Reef Renewal Bonaire outplants three species of boulder coral

Reef Renewal Foundation Bonaire, World Wide Fund for Nature – Netherlands
27-JAN-2023 - For the first time in history, three species of boulder coral have been outplanted back to Bonaire’s reefs: lobed star coral, mountainous star coral, and great star coral. In late 2022, Reef Renewal Foundation Bonaire began outplanting boulder coral fragments that were spread via fragmentation almost two years prior and reared in nurseries.

Trays of boulder coral fragments in the nurseryAll three species of boulder coral, two of which are endangered, are key building blocks of the marine ecosystem and will increase the resilience of Bonaire’s reefs for years to come. In 2019, Reef Renewal Foundation Bonaire, with a government permit and input from STINAPA, collected a few boulder coral fragments from four wild colonies around the island. These fragments were hung on specially-designed nursery trees and closely monitored for indicators of disease, bleaching, and other stressors over the following two years.

In December 2022, the first 'reef-ready' boulder corals were taken to various restoration sites in Bonaire and outplanted using a novel, cement-based attachment technique. Fragments are pressed into small domes of fresh cement and secured to sand or rock. Once hardened, these structures become part of the reef, where they will be monitored for the coming years by the Reef Renewal team. Although Reef Renewal Foundation Bonaire has been propagating boulder coral larvae for years, this is the first time that colonies were reared and fragmented in a nursery setting before being outplanted. Francesca Virdis, Chief Operating Officer of Reef Renewal Foundation Bonaire states: “Outplanting these boulder coral fragments for the first time was a critical step for us, one that was necessary to fine-tune our restoration techniques and establish proper operating protocols. From now on, our focus is scaling up their production to make sure that, with the help of our incredible community of dedicated volunteers, thousands of corals will be outplanted back to our reefs every year.”

RRFB volunteer outplants multiple colonies near the boulder coral nursery

Wild lobed star coral


The boulder coral project is important not only for the preservation of key species, but also for ensuring the resilience of Bonaire’s reefs in the face of growing local and global threats. By expanding the quantity and species of coral they outplant, the foundation introduces much needed diversity to degraded reef areas, allowing them to better withstand today’s ever-changing environment and the uncertain conditions of the future.

Text and pictures: Reef Renewal Foundation Bonaire (leadphoto: outplanted colony of great star coral)