bluuebunny/crossref_metadata_2025_split huggingface dataset:
FLUORIDE: GEOCHEMICAL AND ECOLOGICAL SIGNIFICANCE IN EAST AFRICAN WATERS AND SEDIMENTS1
Authors: Kilham Peter , Hecky Robert E. 
Published: March 2010

The geochemistry of fluoride in East African lakes and rivers was examined to elucidate processes of fluoride acquisition, concentration, removal, and diagenesis in inland waters in a region relatively little influenced by man. The range of fluoride concentrations (0.02–1,627 mg liter−1) is the greatest found anywhere. A strong correlation was found between the concentration of fluoride in the predominant crystalline rocks of each particular drainage basin and the F:Cl ratio in surface waters. Because fluoride‐rich volcanic rocks are common in East Africa very high fluoride concentrations, the products of chemical weathering, are often observed. Fluoride removal from surface waters is not significant; concentration by evaporation proceeds until saturation with respect to villiaumite is reached. Fluoride : chloride ratios for the interstitial waters of a 7‐m core from Small Momela Lake, Tanzania, indicate that in sedimentary environments fluoride may be removed from pore waters as fluorite and possibly fluorapatite.Geographical evidence suggests that the high fluoride concentrations may influence the distribution of man, livestock, zooplankton, phytoplankton, and higher aquatic plants.
THE PRODUCTIVITY OF HAWAIIAN FRINGING‐REEF CRUSTOSE CORALLINACEAE AND AN EXPERIMENTAL EVALUATION OF PRODUCTION METHODOLOGY1
Authors: Littler Mark M. 
Published: March 2010

Estimates of the mean net total contribution to the Waikiki reef by Porolithon onkodes, P. gardineri, and Sporolithon erythraeum are quite close. Hydrolithon reinboldii and melobesioid “C” contribute 5 and 3 times more. The net contribution to the total reef system by fringing‐reef crustose Corallinaceae is 5.7 g C m−2 day−1. Crustose coralline algae are comparable, as producers, to other photosynthetic reef organisms.Several measurements of productivity were used in replicate on the same thalli. The 14C data, although somewhat higher, were not significantly different from the O2 and pH electrode data; rates determined by all three techniques showed the same serial order, by species, from highest to lowest producer. The pH and O2 electrode methods are more useful and reliable than the 14C data where high sensitivity is not critical.
ORGANIC CARBON PRODUCTION ON THE WINDWARD REEF FLAT OF ENIWETOK ATOLL1
Authors: Smith Stephen V. , Marsh James A. 
Published: March 2010

Oxygen and carbon dioxide were used to make two separate but simultaneous estimates of organic carbon production on the windward reef flat of Eniwetok Atoll. The methods give correlated results, showing a metabolic ratio (ΔCO2:ΔO2) of −1, uncorrected for gas exchange.A predominantly algal community had both a higher gross production and a higher ratio of gross production to respiration than one visually dominated upstream by algae and downstream by corals. The two communities exhibited similar respiration rates, perhaps as a result of limitations imposed by O2 diffusion rates.The mixed coral‐algal community had an overall gross production to respiration ratio near 1; the coral‐dominated part of that community is apparently heterotrophic. The autotrophic (algal‐dominated) portion of the community may limit the metabolic rate of the heterotrophic (coral‐dominated) portion.
Concentration and removal of liquid microlayers from a seawater surface by bursting bubbles1
Authors: Bezdek H. F. , Carlucci A. F. 
Published: March 2010

A monomolecular layer of radioactive stearic acid has been used to determine the concentration and transport of surface liquid microlayers from a natural seawater surface. The monolayer was prepared by allowing drops of a 0.08 mM solution of stearic acid dissolved in hexane to spread over the sample area, and then laterally compressing the resultant monomolecular layer with a castor oil film. The surface microlayers were sampled by collecting the top drop resulting from a gas bubble bursting at the air‐liquid interface.The ratio of surface liquid to bulk liquid in a drop increases with decreasing drop size, supporting our previous model. The measurements also show that small drops (diameters of 28–108 µm) are effective for removing organic surface‐active material from a seawater surface.
Seasonal variation of the water mass along the Oregon‐northern California coast
Authors: Bourke Robert H. , Pattullo June G. 
Published: March 2010

