Underwater sound-emitting devices (maximum level of intensity equivalent to approximately 175 dB re 1 µPa @ 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 (±2) kHz at 132 (±4) dB re 1 µPa @ 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).
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Black-browed albatross
The Endangered black-browed albatross is threatened throughout its range by commercial fisheries bycatch, primarily from longline vessels. Its vulnerability is due to the fact that, like other albatross species,…