Short term assessment of nutrients and physicochemical parameters considering different depths in a hypersaline lagoon – Araruama Lagoon –RJ

The Araruama lagoon water quality has deteriorated at an accelerated pace during the last decades, mainly due to expansion of urban occupation. nutrients input increased by domestic effluents could reach eutrophication, which may cause episodes algal blooms and fish mortalities. aim this study was evaluate stratification parameters in same sampling campaign. Eleven samples were collected surface, middle, bottom along lagoon. For each sample, following analyzed: biochemical oxygen demand (BOD5), dissolved (DO), turbidity, particulate organic carbon (POC), nitrogen phosphorus (dissolved particulate). hydrodynamic characterization showed that regardless connection with ocean, a large part is more influenced winds than tides. In general, homogeneous behavior column. results DO BOD5 confirmed highly oxygenated. High values combined result rates ratio (N:P) show P limiting factor. concentrations BOD5, total phosphorus, chlorophyll-a phaeopigments corroborate result.