bluuebunny/crossref_metadata_2025 huggingface dataset:
COMPARISON OF FILTERING RATES OF DAPHNIA ROSEA IN LAKE WATER AND IN SUSPENSIONS OF YEAST1
Authors: Burns Carolyn W. , Rigler F. H.
Published: March 2010

Filtering rates of Daphnia rosea in natural lake water and in pure cultures of a yeast, Rhodotorula glutinis, were measured by adding 32P‐labeled yeast cells to the medium. The effects of the concentration of food, body length, and water temperature on filtering rates and feeding rates were examined. Results showed that filtering rate increased with increasing body length and increasing temperatures up to 20C. Above a concentration of 0.25 × 105 yeast cells/ml, filtering rate decreased with increasing cell concentration; below this concentration, filtering rate was maximal.

From the results of these experiments, theoretical maximum filtering rates for the Daphnia population in Heart Lake over summer were predicted. A comparison of these theoretical rates and those measured in lake water in the laboratory revealed that from June to November the Daphnia were filtering at less than maximal rates.
RED WATER IN LA JOLLA BAY, 1964–19661
Authors: Holmes R. W. , Williams P. M. , Eppley R. W.
Published: March 2010

Five red water dinoflagellate blooms took place in La Jolla Bay, California, between May 1964 and Deeember 1966. Predominant organisms were Gymnodinium spp. and Cochlodinium spp. (May 1964), Prorocentrum micans (April 1965) and Gonyaulax polyedra (June–July 1964, June—July 1965, and December 1966). Cell concentration and chlorophyll a content were measured during each bloom with values up to 20 × 106 cells/ liter and approximately 500 µg chlorophyll a/liter. During the day, the organisms appeared in discrete patches that apparently dispersed at night. Cell carbon and nitrogen content of the organisms often exceeded that available in surface waters or in the water column. Cells must be concentrated both vertically and horizontally to account for the numbers observed in patches during the day. Even in the densest patches the cells appeared to be physiologically active based upon measurements of photosynthetic rate, nitrate reductase activity, and observed motility. Decline of blooms was associated with increases in dissolved organic carbon, orthophosphate and monophosphate esters. The May 1964 bloom was decimated by grazing of Polykrikos sp., Noctiluca sp., and rotifers. A steep shallow thermocline was associated with the blooms.
ZOOPLANKTON STANDING CROPS IN A NEW AND AN OLD OZARK RESERVOIR
Authors: Applegate Richard L. , Mullan James W.
Published: March 2010

The zooplankton populations (April 1964 through June 1966) of Beaver Reservoir before full impoundment are compared with those of 14‐year‐old Bull Shoals Reservoir, both on the White River in the Arkansas‐Missouri Ozarks. Seasonal standing crop estimates show a unimodal curve in the old reservoir and a bimodal curve in the new reservoir. Significant seasonal differences between the reservoirs occurred in densities, species composition of cladoceran communities, and horizontal distribution. An increase in the standing crop in the new reservoir in spring 1966 was associated with species changes within the genus Daphnia. Mean annual standing crops of entomostracans and rotifers were similar in the two impoundments.
PRIMARY PRODUCTIVITY IN SURFACE WATERS OF THE SOUTH PACIFIC OCEAN1
Authors: Burkholder Paul R. , Burkholder Lillian M.
Published: March 2010

Chlorophyll a and carbon assimilation were studied during cruises 13, 14, and 15 of the RV Eltanin, operating in the Antarctic convergence region of the South Pacific Ocean, during May–December 1964. Chlorophyll a was generally distributed uniformly at different depths in the euphotic zone, varying with season and location, but the average ranged from 0.1 to about 0.3 mg/m3. Values up to 2.58 mg/m3 were observed in surface waters near New Zealand during December. On the three cruises, carbon assimilation (mg C m−3 hr−1) in surface waters, determined at light saturation in a fluorescent incubator, averaged 0.075, 0.154, and 0.366 at stations in the region south of the convergence and 0.216, 0.258, and 0.392 at stations just north of it. The average primary production (mg C m−2 day−1) on each of the three cruises was 0.8, 26.3, and 152.2 south of the convergence and 2.2, 38.3, and 175.1 just north of it.
LABORATORY CULTURE, GROWTH RATE, AND FEEDING BEHAVIOR OF A PLANKTONIC MARINE COPEPOD1
Authors: Mullin Michael M. , Brooks Elaine R.
Published: March 2010

Rhincalanus nasutus was cultured through seven consecutive generations in 19‐liter carboys when provided with a mixture of diatoms and Artemia salina nauplii as food. The mean generation length was 8.7 weeks, similar to that of the local field population of this species during some seasons. Fecundity of laboratory‐reared animals was lower than that of the field population. Instantaneous coefficients of individual exponential growth (k in the expression, W = W0 ekt, where W is body weight of organic carbon and t is days) were 0.24 to 0.12/day, depending on the age of the individual. About 10 µg of detrital carbon were produced as exuviae during the growth of an individual. Even young nauplii fed preferentially on large food particles. The suggestion that the copepods’ first antennae are used in the feeding process was not supported by an experimental test. R. nasutus nauplii are apparently active enough to avoid being eaten by their parents.
STANDING CROP, VERTICAL DISTRIBUTION, AND MORPHOMETRICS OF AMMONIA BECCARII (LINNÉ)1
Authors: Brooks Albert L.
Published: March 2010

Certain aspects of the ecology and the biology of the foraminifera Ammonia beccarii were investigated.

