bluuebunny/crossref_metadata_2025_split huggingface dataset:
Primary Production Characteristics of a Himalayan Lake in Kashmir
Authors: Wanganeo Ashwani 
Published: February 2007

AbstractLake Manasbal is the only valley lake in the region with a true thermal stratification during summer. Seasonal and annual rates of carbon fixation in the water column by plankton populations were related to physical and chemical parameters on specific days. The temporal and spatial changes showed the strong influence of nutrients on the primary production. No significant dependence of carbon uptake on either phytoplankton density or biomass was determined. The overall production pattern during the study period was definitely bimodal, with one minor peak in spring (719.3 mgC m−2 day−1) and a major one in summer (1496.2 mgC m−2 day−1 in June). The study also revealed that nannoplankton was responsible for 69% of the primary production.
Bag Experiments on the Effect of Phosphorus and Base Additions on the Algal Biomass and Species Composition of an Acid Lake
Authors: Wilcox Gerald R. , Decosta John 
Published: February 2007

AbstractBag experiments were conducted to determine the effect of neutralization and phosphorus additions on phytoplankton in a lake acidified by mine drainage. Neutralization and phosphorus additions caused a lag of several days before algal growth occurred.
Dégradation d'acides aminés à l'interface eau‐sédiment réconstitué d'une lagune méditerranéenne (Golfe du Lion)
Authors: Daumas R. , Gadel F. , Cahet G. , Dinet A. 
Published: February 2007

Degradation of Amino Acids at a Simulated Water‐sediment Interface of a Mediterranean Lagoon Environment, Golfe du LionThe degradation of two 14C and 3H labelled amino acids at the simulated water‐sediment interface of a Mediterranean lagoon was studied.The four day experiments included the respiratory activity measurement and the study of incorporation processes of the radioactivity in specific organic fractions of the 14C arginine. After active mineralization occurred during the first day, the radioactivity in the acid‐soluble fraction decreased and polycondensed products were progressively incorporated. The radioactivity of the 3H lysine was included mainly in the acid soluble fraction.The nature of the substrate, and the reducing conditions in the environment affect the radioactivity distribution in the organic fractions.The identification of amino acids in the acid‐soluble and base soluble fractions shows that the labelled arginine and lysine and other amino acids in the acid soluble and base soluble fractions shows that the labelled arginine and lysine released from the initial compounds are important quantitatively.
Production and Distribution of the Microphytobenthos in the Sediment of Lake Mikolajskie
Authors: Wasmund Norbert 
Published: February 2007

AbstractChlorophyll‐α concentration, algal biomass and photosynthetic activity decrease with increasing sediment depth. Chlorophyll‐α and biomass minima were found at the sediment surface on several occasions. This may be due to the removal of algae by wave action or vertical migrations of the algae in the sediment. By comparing stations with different degrees of exposure it was shown that wave action affects the size of the benthic populations. The epipsammic microphytobenthos is an important primary producer in the littoral zone of Lake Mikolajskie.
Le phytoplancton des étangs de Berre et Vaïne (Méditerranée Nord‐occidentale)
Authors: Kim Ki‐Tai , Travers Marc 
Published: February 2007

Phytoplankton of the Etang de Berre and Etang de Vaïne (N.W. Mediterranean)The phytoplankton in the brackish Etang de Berre and Etang de Vaïne was studied regularly at 12 stations for two years. The recent diversion of the Durance River into the Etang de Berre has effected a fundamental change in this formerly marine environment, which has had a great impact on its plankton populations. A total of 182 taxa were identified, including 111 Bacillariophyceae, 44 Chlorophyceae, and 15 Cyanophyceae. The most abundant species are small freshwater algae, mainly Chlorophyceae, since the salinity is generally less than 3 0/00. However, during summer and fall, as well as in waters near the bottom, the salinity can reach 15 0/00 and marine diatoms are predominant.Because the nutrients in the environment are constantly replenished, phytoplankters are always numerous, ranging in abundance between several million to several hundred million per liter. There is a somewhat irregular seasonal cycle. The average density is about 108 cells/1 in the Etang de Berre, and about double that amount in the Etang de Vaïne. Differences in phytoplankton abundance and composition at the various stations or at various depths are slight.
Phytoplankton Distribution in the Coastal Area Subject to the Impact with the Tiber River Outfall
Authors: Puddu A. , Arfi R. 
Published: February 2007

