bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Further Investigation on the Primary Productivity in the Divergence Zone Near the French Mediterranean Coast
Authors: Slawyk Gerd , Minas Hans Joachim , Minas Monique , Packard Theodore T. 
Published: February 2007

AbstractThe present investigation re‐examines hydrological features, the inorganic phosphate distribution and primary productivity near the “Hyères” Islands in the French Mediterranean in the early summer divergence zone as previously studied by MINAS and BLANC (1970). In addition, concentrations of particulate nitrogen, Chl‐a and nitrate have been determined. Uptake rates of 15N‐labelled nitrate (“new production”) and the oxygen consumption (ETS‐activity) by the phytoplankton population have been estimated.
The Ecology of Temporary Streams I. The Faunas of Two Canadian Streams
Authors: Williams D. Dudley , Hynes H. B. Noel 
Published: February 2007

AbstractThis, the first of two papers on the ecology of temporary streams, describes, in detail, the faunas of two such habitats in southeastern Canada. The adaptive mechanisms for coping with the summer drought are documented for a variety of species and faunal succession is shown to occur from the stream stage (fall‐winter) through the pool stage (spring) to the terrestrial (summer).
Phytoplankton Primary Productivity and Population Efficiency Studies in a Prairie‐Parkland Lake Near Edmonton, Alberta, Canada
Authors: Hickman Michael , Jenkerson C. G. 
Published: February 2007

AbstractThe standing crop and primary productivity of a small eutrophic, prairie‐parkland lake were measured. In general, both standing crops and primary productivity were large, 29.4 and 73.09 mg chlorophyll a m−3 and m−2 and 78.71 and 196.77 mg C hr −1m−3 and m−2 respectively. Productivity decreased with increasing depth, therefore, decreasing light intensity. Relations between productivity and chlorophyll a content, productivity and light intensity, phytoplankton productivity efficiency and light intensity, productivity and water temperature were investigated, as was the photosynthetic index. Experiments designed to determine the photosynthetic capacity of the phytoplankton distinguished between actively growing and senescent populations. The latter were present during the winter ice cover.
Effects of Artificial Rise of Temperature on Stagnant Waters and Their Biocenoses
Authors: Biesiadka Eugeniusz , Kaspbzak Krzysztof , Kolasa Jerzy 
Published: February 2007

AbstractA change of the thermal regime results in a variety of reactions of both abiotic and biotic components of the environment. The aim of this paper is to present new data (on Turbellaria, Oligochaeta, Hirudinea, Coleoptera and Hydracarina) on biological responses to the thermal factor discussed in a broad context of literature and, to evaluate their impact on the subsequent ecosystem development. A theoretical interpretation of all phenomena related to this factor is proposed within a widely‐conceived theory of adaptation.
Phytoplankton Production at Two Stations in Lindåspollene, a Norwegian Land‐locked Fjord, and Limiting Nutrients Studied by Two Kinds of Bio‐assays
Authors: Lännergren Christer 
Published: February 2007

AbstractAt two stations in a Norwegian land‐locked fjord, one more and one less influenced by freshwater run‐off, studies were made of the primary production, chlorophyll a concentrations, and the quantity and composition of phytoplankton. Samples were taken for analyses of phosphate, nitrate, and silicate, and temperature and salinity were measured. Two kinds of bio‐assays were performed: combinations of phosphate, nitrate, and silicate were added to I, natural water incubated in situ, and II, natural water incubated in the laboratory. Lower salinities and higher concentrations of all nutrients were found at the station most influenced by fresh‐water. Although the bio‐assays indicated that nitrogen was the main limiting nutrient, the biological parameters showed no consistent differences between the two stations. The similarity is tentatively explained by the growth of nanoplankton algae, partly depending on nutrients other than those analysed.
Population Dynamics and Production of a Planktonic Marine Copepod,. Acartia clausii, in a Small Temperate Lagoon on San Juan Island, Washington
Authors: Landry Michael R. 
Published: February 2007

