The hit happened shortly before midnight. According to police, two vans pulled into Gansbaai Harbor, a small fishing port outside Cape Town, South Africa, and stopped at a factory beside the slipway. More than 10 armed men climbed out and hustled through a side gate, kidnapping four guards and making off with over 1.6 tons of dried abalone, worth more than $220,000.

Heists like this one, which took place on September 24, are becoming more common in South Africa’s abalone industry as wild stocks of the shellfish decline. Abalone is a status food in China, selling for more than $90 a pound alongside other dried marine delicacies like sea cucumbers and shark fin.

During the past 25 years, according to data from TRAFFIC, an NGO that monitors the illegal wildlife trade, Chinese-backed syndicates have illegally shipped more than 55,000 tons of South African abalone to Hong Kong, the nucleus of the industry. This has all but destroyed South Africa’s legal abalone fishery, which sustainably harvested some 770 tons of abalone a year until the poaching groups muscled in. (Read more: “Poaching for Abalone, Africa’s ‘White Gold,’ Reaches Fever Pitch.”)

With demand for South African abalone from China’s middle class increasing, and wild stocks now drastically depleted, a thriving abalone farming industry has emerged. Now the country’s fastest-growing aquaculture sector, abalone brought in more than $73 million in 2015. The shellfish are grown in tanks and fed a synthetic diet. When they grow to market size, ranging from one to nine ounces, they’re harvested and exported live, canned, or dried.

View Images Abalone is a prized delicacy in Asia, where it’s sold in markets, such as this one in Seoul, alongside other fish and shellfish. Demand has caused the value of abalone to skyrocket, and now farmers and processors in South Africa must hire security guards to protect their product. Photograph by Ed Jones, AFP/Getty

Not surprisingly, given the dearth of wild abalone, traffickers have begun targeting this legal supply chain, including factories and transit vehicles.

“If you've got a wild resource, and everybody’s attacking it, and experts agree that it isn't going to last much longer, then you need to find another source,” says a risk analyst for the abalone industry, speaking on condition of anonymity. “This is another form of the poaching business.”

Abalone farmers in South Africa—there are now 13 commercial operations, concentrated on the southern coast near Gansbaai—are reluctant to speak on record about the growing poaching threat, fearing reputational damage in China. Producers who can’t guarantee safe shipping of their abalone, which are paid for in advance by Chinese clients, are considered a liability in the sector.

Most farmers have hired expensive private security firms to protect their premises and transport abalone in armored vehicles, often under armed escort. Even so, this hasn’t stemmed attempts to rob or hijack batches of the coveted shellfish.

A truck delivering live abalone to Cape Town airport in January 2014 was struck in a “highly professional” operation, according to the risk analyst. Taking a highway exit near the airport, the driver found himself blocked by a stationary car. A second vehicle drew up from behind, boxing him in. Within seconds there were gunmen at both doors. The thieves took over the truck and raced into a nearby township, where a response team tracked them by GPS and recovered the shipment. The thieves ran away, and police made no arrests.

Two years later another abalone driver dodged hijackers at the same exit. Nobody was hurt in these attacks, but this April a guard was shot in the abdomen during a hijacking, and two robbers and a guard were injured in a shootout in July.

On one stretch of highway farther out of Cape Town, assailants have shot at drivers and tried to force them off the road on three separate occasions, according to the risk analyst.

SHELLFISH AS BLACK-MARKET CURRENCY

The resemblance of these hits to bank robberies and cash-in-transit holdups is no coincidence: During the past two decades abalone has become hard currency on South Africa’s black market, bartered in bulk for drugs from China, including methamphetamine and its chemical precursors.

“The gangs who control the trade need to keep bringing in drugs, which means they’re going to keep looking for abalone,” says Marcel Kroese, a program manager at TRAFFIC and the former director of enforcement in South Africa’s Department of Agriculture, Forestry and Fisheries. “If they can’t get it from the sea, they’ll try elsewhere.”

View Images The abalone farming industry is thriving in South Africa, where it brought in more than $73 million in 2015. There are also abalone farms in California, as pictured here, as well as China, Taiwan, Japan, and elsewhere. Photograph by Universal Images Group, Getty

Abalone has become such a hot commodity that poached stocks confiscated by South African authorities have also been stolen. In October 2015 the fisheries department acknowledged that masked gunmen had overpowered guards at a government warehouse in Cape Town, making off with several bags. This has happened at least twice in Cape Town and once in the city of Port Elizabeth, also a poaching hot spot, says a consultant who has worked with the department and asked not to be named.

The fisheries department auctions off confiscated abalone—dozens of tons every few months—to subsidize its anti-poaching operations. With as much as 30 percent of its entire budget funded by abalone sales, according to Beverly Schäfer, a member of the opposition party in parliament, critics say this system gives the department a financial stake in poaching.

The fisheries department did not respond to questions for this story.

A “SUSPICIOUS” AGREEMENT

In December 2016, Willjarro, the Johannesburg-based company that operates the Gansbaai abalone factory that was robbed this September, signed a contract with the fisheries department to process 90 tons of confiscated abalone—a deal worth more than $1.3 million. At the time the fisheries minister said that the contract was issued to reduce the “security risk” of storing abalone on government premises.

A month later, however, following a court challenge by a rival processing company, Shamode Trading Investments, the fisheries department suspended the contract.

Shamode alleged that the agreement was “suspicious” because Willjarro had no experience in aquaculture or the fishing industry. A subsequent forensic investigation, commissioned by the fisheries department, found further irregularities in Willjarro’s application: Court documents show that the company had registered with the department just a day before the tender was advertised and did not have necessary permits for processing or transporting abalone. This means that Willjarro should never have won the contract. The department has now launched an internal corruption investigation.

In suspending the contract, the fisheries department also revoked a permit they’d issued to Willjarro to export four tons of abalone. Willjarro then refused to return the confiscated abalone in its possession, weighing more than 33 tons. The company also ignored multiple court orders to insure the consignment. Around 1.6 tons of this stock was eventually stolen in the September heist, routed back onto the black market.

Willjarro has no listed contact details. A manager at the factory told National Geographic he would answer questions but then stopped responding to calls and messages. The company’s sole director, Ronald Ramazan, could not be reached for comment. A company belonging to Ramazan's son, Gershom, was accused in June of improperly winning a government contract—worth more than $1.5 million—to provide drought relief services in South Africa's Eastern Cape province. That contract was awarded by the same department that manages fisheries. Court documents show that Gershom Ramazan falsely signed as the director of Willjarro in the abalone processing agreement. He did not respond to questions from National Geographic.

Police did not respond to detailed questions about Willjarro and the Gansbaai heist, and there have been no arrests since the robbery. According to police captain F.C. Van Wyk, “the investigation continues.”

Beyond this knotty saga, the threat of hits on producers will likely increase as abalone stocks concentrate further into private facilities. “Syndicates will follow the abalone,” predicts TRAFFIC's Kroese, quoting early-20th-century American bank robber Willie Sutton: “I rob banks because that’s where the money is.”

Kimon de Greef is a freelance journalist from South Africa. He is working on a book about the illicit abalone trade. Follow him on Twitter.