The fate of an oil spill in São Sebastião channel: a case study

A ruptura de um oleoduto em maio de 1994 introduziu 2.700 tons de óleo cru no Canal de São Sebastião, contaminando algumas áreas. Na ocasião um monitoramento de hidrocarbonetos em sedimentos estava sendo realizado na região, utilizando o método de cromatografia em fase gasosa/ detecção por ionização de chama. Os dados obtidos nesse monitoramento foram comparados aos resultados das amostras coletadas logo após o acidente, com o objetivo de verificar a extensão da contaminação por óleo e os lugares mais atingidos. Os dados prévios mostraram duas fontes de introdução de hidrocarbonetos: biogênica, com predomínio de plantas superiores, e antrópica, causada por atividades náuticas e esgotos. Os dados posteriores mostraram que a estação de coleta mais próxima ao oleoduto foi a mais atingida. Na sequencia, as duas estações localizadas na entrada norte do canal apresentaram as maiores concentrações de n-alcanos, sugerindo que as correntes NE, impulsionadas pelo vento, transportaram o óleo no sentido norte do canal. Sete meses depois uma destas estações, aquela situada em local de alta energia, mostrou sinais de recuperação, o que, contudo, não foi observado na outra, considerada de ambiente deposicional. Em conclusão, pode-se afirmar que análises de hidrocarbonetos são ferramentas poderosas para avaliar o destino de um óleo e que a parte norte do Canal de São Sebastião tem maior probabilidade de ser afetada na ocasião de um derrame de óleo.An oil pipeline ruptured in May 1994 and 2 700 tons of crude oil leaked into the São Sebastião Channel, affecting several neighboring areas. A program for the monitoring of hydrocarbons in sediments, using the gas chromatography / flame ionization detector methodology, was being undertaken in the area at the time. The data obtained were compared to those of samples collected after the accident to determine the fate of the oil spilled and ascertain its contribution to the environment. The earlier results showed that hydrocarbons were introduced from two different sources: biogenic, mainly from terrestrial plants, and anthropogenic, as oil, in sewage and from shipping. The later data indicated that the site closest to the pipeline rupture had been the most affected. Following that, two stations located at the north entrance of the channel presented the highest n-alkane concentrations, suggesting that the northeasterly wind-driven currents had carried the oil northward. Seven months later, one of these stations, a high-energy site, showed some signs of recovery, but this process was not observed at the other, which seemed to be a low-energy site. In conclusion, the data showed that the aliphatic hydrocarbon analyses were powerful tools for the assessment of the fate of the oil spill and that the northern part of the São Sebastião Channel is more subject to the effects of oil spills

Four-year survey of dissolved/dispersed petroleum hydrocarbons on surface waters of Admiralty Bay, King George Island, Antarctica

Seawater from 8 stations in Admiralty Bay was systematically sampled during the summer of 1994, 1995, 1996 and 1997 and analyzed by spectrofluorimetry to measure dissolved/dispersed petroleum hydrocarbons (DDPHs). The purpose of this study was to detect some temporal and spatial changes in terms of oil contamination of the region. The results indicate low levels of oil pollution with relatively high concentrations near the research stations located in the study area. During the summers of 1995 and 1996 the average concentrations for individual stations were low and below of 0.50 ¼g.L-1. Summers of 1994 and 1997 had relatively higher average concentrations (up to 1.57 ¼g.L-1), mainly in front of Arctowski and Ferraz Research Stations.Amostras de água na Baía do Almirantado, Península Antártica, foram sistematicamente coletadas em 8 estações durante os verões de 1994 a 1997 onde foram analisados hidrocarbonetos do petróleo dispersos e dissolvidos por espectrofluorescência. O objetivo foi avaliar variações temporais e espaciais em termos de contaminação por óleo na região. Os resultados em geral indicam baixos níveis de poluição embora tenham sido verificadas algumas concentrações relativamente maiores nas proximidades das estações de pesquisa fixadas na região de estudo. Durante os anos de 1995 e 1996 a média das concentrações foram baixas e menores que 0,50 ¼g.L-1 para os pontos individuais. Os verões de 1994 e 1997 tiveram concentrações médias mais elevadas (até 1,57 ¼g.L-1), e os maiores valores foram nas proximidades das estações brasileira e polonesa

