New images illustrate devastating coral bleaching in Australia’s Great Barrier Reef

New footage of Great Barrier Reef’s coral bleaching
New footage of Great Barrier Reef’s coral bleaching

Dramatic new images and video have been released of coral bleaching along Australia’s Great Barrier Reef, prompting the Australian government to raise its response to a level three, its highest.

“A level three response level means we’re stepping up surveys in response to the coral mortality to help us better understand the effects of various pressures on the Reef and help guide management actions,” said Russell Reichelt, chairman of the Great Barrier Reef Marine Park Authority (GBRMPA), in a statement Sunday.

The video was shot by a team from CoralWatch, a citizen science project based out of the University of Queensland, Australia, that aims to raise awareness surrounding the health and conservation of coral reefs. WWF Australia released the video and images Monday.

Great Barrier Reef
An image released by WWF Australia of coral bleaching in the Great Barrier Reef. Catlin Seaview Survey/WWF Australia

Coral is an animal. What we typically refer to as coral is made up of hundreds to thousands of small creatures called polyps. These coral are extremely sensitive and can only live in a very narrow range of temperatures. Microscopic algae called zooxanthellae live inside their tissue and are responsible for providing coral with their colour, as well as with 90 per cent of the energy they need to grow as well as reproduce.

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Great Barrier Reef
An example of the coral bleaching that has occurred along the Great Barrier Reef. XL Catlin Seaview Survey/WWF Australia

Coral bleaching occurs when the relationship between the coral and the zooxanthellae breaks down, revealing the white “skeleton” of the host coral.

Usually, high ocean temperatures are the cause of coral bleaching. Even a one degree increase for just a month can result in bleaching, which in turn starves the coral.

According to the GBRMPA, much of the recent coral bleaching — and mortality — has occurred around Cape York at the most northern point of Australia. Up to 50 per cent of the coral deaths have occurred due to sustained above-average sea surface temperatures.

There has been a bit of good news over the past week: the late arrival of the country’s wet season has helped spare the 344,000 square kilometre-area from further die-off.

Great Barrier Reef
Coral bleaching has killed off much of the coral along the northern Australian coast. Catlin Seaview Survey/WWF Australia

“Further wet weather has brought down ocean temperatures, providing reefs south of Cooktown with a much-needed reprieve,” said Reichelt.

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However, they still need to determine the extent of the damage caused by the country’s unseasonably warm temperatures. This year’s record strong El Niño has almost certainly played a role in the warm ocean. In 1998 — the last time we experienced such a strong El Niño — more than 50 per cent of the reef was affected.

There is worldwide concern over how climate change and the resulting rise in sea surface temperatures will affect coral around the world.

“The health and future of the Great Barrier Reef is a priority for us — bleaching reinforces the need for us to continue working with our partners to improve the Reef’s resilience to give it the best possible chance of dealing with climate change impacts,” Reichelt said.