ReefGrazers

Since the 1970s, Caribbean reefs have transitioned from coral-dominated to algal-dominated ecosystems. The prevalence of algae reduces coral recruitment, rendering the reefs unable to recover from additional disturbances and jeopardizing crucial ecosystem services, including coastal protection, fisheries, and tourism. One of the main factors to the proliferation of algae is the scarcity of grazers, which is a result of overfishing and disease outbreaks. While fishing supports livelihoods, enhances local food security, and is an integral part of the Caribbean communities' culture, it remains a significant threat to coral reefs.

Consequently, the Nature and Environmental Policy Plan (NEPP) 2020-2030, outlining conservation and restoration priorities in the Caribbean Netherlands, underscores the necessity of an integrated approach to tackle the complex challenges of coral reef restoration and fisheries development. The Saba government, and nature management organizations of Bonaire, St. Eustatius, and Saba are implementing the NEPP. Together with University of Applied Sciences Van Hall Larenstein, Wageningen University and WWF, they aim to identify novel species of native invertebrate grazers with the dual purpose of reef restoration and fisheries diversification. The Caribbean king crab (Maguimithrax spinosissimus), the West Indian sea egg (Tripneustes ventricosus), and the West Indian top shell (Cittarium pica) have been identified as potential candidates. Despite their preference to graze on macroalgae, their current densities are inadequate. Population enhancement of these species holds promise for reducing algae, promoting biodiversity, and simultaneously supporting small-scale fisheries. However, there is limited knowledge regarding the ecological effects and socio-economic potential of these grazers.

The ReefGrazers project aims to assess the current densities of these herbivores around the BES islands, analyze their impacts on the reef, and evaluate their retention post-restocking. Socio-economic research will quantify current small-scale fishing practices, while market analysis will help assess the potential for the development of these novel resources as sustainable fisheries.