bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variabilité à court terme des propriétés physiques, chimiques et biologiques du Saguenay, fjord subarctique du Quebec (Canada)
Authors: Cǒté Raynald , Lacroix Guy 
Published: February 2007

AbstractTidal variability of water mass characteristics has been assessed in the upper 100 metres of the Saguenay, a subarctic fjord in Québec, Canada. Temperature and salinity show a maximum variability in the 5‐15 m layer in which vertical oscillations of a very sharp pycnocline are observed. Phosphates, nitrates and chlorophyllaare highly variable above this pycnocline during a tidal cycle, but dissolved oxygen content is remarkably stable in the whole water column. It is concluded that fluctuations of many variables in the subsurface waters might be large enough to hinder high rates of primary production.
The Saline Lakes of Saskatchewan IV. Primary Production by Phytoplankton in Selected Saline Ecosystems
Authors: Haynes Robert C. , Hammer U. Theodore 
Published: February 2007

AbstractPrimary production by phytoplankton, efficiency of photosynthesis, and chlorophyll‐a concentrations were determined for seven saline lakes that varied widely in ionic concentration and composition. The investigations were done during the summer months of 1972 and 1973. Productivity ranged from 0.001 to 11.135 g C m−3 day−1 and 0.053 to 7.968 g C m−2 day−1. Highest productivities were measured in two lakes that supported blooms of Aphanizomenon flos‐aquae and Nodularia spumigena, respectively. Species of Cyanophyceae, Bacillariophyceae and Chlorophyceae dominated the phytoplankton of the study lakes. Active chlorophyll‐a ranged from 0.01 to 116 mg m−3. Integral photosynthetic efficiency estimates were <1% except during phytoplankton blooms when they were considerably higher. The overall range of 0.03 to 3.8% is concordant with estimates for other lacustrine ecosystems. The extinction of light caused by photo‐synthetic processes, or in situ efficiency, was <1% in the trophogenic zone for most lakes but, it was considerably higher during blooms. In situ efficiencies invariably increased with depth in ail lakes.
Man‐made Changes in Some Dutch Moorland Pools, as Reflected by Historical and Recent Data about Diatoms and Macrophytes
Authors: van Dam Herman , Blokland Hannie Kooyman‐Van 
Published: February 2007

AbstractThe diatoms of plankton samples taken between 1916 and 1929 and in 1975 from shallow pools, which were originally oligotrophic, are compared. Data about the past and present distribution of macrophytes were gathered from the literature and by field studies. Eutrophication caused by agriculture and recreation, and acidification from precipitation led to important changes in the biocenoses of the moorland pools during the last fifty years.
Discharge Measurement in Lower Order Streams
Authors: John Peter H. 
Published: February 2007

AbstractA large number of conventional and less conventional discharge measuring techniques applicable to lower order streams are discussed. The intention is to provide aquatic biologists and water chemists with sufficient alternative methods so that a suitable choice may be made based on factors such as stream characteristics, required accuracy and available funding and man‐power. In each case the method is described, details of design and use outlined, and areas of application and possible deficiency noted. In addition the criteria determining method selection are discussed.
Ökologische und systematische Studien über das Neuston alpiner Kleingewässer, mit besonderer Berücksichtigung der Ciliaten.
Authors: Foissner Wilhelm 
Published: February 2007

AbstractEcological and Systematic Studies on the Neuston of Alpine Pools, with Special Regard to Ciliated ProtozoaThe qualitative and quantitative composition of the neuston of 31 alpine pools with different degrees of organic pollution was investigated. Phytoflagellata and Ciliophora dominated in highly eutrophic pools, Phycomycetes in less eutrophic ones. The light‐dependent migration of the photoautotrophic heloneuston from the plankton to the surface film caused a strong depression of the neustonic Phycomycetes. Ciliates specially adapted to a neustonic mode of life were not found. The morphology, infraciliature, silverline system and ecology of nine species occuring more frequently in the hyponeuston were studied. A new species (Kreyella minuta)., a new genus (Pseudochilodonopsis). and a new family (Kreyellidae). are described. Some problems dealing with the ecology of ciliates in the surface films of natural pools and of enrichment cultures are discussed.
Intertidal Benthic Invertebrates and Sediment Stability at the Mouth of Delaware Bay
Authors: Maurer Don , Aprill Glenn 
Published: February 2007

