Chilean jack mackerel caught in a purse seine

Wild caught fish suffer slow and distressing deaths in enormous numbers.
Credit: National Oceanic and Atmospheric Administration/Department of Commerce.

How big is a problem of animal suffering? This depends on the numbers of animals involved. The total magnitude of animal suffering may be quantified with the equation:

Magnitude of welfare problem = Severity x Duration x Numbers.

For most wild-caught fish, and also most farmed fish, during capture and subsequent processing the severity and duration of suffering will be high. Most wild-caught fish are likely to die from being crushed in nets or from suffocation, freezing or live dissection after landing. This process will probably take many minutes, or even hours. Most of the world’s farmed fish are also killed by slow and inhumane methods.

The following studies estimate the numbers of fish killed globally each year in fishing and fish farming, using FAO fisheries capture and aquaculture production tonnages together with estimated mean weights for fish species. It is estimated that, each year:

  • 970 – 2,700 billion fishes are caught from the wild, of which
  • 450 – 1,000 billion fishes are caught to make fishmeal and fish oil.
  • 37 – 120 billion farmed fish are killed for food.

These huge numbers mean the treatment of fishes in commercial fishing and fish farming are major animal welfare issues.

 
Numbers of fish caught from the wild each year

Japanese jack mackerel (Trachurus japonicus).
An estimated 3.5 to 20 billion individuals of this species are caught each year.
Credit: Nemo's great uncle.

In this study it is estimated that between 0.97 and 2.7 trillion* fish (ie 970,000,000,000 to 2,700,000,000,000) were caught from the wild globally each year for 1999-2007.

 
Numbers of farmed fish slaughtered each year

Grass carp (Ctenopharyngodon idellus) in aquarium.
An estimated 1.7 to 8.7 billion farmed individuals of this species are "harvested" for food each year.
Credit: Lebatihem Ehsan.

In this study it is estimated that between 37 and 120 billion* (ie 37,000,000,000 – 120,000,000,000) farmed fish slaughtered for food globally in 2010.

 
Numbers of wild fish caught for reduction to fish oil and fishmeal

The above study to estimate numbers of farmed fish also estimates that, on average each year for 2005-2009, between 0.45 and 1.0 trillion* (ie 450,000,000,000 – 1,000,000,000,000) wild fish were caught for reduction to fish oil and fishmeal, mainly used to feed farmed fish.

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* rounded to 2 significant figures.