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1

Microbial and classic food web components under ice cover in eutrophic lakes of different morphometry and fisheries management

Kalinowska K., Napiórkowska-Krzebietke A., Bogacka-Kapusta E., Hutorowicz J., Pyka J., Stawecki K., Kapusta A., Chybowski Ł.

Oceanological and Hydrobiological Studies

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2017

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Vol. 46, No. 3

271--282

EN

The thickness and duration of ice cover are strongly influenced by global warming. The aim of this study was to determine chemical (organic carbon, total nitrogen and phosphorus concentrations) and biological (nanoflagellates, ciliates, phytoplankton, rotifers, crustaceans) parameters under the ice cover in three eutrophic lakes (Masurian Lake District, Poland), differing in their morphometry and fisheries management. All the studied groups of organisms showed high variability over a short time. Taxonomic composition of planktonic communities, except for rotifers and phytoplankton, was similar in all lakes. Nanoflagellates were dominated by autotrophic forms, while ciliates were primarily composed of small oligotrichs and prostomatids. Nano-sized diatoms and mixotrophic cryptophytes were the most important components of phytoplankton and they formed an under-ice bloom in one lake only. Rotifers were mainly represented by Keratella cochlearis, Polyarthra dolichoptera and Asplanchna priodonta. Among crustaceans, copepods clearly dominated over cladocerans. Our research suggests that winter was a very dynamic period. In the under-ice conditions, pelagic organisms were strongly dependent on each other. The shallow lake and the deeper, small lake differed significantly in nutrient and chlorophyll concentrations, ciliate and phytoplankton biomass and the ratio of autotrophic to heterotrophic biomass. These results suggest that morphometric parameters may affect planktonic organisms during the ice-covered period.

2

Wrotki : wielofunkcyjne biologiczne narzędzie w oczyszczalniach ścieków

Pajdak-Stós A., Fiałkowska E., Kocerba-Soroka W., Sobczyk M., Starzycka J., Fyda J.

Forum Eksploatatora

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2016

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Nr 6 (87)

18-20

PL

Wrotki to niewielkie bezkręgowce często występujące w osadzie czynnym. Ich pozytywna rola w procesie oczyszczania ścieków jest znana od lat [ 2000; Lapinski i Tunnacliffe 2003]. Wrotki uznawane są za wskaźniki zdrowego, ustabilizowane i dobrze funkcjonującego osadu. Odżywiają się zarówno bakteriami jak i zawieszonymi cząstkami materii organicznej. Dzięki temu przyczyniają się do lepszego kłaczkowania osadu, poprawiają jego właściwości sedymentacyjne, a tym samym wpływają na klarowność odpływu. Wrotki są w stanie zarówno odfiltrowywać bakterie rozproszone dzięki specjalnemu aparatowi wrotnemu, kierującemu strumień wody do aparatu gębowego, jak i zjadać bakterie z powierzchni kłaczków dzięki mastaksowi, czyli specjalnej wapiennej strukturze ułatwiającej chwytanie i miażdżenie pokarmu. To właśnie dzięki specyficznej budowie aparatu gębowego niektóre gatunki wrotków są w stanie odżywiać się bakteriami nitkowatymi, które są niejadalne dla niemal wszystkich pierwotniaków i pozostałych bezkręgowców. Po raz pierwszy ta unikatowa zdolność wrotków została opisana przez Fiałkowską i Pajdak-Stós [2008] w pracy, w której wykazano zdolność wrotków z gatunku Lecane inermis do ograniczania zagęszczenia Microthrix parvicella w osadzie czynnym. Możliwość wykorzystania wrotków przy kontroli puchnięcia osadu została objęta ochroną patentową w Polsce i kilku krajach europejskich.

3

Rotifer trophic state indices as ecosystem indicators in brackish coastal waters

Gutkowska A., Paturej E., Kowalska E.

