"This is an historic moment for the Pacific, its people, marine life and future food security," Lagi Toribau, Greenpeace Australia's Pacific Oceans campaigner said on Wednesday.

Toribau was speaking from the environmental group's ship Esperanza, which has pestered tuna vessels in the Pacific in recent weeks as part of a campaign against overfishing of tuna.

Worldwide stocks of bigeye tuna, a prime source for Japanese restaurants serving sushi and sashimi around the world, are on the verge of collapse from overfishing, say conservationists.

The 4th Forum Fisheries Ministerial Meeting said in a statement that South Pacific island states had agreed to take immediate steps to protect bigeye and yellowfin tuna stocks.

The ministers said "high seas enclaves or donut holes" between island nations would be declared off limits to commercial fishing. Japan, Taiwan, Korea and China are the main foreign tuna fishing nations operating in the South Pacific.

The ministers also agreed to prohibit the use of fish aggregating devices (FADs), or ocean buoys and floats which attract fish, for three months each year.

Tuna vessels will also have to continuously use automatic location communicators and vessel monitoring systems and carry fisheries observers at all times, the Forum said in a statement.

"Our region will achieve success if our countries band together to adopt and implement action plans to fight illegal, unregulated and unreported fishing, both on national levels and with respect to fishing on the high seas," Palau Vice President Elias Chin told the meeting.

But Chin said the island states needed to "balance the need to preserve the fish stocks for future generations with the need to develop our economies and feed our people".

"FISH TOMORROW?"

In February the island nation Kiribati created the world's largest protected marine reserve, a California-sized watery wilderness covering 410,500 square km (158,500 square miles), to preserve tuna spawning grounds and coral reef biodiversity.

Greenpeace said decades of over-exploitation has reduced some of tuna stocks in the Pacific to just 15 percent of what they once were and that European fishing firms are now chasing tuna in the Pacific after tuna stocks fell in the Atlantic.

"It is time for fishing nations to realise that if they want fish tomorrow, we need marine reserves today," said Sari Tolvanen of Greenpeace International.

Scientists warn THAT stocks of the Atlantic bluefin tuna are dangerously close to collapse after a decade of overfishing, which has been driven by growing Asian demand for sushi.

A decline in bluefin stocks has increased demand for the bigeye tuna, which is fished in the Indian and Atlantic oceans and the Western and Central Pacific.

Indian Ocean tuna fishermen landed their smallest catch for 11 years in 2007, citing overfishing and warmer sea surface temperatures sending tuna into deeper ocean.