The Pacific islands ‘tuna cartel’ is boosting jobs by watching fish Monitoring fishing vessels could be a growth industry in the Pacific island nations that govern the world’s largest tuna fishery. By flexing its collective muscle, the PNA “tuna cartel” – the source of more than half the world’s tuna cannery supply – has generated significant benefits for members. Explain how the Pacific islands’ action influences the efficiency of the use of tuna resources and illustrate your answer with a graph of the tuna market.