Relocating 2,300 coral colonies to protect marine biodiversity while advancing national infrastructure growth

As part of the Tuas Port development to consolidate Singapore’s container port activities at a single location, the Maritime and Port Authority of Singapore (MPA) identified vulnerable coral communities at Sultan Shoal at risk from port land reclamation and construction works. To protect the corals, MPA commissioned DHI in Singapore to lead a coral relocation programme between September 2013 and August 2014.

Around 2,300 hard coral colonies were carefully harvested, transported and transplanted to recipient sites at St John’s Island and the Sisters’ Islands Marine Park. MPA’s efforts preserved a significant portion of the reef ecosystem that might have otherwise been lost to development. The project became a model for integrating marine biodiversity conservation into large-scale infrastructure development, demonstrating that infrastructure growth can coexist with ecological protection.

Challenge

Sultan Shoal supported high biodiversity despite being located in port influenced zones, and was home to approximately 2,800 hard coral colonies. The planned reclamation for Tuas Port, a multi-phase port expansion, would directly affect much of this reef habitat. With land scarcity driving rapid infrastructure growth, MPA needed a strategy to balance port development and ecological preservation. The challenge was to protect Singapore’s coral heritage while enabling reclamation works: relocating corals without harming them, identifying suitable relocation sites, ensuring navigational and logistical safety as well as monitoring long-term coral health – all within regulatory timelines and technical feasibility.

Solution

DHI led the relocation programme after its environmental impact assessment identified reef vulnerability at Sultan Shoal. A team of DHI marine biologists and divers conducted the transplantation works over 12 months, using tools to detach coral colonies with minimal damage. The corals were placed in baskets for transport to recipient sites within the Sisters’ Islands Marine Park, where conditions supported long-term survival. During transport, each basket was covered with wet towels and doused with seawater every 10 to 15 minutes to prevent desiccation. Once introduced to their new home, the corals were secured to the natural reef using underwater epoxy. The relocation was carried out in collaboration with volunteers from environmental interest groups.

Post-transplantation, DHI monitored the health of relocated corals and surrounding reef communities over five years. Water quality indicators such as turbidity, temperature and sedimentation were also tracked for changes.

Throughout the project, DHI worked closely with MPA and local stakeholders to ensure compliance with environmental, navigational and operational standards. The multi-pronged approach combined field expertise, ecological planning and scientific monitoring to support the successful relocation and recovery of coral communities.

Results

The project resulted in the successful relocation of approximately 2,300 coral colonies from Sultan Shoal, preserving a substantial portion of the reef ecosystem that would have otherwise been lost to development.

Monitoring at the new sites showed encouraging signs of reef adaptation. Many of the transplanted corals continued to thrive, supporting reef-associated marine life such as reef fish and invertebrates. Results suggested that the relocation helped preserve coral colonies while supporting the health of existing reef systems.

The project became a model for integrating marine biodiversity conservation into large-scale infrastructure development. It demonstrated that with careful planning, technical skill and commitment to sustainability, infrastructure growth can coexist with ecological protection. DHI’s leadership in executing the relocation reinforced the importance of science-based solutions in managing environmental impact in urbanised marine environments like Singapore.