Erik Cordes, professor and chair of the Department of Biology, and PhD candidate Morgan Will are part of a deep-sea research project in Argentina focused on discovering and restoring largely unknown cold-water coral reefs.
One Argentine Bathelia candida coral mound is now believed to be among the largest reef systems in the world.
Photo by ROV SuBastian/ Schmidt Ocean Institute
The Great Barrier Reef is a vast, colorful ecosystem teeming with underwater life. It is the largest shallow water reef in the world and a household name. But scattered across the planet, up to a mile beneath the ocean’s surface, exists a more mysterious kind of reef system, called deep-water, or cold-water coral reefs.
Little is known about these reefs, and the deep-sea research community only recently gained the tools to properly explore them. Two researchers from 51Թ’s have joined the global effort to shed figurative light on these reefs where no light reaches. They’ve recently helped uncover what may be one of the largest cold-water reef systems in the world, and they’re simultaneously working to restore these vital, deep-sea ecosystems.
“We now think Argentina is home to one of the largest reef systems on earth,” said , professor and chair of the Department of Biology. “Something that we didn’t really know existed a year ago now turns out to be one of the largest cold-water coral ecosystems on the planet.”
Cordes and Morgan Will, a biology PhD candidate, are part of a $1.5M research project by the G20 Coral Research and Development Accelerator Platform (CORDAP) to locate, characterize and restore cold-water coral reefs off the coast of Argentina. They’re conducting the project in collaboration with the University of Buenos Aires and the Argentine Museum of Natural Sciences (CONICET).
Will also recently embarked on a cruise on board the Schmidt Ocean Institute’s R/V Falkor (too) to Argentina’s deep sea in December and January, where she carried out work for the CORDAP project. The expedition was led by scientists from Facultad de Ciencias Exactas y Naturales, part of the University of Buenos Aires.
Our latest estimates suggest that cold-water coral reefs cover about twice as much area as shallow water coral reefs (such as the Great Barrier Reef).
Erik Cordes
professor and chair of the Department of Biology
A key part of the project is locating and characterizing the baseline conditions of healthy cold-water reef ecosystems, which are prone to damage from fishing trawls, oil and gas development, and discarded trash and debris.
“We wanted to create a baseline, so that if we come back and see effects of human impacts, we know how to measure that against what a healthy reef should look like,” said Cordes, a deep-sea expert who has published more than 100 papers on the ecology of the deep sea and spent almost two years at sea on research expeditions.
The Argentina cruise’s main feature was the high-tech, remotely operated vehicle (ROV) SuBastian used by researchers to dive to the ocean floor and search for ecosystems like coral reefs and cold seeps, which are places where natural gasses seep out of the ocean floor.
Until recently, the scale and prevalence of cold-water reefs remained largely unknown, but cruises outfitted with ROVs and advanced mapping tools are revealing just how expansive and important the ecosystems are.
“Our latest estimates suggest that cold-water coral reefs cover about twice as much area as shallow water coral reefs (such as the Great Barrier Reef),” Cordes said.
Argentina’s deep sea is home to an uncommon coral species called Bathelia candida. Scientists knew Bathelia reefs existed in the deep seas of South America, but they now believe one Argentine cold-water Bathelia coral system is among the largest in the world.
“That really surprised me,” Cordes said. “I knew we were going to find coral mounds, but just how far they extended was really remarkable.”
Finding and protecting these reefs is important, Cordes and Will explained. They are hotspots of biodiversity, and they play an important role in sequestering carbon from the environment. They also cycle nutrients from the deep sea to the ocean’s surface, which plays a role in food production.
“The most productive fisheries in the world are in places where there is an upwelling of deep-water nutrients,” Cordes said. “We’re learning that a lot of those nutrients are coming from these cold-water coral reefs.”
Beyond exploration, the researchers are tackling an even greater challenge: restoring damaged cold-water reefs.
“The issue in the deep sea is that reef restoration hasn’t really ever been done before,” Cordes said. “We have to create the methods for restoring these communities while we’re in the middle of exploring the deep ocean to find them.”
Fortunately, Cordes and Will can borrow strategies from another ongoing project off the coast of Louisiana, where they’re restoring reef communities impacted by the 2010 Deepwater Horizon oil spill.
Cordes explained that cold-water coral reefs grow slowly. Some of the corals damaged in the Deepwater Horizon disaster can be over 500 years old. Cordes and Will are developing strategies to skip, so to speak, some of the early steps of reef development.
One approach is to build artificial coral skeletons out of cement and crushed up coral sand and deploy them in the environment. This simulates a coral habitat in an attempt to bring some of the wildlife back.
Will focused much of her time on the cruise building and deploying these artificial coral structures in Argentina’s cold-water reefs.
“This was my first cruise out really deep where we could see a lot of structure-forming cold-water corals. I’ve studied them for a couple of years in the lab but had never gotten to see them myself,” Will said. “The coolest thing I saw on a dive was this massive Bathelia mound. The number of organisms and coral species living with that structure-forming coral was breathtaking.”
Morgan Will (left) deployed reef restoration methods that she and Cordes developed in response to the 2010 Deepwater Horizon oil spill.
Photo by Misha Vallejo/ Schmidt Ocean Institute
The project also fostered an exchange of information and resources between 51Թ and Lehigh University in the United States and the University of Buenos Aires and the Argentine Museum of Natural Sciences. In the coming year, 51Թ, Lehigh and the Argentinian institutions will take turns hosting each other’s researchers and educating each other about the work they lead.
CORDAP is also funding a new deep sea camera platform for Facultad de Ciencias Exactas y Naturales. The platform will revolutionize the group’s ability to explore the deep sea, and Cordes is lending his expertise to help the group become familiar with the platform for future expeditions.
“Much of this project is really focused on improving the capacity to do deep sea research in Argentina, because it just wasn’t there until now,” Cordes said. “The capacity to conduct this research isn’t just in the hardware. It’s in the knowledge of how to organize and conduct an offshore cruise. That’s not something you can just step into, so we’re happy to be a resource and a partner.”
Visit the for breathtaking videos and livestreams from Will's cruise and the institute’s other expeditions.