The Destruction of Our Oceans: The Global Fishing Industry’s Hidden Connection to Pet Food and Livestock Feed

Industrial fishing devastates marine ecosystems, and a hidden connection links the global fishmeal trade to pet food, livestock feed, and farmed seafood.

When investigative reporter Ian Urbina published his groundbreaking five-year investigation in The New York Times, “The Dirty Secret Behind the Farmed Fish You Eat,” it exposed the global aquaculture industry and pulled back the curtain on a massive, secretive supply chain.

The reporting mapped operations across 64 countries, 2,400 fishing vessels, and 1,400 fish meal processing plants, where billions of wild-caught forage fish are ground down annually to make fish meal used to feed pets, livestock, farmed salmon, tuna, shrimp, and yellowtail.

While the NYT article focused on human seafood, pet and livestock food draws from the same unmonitored global marine ingredient pool, and the consequences for our oceans are devastating.

My story begins where the Times investigation left off. It exposes how the fish meal and fish oil market works in the animal food industry. It also shows how the pet food and animal feed industries are inextricably linked to an ecological nightmare.

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The Ecological Disaster: The Inescapable Link to Pet Food

When fish are caught, enormous nets and trawlers of unimaginable size catch the target fish used to make fish meal. Along with the target fish, the catch, including bycatch, is eventually processed into fish meal. That fish meal ends up in pet food, livestock feed, and farmed-fish feed.

What most pet owners never see is what happens long before those ingredients reach a pet food manufacturer. Behind the familiar names on ingredient labels is an industrial fishing trade that removes enormous quantities of marine life from the ocean, often with devastating consequences for animals that were never the intended catch.

Habitat Destruction: Modern reduction fleets do not use modest nets; they operate on a staggering industrial scale. Industrial purse seine nets can stretch over a mile long and drop 1,000 feet deep—enclosing an area equal to 40 to 50 football fields in a single sweep—while the mouths of pelagic supertrawler nets are wide enough to swallow twelve Boeing 747 jumbo jets side-by-side. Urbina describes the nets as destroying virtually everything in their path. In these industrial reduction operations, the nets scrape the seafloor clean, leaving a desert devoid of sea life.

And the destruction does not end with the fish these vessels set out to catch. An untold number of other marine animals are caught in the same fishing gear, casualties of an industry harvesting the ocean on an industrial scale.

Catastrophic Bycatch: Non-selective harvesting on this scale can cause catastrophic bycatch—an inescapable mathematical certainty—capturing and killing marine life far beyond the intended catch. Whales, dolphins, porpoises, seals, and sea lions; sea turtles; sharks, stingrays, skates, and other fish species are trapped in ship holds, suffocating under thousands of tons of pressure; and countless bottom-dwelling organisms, including octopuses, crabs, lobsters, sea stars, sea urchins, sea cucumbers, sponges, and corals, can be swept up in fishing gear, injured, crushed, or killed during harvesting.

Industrial fishing gear can entangle marine mammals ranging from dolphins and porpoises to fully grown whales. While smaller animals may be trapped and drowned in fishing nets, whales can become entangled in nets and ropes, suffering severe injuries, starvation, or drowning.

Fisheries never separate bycatch or return it to the water; they grind it into bulk fish meal, and fish oil is used to produce fish meal, an ingredient used to make pet food, animal feed, and farmed fish—salmon, tuna, and yellow fish.

This is the connection that rarely appears in pet food advertising. The fish meal listed on a package tells pet owners nothing about the animals caught alongside the intended harvest, the destruction left behind, or the true ecological cost of producing that ingredient.

The Starvation of Predators: When those massive industrial trawlers and purse seiners sweep through coastal waters, they scoop up entire schools of forage fish, starving wild predators like sea lions, penguins, and seabirds. Removing forage species deprives marine predators of primary dietary sources. Harvesting juvenile fish prevents species from reaching reproductive maturity, threatening the collapse of the entire food web.

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Pushing Marine Ecosystems Toward a Catastrophic Threshold

The ecological footprint of marine ingredients used in animal feed and pet food extends far beyond the mass of fish declared on ingredient labels. Industrial harvesting methods used to supply fish meal, fish oil, and wet pet food recipes inflict deep, systemic damage on marine ecosystems.

