@article {Beaudoin2016,
	title = {{Impact of protists on a hydrocarbon-degrading bacterial community from deep-sea Gulf of Mexico sediments: A microcosm study}},
	journal = {Deep-Sea Research. Part II: Topical Studies in Oceanography},
	volume = {129},
	year = {2016},
	pages = {350{\textendash}359},
	abstract = {In spite of significant advancements towards understanding the dynamics of petroleum hydrocarbon degrading microbial consortia, the impacts (direct or indirect via grazing activities) of bacterivorous protists remain largely unknown. Microcosm experiments were used to examine whether protistan grazing affects the petroleum hydrocarbon degradation capacity of a deep-sea sediment microbial community from an active Gulf of Mexico cold seep. Differences in n-alkane content between native sediment microcosms and those treated with inhibitors of eukaryotes were assessed by comprehensive two-dimensional gas chromatography following 30{\textendash}90 day incubations and analysis of shifts in microbial community composition using small subunit ribosomal RNA gene clone libraries. More biodegradation was observed in microcosms supplemented with eukaryotic inhibitors. SSU rRNA gene clone libraries from oil-amended treatments revealed an increase in the number of proteobacterial clones (particularly $\gamma$-proteobacteria) after spiking sediments with diesel oil. Bacterial community composition shifted, and degradation rates increased, in treatments where protists were inhibited, suggesting protists affect the hydrocarbon degrading capacity of microbial communities in sediments collected at this Gulf of Mexico site.},
	keywords = {HOV Alvin (Human Occupied Vehicle)},
	issn = {0967-0645},
	doi = {10.1016/j.dsr2.2014.01.007},
	url = {http://www.sciencedirect.com/science/article/pii/S0967064514000216},
	author = {Beaudoin, D J and Carmichael, C A and Nelson, R K and Reddy, C M and Teske, A P and Edgcomb, V P}
}
@article {Ventura2012,
	title = {{The composition, origin and fate of complex mixtures in the maltene fractions of hydrothermal petroleum assessed by comprehensive two-dimensional gas chromatography}},
	journal = {Organic Geochemistry},
	volume = {45},
	year = {2012},
	pages = {48{\textendash}65},
	abstract = {Sedimentary organic matter in hydrothermal systems can be altered by high temperature fluids to generate petroleum. The saturated and aromatic fractions of these hydrothermal oils are compositionally similar to conventional oil with the exception that they often contain higher concentrations of polycyclic aromatic hydrocarbons (PAH) as well as substantial mixtures of coeluting organic compounds that produce dramatically rising signal on the baseline of gas chromatograms termed unresolved complex mixtures (UCMs). Little is known about the compounds that compose UCMs and why or how they form. This is in part due to an inability to discriminate between in situ and migrated components that characterize the petroleum generated in hydrothermal systems. However, UCMs are also a product of the limitations imbedded in analytical separation techniques. With the advent of comprehensive two-dimensional gas chromatography (GC~{\texttimes}~GC), a revision of what should constitute molecular complexity needs to be considered. We address these problems by comparing the molecular compositions of the maltene fractions of three previously published hydrothermal petroleum samples using time of flight-mass spectrometry (GC~{\texttimes}~GC{\textendash}ToF-MS) and 12 hydrothermal petroleum samples in cores from three locales using comprehensive two-dimensional gas chromatography with flame ionization detection (GC~{\texttimes}~GC{\textendash}FID). The sediment cores were collected from Middle Valley, located off the axis of the Juan de Fuca Ridge, and the Escanaba Trough, along the Gorda Ridge, both in the NE Pacific Ocean, as well as from the Guaymas Basin in the Gulf of California. We define a UCM in GC~{\texttimes}~GC data to be a condition in which ⩾25{\%} of the detected peaks within a chromatographic area coelute in either the first or second dimension. In turn, complex (CM) and simple mixtures (SM) are defined as having 5{\textendash}24{\%} and and migrated components that characterize the petroleum generated in hydrothermal systems. However, UCMs are also a product of the limitations imbedded in analytical separation techniques. With the advent of comprehensive two-dimensional gas chromatography (GC~{\texttimes}~GC), a revision of what should constitute molecular complexity needs to be considered. We address these problems by comparing the molecular compositions of the maltene fractions of three previously published hydrothermal petroleum samples using time of flight-mass spectrometry (GC~{\texttimes}~GC{\textendash}ToF-MS) and 12 hydrothermal petroleum samples in cores from three locales using comprehensive two-dimensional gas chromatography with flame ionization detection (GC~{\texttimes}~GC{\textendash}FID). The sediment cores were collected from Middle Valley, located off the axis of the Juan de Fuca Ridge, and the Escanaba Trough, along the Gorda Ridge, both in the NE Pacific Ocean, as well as from the Guaymas Basin in the Gulf of California. We define a UCM in GC~{\texttimes}~GC data to be a condition in which ⩾25{\%} of the detected peaks within a chromatographic area coelute in either the first or second dimension. In turn, complex (CM) and simple mixtures (SM) are defined as having 5{\textendash}24{\%} and},
	keywords = {HOV Alvin (Human Occupied Vehicle)},
