Via Ocean Acidification:

Great Barrier Reef in Australia - Ocean acidification is of great concern due to its potential impact on marine life. Coral and other marine organisms use free carbonate ions in sea water to build calcium carbonate shells and exoskeletons, but as atmospheric carbon dioxide levels rise and more carbon dioxide is absorbed by the world's oceans, sea waters become increasingly acidic by stripping out carbonate ions. Lower carbonate ion concentrations make it more difficult for organisms to form shells, leaving them vulnerable to predators and environmental conditions. Increasing atmospheric CO2 is likely to cause a corresponding increase in oceanic acidity by lowering pH by 0.2-0.5 pH units by the end of the 21st century [Royal Society, 2005]. In light of increasing acidity, there are growing concerns about the future health of a variety of marine organisms, particularly shellfish, which in the United States is a $1.6 billion industry. Shellfish predominantly inhabit coastal regions, and in addition to the projected stress caused by the global trend in ocean acidification, some coastal ecosystems receive persistent or episodic acid inputs as a result of interactions with river water, bottom sediments, or atmospheric deposition of terrigenous materials. Most river plumes are acidic relative to the receiving ocean, and river water is mixed extensively over the continental shelf. Moreover, the chemical nature and magnitude of discharge are changing rapidly due to climate change and land-use practices.
Salisbury J., Green M., Hunt C. & Campbell J., 2008. Coastal acidification by rivers: A new threat to shellfish? Eos, Transactions, American Geophysical Union 89(50):513. Article (subscription required).

Coastal acidification by rivers: A new threat to shellfish?
Tue, 13 Jan 2009 08:22:17 GMT

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