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Faecal sterols and stable isotopes (δ 13 C and δ 15 N) from bulk organic matter (OM) were analysed in three sedimentary cores collected in two subtropical bays located in the South Atlantic to evaluate historical trends in the sewage input and to track possible changes in the bulk isotopic composition of OM in recent decades. The values of δ 13 C and δ 15 N ranged from -27.4 to -25.0‰ and from 0.5 to 3.9‰, respectively, without a clear trend in the variation over the whole period covered by sediment cores and with no conclusive interpretation of a specific range value typically related to the sewage input for these areas. The maximum coprostanol concentration was 0.19 μg g -1 in the upper 4 cm of one core, which was not considered contaminated by evaluation of the sterols diagnostic ratios. Even at low levels, the coprostanol concentrations followed variations in urban and economical regional development. Baseline values for faecal sterols (in average between 0.03 and 0.05 μg g -1 ), which may represent a previous non-impacted environment scenarios, were calculated for use in comparative perspectives for future evaluations of the sewage input and contamination., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Hydroid assemblage's responses to organic contamination were evaluated using sedimentary sterols as explanatory variables. At seven coral reef sites in the Havana west coast, hydroids were collected along three 10 m × 1 m, 10 m deep transects. Five sterols were analysed, i.e., coprostanol, an indicator of faecal contamination, and cholestanol, cholesterol, stigmasterol and brassicasterol, indicators of biogenic organic matter inputs. The sampling sites were classified by level of contamination. A total of 65 species comprised the hydroid assemblages. Hydroids community abundance and richness decreased in the contaminated sites. Coprostanol had the highest relative importance for these variables and also for Plumularia floridana and Clytia gracilis abundances. Obelia dichotoma and Halecium bermudense were relatively abundant in the contaminated sites. The results indicate that faecal contamination negatively affected the hydroid assemblages, highlighting the importance of integrated biological and chemical indicators to evaluate the environmental conditions of the Havana coral reef., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The quality of water bodies has been regulated by national environmental agencies and based on faecal indicator bacteria, such as thermotolerant coliforms Escherichia coli and Enterococcus sp. Additionally, faecal sterols (mainly coprostanol) have been used to corroborate sewage discharge in marine environments. In this study, faecal material input was evaluated in two sampling campaigns in transects of two tidal creeks using bacterial and chemical indicators to both compare and establish the water quality in a South Atlantic subtropical estuary. The Itiberê tidal creek (S1) was classified as "contaminated" by faecal material, while the Peças tidal creek (S2) presented variable water quality according to the sampling period and sewage indicators considered in this evaluation. Then, the integrated application of chemical and bacterial indicators was applied for tidal creeks with different sewage contamination levels and under distinct environmental conditions and confirmed that Enterococcus sp. and coprostanol are the most suitable for estuarine environments., (Copyright © 2018 Elsevier GmbH. All rights reserved.)

We report the distribution of selected lipid biomarkers specifically sterols and aliphatic hydrocarbons in sediment cores from Cabo Frio, SW Atlantic continental shelf, Brazil, corresponding approximately to the last 700 years. In the Cabo Frio region, a costal upwelling occurs as a quasi-seasonal phenomenon characterized by nutrient-rich bottom waters that intrude on the continental shelf and promote relatively high biological productivity compared to other Brazilian continental shelf areas. The results for sterols indicate the predominance of organic matter (OM) inputs related to marine organisms, mainly plankton, in all of the cores along the time scale studied. Principal component analyses show three different groups of variables, which may be associated with (i) the more effective intrusion of the nutrient-rich South Atlantic Central Water, resulting in the increase of marine lipid biomarkers such as sterols and short-chain n-alkanes; (ii) the influence of the Coastal Water with higher surface water temperature and subsequently lower primary productivity; and (iii) OM characterized by high total organic carbon and long-chain n-alkanes related to an allochthonous source. Relatively high concentrations of sterols and n-alkanes between 1450 and 1700 AD, chronologically associated with the Little Ice Age, suggest a period associated with changes in the local input of specific sources of these compounds. The concentrations of lipid biomarkers vary over core depth, but this does not suggest a notably high or low intensity of upwelling processes. It is possible that the climatic and sea surface temperature changes reported in previous studies did not affect the input of the sedimentary lipid biomarkers analyzed here.

