Pelagic longline fishing trials to shape a mitigation device of the depredation by toothed whales

  • Published source details Rabearisoa N., Bach P., Tixier P. & Guinet C. (2012) Pelagic longline fishing trials to shape a mitigation device of the depredation by toothed whales. Journal of Experimental Marine Biology and Ecology, 432-433, 44-63.


This study is summarised as evidence for the following.

Action Category

Use catch and hook protection devices on fishing gear

Action Link
Marine and Freshwater Mammal Conservation
  1. Use catch and hook protection devices on fishing gear

    A controlled study in 2007 of a pelagic area in the Indian Ocean off the Seychelles (Rabearisoa et al. 2012) reported that using ‘spider’ devices on fishing hooks did not reduce toothed whale (Odontoceti) predation and damage to fish catches. Results are not based on assessments of statistical significance. The proportion of fish damaged by toothed whales was higher on hooks protected with ‘spider’ devices (4 of 6 fish, 67%) than on unprotected hooks (8 of 15 fish, 53%). Fishing trials were carried out by a ‘long line’ fishery targeting tuna Thunnus spp. and swordfish Xiphias gladius. On each of 13 days, two fishing line sections were deployed, each with 480 hooks and 27–126 ‘spider’ devices (one device on every 2–4 hooks). Devices (8 x 120 cm polyester strands attached to a plastic disc on the branch line) were designed to automatically trigger and cover hooked fish. Fish damage by toothed whales (ragged wounds, torn flesh, conical tooth marks) were recorded during each of the 26 hauls in November–December 2007.

    (Summarised by: Anna Berthinussen)

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