Current trends in the traceability of geographic origin and detection of species-mislabeling in marine bivalves

Marine bivalves are increasingly consumed worldwide, with their complex supply chain being particularly prone to fraud. This scenario drives economic losses and is a threat to public health, with multiple recent food worries driving consumers to demand more transparency and information on the seafood they buy. To increase consumers confidence in bivalves and enforce current legislation, robust tools are needed to fight species mislabeling and confirm the place of origin of bivalves being traded. The present study provides a critical overview based on a databases search, over the traceability of geographic origin and detection of species-mislabeling in marine bivalves, summarizing the tools currently available to confirm claims on these topics along the supply chain. We also identify current trends on the use of tools, pinpoint which countries contribute to advance the state of the art on these topics, and highlight the bivalve groups/species being more commonly surveyed. The most used tools to expose species mislabeling in marine bivalves are DNA and fatty acid analysis, while elemental analysis is the most commonly employed approach to confirm their geographic origin. Stable and unstable isotope analysis, as well as metabolomics, are also starting to be increasingly used to verify species authenticity and provenance in marine bivalves. Further studies are still needed to identify annual/seasonal variations and determine if these can be a constraint for the optimization of protocols to fight fraudulent practices. The implementation of an open global database to allow realtime data comparison will be paramount to advance the state of the art.