The MSC Foundation has completed a further phase of coral restoration in The Bahamas, outplanting 32 nursery-grown fragments of critically endangered elkhorn coral on a reef near Browns Cay, bringing the total number of corals planted to 285, through its Super Coral Reefs Program.
With marine scientists forecasting high ocean temperatures later this summer, the Foundation has also taken the precautionary decision to retain additional coral fragments in underwater nurseries until conditions are more favorable.
Elkhorn coral (“Acropora palmata”) is endemic to the Caribbean but is critically endangered, with reports indicating a 97% loss across the Caribbean since the 1980s and eradication at many locations following the 2023-2024 marine heat wave. For The Bahamas, elkhorn coral remains a vital reef-building species, supporting both marine ecosystems and the economy by providing coastal protection and critical nursery and feeding habitat for fish and invertebrates that underpin the country’s fisheries and tourism industries.
“Exceptionally warm ocean conditions are forecast this year, which could place corals under significant stress.” Emeline Bouchet, Marine Program Manager at the Ocean Cay Marine Conservation Center, said. “The NOAA Coral Reef Watch’s July outlook predicts level 2 bleaching conditions for The Northern Bahamas into September. We therefore kept more fragments in our underwater nurseries, where the team can monitor and manage them closely. Restoration is not simply about planting more corals – it’s also about putting them in the best position to thrive.”
As part of the program, coral fragments are grown in underwater nurseries before being “outplanted,” a process in which they are carefully returned to natural reefs to support reef recovery and generate data to inform future restoration decisions.
The Browns Cay site was selected following reef surveys and biodiversity assessments that identified suitable conditions for outplanting. Forecasts indicate an increased risk of marine heat stress in the northern Caribbean during the late summer. Heat stress disrupts the relationship between corals and the microscopic algae that live within them, which give them their color and provide much of their food. This causes corals to expel the algae and turn white—a process known as coral bleaching. Without their primary food source, corals essentially starve and become more vulnerable to disease and death.
The corals being harvested, grown, and outplanted at Ocean Cay were carefully sourced from colonies that demonstrated natural tolerance to heat stress and 100% survival through the 2023-2024 heat wave. As temperatures forecast for the upcoming marine heat wave are expected to reach even higher levels, marine scientists will monitor the coral reefs around Ocean Cay monthly to track the health and resilience of both outplanted and natural corals. A photogrammetry technique allows them to create 3D models that track the growth and health of the coral over time. The next steps will be to resume outplanting once the marine heat wave has passed and replenish the nursery with new coral fragments to ensure a continuous cycle of growth and restoration.
