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Full-Text Articles in Physical Sciences and Mathematics
The Distribution Of Cesium-137, Copper, Lead And Zinc In Various Sedimentary Environments Of The James River Estuary, Virginia, Colin Stevenson Moy
The Distribution Of Cesium-137, Copper, Lead And Zinc In Various Sedimentary Environments Of The James River Estuary, Virginia, Colin Stevenson Moy
OES Theses and Dissertations
Ten grab samples and eight cores were obtained within a short stretch of the James River estuary. The distribution of CU, Pb, Zn, Cs-137, organic carbon (TOC) and fine-grained sediments in various depositional environments were examined. Within the past quarter of a century, these measured parameters have been accumulating preferentially in the low energy environment (Burwell Bay). The inventory of Cs-137 in the cores was linearly related to the inventory of heavy metals and TOC. The concentrations of Cs-137 in the surface sediments vary linearly to those of the other parameters suggesting that Cs-137 may be used as a tracer …
Coherence Between Wind And Current Events In A Nearshore, Shallow Water, Wave Dominated Environment, George Milton Hecker
Coherence Between Wind And Current Events In A Nearshore, Shallow Water, Wave Dominated Environment, George Milton Hecker
OES Theses and Dissertations
Five days of observation were made of the current at four depths in a water depth of eight meters, and accompanying record of local wind one-half Kilometer from shore at the U.S. Army Corps of Engineers Coastal Engineering Research Center field facility at Duck, North Carolina beginning five May 1978. The current was measured with a state-of-the-art electromagnetic current meter having a 0.2-second response time and an accuracy of (+/-) 2 centimeters per second. At each depth a ten-minute record was made each hour with a sampling interval of one-eighth second. The frequency components of the record were analyzed and …
The Effects Of Elevated Calcium Chloride And Magnesium Chloride Levels On Larval Growth And Survival Of Macrobrachium Rosenbergii (De Man) (Decapoda Palaemonidae) Reared In The Laboratory, James Thomas Michaels Ii
The Effects Of Elevated Calcium Chloride And Magnesium Chloride Levels On Larval Growth And Survival Of Macrobrachium Rosenbergii (De Man) (Decapoda Palaemonidae) Reared In The Laboratory, James Thomas Michaels Ii
OES Theses and Dissertations
The effects of elevated CaCl2 , MgCl2 , combination CaCl2 and MgCl2 concentrations and their associated ionic strengths on larval growth and survival of the freshwater prawn, Macrobrachium rosenbergii were investigated in the laboratory. Larvae were reared in diluted seawater of 15 parts per thousand salinity with elevated calcium concentrations of 330 parts per million and elevated magnesium concentrations of 1275 parts per million. Control larvae were also reared with elevated NaCl concentrations to duplicate the ionic strength increases of the combination CaCl2 - MgCl2 test solution which had the highest ionic strength. A …
The Effects Of Salinity On The Growth And Survival Of The Crayfish, Procambarus Actus Actus (Girard), Emily Deaver
The Effects Of Salinity On The Growth And Survival Of The Crayfish, Procambarus Actus Actus (Girard), Emily Deaver
OES Theses and Dissertations
The white river crayfish, Procambarus acutus acutus was tested in low salinity water for growth and survival. Thirty animals were placed in each test pool at O, 4 and 8 ppt and grown for 75 days. Growth was defined as increase in carapace length and wet weight. Crayfish grew at a faster rate and had the lowest mortality at 4 ppt. Water hardness, defined as the total concentration of calcium and magnesium expressed as the calcium carbonate equivalent, ranged from 35 mg/1 to 195 mg/1. Pools of crayfish tested at concentrations of approximately 100 mg/1 total hardness exhibited the best …
Surface Circulation And Horizontal Diffusion Processes Of The Lower Chesapeake Bay, Frederick A. Hilder
Surface Circulation And Horizontal Diffusion Processes Of The Lower Chesapeake Bay, Frederick A. Hilder
OES Theses and Dissertations
A Lagrangian method utilizing clusters of four or five buoyed drogues is used to study the surface circulation and horizontal diffusion processes of the lower Chesapeake Bay. The study area encompasses some 160 km2 and includes the area north of Thimble Shoal Channel, southwest of Chesapeake Channel and west of the Chesapeake Bay Bridge and Tunnel. Eleven trials utilizing buoyed drogues were conducted in the time frame February to October, 1979. Four trials were interrupted when buoys entered neighboring channels or dispersed too far for tracking, so that a total of sixteen runs were completed on the eleven trial …
Filtration Ingestion And Assimilation Rates Of The Mysid Shrimp Neomysis Americana Smith, Fed Three Food Sources, Robert W. Grabb
Filtration Ingestion And Assimilation Rates Of The Mysid Shrimp Neomysis Americana Smith, Fed Three Food Sources, Robert W. Grabb
OES Theses and Dissertations
Laboratory grazing and assimilation experiments were conducted on the mysid shrimp Neomysis americana in an attempt to assess the suitability of three potential food sources. It was hypothesized that the smaller size classes were primarily herbivores, not becoming omnivorous until attaining lengths of approximately 5-6 mm. Four size classes of mysids from the summer generation, juveniles, immature, adult males, and adult ovigerous females were each fed three concentrations of Artemia salina nauplii, the rotifer Brachionus plicatilis, and the diatom Coscinodiscus lineatus. The mean lengths of the size classes utilized, plus or minus one standard deviation, were 2.5 …
Distribution Of The Dinoflagellate Symbiosis In Astragia Danae As Affected By Light Attenuation, Michael Perry Weston
Distribution Of The Dinoflagellate Symbiosis In Astragia Danae As Affected By Light Attenuation, Michael Perry Weston
OES Theses and Dissertations
Spatial zonation of symbiotic and aposymbiotic forms of the temperate coral Astrangia danae provides evidence that light attenuation is an important factor in the distribution of this animal. At four locations in the lower Chesapeake Bay and adjacent offshore waters, symbiotic colonies were observed only in well illuminated surface waters, while aposymbiotic colonies were observed in less illuminated deeper waters. A transition zone exists in which both colony types are found. Colonies on substrates forming a plane parallel to the sea-surface receive a greater radiant flux than colonies on vertical substrates. This extends the depth range of symbiotic colonies located …