Marine phytoplankton and zooplankton form the basis of the ocean's food-web, yet the impacts of climate change on their biodiversity are poorly understood. This study uses an ensemble of species distribution models for 336 phytoplankton and 524 zooplankton species to determine their present and future habitat suitability patterns. Under a high emission scenario, by the end of the century, an overall increase in plankton species richness is projected, driven by ocean warming and a poleward shift of species' distributions. Significant regional variations are observed, with increases in phytoplankton richness in most regions (except the Arctic), and increases in zooplankton richness in temperate to subpolar latitudes but decreases in the tropics. Substantial assemblage replacement (nearly 40%) is predicted in temperate and subpolar latitudes, posing a threat to plankton-mediated ecosystem services.

Fabio Benedetti, Meike Vogt, Urs Hofmann Elizondo, Damiano Righetti, Niklaus E. Zimmermann, Nicolas Gruber