The Illicit World of Sea Cucumbers

On an August afternoon in 2017, former U. S. Border Patrol agent Cesar Daleo attempted to smuggle what he thought was a kilogram of illicit fentanyl precursor chemicals from San Ysidro, California, across the border into Mexico. He did not know that weeks earlier, a customs agent at Los Angeles International Airport had intercepted the package en route from China. Homeland Security Investigations agents then swapped the controlled substance, disguised as lotus root starch, for a harmless white powder and sent it along to its intended destination. Law enforcement intercepted Daleo just before he crossed the border and arrested him for conspiracy to distribute a controlled substance. He had picked up similar packages 13 times before; he was sentenced to 30 months in prison in 2019. On an August afternoon in 2017, former U. S. Border Patrol agent Cesar Daleo attempted to smuggle what he thought was a kilogram of illicit fentanyl precursor chemicals from San Ysidro, California, across the border into Mexico. He did not know that weeks earlier, a customs agent at Los Angeles International Airport had intercepted the package en route from China. Homeland Security Investigations agents then swapped the controlled substance, disguised as lotus root starch, for a harmless white powder and sent it along to its intended destination. Law enforcement intercepted Daleo just before he crossed the border and arrested him for conspiracy to distribute a controlled substance. He had picked up similar packages 13 times before; he was sentenced to 30 months in prison in 2019. Investigators uncovered that Daleo was a middleman between Chinese chemical manufacturers and Mexican drug cartels. In one direction, he brought the precursor chemicals, and in the other he brought the payment: sea cucumbers. The court found that on at least 80 occasions between 2014 and 2016, Daleo paid another person to smuggle bags of dried Isostichopus fuscus, a protected species of sea cucumber, into the United States, at a total value of over $250,000. A person in a white uniform shirt, face mask, and disposable gloves kneels down to inspect a small sea cucumber. Open sacks filled with harvested sea cucumbers sit on the ground in front of large white bags stored in the back of a vehicle. A customs officer prepares to destroy 5.69 tons of smuggled sea cucumbers seized in Nanning, China, on April 16, 2020. Chen Guanyan/China News Service via Getty Images Sea cucumbers—which are marine animals, not vegetables—are a delicacy in parts of Asia, including China, where they are thought to act as immune system boosters, aphrodisiacs, or fertility enhancers. They are prized as symbols of status and wealth, often served at festive dinners or business events, and can retail for up to $3,000 per kilogram depending on the species. Because of this lucrative market, criminal groups in China have increasingly accepted sea cucumbers instead of cash payment as “a mechanism to avoid the international banking system,” Vanda Felbab-Brown, an expert in transnational organized crime at the Brookings Institution, said. From illegal fisheries on the Mexican coast to luxury restaurants in Asia, sea cucumbers link labor, crime, and taste in a multimillion-dollar black market across hemispheres. A net scoop filled with spiky sea cucumbers is held up in the foreground over an aquaculture facility. In the background, workers stand on floating platforms managing fish farm structures. Workers harvest sea cucumbers in China’s Fujian province on April 14, 2025. Wang Wangwang/VCG via Getty Images Sea cucumbers are an unlikely source of geopolitical intrigue. “People don’t know what it is,” said Teale Phelps Bondaroff, a sea cucumber expert and the research director for OceansAsia. They lack eyes and power their tentacles and feet through tubes that act as a water-pump system, propelling them across the sea floor. Some species bury themselves in the sand and filter the seabed for nutrients. But the sea cucumber is crucial to underwater ecosystems. Without these “earthworms of the sea,” Bondaroff said, life on the ocean floor can die, microbes that lead to coral death build up, and phytoplankton—which produce about half of the world’s oxygen—can’t grow. The sea cucumber harvesting process varies somewhat by region, but it is labor-intensive. They are often collected by hand from the bottom of the seafloor, though in some places they may be harvested nearer to shore. Population declines have been observed in 81 percent of surveyed sea cucumber fisheries, an alarming retreat driven by overfishing and a massive illegal trade, which has raked in millions of dollars in the last decade across Mexico, Sri Lanka, and other countries. Take Mexico’s Yucatán Peninsula, which once harbored one of the world’s most lucrative sea cucumber harvesting operations. Only licensed fishing cooperatives could collect sea cucumbers, and fishers dove to snatch the bottom-dwellers off the seabed, said Abigail Bennett, an assistant professor in the department of fisheries and wildlife at Michigan State University. Around a decade ago, a single fisher could earn upwards of $1,628 daily during the sea cucumber season. By 2019, the Mexican government had shut down the legal fishery due to overfishing. That hasn’t stopped illegal harvesting. Fishers looking to avoid financial penalties will often log lucrative species of sea cucumbers as so-called bycatch caught by accident, according to Felbab-Brown. More menacingly, in the last two decades, the Sinaloa Cartel and, to a lesser extent, the Jalisco New Generation Cartel have gradually encroached on the country’s fisheries and sea cucumber harvesting, offering fishers attractive prices and quashing the competition through a mix of kidnappings, threats, and buyouts. A diver wearing a bright orange drysuit, hood, and snorkel mask emerges from choppy green ocean water, holding up two sea cucumbers in gloved hands. A fisherman harvests wild sea cucumbers at Guanglu Island in China, on Oct. 24, 2023. Piao Feng/VCG via Getty Images “You have the cartels moving in, inserting themselves to be mediators between the Chinese buyers and transporters and the fishermen … You end up with a huge unrestrained fishing for sea cucumbers,” Felbab-Brown said. The number of sea cucumber seizures at