bluuebunny/crossref_metadata_2025_split huggingface dataset:
CARBON DIOXIDE DYNAMICS: A RECORD OF ORGANIC CARBON PRODUCTION, RESPIRATION, AND CALCIFICATION IN THE ENIWETOK REEF FLAT COMMUNITY1
Authors: Smith S. V. 
Published: March 2010

Organic carbon production, respiration, and calcification alter the CO content of water crossing the Eniwetok windward reef flat. Changes in pH and total alkalinity can be used to partition the CO2 changes into those due to production‐respiration and those due to calcification. Gas transfer across the air‐sea interface is minor.Both a transect visually dominated by a mixture of corals and algae and a transect dominated by an algal turf calcified at an average rate of 4,000 g CaCO3 m−2 yr −1, with no apparent day‐to‐night difference. Although nighttime respiration on both transects was 0.12 g C m−2 hr−1, the algal transect exhibited a much higher daytime net production rate than did the coral‐algal transect (0.72 vs. 0.25 g C m−2 hr−1).Although little particulate CaCO3 was removed from the reef flat during these studies, there has been virtually no net CaCO3 accumulation there over the last several thousand years.
DETAILED TIME VARIATIONS IN MEAN TEMPERATURE AND HEAT CONTENT OF SOME MADISON LAKES
Authors: Stewart Kenton M. 
Published: March 2010

Detailed variations in the mean temperature and heat content were studied for 5 years in Lake Mendota and 3 years in Lakes Monona and Waubesa near Madison, Wisconsin. The data show that the heat content may vary significantly within 2 or 3 days and that the specific time of maximum heat content is unpredictable. Accurate determinations of heat budgets require frequent sampling over long periods. A Birgean annual heat budget may not necessarily reflect the influence of a lake on the surrounding environment.Thermal discharges had little influence in determining the mean temperatures of Lake Monona.
An evaluation of liquid scintillation counting techniques for use in aquatic primary production studies1
Authors: PUGH P. R. 
Published: March 2010

Methods evaluated for the liquid scintillation counting of samples from aquatic primary production studies include the counting of intact filters and cells in a toluene fluor, solubilization and counting of membrane filters and cells in various reagents, and counting of a suspension of cells mixed with the fluor. A 1:1 Triton X‐100:toluene fluor was very effective for the suspension of cells and gave high counting efficiencies. Up to 5 ml of sample could be mixed with the fluor, but this was considered inadequate for most primary production studies.The filter standardization method for the counting of intact filters was investigated further and found to be applicable over a wide range of conditions but only accurate when the weight of algae on the filters was small (< 1 mg).Direct solubilization of the filters and cells in a naphthalene‐dioxane or 2‐methoxyethanoltoluene fluor were the simplest, most accurate, and economical methods for primary production studies; the latter dissolved both wet and dry cellulose nitrate membrane filters and gave excellent replicate counting.
A STUDY OF PLANKTON DYNAMICS AND NUTRIENT CYCLING IN THE CENTRAL GYRE OF THE NORTH PACIFIC OCEAN1
Authors: Eppley Richard W. , Renger Edward H. , Venrick Elizabeth L. , Mullin Michael M. 
Published: March 2010

The dynamics of phytoplankton growth in relation to nutrient concentrations were studied in the subtropical central gyre of the North Pacific in November 1971. Rates of excretion of phosphate, ammonium, and urea‐N by zooplankton and rates of assimilation of carbon, nitrate, ammonium, and urea‐N by phytoplankton were measured. The growth rate of phytoplankton was estimated to be about 0.2–0.3 doublings day−1 in the 70–80‐m mixed layer, apparently limited by concentrations of both nitrogen and phosphate. Only nitrogen concentration was so limiting at a station near the western edge of the California Current. No diel changes in concentrations of ambient nutrients were observed. Urea‐nitrogen appears to be an important source of nitrogen for phytoplankton growth in these waters and to be an important excretory product of zooplankton.Concentrations of phosphate and ammonium were extremely low, but turnover times were estimated to be of the order 3–5 days for ammonium and >10 days for urea and phosphate. Bioinass of phytoplankton in the mixed layer was also very low, and corresponded approximately to that expected if a laboratory culture were operated as a nitrogen‐limited chemostat with a concentration of about 0.48 µg‐atom N liter−1 in the incoming culture medium and a dilution rate of about 0.13 per day.Physiological differences were noted between the phytoplankton in the mixed layer and that living below the thermocline, as were differences in chemical composition (ratio of C:Chl a and C:N).
GRAZING OF PSEUDOCALANUS MINUTUS ON NATURALLY OCCURRING PARTICULATE MATTER
Authors: Poulet S. A. 
Published: March 2010

