Oceanography and Atmospheric Sciences and Meteorology Commons^™

Analysis Of Central Equatorial Pacific Water Masses By Method Of Principal Components, Ross Tuxhorn

OES Theses and Dissertations

The distribution of Antarctic Intermediate Water at the extent of dispersion in the equatorial Pacific Ocean was investigated by means of multivariate analysis. Interrelationships among the upper intermediate water masses at this location are proposed.

Oceanographic data contained in seven cruise legs measured during the 1979-80 Hawaii to Tahiti Shuttle Experiment formed the basis of this study. Six parameters -- temperature, salinity, dissolved oxygen, phosphate, silicate and nitrate -- were used in the method of principal component analysis to classify water masses between the sea surface and 1000m. The derived water masses were compatible with previously described oceanographic features of …

An Examination Of The Variability Of Migratory Timing Statistics Estimated From Catch And Effort Observations, Arthur J. Butt

OES Theses and Dissertations

The estimate of the mean arrival time based on catch or CPUE of fishes migrating into a fixed harvest area is a function of the number of days fished. Simulation studies using chinook salmon catch and effort data from the Yukon River delta, Alaska indicate that fishing effort concentrated at the tails of the migratory distribution which would tend to erroneously weigh the estimated mean arrival time in the direction of the sample, away from the true mean, is only a significant problem when the number of days open to fishing is small, covering less than 12% of the total …

A Method For Determining Creosote Contamination Of Sediment From The Elizabeth River, Norfolk, Va, Elizabeth G. Merrill

OES Theses and Dissertations

Hydrocarbon input sources to the Elizabeth River were investigated. Carbonized coal products (creosote, coal tar, and roof tar), petroleum products (Kuwait Crude Oil, No. 2 Fuel Oil, and a fuel oil spill sample) and soot (woodstove and diesel engine) have unique hydrocarbon distributions. Elizabeth River sediment hydrocarbon distributions indicate that they are contaminated with both carbonized coal and petroleum products. Using a simple two member mixing model, greater than 65 percent of Elizabeth River sediments' resolved aromatic compounds were determined to originate from carbonized coal products. These aromatic hydrocarbons include the EPA priority pollutant polynuclear aromatic hydrocarbons which are known …

A Description And Analysis Of The Timing Of Virginia's Weakfish Fishery, Bruce William Hill

OES Theses and Dissertations

The seasonality of Virginia's weakfish fishery is quantitatively defined by providing a mean time of catch and variance of catch for the years 1960 - 1981. On the average. the central half of the population is available for harvest from mid-May through September in all of Virginia's waters and the mean date of harvest is July 20th • The 22 year average variance of catch for Virginia's waters is 3.97. In Virginia's Chesapeake Bay tributaries the mean date of harvest is July 17th and the 22 year average variance of catch is 2.50. There is evidence for an inverse relationship …

Phytoplankton Ecology And Dynamics In The James River Estuary Virginia, U. S. A., Margaret J. Filardo

OES Theses and Dissertations

Autotrophic biomass and productivity as well as nutrient distributions and phytoplankton cell populations in the James River estuary, Virginia, from Newport News Shipyard to the 0 o/oo isohaline, were sampled on a monthly basis from August of 1981 to December of 1982. Particular emphasis was placed on the very low salinity region (defined as the location where surface salinity measured between 0.0 and 0.75 o/oo based on conductivity) in order to determine the fate of fresh water phytoplankters upon being advected into the estuary because of their suspected role in the biogeochemical cycling that occurs there.

Both chlorophyll a and …

Determinants For The Timing Of Escapement From The Sockeye Salmon Fishery Of The Copper River, Alaska: A Simulation Model, Howard A. Schaller

OES Theses and Dissertations

A model to estimate determinants for migratory timing of catch and escapement in a terminal salmon fishery is presented. A method was developed to estimate average seasonal migration rates of salmon through a harvest area from catch and escapement data. The time series for the total population of Copper River sockeye salmon (Oncorhynchus nerka) was reconstructed in the reference frame of the commercial harvest area from catch and escapement data.

