How Many Fishes Are Slaughtered Annually?
According to the Food and Agriculture Organization of the United Nations (FAO), in 2019, we produced 56 million tons of farmed finfish, more than 6.5x the number produced in 1990. Although farmed finfish production is increasing globally, Asia accounts for 88% of the increase.
These statistics help us see the overall picture of aquaculture’s growth, but measuring animals in tons rather than in numbers of individual fishes makes it difficult to grasp the magnitude of related welfare problems. For example, if people eat large fishes, many fewer individuals are affected than if people eat small fishes. Tackling the larger issue of fish consumption requires reliable and accessible statistics.
Researchers calculated an estimated number of fishes slaughtered in farms each year from 1990 to 2019, in each country, for each species. They collected estimated mean weights from a variety of data sources. The weights range from the lowest estimate to the highest, to account for uncertainty. They tried to use the most reliable sources they could find, such as census data, but for many species no reliable source was available. They made adjustments when they couldn’t find the mean weight estimates for a given species, or when production data were only available for a genus rather than a single species.
The scientists estimated that 78 to 171 billion farmed fishes were slaughtered across the globe in 2019. This is more than the number of farmed birds and mammals combined, which averages 80 billion. Most farmed fishes are produced in Asian countries, including China and Indonesia. The most common species farmed worldwide include carps, pond loaches, and catfishes. However, different farmed fish species are more common on different continents: for example, tilapia is the top species in Africa, while salmon is the most common species in Europe.
It’s important to know how many fishes are legally protected. The researchers collected data on humane slaughter legislation by country. 70% of farmed fishes are produced in countries with no animal welfare legislation that covers fishes. 28% of farmed fishes are produced in countries that have animal welfare legislation that covers animals in general, but none that specifically mentions fishes. Only 0.3% of farmed fish come from the three countries with fish-specific legislation: Norway, Switzerland, and New Zealand. While certification has the potential to improve fish welfare, only 2% of farmed fishes are covered by a certification program.
The authors point out that these findings are very imprecise. The estimates don’t include the many finfishes who die before slaughter or are used for purposes other than food, such as bait, those released into the wild, or those sold as ornaments for fish tanks. While the FAO tries to ensure that its data is as accurate as possible, some countries send in their data late, over- or underestimate their production, or accidentally include wild-caught fishes in their estimates. The researchers also have no idea whether the mean weight estimates are remotely close to the actual weights. Some countries slaughter fishes at a smaller weight than other countries, which further increases the uncertainty.
Aquaculture is an enormous and growing animal welfare problem. Accurate data allows animal advocates to prioritize the species and countries where their actions will have the largest effect. To establish more reliable estimates in the future, advocates can push the FAO to collect more data about the number of individuals farmed. Ultimately, this can help animal protection organizations make more informed decisions in their fish advocacy campaigns.