The Great Barrier Reef is not doing so well.
Warm ocean temperatures for the last two years have left more than two-thirds of the reef's coral bleached, Australian researchers said Monday, meaning it's expelled the symbiotic algae that lives on its surface and turned white. When coral is bleached, it's not dead, but it's under intense stress and is much more vulnerable to dying off, which is why conservationists are flipping out about this UNESCO World Heritage Site experiencing bleaching in over 900 miles of its 1,400-mile expanse.
The news is dire, because coral reefs are rich biodiverse ecosystems that provide habitat for marine life, host algae that produces oxygen, and even protect our shorelines from storms. It's an important reminder of the impacts of climate change on our planet, but all hope is not lost. In the past few years, coral conservation researchers have made a number of scientific advances that have many optimistic about the possibility of preserving and restoring our coral reefs—even as ocean temperatures continue to rise.
"It gets depressing, but we've made some great strides in coral restoration that I never would have thought possible even ten years ago," said Dave Vaughan, the executive director and manager of the coral restoration program at the Mote Tropical Research Laboratory in the Florida Keys. "There's definitely hope."
At Mote, Vaughan and his team use special ocean simulators to test out how different species of coral handle various ocean temperatures and PH levels, giving them a preview of which coral will be able to survive the ocean conditions predicted to be coming in 10, 20, or 50 years. He told me that the coral reefs in Florida and the Caribbean experienced several bleaching events back in the 70s, but due to extreme cold temperatures instead of warmth. This led to between 15 and 40 percent of that coral dying off. But it also allowed scientists to begin to understand which coral species, and which genetic strains, could withstand a bleaching event.
That information was the first piece of the puzzle towards being able to "reforest" coral reefs: pick species that can survive the extreme conditions of our changing oceans. In the 80s, scientists finally began to understand how coral reproduces, and soon after were able to start breeding coral in the lab. But there was another hurdle: coral grows very slowly.
A new coral spawn the size of a pinhead takes a full year just to grow to the size of a pencil eraser, Vaughan said. At that rate, there's no way we can repopulate reefs before they get wiped out. But nearly a decade ago, Vaughan made an accidental discovery that changed the way coral is bred: coral that is broken apart into small pieces regenerates at a much more rapid pace, able to grow to a size that typically takes two years in as little as two weeks.
"The analogy I give people is that your skin doesn't grow very fast, otherwise you'd be dragging your skin down the sidewalk when you walk," Vaughan said. "But when you get a scrape the size of a quarter, it grows back in two weeks. We think that the healing process in the coral is a similar thing that stimulates your skin to grow rapidly and heal itself."
This discovery, combined with natural genetic selection—breeding coral species for specific, climate change-resistant traits—means we actually can repopulate coral reefs with species that can survive the stressors of climate change.
Other researchers around the world are using similar techniques to breed new strains of coral that can withstand climate change, with the goal of repopulating our shrinking reefs. There's still work to be done, and the Great Barrier Reef is already facing near extermination. But the advances of the last half-decade leave experts like Vaughan hopeful we can save the coral before it's too late.
"I'm very optimistic," Vaughan said. "If everyone around the world could work on the same things, we could literally talking about producing 1 billion corals, and we could replant coral reefs just like we replant forests."