• 32 nursery-grown elkhorn coral fragments outplanted near Browns Cay, bringing the programme total to 285
• Further outplanting paused and fragments retained in underwater nurseries as marine heat stress threatens the northern Caribbean

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 Programme.

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 favourable.

Elkhorn coral (“Acropora palmata”) is endemic to the Caribbean but is critically endangered, with reports indicating population losses of 97% loss across the Caribbean since the 1980s and eradication at many locations following the 2023-24 marine heat wave. For The Bahamas, Elkhorn is extremely important as one of the main reef-building corals supporting its environment and economy through coastal protection and providing nursery and feeding grounds for many fish and invertebrate species which sustain fisheries and tourism.

“Exceptionally warm ocean conditions are forecast this year, which could place corals under significant stress.” said Emeline Bouchet, Marine Programme Manager at the Ocean Cay Marine Conservation Centre. “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 programme, 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, giving them their colour and providing much of their food. This causes corals to expel the algae and turn white-a process known as coral bleaching. Without their main source of food, 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 2023-24 heat wave. As the temperatures forecast for the upcoming marine heatwave are expected to reach even higher levels, the marine scientists will monitor the coral reefs around Ocean Cay monthly to track the health and resilience of the outplanted and natural corals. A technique using photogrammetry allows them to create 3-D models which 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.