Despite increasing protection measures, these fish are among the most endangered animals in the world. New tests to detect commercial species, as well as population studies, aim to contribute to their preservation.
The difficult identification of threatened species
Many of the fins look similar, making it difficult to know whether they belong to sharks listed on Appendix II of CITES, the international convention that regulates trade in endangered species. To solve this problem, researchers have developed a genetic test capable of identifying the species from a simple piece of fin, even in a soup or cosmetic product made from shark liver oil.
This method, called “DNA barcoding”, uses short fragments of DNA as molecular markers specific to each species. It thus makes it possible to detect the presence of protected sharks in major world markets, such as Hong Kong.
A portable lab to control illegal trade
To facilitate these checks, researchers have even developed a portable laboratory capable of carrying out these genetic analyzes directly at the ports, in less than 4 hours and for less than 1 dollar per sample. A valuable tool for port authorities, even in low-income countries.
With the recent addition of 60 new shark species to CITES Appendix II, bringing the total to more than 70, even more powerful tools will be needed to identify protected specimens among products in trade. Researchers are already working to adapt their tests to meet this challenge.
Identify key areas for shark conservation
Beyond the detection of illegal trade, genetic analysis also makes it possible to determine the geographical origin of exploited sharks. Crucial information for identifying marine areas that deserve to be protected as a priority.
Marking monitoring and population genetics studies have revealed that at least 31 species of sharks exhibit coastal behavior, remaining faithful to certain geographic areas. These populations could greatly benefit from well-designed marine protected areas and appropriate national legislation.
An ambitious global shark monitoring project
This is the challenge of the Global FinPrint project, the largest global study on coral reef sharks. By deploying baited cameras in more than 400 reefs in 58 countries, researchers were able to compare shark abundance in protected and unprotected areas.
The results are sometimes surprising: despite the poor state of many reefs, certain areas such as the Seaflower biosphere reserve in the Colombian Caribbean are home to a great diversity of sharks, undoubtedly thanks to feeding areas that are inaccessible to fishing boats and compliance with regulations by local communities.
Science for shark protection
Building on these initial results, researchers launched the second phase of Global FinPrint at the end of 2023, with a return planned to 26 countries to assess the effectiveness of marine protected areas for sharks. This data should help states identify key areas for these animals and create new ones.
Scientists say they are cautiously optimistic for the future of sharks globally, provided science, public opinion and legislation – and enforcement – work hand in hand. In the United States, the end of overfishing has already led to a rebound in populations, an example to follow for many countries.
Because preserving sharks is not a luxury: present in our oceans for 400 million years, these fish play a key role in marine ecosystems, from carbon recycling to maintaining seagrass beds. Ensuring their survival is a crucial issue for biodiversity and the balance of the seas.
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