O Estuário de Paranaguá é um dos ambientes mais importantes da costa Sul-Americana. A ocupação urbana, a pesca, o turismo, as indústrias, a introdução de esgoto e o principal porto de exportação de grãos do Brasil são fontes de impactos ambientais. As fontes de matéria orgânica sedimentar foram avaliadas através das concentrações de esteróis, obtidas por cromatografia gasosa acoplada à espectrometria de massas (GC-MS). Os níveis de coprostanol foram comparativamente baixos, exceto próximo da cidade de Paranaguá, onde as altas concentrações indicaram contaminação de esgotos. A análise de componentes principais mostrou a distinção entre os esteróis de origem marinha (colesterol, colestanol, estigmasterol e campesterol), fecal (coprostanol e epicoprostanol) e aportes terrígenos (β-sitosterol). A composição dos esteróis nos sedimentos indicou predomínio de matéria orgânica marinha associada ao fitoplâncton. Contribuições terrígenas foram verificadas próximas a manguezais, rios e pequenas baías não contaminadas. Contribuição de esgotos é restrita ao entorno da cidade de Paranaguá.The Paranaguá Estuarine System is one of the most important environments of the South American coast. Fishing, urban and tourist activities, industries, sewage and the main shipping port for the export of grains in Brazil are sources of environmental impacts. The sources of sedimentary organic matter were evaluated by sterol concentrations which were obtained by gas chromatography with a mass spectrometer (GC-MS). The coprostanol levels were comparatively low, except at sites close to Paranaguá City, where high concentrations have shown sewage contamination. The principal component analysis showed the distinction between sterols from marine (cholesterol, cholestanol, stigmasterol and campesterol), fecal (coprostanol and epicoprostanol) and terrigenous inputs (β-sitosterol). The sterol composition of the sediments indicated that the estuary system is an embayment dominated by inputs of marine organic matter associated with phytoplankton. Terrestrial inputs were detected only at sites close to mangroves, uncontaminated rivers and semi-closed inlets. Fecal input is restricted around Paranaguá City.Keywords: sterols, sediments, sewage, Paranaguá Bay, organic matter
IntroductionThe Paranaguá Estuarine System (25°30'S; 48°25'W) is the third most important estuarine environment of the Brazilian coast. Its economic importance is related to fishing activities, urban and tourist areas and industries, associated with fertilizer plants, fuel terminal and the main shipping port for the export of grains in South American, being the third most important in loading and unloading operations with 22,563,975 ton (in 2008).1 The estuary is encompassed by an Environmental Protection Area (EPA) and has a major ecological function, grouping at least ten conservation units, with a great diversity of environments such as islands, mangroves, salt marshes, rivers, tidal creeks, rocky shores and sand beaches. Despite the ecological and economic importance of the Parana...