Illegal Ocean Fishing

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Japanese fisheries patrol boat pursues a Chinese Illegal fishing boat

Illegal fishing can refer to three things: 1) fishing for banned species such as toothfish and great white sharks; 2) using illegal nets or gear such as drift nets; and 3) fishing where one is not supposed to such as in exclusive economic zone (EEZ) of country that a fishing vessel doesn't have permission to operate in. An “EEZ” is an area of the ocean, generally extending 200 nautical miles (370 kilometers, 230 miles) beyond a nation's territorial sea, within which a coastal nation has jurisdiction over both living and nonliving resources.

Studies have shown that illegal and underreported fishing accounts for up to 31 percent of the world’s catch. The trade thrives in part because it is difficult to trace where fish originally comes from and regulations and documentation are minimal and easy to skirt.

According to the Washington Post: Fishing vessels and seafood processors rely on a shell game to deliver illegal and unreported catch...Ships fish at different spots on the high seas often for months at a time, using “transition vessels” to taxi the catch to market while they keep trolling for fish. Documentation of where the fish is caught is lax studies have found. Many of the fish, crab, shrimp and other products are rushed to Chinese processing plants, where low-paid workers fillet salmon, clean the guts of tuna and pull meat from crabs. Illegally caught fish are easily mixed at the plants with those that were caught legally.

How fish are processed is sometimes puzzling. For example, prawns caught off of Scotland are often sent to China for processing and then shipped back to Scotland, because low-wage processors are cheaper, Tony J. Pitcher, a professor of fisheries at the University of British Columbia, said. Pollock caught in Russia is frozen there, shipped to China, where it is thawed and processed, then frozen again for the trip back to Russia or elsewhere in the world.

Difficulty Amassing Illegal Fishing Data

Its hard to get a handle on the full scope of illegal fishing. Daniel Pauly, a biologist at the University of British Columbia’s Institute for the Oceans and Fisheries, told Smithsonian magazine pirate vessels account for a substantial amount of catch, but it’s hard to measure. “That’s a huge problem in itself,” he adds. “It’s like saying we know there’s a substantial number of murders in my neighborhood but we don’t know how many.” [Source: Tristram Korten, Smithsonian magazine, September 2020]

Tristram Korten wrote in Smithsonian magazine: Pauly and his team use thousands of sources to assemble a truer picture of what’s being taken from the oceans. To estimate U.S. totals, for instance, they add recreational and subsistence fishing as well as bycatch from major fisheries — none of it reported to the U.N.[Source: Tristram Korten, Smithsonian magazine, September 2020]

“What Pauly and his team can calculate is how many foreign boats are fishing in other countries’ waters. This happens most often off the coasts of poor countries that can’t afford to patrol their own territories. To help piece together figures for West African countries, for instance, Pauly and his team use satellite images of fishing vessels and calculate how much fish each one would need to catch to stay in business. These totals often far exceed the U.N. reports. To further explore Pauly’s data — country by country and species by species — visit

Study Finds Up to 32 Percent of U.S. Seafood Is Illegally Caught

Trawler accused of illegal fishing brought ashore

A study published in April 2014 in the journal Marine Policy that examined illegal and unreported marine harvests brought into the United States found that up to 32 percent of imported wild shrimp, crab, salmon, pollock, tuna and other catch was poached. “That was really a surprise to us,” said Tony J. Pitcher, a professor of fisheries at the University of British Columbia and co-author of the study. “We thought a well-governed country like the U.S., with tighter controls, would be better,” Pitcher said. Inspectors in the United States, which imports 14 percent of the global total, are not required to ask for documentation that shows a bounty’s origin. [Source: Darryl Fears, Washington Post April 20, 2014

U.S. inspectors are more concerned with the freshness of seafood and its potential impact on human health. What gets by inspectors is valued in the study at $1.3 billion to $2.1 billion per year, a sum that encourages more illegal and unreported fishing, Pitcher said. “It’s quite clear that most consumers don’t have an idea what’s coming into the supply,” he said. “If so much of the overall harvest is under the radar, what about the by-catch,” the marine life caught in nets or on hooks, said Tom Bigford, policy director of the American Fisheries Society, a nonprofit group in Bethesda, Md. “I’m thinking the implications could be pretty severe,” Bigford said. Americans assume that seafood that makes it into the United States was legally caught, he said. “But the chain is so complicated that it’s hard for us to be positive.”

