The invention relates to a polymer composition comprising a biologically degradable polymer and a material from sea plants and/or shells of sea animals or at least two components selected from the group consisting of saccharides and the derivatives thereof, proteins, amino acids, vitamins and metal ions. The invention additionally relates to a molded article comprising said polymer composition. Said molded article may be used packaging material or fibrous material, in the form of fibrous material as mixing component for the production of yarns, and in the form of fibrous material for the production of nonwoven fabrics or woven fabrics.