The top 4 cm c replicate core samples from near the entrance to the West Passage of Narragansett Bay, Rhode Island, taken in 1963 were individually examined; presumed living and dead specimens were found at all four levels. Data on over 5,000 living and 7,500 dead specimens were collected from 283 samples.

The use of a two‐stage sampling technique for determination of an optimum number of samples is described. The frequency distributions of the numbers of both presumed living and dead A. beccarii could be normalized successfully with a log (X + 1) transformation.

At each of the four levels, the numbers of both living and dead individuals remained statistically constant, and the number of presumed living A. beccarii was the same in the three top 1‐cm levels but significantly greater there than at the fourth, while there were significantly fewer dead specimens in the first centimeter than in the third and fourth.
NUTRIENT LIMITATION IN THE SEA: DYNAMICS, IDENTIFICATION, AND SIGNIFICANCE1
Authors: Dugdale R. C.
Published: March 2010

A mathematical model has been constructed to provide a theoretical framework for the investigation and discussion of nutrient limitation in the sea. The euphotic zone is divided into nutrient‐limited and light‐limited regions. For simplicity, the regeneration term is ignored, and a steady state is assumed. The uptake of major nutrients is assumed to follow the Michaelis‐Menton expression, and some data indicate that the assumption is probably correct. Also assuming a dominant phytoplankton population, with characteristic Michaelis‐Menton kinetic parameters, it is demonstrated that the size of the population, fractional growth rate, the rate of production, and the concentration of limiting nutrient are determined by the sum of the fractional loss rates for the phytoplankton. The role of micronutrient components of enzymes is developed theoretically using the effect of molybdenum on a nitrate‐limited system as an example.

For the sea, the significance of nutrient limitation theory is primarily in the study of phytoplankton competition and succession. Applications to lakes are discussed, and it appears that the effects of micronutrient deficiencies are more likely to be observed there than in the sea.
ENVIRONMENTAL PARAMETERS AND MARSH FORAMINIFERA1
Authors: Bradshaw John S.
Published: March 2010

Continuous records of the following environmental factors were made in a marine marsh: air and water temperature, light intensity, wind speed, oxygen concentration, pH, Eh, sodium ion, sulfide ion, salinity, and tide height. Vertical changes in pH, Eh, oxygen, and sulfide were relatively large compared to other variations. Horizontal differences in pH and oxygen were due to varying amounts of vegetation. Variations due to tidal action affected all water parameters. At ebb tide, salinities increased from approximately 34‰ to as much as 50‰, while pH decreased from approximately 8.2 at high water to as low as 6.8. Diurnal variations were large, with per cent oxygen saturation values varying from approximately 10% to as high as 270%. Maximum and minimum values as well as the per cent of time these values fall between a given set of conditions are presented and various applications to seasonal occurrences of Foraminifera are discussed.
MACROINVERTEBRATE COMMUNITIES OF THE SEDIMENTS OF HAMILTON BAY AND ADJACENT LAKE ONTARIO
Authors: Johnson M. G. , Matheson D. H.
Published: March 2010

The distribution and abundance of benthic macroinvertebrates in Hamilton Bay and adjacent Lake Ontario were related to physical and chemical characteristics of the water and sediments and to hydrodynamic factors. The profundal sediments of Hamilton Bay, rich in organic matter, contained an abundance of Limnodrilus hoffmeisteri and Tubifex tubifex, while lesser numbers of five Limnodrilus species occupied poorer sublittoral sediments. No macroinvertebrate community occurred in sediments containing more than 25% Fe2O3. The combination of more favorable water chemistry, circulation, and moderately rich sediments near the canal connecting the bay with Lake Ontario increased biomass of oligochaetes over that in the richer, profundal sediments of the main basin of the bay. In Lake Ontario the oligochaetes, L. hoffmeisteri, T. tubifex, and Stylodrilus heringianus and the amphipod, Pontoporeia affinis increased in numbers with increasing depth and richness of sediments. Emissions of bay water to Lake Ontario clearly influenced the specific composition of macroinvertebrate communities. The community of several oligochaetes and Chironomus attenuatus found in the lake near the canal resembled the sublittoral bay community. T. tubifex occurred in the lake only in the plume of rich sediments projecting into the lake from the canal, while sphacriid populations were more abundant and contained more species in the sandy or loamy sediments outside the plume.
RECENT STUDIES ON THE ROLE OF MICROORGANISMS IN THE CYCLING OF SUBSTANCES IN LAKES1
Authors: Kuznetsov S. I.
Published: March 2010

This paper presents a review of current trends in research in the Soviet Union on the ecology of aquatic bacteria. The paper shows an increasing emphasis on in situ measurements of the rate or extent of conversion of carbon, nitrogen, sulfur, and iron from one form to another and on the bacteria responsible for these conversions. Theoretical considerations and results of several studies are summarized. These include measurement of bacterial biomass production and nitrogen fixation with isotopes, factors affecting decomposition of water humus in bog lakes, annual succession of iron bacteria in relation to the cycling of iron, nitrogen exchange between bottom sediment and benthic waters, the concept and calculation of nitrogen balance in a lake, and the bacteria responsible for the oxidation of sulfur. An attempt is made to incorporate this information into flow diagrams showing the dynamics of the cycling of the four elements discussed.
CHARACTERIZATION OF PHOTOSYNTHETIC SULFUR BACTERIA CAUSING RED WATER IN LAKE FARO (MESSINA, SICILY)1
Authors: Trüper Hans G. , Genovese Sebastiano
Published: March 2010

