The influence of the nutrients phosphorus and nitrogen in the amount of chlorophyll a in the waters of Esgotao Stream in the city of Sabino/SP-Brazil

摘要

The great majority of anthropogenic activities produces waste, which ends up being incorporated into the body of water in form of pollution. The region has diverse agricultural, livestock, and tourism activities, which is characterized by the absence of riparian vegetation along its banks. The objective of this study is to correlate and identify the environmental damages and the consequences on the water quality of Esgotao Stream through the correlation of the nutrients phosphorus and nitrogen with the amount of chlorophyll a in the vicinity of Sabino Beach (SP). The evaluation of environmental damages occurred in Sabino Beach, along the Esgotao Stream, was conducted in two points of the beach, between the months of February and June 2012. In the warmer months (February) the proliferation of cyanobacteria is increased due to high temperature and because of the nutrient phosphorus, which in February was the highest amount of the sampled months and then these factors reflected in the high levels of chlorophyll a. Such concentration has not been exceeded in only one sample of point 1 on 03/03/12; in the other samples, the value is high, with peaks of 2.60 mg/L, on 02/06/12. It is necessary to make changes in management techniques of cultivated areas and greater rigor in standards and supervision of aerial fertilization, actions that will represent reduction in nutrient loading that incorporates the stream.