Search The Database
Location | Gear | Catch | Technique | Bycatch species | Type | Results |
---|---|---|---|---|---|---|
United States |
Gillnets
|
Multiple species |
Acoustic deterrent devices
|
Pinnipeds | Field study in the wild | Acoustic alarms reduce bycatch of harbor porpoises (Phocoena phocoena) in the Gulf of Maine sink gillnet fishery. Gillnets with and without acoustic alarms caught similar quantities of target species, cod and pollock. Acoustic alarms did not affect catch of bycaught silver hake, but Atlantic herring was caught less frequently in experimental nets with alarms. Harbour seals depredated fish caught in both nets with and without acoustic alarms. Seals depredated nets with and without pingers |
Washington State |
Trout |
Acoustic deterrent devices
|
Pinnipeds | Field study in the wild | Worked temporarily, then habituation occurred |
|
Gulf of Maine |
Gillnets
|
n/a |
Acoustic deterrent devices
|
Small Cetaceans (maximum length < 7.5 meters), Phocoena phocoena (Harbor porpoise) | Field study in the wild | Gillnets equipped with acoustic pingers caught only one harbor porpoise (Phocoena phocoena) compared to 42 caught in control nets off of New Hampshire, USA. Alarms sounds are above groundfish hearing and are not expected to affect fish catch. |
Washington State |
Gillnets
|
Salmon |
Acoustic deterrent devices
Visual deterrents
|
Seabirds | Field study in the wild | Variable depending on seabird species |
Washington State |
Gillnets
|
Salmon |
Acoustic deterrent devices
Visual deterrents
|
Seabirds | Field study in the wild | Reduced bycatch but results varied by mesh size |
United Kingdom |
Trawls
|
Bass |
Acoustic deterrent devices
|
Small Cetaceans (maximum length < 7.5 meters) | Field study in the wild | Acoustic pingers placed around the mouth of a pair trawl net in the United Kingdom bass pair trawl fishery did not reduce common dolphin (Delphinus delphis) bycatch. Did not reduce bycatch |
United Kingdom |
Trawls
|
Bass |
Acoustic deterrent devices
|
Small Cetaceans (maximum length < 7.5 meters), Phocoena phocoena (Harbor porpoise) | Field study in the wild | Acoustic pingers placed in the rear of a pair trawl net in the United Kingdom bass pair trawl fishery did not reduce bycatch of common dolphins (Delphinus delphis). Multi-monofilament net, placed in the North Sea and West of Scotland gillnet fisheries, had no significant impact on harbour porpoise (Phocoena phocoena) bycatch when compared to traditional monofilament net. Thin twine monofilament nets (.4mm twine diameter, 90 mm mesh size) reduced bycatch of harbour porpoise (Phocoena phocoena) and seals in the North Sea and West of Scotland gillnet fisheries when compared to thick (.6mm twine diameter, 267 mm mesh size) monofilament nets. Barium sulphate nets had higher bycatch of harbour porpoise (Phocoena phocoena) and seals in the North Sea and West of Scotland gillnet fisheries when compared to traditional gillnets. |
Sweden |
Gillnets
|
Cod and pollock |
Acoustic deterrent devices
|
Small Cetaceans (maximum length < 7.5 meters), Phocoena phocoena (Harbor porpoise) | Field study in the wild | No bycatch in nets with or without pingers |
California |
Gillnets
|
swordfish and sharks |
Acoustic deterrent devices
|
Small Cetaceans (maximum length < 7.5 meters) | Field study in the wild | Acoustic pingers reduced bycatch of beaked whales to zero in the California drift gill net fishery. |
Brazil |
Gillnets
|
Acoustic deterrent devices
|
Small Cetaceans (maximum length < 7.5 meters) | Field study in the wild | Underwater acoustic pingers were tested in Brazil to evaluate the behavioral responses of tucuxi (Sotalia fluviatilis). Five pingers were evenly placed on a floating 100 m line set along the dolphins' swimming parth in and out of sheltered waters. Dolphin sighting frequencies were recorded for functional and dummy pingers and control trials. Dolphin sightings were significantly lower in areas where the pinger line was set. Sighting frequency was significantly lower with active pingers than in dummy or control trials, but there wre no significant differences between the dummy and control trials. Preliminary results suggest that acoustic pingers attached to gillnets may be used to successfully prevent tucuxi bycatch. |