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

Abstract

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. R E S U M OA 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.

Cetaceans along the southeastern Brazilian coast: occurrence, distribution and niche inference at local scale

“…The state of São Paulo (∼24 • S) is the most developed throughout the Brazilian coast, hosting the largest port in Latin America (CODESP, 1992) and the largest terrestrial oil reservoir (Zanardi-Lamardo, Bícego & Weber, 2013), with the outcome of an intense traffic of large ships along its shore, where conflicts on the use of space with cetaceans have been turning into a cause of concern (Santos et al, 2010;Figueiredo et al, 2017). As of April 2020, 30 cetacean species were recorded along the shore of the quoted state (Santos et al, 2010;Santos & Figueiredo, 2016), considering year-round residents such as Guiana (Sotalia guianensis) and franciscana (Pontoporia blainvillei) dolphins, seasonal visitors such as the southern right (Eubalaena australis) and the humpback (Megaptera novaeangliae) whales, and strays from their original areas of distribution, such as several beaked whales and blackfish.…”

A vessel collision report for Bryde's whales (Balaenoptera brydei) off the northern coast of São Paulo, Brazil

“…This all occurs close to São Sebastião Port, where intense tourism and fishing activities take place, along with oil and natural gas exploration, under way since the 1970s (Zanardi‐Lamardo, Bícego & Weber, 2013). It is also en route to Santos Port, the busiest port in Brazil.…”

Temporal variation of the gammaridean fauna (Crustacea, Amphipoda) associated with the sponge Mycale angulosa (Porifera, Demospongiae) in southeastern Brazil

“…There may be differences in contamination among the sites where these sponges were collected in the two studies. These differences may be related to the presence of the oil terminal located in the São Sebastião Channel, and to heavy traffic of ships and tourist boats, which may contaminate the water and sediment with heavy metals and petroleum hydrocarbons (Zanardi-Lamardo et al, 2013). In addition, there is high organic contamination in Araçá Bay, also situated in São Sebastião (Amaral et al, 2010).…”