The eight member fisheries coalition, the Parties to the Nauru Agreement, says its leading role in conserving Bigeye tuna stocks has helped recovery of the resource.
The PNA's chief executive Ludwig Kumoru said the Western and Central Pacific Fishery Commission announced the improved status of Bigeye stocks at a recent meeting in the Cook Islands.
Mr Kumoru said since 2007, PNA countries had been strongly focused on Bigeye recovery by managing fishers who used aggregation devices, or FADs.
He said the PNA had led the region's tuna conservation initiatives in their exclusive economic zones, which covered a combined area of 14.8 million square kilometres, with measures including 100 percent observer coverage on fishing vessels.
But Mr Kumoru said regrettably many fishing nations operating industrialised longliner vessels that target mature Bigeye for the sashimi trade, had failed to take equivalent measures to protect the tuna.
He said despite this non-compliance he was looking forward to continued improvement in the next Big Eye tuna stock assessment in 2020.