The Fate of an oil Spill In São Sebastião Channal: A case study

An oil pipeline ruptured in May 1994 and 2 700 tons of crude oil leaked into the São Sebastião Channel, affecting several neighboring areas. A program for the monitoring of hydrocarbons in sediments, using the gas chromatography / flame ionization detector methodology, was being undertaken in the area at the time. The data obtained were compared to those of samples collected after the accident to determine the fate of the oil spilled and ascertain its contribution to the environment. The earlier results showed that hydrocarbons were introduced from two different sources: biogenic, mainly from terrestrial plants, and anthropogenic, as oil, in sewage and from shipping. The later data indicated that the site closest to the pipeline rupture had been the most affected. Following that, two stations located at the north entrance of the channel presented the highest n-alkane concentrations, suggesting that the northeasterly wind-driven currents had carried the oil northward. Seven months later, one of these stations, a high-energy site, showed some signs of recovery, but this process was not observed at the other, which seemed to be a low-energy site. In conclusion, the data showed that the aliphatic hydrocarbon analyses were powerful tools for the assessment of the fate of the oil spill and that the northern part of the São Sebastião Channel is more subject to the effects of oil spills

Intratidal variability and transport of petroleum aromatic hydrocarbons in an anthropized tropical estuarine system: the Suape estuary (8.4S 35W)

A instalação do Complexo Industrial Portuário de Suape (CIPS) modificou algumas características físicas, químicas e biológicas do Estuário de Suape. Este estudo apresenta a primeira caracterização física deste sistema, focando na hidrodinâmica local, transporte de materiais e a influência destes sobre algumas propriedades locais. Os parâmetros físicos também foram associados aos hidrocarbonetos de petróleo dissolvidos e/ou dispersos (HPDDs). Durante um ciclo completo de maré (13 h), foram registrados o nível, fluxo e propriedades da água (salinidade, temperatura, material em suspensão - MS -, clorofila e oxigênio dissolvido), além da velocidade e direção das correntes, usando ADCP e CTD. Os HPDDs foram investigados nas águas superficiais e de fundo, através de espectrofluorescência. Os resultados revelaram uma estrutura vertical homogênea, um regime de maré semidiurno e um padrão térmico diurno. As concentrações de HPDDs na superfície e no fundo são baixas e similares, devido à ação da maré. A fonte mais provável é o CIPS, uma vez que o transporte residual dos hidrocarbonetos de petróleo, da clorofila e do oxigênio dissolvido são no sentido do estuário do Massangana. Um padrão oposto foi observado para o transporte residual da salinidade e MS, no sentido da lagoa. Estes resultados indicam que a hidrodinâmica local é essencial para entender o transporte e troca de materiais entre os vários segmentos do estuário. Estudos mais completos são necessários para se obter conclusões mais consistentes.The Suape Estuary encompasses the Suape Industrial Port Complex (SIPC), a major industrial development in Brazil's Northeast region, which, in order to be implanted, caused drastic environmental changes in this system. This study presents the first physical characterization of the Suape estuarine system, focusing on the local hydrodynamics, material transport and its influence on some specific properties. Physical properties were also associated to dissolved dispersed petroleum hydrocarbons (DDPHs). A study was undertaken during a complete semi-diurnal tidal cycle (13 hr), during which water level, water flow, current velocity and direction, water properties (salinity, temperature, suspended particulate matter - SPM -, chlorophyll and dissolved oxygen) were recorded using ADCP and CTD systems. The DDPHs were investigated in surface and bottom waters, by spectrofluorescence, using Carmópolis oil and chrysene as analytical standards. Results showed a well-mixed vertical structure, a semi-diurnal tide regime and a diurnal thermal pattern. There was no statistical difference between DDPH concentrations at surface and bottom, due to the tide acting as an important homogenizer. DDPHs were low and the main contribution seems to be that from SIPC, as the residual transport of DDPHs, chlorophyll and dissolved oxygen, was towards the Massangana estuary. An opposite pattern was observed for salinity and SPM, whose residual transport was towards the lagoon. The results pointed local hydrodynamics as an essential tool for understanding material transport and exchanges among the estuarine segments. A longer time series should be studied in order to obtain more robust conclusions

Molecular mass and optical characterization of size-fractionated CDOM in riverine to marine transition zone

