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1.
Saúde debate ; 48(spe1): e8513, 2024. tab, graf
Artigo em Português | LILACS-Express | LILACS | ID: biblio-1576872

RESUMO

RESUMO Em agosto de 2019, 11 estados brasileiros foram atingidos por um extenso derramamento de petróleo. Nesse contexto, quais os principais impactos socioambientais e psicossociais causados pelo derramamento de petróleo na vida de famílias e indivíduos que vivem da pesca artesanal? Trata-se de uma pesquisa com métodos mistos que utilizou como técnicas: grupo focal e aplicação de formulários desenvolvidos de forma participativa com comunidades da foz do rio Jaguaribe, Ceará, e efetuados entre julho e agosto de 2020. Sua aplicação foi selecionada a partir de uma amostragem não probabilística do tipo intencional por julgamento, cujos dados foram processados com o suporte do software IBM Statistical Package for Social Sciences (SPSS). Os resultados indicam impactos ambientais, como: presença de óleo no rio e em animais; exposição humana direta ao petróleo; sintomas na saúde após exposição; efeitos psicológicos; consumo de recursos alimentares como peixes e crustáceos; e redução da renda dos Pescadores e Pescadoras Artesanais. Assim, compreende-se que a vida, o ambiente, a saúde e o trabalho dessas populações foram agravados, principalmente aqueles de ordens socioeconômicas, de segurança alimentar e hídrica e de saúde.


ABSTRACT In August 2019, eleven Brazilian states were hit by an extensive oil spill. In this context: what are the main socio-environmental and psychosocial impacts caused by the oil spill on the lives of families and individuals who make their living from artisanal fishing? This is a research with mixed methods that used the following techniques: focus group and application of forms developed in a participatory manner with communities at the mouth of the Jaguaribe River, Ceará, and applied between July and August 2020. Its application was selected from a non-probabilistic sampling of the intentional type by judgment and was processed with the support of the IBM Statistical Package for Social Sciences (SPSS) software. The results indicate environmental impacts, such as: finding oil in the river and in animals; direct human exposure to oil; health symptoms after exposure; psychological effects; consumption of food resources such as fish and shellfish; and reduction in the income of Artisanal Fishermen and Fisherwomen. That way, it is understood that the lives, environment, health, and work of these populations were aggravated, especially those of socioeconomic, food and water security, and health orders.

2.
Ciênc. Saúde Colet. (Impr.) ; Ciênc. Saúde Colet. (Impr.);29(7): e03612024, 2024. tab
Artigo em Português | LILACS-Express | LILACS | ID: biblio-1564288

RESUMO

Resumo Objetivou-se analisar os processos críticos, protetores e destrutivos do trabalho de 34 mulheres das águas nos municípios de Cabo de Santo de Agostinho e Ipojuca (PE), de fevereiro de 2021 a agosto de 2022. As etapas do processo de trabalho foram sistematizadas pelo fluxograma do trabalho e organizadas na matriz de processos críticos de Breilh. Os processos destrutivos, no domínio geral, foram: injustiça e vulnerabilização socioambiental como modelo de desenvolvimento econômico, o Complexo Industrial Portuário de Suape, o desastre-crime de petróleo ocorrido em 2019, a pandemia de COVID-19 e dificuldade de acesso às políticas públicas; no particular: jornadas e sobrecargas de trabalho, uso de equipamentos e ferramentas rudimentares e relações desiguais de gênero, classe e raça; no singular: adoecimentos físicos, mentais e mortes. Os processos protetores, no domínio geral: os objetivos de desenvolvimento sustentável, políticas públicas de saúde e assistência social; no particular: trabalho e beneficiamento em grupo, consumo para subsistência; no singular: a pesca como processo terapêutico, prazeroso e de partilha. O estudo destacou os problemas centrais das mulheres das águas e a necessidade do estabelecimento de políticas públicas voltadas ao seu cuidado.


