bluuebunny/crossref_metadata_2025 huggingface dataset:
Control of Tellinacean (Mollusca: Bivalvia) Feeding Behavior by Predation1
Authors: Levinton Jeffrey S.
Published: March 2010

Macoma tenta, a small tellinacean deposit‐feeding bivalve, inhabiting shallow‐water subtidal muddy bottoms of Buzzards Bay, Massachusetts, deposit feeds only at night in its natural habitat. This was determined by in situ studies in Quisset Harbor using time‐lapse underwater movie photography and by observations of feeding animals in running seawater aquaria. This feeding periodicity is probably selected to avoid exposure of the siphon to predation by bottom‐feeding fishes, and feeding behavior in the Tellinacea is thus controlled by predation and substrate.
Intrazooplankton Predation by Mesocyclops edax at Natural Prey Densities1
Authors: Confer John L.
Published: March 2010

Predation by Mesocyclops edax on Diaptomus floridanus was studied. Selective predation on Diaptomus copepodites rather than cladocerans was strong. Observed feeding rates on Diaptomus copepodites at lake densities varied from 0.07–1.30 prey per predator per day. Maximum estimates of in situ predation rate for two lakes with similar species composition were 1 and 6% of the standing crop of copepodites per day. The highly selective predation and the rate of predation are considered sufficient to greatly influence the species and size composition of the herbivores.
CHEMICAL CHANGES, INCLUDING NITRATE REDUCTION, IN DARWIN BAY, GALAPAGOS ARCHIPELAGO, OVER A 2‐MONTH PERIOD, 19691
Authors: Richards F. A. , Broenkow W. W.
Published: March 2010

Observations in March and May 1969 in Darwin Bay, Isla Genovesa, Galapagos Islands, show that nitrate reduction occurred in the deeper stagnant water at a minimum rate of about 60 µg‐atom liter‒1 yr‒1 and at the sediment‐water interface at a rate of about 1.3 g‐atom m‒2 yr‒1. Apparently about 50% of the organic material produced in the water column is oxidized by nitrate‐reducing bacteria in the water column below 40 m and in the sediment. At the observed rates, it would require no more than 4 to 6 months to reduce completely the nitrate in the water column at the beginning of nitrate reduction.
POLAROGRAPHY OF SEAWATER II. COMPLEX FORMATION OF CADMIUM WITH EDTA1
Authors: Maljkovic Dubravka , Branica Marko
Published: March 2010

Complex formation of cadmium‐ethylenediaminetetraacetic acid (Cd‐EDTA) in seawater and in sodium chloride solution has been studied by square‐wave polarography. The rate of Cd‐EDTA complex formation in seawater is lower than that of the same reaction in the corresponding solution of sodium chloride or calcium and sodium chloride. The influence of chloride and calcium ions on complex formation of Cd‐EDTA in sodium chloride solutions has been investigated and the results indicate that the degree of complex formation of cadmium with EDTA is diminished by the formation of cadmium monochloro complex and by the competition between calcium and cadmium.
THE STATISTICS OF SUBSAMPLING1
Authors: Venrick E. L.
Published: March 2010

Formulae are developed for the variance of data based on the enumeration of subsamples of subsamples. The fractions of the initial samples that are enumerated determine the contribution of the initial population variance to the overall variance and the precision with which the initial variance can be estimated.
Oxidation‐Reduction Determinations at the Mud‐Water Interface1
Authors: Schindler J. E. , Honick K. R.
Published: March 2010

An uncomplicated technique for determining oxidation—reduction potentials of the mud—water interface region in aquatic systems is presented. Laboratory and field observations of the oxidation and reduction of hypolimnetic water and lake sediment are reported.
EFFECTS OF TEMPERATURE, SALINITY, AND SURFACE WATER FLOW ON DISTRIBUTION OF THE SEA SNAKE PELAMIS1
Authors: Dunson William A. , Ehlert Gary W.
Published: March 2010

The pelagic yellow‐bellied sea snake Pelamis platurus is a surface feeder which apparently drifts passively with surface currents. In areas of horizontally convergent surface water flows, hundreds or even thousands of Pelamis are concentrated in slicks, apparently characteristic members of a community of organisms associated with slicks.

The distribution of Pelamis in the tropical Indian and Pacific Oceans is correlated with surface water temperatures; colonization of the Atlantic Ocean has likely been prevented by low surface temperatures off the tips of South Africa and South America. Breeding populations apparently occur only in areas in which mean monthly temperatures exceed 20C. The upper lethal temperature of Pelamis is about 33C. Thermoregulatory diving may be a mechanism of avoiding heat death in tropical seas where surface water temperatures reach 31C and insolation is intense.

Pelamis can survive in freshwater for periods longer than 6 months.
MIGRATION OF MAJOR CONSTITUENTS FROM LAKE SEDIMENTS INTO LAKE WATER AND ITS BEARING ON LAKE WATER COMPOSITION
Authors: Lerman Abraham , Brunskill Gregg J.
Published: March 2010

Differences in concentrations of major ions and silica between interstitial and lake water suggest that some fraction of the total chemical budget of a lake may be supported by diffusional flux of dissolved constituents from sediment into lake water. Estimates of flux from the lake floor give a mean rate of dissolution of sediment or the rate of subaqueous weathering. In the case of two lakes on the Precambrian shield near Kenora, Ontario, flux from the lake floor contributes 15–30%, or less, of the four major cations (Ca, Mg, Na, K) in the lakes. Flux of this magnitude corresponds to dissolution of 0.02–0.04 cm yr‒1 of bulk (solids + water) sediment. The rate of dissolution is less than the typical rates of deposition in postglacial lakes. For such events as lasting changes in the concentrations of dissolved constituents in inflow, new steady‐state concentrations in lake water are attained faster in the presence of flux from the sediment. Mixing of a thin layer of lake floor sediment with lake water may produce transient increases in concentration in lake water comparable in magnitude to the contribution of flux from sediments.
SIZE RELATIONS OF THE FILTERING AREA OF TWO DAPHNIA SPECIES1
Authors: Egloff David A. , Palmer David S.
Published: March 2010

