When drift net fishing grew in scale during the 1950s, the industry changed to synthetic materials with smaller mesh size.
[3] In 1987 the U.S. enacted the Driftnet Impact, Monitoring, Assessment and Control Act limiting the length of nets used in American waters to 1.5 nautical miles (1.7 mi; 2.8 km).
In 1989 the United Nations General Assembly (UNGA) placed a moratorium on the practice of drift net fishing.
In 1994 United Nations Food and Agriculture Organization (UNFAO) estimated global by-catch rates to be as high as 27 million tons of fish discarded by fisheries each year.
[7] Species caught as by-catch include sharks, dolphins, whales, turtles, sea birds, and other marine mammals.
[8] In the 1990s, drift net fisheries were responsible for 30,000 tons of sharks and skates in global by-catch annually.
The nets were one mile long each and nearly 100 feet (30 m) high placed to target swordfish and thresher sharks.
[13] Large amounts of dead matter decomposing in the ocean causes the surrounding levels of dissolved oxygen to decrease.
[14] In addition, oceanic microplastics pollution is largely caused by plastic-made fishing gear like drift nets, that are wearing down by use, lost or thrown away.
[15][16] Most countries have jurisdiction over the waters within 200 nautical miles of their shores, called the exclusive economic zone, set by the Law of the Sea.
While fishing in international waters, vessels must comply with regulations of the country in whose flag they fly, but there are no enforcers on the high seas.
A new definition was established in 2007 as "any gillnet held on the sea surface or at a certain distance below it by floating devices, drifting with the current, either independently or with the boat to which it may be attached.
The first Bush administration opposed a U.S. driftnet ban because it would allegedly conflict with a treaty with Japan and Canada regarding salmon fishing in the North Pacific.