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These are gears which are dragged along the bottom to catch shellfish. They consist of a mouth frame to which a holding bag constructed of metal rings or meshes is attached. There are two main type of dredges; heavy dredges towed by boats (boat dredges), and lighter ones operated by hand in shallow waters (hand dredges).Geartype Handling EquipFor operating dredges from boats derricks and winches are used to shoot and haul the dredges. Hand dredges are handled without any specific equipment.Vesseltype OverviewThe Dredgers are medium to large vessels ( maximum 4-50 m long) and in general with powerful engines. Some larger dredgers are outrigger type with strong outrigger boom allowing the operation of two or more dredges at the same time.Fish OperationThe dredges are gears which are dragged along the bottom. They scrape up American sea scallop and other shellfish from the sea bed. One or more dredges can be used at the same time. At industrial scale up to 10 dredges can be mounted side by side on a beam which is towed from a unique warp.Target SpeciesDredges are employed usually to collect shellfish and molluscs such as mussels, oysters, scallops, clams, etc.Water Area OverviewAll over the world.Geartype EnvironDredges are generally operated not too far from the coastline always in "hard" contact with the bottom in both inland and in marine waters. Dredges might also be used for harvesting sea bed farmed mussels.ImpactsSpecies Impact EntryA dredge may give rise to various degree of impacts to the sea floor and the benthic organisms living there.
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