It's said that coral reefs are the rainforests of the oceans, and just like them they are depleting.

Just like them, they indicate the well-being of the planet, and equally they are home to millions of species which rely on their life-giving benefits for sustenance and survival.

As most of the world's rainforests are under serious threat from over-population, encroaching development, illegal logging and land reclamation, so too are the coral reefs being exploited for their resources. Add to that global warming and climate change, and the earth's sorely beating heart is slowly suffering from continuous cardiac arrest.

Dating back to the Mesozoic period 225 million years ago, coral reefs are one of planet's oldest and complex ecosystems. They play host to marine life from simple anemones to sea turtles, dolphins and whale sharks.

So what exactly is coral and how important is it to mankind? Coral and their reefs develop very slowly. It can take years for some corals to grow an inch. They consist of minuscule soft bodied animals called polyps. Together with a well measured and balanced relationship with algae they produce an abundance of colour.

This symbiotic relationship acts harmoniously with the algae (zooxanthellae) which absorbs carbon dioxide through photosynthesis, and emits oxygen that is used by the polyp. Millions of these polyps grow, replenishing from remains of former colonies to create the reefs. These reefs, visible from space, are actually millions upon millions of tiny animals.

Coral reefs require clean water. An imbalance will produce vast quantity of algae, which will compete against the slow growing coral for space. When this occurs, it starves the coral of oxygen and increases chlorophyll, which in turn reduces sunlight necessary for photosynthesis. The coral becomes susceptible to disease as less oxygen is available, which in turn decimates all the sea life dependent on it.

With the advent of fertilizers and pesticides which find their way into the sea, industrial and human sewage, toxic discharges from shipping, debris like oil and plastics, and an ever increasing tourist trade in scuba diving and general recreation, as well as cherry-picking for souvenir shops and aquariums, all are having a significant detrimental effect.

Add to that unsustainable coastal development and greater demand for marine resources to supply ever-expanding fisheries and seafood markets, and the situation is chronic. It doesn't end there. Modern fishing techniques which employ huge trawling nets, dynamite and cyanide all conspire to damage the reefs.

There's more. Global warming and climate change (man-made or otherwise) are causing sea temperatures to rise. This creates coral bleaching, which is an unusual scientific term meaning "dead coral". The coral loses its colour, as the symbiotic relationship with the algae has gone, and it become white and brittle - dead or dying.

Unsustainable coastal development, rampant exploitation and global climate change will not only see the demise of coral reefs, it will have social and economic consequences not only now, but impact on future generations who will not view us kindly.

They are the pearl necklaces of the seas, sustaining life and beauty to a fragile earth.

The heartbeat is weak, but we still have time to revive it.

Learn more about this author, Bar De Ness.
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