title: Multidecadal increase in North Atlantic coccolithophores and the potential role of rising CO₂.
abstract: As anthropogenic carbon dioxide (CO2) emissions acidify the oceans, calcifiers generally are expected to be negatively affected. However, using data from the Continuous Plankton Recorder, we show that coccolithophore occurrence in the North Atlantic increased from ~2 to more than 20% from 1965 through 2010. We used random forest models to examine more than 20 possible environmental drivers of this change, finding that CO2 and the Atlantic Multidecadal Oscillation were the best predictors, leading us to hypothesize that higher CO2 levels might be encouraging growth. A compilation of 41 independent laboratory studies supports our hypothesis. Our study shows a long-term basin-scale increase in coccolithophores and suggests that increasing CO2 and temperature have accelerated the growth of a phytoplankton group that is important for carbon cycling.
authors.affiliation: Department of Earth and Planetary Sciences, The Johns Hopkins University, Baltimore, MD, USA. Applied Physics Laboratory, The Johns Hopkins University, Baltimore, MD, USA. sara.rivero@jhu.edu gnanades@jhu.edu.
authors.forename: Sara
authors.initials: S
authors.lastname: Rivero-Calle
authors.affiliation: Department of Earth and Planetary Sciences, The Johns Hopkins University, Baltimore, MD, USA. sara.rivero@jhu.edu gnanades@jhu.edu.
authors.forename: Anand
authors.initials: A
authors.lastname: Gnanadesikan
authors.affiliation: Department of Earth and Planetary Sciences, The Johns Hopkins University, Baltimore, MD, USA. Goddard Space Flight Center, National Aeronautics and Space Administration, Greenbelt, MD, USA.
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Del Castillo
authors.affiliation: Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, USA.
authors.forename: William M
authors.initials: WM
authors.lastname: Balch
authors.affiliation: Department of Industrial and Operations Engineering, The University of Michigan, Ann Arbor, MI, USA.
authors.forename: Seth D
authors.initials: SD
authors.lastname: Guikema
mesh_terms: D001267:Atlantic Ocean; D002245:Carbon Dioxide / Q000378:metabolism*; D057232:Global Warming; D006358:Hot Temperature; D009792:Oceans and Seas; D010839:Phytoplankton / Q000378:metabolism*; D012623:Seawater
chemical_list: D002245:Carbon Dioxide