Nearly a hundred miles off the shore of Port Douglas, Australia, tourists jump into the water of the outer reef. On their dive, they see giant clams, sea turtles and a rainbow of tropical fish, all swimming above brightly colored coral.
On a boat, marine biologist Lorna Howlett quizzes the tourists in the sunshine. "How many people out there saw a coral highlighter-yellow?" she asks, eliciting a show of hands. "What about highlighter-blue? Yeah? Anyone see some hot pinks?"
Eager hands shoot up among the few dozen tourists lounging on the deck of the boat in their wetsuits. Everyone's still smiling from their Technicolor tour of the Great Barrier Reef, a UNESCO World Heritage site that encompasses the world's biggest coral reef system and is home to some 400 different types of coral.
Then Howlett breaks the news: "Those are not natural coral colors," she tells them, prompting quizzical looks. "That is actually coral that is stressed, OK. So it's got a sniffly nose, got a bit of a sore throat."
It turns out a reef filled with neon coral is not normal. Healthy coral is usually earth-toned. The bright pinks, blues and yellows these tourists saw in their dive along the northern part of the Great Barrier Reef are the first signs that coral is dying.
And then, says marine biologist John Edmondson, "You see it going white."
That's the second sign of dying coral, says Edmondson, who runs Wavelength Reef Cruises, a tour operator on the reef.
"That's when it's most dramatic looking," he says, pointing to a bleached brain coral that is hundreds of years old. "But you don't know if it's going to die or it's going to recover. ... And when you start to see the coral actually dying, getting covered with algae and looking horrible, that is when it really hits home."
In the past 18 months, Edmondson has watched as two-thirds of the coral along this 400-mile northern stretch of the Great Barrier Reef has turned white and died. Rising ocean temperatures have caused the single greatest loss of coral ever recorded along the reef.
The die-off is devastating for the thousands of species that depend on the reef, including those responsible for its decline — humans, who depend on it for $6 billion in tourism revenue annually.
Those who work on the reef never thought things would get so bad so fast.
"I did not expect to see a loss of corals to this extent in my lifetime. This has come sooner than we had hoped," says Terry Hughes, director of the Coral Reef Center at James Cook University in Townsville, along the midsection of the reef.
The world's oceans have absorbed some of the heat from the global rise in greenhouse gas emissions, and in many cases, their waters are now warmer than at any time in recorded history. Corals are sensitive to temperature swings. Much like a human body, a rise of a few degrees can lead to illness, and eventually, death. The average ocean temperature has risen by more than 1 degree Fahrenheit. UNESCO expressed "serious concern" about the reef's health last week — though it left the reef off its endangered list.
"The new normal"
For the past two years, Hughes has led a team of scientists in both aerial and underwater surveys of the reef. It took a while — the Great Barrier Reef is made up of more than 3,000 individual reefs stretching as long as the entire West Coast of the United States. Their findings, published in March in the journal Nature, estimate that a third of the coral died along the entire Great Barrier Reef between March and November 2016, due to warmer-than-average water temperatures.
"Close to half of the corals on the Great Barrier Reef have died in a period of about 18 months," Hughes says. "This is the new normal."
Hughes is calling on everyone who studies and protects the world's coral reefs to adjust to this new normal. He says coral reef management has always focused on restoring reefs to their pristine condition — before the oceans began to warm.
"And we argue that's no longer possible," says Hughes. "What we should be aiming for is keeping the reefs functional, recognizing that the world is on a conveyor belt. We are going to a new type of coral reef ecosystem, but if we're careful how we do that, we will have a functioning ecosystem that will provide benefits to people."
He doesn't have any specific answers as to how to make that happen, but he's calling on reef managers around the world to come up with plans.
Not everyone at the Coral Reef Center shares Hughes' optimism. Research fellow Jon Brodie used to direct water quality for the Great Barrier Reef Marine Park. He believes it's too late to save the coral. Water temperatures are rising too fast, he says, and he predicts that in 30 years, most of it will be gone.
The 70-year-old has given his life to the reef. For him, the new normal is hard to accept.
"I have lots of young or youngish Ph.D. students and the like, and it wasn't too many years ago when I could inspire them that this was a great area to work in and make a difference," he says. "I find that more difficult now; much more difficult now."
A multibillion-dollar business
But along the waterfront in Cairns, where kids splash in a pool and diving boats sound their horns, his concerns seem far away. The city is the main hub of tourism along the Great Barrier Reef, a $6 billion industry employing 60,000 people. Many tour operators here take issue with the surveys scientists like Hughes have conducted of the reef's health.
"When they try to paint holistic pictures from sampling, you don't get the real story," says Col McKenzie, who directs the Association of Marine Park Tourism Operators in Cairns.
McKenzie questions how accurate these scientific surveys have been, and he thinks the media has influenced people to think the reef has become the Great Barrier Graveyard.
"If we're taking tourists out of Cairns to reefs that are destroyed, our business wouldn't survive for more than a month," says McKenzie, laughing. "We just wouldn't be able to keep doing it. Yet you go and talk to people coming off these boats, they've had a fantastic time. They've seen what they came here to see!"
McKenzie maintains that there's still a lot of healthy habitat to see, and there will be for years to come. But he does worry about the amount of coral that has died and what it's going to do to the region's bottom line.
"My guess is we've seen the end of double-digit growth," he says, furrowing his brow. "We're probably going to go back to 2 to 3 percent growth instead of 20 to 30 [percent]. The big issue is we got a lot of money being spent on additional infrastructure here in Cairns: new pontoons, new boats, new hotels going up."
And that's why McKenzie thinks rash measures should be taken to save the reef. He proposes installing enormous turbines in the deep ocean surrounding the reef. "If you could imagine a massive big ceiling fan, like a turbine pushing cool water to the surface," he says.
In an email, Terry Hughes called McKenzie's proposal one of the most "hare-brained" ideas he's ever heard. He says tackling climate change would be easier.
Caught between the scientists and tour operators are the tourists themselves. Seventy percent of them come from outside Australia, like Alan Crabtree from Bellingham, Wash.
"One of the reasons we came now is because we wanted to see the barrier reef before it disappeared," says Crabtree. "We wanted to take advantage of that."
At the end of a day of snorkeling, the tourist boat pulls into Port Douglas, where thousands of colorful lorikeets fly between palm trees as the sun sets behind them. Wavelength Reef Cruises' owner John Edmondson sits on his boat, talking about how the tourism industry is having a hard time dealing with the reef's loss of coral.
Some operators don't mention it to tourists for fear of spoiling a fun day out, but he's chosen to educate his customers about what's going on and what they can do to prevent climate change.
"If you've got a fantastic product, but there's a negative aspect of it, how do you deal with that negative aspect?" Edmondson asks. "It's best, I think, to explain it because most people are understanding."
After all, says Edmondson, this isn't Disneyland. It's the world. Our world.