant ecosystems. Why?
Well, coral reefs protect coastal dwellings, agricultural land and beaches by forming natural barriers along the shorelines of the sea. Parts of Florida would have been under water if coral reefs would have not existed. Less known, coral reefs are widely used in the treatment of cancer, HIV, cardiovascular diseases and ulcers. Porous limestone skeletons of the corals have been used in grafting human bones. If you cut yourself on coral and don´t clean it properly, it can grow inside your skin!
There are many different types of corals, and most of them have self descriptive names, just as fish do. Fan coral, brain coral, staghorn coral and table coral to name but a few.