bluuebunny/crossref_metadata_2025 huggingface dataset:
BENTHIC STUDIES IN BUZZARDS BAY III. THE STRUCTURE OF THE SOFT‐BOTTOM COMMUNITY1
Authors: Sanders Howard L.
Published: March 2010

A series of 24 samples was taken at periodic intervals at a single locality in Buzzards Bay from February 1956 to January 1958. With the exception of 4 samples which departed markedly from the others in regard to sediment composition, very high indices of faunal affinity were obtained within the series. The silt‐clay fraction of the sediment in the 20 samples with high faunal indices varied from 78–91%, and when the contained species were ranked by abundance, the commoner species achieved approximately the same rank from sample to sample. Thus, 8 or 9 species are a constant part of the biological environment of this association, and there is an approximately constant numerical proportionality among them. Seventy‐nine species were obtained from the 20 samples of typical sediment composition. However, 11 species comprised almost 95% of the total fauna by number while the lamellibranch Nucula proxima (58.86%) and the polychaete Nephthys incisa (17.21%) were commonest, Ten species make up 95% of the total biomass. Thus the community, both numerically and by biomass, is characterized by pronounced dominance of few species. The niches of the 9 most common species, representing 93.5% of the community by number, were categorized by method of feeding, kind of food and spatial distribution. Considering only these few factors, it was possible to demonstrate certain differences in niche preference. The relationship of animal numbers to animal weight revealed the expected pyramid of numbers with very few organisms in the largest weight categories and numerous individuals in the smaller weight groups. However, when the biomass within each weight category was determined, the expected inverted pyramid did not result. Numbers are considered more valid than biomass in quantitative benthic studies, since only 0.15% of the fauna constitute 55.17% of the entire weight. The presence or absence of a rare, randomly distributed large animal may alter the biomass of an individual sample by two orders of magnitude.
BIOLOGICAL AND GEOLOGICAL OBSERVATIONS ON THE FIRST PHOTOGRAPHS OF THE ARCTIC OCEAN DEEP‐SEA FLOOR1
Authors: Hunkins Kenneth L. , Ewing Maurice , Heezen Bruce C. , Menzies Robert J.
Published: March 2010

The first series of Arctic bottom photographs give the following indications regarding conditions on the Arctic sea floor: Bottom life appears to be less abundant than in the Atlantic Ocean at similar depths. Loose rocks are more numerous. Ripples seem to be less abundant in the Arctic area photographed than they do at comparable depths in the Atlantic. A bottom current of 0.3 to 0.6 cm/sec is indicated from movements of sediment clouds. The area is abundantly supplied with curious short “tracks” of uncertain origin. Small irregular holes in the pictures probably represent holes produced by ice‐rafted stones and pebbles.
THE TOXICITY OF GONYAULAX MONILATA HOWELL TO MUGIL CEPHALUS
Authors: Gates Jean A. , Wilson William B.
Published: March 2010

Laboratory experiments were conducted to determine the effects of in vitro cultures of the marine dinoflagellate, Gonyaulax monilata Howell, on fishes. Results indicate that the organism produced a substance (s) toxic to fishes and that the toxicity of the medium is increased if the dinoflagellate cytolyses.
COMPETITION BETWEEN SIMOCEPHALUS VETULUS AND CYCLOPS VIRIDIS1
Authors: Parker Richard A.
Published: March 2010

Simocephalus vetulus and Cyclops viridis were raised in pure and mixed cultures under controlled laboratory conditions. Cyclops numbers were depressed markedly in the presence of Simocephalus, whereas Cyclops had essentially no influence on numbers of Simocephalus.
A METHOD FOR DEVELOPING BRACHYURAN EGGS IN VITRO1
Authors: Costlow John D. , Bookhout C. G.
Published: March 2010

The larvae of six species of Brachyura have been successfully hatched by detaching the eggs from the female, placing them in compartmented boxes, and maintaining them on an Eberbach variable speed shaker at constant temperatures at different salinities. In addition to providing thousands of normal larvae of known species for experimental purposes, the method has the following advantages: it provides adequate aeration, prevents the spread of fungi and protozoans throughout the egg mass, and permits the use of a relatively small number of eggs from the same animal in a limited space.
THE CAUSE OF A METALIMNETIC MINIMUM OF DISSOLVED OXYGEN1
Authors: Shapiro Joseph
Published: March 2010

Coincident with a condition of rapidly increasing eutrophication, Lake Washington, a large, deep lake, near Seattle, is exhibiting an increase in the magnitude of a metalimnetic depletion of dissolved oxygen. Possible causes of this depletion are examined, and the conclusion is that the respiration of a metalimnetic population of non‐migrating copepods is the prime agent. Calculations are presented in support of this conclusion, and chemical properties of the notch are compared with those of a hypolimnetic notch due to morphometric causes, to provide further evidence. The recent increase in magnitude of the phenomenon is considered to be due to the increase in numbers of copepods.
UPTAKE OF CESIUM137 BY CELLS AND DETRITUS OF EUGLENA AND CHLORELLA
Authors: Williams Louis G.
Published: March 2010