Abstract This study aims to analyze the protective and destructive critical processes of 34 water women in the municipalities of Cabo de Santo de Agostinho and Ipojuca, Pernambuco, Brazil, from February/21 to August/22. The work process stages were systematized by the work flowchart, and we employed Breilh's critical processes matrix to organize the data. The destructive processes identified in the general domain were injustice and socio-environmental vulnerability, such as the economic development model, the Suape Industrial Port Complex, the 2019 oil spill crime disaster, the COVID-19 pandemic, and the difficult access to public policies; in the particular domain: overloads and extended working hours, use of rudimentary equipment and tools, and unequal gender, class, and race relationships; in the singular domain: physical and mental illnesses and deaths. The protective processes identified in the general domain were sustainable development objectives, public health, and social assistance policies; in the particular domain, group work and processing, consumption for subsistence; in the singular domain, fishing as a therapeutic, pleasurable, and sharing process. The study highlighted the central issues of the water women and the need to establish public policies targeting their care.

3.
Mar Pollut Bull ; 197: 115682, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37951119

RESUMO

The current case study focuses on the Environmental Sensitivity Index (ESI) mapping of Guanabara Bay, Rio de Janeiro, Brazil - a region at risk from petroleum sector pollution. By mapping 981.5 km of coastline and classifying it in 10 oil sensitivity indices, we integrated biotic resources, socioeconomic attributes, and geoenvironmental diversity into a georeferenced database. Results reveal a high oil sensitivity of the bay, with approximately 89 % of the mapped coast scoring ESI 8 and ESI 10. These scores comprise, respectively, estuarine and solid substrate habitats that are sheltered from wave action. Notably, numerous manufacturing and oil handling plants, along with intensive urbanization, also contribute to the bay's oil sensitivity. Additionally, the rich biotic diversity in the study area, particularly in protected areas housing 79 conservation units, further amplifies its environmental vulnerability. This study aims to serve as a reference for detailed ESI mapping of coastal areas in tropical rainy zones with significant environmental diversity, industrial development, and a dense population.


Assuntos
Poluição por Petróleo , Brasil , Monitoramento Ambiental/métodos , Ecossistema , Bases de Dados Factuais
4.
Mar Pollut Bull ; 197: 115676, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37897965

RESUMO

This research presents a procedure for determining the origin of marine pollution through the use of a time-direct trajectory modeling, associated with a Kriging metamodel technique and Monte Carlo random sampling. These methods were applied to a real case, specifically the oil spill that affected the Brazilian coast in the second half of 2019 and early 2020. A total of 140 trajectories, defined by the geographical coordinates of the origin and the spill date, were generated through Latin Hypercube Sampling and simulated using the PyGNOME model to construct the Kriging metamodel. The metamodel demonstrated cost-effectiveness by efficiently simulating numerous input data combinations which were compared and optimized based on available real data regarding temporal and spatial pollution distribution.


Assuntos
Poluição por Petróleo , Poluição por Petróleo/análise , Brasil , Poluição Ambiental , Geografia , Método de Monte Carlo
5.
Mar Pollut Bull ; 193: 115195, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37356128

RESUMO

A goal for conservation biologists is to show that policies enacted on behalf of an imperiled species results in direct benefits for it. In Argentina, tens of thousands of Magellanic penguins (Spheniscus magellanicus) were estimated to have died from chronic oil pollution each year through the early 1980s. From 1982 to 1990, surveys at sites along approximately 900 km of Chubut Province coastline found that >60 % of penguin carcasses had evidence of oiling in some years. In response to these findings, as well as pressure from non-governmental organizations and the public, provincial and federal authorities in Chubut moved the commercial tanker lanes 20 nautical miles farther offshore in 1997 and required oil tankers to have double hulls. During a second round of surveys in 2001, using most of the same sites as the first survey period, the number of dead and oiled penguins dropped effectively to zero. A policy change not only led to fewer oiled penguins, but also likely increased the survival of adult Magellanic penguins near some of their most significant breeding colonies in Argentina.


Assuntos
Poluição por Petróleo , Spheniscidae , Animais , Argentina , Spheniscidae/fisiologia
6.
Environ Sci Pollut Res Int ; 29(29): 43501-43515, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35386087

RESUMO

Oil spills generate several environmental impacts and have become more common with the increase in petroleum extraction, refining, transportation, and trade. In soil, oil contamination increases water and nutrient availability and compaction, directly affecting plant growth and development. Different aspects of phytotoxicity can be observed and will vary according to the characteristics of soil and plants. Oil-contaminated soil also results in negative effects on biomass and changes in leaves and roots. Investigating the effects of oil contamination on plant growth and development can aid in the conservation of plant species and in the development of techniques such as bioremediation and biomonitoring. Thus, this review aims to discuss the main effects of oil contamination on plants, such as environmental stress and morphological, physiological, and anatomical changes, and the strategies developed by plants to survive contamination, as well as to identify plants with phytoremediation potential that can assist in removing oil from the environment.


