Today, coral reefs are 4 times more likely to suffer bleaching than in the 1980s. But some scientists see hope in the corals that haven’t been bleached. Somehow, the genes of these “super corals” allow them to hold onto beneficial algae and survive as waters warm.
Can Super Corals Save Reefs?
Published: February 26, 2019
Onscreen: Can Super Corals Save Reefs? When coral polyps are stressed they become bleached by ejecting tiny algae cells that normally live inside them and provide food and color. Today, coral reefs are 4x more likely to suffer bleaching than in the 1980s. But some scientists see hope in the corals that haven’t been bleached.
Ruth Gates: If 50% of the reef has died, let’s turn that around and talk about the fact that actually 50% of the reef has survived and survived extremely difficult conditions. Our question is, why? What is it that’s different about those two categories of corals?
Onscreen: To find out, Gates studies the survivors of the super corals. Somehow their genes allow them to hold onto their algae partners.
Gates: The super corals are the best of the best on the reef today. They are the most likely to survive the future. We go out into the environment and we identify the corals that are doing the best when it’s very stressful on the reef. Then we bring those corals into the lab and we condition them in environmental treadmills.
Onscreen: She’s exposed them to warmer, more acidic water. In the lab, some of the super corals’ descendants have seemed to be more flexible.
Gates: The offspring from exposed parents are better able to withstand acidified water when re-exposed. That’s fascinating stuff. That’s the best case scenario.
Onscreen: But finding super corals underwater takes time. With some new partners Gates hoped to scale up her efforts.
Gates: With our airborne observatory we’re uniquely capable of finding these surviving corals. Onscreen: Greg Asner and his team normally use LiDAR technology to measure tree health from the sky. They’ve adapted it for corals.
Greg Asner: We fly over the bay and we can do the entire bay, all of the coral in about an hour. You find out that there are millions of corals out here, not thousands - millions and they’re in a vast array of conditions. So we can fly over and get the entire mosaic and then direct the science to the different types of corals that are out there. Rather than just diving on a few corals here and there, let’s look at the entire thing and make a plan.
Onscreen: The more super corals they can find and breed, the greater the chances these reefs could survive. But the clock is ticking.
Gates: We don’t have the luxury of being a gentlemanly scientist in the 1850s. We have ten years to make a difference on the reef right now.
Decoding the Weather Machine
Produced and Directed by: Doug Hamilton
Co-Produced by: Caitlin Saks
Director of Photography: Paul Atkins
Digital Producer: Brian Kantor
Additional Footage: David Hannan, Ocean Ark Alliance, The Ocean Agency, Exposure Labs, XL Caitlin Seaview Survey, Brett Lewis — QUT
Sound Effects: Freesound, Digifish Music
© WGBH Educational Foundation 2019