Great Barrier Reef More Resilient than Assumed

The Great Barrier Reef has survived a wide range of temperature in the past, a new study from Australia shows.

Researchers at Australian National University and colleagues collected fossilized coral samples from the Reef and mapped its history. The team used the corals to reconstruct the ocean surface temperature between 20,000 and 13,000 years ago, abc news reported.

They found that the Reef grew during the last ice age, when the ocean temperature was four to five degree lower than it is now.

"It was right at the colder limit of what corals can take, but the reef grew and developed from there," said Dr Helen McGregor, from ANU Research School of Earth Sciences, according to a news release.

The study shows that the Great Barrier Reef is much tougher than previously assumed and has the ability to cope with warm oceans.

"The Great Barrier Reef has previously coped with changes in ocean temperature and corals seem to be able to adapt to warmer temperatures, at least when the changes occur over a few thousand years," McGregor told ABC news.

Coral reefs are also called the "rainforests of the ocean" as they provide shelter to millions of marine organisms.

The Great Barrier Reef stretches 2,300 kilometres along the coast of Queensland and has around 2,900 reefs, according to WWF. The Reef is home to 1,500 species of fish, 134 species of sharks and rays, six species of threatened marine turtles and over 30 species of marine mammals.

Researchers fear that the abrupt changes in ocean temperature along with rise in acidity levels will damage the corals. The coral reef is also facing higher sediment load and attacks from predators such as crown of thorns starfish, which eats hard or stony coral polyps.

"The corals survived a gradual temperature rise from 20,000 to 12,000 years ago. However we don't know if the reef will survive that change over the next 100 years," Dr McGregor said. "We do know that if summer temperature extremes occur more frequently, then corals are likely to bleach more regularly."

The study is published in the journal Nature Communications.

Research has shown that saving coral reefs is a cheap and efficient way of protecting coastlines from storms and rising sea levels.