Quarter of world's corals destroyed

A A A

More than a quarter of the world's coral reefs have now been destroyed, mostly in the past decade, and nearly three-quarters are likely to be gone within 50 years, a startling new international study says.

More than a quarter of the world's coral reefs have now been destroyed, mostly in the past decade, and nearly three-quarters are likely to be gone within 50 years, a startling new international study says.

The report, by the official Global Coral Reef Monitoring Network, is the most alarming yet on the fate of the richest and most beautiful celebrations of life in the seas. Although corals cover only one-fifth of 1 per cent of the area of the oceans, they are home to one-quarter of all their species.

The report documents how the reefs of 93 countries - living entities built over centuries by tiny creatures - are being destroyed by over-fishing, pollution, global warming and tourism.

The United Nations Environment Programme, one of the international bodies that established the monitoring network, has just set up a Coral Reef Unit to tackle the crisis. Professor Klaus Töpfer, its executive director, said: "Coral reefs may be the equivalent of the canaries in coal mines giving early warning that the world's ecosystems can no longer cope with growing human impact."

The report says that by 1992 10 per cent of the world's reefs had been lost, but this had shot up to 27 per cent by the end of last year. The worst-affected areas are the Indian Ocean, where 59 per cent of the reefs have been lost, the Middle East (35 per cent) and South-East and Eastern Asia (34). The healthiest ones are in the Pacific and off Australia.

The Caribbean, which has lost about a quarter of its reefs, has some of the longest-standing problems. Decades of over-fishing and pollution have severely undermined the reefs' health, making them prey to disease.

Sewage and fertiliser running off the land encourage the growth of algae which choke the living coral polyps and cut off their supplies of light and oxygen. Over-fishing makes this even worse because it takes away the fish that would otherwise eat the algae and keep them in check.

Building on the coasts - or even cutting down forests inland - causes soil to be washed into the sea, smothering the polyps. Garbage has the same effect. Chemical and oil pollution poisons them and so does cyanide often used by fishermen to stun their prey off the Philippines and other areas.

Reefs are mined and dynamited to provide construction materials and careless tourists can also damage them by dropping anchors from pleasure boats onto the reefs, or even walking on them.

The biggest threat of all, however, says the report, is global warming. When water temperatures get too high the polyps turn white and die. About 16 per cent of the world's reefs were destroyed by such "bleaching" in just nine months in 1998, when temperatures in parts of the tropics exceeded all records, particularly affecting the Indian Ocean, South-East Asia and the far-western Pacific. In many areas, 60 to 90 per cent of the reefs were lost. The Seychelles, Maldives, Philippines, Kenya and Taiwan were among the worst-affected areas, but Australia's Great Barrier Reef and most of the Pacific largely escaped.

Some of these reefs, the report says, may revive if the oceans cool again, but scientists fear that as global warming increases the crisis will go on getting worse. It predicts that if global warming and other damage continues, 40 per cent of all the world's reefs will be lost by the end of this decade, and 70 per cent by the middle of the century. The effects will damage economies: 20 countries have few sources of income other than fish caught on the reefs and the tourists the corals attract.

Have you tried new the Independent Digital Edition apps?
News
Jerry Seinfeld Comedians in Cars Getting Coffee
peopleSitcom star urges men to be more supportive of women than ever
Life and Style
Living for the moment: Julianne Moore playing Alzheimer’s sufferer Alice
health
News
Jay Z
businessJay-Z's bid for Spotify rival could be blocked
Sport
Louis van Gaal is watching a different Manchester United and Wenger can still spring a surprise
News
The spider makes its break for freedom
VIDEO
Voices
A propaganda video shows Isis forces near Tikrit
voicesAdam Walker: The Koran has violent passages, but it also has others that explicitly tells us how to interpret them
Arts and Entertainment
books
News
people
Sport
Ashley Young celebrates the winner for Manchester United against Newcastle
footballNewcastle v United player ratings
Life and Style
love + sex
Arts and Entertainment
Victoria Wood, Kayvan Novak, Alexa Chung, Chris Moyles
tvReview: No soggy bottoms, but plenty of other baking disasters on The Great Comic Relief Bake Off
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
iJobs Job Widget
iJobs General

Recruitment Genius: Mechanical and Electrical Engineer

£35000 - £38000 per annum: Recruitment Genius: This leading provider of refrig...

