Marine Biology Commons^™

The Effects Of Dredged Materials On The Copeod, Acartia Tonsa, Renee Suzanne Crouch

Biological Sciences Theses & Dissertations

A study was conducted to determine the potential impact of open ocean disposal of sediments dredged from a highly industrialized seaport. Sediments from three potential dredge sites along the Southern Branch of the Elizabeth River, Hampton Roads, Virginia were evaluated for acute toxicity. The suspended particulate fractions of dredged materials were tested in a series of 96-hour, static bioassays using the calanoid copepod, Acartia tonsa Dana. Significant mortalities were observed for all three sites with the sediments from the most heavily industrialized site producing immediate and severe mortality. Analysis of results indicates that mortality was highly related to the volatile …

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 …

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 …

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 …

York River Slack Water Data Report : Temperature, Salinity, Dissolved Oxygen, 1971 - 1980, T. J. Brooks

Reports

The slack water survey program, provides an extended series of temperature, salinity, dissolved oxygen and nutrient measurements along the York River. These have been used to:

1) calibrate, verify, and update mathematical models; 2) provide a baseline against which effects of unusual events have been measured; and could be used to: 3) establish annual and longer period "climatological" trends in response to changing natural phenomena and man-made modifications to the estuary; 4) provide a basis against which fluctuations in biota could be compared.

This report contains station locations, survey schedules, field procedures, sample handling procedures, and data reduction and storage …

Postmarsupial Development And Growth Of Pagurapseudes Largoensis Mcsweeny (Crustacea, Tanaidacea), Charles G. Messing

Marine & Environmental Sciences Faculty Articles

Postmarsupial development of the gastropod shell-inhabiting tanaidacean Pagurapseudes largoensis McSweeny is described and compared with that of Heterotanais oerstedii (Krøyer) and Neotanais micromopher Gardiner. This is the first such study of an apseudomorphan based on experimentally reared animals. P. largoensis is gonochoristic; two manca instars are typical of all tanaidaceans so far investigated. In females, the mancas are followed by two or possibly three juvenile instars (=neutra), one or two preparatory instars characterized by rudimentary oostegites, and a copulatory stage with complete marsupium. Laboratory maintained animals pass through up to three copulatory stages, each separated by a preparatory stage of …

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 …

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 …

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 …

Precise And Accurate Determination By Infrared Photometry Of Co2 Dynamics In Marine Ecosystems, Kenneth M. Johnson, Curtis M. Burney, John Mcn. Sieburth

Marine & Environmental Sciences Faculty Articles

Preliminary studies with an ampule analyzing unit and infrared (IR) detector showed that procedures for standardization and determination of total carbon dioxide (ΣCO₂), while often precise, lacked the accuracy required to estimate the net productivity and respiration of aquatic ecosystems during studies in which sampling over diel cycles was used. Scaling down sample and standard volumes to the µl range and the use of a commercial sodium carbonate standard without dilution before and after replicate sample injections gave accurate results as shown by comparison with indirect (pH-alkalinity) ΣCO₂, determinations with a standard error of ±3 µmoles …

Frequency Distribution Patterns And Partitioning Of Copper, Iron And Zinc In Selected Tissues Of The Black Mullet (Mugil Cephalus), Charles J. Venuto, John H. Trefry

Ocean Engineering and Marine Sciences Faculty Publications

Copper, iron and zinc concentrations were determined for muscle, gill and liver tissue from 45 black mullet (Mugil cephalus) collected in Turkey Creek, an embayment of the Indian River Lagoon, Florida. In the liver, Fe concentrations (2420+ 1040 jig/g, dry wt) were higher than for Cu (510 ± 350 fig/g) and Zn (330 ± 120ng/g). Gill tissue iron levels (380 ± 140/xg/g) were greater than those for Zn (96 ± 26 jtg/g) and Cu (6.3 ± 4.4 fig/g). Muscle tissue concentrations were lowest with Fe values (19 ± 15/tg/g) greater than thosefor Zn (13.5 ± 4.9 fig/g) and Cu (1.1 …

Climate Scale Environmental Factors Affecting Year-Class Fluctuations Of Atlantic Croaker (Micropogonias Undulatus) In The Chesapeake Bay (Maryland, Virginia), Brenda L. Norcross

Dissertations, Theses, and Masters Projects

A conceptual life history of the Atlantic croaker (Micropogonias undulatus) identifies the effects of the environment on juvenile recruitment. In a multi-disciplinary approach to modelling, the major effects are investigated, quantified and presented in a flow chart. The model is divided into three sub models, each representing a major component which affects juvenile recruitment. North/south spawning location in the Mid-Atlantic Bight is affected by the bottom water temperature as influenced by the cessation of the summer winds in relation to timing of croaker migration. The pelagic phase is the most critical time in the life history of a larval croaker …

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 …

Environmental Correlates Of Hermatypic Coral (Montastrea Annularis) Growth On The East Flower Gardens Bank, Northwest Gulf Of Mexico, Richard E. Dodge, Judith C. Lang

Marine & Environmental Sciences Faculty Articles

Time series of annual linear growth increments from 12 Montastrea annularis (E. and S.) collected at the East Flower Gardens Bank reef in the northwestern Gulf of Mexico have a common pattern. This is best expressed in an index master chronology (average by year of the annual percentage deviations from the mean of each coral.)

Comparisons with time series of environmental data indicate that coral extension rates vary positively with seasonal (February through May - 4 months) surface water temperature and negatively with annual discharge of the Atchafalaya River. We propose that secular variations of water temperature and other parameters …

Curidia Debrogania, A New Genus And Species Of Amphipod (Crustacea: Ochlesidae) From The Barrier Reefs Of Belize, Central America, James Darwin Thomas

Marine & Environmental Sciences Faculty Articles

The family Ochlesidae is amended to include the new genus Curidia, which differs from all other members by possessing maxiIIipedal palps. Curidia debrogania is described and compared to other genera and species within the family Ochlesidae.

Curidia debrogania is plesiomorphic by possession of maxillipedal palps, suggesting this member of the small, cryptic family might have originated in the tropical Western Atlantic. Distribution records and ecological notes are included.

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.

Energy Utilization In Bay Anchovy And Black Sea Bass Eggs And Larvae Contrasting Ecological Roles, John Wotring Tucker Jr

Dissertations, Theses, and Masters Projects

The objective of this study was a comparison of developmental changes and energy utilization in eggs, unfed larvae, and fed larvae of two marine fish species that both have pelagic early stages, but differ in phylogeny and early life ecology. The bay anchovy (Anchoa mitchilli), a clupeiform, spawns in estuaries and shallow coastal waters. The black sea bass (Centropristis striata striata), a perciform, spawns offshore at 15-50 m depths. Densities of zooplankton eaten by first-feeding fish larvae are normally higher in coastal waters than offshore. An important determinant of survival of larval fishes is their ability to fulfill nutritional requirements …

An Environmental Model Predicting The Relative Recruitment Success Of Blue Crab, Callinectes Sapidus (Rathbun), In Chesapeake Bay, Virginia, Andrew Jackson Applegate

Dissertations, Theses, and Masters Projects

No abstract provided.