Environmental assessment of two small reservoirs in southeastern Brazil, using

macroinvertebrate community metrics

FUSARI¹, L.M. & FONSECA-GESSNER¹, A.A.

¹ Laboratório de Entomologia Aquática, Depto. de Hidrobiologia, Universidade Federal de São Carlos, C.P.676, 13.565-905, São Carlos, SP.

liviafusari@yahoo.com.br; gessner@power.ufscar.br

 ABSTRACT: In the work reported here, the aim was to investigate the applicability of benthic macroinvertebrate community metrics in the assessment of the environmental condition of two small reservoirs in southeast Brazil with differing inputs of nutrients and states of conservation. Eleven metrics were applied, organized in five categories: richness, enumeration, diversity, similarity and functional feeding groups. Most metrics responded as predicted in the literature, in accordance with the amount of human interference and state of conservation of the two reservoirs, except the Shannon Diversity, Pielou Uniformity and McNaughton Dominance indices, which should be avoided, at least for discriminating the environmental condition of these two tropical reservoirs.

Key-words: diversity, richness, Chironomidae, Oligochaeta, lentic systems.