The catchability coefficients (q), derived from the reconstructed populations were found to vary within season and between seasons. The relation between q and effort was attributed to a …

Timing Of The Blue Crab Fisheries Of Virginia And Its Application To Harvest Management, J. Dale Shively

OES Theses and Dissertations

The timing of a fishery is a quantitative expression of the composite behaviors of harvesters, markets, animals and climatic events. A quantitative description of the timing of the blue crab (Callinectes sapidus) fisheries of Virginia was established using the time density model of Mundy (1979). Blue crab catch statistics supplied by the National Marine Fisheries Service and the Virginia Marine Resource Commission were divided into two fisheries based on gear type; the summer and winter fisheries. Average performance curves were then constructed using average cumulative proportions of catch. Annual yield estimates were also made and timing in five …

The Marine Biogeochemistry Of Selenium: A Re-Evaluation, Gregory A. Cutter, Kenneth W. Bruland

OES Faculty Publications

Vertical and horizontal profiles from the North and South Pacific Oceans demonstrate the existence of three species of dissolved selenium: selenite, selenate, and organic selenide (operationally defined). In surface waters, organic selenide makes up about 80% of the total dissolved selenium, selenite concentrations are uniformly low, and selenate concentrations rise with increased vertical mixing. The organic selenide maximum (thought to consist of seleno-amino acids in peptides) coincides with the maxima of primary productivity, pigments, bioluminescence, and dissolved free amino acids. Deep ocean waters are enriched in selenite and selenate, while organic selenide is nondetectable. In suboxic waters of the tropical …

Episodic Nutrient Supply To A Kelp Forest Ecosystem In Southern California, Richard C. Zimmerman, James N. Kremer

OES Faculty Publications

Temporal patterns of nutrient input into a Southern California kelp forest were measured using traditional hydrocast sampling coupled with high frequency temperature profiling. Patterns of nutrient input were related to growth rates of Macrocystis pyrifera located in an adjacent kelp forest. There were 2 distinct components to the pattern of nutrient availability. The long term, or seasonal, component was consistent with large-scale storm-induced mixing and horizontal advection during winter months. In addition, vertical motions of the thermocline, bringing nutrients into the kelp forest, occurred throughout the year with a frequency of about 2 per day and were strongest during the …

Changes In The Lower Chesapeake Bay Food-Chain In Presence Of The Sea Nettle Chrysaora-Quinquecirrha (Scyphomedusa), David Feigenbaum, Michael Kelly

OES Faculty Publications

The abundance of 4 levels of the lower Chesapeake Bay food chain (Chlorophyll a, herbivores, ctenophore Mnemiopsis leidyi, and Scyphomedusa Chrysaora quinquecirrha) were moni­tored twice weekly at 4 stations from May 10 through Sep 30, 1982 in the Lafayette and Elizabeth Rivers (Virginia). The herbivore standing stock, largely copepods, declined sharply in late May when M. Jeidyi appeared, but rebounded a month later when C. quinquecirrha medusae reduced the ctenophore population. Despite the additional presence of Aurelia aurita (Scyphomedusa) from Jul onward, herbivore abundance remained at moderate levels until the end of the study period. Phytoplankton abundance fluctuated …

Review Of Upwelling Off The Southeastern United States And Its Effect On Continental-Shelf Nutrient Concentrations And Primary Productivity, Larry P. Atkinson, James A. Yonder, Thomas N. Lee

CCPO Publications

Gulf Stream induced upwelling occurs along the length of the southeastern United States continental shelf break. Upwelling events are produced by northward propagating Gulf Streams frontal meanders and eddies and travel northwards with these features. Meanders and eddies occur throughout the year in a period band of 2-14 days; however, resultant upwellings can affect the shelf quite differently. During fall, winter, and spring, upwelling is restricted to the outer shelf by cross-shelf density distributions, but in the summer upwelled water may penetrate across as a subsurface intrusion if aided by upwelling-favorable winds. If water does penetrate across the shelf, it …

Coastal Upwelling Off The Rias Bajas, Galicia, Northwest Spain I: Hydrographic Studies, J. O. Blanton, L. P. Atkinson, F. Fernandez De Castillejo, A. Lavin Montero

CCPO Publications

Coastal upwelling occurs off the Rias Bajas of Spain between April and October. Superimposed on large-scale upwelling is a mesoscale regime of enhanced upwelling induced by topographic influences. We show that the region surrounding Cape Finisterre has intensified topographically induced upwelling.

