bluuebunny/crossref_metadata_2025_split huggingface dataset:
Germination and Growth of Potamogeton pectinatus (L.) at Different Water Depths in Lake Nainital, Uttar Pradesh, India
Authors: Purohit Rekha , Singh S. P. 
Published: February 2007

AbstractData on germination of tubers and subsequent growth of young plants of Potamogeton pectinatus were recorded at different depths of the water column in Lake Nainital. The depth of euphotic zone is about 5 m. Tubers were placed at 1, 2.5, 5.0, 7.5 and 10 m water depth in brass net bags. A highly significant negative correlation was found between depth on one hand and germination percentage of tubers, length of shoots and number of leaves on the other hand. Germination of tubers was positively related to pH, dissolved oxygen and temperature of water.
Sediment Oxygen Consumption in Tropical Undrainable Fish Ponds
Authors: Oláh J. , Sinha V. R. P. , Ayyappan S. , Purushothaman C. S. , Radheyshyam S. 
Published: February 2007

AbstractThe magnitudes of sediment oxygen consumption in the rural undrainable fish ponds of Orissa, India, were quantified and partitioned into bacterial, animal and chemical uptakes. It was in the low range, comprising a maximum of 30 % of the total community respiration. Chemical uptake was generally predominant, followed by bacterial respiration and low macroinvertebrate respiration. Evidence has been produced to the limiting effects of oxygen levels, mechanical disturbances and bioturbation on uptake rates in these ponds. The sediment layers are shown to act as energy traps, and measures are suggested for improved sediment ‐water interaction and enhanced nutrient recycling.
Approche discriminante de la contribution de différents échelons microplanctoniques aux mesures globales d'ETS dans des échantillons d'eau de mer. a. Phytoplancton
Authors: Romano Jean‐Claude , Mimura Toru , de Souza‐Lima Yolanda 
Published: February 2007

Discriminating Approach of Various Microplanktonic‐stage Contributions to Whole ETS Measurements in Sea‐water Samples. a. PhytoplanktonData obtained from algal cell cultures were applied to various sea water samples in order to estimate the specific contribution of phytoplanktonic organisms to whole ETS (electron transport system) measurements of these samples which have been collected at eleven stations in the northwest Mediterranean Sea. When the phytoplankton ETS contributions were quantified by cell enumerations or by other indirect‐biomass‐indicator measurements, the results are in good accordance to the recorded ETS measurement values of the sample. More specific of the phytoplankton stage is the index used for such an estimation (as chlorophyll a), and better is the relationship between both estimated and measured ETS values.
Malathion Toxicity: Effect on the Ovary of the Zebra Fish Brachydanio rerio (Cyprinidae)
Authors: Ansari Badre Alam , Kumar Kaushal 
Published: February 2007

AbstractThe nucleic acids (DNA and RNA), protein contents and the activity of alkaline phosphatase was significantly decreased in the ovary of Brachydanio rerio after exposure to different concentrations of malathion, an organophosphorus pesticide. Total free amino acids and acid phosphatase activity, however, were enhanced. The decrease in the measured parameters depended on both concentration and time. Histopathological studies revealed developmental arrest at all levels from oogonium to tertiary stage oocytes. After transfer to fresh water without the pesticide, there was a marked trend of recovery in al' the parameters studied.
Secondary Production and Energy Transfer in the Polluted River Saale (Thuringia, Southern GDR)
Authors: Schönborn Wilfried 
Published: February 2007

AbstractIn the middle reaches of the Saale (α‐mesosaprobic region) there are two final consumers: Erpobdella octoculata (leech) and fish. Three main flows of energy in the river ecosystem are described and quantified. The food web is only poorly developed. In the River Saale Erpobdella is the main predator and controls most of the meio‐ and macrozoobenthos. The type of energy transfer described here seems to predominate in polluted rivers. A qualitatively different type of energy transfer predominates in clean running waters. The relationships between energy transfer and self‐purification are discussed.
A Guide to the Study and Identification of Fossil Testate Amoebae in Quaternary Lake Sediments
Authors: Ellison Robert L. , Ogden Colin G. 
Published: February 2007

AbstractFossil shells of testate amoebae, commonly found in Quaternary sediments, provide another key for the interpretation of the recent history of lakes. Outline drawings and details of shell composition provide the micropalaeontologist with a practical guide to the taxonomy of these organisms.
Relationship between Zooplankton Development and Environmental Conditions in Different Types of Lakes in the Zone of Temperate Climate
Authors: Ivanova Marina B. 
Published: February 2007