The area of the filtering setae of thoracic limbs 3 and 4 of two Daphnia species increases approximately as the square of the body length. In contrast, the rate of increase in the filtering rate relative to body length attains maximum exponential values of 2.5–3.0. The filtering area and the filtering rates of Daphnia rosea become increasingly greater than those of Daphnia magna as body length increases, but the difference in the calculated rate of flow of water through the filtering setae remains nearly constant at all body lengths.
THE EFFECT OF TEMPERATURE ON THE DEVELOPMENT OF RESTING EGGS OF DIAPTOMUS OREGONENSIS LILLJ (COPEPODA: CALANOIDA)
Authors: Cooley John M.
Published: March 2010

Diaptomus oregonensis in Teapot Lake produces diapausing eggs between October and the time in November when a fall overturn deoxygenates the water and kills all zooplankton. The only visible difference between resting and subitaneous eggs was that the former were reddish‐brown and the latter green. Resting eggs incubated in the laboratory at about 4C in October and November will hatch at about the same time the following spring in the laboratory as they do in Teapot Lake, but they can be induced to hatch sooner at higher temperatures if they have experienced about 3–4 weeks at 4C. Diapausing eggs that have not initially experienced the low temperature are capable of surviving at warmer temperatures (14C) for extended periods and can subsequently be induced to hatch by exposure to cold.
STUDIES ON PIGMENTED MICROORGANISMS FROM APHOTIC MARINE ENVIRONMENTS. II. NORTH ATLANTIC DISTRIBUTION1
Authors: Fournier Robert O.
Published: March 2010

Samples collected on three cruises in the North Atlantic Ocean and Mediterranean Sea indicate the existence of regional differences in the so‐called “olive‐green cells,” visible throughout most of the 5,000‐m water column, which appear to be related to euphotic phytoplankton activities. Despite the observed regionality in cell concentrations the mean vertical pattern of distribution for each cruise is identical

Microscopic observations and settling rate calculations suggest that clumping of cells may be an important mechanism aiding the vertical transport of these microorganisms through the water column.

Average estimates of the carbon represented by these cells yielded a range of 0.59–0.05 µg C/liter, which accounted for about 10% of the total particulate organic carbon present at 400 and 4,800 m, respectively. However small these variations, they clearly demonstrate the variability in deep water of at least one component of the total particulate organic carbon pool.

Microzooplankton are suggested as the most likely predators on these cells, which average 3.5‐µ diameter. Since the standing stock of olive‐green cells is exceedingly small, any assessment of their importance as a nutritional source in deep water is intimately related with estimates of their renewal rate.
LEUCOTHRIX MUCOR INFESTATION OF BENTHIC CRUSTACEA, FISH EGGS, AND TROPICAL ALGAE1
Authors: Johnson Paul W. , Sieburth John McN. , Sastry Akella , Arnold C. R. , Doty Maxwell S.
Published: March 2010

Appendages and eggs of benthic marine crustacea are often populated with the characteristic filaments of the bacterium Leucothrix mucor. Planktonic crustacea and fish eggs free of L. mucor become infested when held in aquaria in the absence of antibiotics. Isolates from these organisms are grossly indistinguishable from isolates from algae. Although L. mucor is not a pathogen, it may be involved in high mortalities by causing pelagic eggs to sink below the surface and by interfering with the filtering apparatus of larval forms. Antibiotics that prevent development of L. mucor (and other microorganisms) reduce the mortality in developing eggs and larvae. Direct microscopic examination of 48 seaweeds from the lagoon at Majuro Atoll in the Marshall Islands for L. mucor indicated its presence on 81% of the samples. When 18 randomly chosen samples were put in enrichment culture, detection increased to 100%. These observations are at variance with a previous report that L. mucor is either absent or rare in warm waters.
An in Situ Method for the Measurement of Zooplankton Grazing Rates
Authors: Haney James F.
Published: March 2010

A radioisotope method is described with which one can measure the rate of ingestion of small particles by zooplankton under natural conditions. Zooplankton is captured and permitted to feed for a short time on trace amounts of 32P‐labeled yeast (Rhodotorula) automatically released within the specially constructed sampler or grazing chamber; an appropriate experimental time is 5 min, less than the time required for the isotope‐labeled food to pass through the gut of the dominant cladoceran grazers. From the uptake of labeled food by the zooplankton retained on a 75‐µ net, the filtering rate of the zooplankton community and of individual species can be calculated. High sensitivity, simplicity of measurement, and naturalness of conditions during the experiment are achieved with this experimental technique.
Anomalies of Ca2+ and SO42 in the Bardawil Lagoon, Northern Sinai
Authors: Levy Yitzhak
Published: March 2010

The waters of the inner lagoons in the Bardawil lagoon show a positive Ca2+ and SO42‒ anomaly, caused by the dissolution of gypsum layers from the bottom. The gypsum layer that was precipitated in the past from brines having chlorinities higher than 3.3 times that of normal seawater is being redissolved in the present lagoon waters, from which gypsum could not precipitate as the chlorinity now does not exceed 2.5 times that of normal seawater.
SUSPENDED MATTER IN SURFACE WATERS OF THE NORTHERN GULF OF MEXICO1
Authors: Manheim Frank T. , Hathaway John C. , Uchupi Elazar
Published: March 2010

Analyses of about 200 surface water samples collected during late fall 1966 show that concentrations of suspended matter greater than 1 mg/liter were restricted to within a few kilometers off Florida, but extended more than 100 km off Louisiana and Texas. Suspensates from areas farther than 100 km from shore contained mainly combustible organic matter, part of which was attributable to living plankton.