But what industrial fishing removes from the ocean is only part of the story. What it leaves behind may be just as devastating: damaged seafloors, polluted coastal waters, and marine habitats increasingly unable to support the life that once flourished there.

According to the United Nations Food and Agriculture Organization’s 2026 assessment, 37.6% of global marine fish stocks are being fished at biologically unsustainable levels. Meanwhile, the United Nations’ Third World Ocean Assessment describes a marine environment suffering widespread ecological damage, with climate change, biodiversity loss, pollution, and destructive human activities pushing vulnerable ecosystems toward dangerous tipping points.

Species Overexploitation: Urbina’s investigation found that scientists classify at least half of the species caught by those 2,400 ships as overexploited. The consequences extend beyond the declining populations of individual species, threatening the complex relationships between marine animals and the ecosystems that sustain them.

Warming Waters and Oxygen Depletion: Urbina describes how dragging fishing gear across the seafloor releases CO₂, adding to the pressures facing already warming oceans. Bloodwater discharged during fish processing can also deplete oxygen in coastal waters and spread pathogens.

The destruction doesn’t stop when the fishing vessels return to port. What began offshore can continue on land, where the processing of millions of fish creates enormous quantities of waste that threaten surrounding coastal waters and the communities that depend on them.

Toxic Runoff: Fishmeal reduction facilities and coastal processing plants discharge millions of gallons of organic waste into coastal waters. Hidden industrial boreholes illegally dump toxic runoff directly into local groundwater, poisoning waterways.

Dead Zones: High concentrations of decomposing organic matter can trigger algal blooms and oxygen depletion, causing localized hypoxia and creating dead zones where native marine life cannot survive.

And yet, much of this destruction remains invisible to consumers. By the time marine ingredients reach the pet food industry, the fish have become little more than commodities, divorced from the extraordinary living ecosystems from which they were taken.

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The Machinery of Reduction: How Wild Oceans Become Dry Kibble and Canned Pet Food

What begins as an enormous harvest of wild marine life ends in something almost unrecognizable: a dry, brown powder and a concentrated oil, sold as commodities to manufacturers of pet food, livestock feed, and aquaculture feed. The transformation takes place in industrial facilities known as fishmeal reduction plants, where millions of tons of fish are processed into ingredients destined for animal food.

Once small fish such as anchovies, sardines, menhaden, and sardinella are harvested, they are transported to reduction plants, where they are cooked, pressed, and dried. The solid material is ground into fishmeal, a concentrated source of protein, while the separated oils are processed into fish oil. These ingredients become part of a global trade supplying commercial pet food manufacturers, livestock producers, and aquaculture operations raising salmon, shrimp, and other farmed seafood.

Fishmeal can find its way into dry kibble, canned pet food, and animal feed, while fish oil is added to certain pet food recipes and sold separately as an omega-3 supplement for dogs and cats. The same industrial reduction process supplies ingredients for poultry and pig feed, as well as feed used to raise carnivorous farmed fish. In this way, wild marine animals that humans might never eat directly are harvested to feed the animals humans raise for food, and the dogs and cats we keep as companions.

By the time these ingredients reach a pet food manufacturer, the original fish have been reduced to anonymous commodities, bought and sold in bulk. What began as living marine animals, part of an intricate ocean food web, has become a protein or fat source on a commercial ingredient label. Nothing on that label tells pet owners where those fish were caught, what fishing methods were used, or what other marine life may have been harmed in the process.

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Chemical Contamination and the Hidden Hazards of Fishmeal

Fire Retardant in Fish: A chemical called ethoxyquin helps prevent fishmeal from spontaneously combusting as it decays and oxidizes, a serious risk, especially when vessels do not refrigerate their catch. Ethoxyquin is used not only as a fire retardant but also as a preservative. The problem is that ethoxyquin is potentially carcinogenic. The European Food Safety Authority said it can cause mutations in genetic material. Today, ethoxyquin is banned in most of the E.U., but in the U.S. it remains legal for use as a preservative in pet food and animal feed.

