Rabalais has been mapping hypoxia for almost 30 years. Her research helped spawn a state/federal task force, which set a goal of cutting the Gulf’s dead zone almost in half, to about 1,930 square miles, by 2015.
Yet the dead zone keeps growing fatter, like an obese patient unable to shed weight. Last year it was 6,800 square miles – more than triple the goal.
“We’re a long way from the target now – a very long way,” she said. “When that target was set, it didn’t seem impossible, but it’s just getting harder and harder.”
In addition to the 75 percent increase at Hermann, nitrate levels have increased 76 percent since 1980 along the upper Mississippi River at Clinton, Iowa, according to the USGS research. In all, nitrate runoff in the entire basin increased 9 percent over the past 30 years, and much of that increase came from the watershed upstream of Hermann and Clinton.
“This the first time anyone has been able to show the actual concentrations have either not changed or actually increased when we’re supposed to be reducing the loads,” said Don Scavia, a professor of environmental sustainability at the University of Michigan in Ann Arbor who studies the dead zone.
“Whatever conservation practices have been put in place are not enough,” he said.
The corn theory
One theory is that more fertilizer is washing into the watershed because corn acreage has skyrocketed. But urban runoff, livestock and other sources could play a role, too.
“These are really large watersheds with a lot of things happening – changes in crop patterns, livestock use, human population,” said Lori Sprague, a USGS hydrologist based in Denver who was lead author of the nitrate study. “All of those things change water quality.”
Farm fertilizer and livestock manure are the two biggest sources of total nitrogen in the Missouri River watershed, together responsible for 70 percent, according to 2011 USGS data. A 2008 study of the entire Mississippi River watershed had similar findings, with agriculture contributing 70 percent of the nitrogen and phosphorous that ended up in the Gulf. Scientists in 2009 also reported a direct correlation between intensive crop production, particularly corn, and nitrate-nitrogen levels in rivers.
Nationally, consumption of nitrogen fertilizer has tripled since the 1960s, surging to 12.3 million tons in 2010, according to USDA data. The amount of nitrogen applied as farm fertilizer grew 18 percent between 1987 and 1997, according to a 2006 USGS study.
It sounds clear-cut. Many farmers, however, tell a different story.
In the Bootheel area of southern Missouri, farmer Mike Geske grows about 2,000 acres of corn, cotton, rice and soybeans near Matthews, Mo. The land lies flat as a plate, the northernmost reaches of the fertile Mississippi delta.
Geske, a third-generation farmer, said when he first started farming in the 1970s, he would lay a thick dose of fertilizer on his fields in the spring. “Anhydrous ammonia was so cheap, we put on 80 to100 pounds extra,” he said.
Today, he applies fertilizer three or four times throughout the year so plants can use it as they need it. He said he uses 20 to 25 percent less fertilizer these days, yet he gets 25 to 30 percent more bushels of corn per acre. He credits better seed technology and careful management of nutrients in the soil.
Farther upstream, Ron Hardecke raises crops, hogs and cattle on 2,000 acres in Owensville, Mo., about 35 miles south of Hermann. He said he carefully monitors his nitrogen use.
“Sometimes it’s portrayed we’re out here dumping fertilizer for fun,” he said. “But if you pay the bill, why, you don’t use more than you need.”
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8 Comments
Add CommentWhat is needed to get a clearer picture of the problem and its sources is to be able to deploy a large number of remote sensing devices that can monitor the water at many locations without having to send samples to a lab. This would give a better indication as to the principle entry points of the nitrates into the rivers and allow a more responsive methodology for characterizing and controlling the situation.
Reply | Report Abuse | Link to thisAs more data is collected, additional sensors can be deployed to narrow the search for the sources. Once sources are identified, they can controlled using either a nitrate tax to make it too expensive to continue allowing nitrates to enter the system or some other sort of incentive to fix the problem locally.
I am sure that there is room for research in ways to break the nitrates down before they reach the gulf as well. Perhaps systems located at the various dams along the way to process the water as it goes through. It would have to be pretty massive to be able to treat the volumes of water flowing through but perhaps it could be distributed more easily along the streams flowing into the rivers instead.
