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Long-Term Acclimation of Massive Corals to End-of-Century CO2

Paper Reviewed
Wall, M., Fietzke, J., Schmidt, G.M., Fink, A., Hofmann, L.C., de Beer, D. and Fabricius, K.E. 2016. Internal pH regulation facilitates in situ long-term acclimation of massive corals to end-of-century carbon dioxide conditions. Nature/Scientific Reports DOI: 10.1038/srep30688.

Introducing their study, Wall et al. (2016) write that "the resilience of tropical corals to ocean acidification depends on their ability to regulate the pH within their calcifying fluid (pHcf)." And in this regard they note that recent work has suggested the existence of "pHcf homeostasis under short-term exposure to pCO2 conditions predicted for 2100." But they also note that "it is still unclear if pHcf homeostasis can be maintained throughout a coral's lifetime."

Determined to clarify this situation, the seven scientists note that "at CO2 seeps in Papua New Guinea, massive Porites corals have grown along a natural seawater pH gradient for decades," while further noting that "this natural gradient, ranging from pH 8.1-7.4, provides an ideal platform to determine corals' pHcf (using boron isotopes)." And what did they thereby learn?

Wall et al. write that "Porites maintained a similar pHcf (~8.24) at both a control (pH 8.1) and seep-influenced site (pH 7.9)." And noting that "a growth response model based on pHcf mirrors the observed distribution patterns of this species in the field," they go on to suggest that "Porites has the capacity to acclimate after long-time exposure to end-of-century reduced seawater pH conditions" and that "strong control over pHcf represents a key mechanism to persist in future oceans."

Posted 21 March 2017