bluuebunny/crossref_metadata_2025 huggingface dataset:
Length, Weight, and Age Composition of the Menhaden Catch in Virginia Waters1
Authors: McHUGH J. L. , OGLESBY R. T. , PACHECO A. L.
Published: March 2010

Major features of life history of menhaden (Brevoortia tyrannus) were deduced by examination of samples from commercial purse‐seine and pound‐net fisheries, and collections made by plankton nets, gill nets, and otter trawls. Menhaden are present in Virginia waters throughout the year. Spawning probably takes place in the ocean, and young move into Chesapeake Bay and its estuaries soon after hatching. As they grow, they move back down the estuaries toward the sea, so that, in most seasons, mean sizes of fish are progressively greater in a seaward direction. Few fish older than three years arc taken in the commercial fisheries. The purse‐seine fishery takes about 98 per cent of the total catch, operates from May to October, and exploits primarily fish in their third year of life in spring and early summer, and fish in their second year in late summer and fall. The pound‐net fishery takes principally fish in their second year in spring and early summer, and fish in their first year in late summer and fall. Prior sampling by the pound‐net fishery offers a method of forecasting purse‐seine catches at least a year in advance. Ages of menhaden up to the end of the third year of life may be determined by the length‐frequency method or by reading scales. Validity of the scale method has been established, and there is evidence that two groups of fish, characterized by their size at the time of formation of the first annulus, enter the Virginia fishery. Mean lengths at the end of each calendar year of life are approximately 125, 200, and 230 mm. Mean weights are about 30, 130, and 200 g. Spawning in the Chesapeake region probably is most intense in late fall and the following spring, associated with seasonal waves of emigration from and immigration to Chesapeake Bay. In this region maturity is reached at about one and one‐half years of age.
A Mechanism for the Mixing of the Waters of Lake Huron and South Bay, Manitoulin Island1
Authors: BRYSON REID A. , STEARNS CHARLES R.
Published: March 2010

The seiche in South Bay, Manitoulin Island, Ontario, consists of several components, some of which produce considerable displacements of the water which occupies the narrow entrance channel. Lateral currents displace Lake Huron water intruded into the bay by the seiche excursion, so that the return portion of the seiche cycle replaces the intruded water with Bay water, the exchange providing the mixing process. The seiche amplitude appears to be the major variable controlling the intensity of the mixing process.
Lake Water and Sediment
Authors: HAYES F. R. , MACAULAY M. A.
Published: March 2010

In defining the ability of a lake to produce a crop, one begins by taking a unit area for measurement, which is tantamount to saying that productivity is proportional to area. The productivity per unit area, P, has been stated by Hayes to be inversely related to depth, being where m is the mean depth in meters. P will have to be multiplied by a factor K which defines the crop, whether fish, plankton, etc. It is further necessary to recognize that lakes, like farms, are sometimes on good land, sometimes on poor. This important variant may be given numerical expression as a quality index, QI, which is supposed to tell what a given lake could produce if it were considered as of standard depth 5 m. QI was previously determined for a number of lakes on the basis of fish population, factored for length of food chain. It is made to fluctuate around unity so that K is given a value of unity for fish. Finally there is a reducing correction b to be applied to certain measurements on bog lakes, which have, for example, high oxygen consumption and bacterial counts but support few fish. The bog factor may be a function of color. The foregoing considerations lead to the equation

urn:x-wiley:00243590:media:lno1959430291:lno1959430291-math-0002

If a measurement were made on fish in a lake of 5 m depth, P would be the same as QI, all other terms having become unity.

Measurements are given of the oxygen consumption of water over mud in undisturbed profundal Jenkin cores from 16 east coast Canadian lakes. These are compared with artificial cores made by plunging a Jenkin tube into the mud of a dredge sample, and also with surface mud packed by centrifuge in bottles. All three methods gave the same values. On four lakes the field hypolimnetic deficit was compared with the laboratory tests. The mean oxygen consumptions were indistinguishable, but the field results did not arrange the lakes in the same order as laboratory tests and are judged to be related to basin dimensions rather than to productivity. Laboratory tests appear to be more accurate than field tests and of wider applicability, e.g., to unstratified lakes or bog lakes. In laboratory tests a water blank is subtracted so that consumption can be obtained for mud surface only.

For 9 lakes a regression is calculated between oxygen consumption and QI for fish. The relation is highly significant and is given as

urn:x-wiley:00243590:media:lno1959430291:lno1959430291-math-0003

where the units of oxygen consumption are mg used per cm2 mud surface per day.
Lake Water and Sediment
Authors: HAYES F. R. , ANTEIONY E. H.
Published: March 2010

Procedures are given and field apparatus described for use of the millipore filter technique for lake water and sediment bacteria. Agar plate and filter procedures give the same counts using a supplemented sodium caseinate medium. Direct counts were higher than colony counts by factors from 59 to 233, with a mean of 111. Cultures made on lake sediment extract in agar were inferior to the caseinate medium in unproductive lakes, but when taken from productive lake soils they were adequate to produce colony growth. Several hundred quadruplicate tests were studied to establish errors, which had two components: the theoretical error of a Poisson series which depends on the number of colonies on a filter, and a handling error which is ±9%. Combining the above errors with the natural variability of profundal sediment from station to station and visit to visit, and expressing the standard error of the mean as a per cent, the expectations are: one visit to take one core at each of four profundal stations comprising the top two or three cm will yield, on quadruplicate plates, an error of ±130%. Hence, while a single visit may set a quite useful maximum it cannot be used to set a minimum. In the procedure adopted four field trips as above were made, by which the error was reduced to ±36%.

