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1
Content available remote Is zooplankton an indicator of the water trophic level in dam reservoirs?
EN
The trophic state of ten dam reservoirs was assessed using a zooplankton community. In order to determine the trophic state of dam reservoirs, we used indices calculated on the basis of density and species structure of Rotifera and Crustacea communities. Samples were collected once during summer 2012 in ten dam reservoirs. The largest numbers of zooplankton taxa were found in a lowland high meso-eutrophic dam reservoir (Koronowski) and the lowest ones in a submontane low eutrophic dam reservoir (Lubachowski). The trophic state was determined for the investigated dam reservoirs. In the case of the Rotifera community, the percentage of the tecta form in the Keratella cochlearis population and the proportion of high-trophic species in the total species density were the best indices to describe the water trophic status. In the case of the crustacean community, the best indices were the density of Crustacea and the biomass of Cyclopoida. The high value of all indices calculated on the basis of density and species structure of Rotifera and Crustacea was determined for Zygmunt August Lake, whose trophic status was defined as highly eutrophic to polytrophic. Our study has shown that zooplankton could be a good ecosystem indicator of the water trophic level in dam reservoirs.
2
Content available remote Biodiversity of rotifers in urban water reservoirs of Southern Poland
EN
Rotifer diversity was studied in three different types of artificial water bodies situated in one of the largest cities in Poland. The bodies of water were as follows: a fountain in a city park, the Nowa Huta dam reservoir, and the Bagry gravelpit. The lowest number of rotifer species (23) was noted in the urban fountain, and the highest (36) in the Bagry gravel-pit lake. Rotifers’ communities in the investigated water reservoirs showed different levels of diversity and density. The most numerous species in the dam reservoir was Trichocerca similis (2511 ind. l-1) and in the Bagry gravel-pit lake was Polyarthra dolichoptera (2634 ind. l-1). However, the most abundant species in the fountain was Brachionus urceolaris (863 ind. l-1). The highest values of Shannon and evenness diversity indices were found in the Bagry gravel-pit lake (H’ = 2.521, J’ = 0.783), while the lowest in the urban fountain (H’ = 0.568, J’ = 0.258). The DCA analysis (Detrended Correspondence Analysis) showed that the diversity of rotifers communities in the studied reservoirs was related to the concentration of magnesium and calcium, and to water conductivity.
3
Content available remote Wpływ wód Wisły na zanieczyszczenie chronionych starorzeczy w rejonie Spytkowic
PL
Starorzecza Wisły w rejonie Spytkowic w dolinie górnej Wisły stanowią obszar chroniony Natura 2000 zagrożony wskutek napływu jej zanieczyszczonych wód. Przeprowadzone badania wód starorzeczy pokazują kilkukrotny wzrost zawartości chlorków, siarczanów, węglanów, fosforanów, azotanów, sodu, potasu, magnezu, wapnia oraz przewodności przy wyższych niż przeciętne stanach wody w Wiśle, chociaż powodzie powodują zmniejszenie koncentracji większości z tych składników. Również osady denne w części starorzecza, do której dopływa woda z Wisły, zawartości cynku, ołowiu i kadmu są przeciętnie 3 razy wyższe niż w jego części położonej poza wałami. Znacząca część kadmu, około 50-70%, pozostaje w formach łatwo przyswajalnych dla organizmów i może powodować ich kumulację w żerujących w dnie małżach.
EN
The oxbow lake at Spytkowice in the upper Vistula River valley is a protected area Natura 2000 endangered by the inflow of contaminated Vistula waters. Investigations of waters of the oxbow lake exhibit multifold increase of chlorides, sulphates, carbonates, phosphates, nitrates, sodium, magnesium, calcium and conductivity at Vistula water stages higher than average however, floods effects in a dilution of these contaminants. Moreover, bottom sediments in parts of the lake affected by the Vistula water inflow are 3 times more contaminated with zinc, lead and cadmium, on average, than that behind flood dykes. The significant part of cadmium, about 50-70% occurs in form the most available for benthic organisms, which may cumulate in sediment-feeding mussels.
EN
This investigation focused on plankton inhabiting fishponds, which previously received mine waters from the lead-zinc mine ‘Matylda’, located in southern Poland (Upper Silesia). The purpose of the investigation was to study the effects of chronic and persistent contamination of fishpond bottom sediments with heavy metals originated from the lead and zinc mine. The phytoand zooplankton in the four fishponds were dominated by diatoms, green algae and rotifers. Plankton composition of the reference non-contaminated pond was different, since Chrysophytes dominated, and Copepoda were the most numerous among zooplankton. In the contaminated fishponds, we observed teratological forms, both for phyto-and zooplankton species, but only as individuals. Our results showed that planktonic communities had adapted to chronic and persistent heavy metal contamination.
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.
EN
During a winter–spring season, physicochemical variables and plankton dynamics were studied in Lough Derg (Ireland). Samples were collected monthly from three water layers (surface, middle and bottom) at a deep central sampling point on the lake. As expected, phytoand zooplankton densities and chlorophyll a concentrations were low during the study period, probably reflecting low temperatures and wind-driven turbulence typical of the winter-spring period. Diatoms and rotifers were the most abundant phyto- and zooplankton groups, respectively.
EN
During a monitoring programme the diet composition of Asplanchna priodonta was studied. Samples were collected every month from the deepest part of the Dobczycki dam reservoir (Southern Poland). The diet of A. priodonta, which included colonial cyanobacteria, diatoms, dinoflagelates and protozoa, indicated that it is both a grazer and a predator. These results support the hypothesis that A. priodonta is an opportunistic feeder. Additionally these results include the first observations of the protozoan Tintinnopsis sp. as a food source of Asplanchna.
EN
The structure of the zooplankton community and its spatial distribution were examined in two stratified rheolimnic Pomeranian reservoirs, Rosnowski (7 sampling sites) and Hajka (4 sampling sites), in July 1999. These reservoirs are part of the cascade system situated on the Radew River in northern Poland. In the Rosnowski reservoir 34 species of zooplankton were identified and in Hajka, 32. The two dominant species of rotifers in both reservoirs were Keratella cochlearis f. tecta and Polyarthra vulgaris. The dominant copepod and cladoceran species in both reservoirs were Mesocyclops leuckarti and Daphnia cucullata, respectively. Along the longitudinal axis of both reservoirs, rotifers were the dominant group at all sampling sites, except for the hypolimnion layer in both reservoirs and the metalimnion layer in Hajka reservoir at site HI. This initial study was undertaken in order to determine the spatial distribution of rotifer, copepod and cladoceran communities in riverine reservoirs built in the cascade system.
EN
Zooplankton was the only food component of common bream and silver bream, and the main food component of roach and bleak in the pelagic zone of the Dobczyce Reservoir (southern Poland) from April to October 1994. Cladocera and Copepoda constituted 67.9% of the food consumed by the whole fish community. The average size of eaten individuals ranged from 0.62 to 1.43 mm. Planktivorous fishes selected phytoplankton-controlling filtrators, mainly large Daphnia species, which were eliminated most effectively in the summer.
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