Across multiple species of oceanic fungi, multi-omics analyses identified esterases, cutinases, and laccase-like enzymes that cut polyurethane polymer chains into smaller chemical fragments, producing measurable mass loss and visible surface erosion of plastic films within weeks, alongside a surge of breakdown products detected by metabolomics. The findings indicate ocean fungi possess complete biochemical toolkits for true plastic digestion, not mere colonization, and point to realistic fungal-enzyme strategies for large-scale marine plastic bioremediation.