bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evolutionary morphological development of the cladocera of the superfamily sidoidea and life strategies of crustaceans of continental waters
Authors: Korovchinsky Nikolay M. 
Published: February 2007

AbstractComparative‐morphological analysis of the structure of the Cladocera of the superfamily Sidoidea ( = Ctenopoda) comprising the families Sididae and Holopediidae, compared with representatives of other groups: Chydoroidea (=Anomopoda), Limnadiiformii (= Conchostraca), Polyphemiformii (Polyphemiformes (= Onychopoda) and Leptodoriformes (= Haplopoda)) and Branchipodiones (Branchipodiformes (= Anostraca) and Triopiformes (= Notostraca)) is made. The main parameters and structures important in functional‐morphological and ecological aspects are considered: including dimensions of the body, its form and proportions, the complex eye, swimming antennae, body covers, thoracic limbs, the postabdomen. In distinction from all crustaceans under consideration in the Sididae and the Polyphemiformii organs contributing to rapid manoeuvrable swimming, soaring and good orientation in the environment received the prevailing development in evolution: antennae, stabilizing appendages of the posterior part of the body, the eye, etc. All this predetermined elaboration of the life strategy in these forms mainly aimed, especially in the Sididae, at active avoidance of predation combined with elements of passive protection (imperceptibility attained by various methods). Representatives of the Sididae, including planktonic Diaphanosoma, well survive in water bodies with the intensive press of predation. All others, including the Holopediidae, clearly possess the passive protection (development in localities inaccessible to predators, imperceptibility, protective structures on the body surface, etc.).
Evolution du Recrutement de la Civelle (Anguilla anguilla) dans l'estuaire de la Loire, France, de 1977 à 1988. The Evolution of Recruitment of Glass Eel (Anguilla anguilla) in the Loire Estuary, France, from 1977 to 1988
Authors: Guerault D. , Desaunay Y. 
Published: February 2007

AbstractTwo series of indices, based on glass‐eel fisheries data, are used: From 1977 onwards, average catch shows a decreasing trend, becoming moderate after 1982. Fisheries indicators (CPUE, fishing effort and total yield), estimated since 1985, demonstrate contrasting evolutions inside the Loire fishery, according to location (upstream/downstream zone) and to climate. The coastal recruitment of glass‐eel is likely to be less biased by catchability variation.
The Growth of Eels: A Critical Assessment of Data from Open Waters
Authors: Berg R. 
Published: February 2007

AbstractIn the literature, annual growth data of eels between about 3 cm and 25 cm are reported. The high growth values were often especially taken as average for the growth of populations in open waters. A critical assessment of data in the literature shows that the average annual growth in different regions of Europe is between about 3 cm and 6 cm and does not exceed 10 cm.
Distribution du peuplement d'anguilles à l'échelle régionale Bretagne et Basse Normandie (France). Distribution of Eel at a Regional Scale, Brittany and Lower Normandy (France)
Authors: Legault A. , Porcher J. P. 
Published: February 2007

AbstractThe cartography of eel population in Brittany and Lower Normandy shows that the fitting out of rivers may be considered as the essential degradation factor of eel distribution. The setting up of not passable dams and the multiplication of partially passable dams also reduces eel stocks of numerous rivers. The improvement of eel migratory paths should be constituted a priority of protection and restoration of the natural stock.
Les passes à anguilles en Europe. Eel ladder devices in Europe
Authors: Legault A. , Fontenelle G. , Gascuel D. , Rigaud C. 
Published: February 2007

AbstractAfter a study trip through seven european countries, a synthesis about 24 eel ladder devices was written as a special report. A detailed description and the role of these fish facilities are discussed. In spite of very simple design principles and after experiments on a French river, efficiency tests are recommended.
Growth and Reproductive Responses of Daphnia to Cyanobacterial Blooms on the Potomac River
Authors: Fulton Rolland S. , Jones R. Christian 
Published: February 2007

