Benthic macrofauna of a urban stream (Angatuba, SP) under the influence of different anthropogenic pressures: a longitudinal and seasonal analysis of the composition and diet

Abstract

In lotic ecosystems, the benthic macroinvertebrates have a great ecological importance, taking part in the energy flow and nutrient cycling. They also have been described as the group which best reflects the degree of integrity of the environment. This study aims to analyze the composition and organization of benthic macrofauna along a longitudinal transect in Ribeirão Grande stream, located in the urban area of Angatuba, SP. Spatial variations will be verified based on the influence of different anthropogenic pressures on the stream. Seasonal changes will be analyzed due to temporary alterations in the environment structure. For aquatic insects, the gut content will be analyzed in order to define species diet and trophic groups. In July 2013 (dry season) and January 2014 (rainy season), environmental analysis and macrofauna samples with Surber sampler (mesh 250m¼) will be performed at five collecting sites. The macroinvertebrates will be collected in riffles and runs, which are the prevalent and greater extent mesohabitats in all points of the longitudinal transect. (AU)