A meta-review of DNA-based identification methods and mislabeling analysis of Eastern South Pacific seafood

The Eastern South Pacific Ocean is a nutrient-rich and highly diverse region that plays a pivotal role in the global seafood trade. Despite its importance, the seafood industry in this region is hindered by complex supply chains and insufficient regulation frameworks, which facilitate illegal practices, including mislabeling. DNA-based methods have emerged as essential tools for seafood authentication, helping to mitigate mislabeling and supporting conservation strategies. This study provides the first comprehensive review of DNA-based methods used globally to identify seafood species from the Eastern South Pacific Ocean. Historical and current techniques were systematically examined, with a focus on emerging technologies that offer promising applications in the field. Nearly three decades of research have enabled the successful identification of over 200 commercially valuable species using more than ten distinct DNA-based methods. Fish and mollusks constituted the most extensively studied seafood groups, with DNA sequencing emerging as the predominant technique. Furthermore, a global mislabeling meta-analysis, encompassing 1,806 seafood products from the Eastern South Pacific Ocean, revealed an estimated mislabeling rate of 24.8% (95% CI [22.9-26.9]). Notably, a substantial proportion of mislabeled and substituted products corresponds to highly threatened shark species. This raises serious conservation concerns, particularly given that nations bordering the Eastern South Pacific Ocean are major players in the global shark trade. Overall, the findings of this review underscore the urgent need to integrate advanced DNA-based techniques into existing regulatory frameworks. They also establish a solid foundation for developing targeted policies and encouraging collaborative efforts among nations in this region.