US EPA

6332489 

Journal Article 

Environmental factors driving the dominance of the harmful bloom-forming cyanobacteria Microcystis and Aphanocapsa in a tropical water supply reservoir 

de J Magalhães, AA; da Luz, LD; de Aguiar Junior, TR 

2019 

1 

Water Environment Research
ISSN: 1061-4303
EISSN: 1554-7531 

John Wiley and Sons Inc. 

91 

11 

1466-1478 

English 

31074893 

10.1002/wer.1141 

WOS:000492298800006 

Harmful cyanobacterial blooms in reservoirs have become a serious global issue for environmental health. However, dominance among different toxic cyanobacteria genera remains poorly understood, especially in tropical areas. We evaluated the influence of environmental factors, including total phosphorus, dissolved aluminum, water level, and precipitation on the change of the dominant genus from Microcystis to Aphanocapsa, in a hypereutrophic tropical reservoir, using 443 water samples over six years of field monitoring by applying generalized linear models (GLM). The results pointed out the prevalence of longer hydrologic retention time leading to enhanced water stability, and nutrients' accumulation into the hypolimnetic zones of the reservoir may have favored the ecophysiological advantages for the picocyanobacteria Aphanocapsa, which reached densities greater than 1 million/ml. In addition, this article also suggests that physical-chemical remediation methods applied for immobilizing phosphorus in the sediments of the reservoir may be low effective in limiting cyanobacterial growth. These findings are not only meaningful to the understanding of the dynamics of cyanobacterial genera but also to improve the management of eutrophic reservoirs in tropical regions. PRACTITIONER POINTS: We assessed cyanobacterial dominance changes based on 6-year field monitoring. First article addressing the dominance of Aphanocapsa spp. in a tropical reservoir. Species of Aphanocapsa responded better to hydrological changes in the reservoir. The use of remediators was accompanied by an increase in cyanobacteria biomass. 

Aphanocapsa; generalized linear models; microcystin; Microcystis; picocyanobacteria; residence time; South America, Brazil; toxic blooms; water-level reduction; Abstracting; Phosphorus; Reservoir management; Tropics; Water levels; Water supply; Aphanocapsa; Generalized linear model; Microcystins; Microcystis; Picocyanobacteria; Residence time; South America; Toxic blooms; Reservoirs (water); aluminum; microcystin; microcystin LA; microcystin LF; microcystin LR; microcystin LW; microcystin RR; microcystin YR; phosphorus; fresh water; cyanobacterium; ecophysiology; environmental factor; growth; phosphorus; physicochemical property; precipitation (chemistry); reservoir; residence time; toxin; water supply; air temperature; Aphanocapsa; biochemical oxygen demand; conductance; cyanobacterium; Cylindrospermopsis; environmental factor; land use; light; Merismopedia; Microcystis; nonhuman; Oscillatoria; precipitation; priority journal; sediment; vegetation; water analysis; water quality; water supply; water temperature; environmental monitoring; water supply; Brazil; Aphanocapsa; Cyanobacteria; Microcystis; Cyanobacteria; Environmental Monitoring; Fresh Water; Microcystis; Water Supply