Shallow cores, down to 15 cm or more, were sectioned. Surface scrapings did not yield the very high counts that others have reported. There was no significant decline in numbers down to about 5 cm, which comprises Naumann’s “actual” layer. Below this a decline sets in upon entering the “historical” layer. Deep cores were taken on two lakes down to base gravel presumed 15,000 yr old. There was a decline with depth which appeared to be logarithmic, although the deep counts were too close to zero to prove it.

The authors’ counts, supplemented by those of Henrici and McCoy, are plotted against other measurements thought to be related to productivity, namely methyl orange alkalinity, conductivity, and (in paper V of the series) oxygen consumption over mud. A good regression is observed in all clear‐water lakes. However, brown‐water lakes, although low in alkalinity and conductivity, have high bacterial counts. In these lakes there is a good correlation of bacterial count with water color. This provides a possible basis for stating what part of the bacterial count of any lake is to be attributed to bog. By subtraction of the bog fraction the real or useful measurement as indicative of productivity is obtained.
The Physical Oceanography of Narragansett Bay1
Authors: HICKS STEACY D.
Published: March 2010

Analyses of pertinent data from various physical oceanographic programs carried out in Narragansett Bay are presented in an effort to give a useful description of tidal characteristics, temperature and salinity distributions, and the nontidal circulation. The observed tides and tidal currents are shown to be the result of a standing tidal wave with a slight progressive component and a damping coefficient of 1.6. Both temperature and salinity distributions indicate essentially homogeneous bottom water in the upper part of the Bay as contrasted with the surface layer which possesses marked progressive changes over the same area. One direct measurement and the salinity distribution seem to confirm the nontidal circulation calculations which are based on river run‐off, surface nontidal currents, and cross sectional areas. Narragansett Bay appears to be an estuary in which the salt balance is maintained, under steady state conditions, by horizontal advection, vertical advection, and vertical eddy diffusion.
Antibacterial Activity of Antarctic Marine Phytoplankton1
Authors: SIEBURTH JOHN MCNEILL
Published: March 2010

Water and phytoplankton samples from the Weddell Sea were assayed for their antibacterial activity during the 1957–58 Argentine Antarctic Expedition. Four of seven sea water samples contained sufficient phytoplankton in volumes of 1 to 500 ml to inhibit bacterial growth. At three hydrographic stations phytoplankton retained by a coarse zooplankton net was inhibitory in concentrations as small as 100 parts per million on a wet volume basis (5 ppm dry weight basis). This antibacterial substance, which inhibited Gram positive organisms to a greater extent than Gram negative organisms, was active in fresh preparations, stable at 60°C for 30 min., labile when heat dried at 85°C for 40 min., water soluble and filterable. Phytoplankton in the stomach of euphausiids, Euphausia superba, also exhibited similar antibacterial properties. Such euphausiids, the staple diet of the penguins examined, apparently modify the gastrointestinal microflora of penguins.
Evidence of Internal Wave Activity in Cayuga Lake, New York1
Authors: HENSON E. B.
Published: March 2010

Temperature observations from a station near the southern end of Cayuga Lake, New York, reveal variations in the depths of the isotherms which suggest the presence of temperature seiches, or internal waves. The theoretical period of oscillation of a uninodal internal wave, based on summer temperature conditions of the lake, ranges between 55 and 58 hours. A sequence of temperature observations at the level of the metalimnion for the first eight days of August, 1951, are presented, and the observed variations are in accord with the theoretical variations. The winds during the time under consideration were reinforcing and occurred in synchrony with the seiche movements, producing an amplitude in excess of 20 meters which is about twice the normal amplitude. Observations of surface currents and temperatures give supporting evidence for the presence of internal wave activity.
DISSOLVED OXYGEN IN SWEETWATER LAKE
Authors: Ramsey W. L.
Published: March 2010

In Sweetwater Lake, near San Diego, California, vertical distribution of dissolved oxygen was observed to be highly stratified during the early summer months. With the lake at a maximum depth of about 32 ft, the lower 5 to 10 ft were devoid of oxygen by early July but mid‐depths and upper levels remained well‐oxygenated throughout the period of observation. The pattern of oxygen distribution in the lake appeared to reflect the prevailing summer circulation which consisted of rapid down‐wind movement at the surface with counter‐currents at mid‐depths and smaller circulation cells at lower depths. Rising summer temperatures caused an increase in the depth of the upper layer of water saturated or supersaturated with oxygen. The drop in solubility of oxygen due to heating of the surface layers of water was proportionally greater than the decrease in oxygen content, producing an increase in saturation values. Thermal stratification seemed to be sufficient, by reduced vertical mixing, to maintain the lake in a condition of oxygen‐rich epilimnion and oxygen‐depleted hypolimnion.

Serial observations showed a diurnal cycle of rising oxygen content in the surface layers in late afternoon and evening, probably the results of the photosynthetic activity of the phytoplankton and the circulation of high oxygen water from the shallow end of the lake.

