New paper finds corals are thriving in 'naturally acidified' waters

A paper published today in Geophysical Research Letters finds coral reefs are thriving in "naturally acidified" waters in Palau, one of the top diving destinations in the world.

According to the authors, "we report the existence of highly diverse, coral-dominated reef communities under chronically low pH and aragonite saturation state...where acidification levels approach those projected for the western tropical Pacific open ocean by 2100. Nevertheless, coral diversity, cover and calcification rates are maintained [normal] across this natural acidification gradient."

Diverse Coral Communities in Naturally Acidified Waters of a Western Pacific Reef

Kathryn E. F. Shamberger, et al

Anthropogenic carbon dioxide emissions are acidifying the oceans, reducing the concentration of carbonate ions ([CO32-]) that calcifying organisms need to build and cement coral reefs. To date, studies of a handful of naturally acidified reef systems reveal depauperate communities, sometimes with reduced coral cover and calcification rates, consistent with results of laboratory-based studies. Here, we report the existence of highly diverse, coral-dominated reef communities under chronically low pH and aragonite saturation state (Ωar). Biological and hydrographic processes change the chemistry of the seawater moving across the barrier reefs and into Palau's Rock Island bays, where acidification levels approach those projected for the western tropical Pacific open ocean by 2100. Nevertheless, coral diversity, cover and calcification rates are maintained across this natural acidification gradient. Identifying the combination of biological and environmental factors that enable these communities to persist could provide important insights into the future of coral reefs under anthropogenic acidification.


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New paper finds prior claims about effects of ocean "acidification" may be overblown

Prior posts on ocean 'acidification'