Abstract
A community of fish from the Quarenta stream were shown to have been affected by urban pollution
(domestic drains and industrial effluents). The structure of the community, number of individuals, richness
of species, index of diversity and the degree of stability were significantly different from those of the
Candiru stream, which is still in a natural state. The low concentration of dissolved oxygen and the low
diversity of habitats are the principal factors that are influencing the fish community of the Quarents
stream.