AbstractWe examined reproductive responses of the cladoceran Daphnia parvula to algal assemblages from the Potomac River, during and after Cyanobacterial blooms. Algal assemblages were manipulated by filtration, dilution, or additions of nutritious algae, in order to determine causes for growth inhibition. There was no evidence for lethal toxic effects or food limitation of population growth rates during the algal bloom, although growth was food limited later in the year. However, growth rates were lower in the experiment conducted during the Cyanobacteria bloom than in later experiments, and the results suggest an inhibitory factor associated with the particulate material. Results from filtered treatments indicate that picoplankton present in hypereutrophic waters can support Daphnia growth and reproduction.
The Influence of Toxic and Filamentous Blue‐green Algae on Feeding and Population Growth of the Rotifer Brachionus rubens
Authors: Rothhaupt Karl Otto 
Published: February 2007

AbstractThe effect of toxic and of filamentous blue‐green algae on feeding and population growth of the rotifer Brachionus rubens was investigated in laboratory experiments. A toxic strain of Microcystis aeruginosa was ingested, but rotifers cultured with Microcystis died faster than nonfed controls. The rigid filaments of Cylindrospermopsis raciborskii were not ingested, reduced the ingestion of simultaneously offered algae, and depressed population growth rates. The soft filaments of Anabaena flos‐aquae were ingested at a moderate rate, did not reduce ingestion of other algae, and were used as an additional food in population growth experiments.
Development, Growth and Survivorship of Juvenile Calanoid Copepods on Diets of Cyanobacteria and Algae
Authors: Xu Zhenkang , Burns Carolyn W. 
Published: February 2007

AbstractNauplii and immature copepodites of Boeckella triarticulata, B. hamata and B. dilatata were tested for their ability to survive and grow on monospecific diets of four species of filamentous cyanobacteria, Cyclotella (Cy) and Cryptomonas (Cr) at 2 mg dry weight 1−1. Cr supported the development from nauplius to adult of all three calanoid species; complete development on other diets occurred only in B. dilatata on Cy and Anabaena oscillarioides (Ao). Differences between nauplii and copepodites of B. dilatata and B. hamata in survivorship and development on diets of Cy, Anabaena flos‐aquae (Af), Ao and Nostoc sp. 2 (N2) imply ontogenetic shifts in resource utilization with developmental phase. Ranked in order of their ability to support the development of juvenile boeckellids the foods were Cr > Cy > Ao > N2 > Af > Nostoc calcicola = no food.
Studies of Aquatic Fungi. XVIII. Aquatic Fungi in Lake S̀niardwy and Eighteen Neighbouring Lakes
Authors: Czeczuga Bazyli 
Published: February 2007

AbstractThe work was undertaken to investigate the mycoflora of Lake S̀niardwy and eighteen adjacent lakes.Samples of water were collected once a month (1984‐1987) for hydrochemical analysis and studies of the fungi content.Forty species of fungi were found in lake S̀niardwy and 60 in other lakes. The following fungi unknown from Poland were found in these lakes: Olpidium endogenum, Olpidium granulatum, Dictyomorpha dioica, Phlyctochytrium aureliae, Rhizophydium planktonicum, Zygorhizidium melosirae, Cladochytrium polystomum, Blastocladia rostrata, Olpidiopsis achlyae, Olpidiopsis pythii, Lagenidium rabenhorstii, Pythiella vernalis, Achlya rodrigueziana, Anguillospora gigantea, Dimorphospora foliicola and Mycocentrospora aquatica.
Fish in Reservoirs
Authors: Fernando C. H. , Holčík Juraj 
Published: February 2007

AbstractIn all reservoirs the fish fauna is recruited from their riverine antecedents. The nature of the riverine environment, created by its unstable hydrological regime, favours the evolution of generalist species. Of these species, only a few are preadapted to lacustrine conditions. When riverine fish communities are trapped in a reservoir, most of the fish stay close to the shore, the mouth of tributaries and in shallows. The pelagic and deep waters are poorly utilized and the yield of fish is below the natural productivity of these water bodies, especially in the case of deep and large reservoirs. This occurs unless the dammed river contains fish species from families which are preadapted for lacustrine conditions. A positive correlation between the percentage of pelagic fish and the total yield of fish in reservoirs indicates that the pelagial represents a vacant habitat, only seldom invaded by riverine species. This situation probably applies to the deep water of reservoirs too, although sufficient data to demonstrate this are not available. The littoral region of reservoirs is utilized by some generalists of euryoecious species derived from the indigenous riverine fauna which may be preadapted for lacustrine conditions. If such preadapted lacustrine species are not present, the introduction of lacustrine species or those preadapted for the lacustrine environment is desirable under certain circumstances. However, caution must be exercised in any introduction.
A Study of Phytoplankton in the Adriatic Sea after the July 1984 Bloom
Authors: Viličió Damir 
Published: February 2007

