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Degradation of the recreational functions of urban lake: a preliminary evaluation of water turbidity and light availability (Strzeszyńskie Lake, western Poland)

100%

Joniak T., Jakubowska N., Szelag-Wasilewska E.

Polish Journal of Natural Sciences

2013

tom 28

nr 1

Turbidity, as an optical property describing water clarity, is a measure of the degree to which water loses its transparency due to the presence of suspended solids, including phytoplankton and dissolved substances. Lake Strzeszyńskie was regarded as the clearest lake in Poznań (western Poland) for many years. In July 2011 first time in the history of lake the watering place was closed due to picocyanobacteria bloom and high water turbidity. The subject of paper was the preliminary assessment of changes the vertical propagation and availability of PAR, turbidity and content of OAS in the lake before and at the time of phytoplankton bloom. To comparison were taken sample from a peak of summer season of 2009 and 2011, respectively. Large changes in depths of photic zone in both periods were stated as well as reducing of euphotic zone and increase the darker disphotic zone. Picocyanophyceae bloom and high light scattering caused by high content of OAS in surface layer resulted in visible effect of the water opalescence.

Water blooms and cyanobacterial toxins in lakes

100%

Jakubowska N., Zagajewski P., Goldyn R.

Polish Journal of Environmental Studies

2013

tom 22

nr 4

In summer 2007 water samples were collected in three lakes situated in the region of the Great Mazurian Lakes (northeastern Poland) displaying different types of catchment area: Lake Niegocin, Lake Piłwąg and Lake Rekąty. The main objective of this study was to analyze the difference in species composition of cyanobacteria and to determine the concentration of cyanotoxins. Potentially toxic species of cyanobacteria were found to be the dominant species in each sample. Microcystis aeruginosa was dominant in Lake Niegocin, Limnothrix redekei and Planktolyngbya limnetica in Lake Piłwąg, and Planktothrix agardhii in Lake Rekąty. Furthermore, the occurrence of an invasive cyanobacteria species, Cylindrospermopsis raciborskii, was detected in two lakes, Rekąty and Piłwąg. The toxin concentration in all of the samples did not exceed the guideline value of 5 μg·l-1 recommended by the World Health Organization for recreational waters, which may indicate the dominance of non-toxic strains.

Ograniczanie wyników

1 Polish Journal of Environmental Studies

1 Polish Journal of Natural Sciences

2 Jakubowska N.

1 Goldyn R.

1 Joniak T.

1 Szelag-Wasilewska E.

1 Zagajewski P.

2 2013

Wyniki wyszukiwania

Degradation of the recreational functions of urban lake: a preliminary evaluation of water turbidity and light availability (Strzeszyńskie Lake, western Poland)

Water blooms and cyanobacterial toxins in lakes