Oceanologia

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2013

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No. 55 (4)

997--899

EN

Thanks to their short life cycles, rotifers react rapidly to changes in environmental conditions and so may be useful for biological monitoring. The objective of this paper was to investigate the applicability of rotifer trophic state indices as indicators of the trophic state of brackish waters, as exemplified by the Vistula Lagoon. Carried out in summer from 2007 to 2011, this study showed no significant correlation between the Lagoon's trophic state and the rotifer structure. This confirms the limited applicability of rotifer trophic state indices for evaluating water quality in brackish water bodies.

4

The Toxicity of Aluminium Salts to Lecane Inermis Rotifers : Are Chemical and Biological Methods Used to Overcome Activated Sludge Bulking Mutually Exclusive?

Klimek B., Fiałkowska E., Fyda J., Kocerba-Soroka W., Pajdak-Stós A., Sobczyk Ł.

Archives of Environmental Protection

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2013

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Vol. 39, no. 3

127--138

EN

The aim of this study was to assess the effects of two flocculants that are often used to overcome activated sludge bulking problems - aluminium chloride, AlCl3, and aluminium sulphate, Al2(SO4)3 - on Lecaneinermis (Rotifera, Monogononta) at three different temperatures: 8, 15 and 20°C. The mean EC50 value (effective concentration, mg dm-3) calculated for the 24 h mortality test was 0.012 mg Al3+dm-3. Next, the effects of low concentrations of the Al-salts on the population development from single individuals (parthenogenetic females) were tested in a 21-day experiment. At concentrations as low as EC4.8 and EC0.48, both Al-salts affected rotifer population negatively. However, temperature was the most pronounced factor that modified the toxicity of the Al-salts to the rotifers. On the 12th day of the experiment, there were significant interactions between temperature and the Al-salts, indicating that the chemicals were more toxic to the rotifers at 20°C than at lower temperatures. The weaker rotifers sensitivity to Al-salts (especially to AlCl3) in temperatures below 15°C, when the biggest problems associated with sludge bulking occurs,may means use both rotifers and chemicals reasonable and effective.

PL

Sole glinu są powszechnie stosowanym fl okulantem, służącym zwalczaniu puchnięcia osadu czynnego w biologicznych oczyszczalniach ścieków. Nowa idea biologicznego zwalczania tego niekorzystnego dla prawidłowej pracy oczyszczalni zjawiska polega na zastosowaniu wrotków z gatunku z Lecaneinermis. Wrotki te naturalnie występują w osadzie czynnym i są w stanie zjadać bakterie nitkowate, jak Microthrixparvicella, sprawiające najwięcej problemów w eksploatacji oczyszczalni podczas miesięcy zimowych. Celem badań było porównanie toksyczności chlorku glinu AlCl3 oraz siarczanu glinu Al2(SO4)3 dla wrotków Lecaneinermis w trzech temperaturach: 8, 15 and 20°C. Średnią wartość EC50 (stężenie powodujące 50% efekt, mg dm-3) dla śmiertelności wrotków na podstawie 24-godzinnego testu ustalono na poziomie 0.012 mg Al3+ dm-3. Następnie, badano wpływ niskich stężeń soli glinu na tempo wzrostu populacji z pojedynczego osobnika (partenogenetyczna samica) w 21-dniowym eksperymencie. Ustalono, że stężenia na poziomie odpowiadającym EC4.8, a nawet EC0.48 wpływają negatywnie na tempo wzrostu populacji. Temperatura silnie wpływała na toksyczność glinu. W 12-tym dniu eksperymentu stwierdzono, że zachodzi istotna interakcja pomiędzy toksycznością glinu i temperaturą, wskazująca, że w 20°C glin jest bardziej toksyczny dla wrotków niż w niższych badanych temperaturach. Mniejsza wrażliwość wrotków na glin w temperaturze poniżej 15°C może oznaczać, że łączenie tych dwóch metod zwalczania puchnięcia osadu czynnego w miesiącach zimowych może być racjonalnym i efektywnym rozwiązaniem.

5

Has zooplankton 24 hour vertical distribution pattern in Lough Derg (Ireland) been changed over the period of ~90 years?

