Oceanography Commons^™

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 …

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 …

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

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 …

Feeding Morphologies And Distribution Patterns Of Marine Cladocera In The Lower Chesapeake Bay, Sandra Layne Gilchrist

OES Theses and Dissertations

Temporal and spatial distributions of marine cladocera in the lower Chesapeake Bay estuary were observed over a year-long sampling period. The distributions of cladoceran species throughout the Bay were studied in relation to temperature and salinity. A survey of the species over the entire Bay is included to establish distribution patterns of the various species during a short time period.

Theoretical mathematical principles were used to predict feeding abilities of the Bay species. Mouthparts are described qualitatively and quantitatively to infer function. A mandibular index developed by Itoh (1970) was revised and employed in evaluating feeding methods interspecifically and interspecifically. …

The Spatial And Temporal Distribution Of Fish Eggs And Larvae In Hempstead Bay Estuary, Joseph Adelard Lessard

OES Theses and Dissertations

The ichthyoplankton of Hempstead Bay estuary was sampled from December 1972 to mid March 1974. Eleven stations were sampled by towing a 0.5 meter diameter plankton net. Eggs were most abundant during June and July with an average concentration calculated to be above 5,500/100m³. Egg densities were the lowest during the fall and winter. Larvae were most frequently taken from March through July with densities varying greatly among the samples. The eggs of Brevoortia tyrannus, Anchoa mitchilli, Tautoga onitis, Tautogolabrus adspersus, and Scophthalmus aguosus and the larvae of Menidia menidia, Ammodvtes hexapterus and Pseudopleuronectes americanus constituted most …

Mercury, Copper, And Zinc In Selected Ichthyofauna Of Lower Chesapeake Bay And Hampton Roads, Virginia, W. Bruce Aitenhead

OES Theses and Dissertations

Anchovys, croaker, spat, summer flounder and hogchokers were collected monthly to seasonally from November 1972 to October 1973 at three locations in the southern Chesapeake Bay region of Virginia.

The concentrations of mercury, copper and zinc were determined by atomic absorption spectrophotometry in whole fishes. Metal concentration varied with species and location. Anchovys had the highest mean concentrations of mercury and zinc while hog- chokers had the highest mean copper concentration. Mercury levels exceeding O.5 ppm were observed in species from all three loca- tions, but maximum heavy metal concentrations per species were highest in Craney Island fishes.

Temporal variations …

The Photosynthetic Action Spectra Of The Phytoplankton And Their Role In Governing Spatial And Temporal Distribution: A Numerical Modeling Approach, William Morrow Willis

OES Theses and Dissertations

In the present study a numerical modeling approach is employed to examine the role of division spedific differences in photosynthetic action spectra in governing the relative size of diatom and dinoflagellate carbon synthesis along various marine light regime gradients. A radiative transfer model taking into account both Rayleigh and Mie atmospheric optical properties is employed to define the light regime incident on the sea surface. The hydrospheric light regime is defined by an exponential decay model with a correction for diffuse back scatter. Taken together, the atmospheric and hydrospheric models define the spectral composition and intensity of light in the …

Experiments In Attempted Interspecific And Interpopulational Hybridzation Of Grass Shrimp Of The Genus Palaemonetes (Caridea Palaemonidae), Mark Andrew Boston

OES Theses and Dissertations

The present study investigates the interfertility of Palaemonetes populations, Interspecific crosses were attempted between representatives of sympatric :populations of P. pugio, P. vulgaris, and P. intermedius, Intraspecific crosses were undertaken between geographically separated :populations of P. pugio. Laboratory conditions of 25°c, 25°/oo, and 14.5 hour photoperiod per day were maintained for all breeding attempts, Under these conditions interspecific hybridization of Palaemonetes pugio and P. vulgaris was not feasible. P. intermedius could not be hybridized with P. pugio and P. vulgaris. At 40 days of age P. pugio juveniles were significantly larger than P. vulgaris juveniles of …

Description Of The Larval Development Of Squilla Empusa Say (Crustacea Stomatopoda) With Aspects Of Larval Ecology In Chesapeake Bay, Steven Gaines Morgan

OES Theses and Dissertations

Larvae of Sguilla empusa were collected from the plankton and were reared in the laboratory to describe the pelagic larval development and the postlarval stage. Nine pelagic stages are passed through before the postlarval stage is attained.

