Sharks in hot soup: DNA barcoding of shark species traded in Singapore

Sharks are apex predators that play important roles in marine ecosystems, yet many species of shark are facing significant conservation challenges. Globally, shark populations have declined by as much as 90 % in the past 50 years, largely a consequence of overfishing to support a growing demand for shark products. Numerous regulations implemented by international trade and conservation bodies have been established in efforts to prevent further population declines, but, the misidentification of dried and processed fins along with the deliberate act of finning prevents the effective enforcement of established regulations and conservation framework. In this study, we use DNA barcoding to identify shark species from a variety of shark products collected across Singapore. We amplified a fragment of the mitochondrial cytochrome c oxidase subunit I (COI) gene from processed shark products. DNA barcoding of 296 tissue samples resulted in the identification of 16 different species, 2 of which are listed under CITES Appendix II, and 6 species were classified as either - Critically Endangered, Endangered, or Vulnerable on the International Union for Conservation of Nature Red List.

Automated summary

Shark populations have declined by as much as 90% in the past 50 years due to overfishing to support demand for shark products. Despite regulations established by international bodies, misidentification of dried fins and finning prevent effective enforcement. This study used DNA barcoding to identify 16 different shark species from products collected in Singapore, with some species listed as endangered on conservation lists.