Restoration Efforts

All DC islands

Photo credit: Alwin Hylkema

The Diadema RAAK Project is a collaborative effort between University of Applied Sciences Van Hall Larenstein, Wageningen Marine Research and Wageningen University, STENAPA, Saba Conservation Foundation, Caribbean Netherlands Science Institute, University of Applied Sciences HZ, ISER Caribe, Wortel Product Design en Golden Rock Dive Center and is funded by Dutch Research Council (NWO)

This project is working to improve local populations of long-spined sea urchins around Saba and St. Eustatius by collecting larva from the reef and allowing specimens to mature in a lab before being returned to the wild. Culturing Diadema can provide a number of benefits, including the ability to restock reefs which don’t have a natural larvae supply yet and allowing scientists to study the larval development and settlement cues. The results can consequently be used to develop new and more effective restoration methods.

In april 2022, the Dutch Caribbean Nature Alliance (DCNA), together with the University of Applied Sciences Van Hall Larenstein, hosted a sea urchin (Diadema Antillarum) restoration workshop on Saba. 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. Throughout the workshop important discussions took place to determine the next steps needed to mitigate the loss of Diadema sea urchins on a regional scale.


Presentation Overviews

2022 Diadema Die-off

Presenter: Alwin Hylkema (Van Hall Larenstein)

The first session covers the current status of Diadema populations within the Dutch Caribbean as well as an update on the current Diadema die-off events, scale, symptoms, treatments and update.  Put in the context of restoration, this presentation stressed the importance of RAAK Pro Diadema project and how it can assist in natural recoveries within Caribbean populations.


Introduction on Diadema Restoration

Presenter: Alwin Hylkema (Van Hall Larenstein)

This portion of the workshop introduced Diadema restoration and the various approaches to restore this important herbivore within the Caribbean.


Diadema Cultivation

Presenter: Tom Wijers (Van Hall Larenstein)

There are several restoration methods, most of which are dependent on natural larvae supply within the water (translocation, settler collection and assisted natural recovery).  However, for locations lacking adequate natural larvae supply, its possible to cultivate Diadema larvae from gametes to juveniles.  This presentation covers this process and explores its potential within the Caribbean.

The Diadema workshop was 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).


Special Diadema BioNews Edition Navigation



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