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Full-Text Articles in Life Sciences

Experimental Assessment Of Lionfish Removals To Mitigate Reef Fish Community Shifts On Northern Gulf Of Mexico Artificial Reefs, Kristin A. Dahl, William F. Patterson Iii, Richard A. Synder Oct 2016

Experimental Assessment Of Lionfish Removals To Mitigate Reef Fish Community Shifts On Northern Gulf Of Mexico Artificial Reefs, Kristin A. Dahl, William F. Patterson Iii, Richard A. Synder

C-IMAGE Publications

Substantial declines in reef fishes were observed at northern Gulf of Mexico artificial reef sites between 2009−2010 and 2011−2012, a period that bracketed the appearance of invasive lionfish in this ecosystem. Small demersal reef fishes, the predominant prey of lionfish in other systems, displayed the greatest declines. However, a confounding factor during this time was the Deepwater Horizon Oil Spill (DWH) in summer 2010. In some areas, targeted lionfish removals have been demonstrated to mitigate negative effects on native fishes. Therefore, we conducted a 2 yr experiment to examine the effectiveness and ecological benefits of targeted lionfish removals at artificial …


Responses Of Microbial Communities To Hydrocarbon Exposures, Samantha B. Joye, Sara Kleindienst, Jack A. Gilbert, Kim M. Handley, Pamela Weisenhorn, Will A. Overholt, Joel E. Kostka Aug 2016

Responses Of Microbial Communities To Hydrocarbon Exposures, Samantha B. Joye, Sara Kleindienst, Jack A. Gilbert, Kim M. Handley, Pamela Weisenhorn, Will A. Overholt, Joel E. Kostka

C-IMAGE Publications

The responses of microbial communities to hydrocarbon exposures are complex and variable, driven to a large extent by the nature of hydrocarbon infusion, local environmental conditions, and factors that regulate microbial physiology (e.g., substrate and nutrient availability). Although present at low abundance in the ocean, hydrocarbon-degrading seed populations are widely distributed, and they respond rapidly to hydrocarbon inputs at natural and anthropogenic sources. Microbiomes from environments impacted by hydrocarbon discharge may appear similar at a higher taxonomic rank (e.g., genus level) but diverge at increasing phylogenetic resolution (e.g., sub-OTU [operational taxonomic unit] levels). Such subtle changes are detectable by computational …


How Did The Deepwater Horizon Oil Spill Impact Deep-Sea Ecosystems?, Charles R. Fisher, Paul A. Montagna, Tracey T. Sutton Aug 2016

How Did The Deepwater Horizon Oil Spill Impact Deep-Sea Ecosystems?, Charles R. Fisher, Paul A. Montagna, Tracey T. Sutton

C-IMAGE Publications

Approximately 90% of the volume of the Gulf of Mexico is contained in water deeper than 200 m, a region where the Deepwater Horizon (DWH) blowout had more impact on ecosystems than any previous oil spill. The remoteness and relative inaccessibility of the deep sea makes documenting even acute impacts to the animals that live in this realm difficult. This article reviews Natural Resource Damage Assessment studies and follow-up work funded as part of the Gulf of Mexico Research Initiative that targeted deepwater pelagic and benthic fauna. Oil was incorporated into the pelagic food web, and a reduction in planktonic …


How Do Oil, Gas, And Water Interact Near A Subsea Blowout?, Scott A. Socolofsky, E. Eric Adams, Claire B. Paris-Limouzy, Di Yang Aug 2016

How Do Oil, Gas, And Water Interact Near A Subsea Blowout?, Scott A. Socolofsky, E. Eric Adams, Claire B. Paris-Limouzy, Di Yang

C-IMAGE Publications

Oil and gas from a subsea blowout shatter into droplets and bubbles that rise through the water column, entraining ambient seawater and forming a plume. Local density stratification and currents eventually arrest this rising plume, and the entrained water, enriched with dissolved hydrocarbons and some of the smaller oil droplets, forms one or more subsurface intrusion layers. Beyond the plume and intrusion layer(s), droplets and bubbles advect and diffuse by local currents and dissolve and biodegrade as they rise to the surface, where they are transported by wind and waves. These processes occur over a wide range of length scales …


Methods Of Oil Detection In Response To The Deepwater Horizon Oil Spill, Helen K. White, Robyn N. Conmy, Ian R. Macdonald, Christopher M. Reddy Aug 2016

Methods Of Oil Detection In Response To The Deepwater Horizon Oil Spill, Helen K. White, Robyn N. Conmy, Ian R. Macdonald, Christopher M. Reddy

C-IMAGE Publications

Detecting oil in the northern Gulf of Mexico following the Deepwater Horizon oil spill presented unique challenges due to the spatial and temporal extent of the spill and the subsequent dilution of oil in the environment. Over time, physical, chemical, and biological processes altered the composition of the oil, further complicating its detection. Reservoir fluid, containing gas and oil, released from the Macondo well was detected in surface and subsurface environments. Oil monitoring during and after the spill required a variety of technologies, including nimble adaptation of techniques developed for non-oil-related applications. The oil detection technologies employed varied in sensitivity, …


Chemical Composition Of Macondo And Other Crude Oils And Compositional Alterations During Oil Spills, Edward B. Overton, Terry L. Wade, Jagoš R. Radović, Buffy M. Meyer, M. Scott Miles, Stephen R. Larter Aug 2016