Standard “Euglena” medium putrefied by three common species of bacteria and filtered was found to support unusually heavy blooms of Euglena and Chlorella. Mass culturing demonstrated that uptake of Cs137 by Euglena and Chlorella is linear with concentrations at all levels that might be encountered in natural aquatic habitats. The rate of uptake of cesium during population growth is greatest in cells of Euglena during the stationary period following the exponential growth phase. At this stage the cesium taken in is mostly unbound Following this it is released so that in old cells and detritus it is largely bound cesium. Cesium and potassium behave independently in killed cells of Chlorella. Alkali ions, known to be chemically similar, are selected or rejected discriminately by these algae. The presence of antibiotics significantly depresses the uptake of cesium by Chlorella and Euglena.
A STATISTICAL STUDY OF THE ESTIMATION OF ABUNDANCE OF SARDINE (SARDINOPS CAERULEA) EGGS1
Authors: Taft Bruce A.
Published: March 2010

The reliability of the estimation of abundance of sardine (Sardinops caerulea) eggs is examined from two points of view. Analysis of egg observations collected on spawning surveys off southern California in 1941 indicates that the counts are consistent with the hypothesis that the egg population is distributed according to the negative binomial contagious distribution. Calculation of 95% confidence limits shows that the cruise estimates are subject to a variation of one‐half or double the estimate on the average. A seasonal estimate is probably subject to wider variation than the cruise estimates. Sardine egg observations collected from a 400 square mile grid of 25 stations off Baja California in 1952 over five days show important time and spatial variations. The coefficient of variation of an estimate of abundance of the egg population within the grid for the five day period from a single observation is estimated to be 31.1. The corresponding coefficient of variation of a sum of 40 counts from the grid is 4.9. The implications of this variability for the design of egg sampling surveys are discussed.
FIRST‐YEAR GROWTH OF THE WALLEYE, STIZOSTEDION VITREUM VITREUM (MITCHILL), AND ASSOCIATED FACTORS IN THE RED LAKES, MINNESOTA1
Authors: Smith Lloyd L. , Pycha Richard L.
Published: March 2010

First‐year growth of the walleye, Stizostedion vitreum vitreum (Mitchill), was studied from 4,544 fish collected during the first summer of life in the Red Lakes in six seasons and from back calculations on 4,474 fish one year or more in age representing 17 year classes. Sexes did not differ in growth rate. Growth within the season varied greatly in different years and total growth deviated as much as 15.3% from the mean of the entire period. Water temperature, size of brood, and abundance of large walleyes and perch did not affect growth rate. Very early or late spawning influenced total growth during the season and final size and goodness or poorness of a season’s growth was determined by the middle of July. Growth rate of young‐of‐the‐year perch and total use of perch as food did not significantly influence growth. Incidence of perch in walleye stomachs ranged from 10.9 to 98.0% and spottail shiner was a more important food item in most years than perch. Total first‐year growth of the walleye was apparently determined before fish became a major item in the diet.
THE LIMNOLOGY OF CANYON FERRY RESERVOIR: III. SOME OBSERVATIONS ON THE DENSITY DEPENDENCE OF PHOTOSYNTHESIS AND ITS CAUSE1
Authors: Wright John C.
Published: March 2010

A series of 24‐hr determinations of net photosynthesis confirmed the conclusions derived from previous 6‐hr experiments that the relationship between photosynthesis and standing crop is not linear. The optimal rate of net photosynthesis per unit chlorophyll varied inversely with chlorophyll concentration. As a result net euphotic zone photosynthesis was maximal at intermediate values of chlorophyll concentration and was less at chlorophyll concentrations above or below the intermediate range. From previously derived relationships between chlorophyll, gross photosynthesis, and respiration, values of net euphotic zone photosynthesis were computed for each chlorophyll concentration. The computed values agreed well with the observed values. The decline of CO2 concentration as standing crop increased was suggested as the most probable cause of the observed photosynthesis standing crop relationship.
PHYTOPLANKTON COMMUNITIES OF WESTERN LAKE ERIE AND THE CO2 AND O2 CHANGES ASSOCIATED WITH THEM
Authors: Verduin Jacob
Published: March 2010

Phytoplankton studies using samples concentrated by settling revealed population densities several times higher than those reported previously, based on centrifuge and bolting cloth concentrates. Clear and dark bottle experiments employing natural population densities revealed photosynthetic yields averaging 1.6 µmoles of CO2 absorbed per microliter of plant volume per hour. This yield is three times higher than previously reported yields based on artificially concentrated populations. Comparison of daily photosynthetic yields per square meter of water as computed from bottle data with yields measured under completely natural conditions indicated an additional twofold discrepancy, with the natural condition yielding the higher value. The reduction of turbulence in bottles may be operating to reduce the photosynthetic yield. Eddy diffusivity in western Lake Erie, computed from pH change in the dysphotic zone, and vertical pH gradients, is about 25 cm2/sec. Simultaneous determinations of CO2 and O2 changes showed that O2 changes usually were lower than CO2 changes, suggesting that processes other than photosynthesis are influencing the CO2 and O2 budgets.
INTERTIDAL ZONATION IN POPULATIONS OF MYA ARENARIA1
Authors: Matthiessen George C.
Published: March 2010

Observations over a 2‐year period on the distribution of two successive year‐classes of Mya arenaria in a tidal area near Quincy, Mass., indicated that young clams 2–15 mm in length were subject to appreciable changes in location in intertidal areas. Such changes involved a shoreward displacement of the members of the population as they exceeded 5 mm in length, with a marked tendency for successive populations ultimately to become concentrated near an abrupt change in the beach profile.