The quantity and size of particulate matter consumed by Pseudocalanus minutus were studied in seawater samples collected from different depths and from closely spaced stations.The heterogeneity in particle distribution resulted from quantitative and qualitative fluctuations in the particle spectrum, although at times the total concentration was about the same. Pseudocalanus minutus consumed particles between 4 and 100 µ. An electivity index value was more often positive for 25.4–57.0‐µ particles. On the average, particles <39 µ were more readily eaten than larger particles. The consumption by copepods at different locations was related not only to particle concentration but also to the pattern of the particle size spectrum. Pseudocalanus was able to shift its grazing pressure from small to large particles to compensate for a reduction in density of small particles.
DISTRIBUTION OF TRACE METALS IN THE PORE WATERS OF SHALLOW WATER MARINE SEDIMENTS
Authors: Duchart Patricia , Calvert S. E. , Price N. B. 
Published: March 2010

The concentrations of seven trace metals in the pore waters of marine sediments from Loch Fyne, Scotland, have been analyzed by atomic absorption spectrophotometry following solvent extraction. The samples were taken from sediments containing variable amounts of sulfide at depth and variable thicknesses of oxides at the surfaces; one core contains abundant manganese nodules and manganese‐calcium carbonate concretions.The distribution of dissolved Mn shows a regular downward decrease in all cores examined which is interpreted as an indication of recycling of Mn between solid diagenetic mineral phases and pore solutions. Dissolved Fe, in much lower concentrations, either decreases or increases down the core depending on the type of sediment; Cu, Ni, Zn, Co, and Pb also show variable concentration profiles indicating control by different post‐depositional reactions in the sediment, which in turn depend on different physiochemical environments generated by variable amounts of contained organic material and different accumulation rates.
ANAEROBIC METABOLISM IN LAKE WASHINGTON SEDIMENTS1
Authors: Pamatmat Mario M. , Bhagwat Ashok M. 
Published: March 2010

A method of measuring the dehydrogenase activity of sediments at 10°C was calibrated by direct microcalorimetry at the same temperature. Field measurements of dehydrogenase activity of sediments in Lake Washington were converted to rates of metabolic heat release by means of the significant regression of dehydrogenase activity on metabolic heat release. Simultaneous field measurements at 10°C of oxygen uptake by undisturbed sediment cores were converted to rates of metabolic heat release by the factor 4.8 cal liberated per milliliter of oxygen consumed.Dehydrogenase activity varies from place to place and differs between layers of the same core. Although there is a general trend of decreasing activity with sediment depth, some subsurface layers have relatively high activity. Dehydrogenase activity, which was detected down to the deepest layers of the sediment cores, 21 to 31 cm, appears to be more a function of plankton remains than of total organic carbon in the sediment. The integrated metabolic heat release based on dehydrogenase activity of the entire core was invariably greater than the metabolic heat release calculated from the rates of oxygen uptake. Thus, it appears that the rate of total oxygen uptake by the sediment surface underestimates benthic community metabolism in the sediment column.
BREEDING AND GROWTH OF THE CHAETOGNATH SAGITTA ELEGANS IN BEDFORD BASIN1
Authors: Zo Zinntae 
Published: March 2010

