Social Media,Public Participation,and the 2010 BP Deepwater Horizon Oil Spill

This research examines how information about an oil spill, its impacts, and the use of dispersants to treat the oil, moved through social media and the surrounding Internet during the 2010 BP Deepwater Horizon oil spill. Using a collection of tweets captured during the spill, we employ a mixed-method approach including an in-depth qualitative analysis to examine the content of Twitter posts, the connections that Twitter users made with each other, and the links between Twitter content and the surrounding Internet. This article offers a range of findings to help practitioners and others understand how social media is used by a variety of different actors during a slow-moving, long-term, environmental disaster. We enumerate some of the most salient themes in the Twitter data, noting that concerns about health impacts were more likely to be communicated in tweets about dispersant use, than in the larger conversation. We describe the accounts and behaviors of highly retweeted Twitter users, noting how locals helped to shape the network and the conversation. Importantly, our results show the online crowd wanting to participate in and contribute to response efforts, a finding with implications for future oil spill response.     

Regime Shift in Sandy Beach Microbial Communities following Deepwater Horizon Oil Spill Remediation Efforts

Sandy beaches support a wide variety of underappreciated biodiversity that is critical to coastal ecosystems. Prior to the 2010 Deepwater Horizon oil spill, the diversity and function of supratidal beach sediment microbial communities along Gulf of Mexico coastlines were not well understood. As such, it was unclear if microbial community compositional changes would occur following exposure to beached oil, if indigenous communities could biodegrade oil, or how cleanup efforts, such as sand washing and sediment redistribution, would impact microbial ecosystem resiliency. Transects perpendicular to the shoreline were sampled from public beaches on Grand Isle, Louisiana, and Dauphin Island, Alabama, over one year. Prior to oil coming onshore, elevated levels of bacteria associated with fecal contamination were detected (e.g., Enterobacteriales and Campylobacterales). Over time, significant shifts within major phyla were identified (e.g., Proteobacteria, Firmicutes, Actinobacteria) and fecal indicator groups were replaced by taxa affiliated with open-ocean and marine systems (e.g., Oceanospirillales, Rhodospirillales, and Rhodobacterales). These new bacterial groups included putative hydrocarbon degraders, similar to those identified near the oil plume offshore. Shifts in the microbial community composition strongly correlated to more poorly sorted sediment and grain size distributional changes. Natural oceanographic processes could not account for the disrupted sediment, especially from the backshore well above the maximum high-tide levels recorded at these sites. Sand washing and tilling occurred on both open beaches from August through at least December 2010, which were mechanisms that could replace fecal indicator groups with open-ocean groups. Consequently, remediation efforts meant to return beaches to pre-spill compositions caused a regime shift that may have added potential ecosystem function, like hydrocarbon degradation, to the sediment. Future research will need to assess the persistence and impact of the newly formed microbial communities to the overall sandy beach ecosystems.     

Abundance and Size of Gulf Shrimp in Louisiana's Coastal Estuaries following the Deepwater Horizon Oil Spill

The Deepwater Horizon oil spill impacted Louisiana''s coastal estuaries physically, chemically, and biologically. To better understand the ecological consequences of this oil spill on Louisiana estuaries, we compared the abundance and size of two Gulf shrimp species (Farfantepeneus aztecus and Litopeneus setiferus) in heavily affected and relatively unaffected estuaries, before and after the oil spill. Two datasets were used to conduct this study: data on shrimp abundance and size before the spill were available from Louisiana Department of Wildlife and Fisheries (LDWF). Data on shrimp abundance and size from after the spill were independently collected by the authors and by LDWF. Using a Before-After-Control-Impact with Paired sampling (BACIP) design with monthly samples of two selected basins, we found brown shrimp to become more abundant and the mean size of white shrimp to become smaller. Using a BACIP with data on successive shrimp year-classes of multiple basins, we found both species to become more abundant in basins that were affected by the spill, while mean shrimp size either not change after the spill, or increased in both affected and unaffected basins. We conclude that following the oil spill abundances of both species increased within affected estuaries, whereas mean size may have been unaffected. We propose two factors that may have caused these results: 1) exposure to polycyclic aromatic hydrocarbons (PAHs) may have reduced the growth rate of shrimp, resulting in a delayed movement of shrimp to offshore habitats, and an increase of within-estuary shrimp abundance, and 2) fishing closures established immediately after the spill, may have resulted in decreased fishing effort and an increase in shrimp abundance. This study accentuates the complexities in determining ecological effects of oil spills, and the need of studies on the organismal level to reveal cause-and-effect relationships of such events.     

