A geosynthetic mat comprises an upper and a lower cover layer and a middle filler layer arranged between the upper cover layer and the lower cover layer and consisting of a filler layer material comprising a swellable material. The top cover layer and/or the bottom cover layer consist of a biodegradable material or comprise a biodegradable material, the peel strength being characterised by a residual peel strength degree at a predetermined point in time after the start of the biodegradation process, which is formed by the square number of a quotient of a reduced peel strength, which the upper and lower cover layer and a connecting structure have at the predetermined point in time, to an initial peel strength, which the upper and lower cover layer and the connecting structure have before the start of a biodegradation process.