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Methods of reduction of excessive biomass of phytoplankton
CHADTOVÁ, Gabriela
The aim of this study was to prepare review of methods to combat over development of phytoplankton. The work also includes a critical evaluation of usability, efficacy and risks of these methods. The methods to combat over-development of phytoplankton can be divided into direct and indirect. While the direct methods acts directly against phytoplankton, indirect methods are based mostly on reducing the amount of nutrients available for phytoplankton growth. Both of these methods can be further divided to biological, physico-mechanical and chemical. The direct methods of physico-mechanical include ultrasound, flushing and dilution, direct chemical methods include the use of chemical algaecides, coagulants and flocculants. Direct biological methods are especially divided by the principle of parasites(viruses,bacteria and fungi), competitors (algae), allelopathy (extracts from higher plants),predation (protozoa and herbivorous fish). The indirect physico-mechanical methods include extraction and overlapping sediment. Chemical methods are meant by the binding of nutrients to insoluble compound in the sediment and the biological methods are meant use of communities of bacteria for mineralization of sediments. The next part of the work is devoted to the characteristics of algae and cyanobacteria, as well as factors affecting the formation and development of algal blooms. In this part of the work I focus mainly on cyanobacteria, their toxins and the effect they have on the individual components of aquatic ecosystems.
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Anabaena - Phenotypic and genotypic diversity of planktonic strains in fishponds and reservoirs of the Czech Republic
ZAPOMĚLOVÁ, Eliška
Morphological diversity of 61 Anabaena populations of 13 morphospecies was described under the field conditions of Czech fishponds and reservoirs. Polyphasic approach was then applied in classification of 45 clonal strains isolated from those populations. Detailed morphological analyses were performed and partial 16S rRNA gene sequences were obtained for 33 of the strains, and secondary metabolite production was evaluated in 20 strains. Plasticity of morphological characteristics under varied conditions of light, temperature, nitrogen and phosphorus was studied in selected strains, as well as their temperature and light growth requirements. The results were then discussed with respect to the delimitation of single Anabaena morphospecies. A new genus Sphaerospermum was defined for the morphospecies Anabaena kisseleviana, A. reniformis and Aphanizomenon aphanizomenoides, whose phenotypic and genotypic features differed considerably from all other Anabaena morphospecies. Unique information was provided on the occurrence and distribution of A. reniformis and Aph. aphanizomenoides in the Czech Republic.
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Analysis of phytoplankton pigments from freshwater systems.
ŽIŠKOVÁ, Eva
The aim of this study was to use pigments to determine freshwater phytoplankton composition . The samples were collected from freshwater lakes in the Czech Republic and Germany. The pigment analyses were conducted using the High Performance Liquid Chromatography (HPLC). The HPLC data were processed by computer program CHEMTAX to calculate the composition of phytoplankton. The obtained pigment data were compared with standard light microscopy which was used to obtain more detailed taxonomic resolution.
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Alien, invasive and expansive species of cyanobacteria and algae in county Jihlava
MELICHAR, Antonín
The phytoplankton from 30 water reservoirs in county Jihlava was sampled during the year 2007. Species composition and relative abundance of species was studied and abiotic factors like pH, conductivity, temperature and dissolved ions were measured. High attention was paid to an appearance of alien, invasive and expansive species of algae and cyanobacteria. Literature search about alien species of diatoms in the Czech Republic was compiled.
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Nízkoteplotní emisní spektroskopie v ekofyziologii fytoplanktonu
Prášil, Ondřej
Low temperature (77K) emission spectroscopy is standard techniques of photosynthesis research. Emission spectroscopy provides wealth of information about both photosystems, their pigment composition, relative activity and stoichiometry and has been successfully applied in stress physiology. In this talk I will discuss examples of the use of portable versions of spectrofluorometer. Specifically, I will show that 77K emission spectra of phytoplankton from oligotrophic HNLC areas of subtropical gyres contain information that can be used as marker of iron limitation and provide clues about mechanisms of observed high intrinsic fluorescence yield in these areas
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