Pociecha A., McCarthy T.K.

Oceanological and Hydrobiological Studies

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2011

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Vol. 40, No.3

28-35

EN

The vertical distribution of zooplankton was examined in Lough Derg, Ireland. Zooplankton was collected at one location every 2 m from the surface to the bottom during 24 hours at four-hour intervals. Zooplankton was identified to the species level and its density was calculated for each taxon, depth and hour. We recorded 9 rotifer, 3 copepod, and 4 cladoceran species. The highest total zooplankton density (rotifers, copepods, cladocerans, mysids and zebra mussel larvae) was recorded at 3 a.m. Rotifers preferred mainly a depth from 0 to 8 m, while copepods and cladocerans were observed within the whole water column during a 24 hour observation. It was a different pattern of diurnal migration than that Southern and Gardiner (1932) received, though they didn’t study rotifers. Probably food concentration and/or predators, or other environmental factors could influence the diel vertical migration of zooplankton from Loug Derg.

6

Efektywność wrotków w kontroli puchnięcia osadu w zależności od temperatury

Pajdak-Stós A., Fiałkowska E.

Forum Eksploatatora

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2011

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Nr 5 (56)

18-24

PL

W oparciu o wyniki wcześniejszych badań, które pokazały, że wrotki Lecane inermis wyizolowane z prób osadu czynnego są zdolne do odżywiania się bakteriami nitkowatymi, przeprowadzono badania mające na celu sprawdzenie, czy efektywność wrotków w ograniczaniu rozwoju bakterii nitkowatych odpowiedzialnych za puchnięcie osadu czynnego jest zależna od temperatury. Wyniki pokazały, że wrotki Lecane statystycznie istotnie zmniejszyły zagęszczenie nitek Microthrix parvicella i Nostocoida limicola. Wrotki nie tylko przetrwały przeniesienie z hodowli do osadu czynnego, ale też szybko się tam rozmnażały w warunkach eksperymentalnych. Ich liczebność osiągnęła najwyższe wartości w temperaturze 20oC, doprowadzając do znaczącego zmniejszenia zagęszczenia bakterii nitkowatych. W temperaturze 8oC efektywność wrotków w ograniczaniu zagęszczenia bakterii nitkowatych okazała się nieistotna w porównaniu z kontrolą, ale - co ważne - wrotki przeniesione do osadu w tej temperaturze przetrwały i utrzymały aktywność. W eksperymencie z osadem czynnym, w którym dominowała bakteria nitkowata Nostocoida limicola, zagęszczenie bakterii nitkowatych w 20oC zmniejszyło się pod wpływem wrotków o 95 %, podczas gdy w przypadku Microthrix parvicella o 50%. Wyniki opisanych eksperymentów pokazują, że wrotki potencjalnie mogą być stosowane jako biologiczny czynnik ograniczający puchnięcie osadu w oczyszczalniach ścieków. Po raz pierwszy zwrócono też uwagę na fakt, że sezonowość przypisywana zjawisku puchnięcia osadu może być wynikiem zależnych od temperatury zakłóceń zależności troficznych wrotki-bakterie nitkowate.

7

The role of lake shore sand deposits as bank of ciliate, rotifer and crustacean resting forms : experimental approach

Kalinowska K., Ejsmont-Karabin J., Rybak J.

