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Whale Tracker

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A DNA detective tracks endangered whales into the marketplace.

Scott Baker is a sleuth of sorts. Hunched over a dimly lit desk in a hotel room in Tokyo or Seoul, analyzing samples of flesh with lab equipment that fits into a suitcase, this conservation geneticist looks as if he might be at home on the television show CSI.

What crime is he investigating? The illegal sale of meat from protected whales in shops and restaurants in Japan and Korea.

Despite a worldwide ban on commercial whaling in effect since 1986, Japan and Korea enjoy a circumscribed legal market in whale meat, a traditional delicacy. A stroll through fishmongers' shops in coastal cities reveals a host of products: whale steaks and chops, sashimi and sushi; whale meat smoked and teriyaki-marinated, canned and frozen; whale skin with or without blubber; whale organs; even whale bacon. "There is some whale meat that is sold legally, some that is of questionable legality, and some that is illegal," says Baker, who is the associate director of OSU's Marine Mammal Institute.

Using a method of DNA detective work similar to methods used in human genetics profiling, Baker can identify whale meat in all these products down to the species, subpopulation, and even the individual whale. Coupling that technique with sophisticated statistical analysis, he and his colleagues are producing convincing evidence that some of the whale meat enjoyed by Asian diners originated from illegal or unregulated sources.

whale photo by Wong.

Endangered minke whales are still showing up in Asian meat markets, despite a 1986 ban on hunting them. Photo: Wong

Baker serves on the scientific committee of the International Whaling Commission, the multinational body charged with managing whaling and monitoring endangered populations. "The primary objective of our work," Baker says, "is to bring accurate information to the IWC. More effective management and conservation requires greater certainty about how many whales are being killed."

Intensive commercial hunting of whales in the past century and a half caused whale populations to plummet, and some stocks were pushed to the verge of extinction. The IWC, formed in 1946, now has 78 member countries. They include nations that once had a whaling fleet but have ceased whaling, such as the United States, the Netherlands, and the United Kingdom. Other members, including Korea, Japan, Norway, and Iceland, actively hunted whales until the 1986 ban and now continue some whaling through loopholes or exceptions to the moratorium. For example, whales taken under a Japanese scientific research program are sold commercially, as are whales caught and killed as by-catch in fishers' nets, as long as they are reported.

whale bacon photo by Minden pictures.

About ten percent of whale meat samples collected from local markets (as above) proved to be from protected species. Photo: Flip Nicklin/Minden Pictures

There have been ongoing suspicions, both within and outside the IWC, that more whale meat was available in Asian markets than could possibly have been taken legally. Reports of whales killed as incidental by-catch from commercial fishing fleets also didn't square with the low numbers of whales sighted during systematic surveys of abundance.

In their latest study, published this year in the journal Molecular Ecology, Baker and his team focused on the South Korean catch of minke whales in the Sea of Japan between 1999 and 2003.

Because of a ban on international traffic in whale meat (even tiny samples for scientific research), Baker and his team had to travel to South Korea do to their research—hence the portable lab-in-a-suitcase. They made two or three trips each year of the study, sending a Korean-speaking colleague over a few days ahead to shop for whale meat in the local markets.

In his hotel-room laboratory, Baker used a method known as polymerase chain reaction, or PCR, to extract DNA from the whale meat samples. PCR makes it possible to recover DNA from practically anything living or once-living, even if it's since been pickled, smoked, cooked, or canned. What is more useful for Baker's purposes is that PCR makes a synthetic copy of the target DNA. The copied genetic coding is not technically whale tissue, and it is not subject to the import ban. "We can take the synthetic DNA back home to our lab," Baker says, "where we can sequence it and compare it to reference samples from all known species of whales."

Baker's team purchased 289 samples of minke whale meat from several shops in Korean coastal cities over the five years of the study. Their DNA profiling revealed that the samples originated from 205 individual whales. They used a statistical technique called capture-recapture, developed by coauthor ustin Cooke, to estimate how many individual whales had passed through the market during that five-year period.

The capture-recapture technique is similar to the one that wildlife biologists use when they capture and band a bird, and then capture that same individual months or years later. Using a similar method of repeated sampling, the researchers tracked how quickly the meat from an individual whale disappeared from the market as time passed. From this they estimated that the "half-life" of minke whale products in the South Korean market is six or seven weeks. In other words, about half of the whale is sold in the first six weeks and then half of the remaining products are sold during the next six weeks.

Scott Baker photo by Scott Baker.

Baker set up his portable DNA-testing lab in hotel rooms in Asian cities where he examined the genetic fingerprints of samples. Photo: Scott Baker

This meant that the 205 whales represented in the samples was a suspiciously high number. A whale is a big animal—a single individual, or a few, might be expected to dominate local markets for weeks, and then be replaced by meat from another one or two whales. Instead, the researchers found bits and pieces of many animals. "Since the half-life of whale meat is so short," says Baker, "we should have found far fewer individuals—either that, or the number of whales being killed is much greater than is being reported."

The combined findings from the DNA profiling and the statistical analysis revealed that 827 minke whales had likely passed through the South Korean market during the five-year period— nearly twice as many as the 458 reported to the IWC by the South Korean government. Most of these whales belonged to an endangered coastal population of minke whales, which had been hunted intensively prior to the 1986 ban.

Since beginning his forensic genetics work nearly 15 years ago, Baker and his colleagues have sampled about 2,000 products in Korea and Japan and have found meat from 28 different whale species and stocks. About 10 percent of their samples have proved to be from protected species.

It was particularly disturbing, he says, to find gray whale sold in several Japanese whale meat markets during a survey in 1999. Unlike eastern or California grays, western gray whales are critically endangered—only 80 to 100 individuals are estimated to be alive. The official explanation was that the meat had come from a stranded gray whale, but later investigation found 27 small harpoon wounds puncturing the whale carcass.

Illegal, unregulated, and unreported whaling is potentially lucrative. Sashimi-quality whale meat can command up to $600 a pound in Tokyo. A single whale can be worth as much as $100,000 to a Korean fisherman—many times his annual income. "There's little oversight of this by-catch," says Baker, "so it's impossible to tell which came first, the net or the harpoon."

Stemming the illicit traffic is a challenge for the IWC, an international body whose rules rely on agreement among its members—a group sharply divided between conservation and commercial interests. All the more reason, says Baker, why good science is a critical first line of defense. "The first obligation of science is to provide accurate information," he says.

"Those who participate [in the IWC] as scientists wear another hat as well: to see that the science gets interpreted for management," Baker says. "There is a growing recognition that we need improved systems for verification, for making the trade more transparent. These methods of DNA profiling are crucial to effective observation and inspection."

OSU Marine Mammal Institute

Published in: Ecosystems, People