bluuebunny/crossref_metadata_2025_split huggingface dataset:
ENVIRONMENTAL CONTROL OF PHOTOSYNTHESIS IN THE SEA
Authors: Steele J. H. 
Published: March 2010

A theoretical equation for the photosynthesis‐light relation is developed which includes the effects of inhibition in intense light. Assuming 1) that phytoplankton adapts to seasonal light changes and 2) that nutrient deficiency affects the carbon:chlorophyll ratio of natural phytoplankton populations, equations arc derived which determine photosynthesis per unit chlorophyll and the carbon: chlorophyll ratio as functions of incident radiation and nutrient concentration.These equations appear to describe the main trends in the open North Sea and in a sea loch on the west of Scotland. The photosynthesis‐chlorophyll relation also describes the main trends of observations in the Sargasso. For a very shallow turbid area, the agreement was not so good.
MEASUREMENT OF VISIBLE LIGHT ABSORPTION BY PARTICULATE MATTER IN THE OCEAN1
Authors: Yentsch Charles S. 
Published: March 2010

For the measurement of visible light absorption by particles in sea water, optical arrangements have been devised where scattered light is integrated and the photodetector “sees” mostly diffused light. High spectral resolution has been obtained by removing particulate matter from sea water using a membrane filter and scanning the filter against an unused filter as the reference blank in the Cary spectrophotometer. In this fashion spectral curves for particulate matter in the oceans have been obtained. These curves show pigment banding in the upper 100 m of water characteristic of absorption by chloroplastic pigments. Below this depth the absorption of particulate matter is characterized by a gradual increasing attenuation from long to short wavelengths. Optical density ratios of chloroplastic pigment bands seen in the particulate matter of the upper 100 m suggest the presence of absorbing components not generally seen in algal cultures.Differential filtration through graded filter sizes (5.0 µ‐0.3 µ) followed by the spectral scanning of filters, shows that practically all of the chloroplastic pigments are retained by the 5.0 µ filter. Particles passing this filter show little selective attenuation of visible wavelengths.The nature of sea water particulate matter is discussed in terms of its absorbing characteristics as well as the significance to phytoplankton ecology.
FACTORS INFLUENCING THE MINERALOGY OF CARBONATE SEDIMENTS1
Authors: Chave Keith E. 
Published: March 2010

The mineralogy of carbonate sediments from Campeche Bank and Bermuda has been studied by use of X‐ray diffraction techniques. The sediment mineralogy appears to be mainly controlled by the skeletal mineralogy and size of organisms living locally. Selective physical destruction and transport and selective solution of more soluble skeletal elements appear to exert an influence on sediment mineralogy.Reef and near‐reef sediments contain the largest concentrations of high‐magnesium calcite, largely due to the presence of coralline algae such as Lithothamnium. Lagoonal sediments contain the most aragonite, and also contain abundant fragments of the green algae, Halimeda. Shelf, slope, and deep‐water carbonates are rich in low‐magnesium calcite, probably due to the presence of planktonic Foraminifera and algae.The effects of non‐biological processes on sediment mineralogy can be seen in the distribution of mineralogies among the different size fractions of the sediment. The most prominent feature of this is the regular increase in mineral stability—and associated decrease in mineral solubility—from the coarse to the fine fractions of sediments from a wide range of environments. It appears that in some areas the more soluble mineralogies are dissolved from the fine fractions of the sediments.
EFFECTS OF SUBLETHAL CONCENTRATIONS OF SEVERAL TOXICANTS ON GROWTH OF THE COMMON GUPPY, LEBISTES RETICULATUS1
Authors: Crandall Catherine A. , Goodnight Clarence J. 
Published: March 2010

The effect of prolonged exposure to sublethal concentrations of lead, zinc, and sodium pentachlorophenate were studied in the common guppy, Lebistes reticulatus. The concentrations used were 2 ppm lead nitrate (1.25 ppm as lead), five ppm hydrated zinc sulfate (1.15 ppm as zinc), and 0.5 ppm sodium pentachlorophenate. In addition, several fish were placed in 5 ppm lead nitrate (2.48 ppm as lead) and 10 ppm hydrated zinc sulfate (2.30 ppm as zinc).Newborn fish were added to the experimental and control solutions. At 30 days of age, the fish were weighed individually on an analytical balance. After this initial weighing, the fish were weighed at 15‐day intervals until the 90th day. Daily observations were made for the presence of sexually mature fish and any dead fish.It was found that with all three toxicants growth was retarded, mortality was increased, and sexual maturity was delayed.
LIMNOLOGY OF THE MIDDLE MISSISSIPPI RIVER. III. MAYFLY POPULATIONS IN RELATION TO NAVIGATION WATER‐LEVEL CONTROL1
Authors: Dorris Troy C. , Copeland B. J. 
Published: March 2010

