USGS water quality technician Kelly Brady is a foot soldier in the war against hypoxia. He takes water samples once a month that end up being used in the recent USGS study.
On a recent trip, the Missouri River looked deceptively smooth, but Brady knew it could quickly turn deadly. On average, 88,500 cubic feet of water – enough to fill an Olympic-size swimming pool – slip past here every single second. If water were oil, the volume of the entire BP oil spill could pass by in five minutes.
Brady launched the work boat, a 26-foot sealed-hull aluminum skiff that he jokes looks like a gunboat out of “Apocalypse Now.” “It’s supposed to be unsinkable and self-righting, but I don’t want to try that out,” he said. “I like swimming, but I don’t want to do it on the job.”
The crew used a laptop, radar and high-precision GPS to find sampling locations. A crane hanging over the front of the boat dipped a Teflon-lined sampler into the water and hauled up several liters of water. Brady and his team processed the samples in mobile labs in the back of their trucks. These were put on ice and shipped to Denver for analysis.
Brady’s data are essential for keeping tabs on water quality. Dale Blevins, a USGS scientist emeritus who is an expert on the Missouri River, has studied historical nitrogen concentrations in the river in the past century. "It’s a cycle; it goes up and down," he said. "We’re in upward trend in one of those cycles and we’re about to bust out the top of where we’ve ever been before." Why? He’s not sure.
The total nitrogen concentration in the Missouri is not much different now than in the early 1900s, Blevins said. But most of that used to be organic nitrogen, whereas now, it's mostly nitrate, a form that many algae and other organisms can take in directly.
"It has reached almost its maximum concentration by time it reaches St. Joe," Mo., he said. "If you look at the location where the nitrate’s coming from, those are pretty much agricultural areas."
There is another possible explanation for the increasing nitrate numbers, a third view that blames neither today’s farms nor urban areas. The pollution could come from historic nitrogen deposits – the legacy of years of earlier excess that is just now showing up.
The USGS study found that a lot of nitrate poured into the river even when the water flow was low. One might expect heavy rain to wash nutrients off the land, but where did nitrate come from under dry conditions?
Sprague concluded groundwater was the source. Rain falls on the surface, percolates through the soil and drains out from days to decades later.
Norfleet, the USDA soil scientist, said nitrogen could stay in an aquifer for years before finally spilling into streams. “It’s kind of like having clogged arteries,” he said. “It’s going to take a while to clean those out.”
If groundwater really is responsible, it could take years for conservation measures to make a significant difference in the Gulf.
“Even if we stopped applying nitrogen now, the groundwater’s going to have a lot of nitrogen in it for 5 to10 years, or in some places, 20 to 30 years,” said Andrew Hug, an analyst with the Environmental Working Group who focuses on agriculture’s environmental impact. “It’s going to take a long time to fix this problem.”
Iowa farmers and Louisiana fishers
Up at the top of the watershed, Bill Northey spends a lot of time thinking about the Gulf’s dead zone. As secretary of the Iowa Department of Agriculture and Land Stewardship, he looks for science-based ways to maintain farm productivity while also reducing runoff to the waters below.
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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.