Our everyday pollution: Are rural streams really more conserved than urban streams?

Abstract

Due to the higher anthropogenic impacts, streams from urban regions are expected to suffer more damage than those from rural regions. This study investigated whether environmental changes caused by human activities negatively affect the variability in ecomorphological and dietary characteristics of the ichthyofauna from ten streams (five urban and five rural). Contrary to expectations, ecomorphological characteristics and diet from the fish assemblage did not differ between urban and rural streams, even though urban streams tended to present smaller variability in traits and diet than rural ones. Human activities, though with different origins, have been negatively affecting both streams types, resulting in similar structure of the fish assemblages, that is, artificial structures, blocks, salinity, and total solids have directly influenced the ecomorphology of the fish assemblage, compromising adaptability, in view of the ichthyofauna's sensibilities for the physicochemical variables. These results reinforce the need to develop environmental management efforts to preserve and conserve stream ecosystems improving their quality, especially in degraded areas.