the southern U. S. border has more than doubled since 2018. India and Sri Lanka are likewise global hotspots for the sea cucumber trade. Though India protects around 200 species of sea cucumbers and has maintained a blanket ban on sea cucumber fishing since 2001, Sri Lanka still permits harvesting. These uneven regulations enable a black market in which sea cucumbers are “caught illegally in India and smuggled to Sri Lanka and then introduced into the legal market to be sent to Hong Kong or China,” Bondaroff said. In February, the Sri Lankan Navy seized 685 kilograms of processed sea cucumbers suspected to have come from Indian coastal villages. Last April, the Indian Coast Guard seized 145 kilograms of sea cucumbers—worth more than $60,000—during an anti-poaching operation off the coast of the southern state of Tamil Nadu. A few months later, the local coastal police seized another 30 kilograms, valued around $4,200, intended to sail to Sri Lanka. An aerial view of numerous small motorboats navigating across turquoise coastal waters, creating white wakes behind them. An aerial view shows fishing boats setting sail to harvest wild sea cucumbers at Guanglu Island on Oct. 24, 2023. Piao Feng/VCG via Getty Images Once harvested, sea cucumbers are boiled, dried, salted, and exported to Chinese markets, as well as to Taiwan, Singapore, and Malaysia, where local sellers use names like “donkey dung” and “cookie dough”—reflecting their brown, lumpy appearances. They appear in grocery stores and apothecaries from Hong Kong to Queens, New York. At high-end restaurants, they might be served braised with mushrooms, cold in a vinegar salad, or chopped into a soup. Sea cucumber consumption is booming, especially in China. In recent years, China has sought to replace pork with seafood as the primary supply of protein for its citizens. Sea cucumbers are unlikely to sustain the country’s demand for protein, but the vibrant trade is driving a side market increasingly associated with illegal activity. Chinese fishing vessels venture far from Chinese territorial waters in pursuit of sea cucumbers. Often, fleets will act as middlemen, offering local fishers in foreign waters high prices for any sea cucumbers that can be transported back to China, triggering mass harvesting. “Everything will be gone within 24 hours,” said Ian Urbina, founder of the Outlaw Ocean Institute. “The locals are complicit, so it’s not a clear victim-perpetrator situation.” China has used its influence on the United Nations’ Food and Agriculture Organization (FAO) to aid its quest for sea cucumbers and protect its commercial interests. Since the election of Qu Dongyu, China’s former vice minister of agriculture and rural affairs, to lead the FAO in 2019, China has used its clout to exclude some sea cucumber species farmed in the country from the CITES Appendix II endangered species list. (There are currently only three species of sea cucumber on the list.) The most notable exclusion is the Apostichopus japonicus—the most economically important sea cucumber for China’s domestic aquaculture industry. In 2023, China produced nearly 300,000 tonnes of Apostichopus japonicus, commonly known as the Japanese sea cucumber, mostly across the temperate northern regions of Liaoning and Shandong. China recognized that wild stocks of sea cucumbers were declining and began pouring money into aquaculture, converting disused fish and shrimp ponds. According to the China Fishery Statistical Yearbook, as of 2022, the country used around 250,000 hectares for sea cucumber aquafarming, around the size of Luxembourg. There are hopes that increased production via aquaculture could disincentivize illegal behavior. “[But] just having a legal supply is not enough,” Felbab-Brown said. “I certainly have not heard that the sea cucumber aquafarms in China has stopped the exploitation of sea cucumbers in Mexico.” Two men carry a heavy plastic crate loaded with harvested sea cucumbers across a sunlit concrete pier near parked boats. Fishermen carry a plastic crate loaded with sea cucumbers they just harvested, a day before the legal fishing season ends, in Mérida, a town in Yucatán, Mexico, on April 20, 2018. Hugo Borges/AFP via Getty Images The surge in supply from Chinese aquaculture is affecting the legal Japanese sea cucumber market, which long guarded wild stocks of Apostichopus japonicus. In fact, the fraught global sea cucumber trade has now found itself intertwined with diplomacy—or lack thereof. This dynamic isn’t new: Sea cucumbers have historically played a role in trade negotiations in Asia. Japanese-caught sea cucumbers have been exported to China for at least 350 years. They were so valuable that the 17th-century Tokugawa Shogunate used sea cucumbers in place of silver in exchange for Chinese silk. In traditional Japanese kaiseki restaurants—where politicians often meet, sometimes with foreign diplomats—courses often feature fermented sea cucumber intestines on the side. But in recent years, this particular sea cucumber trade has been disrupted. China banned seafood imports from Japan due to alleged contamination from the Fukushima nuclear plant between August 2023 and the end of June last year. The restrictions were lifted for just four and a half months before Beijing reinstated a ban on Japanese seafood last November, following inflammatory rhetoric from Japanese Prime Minister Sanae Takaichi over Taiwan that soured bilateral relations. The economic lifeline to Japan’s exotic seafood market has closed; sea cucumber fisheries in Japan were already suffering, with prices falling by as much as half between the initial 2023 ban and 2024. Just as sea cucumber fisheries in Mexico have found partners in organized crime, Japan’s criminal underworld might find a way to turn a profit despite China’s ban. A group of eight men believed to be associated with the yakuza were caught smuggling nearly 500 kilograms of sea cucumbers last year. Japanese seafood might yet find routes into China’s massive market. As long as the demand for exotic seafood in China and the rest of Asia remains voracious, suppliers will pilfer seabeds and shirk maritime laws; others might pursue aquaculture projects of country-size dimensions or opt for more sustainable scales. Below the surface, a global economy hums for an eyeless, limbless echinoderm.