Acoustic harassment devices reduce seal interaction in the Baltic salmon-trap, net fishery

AHDs with a source level of 179 dB re 1 µPa rms at 1 m were deployed during three consecutive fishing seasons. Fish catches in traps with AHDs were significantly higher than in the controls, while catch damage in the traps with AHDs was lower. However, towards the end of the fishing season catch damage increased in traps with AHDs.
Field Studies:

Location	Fishing gear	Reduction technique	Bycatch species	Effect on bycatch species	Catch	Effect on target catch	Type
Baltic sea	Traps	Acoustic harassment devices	Pinnipeds	Reduced depredation of salmon traps by grey seals (Halichoerus grypus)	Salmon	Increased target catch and reduced seal damage to the catch	In the wild