Study

Underwater observations of seal-fishery interactions and the effectiveness of an exclusion device in reducing bycatch in a midwater trawl fishery

  • Published source details Lyle J.M., Willcox S.T. & Hartmann K. (2015) Underwater observations of seal-fishery interactions and the effectiveness of an exclusion device in reducing bycatch in a midwater trawl fishery. Canadian Journal of Fisheries and Aquatic Sciences, 73, 436-444.

Actions

This study is summarised as evidence for the following.

Action Category

Install exclusion and/or escape devices for mammals on fishing nets

Action Link
Marine and Freshwater Mammal Conservation
  1. Install exclusion and/or escape devices for mammals on fishing nets

    A replicated study in 2006–2007 of three pelagic sites in the Tasman Sea and Indian Ocean, Tasmania, Australia (Lyle et al. 2015) found that exclusion devices on trawl nets with large escape openings had lower fur seal Arctocephalus spp. mortality than those with small escape openings. Fewer fur seals died in exclusion devices with large escape openings (6 of 90 seals, 7%) than in exclusion devices with small escape openings (14 of 56 seals, 25%). Midwater trawls were carried out by a commercial fishing vessel at each of three sites using exclusion devices with a small escape opening (1 m2; total 30 trawls) or large escape opening (1.9 m2; total 48 trawls). Exclusion devices had two vertical steel grids (2.3 m2) angled forwards with an escape opening at the base. An underwater video camera recorded behaviour and mortality of seals within the exclusion devices during each of the 78 trawls in 2006–2007.

    (Summarised by: Anna Berthinussen)

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