Hakai Magazine

The global harvest of sea cucumbers has skyrocketed over the past three decades, and in many places, the fishery quickly collapses from over-exploitation. Photo by Arne Hodalic/Corbis
The global harvest of sea cucumbers has skyrocketed over the past three decades, and in many places, the fishery quickly collapses from over-exploitation. Photo by Arne Hodalic/Corbis

The Sea Cucumber’s Vanishing Act

Coastal communities don’t always realize their sea cucumbers are targets of a voracious, international fishery until it’s too late.

Authored by

by Ilima Loomis

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Soft, slimy, and wrinkled, they looked like a heap of waterlogged, disembodied phalluses.

The photographs, snapped by bystanders in the spring of 2015, showed sea cucumbers being hauled away from Hawai‘i’s beaches by the truckload. The animals slid over one another in a pool of mucus. As the images began spiraling through social media channels, locals reacted with surprise and dismay. Sea cucumbers had slunk peacefully along the seafloor for generations, largely ignored and unnoticed, so why were they suddenly under siege, plucked by the thousands from Hawai‘i’s nearshore waters? What would happen to the reefs without them? And where were they all going?

These questions landed like a 10-tonne octopus on Russell Sparks’s lap. The aquatic biologist with Hawai‘i’s Department of Land and Natural Resources (DLNR) admits he spent little time thinking about sea cucumbers before the organization suddenly started fielding reports from beachgoers and local fishermen about people taking all the sea cucumbers from around Maui and Oʻahu. His division focuses on the health of the islands’ reefs and aquatic resources; they monitor issues like coral bleaching and the impacts of runoff. The homely, sluggish invertebrates that lay like half-buried lumps on the sandy ocean floor had never been cause for concern before. In fact, the threat of sea cucumber overharvesting was so far from their minds that state biologists had never even done a comprehensive population survey, making it difficult to assess the extent of the damage or figure out what parts of the shoreline had been hardest hit.

“We didn’t have a good, solid baseline prior to this,” Sparks says. “It’s not like sea cucumbers were on our radar screen as an imminent fisheries concern.”

As officials and conservationists soon found out, Hawai‘i was only the latest in a long string of coastal communities hit hard by a global sea cucumber fishery that has grown into a voracious, fast-moving, highly organized—and, at times, devastating—industry.

While much of the Western world forgets about them or regards them with disgust because of their slimy, squishy texture, sea cucumbers are a delicacy in many parts of Asia, often known as bêche-de-mer. They exist all over the world—from the poles to the tropics and from coastal shallows to the deep ocean floor—in a spectrum of sizes, textures, and colors. Of roughly 1,700 species, 66 are targeted for food.

The California sea cucumber, found from Alaska to California, is one of 66 species harvested worldwide. Photo by Stuart Westmorland/Corbis

Overfishing of sea cucumbers may be a modern problem, though the fishery itself is more than 1,200 years old. Sea cucumbers have been harvested since as early as 800 CE. In the 1700s, Indonesians traveled as far as Australia to harvest sea cucumbers for trade with Chinese merchants.

Demand dropped off during the Second World War due to global unrest, but it rebounded with a vengeance in the late 20th century, explains Hampus Eriksson, a fisheries scientist for the international nonprofit research organization WorldFish. “With China opening up its doors to the global economy in the 1980s, it just took off.” Serving sea cucumbers at Chinese family celebrations and business banquets has become an almost expected show of prosperity, he says.

For decades, the regional fishery was enough to meet consumers’ needs, but that’s no longer the case. Demand driven by China’s red-hot economy and growing wealthy class has forced the fishery out across the globe.

Today, an international sourcing network has emerged. The fishery has grown from 35 countries in 1996 to 83 countries in 2011, shipping to Hong Kong and then on to China, Japan, and other parts of Asia.

The majority of sea cucumbers harvested across the globe arrive in Hong Kong and then are shipped to China. Photo by Jake Wyman/Corbis

In one community after another, across the Indo-Pacific and off the coasts of Africa, South America, and Central America, the fishery often follows a similar pattern: sea cucumber traders—either recent arrivals from Asia or locals working with overseas traders—set up shop, enlist local fishermen to strip the invertebrates first from shallow waters and then from greater and greater depths, and finally move on when there’s nothing left. Even if a population isn’t entirely wiped out by the fishers, recovery is difficult: sea cucumbers spawn externally, so if density is too low, their reproduction fails and the local population can go extinct.

