The invention relates to a trawl (1) for collecting materials such as green algae, hydrocarbons, and other large waste polluting the sea or a river, comprising a filtering bag (2) for confining said materials, said bag (2) comprising an opening means (3, 4) allowing the bag to open once placed in the water with a front opening located in a plane perpendicular to the water surface, and a means for pulling and raising (5) the bag (2) loaded with collected materials, which is connected to said opening means (3, 4) and comprises a member for linking to at least one warp (8) of a crane mounted on a trawler boat (1).