AbstractThe population dynamics and production of Acartia clausii, a planktonic marine copepod, were studied during 1973 and 1974 in a small temperate lagoon. An approach which integrated laboratory and in situ experiments with time‐series sampling of the field population was used to analyze seasonal changes in the parameters of population growth (development, growth, fecundity, and mortality) and to elucidate the processes which affect these changes. The objective of the study was to understand the factors which control the seasonal cycle of abundance.The cycles of abundance were similar in the two years of study and were not affected by differences in the cycles of tidal inflow, temperature, and food availability even though the latter two factors appreciably affected growth, development, and fecundity rates. The abundance cycle is controlled by an annually consistent pattern of copepodid and adult mortality believed to be due to predation by the three‐spined stickleback, the dominant fish species in the lagoon. Cannibalism and periodic tidal stimulation of hatching of accumulated eggs in the sediment help to regulate population abundance within seasonal limits.Production by the lagoon population was 229 kg C for the entire study period; 84—88% of the annual production occurred from April through July. In the area of the lagoon greater than 3‐m deep the mean daily productions during the peak months of each year were 70 and 55 mg C m−2 for 1973 and 1974, respectively.
The Saline Lakes of Saskatchewan II. Locale, Hydrography and other Physical Aspects
Authors: Hammer U. Theodore , Haynes Robert C. 
Published: February 2007

AbstractThe geology and physiography, climate, soils and vegetation of the saline lakes region of southern Saskatchewan are briefly reviewed. The location and morphometry of 60 saline lakes was determined. Some of them are large (307 km2) but mean depths do not exceed 10 m and many are very shallow. Light penetration varied considerably from very turbid shallow lakes to Redberry Lake where the 1% light level was below 16.5 m. Light extinction coefficients for the entire water column of deeper lakes (7) varied from 0.256 to 2.558.Shallow lakes failed to stratify thermally but a dozen deeper lakes stratified for at least several months. Higher salinity tends to prolong stratification. Thermal stratification augmented chemical stratification in two meromictic lakes. Maximum temperature up to 30 °C in very saline shallow waters was recorded while temperatures as low as‐3 °C occurred under the ice. Freezing was delayed and thawing accelerated in more saline lakes. Annual heat budgets varied from 3350 to 13,900 g cal cm‐2 in seven lakes.Oxygen concentration was reduced below thermoclines and was virtually absent below the ice in very shallow lakes and, at times, in a very productive lake.
Zur Autökologie von Opistomum pallidum O. Schmidt, 1848, einer Turbellarienart astatischer Kleingewässer. Autecology of Opistomum pallidum O. SCHMIDT, 1848, a Turbellarian Species of Astatic Freshwater Biota
Authors: Heitkamp Ulrich 
Published: February 2007

AbstractIn the freshwater turbellarian, Opistomum pallidum, facultative self‐fertilization occurs. The duration of development follows the van't Hoff/Arrhenius temperature rule. An acceleration of development is caused by a crowding effect at low temperatures. In the natural habitat, one generation requires 6‐7 months, lasting from November to May, or 2‐3 months from March to May.
Wirkungen von Silberkarpfen (Hypophthalmichthys molitrix) auf das Plankton in Flachgewässern nach Untersuchungen in Karpfenteichen. Influence of Silver Carp (Hypophthalmichthys molitrix) on Plankton of Shallow Waters According to Investigations in Carp Ponds
Authors: Barthelmes Detlev 
Published: February 2007

AbstractNo severe changes take place in the plankton of highly eutrophic non‐stratified water bodies up to a stocking rate of 1,000 Si3/ha. This rate gives additional yield of 200‐300 kg/ha. Stocking rates of 10,000 Si3/ha allow selective overexploitation of microphytoplankton incl. bluegreens and of nearly all zooplankton. Yield reaches in this case 1 t/ha in 1 m deep waters.
Effect of Thermal Effluents and Retention Time on Lake Functioning and Ecological Efficiencies in Plankton Communities
Authors: Hillbricht‐Ilkowska Anna , Zdanowski Bogusław 
Published: February 2007

AbstractThe following changes were observed in three lakes as a result of their heating and decrease of retention time (data for summer periods): increase of mixing rate, active bottom area, and nutrients (Pinorg., Ninorg.) concentrations; significant changes in gross primary production, phytoplankton biomass and production of filtering cladocerans. These changes seem to indicate the higher efficiency of utilization of autochthonous trophic resources and energy transfer in plankton.
Spatial Distribution of the Phytoplankton in a Tropical Lake (Lake Lanao, Philippines)
Authors: Lewis William M. 
Published: February 2007

