Gulf of Mexico Dead Zone: What, Where, Why?
What Is Hypoxia (The Cause of the Dead Zone)?
Every summer a hypoxic zone, or area with depleted oxygen levels, occurs in the Gulf of Mexico as a result of nutrient run-off within the Mississippi/Atchafalaya River Basin (MARB). Excess nutrients cause increased algae growth, when the algae die the decomposition process consumes oxygen resulting low oxygen levels in the water. The direct effects of hypoxia are young fish kills, which cause ripple effects up the food chain, along with other commerce (seafood and recreation) related issues.
Where do the increased nutrient levels come from?
- Physical Environment (Shape and flow of water body)
- Fertilizers from Golf Courses, Agriculture, and Lawn Treatment
- Atmospheric Nitrogen Deposits
- Soil Nutrient Erosion/ Groundwater
- Urban Run-off
- Sewage Treatment Plant Discharge
Agricultural Nutrient Use
In the last 26 years, there have been significant decreases in nutrient application as technology and genetic plant research has created more efficient application and nutrient retention. For corn and soybeans both have decreased in nitrogen application by 31 percent. Additionally, 31 percent for corn represents 3 billion pounds, and 109 million pounds of nitrogen in soybeans. Nutrient decreases in agriculture have occurred even as production has increased. Serious consideration of environmental protection is a regular occurrence in agriculture because of the need for a balanced and healthy environment to provide for successful farming.
Part of the Solution
With all that agriculture is currently doing to protect water ways there are still ways to manage runoff. The EPA recommends:
- Manage animal waste to minimize contamination of surface water and ground water.
- Protect drinking water by using less pesticides and fertilizers.
- Reduce soil erosion by using conservation practices and other applicable best management practices.
- Use planned grazing systems on pasture and rangeland.
- Dispose of pesticides, containers, and tank rinsate in an approved manner.
A large portion of the MARB covers the Midwest, and often agriculture is referred to as the culprit, however, it is important to understand that farmers and agricultural leaders are making great efforts to decrease unnecessary nutrient application. Additionally, there are also many other players and if all work together there will be improvement.
Preston Lyman is a Research Analyst with Decision Innovation Solutions (DIS). DIS is an Iowa-Based economic research firm which provides regular farm economics research and analysis to the Iowa Farm Bureau staff and members.
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