Commercial fishing is a major animal welfare issue. The suffering caused to a wild-caught fish is likely to be high, both in severity and duration. The number of animals affected is also very high. It is estimated that in the order of a trillion fish are caught each year.

The sentience of fish has huge ethical implications for the way they are caught and killed in fisheries.
Credit: OAR/National Undersea Research Program (NURP); University of North Carolina at Wilmington.
There is increasing acceptance that fish are able to feel fear, pain and distress. The methods by which wild fish are caught and die are likely to cause considerable suffering.
The greatest suffering caused may be that experienced by small fish used as “live bait”. These fish are thrown live to tuna, or worse still, impaled on hooks. This practice is common in long line fishing. Live fish should not be used as bait. Other modifications to fishing practice can also help reduce the stress and injury caused to fish during capture. Such measures can help improve the survival chances of released bycatch too. Suffering could be substantially reduced by shorter time intervals between setting and retrieving nets and lines (shorter capture durations).
Most commercially-caught wild fish, that are alive when landed, die either from being left to suffocate in air, or by a combination of suffocation and live dissection. Fish treated in this way may take several hours to lose consciousness. Sometimes fish are put onto ice as they suffocate, or into iced water which may both increase and prolong their suffering.
There are two traditional methods for killing fish that have the potential to be humane, namely percussive stunning and spiking. These methods kill fish individually, and so may not be practical for larger fishing operations with large numbers of smaller fish. For these cases, humane slaughter technology used on fish farms needs to be adapted for use on fishing vessels. More humane capture and killing are likely to result in improved eating quality.
Suffering could be reduced by strategies to catch fewer fish. This could be achieved by fishing at more sustainable levels; reducing bycatch and reducing the numbers of fish caught to make fishmeal. A substantial proportion of fish caught are caught to feed to farm animals. Catching fewer fish, and catching them at a larger size, reduces the suffering for the same amount of food.
Various stakeholders (animal welfare scientists, animal protection NGO’s, environmental NGO’s, government and inter-government bodies, supermarkets and retailers, animal welfare certification schemes) have worked to address the welfare of farmed fish. A similar approach is needed to address the welfare of wild-caught fish.