AbstractThe taxonomic composition and geographical distribution of phytoplankton in the coastal zone surrounding the River Tiber mouth were investigated in twelve surveys from April 1978 to September 1979. Ninety phytoplankton species were identified from 168 samples. Diatoms were clearly the dominating species, accounting for more than 95 per cent of total phytoplankton.— Principal Component Analysis was utilized to analyse the total information obtained.—The direct impact on the coastal environment of River Tiber water and its considerable nutrient load were seen as providing a permanent potential for the development of less structured phytoplankton communities. Heterogeneity of local hydrological conditions and fluctuations in the river's impact, lead to a virtually constant instability in the neritic environment near the Tiber River outfall.
Limnology of a Sewage Polluted Tank in Central India
Authors: Unni K. Sankaran 
Published: February 2007

AbstractThe limnology of a sewage polluted pond was studied from 1978 to 1981. Stratification of temperature, dissolved, oxygen, conductivity, pH, alkalinity and chloride was recorded. The surface stratum down to 0.5 m was supersaturated throughout the year. The pond recorded a permanent water bloom dominated by Anacystis during the summer months. This was followed by Anabaena and Anabaenopsis during winter. The growth of Chlorococcales was retarded due to intraspecific competition, self‐shading and low carbon dioxide levels though the waters were nutrient rich. Before the summer overturn, accumulation of calcium bicarbonate produced temporal meromixis. In general, a reduction in the number of zooplankters was recorded.
Assessment of Components Controlling Phytoplankton Photosynthesis and Bacterioplankton Production in a Shallow, Alkaline, Turbid Lake (Neusiedlersee, Austria)
Authors: Dokulil Martin 
Published: February 2007

AbstractVarious aspects of phytoplankton photosynthesis were investigated between 1968 and 1980 in Neusiedlersee, Austria, a shallow (z̄ = 1.3 m), well mixed lake with much turbidity resulting from frequent resuspension of inorganic sediment particles. The influences of the great environmental variability on biomass, photosynthesis and phytoplankton production were determined and discussed with respect to the increasing nutrient concentrations in the lake. Investigations of bacterioplankton biomass and production revealed their importance for nutrient regeneration and as food for large zooplankton populations. The results are compared with those from several other shallow lakes, and an attempt is made to identify characteristics to distinguish the different types.
Faunistische Untersuchungen im hyporheischen Interstitial des Flusses Mur (Steiermark, Österreich)
Authors: Kirchengast Michael 
Published: February 2007

Faunistic Investigations of the Hyporheic Interstitial of the River Mur (Styria, Austria)Two distinct sections of the River Mur (Styria, Austria), one almost unpolluted and the other heavily polluted by domestic and industrial waste waters, were investigated for two years. Faunistic, hydrographic, and ecological investigations were carried out at the river bottom, including particularly the hyporheic interstitial zone. All species found were investigated qualitatively and quantitatively, and ecological factors are stressed. The composition of the fauna of the unpolluted area differs markedly from that in the polluted section.
Form Variations in the Rotifer Brachionus calyciflorus Pallas from a Perennial Impoundment in India
Authors: Sharma Surya Prakash , Saksena Devendra Nath 
Published: February 2007

AbstractAll three classical forms of Brachionus calyciflorus Pallas viz., calyciflorus, dorcas and amphiceros were recognised in the impoundment. The form amphiceros was most abundant, and its occurrence is attributed to the presence of Asplanchna brightwelli in the tank. Euglena viridis appears to be the preferred food of B. calyciflorus in this impoundment.
Influence of Water Hyacinth Cover on the Physico‐chemical Characteristics of Water and Phytoplankton Composition in a Reservoir near Jaipur (India)
Authors: Gopal B. , Trivedy R. K. , Goel P. K. 
Published: February 2007

