Scientists use cheap picnic coolers to identify heat-resilient corals for reef restoration

In Palau’s protected waters, scientists are using low-tech heat tests to screen coral fragments for climate resilience. Marine ecologist Steve Palumbi, together with researchers from the Palau International Coral Reef Center and partners such as Stanford University, place coral cuttings in inexpensive picnic coolers that are gradually heated over several days. Colonies that retain their color are deemed heat-tolerant and are earmarked for planting on a reef garden near Ngaraard.

The method, which costs less than $1,000 for a set of four coolers, seeks to address the high failure rate of traditional reef-restoration efforts that are undone by warming seas. Early results suggest that corals passing the short-term tests survived a 2024 bleaching event better than untreated ones, though scientists caution that the correlation is not yet fully proven. Nonetheless, the technique offers a practical tool for restoration groups lacking extensive laboratory resources.