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Postdoctoral researcher is a shark DNA detective

Postdoctoral researcher is a shark DNA detective

March 15, 2022 at 1:34pm

Diego Cardeñosa first chased after a shark when he was 11 years old.

He was on a scuba diving trip with his parents in Providencia, a tiny Colombian island in the Caribbean more than 770 miles away from his home in Bogotá.

The scuba instructor told the group they were supposed to stick together. As soon as Cardeñosa noticed a nurse shark, he chased after it for a closer look.  The instructor raced after him. And since that day, Cardeñosa has never stopped chasing them.

Today, Cardeñosa is a distinguished postdoctoral scholar in FIU’s College of Arts, Sciences & Education. In the past decade, he’s traveled the world trying to learn more about how to protect these important predators. In Bimini, he studied the impacts of habitat loss on the growth and survival rate of juvenile lemon sharks. In Fiji, he searched for critically important shark nursery areas. He even moved to Hong Kong and lived in a 10-square-meters shoebox apartment to work in the hub of the global shark fin trade.

Now, he’s been working with longtime mentor Demian Chapman to continue using DNA detective work to uncover the mysteries of the global shark fin trade. Cardeñosa and Chapman have led some of the most original, groundbreaking research on the fin trade. They genetically analyzed more than 12,000 fin samples — and from that have determined the species most commonly found in markets in Hong Kong and China.

Now comes the next step — using DNA to actually track the fins back to where the sharks were caught. Cardeñosa will be gathering this information, which is crucial for pinpointing where endangered species face the highest risk of overexploitation and possible extinction from illegal fishing practices.

He’s also investigating where smaller shark fins are coming from with support from the ADM Capital Foundation. In Hong Kong, Cardeñosa saw huge volumes of small fins passing through customs. Hundreds of thousands could fit in a single sack. Most of these fins — small enough to fit in the palm of a hand — come from juvenile sharks. Genetically tracking them can pinpoint nursery areas where sharks are in the gravest danger. For Cardeñosa, smaller fins ending up in the trade cannot be ignored. It is especially worrisome because it might mean the proverbial candle is being burnt at both ends — with both adults and juveniles being targeted by the trade.

Cardeñosa’s research findings provide a clearer idea of whether trade regulations are working — specifically, the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). The international agreement protects animals and plants from over-exploitation in international trade. Oftentimes, illegally traded species are still ending up for sale in the markets.

Where there’s a problem, there are also solutions. The issue of illegally traded fins gave Cardeñosa and Chapman an idea. With funding from the Paul G. Allen Family Foundation, they created a portable, easy-to-use DNA testing toolkit that gives customs officials and inspection personnel something they never had before — the power to identify illegal species on-site and have the proof to prosecute crimes.

The tool is already being used with great success. Earlier this year Hong Kong customs officials intercepted an illegal shipment from Ecuador of 26 tons of thresher fins. The team’s DNA toolkit was behind this historic seizure of shark fins.

The tool is also helping detect other illegal trade. When Cardeñosa was living in Hong Kong, officials asked him for a test to detect European eels leading to the first prosecution of European eel smugglers in Hong Kong history. And more recently, Colombian officials also used the tool to stop an illegal shipment of 2,200 Matamata turtles.

Cardeñosa was also a part of another major project — Global FinPrint, the world’s largest reef shark and ray survey. It’s this sheer breadth of research on sharks that has caught the attention of stakeholders across the globe. And also in the one place, Cardeñosa has always wanted to do shark conservation work the most. Back home in Colombia.

After nearly 20 years, Cardeñosa recently returned to Providencia. And yes, he’s still chasing after sharks. This time, though, he’s trying to gather data about the number of sharks living there.

With Colombian officials and stakeholders supporting him, Cardeñosa hopes to launch a sort of mini-Global FinPrint project that would cover Colombia’s Atlantic and Pacific coasts, as well as the remote offshore islands, including Providencia.

“Regardless of the tool — whether it’s using tags to track movements or genetic analysis — I have always been interested in doing science that has a specific goal for conversation,” Cardeñosa said. “I want to share information that can be translated into conservation, directly into policy and management action.”