*Gulf of Mexico "Dead Zone" to Hit Record Size - NOAA *
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US: July 17, 2008


*HOUSTON - The Gulf of Mexico's "dead zone" -- a swath of algae-laden
water with oxygen levels low enough to choke out marine life -- will
likely reach record size this year, and the main culprits are rising
ethanol use and massive Midwest flooding, scientists said on Tuesday. *


The dead zone, which recurs each year off the Texas and Louisiana
coasts, could stretch to more than 8,800 square miles (22,790 sq km)
this year -- about the size of New Jersey -- compared with 6,662 square
miles (17,250 sq km) in 2006 and nearly double the annual average since
1990 of 4,800 square miles (12,430 sq km).

Scientists from the US National Oceanic and Atmospheric Administration,
Louisiana Universities Marine Consortium and Louisiana State University
said the algae that lowers oxygen levels in the dead zone is being fed
by farm use of fertilizers like nitrogen and phosphorus.

For fishermen who look to the Gulf of Mexico for crabs, shrimp, crawfish
and other seafood, the growing dead zone means they must venture farther
out into the gulf's waters to find their catch.

The record dead zone is due to soaring use of ethanol in US motor
gasoline supplies and by massive flooding in the Midwest earlier this
year, scientists said.

"We're planting an awful lot of corn and soybeans," said Eugene Turner,
a scientist at Louisiana State University. "It rinses off easily when
there is a rain."

One-third of this year's US corn crop, or 4 billion bushels, will go to
make the alternate fuel ethanol, the US government has projected,
compared to 3 billion bushels of the 2007 crop.

The dead zone starts in Midwestern corn country when farmers fertilize
their fields with nitrogen. The fertilizer run-off flows down the
Mississippi River into the Gulf of Mexico, making algae bloom on the
surface and cutting oxygen to creatures that live on the bottom.

Substances in this runoff include the nutrients nitrogen and phosphorus,
which can stimulate the growth of algae. These algae settle and decay in
the bottom waters of the Gulf, and the bacteria that decompose them
gobble up oxygen faster than it can be replenished from the surface,
which means lower levels of dissolved oxygen in the water.

US scientists estimate that a record 83,000 tons of phosphorus seeped
into the Gulf of Mexico from April through June, up to 85 percent above
normal seasonal levels.

"Excess nutrients from the Mississippi River watershed during the spring
are the primary human-influenced factor behind the expansion of the dead
zone," said Rob Magnien, director of the NOAA Center for Sponsored
Coastal Ocean Research.

To reverse the pattern, US farmers must plant more perennial crops that
trap rainwater and keep it from running into the Gulf of Mexico, Turner
said.

And eventually, scientists need to invent new breeds of perennial corn
plants that can remain in the soil from one planting season to the next,
avoiding the need to strip fields bare and leave them susceptible to
flooding, he said. (Reporting by Chris Baltimore, editing by Anthony
Boadle)


Story by Chris Baltimore


REUTERS NEWS SERVICE


-From a cool New Scotland night,
Ross Mayhew.
http://www.schnr-specimen-shells.com/

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