Coral expert predicts ''end in sight'' for reefs

By Steve Humphreys - 08 Dec 2010 21:45:1 GMT
Coral expert predicts ''end in sight'' for reefs

A foremost expert predicts that coral reefs could disappear in our children's lifetime. J.E.N. Veron, former chief scientist of the Australian Institute of Marine Science, has written in Yale Environment 360 that climate change will have catastrophic effects on reefs around the world. His article, reprinted in The Guardian, says that ''coral reefs can indeed be utterly trashed in the lifetime of today's children.''

As previously reported by The Earth Times, ocean acidification has a disastrous effect on coral. CO2 dissolves in sea water to form carbonic acid. This is a normal process, and over millions of years the oceans have remained slightly alkaline, as more acidic surface water mixes with deeper water, and carbonic acid is converted to bicarbonate ions.

When there is excess CO2 in the atmosphere, water near the ocean surface becomes acidic too quickly for this normal process to take place. All creatures which deposit calcium carbonate - not only corals, but crabs, sea urchins, and many others – are affected by the acidity of the water around them. If waters around coral reefs become too acidic, we will no longer see beautiful coral sculptures, but only a slimy coating of tiny organisms on the sea bed.

The world's oceans contain about 36,000 gigatonnes of carbon. But, according to Dr Veron, it is not only their part in the carbon cycle that is affected by climate change. The oceans also absorb heat from the atmosphere. Over the past fifteen years there has been a measurable rise in ocean temperature. When waters around coral reefs become warmer, algae which live in coral reefs produce increased levels of oxygen. Too much oxygen is toxic to the coral – so the algae are expelled, leading to coral bleaching and potentially killing the reef.

Coral reefs are among the most diverse ecosystems on the planet, supporting a huge range of other marine life. If they disappear - or are greatly reduced - within the next fifty years, our children's children will not only miss one of the wonders of the natural world, but will also have to deal with the consequences of huge environmental change. ''We cannot afford to wait until the predictions of science can be totally verified,” says Dr Veron. “How many of us wish to explain to our children and children's children that the predictions were there but we wanted confirmation?''