The similarities between the patterns of clam and surface sediment distribution in this area are discussed, and it is suggested that, as in the case of sediment particles, hydrodynamic forces are primarily responsible for the zonation of Mya populations in intertidal areas.
SOME OBSERVATIONS OF CURRENTS IN THE HYPOLIMNION OF LAKE MENDOTA
Authors: Lathbury Alison , Bryson Reid , Lettau Bernhard
Published: March 2010

Observations of hypolimnetic currents in Lake Mendota, integrated over entire seiche periods, indicate that steady motions exist below the thermocline. Seiche currents and turbulence are shown to be insufficient to explain the observed currents.
SESTON COMPOSITION IN TWO FRESIIWATER POOLS
Authors: Moss Brian
Published: March 2010

Seasonal changes in organic components of the seston were measured in two small pools during two years. In one pool, little disturbed by wind and having few aquatic macrophytes, about a third of the seston organic matter was detritus, derived largely from marginal sediments. A small fraction in summer was probably bacteria or microzooplankton. Positive correlations between chlorophyll a, carotenoids, particulate carbohydrate, and particulate organic matter were highly significant. Seasonal changes in ratios of chlorophyll a to organic matter and chlorophyll a to carotenoids were much smaller than the ranges for these ratios from laboratory cultures.

The second pool, shallower and more exposed than the first, was almost entirely colonized by Equisetum fluviatile, whose epiphytic communities contributed much organic matter to the seston. About half of the organic seston was living algae, of which many cells may have been detached epiphytes. Bacteria caused large increases in particulate organic matter in summer. The complex origins of the seston precluded the detailed analysis of changes in various components that was possible for the first pool.
GNOTOBIOTIC CULTURE AND PHYSIOLOGICAL ECOLOGY OF THE MARINE NEMATODE RHABDITIS MARINA BASTIAN1
Authors: H. Tietjen J. , J. Lee J. , Rullman J. , Greengart A. , Trompeter J.
Published: March 2010

The marine nematode Rhabditis marina Bastian has been isolated in gnotobiotic culture from collections of Zostera marina made in North Sea Harbor, Southampton, New York. A strain of R. marina has been maintained with three species of bacteria (Pseudomonas sp., Flavobacterium marinum, and Micrococcus sp.) for over 120 generations. A monoxenic strain with Pseudomonas sp. has been maintained for over 25 generations. The life cycle is completed in 5 days under “normal” laboratory growth conditions. Reproduction occurs over a wide (0–80‰) salinity range (the highest salinity tested) and a wide (10–38C) temperature range; optimum growth occurs at 45–55‰ and 25–30C. Normal development is oviparous, but ovoviviparous development is seen in older females. Tracer feeding and synxenic culture experiments have shown that R. marina has rather specific nutritional requirements, which seem to be completely satisfied by a relatively restricted group of microorganisms. Selected species of bacteria comprise the normal diet of this organism. Microscopic observations of intact algae in the digestive tract of the worms and failure of 32P to transfer to the worms from the ingested algae indicate that the worms are not able to digest all ingested potential food organisms.

The geographical distribution of the species in relation to its physiological ecology is discussed.
AEROBIC LAKE MUDS FOR THE REMOVAL OF PHOSPHORUS FROM LAKE WATERS1
Authors: Fitzgerald George P.
Published: March 2010

Phosphorus‐limited Selenastrum and Cladophora sp. will respond by growth or changes in extractable PO4‐P to as little as 0.02 mg PO4‐P in solution; these same species did not respond when exposed for a period of 1 or 2 weeks to as much as 2 mg of phosphorus as lake muds under aerobic conditions. Studies of the rate of sorption of phosphorus by lake muds, under aerobic conditions, from two lakes and from three depths in one lake, indicated that as little as 0.4 g (dry wt) of mud could sorb about 0.05 mg PO4‐P in less than 30 min. These findings suggest that the sorption of phosphorus by lake muds under aerobic conditions can be used to remove phosphorus from lake water.
THE INFLUENCE OF PREDATION ON THE ADULT SEX RATIOS OF TWO COPEPOD SPECIES1
Authors: Maly Edward J.
Published: March 2010

Males and females of two species of copepods were subjected to predation by three different predators in a laboratory environment. Ambystoma tigrinum tadpoles ate more female than male Diaptomus shoshone, Lebistes reticulatus ate more male than female Diaptomus oregonensis, and Hydra cauliculata ate equal numbers of male and female D. oregonensis in a given length of time. Predation alters the adult sex ratios of these prey in the laboratory in a manner influenced by differences in predator hunting behavior and by differences in size and activity of male and female prey. Predictions concerning adult prey sex ratios in natural conditions are discussed.
PRODUCTION OF PARTICULATE ORGANIC MATTER BY THE REEF ON KAVARATTI ATOLL (LACCADIVES)
Authors: Qasim S. Z. , Sankaranarayanan V. N.
Published: March 2010

The concentration of particulate organic carbon in the vicinity of Kavaratti Atoll is much greater than that of the surrounding sea. The particulate organic matter, which is largely produced by the coral reef, amounts to about 20% of the total gross production of the reef community. It is suggested that, in the absence of an adequate standing crop of phytoplankton, the particulate matter may form an important source of energy to zooplankton in coral reef waters.
CURRENTS NORTH OF BERING STRAIT IN WINTER1
Authors: Coachman L. K. , Tripp R. B.
Published: March 2010

Four days of current record were obtained about 190 km NNE of Bering Strait during March 1968. The mean current was the same for the location as in summer, suggesting that the generally north flow from the Bering Sea to the Arctic Ocean occurs also in winter.

