bluuebunny/crossref_metadata_2025 huggingface dataset:
A SAND—BOTTOM EPIFAUNAL COMMUNITY OF INVERTEBRATES IN SHALLOW WATER
Authors: Fager Edward W.
Published: March 2010

A community of nine species of epifaunal invertebrates living on sand in shallow water was censused for six years. The community consisted of three coelenterates, three gastropods, two echinoderms and one decapod. Seven of the species had aggregated distributions, but individuals of the first and fourth most abundant ones were randomly distributed. The relationship of distribution to settlement and mortality is discussed. The importance of each species population in relation to its demands on the environment, and its effects on it, was assessed in terms of frequency, density, biomass, cover, and motility. The results suggest that it is often misleading to label some species in a community “important” and others “unimportant,” especially if this means that the latter are ignored in studies of community structure and dynamics. Populations of the nine species comprising the community remained constant (within sampling variability) over the six years. This community of few species, thus, appears to be a steady‐state system. This was unexpected in view of the short species list, the lack of indication of substantial interspecific interactions, and the rigorous conditions in the environment.
INFLUENCE OF HUMIC SUBSTANCES ON THE GROWTH OF MARINE PHYTOPLANKTON: DINOFLAGELLATES1
Authors: Prakash A. , Rashid M. A.
Published: March 2010

Humic substances, in small amounts, exert a stimulatory effect on marine dinoflagellates that is reflected in increased yield, growth rate, and uptake. Humic acid was found to be more active than fulvic acid; in both cases the growth responses were dependent on concentration. Of the various fractions isolated, the low molecular weight fractions of humic acid produced the greatest growth response in unialgal cultures of dinoflagellates.

The positive effect of humic substances on phytoplankton growth is, for the most part, independent of nutrient concentration and cannot be attributed entirely to chelation processes. It appears that growth enhancement in the presence of humic substances is linked with stimulation of algal cell metabolism. Because of their high concentrations in coastal waters, humic substances may thus be regarded as an ecologically significant entity influencing phytoplanktonic production.
THE NUTRITIONAL INADEQUACY OF CHLORELLA AND CHLAMYDOMONAS AS FOOD FOR DAPHNIA PULEX1
Authors: Taub Frieda B. , Dollar Alexander M.
Published: March 2010

Daphnia pulex failed to reproduce normally when fed either Chlorella pyrenoidosa or Chlamydomonas reinhardtii cultured and suspended in defined inorganic media. Lifespan was shorter, ovulation was reduced, and a large percentage of ovulated eggs failed to complete embryonic development. The same algal culture suspended in “biologically conditioned water” supported a normal lifespan and ample but not maximal reproduction. The active factors are heat‐stable. Several organic compounds were tested to find a substitute for aquarium water. Calcium pantothenate (300 mg/liter) improved survival and reproduction significantly, but for only one generation; alanine, glucosamine, and carnatine were not significantly beneficial. CaC12 improved survival and reproduction of two succeeding generations. Despite increases in the amount of calcium added, Daphnia cultures could not be maintained indefinitely on Chlamydomonas suspended in a defined salt solution.

The algae appear to be deficient in meeting the nutritional requirements of Daphnia pulex, especially with respect to reproduction. Their proper utilization seems to depend on factors supplied by other organisms, probably bacteria, and probably provided in the water from natural sources used in most experiments.
EFFECT OF HYDROSTATIC PRESSURE ON SYNTHESIS OF PROTEIN, RIBONUCLEIC ACID, AND DEOXYRIBONUCLEIC ACID BY THE PSYCHROPHILIC MARINE BACTERIUM, VIBRIO MARINUS1
Authors: Albright Lawrence J. , Morita Richard Y.
Published: March 2010

The temperature and hydrostatic pressure maxima for growth of the marine psychrophilic bacterium, Vibrio marinus MP‐4, were 20C and 425 atm. The effects of pressures of 200, 400, 500, and 1,000 atm at 15C on synthesis of net protein, RNA, and DNA by growing cells of V. marinus MP‐4 were determined. A pressure of 1,000 atm completely inhibited protein and DNA synthesis but allowed RNA synthesis decreased for approximately 60 min and then resumed the 1‐atm rates, whereas DNA synthesis was unaffected. Pressures of 400 and 500 atm immediately lowered the rate of protein synthesis, whereas RNA synthesis was unaffected by 400 atm. At 500 atm, RNA synthesis continued at the 1‐atm rate for 30 min and then shifted to a lower rate. Synthesis of DNA, at 400 and 500 atm, continued at the 1‐atm rate for approximately 60 min after pressurization, then gradually shifted to lower rates. The data suggest that the primary effect of pressures from 400 to 500 atm was to lower the rate of protein synthesis, which in turn may have lowered the rates of RNA and DNA synthesis.
THE CHARACTERISTICS AND DISTRIBUTION OF MARINE BACTERIA ISOLATED FROM THE INDIAN OCEAN1
Authors: Johnson Roy M. , Schwent Rose Mary , Press Wesley
Published: March 2010

During the eighth cruise of the RV Anton Bruun in the Indian Ocean, bacteria were collected from water, mud, fish, shark, and one island. The marine samples were collected from depths ranging from 100 to 3,050 m. A total of 127 isolates was classified to genus and the physiological response of the cultures to 17 diagnostic tests was related to their source. The physiological test response of the isolates, regardless of genus, was more highly correlated with the source of the cultures than were the genera as such.
SALINITY AND WATER CIRCULATION IN THE VELLAR ESTUARY
Authors: Dyer K. R. , Ramamoorthy K.
Published: March 2010