AbstractWater hyacinth (Eichhornia crassipes (Mart.) Solms.) invaded a eutrophic reservoir receiving domestic sewage near Jaipur (India) during 1975 and gradually developed a complete thick cover over the whole water body during Sept.–Oct. 1978. The physico‐chemical characteristics of the water and the phytoplankton composition were studied during Sept. 1977–Sept. 1979 by fortnightly sampling. The changes observed during the second year of study are ascribed to the water hyacinth cover. The important changes were: lowering of water temperature, pH, dissolved oxygen content and nitrate nitrogen, and increase in total alkalinity, free carbon dioxide, chemical oxygen demand, ammonia nitrogen, sulphides, calcium, magnesium and phosphate phosphorus. The changes in the phytoplankton were both qualitative and quantitative. The green algae, particularly the species of Ankistrodesmus, Chlorella, Crucigenia and Selenastrum, increased considerably and replaced the blue‐green algae, of which Oscillatoria and Microcystis disappeared totally. The densities of several other taxa changed significantly.
Attraction of Fish to Mercury Vapour Light and Its Application in a Generating Station Forebay
Authors: Haymes Gerard T. , Patrick Paul H. , Onisto Lawrence J. 
Published: February 2007

AbstractLaboratory and field tests were conducted to determine the effectiveness of filtered mercury vapour lights in attracting fish with possible utilization in a fish conserving scheme at an electrical generating station. In laboratory tests, alewife demonstrated an attraction to the mercury vapour light which was associated with an increase in swimming activity. This response was maintained over a 48‐hour period. When the filtered mercury vapour lights were utilized in association with a fish pump in the Nanticoke Generating Station forebay, juvenile gizzard shad and smelt were attracted to the pump area. Although there was variation with time of day, tubidity and lighting array; the results suggested that the number of fish passing through the pump increased when the mercury vapour lights alone or when the mercury lights in association with a white strobe light were employed.
Acanthostoella norvegica(Daday) in Insular Newfoundland Waters, Canada (Protozoa: Tintinnina)
Authors: Davis Charles C. 
Published: February 2007

AbstractThe seasonal and vertical distributions ofAcanthostomella norvegicaare described from two fjord‐like bays in insular Newfoundland, Canada. Resting spores are figured and described.
Spectral Analysis of the Automatically Recorded Data from Slapy Reservoir, Czechoslovakia
Authors: Nesmêrák I. , Straškraba M. 
Published: February 2007

AbstractThe data for solar radiation (S), air temperature (Ta), surface water temperature (Tw) and pH recorded at 0.5 hr intervals at Slapy Reservoir were subject to spectral analysis. The complete series covered the month of July 1978, where three characteristic sections were distinguished, of which one was characterized by low variations, more irregular values and a slowly decreasing trend and another with high and regular variations as well as a steeply increasing trend. These sections were analysed separately in addition to the complete series. The period of 24 hrs was most important and represented forS,Taand pH 60, 38 and 18 % of the total variances, respectively. The deterministic periodic component represented 65–95 % of the total variance. The cross‐correlation and cross‐covariance between selected pairs of variables suggested lags of up to 4.5 hrs, the longest lag being observed forTwandS. An autoregressive model of the interrelation between the signals was formulated.
Hydrology and Changes in the Nutrients and Phytoplankton Levels in Goat Island Bay, Northern New Zealand
Authors: Taylor Nigel J. , Taylor F. J. 
Published: February 2007

AbstractA survey of the phytoplankton and nutrient levels in Goat Island Bay, northern New Zealand was carried out in 1981–82 and the data compared with an earlier survey in 1966–69. The contribution of nutrients from the inflowing creek was also measured. The only significant change was a doubling of the dissolved nitrate levels in the sea, which appeared to be related to increased nitrate levels in the freshwater creek. It is suggested that the increase is due to an increase in the farming and recreational use of the catchment area.The standing crops of phytoplankton in the bay showed no correlation with nutrient levels, but there were significant correlations with the radiation received.
Etudes expérimentalles sur la sensibilité du phytoplancton d'eau douce aux variations de salinité dans le fjord du Saguenay (Estuaire du St‐Laurent), Canada Experimental Studies on the Susceptibility of Freshwater Phytoplankton to Variation of Salinity in the Fjord of Saguenay (St. Lawrence Estuary), Canada
Authors: Cloutier Sylvain , Cǒté Raynald 
Published: February 2007

AbstractThe Saguenay Fjord is characterized by very high run‐offs. The annual flow varies between 1.2 and 4.2 × 103 m3 . s−1. During the summer the surface salinity shows a sharp horizontal gradient (from 1 0/00 to 20 0/00). The surface phytoplankton, mainly freshwater and even some euryhaline species is submitted to salinity stress. Continuous culture experiments were conducted to study the susceptibility of this freshwater phytoplankton under different salinity conditions. Some pennate diatoms (dominant group) are found as relatively tolerant to salinity. Microflagellates have been found to be resistant to salinity up to 26 0/00. Chlorophyll concentrations and rates of primary production of those organisms are as high as those of the control.
Qualitative Analysis of the Pelagic Foodwebs of Three Acid‐impacted Lakes in Nova Scotia, Canada
Authors: Lane Patricia A. , Blouin Anthony 
Published: February 2007