The rias have a relatively unobstructed connection with the open ocean. Upwelling of high nitrate water on the continental shelf by Ekman transport sets up pressure gradients at the mouth of the rias that induce upwelled water to flow into the rias. Deep water in the rias responds directly to cycles of upwelling and downwelling on the continental shelf.

Underwater Acoustic Wavefront Phase Fluctuations, George L. Vojtech Jr.

OES Theses and Dissertations

In conventional underwater acoustics sound propagation is generally modeled and applied as a coherent or incoherent process. This paper addresses a relatively new theory, that of a range driven increasingly incoherent ray propagation through a real ocean environment, Possible mechanisms are discussed and experimental data presented to reinforce the theory.

The Effect Of Polynuclear Aromatic Hydrocarbons On The Fecundity Of Acartia Tonsa (Calanoid Copepoda), Juanita Y. Grabarczyk

OES Theses and Dissertations

The concentrations of polynuclear aromatic hydrocarbons (PNAHs) were determined for several stations in the Elizabeth River. Thirteen PNAHs of the sixteen EPA priority pollutant PNAHs were present in the particulate fraction. The concentrations ranged from 10.0 ng/1 to 1000 ng/1. Ten of the sixteen EPA priority pollutant PNAH were present in the dissolved phase. Concentrations ranged from 2.0 ng/1 to 100 ng/1.

The environmental PNAHs concentrations were used to determine test concentrations. Bioassays were conducted to determine the effects of indigenous concentrations of seven predominant PNAHs (0.01 mg/1 to 2.4 mg/1 concentrations) on the fecundity of Acartia tonsa (calanoid Copepoda). …

The Effect Of Sea Nettle Abundance On The Food Chain Of The Lower Chesapeake Bay, Michael Glenn Kelly

OES Theses and Dissertations

The significance of sea nettle abundance on lower levels of the Chesapeake Bay food chain was examined in a field study and by the analysis of medusa gut contents. In the field study, the abundance of four levels of the food chain (Chlorophyll (a), copepods, the ctenophore Mnemiopsis leidyi, and the Schyphomedusa Chrysaora guinguecirrha) were monitored twice weekly at four stations from May 10 through September 30, 1982. The copepod standing stock declined sharply in late May when M. leidyi appeared, but rebounded a month later when C. guinguecirrha medusae reduced the ctenophore population. Despite the additional presence …

The Distribution Of Phytoplankton In Frontal Regions Of The Lower Chesapeake Bay, Richard V. Lacouture

OES Theses and Dissertations

The spatial and temporal distribution of phytoplankton was measured in relation to frontal areas located in the entrance to the Chesapeake Bay. Phytoplankton biomass, taxonomy, and several physical parameters were measured on fifteen sampling cruises between September,1981 and February, 1983.

Several statistical tests revealed that phytoplankton biomass did not accumulate at the fronts and that generally the distribution of phytoplankton biomass was homogenous across the frontal region. The cell count data indicated that the community structure of the phytoplankton assemblage was usually very similar on both sides of the front. The data which was concerned with temporal variations in the …

Adaptations Of Dolphin Vision To The Oceanic Environment, Andre Rivamonte

OES Theses and Dissertations

The objective of this study has been to develop an hypothesis explaining comparable aerial and underwater visual acuity of the bottlenose dolphin, Tursiops truncatus. This objective was accomplished by integrating the findings of other dolphin researchers working in the fields of comparative psychology, histology and ophthalmology. Their combined results enabled the formulation of a schematic dolphin eye. It is proposed that a dolphin lens, similar to the spherical lens of teleost fish with a rigid core of uniformly high refractive index and a margin of radially decreasing refractive index, could function as a bifocal lens and compensate for the eye's …

Simultaneous Functional Hermaphroditism In The Shrimp Hippolysmata Wurdemanni (Gibbes) (Decopoda: Caridea: Hippolytidae), Marie Hollister Bundy

OES Theses and Dissertations

The caridean shrimp Hippolysmata wurdemanni Gibbes was studied from a histological and a behavioral basis and was found to be a protandric hermaphrodite which later adopts simultaneous functional hermaphroditism. When the animal reaches a certain size, the androgenic gland degenerates, the male secondary sexual characteristics are lost, and vitellogenesis occurs in the anterior portion of the gonad. The animals do not lose the ability to function as males as evidenced by the presence of mature sperm in the gonad and the gonadal lumen of gravid shrimp, and the ability of both members of an isolated pair of shrimp to repeatedly …

The Growth And Feeding Behavior Of Juvenile Spot, Leiostomus Xanthurus Lacepede, In The Nursery Region Of The James River, Virginia, John Thomas Mccambridge Jr.

