Fast Solutions for an Urgent Problem: Genetic Identification for the Protection of Sharks and Rays
A new scientific paper describes how protecting shark and ray populations from the black-market wildlife trade can begin with DNA analysis.
School of Scalloped Hammerhead Sharks (Sphyrna lewini), off Cocos Island in Costa Rica, is one of the species with the most molecular resources available. Credit: Erika Beux.
Rapid genetic testing is emerging as a powerful ally in monitoring and protecting shark and ray populations from the black-market wildlife trade. By analyzing DNA collected either directly from animals or as environmental DNA (eDNA) floating in seawater, scientists can quickly and accurately identify species. A new study in Molecular Ecology Resources, led by researchers from the United States, Brazil and Portugal, highlights just how transformative these methods can be.
“Advances in genetic methods now let us confirm the identity of threatened species faster and more reliably than ever before—a critical boost for enforcement and conservation,” said Ingrid Bunholi, the study’s first author and a doctoral researcher at the University of Texas Marine Science Institute. “These tools give environmental authorities and scientists timely, accurate data essential for protecting vulnerable shark and ray species.”
Reviewing research from 2000 to 2025, the team examined several studies that tested and applied ten rapid molecular techniques, including multiplex PCR, qPCR, ddPCR, and LAMP. These approaches are invaluable for tackling illegal wildlife trade and tracking population trends. Because these techniques pinpoint species-specific genetic signatures without the need for full sequencing, they significantly cut costs and speed up results for enforcement agencies, conservation managers, and researchers.
The study identifies multiplex PCR as the primary rapid method employed to address illegal wildlife trade, while qPCR has been widely applied in eDNA monitoring. To support broader understanding and application, the authors provide a comprehensive summary table detailing each technique’s practical uses, advantages, and limitations, offering a valuable reference for both specialists and the general public.
Author Ingrid Bunholi, UTMSI Ph.D. graduate student, prepares to take a takes a water sample with an eDNA filtration backpack sampler from Packery Channel in Corpus Christi, Texas. Credit: Christina Marconi
Pilot projects have already demonstrated the promise of these tools for identifying threatened species in fish markets and mapping populations in marine ecosystems. To support practical use, the article’s supplementary material directs readers to resources from multiple species, including lists of primers, enzymes, and equipment. Researchers can select the right technique, source materials, and implement testing directly in their labs. Beyond the paper itself, the team is preparing an e-book for release in 2025 to guide practitioners, which will serve as a straightforward guide for those who need to use genetic tools for species identification. These materials will explain what rapid molecular tools are and how to apply them effectively, making them more accessible.
However, the current study stresses that challenges remain: standardized testing protocols are still lacking, and global genetic reference databases need to be more robust because a lot of threatened species still lack information.
The analysis also reveals geographic gaps. The United States accounts for 32 percent of the studies, positioning it as the frontrunner, while Brazil follows with 19 percent. Yet much of Brazil’s work still focuses on tissue-based DNA, leaving eDNA largely unexplored. Meanwhile, major shark-trading nations such as China and Indonesia show little scientific output in developing rapid ID technologies.
Marcela Alvarenga, the project’s other first author and a researcher at the University of Porto, said the idea grew from a simple question by an environmental officer about whether quick genetic identification resources existed.
“We responded by compiling a comprehensive guide to rapid molecular tools and resources for developing new methods, which we hope will be a game-changer for conservation professionals,” she noted.
The research was supported by The University of Texas Marine Science Institute, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Fundação de Ciência e Tecnologia (FCT), Portugal, Fundação de Amparo à Pesquisa do Estado de São Paulo, Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico, Swiss National Science Foundation, Save Our Seas Foundation, and Fulbright Brazil.
In addition to the first authors, coauthors of the work were Aisni Adachi, Marcelo Cruz, Leonardo Feitosa, Eduarda de Jesus, Maria Eduarda Lopes, Cintia Povill, Daniela Souza, Yan Torres, Antonio Solé-Cava, Rodrigo Domin
