‘It shouldn’t be white’: One of the Great Barrier Reef’s healthiest reefs is succumbing to bleaching | Surroundings

tthrough a snorkel mask, the corals struggling to survive in the heat are easy to see. Some have turned white, while others infused a fluorescent pigment into their flesh – it’s spectacular, but it’s also a sign of a coral in deep distress.

This is John Brewer Reef, about 70km from Townsville in Queensland – the center of a widespread coral bleaching event. For hundreds of miles in both directions, reefs fight the same battle.

While drifting over one of the roughly 3,000 individual reefs of the vast Great Barrier Reef on Sunday afternoon, two scientists land in Brisbane for a 10-day United Nations monitoring mission.

A submarine on the John Brewer Reef where researchers investigate coral bleaching. Photo: Harriet Spark

Just to the south there is another mission. Scientists are in the air, observing the bleaching from above in a series of government-chartered flights that will have traversed the entire length of the 2,300km reef by mid-week.

When the Guardian enters the water, the first thing Dr. Adam Smith does is glance at his dive watch. It tells him that the water is 29C. That’s hot.

Staghorn corals clinging to the edge of the reef come into view and almost all of them are partially or all white.

Thousands of colorful reef fish, some graceful sharks and many still healthy corals share the space with the fighters. Soft corals nestled in the holes at the top of the reef are white.

Other corals in the form of giant plates do better, but about half put off a spectacular but worrying fluorescent show of pink and blue.

The same piece of coral on the John Brewer Reef photographed on February 3, 2022, and then again on March 20.
The same piece of coral on the John Brewer Reef photographed on February 3, 2022 and again on March 20.

“The coral is actually starving,” said Smith, the director of consulting firm Reef Ecologic.

“We’ve definitely just seen corals that are stressed and white.

“This is one of the healthiest reefs off Townsville and one of the best in the entire Great Barrier Reef. So to tax and damage these corals… well, it’s probably the same with other reefs down here.”

The UN Mission to the Reef will examine the response of the state and federal government to reef management and policies.

Last year, the World Heritage Commission ignored UNESCO’s scientific advice that it should be placed on the “at risk” list due to the impact of global warming and slow progress in fighting pollution the reef faces.

Coral bleaching across thousands of miles of the world’s largest reef system is just one of Australia’s struggles with the climate emergency. Wildfires, floods, fluctuating rainfall, heat waves and extreme weather are all amplified by the rising amount of greenhouse gases in the atmosphere.

The Reef Marine Park Authority is waiting for the aerial surveys to be completed before it can compare this bleaching event with other events in 1998, 2002, 2016, 2017 and 2020.

But this is the first time widespread bleaching has occurred during a La Niña weather pattern — the phase of a cycle of shifting warm areas in the Pacific that brings more cloud and rain and cooler conditions over the reef.

Coral bleaching on the John Brewer Reef, off the coast of Townsville in the Great Barrier Reef Marine Park.  Queensland.  Australia.
Experts say there’s a chance John Brewer Reef could recover from coral bleaching, but there are still “physiological costs.” Photo: Harriet Spark

Scientists had hoped that a La Niña would be an opportunity for the corals to grow, spawn and multiply. A break from his fight with climate change. But no.

“This is the first time we’ve seen mass bleaching in a La Niña. That’s because of global warming,” said Prof. Terry Hughes, a leading coral scientist at James Cook University in Townsville.

Hughes and others who viewed the Guardian’s images of John Brewer said there’s a chance many corals could survive if the water temperature drops — and there are signs that it will.

“That’s a moderately bleached reef,” Hughes says after seeing drone footage. Early signs of the aerial flights suggest that John Brewer may have streamlined better than other reefs in this central region.

But Hughes warns that there are “physiological costs even if the coral is alive.”

Due to heat stress and producing fluorescent pigments or losing their color, the corals are completely weakened, making them more susceptible to disease, slowing their growth and affecting their ability to reproduce.

Scientists sincerely fear what awaits the reef when the next warm phase known as El Niño hits. That could happen in the coming years.

“It’s depressing to think about,” Hughes says.

On the boat Sunday afternoon, Paul Crocombe, the owner of Adrenalin Snorkel and Dive, tried to navigate the complex story of bleaching and reef health in a passenger briefing. He has seen this reef bleach before and he sees it today.

“There’s plenty of evidence of bleaching here. That’s tough for [those corals]but there are many corals that still have a lot of color.

“The reef is really resilient. It will come back. But it will be hard for it to keep up if they [bleaching events] come by too often. At the 2016 event, there were large white areas [at John Brewer]† This is serious, but not serious.

“In the last two weeks we have seen an increase in the amount of bleaching. It’s always a concern.

“But how many times have you heard that the reef will be dead in 20 or 30 years. That’s just not true.

“Yes, it will change and what we have seen today may be very different from what you will see in 30 years, but there will be a reef and there will be corals. We are asked if there is anything else to see. There is so much misinformation.”

Crocombe’s business doesn’t need any more bad news. He says he has reached the limit of his loan after the number of visitors fell due to the pandemic.

Coral bleaching on the John Brewer Reef, off the coast of Townsville in the Great Barrier Reef Marine Park.  Queensland.  Australia.
Jeremy Gacel, who made his first trip to the Great Barrier Reef on the submarine, was disappointed to see the coral on John Brewer. ‘It’s sad for me, because I like diving. It shouldn’t be white.’ Photo: Harriet Spark

Crocombe says action must be taken quickly to reduce greenhouse gas emissions, and believes that all pollution — which comes from agriculture during floods and what people pump into the air by burning fossil fuels — should be taxed.

Jeremy Gacel, 31, was one of the divers on John Brewer. He has been traveling the world for nearly five years, diving in Central America and the west coast of Australia. This was his first dive on the Great Barrier Reef.

Smaller fish are usually hard to see in the dark staghorn corals, but as they turn white they are easier to see. “It was full of life and lots of fish. The bleaching is a bit disappointing – it’s sad for me because I like diving. It shouldn’t be white.”

Does he know what causes the bleaching? “People,” he says.

“It’s not just the ocean. I am an ice climber and I have seen the ice disappear. The water is getting warmer and warmer and reefs are super fragile. I know.”

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