Ian James

The Desert Sun

Off the northeastern coast of Australia, I stood on the deck of a dive-boat watching whitecaps under a blue sky, excited that my 13-year-old son and I were on our way to the Great Barrier Reef.

We listened on deck with dozens of other scuba divers and snorkelers as one of the crew members gave a pre-dive talk. He said many people have been asking him lately whether a lot of the coral is now dead, and how long the reef might last. He explained that human-caused climate change is taking a major toll, leading to bleaching events that have degraded large portions of the reef. That degradation comes on top of other problems including ocean acidification and outbreaks of crown-of-thorns starfish.

“But really, is the reef dead? No, it’s definitely not dead,” he said, speaking into his headset microphone. “Basically, the reef is undergoing more and more threats every day. We’ve got to do something to preserve it.”

As we motored on, I wondered how the reef would look. In the Caribbean and the Florida Keys, I’ve seen reefs at both ends of the spectrum — colorful corals filled with life, and patches of dead coral reduced to gray rubble. I’ve been dismayed to read scientists’ increasingly urgent warnings that as the world’s oceans heat up due to the burning of fossil fuels, many coral reefs may not be able to survive much longer.

I hadn’t been diving in several years, and my son’s school band trip to Australia in July seemed the perfect opportunity for him to be scuba certified so we could go diving together for the first time. I learned to dive when I was 13, and I’ve been fascinated ever since by the abundant kaleidoscope of life around coral reefs, and by the experience of exploring these oceanic rainforests. I wanted to share with him the magical experience of floating weightlessly beneath the waves, the excitement of discovery at spotting eels and sea turtles, and the awe of swimming through a living undersea sanctuary — one of the most diverse and productive ecosystems on the planet.

Even as I’ve learned about the serious threats facing reefs, I’ve also seen signs of resilience that have given me some hope. On a moonlit night 16 years ago on the island of Culebra off Puerto Rico, while I was working on a story about dying coral reefs in the Caribbean, I witnessed an amazing spectacle: the annual spawning of boulder coral. Tiny peach-colored eggs were released from the surface of the coral and floated away to form a new colony. The eggs drifted across the beam from my light and disappeared into the darkness.

I’ve always wanted to visit the Great Barrier Reef to see one of the world’s largest natural wonders. Built slowly over the ages by colonies of tiny coral polyps, it is so immense that it's visible from space.

As we prepared for our trip, I read about the alarming bleaching events that ravaged the reef in 2016 and again in 2017. This bleaching happens during extreme heat when coral polyps become stressed and expel their essential symbiotic algae, the zooxanthellae. When a coral colony is left white, it may be able to recover eventually if conditions are favorable. If not, the coral dies.

Last year, the northern section of the Great Barrier Reef suffered severe bleaching. This year, a central stretch of the reef was hit hardest, including some of the areas off Cairns where we were headed that day.

We gathered our masks and wetsuits, and began to suit up.

This day out was our second dive on the Great Barrier Reef. Earlier in the week we had taken a daylong snorkel-and-scuba trip to another part of the reef. There we saw schools of yellow and blueback fusilier, a huge Queensland grouper, outcroppings of living coral and a clownfish nestled among the undulating tentacles of an anemone.

This time, we were going out for a longer three-day cruise, and I was anxious to see how the coral was faring in this area.

At Norman Reef, we stepped off the boat’s back deck. As the bubbles cleared and I began to breathe from the regulator, my son and I gave each other “OK” signs and descended along the anchor line toward the sandy bottom. I was happy and proud seeing how he had learned his diving skills and seemed comfortable underwater.

Ahead of us, a column of coral and a reef wall rose from the sand. Swimming along the reef were multicolored parrotfish, sweetlips and wrasse. A moray eel peered out from the coral. Lionfish gathered around the base of a coral outcropping. A green sea turtle swam near the surface.

There were boulder corals the size of cars, and looking closely at the surface of the coral, we saw spiral-shaped Christmas tree worms. As we approached, the worms quickly retracted into holes.

The Great Barrier Reef is made up of hundreds of different types of corals, and some of them are faring better than others as global temperatures rise.

I noticed that many of the corals were alive, with colors from green to brownish to pink. But the branching tips of some corals were bleached white.

I found myself wondering: What would this reef have looked like 20 years ago? And how might it look 20 years from now?

Another thought troubled me: Might I be looking at a reef that future generations won’t have the opportunity to see alive?

Over the next two days, we anchored at other reefs. We spotted yellow butterflyfish, pufferfish and the aptly named unicorn fish. We saw a whitetip reef shark sleeping on the sandy bottom, and gray reef sharks circling near the boat.

