Climate Change Drives Marine Mammals Out of Habitat, Study Finds

A new study published by the Swiss publisher MDPI reveals that climate change is increasingly forcing marine mammals into unfamiliar and unsuitable habitats. The research, based on an online survey of experts across six continents, documented 42 species of marine mammals outside their normal ranges, including the Arctic walrus 'Magnus' off Scotland and a beluga whale in the Thames. At least 34% of all known seal and whale species are affected. The study highlights that oceans have absorbed over 90% of the excess heat from human-caused climate change, with the upper ocean warming significantly. A team led by physicist Lijing Cheng calculated that between 1995 and 2019, the oceans absorbed 228 zettajoules of energy—equivalent to 3.6 billion Hiroshima atomic bombs, or about four bombs per second. This heat is already devastating coral reefs, with 70% expected to die by mid-century and 99% by century's end. The phenomenon, termed 'out-of-habitat,' is understudied, but scientists argue that shifting water temperatures and food availability force animals to seek new habitats. Notably, a population of endangered Galápagos sea lions now lives in its third generation on an island 1,800 kilometers from its original home, according to lead author Maia Killing of the University of Bristol.