An assessment of the number 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.
The chief executive of the Ministry of Fisheries, Dr Vailala Matoto, says the main thing is to complete an assessment of how much tuna is available but recent catch rates are good.
"Like 30 day trips - 30-day trips are easily more than 30 ton up to close to 50 ton."
Dr Vailala Matoto says Tonga's fishery is concentrated on South Pacific albacore, yellowfin and bigeye.