AbstractDistribution of nano‐ and microphytoplankton cell density and biomass (expressed as biovolume) were analyzed at 64 stations in the Adriatic Sea, in July 1984, after the northern Adriatic bloom. Biomass distribution may be indirectly linked with the position of eutrophication sources and currents. „Macroaggregates”︁ formed after the bloom are descriptively analysed.
The Distribution and Origins of Freshwater Fishes in the Balkan Peninsula, Especially in Greece
Authors: Economidis Panos S. , Banarescu Petru M. 
Published: February 2007

AbstractZoogeography of freshwater fish fauna of the Balkan peninsula south of the Danube has been studied. Four main divisions ‐ Ponto‐Aegean, Attiko‐Beotia, Dalmatia and South Adriatic‐Ionian ‐ were recognized. All endemics belong to European, Euro‐Siberian or Palaearctic taxa, originated from ancestors of the Euro‐Siberian stock and reached the area as well as Asia Minor in Oligocene or Miocene. Central European and Danubian species are intruders of late Pliocene to Pleistocene arriving by the freshened Black Sea and its drainage basin or directly from the North (Middle Danube) by river captures.
Trend Analysis of Biological Parameters in the Baltic (1976‐1988)
Authors: Schulz Sigurd , Kaiser Wolfgang , Breuel Günther 
Published: February 2007

AbstractEutrophication of the nature is one of the most relevant problems for the human society today. In comparison to terrestrial and limnological ecosystems, however, the marine environment is affected with some exceptions of coastal waters in a minor degree. On the basis of data from 1976–1988 trend analysis for chlorophyll, primary production, zooplankton biomass and water transparency have been carried out for the Mecklenburg Bight and different areas of the Baltic proper.As expected from the longterm increase in the nutrient levels, also for some pelagic biological variables increasing trends could be observed. At least for chlorophyll they are significant in the 95% probability level for all investigated areas. Primary production shows also an increase, however, not significant for each subarea. For zooplankton nearly no changes could be observed. All data reflect a high interannual variability, which can partly be explained by meteorological and oceanological conditions. The results are discussed from an ecological point of view. The increase in phytoplankton variables is considered to be at least partly related to the eutrophication of the Baltic.
Influence of Eutrophication on the Distribution of Phytobenthic Plant and Animal Communities
Authors: Kautsky Hans 
Published: February 2007

AbstractA short review of effects of eutrophication on the phytobenthic communities in the Baltic Sea is given. Future monitoring aspects are briefly discussed. Local changes in phytobenthic communities outside point sources (e.g. industry outlets, enclosed bays receiving effluents from land runoff etc.) are easily detected and can be due to nutrient enrichment and/or toxic substances. In recent decades, changes have been reported from apparently unaffected areas. The disappearance of Fucus vesiculosus is the most conspicuous. The cause of events is similar in those areas: increases in epiphytes give increases in grazer populations. The thallus of algae is heavily grazed upon. The epiphytes shade their host and filamentous algae compete for space, disturbing recruitment and leading to a decrease in diversity. The rapid response of opportunistic filamentous algae on nutrient enrichment and changing herbivore pressure can easily be observed. Therefore, repeated surveillance in defined areas, which integrates the environmental response in both animal and plant communities, may be a fruitful approach for detecting large scale eutrophication of the Baltic Sea.
Eutrophication and Restoration Measures in the Darß‐Zingst Bodden Chain
Authors: Nausch Günther , Schlungbaum Günter 
Published: February 2007

AbstractThe Darß‐Zingst Bodden chain, part of the brackish inner coastal waters of Mecklenburg‐Vorpommern, Germany, is supplied by large amounts of phosphorus and nitrogen from the catchment area. Due to the shallowness an additional nutrient input is realized via sediment‐water interactions. The results are highly eutrophicated water bodies. But in contrast to other systems the actual nutrient concentrations are mainly influenced by hydrographical features and don't reflect the loading situation. Possible rehabilitation methods are discussed for the Bodden chain handling, especially the sediment problem.
Picoplankton in Six New Zealand Lakes: Abundance in Relation to Season and Trophic State
Authors: Burns Carolyn W. , Stockner John G. 
Published: February 2007

