When a major coral bleaching event swept across the reefs of Mauritius last summer, one small group of corals remained as vibrant as ever. While neighboring wild reefs experienced bleaching rates as high as 80%, Dr. Nadeem Nazurally's heat-resistant corals achieved nearly 99% survival rates.
The island nation of Mauritius, off Africa's east coast, is home to nearly 250 coral and hydrozoan species. The reefs they form support fisheries worth billions and provide homes for one-fourth of all Mauritius' sea life.
Since 1998, the islands have recorded five coral bleaching events—the most recent last summer when water temperatures reached 88°F. Previous bleaching events revealed that regular coral restoration strategies were no longer viable in a warming ocean.
With government and UN support, organizations like the Mauritius Oceanography Institute, the University of Mauritius, and Odysseo Oceanarium now work to advance the science of heat-resistant coral breeding. Nazurally's success is a testament to the progress the country's marine science community has made.
The science of coral breeding has come a long way in the last decade. Odysseo has leveraged worldwide advancements to predict spawning events and collect eggs and sperm from corals by boat. These are then used to breed corals in protected nurseries, with those that survive in warmer water being selected to reproduce.
A study published by Dr. Nazurally showed that the hydrozoan genus Millepora, when bred this way, showed a 99.8% survival rate during bleaching, compared to an 88% average across all coral genera and just 10% survival for corals bred without heat-resistance focus.
The study also examined growth differences when corals are cultivated on floating platforms versus the seabed. Results suggest that in high-development tourist areas, floating platforms protect corals from damaging sedimentation, while less frequented zones would merit a seabed nursery approach.
'This is about giving reefs a fighting chance,' Nazurally explained. 'We're not just restoring coral—we're evolving it to survive the ocean of tomorrow.'