A turtle excluder device or TED is a specialized device that allows a captured sea turtle to escape when caught in a fisherman's net.
Sea turtles are occasionally caught as bycatch by commercial shrimp fishers. These fishing boats commonly use a process known as bottom trawling to catch large amounts of shrimp, along with other marine organisms. When a turtle gets caught or entangled in a trawl net, it becomes trapped and is unable to return to the surface. As sea turtles are air-breathing creatures with lungs, they eventually drown.
A small opening in the net is then available either above or below the grid so that the creatures that are stopped by the TEDs are allowed to escape the net, relatively unharmed. Targeted species such as shrimp however, are pushed to the back of the net. As a conservation measure, turtle excluder devices are very effective. The rate of turtle mortality due to shrimping has been found to decrease by 97% with the use of TEDs.
In 1987, the United States required all trawling shrimping boats to equip their nets with turtle excluder devices. As a follow-up two years after, the shrimp-turtle law was implemented. This required all countries that the USA was importing shrimp from to certify that the shrimp they shipped were harvested by boats equipped with TEDs. Countries that cannot guarantee the use of the escape devices were banned from exporting shrimp to the USA.
In 1996, the Indian government proposed legislature for the requirement of modified "indigenous" TEDs, which they called TSDs (Turtle Saving Devices) to be used by local fishermen. This was a response to the declining olive ridley population that were nesting in beaches such as in Orissa. The modified TSDs were similar to standard TEDs except for having fewer bars. This resulted in the increase of the distance between each pair of bars to ensure that bigger specimens of shrimp and fish were able to pass through the TSD and into the net.