One of the most important natural sunlight absorbing substances in water is the chromophoric dissolved organic material (CDOM).Two series of CDOM samples from two Southwest Florida Rivers (Caloosahatchee (CR) and Shark (SR)) were characterized in terms of molecular mass (MM) and diffusion coefficients (D) by FIFO-FIFFF with absorbance and fluorescence detectors. The SR receives DOM from the Everglades and, by contrast, the CR arises from Lake Okeechobee in central Florida, and receives anthropogenic inputs and farming run-off. Both rivers extend to the Gulf of Mexico. Fluorescence identified, for both rivers, two different MM distributions in low salinity water samples: the first was centered at ∼1.7 kDa (CR) and ∼2 kDa (SR); the second, which gradually disappeared in the river plumes to below the detection limit in coastal waters, centered at ∼13 kDa for both rivers. Absorbance detected only one MM distribution centered at ∼2 kDa (CR) and 2.2--2.4 kDa (SR). Fluorescence in general peaked at a lower MM than absorbance, suggesting a different size distribution for fluorophores vs. chromophores. The differences observed between the rivers in the optical characteristics, MM distributions and D values suggest that the CDOM inputs, mixing rates, and photochemical degradation processes are different for these two rivers.During the year 2001 three cruises were undertaken in the coastal waters of Southwest Florida: one in the dry period (June) and two during the rainy season (September and November). The CDOM water samples collected during these cruises were characterized in terms of MM distribution and optical characteristics. On the basis of the results, water mass mixing seems to be the dominant factor in the area, but evidence of different sources of CDOM and degradation processes were observed. During the dry season the MM distribution did not change significantly and was centered at ∼1.4 kDa for chromophores and ∼1.1 kDa for fluorophores. Results suggest that chromophores were broken down to smaller MM compounds faster than fluorophores, indicating that the fluorescence moieties are more resistant to degradation/removal processes than the non-fluorescing compounds, even though the fluorophores were always centered at lower MM. The differences in the optical characteristics, MM distributions, and C concentration observed suggest that the CDOM sources, physical, and photochemical degradation processes change seasonally. (Abstract shortened by UMI.)</p

Molecular mass and optical characterization of size-fractionated CDOM in riverine to marine transition zone

One of the most important natural sunlight absorbing substances in water is the chromophoric dissolved organic material (CDOM).Two series of CDOM samples from two Southwest Florida Rivers (Caloosahatchee (CR) and Shark (SR)) were characterized in terms of molecular mass (MM) and diffusion coefficients (D) by FIFO-FIFFF with absorbance and fluorescence detectors. The SR receives DOM from the Everglades and, by contrast, the CR arises from Lake Okeechobee in central Florida, and receives anthropogenic inputs and farming run-off. Both rivers extend to the Gulf of Mexico. Fluorescence identified, for both rivers, two different MM distributions in low salinity water samples: the first was centered at ∼1.7 kDa (CR) and ∼2 kDa (SR); the second, which gradually disappeared in the river plumes to below the detection limit in coastal waters, centered at ∼13 kDa for both rivers. Absorbance detected only one MM distribution centered at ∼2 kDa (CR) and 2.2--2.4 kDa (SR). Fluorescence in general peaked at a lower MM than absorbance, suggesting a different size distribution for fluorophores vs. chromophores. The differences observed between the rivers in the optical characteristics, MM distributions and D values suggest that the CDOM inputs, mixing rates, and photochemical degradation processes are different for these two rivers.During the year 2001 three cruises were undertaken in the coastal waters of Southwest Florida: one in the dry period (June) and two during the rainy season (September and November). The CDOM water samples collected during these cruises were characterized in terms of MM distribution and optical characteristics. On the basis of the results, water mass mixing seems to be the dominant factor in the area, but evidence of different sources of CDOM and degradation processes were observed. During the dry season the MM distribution did not change significantly and was centered at ∼1.4 kDa for chromophores and ∼1.1 kDa for fluorophores. Results suggest that chromophores were broken down to smaller MM compounds faster than fluorophores, indicating that the fluorescence moieties are more resistant to degradation/removal processes than the non-fluorescing compounds, even though the fluorophores were always centered at lower MM. The differences in the optical characteristics, MM distributions, and C concentration observed suggest that the CDOM sources, physical, and photochemical degradation processes change seasonally. (Abstract shortened by UMI.

