How are fish killed, and how many?
Short answer: Roughly a trillion fish a year, likely 1-2+ trillion, mostly killed with no stunning at all: left to suffocate, crushed in nets, or gutted while still alive.
Estimates are derived from catch tonnage divided by mean body weights, so they carry wide uncertainty, best cited as a range. Wild numbers dwarf farmed. These exclude unrecorded catch and bycatch, so the true total is likely higher.
fishcount.org.uk estimates
The objection
“Fish are different. They’re caught, not really ‘slaughtered’, and anyway it’s a clean, quick end out at sea.”
The answer
The numbers alone reorder everything. Land-animal slaughter, at roughly 80 billion a year, is dwarfed by what happens in the water. The best estimates, from fishcount.org.uk, put wild-caught fish at somewhere between 0.79 and 2.3 trillion a year, with hundreds of billions more farmed on top [1]. These are estimates derived from catch tonnage divided by average body weights, so the range is wide and the figure uncertain. Even the low end makes this the largest deliberate killing of animals humans carry out, by a vast margin.
Now the “quick, clean end.” There is almost no humane slaughter in commercial fishing. Wild fish are typically hauled up in nets, many crushed by the sheer weight of the catch or by decompression as they’re dragged from depth, and those still alive on deck are left to suffocate in air, which can take many minutes [2]. In some fisheries they are gutted while still conscious: fishcount cites gutting-alive taking tens of minutes for the fish to lose consciousness, with asphyxiation alone far longer [2]. Stunning, the basic mercy mandated for land animals, is vanishingly rare at sea.
Both halves of the objection collapse. Calling it “catching” rather than slaughter doesn’t shrink the harm; it’s by far the biggest we inflict. And nothing about it is quick or clean. It is suffocation, crushing and live gutting, at a scale with no equal anywhere else in what we do to animals.