Near-shore Antarctic pH variability has implications for the design of ocean acidification experiments

TitleNear-shore Antarctic pH variability has implications for the design of ocean acidification experiments
Publication TypeJournal Article
Year of Publication2015
AuthorsHofmann G., Kelley A.L, Shaw E.C, Martz T.R, Hofmann G.E
JournalScientific Reports
Date Published2015/04
Type of ArticleArticle
ISBN Number2045-2322
Accession NumberWOS:000352468500001
Keywordsadaptation; annual cycle; carbonic-acid; east antarctica; local; mcmurdo-sound; prydz bay; ross sea; seasonal patterns; seawater; southern-ocean

Understanding how declining seawater pH caused by anthropogenic carbon emissions, or ocean acidification, impacts Southern Ocean biota is limited by a paucity of pH time-series. Here, we present the first high-frequency in-situ pH time-series in near-shore Antarctica from spring to winter under annual sea ice. Observations from autonomous pH sensors revealed a seasonal increase of 0.3 pH units. The summer season was marked by an increase in temporal pH variability relative to spring and early winter, matching coastal pH variability observed at lower latitudes. Using our data, simulations of ocean acidification show a future period of deleterious wintertime pH levels potentially expanding to 7-11 months annually by 2100. Given the presence of (sub) seasonal pH variability, Antarctica marine species have an existing physiological tolerance of temporal pH change that may influence adaptation to future acidification. Yet, pH-induced ecosystem changes remain difficult to characterize in the absence of sufficient physiological data on present-day tolerances. It is therefore essential to incorporate natural and projected temporal pH variability in the design of experiments intended to study ocean acidification biology.

Short TitleSci Rep
Student Publication: