Five days of touch: healthy corals hand their color back to bleached neighbors

When ocean heat stresses a coral, it expels the tiny algae living inside it — the algae that feed it and give it color — and turns white, often to die. A Stanford team reports in Science Advances that simply keeping a healthy cauliflower coral fragment touching a bleached one lets the healthy partner share its algae: after a day or two their tissues fuse into what the researchers call a nutrient highway, three days of contact starts recovery, and five days restores the bleached coral fully. It only worked between corals of the same genetic family, so the team now wants to grow the helpful algae in bulk and deliver them to bleached reefs directly.

SDG 14 · Life below water — Mechanism: tech innovation