Study

Using a modified Nordmøre grid for by-catch reduction in the Portuguese crustacean-trawl fishery

  • Published source details Fonseca P., Campos A., Larsen R.B., Borges T.C. & Erzini K. (2005) Using a modified Nordmøre grid for by-catch reduction in the Portuguese crustacean-trawl fishery. Fisheries Research, 71, 223-239.

Actions

This study is summarised as evidence for the following.

Action Category

Fit a size-sorting escape grid (rigid or flexible) to a prawn/shrimp trawl net

Action Link
Marine Fish Conservation
  1. Fit a size-sorting escape grid (rigid or flexible) to a prawn/shrimp trawl net

    A replicated study in 2001–2002 of a seabed area in the Atlantic Ocean, off southern Portugal (Fonseca et al. 2005) found that prawn/shrimp trawls fitted with a rigid size-sorting escape grid allowed most unwanted blue whiting Micromesistius poutassou and boarfish Capros aper to escape capture. Data were not tested for statistical significance. Overall, a total of 73–74% in number of blue whiting catch and 47–63% of the catch in number of boarfish, escaped through the grids. Losses of target shrimp species (rose shrimp Parapenaeus longirostris, Norway lobster Nephrops norvegicus and red shrimp Aristeus antennatus) were 4–15%. In May 2001 and April-May 2002 a total of 41 and 15 trawl deployments respectively were carried out on shrimp and Norway lobster fishing grounds off the Algarve. Trawl nets were fitted with a steel grid system (a modified Nordmøre grid) with 25 mm bar spacing, a guiding funnel, top escape opening and a 20 cm high section without bars at the bottom to allow target lobster catch to enter the codend directly (see paper for specifications). The escaping fish were collected in a mesh cover fitted over the escape opening.

    (Summarised by: Leo Clarke)

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