Analysis of Galveston and Port Aransas tarballs after

the Texas City Y oil spill

Stefanie PlunkettLiu Laboratory

Texas City Y Spill

• March 22, 2014 • in Galveston Bay• 168,000 gallons of marine residual oil

(RMG 380) released

What is in crude oil?

What is in crude oil?Aliphatic HydrocarbonsAromatic Hydrocarbons

Polycyclic Aromatic Hydrocarbons (PAHs)

TOXIC

Tarball Location

Evaporation, biodegradation, photoxidation, dissolution

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?

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

METHOD: Tarball collection

Location Sample Time of collection

Galveston

GV1 6 daysGV2 6 daysGV3 6 daysGV4 11 monthsGV5 11 monthsGV6 11 monthsGV7 11 months

Port Aransas

PA1 10 daysPA2 10 daysPA3 10 daysPA4 3 monthsPA5 3 monthsPA6 3 months

13 samples

METHOD: Hydrocarbon analysisSilica gel fractionation

Aliphatics Aromaticsmi n

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

mV0

25

50

75

100

125

150

175

200

225

250

275

mV

0

25

50

75

100

125

150

175

200

225

250

275 1検出器2011/ 07/ 25 14: 44: 58

Gas Chromatography –Mass Spectrometry (GC/MS)

Freeze-drying at -70ºC

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

trisnorhopane norhopane 22S-homohopane 22R-homohopane 0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

RMG 380 GV1 GV2 GV3 PA1 PA2 PA3 PA4 PA5 PA6 GV4 GV5 GV6 GV7

Hop

ane

Rat

io

Fingerprinting the Tarballs using Hopanoids

Location Sample Time of collectionPA1 10 daysPA2 10 daysPA3 10 daysPA4 3 monthsPA5 3 monthsPA6 3 monthsGV1 6 daysGV2 6 daysGV3 6 daysGV4 11 monthsGV5 11 monthsGV6 11 monthsGV7 11 months

Port Aransas

Galveston

Aliphatic Hydrocarbons

PAHs Analysis

n-alkanes

P-values C14 to C17: 0.031, 0.001, 0.028, 0.046

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

0

2

4

6

8

10

12

RMG 380 GV 1-3 PA 1-3

Hop

ane

Rat

io

C9 C10 C11 C12 C130

1

2

3

4

5

6

7

RMG 380 GV 1-3 PA 1-3

Hop

ane

Rat

io

C14 C15 C16 C170

1

2

3

4

5

6

7

8

9

RMG 380 GV 1-3 PA 1-3

Hop

ane

Rat

io

Naphth

alene

Biphen

yl

Acyna

pthyle

ne

Acena

pthen

e

Fluoren

e

Dibenz

othiop

hene

Phena

nathr

ene

Anthrac

ene

Fluoran

thene

Pyrene

Benz[a

]anthr

acen

e

Chryse

ne

Benzo

[b]flu

oranth

ene

Benzo

[k]flu

oranth

ene

Benzo

[a]py

rene

Benzo

(e)py

rene

Inden

o[1,2,

3-cd]p

yrene

Dibenz

[a,h]a

nthrac

ene

Benzo

[g,h,i

]peryl

ene

Perylen

e0

0.5

1

1.5

2

2.5

RMG 380 GV PA

Rat

io N

orm

aliz

ed to

Hop

ane

Polycyclic Aromatic Hydrocarbons (PAH)

C1-Nap

hthale

ne, 2

C1-Nap

hthale

ne, 1

C2-Nap

hthale

ne, 2

,6

C2-Nap

hthale

ne, 1

,6

C2-Nap

hthale

ne, 1

,2

C3-Nap

hthale

ne, 2

,3,5

C1-fluo

rene,

1

Dibenz

othiop

hene

C1-Dibe

nzoth

iophe

ne, 4

C1-Phe

nanth

rene,

3

C1-Phe

nanth

rene,

2

C1-Anth

racen

e, 2

C1-Phe

nanth

rene,

9

C1-Phe

nanth

rene,

1

C2-Dibe

nzoth

iophe

ne, 4

,6

C2-Phe

nanth

rene,

1,7

C1-Fluo

ranthe

ne, 3

Retene

C1-Pyre

ne, 1

C1-Pyre

ne, 4

C1-Chry

sene

, 3

C1-Chry

sene

, 60

1

2

3

4

5

6

7

RMG 380 GV PA

Rat

io N

orm

aliz

ed to

Hop

ane

Alkylated PAHs

Next-generation sequencing (Illumina)

Bacterial community analysis

DNA ExtractionTarballPeripheral sand

Sand Sample 1 Sand Sample 2 Sand Sample 3 PA1 PA2 PA30

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

TARBALLS

Rel

ativ

e C

ompo

sitio

n

PERIPHERAL SAND

Port Aransas bacterial community

Vibrionales

Oceanospirillales

Alteromonodales

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.

QUESTIONS