“Is corn boom expanding Gulf of Mexico’s ‘dead zone’?” That’s the title of an article written by Conrad Wilson of the (Minneapolis) Star Tribune, published Oct. 1, 2008. His sub-heading read “Some fear an ethanol-fueled harvest in the Midwest may be behind the hard times for marine life at the other end of the Mississippi River.” His lead paragraphs read “Last fall, the farm fields of the Midwest yielded record profits and the greatest corn crop in recent history. But there may have been an unintended consequence hundreds of miles to the south: As the corn grew, so did the size of the ‘Dead Zone’ in the Gulf of Mexico. The Dead Zone is a low-oxygen area virtually uninhabitable by marine life. It emerges in the spring and summer, created in large part by high nitrogen levels and other nutrients such as phosphorus. Its size varies: Last year it was about as big as Massachusetts.”
One month prior to the printing Wilson’s story, the Chicago Board of Trade price for U.S. #2 shell corn cleared $8/bushel, the highest price on record. That was then, so what’s the situation now – or at year’s end 2021, when the NOAA published the story (at oceantoday.noaa.gov/deadzonegulf-2021/n)?
The lead paragraphs of that article read “The numbers are in. The 2021 Gulf of Mexico Hypoxic Zone, or Dead Zone, an area of low oxygen that can kill fish and marine life near the bottom of the sea, measures 6,334 square miles. This year’s Dead Zone is larger than the average measured over the past five years. That area measurement is equivalent to more than four million acres of habitat potentially unavailable to fish and bottom species. This ‘Dead Zone’ begins innocently enough. Farmers use fertilizers and manure to increase the output of their crops so that we can have more food on our tables and more food to sell to the rest of the world.” Too often, huge amounts of fertilizer used to feed these crops kicks loose excess plant nutrients into the Mississippi River Basin, an area that drains 41% of the continental U.S.
NOAA writers stated that it’s this ag fertilizer pollution, combined with urban runoff and wastewater, that brings excessive plant food nutrients into waterways that feed the Mississippi River. The Mississippi River is similar to a drainage system for our streets, but it connects 31 U.S. states and even parts of Canada. These nutrients are ultimately funneled into the Gulf of Mexico, often traveling more than 1,000 miles downstream to start a chain of events in the Gulf that turns deadly. The nutrients fuel large algal blooms that then sink, decompose and deplete the water of oxygen. This is hypoxia, when oxygen in the water is so low it can no longer sustain marine life at the bottom or near the bottom waters – hence its moniker. For many decades, this misfortune has taken place every summer.
When the water reaches this hypoxic state, fish and shrimp leave the area and anything that can’t escape, like crabs, worms and clams, dies. If the amount of pollution entering the Gulf isn’t reduced, the Dead Zone will continue to wreak havoc on the ecosystem and threaten some of the most productive fisheries in the world. This raises the question, just what are the states doing to help? NOAA explained that a variety of innovative technologies and practices are being implemented across the Mississippi River watershed to reduce nutrient pollution such as technology that removes nutrients from wastewater, practices on the land to limit nutrients entering into waterways and programs to support farmers in their efforts to implement conservation practices that protect water quality.
There are even steps that non-farming landowners can take at home, such as reducing erosion and excess runoff from areas around the house, planting trees and other native plants in their yards and applying slow-release fertilizers – and only when needed. Even though these efforts may take place far from the Gulf, they can still reduce the harmful impact of the Dead Zone.
The Northeast contributes a small amount to the Gulf’s pollution problems compared to the “donations” from the other 29 states in the Mississippi watershed. Still, I want to show that for Pennsylvania and New York residents, the Gulf’s issues shouldn’t be relegated to the “somebody else’s problem” category. The Allegheny River is a principal tributary of the Ohio River, located in the eastern U.S. It joins with the Monongahela River to form the Ohio River at Point State Park in downtown Pittsburgh. The Allegheny River is, by volume, the main headstream of the Ohio River, actually starting in Potter County, PA, then weaving its way into New York, then back into the Quaker State. Then Ohio River spills into the Mississippi.
Nancy Rabalais, Ph.D., a marine biologist at Louisiana State University, explained the basic biology of Dead Zone formation. She said that the nitrogen (N) and phosphorus (P) pollutants from upstream stimulate the growth of microscopic organisms (phytoplankton). Microscopic animals (zooplankton) eat the phytoplankton. Tiny fish eat the zooplankton, and big fish eat the tiny fish.
Problems occur with excess N and P causing excess phytoplankton growth. These tiny plants are basically crowded to death. They are consumed by bacteria, who gobble up the oxygen, causing that part of the Gulf to become a Dead Zone, destroying ecosystems, particularly that of shrimp populations.
Borrowing the close from Wilson’s article, wherein he quotes Steve Albers, a prominent Minnesota corn/soybean farmer, praising new ecologically sensitive methods: “The new practices include testing soil before adding fertilizer, not planting along waterways and using more advanced plowing techniques. By knowing exactly how much fertilizer to use, farmers can save money (and avoid pollution). I don’t want anything leaving my farm unintentionally. I don’t want my soil, my fertilizer, or my kids leaving the farm.”