NOAA - MS Delta Dead Zone This Year 1/2 Size Of Maryland - "Above Average"

[hatrack]

July 24, 2006 — A team of scientists from the NOAA National Centers for Coastal Ocean Science, Louisiana Universities Marine Consortium and Louisiana State University is forecasting that the "Dead Zone" off the coast of Louisiana and Texas this summer will be larger than the average size since 1990. (Click NOAA image for larger view of Bottom Dissolved Oxygen Contours in the Gulf of Mexico taken July 14-16, 2006. Click here for high resolution version. Please credit “NOAA.”)

This NOAA supported modeling effort, led by Eugene Turner, Ph.D., of LSU, predicts this summer's "Dead Zone" will be 6,700 square miles, an area the half the size of the state of Maryland. Since 1990 the average annual hypoxia-affected area has been approximately 4,800 square miles. The forecast is based on nitrate loads from the Mississippi and Atchafalaya rivers in May and incorporates the previous year's load to the system. The nitrogen data are provided by the U.S. Geological Survey. NOAA funds research cruises to track development of hypoxia.

The "Dead Zone" is an area in the Gulf of Mexico where seasonal oxygen levels drop too low to support most life in bottom and near-bottom waters. It is caused by a seasonal change where algal growth, stimulated by input of nutrients such as nitrogen and phosphorus from the Mississippi and Atchafalaya rivers, settles and decays in the bottom waters. The decaying algae consume oxygen faster than it can be replenished from the surface, leading to decreased levels of dissolved oxygen.

There are multiple models of the size of the hypoxic zone that are useful in evaluating the influence of nitrogen load and variations in ocean currents on the size of the "Dead Zone." These models do not always produce similar results, and model improvement is one focus of ongoing research. Over the past four years, NOAA and its collaborators have compared two independent models. The LSU model is the most accurate model based on past performance, but it is still in the experimental stages. Additional research for model improvement is required before this annual prediction can become an operational forecast.

"We are anticipating a larger hypoxic zone this summer because the nitrate loading this May, a critical month influencing the size of the area, is higher than last year," said Turner, explaining the NOAA forecast. "The result is that we will have some additional key information about the relative contribution of stratification and nutrient concentrations in different years which should help us better understand the causes behind this annual event."

"This prediction is an example of the ecological forecasting capabilities of NOAA and its partners," said David Whitall, Ph.D., a NOAA scientist involved in the project. "We believe such forecasts will become important tools for coastal managers in the coming years."

Research indicates that nearly tripling the nitrogen load into the Gulf over the past 50 years has led to the heightened Gulf of Mexico hypoxia problem. The scientists say their research will improve assessments of hypoxic effects under various Gulf Coast oceanographic conditions.

These research, observational and modeling studies are part of a larger NOAA sponsored effort to develop a fundamental understanding of the northern Gulf of Mexico ecosystem with a focus on the causes and effects of the hypoxic zone over the Louisiana continental shelf and the prediction of its future extent and impacts to ecologically and commercially important aquatic species.

In 2007, NOAA, an agency of the U.S. Commerce Department, celebrates 200 years of science and service to the nation. From the establishment of the U.S. Coast and Geodetic Survey in 1807 by Thomas Jefferson to the formation of the Weather Bureau and the Bureau of Commercial Fisheries in the 1870s, much of America's scientific heritage is rooted in NOAA.

NOAA is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and information service delivery for transportation, and by providing environmental stewardship of the nation's coastal and marine resources. Through the emerging Global Earth Observation System of Systems (GEOSS), NOAA is working with its federal partners and more than 60 countries to develop a global monitoring network that is as integrated as the planet it observes.

Relevant Web Sites
NOAA Bottom Dissolved Oxygen Maps and Related Data

NOAA National Centers for Coastal Ocean Science Gulf of Mexico Ecosystems & Hypoxia Assessment

Media Contact:
Ben Sherman, NOAA Ocean Service, [phone] ext. 178

EDIT/END

MODS: Press release, given here in its entirety.

http://www.noaanews.noaa.gov/stories2006/s2669.htm

[NNadir]

1. This issue is hardly discussed enough.

[Dead_Parrot]

2. It is, if you'll pardon my French...

...pissing in the ocean, at this point.

[NNadir]

3. Given that a common fertilizer is urea, that sums it pretty well.

[Dead_Parrot]

4. Ouch...

...I'll try to pick my analogies better from now on. :D

[NNadir]

14. It turns out that urea is an important intermediate in the nitrogen cycle.

In most living tissues, the urea cycle is an important part of amino acid metabolism. Without it, one would not be able to obtain the energy value of the amino acids that make up proteins.

In the natural world, before industrial nitrogen fixation, piss was an important fertilizer.

We don't like to think of that, but it's true.

[XemaSab]

6. Not to also mention the fact that a lot of the nutrient-rich runoff

comes from CAFOs.

[NNadir]

7. What's a CAFO?

[XemaSab]

8. Concentrated Animal Feeding Operation

[NNadir]

9. Thanks.

It would seem that being concentrated, something could be done about that.

[Dead_Parrot]

10. I have never understood...

why cows don't eat grass. They do in the UK and NZ...

Hey Xema - seen this yet? :)

[XemaSab]

11. I did in fact see that

:eyes:






































:eyes:

[XemaSab]

5. What could be done about this?

Once the nutrients live the soil upstream, how do you contain something like this?

[Dead_Parrot]

12. As far as I know, you don't...

the trick is, to not put that shit on the ground in the first place...

[jpak]

13. Restore historical riparian zones in the Mississippi basin

and divert more Mississippi River water down the Atchafalaya basin.

~30% of the Mississippi River is diverted down the Atchafalaya by the Army Corps of Engineers. In contrast to the lower Mississippi River, which has lost most of its historical riparian zones and is extensively leveed, Mississippi River water diverted down the Atchafalaya interacts with extensive areas of wetlands and riparian forests. These serve as potential sinks of dissolved inorganic nitrogen.

I participated on several research cruises to the "Dead Zone" in the mid-90's. During the Great Flood year of 1993, nitrogen concentrations in the Mississippi River were astronomical. In contrast, nitrogen concentrations in the Atchafalaya River were substantially lower. We attributed this to biological nitrogen uptake, immobilization and denitrification in the Atchafalaya basin.

In upper Mississippi basin agricultural zones, create and/or restore wetlands, retention ponds and uncultivated buffer strips along first order streams. Even small retention ponds are effective in reducing nitrogen inputs to streams (through algal production and bacterial denitrification).

Provide (more) incentives for organic and low-input agriculture and conservation lands in areas where hydrology favors rapid runoff of nutrients into streams.

Provide incentives to build biogas digesters at livestock operations to reduce nitrogen in manure pond effluents and recycle the processed water back to agricultural fields or artificial wetlands.

Mississippi river flow has an enormous impact on the size of the Dead Zone. During the Great Drought year of 1988, when Mississippi River flow declined to historic lows (and a year where US corn production declined precipitously), the Dead Zone was dramatically reduced. In the Great Flood year of 1993 it was at its greatest extent ever recorded (at that time).

Finally, there is a good chance that the Dead Zone is a major source of nitrous oxide (a powerful greenhouse gas that also destroys stratospheric ozone). Conditions in the hypoxic water are more than a little favorable for bacterial production of N2O. This is something no one has really investigated...(yet).

:)

[XemaSab]

15. Awesome!

Thanks for the details! :bounce:

I was laboring under the impression that saturated systems did not take up nutrients very effectively, but I dunno why I would have thought that. :shrug: