Ocean Chemistry Changing At 'Unprecedented Rate'

Deborah Zabarenko, PlanetArk 23 Apr 10;

Carbon dioxide emissions that contribute to global warming are also turning the oceans more acidic at the fastest pace in hundreds of thousands of years, the National Research Council reported Thursday.

"The chemistry of the ocean is changing at an unprecedented rate and magnitude due to anthropogenic carbon dioxide emissions," the council said. "The rate of change exceeds any known to have occurred for at least the past hundreds of thousands of years."

Ocean acidification eats away at coral reefs, interferes with some fish species' ability to find their homes and can hurt commercial shellfish like mussels and oysters and keep them from forming their protective shells.

Corrosion happens when carbon dioxide is stored in the oceans and reacts with sea water to form carbonic acid. Unless carbon dioxide emissions are curbed, oceans will grow more acidic, the report said.

Oceans absorb about one-third of all human-generated carbon dioxide emissions, including those from burning fossil fuels, cement production and deforestation, the report said.

The increase in acidity is 0.1 points on the 14-point pH scale, which means this indicator has changed more since the start of the Industrial Revolution than at any time in the last 800,000 years, according to the report.

The council's report recommended setting up an observing network to monitor the oceans over the long term.

"A global network of robust and sustained chemical and biological observations will be necessary to establish a baseline and to detect and predict changes attributable to acidification," the report said.

ACID OCEANS AND 'AVATAR'

Scientists have been studying this growing phenomenon for years, but ocean acidification is generally a low priority at international and U.S. discussions of climate change.

A new compromise U.S. Senate bill targeting carbon dioxide emissions is expected to be unveiled on April 26.

Ocean acidification was center stage at a congressional hearing Thursday, the 40th anniversary of Earth Day in the United States.

"This increase in (ocean) acidity threatens to decimate entire species, including those that are at the foundation of the marine food chain," Democratic Senator Frank Lautenberg of New Jersey told a Commerce Committee panel. "If that occurs, the consequences are devastating."

Lautenberg said that in New Jersey, Atlantic coast businesses generate $50 billion a year and account for one of every six jobs in the state.

Sigourney Weaver, a star of the environmental-themed film "Avatar" and narrator of the documentary "Acid Test" about ocean acidification, testified about its dangers. She said people seem more aware of the problem now than they did six months ago.

"I think that the science is so indisputable and easy to understand and ... we've already run out of time to discuss this," Weaver said by telephone after her testimony. "Now we have to take action."

(Editing by Sandra Maler)

CO2 emissions causing ocean acidification to progress at unprecedented rate
National Academy of Sciences, EurekAlert 22 Apr 10;

WASHINGTON -- The changing chemistry of the world's oceans is a growing global problem, says the summary of a congressionally requested study by the National Research Council, which adds that unless man-made carbon dioxide (CO2) emissions are substantially curbed, or atmospheric CO2 is controlled by some other means, the ocean will continue to become more acidic. The long-term consequences of ocean acidification on marine life are unknown, but many ecosystem changes are expected to result. The federal government's National Ocean Acidification Program, currently in development, is a positive move toward coordinating efforts to understand and respond to the problem, said the study committee.

The ocean absorbs approximately a third of man-made CO2 emissions, including those from fossil-fuel use, cement production, and deforestation, the summary says. The CO2 taken up by the ocean decreases the pH of the water and leads to a combination of chemical changes collectively known as ocean acidification.

Since the beginning of the industrial revolution, the average pH of ocean surface waters has decreased approximately 0.1 unit -- from about 8.2 to 8.1 -- making them more acidic. Models project an additional 0.2 to 0.3 drop by the end of the century. This rate of change exceeds any known to have occurred in hundreds of thousands of years, the report says. The ocean will become more acidic on average as surface waters continue to absorb atmospheric CO2, the committee said.

Studies on a number of marine organisms have shown that lowering seawater pH with CO2 affects biological processes, such as photosynthesis, nutrient acquisition, growth, reproduction, and individual survival depending upon the amount of acidification and the species tested, the committee found. For example, some of the strongest evidence of the potential effects of ocean acidification on marine ecosystems comes from experiments on organisms with calcium carbonate shells and skeletons. The results showed decreases in shell and skeletal growth in a range of marine organisms, including reef-building corals, commercially important mollusks such as oysters and mussels, and several types of plankton at the base of marine food webs.

The ability of various marine organisms to acclimate or adapt to ocean acidification is unknown, but existing data suggest that there will be ecological winners and losers, leading to shifts in the composition and functioning of many marine ecosystems, the committee said. Such ecosystem changes could threaten coral reefs, fisheries, protected species, and other natural resources.

Although changes in ocean chemistry caused by increasing atmospheric CO2 can be determined, not enough information exists to assess the social or economic effects of ocean acidification, much less develop plans to mitigate or adapt to them, the committee noted.

The federal government has taken initial steps to respond to the nation's long-term needs with the development of the National Ocean Acidification Program. The committee found that legislation has laid the foundation for a program that will advance our understanding and improve our response to ocean acidification.

The committee recommended six key elements of a successful National Ocean Acidification Program:

* an integrated ocean acidification observation network that includes the development of new tools, methods, and techniques to improve measurements
* research in eight broad areas to fulfill critical information gaps
* assessments to identify stakeholder concerns and a process to provide relevant information for decision support
* a data management office that would ensure data quality, access, and archiving, plus an information exchange that would provide research results, syntheses, and assessments to managers, policymakers, and the general public
* facilities to support high-quality research and training of ocean acidification researchers
* an effective 10-year strategic plan for the program that will identify key goals, set priorities, and allow for community input, in addition to a detailed implementation plan

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The study is funded by the National Oceanic and Atmospheric Administration, NASA, the U.S. Geological Survey, and the National Science Foundation. The National Academy of Sciences, National Academy of Engineering, Institute of Medicine, and National Research Council make up the National Academies. They are independent, nonprofit institutions that provide science, technology, and health policy advice under an 1863 congressional charter. Committee members, who serve pro bono as volunteers, are chosen by the Academies for each study based on their expertise and experience and must satisfy the Academies' conflict-of-interest standards. The resulting consensus reports undergo external peer review before completion. For more information, visit http://national-academies.org/studycommitteprocess.pdf.