"Sabotage by activists is a major factor behind our failure to achieve our target," a Fisheries Ministry official said
The Sea Shepherd Conservation Society says its campaign saved 500 whales.
Greenpeace Japan, which also carried out activities aimed at obstructing the hunt, said it was not satisfied with the reduced catch.
"They say that one reason for the lower catch is that they didn't see so many whales," said Junichi Sato of Greenpeace. "That is a good reason why they should not conduct lethal research."
He added that, despite the reduction, the number of whales actually killed was more than three years ago.
Japan kills whales under an internationally permitted research program, despite a 1986 ban on commercial whaling. Critics, however, say the program is a cover for Japan's ailing whaling industry, and demand it be stopped.
Greenpeace says the international convention that helped save the elephant and rhino from extinction at the hands of poachers is being ignored by the Japanese Fisheries Agency to continue whaling in the Southern Ocean Whale Sanctuary.
"Japan's research whaling program is a national embarrassment," said Greenpeace Japan Whales Project Leader Junichi Sato, "it is riddled with illegalities and instances where international law has been bent, broken, and bypassed; it continues to strain relations with our allies around the world and tarnish Japan's reputation. It's time for Japan to stop whaling in the Southern Ocean forever."
Greenpeace is also calling for an investigation into the refuelling of the fleet in the Antarctic treaty zone - breaching the spirit of the Antarctic treaty, to which they are a signatory, and using a vessel with no permit as part of the fleet to do so.
Meanwhile the Japanese fisheries agency said Friday up to 60 minke whales in the north Pacific Ocean will be caught in the coming month for "research."
Five boats will be dispatched today off northern Japan for the "research" mission that will run through late May. The agency said "researchers" will study the whales' dietary intake and the data will be used to analyze the whale population's impact on fishery resources.
Business Week says Japanese consumers' demand for whale meat peaked after World War II, when protein was in short supply; it has declined steadily since, although whale meat is still considered a traditional food.
By the way, it isn't only Japan. That other cruel and ecologically insensitive whaling nation Norway has set a kill quota of 1052 whales for 2008.
The quota is the same as last year despite the whalers being unable to find enough whales to meet that quota. The actual kill was 97 whales short of 1052.
The majority of these whales will be taken from the coastal areas around the Barents Sea, Svalbard and the North Sea.
The following is from TV3 News, New Zealand.
Japan catches fewer whales because of protestors
Japan's Antarctic whaling catch fell far short of its target in the season just past - because of the efforts of anti-whaling protesters.
Fisheries Ministry statistics released last night show the fleet caught only 551 minke whales - compared to a planned catch of 850.
No fin whales were caught at all, although the fleet had set itself a target of 50.
The ministry says sabotage by activists was the major factor behind the failure to achieve the target.
Greenpeace sent a ship to the Southern Ocean to disrupt the whale hunt, but most of the problems were caused by the Sea Shepherd Conservation Society, which repeatedly confronted the fleet.