Polish Journal of Ecology

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2010

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Vol. 58, nr 2

323-332

EN

The experiment, with the use of sand deposit from hygroarenal (shore sand beach wetted by lake waves) of the beach of eutrophic Lake Mikołajskie (Masurian Lakeland, Poland), was performed in order to test the hypothesis that shore sand deposit is the bank of resting forms of ciliate, rotifer and crustacean species. The experiment was conducted over a 38 days period in March-April 2004. Frozen sand taken in winter was exposed in aquariums filled with pre-filtered (GF/C) lake water in stable temperature (20[degrees]C), oxygen saturation and 12:12 light/dark conditions. Samples (three replicates) were taken each day. A total number of 44 ciliate, 59 rotifer and 9 crustacean taxa were identified during the studied period. Resting forms of different species and/or taxonomic groups developed in different time and it may be the result of different strategies in colonization of new habitats. Organisms forming resting cysts such as ciliates (11 species) and bdelloid rotifers appeared after the first day of the incubation whereas organisms hatching from resting eggs (monogonont rotifers and crustacea) were observed from the 2nd-3rd day of the experiment. The numbers of all the studied groups of organisms increased gradually and then strongly decreased indicating probably nutrient and/or organic matter limitation. The highest numbers of ciliates (731 ind. cm[^-2] of sand) was found on the 5th day, rotifers (987 ind. 100 cm[^-2]) on the 23rd day, cladocerans (60 ind. 100 cm[^-2]) on the 21st day and copepods (30 ind. 100 cm[^-2]) on the 33rd day of the experiment. The results of this study suggests that shore sand deposits being the temporal refugium for the small-bodied invertebrates transported here with the wave action may also play an important role as the transfer for their further dispersal in addition to postulated ways of expansions such as wind, rain, animals and surface runoff.

8

Prace nad nowatorskimi metodami zwalczania puchnięcia osadu otrzymują wsparcie z funduszy strukturalnych Innowacyjna Gospodarka

Fiałkowska E., Pajdak-Stós A.

Forum Eksploatatora

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2010

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Nr 1 (46)

30-30

PL

Już w latach 70. ubiegłego wieku rozpoczęto badania dotyczące nadmiernego rozwoju bakterii nitkowatych w oczyszczalniach ścieków i poszukiwania sposobów ograniczania tego niekorzystnego zjawiska. Jednak dopiero dwie ostatnie dekady przyniosły rozwiązania, które pozwalają w miarę skutecznie ograniczać puchnięcie osadu czynnego. Niestety metody te, polegające głównie na stosowaniu środków chemicznych, są w większości niedoskonałe i obarczone wysokimi kosztami. Nadal trwają poszukiwania metod które będąc skuteczne byłyby jednocześnie tanie i przyjazne dla środowiska naturalnego. Prowadzone przez nas kilkuletnie badania osadu czynnego z wielu oczyszczalni ścieków zwróciły naszą uwagę na wyraźną zależność pomiędzy licznym występowaniem wrotków a ograniczonym rozwojem bakterii nitkowatych, o czym można przeczytać w artykule "Alternatywne metody zwalczania bakterii nitkowatych" w Forum Eksploatatora nr 5/2009. Wyniki naszych pierwszych eksperymentów przeprowadzonych w skali laboratoryjnej dają nadzieję na opracowanie nowatorskiej, biologicznej metody ograniczania puchnięcia osadu, która opierać się będzie na wykorzystaniu zależności pokarmowych między organizmami naturalnie występującymi w osadzie czynnym.

EN

Despite numerous researches concerning ways of limiting the excessive growth of filamentous bacteria in activated sludge, there is still no universal method which would help to achieve this goal. The most popular chemical methods, apart from being not always effective, are rather expensive. The results of our preliminary studies indicate that some rotifers occurring naturally in activated sludge and feeding on filaments, might be used as a factor significantly limiting bacteria growth. Preparing a new biological method requires a lot of studies carried out in cooperation with other scientific centers and wastewater treatment plants. Further research will be supported by a grant co-financed from EU resources in a frame of the Program lnnovative Economy - one of six national programs under National Strategic Reference Framework. The project will last three years and is divided into several stages. The goal of the first of them is to select species of rotifers most effective in limiting the growth of bacteria and to find the best method of mass-cultivating them. In the laboratory, the influence of food, temperature and oxygen concentration on the proliferation of rotifers from different clones will be tested. In the next stage rotifers' resistance to toxic wastes will be tested. Another very important goal is to check the influence of high quantities of rotifers on the volume index of the sludge and on the effluent chemistry. The end result of the whole project is to prepare appropriate procedures and utilities which would enable plant operators to use the method directly in treatment plants.

