Species Composition Of Cladocera Research Articles

Preboreal oscillation in the light of multiproxy analyses—Early Holocene in Lake Jelonek (North Poland)

In this work, we studied the course of climatic fluctuations at the beginning of the Preboreal period using multiproxy analyses (Chironomidae, pollen, diatoms, Cladocera, stable isotopes, macrocharcoal, microlithofacial) combined with varve chronology of sediments. The results showed a decrease in the mean July temperature and stronger continentalism followed by climate wetting at the start of the Preboreal period. This was reflected in the remodeling of the vegetation cover from birch forests to more open spaces with grass vegetation dominance, as well as that of the species composition of Cladocera and diatoms, and the high variability of isotopic composition. In addition, the results showed the impact of local conditions (fires and relict permafrost) on the amplification of environmental responses due to climate cooling. The environmental transformations presented here correspond temporally to the changes that are well documented in other parts of Europe as the Preboreal Oscillation.

Cladocera paleocommunity to disentangle the impact of anthropogenic and climatic stressors on a deep subalpine lake ecosystem (Lake Iseo, Italy)

In big lakes with strong anthropogenic pressure, it is usually difficult to disentangle the impacts of climate variability from those driven by eutrophication. The present work aimed at the reconstruction of change in the species distribution and density of subfossil Cladocera in Lake Iseo (Italy) in relation to climate and anthropogenic pressure. We related subfossil Cladocera species composition and density in an 80-cm sediment core collected in the pelagic zone of Lake Iseo to long-term temperature trends and phosphorus concentration inferred by diatoms frustules. The Cladocera remains detected in Lake Iseo sediment reflected the species composition and density of modern pelagic Cladocera assemblages. Cladocera rapidly respond to environmental change, and that climate change combined with eutrophication can induce changes in community composition and species density. At the beginning of twentieth century, when global warming was not yet so accentuated, the nutrient increase in water resulted as the principal driver in determining the long-term development of plankton communities and pelagic food web structure. Moreover, catchment-related processes may decisively affect both species composition and density of the lake planktonic communities due to the decrease of lake water transparency induced by input of inorganic material from the catchment area to the lake. The paleolimnological investigation, through the combined study of biotic and abiotic factor, allowed clarifying the synergic effects of the most important drivers of change in lake ecosystems, suggesting that climatic factors should be considered with nutrient availability as determinant element in controlling the temporal development of plankton communities and pelagic food web structure.

Fauna of Cladocera and Copepoda from Xinjiang Uyghur Autonomous Region (China).

This study evaluates the species composition of Cladocera and Copepoda in the five lakes of the Bogda-Shan Mountain range and in the floodplain of the Tarim and Konchedarya rivers located in the Xinjiang Uygur Autonomous Region of China (Xinjiang). We collected seven species of Cladocera and six species of Copepoda. Seven species were identified as new for Xinjiang fauna, and two species (Cyclops cf. herberti Einsle, 1996, and Eucyclops roseus Ishida, 1997) were first records for China. Herein, we characterize the distribution ranges for the detected species and provide taxonomic remarks. The total species list for water bodies in Xinjiang compiled from original data and available literature includes 56 species of Cladocera and 33 species of Copepoda. We also discuss the biogeographical structure of Cladocera and Copepoda faunas in Xinjiang.

The first data on the freshwater microcrustaceans of Shokalsky Island (Russian Arctic).

BackgroundInformation on freshwater invertebrates of the Russian Arctic is very scarce, especially concerning insular biota. The species composition of microcrustaceans (Cladocera, Copepoda) of many arctic islands is still unknown and have never been explored. Here we report the results of the first investigation of the zooplankton of the Shokalsky Island (Yamalo­Nenets Autonomous Okrug, Russia).Information on freshwater invertebrates of the Russian Arctic is very scarce, especially concerning insular biota. The species composition of microcrustaceans (Cladocera, Copepoda) of many arctic islands is still unknown and have never been explored. Here we report the results of the first investigation of the zooplankton of the Shokalsky Island (Yamalo­Nenets Autonomous Okrug, Russia).New informationThe new records reported here are novel for the region and significantly expand the knowledge of the high­-latitude aquatic biota. We studied the species composition of Cladocera and Copepoda of 21 freshwater habitats located on the south­western part of Shokalsky Island. We found 15 species of microcrustaceans in total and all of them are reported for the first time here. Also, the obtained data expand the existing ranges of distribution of some species and report several new taxa for the whole Yamalo­Nenets region of Russia.