Organic aggregates encompassing appreciable amounts of inorganic detritus were particularly noteworthy in transitional areas. Zooplankton metabolism and fecal pellet production appears to be a geologically significant mechanism for depositing fine suspended matter and may contribute to the zonation of bottom sediments.

The mineral composition of surface suspensates ranges from a low magnesian calcite‐aragonite suite off Florida to montmorillonite‐kaolinite combinations from Alabama to Texas. The mineral composition of the suspensates resembles that of the bottom sediments in each area.
USE OF MULTIVARIATE ANALYSIS TO IDENTIFY FUNCTIONAL COMPONENTS OF THE BENTHOS IN ST. MARGARET'S BAY, NOVA SCOTIA1
Authors: Hughes Roger N. , Peer D. L. , Mann K. H.
Published: March 2010

Trends in the frequencies of occurrence of polychaetes and echinoderms in St. Margaret’s Bay, Nova Scotia, were isolated by principal components analysis and cluster analysis. Five principal components accounted for 70% of the total variance, three of them (46% of the variance) associated with sediment type, and one (16% of the variance) with distance from the head of the bay, probably with tidal water movements. The largest component of variance (23%) was due to the difference between fauna from clay (characterized by Pectinaria hyperborea and Synapta sp.) and fauna from more heterogeneous, coarser sediments. It was concluded that the large, contiguous area of soft mud in the deep part of the bay supports a reasonably well‐defined, integrated community.
INTERSPECIFIC INTERACTIONS AND SELECTIVE FEEDING BY TUBIFICID OLIGOCHAETES1
Authors: Brinkhurst Ralph O. , Chua Kian E. , Kaushik Narinder K.
Published: March 2010

Improved values of respiration and growth have been determined for three tubificid species. Maintaining the same individuals in mixed species culture before or after maintaining them separately lowered respiration by about a third, whereas lowering the population density of a single species had no such effect. The presence of Peloscolex multisetosus increased the weight gain of Tubifex tubifex and Limnodrilus hoffmeisteri by a factor of 2–3 times that in pure culture in a 6‐month period, although the first species seemed to remain unaffected. More energy was used for growth plus respiration when the three species were mixed than when maintained in pure culture. Attempts to measure ingestion and egestion were handicapped by failure to demonstrate a reduction in percent organic matter, percent nitrogen, or caloric content in feces as opposed to the mud presented as food; this indicates selective feeding. Further, variation in defecation rate was noted, which complicates the measurement of material cycling. The study suggests that the attempt to recreate energy or material budgets for communities from laboratory studies of isolated components is less promising than the attempt to study communities in situ.
A FREEZING CORE METHOD FOR DESCRIBING THE VERTICAL DISTRIBUTION OF SEDIMENTS IN A STREAMBED
Authors: STOCKER Z. S. J. , WILLIAMS D. DUDLEY
Published: March 2010

A new technique is described for obtaining in situ samples of substrate from stony streambeds, using liquid nitrogen to freeze the substrate around a standpipe driven into the bed.

Various physical parameters are calculated for the substrate obtained.
HETEROTROPHIC ASSAYS IN THE DETECTION OF WATER MASSES AT LAKE TAHOE, CALIFORNIA1
Authors: PAERL HANS W. , GOLDMAN CHARLES R.
Published: March 2010

A sensitive biological method for water mass detection has been successfully tested in the extremely oligotrophic waters of Lake Tahoe, California. A trace amount of 14C dissolved acetate is added to water samples and microbial incorporation monitored; assimilation rates demonstrate the presence of water masses originating from stream outflow. The same technique also shows microbial stimulation of Tahoe water when stream water is added in culture experiments. Autoradiographs indicate that bacterial cells, sometimes associated with detrital matter, are responsible for the acetate uptake.
ECOLOGY OF YELLOWSTONE THERMAL EFFLUENT SYSTEMS: NET PRIMARY PRODUCTION AND SPECIES DIVERSITY OF A SUCCESSIONAL BLUE‐GREEN ALGAL MAT1
Authors: Wiegert Richard G. , Fraleigh Peter C.
Published: March 2010

Net primary production and species diversity were studied during the successional development of a thermal blue‐green algal community on a linear series of wooden troughs. The source spring was high in dissolved silica and CO2. During July–August 1968 net primary production (minus grazing and export) was 25 kcal m‒2 days‒1 on board 1 and decreased downstream to 17 kcalm‒2 days‒1 on board 4. Linear increases in standing crop were observed during the first month of succession. An identical pattern of productivity and mat increase was observed during August–September 1969. Measurements of particulate export in the second year indicated that as much as 22% of total net production (minus grazing and dissolved organic export) may be lost via this pathway. Efficiencies of conversion of solar energy ranged from 1.0–1.6%. The chlorophyll content per gram organic matter increased and the ratio of OD 480:665 nm decreased with successional age of the mat. Species diversity (H̄) peaked after 2 weeks and increased with distance from the source. Although ten species of blue‐green algae were recognized, three made up most of the volume. Phormidium was dominant during the first few days but declined in importance as Mastigocladus increased. After 3 weeks a species of Oscillatoria increased; its volume varying directly with distance from the source. A hypothesis naming free CO2 as an important nutrient limiting the growth rate of the mat is developed.
PRODUCTION OF DISSOLVED ORGANIC MATTER FROM DEAD GREEN ALGAL CELLS. I. AEROBIC MICROBIAL DECOMPOSITION
Authors: Otsuki Akira , Hanya Takahisa
Published: March 2010