9

Zooplankton community structure within various macrophyte stands of a small water body in relation to seasonal changes in water level

Kuczyńska-Kippen N., Nagengast B., Celewicz-Gołdyn S., Klimko M.

Oceanological and Hydrobiological Studies

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2009

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Vol. 38, No.3

125-133

EN

Different morphological features of particular water bodies, physical and chemical factors of their waters and sediments will have an impact on the development of specific aquatic vegetation types, which in turn will affect the creation of specific communities of plankton organisms. Therefore the aim of this study was to analyse the quantity and quality changes of macrophyte structure in relation to the lowering of the water level. Furthermore, the relationship between zooplankton community densities and environmental parameters was studied. Another aspect of the study was to investigate the similarity of the zooplankton communities of particular sampling stations in the three examined seasons. The study was carried out on Dąbrówka water body, a shallow and macrophyte-dominated pond, situated 10 km west of Poznań, Wielkopolska region, western Poland. The examination was conducted in the three seasons: spring, summer and autumn. The results revealed that during one vegetative period, including three seasons – spring, summer and autumn, three different layouts of aquatic vegetation were obtained, which reflected a significant transformation in the macrophyte cover. Along with the lowering of the water level the structural changes, especially in the case of submerged vegetation were recorded, which in each season was represented by different dominating species. Only three significant correlations between zooplankton densities and environmental factors observed. Negative relationship concerned total nitrogen and two positive related to biometric parameters of the macrophyte habitat (plant biomass plant stem volume). The plant biomass was a predictor of cladoceran abundance and plant stem volume referred to rotifers, which may reflect the complexity of the aquatic plant habitat, indirectly relating to the effectiveness of the macrophyte stand as anti-predator refuge. The analysis of the similarity of the zooplankton communities of particular sampling stations in the three examined seasons did not reveal any clear relationship, either in relation to a particular season or a sampling station. The participation of eutrophic species was highest in the spring and lowest during the autumn season. The open water zone possessed the highest participation of these species compared to the macrophyte zones.

10

The impact of biometric parameters of a hydromacrophyte habitat on the structure of zooplankton communities in various types of small water bodies

Kuczyńska-Kippen N., Nagengast B., Joniak T.

Oceanological and Hydrobiological Studies

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2009

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Vol. 38, No.2

99-108

EN

Hydromacrophyte habitats, which can differ in a multiplicity of biometric parameters, are among the most important factors affecting zooplankton community structure. The main goal of this work was to determine the impact of plant habitat parameters expressed by density, biomass, and plant volume along with chemical features on the composition and dynamics of rotifer and crustacean communities. A number of small water bodies of different origin (12) located in different catchment areas of the Wielkopolska region were analyzed. It was found that helophytes and nymphaeids had the highest biomass and the lowest stem density, while elodeids were of the lowest biomass and the greatest stem density. Similarity analysis confirmed this distribution of biometric parameters among particular ecological groups of macrophytes. The greatest numbers of zooplankton were noted among vegetated zones, which supports the idea of zooplankton using macrophytes as anti-predator refuge. Based on the study of a total of 23 plant stands, it was found that macrophyte biomass and the density of the plant habitat were the strongest predictors of three biometric parameters of zooplankton abundance.

11

The diurnal distribution of the zooplankton community of the littoral zone of Lake Wielkowiejskie (Wielkopolski National Park, Poland)

Kuczyńska-Kippen N., Milecka E.