This paper reports a series of measurements of salinity, temperature, and current velocity in the Vellar estuary. This typical bar‐built estuary is shown, by comparison with dimensionless stratification parameters, to be a salt wedge at high river discharge and well stratified at low river discharge. During the tidal cycle, the salt wedge near the bottom became isolated in a series of basins during ebb tide; short period diffusion along the intense halocline seems to have been an important process in the salt balance of the water column. The water circulation at high river discharge was dominated by a meander system of alternating scour holes, with the high seaward flow in the deepest areas. Superimposed on this was a secondary lateral circulation system that broke down and reversed its sense at low river flows when the saline inflow developed.
THE USE OF A DEEP TANK IN PLANKTON ECOLOGY. I. STUDIES OF THE GROWTH AND COMPOSITION OF PHYTOPLANKTON CROPS AT LOW NUTRIENT LEVELS1
Authors: Strickland J. D. H. , Holm‐Hansen O. , Eppley R. W. , Linn R. J.
Published: March 2010

A deep tank (3‐m diam, 10 m deep), in which phytoplankton crops can be grown under simulated natural conditions of nutrient concentration and cell density, is described. Three growth experiments have been performed in the tank with Ditylum brightwellii (a centric diatom), Cachonina niei (an armored dinoflagellate), and with a mixed crop of the dinoflagellate Gonyaulax polyedra and Phaeocystis sp. (a colonial member of the Haptophyceae). Each experiment lasted about two weeks. In each case ammonia was assimilated first, then nitrate as the plants grew. Successful nitrogen budgets were achieved in the experiments with D. brightwellii and C. niei. The chemical composition of the tank‐grown cultures of D. brightwellii, C. niei, and G. polyedra is reported for cell carbon, nitrogen, phosphorus, lipid, carbohydrate, DNA, ATP, chlorophyll a, and carotenoids. The composition of these cultures was very similar to that obtained in laboratory cultures grown with relatively high nutrient levels.
EFFECTS OF TOXICANTS ON COMMUNITY METABOLISM IN POOLS
Authors: Whitworth Walter R. , Lane Thomas H.
Published: March 2010

Estimates of community metabolism of simulated natural environments were derived by diel oxygen techniques over a period of nine months. During this time, toxicants were added to some of the pools. “Natural” environmental factors and toxicants that did not affect the communities (0.02 mg/liter p,p′ DDT; 0.1 mg/liter antimycin A; and 9.2 mg/ liter KMnO4) usually resulted in simultaneous changes, up or down, in both community photosynthesis and respiration. Concentrations (mg/liter) of 0.9 and 2.6 formalin, 10.0 nigrosine black, 10.0 and 2.0 malachite green, 0.1 Diquat, and 0.5 and 5.0 CuSO4 usually depressed community oxygen production and increased community respiration for periods of 1 to 20 weeks.
VERTICAL DISTRIBUTION OF ANTARCTIC PHYTOPLANKTON. II. A COMPARISON OF PHYTOPLANKTON STANDING CROPS IN THE SOUTHERN OCEAN WITH THAT OF THE FLORIDA STRAIT1
Authors: Walsh John J.
Published: March 2010

A comparison of phytoplankton standing crops, in terms of the number of chlorophyll fluorescing cells throughout the water column per m2 of surface, is extended on a yearly basis for areas of the Southern Ocean and the Strait of Florida. It is suggested that, despite apparent high production during the austral summer, the overall production of Antarctic and temperate and subtropical areas may be at least of the same order of magnitude.
POPULATION STUDIES OF FOUR SPECIES OF MOLLUSCS IN THE MADISON RIVER, YELLOWSTONE NATIONAL PARK1
Authors: Gillespie D. M.
Published: March 2010

Population statistics were calculated for natural populations of Physa gyrina, Gyraulus deflectus, Valvata humeralis, and Pisidium compressum.

Total net production calculated for model populations was within 10% of the value calculated graphically. Data showed a generally good fit to the model curve. The average of the two methods of determining total annual net production of the gastropods was 5.150 g/m2. Assuming an efficiency of 0.25, total gastropod assimilation was approximately 10% of the annual net primary production. Growth rates apparently were not limited by food supply. Mortality rates were highest in spring and summer and lowest in winter with the principal causes predation and loss during high water. Reproductive periods of Physa, Gyraulus, and Pisidium extended from spring to fall; Valvata reproduction was largely limited to August.
MEASUREMENT AND ANALYSIS OF THE ANNUAL HEAT BUDGET FOR THE SEDIMENTS IN TWO WISCONSIN LAKES1
Authors: Likens Gene E. , Johnson Noye M.
Published: March 2010

Temperature was measured in the water, bottom sediments, and bog surrounding Stewart’s Dark Lake and Tub Lake, Wisconsin, five times during 1965–1966. A thermal probe was used to penetrate to depths to 8 m into the bottom.

In the deepest water of Stewart’s Dark Lake, with no seasonal temperature fluctuation, a steady‐state thermal gradient (0.20°C/m) was observed in the bottom sediments. Thermal conductivity of these gelatinous sediments was measured at 1.10 × 10−3 cal cm/cm2 sec°C; thus prescribing a steady‐state heat flow of 2.1 × 10−6 cal/cm2 sec or 66 cal/cm2 year.

The pattern of isotherms within the bottom sediments and bog demonstrates the importance of solar radiation and the effects of absorption and circulation within these lakes. Seasonal changes in isotherm patterns are similar for both lakes. Seasonal temperature fluctuations are largely damped at depths below 4 m in the surrounding bogs. There is a negative (into the sediments) steady‐state thermal gradient associated with the shoreline, but the gradient becomes positive lakeward and landward. Thus, with respect to mean sediment temperatures, each lake is surrounded by a relatively warm rim.

