In preparing shark fin soup, a dish considered a delicacy in certain cultures, chefs use scant bits of cartilage from the animal’s fins, rather shark meat, as is the common assumption. This has created a market in which fishermen—barbarically, critics cry—slice off the shark’s fin and toss the fatally damaged animal back in the water to perish.
Over the past century, shark populations have been decimated from both commercial and recreational fisheries. Somewhere in the expansive neighborhood of between 23 million and 75 million sharks are reportedly killed each year to feed the world’s hungry appetite for shark fin soup.
Although sharks carry a notorious reputation in Hollywood, fanning fear among summer beachgoers, marine biologists are learning more about sharks and their crucial role as the top predator in the ocean. For example, Scripps Institution of Oceanography at UC San Diego scientists have studied their importance in keeping ecosystems such as coral reefs healthy and thriving. Coral reefs in which sharks have been fished away are much more sickly and dominated by tiny fishes and algae (link to Sandin study: http://scrippsnews.ucsd.edu/Releases/?releaseID=1179)
The heart of the shark finning problem, according to Dominique Cano-Stocco, who recently received her Master’s degree from Scripps, is a surprising lack of data, enforcement, and effective legislation to curb shark finning practices. Economically incentivized fishermen scour international waters to land as many shark fins as they can. The fins then enter a clandestine “world market” in Asia and move from there to destinations around the globe leaving little, if any, tracking data behind.
“The most important factor limiting the number of sharks a fishing vessel can take is the capacity of its cargo hold,” said Andy Nosal, a graduate student at Scripps researching sharks. “If solely the fins are retained, which fetch a higher price than the meat—but account for only 1 to 5 percent of the total body weight—many more sharks can be killed before the cargo hold is filled, forcing the crew to return to port.”
Although it is illegal to remove shark fins within U.S. waters, selling fins or consuming shark fins soup is legal in most of the United States. The result is a thriving market that sells shark fins for several hundreds of dollars per pound.
Cano-Stocco is addressing the issue with both science and legislation.
Because surprisingly little is known about the different species consumed for shark fin soups in the U.S., Cano-Stocco recently completed a shark fin DNA study for her Master’s degree research in the Scripps Center for Marine Biodiversity and Conservation.
She purchased 23 shark fins from markets in San Diego and Los Angeles County’s Monterey Park (the priciest checked out at $629.10 per pound) and, under the guidance of Scripps Marine Biology Professor Ron Burton, deciphered the genetic sequence of the fins. DNA sequences reveal animal identities somewhat like commercial barcodes (hyperlink “Life Behind Bars” http://explorations.ucsd.edu/archives/2009/life_behind_bars/) identify retail products.
Of the species she was able to identify, including pelagic threshers, smooth hammerheads, brown smooth-hounds, and tiger sharks, one-third are considered “vulnerable” or “threatened” species, according to the International Union for the Conservation of Nature.
“Fin species data are rarely recorded in the shark fishing trade,” said Cano-Stocco. “So this project was a starting point in the process. Science helps bridge the gap of information.”
In her other life, Cano-Stocco is director of advocacy, state, and local government relations for UC San Diego. She is sharing the results of her study with California legislators, who are considering a new measure that would make it illegal to trade, sell, or possess shark fins. Now being reviewed in the state senate, Assembly Bill 376 would follow Hawaii, Washington, and Oregon’s lead in enacting similar bans.
The measure, however, is being met with opposition from some members of the Asian-American community, who feel they are being unfairly targeted by the legislation. Shark fin soup is a delicacy served at Chinese special occasions.
“The proposed legislation is not targeting a particular heritage, but rather its intent is to get to the core of the problem and protect shark species,” said Cano-Stocco. “The genetic analysis project is an opportunity to educate legislators on science-based solutions to economic and conservation policy issues.”
—Mario C. Aguilera