Ecology of Cladocera species from Central America based on subfossil assemblages

<p>Cladocera species composition was analyzed in surface sediments of 29 lakes in Central America (Guatemala, El Salvador and Honduras). The material studied was collected with an Ekman grab in autumn 2013 from lakes located in lowland, highland and mountain regions. The study revealed high variability in qualitative and quantitative composition of subfossil Cladocera. A total of 31 Cladocera species (5 planktonic and 26 littoral) were identified, as well as 4 morphotypes that could not be identified (NRR<em> </em>1-4). Planktonic Bosminidae<em> </em>and<em> </em>Daphniidae were the most abundant families. Daphniidae were restricted to water bodies in mountain regions, whereas Bosminidae were widely distributed in lakes with different abiotic conditions. Moreover, Bosminidae species also occurred in highly mineralized waters (> 900 µS cm<sup>-1</sup>). The great majority of the identified Cladocera species belonged to the littoral family Chydoridae. <em>Chydorus </em>cf.<em> sphaericus</em> was the most common species (found in 20 lakes), which probably reflects its tolerance to a wide spectrum of habitat conditions. Cluster analysis discriminated 6 groups of Cladocera species with a high correlation level within groups (≥0.8), which showed different types of correlation with lake characteristics and environmental variables. Canonical correspondence analysis (CCA) showed that altitude and secondly water electrical conductivity were the most important drivers of Cladocera species composition in the region studied. Furthermore, CCA analysis indicated lowland lakes with low water transparency were also characterized by peculiar species assemblages. <strong></strong></p>

Cladocera Community Composition as a Function of Physicochemical and Morphological Parameters of Dystrophic Lakes in NE Poland

Cladocera are one of the most important freshwater biological indicators for a wide range of environmental variables. They show strong responses to several environmental factors (e.g., trophic state, water depth, temperature) and are very sensitive to changes in water pH. The main interest of this study was to evaluate the relationship between subfossil Cladocera community composition and environmental properties of dystrophic lakes (pH, water transparency, conductivity, dissolved oxygen, depth and area). We hypothesize that Cladocera species composition depends on a dystrophication index (HDI); thus, Cladocera assemblages change with the degree of dystrophication. For the study, we selected a group of dystrophic lakes located in Wigry National Park (WNP), NE Poland, where we found subfossil remains of 24 Cladocera species belonging to four families (Chydoridae, Bosminidae, Daphniidae, and Sididae). A non-metric multidimensional scaling (NMDS) was used to elaborate on the similarities among samples in cladoceran-community composition and structure. Statistical analyses showed that Cladocera assemblages in all the studied lakes were similar, and individual Cladocera species respond to the measured environmental parameters (e.g., pH, lake size and depth). Our results suggest that in dystrophic lakes, Cladocera community composition is an emerging characteristic of individual species responses to the environment.

The effect of fish stocking on mountain lake plankton communities identified using palaeobiological analyses of bottom sediment cores

The artificial introduction of fish into a naturally fishless lake can effectively modify the food web and trophic status of that lake. We observed changes in the zooplankton community after stocking fish in Przedni Staw Polski, an oligotrophic mountain lake in the Tatra Mountains (Poland). Results were compared with observations about a stocked lake that naturally contained fish (Morskie Oko), and with two fishless lakes that served as reference sites. The main change observed in the cladoceran community of Przedni Staw Polski was the elimination of large-bodied Daphnia ~10 years after stocking fish. The introduction of fish also affected the phytoplankton community and resulted in an increase in diatom species related to higher trophic state, most likely due to the fish-induced alteration of the phosphorus cycle. Moreover, all of the studied lakes have been influenced by global and regional climatic and environmental changes, including intensive tourism and acid deposition. Changes in diatom communities were observed after fish stocking even in the lake with a natural fish population, while the zooplankton did not reflect higher fish density. These findings suggest that the natural balance between fish and phytoplankton was destroyed by fish stocking, and although it caused eutrophication in the lake, the higher fish density did not strongly modify the species composition of Cladocera.

The freshwater crustaceans (Cladocera: Copepoda) of Bering Island (Commander Islands, Russian Far East): species richness and taxocene structure

ABSTRACTThe crustaceans of the fresh waters of Bering Island and their link to the fauna of adjacent regions were studied. Based on original data and existing literature, the species composition of Cladocera and Copepoda was described. The compiled list includes 22 species of Cladocera and 30 species of Copepoda. In the original data, 35 species native to the Commander Islands were reported for the first time. Six species were newly reported in the Far East, and two were newly reported in Russia. The ecological peculiarities of several species and some biogeographical features of the freshwater zooplankton of the island are discussed. The main part of the fauna of the island form Holarctic widespread species (64.3%), another slightly smaller group of the fauna is comprised of Palaearctic species (20.1%), and the remainder comprise Nearctic (6.7%) and Beringian species (8.9%). Particular patterns in the distribution of freshwater zooplankton and the factors underlying the occurrence of these species on the island are considered.