Naiad populations of the mayfly Hexagenia rigida were studied in an isolated channel of the Mississippi River. Egg‐laying by adult females was concentrated at the upper end of the channel. Numbers of naiads were greatest at the upstream end of the channel during most of each summer. The naiads moved downstream prior to emergence.Following a winter in which the water level was drawn down about 4 ft for 6 weeks, the numbers of naiads were reduced at all stations. Populations near shore were reduced more than those in deeper water.
RESPONSE OF GAMMA SCINTILLATION DETECTORS FOR FIELD SURVEY USE
Authors: Proctor Charles M. , Lowrey Andrew R. , Papadopulos Emanuel , Penning John R. 
Published: March 2010

Gamma scintillation spectra were obtained with several sizes of NaI (Tl) crystal, Pilot B plastic, and liquid detectors which were immersed in solutions of gamma‐emitting nuclides contained in a 2,300‐gal tank. The count rates for gamma photons in the Mev energy range were proportional to detector volumes. Integral count rates with plastic and liquid detectors were, respectively, 39% and 33% of the rate with NaI(Tl).Factors in the selection of detectors for field use are discussed.
NITRATE MEASUREMENTS IN THE PRESENCE OF HIGH NITRITE CONCENTRATIONS1
Authors: Vaccaro Ralph F. , Thunberg Jon C. , Ketchum Bostwick H. 
Published: March 2010

Most accepted analytical procedures for nitrate in sea water become increasingly unreliable as tho nitrite concentration increases. We have developed an ozonation technique whereby nitrite is quantitatively oxidized to nitrate. In addition, we have formulated an equation to be used with the Mullin‐Riley (1955) reduction method when nitrite and nitrate are both present. This equation, unlike other recommended corrections, is based on demonstrated recoveries from known mixtures of nitrate and nitrite.In the ozone method the amount of nitrate produced is compared with the initial amount of nitrite. The difference in nitrogen, as determined by the two analyses, provides a method for estimating the quantity of nitrate originally present.Both the ozonation and numerical solutions appear particularly suited for studying nitrogen physiology of algal or bacterial cultures. Such studies often require analytical estimates for dissolved nitrate in the presence of high nitrite concentrations.
SUCCESSION OF TWO ACARTIA SPECIES IN ESTUARIES1
Authors: Jeffries Harry P. 
Published: March 2010

In New England and Middle Atlantic estuaries Acartia clausi, a winter—spring copepod, and A. tonsa, a summer—fall form, alternate cycles of dominance. Succession from clausi to tonsa during spring starts near the head of an embayment and spreads seaward.Concurrent observation in Narragansett Bay, Raritan Bay, and the York River plus an additional program in two Rhode Island lagoons indicated that this pattern of species replacement was not solely due to summer warming. Between 11 and 18°C, intermediate temperatures for reproduction of both species, tonsa was favored because it appeared less sensitive to brackish water than clausi.
OBSERVATIONS ON THE BIOLOGY OF THE AMERICAN LOBSTER, HOMARUS AMERICANUS
Authors: Hughes John T. , Matthiessen George C. 
Published: March 2010

American lobsters (Homarus americanus) have been hatched and reared at the Massachusetts State Lobster Hatchery, Oak Bluffs, Mass., since 1951. Individual lobsters have been held for as long as 10 years. Records have been maintained on seasonal occurrence of hatching, duration of the larval period, occurrence of molting with age and season, and rates of growth.The peak in hatching intensity occurs in late June or early July when water temperatures approximate 20°C. Time required for larvae to attain the 4th stage appears to be inversely related to temperature above 18°C, with less evidence of temperature‐dependence below this level. Molting frequency declines with age; lobsters molt approximately 9 times during their first growing season but no more than once annually by their sixth growing season. Molting occurs most frequently in early summer and again in early fall. Growth rates indicate that a period of 5 years from date of hatching is required for a lobster to attain legal marketable size—3 3/16 in. carapace length—in Massachusetts. Percentage increase in length per molt declines with age.
ISOLATION OF PYRITE SPHERULES FROM RECENT SEDIMENTS
Authors: Vallentyne J. R. 
Published: March 2010