The annual heat budget of the sediments at the shoreline in Tub Lake was 3,670 cal/cm2; at a water depth of 8 m, it was 70 cal/cm2. The mean annual budget for the entire sediments of Stewart’s Dark Lake was 730 cal/cm2 and for Tub Lake was 970 cal/cm2. These values represent about 10 and 12%, respectively, of the total annual heat budgets for the water in each lake. The heat budget of the sediments is dependent on the amplitude of temperature variations of the overlying water and the thermal properties of the sediment.
STUDIES OF NITRATE REDUCTASE IN MARINE PHYTOPLANKTON1
Authors: Eppley R. W. , Coatsworth J. L. , Solórzano Lucia
Published: March 2010

Certain marine phytoplankton contain the enzyme nitrate reductase when growing on nitrate, but only low levels of enzyme were found during growth with ammonium or when the nitrogen source was depleted. Netted samples of oceanic phytoplankton contained the enzyme when taken from waters with nitrate concentrations 2–10 µm. Ammonium was assimilated in preference to nitrate in phytoplankton cultures supplied with both forms of nitrogen at 5–15 µm. Enzyme synthesis and nitrate use began when ammonium was depleted to 0.5–1.0 µm.

Nitrate reductase assay of phytoplankton samples is a useful tool in that a positive result indicates utilization of nitrate and a negative one implies growth on ammonium, nitrogen depletion, or, improbably, growth with other N‐sources such as nitrite, urea, or amino acids. The enzyme assay seems especially useful for studying the timecourse of phytoplankton blooms because it provides a sensitive measure of the initiation and cessation of nitrate assimilation.
FIELD AND LABORATORY EVALUATIONS OF BIOASSAYS FOR NITROGEN AND PHOSPHORUS WITH ALGAE AND AQUATIC WEEDS1
Authors: Fitzgerald George P.
Published: March 2010

The rate of absorption of ammonia in the dark and the amount of orthophosphate extracted by boiling water can be used to follow changes in the nutritional status of nitrogen and phosphorus in algae and aquatic weeds with relation to changes in supply of these elements. Measurements of alkaline phosphatase activity carried out in phosphorus‐free media can also be used to follow changes in the phosphorus nutrition of aquatic plants; growth under conditions of surplus available phosphorus reduces (by dilution) their alkaline phosphatase activity. Only terminal portions of aquatic weeds should be used for nutritional bioassays because of nutritional differences between young and old portions of the same plant. The importance of testing each species of plants separately is shown by contrasting results obtained with nitrogen‐fixing (phosphorus‐limited) and nonfixing (nitrogen‐limited) blue‐green algae from the same environment. These methods provide simple but useful bioassays for studies of eutrophication.
OXYGEN CONSUMPTION OF EUPHAUSIA PACIFICA: THE LACK OF A DIEL RHYTHM OR LIGHT‐DARK EFFECT, WITH A COMPARISON OF EXPERIMENTAL TECHNIQUES1
Authors: Pearcy William G. , Theilacker Gail H. , Lasker Reuben
Published: March 2010

We found no evidence for diel rhythms in the respiration of individual Euphausia pacifica during long‐term (11–32 hr) Warburg manometric experiments. Changes from light (1.2 × 102 µw cm−2) to dark (<1.8 × 10−5 µw cm−2) also had no appreciable effect on oxygen consumption of most of these euphausiids. Respiratory rates often decreased with time regardless of light conditions, but 2 of 20 animals respired consistently more in the dark than the light.

Larger animals consumed less oxygen per unit weight than smaller ones. This factor contributed to differences between mean oxygen consumption rates of separate experiments. Although we obtained higher rates from the Winkler than the manometric method, the differences were not significant. The average rate (1.34 µl O2 mg−1 hr−1) from all our experiments (79 animals) was intermediate in the range of values reported in the literature.
MONTHLY SURVEY OF VITAMIN B12 CONCENTRATIONS IN SOME WATERS OF THE ENGLISH LAKE DISTRICT
Authors: Daisley K. W.
Published: March 2010

The vitamin B12 activity for Euglena gracilis of water from nine lakes of the English Lake District was assayed at 15 consecutive monthly intervals. Filtration through glass‐fiber filters was used to differentiate between dissolved vitamin and that in gross particulate matter. The average vitamin B12 concentrations correlated with what has previously been described as the evolutionary series of the lakes: the “primitive” rocky lakes of low productivity are low in vitamin B12, the “evolved” silted lakes, richer in sediments, nutrients, and organisms have higher levels of the vitamin.
INVESTIGATIONS OF CERTAIN MICROCONSTITUENTS IN TWO TUNICATES1
Authors: Strohal Petar , Tuta Josip , Kolar Zvonimir
Published: March 2010

Concentrations of 11 trace elements—scandium, lanthanum, cerium, europium, thorium, rubidium, cesium, strontium, iron, zinc, and cobalt—have been determined by activation analysis in two tunicates. Their concentration factors were calculated and are discussed in relation to radioecology and to seawater pollution with radionuclides. The treatment of samples and the radiochemical procedure are described.
OCEANIC HEAT CONTENT OFF OREGON: ITS VARIATIONS AND THEIR CAUSES1
Authors: Pattullo June G. , Burt Wayne V. , Kulm Sally A.
Published: March 2010

Heat content, surface to 100 m, was computed for oceanographic stations within 165 nautical miles (305 km) of the Oregon coast. Mean content, 1962 through 1965, was 100 kg cal cm−2, with a root mean square deviation of 13 kg cal cm−2. The principal fluctuation around the mean was seasonal; the seasonal range among monthly mean values was twice as large offshore, beyond 100 miles (185 km) from the coast (35 kg cal cm−2) as the range inshore, within 65 miles (120 km) of shore (15 kg cal cm−2). The cause of the seasonal variation offshore was local heating, but advection was important inshore. Observed ranges in heat storage inshore were only a third as large as expected from the computed local heating. The results are consistent with inshore currents from the south in winter and coastal upwelling associated with offshore transport of water and heat in summer.