The meromictic saline Lake Faro (Messina, Sicily) contains a layer of brownish‐red water at the interface between hypo‐ and epilimnion, the depth of which varies between 8 and 13 m. The photosynthetic sulfur bacteria that cause this phenomenon were isolated and described. The predominant organism of the red water is the brown photolithotropic bacterium Chlorobium, phaeobacteroides Pfennig (Chlorobacteriaceae). In addition, a small, violet Chromatium species (Thiorhodaceae) was isolated, which had been observed in smaller numbers in the red layer. Although the Chromatium strain is motile and able to use a considerable variety of organic carbon compounds besides bicarbonate, in the natural environment of the lake the brown Chlorobium finds more advantageous growth conditions; it is suggested that its brown carotenoids allow more effective use of the penetrating wavelengths of daylight.
A PERSISTENT DIURNAL RHYTHM IN CHAOBORUS LARVAE. I. THE NATURE OF THE RHYTHMICITY1
Authors: LaRow Edward J.
Published: March 2010

Larvae of Chaoborus punctipennis Say (Diptera: Culicidae) were maintained under constant conditions in two 152‐ × 10‐cm columns containing lake water and sediments. Visual counts of the larvae in the columns were made hourly with a flashlight equipped with a red filter and darkened reflector. Activity was observed during dark periods; however, no activity was observed during light periods. A diurnal rhythm of activity persisted up to 10 days in constant darkness. The phase of the rhythm was reset by entrainment under differing light regimes, as well as by temperatures of 5C or less. These critical low temperatures also abolished activity. The offset of light was demonstrated to be the Zeitgeber for this rhythm; therefore it is necessary that under natural conditions these larvae receive some offset stimulus from the setting sun.
PHOSPHORUS EXCRETION BY ZOOPLANKTON
Authors: Hargrave Barry T. , Geen Glen H.
Published: March 2010

The excretion of dissolved inorganic and organic phosphorus by several species of marine crustaceans and a planktonic rotifer was measured under laboratory conditions. The rate of excretion decreased as bacterial activity and duration of experiments increased and was directly related to temperature and salinity. Excretion rates were higher in early evening than at other times of day.

The daily phosphorus requirements of the phytoplankton, calculated from 14C measured rates of production and an assumed C : P ratio of 40 : 1, were compared with phosphorus released by zooplankton. The rates of excretion and the abundance of zooplankton were used to calculate an average daily addition of inorganic phosphorus to the photic zone. In Bras d’Or Lake, zooplankton released twice the average daily phytoplankton phosphorus requirement; in Morrison’s Pond, only one‐fifth was supplied by animal excretion. Microzooplankton excretion (not considered in this study) may explain the discrepancy between phytoplankton requirements and regeneration rate in Morrison’s Pond. Phosphorus supplied from the hypolimnion by eddy diffusion in Bras d’Or Lake was one‐tenth that regenerated by the zooplankton.
LIMNOLOGICAL EFFECTS OF ORGANIC EXTRACTS OF LITTER IN A SOUTHWESTERN IMPOUNDMENT
Authors: McConnell William J.
Published: March 2010

Watershed litter in semiarid southeastern Arizona is relatively unleached, and the accumulation of a year or more is occasionally delivered to lakes within the first few days of the summer rainy season. Pena Blanca Lake received at least 750 g/m2 of oak litter during the summer of 1959. About 329 kg cal/m2 were delivered to the lake in oak litter extracts of which 26% were probably from carbohydrates, 54% from phenolic compounds, and 20% from unidentified compounds.

Oak leaf extracts were experimentally effective as an energy source for microorganisms used as food by filter‐feeding organisms (Xenopus laevis) and snails. Efficiency of the extract‐microorganisms‐Xenopus and snail food chain was 3.28%.

Based on an estimated ecological efficiency of 0.56% for the food chain: litter extract‐microorganisms‐zooplankton‐young Micropterus salmoides, Micropterus biomass production may have been increased 0.4 g/m2 by organic components in oak litter extracts contributed to Pena Blanca Lake in 1959. This increase represents 16.7% of the average annual fish harvest for 1959, 1960, and 1961.
OBSERVATIONS OF LIGHT SCATTERING IN SEAWATER1
Authors: Spilhaus A. F.
Published: March 2010

A study of the variability of the volume scattering function in and among water types was made using a standard laboratory device on shipboard. Samples were taken from the surface and at depth. Water in the Sargasso Sea had a significantly different scattering function from that of the slope and coastal waters. In a thermal front, south of Bermuda, the water along one isotherm was different from that on either side of it. The thermohaline front on the edge of the shelf in winter is marked by a threefold change in the magnitude of the scattering.
OBSERVATIONS ON THE DECOMPOSITION OF A MARINE SEDIMENT
Authors: Seki H. , Skelding J. , Parsons T. R.
Published: March 2010

The decomposition of organic material deposited in a small bay has been investigated. With a marine species of Pseudomonas as an assay organism, material deposited during summer and during winter were both actively decomposed. However, differences in the two types of sediment were apparent from the quantities of nutrients and carbohydrate available to the assay organism, as well as to the antibiotic activity of the two sediments.