The green alga, Scenedesmus sp., killed by freeze‐drying, was experimentally decomposed by microflora extracted from lake mud under aerobic conditions. The production of dissolved organic matter was about 7% as carbon and about 6% as nitrogen by the 30th day. These amounts probably were minimal. The dissolved organic product was fractionated between butanol and acidified water. One fraction was insolubilized when mixed with butanol, became suspended at the interface between the two solutions, and gave a white amorphous solid after vacuum drying. Its infrared spectrum showed it was proteinaceous; it contained more than 14 kinds of amino acids. The other was extracted with butanol and gave a dark brown viscous substance on drying.

Aerobic microbial decomposition of Scenedesmus can be approximated to a first‐order reaction during the first 30 days under laboratory conditions. Kinetic considerations of the decomposition pattern of the cell nitrogen and the production of dissolved organic nitrogen suggest that dead algal cell substance may be divided into labile and refractory constituents by their relative resistance to the action of bacteria. The dissolved organic nitrogenous material produced is composed of two major fractions: One is produced with the decomposition of algal cells and the other is probably excreted by bacteria through reassimilation of mineralized nitrogen.
PLANKTONIC FORAMINIFERA: DIFFERENTIAL SETTLING, DISSOLUTION, AND REDEPOSITION1
Authors: Berger Wolfgang H. , Piper David J. W.
Published: March 2010

The settling velocities of empty tests of planktonic foraminifera have been determined experimentally, using tests both from sediment samples and from combusted plankton samples. The modal settling velocity of the species studied was equivalent to that of a quartz sphere of diameter approximately 2.4 times less than the maximum diameter of the foraminifera. Large variations from this mode occur and result from varying test shapes and wall thicknesses. The sequence of foraminifera in graded beds corresponds closely to their settling behavior determined experimentally. The significance of this new information for the production, dissolution, and redistribution of foraminiferal tests is considered briefly.
CREATINE IN SEAWATER1
Authors: WHITLEDGE T. E. , DUGDALE R. C.
Published: March 2010

Manual and AutoAnalyzer methods for the determination of creatine in seawater are described. Data are presented for creatine and nutrient excretion of Peruvian anchoveta, Engraulis ringens, and creatine found in a representative hydrostation near an anchoveta school in the Peru Current.
VITAMIN B12, THIAMINE, AND BIOTIN IN LAKE SAGAMI1
Authors: OHWADA KOUICHI , TAGA NOBUO
Published: March 2010

Vitamin B12 thiamine, and biotin concentrations in Lake Sagami were determined by microbiological assay methods and were compared with other biological and chemical factors. Fluctuations in vitamin concentrations corresponded with the succession of phytoplankton during the year.
THE SPECTRUM OF PARTICULATE ORGANIC MATTER OF SHALLOW‐BOTTOM BOUNDARY WATERS OF JAMAICA1
Authors: Reiswig Henry M.
Published: March 2010

Samples of near‐bottom shallow waters of Jamaica were analyzed for particulate matter by direct microscopy and for total particulate organic carbon (POC) by wet ashing. Aggregates comprise less than 5% of discrete particulate material and less than 0.5% of total POC. About 88% of POC is not accounted for by discrete particulate material. Parallel analyses of exhalant water samples from marine sponges indicate that about 35% of the missing POC is available to these filter feeders and is probably colloidal in nature.
SEDIMENTS AND WATERS OF SOMES SOUND, A FJORDLIKE ESTUARY IN MAINE1,2
Authors: Folger David W. , Meade Robert H. , Jones Blair F. , Cory Robert L.
Published: March 2010

Bottom sediments in the Somes Sound estuary coarsen progressively seaward from clay in the upper and middle parts through silt and sand to gravel at the mouth. Most contain <5% CaCO3 except in the lower sound where shell fragments are abundant and concentrations reach 20%. Organic carbon is most abundant (3–5%) in the clay of the upper sound, which smells strongly of II2S. Epifauna, especially holothurians, cover most of the bottom near the mouth of the sound. Infauna predominate in the fine sediments of the middle and upper sound but are absent where II2S is high.

Waters in the sound during August 1969 were well mixed and well oxygenated (6.7– 4.7 ml/liter) from surface to bottom, despite the shallow sill that restricts water circulation at the narrow mouth. Anaerobic bottom waters were not observed. The movement of a bottom drifter suggests that the net direction of flow of bottom water is landward, and the distributions of some sediment components that bottom‐water flow is counterclockwise. Particulate matter suspended in the water ranged from 0.6–4.1 mg/liter, with greatest concentrations in bottom waters above areas covered with fine‐grained sediments.
LAKE MOVEMENTS WITH PARTIAL ICE COVER
Authors: Palmer M. D. , Izatt J. Bryan
Published: March 2010

A recording current meter was operated under a winter ice sheet at Nanticoke, Lake Erie, in 11 m of water at a depth of 3 m from the bottom. Current magnitude and direction and water temperature were measured every 10 min. Current magnitudes up to 1 month after the ice sheet formed were similar to measurements made without ice; autovariance density spectra for this period showed energy concentrations at frequencies corresponding to the free oscillation modes of Lake Erie. Several months after the ice had been in place the measured currents were half as fast (3–9 cm/sec) and spectra during this period showed no energy concentrations at Lake Erie oscillation frequencies.
PHYTOPLANKTON IN LAKE TAHOE: DEEP‐LIVING POPULATIONS1
Authors: Kiefer Dale A. , Holm‐Hansen Osmund , Goldman Charles R. , Richards Robert , Berman Thomas
Published: March 2010