AbstractThe distribution of phytoplankton was studied in Lake Lanao, Philippines. In calm weather, the species segregate vertically with motile species and buoyancy‐regulating species above other species in the water column. On a distance scale of 12.5 km, horizontal variability yields a coefficient of variation of 23.6% for total biomass, 30.2% for net primary production, and an average of 30.3% for individual species biomass after removal of error variances. Variabilities on a scale of 1 km are about half as large. Horizontal patchiness of individual species is not related to their abundance, surface to volume ratio, morphotype, or taxon, but is negatively related to their size.
Setting of Estuarine Invertebrates in Delaware Bay, New Jersey, Related to Intertidal‐Subtidal Gradients
Authors: Hidu Herbert 
Published: February 2007

AbstractAttachment of eight groups of estuarine benthic species was recorded on a 4000 ft. intertidal‐subtidal transect on Delaware Bay, Cape May, New Jersey. Asbestos‐board panels were spaced at 3‐foot vertical intervals and harvested at weekly intervals for two seasons. Intraspecies attachment patterns were very regular both spatially, and temporally indicating specific setting behavior interacting with a relatively stable environmental influence.Intertidal, on‐bottom patterns were associated with Crepidula sp. and Balanus sp. whereas Sabellaria vulgaris preferred subtidal, on‐bottom panels. Subtidal, off‐bottom panels were colonized by Tubularia crocea, Conopeum tenuissimum, Caprellidae and Gammaridae. Crassostrea virginica showed a variable pattern, predominantly on‐bottom and subtidal, but occasionally on‐bottom intertidal, inshore. Factors producing concentration of larvae and release of the setting response are important in the inshore recruitment of oysters. All information indicates that the mechanism of selective settlement is a dominant factor in producing benthic assemblages.
Résultats de la mission Hydratlante I du N. O. Jean Charcot (au large des côtes atlantiques françaises) I. Dénombrement des population microplanctoniques. Results of Hydratlante I cruise of R. V. Jean Charcot (off the Atlantic French coast). I. Microplankton enumeration
Authors: Travers Marc 
Published: February 2007

AbstractAmong numerous physical, chemical and biological parameters, the enumeration and identification of microplankton cells have been carried on at all stations and depths, by means of UTERMÖHL'S method (on board and on land). After dealing with space and time distribution of the data, they are compared with some features of environment and particulate organic matter. Abundance and composition of the populations depend on the supply of nutrients, which on its turn depends on the thermal stratification. More or less clear or sure other correlations are discussed: with density, light, bacterioplankton, varied seston parameters, etc….
Limnological Studies on the River Tigris, Iraq. I. Environmental Characteristics
Authors: Saad Massoud A. H. , Antoine Samir E. 
Published: February 2007

AbstractRegional and seasonal variations of some environmental characteristics in the 630 km stretch of the lower Tigris were studied and discussed. The lowest air and average water temperatures were recorded in January. The highest average pH values, generally found in October and July, are due mainly to the abundance of phytoplankton. The remarkably low average chlorosity values found in the periods of high water were correlated with the high discharge. The highest average values for dissolved oxygen concentration were generally recorded in January and April, and the lowest ones were observed in October and July.
Limnological Studies on the River Tigris, Iraq. III. Phytoplankton
Authors: Saad Massoud A. H. , Antoine Samir E. 
Published: February 2007

AbstractVariations in quantity and structure of phytoplankton in the lower 630 km stretch of the Tigris were studied and discussed. The Chlorophyceae generally contributed more genera to the phytoplankton community, and the Bacillariophyceae and Cyanophyceae ranked second and third, respectively. The phytoplankton generally showed considerable local and seasonal variations at the surfaces of the sampling locations.
The Hydrochemical and Physical Characteristics of the Breeding Sites of the Simulium neavei Roubaud Group and their Associated Crabs in the Eastern Usambara Mountains in Tanzania
Authors: Grunewald Jörg , Grunewald Barbara E. , Raybould John N. , Mhiddin Haji K. 
Published: February 2007