Most wild-caught imports to the United States come from 10 countries: China, Thailand, Indonesia, Ecuador, Canada, Vietnam, the Philippines, India, Mexico and Chile. For the study, researchers looked only at fish caught under flags outside the United States, although illegal and unreported fishing does occur in relatively small amounts in the country.

Scientists sought out information regarding illegal and unreported catches in 30 countries, looking at various species and where they are caught. They then determined the top countries and species, and examined the weight of the catches. Based on earlier and similar studies, researchers determined that nearly half of wild-caught seafood imports to the United States could be scrutinized as possible illegal catch.

Toothfish — A Primary Target of Illegal Fishing

The toothfish is a primary target of illegal fishing and much of the fish’s population lives outside the domain of any country. Tristram Korten wrote in Smithsonian magazine: “ It comes in two species: the remote Patagonian toothfish and the even more remote Antarctic toothfish. Together, their range covers parts of the Southern Ocean, the Indian Ocean and the South Atlantic. For many years, both kinds of toothfish were minor bycatch for ships searching the cold southern waters for marbled and gray rock cod. But as those stocks dwindled in the 1970s, fishers started paying more attention to the yellow-eyed bottom-dwellers with jagged teeth that came up in their nets. As it turned out, toothfish flesh was white and delicate, without the dark muscle of stronger-swimming fish. Its taste was mild and it melted on the palate like butter. Even if you don’t think you’ve ever tasted it, chances are you have. It’s sold in the States as “Chilean sea bass,” though it is not a bass. [Source: Tristram Korten, Smithsonian magazine, September 2020]

Patagonian toothfish

Since the mid-2000s, Antarctic toothfish has accounted for a larger share of the illegal market than its Patagonian cousin. The problem is that Antarctic toothfish is very easy to overfish because of its unhurried reproduction cycle. It grows to be about six feet long and lives an average of 31 years, but females don’t reach sexual maturity for more than 16 years.

“In 1980, 15 countries signed the Convention on the Conservation of Antarctic Marine Living Resources, or CCAMLR, an agreement to protect the toothfish and other Antarctic species, ranging from mollusks to birds. Today, 26 countries are signatories, including the United States, China and the Russian Federation. Legitimate members of the fishing industry have also banded together to form the Coalition of Legal Toothfish Operators, which has offered rewards for information on poachers, and requires members to document their catch at every stage along the way to market.

“Still, the demand for toothfish continued to grow, and illegal operators made up the difference. In 2002, the year after Bon Appétit magazine named Chilean sea bass the dish of the year, illegal fishing accounted for up two-thirds of toothfish supply. In 2016, there were 33 ships licensed to catch Antarctic toothfish. The Andrey Dolgov was not one of them.

800 ‘Dark’ Ships Suspected of Illegal Fishing

Tristram Korten wrote in Smithsonian magazine: “Ever since 2002, most ships weighing 300 gross tons or more have been required to continuously broadcast a unique nine-digit Maritime Mobile Service Identity number, or MMSI. The system was developed to prevent inshore ships from colliding. At first, VHF radio waves just pinged the numbers off shoreside receivers. But recent satellite technology has allowed monitors to read these ID numbers from space, meaning ships can be tracked anywhere. Turning off this signal is called “going dark.”

Huge fishing fleets, primarily from China, switch off their tracking beacons to evade detection while they engage in a possibly illegal hunt for squid and other lucrative species on the edge of Argentina’s extensive fishing grounds, according to a study by Oceana, an international NGO dedicated to ocean conservation, published in May 2021.

