Marine Biology Commons^™

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 …

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 …

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 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 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 …

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 …

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.

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.

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 …

Environmental Influence On The Migratory Behavior Of The Brown Shrimp In Pamlico Sound North Carolina, Michael Andrew Matylewich

OES Theses and Dissertations

Environmental conditions in the nursery areas during times of development affect the migratory behavior of the brown shrimp (Penaeus aztecus) by influencing growth and natural mortality. A linearized logistic model and a multiple linear model are used to relate environmental factors (week number, water temperature, salinity, air temperature, precipitation, net heating degree days, river discharge) to the cumulative proportion of catch and catch-per-unit-effort, respectively. Multiple regression analysis yielded equations containing the week number, the water temperature and an interaction term as the independent variables. Predictions of total annual yield and total annual catch-per-unit-effort are made using the migratory …

Quantitative Reef Assessment Studies In Bermuda: A Comparison Of Methods And Preliminary Results, Richard E. Dodge, Alan Logan, Arnfried Antonius

Marine & Environmental Sciences Faculty Articles

To compare in quantitative terms both ecological characteristics of the stony coral fauna at various reef sites in Bermuda and available assessment methodologies, we present a study of four separate methods at each of three reef sites. Three plotless (Intersected-length, Quarter point, Point) and one quadrat (Belt-quadrat) methods were employed. Each technique gave similar results but had inherent advantages and disadvantages which involve trade-offs in quantity and type of information generated and time required for use.

Pooling of method results revealed that total coral coverage was highest at North Rock (26%), intermediate at Three Hill Shoals (17%), and lowest at …

A Comparison Of Recruitment Strategies Among Brachyuran Crustacean Megalopae Of The York River, Lower Chesapeake Bay And Adjacent Shelf Waters, David Franklin Johnson

OES Theses and Dissertations

Twenty-one stations forming a transect of the Pamunkey River, York River, lower Chesapeake Bay and adjacent coastal waters were sampled from July through September 1980. The megalopa stages of 11 brachyuran species were sampled. Vertical and horizontal distributions are described for each species in relation to salinity and water column stratification. The megalopae are assigned to three apparent recruitment strategies: retained estuarine, expelled estuarine and retained coastal megalopae. the megalopa stages of estuarine adults, such as Hexapanopeus angustifrons, Neopanope sayi, Panopeus herbstii and Pinnotheres ostreum, are retained in estuarine epibenthic waters, while Rhithropanopeus harrisii are retained in slightly shallower …

A Laboratory Study Of Nongenetic Embryonic Adaptation To Salinity And Its Subsequent Effects Upon Larval Development Of The Grass Shrimp Palaemonetes Pugio Holthius, Paul Jay Anninos

OES Theses and Dissertations

Fertilized embryos of the grass shrimp Palamonetes pugio Holthuis (Decapoda; Caridea) were exposed to two levels of salinity [5 ppt (exposed) and 20 ppt (control)] during incubation to determine the extent to which embryonic adaptation influences subsequent larval development. Larval response to embryonic exposure was measured at three salinities (5 ppt, 10 ppt, and 20 ppt) as the fraction of larvae surviving to metamorphosis and the duration (in days) of larval development. The survival rate of larvae hatched from control, or non-adapted, embryos was significantly influenced by rearing salinity. The differences in survival of pre-adapted larvae (exposed group), however, were …

Fishery Report No 55 - The Western Rock Lobster Fishery 1961 - 1971, G. R. Morgan, E H. Barker

Fisheries Research Reports

The fishery for the western rock lobster, Panulinus cygnus is one of the most important single fisheries in Australia and one of the major rock lobster fisheries of the world with catches in recent years averaging some 8000 tonnes annually. The history of the commercial fishery extends back to 1944/45 factory when a canning was opened at the Abrolhos Islands (Figure 1) with a view to supplying the Australian armed forces. After the World war, an export market for fresh frozen rock lobster tails was quickly established in the U.S.A. and the industry, sharing in the advantages of postwar reconstruction, …

Fisheries Report No 51 - 'Taiyo Maru 71" Demersal Trawling Cruise In Western Australian Coastal Waters South Of 21 S, July-September, 1979, D. I. Heald, M. H. Walker

Fisheries Research Reports

A Japanese demersal trawler, 'Taiyo Maru 771' was given special permission to conduct exploratory trawling in the period 73.7.79-16.9.79 off the Western Australian coast between 21°S Latitude and 35°30'S Latitude, an area which partly overlapped the fishing grounds for the western rock Lobster. The vessel was required to complete a catch, fishing effort and species composition log book issued by the Commonweath Department of Primary Industry. Two Western Australian Department of Fisheries and Wildlife observers on board monitored fishing operations for the entire duration of the cause and undertook research.