Simultaneous sampling of the water at various depths for oxygen analysis and measurement of light transmission with a hydrophotometer produced no correlation between oxygen content and turbidity. Simultaneous measurement of sound velocity, attenuation and oxygen content also produced no conclusive results.
BENTHIC STUDIES IN BUZZARDS BAY II. THE MEIOFAUNA1
Authors: Wieser Wolfgang
Published: March 2010

During the summer of 1957 a study of the small metazoans (meiofauna), based on a series of Phleger core samples, was undertaken at three stations in Buzzards Bay, Massachusetts. The number of animals ranged from 1.69 x 105 to 1.86 x 106/m2, the dry weights varied from approximately 100 to 600 mg/m2. The nematodes and kinorhynchs, which comprised between 89 and 99% of the total mieofauna, were studied in detail. The sandy localities (stations P and J) were characterized by a number of nematodes restricted to this habitat, particularly by three representatives of the genus Odontophora and by all representatives of the genus Leptonemella. The locality rich in fine deposits (station R) was characterized by the relative abundance of several nematodes, particularly of Terschellingia longicaudata, and the three kinorhynch species. It was possible to recognize an Odontophora‐Leptonemella community in the sandy habitats, and a Terschellingia longicaudata‐Trachydemus mainensis (kinorhynch) community in the silty habitat, the former being equivalent to the Ampelisca community, the latter to the Nucula proxima‐Nephthys incisa community described for the macrofauna in the same area. However, these “communities” can also be considered as two ecological groups of species, the former dependent on the presence of sand, the latter on that of fine deposits, which actually live side by side, forming an intricate meshwork of faunal combinations. Each combination is determined by the relative amounts of sand and fine deposits present.

The uniformity of the nematode fauna within each station was greater than that between two different stations. Most important in determining the degree of faunal uniformity between paired samples is the similarity in their silt‐clay content. However, other mechanical factors also play a role.

An analysis of the total species composition of the nematode fauna revealed that Terschellingia longicaudata was the most abundant species at station R, whereas at the stations P and J there were three or four equally dominant species. This is interpreted as indicating a splitting up of the sandy habitat into subhabitats. The simultaneous occurrence of closely related species in this environment further supports the conjecture.

The distribution of “buccal types” amongst nematodes is correlated with the distribution of sediments.
A LIMNOLOGICAL COMPARISON OF TWELVE LARGE LAKES IN NORTHERN SASKATCHEWAN
Authors: Rawson D. S.
Published: March 2010

Five large lakes on the rocky Precambrian Shield of northern Saskatchewan are definitely oligotrophic. Five others on the glacial drift south of the Shield are clearly eutrophic and two across the boundary are intermediate. From the analysis of extensive data, five physical and three biological criteria have been selected which tend to agree in indicating the trophic nature and relative productivity of these lakes.
OXYGEN CONSUMPTION OF BIVALVE PREY AND THEIR ATTRACTIVENESS TO THE GASTROPOD, UROSALPINX CINEREA1
Authors: Blake John W.
Published: March 2010

Relative attractiveness of Crassostrea virginica and Modiolus demissus to Urosalpinx was studied to determine whether oxygen consumption of prey is correlated with selection by the predator. Comparisons between individuals of one prey species and both species demonstrated a direct correlation between oxygen consumption (used as an index of respiratory metabolism) and number of Urosalpinx attracted. Four factors affecting metabolic rate of prey were studied: species, age, growth rate, and feeding. In each case the more attractive animals had a proportionately higher respiratory rate. Urosalpinx responded in equal numbers to groups of prey of different individual, but equal group, respiratory rates. Thus this work supports the hypothesis that a metabolic product mediates the predator’s choice of a particular individual within a group of prey. Selection is independent of concentration of dissolved oxygen or carbon dioxide.
OBSERVATIONS ON THE ECOLOGY OF THE SOFT CLAM, MYA AREN ARIA, IN A SALT POND1
Authors: Matthiessen George C.
Published: March 2010

Observations were made on the ecology of the soft clam, Mya arenaria, in a salt water pond on Martha’s Vineyard, Mass., during the summer and fall of 1958. Primary consideration was given to the tolerance of this species to low and fluctuating salinities, the effect of salinity upon rate of growth, and possible correlation between growth rate and the nature and abundance of phytoplankton.

Field observations supplemented by laboratory experimentation indicated that Mya longer than 2 mm can tolerate salinities less than 1‰ for at least 24 hrs and can withstand sudden salinity fluctuations of an order of 18‰. Tolerance of clams 2–5 mm in length to low salinities was found to be proportional to their size.

Growth rate of clams living under different salinity conditions ranging in mean value from 3.5‰ to 14‰ was found to vary directly with salinity. The fact that the pumping rate of clams was observed to vary directly with salinity within the limits 0–31‰ is considered significant in this respect.

Comparisons of growth rates with phytoplankton concentrations suggested that flagellates form an important source of nutrition for Mya and that diatoms may be of relatively little importance.
BIOTIC CHANGES IN A BAY ASSOCIATED WITH THE END OF A DROUGHT1
Authors: Hoese H. Dickson
Published: March 2010

Heavy rainfall in early 1957 broke the most severe drought in the history of Texas. Resultant heavy river discharge reduced salinities in Mesquite Bay on the Central Texas Coast by over 30‰ in two months. Effects on the bay fauna were catastrophic with complete mortality of stenohaline marine sessile and infaunal mollusks. The flora and fauna of the high salinity drought period and of the subsequent low salinity period are compared. A high salinity Ostrea equestris‐Brachidontes exustus community was replaced in 1957 by a Crassostrea virginica‐Brachidontes recurvus community. The rapid lowering of salinity apparently did not kill fishes and other motile forms; in most cases these must have escaped by moving out of the area, but several stenohaline species were found in very low salinities immediately after the influx of fresh water. Mortality of euryhaline mollusks occurred in 1958 when salinities fell below 3‰. Some relations of organisms to salinity are discussed from ecological and paleoecological viewpoints.
UPTAKE OF Zn65 AND PRIMARY PRODUCTIVITY IN MARINE BENTHIC ALGAE1
Authors: Bachmann Roger W. , Odum Eugene P.
Published: March 2010

