Changes in pH at the exterior surface of plankton with ocean acidification

Kevin Flynn, Jerry C Blackford, Mark Edward Baird, John A Raven, Darren R Clark, John Beardall, Colin Brownlee, Heiner Fabian, Glen L Wheeler

Research output: Contribution to journalArticleResearchpeer-review

124 Citations (Scopus)


Anthropogenically released CO 2 is dissolving in the ocean, causing a decrease in bulk-seawater pH (ocean acidification). Projections indicate that the pH will drop 0.3 units from its present value by 2100 (ref. 1). However, it is unclear how the growth of plankton is likely to respond. Using simulations we demonstrate how pH and carbonate chemistry at the exterior surface of marine organisms deviates increasingly from those of the bulk sea water as organism metabolic activity and size increases. These deviations will increase in the future as the buffering capacity of sea water decreases with decreased pH and as metabolic activity increases with raised seawater temperatures. We show that many marine plankton will experience pH conditions completely outside their recent historical range. However, ocean acidification is likely to have differing impacts on plankton physiology as taxon-specific differences in organism size, metabolic activity and growth rates during blooms result in very different microenvironments around the organism. This is an important consideration for future studies in ocean acidification as the carbonate chemistry experienced by most planktonic organisms will probably be considerably different from that measured in bulk-seawater samples. An understanding of these deviations will assist interpretation of the impacts of ocean acidification on plankton of different size and metabolic activity.
Original languageEnglish
Pages (from-to)510 - 513
Number of pages4
JournalNature Climate Change
Issue number7
Publication statusPublished - 2012

Cite this