Foraminifera and geomicrobiology as indicators of the environmental recovery in a mangrove affected by oil spills in the Guanabara Bay (Brazil).

Foraminifera could be used as indicators to evaluate the impacts of oil spills because the crude oil causes several disturbances on the development and reproduction of the species. However, little is known about the relationship between mangrove species and this pollutant. Foraminiferal assemblages were studied in 22 surface sediment samples collected from a mangrove in Guanabara Bay (Brazil) that was severely impacted by an oil spill six years earlier.

Applying enzymatic biomarkers of the in situ microbial community to assess the sediment risk from Sepetiba Bay (Brazil).

The Quality Ratio (QR) index was applied in Sepetiba Bay to integrate geochemical and microbiological parameters of the in situ microbial community in order to classify the ecological risk of sediments. Total concentrations (C) of Hg, Cd, As, Pb, Cr, Cu and Zn (indicators of the mixture of contaminants) were determined at 26 stations and at a background area (C) to calculate the contamination factor (CF = C/C) and the degree of contamination (ΣCF). Enzymatic biomarkers of energy production into cell (dehydrogenase - DHA) and hydrolase of organic matter outside the cell (esterases - EST) were determined.

Effects of aeration on the suspended matter from a tropical and eutrophic estuary.

A comprehensive understanding of the complex biogeochemical interactions between organic matter and persistent contaminants in the suspended matter is vital for eco-efficient estuary recovery. However, little is known regarding aeration effects in suspended particulate aggregates. Therefore, this study aimed to investigate the effects of aeration on the suspended matter from a Tropical and Eutrophic estuarine environment.

Assessment of the trophic state of a hypersaline-carbonatic environment: Vermelha Lagoon (Brazil).

Vermelha Lagoon is a hypersaline shallow transitional ecosystem in the state of Rio de Janeiro (Brazil). This lagoon is located in the protected area of Massambaba, between the cities of Araruama and Saquarema (Brazil), and displays two quite uncommon particularities: it exhibits carbonate sedimentation and displays the development of Holocene stromatolites. Due to both particularities, the salt industry and property speculation have been, increasingly, generating anthropic pressures on this ecosystem.

Seasonal variation of polycyclic aromatic hydrocarbons concentrations in urban streams at Niterói City, RJ, Brazil.

Polycyclic aromatic hydrocarbons (PAHs) were determined in water samples collected in two streams and a lake located at Niteroi City, Rio de Janeiro State, Brazil between October 2008 and September 2009. Samples were extracted using liquid-liquid extraction and analyzed using high performance liquid chromatography with fluorescence detection. The limits of quantification were sufficiently low to accomplish PAH determination below the maximum concentration levels established by the Brazilian (50 ng/L) and USEPA legislations, with recoveries larger than 81.

Superficial distribution of aromatic compounds and geomicrobiology of sediments from Suruí Mangrove, Guanabara Bay, RJ, Brazil.

The distribution of selected aromatic compounds and microbiology were assessed in superficial sediments from Suruí Mangrove, Guanabara Bay. Samples were collected at 23 stations, and particle size, organic matter, aromatic compounds, microbiology activity, biopolymers, and topography were determined. The concentration of aromatic compounds was distributed in patches over the entire mangrove, and their highest total concentration was determinated in the mangrove's central area.

Geomicrobiology of cores from Suruí Mangrove--Guanabara Bay--Brazil.

The aim of this work was to quantify the biopolymers associated to esterase enzymes and identify bacterial respiratory activity in four cores collected in Suruí Mangrove, Guanabara Bay - RJ. Biopolymer concentration was 1000 times lower than previously reported in the literature, indicating the need for creating and establishing eutrophication indicative rates and records compatible with tropical coastal systems. The biochemical representative relationships in the cores were equivalent to those from studies on coastal marine environments made in the Northern Hemisphere.