The Gulf dead zone

Discussion in 'Environment' started by Chris, Jul 19, 2011.

  1. Chris
    Offline

    Chris Gold Member

    Joined:
    May 30, 2008
    Messages:
    23,154
    Thanks Received:
    1,958
    Trophy Points:
    205
    Location:
    Virginia
    Ratings:
    +2,089
    Researchers from Texas A&M University who have just returned from a visit to the Gulf of Mexico to explore the scope and size of this year’s dead zone have measured it to be currently around 8,500 square kilometres; approximately the same size as the states of Delaware and Rhode Island combined.

    However researchers believe that 2011′s dead zone may continue to grow and become one of the largest ever, thanks in part to the record amounts of water being deposited into the Gulf from the Mississippi River.

    Lead by Steve DiMarco, an oceanography professor at Texas A&M, the team of researchers traveled more than 2,300 kilometres throughout the Gulf of Mexico over a five day period. This was the first ever mission to focus on the dead zone’s size in June.

    The dead zone off the coast of Louisiana has been continually monitored for about 25 years, and previous research has shown that nitrogen levels in the Gulf of Mexico intrinsically related to human activities have risen by 3 times over the past 50 years. Over the past 5 years, the dead zone in the Gulf of Mexico has averaged around 15,000 square kilometres, but is predicted to exceed 24,000 square kilometres this year, making it one of the largest ever recorded, according to the Louisiana Universities Marine Consortium.

    Source: Planetsave (2011 Gulf Dead Zone Could Be Biggest Ever | Planetsave)
     
    • Thank You! Thank You! x 1
  2. aplcr0331
    Offline

    aplcr0331 ConvenientHeuristic

    Joined:
    Jan 3, 2011
    Messages:
    563
    Thanks Received:
    80
    Trophy Points:
    78
    Location:
    Washington State
    Ratings:
    +86
    Interesting. The runoff from the Mississippi contain fertilizers and animal waste and this increases the hydrogen level in the water, creating a dead zone. Correct?

    How big is the dead zone after winter storms break them up? Are there studies that compare and perhaps give us an idea of the overall size of dead zones spread out over the entire year?

    by dead zone does that mean nothing can live there? Or only certain species cannot make it? Where do they go every spring? Do these species return in the fall?

    Can we reverse this trend? Anyway to treat the dead zone with a chemical?
     
    Last edited: Jul 19, 2011
  3. konradv
    Offline

    konradv Gold Member

    Joined:
    Mar 23, 2010
    Messages:
    22,558
    Thanks Received:
    2,558
    Trophy Points:
    280
    Location:
    Baltimore
    Ratings:
    +5,672
    Runoff increases nitrogen, not hydrogen. Can't answer all your questions, but dead zones usually mean lack of oxygen. If it goes low enough, nothing but anaerobic bacteria would survive.
     
  4. Patrick2
    Offline

    Patrick2 Senior Member

    Joined:
    Jul 12, 2011
    Messages:
    1,576
    Thanks Received:
    104
    Trophy Points:
    48
    Ratings:
    +104
    The US is an economic dead zone. Let's continue to ilegalize all our REAL sources of energy - THAT'LL help the economy.
     
  5. martybegan
    Offline

    martybegan Gold Member

    Joined:
    Apr 5, 2010
    Messages:
    29,329
    Thanks Received:
    4,002
    Trophy Points:
    290
    Ratings:
    +10,948
    Good luck getting an explaination out of Chris.

    The proper term for a "dead zone" is hypoxia, or low levels of oxygen. While the root cause is nutrients, the true cause is algae blooms that feed on the excess nutrients in the water.

    Hypoxia in the gulf is likely a natural event, however human activties lead to it lasting longer and getting bigger. Nitrogen rich water from the missisippi mingles with gulf water. Algae grow rapidly in the high nutrient water, however the mats get so big that the lower strata of algae end up not getting sunlight, and then they die off. This decay leads to bateriological growth, and the uptake of oxygen beyond the ocean's ability to replenish.

    Low oxgen leads to fish stress, fish death, sea floor die offs, and all sorts of bad stuff. The situation usually rectifes itself in winter, with higher DO diffusion rates, as well as lower biological activity rates.

    To control nitgrogen you need to control and treat both farming runoff (hard) and wastewater nitrogen content (easier).
     
  6. Moonglow
    Offline

    Moonglow Diamond Member

    Joined:
    Jun 27, 2011
    Messages:
    81,675
    Thanks Received:
    8,003
    Trophy Points:
    2,070
    Location:
    sw mizzouri
    Ratings:
    +29,413
    do u always piss when u need to shit?
     
