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.).