This story is part of a series supported by Animal Charity Evaluators, which received a grant from EarthShare.

The last few decades have seen, arguably, the most sweeping transformation in how humans produce meat, and it has nothing to do with chickens, pigs, or cows. It has to do with fish.

Inside this story

• Over half of the world’s seafood now comes from fish farms, which resemble underwater factory farms.
• Chickens, pigs, and cows were domesticated over thousands of years, but fish have been domesticated in under a century. It’s created serious welfare issues, especially for salmon.
• Salmon are carnivorous and migrate thousands of miles. On farms, they’re reduced to swimming in small tanks and eating pellets.
• Fish farming has taken over the seafood sector, but some experts argue that it’s moved too fast, and we need to better understand welfare issues.

Traditionally, the vast majority of fish that people consume has come from the ocean. But in 2022, humanity hit a significant milestone: Seafood companies began to raise more fish on farms than they caught from the sea. And they farm astonishingly large numbers of fish — in tiny, cramped enclosures that resemble underwater factory farms.

It amounts to the fastest and largest animal domestication project that humanity has ever undertaken.

For most of the land animals we eat today, domestication — or, as French fish researcher Fabrice Teletchea defined it, the “long and endless process during which animals become, generations after generations, more adapted to both captive conditions and humans” — has taken place over thousands of years. “In contrast,” a team of marine biologists wrote in the journal Science in 2007, the rise of fish farming “is a contemporary phenomenon,” taking off on a commercial scale around the 1970s.

By the early 2000s, humans were farming well over 200 aquatic animal species, virtually all of which had been domesticated or forced into unnatural conditions in extreme captivity over the course of the previous century, with many in just the prior decade. To put it another way, the marine biologists wrote, aquatic domestication occurred 100 times faster than the domestication of land animals — and on a vastly larger scale. Today, some 80 billion land animals are farmed annually, while an estimated 763 billion fish and crustaceans are farmed each year, a figure projected to quickly grow in the decade ahead.

What’s more, this attempt to speedrun domestication occurred even as a clear scientific consensus emerged in recent decades that fish can suffer and feel pain.

The revolution in how humans produce seafood has enormous implications for our relationship with species we’ve barely given any thought to. To understand why, consider America’s favorite fish to eat, and one of the most difficult to farm: salmon.

Like farming tigers

Salmon farming is a relatively new industry, and it emerged largely in response to manmade problems.

Over the last century, overfishing — combined with industrial pollution, climate change, and heavy damming — has decimated wild Atlantic salmon populations. By 2000, the species gained protection under the Endangered Species Act after it was nearly driven to extinction in the US, effectively banning the commercial fishing of Atlantic salmon.

Salmon populations in Europe, along with Pacific salmon populations on the West Coast of the US and beyond, have also experienced significant declines.

To take pressure off depleted wild populations, seafood producers began to scale salmon farming in the 1970s, with ample help from governments in the form of R&D, grants, state financing........

© Vox