ASSESSMENT OF CYANOBACTERIA SPECIES ABUNDANCE AND CYANOTOXINS PRODUCTION IN SEMI-ARID RESERVOIRS IN BRAZIL

Código

XVII-SRHNE0347

Autores

Regina Anya Otogo, Camila Ferreira Mendes, RANIELLE DAIANA DOS SANTOS SILVA, Juliana dos Santos Severiano

Tema

20. Poluição das águas

Resumo

Cyanobacteria have been a major concern, especially in semi-arid regions, due to their persistent blooms and release of toxins in aquatic ecosystems, which are detrimental to aquatic biota, humans, and animals? health. The study aimed to assess the physicochemical factors that influence cyanobacteria abundance and cyanotoxin concentrations in two river basins in the semi-arid region of Brazil. In the Piranhas River, temperature, pH, and salinity were significantly elevated, while potential redox (ORP) statistically increased at a significant level in Paraíba River. Raphidiopsis raciborskii exhibited a relative abundance of 92% and 98% in River Paraíba and Piranhas respectively. RDA revealed a positive relationship between the levels of nitrogen and phosphorus with species of cyanobacteria and showed a positive correlation between the levels of phosphorus and saxitoxins, while the levels of nitrogen were related to the concentrations of cylindrospermopsins. These results highlight the importance of eutrophication on the flora of potentially toxic cyanobacterium and concentrations of cyanotoxins, indicating an emerging need to control these nutrients to avoid risks of cyanotoxin poisoning.