HANGBERG, SOUTH AFRICA (NYTIMES) - One man vanished diving at midnight. Another was attacked by a great white shark in deep water. Two more drowned, one in borrowed scuba gear he was not qualified to use.
All four men, who died over the past few months, were casualties of an entrenched illicit trade: poaching abalone, a seafood delicacy that sells for enormous prices in Asia.
The shellfish, which once smothered reefs in South Africa, in some places packed as tightly as cobblestones, has become more difficult to find as a result of overfishing, luring untrained divers into deeper and more deadly waters.
"The old reefs have been hit too hard and haven't had time to recover," said a diver from Hangberg, an impoverished fishing community in Cape Town, who insisted on anonymity because he did not want to alert the police to his poaching.
With stocks of the shellfish declining in South Africa, legal quotas on harvesting it are strictly enforced.
But in Hangberg, hundreds of families have turned to the abalone black market for income, as factory closings and the demise of commercial fishing have contributed to a spike in unemployment in recent years.
Fuelling the demand for exports of the mollusk is China's rising middle class, increasingly eager to consume high-status foods. For more than 2,000 years, abalone has been served to celebrate special occasions and honour guests, taking a pride of place alongside other luxury ingredients like shark fin and sea cucumber.
Abalone has a rich, buttery flavour, and, when prepared correctly, the flesh is tender, though it can be rubbery and tough.
One of the world's most expensive abalone species, Haliotis midae, occurs only on the southern and western shores of South Africa, where its high value, set amid sweeping poverty, has fuelled a poaching epidemic since the end of apartheid in the early 1990s.
When abalone was more plentiful closer to shore, the greatest threat to poachers was arrest, and the authorities continue to patrol the remaining patches where the mollusk can still be found.
Despite the prospect of fines and prison terms, poachers are driven by a strong economic incentive because abalone fetches high prices. As a result, abalone smuggling has become an important part of the underground economy in many fishing communities.
While first-time offenders may face fines as low as US$10 (S$13), the penalties for kingpins can rise to US$10,000, with prison sentences exceeding 15 years. But for most poachers, jail terms are seldom longer than a year, and convictions are rare in South Africa's overburdened court system.
Over the years, the diver from Hangberg said, he has upgraded his house with the money earned from poaching, adding extra rooms and a watertight metal roof, and it stands apart from the lopsided shanties of his neighbours.
But now resource depletion is changing the risk calculus, with divers forced to try to find abalone in turbulent waters and areas known to be frequented by sharks, making death a bigger part of the poaching equation.
"Abalone have been harvested heavily in kelp beds, so now poachers try rougher areas or deeper and more exposed places," said Mr Serge Raemaekers, a researcher from the University of Cape Town, who has studied the abalone trade.
One community, about 100 miles (161km) east of Cape Town, has been hit especially hard as divers venture into some of the most dangerous waters in the world.
In a desolate informal settlement near the town of Gansbaai, divers with no historical connection to the fishing industry have taken to swimming nearly 2 miles out to Dyer Island, a global hot spot for shark cage diving, to hunt in comparatively untouched abalone beds.
In September, one diver, Mr Sivuyile Xelela, was dragged to his death by a great white shark in front of other poachers.
Despite the risk of such violent death, poaching has become an important source of revenue here.
"Before, when we were working on the farms here, we were hungry," said Mr Thami, a diver from the community, who insisted on using only his first name because he feared prosecution for poaching.
Formal employment is hard to find in the township, a clutch of small government homes and metal shacks at the end of a dirt track, and many men have begun diving for abalone, residents said.
"The work is very dangerous, but the men do it for the money," said the Rev. Jonathan Xama. "In church we pray for their safety. This is not a good job for anybody, and we also pray that they find something better."
Within a month of the September shark attack, two more local divers, Mr Bradley Fick and Mr Waylon Love, had drowned, one at Dyer Island and one in the nearby fishing community of Hawston. Both had recently begun using scuba equipment without proper training, friends and family said, in order to access abalone on deeper reefs.
In February, Mr Raeburn Jansson died trying to poach abalone in the waters off Cape Town. His widow told local news media that he was trying to earn money to fend off the threat of the couple's four children being taken by social services.
Divers at the start of the poaching supply chain say they earn around US$15 (S$20) a pound (454g) of shucked meat.
A decent harvest of 35 pounds can bring US$525, almost double South Africa's monthly minimum wage, US$295. When abalone was more abundant, it was common for divers to harvest 150 pounds or more on a single diving trip.
For commercial divers working for legal abalone fisheries, the work is done under safer conditions, for less pay.
Once harvested, the shellfish enters a network of buyers and middlemen, and is predominantly shipped to Hong Kong, where dried South African abalone is worth more than US$200 a pound, meaning large profits for those further up the supply chain.
According to Mr Markus Burgener, a senior programme officer with Traffic, a non-profit organisation that monitors wildlife smuggling, poachers have stripped more than 40,000 tons of abalone from South African waters since 2000.
Some 3,500 tons were poached in 2016, Mr Burgener said, more than 30 times the entire legal catch. "Poaching has been steadily increasing," he said.
Quotas for the legal abalone fishery have been slashed early 85 per cent since the mid-1990s, with three formerly productive zones closed entirely to fishing.
"Illegal harvesting will eventually lead to commercial extinction, where the fishery ceases to be viable at all," said marine biologist Peter Britz at Rhodes University in Grahamstown, South Africa.
Yet, the syndicates controlling the poaching have shown little interest in sustainability: They are Chinese criminal groups who source abalone from local street gangs, often in exchange for drugs like methamphetamine, according to police officials and a report from the Institute for Security Studies.