Anne Cohen spent years studying coral reefs from a distance. Now she’s standing on the bow of an aluminum landing craft in the Marshall Islands, watching a yellow robot named Yellowfin glide across the Majuro lagoon ahead of her.
“She’s the best dive buddy,” says Cohen, a scientist at the Woods Hole Oceanographic Institution. The unmanned surface vehicle navigates to precise coordinates, cutting through small swels like a tiny sailboat — guiding Cohen toward reefs she’s traveled thousands of miles to revisit.
The mission: find coral reefs that can take the heat. As global warming pushes ocean temperatures higher, most corals are bleaching and dying. But some reefs are holding on, and scientists want to know why.
Yellowfin is part of a broader effort to map and study heat-resistant reefs across the Pacific. By identifying which corals survive in warmer waters, researchers hope to understand the biological mechanisms behind their resilience — and potentially use that knowledge to protect or restore vulnerable reefs elsewhere.
It’s urgent work. Coral reefs support roughly 25% of all marine species, protect coastlines from storms, and sustain the livelihoods of hundreds of millions of people. When reefs die, the cascading effects are enormous.
The research in the Marshall Islands is just one piece of a global effort. Scientists are studying “super reefs” in the Pacific, Red Sea, and Caribbean — places where corals have somehow adapted to conditions that kill reefs elsewhere.
Whether that knowledge can be translated into meaningful conservation at scale remains an open question. But finding nature’s survivors is a solid starting point.