Most of the phytoplankton biomass in Lake Tahoe is located below the euphotic zone. Algae from deep water (100–400 m) appear healthy and fix CO2 at significant rates when exposed to near‐surface illumination. The relationship between the distributions of phytoplankton standing crop and production is best explained by passive sinking of cells out of the euphotic zone and accumulation in deep waters. This recruitment of deep phytoplankton from surface waters may be an important feature of deep oligotrophic lakes, limiting primary production and nutrient regeneration in the euphotic zone.
RADIOECOLOGICAL INVESTIGATIONS IN A THERMAL SPRING REGION
Authors: Lovrić G. , Strohal P.
Published: March 2010

Radioactivity of the thermal springs Tuheljske toplice in northwestern Yugoslavia has been studied. Naturally occurring radioactivity due to 234Pa, 226Ra, 222Rn, 214Pb, and 214Bi was detected. Radioactivity was measured in thermal spring water and sediments, as well as in the biota of this region. The level of radioactivity measured suggests the possibility of investigating the influence of small doses of radiation on biocenoses, since such conditions have existed for centuries.
VERTICAL TEMPERATURE STRUCTURE IN CRATER LAKE, OREGON
Authors: NEAL VICTOR T. , NESHYBA STEPHEN J. , DENNER WARREN W.
Published: March 2010

Vertical temperature profiles taken at different seasons in Crater Lake show an isothermal layer at middepth (295 m) with hyperadiabatic temperatures below that point. The lake is apparently meromictic, with circulation limited to the waters above middepth.
PORTABLE SPECTRORADIOMETER FOR UNDERWATER ENVIRONMENTS1,2
Authors: BURR A. H. , DUNCAN M. J.
Published: March 2010

A battery‐powered spectroradiometer is described which can be operated either manually or automatically in remote field applications. The probe can be easily maneuvered into restricted environments. The incident spectrum is determined by measuring successively through 16 interference filters transmitting in narrow wavebands from 401–698 nm. Minimum detectable spectral irradiance is 0.002–0.015 µW cm−2 nm−1 and is lowest at longer wavelengths. The instrument can measure with an accuracy of ±5% or less to depths where spectral irradiance is 0.03– 1.2% of surface.
UNDERESTIMATION OF STANDING CROP BY THE SURBER SAMPLER1
Authors: KROGER RICHARD L.
Published: March 2010

Before the flow of water from Jackson Lake into the Snake River was stopped by closure of a dam, invertebrates were collected in five Surber samples from a downstream riffle. After the water had receded from the riffle, five 0.093‐m2 areas of the exposed streambed substrate were hand‐collected and the invertebrates removed.

Predrawdown samples contained 4,286 invertebrates weighing 6.3 g while postdrawn samples contained 15,490 weighing 13.6 g. Large differences between submerged and exposed samples resulted from passage of smaller insects through the fine mesh of the Surber sampler and from backwash created by the sampler.
COMPARISON OF SAMPLES OF STREAM BOTTOM FAUNA COLLECTED DURING THE DAY AND AT NIGHT1
Authors: CLIFFORD HUGH F.
Published: March 2010

Bottom samples were taken throughout the year at 1600 and 2300 hours from a riffle region of a brown‐water stream of Alberta, Canada. For the abundant taxa, the variance of numbers was much greater than the mean for both day and night samples. For the entire study period, there were no significant differences between day and night samples for total numbers, total number of taxa, and total volume‐biomass.
SEPARATING CONSTITUENTS OF NATURAL PHYTOPLANKTON POPULATIONS BY CONTINUOUS PARTICLE ELECTROPHORESIS1
Authors: BAYNE DAVID R. , LAWRENCE JOHN M.
Published: March 2010

The Beckman continuous particle electrophoresis (CPE) system was used to isolate components of mixed phytoplankton suspensions. Twenty‐one freshwater phytoplankton genera were tested. All algal cells examined migrated toward the anode and different mobilities frequently resulted in fractionation of mixtures of different genera. Organic debris, clay particles, and bacteria often exhibited distinct mobilities that led to their separation from other constituents. Tris (hydroxymethyl) amino methane, pH 9.2, provided greater particle mobility and better resolution than sodium diethylbarbiturate, pH 8.6. Increase in buffer pH tended to make algal particles more negative and increased mobility. A direct relationship existed between applied field gradient and particle mobility. Resolution generally improved at higher field gradients. The effectiveness of the separation was limited by such algal properties as motility, size, formation of aggregates, and buoyancy.
SOME CHEMICAL AND MICROBIOLOGICAL OBSERVATIONS IN THE PACIFIC OCEAN OFF THE HAWAIIAN ISLANDS1
Authors: Gundersen K. , Mountain C. W. , Taylor Diane , Ohye R. , Shen J.
Published: March 2010

Simultaneous chemical and microbial analyses of the water column were made at 33 stations off the leeward Hawaiian Islands. The overall distribution of oxygen, nitrate, and pH was similar at all stations located more than 5 km offshore. These parameters were closely correlated and also correlated with nitrifying and nitrate‐reducing activity in the water column. The distribution of nitrite and ammonium did not correlate with the oxygen distribution. A nitrite band was consistently found in the lower portion of the photic zone and appeared to have originated from reduction of nitrate rather than from oxidation of ammonium. The distribution of aerobic and anaerobic bacteria was regulated by the amount of available organic nutrients and not by the oxygen concentration.
A STUDY OF THE DISTRIBUTION AND ACTIVITY OF MICROORGANISMS IN OCEAN WATER1
Authors: Hobbie John E. , Holm‐Hansen Osmund , Packard Theodore T. , Pomeroy Lawrence R. , Sheldon Raymond W. , Thomas James P. , Wiebe William J.
Published: March 2010

