Distribution and sources of phytosterols in coastal and river sediments of south central Chile

Abstract

ABSTRACT. Phytosterols are potential endocrine-disrupting compounds. Quantification of phytosterols was carried out in sediments from four coastal zones and two rivers in south-central Chile. Sterol concentrations were determined by capillary gas chromatography-mass spectrometry and the sources of sedimentary organic matter were determined using sterol ratios and lipid biomarkers. Total sterol concentrations (0.03 to 10.4 µg g -1 ) were within the range reported for other marine ecosystems and the β-sitosterol concentration (0.01 to 2.01 µg g -1 ) was lower than previously reported for the upwelling system off Peru. Some coastal stations adjacent to the rivers had β-sitosterol of terrestrial origin. High concentrations of β-sitosterol were also found in sediments from more oceanic stations, supporting the notion that this sterol can also be produced by phytoplankton. No differences in the sterol concentration between the coastal zones were found. However, significant differences were found between almost all coastal zones and both rivers, and between rivers. At the station level and using different biomarkers of the source of organic matter, some areas were found to have a clear terrestrial influence; whereby it is assumed that the source of the phytosterols (especially β-sitosterol) would be vascular plants. The BioBío River and its mouth have a wide variety of sterols and lipids and high levels of cholesterol and epicholestanol, which is possibly related to the presence of domestic effluents derived from large cities. No clear spatial pattern emerge between the location of pulp mill industries and β-sitosterol sediment concentration, with the exception of one station located in the Gulf of Arauco. Keywords: phytosterols, biomarkers, endocrine disruption, pulp mill, Chile. Distribución y fuentes de fitoesteroles en sedimentos costeros y de ríos del centro-sur de Chile RESUMEN. Los fitoesteroles son potenciales disruptores endocrinos. Se cuantificaron fitoesteroles en sedimentos de cuatro zonas costeras y dos ríos en el centro-sur de Chile. Se determinó la concentración de esteroles utilizando cromatografía de gas con espectrómetro de masa y las fuentes de materia orgánica sedimentaria se determinaron utilizando proporciones de esteroles y biomarcadores lipídicos. Las concentraciones de esteroles totales (0,03 a 10,4 µg g -1 ) se encuentran dentro del rango informado para otros ecosistemas marinos y la concentración de β-sitosterol (0,01 a 2,01 µg g -1 ) fue menor que la previamente informada para el sistema de surgencia de Perú. Algunas estaciones costeras adyacentes a los ríos presentaron β-sitosterol de origen terrestre. Además se encontró una alta concentración de este compuesto en sedimentos de estaciones más oceánicas, confirmando que este esterol también puede ser producido por fitoplancton. Al considerar la concentración y presencia-ausencia de esteroles en sedimentos, no fue posible encontrar diferencias significativas entre las cuatro áreas costeras. Sin embargo, se obtuvo una clara diferencia entre la...

Methane-related community of a carbonate-enriched pockmark, Brazilian Southeastern continental slope

“…The marine by-products of hydrocarbon metabolization include the sterols, whose total concentration was low compared to other marine sediments such as coastal South-Central Chile (Saavedra et al, 2014). Sitosterol and stigmasterol concentrations were inferior to compared to the East China Sea Shelf (Jeng and Huh, 2004).…”

“…Sitosterol and stigmasterol concentrations were inferior to compared to the East China Sea Shelf (Jeng and Huh, 2004). Interestingly, stigmasterol and its precursor β-sitosterol are both constituents of sphingosine from marine sponge Myxilla sp carbon skeleton (Bunyola et al, 2017), and of marine fish muscle (Ozogul et al, 2015), crustaceans, and mollusks (Pakrashi et al, 1989;Ozogul et al, 2015), given that they are produced by phytoplankton, microalgae, cyanobacteria, and terrestrial vascular plants (Volkman 1986;Saavedra et al, 2014). Sterols and hydrocarbons are recalcitrant molecules often used as tracers of biogenic material origin and transformation processes in the environment (Gagosian and Nigrelli 1979;Saavedra et al, 2014).…”

Endocrine disruption in aquatic species of Chile

“…Sediments were studied in the Biobío river basin, where secondary treatment PPMEs are discharged into the Laja, Biobío, and Vergara Rivers (Hernández et al 2013) and in the discharge locations of nine STPs distributed along the Pacific Ocean coastline of the Biobío Region (Bertin et al 2011). Finally, sediments were collected from coastal areas (Itata river canyon, Coliumo Bay, Biobío river canyon, and Gulf of Arauco) and the Itata and Biobío river basins (Saavedra et al 2014) (Fig. 3).…”

“…Some coastal stations adjacent to rivers presented β-sitosterol of terrestrial origin and a high concentration of this compound (which can be produced by phytoplankton) was found in sediments from more oceanic stations. Samples of sediments from the Biobío River and its mouth have a wide diversity of sterols and lipids and high levels of cholesterol and epicholestanol, possibly related to domestic effluents from large cities (Saavedra et al 2014) (Table 7).…”