Elkhorn coral form thick branching calcium carbonate skeletons. Ocean acidification threatens the integrity of this structural reef builder which provides habitat for other reef dwellers. Ocean acidification also has the potential to compromise the successful fertilization, larval settlement and survivorship of Elkhorn coral. This along with other stressors such as disease, hurricanes, predation, bleaching, algae overgrowth, sedimentation, temperature and salinity variation, and low genetic diversity threaten the long term survival of this endangered species.
The ocean absorbs carbon dioxide from the atmosphere which results in seawater becoming more acidic (lower pH). This increase in ocean acidity makes it difficult for some calcifying organisms (e.g. calcareous plankton, oysters, clams, corals, etc.) to make or maintain their shells or exoskelatons. Other important physiological processes of marine organisms can be disrupted by increased acidity as well. Many of the potentially impacted ocean plants and animals are important in marine food webs or are important commercial species.
Coccolithophores (L) and pteropods (R) are small organisms whose ability to form calcium carbonate shells is affected by ocean acidification.