The rate of uptake of Zn65 from natural sea water and the primary production of 6 species of marine benthic algae were measured in light and dark bottles suspended in a running sea water aquarium under constant light and temperature conditions. Uptake and production of one species (Chaetomorpha Linum) were also measured in bottles suspended at different depths in a marine pond in order to achieve a gradient of light intensities. Definite uptake occurred in the light, but no measurable uptake occurred in the dark. The initial rate of uptake in the light was proportional to the gross oxygen production which varied with the species. The apparent equilibrium uptake rates in Chaetomorpha at different light intensities were proportional to the net oxygen production. The data indicated that in marine seaweeds zinc is taken up in proportion to the gross oxygen production and accumulated in proportion to the net oxygen production. Consequently Zn65 has possibilities as a tool for the measurement of primary productivity.
TEMPERATURE VARIATIONS IN ESQUIMALT LAGOON—A SMALL LANDLOCKED BODY OF WATER SUBJECT TO TIDAL FLUSHING1
Authors: Scrimger J. A.
Published: March 2010

Time series observations, extending over two tidal cycles, of temperatures and micro‐temperature fluctuations at different positions and surface wave amplitudes at two fixed locations have been obtained in Esquimalt Lagoon (Esquimalt, B.C., Canada). The Lagoon is coupled to the sea by a narrow channel which permits about one‐third of the low tide water to be exchanged during a tidal cycle. A technique using drags and aerial photographs has enabled the water circulation to be measured. Temperatures measured two inches from the bottom exhibit remarkable stability (<0.1 °C fluctuation). No correlation between vertical temperature structure and surface waves or between micro‐temperature fluctuations and surface waves is observed.
CARBAMINO CARBOXYLIC ACIDS IN PHOTOSYNTHESIS1
Authors: Smith James B. , Tatsumoto Mitsunobu , Hood Donald W.
Published: March 2010

Cultures of Platymonas sp., Nitzschia closterium, and Porphyridium cruentum were found to utilize the carbamino complex of alanine or sea water concentrates in preference to inorganic forms of CO2 for photosynthesis. Evidence for this was obtained by inhibition of C14O2 uptake of photosynthesizing cells upon addition of the complex. Cell growth and oxygen evolution, however, continued to increase in a normal fashion. By labeling the complex in different portions of the molecule, it was shown that the plants were utilizing the N‐carboxylate group directly as a source of CO2 while utilization of other portions was not evidenced.

Several other organic compounds were tested for response in the algae but only ammonium carbonate, known to contain small portions of ammonium carbamate, acted similarly.
EPIBENTHIC ALGAL PRODUCTION IN AN INTERTIDAL MUDFLAT
Authors: Leach J. H.
Published: March 2010

Epibenthic algal production in an estuarine mudflat was measured during 1968 by a 14C method. Seasonal production was correlated with solar radiation, temperature, and standing crop of functional chlorophyll, but not with the amount of organic carbon. Standing crop of living plant material in the sediments was equivalent to 15% of organic carbon in summer and 10% in winter. Annual production (31 g C/m2) was equivalent to about a third of mean organic carbon in the sediments.
CARBONATE ALKALINITY IN THE PORE WATERS OF ANOXIC MARINE SEDIMENTS1
Authors: Berner Robert A. , Scott Martha R. , Thomlinson Catherine
Published: March 2010

The principal factor affecting carbonate alkalinity in pore waters of organic‐rich aluminosilicate muds from the central Connecticut coast and a Maine fjord is bacterial sulfate reduction. Measured (titration) alkalinity is equal to that calculated from measured changes in SO42−, Mg2+, Ca2+, and NH4+. As a result of alkalinity increase, pore waters of anoxic sediments can become highly supersaturated with CaCO3. Precipitation of Ca.CO3 may not occur, however, possibly because of the inhibiting effect of dissolved organic matter. No evidence is provided by these sediments for authigenic aluminosilicate formation.
THE ROLE OF ZOOPLANKTON IN THE NUTRITION OF SOME SCLERACTINIAN CORALS1
Authors: Johannes R. E. , Coles Stephen Lee , Kuenzel Nancy T.
Published: March 2010

Over 15 days of continuous monitoring, the mean nocturnal concentration of drifting net zooplankton in a coral reef community on the Bermuda platform was 0.83 mg m−3. The mean respiration rate of reef‐building corals at the study site was calculated to be 6.4 g O2 day−1 m−2 of reef bottom. Using these data we show that the energy requirement of these corals was more than an order of magnitude greater than the energy they could obtain by capturing the sparse zooplankton in the surrounding waters.