A microscopic examination of approximately 200 sediment samples, mostly freshwater in origin, revealed an abundance of pyrite spherules in virtually all fine‐grained deposits that contained organic matter and reduced sulfur compounds. A speciel study was made of the spherules in deep‐water sediments of Little Round Lake, Ontario. The spherules there numbered approximately 450,000 per gram of dry sediment, accounting for 0.6% of the inorganic matter in the sediment. They ranged in diameter from 2 to 100 µ, but 75% or more had a diameter less than 11 µ.A method is described for the isolation of spherulitic pyrite from recent sediments based on heavy mineral centrifugation, flotation of pyrite spherules, and differential sedimentation of pyrite after rupturing the spherules into their component microcrystals. A sample of spherulitic pyrite isolated from the sediments of Little Round Lake was composed as follows: 53.16% sulfur, 46.59% iron, 0.13% silicon and 0.009% carbon, with only 0.11% of the weight unaccounted for. The silicon was thought to be partly due to contamination from other heavy minerals. Calculations based on the observed carbon content made it seem unlikely that the spherules could contain the organic microfossils that other workers have reported. The sulfur in the pyrite showed a 0.4% depletion in S34 as compared to sulfate‐sulfur in the surface water of the lake. Attempts to synthesize pyrite spherules in the laboratory were unsuccessful.
ZN65 UPTAKE BY BENTHIC MARINE ALGAE1
Authors: Gutknecht John 
Published: March 2010

The effects of various environmental factors on Zn65 uptake and loss were investigated in benthic algae. Increasing the pH promoted Zn65 uptake and retarded Zn65 loss in Ulva lactuca, Porphyra umbilicalis, and Laminaria agardi. A similar pH dependency was displayed by killed algae of the same species which in all cases absorbed more Zn65 than the live seaweed. The addition of carrier zinc to natural sea‐water wash solutions had little effect on the rate of Zn65 loss from radioactive algae. Increasing the temperature of the wash resulted in a slight increase in the rate of Zn65 loss. Polarographic determinations of the natural zinc content of algae were made. Fucus had the highest zinc concentration, 829 mg/kg dry wt, while Porphyra showed the lowest, 123 mg/kg.Exposure to light stimulated both the uptake and loss of Zn65. Uptake was retarded by two inhibitors, uranyl nitrate and phenylurethane. The biological half‐life of Zn65 in algae in the light and in the dark was estimated. Fucus showed a much higher retention of Zn65 than either Porphyra or Ulva. The effects of photosynthesis‐related pH changes on both metabolic and non‐metabolic uptake mechanisms are considered.
EXCRETION RATE OF ZN65 BY LITTORINA IRRORATA IN RELATION TO TEMPERATURE AND BODY SIZE1
Authors: Mishima Jiro , Odum Eugene P. 
Published: March 2010

Excretion of tracer amounts of Zn65 (in terms of biological half‐life) was followed in 3 sizes of Littorina irrorata at 3 constant temperatures in the laboratory and under field conditions in the natural habitat for a period of 39 days following the ingestion of a single dose. The general pattern of elimination could be resolved into 2 exponential phases, an early rapid loss phase for the first 10 days and a much less rapid loss phase thereafter. Biological half‐life of the “assimilated pool” of the second phase varied inversely with body size and directly with air temperature. Individuals in the field excreted the tracer more rapidly than those confined to glass bowls in the laboratory. Analysis of variance showed that both environmental conditions and body size had a highly significant effect on the excretion rate. Furthermore, trends in relation to temperature paralleled the expected rate of O2 consumption as calculated from data obtained in a previous study.It is tentatively concluded that, after the non‐assimilated tracer has been eliminated in the early phase, Zn65 becomes sufficiently bound to the biomass so that the whole body rate of excretion reflects rate of activity of the individual. Since body retention of a gamma‐emitter can be easily determined in the field by periodic recapture and whole body counts, this technique may provide an index to the long‐term rate of metabolism which can not be measured directly in free‐living animals.
ZOOPLANKTON COLLECTIONS FROM THE HIGH POLAR BASIN WITH SPECIAL REFERENCE TO THE COPEPODA1
Authors: Johnson Martin W. 
Published: March 2010