AbstractFrom December 1970 to December 1972, the monthly species composition, density, species richness, and biomass of marine macroscopic invertebrates were quantitatively studied from a wave‐protected, intertidal sand flat at the mouth of Delaware Bay. Considerable erosion, transportation, and deposition of sand occurred throughout the study period. The fauna was extremely flexible and resilient in its response to a gradient of considerable sediment mobility. This response was similar in scope to one recognized along the coast of California. Comparison of the local biota with other sand flats and beaches from Maine to South Carolina showed that (1). haustoriids were among the dominant species, (2). densities were roughly comparable, and (3). secondary species were similar.Based on the biological index value, three species contained 87.8% of the fauna from the Cape Henlopen tide flat. These species were the polychaete Scoloplos fragilis and the amphipod Neohaustorius biarticulatus, which were characteristic of sand bars, and the polychaete Heteromastus filiformis, which was more characteristic of troughs or depressions. Mean density varied considerably both monthly and annually with almost no cyclic repetition for any of the three species. There was evidence to indicate that specific habitat requirements of a few species can strongly affect the structure which emerges for a total fauna. Morphology, behavior, physiology, and reproductive strategy are aspects of biology which link dominant benthic species of intertidal sand beaches together.
Algological Investigations in the Polluted Ashar Canal and Shatt al‐Arab in Basrah (Iraq)
Authors: Al‐Saadi H. A. , Pankow H. , Huq M. F. 
Published: February 2007

AbstractIn the Ashar Canal in the city of Basrah and in the Shatt al‐Arab directly below the mouth of the Ashar Canal algological and saprobiological investigations were carried out. The water of the Ashar Canal is β‐ to α‐mesosaprobic, the water of the Shatt al‐Arab below the mouth of the Ashar Canal is β‐mesosaprobic.
Age Structure, Growth, and Weight of Branchiostoma senegalense (Acrania, Branchiostomidae). off North‐West Africa
Authors: Gosselck Fritz , Spittler Peter 
Published: February 2007

AbstractBranchiostoma senegalense from a population off North‐West Africa reach an age of 4–5 years. Relative growth decreases logarithmically with age. B. senegalense reaches 50% of its maximum length during the first year. Differences in the average length of these lancelets in samples taken in close proximity of each other are ascribed to the absence of individual year classes. The immigration of larvae into suitable sediments depends on the current and follows the pattern of the larval swarms in the plankton. Colonized areas are not normally left.The functions relating wet and dry weights (WW and DW respectively). to length L are lg WW = 2.71 × lg L – 2.16, and lg DW = 2.96 × lg L – 3.45. The dry weight is 11.85% of the wet weight.
Hydrobiological Outline of the Mongolian Lakes
Authors: Dulma A. 
Published: February 2007

AbstractThe waters of Mongolia can be classified according to their catchment areas into three hydro‐geographic regions: basin of the Arctic Ocean, basin of the Pacific Ocean, Central Asian basin without outlet. After a short historical survey of the exploration of the lakes of the Mongolian People's Republic, the formation and the classification of the lake system is briefly dealt with. Recent hydrobiological findings are presented in addition to hydrological data. As far as possible, statements are made on the size and the depth of the waters, the growth of macrophytes and the trophic level of the lakes. A distinction is made between ultraoligotrophic, oligotrophic, mesotrophic, eutrophic and dystrophic waters. They are characterized by data on the biomass of the plankton and the ichthyofauna. In the zooplankton of the Central Asian basin, 17 copepod, 29 cladoceran and 58 rotatorian species, and in the waters belonging to the drainage basin of the Pacific Ocean 16 copepod, 40 cladoceran and 37 rotatorian species have already been identified.The results represent the basis for an intensification of fishery in the Mongolian People's Republic.
Chemical and Mineralogical Composition of the Mud‐Water Interface of the Lake Huleh (Israel) Preserve
Authors: Cowgill Ursula M. 
Published: February 2007

AbstractThere is scant information about the chemical composition of the mud‐water interface in shallow, aerobic, eutrophic bodies of water. This study is concerned with the chemical and mineralogical composition of the mud‐water interface of the Lake Huleh preserve (Israel). The most important conclusion gleaned from this investigation is that elements preferentially sorbed by the mud from the mud‐water interface in shallow, aerobic aquatic systems such as the Huleh preserve do so by two methods: organic matter sorption (cadmium, bromine) and scavenger action of ferric hydroxide (cesium, beryllium, mercury, tin, titanium, zirconium, bismuth, vanadium, molybdenum and iodine) type complexes. Forty‐six elements were detected in the mud‐water interface; their behavior in this system is described.
Possible Reason for the Expansion of Carassius auratus (Linnaeus, 1758) (Teleostei, Cyprinidae) in the Danube River Basin
Authors: Hholčík Juraj 
Published: February 2007

AbstractThe author found quite a close negative relationship between commercial catches of predatory fishes and of German carp (Carassius auratus) in the lower Danube. He supposes that the main reason for the population explosion and subsequent expansion of German carp in the Danube River basin seems to be a shift in the balance of the fish community due to a reduction in the density of predatory species.
Physical and Chemical Studies of Lago Tupé; a Central Amazonian Black Water “Ria Lake”
Authors: Rai Hakumat , Hill Gary 
Published: February 2007

AbstractLago Tupé, a Central Amazonian dystrophic black water “Ria lake” (blocked valley lake), lateral to the Rio Negro, was studied at all depths for a year. Physical and chemical results of that study are presented here as a prelude to the microbiological studies. The lake's origin and morphology are discussed. Results concerned with thermal properties, suspended matter and dissolved solids are presented, in addition to results on ionic composition, alkalinity, hardness, pH and dissolved oxygen. Nutrient studies include section of phosphate and nitrogen and conclude with silicate results.
Freshwater Ostracods (Crustacea: Ostracoda) of the GenusCyprettaVAVRA, 1895 from Malaysia, Indonesia and the Philippines
Authors: Victor Reginald , Fernando C. H. 
Published: February 2007

AbstractThe genusCyprettaVAVRA, 1895 from Malaysia, Indonesia and the Philippines is reviewed. Currently, eleven species are known from these areas. Two new species are described and two species are redescribed. Remarks and diagnostic illustrations are given for the known species.
Silica Budgets and the Ecology of Planktonic Diatoms in an Unstratified Lake (Lough Neagh, N. Ireland)
Authors: Gibson C. E. 
Published: February 2007

AbstractRiver inputs of dissolved silica into a shallow eutrophic lake (Lough Neagh, N Ireland) are quantified. Exports of silica are high (3.6 to 9.6 tonnes dissolved SiO2 km−2y−1), but the spring concentration of dissolved silica in the lake depends on release of silica from the sediments. Two planktonic diatoms Melosira italica subarctica O. MÜLL, and Stephanodiscus astraea (EHR.) GRUN. dominate the spring flora. Their periodicity is described over ten years and their usage of silica and phosphorus is examined. Data are presented on the resuspension of cells from the sediment, the growth rates of the diatoms in the lake, the incidence of parasites and changes in the filament length of M. italica subarctica.
Primary Productivity of Phytoplankton, Environmental Covariates and Fish Growth in West Bengal Ponds under a Polyculture System
Authors: Jana B. B. , De U. K. 
Published: February 2007

AbstractMeasurements of primary production by phytoplankton in four fish ponds over a period of one year revealed a distinct spatial variation in rate. The ponds were used for polyculture, monoculture, or a traditional system of fish culture. The rates of gross photosynthesis were highly correlated with temperature, free CO2, oxygen, inorganic nitrogen (NH4+, NO2−, and NO3−) and PO4‐P. It was shown by step‐wise multiple regression analysis that in the polyculture pond with a predominantly autotrophic metabolism, gross photosynthesis was the most significant factor correlated with fish growth. In another polyculture system in which the metabolism was mainly hetero‐trophic, the influence of the photosynthesis rate was slight.
Mathematical Investigations into the Longevity of the Ocean Quahog Arctica islandica (Mollusca: Bivalvia)
Authors: Sager Günther , Sammler Rudolf 
Published: February 2007

