Study of water quality using benthic biological indicators in rural and urban streams

Abstract Methods other than physical-chemical and geochemical analyses can be used to assess water quality in surface drainage. This study used intolerant, tolerant and resistant benthic species as bioindicators of changes in water quality of two streams, taking in account particle size of sediments and volatile solids. Eight points were sampled in the stream Bandeirinha and four points in the stream Josefa Gomes in January and September 2013 in the municipality of Formosa-GO. The two streams were chosen in order to study two different environments. The study used the diversity indexes of Shannon (H), Equitability (E) and Bray-Curtis Similarity and the grouping analysis method UPGMA (Unweighted Pair Group Method with Arithmetic Mean). The results of particle size and volatile solids study of Bandeirinha stream located in rural areas showed bioindicator species intolerant of changes in water quality. The stream Josefa Gomes, completely inserted in an urban environment, showed alteration identified by tolerant and resistant species. The results demonstrate differences in water quality in the rural and urban environments and the relationship of bioindicators with sediments. The study aids the interpretation of changes in the water quality of the two drainages areas. Analysis of water quality based upon benthic biological indicators associated with physical-chemical and geochemical analyses of water and sediments provide a better interpretation of the results.