Effect of Ocean Acidification on Iron Availability to Marine Phytoplankton

Abstract

Ironed Out In large regions of the ocean, low levels of the essential nutrient, iron, limits primary productivity. Iron's chemistry and bioavailability are highly dependent on pH. Rising concentrations of atmospheric CO 2 is leading to the acidification of the ocean. Shi et al. (p. 676 , published online 14 January; see the Perspective by Sunda ) show that the bioavailable fraction of iron dissolved in the ocean may decline as a result of the decrease in ocean pH, which affects the rate of iron uptake by diatoms and coccolithophores. Unless iron input to the oceans increases, these changes may lead to an increase in the iron stress of phytoplankton.