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Etiological Studies On Oyster Mortality I. Nematopsis Ostrearum Prytherch 1940 (Sporozoa: Porosporidae), H. Malcolm Owen, Lester L. Walters, Louis A. Bregan Jan 1951

Etiological Studies On Oyster Mortality I. Nematopsis Ostrearum Prytherch 1940 (Sporozoa: Porosporidae), H. Malcolm Owen, Lester L. Walters, Louis A. Bregan

Journal of Marine Research

Oysters from the major producing area of Louisiana were found to be 100% infected with the gregarine parasite Nematopsis ostrearum; those from a check station in Pencacola Bay, Florida, were found to be 95.1 % infected. In Louisiana., the population of N. ostrearum was found to be higher in the area east of the Mississippi River. N. ostrearum infections in oysters increased significantly during summer months in areas of relatively low oyster mortality. It was concluded on indirect and negative evidence that N. ostrearum was not a controlling factor responsible for the condition of oysters or for their extensive mortalities …

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Growth And Setting Of Larvae Of Venus Mercenarid In Relation To Temperautre, V. L. Loosanoff, W. S. Miller, P. B. Smith Jan 1951

Growth And Setting Of Larvae Of Venus Mercenarid In Relation To Temperautre, V. L. Loosanoff, W. S. Miller, P. B. Smith

Journal of Marine Research

Larvae of the hard shell clam, Venus mercenaria, were grown to metamorphosis at constant temperatures of 30.0, 27.0, 24.0, 21.0 and 18.0° C ± 1.0° C. The rate of growth of the larvae was generally, but not always, more rapid at high than at low temperatures. Within this range small differences in temperature, such as 1.0 or 2.0°, were not extremely important in affecting the rate of growth....

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The Sources Of The Deep Water Of The Eastern Mediterranean Sea, M. J. Pollak Jan 1951

The Sources Of The Deep Water Of The Eastern Mediterranean Sea, M. J. Pollak

Journal of Marine Research

The deep water in the two basins of the eastern Mediterranean Sea, the Levant and the Ionian Sea, is identical in temperature and salinity though differing slightly in oxygen content. Contrary to Nielsen's thesis, none of this water is formed in the southern Aegean Sea....

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Notes On The Development Of A Thermistor Temperature Profile Recorder (Tpr), Ernest R. Anderson, Arthur T. Burke Jan 1951

Notes On The Development Of A Thermistor Temperature Profile Recorder (Tpr), Ernest R. Anderson, Arthur T. Burke

Journal of Marine Research

A vertical temperature profile recorder, utilizing a thermistor as the temperature sensing element, has been developed for use on lakes, bays, or other enclosed or semi-enclosed bodies of water where temperature profiles in the upper 30 m are desired. Tests of the instrument indicate that it is rugged and durable, giving easily readable records accurate to ± 0.1 ° C....

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A Plastic Envelope Substitute For Drift Bootles, F. C.W. Olson Jan 1951

A Plastic Envelope Substitute For Drift Bootles, F. C.W. Olson

Journal of Marine Research

A plastic envelope of 0.004 inch thick polyethylene is suggested as a substitute for drift bottles. The return card is sealed hermetically in the envelope, thus forming an inexpensive, compact and convenient means for studying surface currents by conventional drift bottle technique. Tests indicate that "drift cards" actually indicate surface flows and are not at the complete mercy of the winds.

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An Automatic Reagent Dispenser For Shipboard Use, Warren S. Wooster, Dayton E. Carritt, John D. Isaacs Jan 1951

An Automatic Reagent Dispenser For Shipboard Use, Warren S. Wooster, Dayton E. Carritt, John D. Isaacs

Journal of Marine Research

Recent work on modification of the molybdenum-blue method for determination of dissolved inorganic phosphate in sea water (Wooster and Rakestraw, 1951) showed the need for a simple rugged device sui table for rapid and precise delivery of small quantities of reagents at sea. The two reagents used for phosphat e determination impose addit ional requirements on this device. Molybdic acid solution must be protected from the light and must not be allowed to come in contact with rubber;·stannous chloride solution must be protected from contact with the atmosphere.

