At the invitation of the National Marine Sanctuary Foundation, a team of Ph.D. students designed an ocean-cooling system to help stop coral bleaching.
Coral reefs are home to about a quarter of all marine life. They support millions of jobs around the world and protect coastal communities from storms. Scientists report they’re also in the midst of a crisis, with a fourth mass bleaching event spreading around the world.
Bleaching happens when ocean waters heat up, causing corals to expel the colorful algae that live in their tissues. It can lead to disease and death for coral, wiping out critical and complex marine ecosystems.
Four Georgia Tech Ocean Science and Engineering (OSE) Ph.D. students have spent the last few months working on creative ways to prevent bleaching by cooling the water around coral reefs. They presented their ideas in late October to marine biologists and conservations in the Florida Keys as part of the National Marine Sanctuary Foundation’s Coral Reef Thermal Stress Design Thinking Challenge & Workshop.
If designing a system to cool the ocean sounds daunting, Skylar Lama agrees.
“We were initially skeptical,” said Lama, a third-year OSE Ph.D. student and one of the team members. “Cooling down ocean water sounded almost impossible. But working together across disciplines to address such an urgent issue was too intriguing to pass up.”
The challenge was this: devise a simple, deployable solution to lower water temperatures around coral reefs in the Keys. The foundation invited teams from just four universities to develop and present designs.
Lama and the Georgia Tech team — Ph.D. students David Clark, Luisa Lopera, and Kelly Lumpkin — decided on artificial upwelling, a process to draw cooler, nutrient-rich water from deeper ocean layers to the shallower reef. Their concept involved installing long carbon fiber pipes reaching about 150 meters deep, where water is typically around 10 degrees cooler. A surface pump would pull this colder water up, distributing it across the coral via an irrigation-like system.
“Our goal was to provide some relief for the coral by introducing cooler water periodically,” Lama explained. “It wouldn’t completely alter the environment, but it could help alleviate stress for short periods, which might slow bleaching.”
Making the concept work involved addressing a series of technical and environmental challenges. The solution needed to be low-cost, effective, and manageable for local communities.
Calculating the thermodynamics required to cool large volumes of ocean water, the team discovered the energy demands were enormous: “Our initial calculations showed we’d need around 20 billion joules of energy — about 45 solar panels running continuously for months,” Lama said.
Ocean science and engineering Ph.D. students, left to right, Kelly Lumpkin, David Clark, Skylar Lama, Luisa Lopera developed a system to cool the water around coral by drawing up and circulating colder water from 150 meters below the ocean's surface. They were one of four teams invited to devise a cooling system and present their idea to the National Marine Sanctuary Foundation. (Photo Courtesy: Skylar Lama)
In addition to energy concerns, the team had to consider how the colder water would disperse and how to keep it around the coral long enough to have an impact. Using advanced ocean modeling software, they simulated how water would spread from different locations based on currents and temperature stability.
“Some areas retain cool water longer, which makes them ideal for this system,” Lama said. “In others, the water dissipates too quickly.”
Each member of the team brought unique skills to the project: Lama’s research focuses on ocean modeling and coral acoustics, Clark studies paleoceanography using coral reef cores and fossilized coral, Lumpkin studies coral diseases, and Lopera focuses on ocean modeling and coral larval dispersion.
At the workshop, conversation about the team’s design explored the implications of introducing nutrient-rich deep water to surface-level coral reefs and potential impacts on the ecosystem. The expert panel of biologists and conservationists praised the team’s high-resolution modeling for its potential in future environmental projects.
“Getting feedback from experts in coral restoration really helped us see the broader implications of our work,” Lama said. “It’s rewarding to see how our different perspectives combined to create a more comprehensive approach.”
OSE graduate program co-director Annalisa Bracco said the four students worked incredibly hard for 10 weeks to develop a unique solution to a challenging problem.
“The foundation looked specifically to invite students from programs where science and engineering collaborate,” said Bracco, who also is Lama’s and Lopera’s co-advisor. “It’s great that Georgia Tech’s ocean science and engineering program is being recognized as a leading provider of expertise, interdisciplinary research capabilities, and solutions for oceans and sustainability.”
Although the team doesn’t plan to continue developing their artificial upwelling system, elements of their work will persist. Lopera is exploring the use of high-resolution modeling to study the dispersal of pollutants and microplastics along Florida’s coast. Lama will continue her research on coral acoustics, focusing on monitoring coral health through sound.
“Our backgrounds in ocean science, engineering, and biology really complemented each other on this project,” Lama said. “This challenge showed us the power of collaboration and the potential for innovation in conservation.”
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