Options to mitigate bottom habitat impact of dragged gears / Valdemarsen, John Willy J��rgensen, Terje Eng���as, Arill Trawls and trawling Dredging (Fisheries) Aquatic habitats Aquatic ecology 639 FOO 2007 A050 Or. Rome : Food and Agriculture Organization of the United Nations, c2007 c2007 Text xii, 29 p. : FAO fisheries technical paper,