Changes in Sediment Redox Conditions Following the BP DWH Blowout Event

D. W. Hastings; Patrick Schwing; G. R. Brooks; R. A. Larson; J. L. Morford; T. Roeder; K. A. Quinn; T. Bartlett; Isabel C. Romero; David Hollander

doi:10.1016/j.dsr2.2014.12.009

Changes in Sediment Redox Conditions Following the BP DWH Blowout Event

D. W. Hastings, Patrick Schwing, G. R. Brooks, R. A. Larson, J. L. Morford, T. Roeder, K. A. Quinn, T. Bartlett, Isabel C. Romero, David Hollander

University of South Florida

Research output: Contribution to journal › Article › peer-review

Abstract

<p> <p id="x-x-x-sp0055"> Following the blowout of the Macondo well, a pulse in <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/sedimentation" title="Learn more about sedimentation"> sedimentation </a> resulted in changes in sedimentary <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/redox-conditions" title="Learn more about redox conditions"> redox conditions </a> . This is demonstrated by downcore and temporal changes in the concentration of redox sensitive metals: Mn, Re, and Cd. <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/sediment-core" title="Learn more about sediment core"> Sediment cores </a> collected in the NE Gulf of Mexico (GoM) reveal increased sedimentation after the Deepwater Horizon (DWH) blowout. The formation of mucous-rich <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/marine-snow" title="Learn more about marine snow"> marine snow </a> in surface waters and subsequent rapid deposition to underlying sediments is the likely cause. Respiration of this material resulted in decreased <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/porewater" title="Learn more about porewater"> pore-water </a> oxygen concentration and a shoaled redoxcline, resulting in two distinct Mn peaks in sediments following the event, one typically in the top 10 mm, with the other at 20–30 mm. Most cores near the <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/wellhead" title="Learn more about wellhead"> wellhead </a> reveal this non-steady state behavior for up to two years after the event. Associated with the Mn minimum between the two Mn peaks, a modest (15–30%) enrichment of Re consistent with reducing sediments typically exists. A three-year time series of three stations following the event reveal that sediment Re increased 3–4 times compared to the pre-impact baseline value for two years, indicating sediments are increasingly more reducing for two years. In the third year, Re concentration decreased, suggesting a return towards pre-impact conditions. In select sites where the density of <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/benthic-zone" title="Learn more about Benthic zone"> benthic </a> foraminifera was determined, an assemblage-wide decrease occurred coincident with reducing conditions as determined by redox sensitive metals, demonstrating the important consequences of changing redox conditions on benthic ecosystems. Determination of redox sensitive metals will continue to constrain the <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/temporal-evolution" title="Learn more about temporal evolution"> temporal evolution </a> of reducing conditions, which will serve to document the <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/long-term-effect" title="Learn more about long-term effect"> long-term effects </a> of the spill, and the possible return to pre-event conditions. </p></p>

Original language	American English
Journal	Deep Sea Research Part II: Topical Studies in Oceanography
Volume	129
DOIs	https://doi.org/10.1016/j.dsr2.2014.12.009
State	Published - Jul 1 2016

Keywords

Oil spill
Gulf of Mexico
Deepwater Horizon
Paleoredox
Trace metal
Rhenium
Manganese

Disciplines

Marine Biology

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10.1016/j.dsr2.2014.12.009License: CC BY

Changes in Sediment Redox Conditions Following the BP DWH BlowoutFinal published version, 2.08 MBLicense: CC BY

Cite this

@article{4d4d2110171e48ac85a552706829e0f6,

title = "Changes in Sediment Redox Conditions Following the BP DWH Blowout Event",

abstract = " Following the blowout of the Macondo well, a pulse in sedimentation resulted in changes in sedimentary redox conditions . This is demonstrated by downcore and temporal changes in the concentration of redox sensitive metals: Mn, Re, and Cd. Sediment cores collected in the NE Gulf of Mexico (GoM) reveal increased sedimentation after the Deepwater Horizon (DWH) blowout. The formation of mucous-rich marine snow in surface waters and subsequent rapid deposition to underlying sediments is the likely cause. Respiration of this material resulted in decreased pore-water oxygen concentration and a shoaled redoxcline, resulting in two distinct Mn peaks in sediments following the event, one typically in the top 10 mm, with the other at 20–30 mm. Most cores near the wellhead reveal this non-steady state behavior for up to two years after the event. Associated with the Mn minimum between the two Mn peaks, a modest (15–30%) enrichment of Re consistent with reducing sediments typically exists. A three-year time series of three stations following the event reveal that sediment Re increased 3–4 times compared to the pre-impact baseline value for two years, indicating sediments are increasingly more reducing for two years. In the third year, Re concentration decreased, suggesting a return towards pre-impact conditions. In select sites where the density of benthic foraminifera was determined, an assemblage-wide decrease occurred coincident with reducing conditions as determined by redox sensitive metals, demonstrating the important consequences of changing redox conditions on benthic ecosystems. Determination of redox sensitive metals will continue to constrain the temporal evolution of reducing conditions, which will serve to document the long-term effects of the spill, and the possible return to pre-event conditions. ",