For data off Newport, the sum of squares was partitioned by a hierarchal scheme. This revealed that inshore the seasonal regime was not dominant; fluctuations of long and short periods and geographical variations were also appreciable. It is suggested that future sampling in the inshore region be more intensive, with smaller intervals in both distance and time. It is also apparent that long records (tens of years) are needed both inshore and offshore if we wish to describe the major fluctuations of heat content, since long‐period deviations from the average seasonal cycle are indicated.
OSCILLAXANTHIN IN THE SEDIMENT OF LAKE WASHINGTON1
Authors: Griffiths Mary , Perrott Pamela S. , Edmondson W. T.
Published: March 2010

Oscillaxanthin was determined quantitatively in portions of five cores cut in slices 1 cm thick. The distribution varied with depth in a manner qualitatively consistent in all cores, although there were quantitative differences. The pigment was undetectable below 9 cm in two cores, below 8 in another, and below 13 in the remaining two. The amount of pigment per unit dry weight of sediment was highest at the surface and had two subsurface maxima, at 4 cm for the shallow maximum, with a deep maximum at 7 cm for three cores, 8 cm for the fourth, and 9 cm for the fifth. The total accumulated pigment under unit area of bottom mud varied from 27.10 to 6.66 µg/cm2. To some extent these differences also relate to accumulation of organic matter and to other pigments. The oscillaxanthin‐producing algae evidently are somewhat differently distributed during sedimentation, for the differences are not related to differences in distribution of the plankton.

The vertical distribution of oscillaxanthin within the sediments is considered in relation to the recent history of sewage enrichment of the lake. Oscillaxanthin is known to be produced by Oscillatoria rubescens and O. agardhii, both of which have occurred in abundance in Lake Washington since 1955 when O. rubescens was observed for the first time, in a relatively dense population. Oscillatoria agardhii occurred in small quantities in 1950. Cultured Anabaena circinalis, Microcystis aeruginosa, and Aphanizomenon flos‐aquae had negligible amounts of oscillaxanthin.

On the basis of available evidence about sedimentation rates, oscillaxanthin must have been produced in the lake before the appearance of O. rubescens in 1955 and also before 1950. The first appearance of oscillaxanthin probably came early in the period of sewage enrichment that led to the recent diversion of sewage from Lake Washington. The reasons for the two maxima in concentration are not known. The changes apparently cannot be attributed to destruction of pigment or dilution with other components of sediment in varying amounts over the years and therefore seem to reflect changes in the production of Oscillatoria.
THE INFLUENCE OF NITROGEN ON HETEROCYST PRODUCTION IN BLUE‐GREEN ALGAE1
Authors: Ogawa Roann E. , Carr John F.
Published: March 2010

A series of experiments on heterocyst production in Anabaena variabilis provides some strong indirect evidence for the role of heterocysts in nitrogen fixation. Of the algae tested (Anabaena variabilis, A. inaequalis, A. cylindrica, A. flos‐aquae, Tolypothrix distorta, Gloeotrichia echinulata, Aphanizomenon flos‐aquae, Oscillatoria sp., and Microcystis aeruginosa), only those with heterocysts grew in a nitrate‐free medium. Growth in the nitratefree medium was accompanied by an increase in heterocysts. Hetcrocyst formation in A. variabilis was evident 24 hr after transfer from a nitrate‐containing to a nitrate‐free medium. The number of heterocysts was altered by changes in the nitrogen source. Numbers were lowest when NH4‐N was used as a nitrogen source and highest when nitrogen (N2‐N) was derived from the atmosphere. Heterocyst numbers could also be regulated by controlling the concentration of NO3‐N in the medium. Heterocyst production depended on the absence of combined nitrogen and the presence of phosphate. Data are presented on the occurrence of blue‐green algae (with heterocysts) in Lake Erie and the environmental conditions apparently necessary for them to become dominant.
THE ANNUAL AND DIURNAL VARIATION IN THE VERTICAL DISTRIBUTION OF ACID‐SOLUBLE FERROUS AND TOTAL IRON IN A SMALL DIMICTIC LAKE
Authors: McMahon J. W.
Published: March 2010

Changes in the vertical distribution of acid‐soluble ferrous and total iron in filtered lake water were measured weekly for 12 months using the organic reagent bathophenanthroline. Acid‐soluble ferrous iron was present throughout all strata, the concentration fluctuating in a definite annual pattern. Values of Fe2+ changed hourly and followed a diurnal pattern. It is suggested that the concentration of Fe2+ in lake water is controlled by photochemical reactions and, perhaps, also by metabolic activity of microorganisms.
OBSERVATIONS OF GASES IN CHESAPEAKE BAY SEDIMENTS1
Authors: Reeburgh William S.
Published: March 2010

Summer and winter depth distributions of Ar, N2, CH4, and total CO2 in Chesapeake Bay sediments are reported. Methane increased with depth in the sediment from undetectable quantities at the surface to concentrations of 150 and 85 ml/liter in water depths of 30.4 and 15.2 m. The observed maximum concentrations agree well with values calculated assuming that the CH4 is controlled by ebullition from the sediment. Argon and N2 in the surface sediments were present in concentrations near that of the overlying water and decreased with depth to values of 0.1 and 2 ml/liter. Depth variations of the N2 : Ar ratio indicate selective removal of N2. Stripping by bubbles of CH4 accounts for the selective removal of N2 and the decrease with depth of both Ar and N2. Total CO2 increased with depth to concentrations of 1,500 ml/liter and pH remained uniform with depth at about 7. Low values of total H2S and an abundance of acid‐labile sulfides in the sediments indicate that sulfide species are removed by mineral formation. All depth variations showed a break at about 25‐cm depth, indicating that mixing takes place to this depth.
SUBSURFACE CHLOROPHYLL MAXIMUM IN THE NORTHEAST PACIFIC OCEAN1
Authors: Anderson G. C.
Published: March 2010

