Researchers Aim to Take a Bite Out of Illegal Fish Trade

To improve identification, the researchers focused on a technique called high-resolution melt analysis, which involves collecting DNA from a sample, amplifying a specific section of the genetic code, and then applying heat to measure the rate at which the DNA melts over time. The technique can be used as a relatively quick and simple way to spot genetic differences between samples.

After building a library of melting data from 669 known fish samples, the researchers used machine learning to create a model that could compare unidentified samples to the library data. They tested their process using frozen, dried, preserved, processed, and cooked fish samples. The assay, they say, cost about $1.50 per sample, took about two hours to complete using simple equipment that could be installed at ports and other border facilities, and was 99.2% accurate. 

In addition to Lee and Cardeñosa, the paper’s authors were Zhuang Luo, MS ’25; Associate Professor DeEtta Mills, Emma Aitken, and Maria A. Herrera, all of FIU; John Carlson of the National Marine Fisheries Service; and Gavin Naylor of the Florida Museum of Natural History at the University of Florida, Gainesville.

Lee has previously researched the spread of phony and malicious online information, and he has worked with Renata Konrad, professor in The Business School, to understand how technologies and tools might be used to combat illegal wildlife trafficking. Threats to endangered sharks and rays are particularly urgent. 

Sharks and rays have been consumed as food for centuries, notably in Asia. Some Indian communities consider consumption of milk sharks beneficial to pregnant and lactating women. Shark fins are used in traditional Chinese medicine and shark fin soup. However, overfishing has diminished wild populations and endangered many species. 

Lee says the researchers hope their technology can be shared with law enforcement and developed to assist with anti-trafficking efforts focused on other species. The group also plans to work on technologies that can monitor social networks and e-commerce sites for suspicious trade activity. Other parts of the project will involve identifying trafficking routes and determining actions that will disrupt networks.

“This collaboration brings together researchers with unique skills and resources,” Lee says. “Together we’re trying to use our expertise to make a positive impact for social good on an important global problem, which is the illegal and destructive trafficking of wildlife.”