International Scientists Find 'Acidified' Water on the Continental Shelf
from Canada to Mexico

May 22, 2008

Evidence of corrosive water caused by the ocean's absorption of carbon
dioxide (CO2) was found less than 20 miles off the west coast of North
America during a field study from Canada to Mexico last summer. This was the
first time "acidified" ocean water has been found on the continental shelf
of western North America.

The term "ocean acidification" describes the process of ocean water becoming
corrosive as a result of carbon dioxide being absorbed from the atmosphere.

"Acidification of the Earth's ocean water could have far-reaching impacts on
the health of our near-shore environment, and on the sustainability of
ecosystems that support human populations through nourishment and jobs,"
said Richard W. Spinrad, NOAA assistant administrator for oceanic and
atmospheric research. "This research is vital to understanding the processes
within the ocean, as well as the consequences of a carbon-rich atmosphere."

The findings will be published May 22 in the online journal *Science Express
*. "Evidence for Upwelling of Corrosive 'Acidified' Water onto the
Continental Shelf" was written by Richard A. Feely and Christopher Sabine,
both oceanographers at NOAA's Pacific Marine Environmental
Laboratory<http://www.pmel.noaa.gov/>in Seattle, Wash. Their
co-authors are J. Martin Hernandez-Ayon of the
Instituto de Investigaciones Oceanologicas from the University of Baja
California, Mexico; Debby Ianson of Fisheries and Oceans Canada in Sidney,
British Columbia, and Burke Hales, of Oregon State University College of
Oceanic and Atmospheric Sciences, Corvallis, Ore.

"Our findings represent the first evidence that a large section of the North
American continental shelf is seasonally impacted by ocean acidification,"
said Feely. "This means that ocean acidification may be seriously impacting
marine life on our continental shelf right now."

"While this absorption provides a great service to humans by significantly
reducing the amount of greenhouse gases in the atmosphere and decreasing the
effects of global warming, the change in the ocean chemistry affects marine
life, particularly organisms with calcium carbonate shells, such as corals,
mussels, mollusks, and small creatures in the early stages of the food
chain," said Feely.

The study was the first in what is planned to be a biennial sequence of
observations and studies of carbon along the west coast of North America.
The researchers participated in the North American Carbon Program West Coast
Cruise on the *R/V Wecoma*, owned by the National Science Foundation and
operated by Oregon State University. The international scientific team plans
to continue their studies of ocean acidification in follow up cruises in
late 2009.

Previous studies found ocean acidification at deeper depths farther from
shore. The researchers said that the movement of the corrosive water appears
to happen during the upwhelling season during the spring and summer, when
winds bring CO2 -rich water up from depths of about 400-600 feet onto the
continental shelf. The water that upwells off of the North American Pacific
coast has been away from the surface for about 50 years.

The field study collected samples from Queen Charlotte Sound, Canada, to San
Gregorio Baja California Sur, Mexico. The closest they found corrosive water
was about four miles off of the northern California coast.

"We did not expect to see this extent of ocean acidification until the
middle to the end of the century," said Sabine. "Because of this effort, we
have a baseline for future observations as we continue to study and monitor
the relationship of biological and physical processes and their ability to
respond to ocean acidification."

The researchers participated in the North American Carbon Program West Coast
Cruise on the *R/V Wecoma*, owned by the National Science Foundation and
operated by Oregon State University. The study was the first in what is
planned to be a biennial sequence of observations and studies of the carbon
cycle along the west coast of North America.

"We did not expect to see this extent of ocean acidification until the
middle to the end of the century," said Sabine. "Because of this effort, we
have a baseline for future observations as we continue to study and monitor
the relationship of biological and physical processes and their ability to
respond to ocean acidification."

"When the upwelled water was last at the surface, it was exposed to an
atmosphere with much less CO2 than today and future upwelled waters will
probably be more acidic than today's because of increasing atmospheric CO2,"
said Hales, a professor of chemical oceanography, who is also funded by
NASA.

"We don't know how this will affect species living in the zone below the
level of the lowest tides, out to the edge of the continental shelf," said
Ianson, an oceanographer. "We do know that organisms like corals or
pteropods are affected by water saturated with CO2. The impacts on other
species, such as shellfish and other juvenile fish that have economic
significance, are not yet fully understood."

"In Baja California, we have several Mediterranean-climate coastal lagoons
where the main external physical and biogeochemical forcing is from the
neighboring coastal ocean, strongly influenced by upwelling," said
Hernandez-Ayon, a coastal oceanographer. "We are concerned about these areas
because they play an important role as nurseries and feeding grounds of
juvenile fish populations but are also are ideal sites for shellfish
aquaculture."

http://www.noaanews.noaa.gov/stories2008/20080522_oceanacid.html