Every year since the early 1980s, a monstrous algae bloom has risen up in the Gulf of Mexico, fed by fertilizer runoff from Midwest farms. The nasty growth sucks oxygen from the ocean beneath it -- snuffing out sea life even as climate change and other human-induced factors threaten the globe's fish stocks.
Ironically, as fish go belly up in the Gulf, the bulk of the corn and soy grown on Midwest farms ends up in feedlots to fatten the livestock that feed America's ravenous appetite for meat. The writer Richard Manning described the irony memorably in the Winter 2004 American Scholar (unavailable online):
Already, the Dead Zone has seriously damaged what was once a productive fishery, meaning that a high-quality source of low-cost protein is being sacrificed so that a source of low-quality, high-input subsidized protein can blanket the Upper Midwest.
Well, the quixotic attempt to feed not only our CAFOs but also our cars with Midwestern corn isn't improving things down in the Gulf. From the St. Louis Post Dispatch (via Denver Post):
[A Louisiana State University] research team reported this week that an area of oxygen-deprived water in the Gulf of Mexico is expected to grow to over 10,000 square miles this year. The largest the area has ever been measured was in 2002, when it was about 8,500 square miles.
Oh dear. And the cause?
"In the past several years, there's been an expansion of corn, which has the highest fertilizer per acre ... and that's for biofuels," said R. Eugene Turner, a Louisiana State University professor who directed the study into the gulf's water quality.
In the course of a normal growing season, huge amounts of fertilizer leach from the Midwest's corn fields because farmers apply titanic amounts of it to ensure maximum yield. And that factor, as the LSU scientist states, has expanded with the expansion of corn for ethanol.
But I'm not sure if the LSU research team is even taking into account an awful new development in the Midwest: The torrential rains that are pounding the area washing much more fertilizer than normal into the groundwater, down the Mississippi, and into the Gulf.
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Comments
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Wolverine Posted 9:57 am
12 Jun 2008
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Sam Wells Posted 12:55 pm
12 Jun 2008
It should be emphasized that this is a natural phenomena, such as with the spring floods that carry soils bearing natural amounts of nitrogen and other nutrients. What is happening is that due to increased fertilization and run-off from the Mississippi Basin, the affected area is growing rather shockingly large - meaning longer and extending well into offshore Texas waters.
As a fisherman I can say this year is one of the worst for turbidity and green/brown water caused by the Mississippi Outflow. But recently the blue water has been coming in from the south and west, carried on the SE wind and the Mexico Current (which used to be fueled by the Rio Grand). That blue water is nutrient poor but very beautiful - you can see down a good 40 feet from a boat and divers love the even better visibility underwater.
I want to emphasize again that this is a natural process that happens every year - it is not like if we stop growing GMO corn and applying fertilizer it will go away. -sam
Onward through the fog
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Tom Philpott Posted 1:42 pm
12 Jun 2008
http://www.tulane.edu/~bfleury/envirobio/enviroweb/DeadZo ...
The Gulf of Mexico hypoxic zone is a seasonal phenomena occurring in the northern Gulf of Mexico, from the mouth of the Mississippi River to beyond the Texas border. It is more commonly referred to as the Gulf of Mexico Dead Zone, because oxygen levels within the zone are too low to support marine life. The Dead Zone was first recorded in the early 1970's. It originally occurred every two to three years, but now occurs annually. In the summer of 1999 the Dead Zone reached its peak, encompassing 7,728 square miles.
Of course, now it's expected to hot 10,000 square miles. The researcher goes on:
As the fresh, nutrient-enriched water from the Mississippi and Atchafalaya Rivers spread across the Gulf waters, favorable conditions are created for the production of massive phytoplankton blooms. A bloom is defined as an "increased abundance of a species above background numbers in a specific geographic region". Incoming nutrients stimulate growth of phytoplankton at the surface, providing food for unicellular animals. Planktonic remains and fecal matter from these organisms fall to the ocean floor, where they are eaten by bacteria, which consume excessive amounts of oxygen, creating eutrophic conditions. Hypoxic waters appear normal on the surface, but on the bottom, they are covered with dead and distressed animal, and in extreme cases, layers of stinking, sulfur-oxidizing bacteria, which cause the sediment in these areas to turn black. These hypoxic conditions cause food chain alterations, loss of biodiversity, and high aquatic species mortality.
Victual Reality
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Sam Wells Posted 2:00 pm
12 Jun 2008
My purpose was to say it happens all over the world in large basins such as the Mississippi and Amazon. And it's not just corn doing it - a preposterous suggestion. The run-off is a soup that includes wastewater, golf course wash, urban toxics, and many things including just good old eroded soil. The extent to which corn agriculture has added to this soup is great yet but one of many causes.
To blame the Mississippi Dead Zone on corn is beyond all stupidity. It is typical for J-majors to write in such blunt terms without qualification or a scientific understanding.
Onward through the fog
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LGT Posted 3:06 pm
12 Jun 2008
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Tom Philpott Posted 11:31 pm
12 Jun 2008
Here's an abstract of a US Geographical Survey study on the Dead Zone:
http://pubs.acs.org/cgi-bin/abstract.cgi/esthag/2008/42/i ...
Seasonal hypoxia in the northern Gulf of Mexico has been linked to increased nitrogen fluxes from the Mississippi and Atchafalaya River Basins, though recent evidence shows that phosphorus also influences productivity in the Gulf. We developed a spatially explicit and structurally detailed SPARROW water-quality model that reveals important differences in the sources and transport processes that control nitrogen (N) and phosphorus (P) delivery to the Gulf. Our model simulations indicate that agricultural sources in the watersheds contribute more than 70% of the delivered N and P. However, corn and soybean cultivation is the largest contributor of N (52%), followed by atmospheric deposition sources (16%); whereas P originates primarily from animal manure on pasture and rangelands (37%), followed by corn and soybeans (25%), other crops (18%), and urban sources (12%). The fraction of in-stream P and N load delivered to the Gulf increases with stream size, but reservoir trapping of P causes large local- and regional-scale differences in delivery. Our results indicate the diversity of management approaches required to achieve efficient control of nutrient loads to the Gulf. These include recognition of important differences in the agricultural sources of N and P, the role of atmospheric N, attention to P sources downstream from reservoirs, and better control of both N and P in close proximity to large rivers.
Victual Reality
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MAD MAC Posted 2:01 am
13 Jun 2008
Victory in Pattani
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Wolverine Posted 5:43 am
13 Jun 2008
While there are people I've strongly disagreed with on this site, they at least do some positive posting about environmental issues. I haven't seen one post of yours that supports an environmental position.
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