The effect of smaller mesh sizes on catching larger fish with trawls

  • Published source details Mous P.J., van D.W.L.T. & Machiels M.A.M. (2002) The effect of smaller mesh sizes on catching larger fish with trawls. Fisheries Research, 54, 171-179.


This study is summarised as evidence for the following.

Action Category

Use a larger mesh size

Action Link
Marine Fish Conservation
  1. Use a larger mesh size

    A replicated, paired, controlled study in 1989 of bottom fishing grounds in the North Sea, Netherlands (Mous et al. 2002) reported that larger mesh size trawl codends caught fewer non-target small European smelt Osmerus eperlanus and long rough dab Hippoglossoides platessoides compared to smaller mesh sizes. Results were not tested for statistical significance. Codends with 20 mm mesh size caught fewer small smelt than 12 mm mesh codends (data reported as graphical analysis), and 155 mm mesh codends caught fewer small long rough dab than 39 mm mesh codends (data reported as graphical analysis). In addition, it was found that fish of increasing length were caught in increasingly higher numbers in the larger mesh codends compared to the smaller mesh, indicating that larger cod did not enter the smaller mesh codends at the same rate as the larger mesh codends. In September 1989, four 15 min deployments were undertaken using 20 mm and 12 mm mesh codends simultaneously in a trouser trawl. The 155 mm and 39 mm mesh codends were also tested simultaneously with a trouser trawl (published data – see paper for details). The lengths of captured fish were measured. Full gear specifications are given in the original paper.

    (Summarised by: Chris Barrett)

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