As dawn broke over a stretch of beach along East Coast Park yesterday, a group of people were huddled over a hole in the ground.
Slowly, carefully, they extracted what looked like ping pong balls from the sand, placing them in a bucket filled with moist sand.
But they were no sportsmen on a treasure hunt. They were staff and volunteers with the National Parks Board (NParks), on a mission to rescue 152 eggs laid by a hawksbill turtle, a species of sea turtle that is critically endangered around the world.
After the eggs were retrieved, they were moved to the turtle hatchery at Sisters' Islands Marine Park.
Removing the eggs was a laborious process, taking the NParks staff and volunteers about an hour.
The removal had to be done by hand and without any tools, as rescuers were afraid they could damage the eggs.
At the Sisters' Islands hatchery, the eggs were reburied 42cm deep in sand - the same depth they were found at in East Coast Park.
The nest had been spotted about 50 days ago by a National University of Singapore student researcher, who then informed NParks.
After NParks verified the sighting as a nest, a decision was made to move the eggs as the site was deemed risky for the baby turtles, said Mr Collin Tong, senior manager for the coastal and marine branch of NParks' National Biodiversity Centre. He said: "The nest site is next to a construction site, which is brightly lit at night."
Turtle hatchlings use environmental cues, including the moonlight, to make their way from sand to sea. Light from other sources could confuse the young turtles. But there is no light pollution at the offshore Sisters' Islands, said Mr Tong.
The hope is that when the baby turtles emerge from the hatchery, the females would "imprint" on the beach - orienting themselves using the earth's magnetic field to return to Singapore's Southern Islands to nest when they become sexually mature in 25 years or so.
There are two species of sea turtles in Singapore: the hawksbill and green turtles.
These reptiles can be directly affected by climate change, as their sexes are influenced by temperatures. Female turtles hatch in warmer temperatures, whereas males hatch in cooler environments. In a warming world, this could skew the ratio of the sexes.
Saving turtles, egg by egg
Mr Tong said NParks is able to control temperatures at the hatchery, maintaining sand temperatures at about 29 deg C, so it is more likely that a mix of male and female turtles would hatch from the clutch.
Hawksbill turtle nests have been spotted along Singapore's eastern coast, from Changi to the beaches along East Coast Park.
But their nesting grounds may be under threat if land reclamation works take place along the eastern coast.
In his National Day Rally speech on Sunday, Prime Minister Lee Hsien Loong said Singapore is looking into major engineering feats to tackle the issue of sea-level rise - a symptom of climate change that Singapore, an island state, is especially vulnerable to.
Among the strategies being considered are empoldering, a land reclamation technique, along the eastern coast, as well as reclaiming a series of offshore islands there.
He said all options will be carefully considered.
Asked how the potential reclamation of the area could affect turtle nesting grounds, NParks said: "Agencies are still studying the options for coastal protection measures along the eastern coast to determine the best way forward."
Naturalist Bernard Seah, 50, noted that East Coast Park is currently located on reclaimed land.
He said: "I have mixed thoughts about the possibility that East Coast might be reclaimed further. Singapore needs more land, but we're not sure about how it will affect the turtles.
"But if the development eventually goes ahead and is done in a careful way, such as if it is done in segments, turtles will still have room to nest. This way, a balance can be struck," he said.