Variations in speed and direction of the flow were identified and analyzed. The major periodic variation was due to the diurnal tidal wave, and thus the tidal wave rather than inertial currents must be the primary cause of periodic variations. The course of the tidal wave and some features of its behavior are inferred. Other variations of importance include a variation with a period somewhat greater than 2 days, probably caused by atmospheric phenomena, and fluctuations due to relatively large‐scale turbulence (periods between 5 and 60 min).
A LIQUID SCINTILLATION PROCEDURE FOR DETERMINING THE EFFECT OF SIZE ON SELF‐ABSORPTION OF 14C IN DAPHNIA PULEX1
Authors: WARD F. J. , WONG BRIAN , ROBINSON G. G. C.
Published: March 2010

Self‐absorption coefficients for 14C in Daphnia pulex ranging from 1.1 to 2.9 mm long were determined with a liquid scintillation counting procedure. Coefficients were calculated from two regressions: that of the radioactivity of labeled whole animals on size and that of the radioactivity of labeled animals digested for 24 hr at 60C in the solubilizer NCS on size. Self‐absorption coefficients increased from 1.23 for animals with a mean body carbon content of 6.6 µg C/ individual to 2.73 for animals with 44.7 µg C/individual.

If quenching is moderate and digestion complete, specific activities of small animals can be determined directly using an efficient solubilizer, eliminating the need to use self‐absorption coefficients.
LIQUID SCINTILLATION COUNTING OF 14C‐DIATOM MATERIAL ON FILTER PAPERS FOR USE IN PRODUCTIVITY STUDIES
Authors: PUGH P. R.
Published: March 2010

An improved method for the liquid scintillation counting of 14C‐phytoplankton material on membrane filter papers is described. The method involves the incorporation of standard 14C‐sucrose into the filter, and it clearly demonstrates that the counting efficiency of the sample is affected by the amount of material present. It is concluded that the cells and the membrane filter have a self‐absorptive effect that previous methods of counting, using internal and external standardization, cannot have fully detected.
LIGHT‐SCATTERING VECTORS OF SOME MARINE PARTICLES1
Authors: Pak Hasong , Beardsley George F. , Heath G. Ross , Curl Herbert
Published: March 2010

The volume‐scattering function and particle size distribution of several marine sediments and species of phytoplankton were measured. The volume‐scattering function of a single particle at a 45° scattering angle, β̄45 was computed. In general, increases in S̄ accompany increases in β̄45 for the biological material over the size range of particles measured (10–70 µ2). The geological samples displayed a wide range of specific scattering over the much narrower area range studied (5–15 µ2). The specific volume‐scattering function and the mean particle area form a two‐dimensional optical vector(β̄45, S̄) which can be used to characterize the suspended material in seawater. Vertical profiles of the optical vector measured in the eastern equatorial Pacific and off the Oregon coast show surface values that appear to be in the biological section of the optical vector diagram and a smooth transition to the apparent geological portion of the diagram with depth.
INCORPORATION OF ORGANIC CARBON BY DAPHNIA PULEX
Authors: Bell R. K. , Ward F. J.
Published: March 2010

The rate of incorporation of organic carbon by Daphnia pulex from various concentrations of 14C‐labeled phytoplankton and artificial detritus was measured both in situ in West Blue Lake, Manitoba, and in the laboratory.

Incorporation of artificial detritus was independent of dissolved oxygen concentration, down to a level of 2.8 mg O2/liter, during a 4‐hr experiment. Food concentration and temperature were related, for each food type, to incorporation in multiple regression equations. Three estimates, ranging from 2.37 to 5.35 µg C individual−1 day−1, were made of daily incorporation, assuming it was similar in natural and artificial detritus. Of these amounts, from 12 to 17% was estimated to be incorporated by Daphnia below 12 m, in the zone where particulate organic matter was predominantly detritus or moribund organisms. Variations in incorporation rate were caused primarily by temperature differences encountered during vertical migration rather than by food concentration. Because vertical migration patterns varied, temperature regimes also varied, and so, consequently, did incorporation rates. The estimated contribution of detrital carbon to total daily incorporation was much less than the phytoplankton contribution but was significant.
THE EFFECT OF TEMPERATURE ON THE DEVELOPMENT TIME OF EGGS OF THERMOCYCLOPS SP., A TROPICAL CYCLOPOID COPEPOD FROM LAKE GEORGE, UGANDA
Authors: Burgis Mary J.
Published: March 2010

The rate of egg development in Thermocyclops sp., determined in the laboratory, increases linearly from 15–30C. Above 32.5C development is retarded and, although eggs hatch at 35C, the females die after some time at that temperature, At 40C, mortality is 100% within 2 hr.

The mean temperature of Lake George is computed to be 26.3C and, by extrapolation from the laboratory results, a mean development time of 36 hr is obtained. Both these means vary little throughout the year.