Recruitment Genius: Concierge and Porter

£16000 - £18500 per annum: Recruitment Genius: Are you a customer focused, pro...

Ashdown Group: Front-End Developer / Front-End Designer - City of London

£27000 - £33000 per annum + Excellent benefits: Ashdown Group: Front-End Devel...

Recruitment Genius: 1st Line Customer Support Technician

£15000 - £19000 per annum: Recruitment Genius: This Waterlooville based softwa...

Day In a Page

War with Isis: Iraq's government fights to win back Tikrit from militants - but then what?

Baghdad fights to win back Tikrit from Isis – but then what?

Patrick Cockburn reports from Kirkuk on a conflict which sectarianism has made intractable
Living with Alzheimer's: What is it really like to be diagnosed with early-onset dementia?

What is it like to live with Alzheimer's?

Depicting early-onset Alzheimer's, the film 'Still Alice' had a profound effect on Joy Watson, who lives with the illness. She tells Kate Hilpern how she's coped with the diagnosis
The Internet of Things: Meet the British salesman who gave real-world items a virtual life

Setting in motion the Internet of Things

British salesman Kevin Ashton gave real-world items a virtual life
Election 2015: Latest polling reveals Tories and Labour on course to win the same number of seats - with the SNP holding the balance of power

Election 2015: A dead heat between Mr Bean and Dick Dastardly!

Lord Ashcroft reveals latest polling – and which character voters associate with each leader
Audiences queue up for 'true stories told live' as cult competition The Moth goes global

Cult competition The Moth goes global

The non-profit 'slam storytelling' competition was founded in 1997 by the novelist George Dawes Green and has seen Malcolm Gladwell, Salman Rushdie and Molly Ringwald all take their turn at the mic
Pakistani women come out fighting: A hard-hitting play focuses on female Muslim boxers

Pakistani women come out fighting

Hard-hitting new play 'No Guts, No Heart, No Glory' focuses on female Muslim boxers
Leonora Carrington transcended her stolid background to become an avant garde star

Surreal deal: Leonora Carrington

The artist transcended her stolid background to become an avant garde star
LGBT History Month: Pupils discuss topics from Sappho to same-sex marriage

Education: LGBT History Month

Pupils have been discussing topics from Sappho to same-sex marriage
11 best gel eyeliners

Go bold this season: 11 best gel eyeliners

Use an ink pot eyeliner to go bold on the eyes with this season's feline flicked winged liner
Cricket World Cup 2015: Tournament runs riot to make the event more hit than miss...

Cricket World Cup runs riot to make the event more hit than miss...

The tournament has reached its halfway mark and scores of 300 and amazing catches abound. One thing never changes, though – everyone loves beating England
Katarina Johnson-Thompson: Heptathlete ready to jump at first major title

Katarina Johnson-Thompson: Ready to jump at first major title

After her 2014 was ruined by injury, 21-year-old Briton is leading pentathlete going into this week’s European Indoors. Now she intends to turn form into gold
Syrian conflict is the world's first 'climate change war', say scientists, but it won't be the last one

Climate change key in Syrian conflict

And it will trigger more war in future
How I outwitted the Gestapo

How I outwitted the Gestapo

My life as a Jew in wartime Berlin
The nation's favourite animal revealed

The nation's favourite animal revealed

Women like cuddly creatures whilst men like creepy-crawlies
Is this the way to get young people to vote?

Getting young people to vote

From #VOTESELFISH to Bite the Ballot