Assessing the occurrence of cyanobacterial blooms in a large Brazilian reservoir using satellite remote sensing

Abstract

In the last decades many large reservoirs, such as Furnas Reservoir, were built in southeastern Brazil to provide sufficient power supply to the region. External nutrient inputs from agriculture and domestic sewage, however, caused an increase of eutrophication in these systems and, consequently, an increase in cyanobacterial blooms. Blooms of cyanobacteria are associated with several problems in water quality such as dissolved oxygen depletion, taste and odor, and unsafe drinking water due to the presence of cianotoxins (CARMICHAEL 2001, VINCENT et al. 2004). In Furnas Reservoir, cyanobacterial dominance or blooms may occur throughout the year. Several potential toxic species were observed, including Cylindrospermopsis raciborskii, Lyngbya hieronymusii, Microcystis aeruginosa, M. novaceckii, M panniformis, M. protocystis, Planktothrix planctonica, Radiocystis fornandoi, an d Sphaerocavum brasiliensis.