Development of a trawl efficiency device (TED) for Australian prawn fisheries. II. Field evaluations of the AusTED

Published source details Robins-Troeger J.B., Buckworth R.C. & Dredge M.C.L. (1995) Development of a trawl efficiency device (TED) for Australian prawn fisheries. II. Field evaluations of the AusTED. Fisheries Research, 22, 107-117.
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This study is summarised as evidence for the following.

	Action	Category
	Install exclusion and escape devices on fishing gear Action Link
	Fit a size-sorting escape grid (rigid or flexible) to a prawn/shrimp trawl net Action Link

Install exclusion and escape devices on fishing gear

A replicated, paired, controlled study (years not provided) in five oceanic-sand and estuarine-silt-bottomed sites in the coast off of southeastern Queensland, Australia (Robins-Troeger et al. 1995) found that adding a device that included a funnel to direct unwanted catch, an upward-facing flexible grid and covered escape panel (“ausTED” design turtle excluder device) onto a trawl net reduced the catch of loggerhead turtles Caretta caretta compared to a standard net. Using the device reduced the catch of loggerhead turtles (0 turtles) compared to nets without the device (7 turtles). In a separate experiment, six juvenile green turtles Chelonia mydas were placed in the path of nets with the device. Only three passed into the net entrance and all were successfully excluded from the main part of the net. Commercially-targeted prawn Penaeus spp. and Metapenaeus spp. catch rates, size and quality were similar in nets with and without the device (see original paper for details). Two commercial 6.8 m long trawl nets (40 mm mesh) were attached to a 15 m trawler. The device was fitted to one of the nets. Between 13 and 27 linear tows were conducted per site (each 60 minutes long, 85 tows used the device in total). Juvenile green turtles placed in the path of the net were videoed to assess how the device assisted their escape.

(Summarised by: Katie Sainsbury)
Fit a size-sorting escape grid (rigid or flexible) to a prawn/shrimp trawl net

A replicated, paired, controlled study (year not given) of soft seabed at five coastal sites in the Coral Sea, Australia (Robins-Troeger et al. 1995), found that when a catch escape system, incorporating a flexible size-sorting escape grid (‘AusTED bycatch reduction device’) was fitted to a prawn trawl net, catch of unwanted fish was reduced at three of five sites, compared to a standard trawl net without a grid system. At three sites, fewer (33–59% weight) unwanted fish were caught in nets with grid systems compared to standard nets, whereas at two sites the reduction in weight (11–12%) in nets with grids was not significantly lower. The size (and quality) of the commercial catch of prawns Penaeidae was similar between nets (grids: 91–103% of standard net catch). Trials were done using twin prawn nets, one with a grid system and one without, towed simultaneously by a 15 m trawler. In one trawl net, a system incorporating a flexible inclined grid with an escape gap at the top, a large mesh panel and a guiding funnel (AusTED) was installed in front of the codend. Between 13–27 deployments of 60 min were conducted at each of five sites of southeast Queensland. The year(s) the study took place was not reported.

(Summarised by: Rosslyn McIntyre)