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 from Florida International University.
Laura García Barcia, a doctoral candidate working in FIU’s predator ecology and conversation lab, collaborated with a team of scientists from the United States and Hong Kong on the study, published recently in Exposure & Health.
The researchers found most of the shark meat and fin samples they tested had mercury levels surpassing legal food safety limits, and that the greatest risk to consumers is from hammerhead shark products.
Scalloped hammerhead and Atlantic sharpnose shark meat had the highest levels of mercury, surpassing safe consumption limits of one 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 two to three times the one-part-per-million limit.
"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.
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.
Of the 267 fin trimmings, 75 percent exceeded the Hong Kong Center for Food safety's maximum legal limit of 0.5 ppm of methylmercury, the organic and highly toxic form of mercury, FIU said.
The team also analyzed 33 meat samples sold in Trinidad and Tobago, where shark meat is frequently consumed.
“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,” FIU said. “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.”
Photo courtesy of Suwarin Rachanikorn/Shutterstock