Sterols and hydrocarbons were determined in the surface sediments from the transitional environment between Paranaguá Bay and the shallow continental shelf in the South Atlantic to assess the sources of organic matter (OM) and the contamination status of an area exposed to multiple anthropogenic inputs. Total aliphatic hydrocarbon concentrations were less than 10μgg(-1), which is typical of unpolluted sediments, and related to recent inputs from higher terrestrial plants. Total polycyclic aromatic hydrocarbon ranged from

The Antarctic region is one of the best preserved environments in the world. However, human activities such as the input of sewage result in the alteration of this pristine site. We report baseline values of faecal sterols in Admiralty Bay, Antarctica. Four sediment cores were collected during the 2006/2007 austral summer at the Ezcurra (THP and BAR), Mackelar (REF) and Martel (BTP) inlets. Concentrations of faecal sterols (coprostanol+epicoprostanol) were <0.16 μg g(-1), suggesting no sewage contamination and probable "biogenic" contributions for these compounds. Baseline values, calculated using the mean concentration of faecal sterols in core layers for THP, BAR, REF and BTP, were 0.04 ± 0.02, 0.03 ± 0.01, 0.07 ± 0.01 and 0.04 ± 0.02 μg g(-1), respectively. These results established as natural contributions of faecal sterols, suggesting that these markers can be useful indicators of human-derived faecal input and contributing to monitoring programs to prevent anthropogenic impacts., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Estuaries are ecosystems that have been changed by climatic and anthropogenic events, and subtropical estuaries located in the Southern Hemisphere are important examples of historical human occupation, land use and recent degradation. This study aims to assess whether climatic and anthropogenic events promoted the variability of sedimentary organic matter (OM) in two estuarine systems, the Paranaguá Estuarine System and Guaratuba Bay, Brazil, using geochemical multiproxies. In this approach, bulk elementary and isotopic properties were integrated with specific molecular biomarkers (n-alkanes, n-alkanol and sterols) detected in the sedimentary OM from sediment cores. Our results showed a predominance of terrigenous OM in both estuarine systems over the last century. However, sterols proved to be a more robust proxy for indicating changes in the autochthonous input of sedimentary OM, especially in the core top sections. Based on the molecular biomarkers and total annual precipitation data, the climatic effects of periodic events (e.g., El Niño–Southern Oscillation) that occurred during the last century did not seem to have imposed noticeable changes in the sedimentary OM over the period covered by the cores (e.g., between 1912 and 2010 for the Paranaguá Estuarine System). Instead, OM variations may respond to changes in the drainage basin or to specific local human activities. Plant extraction in the drainage basin was recorded in Guaratuba Bay before the 1960s, and the intensification of human occupation after the 1950s was recorded in the Paranaguá Estuarine System. The multiproxy approach demonstrated that local environmental changes related to regional anthropogenic events in the adjacent drainage basin of estuaries may be considered for identifying human impacts in coastal zones. [ABSTRACT FROM AUTHOR]

