Restorative aquaculture is a holistic approach aimed at replenishing depleted marine ecosystems while possibly fostering sustainable food production. Restorative aquaculture can safeguard marine biodiversity, enhancing ecosystem resilience, while ensuring food security in the face of mounting environmental pressures. It also represents a paradigm shift from conventional practices, emphasizing the restoration and conservation of marine habitats alongside aquaculture production. By integrating ecological principles, such as habitat restoration, species conservation, and ecosystem-based management, restorative aquaculture endeavours to mitigate the adverse impacts of traditional aquaculture and other anthropogenic stressors on marine environments.
The degradation of Caribbean coral reefs is concerning, leading to shifts in algae-dominated habitats. Herbivores like sea urchins and crabs, play an essential ecological role as they control algal abundance, which would otherwise outcompete corals and other benthic organisms for space. The Institute for Socio-Ecological Research (ISER Caribe) has developed the first land-based coral, sea urchin and herbivorous crab nursery at the Center for Research and Restoration of Marine Organisms (CIROM in Spanish) in Puerto Rico. ISER Caribe is taking a novel approach to improving coral reefs by enhancing commercially- and ecologically essential herbivore populations in Puerto Rico through restorative aquaculture techniques. The are producing three species of sea urchins and one species of herbivorous crabs. us crabs.
So far, more than 6,000 lab-reared long-spined sea urchin (Diadema antillarum), 300 West Indian Sea eggs (Tripneustes ventricosus), and 200 rock urchins (Echinometra viridis) have been restocked to coral reefs all around Puerto Rico. Significant changes in the benthic structure were observed during the first week after the restocking. Significant reductions of fleshy macroalgae (Dictyota spp.) and thick turf algal/sediment mats (TAS), both unsuitable substrates (e.g., coral settlement), contributed to this change. Additionally, preliminary observations show that coral outplants have a higher chance of surviving when herbivores are present because they do not need to compete for space against cyanobacteria and macroalgae. Our works shows that producing sea urchins through aquaculture techniques provides direct ecological benefits to coral reefs and should be integrated in all coral restoration plans.