From calculations on the in situ nutrient and carbon budget for the sediment in the same area, it was determined that nitrogen was regenerated most rapidly, followed by phosphorus and carbon. The rate of sediment decomposition, determined as the ratio of the input of material to the steady‐state level in the sediment, is suggested as a basis for the biological comparison of nearshore marine sediments.
SEASONAL SUCCESSION AND CONGENERIC ASSOCIATIONS OF DIAPTOMUS SPP. (COPEPODA) IN SOME SASKATCHEWAN PONDS1
Authors: Hammer U. Theodore , Sawchyn William W.
Published: March 2010

Seven species of Diaptomus were collected from nine prairie ponds in southern and central Saskatchewan. D. sanguineus, D. stagnalis, D. arcticus, and D. kiseri were found only in spring and early summer samples. D. sanguineus was found in association with each of the last three species. D. stagnalis, D. arcticus, and D. kiseri were never found together. D. leptopus, D. forbesi, and D. nudus appeared in late spring and persisted throughout the remainder of the ice‐free period. Disappearance of D. sanguineus and D. arcticus was associated with the appearance of D. leptopus or D. forbesi. The latter two species did not appear capable of extended coexistence. The size, the seasonal occurrence and life cycle, and the subgenus of each species are important factors that determine the type of congeneric association where Diaptomus species may coexist.
THE ANNUAL CYCLE OF PRIMARY PRODUCTION IN THE SARONICOS GULF (AEGEAN SEA) FOR THE PERIOD NOVEMBER 1963—OCTOBER 1964
Authors: Becacos‐Kontos Theano
Published: March 2010

Measurements of gross primary production were made approximately twice a month from November 1963 to October 1964 in the Saronicos Gulf (Aegean Sea). The in situ 14C method was used. Results showed that gross primary production varied from 70 to 334 mg of C m−2 day−1. The annual gross primary production was calculated to be 64 g of C m−2. A well‐defined maximum of production was found in the early spring (February– March) while on the average changes in production with depth showed a maximum at about 10 m.
ZINC‐65 AND MANGANESE‐54 IN ALBACORE THUNNUS ALALUNGA FROM THE WEST COAST OF NORTH AMERICA
Authors: Pearcy William G. , Osterberg Charles L.
Published: March 2010

Zinc‐65 and manganese‐54 were the dominant artificial radionuclides in the livers of albacore collected along the coast of North America from Washington to Baja California during the summers 1962–1966. The concentrations and specific activities of these radionuclides changed considerably during summer, indicating rapid responses to different radioecological conditions.

Off Oregon and Washington 65Zn levels, as well as specific activities, in albacore increased markedly during summer months. Association of albacore with the effluent of the Columbia River accounted for this enhancement. The 65Zn concentrations of albacore from southern and Baja California were about 10% of those off Oregon and Washington with no seasonal trends evident. Highest radioactivities per gram and specific activities of 65Zn were found late in summer off Oregon. The 65Zn concentrations off southern Oregon at this time were as high as those off northern Oregon near the mouth of the Columbia River, probably because of the southward drift of plume waters coupled with the lag time for accumulation of 65Zn through several trophic levels. We have no evidence either for immigration of 65Zn‐tagged albacore into the southern California fishery or for immigration of southern albacore, with low 65Zn content, into the northern fishery during one season.

Manganese‐54 enters the ocean primarily from fallout of nuclear weapons tests. Both the radioactivity and the specific activity of 54Mn in albacore off Oregon and Washington decreased during summer. Thus 54Mn appeared to be more available to albacore in offshore waters than in the nearshore waters. The levels of 54Mn in albacore were rather similar during the years of this study; this was unexpected since all the 54Mn presumably originated from 1961–1962 nuclear weapons tests.
MEASUREMENT OF DEOXYRIBONUCLEIC ACID IN THE OCEAN AND ITS ECOLOGICAL SIGNIFICANCE1
Authors: Sutcliffe William H. , Sharp Jonathan
Published: March 2010

A method is described for the quantitative determination of deoxyribonucleic acid (DNA) by measurement of the fluorescence of the complex formed by incubating samples containing DNA with diaminobenzoic acid dihydrochloride. The sensitivity and range (from 0.2 to 40‐µg of DNA) of this method permit DNA determination on seawater samples of 1 liter or less from the euphotic zone and on 1 to 4 liters from deep samples. The concentration of DNA has been measured at various stations in the Atlantic and Pacific oceans, together with measurements on chlorophyll, zooplankton, and organic carbon and nitrogen of the particulate material. These data are discussed in relation to the possible use of DNA as a biomass indicator.

The DNA content of laboratory cultured cells of Skeletonema costatum, Dunaliella tertiolecta, and Monochrysis lutheri have been determined relative to the cellular contents of organic carbon, nitrogen, and chlorophyll. When expressed as a percentage of the total cellular dry weight, the DNA contents of these three marine phytoplankton species were 0.43, 0.66, and 0.40%, respectively.
A SIMPLE METHOD OF ASSESSING THE ANNUAL PRODUCTION OF STREAM BENTHOS1
Authors: Hynes H. B. N. , Coleman Mary J.
Published: March 2010

It is possible to calculate the annual production of stream benthic animals from data obtained from a series of good quantitative samples collected at intervals during the year. The method is explained and its limitations and shortcomings are discussed. This seems at present to be the only simple and direct method of estimating production.
AN INCUBATION METHOD FOR ESTIMATING THE CARBON CONTENT OF PHYTOPLANKTON IN NATURAL SAMPLES1
Authors: Eppley Richard W.
Published: March 2010

