Study

The effect of forced mesh opening in the upper panel of a Nephrops trawl on size selection of Nephrops, haddock and whiting

  • Published source details Ingólfsson Ó.A. (2011) The effect of forced mesh opening in the upper panel of a Nephrops trawl on size selection of Nephrops, haddock and whiting. Fisheries Research, 108, 218-222

Actions

This study is summarised as evidence for the following.

Action Category

Fit mesh escape panels/windows to a trawl net

Action Link
Marine Fish Conservation
  1. Fit mesh escape panels/windows to a trawl net

    A replicated, paired, controlled study in 2009 of bottom fishing grounds in the northeast Atlantic Ocean off Iceland (Ingólfsson 2011) found that one of two designs of a diamond mesh escape panel fitted to prawn trawl nets, reduced the catches of unwanted and undersized whiting Merlangius merlangus and haddock Melanogrammus aeglefinus, compared to standard trawl nets with two square mesh escape panels. Overall, diamond mesh escape panels reduced the total catches of whiting and haddock by 43–48% and 34–57% respectively compared to the square mesh panel trawls. However, only the shorter design of large mesh panel reduced the catches of smaller individuals, and there were no size related differences for haddock and cod in the longer panel design (data reported as statistical models). In addition, target Norway lobster Nephrops norvegicus catches were reduced by 16–42% and fewer smaller (<50 mm) Nephrops were caught in the shorter panel trawl. In June 2009, data were collected from 22 deployments of two test nets and a standard Nephrops trawl nets towed in pairs on a commercial twin-rig vessel. In modified nets, the 135 mm diamond mesh top panel was narrower and longer than the bottom panel resulting in forced opening of the meshes. One design had a 23.2 m long upper panel (five tows) and the other a 16.1 m long upper panel (17 tows). Standard trawl nets were identical except for two mandatory 200 mm square mesh upper panels in place of the test diamond mesh panels. Full trawl details are given in the original study.

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 the latest volume: Volume 18

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