At the meeting of the International Whaling Commission (IWC) in Grenada in the West Indies this month, the UK will ask the Japanese government to cut back on kills of Dall's porpoise, which at more than 18,000 a year are believed to be leading to the species' decline.
The porpoise catch has soared since the abolition of commercial whaling in 1986 and is now thought to be the biggest kill of cetaceans - whales, porpoises and dolphins - anywhere in the world.
It is being carried out in defiance of an IWC resolution from 1990, which the UK helped to frame, asking for the catch to be brought back to 1986 levels or below.
Britain is already on course for a clash with the Japanese at the meeting later this month, over their proposal to abolish the giant Southern Ocean sanctuary for great whales.
Now the Government will be talking to other anti-whaling nations including the US, Australia and New Zealand, to frame a resolution asking the Japanese to cut back on their porpoise kills.
"There is growing concern about the unsustainability of the Japanese catch," Mr Morley said. "We would like to move away from this kind of killing anyway, but at the very least it has to be properly managed in a sustainable way."
Powerful ammunition for the UK position on Dall's porpoise comes today in a new report on the kill from the Environmental Investigation Agency (EIA), the London-based pressure group. The report, which is being released in Tokyo as well as in London, says the effects on the local populations can be seen in the number of lactating females being killed. And it is illustrated by the dramatic photographs of the porpoise hunt, taken by EIA activists.
More than 200 licensed hunters from ports in north-east Japan use powerful motorboats with a harpooner's platform stretched out from the bowsprit. The boats pursue the 6ft-long porpoises until they tire, when the harpooner plunges his hand-held, barbed weapon into an animal's back or head. Sometimes the harpoons deliver an electric shock which helps kill the porpoise; sometimes they are electrocuted on deck.
The animals are gutted and taken to fish markets where they are auctioned. Many of the carcasses find their way to southern Japan and some of the meat is fraudulently sold as "small whale", the EIA says.
The hunt has expanded in recent years, particularly since the moratorium on commercial whaling deprived Japanese consumers of a ready supply of whale meat. Before the 1986 whaling ban the Japanese were taking 10,000 Dall's porpoises annually, but that year the take soared to more than 16,000 and reached a peak of more than 40,000 animals in 1988, triggering international protests.
The 1990 IWC resolution asking the Japanese to bring the kill down to pre-1986 levels was the first time the commission had concerned itself with small cetaceans - species other than the great whales.
The kill fell to 11,000 animals in 1992 but since then, the EIA says, it has climbed steadily climbing back up, reaching more than 18,000 two years ago. Last year's figure is not yet available, while this year's hunt is still going on.
As the number of male porpoises declines, the report says, the hunters are pursuing more and more lactating females, which are easier to track because their calves are slower swimmers. When the mothers are killed, the porpoise calves are left to fend for themselves and are likely to die.Reuse content