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Fish Schools

August 13, 2013

Making fish hatcheries more mentally stimulating may increase the fish’s chance of survival in the wild.



Schools for fish. I’m Bob Hirshon and this is Science Update.

Atlantic salmon, Norway. (Hans-Petter Fjeld)

Imagine growing up in an empty room, and not being let out until adulthood. That’s like the experience of fish bred in hatcheries and released into the wild. But recently, at a salmon hatchery in Norway, Penn State University biologist Victoria Braithwaite and her colleagues spruced up the empty tanks. They added rocks, plants, and other obstacles, and moved and replaced them periodically. After eight weeks, the fish competed with conventionally raised salmon in a maze.

VICTORIA BRAITHWAITE (Penn State University):

The fish that had had the enrichment items, unlike those that were reared in standard conditions, were just much more efficient in getting out of the maze.

Changes in the fish’s brains also indicated a higher capacity for learning and memory. Braithwaite says that if hatcheries can raise smarter fish, they may be able to breed fewer of them, since they’d be more likely to survive in the wild. I’m Bob Hirshon for AAAS, the Science Society.

Photo by Hans-Petter Fjeld