From the work of others, it appears that the effect of temperature on egg development is similar in Mesocyclops leuckarti but less marked in several calanoid copepods.
THE EFFECT OF CONCENTRATION OF FOOD ON BODY WEIGHT, CUMULATIVE INGESTION, AND RATE OF GROWTH OF THE MARINE COPEPOD CALANUS HELGOLANDICUS
Authors: Mullin Michael M. , Brooks Elaine R.
Published: March 2010

Calanus helgolandicus was raised from early nauplius to copepodite stage IV on different concentrations of two food organisms at two temperatures. The dry weights of the resulting C IV individuals were directly correlated with the concentration of food available during growth and were not significantly affected by temperature. The gross efficiency of growth was inversely related to the total amount of food ingested during development. Calanus can apparently grow with high efficiency at natural concentrations of food.
CHEMICAL CHANGES INVOLVING NITROGEN METABOLISM IN WATER AND PARTICULATE MATTER DURING PRIMARY PRODUCTION EXPERIMENTS
Authors: Procházková L. , Blažka P. , Králová M.
Published: March 2010

The uptake of ammonia and nitrate by particulate matter during photosynthesis in large light and dark bottles was followed by colorimetric and mass spectrometric methods. Ammonia uptake as determined by the 15N isotope was always higher than the parallel estimate from colorimetric analysis. The uptake (or release) of ammonia in the dark was inversely related to the protein content of the corresponding sample of particulate matter. Utilization of nitrate in light was inversely proportional to the concentration of ammonia available. The particulate organic matter contained 50.5% protein in light bottles but 61.7% protein in dark ones. The mean ratio of oxygen changes, as calculated from changes in protein, carbohydrate, and lipid to those found experimentally, was 1.03 in light bottles (indicating good agreement) and −0.34 in dark ones. This is interpreted as evidence for some particle formation in the dark that is probably not microbial.
ACETYLENE REDUCTION (NITROGEN FIXATION) IN WISCONSIN LAKES1
Authors: Rusness Donald , Burris R. N.
Published: March 2010

Acetylene reduction has been used as an index of the nitrogen‐fixing capacity of the phytoplankton of representative oligotrophic and eutrophic lakes in Wisconsin. Acetylene reduction was not measurable in samples from oligotrophic Crystal Lake but was vigorous in samples from eutrophicated lakes. The activity during the season fluctuated widely with the development of blooms of nitrogen‐fixing blue‐green algae; no activity was demonstrated during winter months. Activity and population generally decreased with depth. Acetylene reduction was low in early morning, rose to a peak at noon, and then declined.
AN IMPROVED CODE TO CLASSIFY THE LOCATION OF MARINE AND TERRESTRIAL DATA
Authors: SWEERS H. E.
Published: March 2010

A geographically sequenced file is often coded with a Marsden square number. The Marsden keys, however, are unnecessarily complicated and inefficient when used in a global data bank. An alternate way of numbering the 10° and 1° squares, called the COTED system, has been designed. Its main advantages are 1) a clear relationship between the sampling position expressed in latitude and longitude and the COTED key and 2) the possibility of writing a more efficient geographical retrieval for data in an area of an almost arbitrary shape.
AN EXPERIMENTAL APPROACH TO THE PRODUCTION DYNAMICS AND STRUCTURE OF FRESHWATER ANIMAL COMMUNITIES1
Authors: Hall Donald J. , Cooper William E. , Werner Earl E.
Published: March 2010

The effects of three levels of inorganic nutrients and two predator densities on aquatic animal communities were examined in a series of twenty 0.07‐ha freshwater ponds. The treatments were cross‐classified in a randomized block design and continued over 3 years. Analyses of the responses include community composition, secondary production, and demographic description of the dominant species of both zooplankton and benthos. The fish populations and their feeding behavior are described in detail. Ancillary data on water chemistry and primary production were available.

Nutrients generally increased production of the zooplankton but had little effect on community composition. Fish predation had profound effects on the diversity and size distribution of the zooplankton but only affected production at lower nutrient levels. The benthos responded markedly to nutrients during the first year, but this was not apparent the second and third years. The response of the benthos to both nutrients and predation was best shown by changes in the distribution of body size. Both zooplankton and benthic communities showed complementary responses between large‐ and small‐bodied organisms. Differences in the physical structure of the environment (i.e., macrophytes) also produced significant changes in production and composition of both systems. The biomass production of the fish populations was clearly related to nutrient level. Both fish and invertebrate predators were size selective, but the fish had a much greater influence on the prey populations.
PHOTOSYNTHETIC PROPERTIES AND GROWTH OF PHOTOSYNTHETIC SULFUR BACTERIA IN LAKES
Authors: Takahashi Masayuki , Ichimura Shun-ei
Published: March 2010

The photosynthesis‐light curve for purple sulfur bacteria had a steeper inclination than that for green sulfur bacteria at low light intensities. Light saturation occurred at intensities of 5–7 klux in the former, in the latter at 10–30 klux. Light inhibition was observed in purple sulfur bacteria but was negligible in green sulfur bacteria. The optimal temperature for photosynthesis of these bacteria is considerably higher than that of most phytoplankton or green plants. Photosynthetic sulfur bacteria appear ordinarily in the contact layer between oxidative and reductive zones of meromictic or stagnant holomictic lakes; the light intensity in this contact layer is usually less than 10% of that at the surface. On the assumption that the photosynthetic rate of these bacteria is limited mainly by the interaction of hydrogen sulfide concentration with light intensity, their growth was analyzed with a mathematical model. The properties of the growth phase observed in lakes were similar to those calculated. The main factors determining the growth of photosynthetic sulfur bacteria in lakes are the H2S concentration in the upper layer and the light conditions in the deeper layer.
RELEASE OF METHYL MERCURY FROM SEDIMENTS WITH LAYERS CONTAINING INORGANIC MERCURY AT DIFFERENT DEPTHS
Authors: JERNELÖV ARNE
Published: March 2010

When no macroorganisms are present, deposits of inorganic mercury in the upper few centimeters of the sediment are responsible for almost the whole amount of released methyl mercury. If Tubificidae or Anodonta are present at high densities, deposits down to 2.5 or 9 cm from the surface, respectively, are effective.
IMPROVED INCUBATION AND GAS SAMPLING TECHNIQUES FOR NITROGEN FIXATION STUDIES1
Authors: SCHELL DONALD M. , ALEXANDER VERA
Published: March 2010