  7. daveman
    Offline

    daveman Diamond Member

    Joined:
    Jun 25, 2010
    Messages:
    51,299
    Thanks Received:
    5,692
    Trophy Points:
    1,775
    Location:
    On the way to the Dark Tower.
    Ratings:
    +5,758
    And it's the fault of the environuts, insisting we expand corn production for ethanol.

    Got that? Environmentalists are killing the Gulf.
     
  8. konradv
    Offline

    konradv Gold Member

    Joined:
    Mar 23, 2010
    Messages:
    22,558
    Thanks Received:
    2,558
    Trophy Points:
    280
    Location:
    Baltimore
    Ratings:
    +5,672
    You'd rather pay them for not growing corn or are you too dumb to realize it's NOT the corn, but the fertilizer?!?!
     
  9. Old Rocks
    Offline

    Old Rocks Diamond Member

    Joined:
    Oct 31, 2008
    Messages:
    46,471
    Thanks Received:
    5,416
    Trophy Points:
    1,840
    Location:
    Portland, Ore.
    Ratings:
    +10,313
    Daveboy is truly too dumb.

    The increasing number of dead zones, hypoxic and anoxic, that we are seeing is the result of both the chemicals we use in farming, and the increasing heat in the ocean. Add the increasing acifidification of the oceans to the mix, and we are set on destroying another major food source.

    Hypoxia is increasing in the coastal zone of the Baltic Sea - Environmental Science & Technology (ACS Publications)


    Daniel J. Conley , Jacob Carstensen , Juris Aigars , Philip Axe , Erik Bonsdorff , Tatjana Eremina , Britt-Marie Haahti , Christoph Humborg , Per Jonsson , Jonne Kotta , Christer Lännegren , Ulf Larsson , Alexey Maximov , Miguel Rodriguez Medina , Elzbieta Lysiak-Pastuszak , Nijolė Remeikaitė-Nikienė , Jakob Walve , Sunhild Wilhelms , and Lovisa Zillén
    Environ. Sci. Technol., Just Accepted Manuscript
    DOI: 10.1021/es201212r
    Publication Date (Web): July 19, 2011
    Copyright © 2011 American Chemical Society
    AbstractHypoxia is a well-described phenomenon in the offshore waters of the Baltic Sea with both the spatial extent and intensity of hypoxia known to have increased due to anthropogenic eutrophication, however, an unknown amount of hypoxia is present in the Baltic Sea coastal zone. Here we report on the widespread unprecedented occurrence of hypoxia across the coastal zone of the Baltic Sea. We have identified 115 sites that have experienced hypoxia during the period 1955-2009 increasing the global total to ca. 500 sites, with the Baltic Seacoastal zone containing over 20% of all known sites world-wide. Most sites experienced episodic hypoxia, which is a precursor to development of seasonal hypoxia. The Baltic Sea coastal zone displays an alarming trend with hypoxia steadily increasing with time since the 1950s effecting nutrient biogeochemical processes, ecosystem services and coastal habitat.
     
    • Thank You! Thank You! x 1
  10. Old Rocks
    Offline

    Old Rocks Diamond Member

    Joined:
    Oct 31, 2008
    Messages:
    46,471
    Thanks Received:
    5,416
    Trophy Points:
    1,840
    Location:
    Portland, Ore.
    Ratings:
    +10,313
    Growing hypoxic zones reduce habitat for billfish and tuna

    Growing Hypoxic Zones Reduce Habitat for Billfish and Tuna
    ScienceDaily (Dec. 23, 2010) — Billfish and tuna, important commercial and recreational fish species, may be more vulnerable to fishing pressure because of shrinking habitat, according to a new study published by scientists from NOAA, The Billfish Foundation, and University of Miami Rosenstiel School of Marine and Atmospheric Science.

    An expanding zone of low oxygen, known as a hypoxic zone, in the Atlantic Ocean is encroaching upon these species' preferred oxygen-abundant habitat, forcing them into shallower waters where they are more likely to be caught.

    During the study, published recently in the journal Fisheries Oceanography, scientists tagged 79 sailfish and blue marlin with satellite tracking devices in the western North Atlantic, off south Florida and the Caribbean; and eastern tropical Atlantic, off the coast of West Africa. The pop off archival satellite tags monitored horizontal and vertical movement patterns. Researchers confirmed that billfish prefer oxygen rich waters closer to the surface and will actively avoid waters low in oxygen
     

Share This Page