Oceanological and Hydrobiological Studies

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2009

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Vol. 38, No.2

91-98

EN

The main aim of this study was to analyze the diel distribution of zooplankton communities within the zones of Nymphaea albae, Myriophyllum verticillatum, and Typha angustifolia, and, compared to that, in the open water area of a lake. It also aimed to analyze the relationship between zooplankton densities and the concentration of physicochemical factors and chlorophyll a content. A total of 149 zooplankton taxa were noted, and, despite the narrow range of the research in the analyzed lake, some rare species were noted, among which two - Colurella sinistra and Lecane inopinata – were recorded for the first time among Polish fauna. The rush zone was taxonomically the richest, while the open water area was the poorest. The highest number of individuals was observed in the Myriophyllum bed, while the lowest was noted in the zone dominated by Nymphaea alba. The highest densities of zooplankton occurred at dusk, while the lowest occurred during the day, irrespective of the sampling station. Because Lake Wielkowiejskie is a shallow and macrophyte-dominated water body, the differences in the diurnal distribution of zooplankton communities may suggest horizontal migrations between the pelagic zone and the phytolittoral, as well as between particular macrophyte stands. A positive correlation between the densities of some zooplankters and the concentration of chlorophyll a was found, while a negative relationship with the concentration of nitrites was recorded for Lecane quadridentata and Alonella nana.

12

Spatial distribution of zooplankton communities between the sphagnum mat and open water in a Dystrophic lake

Kuczyńska-Kippen N.

Polish Journal of Ecology

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2008

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Vol. 56, nr 1

57-64

EN

The composition and dynamics of zooplankton (Rotifera, Crustacea) communities were studied in a dystrophic lake (Drawieński National Park, northern Poland). The investigated lake was a typical mid-forest lake of a small area (ca. 0.65 ha) but relatively deep (Z[max] = 6.8m) and covered with a peat (Sphagnum sp.) mat. The study was made in the shallow part of the lake (Z = 0.5 m). Zooplankton was collected twice in August 2004, in triplicate subsamples, taken from three stations (1. under the peat mat, 2. the transitional zone between the peat mat and open water area and 3. open water zone) from two different sites within the same lake. The distance between sampling stations within a transect was ca. 1.5 m. The whole area under study was not greater than 10 m[^2]. Therefore the results concern the very small-scale distribution of zooplankton. The aim of the study was to find out whether spatial segregation of the zooplankton community and the dominating species between the Sphagnum mat and open water zone as well as in the transitional zone between both zones takes place in a dystrophic lake and whether the moss mat can be considered as an anti-predator refuge. Both the species number and zooplankton densities differed between the stations along a transect, being the highest (40 zooplankton species and mean 150 ind 1[^-1] for the whole zooplankton community) in the peat mat and lowest (12 species and 72 ind 1[^-1]) in the open water zone. Humic-water species constituted 24% of the species composition of rotifer and 14% of the crustacean community. Cladocerans prevailed numerically over rotifers. Dominating species - Bdelloidae, Keratella cochlearis Gosse, Polyarthra vulgaris (Carlin), Synchaeta pectinata Ehrenberg, Trichocerca insignis Carlin, Alonella excisa (Fischer), Ceriodaphnia quadrangula (O.F. Muller) - revealed a differentiated pattern of spatial distribution. The mean Shannon-Weaver biodiversity index of zooplankton was not notably high and amounted to 1.45. The highest values were found in the peat mat (mean - 1.76 for rotifers and 0.67 for crustaceans), while the lowest values were found in the open water (0.99 and 0.36 respectively). These results suggest that in the site connected with Sphagnum moss in a humic lake more diverse and abundant zooplankton occurs in relation to other habitats. The differences in zooplankton distribution between the peat mat and the open water zone of the dystrophic lake seems to be affected by biological interactions which relate to predator presence, both vertebrate and invertebrate, and competition between large cladocerans and smaller rotifers. Due to the dominance of larger forms of zooplankton it may be supposed that invertebrate predators may have a more pronounced effect. The habitat within the Sphagnum moss can be considered as a predictable refugium.

