BANGKOK, Thailand – Australian researchers said Thursday that analyzing the skin flakes of some whales could help determine their age, a development that could invalidate one argument for killing them.
Japan has long argued that killing baleen whales, such as humpbacks and minkes, is the only way to determine how old they are, and vital to better understanding the animals' behavior.
Tokyo plans to kill over 1,000 minke whales in 2006, over 400 more than last year and more than double the number it hunted a decade ago, as part of its scientific research program.
But a team at the Southern Cross University Whale Research Center in the Australian state of New South Wales said DNA in the whale's skin flakes could tell scientists how long they have lived.
"The Japanese have used a whole series of excuses to kill minke whales, and their latest excuse is a claim that they need to determine their age," Peter Harrison, the center's director, told The Associated Press.
"Essentially, this [analysis] would mean Japan would no longer be able to kill whales in order to determine their age," he said. "So therefore, they would have to either modify their research program to stop killing whales or admit they are really doing commercial whaling with science as an excuse and therefore change the nature of their whaling program."
Officials at the Japanese Fisheries Agency were not immediately available for comment.
Harrison, whose research was highlighted in this week's Nature magazine, said the new aging method relies on extracting DNA from the skin flakes of humpback whales and looking at telomeres — structures that cap the end of chromosomes.
The telomeres progressively shorten with age in many animal species and Harrison said he is hopeful they could be used to determine a whale's age.
Harrison said the team — which is collaborating with Prof. Scott Baker at the University of Oregon in the United States — has determined that the genetic sequencing of a humpback's telomeres is similar to that of humans and other species.
The next step, he said, is to determine how the lengths of the telomeres decrease with age — by using the skin samples of 100 living whales of known age already on file at the center.
"There is no theoretical reason why the telomeres analysis techniques that work perfectly well for humans could not be applied to humpback whales," he said. "Therefore, I'm optimistic of success."
Curt Jenner, managing director of the Centre for Whale Research in the state of Western Australia, said the DNA analysis was a technique that "we are all quite hopeful will be viable in the future."
"It would be bloody fantastic if it works, because it would make null and void one of the last arguments that the Japanese make for scientific whaling," he said. "It's certainly feasible, but it will be a difficult task. Firstly, you need enough DNA material to do the test and, because it is a new field, they don't have a lot of background to compare it to."
The age of a whale is often determined by extracting its teeth. But since baleen whales have no teeth, the only way to gauge their age is to photograph one each year, or dissect a dead whale, said Jenner.