Predicted habitat shifts of Pacific top predators in a changing climate

To manage marine ecosystems proactively, it is important to identify species at risk and habitats critical for conservation. Climate change scenarios have predicted an average sea surface temperature (SST) rise of 1–6 C by 2100 (refs 1, 2), which could affect the distribution and habitat of many marine species. Here we examine top predator distribution and diversity in the light of climate change using a database of 4,300 electronic tags deployed on 23 marine species from the Tagging of Pacific Predators project, and output from a global climate model to 2100. On the basis of models of observed species distribution as a function of SST, chlorophyll a and bathymetry, we project changes in species-specific core habitat and basin-scale patterns of biodiversity. We predict up to a 35% change in core habitat for some species, significant differences in rates and patterns of habitat change across guilds, and a substantial northward displacement of biodiversity across the North Pacific. For already stressed species, increased migration times and loss of pelagic habitat could exacerbate population declines or inhibit recovery. The impending effects of climate change stress the urgency of adaptively managing ecosystems facing multiple threats. Many top predators in marine ecosystems are in decline globally owing to overfishing, bycatch and other indirect anthropogenic threats including habitat loss and changes in prey availability3. Large ocean predators can provide top-down control of food webs and when these species are removed or displaced, resulting trophic cascades can alter the stability of marine ecosystems4,5. Furthermore, changes in habitat may have multiple economic effects on coastal communities through reduced availability of ecosystem services such as fisheries landings and ecotourism. Climate change has resulted in shifts in species distributions in both terrestrial and marine systems6,7. Climate change ranks as one of the greatest anthropogenic threats to terrestrial biodiversity8, although less is known in marine systems. Models assessed by the Intergovernmental Panel on Climate Change estimate that global ocean surface temperatures will rise between 1 and 6 C by 2100 (refs 1,2). Both acute and long-term exposure to warmer waters could impact species distributions through direct physiological and indirect ecological pathways9,10. However, the rates and intensity of climate impacts will not be uniform across the world’s oceans; thus,