Untouched reefs provide a natural baseline as planted structures host more corals in Singapore trial

In Singapore’s Sisters’ Islands Marine Park, eight artificial reef structures were deployed in 2018; six were planted with corals and two were left unplanted as a control. By February 2022, surveys counted 1,961 live coral colonies from 43 genera on the planted structures, compared with 95 colonies from seven genera on the two unplanted structures. Early inhabitants on all structures were barnacles and bivalves, with natural coral settlement appearing about two years after deployment. The two unplanted plots provide a baseline for natural recruitment, while the planted plots show substantial coral establishment, illustrating how natural and human-assisted reef growth interact in this setting.