Secret scientists cast doubt on Japanese whale numbers

Undercover scientists who bought whale meat at Japanese markets for genetic research say claims minke whale numbers are rising are incorrect.

The research has been published as a joint team of New Zealand and Australian scientists prepare to sail to the Southern Ocean to conduct the first ever wholly non-lethal research programme into whales.

In the 20th century, the killing of about two million whales in the Southern Ocean devastated the numbers of blue whales, fin whales and humpback whales, but not minke whales.

The Japanese Institute of Cetacean Research, which hunts hundreds of mainly minke whales in the Southern Ocean each year, says it is looking at ways to "manage" their numbers, as they could be preventing the recovery of other whales by competing for food.

However, Auckland University adjunct professor Scott Baker, said researchers found that the number of minke whales had remained constant, at about 670,000, before and after intensive periods of commercial whaling.

Scientists came to their conclusion as they found minke whales today had a great deal of genetic diversity – which indicated a long history of a stable population size.

He expected its findings to be backed up by the non-lethal study being launched today.

Though scientists in the new study would use darts to take samples from whales, Dr Baker's team had not had access to such advanced technology when they started their study six years ago.

They decided to take DNA from minke whale meat being sold in Japanese markets, including the world's largest one at Tsukiji.

However, as foreigners buying whale meat could attract responses ranging from hostility to suspicion – Dr Baker once met a seller who refused to give him a price – they relied on a Japanese colleague to buy the samples for them. "Towards non-Japanese buying whale meat, sellers can be quite guarded," Dr Baker said.

The team took DNA from 52 samples, and Dr Baker said minke meat "was found everywhere" and sold for about US$600 per kilogram.

The spokesman for the Institute of Cetacean Research could not be contacted yesterday, but the centre responded to the research in a statement.

It said using genetic data to calculate population estimates did not produce "convincing" results, and made it difficult to establish how far back the population estimates were valid for.

Dr Baker welcomed the non-lethal study, which would be launched today by Australian Environment Minister Peter Garrett and Research, Science and Technology Minister Wayne Mapp.

A team of 18 scientists on the National Institute of Water and Atmospheric Research ship the Tangaroa would set sail for the Ross Sea on Monday.

They would prove that scientific research could be gathered without killing whales by taking photographs, collecting "tiny slivers" of skin for genetic testing, and using underwater microphones to monitor the sounds emitted by whales.