“We’re finding that this boom and bust cycle is ubiquitous,” says Eriksson. “Practically every country the fishery emerges in gets overwhelmed by it. It just happens so fast.” While it can take years for some large, complex coastal systems like Papua New Guinea to be overharvested, small atolls can get depleted within months.

Fishery managers struggle to react quickly enough and, in many cases, local governments only step in to close the fishery after it’s been overexploited. That’s what happened in Papua New Guinea, the Solomon Islands, Vanuatu, Samoa, and Kiribati. Recovery can happen, but it often takes much longer than anticipated, Eriksson says.

The fuss Hawai‘i’s residents made over the unprecedented mass harvesting of their cukes was founded on more than just possessiveness. Humble sea cucumbers may resemble sandy dog turds, but they play an important role in the ocean ecosystem.

The echinoderms—relatives of sea stars—sift through sediment on the ocean floor, ingest it, digest organic matter, excrete clean sand, and in the process prevent the ocean floor from getting compacted.

“Farmers like to have a lot of earthworms because they turn over the soil and break down organic matter,” Sparks says. “Sea cucumbers do the same.”

Sea cucumbers play an important role in the ecosystem—they ingest and then excrete sand, helping to prevent the seafloor from becoming compacted. Photo by J.W.Alker/Westend61/Corbis

Recent research indicates that sea cucumbers might help buffer the reef against ocean acidification through their mucus. If that is the case, “they might be increasingly important as more carbon dioxide in the air makes the oceans more acidic,” Sparks says.

They’re also just plain cool. “They’re like the Terminator,” says Haruko Koike, a fisheries researcher at the University of Hawai‘i. “They can literally melt their body and re-form.” Normally very soft, the invertebrates can change the hardness of their skin and body at will, she says. Sea cucumbers will soften themselves to hide under coral and rocks and then reharden to wedge themselves in.

“It’s actually a really hard animal to study,” Koike adds. “We tag them, and they literally just dissolve their skin around it and expel the tag.”

What they can’t do is flee. All fishers need to start plucking them from the seafloor is a bucket. At the same time, they have a powerful incentive to harvest as many as they can. Dried sea cucumber can sell for as much as US $100 per kilogram, Koike notes. “It’s a highly lucrative fishery,” she says. “It’s equivalent to abalone or shark fin.”

That makes sea cucumbers an important resource in many coastal communities. In the Seychelles, for example, the 25 people who hold licenses to collect sea cucumbers are producing one percent of the country’s GDP.

Eriksson believes the value of such a lucrative resource to poor island communities should be considered when regulating the sea cucumber trade. While some conservationists may advocate for a complete ban, he argues that, in some cases, it may be more productive to regulate the fishery to allow for a sustainable harvest. “It’s the second most valuable seafood exported from the Pacific,” Eriksson says. “In some locations, it’s really powering village economies.”

The fishers who helped decimate patches of sea cucumbers in Hawai‘i, it turned out, did have licenses to legally collect sea cucumbers. Local laws hadn’t been crafted with a large commercial fishery in mind, so allowed an unlimited harvest. DLNR catch data shows that three non-aquarium licenses were issued for the commercial collection of sea cucumbers statewide in 2015. Those three license holders reported harvesting 7,454 sea cucumbers, totaling 1,567 kilograms. Over the same period, five aquarium collectors reported harvesting 707 sea cucumbers (weight was not reported).

In June, just a few weeks after this heavy harvest came to light, the DLNR approved a 120-day ban on all sea cucumber harvesting while officials investigated the issue and worked with University of Hawai‘i scientists to craft permanent regulations. They quickly determined that the harvest was not sustainable, says David Sakoda, a marine law fellow with the Division of Aquatic Resources at the DLNR.

Sea cucumbers are laid out to dry on the island of Tongatapu. People have been collecting sea cucumbers for Chinese consumption for hundreds of years. Photo by David Kirkland/Design Pics/Corbis

The harvest had likely been going on for two to three months when it was stopped. The west and north areas of Maui and the east side of Oʻahu were hardest hit. Apparently, all the sea cucumbers that were taken had been collected within wading depth.

“It was an operation which involved residents doing business with a nonresident,” Sakoda says. He declined to provide more details about the fishers involved. The harvested sea cucumbers were exported to Asia, he says.