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An Attitude On "Fishery Hydrography", J. N. Carruthers Jan 1951

An Attitude On "Fishery Hydrography", J. N. Carruthers

Journal of Marine Research

An essay on the theme that the fortunes of North Sea fish broods may be determined by some factor (or by some complex of factors) resident within those broad features of water circulation which are ruled by widespread wind conditions inferable from the study of atmospheric pressure gradients, followed thereafter by an ADDENDUM (due to Günter Dietrich) dealing with month-by-month wind conditions over the northern North Sea during the half century now ending, and by an ADDENDUM NoTE briefly indicating what progress has been made along the lines concerned and what is in prospect.

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Delaying Spawning Of Lamellibranchs By Low Temperature, V. L. Loosanoff, H. C. Davis Jan 1951

Delaying Spawning Of Lamellibranchs By Low Temperature, V. L. Loosanoff, H. C. Davis

Journal of Marine Research

Spawning of oysters (Crassostrea virginica) and clams (Venus mercenaria) was delayed by transferring ripe or nearly ripe animals from Long Island Sound to the cold waters of Boothbay Harbor, Maine, where the temperature, although high enough to permit gametogenesis, was too low to induce spawning. With C. virginica, spawning could be postponed until six or eight weeks after the Long Island Sound population was completely spent, while V. mercenaria held over healthy summer spawn throughout the fall and winter and into the following spring. By similar means, laboratory workers can be provided with ripe animals during the fall when none …

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The Estimation Oof Dissolved Phosphate In Sea Water, Warren S. Wooster, Norris W. Rakestraw Jan 1951

The Estimation Oof Dissolved Phosphate In Sea Water, Warren S. Wooster, Norris W. Rakestraw

Journal of Marine Research

The molybdenum-blue method of determining dissolved inorganic phosphorus in sea water was modified for use with a photoelectric colorimeter. The effect of reagent concentration, time, and temperature on the rate and extent of color development was studied. Practical suggestions are given for carrying out routine analyses at sea.

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Annual Variations In Current Speeds In The Gulf Stream System, Frederick C. Fuglister Jan 1951

Annual Variations In Current Speeds In The Gulf Stream System, Frederick C. Fuglister

Journal of Marine Research

The monthly resultant current speeds in ten segments of the Gulf Stream System are calculated from surface current data published by the U. S. Navy Hydrographic Office. Marked annual variations in the current speeds are found in the Florida Current, in the Caribbean Sea, and in the Trade Wind areas. In other segments of the system the annual variations are not so well defined. The maximum current speeds occur during the summer in the southern segments of the Gulf Stream System and during the winter in the northern segments. The minimum speeds occur during the fall months throughout the system....

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A Further Study Of Upwelling And Associated Vegetation Along Pacific Baja California, Mexico, E. Yale Dawson Jan 1951

A Further Study Of Upwelling And Associated Vegetation Along Pacific Baja California, Mexico, E. Yale Dawson

Journal of Marine Research

A temperature survey in the upper 200 feet of coastal waters of Baja California, from Bahia de Todos Santos to Bahia de la Magdalena, during the spring of 1950, has demonstrated the occurrence of upwelling along virtually the entire coast except within Bahia Viscaino and between Lat. 24° 50' and 26° N. A study of the marine vegetation of this coast and of the outlying islands has shown close correlation with the presence or absence of upwelling water....

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Comparative Studies Of Mineral Constituents Of Marine Sponges I. The Genera Dysidea, Chondrilla, Terpios, Vaughan T. Bowen, Doris Sutton Jan 1951

Comparative Studies Of Mineral Constituents Of Marine Sponges I. The Genera Dysidea, Chondrilla, Terpios, Vaughan T. Bowen, Doris Sutton

Journal of Marine Research

Analyses of Al, Ca, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, Pb, Sn, Ti, and V are presented for specimens of five species of marine sponges: Dysidea crawshayi, D. etheria, Chondrilla nucula, Terpios fugax and T. zeteki; and of F in D. crawshayi….

