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Oilmaggedon & Dead Zones
Photo: Christopher Berkey
Oilmageddon Sequence
Oilmageddon Sequence
May 2, 2010
Oilmageddon Sequence
Oilmageddon Sequence
Magnitude (million gallons)0 50 100 150 200
Deepwater HorizonIxtoc I
Amaco CadizTorrey Canyon
Sea StarPrestigeMetula
Exxon ValdezH. Katrina & Rita
Argo MerchantEkofisk oil fieldSanta BarbaraNew Orleans Buzzards Bay
Deepwater HorizonIxtoc I
Amaco CadizTorrey Canyon
Sea StarPrestigeMetula
Exxon ValdezH. Katrina & Rita
Argo MerchantEkofisk oil fieldSanta BarbaraNew Orleans Buzzards Bay
North America seepsGlobal seeps
Global exploration & productionNA transportation
Global transportationNA consumption
Global consumption
per eventper year
Camilli et al. 2010
What subsurface
plume?
Proliferation of Science
*
Disruption of Science
Effects are more far reachingthan suspended sediment plume,
esp. N & somewhat P
New Orleans
dominant wind direction
Mississippi River
Atchafalaya River
Hypoxic Area *
Mississippi River –Gulf of Mexico Ecosystem Continuum
Nutrients, Increased Growth, Low Oxygen
Time Magazine
•Mid-summer shelfwide cruise•Monthly samples along line C•Bimonthly samples along line F•Deployed oxygen meters
28N 28N
F
C
**
***
30.0
29.0
29.5
29.0
75%
25%
50%
25%
Sabine L.Atchafalaya R.
TerrebonneBay
Mississippi RL. Calcasieu
Bottom Dissolved Oxygen (mg l-1)
0
1
2
3
4
5
6
7
8
F0 -
F1 -
F2 -
F3 -
F2A -
F4 -
F5 -
J JJF M A M A S O N D0
1
2
3
4
5
6
7
8
C1 -
C3 -
C4 -
C5 -
C6C -C6 -
C7 -
C8 -
C9 -
J F M A M J J A S O N D
Bottom Dissolved Oxygen (mg l-1)
F
C
Frequency of Mid-Summer Bottom-Water Hypoxia
•Deployed oxygen meters•WAVCIS/BIO2
CSI-06 CSI-09 CSI-16
28N 28N
C
**
*?
Dissolved Oxygen DOConductivity CTemperature T
Turbidity TBIn vivo Fluorescence F
Currents ADCPNutrient Experiments
(selected)Light Meter Deployments
(selected)
Station C6C/BIO2C/T/DO/TB/F 2.4 m
C/T/DO/TB/F 10.7 m
C/T/DO/TB/F 19 m
C/T 6.6 m
C/T 14 m
ADCP
Station CSI-6, LSU/WAVCIS Full meteorological suite & wave meters
Bottom-water Dissolved Oxygen, July, 2008
Data source: N.N. Rabalais, Louisiana Universities Marine Consortium, R.E. Turner, Louisiana State UniversityFunded by: NOAA, Center for Sponsored Coastal Ocean Research
Bottom-water Dissolved Oxygen, July 25-31, 2010
Bottom-water Dissolved Oxygen, July, 2008
Data source: N.N. Rabalais, Louisiana Universities Marine Consortium, R.E. Turner, Louisiana State UniversityFunded by: NOAA, Center for Sponsored Coastal Ocean Research
Bottom-water Dissolved Oxygen, July 25-31, 2010
Data source: N.N. Rabalais, Louisiana Universities Marine Consortium, R.E. Turner, Louisiana State UniversityFunded by: NOAA, Center for Sponsored Coastal Ocean Research
Bottom-water Dissolved Oxygen, July 25-31, 2010
etc
etc
Tropical storm bears down on delta and Cocodrie on July 23.
Depart July 24 and head west because of water column disruption on eastern end.
Still mixed in middle of study area.
Not as much mixing as head west. Extensive hypoxia. Call it short.
Head east and resume mapping mid-shelf, as hypoxia re-establishes.
Area of 20,000 km2, one of the largest in the history of mapping since 1985.
Hypoxia more developed in June and August than in July 25-31.