We do live in a world where everything is interconnected and where the miracle cure for one can be the eternal curse for another. We need to remember that we all need to share this planet and live more harmoniously with it.
I can't believe our rivers and the Gulf are being polluted by those evil, rotten, money-mongering oil companies...oh...wait...I mean, farmers.
Reply | Report Abuse | Link to thisThe world is becoming scarier than ever.
Reply | Report Abuse | Link to thisLittle progress is being made because global resources are being diverted combating a non-pollutant (CO2). The real significant pollutants are losing out of the trillions invested globally, with no resultant effect.
Reply | Report Abuse | Link to thisWe need to re-focus our attention (and money) to real solvable pollution problems. GK
"Little progress is being made because global resources are being diverted combating a non-pollutant (CO2)."
Reply | Report Abuse | Link to thisDenial is a mental disease far more debilitating then liberalism. In the end it results in a terminal disease.
Nitrogen increases cause phytoplankton to multiply, but this should increase nutrients for species in the food chain that consume the plankton. As the dead zone grows, so should the abundance of sea food as the oxygen further out returns to the balance nature established. This is not the case as evidenced by increasingly smaller catches in the gulf. Unfortunately there is other pollutants at work that are destroying the food chain farther out. Pesticides (which are made from petrochemicals) and crude oil which has been purposely sunk to the floor of the gulf (does anyone remember or care who NALCO was or how much they spent on lobbying during the worlds worst oil spill?)is suddenly and suspiciously not investigated or even suspect according to this article. The excuse is just that scientists don't understand it all. Apparently no one is getting paid enough to put the blame where it belongs. It is far more convenient to blame individuals that fertilize their lawns and farmers growing corn for ethanol.
Everything has a cause and effect and it should be a no-brainer to look at the total picture, but Americans have been so dumbed down by the mainstream media which is funded by big business (not liberal environmentalists as claimed by those responsible) that the obvious now becomes the ridiculous as evidenced by G. Karst's post above.
CO2 is as much a part of the problem as the rest of the oil and coal industry's pollutants. CO2 increases the acidity of the water and raises the water temperature which both benefit algae and ultimately plankton production and destroys coral which lives on live plankton, not dead decaying plankton and the poisonous bacteria it creates.
It is hardly a misunderstood problem. It is just another case of active denial by the very people and industries that are creating the problem in the first place.
What humans need to do is weigh the beneficial and non-beneficial attributes and choose solutions based on logic not greed.
Nitrogen fertilizer is depleting oxygen the dead zone of the Gulf. Why not pump air to the bottom of the gulf like is done in fish tanks? Why not pay for the operation by a tax on nitrogen fertilizer? Let the polluters pay for the consequences of their pollution.
Reply | Report Abuse | Link to thisIn my opinion, the hidden factor here is depletion of the soil in terms of buried carbon. i.e the nitrogen is not being retained as well by the soil because it is becoming more and more just a 'dry hydroponics' sterile medium.
Reply | Report Abuse | Link to thisWe need to make better soil by getting away from the idea that agriculture is about adding nutrients to a dead inorganic media designed only to stabilize the root system.
Move towards ways of allowing more nutrients from fertilizer to be retained, such as biochar, burying stalks, low tillage, etc. Maybe even letting fields lie fallow and alternating to give bacterial and worms time to establish themselves between crops. Investigate multiple crops in the same field (I know it makes harvesting more complicated but nutrients may be taken up faster. We need to develop actual soil as it is MUCH more resistant to losing nutrients than the basic minerals.
Looking over the responses, I despair of the public seeing agriculture as a biological process. They seem to regard it as an industrial one.
Of course doing the common sense thing and completely eliminating the levees south of New Orleans is just not considered of course.
Reply | Report Abuse | Link to thisIf this was done the waters of the Mississippi would then be filtered by the remaining marshlands that CAN utilize those excess nutrients and regrow themselves.
Destruction of these levees doesn't have to entail destroying communities if done right, but like I said since it's not even considered as an option proper planning has never been done. How pathetic.