Plant corals and you get corals — and more. You get a plethora of marine life to boot. A team of researchers from the NUS Reef Ecology Lab discovered that their underwater nurseries, which provide coral fragments for transplantation in barren areas, have functions beyond propagation and rebuilding coral reefs. Besides supporting various marine organisms, these nurseries could well be conservation grounds for threatened species.
This bit of good news came from the final-year project of Bachelor of Environmental Studies graduate Crystle Wee. The paper, supervised by Emeritus Professor Chou Loke Ming from NUS Biological Sciences and Dr Toh Tai Chong from College of Alice & Peter Tan, was published online in Journal for Nature Conservation in May 2019.
The study followed in the wake of an earlier project started in 2013 by a team from the NUS Tropical Marine Science Institute and NUS Biological Sciences led by Emeritus Prof Chou and Dr Toh, which saw six hard coral species successfully transplanted onto artificial seawalls on Lazarus Island off the southern coast of Singapore.
The follow-up study, with Crystle as the lead researcher, used fragments from corals growing off Kusu Island. These were reared in the ocean itself, with each fragment, about the length of a human finger, placed on mesh nets or plastic pipes. Under the team’s care, the fragments can be transplanted to degraded reef areas in six to 12 months.
The projects, funded by the Maritime and Port Authority of Singapore (MPA), are significant in that they have demonstrated that corals can be given a second lease of life and that a sustainable marine environment can be created even in urbanised coastal areas.
Man-made structures such as seawalls and breakwaters are increasingly erected to reduce the impact of rising sea levels brought on by climate change. More than 60 per cent of urban Singapore’s 200km shoreline consists of seawalls. The corals grown on these seawalls showed sustained growth as well as high survival rates of close to 90 per cent on average.
Crystle’s study went one step further as it revealed that the underwater nurseries do not just provide coral materials for future transplanting but also shelter and fodder for marine organisms. Sea creatures like brittle stars, crabs and sea slugs have been found within the live corals of the nurseries.
“Our findings showed that coral nurseries can support a range of mobile invertebrates and function as tools to conserve threatened mobile invertebrates. This ecological function is under studied and should be assessed in restoration programs for the conservation of corals and associated fauna,” the team wrote in their paper.
Emeritus Prof Chou said the findings from this latest study could provide insights for future reef restoration projects. Added Dr Toh, “The next step would be to develop approaches to engineer our coastlines sustainably, so as to balance our economic needs and conservation of our natural environment.”
The Reef Ecology Lab, which conducted the study, is a lab by the NUS Tropical Marine Science Institute and NUS Biological Sciences.