Study

Tailoring codend mesh size to improve the size selectivity of undifferentiated trawl species

  • Published source details Hunt D.E., Maynard D.L. & Gaston T.F. (2014) Tailoring codend mesh size to improve the size selectivity of undifferentiated trawl species. Fisheries Management and Ecology, 21, 503-508.

Actions

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 study in 2011 in an area of seabed in the Tasman Sea, Tasmania, Australia (Hunt et al. 2014) found that using a larger codend mesh size in a trawl net improved the size-selectivity of tiger flathead Neoplatycephalus richardsoni and sand flathead Platycephalus bassensis, compared to a smaller codend mesh size. The length at which flatheads (both species combined) had a 50% chance of escape was greater with a larger 90 mm mesh codend compared to a smaller 70 mm mesh codend (large: 307 mm, small: 294 mm). Length at maturity for female tiger flathead was 337 mm and 247 mm for female sand flathead. Fishing trials were done on trawl grounds off north-east and eastern Tasmania between May and July 2011 using a bottom (demersal) fish trawl. Alternate deployments of two diamond-mesh codends of 90 mm (nine hauls) and 70 mm (eight hauls) mesh size were carried out. A cover attached over each codend collected fish escaping through the meshes. Catch was sorted by species and flathead length measured.

    (Summarised by: Natasha Taylor)

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