In this method, the phytoplankton standing stock as carbon was calculated from carbon assimilation rates, measured at 24 and 48 hr, during incubation of seawater samples on shipboard. The method requires exponential growth at constant specific growth rate of the phytoplankton in the sample during incubation and relies on the fact that the rate of synthesis of cell substance is proportional to the quantity of cell substance present. Growth was so extensive that nutrients had to be added to the samples before the 48‐hr incubations to maintain exponential growth. Light intensity during incubation affected results, and matching the incubation intensity to that in situ seemed best. Carbon: chlorophyll a ratios found in phytoplankton off La Jolla, California, averaged about 90 in nutrient‐depleted surface layers and about 30 in deeper, nutrient‐rich water. Photosynthetic rates per unit chlorophyll a, calculated from 24‐hr incubations, were high due to chlorophyll a synthesis during incubation.
PROPERTIES OF THE YELLOW ORGANIC ACIDS OF NATURAL WATERS1
Authors: Ghassemi Masood , Christman R. F.
Published: March 2010

Gel filtration profiles obtained from a variety of naturally colored waters indicate that color producing molecules are mostly in the apparent molecular weight range of 700–10,000 relative to dextrans. One fraction seems to have a molecular weight in excess of 50,000. The apparent size of the color molecules was found to be pH dependent, increasing as pH increases. Size increases are attributed to increased functional group ionization and a decrease in the adsorbability on Sephadex.

The degree of association of color molecules with iron was also found to be pH dependent, being greater at both high and low pH than in the range of 7–8.
OBSERVATIONS ON THE DISTRIBUTION AND BREEDING OF SAGITTA ELEGANS (CHAETOGNATHA) IN COASTAL WATERS OF THE GULF OF MAINE
Authors: Sherman Kenneth , Schaner Everett G.
Published: March 2010

The chaetognath Sagitta elegans Verrill in the coastal waters of the Gulf of Maine undergoes seasonal fluctuations in abundance, progressing from a spring low to a summer high and declining in fall and winter. These fluctuations are related to the breeding cycle; one generation of S. elegans is produced annually. Breeding extends from spring through fall; maturing specimens dominate in winter and immature specimens in summer. Death of mature individuals after breeding appears to cause the spring population decline. Areal differences in abundance are influenced by the dominant nontidal drift, which moves southwesterly along the Maine coast. In winter, when the drift is poorly developed, S. elegans is evenly distributed along the coast. Numbers increase progressively westward in summer and fall with the development of nontidal drift; they reach an annual peak in the western area (Cape Elizabeth, Maine, to Cape Ann, Massachusetts) during fall. Concentrations of S. elegans along the coast are apparently the result of local breeding. There is no evidence of large‐scale transport of S. elegans to local areas from other breeding centers in the Gulf of Maine.
VERTICAL DISTRIBUTION AND ORGANIC MATTER PRODUCTION OF PHOTOSYNTHETIC SULFUR BACTERIA IN JAPANESE LAKES
Authors: Takahashi Masayuki , Ichimura Shun‐ei
Published: March 2010

The role of photosynthetic sulfur bacteria as primary producers in stagnant lakes having hydrogen sulfide is described. Photosynthetic bacteria normally appear at the boundary layer of the oxidative and reductive zones, where H2S is present and the light intensity is lower than 10% of the surface value. The water of this layer was milky green or pink due to dense populations of Thiorhodaceae or Chlorobacteriaceae. The amount of photosynthetic bacterial biomass measured on a chlorophyll basis ranged from 100 to 828 mg/m3 for Chl‐650, 60.7 to 79.5 mg/m3 for Chl‐660, and 19.8 to 186 mg/m3 for BChl in the growing period from July to October.

In the lakes studied, organic matter was produced by phytoplankton in the epilimnion and mainly by photosynthetic sulfur bacteria in the reducing zone. The organic matter synthesized by these bacteria ranged from 9 to 25% of the total annual production in lakes rich in H2S and from about 3 to 5% in lakes poor in it.
USE OF MODIFIED DIURNAL CURVES FOR THE MEASUREMENT OF METABOLISM IN STANDING WATER.
Authors: Welch Harold E.
Published: March 2010

A modification of diurnal oxygen curves is described, whereby community metabolism can be easily estimated from a succession of twice‐nightly points. The method can be adapted to stratified limnetic waters by using suitable sampling techniques. Results of a study using the method are given for a small, fertile Georgia farm pond. Gross photosynthesis averaged 6.0 g O2 m−2 day−1, ranging from 1.0 to 14 g O2 m−2 day−1. The approximate net loss of oxygen due to diffusion was 101.1 g O2 m−2 yr−1, less than 5% of total gross photosynthesis.
VERTICAL DENSITY CURRENTS—II1
Authors: Bradley W. H.
Published: March 2010

Examples of vertical density currents wholly within the domain of laminar flow, one in a water solution, the other in air, have come to my attention. Both examples illustrate new ways of introducing and dispersing microscopic particles into static fluids and both demonstrate that a stable, clearly defined layer of dispersed particles forms first and that the vertical density currents originate and flow from the lower part of this layer. The new information comes from wholly unrelated lines of research, one in virology, and the other in mycology. Neither investigation was aimed at hydrodynamics yet both provide good experimental support for vertical density currents.
SOME OBSERVATIONS OF THE DIURNAL HEAT WAVE IN THE OCEAN1
Authors: Howe M. R. , Tait R. I.
Published: March 2010

The diurnal heat wave was observed over several days at a station in the subtropical North Atlantic Ocean. Measurements were made every 30 min using an in situ temperature‐salinity‐depth recorder; the isotherms were plotted (to an accuracy 0.01C) at 2‐m depth intervals. For a day of average conditions, the maximum penetration of the discernible heat wave was to about 30 m, but throughout the cycle approximately 80% of the gain of heat in the water column was confined to the top 14 m. Estimates of the coefficient of vertical eddy diffusion were made at several depths, and for the top 4 m the daily values varied between 93 cm2/sec and 432 cm2/sec.
THE FATTY ACID COMPOSITION OF ARCTIC MARINE PHYTOPLANKTON AND ZOOPLANKTON WITH SPECIAL REFERENCE TO MINOR ACIDS1
Authors: Lewis R. W.
Published: March 2010

Collections of phytoplankton and of one species of zooplankton, the amphipod Apherusa glacialis, were made from the same area of the Chukchi Sea off Barrow, Alaska. The collections were analyzed for fatty acids, including branched‐chain acids and positional isomers.