AbstractThe abundance of picoplankton (0.2‐2 μm) was measured seasonally in the surface waters of six New Zealand lakes that represent a range of trophic states. The lakes were: Wakatipu, Te Anau, Manapouri, Hayes, Mahinerangi and Ross Creek Reservoir. Among the lakes, picoplankton abundance was associated positively with temperature; picoplankton were most abundant in summer and autumn when they attained densities of 108,000‐270,000 cells/ml in the oligotrophic lakes. In these lakes, prokaryotic picoplankton was generally an order of magnitude more abundant than eukaryotic picoplankton. Consistent with the hypothesis that picoplankton are more important in oligotrophic than eutrophic ecosystems, there was a weak negative correlation between the density of prokaryotic picoplankton in the lakes and the level of chlorophyll a. The presence of large numbers of chroococcoid cyanobacteria in the guts of Ceriodaphnia dubia and Bosmina meridionalis implies that prokaryotic picoplankton are collected, but not digested, by these species.
The Seasonal Dynamics and Composition of Photosynthetic Picoplankton Communities in Temperate Lakes in Ontario, Canada
Authors: Pick Frances R. , Agbeti Michael 
Published: February 2007

AbstractThe seasonal abundance and composition of photosynthetic picoplankton (0.2‐2 μm) was compared among five oligotrophic to mesotrophic lakes in Ontario. Epilimnetic picocyanobacteria abundance followed a similar pattern in all lakes; maximum abundance (2‐4 × 105 cells · ml−1) occurred in late summer following a period of rapid, often exponential increase after epilimnetic temperatures reached 20 °C. In half of the lakes picocyanobacteria abundance was significantly correlated with temperature, while in other lakes the presence of a small spring peak resulted in a poor correlation with temperature. In all lakes there was a significant correlation between epilimnetic abundance and day of the year. Correlations with water chemistry parameters (soluble reactive phosphorus, total phosphorus, particulate C: P and C: N) were generally weaker or insignificant. However, in the three lakes with the highest spring nitrate concentrations, a significant negative correlation with nitrate was observed. During summer stratification, picocyanobacteria abundance reached a maximum within the metalimnion and at or above the euphotic zone (1% of incident light) in all lakes. These peaks were not related to nutrient gradients.The average total phytoplankton biomass ranged from 0.5 g m−3 (wet weight) in the most oligotrophic lake to 1.4 g m−3 for the most mesotrophic with picoplankton biomass ranging from 0.01 g m−3 to 0.3 g m−3. Picocyanobacteria biomass comprised 1 to 9 % of total phytoplankton biomass in late summer, but in one year for one lake represented a maximum of 56%. Other photosynthetic picoplankton (unidentified eukaryotes, Chlorella spp. Nannochloris spp.), although less abundant (103 cells · ml−1) than picocyanobacteria, represented biomass equal or greater than that of the picocyanobacteria in spring and early summer. On average, half of the photosynthetic picoplankton biomass was eukaryotic in the more coloured lakes, while in the clear lakes less than 20% was eukaryotic. Among the lakes there was a significant positive correlation between the average light extinction coefficient and the proportion of eukaryotic biomass of the picoplankton.In mesotrophic Jack's Lake, the contribution of picoplankton to the maximum photosynthetic rate ranged from 10 to 47% with the highest values in the spring (47%) and late summer (33%), as a result of eukaryotic picoplankton and picocyanobacteria respectively. Picocyanobacteria cell specific growth rates were high during July (0.6‐0.8 day−1) and losses were close to 80% of the growth rate. Thus, despite low biomass, photosynthetic picoplankton populations appeared to turn over rapidly and potentially contributed significantly to planktonic food webs in early spring and late summer.
Autotrophic Picoplankton: Community Composition, Abundance and Distribution across a Gradient of Oligotrophic British Columbia and Yukon Territory Lakes
Authors: Stockner John G. , Shortreed K. S. 
Published: February 2007

