Search The Database

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 (Gadus morhua), pollock (Pollachius virens), haddock (Melanogrammus aeglefinus), and spiny dogfish (Squalus acanthias), 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.

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.

Composite-panel codend netting decreased catch of non-target species, including commercially important whiting (Sillago sp.), while increasing catches of target oceanic prawns (Penaeus plebejus) in the New South Wales, Australia prawn-trawl fishery . Increases in retained octopus and red mullet (Upeneichthys vlamingii) and discarded eastern blue spot flathead (Platycephalus caeruleopunctatus), likely due to their large size, were also observed. 

A Nordmøre sorting grid, which has been required in the U.S. 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. Overall catch rates of shrimp increased, largely driven by higher catch of larger-sized shrimp.

An excluder device, tested in the United Kingdom bass (Dicentrarchus labrax) pair trawl fishery, did not reduce bycatch of common dolphins (Delphinus delphis).

Acoustic pingers placed around the mouth of a pair trawl net in the United Kingdom bass (Dicentrarchus labrax) pair trawl fishery did not reduce common dolphin (Delphinus delphis) bycatch.

Acoustic pingers placed in the rear of a pair trawl net in the United Kingdom bass (Dicentrarchus labrax) 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.

Acoustic pingers placed in the rear of a pair trawl net in the United Kingdom bass (Dicentrarchus labrax) 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.

Acoustic pingers placed in the rear of a pair trawl net in the United Kingdom bass (Dicentrarchus labrax) 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.

Acoustic pingers placed in the rear of a pair trawl net in the United Kingdom bass (Dicentrarchus labrax) 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.