ermanent occurrence of Raphidiopsis raciborskii and cyanotoxins in a subtropical reservoir polluted by domestic effluents (Itupararanga reservoir, Sao Paulo, Brazil

Author(s):Show less -

Machado, Leila dos Santos ^[1] ; Dorr, Fabiane ^[2] ; Dorr, Felipe Augusto ^[2] ; Frascareli, Daniele ^[1] ; Melo, Darllene S. ^[1] ; Gontijo, Erik S. J. ^[1] ; Friese, Kurt ^[3] ; Pinto, Ernani ^[2] ; Rosa, Andre Henrique ^[1] ; Pompeo, Marcelo M. ^[4] ; Moschini-Carlos, Viviane ^[1]

Affiliation

^[1] Univ Sao Paulo State UNESP, ICT, Sorocaba Campus, Sorocaba - Brazil

^[2] Univ Sao Paulo, Lab Toxin & Algae Nat Prod, Sao Paulo - Brazil

^[3] UFZ Helmholtz Ctr Environm Res, Lake Res Dept, Brueckstr 3a, D-39114 Magdeburg - Germany

^[4] Univ Sao Paulo, Dept Ecol, Sao Paulo - Brazil

• Document type: Journal article
• Source: Environmental Science and Pollution Research; v. 29, n. 13 OCT 2021.
• Web of Science Citations: 0

Abstract

Toxic cyanobacteria blooms are a frequent problem in subtropical reservoirs and freshwater systems. The purpose of this study was to investigate the occurrence of potentially toxic cyanobacteria and the environmental conditions associated with the presence of cyanotoxins in a Brazilian subtropical reservoir. Five collections were carried out at seven sampling locations in the reservoir, during the rainy and dry seasons, between the years 2016 and 2017. There was permanent occurrence of Raphidiopsis raciborskii (Woloszynska) Aguilera, Berrendero Gomez, Kastovsky, Echenique \& Salerno (Phycologia 57(2):130-146, 2018), ranging between dominant and abundant, with an average biomass of 38.8 +/- 29.9 mg L-1. Also abundant were Dolichospermum solitarium, D. planctonicum, Planktothrix isothrix, and Aphanizomenon gracile. Saxitoxin (STX) was detected in all the collected samples (0.11 +/- 0.05 mu g L-1). Microcystin (MC) was also detected, but at lower concentrations (0.01 +/- 0.0 mu g L-1). Low availability of NO3- and phosphorus limitation had significant effects on the R. raciborskii biomass and the levels of STX and MC. It was observed that R. raciborskii was sensitive to thermal stratification, at the same time that STX levels were higher. This suggested that STX was produced under conditions that restricted the growth of R. raciborskii. These are important findings, because they add information about the permanent occurrence of STX and R. raciborskii in an aquatic ecosystem limited by phosphorus, vulnerable to climatic variations, and polluted by domestic effluents. (AU)

• FAPESP's process: 16/15397-1 - Organic Carbon cycling in Water Reservoirs of Brazil and Germany: influence of land use and hydrology- ORCWAR
• Grantee: Daniele Frascareli
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 16/17266-1 - The European Union Water Framework Directive: applications using the phytoplankton as an environmental discriminator in Brazilian reservoirs
• Grantee: Viviane Moschini Carlos
• Support Opportunities: Regular Research Grants