Palaeoecological investigations and 230Th/U dating of Eemian interglacial peat sequence of Banzin (Mecklenburg-Western Pomerania, NE-Germany)

A novel occurrence of an Eemian interglacial peat was identified in 2011 in a short-lived outcrop of the NEL-pipeline trench, near the village of Banzin, Germany. The profiles are situated in a shallow kettle hole within the undulated landscape of the Saalian glaciation. The distribution of dominantly till lithofacies in the Banzin area confirms the regional trend of Saalian tills with a locally higher abundance of Cretaceous clasts. In the Banzin kettle, at a depth of 2.2 m, lies a 0.5-m thick, strongly compressed Eemian peat layer. The buried Eemian peat layer is deformed by ice-wedge pseudo-morphological and mega crack structures, indicating a strong periglacial influence during Weichselian stadial phases. The post-Eemian sequence is subdivided into three units, beginning with a mixture of aeolian and gelifluction deposits, which are also modified by cryostructures. The top of the Banzin sequence is covered by a 0.5-m thick colluvisol layer of redeposited humic loam from the Late Weichselian/Holocene. The uppermost unit suggests that solifluction processes occurred in the last few hundred years, likely driven by intensive anthropogenic influence.Limnic sedimentation began during the Late Saalian period in a landscape characterized by herbaceous vegetation and heliophytes. During the latest interval of Saalian deglaciation, shallow waters of the basin most likely attained a depth below 3 m and were abundant in calcium carbonate. The beginning of Eemian interglacial peat accumulation (MIS 5e) is characterized by a dominance of light birch forests followed by pine. The ensuing optimum climate was dominated by the encroachment of oak forests and then hazel-oak forest, and sedimentation ceased in the basin during this phase. At the climatic optimum (PZ III/IV), the Eemian peat included remains of Ceratophyllum submersum and species of higher temperature requirements. The Banzin basin gradually became shallower and overgrown until the closing of its open water at the end of phase III/IVa. The lack of Cladocera species composition in the Eemian sequence proves isolated conditions of a shallow reservoir. We present the first results from NE-Germany for Eemian peat bog samples dated by the U–Th disequilibrium method (230Th/U), using leachate alone (L/L) and total sample dissolution (TSD) analytical techniques. Isochron-corrected 230Th/U ages of 118 ± 8/10ka (L/L) and 121 ± 9/13ka (TSD) were obtained. Both 230Th/U dates ∼118–121ka, obtained using two different techniques, confirm the biostratigraphical classification into the Eemian interglacial.

Early development of late Vistulian (Weichselian) lacustrine sediments in the Żabieniec swamp (central Poland)

Abstract The early sedimentological and ecological developmental stages of a late Vistulian lake in the Żabieniec swamp near Łódź (central Poland) were analysed by radiometric dating, changes in the frequency of specimens and species composition of Cladocera and multivariate statistical analysis (DCA). The longevity of the lake resulted in a fairly complete sedimentary record from approximately 22 ka to 11 ka cal BP. Species composition and the variability in the frequency of Cladocera specimens has made it possible to distinguish eleven zones of their development, which are well correlated with radiocarbon data. The results were compared to those from other sites of north and central Europe. The initial Cladocera development comprises the richest and oldest late Vistulian Cladocera record in Europe. These cladoceran assemblages show that a deep, oligotrophic, moderately cold-water lake was present at the beginning. It appears that the cladoceran development was mainly due to climate change, but also to changes in locally prevailing conditions in the water body. The high frequency of cladocerans, as well as the presence of cladoceran taxa preferring warmer water, was noted before approximately 16 ka BP. The biota suggests that the Oldest Dryas cooling was not severe and fairly variable in terms of humidity and temperature. The changes in Cladocera composition give evidence of what is described as the Intra-Bølling Cold Oscillation. It is also concluded that the Bølling is represented by two phases in the Żabieniec lake sediments.

