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Impacts of Future pH Reductions on the Early Life of Reef Corals

Paper Reviewed
Chua, C.-M., Leggat, W., Moya, A. and Baird, A.H. 2013. Near-future reductions in pH will have no consistent ecological effects on the early life-history stages of reef corals. Marine Ecology Progress Series 486: 143-151.

In the words of Chua et al. (2013), "until recently, research into the consequences of oceanic uptake of CO2 for corals focused on its effect on physiological processes, in particular, calcification." However, they note that "events early in the life history of corals are also likely to be vulnerable to changes in ocean chemistry caused by increases in the atmospheric concentration of CO2." Focusing on these early life history events, Chua et al. thus set out to test "the effect of reduced pH on embryonic development, larval survivorship and metamorphosis of 3 common scleractinian corals from the Great Barrier Reef," employing "4 treatment levels of pH, corresponding to the current level of ocean pH and 3 values projected to occur later this century."

In describing their findings the four researchers report - quite bluntly and very simply - that "none of the early life-history stages we studied were consistently affected by reduced pH." In light of these favorable findings, Chua et al. conclude - again in very blunt and forceful language - that "there will be no direct ecological effects of ocean acidification on the early life-history stages of reef corals, at least in the near future." And so it would appear that wave upon wave of new reef coral "youngsters" might well have a significant period of time during which they - and their descendants' descendants - could conceivably better learn to cope with slowly declining-pH seawater.

Posted 9 October 2014