Understanding the Gulf of Mexico’s Hypoxic Zone

Spanning the shores of 5 US states and 6 Mexican states, the Gulf of Mexico is 10th largest body of water in the world, excluding oceans. Iacts as a vital resource to both of its bordering countries, providing food, sport, oil, and more. Today, the Gulf of Mexico faces a growing threat that’s causing its waters to darken as marine life either leaves or dies. 

It’s called hypoxia. 

Hypoxia refers to low or insufficient oxygen levels in the body, the air, or water supplies. In the case of the Gulf of Mexico, this lack of oxygen has resulted in a massive hypoxic zone primarily bordering Texas and Louisiana. 

Reaching sizes as large as 7838 square miles, the Gulf of Mexico’s hypoxic zone is the Western Hemisphere’s largest aquatic dead zone. For comparison, that’s roughly the size of Massachusetts. Left unchecked, it will continue to grow, causing irreparable damage to the Gulf’s marine life and the local economy. 

But before we can discuss how to fix the problem, we need to better understand what exactly the problem is. 

What is a Hypoxic Zone? 

A hypoxic zone (also called a dead zone) refers to an area in a body of water that lacks the oxygen required to sustain marine life. This results in an imbalance of biodiversity, which can cause further damage to the surrounding area. 

The exact cause of a hypoxic zone can vary, though it typically stems from an increase in nitrogen and/or phosphorus introduced by urbanization, sewage disposal, and farming practices. Nutrients such as nitrogen and phosphorus lead to eutrophication, which causes excessive algae and other plant life to grow in the water. 

When the plant life dies, it consumes the surrounding oxygen, creating hypoxia. The sea life in the affected water either vacates or suffocates. Even if oxygen levels don’t drop low enough to kill local fish, it can affect their reproduction. Studies have shown that fish in low-oxygen water have underdeveloped sex organs, leading to significantly smaller spawn rates. 

What is Causing the Gulf of Mexico’s Hypoxia? 

The main cause of the Gulf of Mexico’s hypoxic zone appears to be excess nutrients flowing from the Mississippi river. In terms of discharge, the Mississippi is the United States’ largest river. Though sewage and general waste disposal contribute to the pollution of the Mississippi, agriculture is believed to be the primary culprit.  

After all, the Mississippi cuts through some of our country’s most prominent farmland. 

Over the next few weeks, we’ll be diving deeper into the agriculture industry’s contribution to the Gulf of Mexico’s hypoxic zone, and how establishing pollinator habitat and native perennials can help combat this terrible situation.  

Want to make sure you don’t miss these posts? Click here to subscribe to us!