AbstractComparison of the number of species and biomass of planktonic crustaceans with morphometric, hydrological, and hydrochemical features of lakes in the zone of temperate climate shows that there are no functional correlations between the development of zooplankton and each of the other separate factors. Results of multiple regression analysis for description of relationships between biotic and abiotic conditions were unsatisfactory (R2⩽0.7) for the greater part of studies. It is apparently necessary to find methods to examine environmental characteristics limiting biological productivity in lakes and to classify lakes on this basis. Such classification may allow to work out quantitative predictions of plankton and benthos biomass development in response to change of some environmental factors.
A Study of Diaphanosoma Species (Crustacea: Cladocera) of the “Mongolianum” Group
Authors: Korovchinsky N. M. 
Published: February 2007

AbstractMaterial from 49 localities in Europe, Asia and Africa is used to study two similar Diaphanosoma species, viz. D. mongolianum UENO, 1938, and D. lacustris KORINEK, 1981, both of which were described earlier under other names, the most common of which were “D. brachyurum”, “D. leuchtenbergianum” and “D. birgei lacustris”. These species are redescribed in detail, consideration being given to interpopulational and individual morphological variability, the type material, and material from type localities. The morphology of the setae of the swimming antennae is studied in detail, and the author concludes that some of them are not only used for swimming but also perform a sensory function. Some aspects of the biology of the species are described. They inhabit water bodies of different types, are often so abundant that they constitute the main component of zooplankton communities, and are an important link in the trophic chain. Little known cases of the co‐occurrence of Diaphanosoma species in a water body are described. Localities known for D. mongolianum and D. lacustris are situated mainly in the temperate and subtropical zones, the former species penetrating farther north than the latter. However, they are also found in the White Nile (Sudan) and Ethiopian lakes. This southward penetration may be connected with the azonal distribution of fluviatile fauna and with the altitude of Ethiopian lakes.
Niche Extension of Aquatic Macrophytes in Hydrolakes: Predictive Assessment of Environmental Impacts
Authors: Rørslett Bjørn 
Published: February 2007

AbstractA statistical model for the survival (potential) niche size of submerged macrophytes is related to fluctuating water levels. Designated as the spatial survival niche model (SSN), this model describes the potential niche by means of a product of spatio‐temporal mortality functions. The SSN model enables quantitative estimates of the niche's width, central location, and percentile points.The model is corroborated by an extensive Isoëtes lacustris L. data set from 17 Norwegian lakes, which included hydro‐electric lakes (hydrolakes) as well as non‐impacted lakes. The close fit between model prediction and the macrophyte's actual spatial performance is remarkable and encouraging from an impact assessment point of view.
Latitudinal Variations in Body Size and Species Diversity in Marine Decapod Crustaceans of the Continental Shelf
Authors: Steele D. H. 
Published: February 2007

AbstractThe number of species of caridean, brachyuran and anomuran decapods increases from high to low latitudes in both hemispheres. This is shown to be due mainly to changes in the abundance of small species. Possible explanations for these variations in abundance are discussed. The other infraorders of decapods are confined to mid and low latitudes.
Detritus and Epibiota on Artificial Substrata: The Possible Role of Food in Structuring Hawaiian Epiphytal Amphipod Communities
Authors: Russo Anthony R. 
Published: February 2007

AbstractEpiphytal amphipods prefer artificial substrata (bottle brushes) which accumulated epibiotic coatings while submerged in the sea for a period of up to 15 days. There is evidence that these amphipods eat epibiota on algae (predominately Padina japonica YAMADEA 1931 and Dictyota crenulata AGARDH 1847) and that food availability may be a factor which helps structure epiphytal amphipod communities.
Seasonal and Spatial Overlap between Cladocerans in Humic Lakes
Authors: Hessen Dag Olav , Schartau Ann Kristin 
Published: February 2007

