Using Coral Stress Memory to Restore Coral Reefs
Posted by Harmony Hancock | Virginia, United States
Coral reefs are in peril, with warming oceans causing coral bleaching & mortality on a global scale. Corals are animals in a partnership with symbiotic algae they depend on for survival. When the corals are stressed, the algae leave, making the coral appear white, or ‘bleached.’ Bleached corals often get sick and die. Projects to restore reefs by planting corals are increasing in number, but unless the corals we plant are strong enough to survive future ocean temperatures, those projects will fail. One solution is planting stronger corals. There is evidence corals can become stronger when they “remember” past stress. Stress memory may provide bleaching resistance, just like vaccines provide disease resistance. Corals that have been given a small dose of heat stress may store that memory in their genes, so the next time there is heat stress, they remember and don’t bleach. We aren't sure what dose of heat stress is required for coral stress memory to provide bleaching resistance, or how long the memory might last; it could be weeks, months or generations. With more research, we may be able to improve restoration success by planting more resilient corals. This project offers a real solution to help confront coral bleaching and restore reefs.