The question follows, why, if corals can exist in the absence of energetically significant quantities of zooplankton, do their elaborate anatomic modifications for catching zooplankton persist? Evidence indicates that corals cannot obtain their phosphorus requirements from solution. We therefore suggest that relatively small amounts of zooplankton may be important as a source of phosphorus and perhaps of other essential nutrients for both the coral and its algal symbionts.
THE SUBSURFACE BOUNDARY BETWEEN SUBARCTIC PACIFIC WATER AND PACIFIC EQUATORIAL, WATER IN THE TRANSITION ZONE OFF SOUTHERN CALIFORNIA
Authors: Blanton Jackson , Pattullo June G.
Published: March 2010

Correlations of temperature with salinity and of temperature with oxygen demonstrated that in summer 1955, between southern California and Hawaii, there was an abrupt transition from Subarctic Pacific Water to a modified Pacific Equatorial at depths where thermosteric anomalies vary between 125 and 70 centiliters per metric ton. Between 125° and 140° W long the transition (a weak east‐west frontal zone) was well defined at about 26.5° N lat. East of 125° W, the front was not well defined.

The oxygen minimum zones were found at different depths and at different thermosteric anomaly surfaces on either side of the transition. The oxygen minimum for Subarctic Pacific Water was about 200 m deeper than that of the water from the south. The two oxygen minimum zones were clearly separated by an “enriched” zone of dissolved oxygen which we take as evidence of vertical mixing. Vertical mixing was most strongly indicated nearshore in the vicinity of Point Conception.

The boundary has a slope, with Subarctic Pacific Water overriding the southern water. The velocity difference across the boundary using the Margules‐Witte equation is 4 cm/sec cyclonically.
A NEAR‐BOTTOM SUSPENDED SEDIMENT SAMPLING SYSTEM FOR STUDIES OF RESUSPENSION1
Authors: SCHIEMER E. W. , SCHUBEL J. R.
Published: March 2010

Studies of the resuspension of bottom sediment require periodic collection of samples at several levels close to the bottom. We have designed a bottom‐mounted support rod with intakes for pumping water samples from fixed levels above the bottom. All of the sampling tubes are purged continuously, and samples are selected with a special 6‐way valve.
THE SECCHI DISK IN TURBID COASTAL WATERS1
Authors: Holmes Robert W.
Published: March 2010

Measurements of Secchi disk depth are correlated with beam transmittance (B) in turbid coastal water. Both k (the irradiance attenuation coefficient) and α (the beam attenuance coefficient) can be estimated from the Secchi depth either on an empirical basis or by using the Duntley‐Preisendorfer equation of contrast reduction. Such estimates possess relatively large standard errors of estimate.

The effects of the size of Secchi disk and viewing techniques are discussed. An estimate of contrast threshold of the human eye under field conditions has been obtained. A modification of the factor in the Poole and Atkins equation for estimating k from Secchi depth is suggested.
CHEMISTRY AND ORIGIN OF FRESHWATER FERROMANGANESE CONCRETIONS
Authors: Hawks Robert C. , Troup Arthur G.
Published: March 2010

Ferromanganese concretions from Grand Lake and Ship Harbour Lake in Nova Scotia and Mosque Lake in Ontario are most common in water 0.5 to 2 m deep. X‐ray diffraction studies show the ferromanganese portions of the concretions to be amorphous. Petrographic and electron probe studies of the ferromanganese material reveal chemical banding of iron and manganese. Bulk chemical analyses indicate that the Fe : Mn ratios of concretions from different sites within a single lake are similar, whereas concretions from different lakes have characteristic Fe : Mn ratios. Trace element concentrations are different in different lakes and are generally several orders of magnitude less than those of oceanic nodules.
CYCLING OF ZINC‐65 BY COLIUMBIA RIVER PERIPHYTON IN A CLOSED LOTIC MICROCOSM1
Authors: Cushing Colbert E. , Rose Fred L.
Published: March 2010

Studies of 65Zn cycling by periphyton were performed in a closed, lotic microcosm under varying light regimes, community state, initial ambient concentrations, and stable divalent cation concentrations.

Uptake of 65Zn was considerable in continuous light, continuous darkness, a 12‐hr photoperiod, or by killed communities, indicating a dominant adsorptive uptake mechanism. Uptake of 65Zn was shown to be proportional to the initial ambient concentration of 65Zn, which decreased during the course of an experiment. Increasing the concentration of stable zinc or magnesium proportionately decreased the uptake of 65Zn, illustrating a competition for binding sites and supporting the adsorptive uptake theory.

A discussion of the significance of this work to the reporting of concentration factors is presented. The similarity in function between the heterogeneous periphyton community and unialgal cultures or single species of plants is pointed out.
SOME LIMNOLOGICAL OBSERVATIONS FROM ENDERBY LAND, ANTARCTICA1
Authors: MacNamara E. E.
Published: March 2010

The physical and chemical properties of freshwater lakes, ponds, and melt pools of coastal ice‐free areas of Enderby Land, Antarctica, and their seasonal dynamics, are discussed. The waters are significantly less mineralized than has been reported in other ice‐free areas of the antarctic. Tentative explanations for the divergencies are the location of the area with respect to storm tracks and the true melt‐water nature of the lakes. Primary production was variable and dependent on many factors, including seasonal temperature cycles in the water bodies.
NITROGEN UPTAKE BY PHYTOPLANKTON IN THE DISCONTINUITY LAYER OF THE EASTERN SUBTROPICAL PACIFIC OCEAN1
Authors: Goering J. J. , Wallen D. D. , Nauman R. M.
Published: March 2010

In the eastern subtropical Pacific Ocean off the continental shelf of Mexico, a pronounced discontinuity layer often exists within the euphotic zone. Phytoplankton in this layer used nitrate as their major inorganic source of nitrogen, while those in the overlying nutrient‐impoverished water used ammonium ion. The uptake of 14C‐HCO3− generally exhibited two maxima, one above the discontinuity layer and the other within it. Chlorophyll a concentrations usually increased with depth and reached maximum concentrations in the discontinuity layer. The chlorophyll a found at the upper boundary of the discontinuity layer exhibited low or undetectable 14C uptake.
THE PRESERVATION OF ACANTHARIANS IN FIXED PLANKTON SAMPLES1
Authors: BEERS JOHN R. , STEWART GENE L.
Published: March 2010