The phytoplankton contained iso and anteiso odd‐numbered acids that have not previously been reported from diatoms. In other respects, the composition was similar to that of diatoms from the North Sea. The amphipods had a simpler fatty acid composition with smaller amounts of polyenoic and branched‐chain acids than the phytoplankton.
SEASONAL COMPOSITION OF TEMPERATE PLANKTON COMMUNITIES: FREE AMINO ACIDS1
Authors: Jeffries H. Perry
Published: March 2010

In marine plankton, the patterns of seasonal succession and free amino acid composition reveal several features in common. Free amino acid levels are generally higher in summer than in winter communities: major changes occur during periods of community change in late spring and early winter. These levels also appear to be an index of physiological condition and productive capacity. The variations are quantitative in terms of concentration per unit tissue weight; relative compositions are the same in both the summer and the winter dominant copepods (Acartia tonsa and Acartia clausi).

Factor analysis reveals an extremely high degree of intercorrelation within the free amino acid pools. The phytoplankton‐microzooplankton, consisting primarily of diatoms and larval crustaceans in varying proportions, has greater consistency of quantitative change (one amino acid in relation to all others) than does the zooplankton. Furthermore, the amino acid communality of an estuarine phytoplankton‐microzooplankton community is surprisingly high.
ZOOPLANKTON STANDING CROP IN THE ARCTIC BASIN1
Authors: Hopkins Thomas L.
Published: March 2010

An estimate of zooplankton standing crop in the central Arctic Ocean was obtained from 118 closing‐net samples collected from Ice Islands T‐3 and ARLIS II. The T‐3 samples were taken from the anticyclonic gyre in the Amerasia Basin north of Alaska; the ARLIS II samples were collected from the Eurasia Basin north of Greenland.

Copepods were the most important group, constituting over 80% of the biomass. The most important genus was Calanus, which averaged half the biomass in the upper 1,500 in. Below 1,500 m the relative importance of Calanus declined. Copepods were also the most numerous (90%) metazoan plankters, though they were outnumbered by small radiolarians in the upper 100 m from July to early September.

There was some evidence of a summer (July–August) increase in biomass in 0–100‐m samples from T‐3 and an increase in ARLIS II 0–100‐m samples from March to January as ARLIS II drifted towards Greenland. Average biomass concentrations for the three principal water masses of the Arctic Ocean were 0.62 mg dry wt/m3 for the Arctic surface layer (0–200 m), 0.14 mg/m3 for the Atlantic layer (200–900 m), and 0.04 mg/m3 for the Arctic deep‐water mass (>900 m). Total zooplankton biomass in the central Arctic was estimated at 1–2 × 106 metric tons (dry weight). Calculations based on available primary production data suggest that photosynthesis alone cannot meet the metabolic demands of the biomass of zooplankton in the central Arctic Basin.
EFFECT OF CLAY ON THE AVAILIABILITY OF DILUTE ORGANIC NUTRIENTS TO STEADY‐STATE HETEROTROPHIC POPULATIONS1
Authors: Button D. K.
Published: March 2010

The effect of clays on the availability of small organic molecules to microorganisms was determined. Recovered suspended sedimentary material and Bentonite was tested for its ability to compete with yeast and bacteria for thiamine or glucose in continuous culture systems at low organism concentrations. The added clays do not render the organics tested unavailable to microorganisms or remove them from solution to a detectable or significant extent. The addition of clays can, however, effect a perturbation to the steady system, possibly by altering the inorganic chemistry of the dissolved phase.
STUDIES ON THE DISTRIBUTION OF COBALT IN LAKES
Authors: Parker Michael , Hasler Arthur D.
Published: March 2010

Cobalt‐57 was added to bottles of lake water to see whether there were any seasonal changes in the apportionment of cobalt between solution (filtrate) and seston after 24‐hr incubation or whether any differences in this distribution could be found between lakes.

Several distinct patterns in the seasonal apportionment of 57Co between “solution” and seston were observed, but no explanation of the basic mechanism causing these changes is offered. In two of the lakes there was a statistically significant relation between certain detrital particles, rhizopods, and the per cent of introduced 57Co associated with solids.

