The total annual catch of skipjack, yellowfin, bigeye and albacore tuna from the Western and Centre Pacific Ocean has recently been as high as 2.5 million tonnes.
Secretariat of the Pacific Community's principal fisheries scientist (climate change) Doctor Johann Bell said about half of this significant catch comes from the exclusive economic zones of Pacific Island countries and territories.
A large team of scientists has identified the changes that are likely to occur to the currents, water temperatures, dissolved oxygen levels and nutrient supply of the tropical Pacific Ocean that influence the distribution of tuna.
The results have been set out in a book published by SPC entitled Vulnerability of Tropical Pacific Fisheries and Aquaculture to Climate Change.
The changes to the ocean are likely to affect where tuna spawn, the survival and growth of juveniles, and where the adults feed.
"The abundant skipjack tuna are expected to move progressively east," Dr Bell said.
He said it was still too early to tell how many more skipjack tuna could be caught in Fiji's waters but some increase in catches was expected over the next few decades.
"The modelling done by the scientists must be considered as preliminary.
"It is very important that further investments in modelling the expected response of tuna to the changing ocean are made," he said.
"Only then will it be possible to advise the government of Fiji about the likely extent of changes in skipjack numbers within the nation's exclusive economic zone with confidence," he added.
The preliminary results of the tuna modelling were presented at a workshop held in Suva this week on 'Priority adaptations to climate change for fisheries and aquaculture in Fiji: reducing risks and capitalising on opportunities'.