Caribbean Experts Join Forces for Sea Urchin Restoration

All DC islands

Last week, the Dutch Caribbean Nature Alliance hosted a sea urchin (Diadema Antillarum) restoration workshop on Saba. This workshop was led by University of Applied Sciences Van Hall Larenstein (VHL). During the workshop experts and representatives from the Dutch Caribbean and Jamaica came together to join forces towards coral reef restoration. This workshop helped 21 coral experts from the Caribbean region and more than 65 online attendants, to obtain a comprehensive view of the overall situation of the Diadema sea urchin in the Caribbean, including the current die-off events and restoration techniques. Important discussions have taken place to determine the next steps needed to mitigate the loss of Diadema sea urchins on a regional scale.

Coral Reef Restoration

Coral reef restoration methods are showing promising results in supporting regional efforts for restoring degraded coral reefs in the Dutch Caribbean. Coral reef restoration in the Dutch Caribbean has focused heavily on corals. This workshop was built upon research and innovation that introduces the restoration of the important algae grazer: Long-spined Sea urchins (scientific name Diadema antillarum).

Photo credit: Stella Grau

Diadema sea urchins

Diadema sea urchins play a critical role in maintaining healthy coral reefs, which are essential for coastal protection and a crucial source of income for people in the Dutch Caribbean as they are a magnet for tourism. Diadema sea urchins help sustain the delicate balance within the reef by grazing on algae, which

are the main competitors of corals. In the mid-1980s, a disease swept through the Caribbean, wiping out nearly the entire sea urchin population. In mid-February 2022, reports started getting in about new extensive die-offs in the Caribbean region. By restoring Diadema sea urchins alongside corals and solving local threats such as wastewater issues, corals will have a higher chance to survive.

Photo credit: Stella Grau

Workshop outcomes

In the RAAK Pro Diadema project VHL works closely together with other research institutes and local partners to restore long spined sea urchin populations on the coral reefs around Saba and St. Eustatius. This project is showing promising results. The lead researchers Alwin Hylkema and Tom Wijers shared their impressive tools, techniques, and latest scientific findings to facilitate the restoration of Diadema in the Wider Caribbean region during the DCNA workshop.

Several topics were discussed, including the status of these reduced Diadema sea-urchins, recent Diadema die-off events and Diadema restoration techniques. The participants also received hands-on training sessions, to improve practical skills related to Diadema restoration. Besides the 21 participants present on Saba, over 65 people followed the open presentations online.

Multi-island project

During the workshop, there was intense dialogue between the Caribbean islands. Important partnerships have been established and knowledge and capacity gaps identified which needs to be solved to restore the Diadema sea urchins in the Dutch Caribbean. VHL, DCNA and the organizations present are now looking into the possibility to set-up a multi-island Diadema restoration project to accomplish a common goal: Restoring one of the most important and damaged marine ecosystems, the coral reefs.

This workshop was generously funded by the Ministry of Agriculture, Nature and Food Quality (LNV) as a support to the Nature and Environmental Policy Plan for the BES-islands, the Dutch Postcode Lottery and SIA, part of the Dutch Research Council (NWO).


Stay up to date

If you would like to learn more about the Diadema workshop and DCNA’s activities, follow DCNA through their free digital newsletter BioNews (, Facebook (Dutch Caribbean Nature Alliance) or Instagram (DCNAnature). For more information about the RAAK PRO Diadema project follow or contact project leader


For more information on the Diadema workshop, please contact:

Tineke van Bussel, Research Communications Liason at and

Dahlia Hassell – Knijff, Projects Officer at




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