The Japanese whaling fleet set sail yesterday in defiance of international condemnation with plans to land what could be the biggest catch of minke and humpback whales since the 1960s.

As it has for more than two decades, the Japanese Government referred to the expedition as “scientific”. It is a description that infuriates anti-whaling activists. Whale meat harvested on the expeditions is sold on to the Japanese market and the profits used to fund “future research”.

As part of its declared mission to collect scientific data on the age and “mode of life” of Antarctic whale stocks, the Japanese fleet is hoping for a haul of 850 minke — an increase of 70 per cent from last season. But for the first time in more than 40 years, the whalers’ harpoons will also be aimed at humpback and fin whales — species beloved of whale-watchers.

Japan, which defends whaling as a cultural tradition, argues that stocks can survive the size of cull it is planning. Estimates by the American Cetacean Society suggest a worldwide population of up to 40,000 humpback whales: the World Conservation Union places the species two rungs below the highest risk of extinction.

Since the 1986 international moratorium on commercial whaling, Japan has conducted its annual outing to the Southern Ocean under the auspices of the Institute of Cetacean Research — a body set up in 1987. The International Whaling Commission does not ban hunting whales for scientific purposes.

The fleet will sail to the Southern Ocean — the hunting grounds where Japanese whalers caught 500 minke last year. That expedition landed far fewer than intended, being cut short when a fire broke out on board the mother ship and a crewman was killed.

The six ships, led by the repaired 8,000-tonne Nisshin Maru, were played off to sea from the southern port of Shimonoseki by a brass band and the cheers of local wellwishers.

But on the high seas, say antiwhaling protesters such as Greenpeace, the fleet is likely to encounter a less than hearty welcome.

The six Japanese whaling ships are expected to face a barrage of attempts to sabotage the hunt. Clashes between the whalers and Greenpeace activists in previous years have involved protesters steering boats into the Japanese harpoon-gunners’ line of fire.

“Although we are subjected to vicious blocking tactics by environmental groups we have to continue this into the future,” said the fleet’s captain, Hajima Ishikawa, at a ceremony to mark its departure. Other officials urged Japan’s people to fight for their whale-eating culture.

But Japanese tastes have changed, and whale-eating is in decline. Previous catches have been held in storage, creating a “blubber mountain” of many thousands of tonnes. Schoolchildren have been given lectures on the delights of grilled whale flesh, and unsold whalemeat has ended up on the menus of old people’s homes.

The whaling debate consistently places Japan on the receiving end of emotional condemnation. Japan’s unflinching support for whaling, say government insiders, stems from a horror of being dictated to by the outside world. Among the fears is that if it gives ground on whaling, conservationists’ next target will be the tuna fleets.

The departure of the whaling fleet had been delayed to accommodate Yasuo Fukuda’s first visit to Washington as Prime Minister. Officials were reportedly concerned that had the fleet left last Thursday, as planned, the issue might have created friction between Mr Fukuda and President Bush.

In London, the Department for Environment, Food and Rural Affairs said it would consider “high-level diplomatic protest” to the Japanese Government. “We do not believe that Japan’s proposed lethal research that targets vulnerable humpback populations is necessary, and we have serious reservations as to its scientific value,” the department said. “We are committed to maintaining the moratorium on commercial whaling and will oppose all efforts by Japan to undermine this with so-called ’scientific’ whaling.

“We will consider high-level diplomatic protest following consultation with like-minded anti-whaling countries.”

Robbie Marsland, of the International Fund for Animal Welfare, said that footage of Japanese whaling “shows whales taking over half an hour to die a very slow and agonising death. Killing endangered whales for products that nobody needs is beneath the dignity of a great nation like Japan.”

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