Study

Effects of a codend mesh size increase on size selectivity and catch rates in a small-mesh bottom trawl fishery for longfin inshore squid, Loligo pealeii

  • Published source details Hendrickson L.C. (2011) Effects of a codend mesh size increase on size selectivity and catch rates in a small-mesh bottom trawl fishery for longfin inshore squid, Loligo pealeii. Fisheries Research, 108, 42-51.

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, paired, controlled study in 2008 of an area of seabed in the Atlantic Ocean, USA (Hendrickson 2011) found that increasing the codend mesh size on a bottom squid Loligo trawl reduced the unwanted catch of one of two fish species, compared to a conventional mesh size. Catch rates of Atlantic butterfish Peprilus triacanthus were lower with the larger 65 mm mesh compared to the standard 50 mm mesh (large: 400 kg/km2, standard: 809 kg/km2), and more than half (54%) of the reduction in catch consisted of smaller and more likely to be immature fish. For silver hake Merluccius bilinearis, catch rates were not significantly different (the authors noted this may have been due to the small sample size and highly variable catches) between mesh sizes (large: 117 kg/km2, standard: 194 kg/km2). However, most (86%) of the reduction in hake catch with the larger mesh consisted of fish smaller than the average size at maturity. Data were collected in September–October 2008, from 65 paired trawl deployments on a fishing vessel using a twin trawl. On one side an experimental 65 mm codend was fished and on the other a conventional 50 mm codend. Trawls were towed for 1 h at 60–134 m depth. Total catch weights, numbers and individual lengths of each species were recorded.

    (Summarised by: Natasha Taylor)

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