Updated publication reference for PubMed record(s): 30113852. It is often necessary to demonstrate measurement capabilities in fields not already using state of the art bioanalytical platforms in order to encourage metrological modernization and adoption of such technologies. Marine mammal proteomics is a burgeoning field with diverse stakeholders and rapid investment in *omic platforms (e.g., genome sequencing). Previous marine mammal proteomic studies have focused on tissues and biofluids such as plasma, serum and cerebrospinal fluid. Despite its utility in human research, to date there has not been a comprehensive proteomic analysis of marine mammal urine. Using best practice sample collection, a retrospective urine sample set was generated. These results serve as a proof of principle for development of assays in other species.