Deterring harbour porpoise from gillnets: observed reactions to passive reflectors and pingers

Authors
Koschinski, S. & Culik, B.
Year
Journal/Publisher Name
SC/48/SM14. Report of the International Whaling Commission 47
Page #s
659-668
Summary

Three different device types were mounted on floatline to test their potential for reducing harbor porpoise (Phocoena phocoena) bycatch. The devices were two passive reflectors (target strength ranging from -38 dB to -24 dB) and a 2.9 kHz pinger. Behavioral responses of 355 harbor porpoise groups were monitored. 92.4% of the groups avoided the pinger equipped floatline, while only half the groups avoided the reflectors and control, empty, floatline.  

Field Studies