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What is ocean acidification?

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» Marine Conservation Biology Institute's Jeff Ardron explains.

» Ocean acidification blog
Stay up-to-date on OA news and research with this blog -- updates are added nearly every day.

The cause of OA is clear

Ocean acidification, or OA, has been called an "inevitable consequence" of rising atmospheric carbon dioxide (CO2) levels. Like a dry sponge absorbing a puddle of water, seawater absorbs CO2 from the atmosphere in an effort to balance the CO2 partial pressures of air and ocean. In the past, this rebalancing occurred over thousands of years, which was slow enough that other natural processes like rock weathering could  make up for this extra CO2 in seawater. Today, atmospheric CO2 levels are rising so quickly that the ocean is absorbing CO2 faster than the Earth can respond, making the world's oceans more acidic and affecting marine life.

The effects of OA are less clear
Scientists around the world are currently researching OA's specific consequences, but at this point they agree that the ocean, and especially ocean life, will be affected in many ways.  Humans could feel OA's effects through changes in food supplies, natural resources, coastal protection, and economic activities. OA's full range of consequences is not yet completely known.

Find OA-related information organized by theme, under "Learn About OA" above. Topics include:
Chemistry---how does CO2 make seawater acidic?
Geology---how do rocks normally control ocean chemistry?
Physics---how does circulation affect ocean CO2 levels?
Biology---how will OA affect marine organisms?
Society---how will OA affect humans?

Ocean acidification's effects could be far-reaching

New Bedford, MA depends on scallop fishing.  Losing scallops to OA could cost fishermen their jobs, which could in turn hurt other industries that depend on either the scallops or the fishermen.

Related Multimedia
Meet some of the scientists studying OA
» View Slideshow

Effects on ecosystems and economies are tough to evaluate
Even after we know how individual marine animals will handle ocean acidification, we still must understand what will happen to marine food webs, many of which are very complex.  We also need to study how changes in marine resources like fish and reefs will affect the human communities that depend on them. Ocean acidification is expected to have many indirect, and sometimes surprising, effects.

A hungry world depends on a healthy ocean

UN FAO statistics 20% of protein

Last updated: March 6, 2009

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