Vacutainers, pre‐evacuated glass tubes with heavy septa, into which gas is introduced through a double‐ended needle, are used to collect and store gas samples for determining acetylene‐reduction nitrogen fixation. Incubation vessels consisting of heavy plastic bags secured to collared glass tubes fitted with septa have proved useful for determining nitrogen fixation by macrophytes.
PHOSPHORUS‐33 AUTORADIOGRAPHY USED TO MEASURE PHOSPHATE UPTAKE BY INDIVIDUAL ALGAE
Authors: FUHS G. WOLFGANG , CANELLI EDMONDO
Published: March 2010

Diatoms from pure cultures and samples of lake phytoplankton were labeled with and autoradiographs were prepared after concentration by centrifuge and membrane filter techniques. Conditions for labeling at a suitable intensity (1–3 dpm/1,000‐µ3 cell volume) were determined. The method is suitable for the detection of nonspecific binding of phosphorus by organic materials and of differential phosphorus uptake by members of a mixed population. It also was used to determine continuity of phosphorus uptake in a cultured diatom.
PHYTOPLANKTON SAMPLING WITH THE SEDGWICK‐RAFTER CELL1
Authors: McAlice Bernard J.
Published: March 2010

Quantitative processing of large numbers of phytoplankton collections requires a sampling method that will yield precise and reproducible estimates of abundance within an acceptably short counting time. A two‐stage sampling plan was developed, using the Sedgwick‐Rafter cell, which satisfies these criteria. The sampling design is appropriate for larger phytoplankton species (> 10–15 µ) having relatively high population densities (⩾ 105 cells/liter) .
CHEMICAL AND PHYSICAL OBSERVATIONS IN GOLFO, DULCE, AN ANOXIC BASIN ON THE PACIFIC COAST OF COSTA RICA1
Authors: Richards Francis A. , Andwso James J. , Cline Joel D.
Published: March 2010

Golfo Dulce is an embayment containing small concentrations of hydrogen sulfide near the bottom due to sulfate reduction. The processes of denitrification, nitrate reduction, and organic decomposition are also evident. Hydrographic data taken 8 days apart indicated an influx of ocean water into the basin. It appears from past observations in the eastern tropical Pacific that the basin erratically receives ocean water during winter and spring.
ENERGY FLOW IN A NATURAL POPULATION OF THE HERBIVOROUS GASTROPOD TEGULA FUNERRALIS1
Authors: Paine Robert T.
Published: March 2010

The gastropod Tegula funebralis (A. Adams, 1855) is confined to the intertidal. At Mukkaw Bay, Washington, it typically occurs in patches of characteristic individual size structure. Various energy flow parameters have been determined for a high intertidal (+ 1.8 to +0.9 m) and a low intertidal (+0.6 to −0.15 m) subpopulation; these values were then combined in a 3:1 ratio to generate a composite population.

Direct and indirect calorimetry and direct observation on the natural population suggest the following: Tegula spawns once per year; the dry weight‐shell diameter relationships for males and females can be expressed by a single regression; different caloric values characterize immature (5.2 kcal/ash‐free g), mature males (5.4), intermediately mature females (5.8), and fully mature females (6.1); rates of aquatic and aerial respiration are different (at 13.5C an average low intertidal individual, 211 mg dry wt, respires at a rate of 75 µl O2/hr in water and 43 µl/hr in air).

The energy budget, in which ingestion was obtained by summation, suggests an assimilation efficiency of about 70%, a gross efficiency of growth of 16.7%, and an ecological efficiency of predators of 4.9%. Other efficiencies are discussed. In Tegula, 60% of energy transferred to other levels is to decomposers. Comparison of the rate of annual consumption by Tegula, 1,071 kcal m− 2 yr−1, and net primary production estimated by cropping, 1,167 kcal m−2 yr−1, indicate a near balance. Importation of primary production may be necessary to the maintenance of the rocky intertidal community at Mukkaw Bay.
RETENTION OF DISSOLVED ORGANIC ACIDS IN SEAWATER BY VARIOUS FILTERS1
Authors: QUINN JAMES G. , MEYERS PHILIP A.
Published: March 2010

Dissolved fatty acids and natural lipid material containing these acids are removed from seawater by certain filters commonly used to separate dissolved from particulate organic matter. Whatman 54 filter paper was the least retentive of the filters tested and is recommended for the isolation of dissolved lipids in seawater.
PATTERN IN THE DEVELOPMENT OF A MARINE COMMUNITY1
Authors: Eager Edward W.
Published: March 2010

The development of a community on experimental 1‐m cubes of asbestos board on iron frames placed at 12–14‐m depth off La Jolla has been examined in terms of the processes leading to patterns of distribution. Differences between the cubes in vectorial factors were kept to a minimum. However, vectorial processes affecting them all, especially water movement, were important in forming and maintaining the community. Only one pattern was clearly ascribable to reproductive processes: spread of a budding anemone. Patterns due to social action were seen in the schools of fish that fed around the cubes. There was competition for space between the anemone and a bushy bryozoan. Competition was not evident within several congeneric pairs that were prominent components of the community. Chance processes appeared to be the causes of differences between the cubes in species composition and size of the large brown algae and in the occurrence and abundance of small fish and nudibranchs. The algae were major contributors to the physical structure of the community; the fish and nudibranchs were important in the food web. The similarities of this community with other more complex ones were considerable: the key role of “detritus,” the constant flux of individuals and species, the stability of numbers of many species, and the qualitative and quantitative variations on a basic species list.
WORLDWIDE DISTRIBUTION AND ECOLOGY OF EURYCERCUS AND SAYCIA (CLADOCERA)1
Authors: Frey David G.
Published: March 2010