Analysis was made of 57 plankton tows taken to depths of 2,000 m from 81°14′ N, 85°16′ N during a portion of the 1957–58 drift of the ice flow Drift Station Alpha in the high Polar Basin. Thirty‐one species of calanoid and 3 species of cyclopoid copepods were identified. Some uncertain species are discussed and figured.The most abundant species were Calanus glacialis, Calanus hyperboreus, and Metridia longa. These were most abundant above 100 to 200 m but were found sparsely distributed to depths of 1,000 to 2,000 m. There was an increased number of species with depth of sampling up to about 1,000 to 1,500 m. There appeared to be a rather wide period over which reproduction takes place in some species especially Pareuchaeta glacialis.Although most copepods carried by water currents from the Bering Sea and Chukchi Sea areas succumb before reaching the high Arctic, still a few expatriates were taken, notably Eucalanus bungii bungii and possibly Mimocalanus distinctocephalus.
PLANKTONIC FISH EGGS AND LARVAE OF NARRAGANSETT BAY1
Authors: Herman Sidney S. 
Published: March 2010

Planktonic fish eggs and larvae were collected weekly at 4 stations in Narragansett Bay, over a period of one year from March 1957 to March 1958. Thirty‐six species of fish eggs and larvae were identified.The peak in spawning activity occurred from late May through mid‐August. The peak of fish egg production occurred in June and July, and the period of low abundance occurred between September and February. Peaks of larval abundance were found in July and August and again in January and March. Deeper areas in the Bay contained greater concentrations and a greater variety of species than did the shallow areas.
PRELIMINARY SURVEY OF THE RELATIONSHIP BETWEEN THE FEEDING HABIT AND THE STRUCTURE OF TIIE MOUTH‐PARTS OF MARINE COPEPODS1
Authors: Anraku Masateru , Omori Makoto 
Published: March 2010

The feeding of 6 copepods (Calanus finmarchicus, Acartia tonsa, Centropages hamatus, C. typicus, Labidocera aestiva, and Tortanus discaudatus) was examined with 3 different foods—a) diatoms (Thalassiosira fluviatilis) alone, b) diatoms plus Artemia nauplii, and c) Artemia alone—and compared with the structure of their mouth‐parts.Calanus finmarchicus is predominantly an herbivore, but in absence of plant food can definitely capture small motile animals. Acartiatonsa is a typical omnivore which can cat either plant or animal food efficiently. Centropages hamatus and C. typicus are also omnivorous, but both prefer an animal diet. Although Labidocera aestiva is predatory, some setae used for filtering food are found at the base of the second maxillae. Finally, Tortanus discaudatus is a typical predatory copepod.There is close relationship between the structure of the mouth‐parts and the feeding habits of these species. In herbivorous species (Calanus finmarchicus), the 2nd antennae, mandibular palps, 1st maxillae, and maxillipeds are well developed to produce a pair of “feeding swirls.” The 2nd maxillae are also formed as efficient filtering nets. The cutting edges of the mandibles are provided with grinding teeth. In predatory species (Tortanus discaudatus), the mouth‐parts have few setae and are on the whole much simpler. The 1st maxillae, 2nd maxillae, and maxillipeds are modified as prehensile appendages. The cutting edges of the mandibles have very sharp teeth. In omnivores, these appendages generally have a structure intermediate between those of the two previous types; the 2nd maxillae are used partly for filtering and are partly prehensile. The teeth are heavier than those of the herbivores, but they are not as stout as for predators.
FURTHER MEASUREMENTS OF PRIMARY PRODUCTION USING A LARGE‐VOLUME PLASTIC SPHERE
Authors: Antia N. J. , McAllister C. D. , Parsons T. R. , Stephens K. , Strickland J. D. H. 
Published: March 2010

