The Coral Restoration Foundation (CRF), a nonprofit organization based in the Florida Keys, was established with the goal of rejuvenating the Caribbean reefs. Two keystone species, Elkhorn (Acropora palmata) and staghorn coral (Acropora cervicornis), grow here in expansive, branching thickets, offering crucial habitat for a myriad of fish and invertebrates. Flourishing in shallow, warm waters, these corals are particularly vulnerable to the adverse impacts of climate change, making them the focal point of CRF’s restoration efforts.
Coral bleaching is an increasingly widespread phenomenon whereby corals lose their vibrant colors due to the expulsion of symbiotic algae residing within their tissues. These algae, known as zooxanthellae, provide corals with sugar through photosynthesis and are essential to their survival. When subjected to thermal stress, corals eject the algae, in a response akin to experiencing a fever. While bleaching does not result in immediate mortality, prolonged instances of elevated temperatures can impede algal recolonization, and ultimately lead to coral starvation and death. Globally, underwater heatwaves are increasing in frequency and intensity, presenting a dire outlook for coral reefs unless concerted actions are taken to address climate change.
During my time at CRF in Bonaire, I had the honor of working alongside Francesca Virdis, a scientist who relocated here to champion the health of the reefs. Our days were filled with meaningful tasks, from mapping reefs and recording coral growth to educating visitors. When establishing a new restoration site, our objective was to selectively gather genetically diverse colonies from around the island — those that had successfully withstood previous bleaching events. Through this process of assisted evolution, we aim for the future offspring of these corals to inherit traits that enhance their potential for survival in increasingly warm waters.
Once selected, the coral fragments are affixed to CRF’s floating nurseries, which serve as a temporary home for the corals to mature. Free from predators and sedimentation, the corals thrive suspended in the shallow, sunlit waters. After several months of growth, they are transplanted back onto degraded areas of the reef, which was the most rewarding part of my experience. We used milk crates to carefully transport the delicate corals and secured them to the reef using zip ties or epoxy. This act requires precision, considering factors such as appropriate spacing and substrate conditions to optimize attachment and ensure future success. Across their restoration sites in the Caribbean, several hundred hectares of reef have been reclaimed, resulting in the resurgence of local fish populations. While the road ahead will be incredibly challenging for coral reefs, I’m heartened by the work of CRF and remain hopeful for the future.
