Acoustic pingers

Underwater sound-emitting devices (maximum level of intensity equivalent to approximately 175 dB re 1 &micro;Pa @ 1m) attached to fishing gear, principally gillnets. [Under NOAA's Harbor Porpoise Take Reduction Plan for the Gulf of Maine, the sound output intensity for pingers is stipulated as 10 (&plusmn;2) kHz at 132 (&plusmn;4) dB re 1 &micro;Pa @ 1m (NMFS/NOAA, 1998)]. Pingers are now mandated for use in some fisheries in the U.S. Northwest Atlantic, California driftnet, and in Europe. The sound of these devices is believed to alert an animal to the presence of the net and thus decrease the probability of entanglement. Although some studies have shown that pingers can have the unintended consequence of attracting pinnipeds to fishing operations (Bordino et al., 2002), this may be controllable by raising the emitted frequency of the pingers above seal hearing (Kraus et al., 1997). <br />

Field Study 123

Study Type: 

wild

Location: 

Argentina

Target catch: 

Sea trout, croaker, letherjack, Patagonian smooth hound

Effect on bycatch species: 

Increased interactions between gear and sea lions

Effect on target catch: 

No effect

Article: 

Bycatch species: 

Reduction technique: 

Fishing Gear: 

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