Gulf "Dead Zone" Threatens Ocean Life

Area Of Oxygen-Depleted Water Aggravated By Flood Runoff Could Reach Biggest Ever At Over 8,800 Square Miles

(AP)  A "dead zone" in the Gulf of Mexico off the Texas-Louisiana coast this year is likely to be the biggest ever and last longer than ever before, with marine life affected for hundreds of miles, a scientist warned.

"It's definitely the worst we've seen in the last five years," said Steve DiMarco, a Texas A&M University professor of oceanography who for 16 years has studied the Gulf of Mexico dead zone, so named because the oxygen-depleted water can kill marine life.

The phenomenon is caused when salt water loses large amounts of oxygen, a condition known as hypoxia that is typically associated with an area off the Louisiana coast at the mouth of the Mississippi River. The fresh water and salt water don't mix well, keeping oxygen from filtering through to the sea bottom, which causes problems for fish, shrimp, crabs and clams.

This year's dead zone has been aggravated by flood runoff from heavy spring rains and additional runoff moving into the Gulf from record floods along the Mississippi.

DiMarco, joined by researchers from Texas A&M and the University of Georgia, just returned from an examination of 74 sites between Terrebonne and Cameron, La. He said the most severe hypoxia levels were recorded in the mid-range depths, between 20 and 30 feet, as well as near the bottom of the sea floor at about 60 feet.

Some of the worst hypoxic levels occurred in the western Gulf toward the state line.

"We saw quite a few areas that had little or no oxygen at all at that site," DiMarco said Tuesday. "This dead zone area is the strongest we've seen since 2004, and it's very likely the worst may be still to come.

"Since most of the water from the Midwest is still making its way down to the Gulf, we believe that wide area of hypoxia will persist through August and likely until September, when it normally ends."

Last year, DiMarco discovered a similar dead zone off the Texas coast where the rain-swollen Brazos River emptied into the Gulf.

The zone off Louisiana reached a record 7,900 square miles in 2002. A recent estimate from the National Oceanic and Atmospheric Administration and Louisiana State University shows the zone, which has been monitored for about 25 years, could exceed 8,800 square miles this year, an area roughly the size of New Jersey.

DiMarco said a tropical storm or hurricane likely would have no impact on this year's zone, believed to be caused by nutrient pollution from fertilizers that empty into rivers and eventually reach the Gulf.

[rushlimpdrug]

Things will only continue to get worse.

This will not be a problem.

People can aclimate to this type of news.

Soon America will be 1 billion people "strong".

This will bring new "challenges" to coming generations.

It is all in the wording.

[csmith1948]

If only the "Corpse of Engineers" would divert some of that nutrient rich water into the marshes south of New Orleans, the wetlands would be rebuilt and lessen the impact of the runoff. But, I digress. They will study it to death (corpse, get it).

[lovesamerica]

AS long as we build in marshes,wetlands,along sea ways these will be common occurances. Mother nature has a system and we humans are doing everything possible to prove her wrong...kind of like my ex husband.....

[downsteamjim]

Notice that the fact that corn production has increased due in part to ethanol ''green fuel'' production has been omitted from the article.

[beehive21-2009]

Funny ,how the scientists been here 30, 60 or even 200 years, think they know some thing about the Earth ? Oh,feel that its a earthquake, and you still can not predict it.