A method of inhibiting biofilm growth on a surface in an aqueous system comprising contacting a surface susceptible to biofilm growth with a solution comprising an amount of a non-decomposed moss or non-decomposed moss extract effective to inhibit biofilm growth. A method of removing biofilm from a surface in an aqueous system comprising contacting a surface having a biofilm with a solution containing an amount of a non-decomposed moss or non-decomposed moss extract effective to remove some or all of the biofilm from the surface.