Cyanobacteria and their impacts on water quality in cascade reservoirs on the Tietê River (São Paulo, Brazil)

• Grant number: 24/17098-8
• Support Opportunities: Regular Research Grants
• Start date: April 01, 2025
• End date: March 31, 2028
• Field of knowledge: Engineering - Sanitary Engineering - Environmental Sanitation
• Principal Investigator: Viviane Moschini Carlos
• Grantee: Viviane Moschini Carlos
• Host Institution: Instituto de Ciência e Tecnologia. Universidade Estadual Paulista (UNESP). Campus de Sorocaba. Sorocaba , SP, Brazil
• Associated researchers: Eduardo Vicente Pedrós ; Marcelo Luiz Martins Pompêo ; Xavier Sòria Perpinyà

Abstract

The 2030 Agenda for Sustainable Development includes Sustainable Development Goal 6, which recognizes the importance of protecting and restoring aquatic ecosystems. Human activities affect the natural processes of ecological systems through physical and chemical interventions, directly interfering with biodiversity. In aquatic ecosystems, the phytoplankton community and, particularly, cyanobacteria are important indicators of the impact and extent of pollution in multiple-use reservoirs. As a consequence of climate change, the proliferation of potentially toxic cyanobacteria is increasing in frequency, magnitude and duration, representing an ecological risk to ecosystems and public health. A complex interaction of regional (climate), local (nutrients, lake morphometry) and biological (species, functional groups) variables determines the presence of cyanobacteria. Considering the problem of cyanobacteria and their potential cyanotoxins in the context of climate change, as well as the scarce scientific information in subtropical regions, aiming at the health of ecosystems and the population that uses these waters for various purposes, the hypothesis of this research project is to verify which are the environmental predictors responsible for the occurrence of cyanobacteria and the production of cyanotoxins. Thus, the objective of this research is to understand the dynamics of cyanobacteria in a set of cascade reservoirs (Promissão, Nova Avanhandava and Três Irmãos) on the Tietê River. To this end, it aims to verify how cyanobacteria and their potential cyanotoxins can impact ecosystem services (quality water for multiple uses). With this information, this project will constitute a scientific basis, with publications of the results in high-impact journals and also aims to assist managers with information for management and recovery measures. The specific objectives are to characterize and compare the water masses of the reservoirs according to the physical, chemical and biological aspects; to analyze the biomass of cyanobacteria in the water column in situ through measurements with a fluorimeter (phycocyanin and chlorophyll-a); to determine the species composition, abundance and biovolume of cyanobacteria; to analyze the cyanotoxins in the water of the reservoirs; to use molecular techniques to detect cyanobacteria that produce cyanotoxins and to verify the existence of gradients in the reservoirs to the cascade system in the Tietê River. (AU)