Although Hawai‘i saw overwhelming public support for stopping the harvest (the case was widely discussed over social media and hearings in June and November saw unanimous public testimony in favor of protecting sea cucumbers), in many other parts of the world, that’s not the case. Often, economic pressures on local fishermen can hamper efforts to close the fishery. In Ecuador, for example, after local fishermen had fished out the reefs in their communities, they borrowed money to buy boats so they could fish farther afield. “You cross a critical threshold,” Eriksson says, adding that once fishers have invested in boats they need to pay off their loans. “It becomes very hard to close the fishery.”

Aside from the sea cucumbers themselves, the fishers may be the most vulnerable actors in the supply chain. While harvesting sea cucumbers may start out as an easy and lucrative operation, it doesn’t stay that way for long.

As they move into deeper and deeper water, the collectors need a mask and fins and then, eventually, scuba gear—often rented from the traders they sell to. “On good days, they’ll earn a lot of money, but on bad days they can’t pay off the rent,” Erikkson says. “They get trapped in this credit arrangement with the traders.” The work becomes increasingly dangerous, with some fishers diving as deep as 50 meters in pursuit of the increasingly scarce sea cucumbers.

Eriksson notes that, in some locales, like parts of Africa, sea cucumbers are just one of many lucrative and “lootable” products of trade, alongside goods such as ivory. But unlike ivory, sea cucumbers can be easy to trade across national borders. Even when it is illegal. For example, even though the fishery is closed in Tanzania, local fishers can sell their illegal catch next door in Zanzibar.

How much sea cucumber trade is illegal? Studies show “pockets” of illegal trade, but it’s been very difficult to get definitive information, Eriksson says. “I would suspect from anecdotal stories that there’s quite a bit, but I really don’t know,” he says. “It’s clear that illegal trade has been a big problem for the fishery, that’s fair to say.”

Commercial farming of sea cucumbers may become a viable alternative. Farmers in China have been raising large quantities of sea cucumbers in former shrimp ponds since the 1980s. And farms have cropped up in places like Madagascar and Vietnam, but the industry is still in its infancy.

Aquaculture has its own potential environmental and ethical problems, Eriksson says. In tropical environments, aquaculture initiatives often involve replacing a diversity of wild sea cucumbers with a single farmable species. To be successful, farms must operate in large lagoons, potentially cutting off the local community’s access to natural resources. In one case in Vanuatu, dishonest entrepreneurs promised a community lucrative jobs in exchange for the exclusive right to harvest in an area. After all the wild sea cucumbers were gone and the farmed animals failed to thrive, the entrepreneurs abandoned the site and the locals were left with nothing. Particularly when it comes to farming tropical species, “there are no great examples of it being done sustainably so far,” Eriksson says.

Plus, Koike points out that only two species—Apostichopus japonicus and Holothuria scabra—have been farmed successfully to date. The creatures’ biology makes aquaculture uniquely difficult. Because of their ability to melt and re-form, sea cucumbers easily slip out of pens and mesh nets, which are easier to build than solid confinement pools. The high value of sea cucumbers makes them a target for poachers, their sluggish nature makes them especially vulnerable to predators, and it can be difficult to ensure they are getting adequate nutrients from the seafloor. Yet, “aquaculture is a possibility,” says Koike, and the high dollar value of the product is attracting a lot of interest from entrepreneurs, despite the challenges.

The temporary ban implemented in Hawai‘i may well have saved the state’s sea cucumbers. “It appears to have been able to stop the fishery before it spiraled out of control,” Eriksson says. A permanent ban on commercial harvesting of sea cucumbers came into effect on January 10, 2016.

The new rules prohibit large-scale commercial sea cucumber harvesting, while allowing very limited collection to continue for the aquarium industry. Individuals are allowed to harvest up to 10 sea cucumbers per day for personal use (although sea cucumbers are not a common part of the traditional Hawai‘ian diet, so there isn’t much of a local appetite for them).

With Hawai‘i now off limits to fishers, what’s going to be the next target by the sea cucumber industry? Eriksson predicts Europe will soon be a hot spot. Fishing for sea cucumbers in the Mediterranean has grown sharply over the past five to ten years—Turkey, Greece, and Croatia are already sources for the fishery—but the region hasn’t yet taken off. With parts of the Indo-Pacific, Pacific Islands, Mexico, Africa, the Atlantic, the Caribbean, and Russia already severely depleted, Eriksson sees the Mediterranean as one of the last untapped sources of sea cucumber. “There’s not that many countries that haven’t already been exploited,” he says. “What’s left?”