The deep stuff saturated
mud out to four kilometers and wreaked it generally out to twelve kilometers or
so on average. That is a pretty serious
foot print for essentially refrigerated toxins.
Unfortunately it is not going anywhere either and it will certainly
takes decades to rot out. The volatiles
and the lights are long gone leaving us the nasties. It would be nice to know if fertilization
could speed this up.
This is really the
final accounting on what damage is caused and just how long it will take to
reverse. It tells us the real cost for
the next one and surely heightens everyone’s game.
Otherwise it is still
contained naturally to around ten square miles and one year to resolve the
immediate effects. It is not great but
it will resolve naturally and completely within a century.
Gulf of Mexico Deep Sea
May Need Decades to Recover From Oil Spill
November
22, 2013
Nicholas
St. Fleur
The
catastrophic explosion that spewed some five million barrels of oil deep into
the Gulf of Mexico in April 2010 will take a heavy toll in the ocean’s lowest
layers for years to come. That’s the stark conclusion of seafloor research
conducted six months after the Deepwater Horizon oil spill.
The
study, published on August 7 in PLoS ONE, examined life in the Gulf’s
deepest waters near the blowout, about 1.6 kilometers below the surface. Here,
the researchers found that the damages will take decades to reverse. The work
is part of the Natural Resource Damage Assessment, created by the U.S. National
Oceanic and Atmospheric Administration. The assessment will help set the
damages charged to British Petroleum (BP), which operated the well.
At
those depths in the Gulf of Mexico, three types of creatures thrive: worms,
shellfish, and mollusks. The scientists studied sediment samples collected at
different distances from the destroyed oil wellhead to determine how the oil
and dispersant chemicals affected the ecosystems. The sediments yielded a
census of the animals that live in the mud, as well as a measure of the
contaminants that lingered.
“The
sediments are like little canaries in the coal mine. We used them to find out
what’s going on,” said lead author Paul Montagna, a deep-sea environmental
scientist from Texas A&M University, in an interview with mongabay.com.
The
closer the team surveyed to the well, the less diversity of marine life they
found. Nearest the disaster site, crustaceans and shellfish suffered greatly;
these creatures are particularly sensitive to pollutants
in the deep sea. Worms were still numerous, although their numbers declined
closer to the well.
The
scientists used the data to designate healthy and unhealthy areas in the deep
sea depending on each location’s “footprint” of oil impacts. High-impact areas
were unhealthy, with heavy contaminants and low levels of animal life.
Low-impact locations were low in contaminants and high in animal
diversity. The researchers then mapped the impact zones across an area
covering 148 sq km, about the size of a small city. They colored the “severely
impacted” zones red, the “moderately impacted zones” orange, the “low zones”
yellow, and the “normal zones” green.
Deep
in the Gulf of Mexico, the Deepwater Horizon oil spill affected large swaths of
marine life. The zoomed-in map covers 6,350 sq km. A recent study shows about
148 sq km (orange) are moderately impacted, while 24 sq km (red) are severely
impacted. (Credit: Paul Montagna, Texas A&M)
“We
didn’t see splotches of color,” Montagna said. “Instead, colors formed a
bull’s-eye target with a big red spot in the middle at the wellhead, and
decreasing colors as it goes around.” The team’s statistical and mapping
methods will help other scientists scrutinize future spills of oil or chemical
contaminants.
Based
on how much oxygen the undersea organisms need and how slowly bacteria grow in
the deep sea, the team estimates that it will take decades for the
ecosystems to recover. However, BP has disputed those claims. The team’s
paper “provides no data to support” the recovery estimates, the company
maintained in a statement.
Not
so, said Holly Bik, a postdoctoral researcher in marine genomics at the
University of California, Davis. The team’s figures “speak for themselves,” Bik
told mongabay.com. In the deep ocean, temperatures are similar to those in a
refrigerator, so contaminants linger longer and can take decades to decay.
“Because
everything is in slow motion in the deep sea, getting back to a normal
ecosystem is going to take a lot longer than at the surface,” Bik said.
About the Author
Nicholas
St. Fleur is a graduate student in the Science Communication Program
at the University of California, Santa Cruz.
CITATION: Montagna
PA, Baguley JG, Cooksey C, Hartwell I, Hyde LJ, Hyland JL, et al. Deep-Sea
Benthic Footprint of the Deepwater Horizon Blowout. PLoS ONE, (2013)
8(8):e70540. doi:10.1371/journal.pone.0070540
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