Larval propagation to assist the recovery and resilience of Bonaire coral populations in the face of new diseases and environmental changes

Lorenzo Mittiga
Published: 31 May 2023
Last edited: 31 May 2023
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In the face of climate change and increasing pressure on our reefs, finding ways to increase the strength of coral populations and assist their recovery is paramount. Although some reefs in Bonaire still feature beautiful coral patches, some areas show visible signs of degradation. For this reason, it's important to rear larvae of key coral species, as genetic recombination could yield new strains that are better adapted to cope with changing environmental conditions. Reef Renewal Bonaire (RRFB) assisted the sexual reproduction of several coral species by propagating thousands of genetically unique coral settlers, which have been outplanted to the reefs or added to the genetic stock of RRFB's nurseries. The project was possible thanks to the establishment of key partnerships and the involvement of local dive operators and volunteers, who had the opportunity to experience the coral propagation process firsthand and its crucial role in reef preservation.


Scale of implementation
Coral reef
Marine and coastal ecosystems
Ecosystem services
Genetic diversity
Science and research
Species management
Loss of Biodiversity
Ocean warming and acidification
Storm surges
Ecosystem loss
Pollution (incl. eutrophication and litter)
Sustainable development goals
SDG 14 – Life below water


Bonaire, Caribbean Netherlands


Caribbean coral reefs are facing rapid ecosystem changes due to pervasive diseases, coral bleaching events, and local threats, such as overfishing, pollution and coastal development. Even Bonaire, whose reefs still feature significant populations of coral species, is not immune to regional trends. Healthy colonies may be too far apart to reproduce successfully through sexual reproduction alone, limiting the formation of new genetic strains. Managing local stressors while repopulating target reefs with resilient, genetically diverse coral populations is critical to preventing their irreversible loss. Integrating the Marine Park management plan with an active restoration strategy that facilitates coral sexual reproduction and promotes genetic recombination is important to give this species a higher chance to survive fast-spreading coral diseases and variable environmental conditions.


  • Bonaire’s local community and visitors, who gain a stronger and healthier reef, a core component of the island's economy

  • STINAPA, Bonaire's National Marine Park management organization

  • Participating local dive operators and volunteers

  • Schools and local youth

How do the building blocks interact?

Sharing knowledge, supporting one another, and engaging the local community has strengthened Reef Renewal Bonaire as an organization and increased its capacity to test and apply new methods and technologies, and allowed RRFB to continue to scale-up restoration efforts on Bonaire to maximize impact. At a time where halting reef degradation is critical, it's paramount to not waste time re-inventing the wheel and instead learn to work together constructively.


  • Larval propagation and rearing protocols were implemented and hundreds of thousands of coral larvae of different coral species were successfully reared in the lab and in-situ floating pools.
  • About 1,250 ceramic substrates with genetically unique coral settlers were outplanted on a degraded reef area of 1,200m2. The surplus of produced coral larvae was released back into the ocean to naturally settle on nearby reefs, extending the benefit of the project beyond the target area.
  • 24 new strains of two coral species were introduced to the current genetic stock present in Bonaire’s in-situ nursery propagation system. These young corals will be used as broodstock to propagate thousands of corals via fragmentation every year. 
  • Spawning data observations in Bonaire were shared within the region to fine-tune the spawning predictions for the South Caribbean.
  • Two important partnerships were formalized, strengthening technical cooperation and building capacity for future projects.
  • The local and international visibility of the larval propagation technique as a critical component of the coral restoration project in Bonaire.
  • The involvement of local dive operators and volunteers in the project has given ownership, built capacity, and laid the foundation for the project to continue even after completion.


Larval propagation of coral species on Bonaire wouldn't be possible without the involvement of many people from different parts of the community (local dive operators, residents, institutional partners, etc). Each person has their own reason for donating their time and energy to this project, with the common theme being ensuring the resilience of Bonaire's reef ecosystem.


We highlight the perspectives of 2 stakeholders involved in our larval propagation program - one a local dive operator and the other a resident volunteer:


"As a dive operator, giving back to the Reef is a must. If we can participate in any activity that involves conservation, restoration and education efforts,  we’ll be the first ones to raise our hands and push forward. Coral spawning efforts summarize what we all strive for: giving a helping hand to our beloved reef.


Personally, being involved in spawning dives in the past, present, and (hopefully) the future counts as my small contribution to such a HUGE effort to preserve the reef we love. From scouting possible colonies, to netting and collecting gametes, spawning is something that rewards and justifies my existence and support towards RRFB's restoration efforts on Bonaire!"


-Augusto Montburn, Dive Shop Manager



"My favorite part of being involved in brain coral spawning dives was watching them release their gametes. It was beautiful to see and incredible to be involved in some small way. Coral spawning is where it begins - and anything I can do to give back to our beautiful reefs here in Bonaire is totally worth it!"


-Ellen McGraw, dedicated Reef Renewal Bonaire volunteer



Contributed by

francesca.virdis_42872's picture

Francesca Virdis Reef Renewal Foundation Bonaire