The larvae reared for descriptive purposes were subjected to sixteen combinations of temperature and salinity to determine their tolerance to the two parameters. Larvae survived longer and molted more frequently when reared at 25°/oo and 20°C or 25°C, which corresponds to the natural conditions of the Chesapeake Bay when the larvae were collected.

A three year planktonic survey conducted in the lower region …

Effect Of Nitrite And Nitrate On The Larval Development Of The Grass Shrimp Palaemonetes Pugio Holthuis, Carl Bingham Hinesman

OES Theses and Dissertations

The effects of nitrite and nitrate on survival and larval development of the grass shrimp Palaemonetes pugio were investigated in the laboratory. Nitrite concentrations assayed were 0 (control), 0.5, 1.0, 10, 25 and 50 mg NO₂/1. Nitrate concentrations tested were 0 (control), 100, 250, 500, 1000 and 2000 mg NO₃/1. Temperature and salinity conditions were 25 C and 25 ‰, respectively, and all tests occurred in the dark. Thirty-six larvae were reared in each assay, twelve from each of three adult females.

Nitrite levels of'5 and 50 mg NO₂/1 significantly reduced survival of larvae …

A Baseline Study On The Possible Mechanisms Of Larval Stomatopod Distribution On The Carolina Shelf, Carl Robert Berman Jr.

OES Theses and Dissertations

The South Carolina Marine Resources Institute provided the author with 198 station samples containing 2,193 stomatopod larvae. These larvae had been collected during ichthyoplankton Bongo tows on five separate cruises aboard the Institute's vessel R/V DOLPHIN (February, 1972 to January, 1975). The larvae were examined microscopically and divided into early, middle, and late stages according to known growth criteria. The larval distribution was plotted geographically, by seasons, and larval density (larvae/m3) was graphed against distance offshore. Using these data, together with the circulation characteristics on the Carolina Shelf, significant distributional data appeared which supported the hypothesis that the stomatopod population …

Temperature And Salinity Tolerance Of The Larvae Of The Sand Shrimp, Crangon Septemspinosa (Say), Karen Lyttle Hinsman

OES Theses and Dissertations

The effects of temperature and salinity on the larval development of the sand shrimp, Crangon septemspinosa, were investigated in the laboratory using 30 combinations of temperature and salinity in a five by six factorial experiment. The five temperatures were 5°c, 10°c, 15°c, 20°c, and 25°c and the six salinities were 10°/oo, 15°/oo, 20°/oo, 25°/oo, 30°/oo and 35°/oo. Thirty-six larvae were used for each temperature-salinity combination. Temperature and salinity produced significant differences (1% level) in survival and the duration of larval development. Highest survival occurred at 15°c and 20°/oo. At optimum temperatures (15°c to 20°c) larvae exhibited the broadest tolerance …

Feeding Ecology Of Black Sea Bass Centropristis Striata On An Artificial Reef Off Virginia (Perciforms: Serranidae), Ping K. Chee

OES Theses and Dissertations

The feeding ecology of the black sea bass, Centropristis striata, associated with artificial reefs shows seasonal and size-related changes. Monthly collections totaling 520 black sea bass taken from an artificial reef near the Chesapeake Light Tower, Virginia, between August 1975 and May 1976, were analyzed for food habits as revealed by number, volume, frequency of occurrence and a modified Index of Relative Importance.

The black sea bass feeds on the artificial reef as well as the adjacent areas. When food was abundant on the reef, food items from the reef and the surrounding area were consumed. Upon depletion of the …

Effect Of The Chesapeake-Elizabeth Sewage Outfall Virginia Beach, Virginia On The Distribution And Ecology Of Benthic Foraminifera, James M. Bates Jr.

