Dead Zones

Dead Zones

By Claire S. and Mara A.

Imagine walking from your car to your work or school, then imagine everything dead. The flowers have wilted and their petals shriveled. The trees’ bark is peeling. With every step you take you hear a brick fall to the dry cracked earth. You try to take a breath but there is no oxygen left, every bit of it has been sucked up. What are you going to do now?

This is what it would be like if we were living in a dead zone. No oxygen, no life,
nothing but water. A dead zone is an area of water (often just off the coast) where the
oxygen had been depleted so all the life in that area dies off.

Ocean---------------Dead Zone








Dead zones are created by nitrogen and phosphorus plant nutrients. Plant nutrients are chemicals many farmers (or even people at their homes) use that encourage their plants to grow. The plant nutrients have a large impact on out environment, but no in a good way. When the nitrogen and phosphorus run off into streams or rivers, it can get into the fish or animals drinking from that water. Many of the fish die, which decreases the population that some people, along with animals, need to survive.

When the run off reaches the larger rivers the nitrogen and phosphorus are carried into the ocean, it spills out into the salt water. The plant nutrients settle in the water, and because the plant nutrients are made to help plants grow, an algae bloom forms on the surface.
Once the algae bloom has formed bacteria start to eat it similar to bacteria eating away fruits and vegetables in a compost bin. The algae will decompose and sink into the saltier water, but as it is decomposing the bacteria that are eating it use up all the oxygen. Once the DO (dissolved oxygen) level has reached two that is called a hypoxia. A hypoxia is usually considered a dead zone, almost nothing can live in those conditions. When the DO level reaches zero that is called an anoxia. There is no possibility of any animal living in those waters. Plants can typically survive because they photosynthesize.

A dead zone does not always stay in one shape or size. The most common way a dead zone changes size is by weather. Weather has a huge impact on the dead zone’s oxygen level and the size of it. The worst thing for a dead zone would be rain. Rainfall causes even more run off full of nitrogen and phosphorus. With more nutrients in the water the algae blooms gets much larger. If it is a significant amount of rain a dead zone could double (if not triple) its area. This is largest in spring and early summer.

Sun also affects the area of a dead zone. Much less then rain does, but it is still a measurable amount of increased dead zone. The algae use photosynthesis to increase in size. Solar energy is strongest in the summer because it is hottest and the days last longer, giving the algae plenty of time to grow.

The last piece of weather is wind. We think wind is one of the more interesting elements because unlike sun and rain, which worsen the dead zone, wind helps. Wind mixes up the water and causes oxygen from the atmosphere to mix into the salt water. The wind is makes the dead zone shrink, but if there are really high winds, a dead zone has been known to disappear. If it does happen to disappear it will not stay gone forever. It will keep coming back until we get off the couch and make a difference.

Dead zones affect many people just like (if not) you, because all the animals in that area of the sea die there is a much smaller amount of seafood we can eat or sell. That means that either the price for seafood will go way up, or the fisherman will not be getting as much of a profit. Either way we are not a huge fans. We all need to help out where we can now. As we said, the main cause of dead zones is nitrogen and phosphorus plant nutrients. Of course the best way to get rid of dead zones would be to stop buying plant nutrients. If for some reason you feel you can not get by without them then PLEASE try to find an organic or earth friendly one, also if you choose to buy one, please use it sparingly. Together, we can make a change.





Works Cited:

* Gulf of Mexico Dead Zone. Science Museum of Minnesota . 18 Apr. 2008 .

* "Dead Zone (ecology)." Wikipedia. 2008: Wikipedia. 18 Apr. 2008 .

* "Gulf of Mexico Hypoxia Watch." National Coastal Data Development Center . 9 Aug. 2007. 25 Apr. 2008 .

* "150 'Dead Zones' Counted in Oceans." msnbc U.S. News/Environment. 29 Mar. 2004. msnbc . 31 Apr. 2008 .

* Bruckner, Monica . "The Gulf of Mexico Dead Zone." Microbial Life. 1 Montana State University. 4 May 2008 .

* Chohan, Rani . "Mississippi Dead Zone." NASA. 10 Aug. 2004. NASA. 4 May 2008 .

* "Lake Erie 'Dead Zone'." Lake Erie 'Dead Zone' and Special Lake Erie Study. Environmental Protection Agency. 8 May 2008 .

* "The Dead Zone in the Gulf of Mexico." Sierra Club. .