Oceans’
Growing Acidity
Alarms Scientists
By
Les Blumenthal
17 December,
2007
McClatchy Newspapers
WASHINGTON
- Seven hundred miles west of Seattle in the Pacific at Ocean Station
Papa, a first-of-its-kind buoy is anchored to monitor a looming environmental
catastrophe.
Forget about
sea levels rising as glaciers and polar ice melt, and increasing water
temperatures affecting global weather patterns. As the oceans absorb
more and more carbon dioxide and other greenhouse gases, they’re
gradually becoming more acidic.
And some
scientists fear that the change may be irreversible.
At risk are
sea creatures up and down the food chain, from the tiniest phytoplankton
and zooplankton to whales, from squid to salmon to crabs, coral, oysters
and clams.
The oceans
are already 30 percent more acidic than they were at the beginning of
the Industrial Revolution, as they absorb 22 tons of carbon dioxide
a day. By the end of the century, they could be 150 percent more acidic.
“Everything
points to dramatic effects,” said Richard Feely, an oceanographer
with the National Oceanic and Atmospheric Administration in Seattle.
“There are suggestions the entire ecosystem could change over
time.”
Originally,
scientists thought the oceans could be one of the solutions to the buildup
of greenhouse gases, as they absorb about one-third of the carbon dioxide
that’s emitted worldwide. But they now know that the fundamental
chemistry of the oceans has changed, and the possible impacts seem to
grow more nightmarish as research accelerates.
“It
seems like it is a one-way street, and that is alarming,” said
Steven Emerson, a professor of oceanography at the University of Washington.
“The pH of the oceans could be lowered permanently.”
Emerson was
the lead scientist on the team that built the buoy at Ocean Station
Papa, where weather measurements have been taken since the 1940s. The
10-foot-diameter buoy is equipped with an array of sensors that, among
other things, measure the amount of carbon dioxide that’s being
absorbed by the North Pacific and the pH, or acid levels, of the ocean.
Anchored in water 5,000 feet deep, the buoy relays its information to
onshore scientists via satellite.
Of all the
oceans in the world, the North Pacific could be the most vulnerable
to acidification.
As the oceans’
deepest waters circulate around the globe, they eventually arrive in
the North Pacific, where they rise near the surface before plunging
deep again to continue their global journey. When the water arrives
in the North Pacific, it’s already acidic from the carbon produced
by decaying organic material during its 1,000-year journey from the
North Atlantic through the Indian Ocean and across the Pacific, Feely
said.
As it surfaces,
or upwells, in the North Pacific, the water absorbs even more carbon
dioxide from the air. Cold water absorbs more carbon dioxide than warm
water does.
“The
older water is in the Pacific, the newer water is in the Atlantic,”
Feely said. “There’s 10 percent more carbon dioxide in the
Pacific than in the Atlantic.”
Corrosive
water 600 to 700 feet deep already has been detected off the continental
shelf of Washington state, Oregon and Alaska, Feely said.
“It’s
butting right up against the coast,” he said. “The concern
is when it gets to the continental shelf, what it will do to the fisheries.”
The increasing
acidity can eat away at the shells of crabs, oysters, clams and nearly
microscopic organisms known as krill and pteropods. It also inhibits
calcification, the process in which these animals rebuild their shells.
Without shells, most of the animals probably would die.
Krill and
pteropods are a major food source for juvenile salmon, herring, pollock,
cod, mackerel and other fish.
“When
you start messing with the lower end of the food chain, it can dramatically
affect the higher end of the food chain,” Feely said.
Squid also
are sensitive to higher acidity, which affects their blood circulation
and respiration. Colonies of coral, including those in tropical waters
and those found deep off the Northwest coast, could disappear.
Feely said
that 500 million to 1 billion people worldwide depended on fish for
survival. Sharp declines in fish populations would affect their lives.
Eventually,
the acidification will reach into inland waters, affecting oyster beds
and clamming areas.
Earlier this
month, the Senate Commerce Committee passed a bill co-sponsored by Sen.
Maria Cantwell, D-Wash., that would create a comprehensive ocean-acidification
research and monitoring program. A similar measure has been introduced
in the House of Representatives.
Cantwell
said she expected her Oceans, Atmosphere, Fisheries and Coast Guard
subcommittee of the Commerce Committee to hold hearings in the Northwest
on ocean acidification early next year.
“It’s
a little-known fact, not widely understood, but it is clear our oceans
are suffering,” Cantwell said.
A San Francisco
environmental group, the Center for Biodiversity, has asked 10 states
- Washington, Oregon, California, Alaska, Hawaii, Florida, New York,
New Jersey, Maine and Delaware - to declare their coastal waters “impaired”
under the Clean Water Act because of rising acidity. Such a move could
clear the way for the states to regulate carbon-dioxide emissions.
“Though
we believe the science is there, the political will may not be there,”
said Miyoko Sakashita, a lawyer for the Center for Biodiversity. “At
least this will raise awareness among policymakers.”
Though cuts
in carbon dioxide and other greenhouse-gas emissions might slow or reverse
global warming, scientist say it could take thousands of years or longer
to reverse the increased acidity of the oceans.
“For
all practical purposes this is permanent,” Emerson said. “That’s
not true of temperature. But with ocean acidification the time scales
are long.”
McClatchy
Newspapers 2007
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