The reasons to fear ocean acidification related to the dissolution of additional carbon dioxide in the world’s oceans continue to mount. In a new article in the journal Science, Shi, et al., Effect of Ocean Acidification on Iron Availability to Marine Phytoplankton, 327 Science 676-679 (Feb. 2010) (subscription required), the researchers conclude that acidfication could decrease the uptake of a critical micronutrient, iron, for many diatoms and coccolithophores. The study found that iron uptake rates decreased by 10-20% in a high ph (8.4) environment for a modeled phytoplankton species. As a consequence, the study concluded that “the net result of seawater acidification should be an increase in the Fe-stress of the phytoplankton in many areas of the oceans.”
Given the fact that phytoplankton help to facilitate the sequestration of significant amounts of carbon dioxide, one wonders if another positive feedback mechanism for warming might be in the making, establishing a nexus between acidification and warming. At the very least, any mechanism that threatens species at the base of the ecosystem is frightening.