Temperature and salinity data collected at five Oregon—northern California coastal stations from 1960 to 1971 are used to assess the influence of local processes in modifying the water mass along the coast. A bivariate model is constructed for the summer and winter seasons at each coastal station permitting a quantitative measure of the degree of importance of each process.In summer the dominant modifying process is different at each shore station with local heating, upwelling, and mixing with shelf/slope water and Columbia River water being the major factors. In winter rainfall and runoff is the dominant process along the coast except near the northern border where mixing with shelf/slope water occurs slightly more frequently.In winter offshore surface waters within 81 km of the coast have nearly the same T–S as the waters at the coast. In summer offshore surface waters become cooler and more saline in the shoreward direction with the coolest and saltiest water occurring at the coast.
Mechanisms that regulate growth rates of phytoplankton in Shagawa Lake, Minnesota1
Authors: Megard Robert O. , Smith Paul D. 
Published: March 2010

Mean concentrations of chlorophyll a at six localities in Shagawa Lake ranged from 15 to 25 mg m−3 during June and July, increased to a maximum of 150 mg·m−3 during a bloom of Aphanizomenon that occurred in August, and decreased rapidly in early September. Theoretical limits for integral photosynthesis and the total annual integral photosynthesis wore calculated from estimates of attenuation coefficients for illumination, specific photosynthetic rates, and chlorophyll concentrations.Mechanisms responsible for the phytoplankton bloom are inferred from the changes of specific rates of production and specific rates of loss of particulate organic carbon in the mixed layer. Both rates decreased as the bloom developed, the latter decreasing faster than the former. The bloom ended when the specific loss rate suddenly increased. The specific production rate may have decreased during the bloom as nutrient utilization was inhibited by self‐shading; buoyancy changes may have been primarily responsible for the changes of specific loss rates, acting as a critical mechanism of population regulation.The effects on phytoplankton populations of changing specific production and loss rates are demonstrated by comparing the integral photosynthetic rates and chlorophyll concentrations that would prevail under steady state conditions.
Production of pelagic Sargassum and a blue‐green epiphyte in the western Sargasso Sea1
Authors: Carpenter Edward J. , Cox James L. 
Published: March 2010

North of 30°N Sargassum production averaged about twice that to the south, possibly related to the degree of winter mixing. Production rates were relatively high in continental shelf areas or near land masses but showed no major seasonal variations nor was there an obvious relationship with concentrations of NO2, NO3, NH3, and PO4. Under normal daylight conditions in October Sargassum photosynthesizes at a maximum rate. Average carbon turnover time is no more than 40 days and Sargassum and its epiphytes contribute no more than 0.5% of the total primary production in the western Sargasso Sea.Carbon turnover rate of the epiphyte Dichothrix exceeded that of its host Sargassum by an average of fourfold. Dichothrix production on the shelf averaged as much as 15% of the pelagic macroalgal production in October. Dichothrix is most abundant in the continental shelf waters and lowest in the Sargasso Sea; this distribution may be related to the available iron in the seawater.
Bacteria in intertidal sediments: Factors related to their distribution1
Authors: Dale Norman G. 
Published: March 2010

Direct counts of bacteria from intertidal deposits support previous suggestions of a strong relationship between bacterial numbers and sediment properties. Bacteria were counted after acridine orange staining. Numbers ranged from 1.17 × 108 to 9.97 × 109 g−1 of dry sediment and were highly correlated with grain size and other granulometric properties. Sediment organic carbon and total nitrogen were correlated with bacterial numbers beyond what would be expected from the relationships of these properties to grain size; yet grain size alone accounts for over 80% of the variance in bacterial numbers.Bacterial biomass to a depth of 10 cm varied from 5.5 to 26.8 g m−2, in the same range as previously reported for meiofauna and mixed macrofauna in sediments.
Remote sensing of water color and sea surface temperatures off the Oregon coast1
Authors: Pearcy W. G. , Keene Donald F. 
Published: March 2010

