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The influence of the ecohydrological rehabilitation in the cascade of Arturówek reservoirs in Łódź (Central Poland) on the cyanobacterial and algae blooming

Szulc B., Jurczak T., Szulc K., Kaczkowski Z.

Oceanological and Hydrobiological Studies

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2015

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Vol. 44, No. 2

236--244

EN

The objective of the studies included a complex of three reservoirs (upper, middle and lower Arturówek) which play an important recreational role for the residents of the Łódź city and the surrounding areas. The reservoirs were constructed on the Bzura River and are located in the area of the Łódź Hills Landscape Park. The river, the ecological status of which was defined as moderate, has a great influence on the quality of water in the Arturówek reservoirs. A total of 36 planktonic samples were collected in 2011-2013 during spring, summer and autumn seasons. During the studies, the selected physical and chemical parameters were measured. In addition to taxonomic analysis of Cyanobacteria and algae, the analyses of abundance and biomass of phytoplankton and the concentration of microcystins in water were conducted. In 2013, ecohydrological rehabilitation of the Arturówek reservoirs was carried out. Investment works included: removal of the bottom sediments to reduce internal loads, construction of buffer vegetation zones (ecotones) and sedimentation-biofiltration systems to reduce the amounts of pollutants flowing into reservoirs with rainwater. Significant changes in the structure of phytoplankton were observed in 2013. Every year, the disappearance of Cyanobacterial blooms was observed in favor of an increasing contribution of algae.

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Allelopathic effects of cyanobacterial filtrates on Baltic diatom

Śliwińska S., Latała A.

Contemporary Trends in Geoscience

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2012

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Vol. 1, iss. 1

103--107

EN

Allelopathy may be one of the factors affecting the formation of massive and harmful algal blooms in aquatic environments. Recent studies indicate that blooms of cyanobacteria in the Baltic Sea has grown significantly in last decades, so it is important to determine the allelopathic interactions between the dominant species of cyanobacteria and microalgae. In this work we investigated the influence of allelopathic compounds on the growth of Skeletonema marinoi by addition of cell-free filtrate of the Baltic cyanobacterium Nodularia spumigena cultures grown under different temperature (15-25ºC). Additionally the effects of filtrates of both an exponential and a stationary growing culture of N. spumigena were tested on diatom. These studies indicate that high temperature affected the donor species by increasing its production of allelochemicals. The highest drop of growth of analyzed diatom were observed after the addition of cell-free filtrate obtained from N. spumigena grown at 25ºC and constituted 70% of their control. N. spumigena was only allelopathic in exponential growth phase, whereas the cyanobacteria filtrate from stationary phase have any effect on S. marinoi. These findings suggest that N. spumigena may reveal allelopathic activity and that the production of allelopathic substances is influenced by the temperature and growth phase of cyanobacteria.

PL

Allelopatia może być kluczowym czynnikiem wpływającym na tworzenie się masowych zakwitów sinic w wielu wodnych ekosystemach. Badania pokazują, że zakwity sinic w Morzu Bałtyckim w ostatnich dekadach znacznie się nasiliły, dlatego tak ważne jest określenie stopnia oddziaływania allelopatycznego dominujących w tym akwenie gatunków fitoplanktonu. W przeprowadzonych badaniach określono wpływ związków allelopatycznych produkowanych przez bałtycką sinicę Nodularia spumigena hodowaną w różnych temperaturach (15-25ºC) na wzrost okrzemki Skeletonema marinoi. Dodatkowo w niniejszej pracy porównano wpływ przesączu komórkowego uzyskanego z hodowli sinic będących w fazie logarytmicznego i stacjonarnego wzrostu. Badania wykazały, że temperatura modyfikuje allelopatyczne oddziaływania i na przykład najwyższy spadek wzrostu zaobserwowano u S. marinoi po dodaniu przesączu uzyskanego z kultur N. spumigena hodowanych w 25ºC. Wynosił on 70% w stosunku do kontroli. Ponadto w pracy stwierdzono, że N. spumigena wykazywała oddziaływanie allelopatyczne na badaną okrzemkę jedynie wtedy, gdy dodawany przesącz komórkowy pochodził z fazy logarytmicznego wzrostu. Wyniki uzyskane w niniejszej pracy sugerują, że bałtyckie sinice mogą wykazywać oddziaływania allelopatyczne w stosunku do okrzemek a produkcja związków allelopatycznych może być zależna od temperatury oraz fazy wzrostu, w której znajdują się organizmy donorowe.

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Toxin-producing blooms of the cyanobacterium Microcystis aeruginosa in rainwater ponds in Saudi Arabia

Al-Shehri A.M.

