10 anos de monitoramento da qualidade ambiental das águas da lagoa Rodrigo de Freitas

Abstract

Environmental monitoring is an indispensable tool to provide the authorities with a value judgment about environmental quality in ecosystems, seeking to use it also to identify the factors and processes that contribute to their degradation agents. This report presents a diagnosis of sanitary conditions and food webs at the Rodrigo de Freitas lagoon waters for the period from 2000 to 2010, from its systematic monitoring and includes observations from the channels Jardim de Alah and Piraquê. The results for that period represent around 10 years of monitoring in four sampling points. There were also two additional points in the adjacent channels since January 2005, which add up to the results of the measurements of vertical profiles (biweekly) for dissolved oxygen parameters (OD), salinity, temperature and Secchi transparency. The results of weekly collections of samples for analysis of physico-chemical parameters in addition to bacteriological and phytoplankton community were also included. The parameters analyzed have been shown to be good indicators of water quality, allowing to the evaluation of the conditions of the aquatic ecosystem and helping in the establishment of the trophic state of the ecosystem, the intensity of the incoming sea water, the phytoplankton succession populations, as well as the activity of production/consumption of oxygen along the water column (refers to the vertical depth - mass - the body of water). This information aims to provide greater understanding of the lagoon, from the fundamental dynamic processes that can contribute to decision-making and increase the possibility of predicting accidents with the ichthyofauna.