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Commercial Fishing: How Fish Get From the High Seas to Your Supermarket

Commercial fishing is cruelty to animals on a colossal scale, killing hundreds of billions of animals worldwide every year—far more than any other industry.

Today’s commercial fishers use massive ships the size of football fields and advanced electronic equipment to track fish. These enormous vessels can stay out at sea for as long as six months, storing thousands of tons of fish onboard in massive freezer compartments.

This industry has decimated our ocean ecosystems. In fact, 90 percent of large fish populations have been exterminated in the past 50 years.


Long-lining is one of the most widespread fishing methods. Ships unreel as many as 75 miles of line bristling with hundreds of thousands of baited hooks. The hooks are dragged behind the boat at varying depths or are kept afloat by buoys and left overnight, luring any animal in the area to grab a free meal. Once hooked, some animals drown or bleed to death in the water, and many others struggle for hours until the boat returns to reel them in.

Large fish such as swordfish and yellowfin tuna, weighing hundreds of pounds each, are pulled toward the boat by the baited line. Fishers sink pickaxes into the animals’ fins, sides, and even eyes—any part of the fish that will allow them to haul the animals aboard without ripping out the hook.

Billions of fish, sharks, sea turtles, dolphins, birds, and other marine animals are injured and killed by long-lines each year.

Gill Nets

Ranging from 200 feet to more than a mile in length, gill nets are weighted at the bottom and held upright by floats at the top, creating what some have deemed “walls of death.” Fish are unable to see the netting, and unless the mesh size is larger than the fish, they get stuck. When they try to back out, the netting catches them by their gills or fins, and many suffocate. Others struggle so desperately in the sharp mesh that they bleed to death.

Because gill nets are set and then left unmonitored, trapped fish may suffer for days. Many bleed to death before the ship returns to take them out of the ocean. Those who make it to the deck alive are ripped out of the net by hand and suffocate or are cut open while still alive. Fish who were caught deep in the ocean suffer from decompression, and the extreme change in pressure can cause their stomachs to be forced out of their mouths.

Purse Seines

Another fishing method involves the use of a purse seine, which is the primary net used for catching tuna but which is also used for a variety of other fish species. This method has aroused public outrage because dolphins are sometimes caught in the nets. However, purse seines also kill millions of tuna—intelligent animals who are just as capable of feeling pain as dolphins.

To catch tuna, fishers track pods of dolphins, who commonly swim with large tuna, and drop a net into the water to surround the school of tuna. The edges of the net are slowly cinched together, trapping hundreds of tuna (usually weighing from 6 to 40 pounds each) in the net, which is then drawn up and closed like a laundry bag.

If they are still alive when they reach the deck of the boat, large fish such as tuna, cod, and haddock are completely conscious when their gills are slit and they are disemboweled.

Bottom Trawlers

Bottom trawlers target species such as orange roughy, cod, and haddock. Enormous bag-shaped nets are pulled along the ocean floor, catching every rock, piece of coral, and fish in their paths. Large metal plates at each end of the net drag along the ground, keeping the net close to the ocean floor while stirring up sediment and forcing all the animals in the net’s path into the closed end. Bottom trawling literally scrapes the ocean floor clean of life and is considered by some to be the underwater equivalent of clear-cutting forests.

The nets rip hundreds of tons of animals out of the ocean, squeezing some of them so tightly against the sides of the nets that their eyes bulge and burst out of their skulls. For hours, trapped fish are dragged along the ocean floor with netted rocks, coral, and ocean debris. Many fish’s scales are completely ground off. When hauled out of the water, surviving fish undergo excruciating decompression. The intense internal pressure ruptures their swim bladders, pops out their eyes, and pushes their esophagi and stomachs out through their mouths.

When first developed, bottom-trawling nets were limited to parts of the ocean that had a soft sediment floor because rocks and coral tore holes in the netting, allowing fish to escape. Now, bottom trawlers have huge wheels along the entire bottom edges of the nets. The heavy metal wheels roll along the ocean floor, crushing everything in their path but keeping the nets just off the ocean floor to prevent them from being torn. This “advance” has dramatically expanded the range of bottom trawlers, killing fish and other animals who had been protected by their rocky habitats. Consequently, bottom trawling is one of the most environmentally damaging fishing techniques, killing animals and destroying endangered coral and other sea life.

Slaughter on Deck

Regardless of the method used to catch them, if the fish are still alive at the end of their terrifying journey to the surface, most have their gills cut and bleed out or are tossed onto ice to slowly freeze or suffocate to death—a horribly cruel and painful death for coldblooded animals, who can take a very long time to freeze or suffocate to death. Scientists estimate that fish endure up to 15 minutes of excruciating pain before they lose consciousness.

Fishing Hurts Fish … and Other Animals Too

Sharks, sea turtles, birds, seals, whales, and other nontarget fish who get tangled in nets and hooked by long-lines are termed “bycatch” and are thrown overboard. They fall victim to swarming birds or slowly bleed to death in the water.

Scientists have found that nearly 1,000 marine mammals—dolphins, whales, and porpoises—die each day after they are caught in fishing nets. By some estimates, shrimp trawlers discard as much as 85 percent of their catch, making shrimp arguably the most environmentally destructive fish flesh a person can consume.

Take PETA’s Pledge to Be Vegan for 30 Days and eliminate fish and other animal products from your diet today. After a month, many people report feeling healthier and more energetic. Most of all, it means saving animals from cruelty.