Multispectral scanner measurements from aircraft revealed complicated and often abrupt changes in ocean color which appeared less conservative than changes of sea surface temperature measured with an infrared radiometer, although the general areal patterns were similar. Color and thermal fronts, which often coincided, were most pronounced between upwelled water, Columbia River plume water, and oceanic waters.Normalized spectra of backscattered light in seven bandwidths and differences between specific bands were useful in identifying water types. The blue (0.45–0.47 µ) minus green (0.52–0.55 µ) differences were highest in oceanic water, intermediate in plume water, and low in chlorophyll‐rich upwelled water. The green (0.52–0.55 µ) minus orange (0.58– 0.63 µ) were highest inshore and lowest offshore. Near the mouth of the Columbia River, where water contained a large load of particulate matter, both blue — green and green — orange differences were low.Multiple color bands in the upwelling zone and fronts along both inshore and offshore margins of the Columbia River plume result from dynamic processes that may influence concentrations of pelagic fishes.
Optically effective area of particle ensembles in the sea
Authors: Owen Robert W. 
Published: March 2010

The optically effective area (OEA) concentration of particles was computed from measured size distributions and concentrations of particles in the upper 100 m of the Pacific Ocean off Baja California and is shown to correspond closely to direct measurements of the volume coefficient of light scattering at an angle of 20°, shown previously to be proportional to total scattering.Plots of OEA as a function of particle diameter exhibit a maximum contribution at about 2 µm diameter at offshore stations and at 3.5 µm at nearshore stations. The roll‐off at smaller particle diameters is attributed to diminished optical efficiency rather than to decreased concentrations of smaller particles.
Some relationships between algal standing crop, water chemistry, and sediment chemistry in the English Lakes1
Authors: Gorham Eville , Lund John W. G. , Sanger Jon E. , Dean Walter E. 
Published: March 2010

Estimates of standing crop, derived approximately from algal counts in surface waters, have been used to separate the English Lakes into three groups of low, intermediate, and high fertility. The fertile lakes are proportionally poorer than the infertile lakes in µ‐algae, but richer in “large algae” and Cyanophyta. The fertile lakes are richer in dissolved ions, especially calcium and bicarbonate, in filter‐passing and particulate vitamin B12, in sedimentary sulfur, and in sedimentary chlorophyll derivatives and carotenoids. The relationship noted by Pearsall between lake fertility and agricultural activity is shown by a strong correlation between algal standing crop and the percentage of the drainage basin under cultivation. Sediment ratios of carbon to sulfur and of chlorophyll derivatives to carotenoids decline with increasing lake fertility, whereas the ratio of carbon to nitrogen shows little change.This study lends support to the use of sedimentary pigments as indices to lake productivity. The pigment data also indicate that much of the organic matter in sediments of productive lakes comes from autochthonous sources within the lakes.
The use of field data to derive population statistics of multivoltine copepods1
Authors: Rigler F. H. , Cooley J. M. 
Published: March 2010

The mean duration of each instar of planktonic copepods is obtained from field data only, by using the relation:

urn:x-wiley:00243590:media:lno19741940636:lno19741940636-math-0001

where Mn is the mean pulse time of instar n and tn is the duration of that instar. The method is used to calculate population statistics of univoltine populations from European lakes and of a multivoltine population of Skistodiaptomus oregonensis in a 0.5‐ha meromictic lake in southern Ontario.As a check on the method, development times of eggs, first nauplius, and second nauplius were determined in the laboratory and combined with in situ vertical distribution and water temperature data to give an independent estimate of in situ development times of these instars. The two compared favorably.Growth rate of S. oregonensis is not simply a function of temperature.
Cesium 137 to strontium 90 ratios in the Atlantic Ocean 1966 through 19721
Authors: Bowen Vaughan T. , Noshkin Victor E. , Volchok H. L. , Livingston H. D. , Wong K. M. 
Published: March 2010

Ratios of 137Cs to 90Sr are summarized from analyses of a large number of seawater samples collected in and about the Atlantic Ocean from 1966 to 1972 at various depths. Analytical comparisons by the participating laboratories are presented.In open‐ocean surface samples the mean ratio is 1.43, and in subsurface samples containing no less than 5 dpm 137Cs per 100 liters the mean is 1.44; in subsurface samples containing less than 5 dpm 137Cs per 100 liters, the mean is 1.64. No trend in this ratio with time can be seen, nor can any systematic difference be seen between North Atlantic, South Atlantic, or Mediterranean samples. Agreement of the various open‐ocean ratios with that predicted in fallout, 1.45, is excellent.In nearshore samples from several different areas however the mean ratio is 1.07. Material balance and other considerations seem to preclude simple selective loss of 197Cs to the sediments. A number of other processes are available, nearshore, for reducing the 137Cs:90Sr ratio, but it is not now possible to evaluate their relative importance, nor to explain why their action should result in about the same ratio in so many different nearshore environments.
Photosynthetic rates of phytoplankton in East African alkaline, saline lakes1
Authors: Melack John M. , Kilham Peter 
Published: March 2010