In general, direct biological uptake did not appear to be significant in removing 57Co from solution in Lake Mendota’s epilimnion. Photosynthetic activity was of little influence. Experiments with inhibitors and heated water also indicated that nonbiological processes were most important. Autoradiographs showed little radioactivity associated with algae.
DISTRIBUTION OF OLIGOCHAETES IN WESTERN LAKE ERIE, 19611
Authors: Hiltunen Jarl K.
Published: March 2010

A total of 52,390 oligochaetes were collected from 40 stations in western Lake Erie in spring 1961. The population was composed of two families, Naididae and Tubificidae. Only six species of naidids were found. One, Paranais frici, is apparently new to the list of North American freshwater Naididae. Among the 14 tubificids found, five species of Limnodrilus were most abundant; they contributed 90% or more of all oligochaetes at 33 of the 40 stations. Numbers of Limnodrilus were generally large near the mouths of the Detroit, Raisin, and Maumee rivers and decreased progressively lakeward. Stylodrilus heringianus, a pollution‐intolerant species common in eastern Lake Erie, was not found in the western end of the lake.
EFFECT OF LIGHT INTENSITY ON PHOTOSYNTHESIS BY THERMAL ALGAE ADAPTED TO NATURAL AND REDUCED SUNLIGHT1
Authors: Brock Thomas D. , Brock M. Louise
Published: March 2010

Thermal algae in alkaline hot springs of Yellowstone National Park (Wyoming) grow as compact mats in which self‐shading is extensive, as shown by measurement by autoradiography of photosynthetic activity of cells at different levels in the mat. The effect of light intensity on photosynthesis of the algal mats was studied using neutral density filters during incubation with 14CO2. Despite the intense sunlight at the altitude of Yellowstone, light inhibition by full sunlight was observed only occasionally; the rate of photosynthesis fell progressively with decreasing light, although the most efficient use was at 7–14% of full sunlight. Later, the light intensity over portions of the algal mats was reduced to 18% of full sunlight by installing neutral density glass plates, and changes of chlorophyll content, cell number, and response of photosynthesis to light intensity were determined over the next year. Although the chlorophyll content of the algae at the surface of the mat rose quickly, the chlorophyll content of the mat as a whole rose slowly or not at all; the photosynthetic response of the algal mats to full and reduced sunlight also changed slowly or not at all. Although individual algal cells can adapt rapidly to changes in light, the entire population, because of its existence in compact mats, adapts slowly. At the latitude of Yellowstone there is sufficient light throughout the year to enable algal growth to occur even at temperatures near the upper limit at which blue‐green algae can grow; in Iceland, hot spring algae cannot grow during several winter months. Natural ultraviolet radiation neither inhibited nor stimulated photosynthesis.
FUNGAL DECOMPOSITION AND AMINO ACID ANALYSIS OF MYSIS RELICTA LOVÉN1
Authors: Tracy Susan F. , Vallentyne J. R.
Published: March 2010

Mysis relicta collected from Cayuga Lake, New York, contained 21% ash, 15.6% lipid, 10.2% N, and 37.0% organic carbon on a dry weight basis. Quantitative data are given for amino acids in a hydrolysate of whole specimens. Digestion by brook trout resulted in the separation, but not destruction, of exoskeletal parts. Laboratory decomposition experiments (5–20C, 2–16 months) in phosphate‐buffered glucose, a sediment‐water mixture, and lake water alone showed that a chytrid fungus, tentatively identified as a species of Allomyces, was associated with the destruction of mandibles and probably other exoskeletal structures as well.
SEASONAL FLUCTUATIONS OF LAKE MICHIGAN DIATOMS1
Authors: Holland Ruth E.
Published: March 2010

Diatoms were collected in four areas of Lake Michigan and in southern Green Bay from April to early November 1965. The flora of the lake was characterized by Fragilaria crotonensis, Tabellaria flocculosa, Melosira islandica, Cyclotella “glomerata‐stelligera,” Cyclotella michiganiana, Asterionella formosa, and Stephanodiscus tenuis. Stephanodiscus niagarae always dominated the diatom biomass in Green Bay; also characteristic of the bay were Melosira granulata, Melosira ambigua, Melosira binderana, Fragilaria capucina, and Fragilaria crotonensis. There was an average of 517 diatoms per ml in the lake and 944 in the bay. Diatom abundance appeared to have one peak in the lake and two in the bay. At times of maximum abundance, optimum depth was usually 5 m. Numbers were greater in Green Bay and the inshore areas than in the offshore areas and appreciably higher near the eastern shore than the western shore of the lake. The higher populations near the eastern shore and in Green Bay appeared to be correlated with higher concentrations of phosphorus and chlorophyll a and lower concentrations of nitrate‐N.
RESPIRATORY ENERGY EXPENDITURE BY THE PREDACEOUS ZOOPLANKTER LEPTODORA KINDTII (FOCKE) (CRUSTACEA: CLADOCERA)1
Authors: Moshiri Gerald A. , Cummins Kenneth W. , Costa Robert R.
Published: March 2010

Respiratory expenditure energy budgets were determined for a natural population of the predaceous zooplankter Leptodora kindtii during two growing seasons. Oxygen consumption, carbon dioxide production, and RQ were determined under a variety of laboratory conditions. Leptodora demonstrated a respiratory regulatory plateau over the temperature range 15 to 25C. Oxygen consumption was highest for males and lowest for fecund females. Annual population maintenance cost (respiration) was calculated to be 22.5 kcal m−3 yr−1 in 1966 and 111.4 kcal m−3 yr−1 in 1967 (4,625 ml O2 m−3 yr−1 and 23,302 ml O2 m−3 yr−1).
ON THE MECHANISM OF LANGMUIR CIRCULATIONS AND THEIR ROLE IN EPILIMNION MIXING1
Authors: Scott Jon T. , Myer Glenn E. , Stewart Ronald , Walther Eric G.
Published: March 2010

Six mechanisms have so far been proposed to explain Langmuir circulations and their associated wind streaks. One mechanism involving shearing instability and two requiring the action of a surface film are supported by the greatest amount of evidence. Studies at Lake George, New York, suggest that more than one mechanism may operate at one location. A particular mechanism may operate at a specific site because of typical conditions at that site, but a different mechanism may be more important at another site. Plots of thermal structure in the near‐surface layer of Lake George and measurements of vertical current velocities suggest that Langmuir circulations are the most important mixing process in the epilimnia of lakes.
THE GENERATION OF LANGMUIR CIRCULATIONS BY THE EDDY PRESSURE OF SURFACE WAVES1
Authors: Faller Alan J.
Published: March 2010

