Shark-fin soup: garnished with pollutants

By now, we all know that the demand for shark fins is leading to a dramatic decrease in the number of sharks. It is also known that shark fins contain a lot mercury. And it is even worse: shark fin soup is not only bad for sharks, but also for consumers…

A short update from Prof Mahmood Shivji, marine scientist and director of the Save Our Seas Shark Centre at Nova Southeastern University, Florida, United States.

Many countries spend considerable effort developing national food safety standards based on toxicological and risk analysis criteria to protect their populations from health hazards associated with consumption of contaminated or spoilt food. Furthermore, the FAO and WHO and their member nations have jointly developed the influential international reference, the Codex Alimentarius General Standard for Contaminants and Toxins in Food and Feed, in part to facilitate global trade while maintaining food safety standards. Our analyses of 126 trade-derived shark fins from several species show that 86-100% of the fins contained detectable levels of one or more heavy metals (total mercury, lead, cadmium or total arsenic). Furthermore, our results show that a large proportion of the market-destined shark fins had individual heavy metal concentrations exceeding one or more of the individual National or Codex Alimentarius standards.

On a national safety level, we have been unable to find food metal safety standards for Mainland China, probably the largest single national consumer of shark fin. However, particularly notable is the fact that over 45% of the fins exceeded maximum permitted safety standards for total mercury, lead or total arsenic as promulgated by the Hong Kong government, despite these safety standards being amongst the most liberal (i.e., least conservative among national standards that we have been able to obtain) for lead and total arsenic. This is significant as Hong Kong is a relatively high consumer of shark fin based on cultural traditions, and has historically been the world’s largest fin trading center supplied from global sources. Singapore, with its majority ethnic Chinese population (76.8%; CIA World Factbook 2010) is likely also to be relatively high consumer of shark fin. With its more conservative food safety standards especially for total arsenic and lead, almost all the fins (92.9%) we tested would have been illegal to import or sell in Singapore.

Further detailed analysis of the results is ongoing.