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An Inexpensive And Rapid Technique For Obtaining Current Profiles In Estuarine Waters, D. W. Pritchard, Wayne V. Burt Jan 1951

An Inexpensive And Rapid Technique For Obtaining Current Profiles In Estuarine Waters, D. W. Pritchard, Wayne V. Burt

Journal of Marine Research

A current indicator, consisting of a confined submerged biplane-shaped drag and a device for reading the angle made by the suspending wire with t he vertical, is introduced in t heory and practice. It was designed for rapid determination of current velocities and directions at any depth from a vessel an chored in shallow water. A number of calibration runs made with t he Drag and with a von Arx Current Meter indicate that the Drag is reliable and suffi ciently accurate for the purpose for wluch it was designed. The gear proved to be rugged, easy to use, and …

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The Spectrophotometric Determination Of Fluoride In Sea Water, Courtenay D. Anselm, Rex J. Robinson Jan 1951

The Spectrophotometric Determination Of Fluoride In Sea Water, Courtenay D. Anselm, Rex J. Robinson

Journal of Marine Research

The zirconium-alizarin sulfonate indicator of Lamar has been applied to the spectrophotometric determination of fluoride in sea water and has been shown to be suitable. Calibration curves have been prepared for different chlorinities. The variation of apparent fluoride content with chlorinity is less than that reported by Thompson and Taylor with their ;eagent. Borate, iron and phosphate have been shown not to interfere at the concentrations found in sea water, while a method has been given to take care of varying alkalinities. The effects of time, temperature and light upon the color intensity have been discussed. Increased accuracy is attained …

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Relation Of Fishes And Other Organisms To The Scattering Of Underwater Sound, Gordon H. Tucker Jan 1951

Relation Of Fishes And Other Organisms To The Scattering Of Underwater Sound, Gordon H. Tucker

Journal of Marine Research

An analysis of concurrent sound-scattering records and biological collections in the sea show a correlation of the deeper and more intense scattering of sound with fishes and of the upper and lighter scattering with a dominant population of euphausiids. The main group of fishes concerned are the Myctophidae, which possess all of the essential qualifications of scatterers.

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Notes On Siphonophores 1. Siphonophores From The Marshall Islands, Mary Sears Jan 1950

Notes On Siphonophores 1. Siphonophores From The Marshall Islands, Mary Sears

Journal of Marine Research

The CROSSROADS plankton collection extends the range of about 30 siphonophores to the Marshall Islands, but only one third of these was taken in the lagoons. Of the species recorded, Galetta bigelowi is new, Lensia grimaldii was taken in the Pacific for the first time, and Diphyes chamissonis, which is restricted to the Indo-Pacific region, was taken in quantity in Rongelap Lagoon, as it had been in the Great Barrier Reef Lagoon. The significance of this habitat in limiting the distribution of D. chamissonis is not apparent.

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Subsurface Pelagic Sargassum, Alfred H. Woodcock Jan 1950

Subsurface Pelagic Sargassum, Alfred H. Woodcock

Journal of Marine Research

Observations are given which indicate that the presence of Sargassum below the sea surface is associated with lines of convergence of surface waters and with wind speeds in excess of about 4 m sec-1. It is suggested that descending currents under the convergence lines carry the plants down. Measurements of compression and of rates of rise of S. natans of various densities were made at Bermuda. Results of these measurements indicate that these plants may be carried down by descending currents in excess of 4.5 to 7.2 cm sec-1, and that the plants can maintain positive buoyancy, for short periods …

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Some Current Meters Designed For Suspension From An Anchored Ship, William S. Von Arx Jan 1950

Some Current Meters Designed For Suspension From An Anchored Ship, William S. Von Arx

Journal of Marine Research

Current velocities measured by means of instruments suspended from shipboard may err significantly if the ship's motion at anchor is permitted to tow the instruments through the water while observations are in progress. Two current meter designs are described which employ a propeller linkage by electromagnetic induction to permit continuous observation of current velocity through, and to determine the extent of, the periods when the anchored ship is essentially at rest. The motions of an anchored ship are described.