The two species of Eurycercus are largely allopatric in the Northern Hemisphere, glacialis tending to be peripheral in distribution in the far north, occurring only as far south as 51‐52° N in the outer Aleutians, Labrador, and the northern Kuriles. There are vigorous disjunct populations of unknown history in oligotrophic heath and dune localities in Denmark and the Netherlands. The center of distribution is Greenland–Iceland. Eurycercus lamellatus is widely distributed over much of continental North America south to Mexico City and over much of Eurasia south to Algeria and southern Tibet. It also is known from farther north than glacialis. It is the only species occupying the large mountain masses of the Northern Hemisphere, where glacialis might be expected to occur. The center of distribution seems to be western Europe. Co‐occurrence of the two species in the same water bodies is known only for a few scattered lakes in Denmark, northern Sweden, Iceland, and Alaska.

Eurycercus lamellatus also occurs as disjunct populations in Argentina and South Africa, but not at comparable latitudes in Australia and New Zealand. Here, Saycia cooki occurs, which might be considered an ecological equivalent of E. lamellatus except that it is confined to temporary water bodies.

The finding of three males of Saycia from Australia—the first males ever recorded— stimulated a detailed study of the morphology of the species and a comparison with Eurycercus. Retention of the two genera in separate subfamilies seems justified. The male of Saycia is unique among chydorid Cladocera in having a plumose sexual seta on the antennule and in having the postabdominal claw spatulate at the tip. The sperm ducts open near the tip of the postabdomen, rather than at the base as in Eurycercus, the latter condition being unique among the chydorids.

Saycia from New Zealand differs from the population in Australia chiefly in having more preanal teeth on the postabdomen and in being higher and having a shorter posterior margin relative to length of the animal. All these characters change with size. These regressions are presented and their significance discussed. The New Zealand population has been designated a new geographic subspecies, pending the eventual recovery of males.

The number of postabdominal teeth in E. lamellatus increases with increasing size, making it likely that the species described as E. polyodontus merely represents individuals from the upper end of this regression. The number of teeth in E. glacialis is smaller than in lamellatus and does not increase with size of animal. The variability of tooth number within each species is so great that the number 100 proposed in the past cannot be used to separate the two species with any reliability. Similarly, the subspecies of Saycia from New Zealand has a larger tooth number, which shows a marked increase with size of animal, than that from Australia.
ENVIRONMENTAL CONTROL OF THE ABUNDANCE AND DISTRIBUTION OF THE CHYDORID CLADOCERA1
Authors: Goulden Clyde E.
Published: March 2010

Littoral populations of chydorid Cladocera were studied in 1968 and 1969 at 3 collection areas in Lake Lacawac, Pennsylvania. The station on the sandy leeward margin of the lake had peak populations in spring, the one on the detritus rich windward shore peaked in late summer and fall, and the one at the interface between the sandy and detritus‐rich shores had peak populations in both spring and fall. At all areas the chydorids were least abundant in summer.

There appeared to be ample food available in summer; chydorids were still able to reproduce after water temperatures had reached the summer maximum; and potential competitor species did not increase as chydorids decreased. Observations indicated that the summer population minimum was largely caused by predaceous tanypodine midges. The midges were most common, and the number of chydorids in their guts increased, just before major chydorid population declines. The midges were rare or absent in spring and fall when chydorids were most abundant.

Eight species of tanypodines were found in the lake. Three were common from mid‐May to June; the others occurred in July. The first pulse of midges in June devastated the chydorid populations. The second pulse appeared only after the chydorids had recovered and began to develop large populations.
A 22,000‐YEAR POLLEN RECORD FROM THE PLATEAU OF ZAMBIA
Authors: Livingstone D. A.
Published: March 2010

Pollen analysis of a core from Ishiba Ngandu in Zambia reveals only one significant change in the pollen assemblage laid down over a period of 22,000 yr. About 3,000 B.P. a number of taxa characteristic of moist to dry evergreen forest at low, moderate, or high altitudes declined from very low levels to even lower ones. This decline was probably both relative and absolute. At the same time a small group of taxa that grow in both swamp forest and savannah increased in a relative sense, although probably not in absolute deposition rate. Possibly this change represents the effects of agriculturalists on the vegetation.

Neither montane forest nor moist forest of low and intermediate altitudes appears to have grown in this part of Zambia during the past 22,000 yr. The lack of dramatic changes in pollen cannot be attributed with any assurance to a stable climate, however, because it is unlikely that the vegetational changes to be expected if the rainfall changed by as much as 50% from the present mean level would be recognizable by pollen analysis.
DEEP‐SEA AMPHIPODA FROM THE WESTERN NORTH ATLANTIC OCEAN. THE FAMILY AMPELISCIDAE1,2
Authors: Mills Eric L.
Published: March 2010

Eleven species of Ampeliscidae (Amphipoda) occur on a deep‐sea benthic transect between Massachusetts and Bermuda. Two species of Byblis and one of Byblisoides are newly described; Ampelisca uncinata Chevreux, Byblis gaimardi (Krøyer), B. serrata Smith, Haploops setosa Boeck, and H. similis Stephensen are redescribed or refigured; and new distributional or ecological information is given for Ampelisca aequicornis Bruzelius, A. agassizi (Judd), and A. declivitatis Mills. There is a rough taxonomic and ecological zonation of Ampeliscidac, with species of Ampelisca in shallow water, blind species of Byblis on the continental slope, species of Haploops on the slope extending into the abyss, and an endemic species of Byblisoides at fully abyssal depths which is adapted for feeding on large quantities of abyssal sediments by having strongly‐modified second antennae and massive antennal muscles. Bathyal species of Byblis and Haploops also appear to be sediment or suspension feeders but are less strongly modified.

