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Summary:

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.

Summary: Passive acoustic deterrents increased avoidance actions of bottlenose dolphins (Tursiops truncatus) to barriers simulating surface-set gillnets in the Moray Firth, Scotland.

Summary:

Preliminary tests of a quick-release metal wire added to the king mackerel (Scomberomorus cavalla) troll fishery in Florida (United States) reduced depredation of catch by bottlenose dolphin (Tursiops truncatus). There was no impact on king mackerel catch.

Summary:

An excluder device, tested in the United Kingdom bass (Dicentrarchus labrax), pair trawl fishery, reduced bycatch of common dolphins (Delphinus delphis). There was a negligible loss of target fish (<1%).

Summary:

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.

Summary:

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.

Summary:

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

Summary:

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.

Summary:

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.

Summary:

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.