There are calls by regulators and environmentalists for the annual catch of bigeye tuna to be reduced by 30 per cent.
But that will draw opposition from commercial fisheries in the western and central Pacific, which is the source of about half the world's global tuna supply.
Correspondent: Cathy Harper
Speakers: Professor Glenn Hurry, executive director for the Western and Central Pacific Fisheries Commission; Nanette Malsol, chair, Parties to the Nauru Agreement; Adam Baske, Pew Environment Group
HARPER: Bigeye tuna is highly sought after in China, Japan, the Unites States and Europe. Fishing fleets in the Western and Central Pacific catch more than 150,000 tonnes of bigeye a year.
The Western and Central Pacific Fisheries Commission - which regulates commercial fishing in the vast area of sea from Hawaii to Indonesia - says that's too much.
HURRY: The scientific advice on it has been consistent over the last three or four years that we need about a 30 percent reduction in the level of catch
HARPER: Professor Glenn Hurry is the executive director of the Western and Central Pacific Fisheries Commission. He's currently in the Philippines capital Manila for the Commission's annual meeting, where hundreds of delegates from interested nations have gathered.
HURRY: The underlying stock is OK. It's not overfished in the sense that we've fished the female stock down too low but there's too much fishing on the stock at the moment and it's got to reduced by about 30 percent.
HARPER: Do you think that big fishing nations like China, Japan and the Unites States will agree to that?
HURRY: We are in the middle of our first debate on it at the moment. And there's a lot of different opinions coming forward about which is the best way to move forward on this. But I think there's an acknowledgement that we do need to deal with this issue.
HARPER: What do you think is the best way to stop overfishing of bigeye tuna?
HURRY: The problem with this stock is that we fish it at both ends of its life cycle. It's caught as by-catch when it's a juvenile fish, so it's picked up as part of using fish aggregating devices, But it's also targetting as a high grade market fish by the long liners in it's adult stage. But we're trying to get a form of closure of the use of FADS in the fishery, which woud be August, September, October, November each year. Alternatively, we get three months and a reduction in the long line catch
HARPER: FADS, or fish aggregating devices, are makeshift structures that float on or just below the surface of the ocean which attract schools of fish, which are then scooped up by large nets.
Smaller Pacific nations are lobbying hard for the use of FADS to be restricted. Nanette Malsol is the chair of a group of eight Pacific nations called PNA, or Parties to the Nauru Agreement.
MALSOL: We are calling on the fishing nations to stop overfishing of the big-eye tuna because it is already in an over-fished state.
HARPER: How bad do you think the problem is?
MALSOL: The problem is really bad because it is already effecting our smaller, domestic tuna fisheries. The PNA countries have already implemented a range of measures and that includes having FAD closures inside our waters, implementing a monitoring system, having observers on board in making sure that all the data collection is provided and monitored. We would also like to see that the distant water fishing nations can also do their part in implementing and making sure that they are putting conservation efforts to protect fisheries that are already effecting the economics of our small island developing countries.
HARPER: Calls for restrictions on the use of fish aggregation devices are supported by the Pew Environment Group, which has used the beginning of the fishing commission's conference to release what it says is the first-ever estimate of the use of FADS. The lead-author of the Pew research is Adam Baske.
BASKE: The current practice over the last 20 years, where the big uncontrolled proliferation of FADS has been happening, industry and governments have really been gambling with sustainability by using this gear and not managing it effectively. So it's time that we cracked down and managed this
HARPER: Heated debate will be held over the next few days, with the fishing industry expected to oppose moves to restrict their catch. Any agreement will have to be reached by Thursday.