English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

STRAKOVA LUCIE, KOPP RADOVAN, MARSALKOVA ELISKA, MARSALEK BLAHOSLAV: Dynamics of the cyanobacterial water bloom with focus to Microcystis and its relationship with environmental factors in Brno reservoir. Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, 2013, LXI, No. 5, pp. 1383–1390 Our paper brings new information about long-term changes of the phytoplankton communities in the Brno reservoir with the focus on the Microcystis abundance using the semi-monthly monitoring data covering the period 2006–2012. The main aim is to extract from this long-term data set diff erences in number of Microcystis cells depending on environmental factors. The development of cyanobacteria in Brno reservoir is caused by excessive phosphate loading from wastewater treatment facilities upstream and from non–point sources along the Svratka river. It focuses management eff ort on upstream controls of reservoir condition. High abundance in millions of cyanobacteria cells in 1ml observed in Brno reservoir before was reduced to values in the order of thousands cells in 1ml in last two years through a combination of measures (liming, precipitation of phosphorus on infl ow, aeration and destratifi cation). Phytoplankton composition was also changed and at the expense of cyanobacteria promoted the development of green algae and diatoms. cyanobacteria, blue-green algae, destratifi cation, phosphorus Eutrophication is one of the greatest challenges for management of water resources, since its eff ects have aff ected the water quality of many ecosystems. The spread and magnifi cation of the eutrophication process in freshwater systems are now o en linked to the increased frequency and extent of cyanobacteria blooms, including harmfull species (Kosten et al., 2012). Cyanobacterial blooms have become a worldwide environmental problem and the mechanisms and processes involved in the initiation of cyanobacterial blooms are of great concern. In freshwater ecosystems, algal blooms caused by several cyanobacteria genera, including Aphanizomenon, Cylindrospermopsis, Dolichospermum (Anabaena), Microcystis and Planktothrix (Oscillatoria) have been extensively documented (Chorus and Bartham, 1999). Among these genera, Microcystis is well known to be the most ecologically damaging group due to its widespread prevalence in water bodies and its toxicity to aquatic and terrestrial organism (Carmichael et al., 2001). The overwhelming dominance of Microcystis in various lakes and reservoirs of the world has been explained by water temperature, underwater light climate, nutrients, buoyancy regulation and zooplankton or fi sh grazing (Reynolds, 2006). High nutrient levels in eutrophic/hypertrophic waters are regarded as the main infl uencing factors for the growth of cyanobacteria water blooms. Smith (1983) concluded that bloom-forming cyanobacteria tended to dominate in lakes and reservoirs where the NT:PT mass ratio was less than 29. On the other hand, Xie et al. (2003) described results indicating that low NT:PT ratio is not the cause of Microcystis 1384 Lucie Strakova, Radovan Kopp, Eliska Marsalkova, Blahoslav Marsalek blooms, but a result of the blooms. The diff erent incorporation rates of P and N from sediments by Microcystis blooms resulted in low NT:PT ratio. Reactive phosphorus is a key regulatory factor for the dominance of the non-nitrogen-fi xing cyanobacteria like Microcystis aeruginosa (Trimbee et al., 1987; Xie et al., 2003). Several studies indicate that Microcystis species rapidly grew in the water column at the end of spring and then dominated during summer period (Preston et al., 1980). However, Microcystis occurrence at unfavourable environmental conditions in winter and early spring was also considered to play an important role in the formation of subsequent water blooms. Many studies have paid attention to cyanobacterial recruitment as determining the contribution of Microcystis in sediments to subsequent water blooms in the water column (Brunberg and Blomqvist, 2002). Microcystis numbers in the water column, especially in the lowest layers, play an important role in forming the next water bloom (Xu et al., 2010). This paper concentrates on long-term changes of Microcystis cells counts using the semi-monthly monitoring data covering the period 2006–2012. The main aim is to extract from this long-term data set diff erences in numbers of Microcystis cells depending on environmental factors. MATERIALS AND METHODS