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SC/68D/SM/03
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Resource ID
19588
Access
Open
Document Number
SC/68D/SM/03
Full Title
Update on the interactions between killer whales and vessel along the Iberian Peninsula
Author
Esteban, R., L?pez, A., Garcia de los Rios, A., Ferreira, M., Martinho., F., M?ndez-Fernandez, P., Andr?u, E., Garc?a-G?mez, J.C., et al.
Publisher
IWC
Abstract
A total of 253 interactions between killer whales and vessels have been recorded mainly along the Atlantic coast of the Iberian Peninsula, although there have also been interactions in the nearby area. 14 individuals have been identified, mostly juveniles, and they are distributed in up to 4 interacting groups. Most of the vessels involved in interactions are medium-sized (<15m) sailboats, with spade rudder, sailing at an average of 6 knots, both under sail and motor. Interactions occur throughout the year, although they are mostly concentrated in the summer and autumn months. Interactions occur at all times of the day and night, although they are concentrated in the midday hours. These interactions last on average 35 minutes. The behaviour of killer whales when interacting with boats was not identified as aggressive. No clear motivation has been found for this new behaviour; however it seems like a curious and playful behaviour, which could be self-induced, or induced by an aversive incident. Some mitigation measures, such as a temporary ban of sailing for sailing vessels, were implemented when interactions intensified in certain areas, or advising the whale watching boats not to approach the animals all along the coast of mainland Portugal. A survey was designed to better understand the motivations of this behaviour and proposed to occur between spring and summer months. The survey should be conducted from a medium-sized sailing vessel, equipped with AIS, to monitor the behaviour of the killer whales, and to test different behaviours of the boats (i.e. stop, accelerate, reverse gear). Two different types of deterrents, metal tubes and pilot whale sounds will also be tested.