AbstractAnnual internal growth banding of Arctica islandica has shown that the species has a surprising longevity of up to 149 years as stated by THOMPSON, JONES and DREIBELBIS (1980). The authors have compiled 100 values of valve height against age as reproduced in Figure 1. Visually gained growth curves have been added for single specimens that leave some doubt as to the existence of an inflexion point. In this paper a cross‐sectional evaluation of growth behaviour is carried out with nine funtions using nonlinear regressions. Five growth functions yield almost equally good results with a final valve height just below 100 mm. An inflexion point is either present in early youth or lacking altogether, depending on the growth function used.
Growth Kinetics of Microcystis aeruginosa (KÜTZ) KÜTZ as a Basis for Modelling its Population Dynamics
Authors: Nicklisch Andreas , Kohl Johannes‐Günter 
Published: February 2007

AbstractThe dependence of the specific growth rate of Microcystis aeruginosa (KÜTZ); KÜTZ f. aeruginosa upon temperature and light intensity was determined under continuous illumination in batch cultures. The result can be well described by the function:magnified image where μmax = 3.44.d−1, Topt = 33.2°C, Tmin = 18.3°C and KI = 71.4 Wm−2. The validity of this function is limited to the range of 10–28 °C and light intensities from 5–25 Wm−2. The dependence of the specific growth rate on the nutrient concentration was investigated a t 25°C and 24 Wm−2 light intensity by means of chemostat cultures. The half saturation constants related to the maximum specific growth rate of 1.1 d−1 measured under these conditions were 0.44 μmol.I−1, 4.3 μmol.I−1 and 26.5 μmol.−1 for orthophosphate, nitrate, and ammonium, respectively.
Distribution and Abundance of Zooplankton in an Alkaline Freshwater Marsh in Northumberland County, Pennsylvania
Authors: Seelbach Paul W. , McDiffett Wayne F. 
Published: February 2007

AbstractThe zooplankton community of two ponds in an alkaline marsh in central Pennsylvania were studied. The ponds were found to be distinctly different from one another with regard to species but similar when only zooplankton types are considered. The ponds were quite similar with respect to a number of physico‐chemical characteristics but differed significantly with respect to alkalinity, conductivity, habitat type, vegetation, depth, and predation pressure.
Effect of Filter‐feeding Zooplankton on Phytoplankton in Fish Ponds
Authors: Vyhnálek Vojtêch 
Published: February 2007

AbstractThe effect of filter‐feeding zooplankton on phytoplankton was investigated in two fish ponds near Blatná (southwestern Bohemia, Czechoslovakia) using enclosures of 50 liters volume. Filter‐feeding activity had a positive effect on the growth of individual net phytoplankton (> 40 μm) species except for Aphanizomenon flos‐aquae and Melosira granulata. Except for Schroederia setigera nanoplankton species (< 40 μm) were suppressed by the filter‐feeding zooplankton. In bags without zooplankton the addition of nutrients induced growth of nanophytoplankton species, but no significant differences were noted in bags with zooplankton.
Seasonality and Structure of a Macrobenthic Seagrass Community on the Florida Gulf Coast
Authors: Bloom Stephen A. 
Published: February 2007

AbstractMacrofauna at two intertidal sites, quantitatively sampled monthly for 25 months, exhibited distinct reoccurring population fluctuations which were poorly correlated with abiotic parameters. Faunal dominants, Laeonereis culveri and Onuphis simoni, showed reciprocal fluctuations. Laeonereis exhibited non‐synchronized reproduction and recruitment while Onuphis exhibited synchronized release. Laeonereis peaked before Onuphis while Oniphis fluctuated with the majority of other species. The faunal dominants exhibited one cycle in autumn at both sites but also exhibited a cycle at only one site in spring. Temperature is thus not indicated as causal and detrital input was suggested as the overriding factor. A hypothesis was advanced that Laeonereis is an opportunistic species exploiting fresh detritus, while Onuphis is a detritus feeder utilizing bacterial populations.
Ammonia Excretion in Snails Viviparus bengalensis (LAMARCK) and Pila globosa (SWAINSON) during Active and Dormant Periods
Authors: Chaturvedi M. L. , Agarwal R. A. 
Published: February 2007