AbstractLoop analysis is a qualitative network technique which is useful for delineating pelagic foodwebs and for predicting production relationships. Loop models were fitted to data sets for three lakes in Kejimkujik National Park, Nova Scotia. Using qualitative correlation signs, there was 80–89 percent agreement of model predictions and data values. Individual networks were integrated by summarizing linkages between pairs of variables. The resultant core network is a three‐layered structure with 5 nutrient, 4 algae, 1 detritus and 10 zooplankton variables. The phytoplankton components utilize different types of nutrient complexes in each lake. Bluegreen algae have a special relationship to ammonia in Beaverskin Lake. Crustacean zooplankton consume phytoplankton directly whereas rotifers are connected to the foodweb via the detrital pool.In contrast to the multivariate statistical results reported by Blouin et al. (1984), loop analysis furnished some robust evidence of the inherent structure in these plankton communities. Qualitative methodology also helps identify casual pathways in the ecological networks. The analysis illustrated which links are oscillating the most and which are expected to remain resilient with increasing perturbation. The models suggest several aspects of these communities that could be verified experimentally.
Photosynthetic Activity of Dominant Algal Species in Eutrophic Shallow Lake (Großer Müggelsee, Berlin) Investigated by Microautoradiography
Authors: Nixdorf Brigitte 
Published: February 2007

AbstractThe photosynthetic activity of dominant phytoplankton in eutrophic shallow lake was investigated by the autoradiographic method in 1979 and 1980. It was shown by light and dark field microscopy that all species of Cyanophyta (Oscillatoria redekei, Oscillatoria agardhii, Aphanizomenon flos‐aquae) were characterized by a continuously high uptake of NaH14CO3. Similarly high photosynthetic activity was observed during the occurrence of Cryptomonas sp. and nanoplankton. Contrary to these observations, diatoms showed remarkably high portions of photosynthetically inactive biomass when their development was abundant. The reasons for this discrepancy between high biomass of diatoms and relatively low primary production (measured by the 14C‐method and autoradiography) are discussed.
A Compositional and Structural Analysis of Phytoplankton in Lake Khurpatal, (U.P.), India
Authors: Pant M. C. , Jaiswal Sudha , Sharma A. P. 
Published: February 2007

AbstractThe phytoplankton community in Lake Khurpatal (Kumaun Himalya), India, was analyzed in relation to physico‐chemical variables. Phytoplankton biomass ranged from 2.7 to 20.0 g m−3 in the euphotic zone of the lake. Dinoflagellates monopolized the algal community with a mean annual contribution of 94.5 % to the total phytoplankton biomass. The community coefficient used to quantify the seasonal changes in algal population reflected the fact that successional episodes were not very significant, the percentage similarity among the consecutive algal samples ranging from 47.8 to 89.9 %. The phytoplankton community was characterized by low species richness, low equitability and species diversity. Various ecological characteristics of the community are discussed and the phytoplankton biomass is also compared with that of some tropical and temperate lakes.
The Influence of Photo‐inhibition on the Estimation of Daily Production Computated from Photosynthesis‐light Response Curves Determined in an Incubator
Authors: Vermij Steven G. , Flik Ben J. G. , Rijkeboer Machteld 
Published: February 2007

AbstractA model is presented which describes the influence of inhibition on photosynthesis as a function of time and light intensity. The model parameters can be estimated from p vs I curves determined by means of an incubator. Daily production computed with the model is compared with that calculated using a model based on a time independent description of photosynthesis‐light response curves. To do this, a hypothetical case study was used, in which the influence of turbulent mixing and recovery from inhibition was also investigated.
Shade‐adapted Algae beneath Ice and Snow in the Northern Bothnian Sea
Authors: Müller‐Haeckel Agnes 
Published: February 2007

