The hawksbill turtle found dead in waters off Pulau Hantu earlier this month had been so tightly bound by a drift net that the man who freed the carcass found the animal's head severed from its body.
It shell also came apart once released from the confines of the net, recounted Mr Wade Pearce, who was preparing to cruise out to the Southern Islands when he was alerted to the trapped turtle.
Mr Pearce, who founded the Singapore Marine Guide platform for the leisure marine and boating community, told The Straits Times: "When I saw it, my first thought was: How many more drift nets are there out there now?"
It was a tragic end for the hawksbill turtle, a critically endangered species native to Singapore. But it will likely not be the last casualty of such indiscriminate fishing practices.
Imagine a gigantic spider web suspended in water. That is, in essence, how drift nets work.
They are kept vertical by floats at the top and weights at the bottom, and they trap everything in their path.
"Nets are likely to indiscriminately kill anything that gets trapped in it, including bycatch such as sharks or turtles," said a spokesman for Marine Stewards, a volunteer group which promotes sustainable fishing practices and marine conservation.
"And if the nets get lost or abandoned, they potentially become ghost nets that continue to kill marine life and coral."
Mr Pearce said he had tried to retrieve the drift net from the water to prevent it from ensnaring more victims. But it was a futile effort - the net was heavy and seemed to be stuck to the seabed. Reinforcements had to be called in.
The Our Singapore Reefs volunteer group sought the help of the Maritime and Port Authority of Singapore (MPA) to remove and dispose of the 100m gill net that was 15m underwater around Pulau Hantu.
"In view of the concerns from the marine community and to ensure the safety of recreational divers and navigational safety in the Port of Singapore, MPA worked with Our Singapore Reefs to retrieve the net on May 21," said an MPA spokesman, who added that a commercial diving boat, floating crane barge and professional divers were deployed.
"As such fishing nets pose risk to the safety of navigation, their use is prohibited in the navigational channels and anchorages of our port waters," the MPA spokesman added.
The net that likely took the life of the turtle was not the first.
Two marine biologists from Our Singapore Reefs last Monday spent about an hour retrieving another net found draped over corals that had grown naturally on a seawall off Lazarus Island, one of Singapore's Southern Islands.
The casualties included two native red egg crabs, which are poisonous and cannot be eaten. One of them was still alive even after losing at least four of its legs in its struggle to be free from the net.
The divers also saw dead and dying coral, some bearing whip-like marks where the net filaments had cut into its tissue.
Dr Toh Tai Chong, one of two marine biologists behind the effort, said the net spanned at least 30m long and was about 1m wide. It also looked like it was handmade, with cruder floats.
The Marine Stewards spokesman noted that netting is mainly carried out by local commercial or subsistence fishermen, or by fisherman in foreign sampans (small vessels).
Most recreational fishermen here usually use more sustainable methods, such as hook and line fishing, she added.
Dr Karenne Tun, director of the National Parks Board's (NParks) National Biodiversity Centre, urged people to fish responsibly at designated fishing spots, using more sustainable fishing methods.
Because of the harm they do to marine life, net fishing and the use of wire mesh traps are not allowed in areas managed by NParks, she added. "We also encourage the practice of catch-and-release fishing, where fish that are not going to be eaten are released back into the sea," she said. "Responsible fishing practices will help us maintain our rich biodiversity."