Role of Bacterial Exopolysaccharides (EPS) in the Fate of the Oil Released during the Deepwater Horizon Oil Spill

Halomonas species are recognized for producing exopolysaccharides (EPS) exhibiting amphiphilic properties that allow these macromolecules to interface with hydrophobic substrates, such as hydrocarbons. There remains a paucity of knowledge, however, on the potential of Halomonas EPS to influence the biodegradation of hydrocarbons. In this study, the well-characterized amphiphilic EPS produced by Halomonas species strain TG39 was shown to effectively increase the solubilization of aromatic hydrocarbons and enhance their biodegradation by an indigenous microbial community from oil-contaminated surface waters collected during the active phase of the Deepwater Horizon oil spill. Three Halomonas strains were isolated from the Deepwater Horizon site, all of which produced EPS with excellent emulsifying qualities and shared high (97-100%) 16S rRNA sequence identity with strain TG39 and other EPS-producing Halomonas strains. Analysis of pyrosequence data from surface water samples collected during the spill revealed several distinct Halomonas phylotypes, of which some shared a high sequence identity (≥97%) to strain TG39 and the Gulf spill isolates. Other bacterial groups comprising members with well-characterized EPS-producing qualities, such as Alteromonas , Colwellia and Pseudoalteromonas , were also found enriched in surface waters, suggesting that the total pool of EPS in the Gulf during the spill may have been supplemented by these organisms. Roller bottle incubations with one of the Halomonas isolates from the Deepwater Horizon spill site demonstrated its ability to effectively produce oil aggregates and emulsify the oil. The enrichment of EPS-producing bacteria during the spill coupled with their capacity to produce amphiphilic EPS is likely to have contributed to the ultimate removal of the oil and to the formation of oil aggregates, which were a dominant feature observed in contaminated surface waters.     

Shifts in Symbiotic Endophyte Communities of a Foundational Salt Marsh Grass following Oil Exposure from the Deepwater Horizon Oil Spill

Symbiotic associations can be disrupted by disturbance or by changing environmental conditions. Endophytes are fungal and bacterial symbionts of plants that can affect performance. As in more widely known symbioses, acute or chronic stressor exposure might trigger disassociation of endophytes from host plants. We tested this hypothesis by examining the effects of oil exposure following the Deepwater Horizon (DWH) oil spill on endophyte diversity and abundance in Spartina alterniflora – the foundational plant in northern Gulf coast salt marshes affected by the spill. We compared bacterial and fungal endophytes isolated from plants in reference areas to isolates from plants collected in areas with residual oil that has persisted for more than three years after the DWH spill. DNA sequence-based estimates showed that oil exposure shifted endophyte diversity and community structure. Plants from oiled areas exhibited near total loss of leaf fungal endophytes. Root fungal endophytes exhibited a more modest decline and little change was observed in endophytic bacterial diversity or abundance, though a shift towards hydrocarbon metabolizers was found in plants from oiled sites. These results show that plant-endophyte symbioses can be disrupted by stressor exposure, and indicate that symbiont community disassembly in marsh plants is an enduring outcome of the DWH spill.     

Extent and Degree of Shoreline Oiling: Deepwater Horizon Oil Spill,Gulf of Mexico,USA

The oil from the 2010 Deepwater Horizon spill in the Gulf of Mexico was documented by shoreline assessment teams as stranding on 1,773 km of shoreline. Beaches comprised 50.8%, marshes 44.9%, and other shoreline types 4.3% of the oiled shoreline. Shoreline cleanup activities were authorized on 660 km, or 73.3% of oiled beaches and up to 71 km, or 8.9% of oiled marshes and associated habitats. One year after the spill began, oil remained on 847 km; two years later, oil remained on 687 km, though at much lesser degrees of oiling. For example, shorelines characterized as heavily oiled went from a maximum of 360 km, to 22.4 km one year later, and to 6.4 km two years later. Shoreline cleanup has been conducted to meet habitat-specific cleanup endpoints and will continue until all oiled shoreline segments meet endpoints. The entire shoreline cleanup program has been managed under the Shoreline Cleanup Assessment Technique (SCAT) Program, which is a systematic, objective, and inclusive process to collect data on shoreline oiling conditions and support decision making on appropriate cleanup methods and endpoints. It was a particularly valuable and effective process during such a complex spill.     

