Gillnet Gillnetting is a common fishing method used by commercial fishermen of all the oceans . Because gillnets can be so effective their use is closely monitored and regulated by fisheries and enforcement agencies , such as the National Marine Fisheries Service in USA. Mesh size , twine strength , as well as net length and depth are all closely regulated to reduce bycatch of non-target species . Most salmon fisheries in particular have an extremely low incidence of catching non-target species . Gillnet , the name of the net employed , illustrates the method used to snare target fish . They try to swim through deliberately sized mesh openings but are unable to squeeze through swimming foreward . Once in this position , they are prevented from backing out due to the tendency for their gills to become caught . This effectively traps them . History Gillnetting began with First Nations fishermen using canoes and cedar fibre nets . They would attach stones to the bottom of the nets as weights , and pieces of wood to the top , to use as floats . This allowed the net to suspend straight up and down in the water . Each net would be suspended either from shore or between two boats . By around 1864 , gillnetting had expanded to European , Japanese , and other international fisheries . The boats used by these fisherman were typically around 25 feet long and powered by oars . Many of these boats also had small sails and were called `` row-sail '' boats . At the beginning of the 1900s , steam powered ships would haul these smaller boats to their fishing grounds and retrieve them at the end of each day . However , at this time gas powered boats were beginning to make their appearance , and by the 1930s , the row-sail boat had virtually disappeared . In 1931 , the first powered drum was created by Laurie Jarelainen . The drum is a circular device that is set to the side of the boat and draws in the nets . The powered drum allowed the nets to be drawn in much faster and along with the faster gas powered boats , fisherman were able to fish in areas they had previously been unable to go into , thereby revolutionizing the fishing industry . During World War II , navigation and communication devices , as well as many other forms of maritime equipment ( ex. depth-sounding and radar ) were improved and made more compact . These devices became much more accessible to the average fisherman , thus making their range and mobility increasingly larger . It also served to make the industry much more competitive , as the fisherman were forced to invest more into there boats and equipment in order to stay up to date with the current technology . This type of net was heavily used by many Japanese , South Korean , and Taiwanese fishing fleets on the high seas in the 1980's . Because of their indiscriminate nature , catching near everything in their path , and lack of regulation as well as a growing concern for the plight of whales and dolphins , gillnets were banned by the United Nations in 1993 in international waters . Types of Gillnets Anchored Sink Gillnet - Drift Floating Gillnet - Drift Sink Gillnet - Anchored Floating Gillnet - Hauling Gear Catch and Bycatch External links Video of gillnets in operation Manual on estimation of selectivity for gillnet and longline gears in abundance surveys - report for Food and Agriculture Organisation of the United Nations , 2000 . Gillnet Fishing - from Canada 's Digital Collections . Categories : Fishing In other languages : 日本語 | Português | Suomi 