More than 200 personnel have been involved in a major cleanup of Singapore's north-eastern coast, where the authorities found beaches covered with a black, tar-like substance after an oil spill in Johor.
The beaches at Changi, Punggol and Pasir Ris were all affected by the oil spill, which was caused by the collision of two vessels near Pasir Gudang Port. Pulau Ubin and Coney Island - two of Singapore's offshore islands - were also hit.
Meanwhile, the authorities have suspended sales from three affected fish farms, and will do so for newly affected farms.
The suspension will be in place until food safety evaluations are complete, the Agri-Food and Veterinary Authority (AVA) said last night.
Cleanups at Pasir Ris and Punggol beaches were completed by yesterday afternoon. Changi seemed to be the worst hit, with an 800m stretch there closed temporarily to expedite operations, said the National Environment Agency (NEA).
Affected areas rich in biodiversity
There may be no colourful coral reefs fringing Singapore's northern coast, but it still thrives with underwater life.
Sea turtles and otters, for example, have been spotted at Changi beach and Pulau Ubin - areas affected by an oil spill that the authorities were working to clean up yesterday.
Mr Stephen Beng, chairman of the Nature Society (Singapore)'s marine conservation group, told The Straits Times that such incidents devastate the marine environment.
"Oil destroys the insulating ability of fur- bearing mammals like our otters, and the water repellency of birds... Spilt oil also affects the eyes, skin and lungs of sea turtles and dolphins, but they are more vulnerable to chemical exposure from what they eat in their contaminated habitat," he said.
Besides animals, oil spills also affect trees. Mangroves, in particular, breathe through pores in their trunks and stilt roots, which can get clogged by oil.
Pulau Ubin - an island off the north-eastern coast of mainland Singapore - is home to 20 per cent of all mangroves that can be found in the country.
These habitats, with their iconic stilt-root trees, have also been affected.
At Pulau Ubin yesterday, The Straits Times found some leaves, saplings and roots of mangroves covered in the black, tar-like substance.
In response to queries, the National Parks Board (NParks) said it had deployed oil- absorbent booms along Pulau Ubin's north-eastern coast, Pasir Ris Park and Coney Island Park on Wednesday to protect the mudflats and mangrove areas.
"Our observation is that the booms have kept the oil out of biodiversity-sensitive sites. NParks is working with the relevant agencies on cleanup efforts," said an NParks spokesman, adding that the board is monitoring the impact of the oil spill on marine life.
Ms Ria Tan, who runs the Wildsinga pore.com nature website, said: "I am glad NParks took swift action to place booms to protect some areas rich in biodiversity."
When The Straits Times team visited the area at about 10am yesterday, there was a strong smell of petroleum. The sand was stained with a black substance, and the water had an oily sheen.
NEA contractors were seen bringing up oil absorbents - which look like large swathes of cotton wool - stained with oil onto a vessel, while workers packed oil-stained sand into trash bags. Workers were also seen putting up signboards advising people to stay away from the contaminated water.
An NEA spokesman said it is also closely monitoring the quality of the seawater.
On Pulau Ubin, cleanup operations were also carried out on a 100m stretch of Noordin beach, which has been closed to the public since 2013 for work to restore the shoreline.
The Maritime and Port Authority of Singapore, which is coordinating the containment and cleanup efforts, deployed 17 vessels to clean up the surrounding waters.
Equipment to skim oil from the surface of the water and prevent further spread was also deployed at the affected areas.
The collision between the two container vessels - Wan Hai 301 and APL Denver - occurred in the eastern part of the Johor Strait near Pasir Gudang Port on Tuesday night. The 50km-long Johor Strait separates Singapore from Malaysia, and is only 2km wide at its broadest.
The incident occurred close to midnight and left 300 tonnes of oil spillage as a result of damage to one of the vessel's bunker tanks.
This is the most recent major oil spill to affect Singapore since 2010, when a collision caused 2,500 tonnes of crude oil to leak into the Singapore Strait, south of the mainland.
The current oil spill, especially since it happened so close to the Chinese New Year on Jan 28, is worrying fish farmers.
There are about 60 farms located in the East Johor Strait area, most of which supply fish to Singapore. Two farms have reported fish deaths, which amounted to about 150kg to 250kg across both farms, according to the AVA .
However, as most of the farms did not report fish mortality, "there is minimal impact to supply", it said.
Mr Timothy Ng, operations manager of 2 Jays fish farm in the area, said this was the first time it had been hit by an oil spill this severe.
He has not yet seen any dead fish floating up to the surface, but he said the AVA yesterday asked his farm to stop sales while tests are ongoing. "We also have to see if our equipment, such as cages, can be reused after the oil spill," he added.
Marine biologist Toh Tai Chong said oil spills can tip the ecological balance if a large enough wild fish population is affected.
"For instance, if herbivorous fish are killed, there will be less grazing of algae in these habitats.
"Without effective control of the algae population, marine algae can proliferate quickly and dominate these habitats," added Dr Toh. In the long run, this could reduce the fish population in those habitats.