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Reactions of dominant of phytoplankton towards different ranges of temperature amplitude in mesotrophic Kaliszany Duże Lake. Fragmenta Floristica et Geobotanica Polonica 10: 259–265. Kraków. PL ISSN 1640 629X. ABSTRACT: Phytoplankton observations were conducted in mesotrophic Kaliszany Duże Lake during 1994–1996. These included identifying the seasonal development of the major phylogenetic categories and characteristic taxa and their vertical composition in the epilimnion, metalimnion, and hypolimnion. Dominant and sub dominant taxa were also associated with three distinct ranges of water temperature. The characteristic species within these categories were: (1) Closterium acutum Brébisson ex Ralfs and Aphanizomenon flos aquae fo. gracile (Lemm.) Elenk. at water temperatures ranging from 0.5 to 0.9°C; (2) Coelastrum reticulatum (Dang.) Senn, Asterionella formosa Hassal, Cyclotella radiosa (Grunow) Lemm., and Chroomonas acuta Utermöhl within the range from 2.8 to 6.9°C; and (3) over a wider range of temperatures from 4.5 to 19.0°C, represented by Rhodomonas minuta Skuja.
Tsunami deposits are often characterized by specific diatom assemblages, which may indicate sediment provenance and help identify paleotsunami deposits. In the present study diatom assemblages were studied in tsunami deposits left by the 2004 tsunami in Thailand, as well as in beach sediments, inner shelf marine sediments and freshwater ponds and streams. The assemblages in tsunami deposits had chaotic structure and consisted of species found in all the studied habitats, suggesting erosion of terrestrial and marine sediments by tsunami. The diatom frustules in tsunami deposits were generally rare and often damaged due to excessive wave force. The most common identified species were Amphora turgida Gregory, Cocconeis scutellum Ehrenberg, Diplomenora cocconeiformis (Schmidt) Blazé, Eunotogramma marinum (W. Smith) Peragallo (typical for benthos of marine and brackish environments), and taxa common in freshwaters, including Cyclotella ocellata Pantocsek, Cocconeis placentula Ehrenberg and Encyonema silesiacum (Bleish) D.G. Mann.
The aim of this study was to analyze and compare the relationship between environmental factors (temperature; pH; total phosphorus - TP and nitrogen - TN and their ratio) and occurrence of microcystin producing cyanobacteria in two shallow, eutrophic Polish water bodies, Sulejów Reservoir (Central Poland) and Bnińskie Lake (Western Poland). Samples for analyses were collected from June till October 2005. Cyanobacteria Microcystis aeruginosa and Planktothrix agardhii, responsible for microcystins production, were detected respectively for Sulejów Reservoir and Bnińskie Lake. Molecular analysis of the mcyE gene, indicated the presence of toxigenic strains of cyanobacteria in both water bodies throughout the whole sampling period. The highest extracellular microcystins toxicity established by PPIA was 2.83 μg dm-3 and 2.19 μg dm-3 in samples dominated by M. aeruginosa and P. agardhii respectively. Two different environmental factors in studied water bodies were crucial in occurrence of hepatotoxic cyanobacteria. The strong correlation between biomass of M. aeruginosa and total nitrogen (TN) in Sulejów Reservoir (R=0.83; p<0.05) was observed. Strong negative correlation was found between biomass of P. agardhii and temperature (R=-0.77; p<0.05 and R=-0.70; p<0.05) in Bnińskie Lake.
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