O2 increase
(Rabalais et al., unpubl data)
Bottom Dissolved Oxygen at 20 m, CSI-6, August 2005Oxygen meter stripped from mooring
Hurricane Katrina approaches
*
0
5,000
10,000
15,000
20,000
25,000Sq
uar
e k
ilom
ete
rs
Year
Area of Mid-Summer Bottom Water Hypoxia(Dissolved Oxygen < 2.0 mg/L)
Data source: N.N. Rabalais, Louisiana Universities Marine Consortium, R.E. Turner, Louisiana State UniversityFunded by: NOAA, Center for Sponsored Coastal Ocean Research
h – hurricane
d – drought
c – currents
h
h
h
d
d
c
c
Predicting Hypoxia in summer(nitrate-N flux in May, year)
Turner et al. 2006
Nutrient Yields from the Mississippi Basin
Alexander et al. 2008
Watershed Landscape ChangeLoss of Virgin Forests Drainage of Land, Tile Drains
0
1
2
3
4
5
6
7
8
9
1042 46 89 85 87 81 72 59 59 46
Re
mai
nin
g W
etla
nd
s (m
illio
ns
of
acre
s)
Wetland Loss
More Nutrients >>> More Phytoplankton >>>
More Carbon Reaches the Bottom >>>More Oxygen Consumed >>>
More Hypoxia
Photo: N. Rabalais, LUMCON
Gulf of Mexico 'dead zone' may reach record size this summerHistoric floods and relentless storms are expected to boost the
dead zone up to 15 percent larger than ever before, experts say.
Did the Oil Spill Cause or Worsen Hypoxia?
typical shelf hypoxia overlapped with the distribution
of emulsified oil
there were areas of lower oxygen associated with the
subsurface oil plume at 1100-1200 m, but never near
approaching hypoxia or natural low oxygen area at
500-800 m
shelf hypoxia was above average in size, severity and
persistence
oil mitigation measures (Mississippi River diversions)
likely increased the noxious & harmful algal blooms,
hypoxia & fish kills to the east of the delta where there
was visible oil
the media really wanted to link the oil spill to hypoxia
Deeper Oxygen Minimum Area
There is a natural lower oxygen concentration area at 300 to 800 m depth in the Gulf of Mexico, due to circulation of older North Atlantic Ocean water.
D. Gilbert
The lower oxygen concentrated waters of the deeper Gulf
of Mexico are not related to the coastal hypoxia area
driven by nutrient over-enrichment
-98 -96 -94 -92 -90 -88 -86 -84 -82 -80
26
28
30
2358
23592360
2361
23622363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
23742378
2379
2380
2381
2382
2383
2384
2385
2387
2388
2389
2390
23912392
2393
2394
2395
2396
239723982399
2401
2402
24032404
2405
• 1935 data: <4.3 mg/l at 250-600 m depth
1996 data: < 2.0 mg/l at 5-30 m depth
Rabalais et al. 2002
Figure 2. Joint Analysis Group (JAG) Review of Preliminary Data
In several instances, lower oxygen conditions were correlated with peaks in fluorescence
Camilli et al. 2010 Fig. S3:
In other instances, lower oxygen conditions were not verified by
Winkler titrations
In all instances, lower oxygen conditions did not reach the
levels of the low oxygen area or levels of hypoxia.
Kessler et al. 2011
In several instances, lower oxygen conditions were correlated with peaks in fluorescence
Max Dissolved O2 Anomaly = 36.7 μM, Avg Dissolved O2 Anomaly = 5.6 ± 5.8 μM
hyp
oxi
a
Mean1935-2010
Maximum
Minimum
2009
2010
Flo
w (
cub
ic f
ee
t p
er
seco
nd
1
00
0)
1600
1400
1200
1000
800
600
400
200
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Bottom-water Dissolved Oxygen, July, 2008
Data source: N.N. Rabalais, Louisiana Universities Marine Consortium, R.E. Turner, Louisiana State UniversityFunded by: NOAA, Center for Sponsored Coastal Ocean Research
Bottom-water Dissolved Oxygen, July 25-31, 2010
-2
0
2
4
6
8
10
12
14
0 200 400 600 800 1000 1200 1400
DE
PT
H
OIL
A'3
A'3
J7
A'3
Rabalais et al. unpubl. data
Fluorescence data from July 2010 indicated high oil presence at many stations directly to the west of the Mississippi River delta; yet dissolved
oxygen levels at the same depths were typical for summer and often supersaturated in DO.
Hypoxia
A'3
DOSal °Cfl
hyp
oxi
a
Harmful Algal Blooms(not oil)
Not just menhaden, but several species
