Small Pacific Island states depend on their commercial fisheries for food supplies and economic health. But our new research shows climate change will dramatically alter tuna stocks in the tropical Pacific, with potentially severe consequences for the people who depend on them.

As climate change warms the waters of the Pacific, some tuna will be forced to migrate to the open ocean of the high seas, away from the jurisdiction of any country. The changes will affect three key tuna species: skipjack, yellowfin, and bigeye.

Pacific Island nations such as the Cook Islands and territories such as Tokelau charge foreign fishing operators to access their waters, and heavily depend on this revenue. Our research estimates the movement of tuna stocks will cause a fall in annual government revenue to some of these small island states of up to 17%.

This loss will hurt these developing economies, which need fisheries revenue to maintain essential services such as hospitals, roads and schools. The experience of Pacific Island states also bodes poorly for global climate justice more broadly.