[MARMAM] New publication: Non-lunge feeding behaviour of humpback whales associated with fishing boats in Norway (Takashi Iwata)

Takashi Iwata iwatatakashi at gmail.com
Thu Nov 16 04:23:31 PST 2023

Dear Colleagues,

On behalf of our collaborators, we are pleased to share the following paper recently published in Ethology, "Non-lunge feeding behaviour of humpback whales associated with fishing boats in Norway."

Takashi Iwata, Kagari Aoki, Patrick J. O. Miller, Martin Biuw, Michael J. Williamson, Katsufumi Sato

You can find the article at: https://doi.org/10.1111/eth.13419

Top marine predators, such as odontocetes, pinnipeds, and seabirds, are known to forage around fishing boats as fishermen aggregate and/or discard their prey. Recently, incidents of humpback whales interacting with fishing boats have been reported. However, whether humpback whales utilise discard fish as a food source and how they forage around fishing boats is unknown. This study reports, for the first time, the foraging behaviour of a humpback whale around fishing boats. Three whales were tagged using a suction-cup tag containing a video camera, and a behavioural data logger in the coastal area of Tromsø, Norway. Video data from one tagged whale showed that the whale remained in close vicinity of fishing boats for 43 min, and revealed the presence of large numbers of dead fish, fish-eating killer whales, fishing boats, and fishing gear. In waters with large numbers of dead fish, the whale raised its upper jaw, a motion associated with engulfing discard fish from fishing boats, and this feeding behaviour differed markedly from lunge-feeding observed in two other whales in the same area. This behaviour was defined as “pick-up feeding”. No lunge feeding was seen on the data logger when the whale foraged around fishing boats. This study highlights a novel humpback whale foraging strategy: low energy gain from scattered prey but also low energy costs as high-energy lunge feeding is not required.

Kind regards,

Takashi Iwata

Takashi Iwata (Ph.D)
Assistant Professor
Graduate School of Maritime Sciences, Kobe University
5-1-1 Fukaeminamimachi, Higashinada, Kobe, Hyogo, 658-0022, JAPAN
Tel: +81 78 4316323
E-mail1: iwatatakashi at gmail.com
E-mail2: iwata at panda.kobe-u.ac.jp

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