Turtle excluder devices
Turtle excluder devices (TEDs) modify trawl nets to allow larger animals to escape. These animals include sea turtles, stingrays, sharks and sponges. TEDs are usually fitted into a trawl net at the beginning of the codend. At this point in the net, water-flow is fastest and maximises the ability of a TED to separate target animals from non-target animals.
The use of TEDs as specified in the Fisheries (East Coast Trawl) Management Plan (2010) helps reduce the catch of endangered and protected sea turtle species.
TEDs consist of either a metal or plastic grid with vertical bars 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 prawns and other animals smaller than the bar spacing pass through the TED and into the codend. Sea turtles, other large animals and debris slide along the grid to an exit hole cut in the top or bottom of the surrounding mesh. The exit hole may be partially covered by a flap of webbing to reduce the possibility of losing prawns.
From 1 March 2015 fishers will have the option of using an accelerator funnel with their TEDs. From this date fishers will also have the option to use scallop mesh up to 90mm when constructing TED flaps for use with their scallop nets.
|Accelerator funnel specifications|
|Mesh size of funnel||38-50mm|
|Attachment of leading edge of funnel to net||At least 18 meshes in front of grid (and trailing edge does not extend past grid)|
|Minimum funnel circumference|
38-42mm mesh – 100 meshes
43-47mm mesh – 83 meshes
48-49mm mesh – 93 meshes
50mm mesh – 100 meshes
|Attachment of trailing edge to grid bars|
Top shooter TEDs – bottom one third of funnel circumference may be attached to grid bars
Bottom shooter TEDs – top one third of funnel circumference may be attached to grid bars
When working properly, catch loss associated with these devices should be minimal. There is evidence that TEDs may improve the quality or the quantity of the prawn catch in certain circumstances. A poorly constructed or maintained TED may cause major losses in prawn catch.
In Queensland's east coast trawl fishery the use of TEDs with bycatch reduction devices (BRDs) is mandatory in all otter trawl nets.
The mandatory use of TEDs is helping to prevent sea turtles from being caught in Australian trawl fisheries. TEDs have been made compulsory in the following trawl fisheries of Australia:
- Queensland east coast trawl fishery - daytime and inshore trawling in all areas except river beam trawl
- northern prawn fishery (Gulf of Carpentaria, Arnhem Land coast and Joseph Bonaparte Gulf)
- Torres Strait prawn fishery.
While TEDs are not compulsory in all Australian fisheries, other trawl fisheries (i.e. South Australia and Western Australia) are using TEDs to improve quality of catch and reduce sorting times through less bycatch.
TEDs technical information guide
This TEDs guide provides technical information to ensure that TEDs are made to a consistent standard and are fitted correctly to trawl nets used throughout the Queensland east coast trawl fishery.
The guide and the standardised design specifications contained within it will help both net makers (to construct TEDs) and fishers (to fit and use TEDs). This will ensure TEDs effectively reduce bycatch (non-target species) while also retaining catches of target and permitted species.
Technical information guide:
- Find out more about bycatch reduction devices (BRDs).
- Last reviewed: 28 Jun 2016
- Last updated: 28 Jun 2016