Stay up to date with notifications from The Independent

Notifications can be managed in browser preferences.

Great Barrier Reef corals could collapse if sea temperatures rise by 0.5°C, scientists warn

Great Barrier Reef corals have developed a mechanism to cope with warmer oceans - but this could break down if they get too hot

Doug Bolton
Thursday 14 April 2016 19:21 BST
Comments
Fish swim in the Great Barrier Reef, off the coast of Australia
Fish swim in the Great Barrier Reef, off the coast of Australia (AFP/Getty Images)

Your support helps us to tell the story

From reproductive rights to climate change to Big Tech, The Independent is on the ground when the story is developing. Whether it's investigating the financials of Elon Musk's pro-Trump PAC or producing our latest documentary, 'The A Word', which shines a light on the American women fighting for reproductive rights, we know how important it is to parse out the facts from the messaging.

At such a critical moment in US history, we need reporters on the ground. Your donation allows us to keep sending journalists to speak to both sides of the story.

The Independent is trusted by Americans across the entire political spectrum. And unlike many other quality news outlets, we choose not to lock Americans out of our reporting and analysis with paywalls. We believe quality journalism should be available to everyone, paid for by those who can afford it.

Your support makes all the difference.

Coral systems in Australia's Great Barrier Reef could collapse if climate change causes the oceans to warm by more than 0.5°C, experts have warned.

Researchers from James Cook University in Queensland made the worrying discovery while studying the link between warming waters and coral bleaching, a phenomenon where coral loses its colour and grows at a much slower rate.

They found that corals within the reef, over time, have developed a tolerance mechanism which allows them to adapt to sharp increases in sea temperatures without bleaching occuring.

By analysing sea temperature data stretching back 27 years, they managed to establish an average maximum monthly temperature for each part of the reef, and found the bleaching threshold was around 2°C above that figure.

Digging into the numbers, they discovered when sea temperatures rose to just below the threshold and then fell again, the coral's tolerance to subsequent temperature increases above the threshold went up.

By contrast, corals which experienced temperatures over the threshold and didn't get the chance to develop this tolerance were more likely to be bleached.

Essentially, the more the coral was exposed to warmer seas, the greater its resistance to temperature-induced bleaching became.

However, this mechanism can only go so far. The team believe that even the corals which have established a tolerance will be vulnerable to bleaching if sea temperatures increase by 0.5°C above the current average - a rise which is expected to happen within the next 40 years if current trends continue.

In the words of one expert from the university's ARC Centre of Excellence for Coral Reef Studies (ARC CoE): "In future summers, bleaching events will occur more often and, without the practice run, become even more severe - with a greater risk for coral mortality and a fast decline in coral cover across reefs."

The centre's Professor Peter Mumby concludes: "Our results underscore, once again, the importance of global action to reduce greenhouse gas emissions. We can still have a beautiful reef if people are willing to change behaviour."

Join our commenting forum

Join thought-provoking conversations, follow other Independent readers and see their replies

Comments

Thank you for registering

Please refresh the page or navigate to another page on the site to be automatically logged inPlease refresh your browser to be logged in