AbstractSeasonal and vertical distribution, migratory patterns and reproductive effort in coexisting cladocerans were investigated in three humic lakes with different, but low phytoplankton abundances and varying fish predation pressure. Seasonal and vertical habitat or niche overlap varied, but were high within most pairs of species in all localities. Migration was conspicuous in presence of planktivorous fish, less so in the fish free lake. Despite algal densities below incipient limiting level (30–200 μg C I−1) and a low ratio (3–10) of algal to cladoceran biomass, zooplankton distribution and reproductive parameters were not clearly related to algal biomass.Bacterial biomass equalled 10–50% of phytoplankton biomass, while detritus by far was the largest of the particulate compartements. It was concluded that with a possible exception of the early summer algal bloom, additional carbon sources (bacteria, detritus) are important to cladoceran nutrition in these humic lakes. A large share of N‐ and P‐poor detritus in the diet would give zooplankton productivity limitation by food quality in terms of elemental composition rather than food quantity. This would permit coexistence even of species with rather high food overlap, but give low production rates for all species in agreement with the observations.
A Physical, Chemical and Biological Characterization of the Ushant Tidal Front
Authors:   Group “Grepma”
Published: February 2007

AbstractA multidiscriplinary study was carried out during the summer of 1982 in the area of the Ushant tidal front at the entrance of the English Channel. The stratified water masses (West of the front) and the mixed water masses (East of it) are characterized with respect to their main physical, chemical and biological properties and a comparative budget of organic carbon is presented. Several physiological, biochemical or taxonomical indices of phytoplankton and zooplankton populations are investigated. The effects of the tidal regime on space‐time variability and nutrient enrichment are emphasized.
Atlantic Salmon (Salmo salar) Smolt Production in a Newfoundland River System Characterized by Lacustrine Habitat
Authors: O'connell Michael F. , Ash Evan G. M. 
Published: February 2007

AbstractIn insular Newfoundland, wild anadromous juvenile Atlantic salmon make extensive use of lacustrine habitat for rearing. Smolt production was determined for a portion of a river system where virtually all rearing habitat is lacustrine. Production in terms of lacustrine habitat was estimated to be 10.1 smolts‐ ha−1. Smolt production is discussed in relation to morphometric characteristics. A comparison is made with smolt production obtained from stockings of swim‐up fry directly into lakes in another insular Newfoundland river system.
Spatial Distribution of the Nematode Fauna and Production of Three Nematodes (Tobrilus gracilis, Monhystera stagnalis, Ethmolaimus pratensis) in the Profundal of Piburger See (Austria, 913 m a.s.l)
Authors: Pehofer Harald E. 
Published: February 2007

AbstractThe species composition and the spatial distribution of the nematode fauna of Piburger See is discussed briefly. The study then concentrates on the three species (Tobrilus gracilis, Monhystera stagnalis, Ethmolaimus pratensis) which form the lake's profundal nematode fauna between depths of roughly 8 and 13 meters. This profundal fauna is separated by a distinct metalimnetic abundance minimum from the very diverse littoral community. In addition to taxonomic and ecological considerations, the zonation of the three species within their main habitat is described, and life cycles cohort production as well as annual production are evaluated from the field data. Total annual nematode production within the profundal habitat (8–13 m) in Piburger See amounts to 11.6 kg per hectare. 65 % of which are contributed by T. gracilis, 22 % by M. stagnalis and 13 % by E. pratensis. For the whole area under observation (6 to 13.5 m, including the scarcely populated border zones) mean annual nematode production is 7 kg per hectare.
Variations temporelles de l'ultrastructure de Scenedesmus quadricauda exposée au cuivre lors d'une expérience à long terme
Authors: Bastien Christian , Cǒté Raynald 
Published: February 2007

AbstractAn experiment was conducted with a continuous culture of Scenedesmus quadricauda for 50 days in a copper concentration of 250 μg l−1. Ultrastructural examinations were carried out at different times to obtain the sequence of events. After 1.5 h of exposure, the ultrastructural effects were obvious: the chloroplasts were retracted and all cell structures appeared diffuse. The same observations were reported after 3, 6, 12 and 24 hours. Between the 3rd and 15th days of the experiment, the cells showed major accumulations of starch, lipid and electron‐dense inclusions in the vacuoles, and the cell walls became thicker. After 22,32 and 50 days the cells appeared normal, but the cytoplasm was densely packed with ribosomes and the endoplasmic reticulum was evident in most cells. However, atomic absorption analysis for copper showed that there was no bio‐accumulation after 50 days of exposure. These findings suggest the implication of a second tolerance mechanism to copper (possibly extracellular complexation or removal) that is activated after long exposure, in contrast to electron‐dense inclusions, which appear after a relatively short time (2 days).
The Life History and Occurrence of Sialis lutaria L. (Megaloptera) in the Littoral Zone of Lake Esrom, Denmark
Authors: Dall Peter C. 
Published: February 2007