Toxic Compounds in Trash Fish: On many fishing vessels, fish were kept in unrefrigerated holds for days before reaching port. Feed manufacturers are well aware of the spoilage hazard. As far back as August 2006, technical reporting in Petfood Industry magazine outlined the industry’s ongoing struggle with biogenic amine formation in decaying fish raw materials, detailing how thermal rendering fails to destroy these chemical decay markers, specifically cadaverine, putrescine, and histamine. Of those compounds, histamine is particularly dangerous for pets—it can overwhelm the pet’s gut defenses and enter the bloodstream, causing chronic low-grade acid reflux, yellow bile vomiting, gut inflammation, and itchy skin that look identical to everyday allergies.

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The Human Misery That Feeds Our Pets

In 2015, The New York Times published Ian Urbina’s groundbreaking investigation, “‘Sea Slaves’: The Human Misery That Feeds Pets and Livestock.” It exposed a horrifying connection between human slavery aboard Southeast Asian fishing vessels and the global trade in fish used to manufacture pet food, livestock feed, and aquaculture feed.

Men and boys, often impoverished migrants lured by promises of legitimate employment, were trafficked and sold into slavery aboard fishing vessels operating far from shore. Some were held captive for years, forced to work without pay under brutal conditions, beaten, shackled, starved, and threatened with death. Survivors described sick workers being thrown overboard and men murdered by their captors. They worked surrounded by the overpowering stench of rotting fish, with catches left unrefrigerated for extended periods in tropical heat. Much of this cheap, low-value catch, commonly called “trash fish,” entered the international trade in fishmeal used to feed pets, livestock, and farmed seafood.

Urbina’s investigation traced fish from vessels linked to enslaved crews into supply chains serving major American pet food brands, including Fancy Feast, Meow Mix, and Iams. The revelations exposed how human suffering could remain hidden behind ordinary pet food products, raising disturbing questions about the industry’s ability to trace its marine ingredients and guarantee that they were not produced through forced labor.

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Pet Food’s Sustainability Halo: Pretty Blue Oceans, Not Much Proof

The Times’ Sea Slaves investigation created a public relations nightmare for pet food companies. To salvage their reputations, they launched campaigns to counter the findings by committing to responsible sourcing, supply chain audits, and sustainability goals. They claim their ingredients are “responsibly sourced,” “ocean-friendly,” or part of an ongoing “sustainability journey.”

This is bluewashing: using environmental messaging to create a sustainability halo around products while concealing the destructive reality of the upstream supply chain. An examination of North America’s top four pet food manufacturers reveals a consistent pattern of grand promises, missed deadlines, and corporate blackouts.

Has anything changed since the 2015 Sea Slaves investigation? Nearly a decade later, the U.S. Department of Labor’s Bureau of International Labor Affairs (ILAB) still identifies forced labor in Thailand’s fishing industry. In its 2024 update to the List of Goods Produced by Child Labor or Forced Labor, the agency identified fishmeal, fish oil, and animal feed produced in Thailand as products at risk of containing fish caught through forced labor. According to ILAB, Thailand processes about 25% of its marine fish catch into fishmeal for animal feed, primarily for shrimp and poultry farming. In 2022, Thailand exported $2.4 billion worth of animal feed to the United States, Malaysia, Japan, Italy, and Australia.

Eleven years after the Sea Slaves investigation exposed the human suffering hidden in the pet food industry’s marine supply chains, the promises keep coming. Mars Petcare, Nestlé Purina PetCare, Hill’s Pet Nutrition, and General Mills have all promoted their commitments to responsible sourcing, sustainability, and corporate accountability. But how much has actually changed? A closer examination of these four pet food giants reveals a troubling pattern: ambitious pledges, shifting deadlines, and persistent gaps in transparency. Despite years of assurances, fundamental questions about the origin of their marine ingredients, how they are harvested, and who is held accountable remain unanswered.

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Mars Petcare (Pedigree, Whiskas, Royal Canin, Sheba, IAMS)

Mars Petcare, one of the world’s largest pet food manufacturers, generated an estimated $29.5 billion in pet food revenue in 2025, representing approximately 14% of the global market. Its sustainability promises date back more than sixteen years.

2010: The Sustainability Promise. Mars partnered with the World Wildlife Fund (WWF) and pledged to source 100% of its fish sustainably by 2020.

