Functional stability of bioindicators macroinvertebrates in streams of the Branco River microbasin - Itanhaém / SP

Abstract

The monitoring of aquatic environments is a tool of utter importance to verify long term impacts on the environment. Besides the physical-chemical analyses, which are widely used, there are also biomonitoring tools, in which is possible to notice refined environmental changes through responses given by aquatic organisms. The macroinvertebrates fauna has been used frequently for biomonitoring studies, since this approach has a low-operational cost and the organisms respond to a wide spectrum and types of pollution. Within this approach, the use of community functional traits rises as a promising new area, with potential to provide mechanistic explanations about anthropic impacts. In the Itanhaém's river basin, there is a Long Duration Ecological Researches Program in current development entitled "Coast rivers and streams from the Itanhaém river Basin", where data is sampled for large scale temporal studies. Our project will be part of this Program, and aims to test the stability of biomonitoring metrics from streams of the Itanhaém River basin through the functional approach using benthic macroinvertebrate communities and also from the description of the temporal trends in the invertebrate communities. For our purpose, we will use collected samples from the Branco river micro-basin during the last three years. The organisms will be identified under stereomicroscopes with the aid of identification keys. We expect that the studied communities will have a high variation in monitoring metrics based on richness and abundance, but we also expect to find a low variation in the functional structure of the communities, providing stability to ecosystem functions of stream along time. (AU)