Who owns the dead zone?

Agricultural pollution flowing out of the Midwest kills aquatic life in the Gulf of Mexico, with seafood harvesters and eaters paying the cost for this displaced cost of “cheap food.”

By Krista Hozyash 
Posted November 18, 2009 


NASA-NOAH image

World-wide dead zones: cause and effect

The Gulf of Mexico dead zone is not unique. There are around 169 known hypoxic areas (zones without oxygen) occurring world-wide. The over-enrichment of nutrients like nitrogen and phosphorus in water, or eutrophication, largely contribute to their creation.

Once nutrients reach aquatic ecosystems, the immediate result is a bloom of growth in phytoplankton, microalgae, and macroalgae. Light penetration into the water is reduced, species diversity decreases, community composition changes, toxic species develop, and oxygen is depleted. The worst-case scenario resulting from eutrophication is ecosystem collapse.

Dead zones do not solely affect aquatic life forms and systems. A large proportion of the world’s population is vulnerable to negative impacts from eutrophication along coasts. Nearly half of the world population lives within 60 kilometers of coastlines, with livelihoods dependent upon tourism, fisheries and recreation negatively affected from depleted aquatic ecosystems.

The actual extent and effects of dead zones around the world are not completely known. Coastal areas of Asia, Latin America, Africa and the Caribbean have few sources of dependable water-quality data. Current estimates of hypoxic and eutrophic areas are likely less than the actual areas affected.

The best way to limit the growth of dead zones is to improve water-quality monitoring and analysis throughout watersheds. Communities can better manage aquatic ecosystems when both sources and types of pollution—and their ecological and environmental impacts—are more clearly described in their dynamic relationship.

Hypoxia 101 (website with resources) Mississippi River Gulf of Mexico Watershed Nutrient Task Force

To understand our impact on nature, there is truth in the saying, “everything is connected.” Few situations illustrate this concept as dramatically as the agricultural wastes from the Midwest that contribute so seriously to the aquatic dead zone in the Gulf of Mexico.

Human activities and natural phenomena occurring on land masses combine to impact air quality and small-scale climate systems. Wastes and sediments flowing off lands affect natural concentrations of nutrients in water and the health of aquatic habitats. Gases suspended in air dissolve into sea water and disrupt the normal chemistry of oceans.

These releases, often invisible where the problems originate, can have repercussions in other states or nations through natural systems that are not at all limited by political boundaries. Time and distance too often obscure the impacts, hiding unintended or unknown connections with downstream costs.

Take the example of crops growing hundreds of miles inland in the “I-states,” and the putrefying aquatic ecosystems in the Gulf of Mexico. The Mississippi River Basin empties into the Gulf below New Orleans. It drains the U.S. Heartland and upper Midwest, home to most of the country’s prime agricultural land outside the state of California. Lots of fertilizer is applied every year in this watershed to produce lots of non-organic corn, soybeans, cotton and rice. Massive amounts of agricultural nutrients escape these fields through erosion, runoff and leaching through soil into groundwater. These intended-nutrients-turned-agricultural-pollutants have disastrous effects when they accumulate in the Gulf waters.

“Dead Zone” The term sounds morbidly ominous, with good reason. During the summer months, a huge amount of water with limited dissolved oxygen ranging from 5,000 to 8,000 square miles in size (approximately the size of Connecticut to that of New Jersey) forms in the Gulf.

Nitrogen and phosphorus runoff nourishes algae, causing massive blooms in the water. As algae decompose, oxygen is removed from the water. Aquatic life forms are asphyxiated and die off. Stocks of large fish dependent on these tiny plants for food are affected, causing fishermen to experience a lower catch and the possible loss of their livelihoods. Result: U.S. consumers are deprived of seafood from one of the nation’s most important fisheries.

Agriculture’s Impact

The Gulf of Mexico dead zone has been a huge problem for the past 20 years impacting all states with significant fisheries along the gulf’s borders: Texas, Louisiana, Mississippi, Alabama and Florida. The production losses of shrimp, crabs, grouper and red snapper from the unique region impact domestic seafood commerce across the country.

Why hasn’t its agricultural cause been aggressively addressed, instead of being treated almost as a cost of doing business?

Federal farm policy designates billions of dollars to fund agriculture through production subsidies. Because subsidy income is based on yield rather than ecological impact, applying fertilizer is considered essential to optimizing commodity production. Trouble is, too much of that fertility leaves the fields. Research conducted by the Environmental Working Group indicates that when spring runoff pollution is at its highest, more than 7.8 million pounds of fertilizer nitrate flow down the Mississippi River to the Gulf of Mexico every day. The United States Geological Society has identified Illinois, Iowa, Indiana, Missouri, Arkansas, Kentucky, Tennessee, Ohio, and Mississippi as the primary contributors within the far-reaching watershed. These states only make up a third of the Mississippi River Basin’s area, and yet are responsible for more than 75 percent of the nitrogen and phosphorus that enters the gulf.

The Clean Water Act  was created to improve the nation’s waters so that natural chemical, physical and biological conditions could be sustained. The legislation determined that pollution from point and nonpoint sources should be minimized, however it can be difficult to identify and reduce nonpoint source pollution such as fertilizer runoff from agricultural operations. Relatively little effort has been undertaken to control nonpoint source pollution, with waterways and fisheries around the country suffering as a result.

Farmer cooperation

Are farmers indifferent to the plight of the seafood community? Absolutely not. Thousands of farmers in the Mississippi River Basin have applied for federally-funded conservation programs to curb agricultural pollution from reaching waterways. Best management practices such as wetland restoration (returning farmed lands to natural areas), vegetated buffer zones along river and stream banks, conservation easements preserving undeveloped lands, and nutrient management efforts have all been pursued by concerned farmers. These strategies work to either slow or absorb nutrients before runoff reaches waterways, prevent severe soil erosion from flood events, create corridors and natural habitats that increase biodiversity, or reinvigorate wetland filtration and biological cleansing processes.
  