keywords = "Oil spill, Gulf of Mexico, Deepwater Horizon, Paleoredox, Trace metal, Rhenium, Manganese",

author = "Hastings, {D. W.} and Patrick Schwing and Brooks, {G. R.} and Larson, {R. A.} and Morford, {J. L.} and T. Roeder and Quinn, {K. A.} and T. Bartlett and Romero, {Isabel C.} and David Hollander",

year = "2016",

month = jul,

day = "1",

doi = "10.1016/j.dsr2.2014.12.009",

language = "American English",

volume = "129",

journal = "Deep Sea Research Part II: Topical Studies in Oceanography",

}

TY - JOUR

T1 - Changes in Sediment Redox Conditions Following the BP DWH Blowout Event

AU - Hastings, D. W.

AU - Schwing, Patrick

AU - Brooks, G. R.

AU - Larson, R. A.

AU - Morford, J. L.

AU - Roeder, T.

AU - Quinn, K. A.

AU - Bartlett, T.

AU - Romero, Isabel C.

AU - Hollander, David

PY - 2016/7/1

Y1 - 2016/7/1

N2 - Following the blowout of the Macondo well, a pulse in sedimentation resulted in changes in sedimentary redox conditions . This is demonstrated by downcore and temporal changes in the concentration of redox sensitive metals: Mn, Re, and Cd. Sediment cores collected in the NE Gulf of Mexico (GoM) reveal increased sedimentation after the Deepwater Horizon (DWH) blowout. The formation of mucous-rich marine snow in surface waters and subsequent rapid deposition to underlying sediments is the likely cause. Respiration of this material resulted in decreased pore-water oxygen concentration and a shoaled redoxcline, resulting in two distinct Mn peaks in sediments following the event, one typically in the top 10 mm, with the other at 20–30 mm. Most cores near the wellhead reveal this non-steady state behavior for up to two years after the event. Associated with the Mn minimum between the two Mn peaks, a modest (15–30%) enrichment of Re consistent with reducing sediments typically exists. A three-year time series of three stations following the event reveal that sediment Re increased 3–4 times compared to the pre-impact baseline value for two years, indicating sediments are increasingly more reducing for two years. In the third year, Re concentration decreased, suggesting a return towards pre-impact conditions. In select sites where the density of benthic foraminifera was determined, an assemblage-wide decrease occurred coincident with reducing conditions as determined by redox sensitive metals, demonstrating the important consequences of changing redox conditions on benthic ecosystems. Determination of redox sensitive metals will continue to constrain the temporal evolution of reducing conditions, which will serve to document the long-term effects of the spill, and the possible return to pre-event conditions.

AB - Following the blowout of the Macondo well, a pulse in sedimentation resulted in changes in sedimentary redox conditions . This is demonstrated by downcore and temporal changes in the concentration of redox sensitive metals: Mn, Re, and Cd. Sediment cores collected in the NE Gulf of Mexico (GoM) reveal increased sedimentation after the Deepwater Horizon (DWH) blowout. The formation of mucous-rich marine snow in surface waters and subsequent rapid deposition to underlying sediments is the likely cause. Respiration of this material resulted in decreased pore-water oxygen concentration and a shoaled redoxcline, resulting in two distinct Mn peaks in sediments following the event, one typically in the top 10 mm, with the other at 20–30 mm. Most cores near the wellhead reveal this non-steady state behavior for up to two years after the event. Associated with the Mn minimum between the two Mn peaks, a modest (15–30%) enrichment of Re consistent with reducing sediments typically exists. A three-year time series of three stations following the event reveal that sediment Re increased 3–4 times compared to the pre-impact baseline value for two years, indicating sediments are increasingly more reducing for two years. In the third year, Re concentration decreased, suggesting a return towards pre-impact conditions. In select sites where the density of benthic foraminifera was determined, an assemblage-wide decrease occurred coincident with reducing conditions as determined by redox sensitive metals, demonstrating the important consequences of changing redox conditions on benthic ecosystems. Determination of redox sensitive metals will continue to constrain the temporal evolution of reducing conditions, which will serve to document the long-term effects of the spill, and the possible return to pre-event conditions.

KW - Oil spill

KW - Gulf of Mexico

KW - Deepwater Horizon

KW - Paleoredox

KW - Trace metal

KW - Rhenium

KW - Manganese

UR - https://digitalcommons.usf.edu/msc_facpub/245

U2 - 10.1016/j.dsr2.2014.12.009

DO - 10.1016/j.dsr2.2014.12.009

M3 - Article

VL - 129

JO - Deep Sea Research Part II: Topical Studies in Oceanography

JF - Deep Sea Research Part II: Topical Studies in Oceanography

ER -

Changes in Sediment Redox Conditions Following the BP DWH Blowout Event

Abstract

Keywords

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