Details of each trawl conducted are given and discussed. Catch …

Fisheries Report No 57 - Exploratory Fishing For Spanish Mackerel In Waters Off Western Australia During The Period June 16 To October 16, 1981, K. Donohue, P. Edsall, J. Robins, R. Tregonning

Fisheries Research Reports

The results of catching Spanish mackerel (Scomberomorus commerson) by gillnet and troll lines during a survey extending from June 16 to October 16 1981 are presented.

The catch rate of mackerel obtained by trolling with six lines was found to be 14.35 times greater than that by gillnet, measuring 0.75 miles in length.

From the results presented, a professional fisherman should be able to assess the economic viability of fishing commercially for Spanish mackerel.

Analysis of biometrial and biological data on fish caught allowed determination of (a) length/weight relationship of (i) Spanish mackerel (ii) wahoo (Acanthocybium solandri); (b) sex ratios …

Fisheries Report No 52 - The Present State Of The Western Australian Fishery For Australian Salmon, Michael H. Walker

Fisheries Research Reports

In 1975, following a number of years of research by the CSIRO Division of Fisheries and Oceanography, it was decided to conduct. a renewed programme cooperatively between CSIRO and W.A. Department of Fisheries and Wildlife. The results of the joint programmes will be presented elsewhere. Meanwhile this paper. describes the Western Australian salmon fishery in 1981 and over the life of the current CSIRO/W.A. salmon research programme i.e. 1975-1981. It considers both the professional and amateur fishery, the disposal of the catch and attempts to discuss any changes in technique, effort, etc. which may have occurred in the period 1975-1981. …

An Evaluation Of Nutrient Sources To Onslow Bay, North Carolina, Larry P. Atkinson, Leonard J. Pietrafesa, Eileen E. Hofmann

CCPO Publications

Hydrographic and current meter data from Onslow Bay, North Carolina, were examined to determine the relative importance of various nutrient sources.

Upwelled Gulf Stream water is the major source of nutrients while rivers represent a minor, if not insignificant, source. In the summer during stratified conditions, the upwelled water penetrates across the shelf, but in the winter the upwelled water is restricted to the outer shelf. Nitrate flux across the 40 m isobath was calculated from continuous temperature and current records. Flux during the summer of 1976 was 2 μM m² sec^-1 which is considerably less than flux …

Benthic Testacida (Rhizopoda, Protozoa) Of Lake Washington, Brevard County, Florida, Haydee Lena

Ocean Engineering and Marine Sciences Faculty Publications

Benthic Testacida from sediments of Lake Washington were studied. The Testacida were extracted using standard foraminiferologic techniques. The determined taxa were photographed using scanning electron microscopy. Twenty-one taxa were found. The majority were cosmopolitan and the most abundant were Difflugia pyriformis and Centropyxis compressa. The Testacida guild was similar to that previously studied in other American and European lakes. However, the type and size of the species were different from those found in soil and mosses.

The Ecology Of Maine's Intertidal Habitats : A Report Prepared For The Maine State Planning Office, Peter F. Larsen, Lee F. Doggett

Maine Collection

The Ecology of Maine's Intertidal Habitats : A Report Prepared for the Maine State Planning Office

by Bigelow Laboratory for Ocean Sciences (Authors: Peter F. Larsen and Lee F. Doggett) , 1981.

Contents: Acknowledgements / List of Tables / List of Figures / Chapter 1 - Introduction / Chapter 2 - Human Impact on Intertidal Fauna / Chapter 3 - A Primer of Intertidal Ecology / Chapter 4 - A Sampler of Intertidal Species / Chapter 5 - Methodology / Chapter 6 - Results of Faunal Studies / Appendix 1 - Habitats With Date Sampled / Appendix 2 - List …

A Quantitative Description Of Migratory Behavior Of The Brown Shrimp (Penaeus Aztecus) With Applications In Fisheries Management, Anne Madolyn Babcock

OES Theses and Dissertations

A quantitative description of the migratory behavior of the brown shrimp, Penaeus aztecus, was established using the density approach. A theoretical time density was estimated by the proportion of catch and catch per boat hour NOAA-NMFS fisheries statistics collected in Pamlico Sound, the Neuse River, and Core Sound. A clear quantitative description of brown shrimp migratory timing is found in the time densities. The impact of various physical tactors on the progress of the fishery in time and space can be objectively evaluated by using the time density statistics as dependent variables in modeling efforts. The distributions also enable …

Notes On Recent Changes In Tanaidacean Terminology, Charles G. Messing

Marine & Environmental Sciences Faculty Articles

no abstract available