South Pacific nations have taken steps to shore up dwindling tuna stocks, banning licensed tuna vessels from fishing in international waters between their islands and requiring them to always carry observers.

The new rules, agreed to at a fisheries meeting in Palau on Tuesday, will take effect beginning June 15.

“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 yesterday.

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.