Coral Relocation and the Innovative Use of Excavated Materials and Dredged Materials for Reclamation


Maritime and Port Authority of Singapore

 
In 2015, MPA completed the relocation of 2,300 hard coral colonies from Sultan Shoal, to three southern sites at St. John’s Island and Sisters’ Islands. The relocation programme was initiated to protect the corals from the impact of the development of Tuas Terminal.

INTRODUCTION

As more economies in developing nations progressively open up and join the global marketplace, Singapore foresees an increasing demand for international shipping and reliable port services.

In land-scarce Singapore, building a new port, or even redeveloping an existing one is never a straightforward matter. Due to the land scarcity issue, reclamation usually has to be carried out to create land for port development. The idea of a next generation port was conceived during the detailed planning of Tuas container terminals in 2014 as a fully integrated port can optimize land use and technology to improve the productivity and safety at ports.

FRAMEWORK AND STRATEGY

Before Reclamation: Relocated Corals to Preserve Marine Biodiversity
Prior to starting on any construction or development project, MPA will perform an environmental impact assessment to evaluate the level of impact the project could have on the surrounding environment. A study in 2012 discovered that the delicate corals at Sultan Shoal would be adversely affected by the construction and reclamation activities. As corals are natural, living habitats for a wide array of marine life, they are critical in sustaining the biodiversity in our waters. MPA commissioned a Coral Relocation Plan to determine the most optimal relocation sites for the corals at Sultan Shoal and adopted the findings of the study to relocate the corals to Sisters’ Island and St John’s Island. MPA also put in place a five year monitoring programme to study how these corals would be adjusting to their new environment.

Reclamation: Inter-agency Collaboration to Recycle Excavated Materials
Reclamation work for the development of Tuas Terminal requires a significant amount of fill material. Instead of relying wholly on sand for the reclamation, the Land Transport Authority (LTA) and MPA developed an innovative solution that would reduce the amount of sand required as well as the cost of the reclamation work. The solution involved using excavated material generated during excavation work for LTA’s many underground construction projects. Each year LTA generates large volumes of excavated material which can be used by MPA for port development.

ACHIEVEMENT AND IMPACT

Coral Relocation In 2015, MPA completed the relocation of 2,300 hard coral colonies from Sultan Shoal to three southern sites at St. John’s Island and Sisters’ Islands. The relocation programme was initiated to protect the corals from the impact of the development of Tuas Terminal. The coral conservation programme saw MPA working with volunteers from various environmental interest groups to relocate corals and set up coral nurseries. The coral conservation programme is a good example of MPA’s commitment to develop the future mega-port at Tuas without compromising on environmental sustainability. To increase public awareness of the coral conservation efforts, a ‘Conserving our Corals’ T-shirt design competition was launched on 29 May 2015.

Reclamation
Based on the original method of reclamation, Tuas Terminal Phase 1 reclamation site would have required 40 million m3 of excavated and dredged materials. However, an increase in LTA’s projects meant that it needed to dump more excavated material, which would have meant the need to acquire additional disposal capacity. To accommodate LTA’s surfeit of excavated materials, MPA devised an optimised reclamation design for Tuas Terminal Phase 1 with a final filling level of +4.5mCD for the excavated material. The revised design also allowed for the use of sand from an earlier constructed sand bund and existing sand from an earlier reclamation project.

FUTURE DIRECTION

Coral Relocation
During the relocation of the corals, some of their fragments were invariably left behind on the shoal. MPA, with the help of NParks and NGOs, harvested these coral fragments and started a research programme with the National University of Singapore to transplant and nurture them in coral nurseries set up at Lazarus Island, St John’s Island and Kusu Island. If the effort is successful, the rejuvenated corals will eventually be relocated to degraded reef and non-reef waters in Singapore to enrich the biodiversity in those areas. The programme also assesses the survivability, adaptability and evolution of remaining corals at Sultan Shoal.

Reclamation
The innovative use of excavated and dredged materials can be adopted by the subsequent phases of Tuas reclamation and other reclamation agencies, resulting in cost savings in terms of sand usage and cost avoidance for seeking alternative disposal means for excavated materials.
The Maritime and Port Authority of Singapore (MPA) was established on 2 February 1996, with the mission to develop Singapore as a premier global hub port and international maritime centre (IMC), and to advance and safeguard Singapore’s strategic maritime interests. MPA is the driving force behind Singapore’s port and maritime development, taking on the roles of Port Authority, Port Regulator, Port Planner, IMC Champion, and National Maritime Representative.