Patterns of dolphin bycatch in a north-western Australian trawl fishery

  • Published source details Allen S.J., tyne J.A., Kobryn H.T., Bejder L., Pollock K.H. & Loneragan N.R. (2014) Patterns of dolphin bycatch in a north-western Australian trawl fishery. PLoS ONE, 9, e93178.


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 before-and-after study in 2003–2009 of a pelagic area in the Indian Ocean, Western Australia (Allen et al. 2014; same study area as Stephenson et al. 2006) found that installing exclusion and escape devices on trawl nets reduced common bottlenose dolphin Tursiops truncatus entanglements for three of four fishing vessels. Dolphin entanglement rates reported by skippers were significantly lower for three of four fishing vessels after exclusion and escape devices were installed (2.4–6.8 dolphins/1,000 trawls) than before (7.1–11.3 dolphins/1,000 trawls). The difference was not significant for the other vessel (after: 5.6 dolphins/1,000 trawls; before: 5.1 dolphins/1,000 trawls). Exclusion and escape devices were introduced to a trawl fishery in March 2006. A semi-flexible metal grid with vertical bars was fitted on trawl nets, either just before the ‘cod-end’ or at the start of the net extension. The grid was angled towards a bottom-opening escape hatch. Numbers of entangled dolphins were extracted from skippers’ logbooks for periods before (August 2003–March 2006; total 11,168 trawls) and after (March 2006–September 2009; total 16,736 trawls) exclusion and escape devices were fitted.

    (Summarised by: Anna Berthinussen)

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