Interactions of Patagonian toothfish fisheries with killer and sperm whales in the Crozet Islands exclusive economic zone: an assessment of depredation levels and insights on possible mitigation strategies

Authors: 

Tixier, P., N. Gasco, G. Duhamel, M. Viviant, M. Authier, C. Guinet

Year: 

2010

Journal/Publisher Name: 

CCAMLR Science

Volume (Issue #): 

17

Page #s: 

179-195

Contact information: 

tixier@cebc.cnrs.fr
Summary: 

The Patagonian toothfish longline fishery has high levels of depredation by killer and sperm whales, which puts the whales at risk of being bycatch. Observations from 2003 to 2008 revealed significant variations of interaction rates with killer whales between vessels, suggesting the influence of operational factors on vessel interaction and depredation. When killer whales were absent at the beginning of the line hauling process, short lines (<5,000 m) provided higher yield and were significantly less impacted by depredation than longer lines. The authors also recommend that when facing depredation, vessels should leave the fishing area and travel distances > 40 n miles to prevent killer whales from finding them within a few hours.