WILLEMSTAD – Last week, a program was once again organized at the CARMABI foundation in Piscadera by SECORE International, in collaboration with local organizations REACT, Reef Renewal Foundation Curaçao, The DiveShop, and CARMABI itself. Thanks to this partnership, local youth, organizations, and interested participants from the Bahamas, Bonaire, St. Croix/USVI, Colombia, Trinidad & Tobago, and Honduras were introduced to techniques developed on Curaçao by SECORE and CARMABI to cultivate coral larvae and how these can be used for research and coral reef restoration.
From May 19 to May 29, SECORE International—an American organization dedicated worldwide to developing new techniques for coral restoration through coral larvae—hosted a workshop at CARMABI. The event gave ten participants from six Caribbean countries the opportunity to deepen their knowledge of the latest methods and possibilities in coral propagation. Additionally, more than 20 local youths participated in parts of the program through CARMABI’s Marine Youth Rangers program.
Although most coral species reproduce en masse during the fall “coral spawning” season, one brain coral species (Diploria labyrinthiformes) spawns multiple months starting in May. During this time, colonies release bundles containing sperm and eggs. When these bundles break apart, eggs and sperm from different colonies fertilize to form coral larvae that settle on the reef floor after a few days. By capturing these bundles with special nets at four coastal locations, the lab at CARMABI was able to cultivate 250,000 coral larvae, which will eventually be reintroduced to the reef using specially designed tiles developed by SECORE.
During the workshop, SECORE demonstrated through lectures and field trips the currently available methods for effectively cultivating coral larvae. Particular focus was given to new techniques that increase genetic diversity in new coral generations, enabling corals to better adapt to challenges such as climate change and pollution. New innovations were also showcased that increase the number of larvae that can be transplanted onto reefs.
Youth rangers
The organizers were pleasantly surprised by the large numbers of coral larvae cultivated during the workshop. Like many other coral species, brain corals in Curaçao and throughout the Caribbean have suffered greatly over the past two years due to high seawater temperatures and the outbreak of the deadly coral disease SCTLD (stony coral tissue loss disease). “Nevertheless, the surviving colonies still appear capable of reproducing, which may be seen as a sign that at least some corals can adapt to changing conditions,” said Dr. Valerie Chamberland from SECORE, who has worked for years with CARMABI.
At the same time, participants were introduced to the latest “cryopreservation” techniques by Dr. Kristen Marhaver, who established a specialized lab at CARMABI. Cryopreservation involves storing eggs and sperm of endangered species, including many corals, at extremely low temperatures to be used later. This “freezing” preserves the genetic diversity of a population. “Now that SCTLD seems to be retreating, we can thaw previously frozen genetic material and use it to fertilize eggs collected during the workshop. This creates a new generation of coral larvae with enormous genetic variation, potentially allowing them to better adapt to current conditions,” explained Dr. Marhaver, who leads this program at CARMABI.
Besides professional participants interested in coral propagation techniques, more than 20 local youths also took part in dives to collect coral eggs and sperm and the subsequent lab work. In total, over 50 participants were involved, ranging from local youth, Caribbean organizations engaged in reef restoration, local NGOs (REACT, Reef Renewal Foundation Curaçao), CARMABI’s education program (NME), park rangers from the Curaçao Marine Park, to scientific researchers. Everyone praised the diverse character of the workshop, which was well represented by international, local, young, and older participants alike. Spending several days together allowed for rich discussions on how self-cultivated coral larvae can contribute to restoring reefs in Curaçao and other Caribbean islands.
The cultivated coral larvae are thriving: 80% survived the first week, far higher than the estimated 1% survival rate in nature. The larvae are now attached to the aforementioned tiles where they continue to grow and will soon be transplanted onto the reef.
