Pair trawling is a fishing activity carried out by two boats, with one towing each

warp Warp, warped or warping may refer to: Arts and entertainment Books and comics * WaRP Graphics, an alternative comics publisher * ''Warp'' (First Comics), comic book series published by First Comics based on the play ''Warp!'' * Warp (comics), a ...

(the towing cables). As the mouth of the

net Net or net may refer to: Mathematics and physics * Net (mathematics), a filter-like topological generalization of a sequence * Net, a linear system of divisors of dimension 2 * Net (polyhedron), an arrangement of polygons that can be folded up ...

is kept open by the lateral pull of the individual vessels, otter boards are not required. With the towing power of two boats and no otter boards, a larger net may be worked than would otherwise be possible, or alternatively, the two boats can share increased

fuel efficiency Fuel efficiency is a form of thermal efficiency, meaning the ratio of effort to result of a process that converts chemical potential energy contained in a carrier (fuel) into kinetic energy or work. Overall fuel efficiency may vary per device, wh ...

. As doors are not necessary, the gear arrangements are simplified, with the warps attaching directly to the wings of the net. Setting and hauling of the nets are carried out by one boat, while the other is only used for towing; usually each will take turns at these operations. Pair trawling is effective on all demersal species. In shallow waters, where the noise from a single vessel may scatter fish, two vessels operating a distance apart tend to herd fish into the path of the net. Catch per vessel often considerably exceeds that attainable through standard

bottom trawling Bottom trawling is trawling (towing a trawl, which is a fishing net) along the seafloor. It is also referred to as "dragging". The scientific community divides bottom trawling into benthic trawling and demersal trawling. Benthic trawling is towin ...

. Pair trawlers targeting

cod Cod is the common name for the demersal fish genus '' Gadus'', belonging to the family Gadidae. Cod is also used as part of the common name for a number of other fish species, and one species that belongs to genus ''Gadus'' is commonly not call ...

off the coast of

New England New England is a region comprising six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York to the west and by the Canadian provinces ...

have reported average per vessel catches of three to six times that from single trawls. Because of the increased efficiency of pair trawling, vessels are able to tow their gears in mid-water at a faster speed to target species which are normally able to escape trawl nets, such as the

European seabass The European bass (''Dicentrarchus labrax'') is a primarily ocean-going fish native to the waters off Europe's western and southern and Africa's northern coasts, though it can also be found in shallow coastal waters and river mouths during the su ...

. This has caused some controversy, due to the high level of

marine mammal Marine mammals are aquatic mammals that rely on the ocean and other marine ecosystems for their existence. They include animals such as seals, whales, manatees, sea otters and polar bears. They are an informal group, unified only by their reli ...

bycatch Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juve ...

associated, leading to the

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introducing a ban on pair trawling for bass in UK

territorial waters The term territorial waters is sometimes used informally to refer to any area of water over which a sovereign state has jurisdiction, including internal waters, the territorial sea, the contiguous zone, the exclusive economic zone, and potenti ...

.The South-west Territorial Waters (Prohibition of Pair Trawling) (Amendment) Order 2005

References

* Thomson, David: Pair trawling and pair seining. The technology of two-boat fishing. Farnham: Fishing News Books, 1978 {{fisheries and fishing Fishing industry