Search The Database
Location | Gear | Catch | Technique | Bycatch species | Type | Results |
---|---|---|---|---|---|---|
Canada |
Gillnets
|
Multiple species |
Metal oxide/barium sulfate nets
|
Seabirds | Field study in the wild | Metal oxide nets containing barium sulphate (that increased their acoustic reflectivity and probably also their stiffness) reduced the bycatch of harbor porpoise (Phocoena phocoena) in an eastern Canada demersal gillnet fishery. No difference in catch of commercial fish species, including cod, pollock, haddock, and spiny dogfish, was observed between the nylon and barium sulphate nets. Metal oxide nets reduced the bycatch of greater shearwater (Puffinus gravis) in an eastern Canada demersal gillnet fishery, probably by increasing the visibility of the blue-dyed nets to the birds. |
Captivity |
Gillnets
|
Trout |
Metal oxide/barium sulfate nets
|
Small Cetaceans (maximum length < 7.5 meters), Phocoena phocoena (Harbor porpoise) | Field study in the wild | Metal oxide nets made from barium sulphate increased the detectability of gillnets by marine mammals when compared to nylon nets when approached at angles of incidence greater than normal incidence but less than 40 degrees. Hypothesized detection ranges indicate bottlenose dolphins (Tursiops truncatus) should be able to detect metal oxide nets in time to avoid entanglement, but harbor porpoise (Phocoena phocoena) may not be able to detect either net in time to avoid contact. |
Australia |
Trawls
|
shrimp |
Excluder devices
|
Bony Fishes | Field study in the wild | Composite-panel codend netting decreased catch of non-target species, including commercially important whiting, while increasing catches of prawns in the NSW, Australia oceanic prawn-trawl fishery. Increases in retained octopus and red mullet and discarded eastern blue spot flathead (probably due to their large size) were observed. |
Gulf of Maine |
Trawls
|
shrimp | Bony Fishes | Field study in the wild | A Nordmore sorting grid, which has been required in the Gulf of Maine Northern shrimp (Pandalus borealis) trawl fishery since 1992, was found to decrease bycatch of 8 groundfish species when observed tows before and after the grate requirement were compared. Catch rates of shrimp increased possibly due to higher catch rates of large shrimp. | |
United Kingdom |
Trawls
|
Bass |
Excluder devices
|
Small Cetaceans (maximum length < 7.5 meters) | Field study in the wild | An excluder device, tested in the United Kingdom bass pair trawl fishery, did not reduce bycatch of common dolphins (Delphinus delphis). |
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. |
Scotland |
Gillnets
|
Trout |
Thin twine nets
|
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. |
Scotland |
Gillnets
|
Trout |
Thin twine nets
|
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. |
Scotland |
Gillnets
|
Scallop |
Thin twine nets
|
Pinnipeds | 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. |