Assuntos
Poluição por Petróleo , Petróleo , Poluentes do Solo , Biodegradação Ambiental , Raízes de Plantas/química , Plantas , Solo , Poluentes do Solo/análise
7.
Mar Pollut Bull ; 175: 113334, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35091343

RESUMO

We present herein a short-term impact on marketed fisheries and human health safety in the first three months following the 2019 oil spill in Brazil. Total PAHs in the edible tissues of 34 finfish and shellfish species ranged from 8.71 to 418 ng g-1 wet weight, with robust evidence supporting crude oil contamination. A prevalence of low molecular weight PAHs was observed, mainly naphthalenes. A decreasing trend in mean total PAHs from mollusks (134 ng g-1) to crustaceans (73.9 ng g-1) and to fishes (45.3 ng g-1) was noted. The spilled oil caused immediate negative impacts on the local seafood market, despite less than 3% of samples exhibited concentrations above levels of concern, revealing a low probability for human health risks. These findings demonstrate that governments must be prepared to provide not only science-based quick responses but also effective science communication for society upon environmental disasters.


Assuntos
Poluição por Petróleo , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Animais , Brasil , Saúde Ambiental , Monitoramento Ambiental , Pesqueiros , Humanos , Poluição por Petróleo/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Alimentos Marinhos/análise , Poluentes Químicos da Água/análise
8.
Mar Pollut Bull ; 173(Pt A): 112952, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34536707

RESUMO

A large-scale oil spill has reached over 3000 km of the NE Brazilian coast since August 2019. The cause and origin of this spill remain mysterious, and the impacts on coastal ecosystems have not been clearly understood so far. Despite the efforts to remove the oil (mainly from local communities), oil stains are still present in beaches, mangroves, and beachrocks. In this short report, we describe the occurrence of the barnacle Chthamalus bisinuatus Pilsbry, 1916 colonizing oil spill stains on intertidal surfaces of beachrocks one year after the first oil records. We quickly assessed oil stains across three different reefs located at the Conde municipality, Bahia (NE Brazil), where the species was identified and its density on oil stains calculated. The occurrence of barnacles in oil stains was restricted to zones in the wake of the reefs. Their densities varied from 0 to 238 ind./dm2, with an average of 34 ± 68 ind./dm2. If we account for dead individuals (empty barnacle plates), they correspond to 25.9% of the sampled population. The presence of oil possibly affected barnacle survival rates but did not seem to prevent barnacle individuals from reaching adult sizes. We also found individuals of the snail Echinolittorina lineolata (d'Orbigny, 1840) crawling on these barnacles, indicating that the barnacle assemblages on oil stains are stable enough to provide refuge for these snails. It is not clear if the presence of barnacles on oil reflects the resistance of these crustaceans to the oil toxicity or is just a result of a low substrate selectivity by the cypris larvae.


Assuntos
Poluição por Petróleo , Thoracica , Animais , Brasil , Ecossistema , Humanos , Invertebrados
9.
Mar Pollut Bull ; 167: 112281, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33826988

RESUMO

The Brazilian oil spill, from August 2019 to January 2020, was considered the most extensive accident in tropical oceans. We estimated the concentration of oil droplets that may be available for ingestion by microzooplankton. The collection was carried out in three areas: estuarine plume, bay and reef (Tamandaré, Pernambuco coast). We highlight the contribution of coral larvae in the reef region, surpassing the copepods, evidencing a spawning event. Oil droplets were recorded in all the sampled areas, with a high numerical abundance in the plume. Traces of oil ingestion by Brachyura zoea and Calanoida, Paracalanidae and Oithonidae copepods were observed, suggesting that these groups might have an important role in the degradation and final destination of oil dispersed after spills. The vulnerability of the larval phases of crabs and reef-building corals has been hypothesized, suggesting that the negative effects of oil on zooplankton can affect the recruitment of benthic invertebrates.


