Sediment Quality Triad in the Deep Sea During Fall 2010Deep‐Sea During Fall 2010

Paul A. Montagna

October 25, 2011

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• Acknowledgements:Acknowledgements:– Funding: BP and NOAA

• Disclaimers• Disclaimers:– The views expressed are mine and not attributable to the agency or the companyto the agency or the company.

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OutlineOutline

• What we know about SQTWhat we know about SQT

• What we know about Platforms

h k b h d• What we know about the deep‐sea

• What we found during Fall 2010 sampling

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Sediment Quality Triad Studies(SQT)

• Chemical Dose: contaminant concentrationsChemical Dose: contaminant concentrations

• Biological Response: in situ toxicity using the Microtox testMicrotox test

• Ecological Response: benthic communities

Used successfully in GOOMEX study!study

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GOOMEX((Gulf Of Mexico Offshore Operations 

Monitoring Experiment*)

• Goals– Identify chronic, sublethal effects of offshore oil and gas production activities

– Relate effects to a contamination gradient

– Recommend monitoring strategies

• Team– GERG/TAMU, UT, UWO, UNC, NMFS, MMS/ , , , , ,

*Canadian Journal of Fisheries and Aquatic Sciences (1996) 53:1584-2654. (8 papers) 5

GOOMEX Sampling schemeGOOMEX Sampling scheme

BoxcoreBulls-eye Design: 50, 100, 200, 500, 3000 mFour Cruises: 1993 - 1994

"Far"

BoxcoreStations

"Near"50 m100 m100 m

200 m

500 m

3000 m

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Summary of GOOMEX ResultsSummary of GOOMEX ResultsGeology‐ Coarser within 100 m of platformsChemistry Elevated contaminants within 100–200Chemistry‐Elevated contaminants within 100–200 m of platforms◦ Bottom shunting caused most contaminationBiolog Responses ithin 100 m of platformsBiology‐ Responses within 100 m of platforms◦ Molecular biomarkers (megafauna)‐ No response◦ Megafauna community– No responseGeneti Di ersit Red ed ithin 100 m◦ Genetic Diversity– Reduced within 100 m

◦ Toxicity– Within 100 m at 2 platforms◦ Macrofauna/Meiofauna– Community change within 100 mmIncreased deposit feeders (worms) relative to surface feeders (crustaceans)Decrease in crustacean populationsp pIncreased abundances, but decreased diversity

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Deep Gulf of Mexico Benthos p(DGoMB*)

D t i i t d t il th t t d• Determine in greater detail the structure and function of northern Gulf of Mexico continental slope communities p– Bacteria Meiofauna Macrofauna Megafauna– Grain size Trace metals Organics Geochemistry– Physical settingPhysical setting

• Infer relationships with local conditions and major driving processes by testing specific hypotheses

• Cruises over 3‐year period (2000–2002)

*D S R h II (2008) 55 2535 2711 (21 )*Deep-Sea Research II (2008) 55: 2535–2711 (21 papers)

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DGoMB experimental design

H01 – Depth H Longitude

H03 – Basins H Canyon

H05 – Escarpment H Primary ProdH02 – Longitude H04 – Canyon H06 – Primary Prod.

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Summary of DGoMB resultsTrace metal chemistry◦ No indication of anthropogenic input trace metals Be

Summary of DGoMB results

◦ No indication of anthropogenic input trace metals Be, Co, Cr, Fe, Si, Ti, V, K, Mg, Ca, Sr and Zn, based on normalization to AlThese metals derived from trace‐metal‐rich Mississippi River outflow

◦ In contrast, a general enrichment of the elements Ba, Ni, Pb, Cd, As, Cu and Mn, which show considerable scatter when normalized to AlThese metals identified as drilling byproducts in GOOMEXThese metals identified as drilling byproducts in GOOMEX

Total PAH concentration ranged from not detected to 1033 ng/g with a mean of 140 ng/gg g g g

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MC‐252 Incident data• Deep‐sea benthic 

MC 252 Incident data

mission was carried out by BP and NOAA from 16 Sept. – 24 Oct. 2011

• 169 stations occupied p– Chemistry

– Microtox

– Infauna

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Microtox Analyses• Method

– Response of luminescent bacteria a freeze‐dried

y

Response of luminescent bacteria, a freeze dried preparation of a specially selected strain of the marine bacterium Vibrio fischeri

– The results are normalized and the EC50(concentration producing a 50% reduction in light) calculated

– Low EC50 values are toxic

• Ecological relevance– Comparable to amphipod exposure– Has good sensitivity to a broad range of toxic 

b tsubstances

• Expedient: small sample, fast analysis, and cheap12

Microtox Analyses Problemsy

• Many false‐positives C t i tMany false positives (common to all toxicity testing)

