Diadema sea-urchins play a vital role in maintaining a balanced coral reef ecosystem by grazing away algae and creating bare substrate for coral recruitment. The RAAKPRO Diadema project aims to develop interventions to improve larval recruitment and juvenile survival to increase local Diadema populations. To do this, researchers are investigating the larval and settlement stage of Diadema populations around the islands of Saba and St. Eustatius. First results show that some locations have a high suitability for “assisted natural recovery”.