Coral bleaching occurs when increased temperatures cause a normal coral, as seen on the left, to turn pale, resulting in the pale coral seen on the right. Photo: Ria Tan
SINGAPORE — The increased likelihood of El Nino could hit Singapore’s coral reefs hard, say nature lovers, who have already observed signs of coral bleaching on the reefs dotting the offshore islands.
With temperatures expected to rise about 1°C on average, as an NEA report issued last week showed, there is concern that the rate of coral bleaching, a phenomenon already plaguing reefs in local waters, will accelerate.
El Nino is the abnormal warming of the tropical Pacific Ocean which, in the case of South-east Asia, leads to prolonged drier and warmer weather.
Coral bleaching occurs when increased temperatures cause algae residing in the coral to be expelled by the millions. Prolonged exposure to higher water temperatures causes the coral to turn pale — hence the term bleaching — and eventually die.
During the strongest recorded El Nino event to date in the 1997 to 1998 period, 50 to 90 per cent of the reef organisms residing in Singapore were adversely affected, resulting in several colonies dying out. In 2010, unusually high water temperatures led to 60 per cent of coral colonies in Singapore showing signs of bleaching.
The NEA has predicted that weak to moderate El Nino conditions could develop in the next few months
Professor Chou Loke Ming, head of the Reef Ecology Lab at the National University of Singapore, said the Republic “can expect to lose some species of corals” if the temperature increases as forecast.
While the NEA did not mention any official plans to mitigate the impact of El Nino on marine life here, Prof Chou said the reefs’ resilience to environmental changes can be increased by managing them properly, adding that the ability of these ecosystems to survive should not be underestimated.
Wildlife enthusiast Ria Tan, who posted photos of coral bleaching at Terumbu Pempang Laut and St John’s Island on her blog Wild Shores of Singapore last week, concurred. “It’s not all bad news”, she said in an email response to queries, citing a report by marine biologist James Guest in 2012 that found certain coral species were recovering rapidly from bleaching, a sign that they were gradually able to cope with higher water temperatures.
While rising sea temperatures are inevitable, Prof Chou believes the fate of the reefs is in the hands of Singaporeans.
“We are blessed with a natural heritage of coral reefs and are within the global centre of coral diversity, with the richest reef species in the whole world. If we throw it away, then we are very poor stewards of the natural environment,” he said. Jordan Skadiang