Shark-fin soup bad for you, not quite so bad for them

February 24, 2012
Dried sharks fin

A new study by University of Miami scientists publish in the journal Marine Drugs has found  high concentrations of BMAA – a neurotoxin linked to neurodegenerative diseases including Alzheimer's and Lou Gehrig Disease (ALS) – in samples clipped from the fins of seven shark sharks in the waters off South Florida. It suggests that consumption of shark fin soup and cartilage pills may pose a significant health risk for degenerative brain diseases.

"The concentrations of BMAA in the samples are a cause for concern, not only in shark fin soup, but also in dietary supplements and other forms ingested by humans," says study co-author Prof. Deborah Mash, Director of the university's Miami Brain Endowment Bank.

In 2009, Mash and her co-authors published a study which showed that dying patients  diagnosed with Alzheimer's and ALS had unusually high levels of BMAA in their brains, whereas normal healthy aged people had no BMAA or only trace quantities of the toxin present.


The shark study found a similar and even higher levels in the BMAA in the fins tested, which overlapped the levels measured in the brains of the Alzheimer's and ALS victims. It also matched the levels found by a study of fruit bats in Guam, which linked the practice of eating these animals to the severe ALS/Parkinsonism dementia that afflicted local indigenous people.

This news will no doubt add momentum to the global movement against shrak-finning, with New York State looking likely to follow California's lead in banning the sale, possession and trade of shark fins starting next year. Just as the tide seem to be turning against the finning, however, some marine life experts are arguing that these bans are pointless.

Speaking at a seminar organized by the Institute of Southeast Asian Studies in Singapore this week, Dr Giam Choo Hoo, a member of the Animal Committee of CITES – the UN convention endangered species – said that media hype is responsible for “misconceptions” about the shark-fishing industry.

Dr Giam said a vast majority of sharks are not killed to feed the tastes of increasingly-affluent Chinese consumers who consider the dish a status symbol. He cited research showing 80 percent of the 73 million sharks killed each year are in fact caught accidentally, and overwhelmingly in developing countries.

According to Dr Giam’s research, 25 percent of the shark catch is made in Indian and Indonesian waters, where “mostly poor” fishermen eat every part of the shark, and then sell off the fin to eager buyers.