Global sea levels are expected to rise by at least half a metre by the year 2100 due to climate change. The projected rise can affect important environmental factors such as habitat suitability and availability of light, threatening the health and survival of marine ecosystems.
For the corals dwelling in the sedimented, turbid waters around Singapore, rising sea levels can imperil species, as those living among the deepest waters could starve due to insufficient light for them to make food.
A team led by Assistant Professor Huang Danwei from NUS Biological Sciences examined nearly 3,000 corals from 124 species at two reef sites in Singapore, namely Pulau Hantu and Raffles Lighthouse. The photograph above shows a variety of corals at the reef slope of Raffles Lighthouse.
The NUS research team discovered that the corals in Singapore waters typically do not extend deeper than eight metres, as light levels beyond this depth are not sufficient to support coral growth. The researchers also found that species present in deeper areas are able to tolerate a wider range of conditions, and are unlikely to be threatened by a rise in sea level, provided that other stress factors such as sedimentation do not increase.
The findings, published online in the journal Marine Environmental Research on 19 April 2019, highlight the resilience of coral reefs in Singapore. The results serve to support reef management, and inform conservation efforts especially in the selection of sites and depths for coral restoration.