Dead Zones: The Water Mass of Death

Matt Katsigianis and Meredith Pease

What Causes the Dead Zone in the Gulf of Mexico?

The dead zone is caused by the eutrophication from nutrients, like nitrogen and phosphorus, which is found in fertilizers especially. The nutrients that are found in the Gulf of Mexico come specifically from farms along the edges of the Mississippi River and down into the Gulf (CNN).


Fig.1 (NOAA)

What Types of Organisms are Involved?

The different types of organisms involved in dead zones are organisms like phytoplankton and algae, which manufacture their own nutrients from sunlight, water, and carbon dioxide (National Geographic). Mostly, hypoxia affects the organisms people eat.

What are the ecological impacts, which species are affected and how is the environment affected?

Due to low levels of dissolved oxygen, fish and shrimp are relocating from their homes in an attempt to find safer areas. Because of the hypoxia, some organisms are unable to reproduce, eliminating any potential for the population to grow. When the population cannot physically grow, and the remaining population is being killed by the hypoxia, fish, shrimp, and other smaller organisms face danger of extermination (NOAA).


The hypoxic areas drain the oxygen from the area, and fish and shrimp migrate to other areas in order to avoid a lack of oxygen that would kill them. Many small organisms that are food for fish and shrimp can’t escape the area and are killed by the hypoxic dangers in their homes. When the fish and shrimp return to the area, they cannot find sufficient amounts of food (CNN).

What Are the Economic Impacts?

Fish and other marine life move out and away in order to avoid dead zones. As a result, fishermen have a harder time finding fish and are forced to travel farther from land, spending more time and money in the process (The Nature Conservancy).

What kinds of geographic areas are affected by dead zones?

There are 550 dead zones occurring annually, with the Gulf of Mexico dead zone being the second largest worldwide (NOAA). The Baltic Sea is the most heavily affected by hypoxia, as the dead zone there is the largest in the world (CNN).


Dead zones are most notably seen along the coasts, as noted by Fig. 2. This is because runoff of fertilizers come from rivers, and are deposited into the ocean, affecting the areas immediately within the vicinity.


Fig. 2 (Simmons)

What Can Be Done to Reduce, Eliminate Or Manage Excess Nutrients and Solve This Issue?

• Use environmentally friendly landscaping techniques that require less fertilizer, prevent erosion, and use native plants. Using a soil test kit will help you determine the amount of fertilizer you actually need

• Leave grass clippings on the lawn the recycle nutrients or start a compost pile to reduce the amount of waste you put into the garbage disposal or garbage can

• Conserve water at home to reduce the volume of wastewater that must be treated by a sewage treatment plant or septic system. This will increase the efficiency of treatment and save you money

• Use safe, non-toxic alternatives for cleaning and for controlling pests. Always take your household/lawn chemicals to a recycling center, not in the trash or down your drain

• Wash your car on a grassy area if possible, so the ground can filter the water naturally. Use soap sparingly and try to use non-phosphate detergents. Empty the bucket of soapy water in the sink, not in the street

(The Nature Conservancy)

Works Cited

"Dead Zone." <i>National Geographic Education</i>. N.p., 21 Jan. 2011. Web. 08 Feb. 2016.

"The Dead Zone." <i>NOAA National Ocean Service Education:</i>. N.p., n.d. Web. 08 Feb. 2016.

"Gulf of Mexico Dead Zone." <i>The Nature Conservancy</i>. N.p., n.d. Web. 08 Feb. 2016.

"Happening Now: Dead Zone in the Gulf 2014." <i>Happening Now: Dead Zone in the Gulf 2014 </i>. N.p., n.d. Web. 08 Feb. 2016.

"Large 2015 Gulf of Mexico Dead Zone | EarthSky.org." EarthSky. Earthsky Communcations Inc, 18 Aug. 2015. Web. 05 Feb. 2016. <http://earthsky.org/earth/large-2015-gulf-of-mexico-dead-zone>.

Simmons, Amy. "Scientists Fear Mass Extinction as Oceans Choke." No Fish Left. 30 Nov. 2010. Web. 09 Feb. 2016.

Smith, Melodi, and Jason Hanna. "Gulf of Mexico 'dead Zone' Is the Size of Connecticut - CNN.com." CNN. Cable News Network, 05 Aug. 2014. Web. 05 Feb. 2016.

"We Need Your Help!" <i>2015 Gulf of Mexico Dead Zone 'above Average'</i> N.p., n.d. Web. 08 Feb. 2016.

"What We Can Do About Gulf Hypoxia." <i>The Nature Conservancy</i>. N.p., n.d. Web. 08 Feb. 2016.

"2015 Gulf of Mexico Dead Zone ‘above Average’." NOAA. 04 Aug. 2015. Web. 05 Feb. 2016.