Detection of Salt Marsh Vegetation Stress and Recovery after the Deepwater Horizon Oil Spill in Barataria Bay,Gulf of Mexico Using AVIRIS Data

The British Petroleum Deepwater Horizon Oil Spill in the Gulf of Mexico was the biggest oil spill in US history. To assess the impact of the oil spill on the saltmarsh plant community, we examined Advanced Visible Infrared Imaging Spectrometer (AVIRIS) data flown over Barataria Bay, Louisiana in September 2010 and August 2011. Oil contamination was mapped using oil absorption features in pixel spectra and used to examine impact of oil along the oiled shorelines. Results showed that vegetation stress was restricted to the tidal zone extending 14 m inland from the shoreline in September 2010. Four indexes of plant stress and three indexes of canopy water content all consistently showed that stress was highest in pixels next to the shoreline and decreased with increasing distance from the shoreline. Index values along the oiled shoreline were significantly lower than those along the oil-free shoreline. Regression of index values with respect to distance from oil showed that in 2011, index values were no longer correlated with proximity to oil suggesting that the marsh was on its way to recovery. Change detection between the two dates showed that areas denuded of vegetation after the oil impact experienced varying degrees of re-vegetation in the following year. This recovery was poorest in the first three pixels adjacent to the shoreline. This study illustrates the usefulness of high spatial resolution airborne imaging spectroscopy to map actual locations where oil from the spill reached the shore and then to assess its impacts on the plant community. We demonstrate that post-oiling trends in terms of plant health and mortality could be detected and monitored, including recovery of these saltmarsh meadows one year after the oil spill.     

Demographic trends of Brown Pelicans in Louisiana before and after the Deepwater Horizon oil spill

Marine oil spills may have extensive and deleterious effects on coastal waterbirds, but pre‐spill data sets are often not available for making comparisons of demographics to the period following a spill. The 2010 Deepwater Horizon oil spill allowed us to compare Brown Pelican (Pelecanus occidentalis) demographics during pre‐ and post‐spill years. We banded 1114 pelicans on Louisiana barrier islands from 2007 to 2009, tracked their distribution via band re‐sighting surveys from 2008 to 2011, and conducted age‐structure surveys. Across Louisiana coastal islands in 2011, we detected 7% of pelicans that had been oiled during the 2010 spill and released following rehabilitation. Similarly, 6% of pelicans (not oiled) banded at the same release site in 2007 were observed across coastal islands 1 yr after banding. We observed variation in proportions of pelicans that were 1, 2, and 3 or more years old among years (2008–2011) and across islands, but little variation could readily be assigned to spill‐related mortality. These Brown Pelican demographic trends one year following the Deepwater Horizon oil spill are contrary to other assessments of the impacts of oil contamination on marine birds. However, additional research is required to evaluate potential long‐term population trends.     

High Numbers of Vibrio vulnificus in Tar Balls Collected from Oiled Areas of the North-Central Gulf of Mexico Following the 2010 BP Deepwater Horizon Oil Spill

The Deepwater Horizon Oil Spill was the largest oil spill in USA history releasing approximately 4.9 million barrels of crude oil into the Gulf of Mexico. Soon after the spill started, tar balls and other forms of weathered oil appeared in large numbers on beaches in Mississippi and Alabama. In this study, we analyzed tar balls for total aerobic bacterial (TAB) counts and also for the presence of Vibrio vulnificus, a human pathogen known to be abundant in the Gulf Coast environment and capable of causing severe wound infections by contact with contaminated surfaces. Our results showed that TAB counts were significantly higher in tar balls than in sand and seawater collected at the same location. In addition, V. vulnificus numbers were 10× higher in tar balls than in sand and up to 100× higher than in seawater. Densities of V. vulnificus were higher than 10(5) colony forming units/g of tar ball in all samples analyzed. Our data suggest that tar balls can act as reservoirs for bacteria including human pathogens.     

