Gillnet fishing is a common practice used in oceans and freshwater environments by commercial fisheries worldwide, and utilizes nylon mesh nets to ensnare fish such as salmon, southern flounder, squid, cod and swordfish. As the gillnets, a form of drift nets, float in the water, fish and other marine animals swim into them, oblivious to the nets’ invisible nylon filaments. Though Native Americans used gillnets for thousands of years, making their nets out of natural fibers such as hemp and cedar, the first modern gillnets were introduced in 1853 in the Columbia River region of the Pacific Northwest. Gillnets use different size mesh for different fish to ensure that the fish can’t swim through the net. These nets are also used by scientists to assess and sample fish populations in certain regions.
According to California’s Monterey Bay Aquarium Seafood Watch, gillnet fishing accounts for 3 percent of total fishing in the United States. Bottom trawl fishing is still the most common fishing method in this country, at 54 percent. Gillnets are largely seen as a more selective and environmentally friendly alternative to bottom trawl fishing, which drags trawl nets across the ocean floor, sweeping away most marine life and destroying the ecosystems in the depths of the ocean. However, gillnets trap other marine mammals, including the critically endangered Pacific Leatherback sea turtle and other turtles as well as several varieties of dolphins, sharks, whales, seals, sea lions and even sea birds. Cetaceans and sea turtles need oxygen to breathe, and when they get caught in the gillnets, they can’t swim to the surface for air, causing them to drown. Gillnets are usually left out at sea for 6 hours to 3 days.
In recent years, gillnet fishing has expanded its scope – once limited in range, technology and modern fishing vessels developed in the 1970s and ‘80s have allowed gillnet fishing to expand and cover more aquatic area. Nets are commonly 3 meters deep, but can span anywhere from 50 to 200 meters long, trapping hundreds of sea turtles each year. Gillnet fishing is considered an easy, economical fishing method, as it requires little fuel, inexpensive equipment and a small crew, but the large amount of by-catch it produces has become a threat to marine animals and the aquatic ecosystem.
In California, three species of sea turtles are critically threatened by the use of gillnets, and the numbers of sea turtles caught in the nets exceeds the number allowed by the US National Marine Fisheries Service. Gillnets along the Pacific coast are one of the main reasons that Pacific leatherback turtles are endangered; similarly, gillnets are thought to be one of the greatest threats to dolphins and porpoises. In addition to their adverse effects on marine life, gillnets can collect garbage and other debris and become floating nets of rubbish in the ocean. In some cases, gillnets have been altered to produce sounds that deter marine animals from nearing the net, but the success rate of this varies.
Efforts to ban gillnet fishing have been met with mixed success. In 2010, North Carolina adopted regulations on gillnet fishing to protect endangered sea turtles, and the United Nations banned drift nets on the high seas in 1992. Some areas of California have banned gillnetting permanently or seasonally to reduce the amount of by-catch. In a Mexican fishing experiment, fisheries switched to hook fishing and caught an amount of fish comparable to the amount caught in gillnetting, with zero turtles affected. However, petitions proposed in Oregon to ban gillnets have failed, and in Oregon’s Columbia River, gillnet fishing is the only legal way to catch fish commercially. ForceChange has set up a petition letter to the National Marine Fisheries Service – add your signature to support a nationwide ban on gillnet fishing!
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