Before a crucial meeting in Cairns next month on the future rules of tuna fishing in the Pacific, the Forum Fisheries Agency says some countries need to lift their standards.
The Deputy Director General of the Forum Fisheries Agency, Wez Norris, says it's hard to gauge the tuna catch of some longline vessels as they are operating on the high seas and offloading their stock onto other vessels.
The observer programme has been effective on vessels that operate closer to the exclusive economic zones, but regional bodies are now looking at electronic monitoring of longline vessels, including video cameras.
Wez Norris says one of the items on the agenda for the Tuna Commission meeting in December will be how distant water nations should hold their vessels to account.
"We do need to step up the standards that the flag states are holding their vessels to in terms of providing information and reporting, and not undertaking some of the sorts of activities that can support illegal fishing, like trans-shipment on the high seas."