Análise da dispersão de óleo no Estuário de Santos através de um modelo hidrodinâmico e lagrangeano

O porto de Santos, maior complexo portuário da América Latina, possui uma intensa movimentação de embarcações, necessária ao comércio nacional e internacional. O porto e seu canal de navegação estão inseridos no Sistema Estuarino de Santos (SES), que banha alguns municípios da Baixada Santista. Os estuários possuem grande importância ecológica, pois funcionam como berçários para espécies aquáticas, e econômica, ao oferecerem fonte de renda para pescadores locais. Esses ambientes têm sofrido pressões antrópicas, como o despejo de efluentes e de contaminantes no corpo aquático, ocasionando degradação ambiental, perda de hábitats e até riscos à saúde humana. O derrame de óleo combustível no mar em águas costeiras tem gerado muita preocupação ambiental e pode ocorrer por abalroamento ou encalhe de navio, falhas de equipamentos, em operações de carga/descarga de navios petroleiros, dentre outros. Assim, o presente trabalho tem como objetivo identificar o destino do óleo, no caso de possíveis vazamentos dentro do SES em diversos cenários, através da modelagem computacional, contribuindo para o gerenciamento ambiental. A partir dos resultados de um modelo hidrodinâmico, foi implementado um modelo de transporte lagrangeano e realizadas seis simulações de derramamento de óleo em quatro pontos estratégicos. Considerou-se dois períodos (verão e inverno) e três condições atmosféricas distintas (vento de SSW, vento de NE e ausência de vento). Os resultados mostraram que as partículas lançadas dentro do estuário encalharam rapidamente na costa e sofreram maior influência do vento, enquanto a trajetória das partículas lançadas na Baía de Santos variou sazonalmente e sofreu maior influência da hidrodinâmica local. Ademais, as áreas afetadas pelas manchas de óleo nas simulações foram identificadas, as quais possuem alta sensibilidade ambiental e necessitam de proteção prioritária em caso de acidentes com derramamento de óleo, destacando-se a importância da elaboração dos planos de contingência. Estudos futuros são necessários para delimitar regiões de maior probabilidade de impacto por derramamento de óleo e também para entender outros cenários possíveis.The Santos Port is the largest port complex in Latin America, and has an intense movement of vessels, necessary for national and international trade. The port and its navigation channel are part of the Santos Estuarine System, which bathes some cities of Baixada Santista. Estuaries are of great ecological importance, since they function as nurseries for aquatic species, and economically, as they provide a source of income for local fishermen. These environments have suffered anthropic pressures, such as the discharge of effluents and contaminants into the water body, causing environmental degradation, loss of habitats and even risks to human health. The spillage of fuel oil in the sea and coastal waters is of great environmental concern and can occur due to the collision or stranding of a ships, equipment failures, during loading/unloading operations of oil tankers, among others. Thus, the present work aims to identify the fate of the oil, in the case of possible leaks within the Santos Estuarine System in different scenarios, by using computational modeling, and seeks to contribute to environmental management. Based on the results of a hydrodynamic model, a Lagrangian transport model was implemented and six oil spill simulations were performed at four strategic points. Two periods (summer and winter) and three different atmospheric conditions (SSW wind, NE wind and no wind) were considered. The results showed that the particles released into the estuary ran aground quickly on the coast and showed greater influence by the wind, while the trajectory of the particles released in Santos Bay varied seasonally and were more influenced by local hydrodynamics. Moreover, the areas affected by oil slicks in the simulations were identified, which have high environmental sensitivity and need priority protection in case of oil spill accidents, this highlighs the importance of drawing up contingency plans. Future studies are needed to delimit regions with greater probability of impact by oil spills and also to understand other possible scenarios

Monitoring of phytoplankton in a subtropical estuarine system through traditional taxonomic, functional diversity and microscopy-imaged-based classification tools.

12th International Phycological Congress, 2021 Também disponível em: (2021) 12th International Phycological Congress, Phycologia, 60:sup1, 74-74, ISSN: 0031-8884 DOI: 10.1080/00318884.2021.1922050Estuarine systems are under human activities pressure that may lead to changes in the structure of planktonic community. Given its importance as the basis of food webs and their rapid responses to environmental changes, phytoplankton is fundamental to understanding the effects of these changes on the general plankton community. The Santos Estuarine System (SES), Brazil, receives a high load of pollutants from petrochemical and fertilizer industries, as well as hosts one of the largest ports in Latin America. The present study aims to establish the bases for the implementation of long-term monitoring programs in this ecosystem combining classical monitoring methods (variation of chlorophyll biomass and taxonomic composition), with methodologies based on functional diversity (Convex hull) and on Microscopy-Imaged-based Classification Tools of plankton. Considering previous dataset from SES, computer vision techniques were employed to perform steps of object identification, filtering and feature extraction in order to obtain the final dataset. The developed software is open-source and available under the MIT license. From March 2020 (except in April and May due to COVID-19 pandemic), monthly surveys are being performed in four stations through the navigation channel of SES. Preliminary results showed dominance of filamentous cyanobacteria during raining/freshwater-influence periods and of diatoms under brackish and seawater-influence conditions. Salinity gradient was also a stressor condition resulting in changes in functional diversity index (FDis, FEve and FRic). Microscopy-Imaged-based Classification first results obtained a mean accuracy of 83.88% considering 4 classes, and 76.67% considering 13 classes.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP: 2018/25816-