Abstract Organic contamination is a major environmental concern in coastal regions, and it can be evaluated by the determination of aliphatic hydrocarbons (AHs), polycyclic aromatic hydrocarbons (PAHs), faecal sterols and linear alkylbenzenes (LABs). The concentrations of these organic markers were obtained from nine surface sediment samples to evaluate a possible contamination near a fringing reef on the west coast of Havana, Cuba. The AH levels ranged from 1.24 to 135.6 μg g−1, the PAH levels were up to 2133 ng g−1, the faecal sterol levels ranged from 0.03 to 1.54 μg g−1, and the total LAB levels were up to 22.7 ng g−1. The highest concentrations were obtained at sites close to Havana Bay and at the sources of untreated sewage input. A decreasing concentration gradient was observed from Havana Bay to the outer sites. Although only two sites presented high levels of contamination, untreated sewage discharged close to the fringing reef may affect its environment. Highlights • Organic contamination was detected near fringing reefs along the west coast of Havana, Cuba. • Hydrocarbons were related to petrogenic sources and combustion residues. • Diagnostic ratios and regional threshold levels were determined for the study area. • High positive correlation was verified between the faecal sterols and hydrocarbons. • Autochthonous OM production is not directly influenced by the input of faecal OM. [ABSTRACT FROM AUTHOR]

Babitonga Bay is a South Atlantic estuary with significant ecological function; it is part of the last remaining areas of mangrove communities in the Southern Hemisphere. The aim of this study was to determine the spatial distribution of the faecal sterols and linear alkylbenzenes (LABs) in surface sediments and to perform an integrated evaluation of several molecular marker indices to assess the sewage contamination status in the study area. The highest observed concentrations of faecal sterols (coprostanol + epicoprostanol) and LABs were 6.65 μg g−1 and 413.3 ng g−1, respectively. Several faecal sterol indices were calculated and correlated with coprostanol levels; these analyses showed that the index limits presented in the current literature could underestimate the sewage contamination in this study area. For the overall estuarine system, a low sewage impact may be assumed based on the low total mass inventories calculated for coprostanol (between 1.4% and 4.8%). [Copyright &y& Elsevier]

Abstract: The discharge of sewage into the Antarctic marine environments by scientific stations has resulted in local changes in these pristine sites. To assess the distribution and concentration of sewage indicators from the Brazilian Antarctic station, sediments were sampled during the 2009/10 austral summer at four points (water depth of 20 and 60m). Concentrations of faecal sterols and linear alkylbenzenes (LABs) ranged from <0.01 to 0.17μgg−1 and <1.0 to 46.5ngg−1 dry weight, respectively. Maximum concentration of faecal sterols was similar to the value previously calculated as the background level for this area (0.19μgg−1), and it is lower than the concentration observed in previous studies (1997–2008), whereas the LABs concentrations remained practically constant (35ngg−1). Despite the low concentrations of sewage markers, the permanent human activities in the region require monitoring programs to determine continuing trends and prevent the increase of anthropogenic impacts. [Copyright &y& Elsevier]

Abstract: The sources and concentrations of aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs), faecal and biogenic sterols, and trace metals at 10 sampling sites located in Laranjeiras Bay, a large Environmental Protection Area in the southern Atlantic region of Brazil, were determined to assess the sources of organic matter and the contamination status of estuarine sediments. Organic compounds were determined by GC-FID and GC–MS, and ICP-OES was used to evaluate trace metals. The total AHs concentration ranged from 0.28 to 8.19μgg−1, and n-C29 and n-C31 alkanes were predominant, indicating significant inputs from higher terrestrial plants. Unresolved complex mixtures (UCM) were not detected at any site, suggesting that the study area was not significantly contaminated by fossil fuels. The total PAH concentration varied from 3.85 to 89.2ngg−1. The ratio between selected PAH isomers showed that combustion of biomass, coal, and petroleum is the main source of PAHs in the study area. The concentrations of the faecal sterols coprostanol and epicoprostanol were below the detection limits, suggesting that sewage was not a significant contributor to sedimentary organic matter. The concentrations of the trace metals (As, Cr, Cu, Ni, Pb and Zn) were low, except near sites located at the mouths of rivers that discharge into the study area and near urbanised regions (Paranaguá city and the adjoining harbour). In general, the concentrations of PAHs were below the threshold effect concentrations (TEL) levels. Although the As, Cr and Ni concentrations were above the TEL levels, the study area can be considered as preserved from human activities. [Copyright &y& Elsevier]