Water Conservation

We're killing the Gulf of Mexico: Learn about what we are doing that causes the ocean to die.

The Gulf of Mexico Dead Zone: What Can Be Done to Change It?

At a staggering 5,052 square miles, the Gulf of Mexico’s dead zone has become a focal point for the growing number of people worried about what humans are doing to harm the planet’s environment.

Now the size of the state of Connecticut, the dead zone is an area of low oxygen water, otherwise known as hypoxia. The area covers almost the entire coast of Louisiana and the section of the Texas Gulf coast extended east from Galveston Bay to the Texas-Louisiana border.

The dead zone typically appears every spring and lasts through the summer.

Hypoxia makes it difficult for plant and marine life to find enough oxygen to survive. While fish and shrimp can move to areas with higher oxygen, some of the smaller marine life can’t escape and eventually die. Many of these ocean floor-dwelling creatures serve as food for fish and shrimp, which prevents the more mobile marine life from returning to the dead zone area even after oxygen levels rise.

In another words, as reported on the federal National Oceanic and Atmospheric Administration (NOAA) website: “Habitats that would normally be teeming with life become, essentially, biological deserts.”

What Causes the Dead Zone?

Learn about the Gulf of Mexico Dead ZoneFirst discovered in 1972, the Gulf of Mexico dead zone has returned each year in varying sizes. The largest was 2002, when the dead zone reached more than 8,000 square miles. But while the zone is smaller this year, it is nowhere near the less than 2,000 square miles scientists had hoped for by 2015. There are more than 500 dead zones around the world, with the largest in the Baltic Sea. The Gulf of Mexico is the second largest.

Scientists believe the primary cause of the dead zone is sewage and fertilizer that is carried by the Mississippi River into the Gulf of Mexico. Some scientists believe the primary source are large agricultural operations that use chemicals which seep into the water table and eventually end up in rivers and tributaries that flow into the Mississippi River.

These extra nutrients cause massive algae blooms that choke off oxygen in the area. They may also turn the water brown.

Scientists with the NOAA and the federal Environmental Protection Agency have worked with agriculture companies to better control the use of fertilizers and other chemicals that contain phosphorus and nitrogen, both of which algae feed on. But the dead zone continues to remain a size that is troubling.

Cause for Concern

There are more casualties from dead zones than simply deep ocean dwelling animals.

For example, the NOAA estimates that the United States seafood and tourism industries lose $82 million annually because of algae blooms.

Also, the United Nations has estimated that the number of dead zones has doubled just about every year, meaning more strain put on the food chain in those areas.

Because intensive farming is the human activity most-linked to dead zones, the practice has come under scrutiny. Critics accuse large, intensive agricultural operations of using large amounts of pesticide and fertilizers to extract the largest amount of crops possible from an acre of land.

Some scientists also think the increased amount of corn being grown for ethanol has increased the amount of nutrients that seep into groundwater and eventually run into the Mississippi River. Corn takes a large amount of fertilizer to grow.

Possible Solutions

Scientists with NOAA, the EPA and other agencies think there are many different strategies that could result in smaller dead zones. These include:

  • Limiting the amount of nitrogen-rich fertilizers used by agricultural operations.
  • Implementing water conservation and increasing the use of recycled water
  • Searching out, finding and fixing leaks from wastewater treatment plants
  • Limiting the amount of animal waste that enters into the waterways
  • Restoration of wetlands. Millions of acres of wetlands have been lost over the last century, making it harder for water systems to absorb chemicals and waste. Federal, state and local governments are working on wetlands restoration projects around the country, including south Louisiana.

Despite the growth of dead zones over the past few decades, scientists remain optimistic that the trend can be reversed with these simple measures. But accomplishing them, given this year’s size of the Gulf of Mexico dead zone, may take longer than first anticipated.

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