Something is rotten in the Gulf of Mexico.
Well – not exactly “rotten” – but a forecast developed by the University of Michigan, Louisiana State University, and NOAA predicts that bad things are on the way for the Gulf’s oceanic ecosystem. Each year, “dead zones” emerge in bodies of water when algal blooms develop and prevent oxygen from reaching life in the bodies of water they inhabit. These blooms occur when excessive nutrients in water encourage algae growth. These algae can cause any number of problems, particularly when they die and bacteria feed on them. These bacteria use up the water’s oxygen and deplete life of the oxygen it needs to survive.
What causes them?
Dead zones can, in fact, occur naturally. The most well-known is the Black Sea, where the lower portion of its body is a dead zone. Other dead zones such as the one in the Gulf, however, are perpetuated by water pollution. Modern farming practices cause excess nutrients to either run off of land or be pumped into rivers such as the Mississippi, which feeds directly into the Gulf of Mexico. These nutrients combined with warming weather cause algae to run rampant.
Why are they a problem?
Undoubtedly, if these dead zones were benign, we wouldn’t care about them quite so much, but algal blooms have the potential to have substantial negative consequences for their ecosystems. When these algae die, they decompose in the water (thanks to those bacteria) and use up the oxygen that is present. That floating algae has the potential to block sunlight from reaching life which requires sunlight for photosynthesis. Often, life such as sea grass and fish below these decomposing blooms die – thus, we have “dead” zones. These dead zones pose more than an ecological threat, however. Obviously, the death of fish will impact the fishing trade, but it will also encourage predators of fish – namely birds – to migrate elsewhere. Furthermore, creatures such as mussels that use filtration to live may be contaminated by this algae, and when eaten by humans, may cause illness.
What is special about this one?
Algal blooms have the potential to turn into dead zones, but the bloom in the Gulf is remarkable because it has the potential to become the largest in history. The current record is 8.495 square miles, but Michigan, Louisiana and NOAA predict that this year’s bloom could top that, making it larger than the state of New Jersey.
References | Learn More
- “Biggest Dead Zone Ever Forecast in Gulf of Mexico” via National Geographic
- Encyclopedic Entry: “Dead Zone” via National Geographic
- Ocean Facts: “Dead Zone” via NOAA
- “Should we be worried about the dead zone in the Gulf of Mexico?” via HowStuffWorks