A well‐developed subsurface chlorophyll maximum is present during summer in oceanic waters off the Oregon coast. It appears to be formed at depth by a photosynthetically active phytoplankton community that is adapted to low light intensity. It may be present and may affect the distributions and concentrations of primary production, oxygen, and nutrients over large areas of the North Pacific Ocean.
RESPIRATION CORRECTIONS FOR BACTERIAL UPTAKE OF DISSOLVED ORGANIC COMPOUNDS IN NATURAL WATERS1
Authors: Hobbie John E. , Crawford Claude C.
Published: March 2010

The uptake of 14C‐labeled organic compounds has been used by many workers to study heterotrophic microorganisms in natural waters. However, if flux rates of organic compounds are to be measured, the loss of 14CO2 during incubation becomes an important source of error. A method is proposed in which the experiment is run in a closed system and the 14CO2 collected after killing and acidification. Phenethylamine on chromatographic paper is the absorbing agent and the paper is counted by liquid scintillation. Studies of 19 compounds from pond water showed that 60% (aspartic acid) to 8% (arginine) of the labeled material entering the microorganisms was respired.
ALKALINITY BUDGET OF THE COLUMBIA RIVER1
Authors: Park P. Kilho , Webster George R. , Yamamoto Roy
Published: March 2010

Columbia River alkalinity essentially consists of carbonate alkalinity (94%) with some silicate alkalinity where dissolved silicate concentration is high. Phosphate and borate contribute insignificantly to the overall alkalinity. The river delivered 2.3 × 1011 equivalents of alkalinity to the Pacific Ocean during the water year 1963, or 11 megatons of calcium carbonate. Regardless of high seasonal flow‐rate variance, the river alkalinity near the river mouth shows little variation with an average value of 1 meq/liter.
BLUE‐GREEN ALGAE AND CARBONATES—SCHIZOTHRIX CALCICOLA AND ALGAL STROMATOLITES FROM BERMUDA1
Authors: Sharp Jonathan H.
Published: March 2010

Algal stromatolites (laminated sedimentary structures) have been studied in the process of formation in subtidal areas of Bermuda. The primary organism responsible for forming these structures is the blue‐green alga, Schizothrix calcicola. Laboratory studies of the formation of nonlaminated algal mats by unialgal cultures of S. calcicola showed that this species could bind sediment particles. The roles of S. calcicola and a secondary species, Oscillatoria submembranacea, in stromatolite formation have been examined.

Since S. calcicola exists planktonically, it can be cultured from water samples. These cultures, and the presence of this species on various substrates in subtidal, intertidal, and supratidal areas indicate its wide distribution in Bermuda inshore waters.

The distribution of S. calcicola and other filamentous cyanophytes, as well as consideration of physical factors of the subtidal environments, indicates that the latter probably control distribution of the Bermudian algal stromatolites.

Reports of developing algal stromatolites from intertidal areas in other parts of the world indicate that S. calcicola is of major, if not primary, importance in the formation of stromatolites everywhere.
NUTRIENT LIMITATION OF SUMMER PHYTOPLANKTON GROWTH IN CAYUGA LAKE
Authors: Hamilton D. H.
Published: March 2010

The effect on natural phytoplankton populations of various components of a defined culture medium has been assayed by measurement of 14C assimilation under controlled conditions. Phytoplankton populations in Cayuga Lake are at least partially nutrient limited during the period of stable conditions succeeding the vernal bloom. Sodium silicate consistently stimulated photosynthesis in June, July, and August; this is associated with the presence of silicon‐requiring plankters, including some nondiatomaceous forms, and correlated with nutrient levels in situ. Both phosphate anl silicate were present in low concentration—the silicon near the lowest values described in the literature. Despite low natural concentration, augmented phosphate did not stimulate photosynthesis, and some evidence is presented for inhibition by phosphorus. Inhibition and enhancement by other components of the medium are discussed, as well as modifications of the 14C enrichment experiment technique.
LIMITATION OF ALGAL GROWTH IN SOME CENTRAL AFRICAN WATERS
Authors: Moss Brian
Published: March 2010

Levels of inorganic nutrients (nitrate, phosphate, sulfate) available for algal growth in nine bodies of water in Malawi were investigated, using enrichment bioassays with naturally present algae as test organisms. Nitrate or nitrate plus phosphate were potentially limiting to algal growth. There was no evidence of sulfate limitation. The relevance of enrichment bioassays to whole water body situations is considered. A model, illustrating invalid use of assays in the interpretation of seasonal succession in algal communities, is discussed.
SOME EFFECTS OF LAKE RENEWAL ON PHYTOPLANKTON PRODUCTIVITY AND SPECIES COMPOSITION1
Authors: Dickman Mike
Published: March 2010

Primary production in Marion Lake is inversely related to the rate at which water enters the lake when light intensity is corrected to a standard level. Increased flushing rates reduce the phytoplankton standing crop thereby lowering the total primary productivity in the lake. Thus seasonal variations in rainfall in southwestern British Columbia exert an appreciable influence on the annual productivity pattern of the lake’s phytoplankton.

