Fishing 101 - Fish look so unlike humans, it's sometimes hard to imagine that they feel pain in the same way we do, but scientists who study pain are in complete agreement that the fish pain response is basically identical to the pain response system in mammals and birds. Fish also lead complex intellectual lives that rival those of dogs and some other mammals.

The fish industry is completely foreign to most people, whose experience with fish is limited to the frozen food section in their local grocery store. These intelligent, complex animals are slaughtered by the billions with very little consideration for their suffering.

For people who oppose cruelty to animals, the abuse of fish by the fishing industry (as well as by sport and recreational fishers) should be a key concern. More than 17 billion fish are killed for food in the U.S. alone each year, and sport fishing and angling kills another 245 million animals annually. Without any legal protection from cruel treatment, fish are impaled, crushed, suffocated, or sliced open and gutted, all while they're fully conscious.

The methods used to kill fish are shocking and horrifying. Fish are so hideously abused that it would warrant felony cruelty charges if the victims were dogs or cats (or even cows or pigs). Some countries are making improvements: The EU includes fish in its cruelty-to-animals statute, and Norway closed down a fish farm for cruelty to cod. However, all countries have extremely inadequate protection for fish, and the U.S. and Canada have no protection for them at all.

Whether they're raised on aquafarms, caught in the ocean by giant nets or "long lines," or hooked at the end of a fishing line, there's no doubt about it: Eating fish supports cruelty to animals.