National Repository of Grey Literature 3 records found  Search took 0.00 seconds. 
Study of Factors Influencing the Development of "Water Bloom" in the Water Reservoir Seč
Forczek, Sándor ; Holík, Josef ; Rederer, L. ; Koza, V.
In this work, we monitored several parameters that influence the development of algal bloom on the\nwater reservoir Sec. Primarily climatic conditions belong to the monitored parameters that influence\nthe population dynamics of algae (air temperature and rainfall, incident light), temperature\nstratification of water, concentration of oxygen, concentrations of total phosphorus, phosphate,\nvarious forms of nitrogen and organic substances, turbidity and also diversity and frequency of\nphytoplankton and zooplankton species. Between 2012 and 2014 have not occurred massive algal\nblooms in the summer months, however the measured physical, chemical and biological data, can be\nused to assess the development of algal population. The population dynamic factors influencing algal\ngrowth must be understand to be able to predict formation and to attempt suppression of algal\nblooms.
Low Molecular Weight Volatile Organochlorine Compounds from Natural and Anthropogenically Influenced Ecosystems
Forczek, Sándor ; Holík, Josef ; Rederer, L. ; Ferenčík, M.
In the biogeochemical cycle of chlorine, chlorinated compounds participate in natural and\nanthropogenically influenced processes forming also compounds, which can be identical to\nchlorinated pollutants and determine by AOX (adsorbable organic halogens) method. Volatile\norganochlorines are in the center of interest due to their toxicity and possible role in degradation of\natmospheric ozone. Some volatile chlorinated hydrocarbons are both reactive and toxic, such as\nchloroform, which also has natural and anthropogenic sources and can be formed in abiotic and\nbiotic processes. In this study the occurrence of chloroform and AOX is determined in a natural\nclean environment at the Hamry water reservoir, Czech Republic. Furthermore, AOX and\nchloroform concentrations will be evaluated in correlation with meteorological and physicochemical\nconditions of water.
Biomanipulation measures at the Hamry water supply reservoir - poor reaction of phytoplankton to planctivorous fish reduction
Jurajda, Pavel ; Adámek, Zdeněk ; Janáč, Michal ; Roche, Kevin Francis ; Mikl, Libor ; Rederer, L. ; Zapletal, T. ; Koza, V. ; Špaček, J.
One measure commonly used for improving water quality in open waters is biomanipulation of fish stock. Previous studies in shallow lakes confirm the importance of reducing cyprinid populations for increasing zooplankton. Empirical results from reservoirs, however, are scarce. The aim of this study was to evaluate the effect of an intensive reduction of cyprinid fishes and perch fry density between 2009 and 2013 on water quality in the Hamry drinking water reservoir. The abundance of common bream broodstock decreased by around 12 000 individuals over the five years, and biomass dropped below 20 kg.ha-1. Stocking with pike and zander proved less effective. In reservoirs similar to Hamry, reduction of bream biomass can be a highly effective means of increasing filtering zooplankton biomass. Phytoplankton dynamics, however, appear to depend on additional factors, with nutrient loading (especially phosphorus) probably playing the primary role.

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