In a way, Dr. Ausubel said, their experiment is a return to an 
earlier era of scientific inquiry. "Three hundred years ago, science 
was less professionalized," he said, and contributions were made by 
interested amateurs. "Perhaps the wheel is turning again where more 
people can participate."

August 22, 2008

Fish Tale Has DNA Hook: Students Find Bad Labels


Many New York sushi restaurants and seafood markets are playing a 
game of bait and switch, say two high school students turned 
high-tech sleuths.

In a tale of teenagers, sushi and science, Kate Stoeckle and Louisa 
Strauss, who graduated this year from the Trinity School in 
Manhattan, took on a freelance science project in which they checked 
60 samples of seafood using a simplified genetic fingerprinting 
technique to see whether the fish New Yorkers buy is what they think 
they are getting.

They found that one-fourth of the fish samples with identifiable DNA 
were mislabeled. A piece of sushi sold as the luxury treat white tuna 
turned out to be Mozambique tilapia, a much cheaper fish that is 
often raised by farming. Roe supposedly from flying fish was actually 
from smelt. Seven of nine samples that were called red snapper were 
mislabeled, and they turned out to be anything from Atlantic cod to 
Acadian redfish, an endangered species.

What may be most impressive about the experiment is the ease with 
which the students accomplished it. Although the testing technique is 
at the forefront of research, the fact that anyone can take advantage 
of it by sending samples off to a laboratory meant the kind of 
investigative tools once restricted to Ph.D.'s and crime labs can 
move into the hands of curious diners and amateur scientists 

The project began, appropriately, over dinner about a year ago. Ms. 
Stoeckle's father, Mark, is a scientist and early proponent of the 
use of DNA bar coding, a technique that greatly simplifies the 
process of identifying species. Instead of sequencing the entire 
genome, bar coders - who have been developing their field only since 
2003 - examine a single gene. Dr. Stoeckle's specialty is birds, and 
he admits that he tends to talk shop at the dinner table.

One evening at a sushi restaurant, Ms. Stoeckle recalled asking her 
father, "Could you bar code sushi?"

Dr. Stoeckle replied, "Yeah, I think you could - and if you did that, 
I think you'd be the first ones."

Ms. Stoeckle, who is now 19, was intrigued. She enlisted Ms. Strauss, 
who is now 18.

Their field technique was simple, Ms. Stoeckle said. "We ate a lot of sushi."

Or, as Dr. Stoeckle put it, "It involved shopping and eating, in 
which they were already fluent."

They hit 4 restaurants and 10 grocery stores in Manhattan. Once the 
samples were home, whether in doggie bags or shopping bags, they cut 
away a small piece and preserved it in alcohol. They sent those off 
to the University of Guelph in Ontario, where the Barcode of Life 
Database project began. A graduate student there, Eugene Wong, works 
on the Fish Barcode of Life (dubbed, inevitably, Fish-BOL) and agreed 
to do the genetic analysis. He compared the teenagers' samples with 
the global library of 30,562 bar codes representing nearly 5,500 fish 
species. (Commercial labs will also perform the analysis for a fee.)

Three hundred dollars' worth of meals later, the young researchers 
had their data back from Guelph: 2 of the 4 restaurants and 6 of the 
10 grocery stores had sold mislabeled fish.

Dr. Stoeckle said he was excited to see a technology used in a new 
way. "The smaller and cheaper you make something," he said, "the more 
uses it has." He compared bar coding to another high-tech wonder 
turned everyday gadget, GPS.

Eventually, he predicted, the process will become more automatic, 
cheaper and smaller so that a handheld device could perform a quick 
analysis and connect to the database remotely. What his daughter did, 
he said, is like dropping film off at the supermarket for developing. 
The next generation could be more like a digital camera that displays 
the results on the spot.

The results of Ms. Strauss and Ms. Stoeckle's research are being 
published in Pacific Fishing magazine, a publication for commercial 
fishermen. The sample size is too small to serve as an indictment of 
all New York fishmongers and restaurateurs, but the results are 
unlikely to be a mere statistical fluke.

The experiment does serve as a general caveat emptor for fish lovers, 
particularly because the students, their parents and their academic 
mentor all declined to give the names of the vendors, citing fear of 
lawsuits. Besides, they noted, mislabeling could occur at any stage 
of the process.

Dr. Stoeckle was willing to divulge the name of one fish market whose 
products were accurately labeled in the test: Leonards' Seafood and 
Prime Meats on Third Avenue. John Leonard, the owner, said he was not 
surprised to find that his products passed the bar code test. "We go 
down and pick the fish out ourselves," he said. "We know what we're 
doing." As for the technology, Mr. Leonard said, "it's good for the 
public," since "it would probably keep restaurateurs and owners of 
markets more on their toes."

Ms. Stoeckle said the underlying message of the research was simple: 
"If you're paying for white tuna and you're eating tilapia, I think 
you'd want to know that."

Although the students did not present the project for a grade at 
school, they made sure to mention it on their college applications. 
Both will enroll at Johns Hopkins University this fall.

Neither, however, expects to major in the sciences. "I've always been 
into art history," Ms. Strauss said, "which is really different from 
this." Ms. Stoeckle, who is the granddaughter of the entertainer and 
arts patron Kitty Carlisle Hart, is thinking about studying writing 
or psychology. But that, they said, is the point. "If we found it 
interesting - which we did - I think lots of people like us can do 
it, too," Ms. Stoeckle said.

Peter B. Marko, a professor at Clemson University who used a more 
detailed genetic technique in a 2004 paper to show that red snapper 
was commonly mislabeled, called their project "quite remarkable," 
though he added that genetic analysis had been simplified to the 
point that high school students could now perform the task without 
sending samples off.

Mr. Marko prefers to work with whole genomes - "more information is 
better," he explained - which can be sequenced now with lightning 
speed. He plans to perform a broad genetic comparison of fishes that 
were separated millions of years ago by the rise of the Isthmus of 
Panama. "The technology is allowing us to ask questions that really 
would not have been possible in the past."

The students worked under the tutelage of Jesse H. Ausubel of 
Rockefeller University, a champion of the DNA bar coding technique. 
As for Ms. Strauss and Ms. Stoeckle, Dr. Ausubel said they "have 
contributed to global science" by adding to the database, built on a 
model similar to that of Wikipedia, in which people around the world 
can contribute.

In a way, Dr. Ausubel said, their experiment is a return to an 
earlier era of scientific inquiry. "Three hundred years ago, science 
was less professionalized," he said, and contributions were made by 
interested amateurs. "Perhaps the wheel is turning again where more 
people can participate."