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 561

Study Type: 

wild

Location: 

Baltic

Target catch: 

None reported

Effect on bycatch species: 

Pingers significantly reduced echolocation encounter rates by 50-100% at 500m; sighting reduced up to 375m. Porpoise return time was 6 hrs when pingers were silent after being active for 24 hrs 50 min

Effect on target catch: 

None reported

Article: 

Bycatch species: 

Reduction technique: 

Fishing Gear: 

Field Study 311

Study Type: 

wild

Location: 

North Sea

Target catch: 

Cod

Effect on bycatch species: 

Reduced catch rates from 0.00229 and 0.00295 for nets with dummy pingers and no pingers respectively, to 0.00015 for nets with active pingers

Effect on target catch: 

None reported

Article: 

Bycatch species: 

Reduction technique: 

Fishing Gear: 

ant

Study Type: 

wild

Location: 

Turkey

Target catch: 

turbot fish

Effect on bycatch species: 

Reduced harbor porpoise interactions with gillnet

Effect on target catch: 

Use of pingers did not signficiantly affect catch rates or size of fish caught

Article: 

Bycatch species: 

Reduction technique: 

Fishing Gear: 

Study Type: 

wild

Location: 

North Carolina, USA

Target catch: 

Mixed

Effect on bycatch species: 

No difference on group size or closest approach to the net between active and control pingers

Effect on target catch: 

None

Article: 

Bycatch species: 

Reduction technique: 

Fishing Gear: 

Study Type: 

wild

Location: 

Mediterranean, Balearic Islands

Target catch: 

Red mullet

Effect on bycatch species: 

Reduced bottlenose dolphin (Tursiops truncatus) depredation

Effect on target catch: 

Increased target catch and reduced dolphin damage to the catch

Article: 

Bycatch species: 

Reduction technique: 

Fishing Gear: 

Study Type: 

wild

Location: 

Balearic Islands, Mediterranean Sea

Target catch: 

Mixed species

Effect on bycatch species: 

49% reduction in depredation rate by bottlenose dolphins (Tursiops truncatus)

Effect on target catch: 

Increased target catch (but not significant)

Article: 

Bycatch species: 

Reduction technique: 

Fishing Gear: 

Effects of pingers on the behaviour of bottlenose dolphins

Study Type: 

wild

Location: 

Shannon Estuary, Ireland

Target catch: 

not applicable

Effect on bycatch species: 

Change in behaviour of bottlenose dolphins (Tursiops truncatus) in boat based trials.

Effect on target catch: 

not applicable

Article: 

Reduction technique: 

Bycatch species: 

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