Research into fish cognition has dramatically revised understanding of their mental complexity, with implications for how we treat them in fisheries, aquaculture, and as pets.
The traditional view of fish as automata incapable of suffering has been overturned by two decades of cognitive and neuroscience research. Fish show sophisticated learning, emotional states, and behavioral indicators of pain that satisfy the scientific criteria for sentience used in welfare policy. However, fish welfare legislation and practice have not kept pace with this scientific understanding. Billions of fish in aquaculture, fisheries, and the pet trade are subjected to conditions that would be considered unacceptable for mammals showing equivalent cognitive capacities.