An application of the Morrison soft TED to the offshore prawn fishery in New South Wales, Australia

Published source details Andrew N.L., Kennelly S.J. & Broadhurst M.K. (1993) An application of the Morrison soft TED to the offshore prawn fishery in New South Wales, Australia. Fisheries Research, 16, 101-111.
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This study is summarised as evidence for the following.

	Action	Category
	Fit a size-sorting escape grid (rigid or flexible) to a prawn/shrimp trawl net Action Link

Fit a size-sorting escape grid (rigid or flexible) to a prawn/shrimp trawl net

A replicated, paired, controlled study in 1991 of a seabed area fished commercially for prawns in the Tasman Sea, New South Wales, Australia (Andrew et al. 1993) found that prawn nets modified with a flexible (mesh) size-sorting escape grid (a Morrison soft turtle excluder device) reduced the capture of unwanted finfish compared to unmodified standard nets. Discards of undersized commercial finfish species were significantly reduced in modified nets, however, retained finfish catch was similar (data reported as difference in average log ratio of catch weights). Use of the flexible escape grid did not reduce catches of the target prawn species Penaeus plebejus (data reported as difference in average log ratio of catch weights). The weight of discarded finfish and invertebrates combined was an average of 32% (9kg/tow) lower in modified nets than unmodified (not statistically tested). In October 1991, fishing experiments were done on two prawn trawlers, each fitted with three trawl nets in a standard triple gear configuration. Four paired 90-minute deployments using the outer trawl nets only were carried out on each of six consecutive nights. One of the outer nets was modified with a large-mesh (197 mm) escape panel/grid, measuring 36.5 meshes across at the leading edge, installed on the inside of the net. An opening of 20 meshes was cut in the net at the end of the panel immediately in front of the codend to allow larger catch to escape. The other outer trawl net of the three was not modified. Codend catches were separated into retained (prawns and other important species of commercial size) and discarded (rest of catch including undersized individuals of commercial species) portions and weight and lengths recorded.

(Summarised by: Natasha Taylor)