Science Source

Reversal of ocean acidification enhances net coral reef calcification

States that approximately one-quarter of the anthropogenic carbon dioxide released into the atmosphere each year is absorbed by the global oceans, causing measurable declines in surface ocean pH, carbonate ion concentration ([CO32−]), and saturation state of carbonate minerals (Ω)
States that laboratory and field studies have shown that calcification rates of many organisms decrease with declining pH, [CO32−], and Ω
States coral reefs are widely regarded as one of the most vulnerable marine ecosystems to ocean acidification, in part because the very architecture of the ecosystem is reliant on carbonate-secreting organisms, yet acidification-induced reductions in calcification are projected to shift coral reefs from a state of net accretion to one of net dissolution this century
Quantifies the net calcification response of a coral reef flat to alkalinity enrichment, and show that, when ocean chemistry is restored closer to pre-industrial conditions, net community calcification increases
Provides evidence that net community calcification is depressed compared with values expected for pre-industrial conditions, indicating that ocean acidification may already be impairing coral reef growth