American researchers are calling for the Western and Central Pacific Fisheries Committee to ban trans-shipping.
Monitors observing a purse seiner unloading in Majuro Photo: Hillary Hosia
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The Pew Charitable Trust said tens of millions of dollars each year was lost to the practice of offloading catch before it reached its final destination.
A 2016 survey found that dozens of vessels were likely carrying out unauthorised trans-shipment in the Pacific.
Lead author Mark Young said the commission needed to introduce stronger monitoring processes, including mandatory fishing observers.
"Just taking a look at the public information that was available, the way they manage it was compromised because of the amount of information gaps or non-standardised reporting, or even the lack of reporting."
Mr Young said changes would come down to the political will of Pacific member states.