The experiments on turtle excluder devices (TEDs) for shrimp trawl nets in Thailand

The purpose of this paper is to determine a suitable type of Turtle Excluder Device (TED) attached to the body of a shrimp trawl to avoid inflicting harm on marine turtles. Seven types of the TEDs were tested; three brought from U.S.A. namely the Anthony Weedless, the Super Shooter and the Bent Pipe, two brought from Mexico namely the Georgia Jumper and the Mexican, and two were designed by Kasetsart University and SEAFDEC/TD, Thailand, namely the Thai-KU and Thai Turtle Free Device (TTFD), respectively. No turtles were caught in any of the areas off Chumporn and Songkhla during a total of 120 hauls. The escape rate by weight of the Super Shooter and TTFD were found to be 2.67% and 1.80% for day-time operation and 1.91% and 1.04% during the night, respectively, this indicated that they were the most efficient TED. The fuel consumption for all TEDs showed little difference. In terms of convenience in operation, the TTFD was found to be the best and the most suitable TED for the use by Thai fishermen

Experiments on the Use of Turtle Excluder Devices (TEDs) in Malaysian Waters

Trawl experiments deploying a research vessel and two chartered fishermen s boats were conducted to study the suitability of different types of Turtle Excluder Devices attached to the local shrimp trawl nets. A total of 23 hauls from R.V. Kerapu 1 and 24 hauls from chartered boats were made during the study in Zone A, i.e area from shore line to 5 nautical miles). The catches were classified into three different groups namely: shrimp, fish and trash fish to observe the effect of TEDs on catch rates. Two types of TTFD (Thai Turtle Free Device with slight modification) were tested namely: small TED (80cm X 80 cm) and medium TED (80cm X 100cm). The TEDs angle for research vessel and fishermen s boat were 45° and 55° respectively. The TEDs was designed in such a way to escape the marine turtle while at the same time maintaining the catch. The result showed that, TEDs prevented marine turtles from being trapped in the net but did not effect the catch of fish and shrimp. The average total escape rates by weight of the small and middle size of TEDs in research vessel were found to be 2.3% and 5.25% for day time operation and 0.01% and 4.67% during the night time operation respectively. The escape rates of small and medium size of TEDs in fishermen s boat were 6.53% and 4.05% for day time and 3.34% and 7.7% during night operation respectively. However, the result of the study showed that the use of TEDs did not reduce the catch rate of shrimp. Therefore the small and medium size of TEDs were found to be suitable for the use by Malaysian fishermen