In her book "Do Fish Feel Pain?" (Oxford University Press, 2010), Braithewaite presents her case that fish, like most other organisms, are capable of experiencing pain and that humans can cause fish to suffer.
Here at Discovery News we've covered similar research that concluded lobsters, crab and other shellfish feel pain too. For me, it would be a surprise if they didn't, but scientists have been struggling for ways of proving the obvious here. I think Braithewaite does a good job of summarizing the latest findings.
Braithewaite found that fish have the same kinds of specialized nerve fibers that mammals and birds use to detect noxious stimuli, tissue damage and pain. She also explored whether fish are sentient beings and whether an organism must possess "awareness" to experience pain.
"We now know that fish actually are cognitively more competent than we thought before -- some species of fish have very sophisticated forms of cognition," she said in a press release. "In our experiments we showed that if we hurt fish, they react, and then if we give them pain relief, they change their behavior, strongly indicating that they feel pain."
She was initially drawn to the issue after reading about fish-farming concerns.
"By 2030, half of all fish that humans eat will come from fish farms," she said. "It seemed logical to me to care about fish, because agriculture in general is confronting animal-welfare issues. If we are concerned about animal welfare, we should be concerned about fish welfare."
She believes the United States is 10 years behind Europe now in its thinking about the way it keeps and kills animals in agriculture. Those concerns are just now starting to be extended to aquaculture.
"Electrical stunning may change the way we harvest fish at sea," she said. "We have a responsibility, I think, to make clean and quick kills of fish we eat. Certainly, most of us are not comfortable with piles of fish slowly suffocating on the decks of fishing trawlers at sea and in port. People are rightly asking: 'Isn't there a better way?'"
To do this on a widescale, commercial level, protections related to pain and suffering that are now given to birds and mammals should be widened to include fish.
"There is a perception that fish have simple brains and are incapable of feelings, and this has somehow made them different from birds and mammals when it comes to our concerns for their welfare," she said. "But we now have strong evidence that suggests fish are more intelligent than previously thought and their behavior more complex."