Molecular identification of shark meat sold in Ecuadorian markets labelled under different names

Abstract

Shark populations worldwide are declining rapidly, primarily due to overfishing, habitat degradation, and mislabeling of seafood products, which exacerbates their exploitation and conservation challenges. This study investigates the presence of shark meat being sold under false labels as fish species in Ecuadorian markets, spanning both coastal and highland regions. Using primers derived from the nuclear ribosomal ITS2 region for molecular identification, 97 samples sold as fish meat in Ecuadorian markets were analyzed for the presence or absence of shark DNA. The results revealed that 47.42% of the samples corresponded to shark meat. These samples came from cities in the highlands (Ambato, Cuenca, Ibarra and Quito). No shark meat was identified in the samples from coastal cities (Guayaquil and Manta). Four shark species were identified: Alopias pelagicus (Endangered), Carcharhinus falciformis (Vulnerable), Sphyrna zygaena (Vulnerable), and Prionace glauca (Near Threatened). These findings highlight the ongoing sale of threatened shark species under misleading labels in the highlands region of Ecuador, posing significant risks to marine biodiversity and consumer rights. The study underscores the need for robust traceability systems, routine monitoring, and public education to combat seafood fraud and support shark conservation efforts.