2015: The Sea Slaves Revelations. Following The New York Times investigation into forced labor in Southeast Asian fisheries supplying animal food, Mars announced new supplier assessments and human-rights initiatives.

2017: The Third-Party Verification Promise. Mars pledged independent verification of 60% of its Thai fish supply chain by 2018 and 100% by 2019. The public documentation examined does not establish whether it met those deadlines.

2020: A Missed Sustainability Deadline. Mars did not demonstrate that it had achieved its goal of 100% sustainable fish sourcing. In 2021, it reported that 81% came from sources it classified as “more sustainable,” falling short of its original commitment.

2022: Undeclared Shark DNA. Researchers identified shark DNA, including species of conservation concern, in Whiskas and Sheba products purchased in Singapore. Shark was not declared as an ingredient. Mars denied intentionally using shark ingredients and said it would investigate.

Where Mars Stands Today. Mars promotes new traceability technology, third-party sourcing assurance, and sustainability certifications. Yet its public disclosures do not establish comprehensive, independently verified labor conditions aboard fishing vessels throughout its global marine supply chain.

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Nestlé Purina PetCare (Fancy Feast, Friskies, Beneful, Pro Plan, Purina ONE)

Nestlé Purina reported estimated global pet food sales of about $22 billion in 2025, representing roughly 16% of the market. Its seafood sourcing practices have faced scrutiny since the Sea Slaves investigation.

2015: Forced Labor Exposed. An independent investigation commissioned by Nestlé confirmed forced labor, debt bondage, violence, and abusive recruitment practices in its Thai seafood supply chain. Nestlé responded with its Thailand Seafood Action Plan.

2017: The Traceability Claims. Nestlé reported 99% traceability for wild-caught Thai tuna to fishing vessels and farmed shrimp to farms. But Thailand accounted for only about 7% of its global seafood purchases. The company reported audits covering more than 10% of vessels in its Thai supply chain.

2020: The Limits of Traceability. Nestlé reported 88% seafood traceability and 69% responsible sourcing. Yet fish by-products could be traced only to broad fishing zones or countries of origin, not necessarily individual vessels.

2022: Undeclared Shark DNA. Researchers discovered shark DNA, including species of conservation concern, in Fancy Feast products purchased in Singapore. Nestlé maintained that it did not intentionally use shark.

2023: Another Human-Rights Assessment. Nestlé commissioned Verité to examine seafood sourcing risks across multiple countries and fishing fleets. Its public findings did not provide comprehensive, independently verified labor inspection results for every vessel supplying its marine ingredients.

Where Nestlé Stands Today. Nestlé continues to expand its responsible-sourcing programs, but acknowledges that fish by-products are particularly difficult to trace. Its public disclosures do not show comprehensive vessel-level traceability or independent labor verification across its global marine supply chain.

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Hill’s Pet Nutrition (Science Diet, Prescription Diet)

Hill’s Pet Nutrition, owned by Colgate-Palmolive, reported approximately $4.6 billion in global net sales in 2025, representing an estimated 3% of the pet food market.

2023: Forced-Labor Risks Acknowledged. Colgate-Palmolive recognized that forced labor could occur in its upper-tier supply chains without the company’s knowledge, including risks in seafood and aquaculture.

2023: Human-Rights Due Diligence. The company introduced supplier questionnaires, initially focusing on agricultural supply chains associated with Hill’s. Public disclosures did not identify how many marine-ingredient suppliers or fishing vessels were assessed.

2024: Sustainability Accreditation. Hill’s announced Pet Sustainability Coalition accreditation. However, the accreditation does not independently establish the origins of all marine ingredients or verify labor conditions aboard fishing vessels.

The Sustainable Fish Sourcing Claim. Hill’s states on its European website that its fish comes exclusively from sustainably caught or farmed sources certified through recognized programs. It does not provide a detailed global accounting of certified fishmeal and fish oil or vessel-level verification throughout its product lines.

Where Hill’s Stands Today. Despite its responsible-sourcing policies and sustainability claims, publicly available evidence does not establish how much of its worldwide marine ingredient supply can be traced to verified fishing vessels and processing facilities.

