Assessment of the quantity of tuna in Tongan waters is underway as part of a government bid to rejuvenate the industry.
At its peak more than a decade ago about 30 local boats were fishing for tuna and the record yearly catch was 2,000 tons.
Climbing fuel prices contributed to an exodus of fishing operators, with only two local boats now bringing in about 200 tons a year.
Annell Husband reports.
Nuku'alofa harbour is littered with the rusting relics of more lucrative times for fishermen and women.
One of those who's weathered the boom and bust cycle and the only woman in Tonga's fishing industry is Tricia Emberson, also the secretary general of the country's Fishing Industry Association.
She says in the late 90s she was hauling in 20 tons of tuna a week, a figure these days that's down by 18 tons.
Ms Emberson says climbing fuel costs, financial recession and mismanagement forced all but one other operator out of business.
She says only way now to make exporting sustainable is by processing the catch in Tonga.
"Here on the ground into vacuum-packed loins which could then either be air-freighted or blast frozen and sea-freighted. Reporter: [What sort of investment would you need to add that onto your plant?] The export - I mean, we do have existing plants here that have been built up to the HACCP standards that are required by the United States etc. And so it would be a minor modification/ investment so say about less than 50,000, 50,000 dollars maybe?"
She says fishing operators have to face reality.
We've been traditionally exporting fresh chilled fish with the head on by air, well, that doesn't work anymore. We've really now had to say to our buyers of fish well, just because we've been doing it that way for 20 years, we can't continue to do it that way.
Tricia Emberson says the Ministry of Fisheries is working diligently to make it possible for more locals to start fishing, for instance by establishing a a charter boat system.
There are five foreign vessels fishing in Tongan waters and Ms Emberson says the licensing of foreign vessels is a faster way of making money from tuna.
The ministry's chief executive, Dr Vailala Matoto, says recent catch rates are good, with 30 day trips resulting in catches of between 30 and 50 ton.
He says the main thing now is to complete an assessment of how much tuna is available.
Still a lot of data we need to check before you can have a very confidence of laying down a long-term development plan for the tuna industry.
Dr Vailala Matoto says Tonga's fishery is concentrated on South Pacific albacore, yellowfin and bigeye.
This is Annell Husband.