The Coral Restoration Foundation (CRF) is a nonprofit organization established in the Florida Keys that seeks to revitalize the Caribbean reefs by replanting coral species that have largely disappeared over the past few decades. Elkhorn and Staghorn corals are two keystone species in the Caribbean that provide fish and invertebrates with critical habitat by growing in a branching pattern towards the surface. They live in shallow, warm waters and are particularly fragile to the impacts of climate change and ocean acidification. Their populations have plunged over the last thirty years as ocean surface temperatures have risen and the acidity of the oceans has been amplified due to our relentless carbon dioxide emissions. These dramatic changes place immense stress on coral, and when combined with other stressors such as destructive fishing practices or water pollution, the corals are more susceptible to bleaching. CRF is diligently working to restore the reefs of the Caribbean by planting Elkhorn and Staghorn coral fragments on the reefs – and their efforts are truly paying off! They have reclaimed several hundred hectares of reef in the Caribbean, and fish populations are rebounding in and around their restoration sites. I had the pleasure of diving with the CRF team lead by restoration specialist Francesa Virdis. Francesca, originally from Italy, moved to Bonaire to champion the health of the reefs through the foundation. She has assembled several “trees,” or vertical coral farms, that hang suspended in the water column and serve as nurseries for the coral fragments. Free from predators and sedimentation, the corals thrive in the shallow, sunlight waters of the nursery.
Fragments of corals from specific genotypes that have survived bleaching events are selected from around the island to ensure genetic diversity and resilience among the newly planted corals. For example, Elkhorn survivor genotype A would produce offspring with a higher chance of survival if bred with Elkhorn survivor genotype B. Through generations of proper breeding of these “survivor corals” the hope is to create a reef that is more resilient to the effects of a warming world. The survivor corals on the island have made it through mass coral bleaching events and by having them reproduce with other survivors it produces a healthy population of corals more resistant to ambient temperature changes.
During our dive, we clipped fragments from one of the trees that Francesca had designated as being mature enough to be planted on the reef. The corals have grown here for months and are now ready to be transplanted. The team uses milk crates to carry the delicate corals underwater from the nursery to the restoration site and then secures them onto the reef with heavy duty zip ties or glue. I helped with analyzing the nursery growth and securing the fragments onto the reef. Mark Evans, a photographer for sport diver magazine UK, photographed the team and I while we were planting the corals. Mark and his family were extremely pleasant all week; the Tinsley’s and I enjoyed getting to know them. I loved having the opportunity to participate in hands-on fieldwork that is truly making a difference in the health of our oceans, one coral at a time. The Coral Restoration Foundation is venerated as a true champion for our oceans, and I feel immensely lucky to have been able to work with such a commendable organization.