Cladocera species composition in lakes in the area of the Hornsund Fjord (Southern Spitsbergen) – preliminary results

Key-words: Cladocera species composition, Spitsbergen, lakes, Hornsund Fjord Species composition of benthic and planktonic Cladocera was analysed in four lakes and ponds located in the southern part of the SpitsbergenIsland near the Fjord Hornsund. This is the first study to provide information on the species composition of the contemporary and subfossil Cladocera in this region. A total of eight Cladocera taxa were found in the sediments and waters of the lakes that have been chosen for the study. The sediments included remains of only five species, while seven Cladocera species were found in the zooplankton samples. The results imply that the lakes are subject to natural transformations driven by the fluctuating climate which was reflected by increasing the number of species, and in particular in the appearance of Bosmina longirostris. Absence of some littoral Cladocera species in the sediments (e.g. ,s mallAlona, Ophyroxus gracilis), with simultaneous occurrence of these species in the water, may be a result of physical and chemical processes influencing the destruction and lack of preservation of the remains in the sediments.

Pelagic cladocera in upper volga water reservoirs

The results of cladoceran crustaceans studies in the pelagial of the Ivankovo and Uglich water reservoirs were generalized. In the period of 1973–1995, both waterbodies were similar in terms of Cladocera species composition and the dominating complex. The list of species composition of pelagic cladocerans has increased since the 1950s. The highest abundance of cladocerans was observed in the Ivankovo water reservoir. Daphnia cucullata G. Sars has been stably dominant in zooplankton summary biomass, while Chydorus sphaericus (O.F. Muller) and Bosmina longirostris (O.F. Muller) prevailed in terms of abundance. Changes in the pelagic cladoceran complex composition is evidence of the waterbodies’ eutrophication. The share of Cladocera in the zooplankton’s total summer biomass was 68 and 53% in the Ivankovski and Shoshinski stretches of the Ivankovo water reservoir, correspondingly, and 60% in the Uglich water reservoir (on average for 1970s–1990s).

Reconstruction of human influence during the last two centuries on two small oxbow lakes near Warsaw (Poland)

Short sediment cores from two small oxbow lakes located in the Vistula valley near Warsaw (Poland) were analysed for chemical composition and zooplankton (Cladocera) remains. The results of these analyses were evaluated using ordination techniques and the results were used to reconstruct the history of human impact of the lakes. The cores were dated using the 210Pb method. These analyses show that the collected sediments (60 cm- and 67 cm-long-cores) were deposited during the last 150–200 years. Cladocera assemblages were different in the two lakes; however, Bosmina longirostris was dominant among subfossil Cladocera species in both lakes. The presence of this species indicates the high trophic state of the lakes. Changes in Cladocera species composition suggest that a significant increase in the lakes’ trophic levels has occurred since the 1920s. The change could be related to the construction of flood dikes along the river Vistula, the isolation of the studied lakes from the river, changes in land use, or some combination of these factors. The chemical composition of sediments, particularly the increase in phosphorus and sulphur concentrations, confirms that the construction of dikes against flood was the major factor inducing eutrophication of the oxbow lakes. This study shows that the Warsaw small water bodies are especially sensitive to local disturbances caused by human activity, mainly water management, land use changes and agriculture.

Human impact on lakes recorded in the remains of Cladocera (Crustacea)

Subfossil Cladocera analysis allows discussion of the influence of human activity on the lake environments from Neolithic times up to the present. Three lakes were chosen for the analysis: two in northern Poland and the third on Cres Island, Adriatic Sea (Croatia). During the Holocene the species composition and the specimen abundance often changed, resulting mainly from climate changes, and also from human activity. This phenomenon is recognized on the diagrams of absolute abundance and percentage ratio of specimens of the pelagic species to the littoral ones. The data from Cladocera analysis were compared with the abundance of some plants reflecting human activity. A large degree of correlation was noted between the increased presence of these plants and the occurrence of the Cladocera species preferring more trophic water. Some phases of increased lake eutrophication were distinguished on the basis of Cladocera species preferring nutrient rich water. According to the comparative palynological and archaeological studies, these phases are correlated with the periods of settler groups’ activity beginning in Neolithic times. The most distinct changes in the species composition of Cladocera have been noted in the lake sediment from the Medieval Period. They were brought on by the agricultural revolution, which has lasted uninterruptedly up to now. It was observed that the intensity of the expressed abundance of index species in sediments is dependent on the size (area and depth) of the lake. The smaller the lake is, the greater is the change in species composition of zooplankton. The smaller water bodies react faster to an excessive supply of eutrophic compounds, and therefore the change is more clearly evident in the sediment record. Considerable secondary influence of these changes on the species composition of plankton was noted in the large lakes: Lednickie Lake (Poland) and Vrana Lake (Adriatic).