Mohammad Ghafori - Razi University Center for Environmental studies, Kermanshah
Mozafar Sharifi

The potential hazard of industrial chemicals and effluents in lotic systems are usually evaluated using standardized single - species bioassay. This bioassay can include both in laboratory and in situ toxicology test. While effective as a screening tool, single-species toxicity tests have limitations on accurate predictions of ecosystem responses in some situations. The experiment was conducted in artificial stream to appraise the long - term effects (21 days) of atrazine and herbivorous snail on periphyton community in artificial streams. Periphyton was exposed to different concentration of atrazine (0, 10 and 100 μg/L). Results showed that atrazine decreased dry mass, AFDM, chlorophyll a, biovolume and density of periphyton community. Periphyton productivity was strongly declined when exposed to snail grazing pressure and high concentration of atrazine treatments.

Atrazine, herbivores, artificial streams, periphyton