Ocean Researchers Predict 'Dead Zone' Growth
Pastor Dale Morgan
Jul 16, 8:16 PM EDT
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Ocean Researchers Predict 'Dead Zone' Growth*
NEW ORLEANS (AP) -- Researchers predict that the recurring
oxygen-depleted "dead zone" off the Louisiana coast will grow this
summer to 8,543 square miles - its largest in at least 22 years.
The forecast, released Monday by the Louisiana Universities Marine
Consortium, is based on a federal estimate of nitrogen from the
Mississippi River watershed to the Gulf of Mexico. It discounts the
effect storms might have.
The "dead zone" in the northern Gulf, at the end of the Mississippi
River system, is one of the largest areas of oxygen-depleted coastal
waters in the world. Low oxygen, or hypoxia, can be caused by pollution
from farm fertilizer, soil erosion and discharge from sewage treatment
plants, according to the U.S. Geological Survey.
The pollution is carried downstream by the Mississippi and comes from
throughout the U.S.
Excess nutrients can spur the growth of algae, and when the algae die,
their decay consumes oxygen faster than it can be brought down from the
surface. As a result, fish, shrimp and crabs can be forced to move or
die, the consortium Web site says.
Eugene Turner, a professor of oceanography and coastal sciences at
Louisiana State University who is involved with the report, said it's
tough to determine whether fish are dying because of hypoxia or other
factors, such as climatic effects. However, "we really don't want to
mess with this, to make it worse," he said.
The dead zone usually begins forming in the spring and stays through
summer and into the fall. Though the size of the dead zone has shrunk
some years, on average it has steadily grown larger, Turner said.
If the prediction stands, it would be the largest dead zone measured
since mapping began in 1985, the report says. The consortium has
scheduled an assessment of the dead zone for summer's end.
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