Petroleum hydrocarbons in Brazilian Northeast continental shelf waters: baseline values Br

Water quality on the continental shelf off the eastern Brazilian Northeast region was investigated in two oceanographic campaigns during winter and summer, when vertical profiles of salinity, temperature, turbidity, chlorophyll and dissolved oxygen were recorded. Dissolved / dispersed petroleum hydrocarbons (DDPH) were also analyzed in sub-superficial water samples using fixed wavelength fluorescence spectroscopy methods. Shelf waters are dominated by Tropical Waters, with high salinity (&gt; 36.5 g kg-1) and temperature (&gt; 26 °C) and little continental influence. Turbidity was higher during winter, which may be due to the higher continental contribution and/or higher wave action. Chlorophyll was mostly &lt; 1 µg L-1&nbsp;and dissolved oxygen saturation was predominantly high (&gt; 90%), but innermost costal stations were influenced by the Capibaribe estuary. Median DDPH concentrations were as low as 0.07 and 0.04 µg L-1&nbsp;Carmópolis oil equivalents during winter and summer respectively, and 0.02 µg L-1&nbsp;chrysene equivalent for both periods. An exception was observed off Suape Harbor (0.35 µg L-1&nbsp;Carmópolis oil equiv. and 0.13 µg L-1&nbsp;chysene equiv.), suggesting navigation activities as the main local source. The overall DDPH median of 0.06 μg L-1&nbsp;Carmópolis oil equivalents and 0.02 μg L-1&nbsp;chrysene equivalents are proposed as the baseline concentration for non-polluted coastal water for the tropical western Atlantic Ocean margin

Four-year survey of dissolved/dispersed petroleum hydrocarbons on surface waters of Admiralty Bay, King George Island, Antarctica

Seawater from 8 stations in Admiralty Bay was systematically sampled during the summer of 1994, 1995, 1996 and 1997 and analyzed by spectrofluorimetry to measure dissolved/dispersed petroleum hydrocarbons (DDPHs). The purpose of this study was to detect some temporal and spatial changes in terms of oil contamination of the region. The results indicate low levels of oil pollution with relatively high concentrations near the research stations located in the study area. During the summers of 1995 and 1996 the average concentrations for individual stations were low and below of 0.50 ¼g.L-1. Summers of 1994 and 1997 had relatively higher average concentrations (up to 1.57 ¼g.L-1), mainly in front of Arctowski and Ferraz Research Stations.Amostras de água na Baía do Almirantado, Península Antártica, foram sistematicamente coletadas em 8 estações durante os verões de 1994 a 1997 onde foram analisados hidrocarbonetos do petróleo dispersos e dissolvidos por espectrofluorescência. O objetivo foi avaliar variações temporais e espaciais em termos de contaminação por óleo na região. Os resultados em geral indicam baixos níveis de poluição embora tenham sido verificadas algumas concentrações relativamente maiores nas proximidades das estações de pesquisa fixadas na região de estudo. Durante os anos de 1995 e 1996 a média das concentrações foram baixas e menores que 0,50 ¼g.L-1 para os pontos individuais. Os verões de 1994 e 1997 tiveram concentrações médias mais elevadas (até 1,57 ¼g.L-1), e os maiores valores foram nas proximidades das estações brasileira e polonesa

The mysterious oil spill in the northeastern coast of Brazil: tracking offshore seawater and the need for improved vessel facilities

A scientific cruise between November 15 and December 18, 2019 aboard R/V Vital de Oliveira collected offshore seawater samples at 59 stations between the states of Ceará and Bahia. The objective was to identify hydrocarbon levels potentially associated with the mysterious oil spill that reached the northeastern coast of Brazil. Median concentrations of aliphatic hydrocarbons (AHs, 0.79 µg L-1) and polycyclic aromatic hydrocarbons (PAHs, 5.39 ng L-1) do not indicate contamination by crude oil and are comparable to baseline levels previously found in other areas of the Brazilian continental margin. The detailed composition of both groups of hydrocarbons revealed that some samples were contaminated during sampling and/or handling on-board. The data set presented herein highlights the difficulty in tracking small oil patches spread over a huge ocean area and, more importantly, the need for improving protocols of national research vessels used to collect seawater samples for trace organic analyses