Settings of demersal longlines reveal acoustic cues that can inform toothed whales where and when to depredate

Gaétan Richard (1) , Flore Samaran (1) , Christophe Guinet (2) , Julien Bonnel (3)

1 Laboratoire des Sciences et Techniques de l'Information, de la Communication et de la Connaissance
2 CEBC - Centre d'Études Biologiques de Chizé - UMR 7372
3 Applied Ocean Physics and Engineering Department [Massachusetts, USA]

Fishing boats produce acoustic cues while hauling longlines. These acoustic signals are known to be used by odontocetes to detect the fishing activity and to depredate. However, very little is known about potential interactions before hauling. This article describes the acoustic signature of the setting activity. Using passive acoustic recorders attached to the buoys of longlines, this work demonstrates an increase in the ambient sound of 6dB re 1 lPa2 Hz1 within 2–7 kHz during the setting activity. This could also be used as an acoustic cue by depredating species, suggesting that predators can detect longlines as soon as they are set.

Domaines: Sciences de l'environnement

Gaétan Richard, Flore Samaran, Christophe Guinet, Julien Bonnel. Settings of demersal longlines reveal acoustic cues that can inform toothed whales where and when to depredate. JASA Express Letters, 2021, 1 (1), pp.016004. ⟨10.1121/10.0003191⟩. ⟨hal-03109933⟩