Contaminants

BiologicalResponse

No Yes

• Need data for trace metals, hydrocarbons, 

Response

No

ammonia, sulfide, and sediments to interpret the response

Yes

the response

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PAH ConcentrationsOperational Science Advisory Team (OSAT) Report 17 Dec 2011Operational Science Advisory Team (OSAT) Report - 17 Dec 2011

25 Km!Km!

75 Km!

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Microtox vs. PAHTo Develop a Threshold (6,016 EC50 Units)

100000

80000

100000

Linear Regression for PAH over DGOMB mean of 140 ug/kgMicrotox = 6016 - 0.3351*PAH, R2 = 0.33

xici

ty (m

g/L)

10000

xici

ty (m

g/L)

60000

Mic

roto

x

Mic

roto

x

20000

40000

PAH (ug/kg)

10 100 1000 10000 100000

1000

PAH (ug/kg)

0 5000 10000 15000 200000

PAH (ug/kg)PAH (ug/kg)

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16

17

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Analyses to Link Biological Response to Environment

1.0

1.5

2.0

Low ToxicityLow Contaminants

Low ToxicityHigh Contaminants

ToxP

C1

-0.5

0.0

0.5

0 Low Contaminants High Contaminants

-2.0

-1.5

-1.0

0.5High ToxicityLow Contaminants

High ToxicityHigh Contaminants

ChemPC1-2 -1 0 1 2

2.0

Source: Long, Carr, Montagna. 2003.

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Analyses to Link Biological Response to Sediment Environment Variables

OSAT 2010 data

0 5

1.0

AlCrFeV

SiltClay

(79%

)

0.0

0.5

TOCTCAg

AsBa

Fe

Mn

SOC

ects

PC 1

-0.5

TPH

imen

t Effe

1 0 0 5 0 0 0 5 1 0-1.0

Sand

Sed

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PC 2 (20%)

-1.0 -0.5 0.0 0.5 1.0

Oil Spill Effects

Linking Microtoxicity to EnvironmentLinking Microtoxicity to Environment

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Log(EC50 = 8.66 + (-0.351 × PC2) r = -0.42, p < 0.0001

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12

1.17

1.19

EC

50)

9

10

1.05

1.06

1.07

1.081.091.101.11

1.121.13

1.141.15

1.17

1.18

1.20

2.25

2.26

2.30

3 35

4.49ALTFF002D055S

D062SD072S D096SD300S

D302S

FF001

FF003FF004

FF011

FFMT1

FFMT2

FFMT3LBNL11LBNL7M014SM015S

M034SM037S

M039SM200SM201SM202SM203S

M204SM205SM206S

M207S

M208S

NF010S012SS016SW

S01SS022SS05S

Log

(

8

90.00

1.011.02 1.031.04

1.16

2.212.22

2.232.24 2.27

2.282.29

3.313.32

3.33

3 34

3.35

4.444.45

4.464.474.48ALTFF012

ALTNF001

ALTNF015

D002SD003S

D006SD007SD009S

D010S

D011S

D012S

D013SD019S

D021SD024S D031SD034S

D042SD046S

D050S

D053S

D057S

D062S

D064SD067S

D068S

D069S

D070S

D071S

D077S

D084S

D085SD089S D101S

D301S

FF003FF004

FF005

FF010FFC4

FFC7

FFMT4

FFMT5

FFMT6

LBNL1

LBNL14LBNL17

LBNL3

LBNL4LBNL5

M001SWM002SW

M004SM009SW

M012S

M013SW

M016SW

M019S

M023SM026SW

NF006MODNF008

NF011

NF012

NF013NF014S016SW

Log EC50 = 8.702

58 stations with spill

6

7

3.34

D008S

D012S

D038SW

D040S

D071SD094S with spill

characteristics and high toxicity

21Sediment Chemistry (PC 2)

-2 -1 0 1 2

Toxicity vs. Contaminants

Uncolored=missing data

PC2<0 +  PC2>0 + 

Color Key:

Log EC50>8.7 Log EC50>8.7

PC2 0

Toxi

city

PC2<0 + Log EC50<8.7

PC2>0 +Log EC50<8.7

←

Contaminants →

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Macrofauna vs. Sediments Macrofauna vs. Contaminants

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Preliminary SummaryPreliminary Summary

• There is wide‐spread oil on the bottom of h d ff hthe deep offshore environment

• There is strong toxicity up to 25 km away, and weaker toxicity everywhere in theand weaker toxicity everywhere in the deep‐sea

• There is a correlation between the chemical signature characteristic of drilling effects and toxicity 

• There is a correlation between the• There is a correlation between the chemical signature and decreases in benthic diversity and biomass

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Thank youThank you

Questions?Questions?

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