Feb 24, 2016

Reversal of ocean acidification enhances net coral reef calcification

Rebecca Albright, Lilian Caldeira, Jessica Hosfelt, Lester Kwiatkowski, Jana K. Maclaren, Benjamin M. Mason, Yana Nebuchina, Aaron Ninokawa, Julia Pongratz, Katharine L. Ricke, Tanya Rivlin, Kenneth Schneider, Marine Sesboüé et al
  • 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