Assuntos
Antozoários , Poluição por Petróleo , Animais , Brasil , Cadeia Alimentar , Oceanos e Mares
10.
Mycologia ; 111(2): 299-318, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30924725

RESUMO

Aquanectria and Gliocladiopsis are two closely related genera of Hypocreales. They are also morphologically similar, forming hyaline, penicillate conidiophores and hyaline, straight to sinuous, 0-1-septate phialoconidia. During a revision of gliocladiopsis-like isolates originating from rain forest areas of South America (Ecuador, French Guiana) and Southeast Asia (Singapore), multilocus phylogenetic inferences, based on DNA sequences encoding partial ß-tubulin (TUB2), translation elongation factor 1-α (TEF1- α), histone H3 (HIS3) genes and the nuc rDNA internal transcribed spacer region (ITS1-5.8S-ITS2 = ITS), revealed the occurrence of seven new phylogenetic species. These phylogenetic species also revealed unique combinations of phenotypes, allowing morphological distinction from their closest phylogenetic relatives. Four new species of Aquanectria and three new species of Gliocladiopsis are described and illustrated. Three of the four Aquanectria species deviate from the other species in the genus by having shorter conidia, which are in the size range observed in Gliocladiopsis species. They are placed in Aquanectria based on the phylogenetic analysis, but this also makes the morphological distinction between these two genera obsolete.


Assuntos
Hypocreales/classificação , Hypocreales/isolamento & purificação , Filogenia , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Equador , Microbiologia Ambiental , Guiana Francesa , Histonas/genética , Hypocreales/genética , Hypocreales/crescimento & desenvolvimento , Microscopia , Fator 1 de Elongação de Peptídeos/genética , RNA Ribossômico 5,8S/genética , Análise de Sequência de DNA , Singapura , Tubulina (Proteína)/genética
11.
Environ Pollut ; 225: 370-380, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28408186

RESUMO

Oil extraction activities in the Northern Peruvian Amazon have generated a long-standing socio-environmental conflict between oil companies, governmental authorities and indigenous communities, partly derived from the discharge of produced waters containing high amounts of heavy metals and hydrocarbons. To assess the impact of produced waters discharges we conducted a meta-analysis of 2951 river water and 652 produced water chemical analyses from governmental institutions and oil companies reports, collected in four Amazonian river basins (Marañon, Tigre, Corrientes and Pastaza) and their tributaries. Produced water discharges had much higher concentrations of chloride, barium, cadmium and lead than are typically found in fresh waters, resulting in the widespread contamination of the natural water courses. A significant number of water samples had levels of cadmium, barium, hexavalent chromium and lead that did not meet Peruvian and international water standards. Our study shows that spillage of produced water in Peruvian Amazon rivers placed at risk indigenous population and wildlife during several decades. Furthermore, the impact of such activities in the headwaters of the Amazon extended well beyond the boundaries of oil concessions and national borders, which should be taken into consideration when evaluating large scale anthropogenic impacts in the Amazon.


Assuntos
Monitoramento Ambiental , Indústria de Petróleo e Gás , Poluentes Químicos da Água/análise , Metais Pesados/análise , Campos de Petróleo e Gás , Peru , Rios , Poluição da Água/análise , Poluição da Água/estatística & dados numéricos
12.
Mar Pollut Bull ; 113(1-2): 94-99, 2016 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-27600275

RESUMO

Monitoring the effects of pollution on mangrove vegetation is a challenge. A specific study using an oil spill simulation on mangrove species was conducted to address this challenge. We tested the effectiveness of the chlorophyll a fluorescence kinetics as a fast and robust method to diagnose the vitality of Laguncularia racemosa. We used L. racemosa plants contaminated with marine fuel oil in mangrove microcosm models. Several parameters of the JIP-test were capable of detecting the impairment of the photosynthetic function prior to the visual manifestation of symptoms in response to oil contamination. The results support the use of the chlorophyll fluorescence transient as a reliable, fast and easy to apply diagnostic method for evaluating oil-impacted mangroves. To the best of our knowledge, it is the first time that consistent data showing photosynthetic impairment in response to oil contamination is shown for a mangrove tree species.