Lake water artificially enclosed within small areas of the lake produced algal blooms while phytoplankton standing crop in the rest of the lake remained low. Nannoplankton appear to have a selective advantage over larger, more slowly reproducing forms in Marion Lake. The production: biomass ratio for lake phytoplankton was used as an indication of the general type of limiting factor affecting the instantaneous rate of productivity in the lake.
A LABORATORY METHOD FOR THE STUDY OF MARINE BENTHIC DIATOMS1
Authors: McIntire C. David , Wulff Barry L.
Published: March 2010

Effects of light intensity and of exposure to desiccation on the vertical distribution and growth of populations of marine benthic diatoms were investigated in a laboratory model ecosystem and a respirometer chamber. The diatom flora that developed in the ecosystem was similar to that from field stations in lower Yaquina Bay, Oregon. The vertical distribution of many species was closely related to light intensity and period of exposure to desiccation. Biomass accumulated most rapidly on substrates subjected to high light intensities, without exposure to desiccation. Communities acclimated to different light intensities and periods of desiccation responded differently to changes in light intensity in the respirometer chamber. Results of these experiments show that the laboratory apparatus described can be useful in the study of simplified intertidal communities.
EFFECT OF TEMPERATURE ON THE pH OF SEAWATER1
Authors: Gieskes Joris M.
Published: March 2010

The temperature coefficient of the pII of seawater, calculated from existing data on the carbonate system in seawater, is confirmed experimentally as +0.0114 pH units per degree Celsius at 1 atm pressure. Although pH measurements with a given system are reproducible to ±0.005 or ±0.000 pH units, direct pH measurements on seawater are accurate only to about ±0.02 pII units; hence computations of components of the carbonate system are uncertain by 1% in bicarbonate and 5% in carbonate. These uncertainties can be halved if pH values are derived from precise determination of other components of the carbonate system, such as alkalinity and total CO2.
SODIUM, MAGNESIUM, AND CALCIUM SULFATE ION‐PAIRS IN SEAWATER AT 25C1
Authors: Kester Dana R. , Pytkowicx Ricardo M.
Published: March 2010

The stoichiometric association constant of CaSO40 ion‐pairs, K*CaSO4 = [CaSO40]/[Ca2+]× [SO42−], was found to be 10.8 ± 0.7 at 25C at an effective ionic strength of 0.67 and at 1‐atm pressure. The percentages of free and ion‐paired species in seawater were calculated from the experimentally determined association constants of NaSO4−, MgSO40, and CaSO40 ion‐pairs. The results were used to calculate the effective ionic strength of seawater and to account for the difference in activity coefficients in seawater and in single‐salt solutions.
THE FEEDING OF CALANUS HELGOLANDICUS ON SYNCHRONOUSLY GROWING POPULATIONS OF THE MARINE DIATOM DITYLUM BRIGHTWELLII1
Authors: Richman Sumner , Rogers Jane N.
Published: March 2010

The filtering rates of Calanus helgolandicus were measured on synchronously growing populations of the diatom Ditylum brightwellii, by following changes in cell numbers and also by measuring the ingestion of 14C labeled cells at selected intervals during 2‐day periods. The growth of the diatoms was adjusted to be one cell division per day by selecting appropriate photoperiods and light intensities. When the alga was synchronized, cell division took place in the dark.

Filtering rates were calculated separately for animals grazing on single cells and on “paired” daughter cells (before separation after division). The volume of paired cells was 1.5 times that of the singles. There was no significant difference in the filtering of single cells in the light or dark part of the cycle. Filtering on paired cells was significantly higher in the dark or at those times when high percentages of pairs were present. Between 0 and 20% pairs, the animals filtered at a constant rate of 50 ml copepod−1 day−1. Above 40% pairs, there was a maximum filtering rate of approximately 170 ml copepod−1 day−1. Between 20–40% pairs, the filtering rate increased proportionally to the percentage of pairs, and ingestion of paired cells increased exponentially in relation to their concentration.

It is suggested that C. helgolandicus actively hunted and selected the paired cells and passively filtered the singles. In addition, the data support the idea that there is no innate diurnal feeding rhythm in these copepods.
THE EFFECTS OF GRAZING BY SEA URCHINS, STRONGYLOCENTROTUS SPP., ON BENTHIC ALGAL POPULATIONS1
Authors: Paine Robert T. , Vadas Robert L.
Published: March 2010

A series of shallow intertidal pools at Mukkaw Bay, Washington, ranging in height from −0.3 to +0.6 m had the urchin Strongylocentrotus purpuratus removed from them. Subtidal rocks at Friday Harbor, −7.3 to −8.2 m, were either caged or had Strongylocentrotus fransiscanus removed at monthly intervals. Observations of the rate and pattern of algal succession for periods of up to three years showed that following an initial establishment of new species, brown algae began to dominate. The rate of domination is related to the area’s tidal height, with succession most rapid in the lower intertidal areas or subtidally. After a variable period, the majority of the algal biomass was vested in a single perennial brown algal species, Hedophyllum sessile in the inter tidal and Laminaria complanata or Laminaria groenlandica subtidally. These plants existed neither in the control areas throughout the study, nor in the experimental pools and rocks before urchin removal. Intermittent urchin browsing could make a major contribution to the variety of algae coexisting within limited areas on these rocky shores.
COLORADO SEMIDRAINAGE MOUNTAIN LAKES1
Authors: Pennak Robert W.
Published: March 2010

A distinctive semidrainage lake type is common at midmountain elevations in Colorado. Such lakes are similar in their small size, shallow depth, lack cf an outlet, high nitrate content, high organic content, and high water color.

“Indicator species” are Rana pipiens, neotenic Ambystoma tigrinum, Gammarus limnaeus, an association of three leeches (Nephelopsis obscura, Glossiphonia complanata, and Helobdella stagnalis), and Nuphar polysepalum. Usually 8 to 14 species of rooted aquatics are present by late summer. Sponges arc abundant, fish are absent, and plankton is sparse.