AbstractThe winter‐spring phytoplankton flora in the coastal waters of the northern Bothnian Sea consists mainly of marine cold water species even adapted to low light. These dinoflagellates and diatoms seem to be selectively promoted by the seven months of low light and water temperature. They are able to grow during this period of subsaturated light and have their abundance maxima around ice‐break. Solar radiation measured under ice and snow cover was in the same order of magnitude as the compensation points of some of the species. In summer, these algae species vanish from the water, and surely survive in the form of inactive life stages.
Clearance Rates of Crustacean Macrofiltrators: The Nature ofin situRate Depressions in a Fertilized Oligotrophic Lake in the Kuokkel Area, Northern Sweden
Authors: Persson Gunnar 
Published: February 2007

AbstractLake seston labelled by14CO2,14C‐acetate and32‐PO4in parallel was used in zooplankton feeding experiments and checked for size distribution of the labelled particulates. Thein situexperiments were made to find out if depressedEudiaptomusandHolopediumclearance rates, in an artificially fertilized lake where seston was dominated by μ‐algae, were due to low retention of such algae.Addition of a labelled reference alga (Chlamydomonassp.) was used to find out if high food concentrations (above the Incipient Limiting Concentration) or toxins caused the depressions. Clearance rates mostly ranked highest for CO2‐labelled seston followed by32P and14C‐acetate labelled seston, reflecting approximately the size distributions of the labelled food. Clearance rates for the added reference alga were high and similar in the fertilized lake and in an oligotrophic reference lake.It was concluded that the detected “rate depression” could be explained purely by poor retention of small particles (passive size selection) by the crustaceans studied, but that active food selection offers optional explanations to the experimental results.
Photosynthetic Production of a Brackish Water Community of Chara tomentosa L. and its Dependence on Environmental Conditions
Authors: Libbert Eike , Walter Thomas 
Published: February 2007

AbstractNet photosynthesis and dark respiration of a natural Chara tomentosa community were continuously recorded. There is a close correlation between net rate of photosynthesis and variations in the PhAR flux under water. The net photosynthesis fluence Px correlates with the PhAR fluence Ix, but the quotient Px/Ix varies seasonally, apparently as a consequence of variations in chlorophyll content following long‐range changes in radiation fluence. No influence of temperature, salinity or pH on net photosynthesis was detected, but water temperature stimulates dark respiration and consequently diminishes net primary production.
Dynamics of the Pikeperch, Stizostedion lucioperca (L.), in Lake Balaton
Authors: Biró Péter 
Published: February 2007

AbstractThe pikeperch populations inhabiting three distinct water areas of Lake Balaton differ in regard of growth. Due to stock depletion, pikeperch in the NE‐basin of the lake grew considerably faster than ten years ago. The annual rate of growth in length (von Bertalanffy's K) varied between 0.09 and 0.19. The specific rate of growth in length (GL) ranged from 0.16 to 0.23 and that of growth in weight (GW) from 0.52 to 0.69. Length and age‐structures of the stocks differed significantly between different areas and years, but the overwhelming majority of the stocks consisted of age‐groups IV–V (98.2–99.3%). From NE to SW, the rates of survival were 34, 29 and 70%, respectively. These differences, and the differences in growth resulted in changes in the productive capacity of the stocks. The ratios of production and biomass were 59% (NE‐basin), 63% (central basin) and 39% (SW‐basin), respectively. The magnitudes of production varied inversely. The 50% retention lengths of the seine nets used in Lake Balaton were 35.0, 35.7 and 42.5 cm with weights of 572, 655 and 1019 g, respectively.
Peculiarities of Philodina roseola (Ehrbg.) (Rotatoria, Bdelloida) – Growth and Reproduction under Various Temperature Conditions
Authors: Lebedeva L. I. , Gerasimova T. N. 
Published: February 2007

AbstractMost investigations dealing with rotifer reproduction have been performed with populations and not with individuals. At the same time the variations in the growth and reproduction rates of rotifers are of considerable interest. This paper presents the results of investigations carried out by culturing individuals of Philodina roseola during the lifespan of an individual under different temperature conditions ranging from 9 to 35 °C. The paper presents curves showing the growth in length and weight, the periods of maximum growth rate and the maximum sizes of Philodina as affected by temperature conditions. The reproduction rate is investigated at the same time. The variation in egg evolution duration, in duration of the reproductive period and in the egg laying rate are shown under all the conditions investigated. The data serve as a basis for estimating the effect of temperature on the productivity of Philodina roseola.