OES Theses and Dissertations

Sediment and bottom water samples from seven stations at the Chesapeake Elizabeth sewage outfall, Virginia Beach, Virginia were collected in order to evaluate the effect of the outfall on benthic foraminifera. The top centimeter of sediment was analyzed for living and total (live plus dead) foraminiferal densities, chlorophyll a, sediment grain size, ATP, percentage of silt and clay, and total organic carbon. Bottom water salinity, temperature, and ammonia were also analyzed.

Living foraminiferal density increased from March to July and with distance from the outfall. Total foraminiferal density also increased from March to July. The set of environmental variables was …

A Comparative Study Of A Salt Water Impoundment With Its Adjacent Tidal Creek Pertinent To Culture Of Crassostrea Virginica (Gmelin), William D. Anderson Iii

OES Theses and Dissertations

Certain physical, chemical and biological characteristics associated with the culture of subtidal Crassostrea virginica were assessed in a salt water impoundment and its adjacent tidal feeder creek. Large seed oysters (initial y = 57.3 mm) were transferred from a somewhat polluted estuary of Charleston Harbor to floating, mid-water, and bottom hardware cloth trays (200/tray) in a four hectare pond. Identical trays at comparable depths were placed in the tidal creek and each location was sampled monthly for growth and survival. Surface and bottom water samples were collected weekly throughout the study and hourly during four seasonal 25 hour stations. Standard …

Test Variation In The Sand Dollar, Mellita Quinquiesperforata (Leske), George Glynn Rountree

OES Theses and Dissertations

Mellita quinguiesperforata is a common member of the benthos along the eastern coast of North America. This study considers variation of the test within the species, specifically: 1) variation in test weight, 2) variation in the length-width relationship, and 3) the average number of pore pairs in the ambulacral petals.

A total of 844 sand dollars from three localities was utilized: 1) Pass-a-Grill Beach, St. Petersburg, Florida,2) Bird Shoal, Beaufort, North Carolina, and 3) Fisherman Island, Virginia.

Animals were measured for length and width and the dry weight determined. Prediction equations for the size-weight relat1onships were computed for the three …

The Natural History Of The Naked Goby Gobiosoma Bosci (Perciformes: Gobiidae), Leonard L. Nero

OES Theses and Dissertations

The purpose of this study was to contribute to the knowledge of re ­ production, growth, age, abundance, habitat preference, feeding habit and behavior of the naked goby, Gobiosoma Bosci.

Monthly collections were made from January through December. 1974 in Deary Cove a apart of the Lynnhaven estuary, Virginia Beach, Virginia. All fish were measured and sexed in the field.

Most were returned to the population, the remainder. were removed for food habit analyses, determination of fecundity, degree of gonadal maturity and aging. Habitat­ preference and abundance were determined in the field.

Gobiosoma Bosci appears to be an annual …

Microbenthic Algal Production Of An Intertidal Sandflat In Little Creek Harbor, Virginia Beach, Virginia, Clayton Barry Shedrow

OES Theses and Dissertations

Estimated annual net microbenthic algal production of an intertidal sandflat on Little Creek Inlet, Virginia Beach, Virginia, was 105 g C/m². Seasonally, primary production was greatest during the summer and fall periods (38 and 49 g C/m², respectively). Productivity was found to vary directly with water temperature and standing crop of benthic diatoms, and inversely with incident solar radiation and standing crops of sedimentary chlorophyll 'a' and 'c'. Orthophosphate and nitrate-N appeared to be limiting factors, nitrate-N more so than orthophosphate. Mean annual net photosynthetic efficiency (based upon total light) for the microphytobenthic community was 0.09%. …

Feeding And Food Preferences By Three Sympatric Species Of Cyprinodontid Fishes, Lawrence J. Baer

OES Theses and Dissertations

The feeding and food utilization by three sympatric species of cyprinodontid fishes was examined using a modified Ivlev Electivity Co-efficient. Results indicated that although Fundulus heteroalitus and Fundulus majalis are sympatric in the area examined,their usage of the available food source varied noticeably. The third investigated species, Cyprinodon variegatus, fed mainly upon a vegetal detritus food source varied by the consumption of invertebrate and vertebrate food items. Slight intra-specific variances of diet between crespuscular periods was also discussed.