The spicular skeletons of acantharians dissolve readily in formalin‐seawater fixative solutions at pH levels of 3, 7, and 8.2. This dissolution has been checked by adding SrCl2· 6H2O to the fixative to increase the concentration of strontium to 10 times the normal seawater level of 8 mg/liter.
INORGANIC ZINC COMPLEXES IN SEAWATER1
Authors: ZIRINO ALBERTO , HEALY MICHAEL L.
Published: March 2010

The variation of zinc peak current with pH in the voltammetric analysis of seawater is interpreted in terms of a metal‐ligand model. The model indicates that at the upper range of pH values in seawater, a substantial fraction of the zinc is present in complex forms. Preliminary field data are presented which suggest that these complexes may occur in the open ocean.
A COMPUTER MODEL STUDY OF ZOOPLANKTON PATCHINESS AND ITS EFFECTS ON SAMPLING ERROR1
Authors: Wiebe Peter H.
Published: March 2010

A computer model using estimates of patch structure parameters determined from an ocean study was developed to study the effects of spatial structure on the error of replicate net tows. The precision of nine replicate tows increases with increasing patch size, regardless of the position of the patch centers, and the largest net provides the most precise estimates. Lengthening the tow also results in significant increases in precision (up to a factor of 2), not related directly to increases in the volume of water filtered, but apparently to the increase in the probability of sampling the “right” number of patches. When spatial structure is homogeneous, increasing tow length results in a larger reduction of sampling error than does a corresponding increase in net diameter. In general, better estimates of species proportions are obtained when the numbers of individuals per species are inequitably distributed and the degree of patch overlap is the greatest.
ON THE APPARENT OXYGEN UTILIZATION AND THE PREFORMED PHOSPHATE IN THE OCEANS1
Authors: Pytkowicx Ricardo M.
Published: March 2010

This work shows that the apparent oxygen utilization (AOU) expresses the oxygen utilized between the surface and some point within the oceans, even though the dissolved oxygen content at that point results not only from utilization by oxidation but also from the mixing of waters. This result is applied to an interpretation of the concept of preformed phosphate.
ULTRAVIOLET COM.BUSTION OF DISSOLVED ORGANIC NITROGEN COMPOUNDS IN LAKE WATERS1
Authors: Manny B. A. , Miller M. C. , Wetzel R. G.
Published: March 2010

Ultraviolet combustion of lake waters combined with sensitive spectrophotometric NO3 + NO2‐N and NH4‐N analyses offers a 100‐fold increase in sensitivity over the micro‐Kjeldahl method for total dissolved organic nitrogen. The procedure permits quantification of two organic nitrogen fractions in lake waters based on the relative rate and amounts of labile NH4‐N and refractory NO3 + NO2‐N released. Combustions of water from six lakes under uniform conditions disclosed widely different amounts of the two fractions and increased amounts of the refractory fraction with increased depth in one lake.

Duration of combustion, pH, and adequate oxygen affected ultraviolet combustions of freshwater samples and must be controlled to achieve uniform results. A recommended procedure for freshwaters consists of 1.5–3 hr of combustion with continuous oxygenation at pH 4.0 buffered with boric acid.

Additions of organic carbon as glucose and glycine or tryptophane to standard solutions and natural lake samples demonstrated that the rate of nitrogen release and the final combustion product expression were a function of: 1) the molecular nature of the dissolved organic nitrogen compound (DONC), 2) the concentration of total dissolved organic carbon (TDOC), and 3) the inorganic salt concentration.

Use of this procedure in comparing lakes of different trophic status should permit investigation of the role of DONC and its decomposition in primary production processes of lake ecosystems.
SUBSURFACE AND SURFACE SAMPLING OF BENTHIC INVERTEBRATES IN TWO STREAM1, 2
Authors: RADFORD D. S. , HARTLAND‐ROWE R.
Published: March 2010

A new subsurface sampling technique for collecting macroinvertebrates in gravel‐bottom streams is described. The cylinder sampler collects all species whose presence is indicated by a Surber sampler, but the percentage composition of the population sampled is different. With this method, a far larger number of benthic invertebrates is obtained, making it possible to reduce the number of samples to 10 or less and yet obtain estimates within 20% of the true mean of the benthic invertebrate population inhabiting the top 17.5 cm of substrate.
PARTICULATE AND DISSOLVED ORGANIC MATTER IN THE AMERASIAN BASIN OF THE ARCTIC OCEANS1
Authors: KINNEY PATRICK J. , LODER THEODORE C. , GROVES JOANNE
Published: March 2010

Vertical profiles for total particulate matter, particulate organic carbon, particulate organic nitrogen, and dissolved organic carbon were determined along with supporting hydrographic and chemical parameters in the Amerasian Basin of the Arctic Ocean.
THE AMERICAN SPECIES OF EUBOSMINA SELIGO (CRUSTACEA, CLADOCERA)
Authors: Deevey Edward S. , Deevey Georgiana B.
Published: March 2010

