A report shows Pacific licensed vessels or fleets are heavily involved in illegal, unreported and unregulated fishing in the region.
The Quantification of IUU Fishing in the Pacific Islands Region Report also concluded that it's dominated by misreporting.
It said most of this misreporting was in the purse-seine fishing sector, despite 100 percent observer coverage providing independent estimates of catch.
But it does say it can be challenging to identify species and estimate catch at sea due to the scale of the catches.
The report further stated about 152 million US dollars of misreported catch volume was accounted for by the purse-seine fishing sector.
While there is less IUU fishing estimated in longline fisheries, because their targetted catch is more valuable their catch comprises more than half the dollar value of IUU fishing - about US$181 million.
The report, which was compiled from a second study after the first in 2016, also highlighted that only 5 percent of the overall estimated IUU catch was thought to be from unlicensed fishing.
Photo: Supplied/ the Business & Human Rights Resource Centre