In 1952, Jacques Cousteau turned his ship Calypso into a mobile laboratory to observe sea life and changed our understanding of the lives of fish forever. Cousteau’s work helped to bring about major improvements in the technology used to study marine life; important scientific advances in the field of fish cognition were quick to follow.
Since then, moving toward an understanding of the intricate social behavior of these intelligent animals has been a revealing (and often surprising) journey, New scientific studies are constantly requiring us to reevaluate the old theories. Previously, we have vastly underestimated the capabilities of these complex creatures, and we still have much to learn.
Recent impressive advances in scientific knowledge about fish cognition were documented in a meta-analysis by the biologists Culum Brown, Keven Laland, and Jens Krause for the journal Fish and Fisheries, the scientists observed,1
“Although it may seem extraordinary to those comfortably used to pre-judging animal intelligence on the basis of brain volume, in some cognitive domains, fishes can even be favorably compared to non-human primates,”
Brown, Laland, and Krause cited more than 500 new studies of fish that show the animals’ advanced capacities for reasoning, memory, and social interaction. Fish are now known to be capable of using tools,2 recognizing and distinguishing between other fish in their shoals based on social hierarchy,3 and exhibiting impressive feats of memory and problem solving, such as recalling a specific escape route from a net up to 11 months after having learned it.4
In light of these discoveries, we recommend reducing or eliminating your consumption of fish.