Gillnets are mesh panels of net made from monofilament plastic. Gillnet fisheries deploy hundreds of yards of net or more that are left in the water for long periods of time, from several hours to several days.
These nets are so effective at capturing marine life that in the process of fishing for their target species, they also capture many other kinds of fish and ocean wildlife, which are usually discarded injured or dead.
Globally, gillnets catch and kill more than 30 different species of marine life, including bottlenose dolphins, harbor porpoises and sea turtles. In the United States alone, gillnets entangle and kill hundreds of endangered and threatened sea turtles every year.