As silky sharks decline, Costa Rica’s dominant trade faces a reckoning

Inside an inspection facility in Hong Kong in 2018, shark biologist Diego Cardeñosa stared at dozens of large white bags. They were stacked, sometimes six or seven high, beneath strip lights hanging from the ceiling. Each bag weighed more than 50 kilograms (110 pounds) — and was stuffed with shark fins. “It was the first time I saw that,” Cardeñosa wrote in an email to Mongabay. “Obviously, as a student, it was a shock and [a] reality check for me.” Cardeñosa, now a shark trade researcher at Florida International University in the U.S., lived in Hong Kong in 2018 and returned repeatedly from 2015 to 2020 as part of his PhD field research at Stony Brook University, also in the U.S. He helped train law enforcement in Hong Kong to use a mobile DNA kit to identify shark species whose trade is regulated under CITES, a treaty signed by 184 countries and the European Union that establishes rules for international trade in imperiled plants, wildlife, and their products. Many of the fins Cardeñosa saw in Hong Kong back in 2018 were cut from silky sharks (Carcharhinus falciformis). Like all shark species, silkies are heavily hunted for their fins, which are used in shark fin soup in China and Southeast Asia; they are also netted in vast numbers as bycatch. Shark numbers have cratered over the last 50 years. A 2024 study found that overfishing has halved populations of roughly 1,200 species of sharks and rays since 1970. An average of…This article was originally published on Mongabay