OES Theses and Dissertations

The in situ growth and feeding behavior of juvenile spot, Leiostomus xanthurus Lacepede, was investigated for populations in the nursery area of the James River, Virginia. Growth of juvenile spot was found to be fairly rapid (11.34 mm/month, standard length) during their first summer in the nursery grounds, but it levelled off in the autumn. The mean size of spot after the first year was calculated to be 195 mm total length. The weight-length relationship was log W = -5.018 + 3.246(log L), where W = wet weight in grams and L = standard length in millimeters.

Juvenile spot appeared …

The Effect Of Crowding On Growth Of The Cichlid Fish, Oreochromis Mossambicus, Bonnie A. Barrows

OES Theses and Dissertations

It has been reported that the Java tilapia, Oreochromis mossambicus, displays hypersensitivity to a substance it produces when biomass levels in a flow-through culture system exceed 20 g/1, resulting in reduced growth and high mortality. Experiments on the growth of this species in small tanks were conducted in order to determine whether O. mossambicus produces a growth-inhibiting compound under crowded conditions. This species was successfully maintained at biomass levels of 38 g/1 and 57 g/1 with a total mortality of only 4.5%.

The Java tilapia can grow rapidly in small aquaria, as indicated by the data taken during Experiment …

A Model Of The Population Dynamics Of The Blue Crab In Chesapeake Bay, Betty Springer Hester

OES Theses and Dissertations

This study has particular application to the blue crab fisheries in Chesapeake Bay, an economically important industry whose successful management has been hindered by relatively poor understanding of the population dynamics. Recent biological studies have indicated a systematic spawning behavior which seems designed for ejection of larvae seaward from the bay entrance where they spend their pre-metamorphosis stages in the neuston. A physical mechanism for retention of the larvae in sufficient proximity to the bay entrance for their return at the proper time which involves the action of wind stress in shallow waters is proposed. Since the supply of blue …

The Relationship Of Size Class Distribution To Migratory Behavior In Brown Shrimp (Penaeus Aztecus) In Pamlico Sound, North Carolina, Mario A. Paula

OES Theses and Dissertations

The potential of migratory timing information for dynamic yield estimation in the North Carolina brown shrimp fishery has been shown. The present research investigates the influence of size class distribution on the quantitative characterization of migratory timing in the brown shrimp. Catch and nominal effort data were stratified into count size ranges and the time density model of Mundy (1979) was specified for each stratum. The recruitment patterns of the shrimp into the fishery was also investigated.

The stratification of time densities by size class has shown a definite pattern in the migratory behavior of the brown shrimp. It appears …

Input And Distribution Of Sewage Derived Sedimentary Material Adjacent To Chesapeake-Elizabeth Sewage Outfall, Virginia Beach, Virginia, Robert Carroll Brown

OES Theses and Dissertations

The concentrations of coprostanol and hydrocarbons were measured in the effluent from the Chesapeake-Elizabeth sewage treatment plant and surface sediments from the area surrounding the effluent discharge site. Most of the coprostanol (>84%) and hydrocarbons (>91%) were associated with particulates in the effluent. Some of these particles were incorporated into the sedimentary column within the study area, while some may have escaped from the area.

The study area is found to be a dynamic area where changes in the percentage and distribution of fine-grained sediments occur over periods of months. The movement of fine-grained sediments is an important …

Variability Of Atmospheric Hydrocarbon Concentrations And Deposition Rates, Charles Thomas Farmer

OES Theses and Dissertations

The atmospheric hydrocarbon concentration was determined at various locations throughout Southeastern Virginia from July 1981 to February 1983. During this period the concentration ranged from 0.4 to 5.5 μg/m³ . From October 1982 to February 1983, WET and dry deposition samples were collected in conjunction with these air samples. Total hydrocarbon dry deposition rates ranged from deposition rates ranged from 4 to 189 μg/m² /day, while WET 22 to 670 μg/m² /day. Hydrocarbon concentrations found were within the ranges reported in the literature for wet, dry and atmospheric hydrocarbon concentrations.

