Volunteer with Coral Reefs

As corals are related to sea anemones they share the same simple structure: the polyp which opens at one end with a mouth surrounded by a ring of tentacles. These tentacles have stinging cells that allow for the capture of small organisms.  Corals also extract calcium carbonate from seawater to create the hard, durable exoskeleton that protects these soft, sac-like bodies.  Shallow water corals also source food from zooxanthellae. These produce food through photosynthesis and in exchange, this helps shallow water corals to grow fast enough to build the enormous structures we call reefs.  Zooxanthellae also provides much of the colour that corals have.

Reproduction occurs during a mass coral spawning event that usually occurs at night and can happen several times a year.  Because coral reefs grow very slowly, many systems can be thousands of years old.  Some estimates suggest that most of the substantial coral reefs found today are between 5,000 and 10,000 years old.

• The largest of the coral reef systems, the Great Barrier Reef in Australia, is more than 2,400 kilometers long? It is so large that it can be seen from space.
• Coral reefs are the largest structures on earth of biological origin?
• Coral reefs can also be started on the shells of sunken boats? In fact, to help preserve different sea biomes, the navy will sink old ships to allow a coral reef to grow.
• Coral reefs are often called ‘the rainforests of the sea’?
• They first appeared in the Cambrian period, 570 million years ago?
• Coral reefs also help to improve the surrounding water quality? They act as a kind of filter that traps things floating in the water.

Coral reefs are increasingly threatened by a number of factors and because they are fragile and take a considerable time to ‘regrow’, the threats to them are all the more severe.  Climate change can seriously affect coral’s ability to produce the hard calcium carbonate exoskeleton that they rely on due to the large amounts of carbon dioxide released into the atmosphere.  Warming water temperatures can also cause coral bleaching.  Destructive fishing practices, can destroy precious reef systems in minutes and careless tourism – like the anchoring of large cruise ships – is also common. Coral reefs are extremely sensitive to pollution and thus agricultural pesticides and fertilisers, oil and gasoline make it difficult for coral to thrive.  In some places, reefs have been entirely destroyed, and in many places today the reefs are a pale shadow of what they once were.  Conservation efforts are thus crucial, and if you want to help, you can take part in volunteering with coral reef restoration and ‘regrowing’, to help speed the growth of much of what has been lost.