Food And Feeding Of Fishes From Magothy Bay, Virginia, Joseph J. Kimmel

OES Theses and Dissertations

No abstract provided.

Morphologic Time Series From A Submarine Sand Ridge On The South Virginia Coast, John F. Mchone Jr.

OES Theses and Dissertations

Submarine sand ridges several km long locally merge southward into the U. S. Atlantic coastline. Shallow (< 8m) observations of -such a ridge at False Cape, Virginia, favor a modern hydraulic origin. Time series maps show the ridge to be paralleled by a landward trough of approximately equal volume. Ridge flanks are usually steeper on the trough side.

Northeasterly winds and waves generate a coast-parallel current which funnels southward into the trough scouring it out and providing sediments for ridge aggradation. The current may be organized as a helical flow cell or cells. Bottom currents converge southward along the ridge crest causing landward transport of traction load along the crest. The trough current eventually breaches the confining ridge at the head of the trough, cutting saddles with steeper seaward slopes and producing outlying sediment fans.

The ridge and trough rest obliquely …

Phytoplankton Distribution In Waters Off The Northeastern Coast Of The United States, Sharon H. Craft

Biological Sciences Theses & Dissertations

Abstract unavailable.

History Of Sedimentation In Montsweag Bay, Detmar Schnitker

Maine Collection

History of Sedimentation In Montsweag Bay

by Setmar Schnitker

Bulletin #25, Department of Forestry, Augusta, Maine, 1972.

Contents: Abstract / Introduction / Geographic Setting / Seismic Profiling / Pleistocene Sediments / Holocene Sediments / Actual Sedimentation /. Suspended Sediments / Recent Changes / Outlook / Acknowledgements / References

Erasure Of Sediment Surface Features By Mellita Quinquiesperforata (Leske), Walter Richard Boehmer

OES Theses and Dissertations

Erasure of sediment surface features by individuals of the species, Mellita guinguiesperforata, observed in this study suggests that all members of the sub-order, Scutellina, are able to erase sediment surface features. Sweep time, the time needed to erase the surface features of an area, depends on the population density, individual size, and speed of movement of the sand dollars. Assuming their pattern of movement as random, the following equation can be used to determine sand dollar sweep time,

T - 3.2 N^-0.76 (W / S) (A/ W² )^1.21

where T is sweep time, N is the …

Diurnal Distribution Of Phytoplankton From A Single Station At The Mouth Of The James River, Harold G. Marshall

Biological Sciences Faculty Publications

Eight sets of water samples were taken to a depth of 36 ft. during a 24-hr. period. A homogeneity was found in the vertical distribution of the total phytoplankton in samples from 7 of the 8 hydro-casts. Skeletonema costatum and Asterionella japonica were the most numerous phytoplankters in every sample, with the majority of their counts each exceeding 500, 000 cells per liter.

The Distribution Of Phytoplankton Along A 140 Mile Transect In The Chesapeake Bay, Harold G. Marshall

Biological Sciences Faculty Publications

The composition of phytoplankton progressively changed in the surface samples taken between Norfolk, Virginia and Cambridge, Maryland. These was an inverse relationship between the numbers of phytoplankters and zooplankters in the transect samples. Vertical stratification of the plankton was studied at two 24-hr, stations at the Great Wicomlco and Patuxent Rivers. The vertical centers of zooplankton and phytoplankton populations fluctuated over the study period and evidence is given to support a grazing phenomenon. Large concentrations of nannoplankters were found in all the plankton samples taken and is attributed to the collection procedure using the Van Dorn sampler.