Study

Progressively evaluating a penaeid W trawl to improve eco-efficiency

  • Published source details Balash C., Sterling D. & Broadhurst M.K. (2016) Progressively evaluating a penaeid W trawl to improve eco-efficiency. Fisheries Research, 181, 148-154

Actions

This study is summarised as evidence for the following.

Action Category

Modify the design/attachments of a shrimp/prawn W-trawl net

Action Link
Subtidal Benthic Invertebrate Conservation
  1. Modify the design/attachments of a shrimp/prawn W-trawl net

    A replicated, paired, controlled study in 2014 in Moreton Bay, Australia (Balash et al. 2016) found that four designs of W-trawl nets caught less non-commercial unwanted catch of crustaceans (discard) compared to a traditional Florida Flyer trawl net. All designs of W-trawls caught smaller amounts of crustacean discard than the traditional trawl (design 1: 1.5 vs Florida Flyer: 5.2 kg/ha; design 2: 5.6 vs 7.6; design 3: 4.9 vs 6.7; design 4: 6.9 vs 9.4). All designs of W-trawl caught lower amounts of the commercially targeted prawn species compared to the traditional trawl (27–39% reductions). In February 2014, unwanted catch from four W-trawl designs were compared to that of the Florida Flyer trawl during paired simultaneous 15–60 min deployments (one net of either one of the four designs on one side of the vessel, one Florida Flyer net on the other; 10–13 deployments/design). Design 1: unmodified W-trawl. Design 2: W-trawl with secured netting at the wing ends. Design 3: design 2 with the top tongue pulled forward and one chain link removed from each side of the ground chain. Design 4: design 3 further modified at wing ends (fitting “Dan lenos”). See paper for technical details. All nets were fitted with batwing otter boards, a “turtle-excluder device” (escape panel), and a “bycatch reducing device” (“fisheye”). At the end of each haul, catches were sorted into commercially targeted catch, commercial unwanted catch (large crabs, squid and octopus), and crustacean discard, and all were weighed.

Output references

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, terrestrial 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 latest volume: Volume 17

Go to the CE Journal

Subscribe to our newsletter

Please add your details if you are interested in receiving updates from the Conservation Evidence team about new papers, synopses and opportunities.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust