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Functional aspects of biological communities influence ecosystem processes and it is urgent to understand how human disturbances affect functional diversity and ecosystem functions and services. Our purpose was to address the use of different functional metrics of nematode assemblages to evaluate the ecological status of tropical estuaries subjected to different human activities, aiming to advance and improve the knowledge about the usefulness of functional attributes as indicators of environmental quality. Three approaches were compared: functional diversity indexes, single trait, and multi traits using the Biological Traits Analysis. The RLQ + fourth-corner combined method was used to identify relationships among functional traits, inorganic nutrients, and metals concentrations. Lower values of FDiv, FSpe, and FOri indicate a convergence of functions, characterizing impacted conditions. A dominant set of traits was related to disturbance, mainly inorganic nutrient enrichment. All the approaches allowed for the detection of disturbed conditions, however, multi traits was the most sensitive one. [Display omitted] • Different sets of nematode traits were related to different inorganic pollutants. • Multitraits analysis was the most efficient approach detecting disturbed estuaries. • Nematodes functional dispersion was not linked to estuaries ecological conditions. • Low functional divergence, specialization, and originality may indicate human impacts. [ABSTRACT FROM AUTHOR]

Since February 1999, the Municipal Wastewater Treatment Plant (MWTP) of Balneário Camboriú, Brazil, started a complementary treatment with ClO2 application on its effluent. It was realized to minimize its impacts caused by increase of the population during summer. This study was realized in order to verify the influence of this compound in the water quality and the environmental evaluations. Samples of surface water were collected in this environment between January 1997 and June 2001 for chemical and microbiological surveys. The results had shown that after application of ClO2, fecal coliforms were decreased about six times in the beach (2.3 × 103 to 3.5 × 102 MPN/100 ml) and three times in the river (3.3 × 104 to 1.0 × 104 MPN/100 ml), during summer time. NH4 + showed an increase of about four times and 1.5 times, respectively, to beach and river. These results are showing the influence of ClO2 on chemical and microbiological parameters. [ABSTRACT FROM AUTHOR]