The experiment described by McAllister, et al. (1961), in which a phytoplankton bloom was induced to occur in a free‐floating 20‐ft diameter thin transparent plastic sphere has been repeated. Daily measurements were made of nutrients, particulate matter, and photosynthetic rates with less frequent assays for vitamins and dissolved organic matter. In situ light was recorded by a bolometer. The experiment was prolonged to 100 days to study phytoplankton decay, most of this period being in the dark.The phytoplankton consisted mainly of 6 species of diatom and one large dinoflagellate. The mean composition of this crop at various stages of its development is reported by ratios involving chlorophyll a and particulate organic carbon.A detailed discussion is given of the findings of the experiment which, in general, confirmed those of the earlier work and yielded, in addition, valuable new information.The plant cells excreted 35–40% of their organic matter during growth. The C14 method of measuring photosynthesis gave results agreeing well with the production of particulate carbon.The growth kinetics of the bloom were dominated by the constancy of the mean cell division rates which were relatively independent of temperature and light. The rate of photosynthesis per unit chlorophyll was also remarkably constant and not proportional to light intensity, cells developing a highly efficient photosynthetic mechanism with respect to available radiant energy.The mean chemical composition of a cell changed after depletion of nutrients from the surrounding water. The carbon, protein, chlorophyll a and phosphorus decreased. The silicon and lipid contents remained nearly constant and the carbohydrate increased.During the decay period over half the particulate phosphorus was remineralized in 2 weeks. Silicon returned to solution more slowly but at a constant rate. There was no significant nitrification even after 75 days. The consumption of oxygen occurred mainly from the oxidation of “dissolved” organic matter and not from the interaction of oxygen with particulate material. The latter may have been important as a surface for bacteria. The evolution rate of carbon dioxide was constant with time but proceeded with a variable RQ, which was around 0.5 immediately after the bloom but increased to nearly 2 in the “old” water present at the beginning and end of the experiment.
STUDIES ON THE MASS CULTURE OF PHAEODACTYLUM. II. THE GROWTH OF PHAEODACTYLUM AND OTHER SPECIES IN OUTDOOR TANKS
Authors: Ansell A. D. , Raymont J. E. G. , Lander K. F. , Crowley E. , Shackley P. 
Published: March 2010

Characteristics of the growth of Phaeodactylum in culture in fertilized sea water in 1,000‐L concrete tanks are described. Successful experiments showed a constant pattern of events as follows: 1) active growth of Phaeodactylum, 2) reduction in growth rate of Phaeodactylum, 3) period of constant cell density, or rapid decline, 4) regeneration period, and, 5) second period of active growth.Growth of Phaeodactylum shows seasonal variation, but final population density reached is more or less constant. N and P utilization follow parallel courses, the mean ratio of N:P uptake during the 1st growth period being 6.5 ± 0.44:1. During growth, inorganic P is incorporated in the cells as particulate organic P. Following decline of Phaeodactylum dissolved organic P increases, and later, inorganic P is regenerated and may be reutilized during the 2nd growth phase. Decline of Phaeodactylum is normally associated with increase of the heterotroph Monas. There was a close relationship between peak numbers of Monas and the number of Phaeodactylum in the previous peak. The second growth phase consisted either of one or more chlorophycean flagellates, or of Phaeodactylum.Estimates of production based on O2 bottle exposures, change in inorganic P, change in pH, and change in packed cell volume agree closely, although initial uptake of P may be excessive. Estimates from change in inorganic P indicate a seasonal variation in the rate of organic production of up to 2.2 gC/m2/24 hr in March, 4.9 gC/m2/24 hr in May–August, and 2.0 gC/m2/24 hr in October, November. For Tetraselmis production rates up to 5.2 gC/m2/24 hr were recorded.The efficiency of utilization of solar energy for Phaeodactylum culture ranged from 3.0 to 4.4% with a mean for 5 estimates of 3.7%. For Tetraselmis values of 1.0–1.3% were obtained.
SOME FACTORS AFFECTING THE FEEDING OF MARINE COPEPODS OF THE GENUS CALANUS1
Authors: Mullin Michael M. 
Published: March 2010

The grazing rates of 4 species of Calanus were measured on several species of marine phytoplankton, both singly and in mixtures. Grazing rates varied inversely with phytoplankton concentration, the duration of the experiment, and the age of the phytoplankton cultures used.Calanus spp. generally removed large cells at higher rates than small when feeding on a mixture of two species of phytoplankton. Because of this selectivity and the difference in volume between large and small cells, the large cells contributed by far the greater fraction of the total volume of food ingested by the copepods, even when considerably less abundant than the smaller cells. Comparison of the grazing rates of the copepodite stage V and adult female animals of C. finmarchicus, C. glacialis, and C. hgperboreus on a mixture of 7 species of diatoms demonstrated further the importance of large cells. Marked quantitative differences in rate of food intake were found between the different developmental stages of each species and between the different species of copepods, and some qualitative differences in selective feeding were also indicated.