Assuntos
Combretaceae/efeitos dos fármacos , Monitoramento Ambiental/métodos , Óleos Combustíveis/toxicidade , Poluição por Petróleo/análise , Fotossíntese/efeitos dos fármacos , Poluentes do Solo/toxicidade , Árvores/efeitos dos fármacos , Brasil , Clorofila/metabolismo , Clorofila A , Combretaceae/crescimento & desenvolvimento , Combretaceae/metabolismo , Ecossistema , Óleos Combustíveis/análise , Modelos Teóricos , Poluentes do Solo/análise , Árvores/crescimento & desenvolvimento , Árvores/metabolismo
13.
Acta toxicol. argent ; 24(2): 87-96, set. 2016. ilus, tab
Artigo em Espanhol | LILACS | ID: biblio-837856

RESUMO

Los pingüinos de Magallanes son entre las aves marinas, la especie más afectada por la contaminación con petróleo en Chubut y Santa Cruz. Una de las consecuencias adversas de la exposición a hidrocarburos y otros contaminantes es el aumento de los niveles celulares de especies reactivas del oxígeno o estrés oxidativo, considerados herramientas útiles como biomarcadores del impacto de la exposición a contaminantes químicos peligrosos. El objetivo de este trabajo fue evaluar parámetros hematológicos y marcadores de estrés oxidativo durante la rehabilitación de tres pingüinos empetrolados provenientes del Área Natural Protegida Punta Tombo, Chubut, Argentina. Se tomaron tres muestras de sangre por individuo: la primera muestra al arribo de los pingüinos al centro de rehabilitación, la segunda una semana después y una última muestra antes de ser liberados. Se obtuvieron la cantidad total de leucocitos, la razón heterófilos/linfocitos, el hematocrito y las concentraciones de glucosa y de proteínas totales. Se analizó la actividad de la enzima catalasa, responsable de la degradación del peróxido de hidrógeno, los niveles de tioles totales no proteicos y el daño a lípidos evaluando las especies reactivas al ácido tiobarbitúrico, como indicadores de estrés oxidativo. El estudio se complementó con la obtención del peso de los pingüinos. En general, los parámetros medidos, aumentaron o se mantuvieron constantes desde la primera toma de muestra hasta la última. Si bien algunas de las variables para cada pingüino se comportaron diferentes durante el tratamiento, en general se observó una tendencia a normalizarse hacia el momento de su liberación. Se concluye que los pingüinos se liberaron en buen estado físico luego de la rehabilitación.


Magellanic penguins are among the most affected seabirds by oil contamination in Patagonia. Hydrocarbons and other pollutants cause an increase in the cellular levels of reactive oxygen species that lead oxidative stress and in this way, the evaluation of oxidative stress parameters could be useful tools as biomarkers to evaluate the exposure to hazardous chemical contaminants. The aim of the present work was to evaluate hematological parameters and oxidative stress biomarkers during the rehabilitation of three oil-spill penguins from Punta Tombo Natural Protected Area in Chubut, Argentina. Three blood samples were taken from each individual, the first sample was obtained at arrival of penguin to the rehabilitation center, the second one was the following one week and last sample was taken before animals were freed. Hematocrit, white blood cell count, heterophil/ lymphocyte ratio as a measure of stress, and concentrations of glucose and total proteins were determined. The thiobarbituric acid reactive species, a well-established method for monitoring lipid peroxidation, the activity of catalase enzyme (involved in the catabolism of hydrogen peroxide) and the thiol levels were evaluated as oxidative stress indicators. In general, the measured parameters remained constant or increased their values from the first to the last blood sampling. While some of the variables for each penguin behaved differently during treatment, generally they tended to normalize when penguins were released. We conclude that penguins were released in good physical condition after rehabilitation.


