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Midwater trawlsIt is a composed image (midwater otter trawls and midwater pair trawls)
Midwater trawls
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Characteristics
OverviewA midwater trawl consists of a cone shaped body, normally made of four panels, ending in a codend with lateral wings extending forward from the opening. It is usually much larger than a bottom trawl and designed and rigged to fish in midwater, including in the surface water. The front parts are sometimes made with very large meshes or ropes, which herd the targeted fish inwards so that they can be overtaken by smaller meshes in the aft trawl sections. The horizontal opening is maintained either by otter boards or by towing the net by two boats (pair trawling). Floats on the headline and weights on the groundline often maintain the vertical opening. Modern large midwater trawls, however, are rigged in such a way that floats are not required, relying on downward forces from weights to keep the vertical opening during fishing.Accessory EquipmentA sonar is useful tool to detect fish concentration ahead the trawler and the trawl path and trawl depth can be adjusted accordingly. The fishing depth and the trawl is usually controlled by means of a netsounder (netsonde) or depth recorder.Handling EquipmentTrawl winches installed on deck control the trawling wires and store them when not in use. Gilson winches and lifting tackle are provided to assist with handling gear at the vessel. Net drums are common tools to handle midwater trawls onboard vessels.Vessel OverviewThis type of Trawl nets may be towed by a single or two Trawlers (pair trawling).Fish OperationMidwater trawls are rigged to fish in midwater, from the surface to great depth depending on the position of the fish. It may be towed by one or two boats.Target SpeciesPelagic species, sometimes some demersal fish.Water Area OverviewAll over the world.Gear EnvironmentMidwater trawling is carried out mainly at sea, on the continental shelf, sometimes in deeper waters as well as in some lakes.ImpactsEnvironmental No impact on bottom habitats and bottom structures.Species In most cases it is a single species fishery, bycatch rates of other species are low. Incidental catch of dolphins and marine mammals may occur in some areas.
 
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