AbstractThe life history and distribution of Sialis lutaria L. in the exposed littoral zone of Lake Esrom, Denmark were examined during 1979/80. Sialis showed an annual life cycle with mean annual abundance of 20 and 40 ind m−2 at 0.4 and 2.0 m depth, respectively. Growth peaked during July with rates of about 10 % d−1. Net annual production averaged 0.2 g DW at 0.4 m depth and 0.8 g DW at 2.0 m depth. The annual P/B‐ratios were estimated in the range of 4.6‐7.1.
Field and Laboratory Studies on Nile Phytoplankton in Egypt IV. Phytoplankton of Aswan High Dam Lake (Lake Nasser)
Authors: Mohammed Ahmed A. , Ahmed Ahmed M. , El‐Otify Ahmed M. 
Published: February 2007

AbstractSeasonal, local and monthly vertical variations in chlorophyll a concentration and in qualitative and quantitative counts in Aswan High Dam Lake (AHDL) phytoplankton were followed from March 1982 to February 1984. The chlorophyll a values correlated more or less with the total phytoplankton counts. Total algal counts exhibited considerable local variations in the different seasons and tended to decrease in the most southern part of AHDL, especially during the flood period. The temporal course of algal development showed an almost inverse trend to that of dissolved nitrate‐nitrogen. The possibility of nitrogen limitation of algal growth was verified.Diatoms and blue‐green algae alternated in the dominance of the phytoplankton community. The genera Cyclotella and Anabaenopsis respectively were the most predominant genera among the diatoms and blue‐greens and consequently in the phytoplankton community.
Phosphorfällung über Calciumcarbonat im eutrophen Wallersee (Salzburger Alpenvorland, Österreich). Coprecipitation of Phosphorus with Calcite in the Eutrophic Wallersee (Alpine Foreland of Salzburg, Austria)
Authors: Jäger Paul , Röhrs Jürgen 
Published: February 2007

AbstractBy chemical analyses at the eutrophic Wallersee (Austria) a considerable precipitation of calcite during autumn overturn was found. It is a pure anorganic calcite precipitation, caused by the loss of free carbonic acid to the atmosphere during the mixing of epilimnic and hypolimnic water.An essential coprecipitation of phosphorus with the anorganic calcite precipitation could be shown by calcium and phosphorus balances and by SEM investigations.During the epilimnic biogenic calcite precipitation (in summer) phosphorus coprecipitation makes 0.19% of the calcium fallout. Phosphorus coprecipitation increases up to 0.42 % during the anorganic calcite precipitation when autumn overturn takes place. With respect to the total phosphorus sedimentation in the lake 25 % are coprecipitated with calcite.
The Importance of Higher Trophic Level in the Process of Eutrophication in Enclosure
Authors: Tátrai István , Tóth László G. , Istvánovics Vera , Zlinszky János 
Published: February 2007

AbstractEnclosures open to the sediments and the atmosphere were used to elucidate the response of algae and bacteria to the nutrient enrichment from fish in the mesotrophic area of Lake Balaton. Active transformation between the forms of nitrogen was observed especially in the enclosure with fish. Both nitrogen and phosphorus values were influenced by fish. Changes in nutrient dynamics, composition and biomass of algae and bacterial production were measured. It has been shown that benthivorous fish with a biomass illustrative of the most eutrophic part of the lake were able to generate high bacterial production rate and a strong outburst of blue‐greens.
Production de CO2 à l'interface air‐mer. Une approche par l'étude des phénomènes respiratoires dans la microcouche de surface. CO2 Production at the Sea‐Air Interface. An Approach by the Study of Respiratory Processes in Surface Microlayer
Authors: Garabétian Frédéric 
Published: February 2007

AbstractSea‐surface microlayer and underlaying water samples were collected in the Bay of Marseilles (France) in order to study respiratory activity of microneuston and its possible influence on respiratory CO2 production.Three methods were tested: Biochemical Oxygen Demand (BOD) as an estimation of community respiration, Electron Transport System activity (ETS) and 14C‐Glucose uptake monitored by 14C‐CO2 liberation.BOD and ETS data clearly showed enhanced respiratory activities (up to 310 μl O2/l/h) in surface‐films as compared to underlaying waters; moreover the slope of the linear regression between these data led to R/ETS value of 0.689 and provides evidence for the presence of an important heterotrophic fraction within the microneuston.Though 14C‐Glucose measurements showed only a slight trend for higher total activity (incorporation + respiration) in surface microlayers, significant enhancement of relative 14C‐CO2 production giving rise to CO2 diffusion across air‐water interface was observed.
The Processing of Leaves of Trees and Aquatic Macrophytes in the Network of the River Rhone
Authors: Chergui Hassan , Pattee Eric 
Published: February 2007

