The researchers found that multiple protected species exist in shark products publicly sold in Singapore. These species are either listed in the appendix to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) or on the IUCN Red List of Threatened Species.
During August 2020, researchers purchased 296 shark products, including sun-dried shark fins, frozen shark fins, and shark bones, at traditional Chinese medicine stores in Singapore, as well as seafood stores. They then extracted DNA information from these shark products to biologically classify them.
The researchers successfully extracted DNA information from 271 shark products and classified them. The remaining 25 samples either did not have DNA information extracted or failed to amplify their DNA fragments.
Of the 271 shark products that were classified, 16 species belonged to 16 species in 12 genera, of which 2 shark species (including 17 shark products) were listed in CITES Appendix II, 2 shark species (including 23 shark products) were classified as "critically endangered" (CR), 2 shark species (including 4 shark products) were classified as "endangered" (EN), and 2 shark species (including 5 shark products) were classified as "vulnerable" (VU). Four shark species (including 47 shark products) were classified as "Near Threatened" (NT) and 2 shark species (containing 14 shark products) were classified as "data-deficient" (DD).
The sphyrna lewini (CITES Appendix II) is the second most common protected shark species in this batch of shark products and is one of the top four species in the global shark fin trade. It is widely present in shark fin trade products, raising suspicions that fishermen may be consciously fishing for it. The researchers call for further research to confirm whether this guess is correct or not. Once the speculation has been confirmed, it is necessary to establish a marine protected area in the breeding area of the Luxe hammerhead shark to avoid further population reduction.
This is the first study to date to use DNA technology to biologically classify publicly available shark products. Often, it is difficult to obtain biological classification information from shark products that have undergone multiple treatments, which undoubtedly makes it difficult for countries to regulate the trade in wild species. The researchers hope that the new study will provide new tools for future regulation.