13

Interactions of con-generic Lecane species (Rotifera) within different macrophyte patches in a shallow lake

Kuczyńska-Kippen Natalia

Polish Journal of Ecology

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2007

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Vol. 55, nr 1

91-100

EN

The research on the distribution of species of the Lecane genus among different types of macrophytes (including rushes, nymphaeids and two zones of submerged macrophytes) in comparison with open water was carried out for three years in a shallow lake (Lake Budzyńskie, western Poland; an area - 17.4 ha, maximum depth - 2.7 m and a mean depth - 1.4 m) in order to determine the possibility of their competition and of co-existence. The distinct species of submerged macrophytes create separate vegetation beds and patches in the lake. The size of a particular macrophyte bed did not exceed the area of 5 m. Zooplankton samples were collected between 1997 and 1999 (from April to October, at about 2-week intervals) in the shallow part (approx. 1m deep) of a lake. Nymphaeids were only sampled during the 1998 and 1999. Samples were taken at each site using a plexiglass core sampler ([the empty set] 50-mm). Subsamples of a volume of about 1.5 l from the surface layer (0-1.5 m) were sampled from randomly chosen places within each macrophyte patch. Six Lecane species were analysed (Lecane bulla (Gosse), L. closterocerca (Schmarda), L. flexilis (Gosse), L. furcata (Murray), L. luna (Miiller) and L. lunaris (Ehrenberg)). L. bulla dominated at most of the examined stations each year. Detailed seasonal analysis of the abundance of particular species of the Lecane genus in most cases revealed the replacement character of their occurrence. The sudden increase in the numbers of one species caused a simultaneous decrease of another within the same macrophyte stand. A distinct replacement pattern was observed for L. bulla, which was replaced by L. closterocerca or L. luna and for another two pairs of species (L. closterocerca with L. furcata and L. flexilis with L. luna). At the same time, pairs of species such as L. closterocerca-L. lunaris (statistically positive correlation was found in the case of Chara bed - r[s] = 0.70; P = 0.007), L. flexilis-L furcata (within Typha - r[s]= 0.58; P = 0.048) and also L. luna-L. furcata (in the Myriophyllum bed - r[s]= 0.80; P = 0.001) exhibited a similar pattern of seasonal changes without, however, revealing the exchange occurrence between each other. The pattern of species replacement within a genus is an example of the competitive exclusion of closely related species. The nature of the seasonal distribution of species of the Lecane genus, replacing each other over a period of time, may be connected with the niche overlap of particular species, which results in time segregation. Exploitative competition cannot be excluded when describing such behaviour.

14

Zooplankton phosphorus excretion in Swarzędzkie Lake (Western Poland) and its influence on phytoplankton

Kowalczewska-Madura K., Gołdyn R., Szyper H.

Oceanological and Hydrobiological Studies

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2007

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Vol. 36, No.1

3-16

EN

Zooplankton phosphorus excretion was studied in Swarzędzkie Lake in 2000-2002. Phosphorus excretion rates were high from spring through autumn, but low in winter. The highest value, 203.7 žgP l-1 d-1 (vertical profile mean), was recorded in June 2000. The mean rate was 26.6 žgP l-1 d-1 and was 10 times greater for rotifers than for both cladocerans and copepods. In most months, the calculated phosphorus excretion rate was greater than the sum of tributary external phosphorus loading and internal bottom sediment loading. Nevertheless, the influence of the zooplankton phosphorus excretion rate on yearly phytoplankton abundance, biomass and chlorophyll a was not statistically significant. Yearly variance in phytoplankton variables was best explained by a canonical variable composed of internal loading and zooplankton phosphorus excretion (total redundancy 32.8%).

15

Zooplankton structure in architecturally differentiated macrophyte habitats of shallow lakes in the Wielkopolska Region, Poland

Kuczyńska-Kippen N.

Oceanological and Hydrobiological Studies

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2006

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Vol. 35, No.2

179-191

EN

The aim of this examination was to study the impact of the physical parameters, understood as spatial and morphological features, of two macrophyte habitats created by Chara tomentosa and Typha angustifolia on the Rotifera and Crustacea communities of three shallow lakes with extensive macrophyte cover. There were 161 zooplankton species in total identified from three lakes, with over 60% of species common among all lakes. Species richness varied between the sampling stations, with lowest values within the open water zone and highest among macrophyte stands. Significant differences in zooplankton densities between particular stations for all groups of zooplankton were observed, with the highest values within the most diverse and complex habitat – the Chara bed. Furthermore, the distribution of pelagic species between particular stations differed significantly in the case of copepods, with the highest abundance also in the stonewort beds.