Associated Press reported: “Every year, vessels crowd together along the limits of Argentina’s Exclusive Economic Zone (EEZ) to take advantage of the lucrative fishing grounds. By monitoring the ships’ tracking beacons between January 2018 and April 2021, Oceana found that more than 800 vessels apparently conducted nearly 900,000 hours of fishing within 20 nautical miles of the invisible border between Argentina’s national waters and the high seas. “During this three-and-a-half-year period, there were over 6,000 instances in which these fishing vessels appeared to go ‘dark’ by potentially disabling their electronic tracking devices, known as Automatic Identification Systems (AIS),” says the report, published on Wednesday, titled, Now You See Me, Now You Don’t: Vanishing Vessels Along Argentina’s Waters. [Source: Uki Goñi in Buenos Aires, The Guardian, June 2, 2021]

“In all, these vessels were “hidden” for over 600,000 hours during which Oceana suspects they crossed over into Argentina’s territorial waters for illegal fishing. “It’s very suspicious that they have their AIS turned off for such a large proportion of the time they are out fishing,” said Marla Valentine, an ecologist at Oceana, an international NGO dedicated to ocean conservation. “Billions of dollars worth of marine life are being removed from the ecosystems, such as squid, hake and shrimp, which are fed on by species like tuna. This can have lasting impacts on their reproductive cycle,” said Valentine.

Common types of illegal, unreported and unregulated fishing

“Nearly 66 percent of the “dark” vessels were Chinese-flagged squid jiggers — vessels with bright lights and hooks designed to catch squid, while 6 percent were Spanish. But the Spanish trawlers that tow heavy nets along the sea bed to catch species such as Argentine hake and red shrimp went “dark” more often than Chinese vessels. “On average, the larger Chinese fleet had 12.88 “gap events” per vessel while the smaller Spanish fleet had an average 45 gaps per vessel,” Valentine said.

“The presence of so many vessels just off Argentina’s waters has caused a number of high-sea confrontations with Argentina’s coast guard. In April last year approximately 100 squid jiggers — mostly Chinese-flagged — were caught allegedly fishing illegally during nighttime incursions in Argentinian waters, each with their AIS turned off. “In 2016, a Chinese trawler was sunk after reportedly trying to ram a Coast Guard vessel and in 2018 four Chinese fishing vessels allegedly teamed up to protect a fifth vessel the Coast Guard was pursuing,” the report says. “There is a fine line between what is legal, sustainable, responsible and regulated,” said Valentine. “They could be just one inch outside Argentina’s exclusion zone and it would be considered legal.”

“Oceana last year also reported on illegal fishing by huge Chinese fleets along South America’s Pacific coast, affecting Chile, Colombia, Ecuador and Peru. Vessels in that group were also accused of disabling their public tracking devices, and engaging in potentially suspect transshipment practices, all of which can facilitate illegal, unreported and unregulated (IUU)

Notorious Illegal Toothfish Boat

Tristram Korten wrote in Smithsonian magazine: “The seas were calm and the winds were light when the Andrey Dolgov, a cargo ship flying the Cambodian flag, motored in from the South Atlantic Ocean toward Walvis Bay, Namibia, one March day in 2016. A crewman radioed ahead and asked for clearance to unload hundreds of thousands of pounds of frozen Antarctic toothfish pieces in sacks and boxes, and an additional 6,200 pounds of toothfish heads. The total- — about 125 tons — would fetch more than $3.6 million on the wholesale market. [Source: Tristram Korten, Smithsonian magazine, September 2020]

“The ship’s forthright declaration raised suspicions. Namibia is part of a coalition of nations that have pledged to protect the Antarctic toothfish, which has a high market value and is biologically vulnerable. When port authorities started asking questions, the Andrey Dolgov’s crew said they had merely offloaded the fish from a Korean ship named the Bochang No. 3. But there was no Bochang No. 3 registered in South Korea. It seemed doubtful the Bochang No. 3 even existed. Namibia denied the ship entry and reported the encounter to international authorities. The Andrey Dolgov sailed on

The Andrey Dolgov, STS-50, photo taken by Sea Shepherd

“Two months later, the same rust-stained ship appeared in the Chinese port of Yantai, on the Yellow Sea. It carried what was most likely the same stock of frozen Antarctic toothfish, but the crew said the haul was Pacific cod for transshipment to Vietnam. This time, though, officials were on alert. Authorities in Yantai tested the flesh and identified it as Antarctic toothfish. They seized the stock and fined the Andrey Dolgov. Once again, though, the ship was allowed to leave.

