At least 18,000 Dall's porpoises are being killed in Japanese waters every year, making it by far the world's largest cetacean kill. Disturbing new evidence has emerged which reveals high catch levels of mature and lactating females in the Sea of Japan hunt, indicating severe overhunting of this population.

Prior to the mid-1980s the annual catch was around 10,000 animals. But in 1986 the hunt surged to over 16,000, increased to over 25,600 the following year and peaked at a shocking catch of over 40,000 porpoises in 1988.

The fact that this growth coincided with the International Whaling Commission's (IWC) 1986 moratorium on commercial whaling is not a coincidence. Deprived of their traditional business, whaling companies got involved in the porpoise trade.

During this period the IWC expressed extreme concerns at the scale of the hunt. Finally in 1990 it passed a landmark resolution which requested the Japanese government to reduce its catch to at least the pre-1986 levels.

To the credit of the Government of Japan the catch did fall to around 11,000 in 1992. Yet this proved to be a false dawn and the hunt has risen almost every year since, to reach over 18,000 in 1997. Japan's official population estimate for the two hunted populations of Dall's porpoises is flawed and dates back to 1991. But it is still used to set quotas despite the fact that over 150,000 porpoises have been caught in the intervening eight years.

The Environmental Investigation Agency (EIA) has raised the alarm over the unsustainable nature of Japan's Dall's porpoise hunt since it first visited the coast of north-east Japan in 1990. This year EIA returned to Japan and for the first time put to sea in order to witness the actual hunt, as well as monitoring the porpoise trade. For three weeks EIA attended the early morning auction of porpoises and sailed to the hunting grounds for a week.

It is clear nothing has changed in the hunt - in fact the situation is worsening. Harpoon boats operating in the Sea of Japan are targeting lactating females, risking the future survival of this population.

Large commercial interests dominate the trade, and porpoise meat is still being fraudulently sold as whale products. The profit motive is clear - a porpoise carcass can be bought at auction for US$193, yet if it can be sold as whale it can fetch a minimum of US$2,333.

For ten years the Japanese government has failed to heed the warnings, while claiming it supports "sustainable" use of porpoises and other cetaceans it contiunes to hunt species until they are in danger of extinction. The present level of hunting is threatening these Dall's porpoise populations. The Japanese government must immediately suspend the hunt off Hokkaido and take urgent steps to reduce its overall catch to well below 10,000 animals.