Avaliação da qualidade da água do Rio bucatu através de bioindicadores

Abstract

Aquatic ecosystems, particularly rivers, are sources of one of the most important natural resources for living things: water. Thousands of species of fauna and flora, including humans, need water to survive, being of good quality for the various uses. However, due to the population increase, a lack of public policies that aim the preservation of rivers and the diversification of water use, or when carried out, in an inadequate way, can have negative consequences for water resources and affect water quality, compromising their use for various purposes. This study aimed to evaluate the water quality of the Bucatu River, located in the county of Conde, south coast of Paraíba. The collections were carried out in the months of April, July, September, and December of 2016 and June and September of 2017 in 3 points in Rio Bucatu in the municipality of Conde -BP For the physical and chemical variables, measurements were made in the subsuperficial layers of the water as temperature water and dissolved oxygen, both through direct reading with portable oximeter, pH and electrical conductivity measurements obtained with probes and also nitrite, nitrate, phosphate, ammonia and total phosphorus were analyzed and compared to reference values established by CONAMA Resolution 357/2005. With respect to zooplankton, this community was collected with a 45μm mesh of plankton by filtering 80L of water with the aid of a bucket. The results determined that all physical and chemical parameters were within the levels recommended by CONAMA resolution for Class 2 rivers, but at point P1 the total phosphorus presented higher values compared to the other points, exceeding by 4 times the limit established by No. 357/2005, such increase may be due to the large amount of macrophytes present at this site. Apart from the total phosphorus value, Bucatu River could be framed in a Class 1 river. This will be possible if the macrophyte bank present in the spring area is managed. Zooplankton was more abundant in July, probably as a response to an increase in primary production, because the river was isolated from the sea without water renewal, demonstrating that it is a community capable of showing cumulative responses to environmental changes. It is concluded that the Bucatu River is a river with good water quality and can be used as reference for studies of environmental restoration in other rivers.