More than half the world's tuna is caught in the region, and the industry's worth more than 5 billion US dollars a year.
But big fishing nations aren't showing the kind of interest conservation agencies say is needed to keep enough fish in the sea to keep tuna-fishing sustainable.
The region's also home to multi-million-dollar tourism industries centred on whale and shark-diving - so there's a lot at stake.
One of the world's leading conservation agencies the Pew Environment Group has been laying out what it says must be achieve in the Philippines.
Corinne Podger reports.
Presenter: Corinne Podger
Speaker: Pew Environment Group's head of global tuna conservation, Amanda Nickson,Pew's manager of Global Shark Conservation, Elizabeth Wilson and Gerald Leape, from the Pew Environment Group in Washington
PODGER: The WCPFC meeting will bring together delegations from 25 countries from December the second to the sixth, to debate the conservation and management of tuna, whales and sharks, and measures to tackle illegal fishing. But there's pressure from Western and Asian nations for more fishing in the high seas and few signs of the traction Pacific island states want on conservation - especially for tuna species like skipjack, bluefin and big-eye. The Pew Environment Group's head of global tuna conservation is Amanda Nickson.
NICKSON: This year, what needs to happen is that based on the scientific advice the new conservation and management measure needs to ensure that there are fewer juvenile tuna being caught when you stack fish aggregating devices in the water and that means that we want to see fish aggregating device closures, their FAD closures and also we want to see a limit on the number of FADS that can be set to 2010 levels which would be about 15,000 FAD sets per year.
We also know from the scientific advice that's been provided that there needs to be action taken, both by purse seiners which are catching on the FADS, but also by the long liners that are catching the adult big-eye tuna. So we need to see actions taken to limit the capture of big-eye on both of those gears.
PODGER: Pew's manager of Global Shark Conservation, Elizabeth Wilson, says while Pacific states have done well in creating new sanctuaries, the WCPFC has done little to broaden or strengthen that work. She says some of the steps involved would be relatively straightforward.
WILSON: They should improve the existing shark finning regulations, which is complicated and difficult to enforce. This should be done by requiring all sharks to be landed with their fins still naturally attached. Second, WCPFC should reduce by catch of sharks by prohibiting the use of wire leaders on long lines. The leader is what connects the hook to the fishing line. Wire leaders are stronger than ones made out of fishing line and they prevent sharks caught from being able to break free, thus increasing shark mortality.
PODGER: A more complicated but equally necessary measure is a ban on the setting of fishing nets around whale-sharks. Ms Wilson says tuna often congregate around these massive creatures, which can be up to ten metres long. Last year more than 50 whalesharks died after getting caught in fishing nets - a serious blow to a species listed as vulnerable by the World Conservation Union.
Pacific nations are planning to lobby in Manila for an end to practices that threaten sharks, but Elizabeth Wilson says their proposals are full of loopholes and it's unclear whether they'll win broader support. But she says progress at last year's meeting at least paved the way for better protection for whalesharks.
WILSON: Well, a similar measure was put in place for citations last year, basically saying that you can't cite your nets around dolphins and whales and that they decided they would consider whaleshark this year. So the parties have had a year to think about it, so we are hopeful that some of those larger countries that raised concerns last time that will be supportive this time.
PODGER: The Pew Environment Group's delegation to Manila will be led by Gerald Leape. He's keen to see the mandatory expansion of an existing ID system for fishing vessels, which link catches directly to the boat that took them from the sea, irrespective of where they put into port.
LEAPE: Currently, there's 59 per cent of all the vessels at the WCPFC has this number. This is like a number of permanent number that you'll find on your car or on your IPhone. You wouldn't buy any those without a permanent identification number and these boats should be required to have them as well. This would be a tool to help track those illegal fishing boats, those who don't have them and prevent them from selling their catch.
PODGER: Mr Leape says he also wants tighter - and broader - inspection responsibilities for port officials, and stronger regulations on trans-shipments, to stop vessels from offloading fish illegally at sea rather than putting into port.
With big fishing nations indicating ahead of the Manila meeting that they don't have the same conservation priorities as Pacific nations, there'll be heated debate in Manila. But Gerald Leape says the outcome of a meeting of the International Commission for the Conservation of Atlantic Tunas earlier this month have left him hopeful of some positive outcomes at least by the WCPFC.
LEAPE: They were faced with a very similar challenge which was whether to stick with the scientific advice or to pay attention to their industry that wanted them to move beyond and many of these same parties that we'll see next week at the Western and Central Pacific Fisheries Mission chose to back the scientific advice over the objections of their industry. And I think there's a growing recognition that changes need to be made to be consistent with the scientific advice they've received. They currently want other people to take the compromises and not themselves. But I think we'll be working with them to remind them of these distant water fishing nations of the actions they took a few weeks ago to say listen, you need to do the same thing here. The science is just as important here as it was in the Atlantic.