For nearly a decade, the Outlaw Ocean Project, the non-profit journalistic organisation that I founded, has produced high-impact investigative stories about lawlessness at sea and the variety of threats posed to the people and biodiversity of a space that covers two thirds of our planet.

Aquaculture was meant to ease pressure on the oceans. By raising fish, fewer would need to be taken from the wild – or so the logic went. In practice, the opposite has occurred. More than a fifth of all marine life removed from the oceans is used for feed, primarily for farmed fish. More than half of the seafood eaten globally comes from aquaculture, which is a $313 billion industry and the fastest-growing segment of global food production.

Over the past five years, our international team of journalists at The Outlaw Ocean Project examined the largely unaccounted-for toll of using food for feed. We focused on one of the world’s most important feed ingredients: fishmeal.

We assembled a global network of more than two dozen journalists operating in as many countries. The team included coders who scraped and structured data from government databases and researchers who monitored local reporting, court records, and social media for evidence of labour abuses, environmental violations, community complaints, and other issues linked to fishmeal production.

The reporting also involved intensive, on-the-ground work. Reporting teams took six voyages at sea, including the South China Sea, the Southern Ocean near Antarctica, and the North Atlantic Ocean. These expeditions involved boarding fishmeal vessels to review logbooks, inspect living conditions, interview workers and document potentially illegal practices. On land, reporters visited fishmeal factories and aquaculture sites across Senegal, Thailand, Peru, Gambia, Vietnam, Indonesia, Cambodia, Greece and India.

Along these supply chains, the investigation documented a wide range of impacts: the depletion of local fish stocks; food insecurity in communities where inexpensive, edible fish is diverted to animal feed; and exposure to hazardous chemicals among residents living near fishmeal plants and waste-dumping sites. The reporting also tracked worker deaths and injuries on fishmeal-associated vessels or in fishmeal plants. The industry impacted the climate by clearing forests of carbon-capturing mangroves and meadows of seagrass to make way for fish farms, and shipping feed to customers thousands of miles away