Photosynthetic rates were calculated in six myxophycean‐dominated alkaline, saline lakes in Kenya and Tanzania from changes in dissolved O2 in light and dark bottles and from diurnal variations in dissolved O2. Rates of gross photosynthesis are exceptionally high for Lake Nakuru, Kenya, by the diurnal free‐water technique (e.g. 36 g O2 m−2 day−1). Gross photosynthesis in Lake Nakuru was compared for two consecutive days: on the first day pronounced thermal stratification developed and the dissolved O2 reached 340% saturation in the upper half meter; on the second day wind‐driven turbulence circulated the algae to depths often greater than 2 m in water with Secchi disk visibility of only 15 cm.Because of analytical difficulties in measuring dissolved O2 in soda lakes, laboratory experiments were conducted to determine the reliability of the titrimetric (Winkler, Miller), gasometric (Scholander), and polarographic (oxygen probe) methods. The polarographic technique was the most suitable for determinations of dissolved O2 in the field.
A kinetic approach to the effect of temperature on algal growth1
Authors: Goldman Joel C. , Carpenter Edward J. 
Published: March 2010

A simple model incorporates the combined effects of temperature and nutrient limitation on the growth rate of algae. The temperature function is described by the Arrhenius equation and the nutrient relationship with the Monod model. The Arrhenius equation is inserted into the Monod model for the maximum growth rate µ̂, so that the growth rate is described by the product of temperature and nutrient expressions.The utility of the Arrhenius equation in describing the effect of temperature on µ̂ for phytoplankton is tested with data from the literature on continuous culture experiments with freshwater and marine algae; the Arrhenius model describes the relationship between µ̂ and temperature extremely well. Several restrictions to widespread use of the model limit its application to laboratory studies, but its general concepts may apply to natural water situations.
Turnover and uptake of dissolved phosphate in freshwater. A study in Lake Kinneret1
Authors: Halmann M. , Stiller M. 
Published: March 2010

The residence times and turnover rates of dissolved phosphate in the surface water of Lake Kinneret and in the Jordan River above and below the lake were measured by adding 32P‐HPO42− tracer to the unfiltered water and determining its disappearance from solution. Residence times varied from 9.1 to 0.2 hr in winter and summer at water temperatures of 14.5 to 30°C: the turnover rates (V) ranged from 0.02 to 0.20 µM hr−1.The rate of uptake by plankton (Vi) of dissolved phosphate could be fitted to a Monod equation, Vi = VmS/(Ks + S), in which Vm and K8 are the maximal rate and the half‐saturation constant. Values of Vm were in the range of 0.04–1.1 µM hr−1 for winter and summer; Ks values ranged from 0.2–0.8 µM, higher than the usual observed natural concentration of dissolved phosphate in Lake Kinneret. This supports the conclusion that in its water, phosphate is the primary limiting nutrient. In the Jordan River, upstream of Lake Kinneret, the dissolved phosphate concentration (0.44 µM) was higher than the Ks value (0.27 µM) and therefore in its water, phosphate may not be the primary limiting nutrient.
Ingestion of detritus by the lagoon pelagic community at Eniwetok Atoll
Authors: Gerber Ray P. , Marshall Nelson 
Published: March 2010

The gut contents of Undinula vulgaris (a calanoid copepod) collected from Eniwetok lagoon consisted of about 95% detritus with only 2% of the gut material fluorescing as chlorophyll. That of Oikopleura longicaudata (a larvaccan) consisted of about 89% detritus with only 6% fluorescing as chlorophyll. By contrast, the gut contents of the calanoid copepod, Acartia tonsa, from Narragansett Bay, Rhode Island, consisted of about 34% detritus with 36% of the gut material fluorescing as chlorophyll. The remaining material in the gut of all these organisms included various microorganisms and diatom frustules.Plankton‐feeding fishes from behind a reef and island were found to have consumed both zooplankton and detrital algal fragments.The higher levels of particulate carbon and nitrogen in the lagoon, which had a lower C : N ratio than found in the incoming oceanic water, indicated that reef detritus enriches the lagoon environment.
A comparative study of the lipids of water‐striders from marine, estuarine, and freshwater environments: Halobates, Rheumatobates, Gerris (Heteroptera: Gerridae)1
Authors: Lee Richard F. , Cheng Lanna 
Published: March 2010

