As the world’s oceans absorb over 90% of excess heat from greenhouse gas emissions, rising sea temperatures are driving major changes in marine ecosystems. We predict that both sperm and blue whales will shift their range southward around New Zealand by 2100, especially under more severe climate scenarios. This mouvement threatens key foraging grounds like Kaikōura and South Taranaki Bight. Protecting emerging southern habitats could offer future sanctuaries for these vital o