http://thinkprogress.org/climate/2015/05/12/3657571/carbon-pollution-sea-life/
"as carbon dioxide is absorbed in water it causes chemical reactions that reduce “saturation states of biologically important calcium carbonate [CaCO3] minerals,” which “are the building blocks for the skeletons and shells of many marine organisms,” as NOAA explains. In the parts of the ocean teeming with life, the seawater has an overabundance (supersaturation) of these calcium carbonate minerals used by so-called “calcifying organisms,” which include corals and algae and mollusks and some plankton.
As the ocean absorbs more carbon dioxide, more and more places are becoming undersaturated with these minerals, thereby threatening calcifying organisms. Besides a decline in calcification, the World Meteorological Organization explained in 2014, “Other impacts of acidification on marine biota include reduced survival, development and growth rates, as well as changes in physiological functions and reduced biodiversity"."
