Tropical coral reefs are the ecosystems most threatened by climate change. Warming surface waters and increasing marine heatwaves are causing coral bleaching and the disappearance of reef-dwelling species, which account for around 1/4 of the world’s marine life. 98% of Australia’s Great Barrier Reef is affected, and more than half of all corals have died in the last 20 years.

Almost all current reef repopulation initiatives involve the cutting of hardy adult corals, with the short-term aim of maintaining the ecosystem services they once provided (including fishing resources and tourist appeal). However, these colonies of the same genetic make-up (clones) are particularly sensitive to bacterial and viral infections, and offer no guarantee of resistance to further warming.

Sexual reproduction in corals enables genetic innovation, and promotes long-term reef resilience, but less than 1% of larvae reach adulthood. Jennifer Matthews’ team has developed an energy mix in the form of lipid nanoparticles, enabling 46% of larvae to eventually form new colonies.