AbstractInvestigations on the hydrochemical and physical parameters of the breeding sites of Simulium woodi (an onchocerciasis vector). and Simulium nyasalandicum, and on their aquatic stages and associated crabs, were carried out for 13 months in the Zigi (Sigi). River system. The conductivity, pH and concentration of the main ions and silicate were all higher in the breeding sites of S. woodi than in those of S. nyasalandicum. S. woodi was restricted to small heavily shaded streams and did not enter rivers and large streams which contained higher concentrations of ammonium and nitrite. S. nyasalandicum was most numerous in rivers and large streams, but invaded small heavily shaded streams during the rainy season when conductivity and pH values were reduced.
Phytoplankton and Primary Production of Lakes in the Matamek Watershed, Quebec
Authors: Janus L. L. , Duthie H. C. 
Published: February 2007

AbstractThe productivity of three Shield lakes on Quebec's North Shore was found to be comparable with that of the most oligotrophic lakes known. Factors contributing to this condition may be that the moderately sized lakes of this study are deep relative to their surface areas, highly stained by humic substances, of very low conductivity, and contain little dissolved CO2. Standing crops of phytoplankton are very low, never exceeding 600 mg/m3. Chrysophyceae are dominant over all other classes of algae in both biomass and numbers, comprising approximately 50% of the fresh weight throughout the season. The abundance of micro‐flagellates implies a large surface area to volume ratio and the ability to move are an advantage in a nutrient poor environment. Much of the phytoplankton present may grow heterotrophically and energy additions from the terrestrial environment may be extremely important to the productivity of northern lakes when photosynthetic production is not significant.
A Contribution to the Phosphorus Loading Concept
Authors: Benndorf Jürgen 
Published: February 2007

AbstractFor the application of the empirical model of Vollenweider and Dillon (1974). and Vollenweider (1976). to reservoirs, the critical phosphorus loading levels have been related to dissolved orthophosphate. 19 reservoirs and primary reservoirs are in optimum accordance with the extended model. To permit the use of the model also in the range of very short residence times, an extremely simple analytical model of phytoplankton growth has been introduced. The reliability of the resulting outwash limits has been checked by means of random sampling at two primary reservoirs. Among 17 samples only 1 does not fit into the model.
A Rationale for the Subclassification of Biogenic Meromictic Lakes
Authors: Dickman M. D. , Hartman J. S. 
Published: February 2007

AbstractAn extension of Walker and Likens' (1974). scheme for the classification of meromictic lakes of the world has been based in part upon the mutual incompatibility of certain common chemical species and their generation within the monimolimnia of biogenic meromictic lakes.
The Feeding of Chaoborus flavicans Meigen (Diptera, Chaoboridae). and its Predation on Lake Zooplankton
Authors: Kajak Zdzislaw , Rybak Jadwiga 
Published: February 2007

AbstractIn a study of Chaoborus feeding in a eutrophic lake, selectivity was found to be positive with Crustacea (especially copepodit stages). and negative with Rotatoria. Daily food rations were about 20% for most of the feeding period, but higher (106%). during the month of intensive growth after hatching. Feeding intensity correlated positively with amount of food an temperature, and negatively with Chaoborus concentration. Elimination of Crustacea (in the epilimnion of the central zone of the lake). equalled about 30–40% of Crustacea production in June and September and slightly exeeded the August production (it was almost zero in the remaining months because Chaoborus larvae stayed at the bottom). This applies, however, only in the central zone – about 50% of the lake volume. Chaoborus probably influences both the density of zooplankton and the quantitative relations between zooplankton species.
System Analysis of Silica‐Diatom Interaction
Authors: Baumert Helmut 
Published: February 2007

AbstractThe prediction of and measures to prevent planktic diatom blooms in shallow lakes and slowly flowing rivers are major problems specific to water quality management. In this paper methods of mathematical systems analysis, computer simulation, and parameter identification are used to analyse a simple system consisting only of a population of planktic diatoms and dissolved silica in a shallow lake.
Factors Influencing the Diversity, Species Composition and Abundance of Phytoplankton in Twenty One Arctic and Subarctic Lakes
Authors: Moore James W. 
Published: February 2007

