Small Pacific island states and powerful foreign fishing nations are heading for a showdown next week over management of the world's largest tuna fishery.

The islands want the annual meeting of the influential Western and Central Pacific Fisheries Commission (WCPFC) in Samoa to limit fishing for bigeye, a tuna prized by sashimi markets in Asia, America and Europe.

They also want limits placed on catches of other tunas to maintain stocks.

Nearly 60 percent of global tuna supplies comes from the central and western Pacific which has been "fished unsustainably, in contradiction to strong scientific and management advice", said Amanda Nickson, director of Global Tuna Conservation at the Washington-based Pew Charitable Trusts.

"Today, 50 more large-scale purse seine vessels are fishing these waters than 10 years ago."

Despite increasing concern over declining tuna stocks in the Pacific's US$6.0 billion fishery, the WCPFC has been unable to agree on measures that will limit fishing to what scientists see as sustainable levels.

The WCPFC includes the so-called "distant water" fleets from as far afield as Europe, China, South Korea, Japan and Taiwan.

Battle lines have now been drawn between these nations, which dominate fishing in the region, and the Pacific islands which have banded together to wield greater influence in the industry.

"The tuna commission needs to change its way of doing business and how it treats small island developing states," Glen Joseph, the Marshall Islands director of fisheries, said ahead of the December 1-5 summit.

Joseph is frustrated by what he says is a lack of action on high seas fishing, a WCPFC responsibility, to back the conservation measures eight Pacific nations, known as the Parties to the Nauru Agreement (PNA), have imposed in their economic zones.

"The WCPFC must step up by taking effective action to curtail overfishing of bigeye in our fishery," said PNA chief executive Transform Aqorau.

"Each year, stock assessments have painted a bleaker picture about the status of bigeye and yellowfin tuna. The WCPFC cannot continue avoiding the issue.

"Bigeye is now subject to overfishing and yellowfin stocks are being fished at their maximum capacity. This is not sustainable and must be reversed."

The PNA has put an action plan on the table at the summit to cutback the catches of long-line vessels which target bigeye and yellowfin.

They also want to reduce the ability of purse seine fishing boats that use large nets to scoop out tonnes of tuna at once.

In the 10 years since the WCPFC was established, several Asian nations have refused to provide their catch data which is a requirement of membership.