AbstractThe quantities of ammonia excreted over a period of 24 h by two prosobranch snails Viviparus bengalensis and Pila globosa were measured at 30 day intervals to compare their excretion during the active and dormant phases of their life. The aquatic snail V. bengalensis excreted 0.5‐1.0 μmole of ammonia per day and snail throughout the year. The ammonia excretion rate of this snail was 40‐50% lower in winter than in the monsoon and summer period. In the amphibious snail Pila globosa excretion of ammonia was limited to only four months of its active life i. e. during July‐October. Also the rate of ammonia excretion in P. globosa (0.2‐0.3 μmole per day and snail) was very low compared with V. bengalensis.
Macrobenthic Communities of the Lower Chesapeake Bay. IV. Bay‐wide Transects and the Inner Continental Shelf Benthic Studies of the Lower Chesapeake Bay 7
Authors: Dauer Daniel M. , Stokes Thomas L. , Barker Howard R. , Ewing R. Michael , Sourbeer Jerry W. 
Published: February 2007

AbstractThe distribution, abundance, and species composition of subtidal macrobenthic invertebrates of the lower Chesapeake Bay and the inner continental shelf off the mouth of the bay were studied. The benthos of the lower bay was sampled on two bay‐wide transects sampled once in June 1978. The benthos of the inner shelf was sampled five times per year from 1979 through 1981. Data from this study were compared with data from previous studies of estuaries and the inner shelf of the mid‐Atlantic Southeastern U.S.
Integrated Samples Provide Accurate Means of Parameters Characterizing Aquatic Ecosystems
Authors: Vietinghoff Ulrich , Erdmann Norbert , Arndt Hartmut , Kell Volkbert , Hubert Marie‐Luise 
Published: February 2007

AbstractThe measurement of ecosystem parameters normally involves considerable effort in terms of sampling and analysis due to their variation in time and space. This contribution describes the advantages and properties of the integrated sample and demonstrates them by comparing the statistical properties of separate samples (number of Filinia longiseta per unit volume), and integrated sample (total chlorophyll a concentration) and phytoplankton samples analyzed by the Utermöhl method. A working hypothesis is presented to explain the causes of the overdispersion that hinders phytoplankton analysis and to suggest ways of eliminating it.
Metabolic Heat Flow Patterns in the Intertidal Mussel Ischadium ( = Modiolus=Geukensia) demissum demissum during Aerial and Underwater Respiration
Authors: Pamatmat Mario M. 
Published: February 2007

AbstractRapid changes in heat production rate by Ischadium demissum demissum (=Modiolus demissus demissus, Geukensia demissa), largely though not exclusively effected by opening and closing of shell valves, signify changing metabolic states, physical activity level, and body processes with time and experimental condition. It is theorized that the relative rates of anaerobic metabolism and oxygen uptake, as influenced by temperature, and the presence or absence of unfavorable external stimuli all interact, in feedback mode, to regulate the opening and closing of shell valves. Knowledge of the pattern of instantaneous changes in metabolic rates of organisms is essential in analysis of, and interpreting and comparing data on, average metabolic rates. Direct calorimetry should be particularly useful in understanding the evolutionary ecology of facultatively anaerobic organisms.
Seasonal Physical, Chemical and Algal Changes in Five Rivers Flowing Through the Oil Sands Region of Alberta, Canada
Authors: Charlton Shirley E. D. , Hickman Michael 
Published: February 2007

AbstractSeasonal studies concentrating upon physical and chemical parameters and the epilithic algal community were conducted at specific sites in five tributary rivers flowing through the oil sands region of northeastern Alberta, Canada into the Athabasca River. Numerically cyanophycean algae (Lyngbya aerugineo‐caerulea, Phormidium sp., Calothrix braunii, Nostoc spp. and Anabaena affinis) dominated followed by diatoms (Achnanthes lanceolata, Cocconeis pediculus, Cocconeis placentula, Epithemia sorex, Epithemia turgida, Gomphonema acuminatum, Gomphonema longiceps v. subclavata, Gomphonema olivaceum, Nitzschia fonticola, Nitzschia palea, Synedra rumpens, and Synedra ulna). One exception was the Hangingstone River where chlorophycean algae (Stigeoclonium pachydermum and Cladophora glomerata) were next in importance to the cyanophytes. Seasonal fluctuations in algal species and numbers were influenced by a myriad of interacting parameters. Physically disruptive forces (current velocity and discharge) appeared more important than dissolved nutrients. They were also responsible for affecting the chemical composition of the water itself.