The lipids of water‐striders from three different aquatic environments (marine‐Halobates germanus and Halobates sericeus; estuarine‐Rheumatobates aestuarius; and freshwater‐ Gerris remigis) differ considerably in their fatty acid composition. The polyunsaturated 22 : 6 fatty acid, present only in Halobates, is presumably derived from its marine plankton food. The 20 : 5 acid is a major component of the lipids of Gerris and Rheumatobates, which feed on terrestrial insects known generally to lack long‐chain (> C‐18) polyunsaturated acids; it is presumably synthesized by chain elongation from C‐18 precursors. Differences in food and habitat may account for some of the observed differences in fatty acid composition.Neutral triglyceride lipids are stored in all three genera: in Halobates this fraction represents 74−92% of the total lipid, while in Rheumatobates and Gerris it is only 46–72%. The triglycerides are rapidly utilized during starvation by Halobates and Rheumatobates. Pristane, the major hydrocarbon of many marine zooplankton, is apparently absent from the lipids of Halobates.
Movement of spilled oil as predicted by estuarine nontidal drift
Authors: Conomos T. J. 
Published: March 2010

Information on water movement obtained from bimonthly releases of surface and seabed drifters in the San Francisco Bay and adjacent Pacific Ocean is used to understand major processes controlling dispersal of oil after a spill of 3,200 m3 of Bunker C in the bay in January 1971. River‐induced nontidal estuarine circulation was the dominant factor controlling net movement of the oil spilled at the entrance of the bay system, reinforcing ebbing tidal currents and causing the seaward movement of floating oil, which followed paths taken by surface drifters released 3 weeks before the spill. In contrast, some oil formed globules which sank to the near‐bottom waters, had the same relative buoyancy as seabed drifters, and moved similarly, beaching in eastern San Pablo Bay after being transported landward in the near‐bottom waters. No oil or surface drifters floated into the south bay because surface waters were drifting seaward, away from the south bay.Notable seasonally modulated phenomena which must be considered in predicting surface and near‐bottom oil drifts of future spills include a summer (low‐river discharge period) diminution of the estuarine circulation mechanism in the north and central bay‐adjacent ocean region and a seasonal reversal in two‐layer drift in the south bay.
Enewetak (Eniwetok) Atoll: Aspects of the nitrogen cycle on a coral reef1
Authors: Webb K. L. , DuPaul W. D. , Wiebe W. , Sottile W. , Johannes R. E. 
Published: March 2010

Changes in the concentrations of dissolved and particulate nitrogen in seawater crossing two interisland reef transects on Enewetak Atoll were measured. The upstream half of transect II consisted largely of algal pavement; the downstream half was visually dominated by corals. The other community, transect III, consisted of benthic algal covered pavement in its entirety, with only scattered small corals downstream. Both transects showed a significant net export of combined nitrogen, implying a large input of nitrogen into the reef system from a source other than the combined nitrogen in overlying waters. High rates of gaseous nitrogen fixation were found.There was a net uptake of nitrate by the community dominated by algae and a net export of nitrate from the transect dominated jointly by algae and corals. Although nitrification is of central importance in the marine nitrogen cycle, this coral‐algal community at Enewetak appears to have been the first marine site at which this process has been measured directly.
Feeding characteristics and predation impact of Chaoborus (Diptera, Chaoboridae) larvae in a small lake1
Authors: Fedorenko Alice Y. 
Published: March 2010

Feeding rates of Chaoborus americanus and Chaoborus trivittatus larvae generally increased with temperature, prey density, and larval size and varied with prey type. Temperature had no effect on feeding rates of old fourth instar C. trivittatus larvae. There was a significant though unexplained variability in the day‐to‐day feeding rates among individual chaoborids.Estimated mean percentage of standing crop of prey eaten by Chaoborus was: 2% for copepod nauplii, 3% for Diaptomus tyrelli, 9% for Diaptomus kenai, and 4% for Diaphanosoma. Chaoborus predation on Eunice Lake zooplankton appears to be reduced by seasonal and spatial segregation of predator and prey and by size incompatibility.