Terrestrial and Aquatic Ecology Commons^™

Spring 1998, Nsu Oceanographic Center

Currents

No abstract provided.

Fall 1998, Nsu Oceanographic Center

Currents

No abstract provided.

Fall 1998, Nsu Oceanographic Center

Currents

No abstract provided.

Stomach Content Analysis Of Stranded Bottlenose Dolphins, Tursiops Truncatus, In Virginia, 1987-1996, John Mcgurk

Biological Sciences Theses & Dissertations

I examined the stomach contents from 94 bottlenose dolphins, Tursiops truncatus, that were stranded along the Virginia coastline from 1987 through 1996. Samples from 1987 through 1991 were obtained from the National Museum of Natural History (NMNH) and samples from 1992 through 1996 were collected by the Virginia Marine Science Museum (VMSM) Stranding Team. Prey species were identified using fish otoliths and cephalopod beaks.

The dolphins examined fed on 23 species of fish and one genus of cephalopods. The primary prey species was Atlantic croaker (Micropogonias undulatus); secondary species were weakfish (Cynoscion regalia), spot (Leiostomus xanthurus), silver perch (Bairdiella chrysoura), …

Western Australian Fisheries - The Way Forward (1997), Western Australian Fisheries

Fisheries Published Reports

Western Australia's fisheries have a bright future.

The State has a pristine marine environment which is enjoyed by both commercial and recreational fishing interests, and the wider community.

There are over 600,000 Western Australians for whom recreational fishing is a favourite pastime and each year they contribute an estimated $500 million to the State's economy. As the popularity of recreational fishing continues to rise so does the sector's importance in overall management of our fisheries.

The commercial industry contributes about $1 billion annually, derived from a wide variety of fish stocks, the major ones being rock lobster, prawns, scallops, abalone …

Zooplankton Community Dynamics In The Elizabeth River, Virginia, William C. Sharp

Biological Sciences Theses & Dissertations

Zooplankton community structure and dynamics were studied over a 12 month period in the Elizabeth River, an industrially polluted tidal river in the Chesapeake Bay estuarine system. An additional site in this estuary (Hampton Roads) was sampled for comparative purposes. Multivariate analysis indicated five distinct temporal groups occurred during the year, but there were no significant differences in spatial composition within the river. Maximum zooplankton concentrations were observed in July and lowest abundances were observed in February, March, and November. Copepods, especially Acartia species, were the most abundant components of the zooplankton community, comprising 67 to 93% of the total …

Seasonal Phytoplankton Dynamics In The Pagan River, David Wade Seaborn

Biological Sciences Theses & Dissertations

The composition and seasonal abundance patterns for phytoplankton in the Pagan River, Virginia, were determined. This river is characterized as a nutrient enriched system with annual mean levels of total nitrogen and phosphorus at 1.8 and 0.8 mg/I respectively. Three phytoplankton maxima occurred during the year with the highest in fall, followed by summer and spring peaks. A diatom flora was dominant throughout the year at concentrations of 107 to 108 cells/I. Other algal populations exhibited distinct periods of abundance, which seasonally varied in magnitude and time of development. Turbidity levels were high throughout the year, with a mean secchi …

Eutrophication And Macrobenthic Communities Of The Lower Chesapeake Bay: Effects Of Organic Enrichment In Pocomoke Sound, Saxis Virginia, Janice D. Mcdonnell

Biological Sciences Theses & Dissertations

The effects of organic enrichment on benthic community structure were evaluated in a field study conducted in Pocomoke Sound in the vicinity of a seafood processing plant. The empirically derived Species Abundance and Biomass (SAB) curves of Pearson and Rosenberg (1978) were used to model patterns of organic enrichment at the study site, called Pig Point, as well as two reference sites located within Pocomoke Sound. The Split Moving Windows (SMW) method was used to detect the ecotone point as defined in the Pearson and Rosenberg (1978) model and the Two Term Local Quadrat Variance (TTLQV) method was used to …

