title: Comment on "Calcareous nannoplankton response to surface-water acidification around Oceanic Anoxic Event 1a".
abstract: Erba et al. (Reports, 23 July 2010, p. 428) attributed calcareous nannofossil morphology and assemblage changes across Cretaceous Oceanic Anoxic Event 1a to the effects of surface ocean acidification. We argue that the quality of carbonate preservation in these sequences, the unsupported assumptions of the biotic response to acidity, and the absence of independent proxy estimates for ocean pH or atmospheric pCO(2) render this conclusion questionable.
authors.affiliation: School of Ocean and Earth Sciences, National Oceanography Centre, Southampton, European Way, Southampton, SO14 3ZH, UK. sxg@noc.soton.ac.uk
authors.forename: Samantha J
authors.initials: SJ
authors.lastname: Gibbs
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Robinson
authors.forename: Paul R
authors.initials: PR
authors.lastname: Bown
authors.forename: Tom Dunkley
authors.initials: TD
authors.lastname: Jones
authors.forename: Jorijntje
authors.initials: J
authors.lastname: Henderiks
mesh_terms: D000222:Adaptation, Physiological; D001272:Atmosphere; D002113:Calcification, Physiologic; D002119:Calcium Carbonate / Q000032:analysis / Q000737:chemistry*; D002245:Carbon Dioxide; D017753:Ecosystem; D005580:Fossils; D019015:Geologic Sediments; D006863:Hydrogen-Ion Concentration; D009792:Oceans and Seas; D010100:Oxygen; D010933:Plankton / Q000166:cytology / Q000502:physiology; D012623:Seawater / Q000737:chemistry*; D013995:Time
chemical_list: D002245:Carbon Dioxide; D002119:Calcium Carbonate; D010100:Oxygen