New map shows coral reefs cover area as little as ten times less than previous estimates

A new atlas of coral reefs around the world has revealed that these marine ecosystems occupy a much smaller area than originally estimated, covering less than one tenth of one percent of the oceans, just half the size of France.

According to the United Nations Environment Programme’s World Conservation Monitoring Centre (UNEP-WCMC), the organisation that published the atlas, this is the most detailed assessment ever of the status and distribution of the world’s coral reefs. According to the UNEP, the new findings give new urgency to protect these habitats.

“Previous estimates of coral reef area, which didn’t have the benefit of our detailed maps, have been double or in some cases ten times over what we have now found to be the case,” said Mark Spalding, lead author of the atlas. “Furthermore, we also found that coral reefs are degrading fast in almost every country of the world. The atlas provides a critical baseline and a focus for action to reverse these trends.”

The atlas shows that the Republic of Indonesia has the largest area of coral reef, covering 51,000 sq km, just under 18% of the world total, followed by Australia, with just over 17%, down to Israel which has less than 10 sq km of coral reef. Perhaps surprisingly, France has the forth largest amount of coral reef, with over 14,000 sq km in its overseas territories, and the UK is the 12th largest coral reef nation, with over 5,500 sq km in its overseas territories. “Many coral reefs are under the ownership of the world’s wealthiest nations,” said Spalding. “Between them, Australia, France, the UK and the USA account for over one quarter of the world’s coral reefs – a critical resource in powerful hands.”

The atlas also contains the latest information on coral biodiversity, and shows that the most diverse region in the world for reefs is centred around the Philippines, Indonesia, Malaysia and Papua New Guinea, with between 500 and 600 species of coral in each of these countries. However, these are also some of the most threatened coral reefs in the world, says the UNEP, with 82% in Indonesia considered to be at risk from activities such as blast fishing – using explosives to kill fish. In Thailand and The Philippines, 96-97% of reefs are threatened, 91% in Malaysia, 46% in Papua New Guinea, and 32% in Australia (see related story in this week’s news).

Not only are coral reefs essential for biodiversity, and supporting the fish on which many people depend, but they are also a source of chemicals for drugs, including AZT, used to treat people with HIV, which is extracted from a Caribbean reef sponge. More than half of all new cancer drug research focuses on marine organisms, says UNEP. Well managed reefs can also be a permanent source of foreign income in the form of tourism. “Australia’s foreign earnings from tourist industries in the Great Barrier Reef alone is greater than income from all of Australian fishing industries combined,” said Dr J.E.N. Veron, Chief Scientist with the Australian Institute of Marine Science, a contributor to the atlas.

“Often remote from reefs, deforestation, urban development and intensive agriculture are now producing vast quantities of sediments and pollutants which are pouring into the sea and rapidly degrading coral reefs in close proximity to many shores,” said Klaus Toepfer, UNEP Executive Director.

However, there is some good news. Initiatives including the new International Coral Reef Action Network (ICRAN), funded by the United Nations Foundation, are taking part in activities such as working with local communities to develop sustainable management practices for coral reefs. “Through ICRAN, many separate activities are being brought together in a coherent way to make a real difference on the ground, where peoples’ needs count,” said Toepfer.

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