What is a Turtle Excluder Devices (T.E.D.)
Turtle excluder devices (also known as TEDs) are designed to help turtles swim out of fishing nets if they are accidently caught.
A TED is essentially a rigid grid or grate of evenly spaced bars placed between the trawl opening and the cod end. The TED allows for target species to pass through the grid whilst removing unwanted catch away from the fishing gear.
Matt Watson, MSC’s Oceania and SE Asia Fisheries Outreach Manager said that although TED’s are not a mandatory step to achieve MSC certification, the use of TEDs or other gear innovations can dramatically reduce impact on sensitive species. They also show a fishery is reducing impact on Endangered, Threatened or Protected (ETP) species recovery.
“In the fisheries world TEDs or Turtle Exclusion Devices have been used in trawl fisheries since the 1970’s.
“The primary intent of a TED is to remove unwanted catch whilst not adversely affecting target catch rates.
“Unwanted catch could be anything from turtles (the giveaway is in the name) through to sharks, larger fish species as well as rocks and boulders which can do untold damage to trawl gear and the catch in the cod end.
“The removal of unwanted catch from a cod end whilst trawling can also improve catch quality”, he said.
Problem
Turtles can become incidentally caught in the trawl gear and become disoriented, unable to escape back through the net mouth.
Solution
TEDs provide an escape opening allowing turtles to be ejected without having to turn around and swim back through the net mouth. They are usually fitted into a trawl net at the beginning of the cod end (narrow end of a tapered trawl net). Water-flow is fastest at this point in the net maximising the ability of a TED to separate target animals from non-target animals.
Trawl nets are modified with either a metal or plastic grid of vertical bars with running from the top to the bottom of the frame (much like a storm-water-drain grate). The grid is then installed in a tube of mesh netting.
Grids are installed in the netting at an angle of 30-55°. This creates a physical barrier that lets small animals such as shrimp pass through the bars and are caught in the bag end of the trawl. When larger animals, such as sea turtles are captured in the trawl, they strike the grid bars and are ejected through the opening.
When larger animals, such as sea turtles are captured in the trawl, they strike the grid bars and are ejected through the opening.