Evidence is presented to show that semidrainage lakes are limnoseres.
FAYETTEVILLE GREEN LAKE, NEW YORK. I. PHYSICAL AND CHEMICAL LIMNOLOGY1
Authors: Brunskill G. J. , Ludlam S. D.
Published: March 2010

A new bathymetric map of Fayetteville Green Lake, New York, has been made. From morphometric parameters and an approximation of the density differential between the mixolimnion and monimolimnion (Δρ = 0.6 × 10−3 g cm−3), a meromictic stability of 1,700 g‐cm cm−2 was estimated. From semimonthly measurements of temperature over a 2‐yr period, the work of the wind in distributing summer mixolimnetic heat income (16,800 g cal cm−2) was 760 g‐cm cm−2. Surface runoff from the 4.33 km2 drainage area of Green and Round Lakes supplies less than 50% of the observed outflow of Green Lake (3.3 × 106 m3/yr) in 1967. A theoretical replenishment time of the total Green Lake water mass was estimated as 2 to 3 years, or 1.0 to 1.7 years if the monimolimnion was considered static. Concentrations of major elements are given for the Green Lake water column and for groundwater of the area.
FAYETTEVILLE GREEN LAKE, NEW YORK. II. PRECIPITATION AND SEDIMENTATION OF CALCITE IN A MEROMICTIC LAKE WITH LAMINATED SEDIMENTS1
Authors: Brunskill G. J.
Published: March 2010

The activities of calcium and carbonate in Fayetteville Green Lake were estimated from detailed seasonal measurements of pH, calcium, and titration alkalinity. By comparison of observed ion activity products (IAP) for Ca2+ and CO32− with the calcite equilibrium activity product (Kcq), the water column was found to be supersaturated throughout the year. In the surface waters of the mixolimnion, the ratio IAP: Keq increased from 2 to 4 in winter to 6 to 8 during late May through October.

Precipitation of calcite was confirmed by collection of crystals in the water column by filtration, identification by X‐ray diffraction, and quantitative measurement by a gas chromatographic technique. Maximal crystal loads of 35 g CaCO3 m−2 in the water column occurred in June and July (1965–1967), while calcite loads in fall, winter, and early spring were reduced by an order of magnitude. From isopleths of suspended calcite, settling rates of 2–4 in day−1 were estimated for spring, which was close to values predicted from Stokes’ Law.

About 90% of the total sedimentation occurred from June through October, and 80% of this mass was calcite. The laminae occurring in monimolimnetic sediments were regarded as annual couplets resulting from seasonal sedimentation of calcite, with deposition of organic matter throughout the year. The sedimentation rate derived from sediment trap data was 300 g dry matter m−2 yr−1. From the chemical composition of these samples, sedimentation rates were derived for CaCO3, acid insoluble organic carbon, acid insoluble nitrogen, and total nitrogen, sulfur, phosphorus, silicon, and iron.
TRACER STUDIES ON CALCIUM AND STRONTIUM MINERALIZATION AND MINERAL CYCLING IN TWO SPECIES OF FORAMINIFERA, ROSALINA LEEI AND SPIROLOCULINA HYALINA1
Authors: McEnery Marie , Lee John J.
Published: March 2010

Mineral cycling in the calcareous foraminifera Rosalina leei and Spiroloculina hyalina was traced with 45Ca and 90Sr. Incorporation of these radionuclides as well as 35S and 32P was proportional to growth when they were introduced into the system in the range of 1 × 104– 1 × 105 dpm/ml of medium (90Sr specific activity ∼ 109 µCi/g; 45Ca specific activity 160 µCi/g; 35S specific activity 95 µCi/g; 32P specific activity 2.03 mCi/g). Although 14C was a good indicator of growth during the first 3 weeks, its usefulness declined as the cultures aged. Some 45Ca and 90Sr was adsorbed to dead tests. Both foraminifera were decalcified by treatment with 0.01% Na2EDTA in seawater at pH 8.1. Recalcification and growth took place when individuals were returned to control media. Ten to 0.1 µm 2‐acetylamino‐1,3,4‐thiadiazole‐5‐sulfonamide (Diamox) inhibited Ca but not Sr incorporation into the test. Calcium and strontium were lightly bound to foraminiferan shells and under conditions of alkaline pH and low hydrostatic pressure these did not exchange with environmental ions.
PLANKTONIC FORAMINIFERA: DIFFERENTIAL PRODUCTION AND EXPATRIATION OFF BAJA CALIFORNIA1
Authors: Berger Wolfgang H.
Published: March 2010

The species composition, living: dead ratios, morphology, and size distribution of planktonic foraminifera were studied in 54 depth‐controlled tow samples using a 333‐µ net (0– 3,000 m) from northwest of Guadalupe Island, Baja California. Paired sampling and replicate tows permitted the determination of confidence limits on concentration and percentage estimates.

Average concentrations of living foraminifera range from about 1/m3 in shallow water to less than 1/1,000 m3 at depth. Concentrations of empty shells are between 3 to 10/1,000 m3 throughout. The depth of equal standing stock for live and empty individuals is between 5,000 and 10,000 in. The minimum replacement time for the living populations corresponds to the settling time through this column and is between 5 and 40 days. The apparent replacement times vary considerably between species and between sizes within species.

The living assemblage consists of a mixture of northern, central, and southern species dominated by northern ones. Central water species are relatively abundant immediately below the surface water. The southern element has a maximum at about 1,000‐m depth. This distribution is in agreement with physical measurements, suggesting shallow entrainment of central water into the California Current and indicating a countercurrent at depth. It is suggested that the fauna contained in the oxygen‐poor intermediate water is expatriated and that its great proportion of specimens with small terminal chambers (“kummerforms”) is due to unfavorable living conditions during submergence.

