title: Effect of ocean acidification on iron availability to marine phytoplankton.
abstract: The acidification caused by the dissolution of anthropogenic carbon dioxide (CO2) in the ocean changes the chemistry and hence the bioavailability of iron (Fe), a limiting nutrient in large oceanic regions. Here, we show that the bioavailability of dissolved Fe may decline because of ocean acidification. Acidification of media containing various Fe compounds decreases the Fe uptake rate of diatoms and coccolithophores to an extent predicted by the changes in Fe chemistry. A slower Fe uptake by a model diatom with decreasing pH is also seen in experiments with Atlantic surface water. The Fe requirement of model phytoplankton remains unchanged with increasing CO2. The ongoing acidification of seawater is likely to increase the Fe stress of phytoplankton populations in some areas of the ocean.
authors.affiliation: Department of Geosciences, Princeton University, Princeton, NJ 08544, USA. dshi@princeton.edu
authors.forename: Dalin
authors.initials: D
authors.lastname: Shi
authors.forename: Yan
authors.initials: Y
authors.lastname: Xu
authors.forename: Brian M
authors.initials: BM
authors.lastname: Hopkinson
authors.forename: François M M
authors.initials: FM
authors.lastname: Morel
mesh_terms: D001267:Atlantic Ocean; D001272:Atmosphere; D002245:Carbon Dioxide / Q000378:metabolism; D017377:Diatoms / Q000378:metabolism*; D004492:Edetic Acid / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry; D007502:Iron Chelating Agents / Q000737:chemistry; D008024:Ligands; D008239:Lysine / Q000031:analogs & derivatives / Q000737:chemistry; D009792:Oceans and Seas; D010788:Photosynthesis; D010839:Phytoplankton / Q000378:metabolism*; D012623:Seawater / Q000737:chemistry*; D017262:Siderophores / Q000737:chemistry
chemical_list: D005290:Ferric Compounds; D007502:Iron Chelating Agents; D008024:Ligands; D017262:Siderophores; D002245:Carbon Dioxide; C041892:azotochelin; D004492:Edetic Acid; D007501:Iron; D008239:Lysine