The Influence Of Temperature Salinity And Postlarval Transport On The Distribution Of Juvenile Spiny Lobsters, Panulirus Argus, In Florida Bay, Jennifer Marie Field

Biological Sciences Theses & Dissertations

Florida Bay is a major nursery for the Caribbean spiny lobster, Panulirus argus. The Bay contains a series of hardbottom or seagrass-covered basins separated by mudbanks, which serve as barriers to water circulation and presumably to transport of postlarvae. Temperatures can fluctuate dramatically in the basins and salinities range from 35 ppt to > 50 ppt. In this study I: i) investigated the physiological tolerance of spiny lobster postlarvae to combinations of temperature and salinity representative of conditions in Florida Bay, and ii) examined how postlarval availability and habitat structure influence spiny lobster recruitment into basins. I measured juvenile lobster …

Phytoplankton Assemblages Associated With A Bloom Of Ptychodiscus Brevis Off The North Carolina Coast, Traycie Lea West

Biological Sciences Theses & Dissertations

A bloom of the dinoflagellate Ptychodiscus brevis occurred off the North Carolina coast in late 1987, and samples were forwarded by NOAA to the Old Dominion University Phytoplankton Laboratory for total phytoplankton analysis. Six sampling stations were chosen to represent different bloom scenarios and these six were clustered into three site groups based on the concentrations of statistically significant taxa. Abundances of phytoplankton taxonomic groups over time were examined in relation to P. brevis concentrations to identify any general tendencies. These results indicated the total phytoplankton concentration, and most taxonomic groups, increased at all three site groups regardless of the …

Evaluation Of Long Term Changes In The Macrobenthic Community Of The Southern Branch Of The Elizabeth River, Virginia, William S. Hunley

Biological Sciences Theses & Dissertations

Long-term changes in the macrobenthos of the Southern Branch of the Elizabeth River, Virginia were investigated by comparing the present study of community structure with that described ten years earlier by Hawthorne (1980). The results indicated that dominant organisms remained relatively constant in composition but exhibited considerable fluctuation in density. Differences in diversity and spatial distribution of fauna were also observed relative to the previous decade.

Multivariate statistical analyses indicated the macrobenthos exhibited significant spatial and seasonal patterns. Sediments characterized as silts and clays predominated down river while sandier sediment types were most common farther upriver. The spatial distributions of …

Observations On The Pearl Oyster Fishery Of Kuwait, S. M. Almatar, Kent E. Carpenter, R. Jackson, S. H. Alhazeem, A. H. Alsaffar, A. R. A. Ghaffar, C. Carpenter

Biological Sciences Faculty Publications

The pearl oyster fishery of Kuwait was monitored daily from January 1989 to May 1990. Landings of pearl oysters in 1989 totaled 287 tons with a market value of U.S. $1.0 million. Commercial pearls (>3 mm) were estimated to be present in one of every 4200 oysters. Most of the pearl oysters landed were new recruits with hinge lengths between 40-56 mm. There was a curvilinear relationship between total weight and size of oysters (length) and the sex ratio approached 1:1. Spawning occurs throughout the year, with a spat settlement peak in early fall. Over the size range examined …

A Multivariate Characterization Of Assemblages Of Planktonic Mysids Decapods And Sergestids In The Chesapeake Bay Mouth Area, John Charles Seibel

Biological Sciences Theses & Dissertations

This study is the first to focus on the assemblages of the planktonic mysids, decapods, and sergestids found in the lower Chesapeake Bay. The assemblages of these organisms in the lower Chesapeake Bay and nearby shelf were characterized using three different statistical approaches, and the methods used were evaluated for their effectiveness at delineating ecologically meaningful assemblages. Three stations were sampled across the Chesapeake mouth and one offshore, with oblique and neuston net tows. Twenty-seven larval stages, representing at least 23 species, were found in sufficient numbers to be analyzed statistically. The statistical approaches were each based upon a different …