Eubosmina is represented in the Americas by at least four species, of which two, E. coregoni (Baird) and E. longispina (Leydig), are Holaretic; E. hagmanni (Stingelin) and E. tubicen (Brehm) appear to be strictly Neotropical. Eubosmina coregoni, which lacks a mucro, has rarely been reported from North America, but now appears to be common in the Great Lakes. Eubosmina longispina, with ventral incisures on the mucro, is familiar as a late‐ and postglacial fossil in the eastern U.S. and is the common bosminid today in northern New England and eastern Canada. The two American endemics, both with dorsal incisures on the mucro, occur widely from Argentina to southern Canada; the more widespread, E. hagmanni, is known from Tierra del Fuego and may occur in the Canadian Arctic. The two can be difficult to separate unless males are present, as they rarely are. In typical summer populations, however, the female rostrum shows positive allometry in E. hagmanni but negative allometry in E. tubicen; the mucro shows zero or weakly negative allometry in E. hagmanni but positive allometry in E. tubicen. In no known locality do these two species occur together, but in a few New England and Canadian lakes, where E. longispina is present, populations that otherwise resemble E. tubicen show negative allometry of the mucro. This situation is provisionally attributed to character displacement.
THE ANNUAL CYCLE IN QUANTITY AND COMPOSITION OF THE ZOOPLANKTON OF THE SARGASSO SEA OFF BERMUDA. I. THE UPPER 500 M1
Authors: Deevey Georgiana B.
Published: March 2010

A year‐round quantitative and qualitative study has been made of the zooplankton collected by oblique 0–500‐m tows with a meter net of No. 2 and No. 8 mesh nylon at semimonthly intervals from 16 March 1961 to 7 April 1962 at station “S,” 24 km southeast of Bermuda in 3,200 m of water. Highest dry weights and displacement volumes were obtained in March 1961 and April 1962, but total numbers remained fairly high for most of the year, with a January–February minimum. Seasonal cycles of all the more numerous organisms are described.

In the Sargasso Sea off Bermuda the annual cycle of zooplankton abundance is related to the degree of seasonal change; when the water column is mixed down to the permanent thermocline, greater quantities of phytoplankton and zooplankton are produced. In 1961– 1962 the mean standing crop of zooplankton was 70% of that recorded for Long Island Sound and Block Island Sound and 30% that of Georges Bank.

Specific diversity in plankton populations was investigated by means of MacArthur’s information‐theory model and values for the coefficient of equitability obtained for the copepods and pteropods in the Sargasso Sea and for copepods in Long Island Sound, Block Island Sound, and Texas coastal waters. A seasonal cycle in equitability of plankton populations is apparently typical of waters where there is a sufficient degree of seasonal environmental change to produce unstable conditions or to permit changes in species composition during a year. The evenness of distribution of copepod species is more dependent on environmental stability than on number of species. The equitability of the copepod populations in the Sargasso Sea appears to be inversely correlated with productivity.
SOME NOTES ON THE CONTROL OF SEXUALITY IN THE ROTIFER ASPLANCHNA SIEBOLDI1
Authors: Gilbert John J.
Published: March 2010

A mictic female‐inducing material, in addition to α‐tocopherol, is present in the grass meal “ex Perth.” This material and α‐tocopherol have Rf values of 0.71 and 0.65 when chromatographed on thin layers of silica gel G in petroleum ether, diethyl ether, and acetic acid (70 : 30 : 1). The activity in this less polar material cannot be attributed to a tocopherol isomer. Gas‐liquid chromatographic analysis showed this active material to contain at least 12 components, The only detectable source of biological activity in the grass Poa annua, both when fresh and when dried at 115C for 4.3 hr, was α‐tocopherol. When stored by a laboratory window at 23C for 2 weeks, P. annua contained no detectable α‐tocopherol but did contain a biologically active material with an of 0.71. This material probably is the same as that with an Rf of 0.71 in the grass meal and may be derived from α‐tocopherol, possibly through some heat‐labile or enzymatic process. Suspended particulate detritus originating from the decomposition of fresh P. annua in distilled water for 2 weeks had an average dimension of 30.6 µm and contained biological activity with an Rf of about 0.65. Information on the ecology of mictic female production in both Asplanchna brightwelli and A. sieboldi is summarized and discussed. The activity of P. annua detritus suggests that autochthonous and allochthonous algal and higher plant material which in the living state is unavailable to these rotifers subsequently may become available as particulate detritus material and provide an important source of compounds that induce mictic females.
THE HORIZONTAL‐VERTICAL DISTRIBUTION HYPOTHESIS: LANGMUIR CIRCULATIONS AND DAPHNIA DISTRIBUTIONS1
Authors: Stavn Robert Hans
Published: March 2010

The individual positions of a population of Daphnia magna Straus in a plastic chamber were recorded by infrared photography. The distribution of the Daphnia in the chamber was first observed during a 12‐hr light : 12‐hr dark regime and then during the photoperiod portion of the regime when spiral currents were introduced into the chamber. Observations during the 12L : 12D regime revealed a vertical migration tendency in the chamber while the horizontal position of the population oscillated from left to right.

The currents introduced into the chamber were analogous to natural Langmuir spirals: horizontal components at the top and bottom, a downwelling at the left, and an upwelling at the right of the chamber. A slow current system, of velocity range 0.8–2.4 cm/sec, and a fast current system of velocity range 2.0–8.8 cm/sec were studied. During the photoperiod (light intensity above 70 ergs cm−2 sec−1), the Daphnia shifted to the left side of the chamber in the slow current system and to the right in the fast current system. The population shifts were caused by Daphnia’s steady swimming position heading into the current and counterbalancing a current velocity of 1–2 cm/sec by its swimming efforts. When the light intensity was below 70 ergs cm−2 sec−1, at the beginning and end of the photoperiods, the Daphnia populations drifted with the currents, unable to oppose them. The dorsal light reaction functions above a threshold light intensity of 70 ergs cm− 2 sec−1, so the current orientation must be made possible by visual detection of currents. Vertical displacements decreased in both experiments.

