The Guardians of the Great Barrier Reef
Australia’s scientists are working against time and climate change politics to save their beloved coral reef.
On a hot, still day in March, Terry Hughes climbed aboard a single-engine Cessna in the tropical Australian port of Cairns.
The world’s most-cited coral reef researcher, Hughes was with James Kerry, a marine biologist, and a local pilot. In seven hours’ time, they would arrive in the remote Aboriginal community of Lockhart River, but the purpose of the journey was not to reach that destination. It was to spend the time crisscrossing the 3,000 coral shoals and pinnacles of the Great Barrier Reef to look for traces of what they most feared to see: coral bleaching.
This kind of survey work is grueling, demanding constant concentration amid intense heat and engine noise. The scientists spend hour after hour peering out the plane’s small windows, calling out and recording numbers to score the condition of the coral of each individual reef, using spare moments to take photographs and video footage.
Just minutes after the plane buzzed northward over the turquoise and sapphire waters of the reef, Hughes and Kerry saw it: bone-white spots scattered among the smaller reefs that comprise the Great Barrier Reef — the telltale sign of mass coral bleaching. From the plane’s height, the pale patches were so large that to the untrained eye they might resemble stretches of white sand or surf breaking over the fringes of cays. As the plane flew so low that the two scientists could see turtles and crocodiles in patches of deeper water, there was no mistaking the white coral of the damaged reefs among the greens, purples, and pinks.
“There are other circumstances in which flying over the length and breadth of the Great Barrier Reef would be a fantastic adventure,” says Hughes, a phlegmatic Dubliner with tousled hair and a reluctant smile who directs the Australian Research Council’s Centre of Excellence for Coral Reef Studies at James Cook University. But this trip was “confronting.”
Coral bleaching occurs when excessively warm water kills off the algae that sustain tropical coral, causing it to turn white. The bleaching that struck the Great Barrier Reef in 2016 was the worst episode on record, killing off nearly 30 percent of the reef’s coral. Bleaching plagued the reef again in February and March, extending the cumulative damage to almost half of its coral cover. And now, the U.S. National Oceanic and Atmospheric Administration (NOAA) sees indications that the next summer peak (in Australia), in early 2018, could raise water temperatures enough to bleach large areas of coral — an event almost unknown in marine science a few decades ago — for a third consecutive year.
These developments have been profoundly distressing for a generation of respected coral reef researchers including Hughes and John “Charlie” Veron, the former chief scientist of the Australian Institute of Marine Science, who’s credited with having named a fifth of the world’s tropical coral species.
According to Veron, the world is seeing the demise of coral reefs. “I used to say there are children alive today who’ll see the complete collapse of coral reefs,” he says. “Well, I’m 72, and I might see that myself.”
Living coral and fish in the Great Barrier Reef on Oct. 13, 2009. (LCDR Eric Johnson/NOAA Corps)
Coral reefs are often likened to tropical rainforests, but they more closely resemble oases. The warm seas in which they thrive are the ocean’s deserts — starved of nutrients, constantly irradiated by brutal sunlight. The photosynthesizing plankton that form the basis of most marine food chains thrive in the colder, murky waters farther from the equator.
Tropical corals offer a way to survive these harsh conditions. Single-celled algae that would struggle to survive on their own take up residence in the tissues of anemonelike creatures known as polyps. In return for this protection, the algae, known as zooxanthellae, provide most of the nutrients the polyps need to survive. They also supply oxygen to form the white calcium carbonate exoskeletons that are the building blocks of reefs.
This relationship generates an astonishing biodiversity — one fundamental to the balance of marine life. Despite the fact that the world’s living coral covers an area of ocean only half the size of France, reefs support roughly a quarter of all marine species. One 2011 study found more crab species in a bathroom-sized area of coral than can be found in all of Europe.
The Great Barrier Reef is unique among such ecosystems. It is the largest living organism in the world, stretching 1,400 miles. Housing 2,900 reefs and 1,050 islands, it is a network of shoals, seagrass beds, mangrove swamps, and reefs covering an area roughly the size of Italy. It’s also home to some 350 species of tropical corals, which is about half the world’s total. Though its foundations date back as far as half a million years, it has gradually changed over that time, shifting southward and growing upward as sea levels and temperatures changed when the ice age receded. In its current form, it’s only about 10,000 years old.
It has been able to respond to climatic changes because when conditions are ideal, the marriage of polyps and zooxanthellae allows coral to grow extremely rapidly. But bleaching changes this equation, upsetting the delicate balance between the polyps and their zooxanthellae. Sometimes the corals can renew their zooxanthellae population. But if the conditions that cause the bleaching last too long, they die.
Even where coral death is widespread, reefs can recover over the course of years and decades. But if the bleaching blows come too close together, the chances of revival diminish. Ironically, some bleached corals appear to flourish at first as their already bright reds, purples, greens, and pinks take on a striking fluorescence. But fluorescent corals are deathly sick, and within a few days, the coral turns bone white. If they die, the harder corals become murky looking and mossy as seaweed colonizes them, while softer ones will rapidly disintegrate altogether.
And when this happens, the symphony of wildlife that surrounds a healthy reef — the pecking of parrotfish as they feed on algae, the clicking of snapping shrimp hunting their prey — disappears and is replaced by an eerie silence. Gone, too, are most of the small, bright fish that used to dart around the reef, leaving the water unusually still.
“It’s very somber, when there’s that much death happening all at once,” says Mark Eakin, who coordinates the coral reef satellite monitoring program at NOAA. “It’s shocking, it’s heartbreaking. Scientists are trained to think analytically and somewhat dispassionately, but you cannot stay emotionally detached when something like this happens.”
