Effect of Salto Grande reservoir management (Paranapanema River, SP/PR) on the macroinvertebrates fauna associated to macrophytes in a pond marginal to the river

• Grant number: 13/05477-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date until: July 01, 2013
• End date until: December 31, 2013
• Field of knowledge: Biological Sciences - Ecology - Ecosystems Ecology
• Principal Investigator: Virginia Sanches Uieda
• Grantee: Eliane Ivonete da Silva
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Submerged rooted macrophytes show large growth and their control in reservoirs has been made by depletion of water level. However, few are known about the consequences of this induced drought upon the aquatic biota. The present work aims to evaluate the effects of the water level changes, used to control the biomass of Egeria spp, on the macroinvertebrates composition and density, with emphasis on aquatic insects. The study site is a pond marginal to Paranapanema River, near the Salto Grande reservoir, SP/PR. To assess the effects of the reservoir depletion on the macroinvertebrates associated to the macrophytes, samples were carried between August and October of 2011 in Guaritá Lake, connected to the main channel of the Paranapanema River. Samplings were conducted in three regions along a longitudinal transect of the pond (near the entrance, center and near the closed edge), before the reduction of the level water (control sample) and 49 days after the impoundment of the reservoir (resilience evaluation). The macrophytes were washed and macroinvertebrates separated and stored in 70% ethanol. The animals will be identified and the data analyzed considering the variables: pond region (spatial analysis) and reservoir management phase (temporal analysis). (AU)