title: Why marine phytoplankton calcify.
abstract: Calcifying marine phytoplankton-coccolithophores- are some of the most successful yet enigmatic organisms in the ocean and are at risk from global change. To better understand how they will be affected, we need to know "why" coccolithophores calcify. We review coccolithophorid evolutionary history and cell biology as well as insights from recent experiments to provide a critical assessment of the costs and benefits of calcification. We conclude that calcification has high energy demands and that coccolithophores might have calcified initially to reduce grazing pressure but that additional benefits such as protection from photodamage and viral/bacterial attack further explain their high diversity and broad spectrum ecology. The cost-benefit aspect of these traits is illustrated by novel ecosystem modeling, although conclusive observations remain limited. In the future ocean, the trade-off between changing ecological and physiological costs of calcification and their benefits will ultimately decide how this important group is affected by ocean acidification and global warming.
authors.affiliation: School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK.
authors.forename: Fanny M
authors.identifier: 0000-0002-8790-0188
authors.initials: FM
authors.lastname: Monteiro
authors.affiliation: GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105 Kiel, Germany.
authors.forename: Lennart T
authors.identifier: 0000-0003-0202-3671
authors.initials: LT
authors.lastname: Bach
authors.affiliation: Marine Biological Association, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK.
authors.forename: Colin
authors.initials: C
authors.lastname: Brownlee
authors.affiliation: Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK.
authors.forename: Paul
authors.identifier: 0000-0001-6777-4463
authors.initials: P
authors.lastname: Bown
authors.affiliation: Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK.
authors.forename: Rosalind E M
authors.identifier: 0000-0002-6095-8419
authors.initials: RE
authors.lastname: Rickaby
authors.affiliation: Ocean Biogeochemistry and Ecosystems, National Oceanography Centre, Southampton SO14 3ZH, UK.
authors.forename: Alex J
authors.identifier: 0000-0002-5149-6961
authors.initials: AJ
authors.lastname: Poulton
authors.affiliation: Ocean and Earth Science, University of Southampton, Southampton SO17 1BJ, UK.
authors.forename: Toby
authors.initials: T
authors.lastname: Tyrrell
authors.affiliation: Aix-Marseille University/CNRS, Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement (CEREGE), 13545 Aix-en-Provence, France.
authors.forename: Luc
authors.initials: L
authors.lastname: Beaufort
authors.affiliation: Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Stephanie
authors.identifier: 0000-0002-0380-9679
authors.initials: S
authors.lastname: Dutkiewicz
authors.affiliation: Ocean and Earth Science, University of Southampton, Southampton SO17 1BJ, UK.
authors.forename: Samantha
authors.initials: S
authors.lastname: Gibbs
authors.affiliation: Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA 95039, USA.
authors.forename: Magdalena A
authors.initials: MA
authors.lastname: Gutowska
authors.affiliation: Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK.
authors.forename: Renee
authors.initials: R
authors.lastname: Lee
authors.affiliation: GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105 Kiel, Germany.
authors.forename: Ulf
authors.initials: U
authors.lastname: Riebesell
authors.affiliation: Museum of Natural History, Cromwell Road, London SW7 5BD, UK.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Young
authors.affiliation: School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK.; Department of Earth Sciences, University of California, Riverside, Riverside, CA 92521, USA.
authors.forename: Andy
authors.identifier: 0000-0003-2333-0128
authors.initials: A
authors.lastname: Ridgwell
mesh_terms: D002113:Calcification, Physiologic / Q000502:physiology*; D002119:Calcium Carbonate / Q000737:chemistry; D017753:Ecosystem; D057232:Global Warming; D058087:Haptophyta / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D009792:Oceans and Seas; D010788:Photosynthesis; D012623:Seawater / Q000737:chemistry
chemical_list: D002119:Calcium Carbonate
keywords: Coccolithophores; calcification; ecological and physiological costs and benefits; ecosystem modeling; photosynthesis; trade-offs