Summary
Acoustic alarms reduce bycatch of harbor porpoises (Phocoena phocoena) in the Gulf of Maine (United States) sink gillnet fishery. Gillnets with and without acoustic alarms caught similar quantities of target species, cod (Gadus morhua) and pollock (Pollachius virens). Acoustic alarms did not affect catch of bycaught silver hake (Merluccius bilinearis), but Atlantic herring (Clupea harengus) was caught less frequently in experimental nets with alarms. Harbour seals (Phoca vitulina) depredated fish caught in both nets with and without acoustic alarms.