New drone image shows that 97% of corals in the northern Great Barrier Reef have died

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At least 97 percent of the corals on a reef in the northern part of the Great Barrier Reef have died during one of the most severe coral bleaching events on record.

The discovery was made by scientists from various institutions who used high-resolution drone images to monitor the reef near Lizard Island.

“At least 97 percent of the corals died in those three months. We were there to do our sea cucumber monitoring work, but there was silence among the nine of us researchers,” said Professor Jane Williamson, a marine biologist at Macquarie University who, with her colleagues, analyzed the coral die-off at North Point Reef on Lizard Island.

She said she was “horrified” after seeing the analysis. “We came out of the water and didn’t know what to say. It’s an iconic reef and the majority of it was dead,” she added.

Drone footage taken in March showed widespread coral bleaching and fluorescent corals, but by June almost all corals had died.

This bleaching event, which follows a similar one last summer, was the fifth in eight years and exposed parts of the reef to extreme heat stress.

Coral bleaching is a phenomenon in which corals lose their bright colors and turn white. This is usually due to temperature changes. Coral reefs are some of the most diverse ecosystems on Earth, providing habitat and food for a wide variety of marine species.

The footage collected by the scientists represents the first quantitative assessment of coral deaths resulting from this mass bleaching.

Four experts independently assessed the condition of each coral in designated areas of the North Point Reef.

“We don’t know how much coral has died beyond this reef. But we do know that according to other aerial photographs, almost a third of the Great Barrier Reef experienced ‘very high’ and ‘extreme’ levels of coral bleaching last summer,” the scientists wrote in The Conversation.

The scientists are calling for further studies to assess coral mortality.

This evidence comes after UNESCO called on the Australian government to publish data on the extent of coral deaths as soon as possible.

Environment Minister Tanya Plibersek recently announced that UNESCO would not list the Great Barrier Reef as a “World Heritage in Danger.” At the same time, however, UNESCO called on Australia to improve its climate action plans and land management practices.

“(Australia) is urged to make mortality rates public as soon as possible,” the UNESCO report said.

Dr Lyle Vail, director of the Australian Museum’s Lizard Island Research Station, said the development was heartbreaking.

“It’s pretty heartbreaking to lose all the coral recovery,” he said.