Analysis of Toxic Metals Found in Shark Fins Collected from a Global Trade Hub

As human activities release increasingly more fossilfuel-derivedemissions directly into the atmosphere, terrestrial, aquatic, or marineecosystems, the biomagnification and bioaccumulation of toxic metalsin seafood is an ever more pressing concern. As apex predators, sharksare particularly susceptible to biomagnification and bioaccumulation.The consumption of shark fin is frequent throughout Asia, and theiringestion represents a pathway through which human exposure to potentiallyunsafe levels of toxic metals can occur. Shark fins processed forsale are difficult, if not impossible to identify to the species levelby visual methods alone. Here, we DNA-barcoded 208 dried and processedfins and in doing so, identified fourteen species of shark. Usingthese identifications, we determined the habitat of the shark thatthe fin came from and the concentrations of four toxic metals (mercury,arsenic, cadmium, and lead) in all 208 samples via inductively coupledplasma mass spectrometry. We further analyzed these concentrationsby habitat type, either coastal or pelagic, and show that toxic metalconcentrations vary significantly between species and habitat. Pelagicspecies have significantly higher concentrations of mercury in comparisonto coastal species, whereas coastal species have significantly higherconcentrations of arsenic. No significant differences in cadmium orlead concentrations were detected between pelagic or coastal species.Our results indicate that a number of analyzed samples contain toxicmetal concentrations above safe human consumption levels. The consumption of toxic metal ladenshark fins has implicationsfor human health; here, we examine the toxic metal concentrationsof shark fins from fourteen species collected from coastal and pelagichabitats. All fins were purchased from the open market in Singapore,a globally significant shark fin trade hub.

Automated summary

As human activities release more and more fossil fuel emissions into the atmosphere and ecosystems, the accumulation of toxic metals in seafood, especially in sharks, is becoming increasingly concerning. The consumption of shark fin, which is prevalent in Asia, can lead to human exposure to unsafe levels of toxic metals. In this study, dried and processed shark fins were DNA-barcoded to identify the species and analyze the concentrations of four toxic metals. The results showed significant variations in toxic metal concentrations between different species and habitats, with some samples exceeding safe consumption levels.