Estimates of living mass and respiratory rate were made by several methods on large water samples taken at several depths at each of two ocean stations. Total microbial biomass estimates based on ATP determinations gave reasonable results in relation to phytoplankton biomass, total particulate organic carbon, and total particulate volume as determined by an electronic particle counter. Respiratory rate estimates based on O2 uptake, electron transport system activity, and ATP were in moderately good agreement in surface water but diverged widely in deep water. Heterotrophic uptake of specific organic compounds seems to be related to numbers of active bacteria and not related to total microbial respiration. Photosynthetic rates and release of dissolved photosynthate are reported for both stations.
SURFACE CONCENTRATION OF MARINE BACTERIA1
Authors: Bezdek H. F. , Carlucci A. F.
Published: March 2010

The drops formed from a single gas bubble bursting at a liquid‐gas interface were used as a technique to sample the surface microlayers, and concentration factors for the drops were determined for the marine bacterium Serratia marinorubra. These factors, varying between 2 and 100, depended on the bulk densities of the bacteria. A model is presented that relates bacterial bulk densities to bacterial densities in a microlayer at the surface. Preliminary experiments with natural seawater populations revealed that concentration factors were markedly higher than those for S. marinorubra.
THE SEASONAL CYCLE OF PHEO‐PIGMENTS IN LAKE ONTARIO WITH PARTICULAR EMPHASIS ON THE ROLE OF ZOOPLANKTON GRAZING
Authors: Glooschenko Walter A. , Moore James E. , Vollenweider Richard A.
Published: March 2010

The annual cycles of chlorophyll a, pheo‐pigments, and zooplankton in Lake Ontario were studied on 32 stations during 13 cruises in 1970. Highest amounts of chlorophyll a were found in inshore waters. The seasonal cycle of phytoplankton biomass as measured by chlorophyll a showed three patterns: 1) a unimodal distribution in the deeper waters which are last to warm up in late spring; 2) a bimodal pattern, with spring and fall peaks, mainly along the central basin and north and south shores; 3) a series of three pulses in nutrient‐rich areas and in the warmer eastern region of the lake. Zooplankton biomass increased eastward in the direction of increasing heat content.

Pheo‐pigments were low during the spring increase of phytoplankton, but their amount relative to that of chlorophyll a was significantly correlated (r = +0.896) with zooplankton abundance. Highest pheo‐pigments were found in the eastern basin of the lake.

The need to correct chlorophyll a values for pheo‐pigments is emphasized especially when zooplankton grazers are abundant.
PROBLEMS AND METHODS OF CONTINUOUS IN SITU MEASUREMENTS OF REDOX POTENTIALS IN MARINE SEDIMENTS1
Authors: MACHAN RUDOLF , OTT JÖRG
Published: March 2010

The construction of a special redox probe and the electronic circuitry for multitrace recording of Eh values are described. The probe, carrying 10 platinum electrodes on its surface, is designed for easy field measurements and long‐term recordings of redox potentials in marine sediments.
AN EFFICIENT, QUANTITATIVE METHOD FOR SAMPLING THE MEIOBENTHOS1
Authors: RUPPERT EDWARD E.
Published: March 2010

Coring‐extraction tubes were designed for quantitative sampling above the water table and subsequent extraction by the Uhlig seawater ice method. An extraction rack to support the tubes is described, along with a modified suction‐corer which with the tubes, provides a set of undisturbed, layered subsamples from below the water table.

The method is applicable to quantitative sampling in the shallow subtidal and in the intertidal zone over a tidal cycle, as well as in unsaturated sediment.
CHANGES IN THE WATER CHEMISTRY OF LOUGH NEAGH OVER A 10‐YEAR PERIOD
Authors: GIBSON C. E. , STEWART D. A.
Published: March 2010

Statistical treatment of water analyses from Lough Neagh during the period 1958–1968 shows an upward trend in chloride, dissolved solids, and conductivity and a downward trend in color (Hazen value). The increase in chloride is closely paralleled by the increased use of road salt in the catchment area. Although the increase in chloride may explain the increase in conductivity, it is likely that other substances are involved in the increase of dissolved solids.
SEICHE AND WATER LEVEL FLUCTUATIONS IN GRINDAVIK HARBOR, ICELAND1,2
Authors: DONN WILLIAM L. , WOLF DAVID M.
Published: March 2010

An IGY gauge installed in Grindavik Harbor on the southern coast of Iceland shows frequent occurrence of a seiche whose period characteristically varies between 3 and 7 min as a function of the height of the semidiurnal tide. The period of the seiche can be accounted for approximately by the application of the open basin formula T= 4L(gh)−½ to a curved basin axis that includes the harbor and the entrance channel. Generation of the seiche is explained primarily as a consequence of water level increase at times of decreased atmospheric pressure and secondarily by the effect of wind direction so that water is driven into the harbor. The harbor itself responds in a way similar to an inverted barometer in response to air‐pressure changes.
A pH‐DEPENDENT MODEL FOR THE CHEMICAL SPECIATION OF COPPER, ZINC, CADMIUM, AND LEAD IN SEAWATER
Authors: Zirino Alberta , Yamamoto Sachio
Published: March 2010

A pH‐dependent model for the speciation of divalent Cu, Zn, Cd, and Pb ions in seawater was constructed with available and estimated thermodynamic stability constants and individual ion activity coefficients. This model was used to calculate the degree of interaction between each of the metal ions and the anions Cl−, SO42−, HCO3−, CO32−, and OH− as a function of pH. Interactions between a cation and an anion were assumed to result only in the formation of complexes with coordination numbers of 1 to 4; polynuclear and mixed‐ligand complexes were not included in the model.

