A brand new study involving ElasmOcean shows how it is done:
In December 2017, 3,049 kg of shark fins were intercepted in transit at Frankfurt Airport. According to the customs declaration, these consisted of sandbar sharks (Carcharhinus plumbeus), but closer analysis of just eight fins led to the identification of three CITES-listed species. CITES, the Convention on International Trade in Endangered Species, mandates that trade in species listed in Appendix II must be monitored.
Following painstaking efforts, 405 kg of these fins were confiscated and sent to the Zoologische Staatssammlung München for analysis.
When morphological assessment using identification keys is no longer sufficient, scientists turn to a method known as "barcoding". In this genetic method, a section of the DNA is sequenced to determine the species. Certain regions in an animal's genome are species-specific, meaning they do not vary fundamentally between individuals, but only between different species. These genes are used as "markers", much like a barcode at a supermarket checkout. Using standard PCR procedures, these are selectively extracted from the genome and replicated millions of times so that they can subsequently be read by a sequencing machine.
This produces a long sequence of A, T, C, G—the nucleobases. Where to go from there?
Over years of global genetic research, the NCBI database, known as Genbank, has been established, containing hundreds of millions of gene sequences for comparison—ranging from viruses and bacteria to plants and animals—including 215,000,000 for animals alone! The BLAST algorithm can search these database entries for a specific query sequence and filters out anything that appears nearly identical. This is highly practical, as the data acquired from the shark fins can now be compared with that in the database.
In this way, the Munich-based scientists established that a random sample of 115 fins contained 11 different species of shark, including scalloped hammerhead, smooth hammerhead, great hammerhead, and silky sharks—the trade of which should be regulated under CITES rules.
Most of these identified shark species are classified as Vulnerable, Endangered, or Critically Endangered on the IUCN Red List. However, the numerous international agreements in place have failed to protect them.
The traders, meanwhile, face a maximum Bußgeld of €50,000—a minor penalty compared to an estimated market value in excess of one million Euros.
Studies like this demonstrate once again that even the most comprehensive trade agreements remain ineffective if they are not implemented and enforced. Fishing prohibitions for threatened species are of no benefit to depleting marine ecosystems if identifying the catches is a bureaucratic impossibility.
Two years of genetic forensic work demonstrate that it is time for a more effective monitoring mechanism.
For this reason, ElasmOcean supports the "Stop Finning" initiative. Opportunities to sign the initiative and further information are available at: www.stop-finning.eu
Source:
M. Villate-Moreno et al. (2021): Molecular analyses of confiscated shark fins reveal shortcomings of CITES implementations in Germany. Conservation Science and Practice. https://doi.org/10.1111/csp2.398