Oceanological and Hydrobiological Studies

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2010

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Vol. 39, No.4

171-187

EN

The present study describes for the first time the toxin production by Microcystis aeruginosa blooms in three rainwater ponds in Saudi Arabia. The cell density of M. aeruginosa correlated with chlorophyll-a, temperature and nutrient concentrations. Microcystis blooms produced the hepatotoxin microcystin (MCYST) with concentrations of 0.988-3.04 mg g-1 dry weight, and a toxin profile consisting mainly of MCYST-RR, -YR and -LR. MCYSTs were also detected in pond waters at levels exceeding the WHO guideline value (11.2-34.6 μg l^-1). The study suggests the monitoring of toxic cyanobacteria in such potable water sources to protect the public from potent toxins.

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Cyanobacterial blooms in the Gulf of Gdańsk (southern Baltic): the main effect of eutrophication

Jóźwiak T., Mazur-Marzec H., Pliński M.

Oceanological and Hydrobiological Studies

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2008

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Vol. 37, No.4

115-121

EN

The most striking aspect of eutrophication in the Baltic are the summer blooms of cyanobacteria. Some of the blooms are toxic to marine organisms and poisonous to people. Our studies, conducted over the last three decades, report on mass occurrences of Aphanizomenon flos-aquae (L.) Ralphs and Nodularia spumigena Mertens. It is generally assumed that cyanobacterial blooms in the Baltic Sea are stimulated by the low ratio of N:P and initiated by high water temperatures. The mean annual value of this ratio in the Gulf of Gdańsk, since 1981, is 7:1-8:1, with the lowest values, of about 4, being seen in July when the cyanobacterial blooms begin. During three years of observations (1992-1994) the smallest number of recorded taxa was reported in 1993, concurrent with the lowest water temperature (16°C in summer). In August 1994, when the temperature increased to 22°C, a huge bloom was seen. Nodularia spumigena was very abundant in that bloom, and nodularin concentration of 2.59 mg toxin per g dry weight of bloom sample was recorded. A similar situation has also been observed in the years 2003-2006.

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The potential causes of cyanobacterial blooms in Baltic Sea estuaries

Pliński M., Mazur-Marzec H., Jóźwiak T., Kobos J.

Oceanological and Hydrobiological Studies

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2007

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Vol. 36, No.1

125-137

EN

Nodularia spumigena Mertens, Aphanizomenon flos-aquae (L.) Ralfs and some species of the genus Anabaena are the dominant cyanobacterial taxa occurring in the Gulf of Gdańsk. The heterocystous cyanobacteria use dissolved molecular N2 as an additional nitrogen source, and this allows them to bloom during the summer when growth of other phytoplankton species is normally nitrogen-limited. Although cyanobacterial blooms have been reported in the Baltic Sea since the mid-19th century, the extent and intensity of blooms have recently increased due to anthropogenic sources of eutrophication. Increased river phosphorus input and changes in the phosphorus to nitrogen ratio are implicated as causal factors. After us the initial cause of the cyanobacterial bloom is a low N:P ratio, which indicates phosphorus excess, i.e. favourable nutrient conditions for nitrogen-fixing algae. An N:P ratio of 10 has been considered an approximate value for the N:P requirements of Baltic phytoplankton. For several years this ratio has been lower than 10. The mean annual value of the N:P ratio for the water of the Gulf of Gdańsk ranged from 3 to 7. Differences in the intensity of blooms observed in different years could be linked to temperature. During hot summers, when the seawater temperature increased to 20°C, large blooms were noted. For the cyanobacterial blooms in the Baltic Sea, the low N:P ratio is the primary factor and high temperature is a starting point.

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Temperature and N:P ratio as factors causing blooms of blue-green algae in the Gulf of Gdańsk

Pliński M., Jóźwiak T.

Oceanologia

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1999

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No. 41 (1)

73-80

EN

The bloom dynamics of two planktonic, nitrogen-fixing species of blue-green algae Aphanizomenon flos-aquae (L.) Ralfs and Nodularia spumigena Mertens in the Gulf of Gdansk were studied. The Gulf of Gdansk is a shallow part of the Baltic Sea where the water has a mean salinity of ca 8 PSU. Increased riverine nutrient input and/or changes in the N:P ratio are indicated as factors causing blue-green algae blooms. A low N:P ratio appears to trigger blooms. The mean annual value of N:P in the Gulf of Gdansk since 1981 is 6.5 with a minimum of ca 3. There could be a link between temperature and the year-to-year differences in bloom intensities. A huge bloom of toxic N. spumigena was reported in July 1994 when the water temperature rose to 22oC.

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Cyanophyta blooms in Koronowski Reservoir in the background of environmental conditions

Wiśniewska M.

Oceanological Studies

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1998

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Vol. 27, No. 1

45-52

EN

On the basis of floristic analysis, the occurrence of 132 taxons of plankton algae in Koronowski Reservoir was determined. The spring and autumn plankton was dominated by diatoms, while summer plankton by blue-green algae. The species composition, structure of the abundance of algae and concentration of chlorophyll as well as physicochemical conditions of water suggested a highly eutrophic character of this reservoir with a starting expansion of blue-green algae, mainly species considered to be toxic.