A new study found that shark fins being sold in markets in China and Hong Kong contained dangerously high levels of mercury.
Florida International University marine biology Ph.D. student Laura Garcia Barcia—collaborating with a team from the United States and Hong Kong—conducted the study. Barcia and her team found found the samples all had levels of mercury that exceeded guidelines and legal limits set by the Hong Kong Center for Food Safety.
The team examined 267 shark fin trimmings from the nine of the most common shark species in the fin trade, testing each one for levels of total mercury and methyl-mercury—the organic, highly toxic form of mercury. The concentrations in each shark fin sampled for this study exceeded the maximum legal limit in Hong Kong of 0.5 parts per million.
The highest of 55.52 parts per million came from a great hammerhead. The lowest level found in the fins sampled was 0.02 parts per million from a blue shark—the most common species found in the trade.
“The results were astonishing,” Garcia Barcia said. “The mercury levels are super high and, on average, 6 to 10 times higher than what a safe level of mercury would be considered in Hong Kong.”
The results were published in the latest issue of Marine Pollution Bulletin.