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General Mills (Blue Buffalo, Tiki Pets, Edgard & Cooper)

General Mills reported approximately $2.47 billion in fiscal 2025 sales from its North America Pet division, representing an estimated 2% of the global pet food market.

2020: Modern Slavery Commitments. General Mills adopted policies prohibiting forced and child labor throughout its supply chain, but did not publicly document vessel-level verification for marine ingredients.

2022–2023: Seafood Supply-Chain Assessments. The company engaged Conservation International to examine environmental and social risks in seafood sourcing. It did not publish comprehensive fishmeal traceability figures or vessel-level labor inspection results.

2024: Human-Rights Risks Reassessed. An LRQA assessment identified forced labor and child labor as significant supply-chain concerns but provided no detailed public account of conditions aboard fishing vessels supplying its pet food operations.

2025: Supplier Audits. General Mills reported 673 audits across its broader corporate supply chain. It did not disclose how many, if any, involved fishing vessels, fishmeal reduction facilities, or upstream marine-ingredient suppliers.

Where General Mills Stands Today. Despite extensive corporate responsible-sourcing programs, publicly available disclosures do not establish comprehensive fishmeal and fish oil traceability or independently verified labor conditions throughout its marine supply chain.

After years of sustainability pledges, third-party assessments, traceability programs, and corporate promises, one fundamental question remains unanswered: Can these companies show that they harvested the fishmeal and fish oil in their pet foods without destructive fishing practices or human exploitation? Their public disclosures still leave significant gaps in the evidence.

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How Much Can You Trust a Sustainability Seal?

MarinTrust: Established by the fishmeal and fish oil industry association IFFO, MarinTrust certifies responsible sourcing and production of marine ingredients. Industry representatives, including Cargill, help develop its standards, raising questions about potential conflicts of interest.

Marine Stewardship Council (MSC): Its blue-label certification evaluates sustainable fishing practices, including bycatch. The 2021 Netflix documentary Seaspiracy challenged the credibility of its certification program, allegations MSC disputed.

NOAA Dolphin Safe: The U.S. government’s tuna-labeling program prohibits deliberately encircling dolphins and requires assurances that none were killed or seriously injured during the fishing operations that caught the tuna. Verification often relies on captains’ statements rather than independent observers aboard every vessel.

Earth Island Institute Dolphin Safe: This private monitoring program works with tuna companies to prevent dolphins from being deliberately targeted or harmed during fishing. Its standards and monitoring are separate from NOAA’s federal program.

Friend of the Sea: Offers broader seafood sustainability certifications, including fishmeal and fish oil, as well as a separate Dolphin Safe standard for tuna fishing. Its criteria address fishing practices, environmental impacts, and traceability.

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Rethinking What’s on Our Plates and in Their Bowls

For decades, I bought canned and kibble cat food with salmon, whitefish, fish meal, dehydrated and freeze-dried minnows, salmon fish skins and treats, bonito flakes, baked salmon, fried scallops and shrimp, and Omega-3 oil for my cats without realizing the cost to our oceans. But after reading Ian Urbina’s report, I will never think of marine life in the same way ever again.

Now I look at the benign cans of fish-flavored cat food sitting on my cupboard shelf, and I can’t help but see that inside those cans is the product of the destruction of ocean life. With all the tragedy I see in this work, I can never look at sea creatures without feeling profound sadness.

For now, here is some advice that will help you move away from fish-based products, whether for yourself or your pets:

Avoid Marine Ingredients: Skip kibble, canned pet food, or treats that contain marine ingredients like fish meal, fish by-products, whitefish, or fish oil. Farmed fish, such as salmon, tuna, and yellowtail, are fed aquaculture feed made with the same fish meal used in pet and livestock diets. Don’t buy fish treats such as minnows, fish skins, dehydrated or freeze-dried fish, or dehydrated bonito.

Ethoxyquin: You’ll never see the name on an ingredient list because it’s considered an incidental additive. On fishing vessels without refrigeration, it acts as a fire retardant to prevent spontaneous combustion during long ocean transits, and in pet food processing, it is sometimes used as a preservative. 

Switch to Microalgae for Omega-3s: Choose land-cultivated microalgae oil for bioavailable EPA/DHA without ocean overfishing, trawling, or heavy metal contamination.

