Improving the selectivity of beam trawls in The Netherlands: the effect of large mesh top panels on the catch rates of sole, plaice, cod and whiting

  • Published source details van Marlen B. (2003) Improving the selectivity of beam trawls in The Netherlands: the effect of large mesh top panels on the catch rates of sole, plaice, cod and whiting. Fisheries Research, 63, 155-168.


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 1994–1996 on bottom fishing grounds in the North Sea, the Netherlands (van Marlen 2003) found that fitting a large diamond mesh escape panel to beam trawl nets resulted in the capture of fewer small Atlantic cod Gadus morhua in one of two cases, and similar amounts of small whiting Merlangius merlangus in two of two cases, compared to standard trawl nets without a large-mesh panel. On small fishing vessels, nets with a large-mesh panel caught fewer undersized (<35 cm) cod (with: 1,134 fish, without: 1,352 fish) and similar amounts of undersized (<23 cm) whiting (with: 577 fish, without: 673 fish) than standard nets. On large fishing vessels, there were no statistical differences in catches between net types for both undersized cod and whiting: (cod, with: 413 fish, without: 596 fish; whiting, with: 78 fish, without 109 fish). In addition, overall, commercial catches of cod, whiting, brill Scophthalmus rhombus and turbot Scophthalmus maximus were lower with the modified trawl compared to the standard trawl, and commercial catches of sole Solea solea and plaice Pleuronectes platessa were similar between trawl types (see original paper for data). Between November 1994 and June 1996, data were collected from 519 valid trawl deployments (sampling area was not reported) over 13 one-week trips on three fishing vessels targeting flatfish; one small (300 hp engine), and two large (1,500 & 2,000 hp engines). On each vessel, a standard diamond mesh trawl net modified with a large diamond mesh top panel, and a standard diamond mesh trawl net were towed simultaneously (see paper for gear specifications). All cod and whiting caught were measured and marketable sizes of other fish.

    (Summarised by: Rosslyn McIntyre)

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