What Eakin describes is an anguish shared by many coral reef researchers. These scientists, who’ve spent their careers working on the Great Barrier Reef, are now contending with an uncomfortable feeling — and for many, that feeling resembles grief.
A panoramic image of coral death at Lizard Island after a bleaching event in May 2016. (The Ocean Agency/XL Catlin Seaview Survey/Richard Vevers)
The realization of just how profound a threat climate change poses to reefs is a fairly recent one. That first mass coral bleaching that occurred off the coast of Panama in 1982 and 1983 was initially believed to be the result of chemical spills. It wasn’t until 1984 that scientists finally identified warmer waters brought by an El Niño pattern as a key contributor. But it took almost two more decades before the scientific community began to seriously consider what global warming might mean.
Ove Hoegh-Guldberg, deputy director of the Centre of Excellence for Coral Reef Studies, was one of the first scientists to study how climate change could make bleaching more common. His study, published in 1999, was the first to link the rapid improvements in climate modeling with the developing science on bleaching to predict that global warming could become a global catastrophe for reefs. “[M]ost indicators point to the fact that mortality rates are likely to rise within the next few decades to levels that may approach almost complete mortalities,” he wrote.
Deciding it was important enough to reach a wider audience, the then-mid-career academic wrote a more accessible version of his research for Greenpeace that same year. The nonprofit launched a global campaign based on his work, attracting broad media coverage. Almost immediately, Hoegh-Guldberg found himself in the spotlight, attacked by conservative media commentators and politicians. His early work on climate change received some scathing peer reviews and “so-called friends were sometimes not so friendly,” his wife, Sophie Dove, who is also a marine biologist, recounted in a 2009 documentary.
“Most of the other researchers in the 1990s, and even into this millennium, were poo-pooing the idea that climate change was a significant threat to coral reefs,” Hoegh-Guldberg says of that period.
In the years since, other coral reef scientists have experienced pushback and criticism for speaking out about climate change. Charlie Veron says academics often feel that it’s unscientific to “parade the science to the general public.” But he — like Hoegh-Guldberg — believes that as the threat to reefs has grown, it has become imperative to reach out to the public.
In 2016, Veron gave 61 interviews on the threat of climate change to coral reefs, motivated in part by the amount of attention given to climate skeptics in the worldwide media. He says he quit his job as chief scientist of the Australian Institute of Marine Science because of the restrictions a government job imposed on his ability to speak openly about the threat of climate change.
And though the link between climate change and bleaching is more widely accepted now than it was in the late 1990s, it can still be risky for coral reef scientists in Australia to discuss their findings, as that kind of public commentary puts them in the middle of the country’s bitter debates about climate change and fossil fuels.
Australia is the world’s biggest exporter of coal. By 2019, it will overtake Qatar as the biggest exporter of liquefied natural gas (LNG). Much of this trade passes through the lagoon of the Great Barrier Reef. Gladstone, the departure port for scientists and tourists visiting the celebrated Heron Island, is also home to three LNG terminals capable of exporting 1.2 trillion cubic feet of gas a year, plus two coal ports totaling 100 million metric tons a year.
Three ports farther north on the reef’s lagoon can load another 190 million metric tons of coal a year, bound mainly for China, Japan, and South Korea. The Australian government is considering a taxpayer loan to support the plan of Indian conglomerate Adani Group to build a coal mine that can export 60 million metric tons a year through the most northerly of the ports.
The value of the LNG exports alone — about $14 billion last year — eclipses the estimated $5 billion that the Great Barrier Reef itself generates annually in spending, mostly through tourism. Tourism is more labor-intensive, though: The reef also accounts for about 64,000 full-time jobs, according to a report by Deloitte Access Economics — more than coal mining and oil and gas extraction combined.
Tour operators are not always staunch allies of reef research scientists. While some are vocal about the threat from climate change, others frequently exhort their colleagues to avoid “scaremongering” — there’s also a pervasive fear that reports of mass bleaching events will be bad for business — and instead advertise the fact that parts of the reef are still in good condition.
“Bleaching is a real bitch from a marketing perspective,” Col McKenzie, the executive officer of the Association of Marine Park Tourism Operators, told the Sydney Morning Herald in March.
Politicians are also sensitive to this risk. Australian government representatives lobbied the U.N. World Heritage Committee not to list the reef as “in danger.” At the committee’s meeting in June, the Reef was not placed on the “in danger” list, although it called for accelerated action on water quality conservation, noted the 2016 and 2017 bleaching, and reiterated a request for another report on its condition before 2020. The following year, Australia successfully objected to the Great Barrier Reef being mentioned in a U.N. report on tourism and climate change.
Despite the recent mass bleachings and warnings from increasingly worried scientists, the World Heritage Committee confirmed again in July that the Great Barrier Reef would not be deemed endangered — a decision that Josh Frydenberg, Australia’s energy and environment minister, called a “big win” for his government.
Though Australia’s conservative prime minister, Malcolm Turnbull, is a strong supporter of the scientific consensus that climate change is a threat caused by human activity, many of the politicians he relies on to hold a single-seat parliamentary majority are not.
George Christensen, a representative whose votes Turnbull needs to pass legislation — and whose division includes three coal ports and reef resorts on the Whitsunday Islands — has likened climate science to the film Waterworld, describing it as “a lot of fiction dressed up as science.” In July, Sen. Matt Canavan, the recently reinstated minister of resources and a staunch supporter of the proposed Adani coal mine, tweeted that “instead of trying to save the planet in 2050,” the Queensland state Labor government “should just concentrate on saving jobs today!”
These attitudes drive coral reef researchers to distraction. “One has to ask, ‘Why don’t they get it?’” Hoegh-Guldberg says. “Is it because they’re complicit and they don’t care? Or [do] they know it’s a major issue but are too driven by greed? Or is it simply a failure to understand this dire situation?”