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The Ray-Particle Analogy, Carl Eckart Jan 1950

The Ray-Particle Analogy, Carl Eckart

Journal of Marine Research

The similarity between the differential equations governing the motion of a particle and the rays in a wave field is recalled. The two become identical if the particle has unit mass and moves under the action of a potential energy V = - 1/c2, where c is the phase velocity of the waves....

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Population Studies, Local Growth Rates And Reproduction Of The Pismo Clam (Tivela Stultorum), Wesley R. Coe, John E. Fitch Jan 1950

Population Studies, Local Growth Rates And Reproduction Of The Pismo Clam (Tivela Stultorum), Wesley R. Coe, John E. Fitch

Journal of Marine Research

Large samples collected, measured, and returned to the beach at monthly intervals at La Jolla, California, for five successive years showed an average initial set of 3 young clams per sq m in an area of 2000 sq m. The annual mortality has been from 67 to 75% for each year-class. Of an annual set of 6000, only 2000, 700, 170 and 50, respectively, have remained at the end of the first to fourth years. The length increases about 21 mm per year for the first two years of life and somewhat less thereafter. Less than one per cent survived …

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Note On The Dynamics Of The Gulf Stream, W. H. Munk, G. W. Groves, G. F. Carrier Jan 1950

Note On The Dynamics Of The Gulf Stream, W. H. Munk, G. W. Groves, G. F. Carrier

Journal of Marine Research

The nonlinear inertial terms have been neglected in Stommel's and in Munk's theory for the wind-driven ocean circulation. Using a method of successive approximations, the effect of these terms on the mass transport in the Gulf Stream region has been computed under greatly simplifying assumptions. These assumptions involve Reid's model of the vertical density structure, which consists of an exponential decrease in the density upward to the thermocline and a homogeneous upper layer....

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Notes On Determining The Depths Of Sampling In Serial Oceanographic Observations, M. J. Pollak Jan 1950

Notes On Determining The Depths Of Sampling In Serial Oceanographic Observations, M. J. Pollak

Journal of Marine Research

In order to interpolate between thermometrically determined depths of sampling in serial oceanographic observations it ha.s been customary to plot a curve of depth to wire length ratio against wire length. It is shown that a simpler and probably more accurate method consists of plotting wire length minus depth against wire length. In this method the surface wire angle is converted into a line of tangency to the curve which always terminates at the zero point of the graph. Furthermore, the limiting slope of this curve is more readily defined and utilized.

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Lateral Mixing And Wind-Driven Currents In An Enclosed Ocean, Koji Hidaka Jan 1950

Lateral Mixing And Wind-Driven Currents In An Enclosed Ocean, Koji Hidaka

Journal of Marine Research

The circulation of water induced by winds in an enclosed ocean comparable in size to the North Pacific is treated by using the "mass transport" instead of current velocity and by taking both horizontal and vertical mixing into account. The numerical solutions have been worked out for the wind system similar to that actually prevailing over the North Pacific, and for different intensities of lateral mixing. It is concluded that the flow pattern best agrees with the actual circulation when the numerical value of the coefficient of lateral mixing is of an order of magnitude of 109 c.g.s. Westward intensification …

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Natural Slicks On The Ocean, Robert S. Dietz, Eugene C. Lafond Jan 1950

Natural Slicks On The Ocean, Robert S. Dietz, Eugene C. Lafond

Journal of Marine Research

Slicks are smooth glassy streaks or patches on the ocean. Prominent slicks are confined largely to near-shore areas where organic production is high. Experiments and observations are described which show that slicks are contaminate films of organic oil, probably derived primarily from diatoms which contain droplets of oil in their cells to assist in flotation and/or as an emergency food supply. Slicks are discernible because of their damping effect on small wavelets. The parallel slicks that develop in light to moderate winds result because the contaminate films pile up at the top of convergences in the homogeneous, wind-stirred layer above …

