Seaweed chokes Australia's Great Barrier Reef

A A A

Australian natural wonder the Great Barrier Reef is overgrown in places by seaweed in what could be a worrying indication of the health of the coral structure, scientists said on Wednesday.

Surveys of the World Heritage-listed reef, already at risk from global warming, found that more than 40 percent of areas closest to shore were dominated by green weed, Professor David Bellwood said.

"We knew there would be some weed there, we were just surprised how much," Bellwood, a marine biologist from James Cook University, told AFP.

"We are concerned about it because it does look like a lot of weed and in other places in the world, weed is an indication of decline."

Bellwood said the offshore reefs, those at least 20 kilometres (12.4 miles) from Australia's eastern coast, were largely untouched by the algae but that some of those closer to shore were choking with weed.

While the reason for the build-up of greenery was not known, Bellwood said he suspected it was because algae-eating fish have died out in those areas.

"The question is, does this mean the Barrier Reef is in real trouble? That the reef is rotting from the inside out? Or does it mean to say that that amount of weed is natural? And the answer is: it's hard to say," he said.

Bellwood, from the Centre of Excellence for Coral Reef Studies, said the best defence for the reef would be clean water and the existence of herbivorous fish which could graze on the weeds.

"The Great Barrier Reef is in the best condition of any reef in the world," he said.

"However, it is suffering. And it has suffered significant declines in coral cover in the last few years. The presence of that weed is just another little red light."

Scientists have already warned that the 345,000-square kilometre (133,000-square mile) attraction is in serious jeopardy as global warming and chemical runoff threaten to kill marine species and cause disease outbreaks.

Bellwood said the seaweed could be just the latest problem for the reef.

"It's just that when you combine run-off and fertiliser and pesticides and climate change and human interaction and coastal erosion and coastal development and fishing and overfishing... these things are all starting to accumulate," he said.

The reef is believed to have deteriorated significantly since European settlement in 1788, after enduring coral disease, toxic blue-green algae and infestation by pestilent species such as the crown-of-thorns starfish.

Latest stories from i100
Have you tried new the Independent Digital Edition apps?
iJobs Job Widget
iJobs General

Tradewind Recruitment: English Teacher

Negotiable: Tradewind Recruitment: This post arises as a result of the need to...

Tradewind Recruitment: Class Teacher Required ASAP In Uminster

£120 - £150 per annum: Tradewind Recruitment: I am recruiting on instruction o...

Ashdown Group: Head of Finance - Financial Director - London - £70,000

£70000 per annum: Ashdown Group: Head of Finance - Financial Controller - Fina...

Ashdown Group: Marketing Executive - Wimbledon, SW London

£24000 - £28000 per annum + benefits: Ashdown Group: Marketing Executive - Wim...

Day In a Page

Greece elections: In times like these, the EU has far more dangerous adversaries than Syriza

Greece elections

In times like these, the EU has far more dangerous adversaries than Syriza, says Patrick Cockburn
Holocaust Memorial Day: Nazi victims remembered as spectre of prejudice reappears

Holocaust Memorial Day

Nazi victims remembered as spectre of prejudice reappears over Europe
Fortitude and the Arctic attraction: Our fascination with the last great wilderness

Magnetic north

The Arctic has always exerted a pull, from Greek myth to new thriller Fortitude. Gerard Gilbert considers what's behind our fascination with the last great wilderness
Homeless Veterans appeal: Homeless in Wales can find inspiration from Daniel’s story

Homeless Veterans appeal

Homeless in Wales can find inspiration from Daniel’s story
Front National family feud? Marine Le Pen and her relatives clash over French far-right party's response to Paris terror attacks

Front National family feud?

Marine Le Pen and her relatives clash over French far-right party's response to Paris terror attacks
Pot of gold: tasting the world’s most expensive tea

Pot of gold

Tasting the world’s most expensive tea
10 best wildlife-watching experiences: From hen harriers to porpoises

From hen harriers to porpoises: 10 best wildlife-watching experiences

While many of Britain's birds have flown south for the winter, it's still a great time to get outside for a spot of twitching
Nick Easter: 'I don’t want just to hold tackle bags, I want to be out there'

'I don’t want just to hold tackle bags, I want to be out there'

Nick Easter targeting World Cup place after England recall
DSK, Dodo the Pimp, and the Carlton Hotel

The inside track on France's trial of the year

Dominique Strauss-Kahn, Dodo the Pimp, and the Carlton Hotel:
As provocative now as they ever were

Sarah Kane season

Why her plays are as provocative now as when they were written
Murder of Japanese hostage has grim echoes of a killing in Iraq 11 years ago

Murder of Japanese hostage has grim echoes of another killing

Japanese mood was against what was seen as irresponsible trips to a vicious war zone
Syria crisis: Celebrities call on David Cameron to take more refugees as one young mother tells of torture by Assad regime

Celebrities call on David Cameron to take more Syrian refugees

One young mother tells of torture by Assad regime
The enemy within: People who hear voices in their heads are being encouraged to talk back – with promising results

The enemy within

People who hear voices in their heads are being encouraged to talk back
'In Auschwitz you got used to anything'

'In Auschwitz you got used to anything'

Survivors of the Nazi concentration camp remember its horror, 70 years on
Autumn/winter menswear 2015: The uniforms that make up modern life come to the fore

Autumn/winter menswear 2015

The uniforms that make up modern life come to the fore