Zoogeographic affinities of the species are varied, especially on the continental slope. Shallow‐water species are Virginian and Carolinian, outer shelf species may range to north or south (but not both), and the Byblisoides is endemic to the North American Basin. The bathyal species are widespread around the North Atlantic or closely related to species from the northeast Atlantic.
CHEMICAL EXCHANGES BETWEEN SEDIMENTS AND WATER IN THE GREAT LAKES‐SPECULATIONS ON PROBABLE REGULATORY MECHANISMS1
Authors: Mortimer C. H.
Published: March 2010

As long as the oxygen concentration at the sediment surface does not fall below 1 or 2 mg/liter, typical deep‐water sediments in the Great Lakes will probably be found to exert a measurable but quantitatively unimportant influence on the chemistry of the overlying waters. This conclusion is supported by the case of Windermere.

The sequence of more conspicuous changes that take place when the oxygen does fall below 1 mg/liter at the interface is illustrated by the case of Esthwaite Water, representative of events in lakes where biological production or organic pollution is high, where the subthermocline volume is relatively small, or both. A progressive decline in oxygen concentration from 2 mg/liter to analytical zero at the interface was accompanied by a fall in electrode potential in the upper few millimeters of sediment, correlated with mobilization and transfer into the water first of manganese and later of iron. There is a concurrent transfer into the water of substantial quantities of phosphate, previously held in complex form, which may have important biological consequences. Other changes include liberation into the water of ammonia and silicate. Further reduction of the water‐sediment system permits microbial reduction of sulfate.

A third example of sediment‐water exchange occurs during winter stratification under ice cover. In Torneträsk, in the course of 95 days of ice cover, a relatively thin layer of bottom water, initially at 1C, gained heat and bicarbonate from and lost oxygen to the sediments. The density increase, arising from the heat gain, set density currents in motion that drained this contact water into the deepest parts of topographically isolated subbasins.
THE EFFECTS OF INCREASING LIGHT AND TEMPERATURE ON THE STRUCTURE OF DIATOM COMMUNITIES
Authors: Patrick Ruth
Published: March 2010

The results of studies concerning the effects of artificially increasing temperature and naturally and artificially increasing day length are discussed. Naturally increasing day length was more favorable for community development than increasing clay length by artificial light. Increasing temperature is most beneficial when temperatures are near 0C. Moving away from the limits of tolerance at either end of the range produced the greatest changes in the structure of diatom communities. Intermediate changes near the optimum range produced less predictable results. One new variety of Gomphonema olivaceoides is described.
ALLOMORPHOTIC RELATIONSHIP OF ANTENNA TO BODY LENGTH IN EUDIAPTOMUS VULGARIS SCHMEIL
Authors: Tonolli Livia
Published: March 2010

Lengths of head plus first thoracic segment and of antennule in 8,400 adult females of Eudiaptomus vulgaris Schmeil, collected in 12 stations of Lake Maggiore during 14 cruises, are positively correlated, but the relationship suggests that these measurements are simply two estimates of the same variate, the size of the copepod. This is a problem of individual allomorphosis. The analysis of covariance demonstrated that the most important source of variation can be ascribed to the seasonal cycle, as it appears from the decomposition of the adjusted value of the length of antennule in “between months,” “between stations,” and “interaction.” Within samples the departure from linearity was not significant, while between samples the regression was quadratic. Temperature is the physical parameter showing the most obvious fluctuation during the year. The analysis of its relationship with the two morphological characters of the copepod demonstrates that the relative length of the antennule is affected by another factor beside temperature, but this other factor has not been identified.
A PHYSICAL‐CHEMICAL STUDY OF THE FLUSHING OF THE SANTA BARBARA BASIN1
Authors: Sholkovitz Edward R. , Gieskes Joris M.
Published: March 2010

Detailed vertical profiles of salinity, temperature, oxygen, nitrate, phosphate, nitrite, and silicate have been taken on 6 cruises over a 14‐month period in the Santa Barbara basin. In May 1970, during a period of intense upwelling, the temperature, oxygen, and nitrate content of the basin water from the sill (475 m) to the bottom (580 m) showed significant changes from their normal conditions: the oxygen content increased from 0.05–0.10 ml/ liter to 0.35–0.43 ml/liter; the nitrate concentration, which previously decreased markedly below the sill due to nitrate reduction showed little nitrate reduction; and the temperature decreased by 0.14–0.19C. The results from 2 subsequent cruises in June and July 1970 kinetically follow the basin water back to its normal conditions. After 2 months the oxygen content had almost returned to normal with a measured average oxygen consumption rate of 1.3 ml liter−1 yr−1, while the water temperature rose at a rate of 0.02–0.04C/ month. These data indicate that the Santa Barbara basin was flushed out with seawater coming over the sill. This first direct evidence for the flushing of any California basin suggests that its oceanography is dynamic and that it is capable of flushing on a shorter time scale than previously thought.