Chemical Composition Of Macondo And Other Crude Oils And Compositional Alterations During Oil Spills, Edward B. Overton, Terry L. Wade, Jagoš R. Radović, Buffy M. Meyer, M. Scott Miles, Stephen R. Larter

C-IMAGE Publications

Crude oils are some of the most complex and diverse organic mixtures found in nature. They contain thousands of different compounds belonging to several compound classes, with the main ones being hydrocarbons and their heteroatom (N, S, and O)-containing analogs, called non-hydrocarbons. In general, all crude oils contain the same types of chemical structures, but these compounds can be in highly variable proportions in crude oils drawn from different reservoir conditions and locations. Both the types of compounds and their respective quantities change rapidly once the crude oil is spilled into the environment, making the circumstances associated with every spill …


Weathering Of Oil Spilled In The Marine Environment, Matthew A. Tarr, Phoebe Zito, Edward B. Overton, Gregory M. Olson, Puspa L. Adhikari, Christopher M. Reddy Aug 2016

Weathering Of Oil Spilled In The Marine Environment, Matthew A. Tarr, Phoebe Zito, Edward B. Overton, Gregory M. Olson, Puspa L. Adhikari, Christopher M. Reddy

C-IMAGE Publications

Crude oil is a complex mixture of many thousands of mostly hydrocarbon and nitrogen-, sulfur-, and oxygen-containing compounds with molecular weights ranging from below 70 Da to well over 2,000 Da. When this complex mixture enters the environment from spills, ruptures, blowouts, or seeps, it undergoes a continuous series of compositional changes that result from a process known as weathering. Spills of petroleum involving human activity generally result in more rapid input of crude oil or refined products (diesel, gasoline, heavy fuel oil, and diluted bitumens) to the marine system than do natural processes and urban runoffs. The primary physicochemical …


Refinement Of The Critical Angle Calculation For The Contrast Reversal Of Oil Slicks Under Sunglint, Yingcheng Lu, Shaojie Sun, Minwei Zhang, Brock Murch, Chuanmin Hu Jan 2016

Refinement Of The Critical Angle Calculation For The Contrast Reversal Of Oil Slicks Under Sunglint, Yingcheng Lu, Shaojie Sun, Minwei Zhang, Brock Murch, Chuanmin Hu

C-IMAGE Publications

It has long been observed that oil slicks under sunglint can reverse their optical contrast against nearby oil‐free seawater. Such a phenomenon has been described through both empirical statistical analysis of the sunglint strength and modeled theoretically using a critical angle concept. The critical angle, in this model, is the angle at which the image pixels show no or negligible contrast between oiled and nonoiled seawater. Pixels away from this critical angle show either positive or negative contrast from the oil‐free pixels. Although this concept has been fully demonstrated in the published literature, its calculation needs to be further refined …


How Did The Deepwater Horizon Oil Spill Impact Deep-Sea Ecosystems?, Charles R. Fisher, Paul A. Montagna, Tracey Sutton Jan 2016

How Did The Deepwater Horizon Oil Spill Impact Deep-Sea Ecosystems?, Charles R. Fisher, Paul A. Montagna, Tracey Sutton

C-IMAGE Publications

Approximately 90% of the volume of the Gulf of Mexico is contained in water deeper than 200 m, a region where the Deepwater Horizon (DWH) blowout had more impact on ecosystems than any previous oil spill. The remoteness and relative inaccessibility of the deep sea makes documenting even acute impacts to the animals that live in this realm difficult. This article reviews Natural Resource Damage Assessment studies and follow-up work funded as part of the Gulf of Mexico Research Initiative that targeted deepwater pelagic and benthic fauna. Oil was incorporated into the pelagic food web, and a reduction in planktonic …


Gulf Of Mexico Low-Frequency Ocean Soundscape Impacted By Airguns, Sean M. Wiggins, Jesse M. Hall, Bruce J. Thayre, John A. Hildebrand Jan 2016

Gulf Of Mexico Low-Frequency Ocean Soundscape Impacted By Airguns, Sean M. Wiggins, Jesse M. Hall, Bruce J. Thayre, John A. Hildebrand

C-IMAGE Publications

The ocean soundscape of the Gulf of Mexico (GOM) has not been well-studied, although it is an important habitat for marine mammals, including sperm and beaked whales, many dolphin species, and a potentially endangered baleen whale species. The GOM is also home to high levels of hydrocarbon exploration and extraction, heavily used commercial shipping ports, and significant fishery industry activity, all of which are known contributors to oceanic noise. From 2010–2013, the soundscape of three deep and two shallow water sites in the GOM were monitored over 10 – 1000 Hz. Average sound pressure spectrum levels were high, > 90 dB …


Sun Glint Requirement For The Remote Detection Of Surface Oil Films, Shaojie Sun, Chuanmin Hu Jan 2016

Sun Glint Requirement For The Remote Detection Of Surface Oil Films, Shaojie Sun, Chuanmin Hu

C-IMAGE Publications

Natural oil slicks in the western Gulf of Mexico are used to determine the sun glint threshold required for optical remote sensing of oil films. The threshold is determined using the same‐day image pairs collected by Moderate Resolution Imaging Spectroradiometer (MODIS) Terra (MODIST), MODIS Aqua (MODISA), and Visible Infrared Imaging Radiometer Suite (VIIRS) (N  = 2297 images) over the same oil slick locations where at least one of the sensors captures the oil slicks. For each sensor, statistics of sun glint strengths, represented by the normalized glint reflectance (L GN, sr−1), when oil slicks can and cannot be …