Effectiveness of Reef Restoration in Singapore’s Rapidly Urbanizing Coastal Environment

Singapore's accelerated coastal urbanization since the 1960s resulted in 65% of its coral reef habitat lost to land reclamation. Increased sedimentation reduced underwater visibility from 10m then to less than 2m today. Under these conditions, reef restoration to increase coral cover of degraded reefs and initiate colonization of non-reef areas remains viable considering the precise mass spawning events, active settlement and vigorous growth of coral larvae. The restoration techniques employed should withstand the high suspended sediment and destabilized reef substrate. Coral fragments were translocated from a reef close to impending port development to reefs further away in a 4-year project aimed at assessing whether 1) restoration can assist recovery of degraded reefs and 2) non-reef areas can be transformed into new reefs. Within the first three years, over 1200 fragments from 22 genera were transferred to in-situ nurseries at the recipient sites, of which almost 900 were subsequently transplanted to a degraded reef site and a non-reef site with an overall survival rate of over 80%. The project's results will help to establish protocols to support management decisions on coral relocation and restoration in a rapidly urbanizing coastal environment.