16

Response of rotifers to hydrochemical and biotic factors

Żurek R.

Oceanological and Hydrobiological Studies

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2006

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Vol. 35, No.2

121-139

EN

The zooplankton community in an open cast sulphur mine impoundment was investigated over two years. Complicated physical and chemical relationships in this pit ecosystem resulted in an atypical planktonic assemblage. Changes in the rotifer populations were examined over time and space in the pit ecosystem. Only 20 species of rotifers were identified in the impoundment. In winter, Polyarthra dolichoptera coexisted with P. bicerca; in spring, one of the dominant species was Keratella quadrata, while, in summer, Hexarthra fennica, Keratella cochlearis and Synchaeta tremula were all present. In autumn, Filinia longiseta dominated the population. On the border of the oxycline and beneath the thermocline lived Keratella testudo. Thermal and chemical stratification generated five variants of diurnal vertical migrations of planktonic animals including two typical, well-known patterns. Some species were able to penetrate the oxygen-free layer in the hypolimnion. These species were also resistant to low concentrations of hydrogen sulfide. Multidimensional scaling and correspondence analysis identified the following factors as important for rotifers: mineralization and the presence of sulfide with hydrogen sulfide, as well as biotic (predators) or the life supporting parameters: temperature, oxygen. Toxic compounds present in the water, especially sulfides or its derivates, were probably responsible for deformation of the rotifers’ spines in 0.1% of the population.

17

Zgrupowanie wrotków (Rotatoria) planktonowych w strefie litoralowej zbiornika Dziećkowice

Penczek K.

Problemy Ekologii

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2005

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R. 9, nr 1

28-36

PL

W artykule przedstawiono wyniki badań przeprowadzonych w strefie litoralowej zbiornika Dziećkowice. Celem pracy było: określenie składu gatunkowego Rotatoria badanego zbiornika, opisanie struktury dominacji, stałości oraz znaczenia ekologicznego wrotków występujących w zbiorniku Dziećkowice, prześledzenie zmian ilościowych Rotatoria, porównanie występujących zespołów na badanych stanowiskach, zbadanie wpływu czynników abiotycznych na występowanie i zagęszczenie wrotków, określenie sezonowych zmian występowania Rotatoria, określenie trofii i saprobowości zbiornika na podstawie zebranych zgrupowań.

EN

The article presents the results of a research carrier out in the littoral zone of the Dziećkowice reservoir. The study was aimed at determining the species composition of Rotatoria living in the Dziećkowice reservoir, describing their domination structure and ecological role alongside with investigating the quantitative changes of Rotatoria population, analyzing the impact of abiotic factors on the occurrence and condensation of rotifers, determining the seasonal variability of Rotatoria occurrence and the reservoir's trophy and saprophy based on the collected groupings.

18

Preliminary investigations of psammon rotifers in two reservoirs in Upper Silesia

Bielańska-Grajner I.

Oceanological and Hydrobiological Studies

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2004

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Vol. 33, No. 1

37--45

EN

Psammon rotifers were investigated in two lakes of different trophy and degrees of pollution. The Pławniowice Duże Reservoir is mesotrophic, while the Dzierżno Duże Reservoir is highly eutrophic and polluted. Samples were collected from three zones on sandy beaches - one meter above the shoreline (eupsammon), at the shoreline (hygropsammon) and below the water level (hydropsammon). A larger number of rotifer species (28) was detected in the Pławniowice Duże Reservoir than in the Dzierżno Duże Reservoir (18). The species structure of the rotifer communities differed in the two reservoirs. While the density of eupsammic rotifers observed in both reservoirs was high, significant differences were noted in the abundance of them. The dominant species were Cephalodella gibba, Cephalodella catellina and Lecane closterocerca.