Farmer interest in conservation far outpaces the availability of funds. Producers in 2004 applied for $124 million more than was available in the Wetlands Reserve Program, and for $235 million more than was available in the Environmental Quality Incentives Program. More alarming is that this data from the USDA’s Natural Resource Conservation Service accounts for requests from only Illinois, Iowa and Indiana, underestimating the real demand for conservation funding being voiced by farmers in the region.

The availability of money for the production of subsidized crops compared to the funding provided for conservation programs pinpoints a main reason the gulf’s dead zone exists. Commodity payments between 1995 and 2002 totaled $59.7 billion while conservation subsidies were $8.5 billion. These imbalanced incentives will result in the further depletion of water quality, enlarging the extent of the gulf’s dead zone and affecting additional fisheries.

Dead Zone solutions

The situation in the Gulf of Mexico is dismal, but certainly not hopeless. A shifting of some funding towards conservation and away from commodity subsidies could have a significant impact on reducing the size of the dead zone. A modest change in current farm policy that directs funding away from degraded lands and towards the conservation of working lands would allow more members of the farming community to benefit from payments.

The federal government is working pro-actively to reduce the dead zone after years of taking a hands-off approach to states’ struggles with limiting pollution from nonpoint sources. A federal-state task force is addressing the problem and the EPA has presented targets to reduce nitrogen and phosphorus by 45 percent by 2015 to limit the size of the dead zone.

Whatever strategies are ultimately undertaken, two main steps to reduce agricultural pollution reaching the gulf are needed: cut application rates so crops absorb more of the fertilizer, and improve barriers to intercept whatever fertility escapes plant uptake. Nutrient management plans coupled with nitrate tests effectively identify how much fertilizer is actually needed for agricultural productivity, reducing wasteful application.

Counting the cost

University and government researchers are beginning a four-year study (through late 2013) on the effects of the increasingly severe seasonal “dead zone” in the Gulf of Mexico on the region’s shrimp fishery.

Another solution would involve converting acres of cropland to organically-grown agriculture that greatly increases soil organic matter and includes nutrient-retaining “trap” crops. Returning crop land to pasture and growing more multi-year forage crops would reduce soil erosion risks and the need for applied fertility. These steps would also increase nutrient retention and water management in wet seasons or floods. Further benefits from organic systems would include more microbiologic activity in soils and greater regional biodiversity.

The Gulf of Mexico dead zone is an intricate problem with a complicated root cause. Dead zones illustrate the connectivity between natural systems and human actions, as water quality and aquatic health react to nutrient pollution. Attacking the problem will be helped by education on the links between farms and the Gulf, and will be further spurred by decreasing subsidy incentives tied to crop yield or some real disincentive for agriculture-related pollution.

Thanks to individuals seeking sustainable innovations that will reduce the escape of nutrients from feedlots and fields, it may be possible to revive a critical fishery through better-managed agricultural production.

Krista Hozyash is a communications intern at the Rodale Institute. She recently graduated with a Masters of Environmental Management from Duke University's Nicholas School of the Environment, and plans to aid communities with conservation and sustainability initiatives.


Sources
Alexander, Richard and LaVista, Jennifer. “USGS Press Release: Agricultural Practices in 9 States Contribute Majority of Excessive Nutrients to the Northern Gulf of Mexico.” U.S. Geological Survey. 29 January 2008.

Booth, Mary, Dr. “Dead in the Water.” Environmental Working Group. April 2006.

Selman, Mindy et al. “Eutrophication and Hypoxia in Coastal Areas: A Global Assessment of the State of Knowledge.” World Resources Institute. March 2008.

Shapley, Dan. “Report: EPA Should Limit Fertilizer Runoff to Prevent Dead Zones.” The Daily Green. 28 August 2009. 

UN Chronicle Online Edition. “Risks, Untreated Sewage Threatens Seas, Coastal Population.” UN Chronicle. Accessed 9 November 2009.
 
US EPA. “Clean Water Act (CWA).” U.S. Environmental Protection Agency. 18 June 2009.

 

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

The dead zone

We are beginning to reap the penalties of chemically oriented farming. The field of organic farming is well explored, documented and validated. It's time we really got back to natural means. The protection of vast pools of profit for chemical and industrial farming interests cannot be allowed to justify damage to the one rock we have to live on. There's a great documentary about this subject. Food Beware: The French Organic Revolution. Here's a link to a clip from it: http://organicconnectmag.com/wp/2010/01/food-beware-video-clip/

dead zone photo

Frank,

The NASA satellite image shows summer phytoplankton conditions along the Gulf Coast, with areas of high concentrations of phytoplankton and river sediment appearing as reds and oranges. More information can be found on this NASA website: http://svs.gsfc.nasa.gov/vis/a000000/a002900/a002979/. Thanks for your question, I apologize that the image wasn't clearly labeled.

Krista Hozyash

dead zone photo

Dear Krista:

What precisely is the NASA image of the Gulf of Mexico showing? I understand that it is related to Mississippi River outfall and the dead zone. Is it an infrared photo of water temps, or some other spectral image related to some other water quality parameter? I teach crop science and would like to know.

Peace,

Frank Kutka

Post new comment

The content of this field is kept private and will not be shown publicly.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Allowed HTML tags: <a> <em> <strong> <cite> <code> <ul> <ol> <li> <dl> <dt> <dd>
  • Lines and paragraphs break automatically.

More information about formatting options

CAPTCHA
This question is for testing whether you are a human visitor and to prevent automated spam submissions.