Experimental testing of acoustic alarms (pingers) to reduce bycatch of harbor porpoise, Phocoena phocoena, in the state of Washington

Pingers do not reduce bycatch of harbor seals (Phoca vitulina) in the salmon and sturgeon gillnet fisheries in northern Washington state but do reduce bycatch of harbor porpoise (Phocoena phocoena). Pingers did not affect catch of target species, chinook salmon (Oncorhynchus tshawytscha) and sturgeon (Acipenser sp.).
Field Studies:

Location	Fishing gear	Reduction technique	Bycatch species	Effect on bycatch species	Catch	Effect on target catch	Type
Washington State	Gillnets	Acoustic pingers	Pinnipeds	Did not reduce seal bycatch	Salmon & sturgeon	Did not affect target catch	In the wild
Washington State	Gillnets	Acoustic pingers	Small Cetaceans (maximum length < 7.5 meters)	Reduced harbor porpoise bycatch	Salmon & sturgeon	Did not affect target catch	In the wild