“Meanwhile, in Lyon, France, Interpol Environmental Security investigators tracked the ship’s supposed owner, the Red Star Company, and its agent, Poseidon Company, to the South Korean port city of Busan. When Korean officials went to the company’s address and knocked on the door, they found an empty apartment and a landlord with few answers. The Commission for the Conservation of Antarctic Marine Living Resources, an international regulatory body, put the ship on a black list of illegal, unreported and unregulated fishing vessels. Interpol sent out a purple notice, a call for more information about a criminal’s methods and devices.

“In October 2017, more than a year after its appearance in Yantai, the ship showed up in the port of Dalian, on China’s Liaodong Peninsula. It was now calling itself the Ayda and flying a flag from the Togolese Republic. Once again, it attempted to offload Antarctic toothfish — about 275 tons. After Chinese authorities boarded the ship to collect information and DNA samples, it fled under cover of darkness. As it headed away from China’s coast in May of 2016, the ship was fast on its way to becoming the most wanted pirate fishing vessel on the open water. Nearly a dozen countries would be roped into the search as Interpol tracked it across two oceans and four seas.

There was a reason the ship remained so elusive: It was a master of disguise. It changed its name six times, and flew the flag of as many nations. It disguised its electronic identification to confuse pursuers. Twice, it was detained — and escaped.

Crew of the Notorious Illegal Toothfish Boat

Tristram Korten wrote in Smithsonian magazine: Somewhere along Russia’s eastern coast in late 2017, Aleksandr Matveev rode a tender out to a huge commercial fishing vessel. Matveev, a solidly built 55-year-old man with a broad, clean-shaven face and graying straight hair neatly parted on the side, had been hired by two men — identified later through text messages and other documents as Volodymyr Bulatetsky and Vita Sokirko — to take the ship to the Southern Hemisphere for toothfish. [Source:Tristram Korten, Smithsonian magazine, September 2020]

“The ship Matveev climbed aboard was no longer called the Andrey Dolgov or the Ayda. It bore a new name, stenciled in black paint: the STS-50. Another stencil stated that the vessel was registered in Lomé, the capital of Togo. Matveev would later claim he had no idea he was taking command of a floating criminal enterprise. But the evidence of its past registrations would have been scattered all over the bridge.

Officials checking on illegal fishing in Indonesia

“In addition to nine Russian and Ukrainian officers, his crew included 20 Indonesian sailors, known for being both highly capable and willing to work for between $350 and $380 a month. With Matveev at the helm, the ship headed southwest in early 2018 on its journey toward Antarctic toothfish grounds.

“Like the cursed ship in “The Rime of the Ancient Mariner,” it was followed by misfortune. Four months later, the STS-50 was off Africa’s east coast without having been able to fish, according to accounts crew members would later give investigators. At some point, the ship’s refrigeration system malfunctioned, and the trip would be useless if the fish couldn’t be frozen immediately.

“In early 2018, the STS-50 docked at Madagascar’s Port d’Ehola. Restrictions on the age and size of ships that could use the port prevented the STS-50 — 33 years old and about 175 feet long — from refueling there. However, during its brief stay, an attentive port inspector — armed with Interpol’s purple notice for the Andrey Dolgov — recognized the vertical stripes of rust staining the hull and promptly made a call. As the STS-50 headed across the Mozambique Channel toward Maputo to refuel, it was tracked by Interpol and Fish-i Africa, a network of eight East African nations cooperating to fight illegal fishing.

