Gulf Dead Zone Suffocating Fish and Livelihoods

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Gulf Dead Zone Suffocating Fish and Livelihoods

• Michelle Levesque

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What Is A Dead Zone?

• Not enough oxygen in water to support
  lifeanimals either leave or die
• More than 400 dead zones exist globally (double
  the number reported two years ago)
• Gulf dead zone measures 8,000 square miles

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Hypoxia

• Water becomes hypoxic when it is deprived of
  oxygen. Normal oxygen levels consist of 6
  milligrams per liter of water
• Louisiana Universities Marine Consortium
• August 14-15 collected sediment and water
  samples from 9 test stations around the gulf
• 6 of 9 stations in the gulf measured oxygen
  levels lt2 mgl

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Hypoxia Watch

• Red0.0-0.5mgl, yellow3.5-4.0mgl, light
  green5.0-6.0mgl, dark green7.5-8.0mgl

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So what causes this dead zone?

• Farmers in the Midwest along the Mississippi
  River produce a lot of corn to meet growing
  demands from ethanol factories and developing
  countries.
• Nitrogen and phosphorous increase productivity
• Runoff into rivers eventually reaches the Gulf
• Lots of flooding occurred this year

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Killer Algae

• High influx of nutrients into the system leads to
  algal blooms of enormous proportions.
• When they die, their decomposition reactions
  require oxygen.
• Fish and shrimp can leave the area, but
  slow-moving animals like snails, small crabs, sea
  stars, and clams suffocate

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Future Implications

• As demand for ethanol and alternative fuel
  sources increases, corn farming will also
  increase, putting even more nutrients into the
  system, expanding the size of the dead zone.
• Fishermen still working in the Gulf must travel
  to the edge of the dead zone, which costs 450
  daily in diesel fuel. This is only economically
  viable if they catch a boatload every time.

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Organizations

• Louisiana Universities Marine Consortium
• Gulf of Mexico Hypoxia Watch (part of the annual
  Southeast Area Monitoring and Assessment Program,
  SEAMAP)cooperative effort between National
  Oceanic and Atmospheric Administration (NOAA),
  National Marine Fisheries Service (NMFS),
  National Coastal Data Development Center (NCDDC),
  and CoastWatch.

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Sources

• http//www.cnn.com/2008/TECH/science/08/18/dead.zo
  ne/index.html
• http//ecowatch.ncddc.noaa.gov/hypoxia
• http//www.ncddc.noaa.gov/website/Hypoxia/viewer.h
  tm
• http//www.steamboats.org/assets/images/traveller/
  map-lower-mississippi-river.jpg
• http//oceancurrents.rsmas.miami.edu/caribbean/mex
  ican.html