Acoustic alarms reduce porpoise mortality

Acoustic alarms reduce bycatch of harbor porpoises (Phocoena phocoena) in the Gulf of Maine sink gillnet fishery. Gillnets with and without acoustic alarms caught similar quantities of target species, cod and pollock. Acoustic alarms did not affect catch of bycaught silver hake, but Atlantic herring was caught less frequently in experimental nets with alarms. Harbour seals depredated fish caught in both nets with and without acoustic alarms.
Field Studies:

Location	Fishing gear	Reduction technique	Bycatch species	Effect on bycatch species	Catch	Effect on target catch	Type
United States	Gillnets	Acoustic pingers	Small Cetaceans (maximum length < 7.5 meters)	Reduced harbor porpoise bycatch	Multiple species	Effect varied by species	In the wild
United States	Gillnets	Acoustic pingers	Pinnipeds	Seals depredated nets with and without pingers	Multiple species	Effect varied by species	In the wild