Florida International University: High levels of toxic mercury in some species of shark meat, fins sold for soup pose dangers to human health

MIAMI, Aug. 23, 2022 /PRNewswire/ -- Shark fins and meat from hammerhead sharks pose a health risk to consumers — especially women of childbearing age — and should not be sold because of their dangerously high levels of toxic mercury, according to a new study.

Laura García Barcia, a Florida International University (FIU) Ph.D. candidate in the Predator Ecology and Conversation lab, collaborated with a team of scientists from the United States and Hong Kong to assess the health risks of eating shark-derived products. They focused on one of the biggest safety concerns associated with consuming shark derived products — mercury. Most of the meat and fin samples tested had mercury levels surpassing local legal safety limits, while the greatest risk to consumers is from hammerhead shark products. The findings were recently published in Exposure & Health.

"For many communities around the world, shark-derived products are an important source of protein — and that's why we need to get a better idea what health risks might be facing those communities," García Barcia said. "After the first study we did in 2020, the next question we wanted to answer was how many bowls of shark fin soup — or how much shark meat — you can have without consuming too much mercury."

The team tested mercury levels in the nine most common shark species in the global shark fin trade — since these would most likely end up in a bowl of shark fin soup. Out of the 267 fin trimmings, 75% exceeded the Hong Kong Center for Food safety's maximum legal limit of 0.5 parts per million (ppm) of methylmercury, the organic and highly toxic form of mercury.

The team also analyzed 33 meat samples sold in Trinidad and Tobago, where shark meat is frequently consumed. Scalloped hammerhead and Atlantic sharpnose shark meat had the highest levels of mercury, surpassing local safety consumption limits of 1 part per million — and should be avoided, particularly by anyone who relies on a lot of shark meat in their diet. Some hammerhead samples were 2 to 3 times that 1 ppm limit.

High levels of mercury have well-known impacts on humans. Prolonged exposure to mercury can lead to brain and central nervous system damage. It can also interfere with fetal cognitive development. While mercury is common in most seafood, sharks are close to the top of the food chain and can also grow to be quite large, so they tend to accumulate more, in the form of methylmercury.

Most health advisories focused on the risk of mercury toxicity in shark products are treated with a broad brushstroke, listing all shark species. But as this study shows, certain species — like hammerheads — pose a greater risk than others. This study aims to better inform consumers of the species-specific risks of consuming shark-derived products. The hope is these findings can encourage the creation of more species-specific advisories for meat and fin products. 

To read the full release: http://news.fiu.edu/2022/mercury

Media Contact:
Angela Nicoletti
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SOURCE Florida International University