The calculations showed the following: All four metals are complexed to a considerable extent in seawater; with the exception of Cd, the distributions of chemical species of the metals vary greatly with changes in pH; Cu interacts primarily with OH− and CO32−, Zn with OH−, Pb with CO32− and Cl−, and Cd with Cl−; complexes with high coordination numbers (i.e. 3 and 4) are not formed to any appreciable extent in seawater.
THE UPTAKE OF UREA BY NATURAL POPULATIONS OF MARINE PHYTOPLANKTON1
Authors: McCarthy James J.
Published: March 2010

Nitrogen‐15 isotopes were used to study the uptake of nitrate, ammonium, and urea by natural phytoplankton populations in 36 samples collected at nine stations off the coast of southern California. The percentage of the total phytoplankton nitrogen productivity accounted for by urea varied from <1% to >60% and for the entire study averaged 28%. The percentage of total available nitrogenous nutrient (ambient nitrate, ammonium, and urea plus the 15N additions) utilized per day varied among the stations from a minimum of 5% at station 4 (12 km off San Diego) to a maximum of 46% at station 19 (off White Point). The average C:N uptake ratio was 12.4.
SOME OBSERVATIONS ON THE RELEASE OF DISSOLVED ORGANIC CARBON BY THE SEA URCHIN, STRONGYLOCENTROTUS DROEBACHIENSIS
Authors: FIELD J. G.
Published: March 2010

Sea urchins fed Laminaria immediately before experiments released more dissolved organic carbon than unfed animals. The difference increased with increasing temperature. Calculations indicate that the calorific equivalent of carbon released is comparable with the energy of respiration at 3–7C and greater at 10–12C.
COPEPODS OF MARINE AFFINITIES FROM MOUNTAIN LAKES OF WESTERN NORTH AMERICA1
Authors: WILSON MILDRED STRATTON
Published: March 2010

Occurrences of Limnocalanus macrurus, Senecella calanoides, a variation of Mesochra rapiens and Huntemannia lacustris, all copepods either euryhaline or related to marine forms, are recorded from lakes in the Cascade and Rocky Mountains, western North America.
COPRECIPITATION OF PHOSPHATE WITH CARBONATES IN A MARL LAKE
Authors: OTSUKI AKIRA , WETZEL ROBERT G.
Published: March 2010

High concentrations of phosphate ion precipitate with carbonates by simple coprecipitation as the pH of marl lake water is increased. High pH microenvironments associated with photosynthesis probably induce phosphate‐carbonate precipitation, which in turn functions as one of several indirect density‐dependent population controls.
HOT SPRING MICROBIAL COMMUNITIES RECREATED IN MODIFIED “WINOGRADSKI COLUMNS”1
Authors: CASTENHOLZ RICHARD W.
Published: March 2010

A modification of the “Winogradski column” in which hot spring sediment and inoculum is used has recreated the sequence of thermophilic microbial communities that develop in the normal thermal gradient of the source spring. The mixed sediment and inoculum is packed into glass cylinders filled with spring water and a spot source of heat applied with an incandescent flood lamp or infrared spot lamp. A thermal gradient from over 90C to less than 40C can be established along the sediment‐glass interface. Photosynthetic and other microbial species developed in their normal range of temperature and have been maintained for several weeks or months.
A THEORETICAL MODEL OF LIGHT SCATTERING BY SARGASSO SEA PARTICULATES1
Authors: Gordon Howard R. , Brown Otis B.
Published: March 2010

Mie light‐scattering theory is applied to particles suspended in Sargasso Sea water to estimate their refractive index. The average index m* = 1.05−0.01i relative to water, when combined with a size distribution consistent with observation, reproduces the experimental volume‐scattering function at 632.8 nm with an average error of about 20%. A simple two species model is developed to demonstrate that the above index implies a significant portion of the suspended particulates is organic in nature.
STRATIGRAPHY OF FOSSIL PIGMENTS AS A GUIDE TO THE POSTGLACIAL HISTORY OF KIRCHNER MARSH, MINNESOTA1
Authors: Sanger Jon E. , Gorham Eville
Published: March 2010

Successional developments in the postglacial ecology and limnology of Kirchner Marsh revealed by concentration and diversity of sedimentary plant pigments include a peak of aquatic production (indicated by maximum pigment concentrations in sedimentary organic matter) reached during the early postglacial warm, humid interval at about 10,000 B.P. Production levels then declined. Very low levels of aquatic production (indicated by low pigment concentrations) seem indicated by about 6,000 B.P., in the middle part of a warm, dry interval following which pigment concentrations remained low (except for a brief interval about 5,000 B.P.), but with a marked rise in the ratio of chlorophyll derivatives to carotenoids, indicating an increase in allochthonous organic input accompanying the return of cooler moister conditions. These resulted in an encroachment of oak forest on the prairie, followed by the succession to reed‐swamp on the lake.

A return to more truly aquatic conditions was reflected by an increase in sedimentary pigments from about 3,000 B.P. to a peak at 1,700 B.P., accompanied by a decline in the ratio of chlorophyll derivatives to carotenoids. Subsequently pigment concentrations fell, and their ratio increased sharply, as emergent aquatics became well established and caused a rapid evolution of pond to grass‐sedge meadow.