The notion that kummerform development indicates termination or slowing of growth is supported by a trend toward increase of kummerform proportions in living populations in large shell sizes and at subsurface depths and by the relatively high empty shell output of kummerforms. Oceanic stability of past ages may be recognized in fossil foraminiferal deposits if oceanic mixing enhances kummerform development and if the effects of differential preservation can be accounted for.
SMALL‐SCALE SPATIAL DISTRIBUTION IN OCEANIC ZOOPLANKTON1
Authors: Wiebe Peter Howard
Published: March 2010

A Longhurst‐Hardy plankton recorder was used near Guadalupe Island (Baja California) to obtain information on the small‐scale horizontal patchiness of a number of zooplankton species. On one occasion, a daytime series of 11 horizontal recorder tows was taken forming a grid over an area 500 m square at 90‐m depth (total number of samples, 459). On another, a single long nighttime horizontal tow was taken at 20 m (82 samples).

A method has been developed to measure spatial structure in terms of patch size and shape, number and distribution of patches in the grid area, concentration of individuals in each patch, and densities of background individuals. The patches were approximately circular with a median patch radius ranging from 13.6 to 15.6 m for the species on the grid and 38.4 to 73.1 m for the night tow. Estimates of the numbers of patches in the grid area ranged from 183 to 222. They were distributed randomly. Average densities of individuals in the patches over the grid varied from 2.6 to 5.1 times the background densities. Although the abundances of different species showed a significant degree of concordance, the relationship between the same species pair on different tows and between different species pairs was quite variable.

The degree of aggregation of the less abundant species was associated with their density; the lower the density the less frequently significant departures from a random expectation were observed.
MECHANISMS FOR THE ACCUMULATION OF HIGH CONCENTRATIONS OF DINOFLAGELLATES IN A BIOLUMINESCENT BAY1
Authors: Seliger H. H. , Carpenter J. H. , Loftus M. , McElroy W. D.
Published: March 2010

The bioluminescent, photosynthetic, tropical marine dinoflagellate Pyrodinium bahamense occurs in persistent high concentrations in Oyster Bay, Jamaica, W. I., although mean tidal flushing rates determined by dye‐tracer techniques would predict their disappearance. As a result of a unique temporal sequence of positive phototaxis and the differential movement of diurnal wind‐driven water layers of different densities, there is a daily transfer of P. bahamense into the eastern shallows of the bay where flushing rates are minimal, reducing the effect of the mean bay dilution. A second phototaxis‐dependent mechanism in the eastern shallow results in zones of high concentration containing up to 10,000,000 P. bahamense per liter. This latter mechanism can explain the production of red water outbreaks in coastal waters. Nitrogen and phosphorus levels observed are consistent with both mechanisms.
ANALYSIS BY DANSYLATION OF AMINO ACIDS DISSOLVED IN MARINE AND FRESHWATERS1
Authors: Litchfield Carol D. , Prescott J. M.
Published: March 2010

Dissolved amino acids in seawater, pond water, and spent algal media have been qualitatively analyzed by dansylation, extraction, and thin‐layer chromatography. The amino acids were dansylated directly following adjustment of the pH of the samples, and at least 1,000‐fold concentration was achieved by using diethyl ether to extract the amino acid derivatives, which were then applied to thin‐layer plates and chromatographed in two dimensions. Analyses revealed aspartic acid to be present in all samples; the other amino acids most frequently found were serine, glycine, alanine, and arginine. Additional amino acids, peptides, and several unidentified spots were also observed.
MEASUREMENTS OF REACTIVE PHOSPHORUS ASSOCIATED WITH PELAGIC SARGASSUM IN THE NORTHWEST SARGASSO SEA1
Authors: CULLINEY JOHN L.
Published: March 2010

Paired surface samples collected within and outside of large patches of Sargassum in the northwest Sargasso Sea in November 1965 contained reactive phosphorus in concentrations generally higher than those previously reported. Sargassum patches apparently form a chemical microenvironment significantly richer in reactive phosphorus than open surface waters of the Sargasso Sea. Diffusion of P‐PO4 from Sargassum masses may increase its concentration in immediately surrounding waters.
A SENSITIVE METHOD FOR THE DETERMINATION OF OPEN OCEAN PHYTOPLANKTON PHYCOERYTHRIN PIGMENTS BY FLUORESCENCE1
Authors: MORETH CLARICE M. , YENTSCH CHARLES S.
Published: March 2010

The concentration of the phycoerythrin pigments is measured in 0.1 m phosphate buffer, pH 6.0–7.0, using a sensitive fluorometer. Ten units on our fluorometer are equal to 0.002 OD 1‐cm cell at 540 nm. The maximum variation after extraction is less than 5%. The method is highly suitable for routine analysis at sea or in the laboratory.
SALINITY EFFECTS ON THE DETERMINATION OF STRONTIUM IN SEAWATER BY ATOMIC ABSORPTION SPECTROPHOTOMETRY
Authors: CARR RODERICK A.
Published: March 2010

Salinity differences between samples and standards may be a source of error in the determination of strontium in seawater by atomic absorption spectrophotometry. If calibration is by reference to artificially prepared standards, these standards must match the sample solutions in salinity. For this reason, recently published values for strontium in the marine environment, determined by atomic absorption, are probably low.
SOME EFFECTS OF FILTRATION ON THE DETERMINATION OF COPPER IN FRESHWATER AND SALTWATER
Authors: MARVIN K. T. , PROCTOR R. R. , NEAL R. A.
Published: March 2010

Analysis of variance calculations were made to interpret the effects of filtration, initial copper concentration, and type of water on the concentration of copper in filtered samples of freshwater and saltwater. Five types of filters were tested. Filtration constituted a significant source of variation. Each filter tested reduced the reliability of the copper determination.
EFFECT OF TEMPERATURE ON THE pH OF SEAWATER
Authors: GIESKES JORIS M.
Published: March 2010

In a recent paper on the effect of temperature on the pH of seawater, I erroneously omitted the effect of borate on the pH. A discussion of this error is presented here.