The Langmuir circulations in lakes and oceans are shown, by theory and by the extension of laboratory experiments, to be the result of wave action. Specifically, the exponential decay of vertical oscillations that are a maximum near the free surface gives rise to an instability that is analogous to thermal convective instability but which may be two orders of magnitude or more greater than strong thermal convection. Laboratory experiments in a wind‐wave tank support the predictions of the theory. Recognition of this mechanism as a primary cause of Langmuir circulations explains apparent differences between observations in lakes and oceans.
DIFFUSION FROM A CONTINUOUS SOURCE IN A UNIFORM SHEAR FLOW1
Authors: Okubo Akira , Karweit Michael J.
Published: March 2010

The importance of velocity shear in the diffusion of a patch of passive contaminant from an instantaneous source is well recognized. Shear is also expected to play an important role in the spread of contaminant from a continuous source, since a continuous source may be considered as a superposition of instantaneous sources. A model for the diffusion of a dynamically passive contaminant from such a continuous source is presented. This source is superposed on a mean flow with uniform shear. An equation is derived which shows— by numerical solution—that the maximum concentration of the contaminant in the resulting plume decreases nearly as the reciprocal of the distance. Small and large time approximations verify this result analytically. The skewness of the concentration distribution at various distances from the source is also presented. This diffusion model compares favorably with diffusion experiments conducted in seas and lakes.
THE RESPONSE OF NATURAL MICROBIAL POPULATIONS IN SEAWATER TO ORGANIC ENRICHMENT1
Authors: Vaccaro Ralph F.
Published: March 2010

When the heterotrophic potential technique is applied to marine situations, its analytical value is frequently impaired. In the open ocean, uptake responses often fail to develop despite use of a variety of 14C labeled substrates. Elsewhere, the incidence of uninterpretable kinetic uptake patterns is excessively high. However, when the period of exposure to organic enrichment is extended to 24 hr or more, natural populations from coastal areas develop measurable and analytically useful uptake patterns. Besides providing an attractive source of test cells for bioassay purposes, this shift in uptake behavior can be exploited for studying the dynamics of heterotrophic behavior. An assessment of the marine environment in terms of these and related observations is provided.
ON ESTIMATING ANNUAL PRODUCTION
Authors: Hamilton Andrew L.
Published: March 2010

The method of Hynes and Coleman is modified to make it more adaptable and more consistent with their underlying assumptions. If most organisms comprising a community are univoltine and have approximately the same maximum size, the average standing crop can be used to obtain a realistic estimate of annual production. The size frequency distribution can be regarded as a first estimate of an “average cohort” when the number of “average cohorts” equals the number of size classes through which the organisms grow. If growth, in terms of the size units used, is assumed to be linear, then numerical differences in adjacent size classes can be attributed to mortality. When all size classes are considered together, the effect of nonlinear growth on the estimate of annual production is not large. In contrast, a serious error is introduced if the organisms are not univoltine. When the growth pattern and generation time are known, it is relatively simple to modify the average size frequency distribution to improve the estimate of the “average cohort” and hence improve the estimate of annual production. A reply to the criticisms of Fager is included.
FAYETTEVILLE GREEN LAKE, NEW YORK. V. STUDIES OF PRIMARY PRODUCTION AND ZOOPLANKTON IN A MEROMICTIC MARL LAKE1
Authors: Culver D. A. , Brunskill G. J.
Published: March 2010

Annual primary production in meromictic Fayetteville Green Lake, N.Y., was estimated to be 290 g C/m2, based on seven measurements by the 14C method. About 83% of this annual production was due to photosynthetic sulfide‐oxidizing bacteria in the chemocline at 18–20‐m depth. Zooplankton densities were higher near the bacterial zone. Bacterial photosynthetic production and concentration of mixolimnetic seston at the chemocline provided adequate food for a relatively large zooplankton population. Evidence for diel migration was observed among the zooplankton.
DETERMINATION OF CARBONATE SATURATION OF SEAWATER WITH A CARBONATE SATUROMETER1
Authors: Ben‐Yaakov S. , Kaplan I. R.
Published: March 2010

A mathematical model has been established for the implementation of the Weyl saturometer, to obtain quantitative data on the degree of saturation (IP: K′sp) of calcite and aragonite to within ±2% when the chlorinity and pH of the measured seawater are known. The method also enables carbonate alkalinity to be estimated to within ±10% of values obtained by titration. Nomograms are given for the determination of degree saturation and total CO2 for seawater of known pH, where a change in potential has been measured after exposing a calibrated glass electrode to a slurry of calcium carbonate in the original seawater.
NATURAL RADIOCARBON IN THE MEDITERRANEAN SEA1
Authors: Broecker Wallace S. , Gerard Robert
Published: March 2010

14C:12C ratios for inorganic carbon extracted from 11 water samples collected in the Mediterranean Sea during the summers of 1956 and 1958 fall within the range of 0.917 to 0.952 of the fractionation corrected 14C:12C ratio for pre‐1900 atmospheric CO2. This small range indicates that vertical mixing takes place within this sea on a time scale of about 100 years. The 14C:12C ratios in the surface and intermediate waters of the Mediterranean are, as expected from hydrologic considerations, nearly equal to those in the adjacent surface North Atlantic.