“It was early March 2018 when the STS-50 entered Mozambique’s territorial waters. An armed escort from the country’s navy, customs enforcement, maritime police and port authority intercepted the ship as it headed toward Port Maputo. They seized the crews’ passports and took the English-speaking first mate, Boris Mitchenkov, ashore for questioning.

Combating Illegal Fishing

Ian Urbina wrote in The New Yorker: “As global fish stocks have been depleted, many wealthier nations have increased their marine policing, often by stepping up port inspections, imposing steep fines for violations, and using satellites to spot illicit activity at sea. They have also required industrial boats to carry mandatory observers and to install monitoring devices onboard. [Source: Ian Urbina, The New Yorker, March 1, 2021]

The NGO Sea Shepherd is involved in tracking down toothfish poachers and other illegal fishing operations. Tristram Korten wrote in Smithsonian magazine: In 2014 and 2015, one of its ships had chased a Spanish-owned poaching vessel named the Thunder for 110 days, the longest open-ocean chase on record. The Thunder was the last remaining member of a fleet of illegal vessels that Sea Shepherd called the Bandit 6. The chase ended abruptly when the crew of the Thunder appeared to sink their own boat, calling out for rescue and sending evidence of their illegal activities to the bottom of the ocean. The Sea Shepherd captain, Peter Hammarstedt, was hailed as a hero and the story became the subject of a 2018 documentary called Chasing the Thunder. [Source: Tristram Korten, Smithsonian magazine, September 2020]

Google Satellite-Based System Helps Crack Down on Illegal Fishing

U.S. Coast Guard and Chinese Coast Guard ships patrolling together against illegal fishing

Brady Dennis wrote in the Washington Post: Illegal and unreported fishing is a multibillion-dollar business around the globe, and one that has proven notoriously difficult to combat. In part, that’s because it involves a constant stream of renegade fishermen being pursued by countries that have only limited resources to carry out a perpetual cat-and-mouse game on the high seas. [Source: Brady Dennis, Washington Post, September 16, 2016]

But a new satellite-based surveillance system powered by Google, which will be publicly unveiled Thursday at a global oceans conference at the State Department, aims to help alter that equation. Global Fishing Watch, as it is called, is designed to act as an eye in the sky, constantly scouring the globe in search of those illegally plundering the oceans. The organizations that partnered to develop it, which include the marine-advocacy group Oceana and West Virginia-based nonprofit SkyTruth, say the free platform will help governments, journalists and everyday citizens monitor roughly 35,000 commercial fishing vessels nearly in real time. “We will be able to see a lot of information about who is fishing where,” said Jacqueline Savitz, vice president for U.S. oceans at Oceana, adding that the platform will help “revolutionize the way the world views commercial fishing.”

The technology uses public broadcast data from the Automatic Identification System (AIS), which uses satellite and land-based receivers to track the movement of ships over time. Not all fishing vessels willingly broadcast their location, of course — particularly those intent on breaking the law — and vessels can switch off their trackers, potentially hindering the usefulness of the new technology. The United States and other countries already require vessels of a certain size to use the locator system, partly as a safety measure to avoid collisions at sea, and more countries are beginning to follow suit. Global Fishing Watch allows users to access that information to track specific vessels over time, going back to 2012.

Savitz said she believes the tool will have an array of uses. Governments could use it to monitor and enforce fishing restrictions in their waters. Journalists and the public can use it to search for suspicious fishing activity, such as vessel that suddenly seems to disappear or one that rarely comes to port, and to make sure officials are safeguarding marine protected areas. Insurance companies can track the vessels they insure.

Image Sources: Wikimedia Commons, National Oceanic and Atmospheric Administration (NOAA)

Text Sources: New York Times, Washington Post, Los Angeles Times, Times of London, Yomiuri Shimbun, The Guardian, National Geographic, The New Yorker, Time, Newsweek, Reuters, AP, Lonely Planet Guides, Compton’s Encyclopedia and various books and other publications.

Last updated April 2023

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