The DIADEMA I project, focuses on restoring populations of Diadema antillarum (long-spined sea urchins, Diadema) around Saba, Dutch Caribbean. Diadema play a vital role in keeping coral reefs healthy by grazing on fast-growing algae that would otherwise smother young corals and take over the reef. Unfortunately, two major die-offs—one in the early 1980s and another in 2022—caused drastic declines in Diadema populations across the Caribbean. Without these urchins, many reefs have become overgrown with algae, making it harder for corals to grow and recover. Even decades later, urchin numbers remain low in many places due to poor survival of juveniles and challenges with natural reproduction, leaving coral reefs at risk of long-term decline.
To address this, the DIADEMA project rears juvenile urchins in laboratory settings and reintroduces them to the reef, where artificial structures provide the three-dimensional complexity and shelter needed to help with survival rates. As part of this effort, I investigated the reintroduction potential of Diadema antillarum using Moreef artificial reefs. My research focused on understanding the retention of lab-reared and wild Diadema on artificial reefs over time and the effect of introduced Diadema on fish assemblages and benthic community development on these reefs. We used underwater camera systems to monitor post-release behaviour, comparing lab-reared and wild individuals to identify factors influencing retention. The findings helped identify optimal reef designs and revealed that predation by the Queen Triggerfish (Balistes vetula) may be a key factor influencing restoration success.
Learn more about the ongoing research under the DIADEMA II project.
In addition to my research, I supported the Saba Conservation Foundation (SCF) and the Saba Bank Management Unit (SBMU) with lobster fisheries assessments and GCRMN coral reef monitoring in the Saba National Marine Park and on the Saba Bank.
Dutch Caribbean
