Turtle excluder devices (TEDs) are tools originally developed by fishermen that benefit both the commercial fishing industry and the marine environment.
In the 1970s and 1980s, American shrimp fishermen invented various TEDs to reduce their bycatch. The shrimp fishery uses large trawl nets that skim the seafloor. The nets' mesh is fine enough that shrimp are caught as the net drags along the bottom.
Unfortunately, trawling can also net other bottom-dwelling creatures. Turtles, such as the loggerhead in this photograph, need air to breathe. They drown as the trawl nets prevent them from returning to the surface. Not only does this bycatch reduce the turtle population, it also reduces the economic value of the fishery. (Fewer shrimp are caught because turtles take up room in the net. The weight of the turtles can also crush the shrimp beneath them, damaging them and reducing the value of the catch even further.)
TEDs have a fairly simple design: a grid of bars is attached to the top or bottom of a trawl net. (The bars are visible behind the mesh directly above the loggerhead in the photograph.) Small animals, such as shrimp, pass right through the bars and into a bag-like net. Animals that are too large to pass through the bars are ejected through an opening below them.
TEDs not only benefit turtles, but also allow other large animals, such as sharks and rays, to escape.
Term Part of Speech Definition Encyclopedic Entry bycatch Noun
fish or any other organisms accidentally caught in fishing gear.
commercial fishing Noun
industry responsible for catching and selling fish.
having to do with money.
to get rid of or throw out.
conditions that surround and influence an organism or community.
industry or occupation of harvesting fish, either in the wild or through aquaculture.
having to do with the ocean.
surface layer of the bottom of the ocean.
(turtle excluder device) tool attached to a trawl net to allow turtles and other large animals or objects to escape.
instrument used to help in the performance of a task.
to fish by dragging a large net along the bottom of the body of water.