Global plastics pollution is a major environmental challenge, and we still have limited knowledge of marine microbiota involved in possible remediation. Our research shows that marine Flavobacteria harbor the potential for PET degradation using dienelactone hydrolases (DLHs, EC 3.1.1.45). The widespread distribution of these microorganisms and the notion that these enzymes are secreted may imply a possible role in marine PET remediation.