Within 1 year two generations of Sagitta elegans were found in Bedford Basin. The spring generation, reaching maturity in mid‐September, reproduced during the remainder of the year. The autumn generation, consisting of the offspring of the spring generation, appeared to overwinter and established the spring adult population.The temperature‐size relationship of S. elegans from Bedford Basin is in close agreement with McLaren’s curve for this species in the eastern Canadian Arctic.Net carbon production rate, calculated from the spring generation, was highest in mid‐September when the majority of the population approached maturity.
THE INTERSTITIAL WATER COMPOSITION IN THE SEDIMENTS OF THE GREAT LAKES. I. WESTERN LAKE ONTARIO
Authors: Weiler R. R. 
Published: March 2010

Four stations in the western end of Lake Ontario were cored and the interstitial water together with the water lying immediately above it were analyzed for the major ions, soluble reactive phosphate, nitrate, silica, iron, and manganese.The interstitial waters are enriched relative to lake waters in all components except chloride, fluoride and sodium and strongly depleted with respect to sulfate. The Eh was generally negative and the pH was around 7.4. No changes from May to August could be observed, but in most cases, silica, alkalinity, manganese, and iron increased with depth in the sediment; chloride, fluoride, sulfate, sodium, and calcium decreased and the other parameters remained more or less constant.The major factors governing the chemistry of the interstitial waters are diffusion, bacterial reduction of sulfate, and equilibrium with various minerals in the sediments. There is evidence that the iron concentration is governed by FeCO3 but no firm conclusions could be drawn concerning manganese.
Recovery of the mud substrate and its associated fauna following a dry phase in a tropical lake1
Authors: McLachlan A. J. 
Published: March 2010

Lake Chilwa was dry for over a year. Following heavy rains, refilling was complete within 5 months, and, after 6 weeks, benthic insect populations of up to 3,500 mg m−2 were recorded. This pioneer population, mainly larvae of Chironomus transvaalensis Kieffer, disappeared 12 weeks later leaving a scanty benthic fauna resembling that of the drying phase.Isolated populations of C. transvaalensis persisted in some peripheral sites. The disappearance of fauna followed precipitation of fine grained material derived from erosion at the advancing shoreline during filling, which lowered the resistance of the larvae to major salinity variations and subsequent seasonal events. Persistence of larvae at the periphery was associated with plant debris which seemed to counteract the effects of the change in the mud.
Resonant and nonresonant motion in a spindle‐shaped basin with an entrance
Authors: Thomas N. D. , Clarke D. J. 
Published: March 2010

Resonant and nonresonant motions in a spindle‐shaped (i.e. formed by the intersection of two confocal parabolae) basin are examined when the assumption is made that they are caused by the formation of a standing wave due to incident wave action through the entrance. The spindle basin is transformed into a square region with two entrances and the modified boundary value problem is solved approximately by the Galerkin method. The trial functions are chosen to satisfy the boundary conditions across the entrances in the square region. The amplification of the incident waves is calculated for the internal points of the spindle basin at various frequencies and those frequencies causing large amplifications are found.The results are applied to Port Kembla Outer Harbor.
The role of amino acids in the nitrogen cycle of Lake Mendota1
Authors: Gardner Wayne S. , Lee G. Fred 
Published: March 2010

Concentrations of most dissolved free amino acids (DFAA) in Lake Mendota, a eutrophic Wisconsin lake, were generally low (< 0.01 µM) but detectable and appeared to be controlled by bacterial uptake. Combined amino acids occurred in concentrations an order of magnitude higher than DFAA. Of 10 amino acids examined, serine and alanine were generally most prevalent in the DFAA fraction (glycine was not measured). Concentrations of dissolved amino acids (free and combined) showed little variation with depth or season, but the levels of particulate amino acids increased in the epilimnion during the warmer months when conditions were favorable for algal growth. In the hypolimnion concentrations of amino acids in particulate material were lower than in the dissolved fraction.Daily examination of shore samples suggested that the concentrations of the DFAA generally remained at trace levels, with substantially higher concentrations during a period of rapid algal decomposition following an Aphanizomenon bloom. Shore water samples from 3 m below the lake surface contained lower and more uniform DFAA concentrations from day to day than did surface samples.
The long‐period internal waves in Lake Biwa
Authors: Kanari Sei‐ichi 
Published: March 2010