From these experimental relations a model of active aggregation of Daphnia in Langmuir spirals has been constructed. The current velocity range within Langmuir spiral circulations will determine whether the Daphnia are aggregated in upwellings, downwellings, or in‐between portions of a spiral during a photoperiod. In darkness, passive aggregation tendencies described by earlier models will prevail. The presence of the dorsal light reaction in planktonic crustacea allows the generalization of the new model to account for at least the aggregation tendencies of planktonic crustacea.
CHARACTERISTIC FEATURES OF ESTUARINE CIRCULATION AS REPRESENTED IN THE MERSEY ESTUARY1
Authors: Bowden K. F. , Gilligan R. M.
Published: March 2010

Measurements have been made at a number of stations in the Narrows of the Mersey estuary of the residual, or nontidal, flow and the salinity distribution under a wide variety of conditions. The data have been analyzed in terms of a stratification‐circulation diagram as introduced by Hansen and Rattray. In this way the characteristics of the Mersey estuary have been compared with those of other estuaries and with the features of Hansen and Rattray’s theoretical model. In the central stretch of the Narrows, the density current circulation is highly developed and the advective mode accounts for about 75% of the upstream transfer of salt. Toward both the upstream and downstream ends of the Narrows, beyond which the estuary becomes wider and shallower, the advective transfer becomes less important than the diffusive processes. The value of the stratification‐circulation diagram in representing the conditions in an estuary and interpreting them in terms of the underlying processes is confirmed.
LAKE KINNERET: THE NUTRIENT CHEMISTRY OF THE SEDIMENTS1
Authors: Serruya C.
Published: March 2010

Lake Kinneret plays an important role in the water supply of Israel. Since the sediments may actively contribute to the nutrient supply causing the winter algal bloom, an extensive study of the mud‐water exchanges has been undertaken; the first results are reported here. The concentrations of Fe, Mn, P, N, organic‐C, and CaCO3 in recent sediments have been determined for the whole lake and the results discussed in the light of the chemical conditions of bottom waters, the detrital input, and the plankton composition. Only 4% of the total autotrophic carbon is withdrawn from the lake cycle by the sediments. The lake muds concentrate phosphorus in spite of the prevailing reducing conditions, which suggests an active physical adsorption. Conclusions are drawn concerning the role of clays as “nutrient fixer” and concerning lake management.
Accumulation of Stones on Beaches by Codium fragile1
Authors: Ben‐Avkaham Zvi
Published: March 2010

The green alga Codium fragile, recently introduced to the area, is a prominent transporter of rocks and gravel to Cape Cod beaches and may cause many sand beaches to evolve into gravel beaches.
Levels of Dissolved Oxygen and Carbon Fixation by Marine Microalgae1
Authors: J. S. Bunt
Published: March 2010

Seven species of marine microalgae including chlorophytes, diatoms, and a chrysomonad, of tropical, Antarctic, and temperate origin, were used to measure photosynthetic carbon fixation as affected by concentration of dissolved O2 at two levels of CO2. An apparent O2 inhibition of carbon fixation was observed in some species, but others were affected little or not at all by concentration of dissolved O2. In several cases, O2 appeared necessary for maximal carbon fixation.
Pigmentation of Algae under Pressure1
Authors: Seckbach Joseph
Published: March 2010

A simple acrylic plastic pressure vessel was designed for growing photosynthetic organisms under gas pressure and at elevated temperatures. Pressures ranging from 20–50 atm of CO2 were found to retard Cyanidium caldarium growth and to alter its pigmentation. In the cells subjected to this range of pressure an absorption shift of the chlorophyll a and carotenoid peak at 432 nm to a shorter wavelength (413 nm) was observed which may serve as an indicator for changes occurring within the algae. It was not observed in cells unaffected by pressure and was reversed in cells retransferred to ambient pressure. Lower hyperbaric CO2 pressures at room temperature or of 50 atm of argon at 45C permitted growth, and the absorption spectra were like those of cells grown under ambient pressure. Thus the pressure injury apparently was caused by toxicity of the gas (hyperbaric doses of CO2) rather than by pressure per se.
Effect of Temperature on the Feeding Behavior of Daphnia rosea
Authors: Kibby H. V.
Published: March 2010

Daphnia rosea were cultured at 12C for a prolonged period; filtering rates then determined over a range of temperature were significantly different from those of animals cultured at 20C.
BIOLUMINESCENCE AND PHYTOPLANKTON SUCCESSIONS IN BAIIIA FOSFORESCENTE, PUERTO RICO1
Authors: Seliger H. H. , Carpenter J. H. , Loftus M. , Biggley W. H. , McElroy W. D.
Published: March 2010

Bioluminescence and phytoplankton successions during 1960 indicate large oscillations from the stable Pyrodintum bahamense populations normally associated with bioluminescent bays. A mathematical model is proposed which relates meteorological conditions to positively and negatively phototactic dinoflagellate populations. The model and additional circumstantial evidence indicate that Bahia Fosforescente may no longer be a stable bioluminescent bay.