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A Streamline Cable Depressor, Donald G. Reed, Trigg Stewart Jan 1950

A Streamline Cable Depressor, Donald G. Reed, Trigg Stewart

Journal of Marine Research

In the past the collection of samples from the deep scattering layer by the familiar horizontal net haul method has been handicapped by the available tools. The time-honored weighted line technique has often been suspected of introducing error in the depth factor of data. The development of the streamlined cable depressor herein described provides an effective tool for oceanographic studies. Because of its form, the depressor has a high lift/drag ratio and is free from the damaging vibration usually characteristic of depressors. Many applications are suggested by its performance in the field.

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Folliculinids Of The Chesapeake As Nomads, E. A. Andrews Jan 1950

Folliculinids Of The Chesapeake As Nomads, E. A. Andrews

Journal of Marine Research

During experiments by the U.S. Fish and Wildlife Service and the Maryland Conservation Department on the fouling of oysters in Chesapeake Bay, shells exposed on the bottom were examined for folliculinids. Observations in the upper part of the Bay, at about 15 stations in 9 to 20 feet of water along some 40 miles from Choptank to Tochester from mid-May to mid-October, showed that settling began the last week of June, or occasionally mid-July, and continued until the last week of September; generally there was a decline in density during August and occasionally an increase in September with cooler water. …

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A Note On The Vegetation Of A New Coastal Upwelling Area Of Baja California, E. Yale Dawson Jan 1950

A Note On The Vegetation Of A New Coastal Upwelling Area Of Baja California, E. Yale Dawson

Journal of Marine Research

Series of surface temperature observations and bathythermograms made during the late summer of 1948 and the spring of 1949 along the Central Pacific Coast of Baja California have revealed the presence of an area of inshore upwelling centering in the vicinity of Isla San Roque and Isla Ascunci6n. Supporting evidence is furnished by the fact that all but five of the 30 known species in the intertidal vegetation of these islands are characteristic of cool water localities to the north in California.

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Reality And Illusion In Oceanographic Surveys, Albert Defant Jan 1950

Reality And Illusion In Oceanographic Surveys, Albert Defant

Journal of Marine Research

Care must be exercised in selecting time intervals and spacings between stations along oceanographic profiles in order to avoid erroneous·conclusions regarding the mean circulation. By proper combinations of time intervals and spacings, the effect of internal waves of tidal periods, which are the source of these errors, can be suppressed. The application of these principles to the Marine Life Research cruises of the Scripps Institution is discussed.

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A Study Of Mixing Processes Over The Edge Of The Continental Shelf, Arthur R. Miller Jan 1950

A Study Of Mixing Processes Over The Edge Of The Continental Shelf, Arthur R. Miller

Journal of Marine Research

By means of T-S area diagrams, a method of analysis is developed for the study of closely spaced hydrographic data. In a transitional zone, such as that over the continental shelf off southern New England, this method is useful for following the continuity of the mixing process. Changes in salinity at the edge of the shelf are due, for the most part, to horizontal advection. There are indications of nonisentropic mixing on a smaller scale. From the turbulent features of the region, as indicated by instabilities, this condition is not unexpected.

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Slicks, Surface Films And Internal Waves, Gifford Ewing Jan 1950

Slicks, Surface Films And Internal Waves, Gifford Ewing

Journal of Marine Research

Slicks, or calm streaks on a rippled sea, are often seen on co11Btal waters and lakes when the wind is light. They are formed by the ripple-damping action of a surface film of organic matter which occurs naturally on biologically productive waters. The ability of films to damp ripples varies radically with the degree of compaction of the film molecules. Such compaction may be caused by horizontally convergent flow in the water surface or by horizontal convergence of the wind stress....

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