Study

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.

Actions

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
Marine Fish Conservation
  1. 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)

Output references
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.


Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust