In the U.S, as in most countries, there are no laws which protect fish from inhumane treatment. Many of us who are naturally sensitive to the suffering of mammals find more difficulty empathizing with fish. It comes as a surprise to many that the pain receptors in fish are similar to those of mammals. In other words, if you’ve ever stepped on a fishing hook and experienced the shooting pain of having the hook drive deep into your flesh, then you can begin to understand how a fish feels when he is hooked by a fishing line. Our pain receptors are similar, so we experience pain similarly. Researchers conclude that “fish have the capacity for pain perception and suffering." According to world-renowned animal behaviorist Dr. Jonathan Balcombe, “fish representatives recognize individual ‘shoal mates,’ acknowledge social prestige, track relationships, eavesdrop on others, use tools, build complex nests, and exhibit long-term memories.”
When fish are pulled from the water, they begin to suffocate. Their gills often collapse, and their swim bladders can rupture because of the sudden change in pressure. Fish are most often killed by being hit on the head repeatedly, bleeding out, suffocating, or freezing.
About half of the fish consumed globally are farmed fish as opposed to wild-caught fish. Like the land-based factory farms, fish farms are often characterized by overcrowding, disease, and pollution caused by high concentrations of excrement and uneaten food. Pollution and disease also pose a threat to wild species, as do the hundreds of thousands of fish who escape farms and threaten the genetic diversity and survival of native species.
Modern fishing techniques don’t just harm the fish intended to be caught. Globally, an estimated 7.3 million tons of marine life is caught incidentally by fishing. This “bycatch” includes turtles, dolphins and juvenile fish. For example, for every pound of shrimp caught by nets dragged behind boats (or trawls) in the Gulf of Mexico, four pounds of other species are dragged up with them. These animals die like the rest and then are simply discarded. Scientists predict that at our current rate of fishing, all fished species will be annihilated within 50 years.
Brown, Culum (2004) Not just a pretty face New scientist, 2451: 42-43.
 Balcombe, Jonathan. 2010. Second Nature: the Inner Lives of Animals. Palgrave Macmillan: New York.
 Animal Welfare Institute. https://awionline.org/content/fish-farming