The long‐period internal wave in a two‐layered model of Lake Biwa is treated numerically by the use of linear hydrodynamic difference equations for the equivalent volume transport rate and elevation.Fourier analysis for the calculated time series of the interface at 29 sampling points in the model lake shows that the wave of the fundamental mode has a period of 66.1 h, about the same as the period of longitudinal internal seiches without the effect of the earth’s rotation, and that the wave progresses along the shore in a counterclockwise direction with an apparent phase velocity of about 1.5 km h−1.Such rotatory behavior of the internal wave is consistent with the results of spectral analysis of the temperature records and with the result of an approximate analytical solution of the two‐layered rotating rectangular lake.
Present and historic geochemical relationships in four Maine lakes1
Authors: Sasseville Dennis R. , Norton Stephen A. 
Published: March 2010

Undisturbed 1‐m cores of profundal sediment and overlying water were collected from four morphometrically paired Maine lakes with differing alkalinities and degrees of cultural development. Vertical variations in sediment chemistry correlate with the onset of European man’s activity in the watersheds of three of the lakes, although behavior is individual for any given element. Precultural core averages of P, S, organic matter, and diatoms are consistently higher in the sediments of the two deep oligotrophic lakes while the sediments of the two shallow mesotrophic lakes contain higher concentrations of quartz and aluminosilicate elements (K, Na, Ca, Mg, Al). This implies strong morphometric control of lacustrine sediment characteristics.Interstitial water chemistry profiles are largely diffusion controlled, although “reactive” zones with very high concentration gradients arc present in all lake cores for various ionic species. The presence of these reactive zones near the sediment surface suggests a localized source and movement of these ions upward through the sediment‐water interface. Average interstitial water concentrations (exclusive of the major reactive zones) of P, Ca, Mg, and K are highest in the sediments of the two shallow mesotrophic lakes. Other dissolved species exhibit no clear relationships to lake type as characterized by alkalinity, trophic status, or degree of cultural influence.
Two samplers for monitoring dissolved gases in lake water and sediments
Authors: Rudd John W. M. , Hamilton R. D. 
Published: March 2010

An in situ vertical point sampler was used over several months to obtain dissolved gas samples from precise and reproducible points in the water column of a stratified lake. Sampling error of the apparatus was negligible.A sediment gas sampler monitors concentrations by equilibration of dissolved pore wa ter gases with water inside plastic sample tubing, eliminating the problems of degassing and air contamination inherent to other sediment sampling systems. It is simple to construct and operate, enables close interval sampling across the sediment‐water interface and causes minimal disturbance of sediments and concentration gradients.
Vertical distribution of nitrate concentration in interstitial water of marine sediments with nitrification and denitrification
Authors: Vanderborght Jean‐Pierre , Billen Gilles 
Published: March 2010

Vertical concentration profiles of nitrate and nitrite in interstitial water of sediment in the Sluice Dock at Ostend (Belgium) commonly show a maximum in nitrate concentration at a few centimeters depth where sediments are sandy and poor in organic matter, while in muddy and organic‐rich sediments, nitrate is lower in interstitial water than in the overlying water and decreases rapidly with depth. Direct measurements of the activity of autotrophic nitrifying bacteria in the sediments show nitrification in the upper few centimeters of sandy sediments but not in muddy sediments.A mathematical model is proposed to analyze quantitatively these experimental results, taking into account nitrification, denitrification, diffusion, and sedimentation. Seasonal variations of nitrate concentration in overlying water are slow enough to justify the use of a stationary (steady state) model. When appropriate values are used for the parameters (rate of nitrification, depth of the sedimentary layer in which nitrification occurs, rate of denitrification, diffusion coefficient), some being experimentally determined, the model predicts concentration profiles in good agreement with experimental data.
Particle retention efficiencies of an herbivorous copepod, Acartia clausi (adult and copepodite stages): Effects on grazing1
Authors: Nival P. , Nival S. 
Published: March 2010