Adrenal Gland and Lung Lesions in Gulf of Mexico Common Bottlenose Dolphins (Tursiops truncatus) Found Dead following the Deepwater Horizon Oil Spill

A northern Gulf of Mexico (GoM) cetacean unusual mortality event (UME) involving primarily bottlenose dolphins (Tursiops truncatus) in Louisiana, Mississippi, and Alabama began in February 2010 and continued into 2014. Overlapping in time and space with this UME was the Deepwater Horizon (DWH) oil spill, which was proposed as a contributing cause of adrenal disease, lung disease, and poor health in live dolphins examined during 2011 in Barataria Bay, Louisiana. To assess potential contributing factors and causes of deaths for stranded UME dolphins from June 2010 through December 2012, lung and adrenal gland tissues were histologically evaluated from 46 fresh dead non-perinatal carcasses that stranded in Louisiana (including 22 from Barataria Bay), Mississippi, and Alabama. UME dolphins were tested for evidence of biotoxicosis, morbillivirus infection, and brucellosis. Results were compared to up to 106 fresh dead stranded dolphins from outside the UME area or prior to the DWH spill. UME dolphins were more likely to have primary bacterial pneumonia (22% compared to 2% in non-UME dolphins, P = .003) and thin adrenal cortices (33% compared to 7% in non-UME dolphins, P = .003). In 70% of UME dolphins with primary bacterial pneumonia, the condition either caused or contributed significantly to death. Brucellosis and morbillivirus infections were detected in 7% and 11% of UME dolphins, respectively, and biotoxin levels were low or below the detection limit, indicating that these were not primary causes of the current UME. The rare, life-threatening, and chronic adrenal gland and lung diseases identified in stranded UME dolphins are consistent with exposure to petroleum compounds as seen in other mammals. Exposure of dolphins to elevated petroleum compounds present in coastal GoM waters during and after the DWH oil spill is proposed as a cause of adrenal and lung disease and as a contributor to increased dolphin deaths.     

Spatial,Temporal, and Habitat-Related Variation in Abundance of Pelagic Fishes in the Gulf of Mexico: Potential Implications of the Deepwater Horizon Oil Spill

Time-series data collected over a four-year period were used to characterize patterns of abundance for pelagic fishes in the northern Gulf of Mexico (GoM) before (2007–2009) and after (2010) the Deepwater Horizon oil spill. Four numerically dominant pelagic species (blackfin tuna, blue marlin, dolphinfish, and sailfish) were included in our assessment, and larval density of each species was lower in 2010 than any of the three years prior to the oil spill, although larval abundance in 2010 was often statistically similar to other years surveyed. To assess potential overlap between suitable habitat of pelagic fish larvae and surface oil, generalized additive models (GAMs) were developed to evaluate the influence of ocean conditions on the abundance of larvae from 2007–2009. Explanatory variables from GAMs were then linked to environmental data from 2010 to predict the probability of occurrence for each species. The spatial extent of surface oil overlapped with early life habitat of each species, possibly indicating that the availability of high quality habitat was affected by the DH oil spill. Shifts in the distribution of spawning adults is another factor known to influence the abundance of larvae, and the spatial occurrence of a model pelagic predator (blue marlin) was characterized over the same four-year period using electronic tags. The spatial extent of oil coincided with areas used by adult blue marlin from 2007–2009, and the occurrence of blue marlin in areas impacted by the DH oil spill was lower in 2010 relative to pre-spill years.     

