Dead Zones, they are not just the scary cell phone commercials you see on T.V, they are the horrifying threat to our marine ecosystems. Dead zones are located in coastal areas where the oxygen concentrations are too low to sustain marine life. Dead zones are caused by excess nutrients, mainly phosphorous and nitrogen, seeping into the water system. These nutrients then fertilize algae blooms throughout the coast. After plants (microscopic plants) die and sink to the bottom, bacteria are fed. Bacteria consume the oxygen in the water which does not allow for fish and other bottom dwelling organisms to survive. Dead zones can be seasonal, usually appearing in the spring and fall, but can last year round if the nutrient levels stay high.
Throughout the world there are more than 400 dead zones today, compared to the 162 dead zones in the 1980's. The largest of these is the Baltic Sea. In National Gepgraphic's Daily News, the article starts out with the worry in the disappearance of the white-tailed eagle. The white-tailed eagle is a main focus for tourist attraction and is greatly affected by the algae blooms. Another species that is affected by algae blooms is the Baltic cod. The Baltic cod, however, has the effect on the sea's well being. The Baltic cod feeds on an organism that in turn, somewhere down the line eats algae. Overfishing is another problem that lessens the numbers of cod, which in turn increases the amount of algae.
Algae blooms are a huge problem. They affect the diversity and the sustainability of the coastal waters. Mainly, nutrients have the biggest impact on creating rapidly expanding blooms. These nutrients are from fertilizers and sewage, which are mainly human produced. Other factors increasing algae blooms are things like overfishing. Even though algae blooms, dead zones, have a major impact on the coastal marine life, other parts of the environment are affected. Surrounding food chains, such as the white-tailed eagle, are effected. Overall, dead zones are a huge problem that may not be able to be reversed and should be taken seriously since they cause a variety of environmental issues.
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Posted by Amanda Hostetter (7)