The Forum Fisheries Agency says two thirds of the 12-hundred foreign vessels working in the Pacific are now equipped with tracking devices.
This allows island governments to keep an eye on them as they fish for tuna inside the exclusive economic zones of Forum members.
At its annual surveillance meeting, held in Palau this year, the FFA's surveillance manager, Andrew Richards, said about 400 hundred smaller vessels have yet to install tracking devices.
They cite the cost of buying and installing the equipment as a barrier to complying with surveillance requirements.
Despite the success of surveillance, Mr Richards says many unlicensed vessels continue to fish in the area illegally.