Researchers - Texas Dead Zones Have Appeared In Gulf For At Least 23 Years - Houston Chronicle

[hatrack]

Low-oxygen waters known as dead zones have appeared as regularly as the tides along the Texas coast, according to a new Texas A&M University study. Although the first report of a dead zone off Texas came in 1979, researchers now believe the condition has repeated itself annually for at least 23 years and will likely continue — not unlike the lethal cycle that has threatened fish and shrimp in the waters off Louisiana for decades.

The cause is probably the slurry of soil that flows out of several rivers and into the Gulf of Mexico, but A&M oceanographer Steve DiMarco said more water-quality studies are needed. DiMarco analyzed samples of Texas coastal waters and found that oxygen-starved dead zones have formed between the Louisiana border and Brownsville in all but one year since 1985, the oldest data available.

Evidence previously suggested sporadic dead zones. The new finding surprised DiMarco because the understanding had been that hypoxia, the scientific term for oxygen deficiency, was not persistent along the Texas coast.

Scientists still don't know the impact of the Texas' dead zone, which extends at least 20 miles offshore. DiMarco and industry officials said there are no reports of lower fishing catches or marine animal die-offs. "We need to be out monitoring the water quality of coastal Texas in a systematic way so that if something really bad happens to the health of the coastal environment, we will at least have some data to have a shot at identifying a cause," DiMarco said.

EDIT

http://www.chron.com/disp/story.mpl/metropolitan/5673526.html

[kestrel91316]

1. It's no doubt been going on as long as we're been overfertilizing

abused farmland and dumping vast quantities of concentrated animal waste into waterways.

DECADES.

Shame on us. Factory farming and industrialized agriculture are a crime against humanity, not to mention other species and entire ecosystems.

[NNadir]

2. This topic is covered in Environ. Sci. Technol. 2008, 42, 2323–2327

A news item with a link to the original paper is here:

http://pubs.acs.org/subscribe/journals/esthag-w/2008/apr/policy/ee_deadzone.html

One need not read the news item, one can only look at the pictures.



From the referenced paper we have:

Nutrient loading increased over the last 200 years as a
consequence of more intense landuse and associated activities (15). Nitrogen yield (mass/area) is greatest in sub-basins with the highest percent of cropland, especially corn, and relatively low amounts of perennials (16, 17). The nutrient load from the Mississippi River watershed, therefore, will increase to even higher levels in the next few years as the area of corn planted increases with the anticipated rise in ethanol production. The amount of corn acreage planted in March, 2007 (92.9 million acres) was 19% higher than in 2006 (18). The increased corn acreage in 2007 came at the expense of cotton, the conservation reserve program, and soybean acreage, which is a crop more efficient in retaining nitrogen once applied. The current price of corn (July 2007; $4.05 per bushel) will support a production capacity of 31.5 billion gallons of ethanol and will require about 95.6 million acres producing 15.6 billion bushels annually; these amounts compare to 11 billion bushels and 79 million acres in 2006 (19). Remedial actions meant to reduce the size of the hypoxic zone must address these future increases in nutrient loading and today’s legacy of eutrophication.

The bold is mine

It is interesting that the cotton acreage fell. Cotton actually sequesters carbon, since people wear their clothes a lot longer than they keep their tanks full.

We'll just pile this with the other schemes that sound great until someone actually tries them.

Even if ethanol were 1:1 with energy content with gasoline, which it is not, it would still represent a very small fraction of US oil demand, a few weeks worth at best.