Occurrence of Cylindrospermopsis (Cyanobacteria) in 39 Brazilian tropical reservoirs during the 1998 drought

Abstract

ABSTRACT:The relationship between the trophic state of 39 reservoirs located in the semi-arid region of north-east Brazil and their planktonic structure was examined by a sampling survey during the 1998 drought (September to November). A total of 30 environmental and biological parameters, with special attention paid to phytoplankton, were studied once at each reservoir to obtain a synoptic view at a state scale (Pernambuco State). The application of the chlorophyll a-total phosphorus standard relationship for grades of eutrophication revealed a classification in which 90% of the sites were eutrophic-hypertrophic. Among the 202 taxa identified in the phytoplankton assemblages, the cyanobacterium Cylindrospermopsis (Wolsz.) Seenayya et Subba Raju represented more than 80% of the total phytoplankton density in 10 reservoirs and more than 50% in 17 reservoirs. The rarity of other phytoplanktonic groups in the case of the Cylindrospermopsis dominance is the most significant biological feature of these reservoirs. Although rotifers were more closely linked to hypereutrophic conditions than copepods or cladocerans, this dominant group did not seem to play an efficient role in cyanobacterial control. A statistical approach based on the analysis of cross tables (co-inertia analysis) allows us to describe species-environment relationships with a special focus on the factors governing the presence of Cylindrospermopsis. As determined by hierarchical analysis, a major group of studied reservoirs (70%) corresponded to deeper, warmer and hypertrophic reservoirs characterized by the combination of (1) low ammonia concentration, high temperature and pH values, and (2) high percentages of Cylindrospermopsis abundances. Lack of water renewal in 1998 linked to the 1997 El Niño consequences seems to be a major determinant for both trophic conditions and Cylindrospermopsis dominance in the reservoirs studied.KEY WORDS: Bacteria · Phytoplankton · Zooplankton · Cylindrospermopsis · El Niño event · Reservoirs · Co-inertia analysis Resale or republication not permitted without written consent of the publisherAquat Microb Ecol 23: [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] 2000 Cyanobacteria are recognized as a critical problem worldwide and their blooms are typical phenomena in eutrophic lakes, often linked to external nutrient enrichment (Paerl 1988). The influence of local climatological factors (e.g. wind, light intensity, temperature) can accelerate these phenomena and modify the phytoplankton structure, as cyanobacteria are strongly driven by physical factors such as local weather conditions (e.g. Tóth & Padisák 1986, Fabbro & Duivenvoorden 1996. Other factors that potentially influence the biomass and composition of phytoplankton include a stable water column with a turbulence limitation defined as a high ratio between the mixing zone and the euphotic zone (Soranno 1997). In addition, cyanobacteria are inedible prey for many zooplankton organisms because of their large colony size, their toxic effects and low...

Cylindrospermopsis raciborskii (Woloszynska) Seenayya & Subba Raju(Cyanobacteria): variação semanal e relações com fatores ambientais em um reservatório eutrófico, São Paulo, SP, Brasil

“…Florações de Cylindrospermopsis raciborskii (Woloszynska) Seenayya & Subba Raju têm sido cada vez mais freqüentes em reservatórios brasileiros o que torna esta espécie um dos mais importantes componentes das comunidades fitoplanctônicas (Branco & Senna 1991, 1996a, Branco & Cavalcanti 1999, Bouvy et al 1999, Bouvy et al 2000, Huszar et al 2000, Komárková et al 1999, Padisák 1997. Sua alta competitividade em ambientes eutrofizados, aliada à sua capacidade de formar florações e produzir toxinas, fazem desta espécie uma das Cyanobacterias mais estudadas tanto do ponto de vista ecológico como de saúde pública.…”

Cyanobacterial blooms in freshwaters bodies in a semiarid region, northeastern Brazil: A review

“…Bouvy et al (2000) made one of the most important reports on cyanoHABs (in almost 40 reservoirs in the Northeast) associated with climate change, when the severe drought of 1998 (a consequence of the El Niño in 1997) made the environment favourable for cyanobacteria proliferation, specially Cylindrospermopsis raciborskii.…”

“…Extreme climate events, like changes in precipitation patterns, can also favour cyanoHABs in subtropical lakes (Haakonsson et al, 2017). In tropical regions, blooms are more frequent and persistent throughout the year, with higher biomass and toxic records (Bouvy et al, 2000;BittencourtOliveira et al, 2014), in contrast with temperate regions where cyanoHABs are restricted to shorter periods of the year, mainly in the summer (Ger et al, 2016).…”

“…Studies focusing on the dominance and toxicity of these organisms emerged only after the "Caruaru tragedy" in 1996, when dozens of renal patients in a haemodialysis clinic died after intravenous exposure to microcystins (Carmichael et al, 2001;Azevedo et al, 2002). After this incident, research efforts were directed to monitor various supply reservoirs, including the important report by Bouvy et al (2000), which monitored water quality and the occurrence of bloom-forming cyanobacteria Cylindrospermopsis Seenayya & Subba Raju in 39 reservoirs in Pernambuco state. Afterwards, many other studies have taken place, and the number of cyanoHABs associated with frequent episodes of toxicity has increased over time.…”

Filtros ecológicos: um estudo da remoção de produtos farmacêuticos e de cuidados pessoais e do efeito da contaminação no biofilme

“…O filtro contaminado com paracetamol apresentou maior concentração de clorofila- A avaliação da disponibilidade de nutrientes na água está diretamente relacionada com a comunidade fitoplanctônica, podendo esta apresentar crescimento acelerado, caracterizando as florações de cianobactérias e algas. No entanto, outras condições e fatores são necessários para que a floração se estabeleça, como as condições de temperatura da água, luminosidade, tempo de residência do sistema, fotoperíodo, atividade do vento, bem como a presença de zooplâncton que se alimentam das algas, dentre outros (REYNOLDS, 1980;PADISÁK, 1997;BENSON-EVANS et al 1999;BOUVY et al, 2000;FERNANDES et al, 2009).…”