Summary
Field testing was conducted in the lower Bay of Fundy, Canada, during 1996 and 1997 to determine the effectiveness of acoustic alarms (Netmark 1000) in reducing bycatch rates of harbor porpoises (Phocoena phocoena) in gillnets. Alarms were spaced 100 m apart along the gillnet float-line. There was a 77% reduction in bycatch of harbor porpoises in nets equipped with alarms compared to those with no alarms. There were no significant differences in catch rates of target species, Atlantic cod (Gadus morhua), Atlantic herring (Clupea harengus) and pollock (Pollachius virens).