Linear trend analysis revealed no correlation between …

Polychlorinated Biphenyl Levels In The Ocean Scallop (Placopecten Magellanicus) Gmelin From The Philadelphia Sewage Sludge Disposal Site, Guy Jeffrey Hall

OES Theses and Dissertations

Ocean Scallops (Placopecten magellanicus) were sampled from stations in and around the Philadelphia Disposal Site. Each sample was dissected and aliquots of adductor muscle and reproductive tissue were chemically extracted for Polychlorinated Biphenyls (PCBs). A perchlorinated procedure outlined by Diosady et al., 1972, Aromour, 1973 and Crist et al., 1977 was employed to increase detection levels and simplify quantitation of PCBs. PCB levels were reported in dry weight and lipid weight of both adductor muscle and reproductive tissue. Findings indicated residual levels or PCB/lipid weight increased as lipid levels decreased in both tissue types. Levels detected in all adductor muscle …

A Study Of Increased Flow Off The Eastern Seaboard Of The United States Within Four Synoptic Flow Patterns During The Winter Months, John Dale Liechty

OES Theses and Dissertations

A study of increased winds during the winter season off the United States Eastern Seaboard was made in each of four synoptic flow patterns: prefrontal; postfrontal; northeast; and southerly. Eight years of synoptic data for the months October through March from two pairs of stations were utilized. Each pair consisted of one land and one sea station; of the sea stations, Frying Pan Light was located in or near the warmer water of the Gulf Stream while Chesapeake Light was situated in colder, coastal water. Both land stations were situated in the vicinity of the coast.

A statistical analysis was …

Immediate Effects Of A Storm On Coastal Infauna, Fred C. Dobbs, Joseph M. Vozarik

OES Faculty Publications

Effects of storms on benthic infaunal communities have thus far been inferred rather than documented; especially lacking are studies examining immediate effects. To this end, the water column and 2 subtidal benthic sites were sampled before and after Storm David in September 1979. There were large post-storm increases in the numbers of infaunal species and individuals in the water column, presumably due to turbulent benthic boundary conditions. At the benthic stations, there were no pre vs. post-storm differences in the density of infauna; however, the number of species decreased at 1 station. There were storm-associated changes in the rank order …

Monitoring Defecation Activity Of Infaunal Deposit Feeders, Fred C. Dobbs

OES Faculty Publications

An inexpensive, reliable thermistor device capable of monitoring infaunal foraging activity was built and used in the laboratory to examine effects of temperature on sediment reworking by the maldanld polychaete Clymenella torquata. The worm defecated at least once per hour 55.0 % (12.0 "C) to 88.2 % (5.5 "C) of the time. Defecation rate was linearly and positively related to temperature. Estimated volume of sediment ejected per defecation (0.015 ml) did not change with temperature. Results are compared with previous reworking studies of C. torquata.

A Pore Water/Solid Phase Diagenetic Model For Manganese In Marine Sediments, David J. Burdige, Joris M. Gieskes

OES Faculty Publications

A steady state diagenetic model is developed which accounts for changes in both the pore water and solid phase manganese profiles in marine sediments as a result of advection, diffusion, and redox reactions. The model is applied to observations on two cores in the E equatorial Atlantic in which pore water and solid phase manganese data are available. In situ reaction rates for manganese oxidation and reduction are estimated. The oxidation rates calculated here are in good agreement with rates measured in laboratory studies. In addition, the calculated manganese oxidation and reduction rates are compared with other estimated rates for …

Transport And Fate Of River Discharge On The Continental Shelf Of The Southeastern United States, J. O. Blanton, L. P. Atkinson

CCPO Publications

We have analyzed 8 years of wind and salinity data from a frontal zone in a region of the inner continental shelf off the southeastern United States. The changes in low‐salinity water stored in the frontal zone have been parameterized by analyzing the monthly rate of change in freshwater content. When the rate of change in freshwater content was negative, we interpreted this as a loss of low‐salinity water from the frontal zone. When this parameter was compared with seasonally averaged alongshore wind stress, the rate of loss was independent of the alongshore wind stress magnitude until threshold of about …