The pigment data are generally in harmony with the ecological conclusions from pollen and macrofossils, but they provide much more information on changes in aquatic productivity at the site. Ratios of chlorophyll derivatives to carotenoids, along with measurements of pigment diversity, reveal changes in the balance between autochthonous and allochthonous organic contributions to the sediment and provide substantial evidence for the presence or absence of open‐water conditions.
MERCURY IN A MARINE PELAGIC FOOD CHAIN1
Authors: Knauer George A. , Martin John H.
Published: March 2010

Phytoplankton, zooplankton, and anchovies collected in Monterey Bay, California, over 10‐month period were analyzed for total mercury. In general, mercury levels were low and no evidence of food chain amplification was observed. Temporal variations of Hg concentrations in phytoplankton were greater than those for zooplankton; however, no seasonal trends were observed for either group. Plankton samples were also collected on a transect between the Hawaiian Islands and Monterey. Mercury levels were approximately equal in inshore and offshore zooplankton. The highest average mercury concentration was found in phytoplankton‐net samples from the open ocean that contained radiolarians and other small zooplankton forms as well as diatoms.
ATP CONTENT OF CALANUS FINMARCHICUS
Authors: BALCH NORVAL
Published: March 2010

Measurements of adenosine triphosphate (ATP), carbon, and nitrogen were made on Calanus finmarchicus held in a food‐free environment in the laboratory. Over a 23‐day starvation period there were significant reductions of absolute amounts of carbon, nitrogen, and ATP, but no significant changes in the relationship between ATP and body carbon. Relative ATP levels in organisms remain sufficiently constant over a range of physiological conditions so as to make them good indicators of biomass. ATP: carbon ratios in lipid‐storing copepods is also considered.
THE EFFECT OF SEASON AND ANIMAL SIZE ON THE CALORIC CONTENT OF DAPHNIA PULICARIA FORBES1,2
Authors: SNOW NORMAN B.
Published: March 2010

The population of Daphnia pulicaria Forbes in Vest Blue Lake, Manitoba, was sampled monthly for over a year. Very small animals were entirely absent during winter when no reproduction was occurring, while large, red, fat‐laden individuals were more numerous than at any other time. In spring, large numbers of small animals appeared and the largest size classes virtually disappeared, to reappear the following winter. The large, fat, winter animals had a very high energy content (~ 9,000 cal/g dry wt) whereas smaller individuals at the same time had values similar to those later in summer. Caloric content of all sizes decreased as summer progressed (~ 4,900 cal/g dry wt) and the inequality between different sizes also disappeared. During November the mean caloric content began to rise again and once more large animals had higher values than smaller ones.
A COMPARISON AT SEA OF MANUAL AND AUTOANALYZER ANALYSES OF PHOSPHATE, NITRATE, AND SILICATE1
Authors: HAGER S. W. , ATLAS E. L. , GORDON L. I. , MANTYLA A. W. , PARK P. K.
Published: March 2010

A shipboard intercalibration of nutrient analyses performed using a Technicon AutoAnalyzer (AA) and manually, using a Beckman model DU spectrophotometer, yielded the following relationships (in µm):

urn:x-wiley:00243590:media:lno19721760931:lno19721760931-math-0001

where R is the correlation coefficient, and the number immediately following ± is the standard deviation. Both AA and manual methods give comparable precision, ±1 %, at present and no significant systematic discrepancies exist between the two technologies for phosphate and silicate analyses. A small discrepancy was found in the nitrate work.
IMPROVED TECHNIQUE FOR ANALYSIS OF CARBOHYDRATES IN SEDIMENTS1
Authors: GERCHAKOV SOL M. , HATCHER PATRICK G.
Published: March 2010

The phenol‐sulfuric acid method for determining total carbohydrates was applied to surface sediment samples from a brackish water lake, using an improved technique in which the order of addition of reagents proved to be essential for reproducibility. Corrections are made for noncarbohydrate materials that may be present in the samples.
Influence of Kmax and R on Fatigue Crack Growth—A 3D‐Model
Authors: Gudladt Hans‐Joachim , Steinbock Johanna
Published: March 2010

To study the influence of the stress intensity factor and the R‐ratio on the fatigue crack growth rate different kind of crack propagation experiment have been carried out on the steels X5CrNi18‐10 and C45E. The experiments show that both parameters the maximum stress intensity Kmax and the R‐ratio affect the crack growth rate. Consequently, the authors developed a 3D‐model, which describes the dependence of da/dN on Kmax and the R‐ratio. Discussing the experiments, special attention has been paid to the threshold behavior of the investigated materials. Finally, a new model to describe the influence of the R‐ratio on the threshold Kmax,th for R‐ratios from −∞ to 1 is presented.
Modeling of Hot Ductility During Solidification of Steel Grades in Continuous Casting – Part I
Authors: Senk Dieter , Stratemeier Sonja , Böttger Bernd , Göhler Klaus , Steinbach Ingo
Published: March 2010

The present paper gives an overview of the simultaneous research work carried out by RWTH Aachen University and ThyssenKrupp Steel Europe AG. With a combination of sophisticated simulation tools and experimental techniques it is possible to predict the relations between temperature distribution in the mould, solidification velocity, chemical steel composition and, furthermore, the mechanical properties of the steel shell. Simulation results as well as experimentally observed microstructure parameters are used as input data for hot tearing criteria. A critical choice of existing hot tearing criteria based on different approaches, like critical strain and critical strain rate, are applied and developed. The new “damage model” is going to replace a basic approach to determine hot cracking susceptibility in a mechanical FEM strand model for continuous slab casting of ThyssenKrupp Steel Europe AG.

Critical strains for hot cracking in continuous casting were investigated by in situ tensile tests for four steel grades with carbon contents in the range of 0.036 and 0.76 wt%. Additionally to modeling, fractography of laboratory and industrial samples was carried out by SEM and EPMA and the results are discussed.