Climate change is shifting tuna stocks eastward, threatening a key revenue source for Pacific Small Island Developing States (PSIDS), particularly the Parties to the Nauru Agreement (PNA), raising urgent climate justice concerns. This brief evaluates three response strategies—global emissions reductions, fisheries governance reform, and climate litigation—through an equity lens (distributional, procedural, intergenerational). It finds that no single strategy is sufficient; instead, a combined, coordinated approach is needed, despite embedded political and equity challenges within each pathway.