From measurements of the distances between setules (mesh size) on the maxilla of Acartia clausi, a spectrum of filtration efficiencies for small particles has been established. The slope of the spectrum decreases from young stages (copepodite I) to adults. The average size of particle that can be collected increases slightly from 3 µ in CI to 7 µ in adult stages, whereas the size for which the efficiency is 100% increases sharply from 5 µ to 12 µ.Two experiments were done to show the reality of the spectrum of filtration efficiency. A model of growth of particles and grazing by copepods, using the initial experimental conditions and the efficiency spectrum, was used to simulate the evolution of particles in the two experiments. The fit of the model to the experimental data is good for experiment I (dark) and the first 4 days of experiment II (natural daylight). The results of experiment II show that processes other than grazing become important in a long term experiment.
Phosphate utilization by an oceanic diatom in phosphorus‐limited chemostat culture and in the oligotrophic waters of the central North Pacific1
Authors: Perry M. J. 
Published: March 2010

Thalassiosira pseudonana from the oligotrophic waters of the central North Pacific Ocean was grown in phosphorus‐limited chemostat culture. When the chemical composition of the cells, expressed as ratios, was compared with that of nitrogen‐limited cultures, several of these ratios varied in excess of a factor of five between the two systems. Among these, which emerged as diagnostic indicators of phosphorus‐starvation vs. nitrogen‐deficiency, were the C : P, N : P. P : Chl a and Chl a : ATP ratios.The physiological responses of a population were determined by its preconditioning history. The minimum cellular phosphorus content, qo, varied with the degree of phosphorus starvation. The rate of phosphate uptake at a saturating concentration of phosphate by phosphorus‐limited cultures of T. pseudonana exceeded the rates of uptake by nonphosphorus‐limited cultures by an order of magnitude; the Ks for phosphate uptake was not a function of phosphorus deficiency.Phytoplankton in phosphorus‐starved chemostat cultures on medium made with central North Pacific Ocean water did not use naturally occurring dissolved organic phosphorus despite the presence of cell‐surface alkaline phosphatase. Phosphate uptake by natural phytoplankton assemblages in the central North Pacific was measured with 33P. Uptake rates in the field were not significantly affected by light intensity. No circadian periodicity in uptake rates was detected in natural phytoplankton or algae cultured on a light/dark cycle.
Skeleton growth of the hydrocoral Millepora complanata Lamarck in relation to light
Authors: Stromgren Tor 
Published: March 2010

The daily length increment of the skeleton of the distal growing edge of Millepora complanata from Discovery Bay, Jamaica, was measured by laser diffraction. The individual variation in growth rates between adjacent and morphologically comparable parts of the same colony was pronounced. There was a significant correlation between length increment rate and light intensity. When daytime light intensities were high the length increment rates were slightly, but significantly, larger during night than during day.A few measurements are also reported for Millepora alcicornis.
Limitation of phytoplankton species in the ocean off western Africa1
Authors: Hulburt Edward M. 
Published: March 2010

The growth rate of phytoplankton off the west coast of Africa appeared not to be nutrient limited for two reasons. First, most of the species characteristic of nonupwelling regions did not show increased abundance in upwelling or productive regions where nutrient or other species were abundant. Second, in an upwelling region, where diatoms dominated, nutrients exceeded the half‐saturation values characteristic of diatoms.A deductive model of the nutrient cycle, covering a complete range of nutrient concentrations, is used to interpret the field data. Since most species in the nonupwelling region were not limited, i.e. were not prevented from being abundant, by the small excess of nitrogen there, the compound statement ‘cells in the nonupwelling region were prevented from being abundant and cells in the upwelling region were not prevented from being abundant’ is false. Instead, the statement that ‘co‐occurrence of cells and excess nitrogen, with small and large amounts in the respective regions, was harmonious’ is true.