Kiwi scientists are helping Tonga make the most of its commercial fisheries.

Scientists are in Tonga working with the government and local fishing industry to explore ways to maximise economic returns for the island nation.

NIWA principal scientist, Stuart Hanchet, says at the moment waters around Tonga are being fished mainly by overseas interests.

"A lot of the Tuna spots in particular are fished by foreign countries, China, Taiwan or Indonesia."

Stuart Hanchet says he'll be teaching Tongan fisheries staff how to better analyse and manage the fisheries industry.