Decline in condition of gorgonian octocorals on mesophotic reefs in the northern Gulf of Mexico: before and after the Deepwater Horizon oil spill

Hard-bottom ‘mesophotic’ reefs along the ‘40-fathom’ (73 m) shelf edge in the northern Gulf of Mexico were investigated for potential effects of the Deepwater Horizon (DWH) oil spill from the Macondo well in April 2010. Alabama Alps Reef, Roughtongue Reef, and Yellowtail Reef were near the well, situated 60–88 m below floating oil discharged during the DWH spill for several weeks and subject to dispersant applications. In contrast, Coral Trees Reef and Madison Swanson South Reef were far from the DWH spill site and below the slick for less than a week or not at all, respectively. The reefs were surveyed by ROV in 2010, 2011, and 2014 and compared to similar surveys conducted one and two decades earlier. Large gorgonian octocorals were present at all sites in moderate abundance including Swiftia exserta, Hypnogorgia pendula, Thesea spp., and Placogorgia spp. The gorgonians were assessed for health and condition in a before-after-control-impact (BACI) research design using still images captured from ROV video transects. Injury was modeled as a categorical response to proximity and time using logistic regression. Condition of gorgonians at sites near Macondo well declined significantly post-spill. Before the spill, injury was observed for 4–9 % of large gorgonians. After the spill, injury was observed in 38–50 % of large gorgonians. Odds of injury for sites near Macondo were 10.8 times higher post-spill, but unchanged at far sites. The majority of marked injured colonies in 2011 declined further in condition by 2014. Marked healthy colonies generally remained healthy. Background stresses to corals, including fishing activity, fishing debris, and coral predation, were noted during surveys, but do not appear to account for the decline in condition at study sites near Macondo well.     

Interspecific differences in growth of somatic and reproductive tissues during the breeding season in Menidia menidia and M. beryllina

The annual atherinid fishes, Menidia menidia and M. beryllina , are extremely similar morphologically, but appear to differ in their energetics and life histories. They emerge from winter in relatively emaciated condition. Menidia menidia males and females showed little change in carcass weight but significant increases in gonad weight in March and April prior to spawning in May. Female liver weight increased in March and remained high. Thus, this species had reached its reproductive size in the autumn and allocated its energy to gonadal growth during the spring. Menidia beryllina showed no significant increases in weight until early May, when carcass, liver and gonad all increased simultaneously, a pattern very different from its congener. The later spawning of M. beryllina is probably due both to its need for carcass growth in spring prior to spawning and to its apparent requirement for warmer water for growth. Females of both species invested more into liver and gonad than did males. Maximum gonadosomatic index was about twice as large for M. menidia males as for M. beryllina males, but the index was similar for females of both species.     

实验动物产生波动性不对称的影响因素

饲养方式、社会环境和化学污染是影响动物发育不稳定的重要环境胁迫因素,会使动物种群的适应和竞争能力等指数降低。而波动性不对称FA（Fluctuating asymmetry）的水平可用来指示某一种群对这种环境压力的进化和适应能力。FA的测量方法比常规的参数更加灵敏,而且可将环境压力的影响定量化,同时其测定和分析都比较简单,不需要昂贵的设备和试剂,使研究和监测成本大大降低。     

Hydrocarbons in Deep-Sea Sediments following the 2010 Deepwater Horizon Blowout in the Northeast Gulf of Mexico

The Deepwater Horizon (DWH) spill released 4.9 million barrels of oil into the Gulf of Mexico (GoM) over 87 days. Sediment and water sampling efforts were concentrated SW of the DWH and in coastal areas. Here we present geochemistry data from sediment cores collected in the aftermath of the DWH event from 1000 – 1500 m water depth in the DeSoto Canyon, NE of the DWH wellhead. Cores were analyzed at high-resolution (at 2 mm and 5 mm intervals) in order to evaluate the concentration, composition and input of hydrocarbons to the seafloor. Specifically, we analyzed total organic carbon (TOC), aliphatic, polycyclic aromatic hydrocarbon (PAHs), and biomarker (hopanes, steranes, diasteranes) compounds to elucidate possible sources and transport pathways for deposition of hydrocarbons. Results showed higher hydrocarbon concentrations during 2010-2011 compared to years prior to 2010. Hydrocarbon inputs in 2010-2011 were composed of a mixture of sources including terrestrial, planktonic, and weathered oil. Our results suggest that after the DWH event, both soluble and highly insoluble hydrocarbons were deposited at enhanced rates in the deep-sea. We proposed two distinct transport pathways of hydrocarbon deposition: 1) sinking of oil-particle aggregates (hydrocarbon-contaminated marine snow and/or suspended particulate material), and 2) advective transport and direct contact of the deep plume with the continental slope surface sediments between 1000-1200 m. Our findings underline the complexity of the depositional event observed in the aftermath of the DWH event in terms of multiple sources, variable concentrations, and spatial (depth-related) variability in the DeSoto Canyon, NE of the DWH wellhead.     

