Oct 28, 2010
Ethanol, billed by Congress as a “green fuel,” may be responsible for the second-largest dead zone in the world.
The foremost cause of aquatic dead zones is fertilizer runoff from agricultural operations, which leads to an explosion of algal growth. Eventually this algae dies, decaying on a scale so massive that it consumes all the oxygen from the surrounding water. All oxygen-breathing life that cannot flee the area suffocates. With a constant influx of fertilizer, the algal boom-bust cycle continues, steadily depleting oxygen  from a larger and larger area.
The world’s largest dead zone is in the Baltic Sea, while the second largest spans the U.S. Gulf Coast from Alabama to Texas. This dead zone has doubled in size since the 1980s, and keeps growing every year. Scientists estimate that it will soon cover 8,500 miles.
How does ethanol  contribute to this ecological calamity? Ethanol, increasingly used as a fuel  additive, is produced from the fermentation of corn . And corn is one of the most fertilizer-intensive crops grown in the Mississippi River basin.
“Subsidies are driving farmers toward more corn,” said Gene Turner of Louisiana State University. “More nitrate comes off corn fields than it does off of any other crop by far. And nitrogen is driving the formation of the dead zone.”
Because it can be produced domestically, ethanol is a perennial favorite alternative fuel in Congress . That scientists have increasingly questioned whether it actually reduces petroleum use or fossil fuel emissions has had little impact on this policy. In 2007, Congress mandated that U.S. ethanol production increase threefold in the next 12 years. The lawmaking body handed out $17 million in subsidies  to the industry between 2005 and 2009.
The National Corn Growers Association has seized on the catastrophic Gulf oil spill to launch an ad campaign for ethanol. But according to Nathaniel Ostrom of Michigan State University, the dead zone may actually be a bigger problem.
- A d v e r t i s e m e n t
“It’s a really tough call,” Ostrom said.
Sources for this story include: http://www.sfgate.com/cgi-bin/artic… .