1. Analysis of Galveston and
Port Aransas tarballs after
the Texas City Y oil spill
Stefanie Plunkett
Liu Laboratory

2. Texas City Y Spill
• March 22, 2014
• in Galveston Bay
• 168,000 gallons of marine residual oil
(RMG 380) released

3. What is in crude oil?

4. What is in crude oil?
Aliphatic HydrocarbonsAromatic Hydrocarbons
Polycyclic Aromatic Hydrocarbons
(PAHs)

5. Tarball Location
Evaporation, biodegradation, photoxidation, dissolution

6. Research Questions?
• Are the tarballs in Port Aransas and
Galveston from the Texas City Y Spill?
• How did the hydrocarbon components of
tarballs change?
• Do tarballs harbor unique bacterial
community?

7. Objectives
• Determine if the tarballs were sourced
from the Texas City Y spill
• Track changes in the hydrocarbon
compounds of the tarballs over time and
space
• Evaluate the bacterial communities
associated with tarballs

8. METHOD: Tarball collection
Location Sample Time of collection
Galveston
GV1 6 days
GV2 6 days
GV3 6 days
GV4 11 months
GV5 11 months
GV6 11 months
GV7 11 months
Port Aransas
PA1 10 days
PA2 10 days
PA3 10 days
PA4 3 months
PA5 3 months
PA6 3 months
13 samples

9. METHOD: Hydrocarbon analysis
Silica gel fractionation
Aliphatics Aromatics min
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
mV
0
25
50
75
100
125
150
175
200
225
250
275
mV
0
25
50
75
100
125
150
175
200
225
250
275検出器 1
2011/07/25 14:44:58
Gas Chromatography
–Mass Spectrometry
(GC/MS)
Freeze-drying
at -70ºC

10. All data is normalized to
Hopane (17α(H)-21β(H)-hopane)
• Resistant to degradation by
bacteria
• Resistant to photooxidation
• Biomarker for oil
fingerprinting
Concentration of X
Concentration of Hopane
Hopane ratio

11. 0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
trisnorhopane norhopane 22S-homohopane 22R-homohopane
HopaneRatio
RMG 380 GV1 GV2 GV3 PA1 PA2 PA3 PA4 PA5 PA6 GV4 GV5 GV6 GV7
Fingerprinting the Tarballs using
Hopanoids

12. Location Sample Time of collection
PA1 10 days
PA2 10 days
PA3 10 days
PA4 3 months
PA5 3 months
PA6 3 months
GV1 6 days
GV2 6 days
GV3 6 days
GV4 11 months
GV5 11 months
GV6 11 months
GV7 11 months
Port Aransas
Galveston
Aliphatic
Hydrocarbons
PAHs Analysis

13. n-alkanes
P-values C14 to C17: 0.031, 0.001, 0.028, 0.046
0
2
4
6
8
10
12
C9
C10
C11
C12
C13
C14
C15
C16
C17
Pristane
C18
Phytane
C19
C20
C21
C22
C23
C24
C25
C26
C27
C28
C29
C30
C31
C32
C33
C34
C35
C36
C37
C38
C39
C40
HopaneRatio
RMG 380 GV 1-3 PA 1-3
0
1
2
3
4
5
6
7
C9 C10 C11 C12 C13
HopaneRatio
RMG 380 GV 1-3 PA 1-3
0
1
2
3
4
5
6
7
8
9
C14 C15 C16 C17
HopaneRatio
RMG 380 GV 1-3 PA 1-3

14. 0
0.5
1
1.5
2
2.5
RatioNormalizedtoHopane
RMG 380 GV PA
Polycyclic Aromatic Hydrocarbons
(PAH)

15. 0
1
2
3
4
5
6
7
RatioNormalizedtoHopane
RMG 380 GV PA
Alkylated PAHs

16. Next-generation
sequencing
(Illumina)
Bacterial community analysis
DNA Extraction
Tarball
Peripheral sand

17. 0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Sand Sample 1 Sand Sample 2 Sand Sample 3 PA1 PA2 PA3
RelativeComposition
TARBALLSPERIPHERAL SAND
Port Aransas bacterial community
Vibrionales
Oceanospirillales
Alteromonodales

18. Conclusions
• Samples Gv1,2,3 from Galveston and PA 1, 2, 3
from Port Aransas were from Texas City Y Oil Spill
• LMW aliphatics and aromatics were dissipated in
these tarballs likely due to evaporation
• Tarballs pose potential toxicity and could harbor
pathogenic bacteria such as Vibrionales.

19. QUESTIONS