|Anti-shark-fin ad featuring former NBA star Yao Ming|
January 1, 2013 marked an important day in California for sharks, as it is the next step in implementation of AB376. Back in 2011, the State of California approved the law, and as 2012 became 2013, it became illegal to import shark fins into the state. Later in the year, on July 1, possession and sale of shark fins will be illegal (details in a San Francisco Chronicle article written after the governor signed the bill into law).
Shark fin soup is a dish revered in China and by Chinese expatriates as a symbol of prosperity. Serving shark fin soup at a wedding or business event shows that the host has plenty of wealth to spread around and highly values his or her guests. But with increased prosperity among shark fin aficionados (in China and elsewhere), demand for shark fins is devastating of shark populations around the world. The Beat, at Environmental Health Perspectives, reports a bit of good news, in that the Chinese government will be issuing guidelines to ban serving shark fin soup at official events in one to three years. It’s not clear why it takes one to three years to write such seemingly rules, and the whether the rules are actually followed will be another matter, as government officials in China have a reputation of playing by their own rules (see, for example, Evan Osnos in the New Yorker on corruption in high-speed rail construction).
Although some argue that a fin ban is not effective when it is still legal to kill or import whole sharks (e.g., this article in the San Francisco Chronicle about an unsuccessful legal challenge), banning importation and possession of just the fin is an important development. The reason is volume: on any fishing vessel, there is only so much space in the hold, and so it is a lot more financially beneficial to fill the hold with thin, highly valuable shark fins, instead of whole shark bodies which have little value beyond the fins.
Removal of sharks from an ecosystem can have significant effects. For example, the New York Times wrote about a study that showed how overfishing of sharks in the Atlantic Ocean led to a crash of the bay scallop fishery. It turns out that some of the creatures eaten by large sharks — like smaller sharks, rays and skates — eat scallops, so as shark populations decline, the population of sharks’ prey increases, and the number of scallops drops.
A bowl full of toxins
As the pinnacle of the food chain, sharks accumulate some of the toxins in the bodies of the creatures below them on the chain (which accumulate toxins of creatures below them, and so on, leading to the term “bioaccumulation”), especially methylmercury (chemical formula CH3Hg, a.k.a. MeHg). MeHg which can cause suppressed immune system function, developmental delays in children, and cardiovascular problems.
A bowl of shark fin soup might also contain another potent toxin, the neurotoxic amino acid β-methylamino-l-alanine (BMAA), a compound produced by cyanobacteria in coastal waters and the open ocean, according to a 2012 study conducted at the University of Miami and reported on by freelance writer Wendee Holtcamp in Environmental Health Perspectives (or here at PMC). Eating or drinking food and water contaminated with BMAA has been associated with increased risk of amyotrophic lateral sclerosis, Alzheimer disease, and Parkinson disease. Since the chemical does not decompose during cooking, it sticks around in the soup.
Deborah Mash, a neuroscientist at the University of Miami Medical School collaborated with Neil Hammerschlag, a research professor at the University of Miami. The team caught sharks near the Florida coast and performed chemical analysis on small pieces of their fins. BMAA was found in 23 of 29 samples, across all species (7 species in total). Experts interviewed in the study are certain that the sharks tested in this study are in the global fin trade, and one of the authors notes that cyanobacteria are found in every ocean, so they are confident that you’d find BMAA in commercially available fins.
But there’s an old saying in toxicology, “the dose makes the poison,” so further research would be needed to look at the actual risk for infrequent eaters shark-fin soup, as well as the concentration of BMAA in commercially available shark fins. Some questions that popped into my mind after reading Holtcamp’s article: Does BMAA bioaccumulate in the human body? If one was to eat a few bowls of soup a year, would the BMAA (and mercury) pile up in your brain? Or is the material flushed out periodically?
Edible delight without the ecological devastation
There might be an alternative to shark fin soup, one that reduces the ecological devastation and still maintains the luxury. It’s a faux shark fin soup, created by Chef Corey Lee using cutting-edge cooking techniques (sometimes called molecular gastronomy or modernist cuisine). Lee knows about luxury, he runs Benu restaurant in San Francisco (a recipient of two stars from the Michelin Guide and four stars from the San Francisco Chronicle), and used to work at the French Laundry in Napa County (three stars from Michelin, four from the S.F. Chronicle).
I got a great video introduction to Lee’s faux shark fin soup through a lecture on science and cooking at UCSF by Professor David Weitz (from Harvard Materials Research Science & Engineering Center, one of the co-founders of that school famous food and science course and lecture series), in which Lee was a special guest. Lee makes his appearance in the second video of the series on YouTube, and beginning at about 22:41 in the second video, Lee describes the creation of the faux shark fin soup.
Lee wanted to create a dish that had the mouth feel of shark fin — something that is soft but also has “snap” — while also creating something luxurious and celebratory. He worked with scientists from CPKelco in San Diego to find the right materials and techniques. They start with a rich stock made from Chinese ham, chicken and aromatic vegetables (even in real shark fin soup the stock is the main flavoring, as the dried fin is relatively flavorless). Next, they add gellan, alginate, and locust bean gum to make a thick liquid, which is then piped into a calcium solution (he wasn’t clear about this, two possibilities are calcium chloride and calcium lactate solution). The extrusions firm up in the solution and are later cut into the right size.
The faux fin is inexpensive, so to create a luxury dish, Lee’s team makes a black truffle custard, adds some Dungeness crab and poached vegetables, then pours the stock over the mixture, finally topping the soup with the faux fin.
The creation stands up to scientific scrutiny: its elastic constant of is pretty close to a real fin. A sample of real fin had a constant of 120 kilopascals, while the faux fin had a constant of 190 kPa (A kiilopascal are a unit of pressure. At sea level, atmospheric pressure is 101.365 kilopascals.).
The greatest compliment Lee has received so far came from Cecelia Chiang, the revered chef and restaurateur who is credited with introducing Northern Chinese cooking to America. “She had no idea it was faux,” he said. (Alice Waters, a friend of Chiang, said in 2009 that she hoped her last meal would be shark-fin soup prepared by Chiang; not long afterward, she signed a Humane Society pledge renouncing shark fins forever.) Chiang, Lee said, has come back many times.
Photo credits: photo of Yao Ming advertisement on an SF Muni bus near Union Square (I think it was a #30 bus, which goes through Chinatown) by the author, photo of Faux shark fin soup at Benu from Pixel Boy128’s flickr collection, subject to a Creative Commons License.