Inside the Quest to Discover Super-Corals at the Bottom of the Sea

The deep sea coral Lophelia pertusa
The deep sea coral Lophelia pertusa
Photo: NOAA Ocean Explorer (Wikipedia)

In the inky depths of the Gulf of Mexico, pearly white corals crisscross the seafloor, their translucent tentacles swaying to the current like flower petals on a midnight breeze. Lophelia pertusa brings life to what is often considered a cold, dead wasteland—and now, scientists are now bringing it back to the surface in the hopes that it help can restore dying coral reefs worldwide.

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Lophelia, you see, has a superpower: It survives in waters too acidic for most other other corals, making it one of our best hopes for the future of reefs as rising carbon dioxide levels cause the oceans to acidify. Acid Horizon, a new documentary directed by Ivan Hürzeler, chronicles a scientific journey to gather specimens of this resilient creature and learn where its true limits lay.

The hour-long film, which follows a 2014 research expedition into the Gulf of Mexico led by Temple University deep-sea biologist Erik Cordes, is a raw, real look at how science gets done. It juxtaposes the lofty ideas that drive scientists to plunge thousands of feet beneath the waves in metal cans (discovering the unknown! saving humanity!), with the seemingly endless barrage of technical difficulties that are part and parcel of field work.

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Ultimately, it’s an uplifting tale, which is rare in an age when most news about corals centers on death and destruction. Through a series of harrowing dives with the famed Alvin submersible, Cordes and his companions are able to collect samples of Lophelia and bring it back to the surface intact. And through subsequent lab work—subjecting the corals to a battery of tests to determine their acid tolerance—they find the “super coral” they are looking for.

“This is a coral that can live, and grow, and calcify, under the acid horizon,” Cordes told Earther, referring to the depth where the ocean becomes so acidic that corals’ calcium carbonate exoskeletons naturally start to dissolve. The hardiest of these corals, Cordes said, show resistance to pH values as low as 7.6—a level researchers believe the world’s oceans could reach by the end of the century. (The average pH of the oceans is currently about 8.1)

It’s been a few years since that fateful research expedition, and the work hasn’t stopped. Cordes has since returned to the Gulf to lead several additional research cruises, including the grim task of checking out damage from the Deepwater Horizon oil spill. Back in the lab, his team has continued to search for genetic markers that can explain Lophelia’s acid-tolerance, in addition to testing its ability to survive oil spills and elevated temperatures.

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The ultimate hope is that Lophelia’s genetic secrets can be used to re-seed coral reefs being ravaged by humanity’s impacts. As a deepwater species that feeds on plankton instead of sunlight, Lophelia itself probably won’t migrate into the shallower depths where corals are now dying in droves due to heat-waves, pollution, and the creeping effects of ocean acidification.

“But it gives us the hope there’s enough genetic variability out there that corals, in general, will make it through the worst of our effects,” Cordes told Earther. “And if we can unlock the secret to how the deepwater corals are doing this, there’s a lot of selective breeding and transplanting of corals starting to happen in shallow water” that could potentially benefit.

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This past August, Cordes led a new research expedition aboard the R/V Atlantis to explore deep-sea ecosystems between Virginia and Georgia that are threatened by the Trump administration’s offshore drilling agenda. Not far off the coast of South Carolina, they came across an enormous Lophelia reef, about 85 miles in length, that hadn’t been documented before. They’ll be returning to the same coastline this spring to do more survey work.

“We’re trying to get in there first [before offshore drilling is expanded] and identify places that might be in need of protection,” Cordes explained.

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It’s the tension between humanity’s ever-increasing impact on the oceans and the hidden wonders beneath the waves that keep scientists like Cordes returning year after year. The acid horizon may be an alien world, but as the new film makes clear, it’s also a world worth fighting for.

Acid Horizon is available on iTunes and Amazon.

Update 11/25: Earther was originally informed that the cruise presented in the film took place in 2010. After publication the filmmakers clarified that it actually occurred in 2014. The article has been updated accordingly.

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Maddie Stone is a freelancer based in Philadelphia.

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DISCUSSION

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Dense non aqueous phase liquid

This kind of research, pieced together, may actually save our dumb asses. Anytime we study mother nature’s adaptive mechanisms she’s given her plants and animals to thrive in nastier than normal conditions is helpful. We call this biomimicry in process engineering. For example, chemical and biological engineers nowadays drill down to the gnat’s ass reasons why silkworms can make silk so seemingly effortlessly. Compared to how we make strands of polyester requiring an entire shale drilling/fracking natural gas liquids (ethane) extraction industry coupled with a petrochemical complex (ethane to ethene to polyethylene) and an international synthetic textile manufacturing and shipping amalgamation.

Now whether or not we can fully understand how supercorals do what they do and spread that all over the globe to soak up CO2 is another story. The problem with synthetic photosynthesis via algae fuels isn’t the science that is limiting deployment. It’s the scale up from lab to plant. That’s the boring engineering part that science writers find boring. There’s no extreme field work going on to film and make into a documentary at a pilot scale algae fuels plant. Just a bunch of engineering dorks walking around pipe traces, tanks, vessels and the odd units of operation.