When we went diving at night, we saw green sea turtles and a silvery fish called giant trevally. A whitetip reef shark swam past at a distance, its eyes glowing green in our lights.

On dives during the day, we saw giant clams four feet across with iridescent green dots on the flesh between their gaping shells, and tiny white gobies that darted into holes in the sand to hide.

We swam through coral canyons and along reef walls, past swaying sea fans, majestic staghorn corals and giant brain corals.

At a place called Coral Gardens at Hastings Reef, on one of our last dives of the trip, I snapped photos of a giant clam and marveled at the variety of fish and the colorful coral. The closer we looked at the coral, the more reef-dependent creatures we saw, from a bright blue fish to a tiny crab camouflaged in the coral.

There too, we saw areas where the corals looked damaged, colorless and gray.

Even as we saw reefs that seemed mostly alive, I thought this must be an example of “shifting baselines,” in which the degradation is unfolding gradually in ways that are hard for casual observers to notice.

Looking at the reef as a whole, though, there is nothing subtle about the devastating changes that scientists have been documenting.

Researcher Terry Hughes, who leads a coral reef studies center at James Cook University, said in a widely cited tweet after last year’s bleaching event that he had showed the results of aerial surveys to his students, “and then we wept.”

The reef was hit by earlier mass bleachings in 1998 and 2002, and warming ocean temperatures are leading to more frequent and more severe damage.

In an article after this year’s bleaching event, Hughes and fellow researcher James Kerry wrote that the combined footprint of the unprecedented back-to-back bleaching now covers two-thirds of the Great Barrier Reef.

“We have a narrowing window of opportunity to tackle global warming, and no time to lose in moving to zero net carbon emissions. We have already seen four major bleaching events on the Great Barrier Reef with just 1°C of global average warming,” Hughes and Kerry wrote in the article.

They warned that “if the world continues its business-as-usual greenhouse emissions for several more decades, it will almost certainly spell the end of the Great Barrier Reef as we now know it.”

RELATED: Two-thirds of Great Barrier Reef ravaged by coral bleaching

MORE: Scientists race to prevent wipeout of world's coral reefs

In one recent study published in the journal Nature, researchers used satellite temperature data from 1985 to 2012 to study the effects of warming in causing bleaching stress on reefs around the world. The scientists found that the frequency of bleaching-level heat stress increased three-fold during that time. They said based on current trends, by 2050 “more than 98% of reefs are expected to be exposed to bleaching-level thermal stress” every year.

Around the world, many coral reefs have already been lost due to pressures ranging from polluted runoff to overfishing, and scientists are trying to find ways to help save at least some of the remaining reefs.

Researchers at the Scripps Institution of Oceanography at the University of California, San Diego, are leading a project called the 100 Island Challenge, using imaging and data technologies to “archive reefs digitally” and monitor how they change over time. The effort aims to generate information about local management approaches that can help protect reefs.

In Australia, scientists collected samples of surviving coral from northern areas of the Great Barrier Reef damaged by bleaching. The researchers packaged samples in boxes filled with seawater and flew them last month to a specialized lab, the National Sea Simulator, where they’re testing whether these corals could help produce offspring that are more heat-tolerant in other areas of the reef.

This research is one of several studies intended to help restore reefs or boost their ability to withstand rising temperatures and worsening acidification. And these efforts speak to just how serious the situation has become for reefs worldwide.

Coral reefs are important for so many reasons. They sustain fishing communities around the world. They generate some of the oxygen that we breathe. And although they cover a small fraction of the oceans, they provide habitat for about a fourth of marine species.

I don’t want to imagine a world with most of its coral reefs dead, but scientists say that looks possible without bigger efforts to combat climate change.

After we returned home, my son wrote some his thoughts about our visit to the reef.

“I saw so much life and movement, fish, turtles and more swimming in every direction,” he wrote. He said that while the reef has been bleached at an alarmingly rapid rate, much of what he saw “was still completely stunning.”

“It is at the tipping point, where we still have the power to help before its demise,” he wrote. “Lowering global greenhouse gas emissions through renewable energy, electric cars and more can help stop the degrading of this marine paradise."

I’m grateful that we saw the Great Barrier Reef together. We came away with a shared appreciation of how magnificent and vital the reef is, and how threatened it has become.

Ian James writes about environmental issues for The Desert Sun. He can be reached by email at ian.james@desertsun.com and on Twitter at @TDSIanJames.

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