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The Animals We Love, and the Animals We Sacrifice

Beyond this story and my awakening to the consequences of fishing, I cannot end this story without acknowledging the profound and systemic suffering of every terrestrial animal — cattle, pigs, poultry, lambs, goats, rabbits, and so many more — raised and slaughtered, whose lifetime was spent in captivity to make the very food I feed my cats. Even though I am a vegan, my anguish remains: how do I continue to live with the guilt of being a very part of a system that inflicts such terrible suffering on other animals to feed my cats?

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References and Further Reading

Associated Press. “AP Investigation: Slaves may have caught the fish you bought.” March 25, 2015.

Association of American Feed Control Officials (AAFCO). Ingredients Model Regulation PF6 and Handling and Storage Instructions Model Regulation PF12: Guidance. April 23, 2025.

Colgate-Palmolive. Respecting Human Rights and Labor Rights: Modern Slavery/Fundamental Human Rights and Decent Working Conditions Statement. 2023.

Courthouse News. “Companies Duck Disclosure of Supply-Chain Slave Labor.” July 11, 2018.

Douglas Insights. Pet Food Market: Market Size, Share and Forecast. October 21, 2026.

European Food Safety Authority (EFSA). EFSA reassesses safety of the feed additive ethoxyquin. March 3, 2022.

Food and Drug Administration (FDA). Labeling and Use of Ethoxyquin in Animal Feed. January 31, 2024.

French, Ian, and Benjamin J. Wainwright. “DNA Barcoding Identifies Endangered Sharks in Pet Food Sold in Singapore.” Frontiers in Marine Science, March 4, 2022.

General Mills. Slavery and Human Trafficking Statement: Fiscal 2025. 2025.

The Guardian. “Revealed: Asian slave labor producing prawns sold in America and Britain.” June 10, 2014.

The Guardian. “Blue ticked off: the controversy over the MSC fish ‘ecolabel’.” July 26, 2021.

Hill’s Pet Nutrition. Hill’s Animal Welfare Statement. No publication date listed.

Hill’s Pet Nutrition. Sustainability at Hill’s Pet Nutrition. No publication date listed.

Human Rights Watch. Hidden Chains: Rights Abuses and Forced Labor in Thailand’s Fishing Industry. January 23, 2018.

Mars Petcare. Advancing Human Rights in the Thai Fish Supply Chain: Progress Update. May 2017.

Mars Petcare. Responsible Fish Sourcing Guidelines. Publication date not confirmed.

Mars Petcare. Protecting ocean ecosystems. No publication date listed.

Morrissette, Mollie. “Slavery-Tainted Fish: The High Price of Cheap Pet Food.” Pet Food Safety News, June 30, 2014.

Morrissette, Mollie. “Nestlé Purina Accused of Using Fish Tied to Slave Labor in Cat Food.” Pet Food Safety News, August 29, 2015.

Morrissette, Mollie. “Mars Petcare’s Sustainable Seafood Pet Food Campaign Sounds Great Until You Do a Little Digging.” Pet Food Safety News, September 8, 2022.

National Oceanic and Atmospheric Administration (NOAA). Marine Mammal Protection Act. No publication date listed.

Nestlé. Responsible Sourcing of Seafood at Nestlé: Thailand Action Plan Update. 2017.

Nestlé. Responsible Sourcing KPIs 2020. 2020.

Nestlé. Fish and seafood sourcing. No publication date listed.

Urbina, Ian. “‘Sea Slaves’: The Human Misery That Feeds Pets and Livestock.” The New York Times, July 27, 2015.

Urbina, Ian. “The Dirty Secret Behind the Farmed Fish You Eat.” The New York Times, October 8, 2026.

Urbina, Ian. “The price paid beyond the plate: the huge costs of farmed seafood.” Daily Maverick, October 9, 2026.

Urbina, Ian. “What is Food for Feed?” The Outlaw Ocean Project, October 9, 2026.

Urbina, Ian. “The Fire Retardant in the Seafood Chain.” Inside Climate News, October 14, 2026.

Wall, Tim. “How is shark in pet food despite Mars, Purina standards?” Petfood Industry, March 21, 2022.