10/17/2026
🪸 A healthy coral helped its bleached neighbor recover, just by touching it. In a new lab study, one week of contact was enough to bring a sick coral back to life.
Corals rely on tiny algae that live inside their tissue. The algae make food from sunlight and give corals their color.
When the ocean gets too hot, corals push these algae out and turn white. This is called bleaching. Without their algae, corals slowly starve.
Researchers at Stanford University noticed something surprising in a lab tank. A bleached coral was regaining its color, but only where it touched a healthy piece of the same coral.
So they tested it. They used 10 pairs of coral pieces, each pair cut from the same animal. In every pair, one piece was bleached and one was healthy.
Five pairs were placed touching each other. The other five were kept just a few millimeters apart.
Within three days of contact, algae began moving from the healthy coral into the bleached one.
The bleached corals that touched a healthy partner fully recovered within seven weeks. Those kept apart died.
Just one week of contact, and sometimes only five days, was enough. After that, the algae kept multiplying on their own, about ten times faster than in wild corals.
"While bleached corals may be dying, they are not dead yet," said lead author Danny Collins.
But this was a small lab experiment with one coral species. It is not yet known whether it would work on real reefs.
The method also needs a healthy, genetically identical copy of each bleached coral, which is not practical across whole reefs.
The team now hopes to find other ways to deliver helpful algae to bleached corals.
It is not a cure for warming oceans, but it could become a useful emergency tool.
📃 RESEARCH PAPER
📌 Danny Collins et al., "Rapid coral bleaching recovery via symbiont transfer from healthy corals," Science Advances (2026).
📸 Danny Collins
