Called the Fish Empathy Project, the campaign reflects a strategy shift by People for the Ethical Treatment of Animals as it challenges a diet component widely viewed as nutritious and uncontroversial.
''No one would ever put a hook through a dog's or cat's mouth,'' said Bruce Friedrich, PETA's director of vegan outreach. ''Once people start to understand that fish, although they come in different packaging, are just as intelligent, they'll stop eating them.''
The campaign is in its infancy and will face broad skepticism. Major groups such as the American Heart Association recommend fish as part of a healthy diet; some academics say it is wrong to portray the intelligence and pain sensitivity of fish as comparable to mammals.
''Fish are very complex organisms that do all sorts of fascinating things,'' said University of Wyoming neuroscientist James Rose. ''But to suggest they know what's happening to them and worry about it, that's just not the case.''
PETA challenges claims by Rose and others that fish caught by anglers do not feel pain. It also decries the high levels of toxins in many fish and the pollution discharged by many fish farms.
The Empathy Project is a departure in two respects - attempting to depict the standard practices of commercial fishing as cruel and seeking to convince consumers there are ethical reasons for not eating fish.
''Fish are so misunderstood because they're so far removed from our daily lives,'' said Karin Robertson, project manager and daughter of an Indiana fisheries biologist. ''They're such inter- esting, fascinating individuals, yet they're so incredibly abused.''
The project was inspired by several recent scientific studies - widely reported in Britain but little-noticed in the United States - detailing facets of fish intelligence. Oxford University researcher Theresa Burt de Perera, for example, reported blind Mexican cave fish are able to interpret water pressure changes to construct mental maps of their surroundings. Chris Glass of the Manomet Center for Conservation Sciences in Massachusetts led another study, showing how North Sea haddock developed abilities to avoid trawlers' nets.