AbstractThe factors influencing the diversity, species composition and abundance of phytoplankton in 21 lakes in the Canadian arctic and subarctic were determined between 1975 and 1978. The maximum number of species (60–75). and highest diversity indices (1. 6–1. 9). were recorded from the most southerly lakes, situated at 63–64°North. Since there were fewer species (40–60). and lower diversity indices (0. 7–1.0). in lakes located at 65–66°North, temperature was the main factor influencing the diversity of the flora. Other parameters, including surface area, depth and the concentrations of nutrients, exerted little influence on the plankton. The maximum densities of several common species (Rhodomonas minutavar.nannoplanktonica, Kephyrion boreale, Ochromonas sphaerella, Ankistrodesmus falcatus, Oscillatoria limnetica). increased significantly in lakes with high concentrations of total phosphorus and total hardness whereas the reverse pattern was recorded for two other common species (Dinobryon bavaricum, D. sociale). Diatoms (mainlyAsterionella formosaandCyclotella glomerata). were restricted primarily to large lakes where turbulence helped keep these algae afloat.
The Ecology of Temporary Streams III. Temporary Stream Fishes in Southern Ontario, Canada
Authors: Dudley Williams D. , Coad Brian W. 
Published: February 2007

AbstractThe 12 fish species living in three temporary streams in Southern Ontario, Canada, during 1973–1974, are listed. Environmental parameters are recorded together with details of the abundance, distribution, age structure, growth, reproduction and food of the more common species. These species are thought to be either physiologically very tolerant, or to be capable of temporal or spatial migrations. Colonization of temporary streams bestows benefits in terms of plentiful invertebrate food, although resource sharing may occur, earlier spring breeding and reduced predation.
The Food and Feeding Chronology of Yellow Perch (Perca flavescens) in Lake Washington
Authors: Costa H. H. 
Published: February 2007

AbstractThe food habits of yellow perch (Perca flavescens) in Lake Washington, Seattle, U.S.A. were studied over a period of nine months. Altogether 549 yellow perch were examined for the stomach contents. The daily activity pattern of the yellow perch in Lake Washington appears to correspond roughly with the feeding pattern. The maximum numbers of perch caught by the nets during 24 hour study periods correspond well with degree of fullness of stomachs noted for the different times of the day. The food consisted mainly of cottids, mysid shrimps (Acanthomysis awatchensis) and chironomid pupae and larvae. There was no difference in the food consumed between the different sexes and between the different size groups. Maximum feeding by perch during the day was observed just before dark and the daily ration was calculated to be about 1.4% of their wet body weight.
Distribution of Peltoperla arcuata Needham (Ins., Plecoptera) in a Small Woodland Stream
Authors: Miller Dale E. , Kovalak William P. 
Published: February 2007

AbstractThe distribution of Peltoperla arcuata in a first‐order stream and its two ephemeral tributaries was studied between March and April, 1977. Overall, the distribution was highly contagious (clumped) with most nymphs concentrated in the lower reaches of the tributaries. The most reasonable explanations for aggregation in tributaries were: 1) higher food quantity and quality in early fall, 2) minimization of downstream transport by erosion of leaf packets and 3) diversion to the tributaries of upstream movement in the mainstream by obstacles (e. g., logs and boulders) in the channel.
Two New Krumbachia (Turbellaria Neorhabdocoela) from Highland Streams near Schlitz, Hesse Schlitz Studies on Productivity No. 32
Authors: Schwank Peter 
Published: February 2007

AbstractThe descriptions of Krumbachia paludicola n. sp. and K. hiemalis n. sp. (Typhloplanidae, Turbellaria Neorhabdocoela) are given, together with brief diagnoses and a general discussion of all species in the genus. The new species are illustrated.
The Dependence of Crustacean Respiration Rate on Body Mass and Habitat Temperature
Authors: Ivleva I. V. 
Published: February 2007

AbstractThe respiratorion rates of Crustacea from temperate and tropical waters of the Atlantic Ocean were measured directly at habitat temperatures of 19, 25 and 29 °C. The results were analysed together with data obtained from similar investigations in previous years (Ivleva, 1977) on Crustacea from moderately cold and polar latitudes at 10, 6 and 0 °C. Variations of the values for A and k in generalized regressions (R = AWκ) for Crustacea within the temperature limits of the physiological range were shown to have quite a clear‐cut and regular character. The coefficient k varied from 0.60 to 0.79 and revealed a tendency to increase as temperatures decreased. The value of A increased with rising temperature within all intervals from 0 to 30 °C. The quantitative relationship between respiration rate and temperature was evaluated by the Arrhenius equation. Statistical processing of resultant data indicated a rather close association between log A and the habitat temperature of the Crustacea but only slight deviations from the theory of empirically found values. The accelerating effect of temperature (μ) was 13 ± 0.13 keal/mol. This value was used to calculate Q10, which was more convenient for practical purposes.