Test of 300 and 600 mm netting in the forward sections of a Scottish whitefish trawl

  • Published source details Kynoch R.J., O’Neill F.G. & Fryer R.J. (2011) Test of 300 and 600 mm netting in the forward sections of a Scottish whitefish trawl. Fisheries Research, 108, 277-282.


This study is summarised as evidence for the following.

Action Category

Modify the design or configuration of trawl gear (mixed measures)

Action Link
Marine Fish Conservation
  1. Modify the design or configuration of trawl gear (mixed measures)

    A replicated, paired, controlled study in 2009 of two areas of seabed in the North Sea off the Shetland Islands, UK (Kynoch et al. 2011) found that modifying the forward sections of a bottom trawl net (increases in mesh sizes) resulted in reduced catch rates of all sizes of four of seven commercial fish species, increased catch rates of one species in one of two cases, and for the other two species the effect varied with fish size, compared to standard forward sections. Overall, increased mesh sizes of 300 mm and 600 mm caught fewer Atlantic cod Gadus morhua (by 49% and 75%), megrim Lepidorhombus whiffiagonis (by 79% and 93%), ling Molva molva (by 36% and 68%) and hake Merluccius merluccius (by 28% and 53%) at all lengths, relative to standard mesh sizes of the forward sections (120/160 mm). Relative catch of haddock Melanogrammus aeglefinus was similar with the 600 mm gear (5% difference) but higher by 42% with the 300 mm gear compared to the standard. The 300 mm and 600 mm gears caught fewer monkfish Lophius piscatorius below 76 cm and 83 cm respectively (and similar catch of fish above these sizes) and saithe Pollachius virens above 53 cm (data reported as statistical results). Trials were conducted on two Shetland fishing grounds 30 nautical miles apart (104–150 m and 163–185 m depths), by a twin-rig trawler in June and July 2009. The 600 mm mesh was deployed only in one area (14 hauls) and the 300 mesh was trialled in both areas (30 hauls in total). Both modified trawl types were fished alongside a standard bottom trawl (see original paper for gear specifications).

    (Summarised by: Natasha Taylor)

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