	issn = {0146-6380},
	doi = {10.1016/j.orggeochem.2012.01.002},
	url = {http://dx.doi.org/10.1016/j.orggeochem.2012.01.002},
	author = {Ventura, G T and Simoneit, B R T and Nelson, R K and Reddy, C M}
}
@article {White2012,
	title = {{Impact of the Deepwater Horizon oil spill on a deep-water coral community in the Gulf of Mexico}},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {109},
	number = {50},
	year = {2012},
	month = {dec},
	pages = {20303{\textendash}20308},
	abstract = {To assess the potential impact of the Deepwater Horizon oil spill on offshore ecosystems, 11 sites hosting deep-water coral communities were examined 3 to 4 mo after the well was capped. Healthy coral communities were observed at all sites {\textgreater}20 km from the Macondo well, including seven sites previously visited in September 2009, where the corals and communities appeared unchanged. However, at one site 11 km southwest of the Macondo well, coral colonies presented widespread signs of stress, including varying degrees of tissue loss, sclerite enlargement, excess mucous production, bleached commensal ophiuroids, and covering by brown flocculent material (floc). On the basis of these criteria the level of impact to individual colonies was ranked from 0 (least impact) to 4 (greatest impact). Of the 43 corals imaged at that site, 46{\%} exhibited evidence of impact on more than half of the colony, whereas nearly a quarter of all of the corals showed impact to {\textgreater}90{\%} of the colony. Additionally, 53{\%} of these corals{\textquoteright} ophiuroid associates displayed abnormal color and/or attachment posture. Analysis of hopanoid petroleum biomarkers isolated from the floc provides strong evidence that this material contained oil from the Macondo well. The presence of recently damaged and deceased corals beneath the path of a previously documented plume emanating from the Macondo well provides compelling evidence that the oil impacted deep-water ecosystems. Our findings underscore the unprecedented nature of the spill in terms of its magnitude, release at depth, and impact to deep-water ecosystems.},
	keywords = {HOV Alvin (Human Occupied Vehicle), ROV Jason (Remotely Operated Vehicle)},
	issn = {0027-8424},
	doi = {10.1073/pnas.1118029109},
	author = {White, H K and Hsing, P-Y and Cho, W and Shank, T M and Cordes, E E and Quattrini, A M and Nelson, R K and Camilli, R and Demopoulos, A W J and German, C R and Brooks, J M and Roberts, H H and Shedd, W and Reddy, C M and Fisher, C R}
}
@article {White2012a,
	title = {{Reply to Boehm and Carragher: Multiple lines of evidence link deep-water coral damage to Deepwater Horizon oil spill}},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {109},
	number = {40},
	year = {2012},
	month = {oct},
	pages = {E2648{\textendash}E2648},
	abstract = {Our original study (1) used visual inspection as well as biological and geochemical analyses of corals and the surrounding sediment to provide complementary and compelling evidence linking the Deepwater Horizon (DWH) oil spill to the presence of damaged deep-water corals and brittle stars 11 km from the site of the leaking oil.},
	issn = {0027-8424},
	doi = {10.1073/pnas.1210413109},
	author = {White, H K and Hsing, P-Y and Cho, W and Shank, T M and Cordes, E E and Quattrini, A M and Nelson, R K and Camilli, R and Demopoulos, A W J and German, C R and Brooks, J M and Roberts, H H and Shedd, W and Reddy, C M and Fisher, C R}
}
@article {Valentine2010,
	title = {{Asphalt volcanoes as a potential source of methane to late Pleistocene coastal waters}},
	journal = {Nature Geoscience},
	volume = {3},
	number = {5},
	year = {2010},
	pages = {345{\textendash}348},
	abstract = {Every year, natural petroleum seepage emits 0.2{\textendash}2 Tg of oil to the ocean1. Significant oil seepage can build large underwater mounds, consisting of tar deposits with morphologies similar to volcanic lava flows, known as asphalt volcanoes2, 3. Such events are typically accompanied by large fluxes of the greenhouse gas methane4, 5. Marine sediments from the Santa Barbara basin, California, contain a record of elevated methane concentrations6, anoxia and tar deposition7 during the Pleistocene epoch that had been attributed to dissolution of methane hydrates. However, the region is known to have exhibited oil seepage in the past7. Here, we document the discovery of seven extinct asphalt volcanoes off the coast of southern California. The morphology of the deposits and geochemistry of samples taken from the two largest structures supports their classification as asphalt volcanoes, derived from a common source. We estimate that the two structures resulted from seepage of 0.07{\textendash}0.4 Tg of oil, accompanied by the emission of 0.35{\textendash}1.8 Tg of methane. Radiocarbon dating of carbonate deposits entrained with the asphalt indicates formation of the volcanoes between 44 and 31 kyr ago. The timing and volume of erupted hydrocarbons from the asphalt structures can explain some or all of the documented methane release and tar accumulation in the Santa Barbara basin during the Pleistocene.},
	keywords = {AUV Sentry (Autonomous Underwater Vehicle), HOV Alvin (Human Occupied Vehicle)},
	issn = {1752-0894},
	doi = {10.1038/ngeo848},
	url = {http://dx.doi.org/10.1038/ngeo848},
	author = {Valentine, D L and Reddy, C M and Farwell, C and Hill, T M and Pizarro, O and Yoerger, D R and Camilli, R and Nelson, R K and Peacock, E E and Bagby, S C and Clarke, B A and Roman, C N and Soloway, M}
}
