Dead Zone in Gulf of Mexico now the size of Conn.

[donsu]

http://www.theneworleanschannel.com/news/4796175/detail.html

Survey: Gulf Dead Zone Nearly The Size Of Connecticut


A new study finds the dead zone off the coasts of Louisiana and Texas is nearly the size of Connecticut and much larger than federal researchers had predicted earlier this year.

An annual week-long cruise led by researchers with the Louisiana Universities Marine Consortium, or LUMCON, found an area of low-oxygen measuring 4,564 square miles and extending from the Mississippi River to the Texas border. On average, the dead zone has measured about 4,800 square miles since 1985.

The dead zone, also known as hypoxia, forms each spring and summer as fresh water enters the Gulf of Mexico and causes large algae blooms. The algae die and sink to the bottom of the Gulf, where they decompose, using up oxygen in the deeper, saltier water. Fish avoid the low-oxygen water, and bottom-living organisms are killed.

Nancy Rabalais, a leading hypoxia researcher with LUMCON, said the dead zone could in the long-term affect the overall health of the Gulf's marine species. She said researchers are studying how the dead zone affects the growth and reproduction of marine species.

Rabalais said the dead zone could grow much larger this year -- perhaps as large as 6,000 square miles -- if major storms do not stir up the Gulf in the coming months.
-----------------------------


in the language of reality - pollution/toxins are killing the Gulf of Mexico

[SteppingRazor]

1. Is this really cause for concern?

This so-called "dead zone" has existed in almost the exact same size every year since it was first noticed in the mid-1980s, predictions for a larger dead zone in the future notwithstanding. In fact, it could have a lot less to do with pollution and a lot more to do with the simple fact that a lot of fresh water enters the Gulf from the Mississippi Delta in the spring and summer months -- when the river's output surges with melted snow. In other words, unlike global warming, which has been shown through scientific research time and again, this dead zone has yet to be shown as the result of pollution. It's likely the natural result of a heavy influx of fresh water into a saltwater ecosystem.

[PaulaFarrell]

2. Yes, it's a cause for concern

The dead zone is not caused by fresh water. Freshwater influx into any ocean system is normal and natural, whereas the dead zone is a recent phenomenom. It is caused by nitrate run-off primarily from agricultural fertilisers.


http://www.tulane.edu/~bfleury/envirobio/enviroweb/DeadZone.htm

... There is growing concern over the safety of seafood as a result of the contamination and chemical pollution of fishing waters. One half of the shellfish producing areas along the gulf coast have either been permanently closed or declared indefinitely off-limits by health officials as a result of pollution....


http://news.bbc.co.uk/2/hi/science/nature/3534658.stm

..A huge "dead zone" of water that has spread across the Gulf of Mexico may be contributing to an unusual spate of shark bites along the Texas coast.

In the last 30 years, the dead zone has been an annual event, fed by the rising use of nitrate based fertilizers.

The extensive area of uninhabitable water may be contributing indirectly to a rise in shark bites in Texas waters.

Three people have been bitten by sharks along the upper Texas coast this year - which is a higher number than normal.

The dead zone has spread across 5,800 square miles (15,020 sq km) of the Gulf of Mexico and is so devoid of oxygen that sea life cannot live in it ...

http://www.theecologist.org/archive_detail.asp?content_id=328

...I’m a commercial fisher from the Texan town of Seadrift on the Gulf of Mexico. I’ve spent more than 40 years on the Texas Gulf Coast. I’ve fished the bays. I’ve been in the rivers. And I have watched those bays and rivers systematically deteriorate...

[Lisa]

3. "the nitrogen glut" -- a major problem ...

We've known about eutrophication for decades (remember Lake Erie?), and it's been getting even more serious. Now it's not just enclosed lakes and rivers that are suffering -- coastal areas are also being affected.

Nitrogen emissions are tied in with so many other environmental problems. As you pointed out earlier, fertilizers are a biggie. Our use of artificial nitrogen fertilizers skyrocketed in the 1980s and 90s, worldwide. (Andrew Goudie claims that more than half of all the artificial fertilizers ever manufactured were used during the past 20 years.) There are also problems with sewage (many cities still dump untreated waste into rivers and oceans), and industrial emissions (NOx, NH3). Some of these compounds are greenhouse gases, and contribute to smog and acid rain.

Peter Vitousek has written extensively about "the nitrogen glut". Humans are now the major source for nitrogen in the world's ecosystems. This isn't just a case of a few gigatonnes compared to the world budget, which is still dominated by natural processes (as in the situation with carbon dioxide). For the first time in geological history, we've effectively seized a major biogeochemical cycle by the 'nads.

http://earthtrends.wri.org/text/coastal-marine/feature-1.html

The United Nations Environment Programme picked nitrogen pollution out as a major issue, back in their 2000 report.

http://www.grida.no/geo2000/ov-e/0003.htm

[walldude]

4. Good post PF.. thanks for the links. n/t