AbstractAutotrophic picoplankton communities were examined in eleven oligotrophic lakes from a broad geographic region of western Canada, representing a variety of physico‐chemical and biological conditions. During our study, several of the lakes were treated with additions of inorganic nitrogen and phosphorus fertilizers. Picoplankton communities in most lakes were dominated (>70%) by unicellular or colonial coccoid cyanobacteria, provisionally identified by morphological and autofluorescence properties as Synechococcus. Also common in some lakes were red‐fluorescing cyanobacteria and Chlorella‐like eucaryotes. Autotrophic picoplankters contributed from 36‐63% to total chlorophyll, from >2‐26% to total phytoplankton carbon, and from 29–53% to total photosynthesis. Average populations ranged from >5‐10,000 cells·ml−1 in winter and early spring to 65‐75,000 cells · ml−1 in summer and fall. Peak densities in most lakes occurred in August‐September and most populations were within the epilimnion or metalimnion/hypolimnion boundary. Subsurface peaks were prevalent only in untreated, strongly stratified lakes. Eucaryotic picoplankters became dominant in acidic (pH < 6.2), humic lakes. Colonial picoplankters were more common in more productive interior lakes in August, and though present, were uncommon in coastal systems. Picoplankton populations exhibited large increases under ice in a Yukon lake, and their abundance and seasonal distribution showed little relation to temperature or to light. Fertilization of lakes resulted in picoplankton population increases (>2x) and the elimination of subsurface peaks. Nutrients were considered to be one of the major factors controlling population abundance in these oligotrophic lakes with average pH < 6.5.
The Nitrogen Budget of a Shallow Lake (Großer Müggelsee, Berlin)
Authors: Dudel Gert , Kohl Johannes‐Günter 
Published: February 2007

AbstractThe nitrogen budget of Lake Gr. Müggelsee (mean depth 4.85 m, area 7.12 km2) was calculated from weekly measurements of nitrogen transformations from 1978 to 1984. Common mass balances for nitrogen were completed by determination of dinitrogen fixation in order to calculate denitrification as residual budget component and resolved for distinct seasonal periods. N sedimentation was calculated from internal P balance. Influence of flushing rate on loss processes were analysed by comparison of years with very different runoff. Time series analyses and multiple comparison show a relation of hydraulic flow, nitrate load, in‐lake nitrate and N elimination to the seasonal cycle of irradiance. Denitrification is the most important loss process and exceeds the effect of sedimentation. Other in‐ and outputs (precipitation, swimmers, volatilization) are rather stochastic and of lower quantitative importance. Nitrate leaching from the catchment and turbulent mixing within the lake are discussed as determining factors of in‐lake nitrogen fluxes.
Investigation of the Shelf Ecological System on the Basis of Modeling and Field Work
Authors: Belyaev V. I. , Konduforova N. V. , Mikhajlov E. A. 
Published: February 2007

AbstractMathematical modelling of the ecosystem of the North‐West shelf of the Black Sea is based on the method of aggregation and averaging with the subsequent hierarchic decomposition (BELYAEV, 1987; BELYAEV and KONDUFOROVA, 1989). This approach includes the step‐by‐step comparison of the modelling results with field observations. The observations have been performed during the integrated oceanographic expedition of the research vessel “Professor Kolesnikov” (1987), for the first time specially organized to verify the modelling results. The comparison of the results of modelling and observation demonstrated that their agreement is satisfactory quantitatively and qualitatively. The efficiency of using models of optical fields for verification is also shown.
Population Dynamics, Growth and Productivity of Abra ovata (Mollusca, Bivalvia) in the Evros Delta (North Aegean Sea)
Authors: Kevrekidis Th. , Koukouras A. 
Published: February 2007

AbstractMonthly samples of Abra ovata were collected during February 1983‐January 1984 in the Evros Delta (N. Aegean Sea). Population density (mean annual value = 2407.5 ind · m−2) was characterized by seasonal variation. An analysis of the length frequency distributions shows that one annual recruitment of juveniles (> 2 mm) occurred in October‐January; and also that, throughout the year, two age groups existed in the population. One growth ring was formed on the shells of the oldest age group during July‐August.Mean growth in shell length can be described by Bertalanffy function. A positive correlation existed between shell length and decalcified dry weight.Secondary production in A. ovata, calculated by the instantaneous growth method, showed a mean biomass of 29.221 g dry weight m−2yr−1, a productivity of 17.086 g dry weight m−2yr−1 and an annual turnover ratio of 0.59.