Fishy labels caught by DNA

In a shipment of tuna, the labels said one thing but DNA told a different story. To get answers, federal agents turned to FIU’s Diego Cardeñosa.

The shark conservation biologist traveled to Los Angeles to help officers with the NOAA Fisheries Office of Law Enforcement master portable DNA testing technologies — fast, accurate genetic tools designed to crack down on illegal trade. What Cardeñosa and the team found was troubling — a widespread mislabeling of imported big eye, yellow fin, blue fin and albacore tuna. This deceptive practice can hide illegal fishing, mislead consumers and threaten protected populations.

“We conducted real-world inspections to test the tool in real cases with great results,” Cardeñosa said. “During the week-long trial, the officers are trained in DNA extractions and running the PCR to identify these species.”

Working at both the Port of Long Beach and Los Angeles International Airport, officers also identified fish filets mistakenly labeled as protected species. The team used the portable DNA kit to confirm the imported species was not endangered but mislabeled. That meant no unnecessary delays and no risk of law enforcement action under the Endangered Species Act. 

During the pilot and training operation, the team inspected and sampled eight imports of fresh and frozen shark and tuna meat. In addition to the false labeling of tuna, they identified shark species listed in the Annexes of the Convention on the International Trade in Endangered Species.

The collaboration with NOAA is part of an ongoing partnership to implement real-time, field-ready forensic science at key inspection points across the country. It builds on successful work last year, when Cardeñosa and agents in New Jersey conducted targeted inspections and uncovered illegal eel shipments. These efforts demonstrate the power of DNA detection as an enforcement tool — not just a research method. Cardeñosa conducts his research as part of FIU’s Institute of Environment and Global Forensic and Justice Center.