Influência de esgotos domésticos no ecossistema manguezal do estuário de Itanhaém-S.P.

Abstract

During 6 months (from september/ 1996 to february/ 1997) we have studied the influence of the domestic sewage “in natura” in the region of the Itanhaém river. The sampling points were choosed according to the access to the place, the tide level and the proximity to the launching sewage. Two kinds of control were used: a comparison between qualitative data of the affluent water, when the high tide brings water, low tide and low level of the effluent water, low tide and low level of the volume of the estuary water. The water physico-chemical and biological parameters analysed were: temperature, pH, dissolved oxigen, salinity, oxigen biochemical demand, oxigen chemical demand, color, turbidity, N-NH4 , N-NO3 , P-PO4 , faecal coliforms and total coliforms. As results we had sensitive differences in the composition of the water that reflows from the estuary in low tide, improving the ecossistem (source of nitrogen e phosphorus) and damaging the estuarin ecossistem (coliforms).