Sea cucumbers in the shadows: molecular analysis of illegal trade in Brazil

Abstract The illegal trade of sea cucumbers is widespread, driven by high international demand, particularly in Asia, where they are valued as culinary delicacies and for use in traditional medicine. Although domestic consumption in Brazil is limited, illegal harvesting for export is a growing concern, with unregulated fisheries posing a threat to local populations. In 2023, the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA) seized dried sea cucumber specimens at Guarulhos International Airport. Using DNA barcoding with the Cytochrome C Oxidase I (COI) gene, we identified 40 specimens as Holothuria grisea and Isostichopus badionotus. Although both species are currently listed as “Least Concern” by the IUCN, the unregulated nature of this trade raises concerns about potential overexploitation, especially given the ecosystems they inhabit are increasingly vulnerable to habitat degradation and unsustainable practices. Additionally, the absence of H. grisea sequences in public genetic databases required us to collect fresh specimens to complete the analysis, underscoring the need for expanded molecular repositories. Our findings highlight the effectiveness of molecular tools in identifying illegally traded species, even in degraded forms, and emphasize the importance of stricter monitoring to protect biodiversity.