- Increasing amounts of atmospheric carbon dioxide (CO2) are being absorbed at the sea surface. When this CO2 enters the ocean it rapidly goes through a series of chemical reactions which lowers the pH of the surface seawater driving the water along the scale toward acidity.
- Models suggest about a 30% decrease in surface pH (an increase in acidity) and a 16% decrease in carbonate ion concentration since 1750. This has been confirmed by long term observations.
- The rate of change in pH is faster than anything experienced in the last 55 million years and is causing concern for marine ecosystems and species.
- Oceans will continue to acidify with increasing CO2 emissions. Whilst we have high confidence that ocean acidification will continue, subsequent impacts on ecosystems are less well understood.
- Currently there is insufficient evidence to determine the impacts of ocean acidification on the three areas of concern for VECTORS (i.e. invasive alien species, outbreak forming species and changes in species distribution and productivity). However, it seems likely that ocean acidification will facilitate the translocation of alien species, increase the likelihood of species outbreaks (such as harmful algal blooms) and significantly alter community composition and productivity.
- Ocean acidification can make species more susceptible to the impacts of other stressors such as warming waters and lower oxygen levels.
VECTORS, 2013. Fact sheet.