Enviro4me- Earth Advocates

Environmental Awareness Leading to Environmental Change

Dumping equals Dead Zones

By: Rachel Knight

Any of us who have lived near the ocean can most likely say that they have seen those painted warnings, “No Dumping, this drains to the ocean”, near street drains. Regardless, people don’t seem to understand this concept and refuse to think twice before dumping into these drains. These are the people who contradict all the hard work others do to help conserve the ocean, keep it clean, and protect all that live in the diverse ecosystems. These are the people who are responsible for the dead sea lions you see lying on the beach, or the huge amount of jellyfish strung out across the sand. You wonder if these deaths happened from natural causes; but deep down, I think we all know they didn’t.

Oceans have become giant dumps for industrial waste, toxic emissions, and garbage. People do not understand how affected the ocean is by the things we put into it. All of this waste we are pouring into our oceans have affected oceans’ overall health and equilibrium, and one of the main effects of us using it as a trash can are ocean dead zones.

What is an Ocean Dead Zone?

An ocean dead zone is an area of water with very low oxygen levels, which in turn makes the area insufficient to support marine life. Imagine that all of a sudden you were walking and you couldn’t breathe because you had walked into an area where there just wasn’t enough oxygen. What would happen? You would suffocate. And unfortunately marine animals are dying on a daily basis because we are too lazy to correctly dispose of our waste. These animals suffocate to death, which is a very scary and unfair experience.

How Do Dead Zones Work?

Spikes in algae growth, a process known as phenomenon algal bloom, create ocean dead zones. The alga grows rapidly because of humans dumping excessive fertilizer from intensive farming, sewage, phosphorus, and nitrogen into the ocean. Many of these nutrients (like nitrogen, phosphorous) are not usually significant factors in the increase of algae growth. In the past, they were depleted by the soil of plants as they traveled down rivers towards the ocean. However, the amount of phosphorous and nitrogen is too great now, and can no longer be used up before entering the ocean. All the excessive algae eventually dies and is then eaten up by bacteria. These bacteria use up surrounding oxygen while devouring the algae. As a result, the oxygen levels become unbalanced and the entire equilibrium of the area is ruined.

Animals and Dead Zones

When an animal’s habitat becomes a dead zone they must fight to survive. Animals have been known to exhibit unusual behavioral mechanisms, like swimming away from the area, or even standing upright in an attempt to reach higher levels of water hoping there will be more oxygen available for them. Sadly, many animals are too slow, and are unable to escape. They then suffocate and die.

The dead zones have not only caused death of marine life, but also death of habitats; habitats of fish and other marine life are destroyed. Those once living in a “dead zone” are forced to seek more oxygen rich areas and cause overcrowding with other local species. Overcrowding leads to marine life becoming more prone to predators and often times become the victims of fishermen. On top of killing innocent marine life and destroying habitats, our careless dumping turns ocean water a dirty brown color and it becomes completely inhabitable.

Dead Zone Locations

In the United States there are multiple dead zone locations:

  • Outfall of the Mississippi River emptying out into the Gulf of Mexico
  • Outfall of the Elizabeth River of Virginia Beach
  • Outfall of Lake Eerie
  • The Pacific Northwest Region

There are also reoccurring dead zones found in New Zealand, Japan, China, South America, and the Gulf of Mexico.

The Gulf of Mexico exemplifies the power of dead zones. In 2006 the Gulf of Mexico’s dead zone was measured at 6662 square miles, and in 2007 only a single year later, the dead zone had grown to 7900 square miles.

According to the United Nation’s Global Environment Outlook Yearbook there were 146 reported dead zones in 2003 worldwide. In 2008 the number of dead zones had increased to 405.

Dead Zones Natural?

It has been found that some dead zones can occur from natural causes. Evidence for this has been found via chemical records of otoliths (a part of the inner ear) of some fish. According to an NOAA climate study, climate change is a key factor in the expansion of dead zones, especially over the past few years. Rising global temperatures mean warmer oceans and warmer body of waters are less capable to hold oxygen. Despite these possible natural causes, human activities and industrial waste only worsen the situation.


Is There Hope?

Thankfully, marine dead zones are reversible, but only we can make this happen. An example of this is the Black Sea, which was formerly the largest dead zone in the world. This dead zone was reversed between 1991-2001, but how and why? Well, during this time period fertilizer became too expensive for many people after the collapse of the Soviet Union. The Black Sea example shows how a decrease in industrial emissions can actually erase and minimize dead zones.

However, with demand for biofuels increasing pressure on farmlands to  continue production and the continuing practice of dumping human waste and garbage into the ocean, we may only see increases in Dead Zones. It also shows how much our habits and activities really affect the oceans of our planet, and only WE can stop this. Our actions and laziness has caused destruction of marine habitats and death of marine life.

Is this what you want our future oceans and beaches to look like?

Unless we change our ways, soon we won’t have much of any ocean left. So think before you dump. Save your oceans, save your planet.

2 comments on “Dumping equals Dead Zones

  1. daydreamemporium
    January 28, 2012

    Healthy mangrove groves at the mouths of rivers are another factor that can guard against dead zones because they filter the water and are host to many other species that do the same.

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