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Happening Now: Dead Zone in the Gulf 2021

Larger-than-average Gulf of Mexico ‘dead zone’ measured

River discharge and nutrient loads contribute to size


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 six thousand three hundred and thirty four square miles.

This year's dead zone is larger than the average measured over the past five years.

This year's 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.

But it is this excess agricultural nutrient pollution combined with urban runoff and wastewater that brings excessive amounts of nutrients into waterways that feed the Mississippi River.

The Mississippi River is like a drainage system for your street, but it connects 31 U.S. states and even parts of Canada.These nutrients are ultimately funneled into the Gulf of Mexico, sometimes traveling more than a 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 in bottom or near bottom waters—literally, a dead zone. And it happens 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 die. 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.

What are States doing to help?

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 you can take at home, such as reducing erosion and excess runoff from areas around the house, planting trees and other native plants in your yard, 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!