Dolphins "are 'non-human persons' who qualify for moral standing as individuals," said Thomas White, who teaches ethics at Loyola Marymount University in Los Angeles.
Research suggests dolphins are smarter than chimpanzees and second only to humans in terms of intelligence, said White and other dolphin advocates, including zoologist Lori Marino of Emory University in Atlanta.
"Many dolphin brains are larger than our own and second in mass only to the human brain when corrected for body size," Marino told The Times of London in a story published Wednesday.
It's unacceptable to kill such intelligent animals for food or to keep them in amusement park aquariums, which is akin to mistreating them, Marino said. estimating about 300,000 dolphins, whales and porpoises are killed each year for food or die in captivity.