AbstractBreakdown rate of terrestrial and aquatic leaves was found to depend on leaf species and on the biotope considered.As the leaves started decaying at different dates and had different breakdown rates, consumable allochthonous or autochthonous organic matter was fed to the aquatic system throughout the year, from one summer to the next.A comparison with former results on the main channel confirms the existence of a transversal gradient in the fluvial network: under the influence of fungal and invertebrate colonization, breakdown was fastest in the channel of the river, slower in an open side‐arm, and slower still in a more lateral and closed side arm, in which organic matter accumulated in hypoxic conditions.
Downstream Changes in Caddisfly Composition and Abundance in Relation to Changes in Water Conductivity and Oxygen in the River Butron Basin
Authors: Basaguren A. , Orive E. 
Published: February 2007

AbstractThis paper deals with the abundance and distribution of caddisfly larvae in the River Butron basin. Spatio‐temporal changes in caddisfly community structure, detected by means of correspondence analysis, are related to physico‐chemical changes, mainly conductivity and oxygen.
Distribution and Seasonal Abundance of Benthic Macroinvertebrates in Lake Naini Tal, U.P., India
Authors: Gupta P. K. , Pant M. C. 
Published: February 2007

AbstractA total of thirty taxa of benthic macroinvertebrates were collected from Lake Naini Tal (area = 48 ha, mean depth = 16.2 m) situated 1937 m above sea‐level in the Kumaun Region of the Himalaya. Of these, Chironomus plumosus and Tubifex tubifex were numerically dominant, while Viviparus bengalensis (Mollusca) was the most abundant species in terms of biomass. The seasonality was characterised by two peaks (May and December) both in density and biomass. The population density as well as biomass declined with progressive water depth up to 7 m. Beyond 7 m water depth not even a single individual was found.
Possible food chain relationships between bacterioplankton, protozoans, and cladocerans in a reservoir
Authors: Šimek Karel , Macek Miroslav , Seďa Jaromir , Vyhnálek Vojtêch 
Published: February 2007

AbstractIngestion of fluorescent particles by natural protozoan assemblage was studied in the Řimov Reservoir (Southern Bohemia) from April to October, 1987. Attached and free‐living bacterial abundance, proportion of active bacteria, density of suspended particles and biomass of cladocerans were also monitored.Heterotrophic nanoflagellates (HNF; 5–12.8 102ml−1) were the dominant bacterial micrograzers during the spring period and consumed 3 to 9% of the total bacteria per day. After the spring phytoplankton bloom maximum densities of suspended particles and attached bacteria (up to 28% of the total counts) were found. Development of cladocerans in May sharply decreased the proportion of attached bacteria and kept them below 5% of the total counts.All the studied components of plankton except Cladocera decreased during the clearwater phase. The most significant drop was observed in the numbers of protozoans, and they were negligible for bacterial elimination. Bacterial losses during that time apparently were due to cladoceran grazing.During the summer period, ciliates (15–142 ml−1) were mostly dominant micrograzers, and protozoan community grazing increased up to 21% of bacterial standing stock per day. The proportion of active bacteria was strongly correlated with protozoan grazing (r=0.83).
Protozoans—the first food of larval herring (Clupea harengus L.)?
Authors: Spittler P. , Brenning U. , Arlt G. 
Published: February 2007

AbstractIn short‐run experiments herring larvae at the end of the yolk sac stage (SL 6.5 to 8.5 m) were fed with maize and potato starch to investigate the effect of particle size on food selection. About 20% of the larvae ingested these particles during the experiments.In the case of maize starch (3 to 26 μm grain size) the size classes from 14 to 25 μm and in the case of potato starch (5 to 80 μm) the size classes larger than 29 μm were preferred. The highest numbers of ingested grains per larva were 150 maize starch grains and 57 potato starch grains.The selective uptake of these size classes leads to the conclusion that planktonic organisms in this size range—in other words mostly protozoans—may play an important role as a first food source of herring larvae.