Fish
The most killed animals on the planet
1.1–2.2TWild fish caught per year
The recorded wild catch is about 1.1 to 2.2 trillion fish a year — a midpoint near 1.6 trillion is about 4 billion wild fishes every day. Farmed finfish add about 130 billion more. About half the wild catch has gone to fishmeal and oil, not to a human plate. They feel pain: rainbow trout have nociceptors like ours, and morphine reduces their pain-related behavior. Cleaner wrasse pass the mirror test and use mirrors to check their size before a fight; some use anvils or jets of water as tools. Calling them “just fish” is how the largest killing on the planet stays easy to ignore. We do not have to harm or eat animals at all.
1.1–2.2T
Wild fishes caught per year (recorded catch)
A midpoint of ~1.6 trillion is about 4 billion wild fishes every day — plus ~130 billion farmed finfish a year. The largest killing on the planet.
Who they are
The main points first. Every claim is tied to a source below.
Far more than all land animals combined
Chickens are the most killed land animal at ~78.5 billion. Farmed finfish already outnumber that — about 130 billion in 2022 (range 86–180 billion). Wild catch is another order of magnitude: 1.1 to 2.2 trillion recorded individuals a year. FAO still reports fish in tonnes, not bodies. That is one reason the number stayed hard to see.
They have pain receptors — and painkillers work on them
Lynne Sneddon’s work on rainbow trout found polymodal nociceptors on the head that respond to pressure, heat, and acid — the same classes described in mammals. Injected with bee venom or acid, trout rock, breathe faster, and stop eating; morphine reduces those changes. This is not a simple reflex. Reviews over the last decade treat bony fish as meeting standard criteria for animal pain.
Some fish pass the mirror test
Bluestreak cleaner wrasse scrape a mark off their throats when they can see it in a mirror — and not when the mark is clear or the mirror is gone. They recognize their own face in photos. Some pick up shrimp and drop it by the mirror to watch how the reflection moves — testing the mirror itself. Recent work shows they use the mirror to check their size before deciding whether to fight. Fish now have some of the strongest experimental support for mirror self-recognition of any animal outside mammals and birds.
Fish use tools
Tuskfish and wrasses smash shellfish on rock anvils. Archerfish shoot jets of water to knock insects down — a skill they learn, including by watching others. Groupers and moray eels signal each other when hunting together. “Just fish” does not fit the behavior.
About half the wild catch never reaches a human plate
Mood & Brooke estimate that around half of recorded wild fishes — hundreds of billions of mostly small bodies — are reduced to fishmeal and oil, much of it fed to farmed animals, including farmed fish. The farmed salmon on the plate is a pile of wild fishes underneath.
Caught, then left to suffocate
Most wild fishes die in nets, on deck, or from crush and asphyxia. Many farmed fishes are killed in air or ice slurry. When there is a real chance an animal can experience what happens to it, it is hard to justify ignoring that. Fish are vertebrates. That chance is on the table.
Sources
Papers and datasets. Caveats stay on the card — small samples and single animals included on purpose.
Animal Welfare, 2024 · Observational
Estimating global numbers of wild-caught fishes, 2000–2019
1.1–2.2 trillion wild finfishes caught annually on average from recorded FAO landings. 2019: 980–1,900 billion, still ~87% of vertebrate numbers killed for food or feed. Excludes illegal fishing, discards, ghost fishing. Authors recommend FAO report numbers, not only tonnes.
Fishcount / Animal Welfare · Observational
Numbers of farmed fishes slaughtered each year
Fishcount / Mood et al.: about 130 billion farmed finfish killed globally in 2022 (range 86–180 billion). 2019 peer-reviewed midpoint 124 billion; a nine-fold rise since 1990. Converted from FAO tonnage using estimated mean weights.
Animal Welfare, 2023 · Observational
Estimating global numbers of farmed fishes killed for food
Peer-reviewed 2019 estimate: 78–171 billion farmed finfish, midpoint 124 billion. Pond loach, Nile tilapia, and carp dominate the count.
Proceedings of the Royal Society B, 2003 · Observational
Do fishes have nociceptors?
Electrophysiology in rainbow trout: polymodal nociceptors on the head with properties like those of higher vertebrates. Noxious acid/venom changed behaviour and physiology for hours.
Animal Cognition, 2015 · Review
Fish intelligence, sentience and ethics
Culum Brown's review: perception and cognition in fishes often match or exceed other vertebrates. Evidence for pain, social intelligence, long-term memory, and tool use. The public picture of fishes is decades behind the data.
PLOS Biology, 2019 · Small sample
Cleaner wrasse pass the mirror mark test
Kohda et al.: bluestreak cleaner wrasse show behaviour interpreted as passing the mark test — they attempt to scrape a mark visible only in a mirror. A 2022 follow-up increased confidence with an ecologically relevant mark.
NYU, 2024 · Review
New York Declaration on Animal Consciousness
Empirical evidence indicates at least a realistic possibility of conscious experience in all vertebrates, including fishes. When that possibility exists, it is irresponsible to ignore it in decisions that affect them.
Applied Animal Behaviour Science, 2003 · Observational
The evidence for pain in fish: morphine as an analgesic
Acid or venom in the lip changed trout behaviour and breathing. Morphine significantly reduced those pain-related behaviours. The authors concluded the responses were not simple reflexes.
Scientific Reports, 2025 · Small sample
Rapid mirror self-recognition in cleaner wrasse
Cleaner wrasse achieved mark-test responses rapidly — in some cases within the first hours of mirror exposure — and some then dropped shrimp by the mirror to watch the reflection move, a form of contingency testing.
Coral Reefs, 2012 · Small sample
Tuskfish use anvils
A wrasse (Choerodon schoenleinii) was filmed smashing a bivalve on a rock anvil. Tool use in fishes is uncommon in the public picture. It is in the record.