Assuntos
Animais , Estresse Oxidativo , Poluição por Petróleo/efeitos adversos , Spheniscidae/sangue , Argentina , Biomarcadores/análise , Ecotoxicologia/métodos
14.
Front Microbiol ; 6: 1325, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26648916

RESUMO

Following the Deepwater Horizon (DWH) spill in 2010, an enormous amount of oil was observed in the deep and surface waters of the northern Gulf of Mexico. Surface waters are characterized by intense sunlight and high temperature during summer. While the oil-degrading bacterial communities in the deep-sea plume have been widely investigated, the effect of natural sunlight on those in oil polluted surface waters remains unexplored to date. In this study, we incubated surface water from the DWH site with amendments of crude oil, Corexit dispersant, or both for 36 days under natural sunlight in the northern Gulf of Mexico. The bacterial community was analyzed over time for total abundance, density of alkane and polycyclic aromatic hydrocarbon degraders, and community composition via pyrosequencing. Our results showed that, for treatments with oil and/or Corexit, sunlight significantly reduced bacterial diversity and evenness and was a key driver of shifts in bacterial community structure. In samples containing oil or dispersant, sunlight greatly reduced abundance of the Cyanobacterium Synechococcus but increased the relative abundances of Alteromonas, Marinobacter, Labrenzia, Sandarakinotalea, Bartonella, and Halomonas. Dark samples with oil were represented by members of Thalassobius, Winogradskyella, Alcanivorax, Formosa, Pseudomonas, Eubacterium, Erythrobacter, Natronocella, and Coxiella. Both oil and Corexit inhibited the Candidatus Pelagibacter with or without sunlight exposure. For the first time, we demonstrated the effects of light in structuring microbial communities in water with oil and/or Corexit. Overall, our findings improve understanding of oil pollution in surface water, and provide unequivocal evidence that sunlight is a key factor in determining bacterial community composition and dynamics in oil polluted marine waters.

15.
Environ Sci Pollut Res Int ; 22(20): 15294-306, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25647496

RESUMO

The Patagonian coast is characterized by the existence of pristine ecosystems which may be particularly sensitive to oil contamination. In this study, a simulated oil spill at acute and chronic input levels was carried out to assess the effects of contamination on the macrobenthic community structure and the bioturbation activity of sediments sampled in Caleta Valdés creek. Superficial sediments were either noncontaminated or contaminated by Escalante crude oil and incubated in the laboratory for 30 days. Oil contamination induced adverse effects on macrobenthic community at both concentrations with, for the highest concentration, a marked decrease of approximately 40 and 55 % of density and specific richness, respectively. Besides the disappearance of sensitive species, some other species like Oligochaeta sp. 1, Paranebalia sp., and Ostracoda sp. 2 species have a higher resistance to oil contamination. Sediment reworking activity was also affected by oil addition. At the highest level of contamination, nearly no activity was observed due to the high mortality of macroorganisms. The results strongly suggest that an oil spill in this protected marine area with no previous history of contamination would have a deep impact on the non-adapted macrobenthic community.


Assuntos
Ecossistema , Sedimentos Geológicos , Poluição por Petróleo , Animais , Argentina , Crustáceos , Oligoquetos , Petróleo
16.
J Geophys Res Oceans ; 120(12): 8364-8380, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27774370

RESUMO

When wind speeds are 2-10 m s-1, reflective contrasts in the ocean surface make oil slicks visible to synthetic aperture radar (SAR) under all sky conditions. Neural network analysis of satellite SAR images quantified the magnitude and distribution of surface oil in the Gulf of Mexico from persistent, natural seeps and from the Deepwater Horizon (DWH) discharge. This analysis identified 914 natural oil seep zones across the entire Gulf of Mexico in pre-2010 data. Their ∼0.1 µm slicks covered an aggregated average of 775 km2. Assuming an average volume of 77.5 m3 over an 8-24 h lifespan per oil slick, the floating oil indicates a surface flux of 2.5-9.4 × 104 m3 yr-1. Oil from natural slicks was regionally concentrated: 68%, 25%, 7%, and <1% of the total was observed in the NW, SW, NE, and SE Gulf, respectively. This reflects differences in basin history and hydrocarbon generation. SAR images from 2010 showed that the 87 day DWH discharge produced a surface-oil footprint fundamentally different from background seepage, with an average ocean area of 11,200 km2 (SD 5028) and a volume of 22,600 m3 (SD 5411). Peak magnitudes of oil were detected during equivalent, ∼14 day intervals around 23 May and 18 June, when wind speeds remained <5 m s-1. Over this interval, aggregated volume of floating oil decreased by 21%; area covered increased by 49% (p < 0.1), potentially altering its ecological impact. The most likely causes were increased applications of dispersant and surface burning operations.

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