Microbial gene functions enriched in the Deepwater Horizon deep-sea oil plume

The Deepwater Horizon oil spill in the Gulf of Mexico is the deepest and largest offshore spill in the United State history and its impacts on marine ecosystems are largely unknown. Here, we showed that the microbial community functional composition and structure were dramatically altered in a deep-sea oil plume resulting from the spill. A variety of metabolic genes involved in both aerobic and anaerobic hydrocarbon degradation were highly enriched in the plume compared with outside the plume, indicating a great potential for intrinsic bioremediation or natural attenuation in the deep sea. Various other microbial functional genes that are relevant to carbon, nitrogen, phosphorus, sulfur and iron cycling, metal resistance and bacteriophage replication were also enriched in the plume. Together, these results suggest that the indigenous marine microbial communities could have a significant role in biodegradation of oil spills in deep-sea environments.     

How Useful is Fluctuating Asymmetry in Conservation Biology: Asymmetry in Rare and Abundant Coenonympha Butterflies

It has been suggested that minor, fluctuating differences in size of bilateral traits could validly indicate individual differences in developmental stability. One plausible reason for instability to occur could be lowered population size, which has been suggested to increase fluctuating asymmetry due to inbreeding, for example. We measured seven wing asymmetries of three Coenonympha butterfly species in central Sweden. One species is abundant (nobreak C. pamphilus), one rather common (C. arcania), and one rare (C. hero). We expected that if fluctuating asymmetry is a reliable indicator of population quality and thus a useful tool for conservation purposes, the most abundant species should show lowest asymmetry and the most endangered, the highest. Contrary to our expectations, the highest wing asymmetry was found in the relatively common species C. arcania and the most abundant and rare species did not show significant differences in levels of wing asymmetry. Our results obtained from three Coenonympha species hence suggest that the use of fluctuating asymmetry as an indicator of population conservation status may be misleading. Possible increase in asymmetry of small and/or isolated populations of butterflies may be masked by local differences in environmental conditions that could have high impact on bilateral development as well.     

Directional and Fluctuating Asymmetry in Sexual and Asexual Otiorhynchus alpicola Populations

This study concerns the contribution of directional asymmetry (DA) and fluctuating asymmetry (FA) as a characterization of variation in six sexual (diploid) and two asexual (triploid and tetraploid) populations of the weevil Otiorhynchus alpicola. It is shown that DA in sexual populations is about 1 % of the mean length of each of the seven bilateral traits and the average contribution of DA to trait variation is even lower in asexual populations (about 0.85 in triploids and 0.65 in tetraploids forms). The average contribution of FA to the total phenotypic variance is about 23 %, 12 % and 19 % in diploid, triploid and tetraploid populations, respectively. Since FA is generally regarded as a measure of developmental stability, our data indicate that triploid forms of O. alpicola are developmentally more stable than diploid and tetraploid forms. The relationship between the level of ploidy and FA is discussed.     

冠心病患者数量皮纹学特征波动性不对称的研究

本文研究了宁夏汉族男性256例(正常: 128例; 冠心病患者: 128例) 双手数量皮纹学特征及其波动性不对称, 比较了其均值的差异性。结果表明: 1)冠心病患者组与正常对照组相比较, 指纹嵴线数、指纹总嵴线数及a-b嵴线数均值均低于正常对照组; 2)冠心病患者组双手atd角及a-b间距均值均高于对照组, 双手atd角表现为显著增高(P<0.05), 右手a-b嵴线数均值表现为患者组低于对照组, 有显著性差异(P<0.01); 3)冠心病患者组数量皮纹性状波动性不对称水平与对照组在FAⅡ(a-b嵴线数, P<0.01)及FAⅤ(atd角, P<0.05)两项上表现出显著增高; 冠心病患者组a-b嵴线数FA分布在|R-L|≥7组显著增高(P<0.05)。