Today’s news that the number of oxygen-starved “dead zones” in the world’s seas and oceans has risen by a third in the past two years is almost too much to comprehend. So let’s try this: according to United Nations marine specialists, there were 149 of these zones in 2004—today there are 200. Does that help drive home the dire state of our marine resources? If you’re a typical Minnesotan, probably not. That’s too bad, because Corn Belt states like Minnesota, Iowa and Illinois are largely responsible for one of the worst dead zones on the planet: a stretch of hypoxic water in the Gulf of Mexico that this year grew to the size of Connecticut and Rhode Island combined. Making Midwestern agriculture more sustainable would go a long ways toward bringing life back to the Gulf dead zone, and could serve as a model for other areas of the world suffering from marine asphyxiation. But first we need to eliminate our aquatic apathy and start caring about this issue—a surprisingly big challenge.
Here are the facts: wayward nitrogen is a key cause of the Gulf dead zone and the Midwest is a major source of that nitrogen. Southern Minnesota, most of Iowa, and parts of Illinois and Indiana are by far the biggest contributors of nitrogen to the Gulf. In fact the upper Mississippi River basin, (upstream from the Missouri River) makes up 15 percent of the drainage basin but contributes more than half of the nitrate-nitrogen discharged to the Gulf. The reason is simple: more corn is grown in the Midwest than anywhere else in the country. Corn needs a lot of nitrogen fertilizer to grow and despite all the best efforts on the part of farmers to utilize this nutrient wisely, a lot of it escapes our farm fields, particularly in heavily drained areas. We also raise a lot of livestock here, and manure is full of nutrients like nitrogen.
All that excess nitrogen makes its way down the Mississippi to the Gulf, where it causes explosive blooms of phytoplankton. Those plants die and sink to the bottom, where they are eaten by bacteria. All of this activity causes oxygen to be consumed at a phenomenal rate, spelling disaster for aquatic life in the area, particularly species that aren’t very mobile, like clams and oysters.
When I first wrote about the Gulf dead zone in 2001 for the Minnesota Conservation Volunteer, one state—Connecticut—was sufficient to describe the size of the region that was hypoxic. I interviewed Donald Lirette, a Louisiana shrimper. He described hauling up nets full of dead, rotting marine life, and how he would move further out to sea in an attempt to make his fishing trips worthwhile. It was clear that excess nitrogen leaving Midwestern corn fields was having a direct, devastating impact on an entire industry miles downstream.
Despite study after study, warnings by the Environmental Protection Agency and National Oceanic and Atmospheric Administration, and many major meetings—some of which have been held right here in Minnesota—the Gulf dead zone remains a distant issue with a morbid name to most of us in the Corn Belt. Some of this can be blamed on the spin some groups have put on the issue. The Fertilizer Institute and the American Farm Bureau Federation, two organizations who have a lot invested in the corn-bean-feedlot machine, have vehemently denied agricultural nitrogen’s role in the dead zone. This despite reams of data showing that as the amount of corn acres have increased over the decades, so has the amount of fertilizer applied, and thus the size of the dead zone. At times, their arguments make them sound a lot like the “global-climate-change-is-a-hoax” crowd. The scientific jury is still out on the causes of the dead zone, say doubters. They have also argued that excessive rainfalls during certain years cause unusually high water flows in the Mississippi, temporarily increasing nutrient loading from all kinds of sources. So there, they conclude, it’s really not something humans can control. But in 2006 the Mississippi had a lower than average flow overall, and the dead zone still grew. Oops.
But a lot of the blame for any real lack of action on this issue can be placed squarely on us. The fishing industry in the Gulf of Mexico is a multi-billion dollar business, but when’s the last time you weren’t able to dine on shrimp because of oxygen-starved water off of Terrebonne Parish? Factory fishing and fish farming seem to be able to supply us with our seafood needs for the time being. High profile environmental icons like whales can swim away from dead zones. Bald eagles probably thrive on all the dead fish it creates.
A veteran grassroots organizer once told me that the Gulf dead zone was a very difficult issue to organize even dedicated environmentalists around. It seems to suffer from a bad case of AIMBY—”ain’t in my back yard.” (Okay, I made that phrase up, and I admit it’s not as catchy as NIMBY.) Environmentalists and sustainble agriculture advocates in the Midwest have had a very difficult time getting institutions and governments, let alone average citizens, to pay attention to the Gulf dead zone. We don’t all have the opportunity to talk to a Louisiana shrimper who is seeing a life’s work being wiped out by excess nutrients.
The key to shrinking the Gulf dead zone, as well as those other 199 hypoxic areas the UN has identified, is to localize its impacts and make the connection between dead Louisiana clams and polluted Minnesota drinking water. That became clear to me while interviewing northeast Iowa farmer Dan Specht for the Conservation Volunteer. Specht lives and farms on a high ridge above the Mississippi. He learned long ago that his farming methods were having a direct impact on the safety of his well water. Nitrogen in rural water supplies is a major health issue, particularly for babies. An avid angler, Specht also knows that runoff can have localized impacts on fishing in the river. Specht has been to the Gulf at the invitation of an environmental group to witness firsthand the impacts of excessive fertilizer runoff.
Specht has seen that what’s bad for Gulf shrimpers is bad for Midwestern farmers. The farmer and some of his neighbors have adopted farming systems that rely on more perennial plant cover such as grass. They also utilize rotational grazing to spread manure in an ecologically sound manner and maintain diverse crop rotations to reduce the need for fertilizer while cutting erosion and runoff.
All of us—rural, suburban and urban—need to make the same kinds of connections Dan Specht and his neighbors have made. Excessive nutrient runoff in Minnesota affects our drinking water and wildlife, even our recreational opportunities and property values. Reducing that runoff enough to have a significantly positive impact here and in the Gulf won’t require all of Minnesota to be covered with prairies and wetlands. The Green Lands, Blue Waters initiative has shown that a few key changes to the landscape could have a big payoff environmentally. If we take localized steps to reduce runoff, it will have positive impacts many miles downstream.
As George Boody and I write in this month’s issue of BioScience, tightening the nutrient cycle and reducing nutrient runoff will require closing the gap that has developed between crops, livestock, farmers, the land and consumers over the past several decades. It will require everything from reforming farm policy and supporting sustainable ag research to buying locally produced food and supporting a township’s right to control where large-scale factory farms are built.
If we can do all that, the Gulf dead zone will take care of itself.