A Laboratory Study Of Predation On The Trinidadian Guppy, Poecilia Reticulata, By Two Natural Piscine Predators: Effects Of Predator Size, Prey Size, And Habitat Complexity, Hayden Thomas Mattingly

Biological Sciences Theses & Dissertations

Test populations of different-sized guppies, Poecilia reticulata, were exposed to individuals of two natural predatory species, the pike cichlid Crenicichla a/ta and the killifish Rivulus harti, under conditions of varying prey (guppy) density and habitat complexity in the laboratory. Rivulus fed most frequently on newborn and juvenile guppies < 14 mm. Crenicichla consumed more and larger guppies than did Rivulus. The mean guppy size eaten by Crenicichla was dependent on the length of the individual predator, but as a group, the 15 Crenicichla tested were non-selective with respect to guppy size and gender. The prey gender preference of Rivulus could not he determined …

Community Structure Of The Macrobenthos In Back Bay, Virginia, Michael F. Lane

Biological Sciences Theses & Dissertations

A study of the subtidal macrobenthos in Back Bay, Virginia was conducted to examine community structure in relation to sedimentary and water quality characteristics. Samples were collected in August and November of 1987 and February and May of 1988 at ten stations.

Three site groups and three temporal groups were identified by cluster analyses of species abundance. Species composition between site groups was relatively homogeneous and eight species accounted for most of the variation between site groups. A comparison of plots of the biological and physical data in discriminant space suggested that variations in the biological data between site groups …

Fisheries Research Report No. 84 - The Marine Open Shelf Environment: Review Of Human Influences, D. A. Hancock

Fisheries Research Reports

For the purpose of this review, the marine environment has been classified into three physical zones - the littoral zone, the open-shelf environment and the coral reef. Since the boundaries are arbitrary, there will inevitably be some overlap, but for this review the subject matter will be related to the area between low water of ordinary spring tides and the edge of the continental shelf; i.e., to a depth varying to 200 metres.

Human influences may have a dual role in affecting the marine environment, firstly in a causative manner and secondly in providing a remedy, in which case the …

Freshwater Fishes Of Shipstern Nature Reserve, Caspar F. A. Bijleveld

Physiology Faculty Research Publications

A survey of fishes in and around Shipstern Nature Reserve in Northern Belize, Central America, was carried out over a period of eight months, from February to September 1990. Its purpose was to establish a preliminary list of the fishes of Shipstern Nature Reserve, including descriptions, distribution and collecting data and additionally to describe some of the habitats in which the fishes were found. This study focuses on fishes considered to be freshwater species. These occurred for the greater part in brackish habitats. Nevertheless, a few fish considered as marine species were caught in the waters of the reserve and …

Picoplankton/Phytoplankton Dynamics In Hampton Roads, Virginia, Leslie E. Dorworth

OES Theses and Dissertations

The biomass distribution of the three main size components of the phytoplankton (net, nano, and picoplankton) was examined in the lower Chesapeake Bay. Work was done at two stations during the spring and neap tidal cycles when freshwater flow into the bay was at its seasonal minimum and maximum. Emphasis was placed on how the picoplankton ( < 2.0 μm, > 0.2 μm) reacted during the sampling period.

Picoplankton made up approximately 13% of the total biomass, during the observed time period, at the more oceanic station. The picoplankton fraction contributed up to 16% of the total biomass at the estuarine station. From this …

Vertical Distribution Of Phytoplankton Populations Along The Northeastern Continental Shelf Margin Of The United States, Bruce Burwell Wagoner

Biological Sciences Theses & Dissertations

A study of phytoplankton vertical distribution at six stations along the northeast continental shelf of the United States was conducted in April 1984.

A total of 168 taxa were identified from nine phylogenetic groups collected at depths up to 150 m. Highest cell concentrations and cell volumes were in the upper 30 m. Greatest cell concentrations were produced by diatoms and a pico-nanoplankton component, with cell volumes mainly the product of diatoms and dinoflagellates. A high degree of variability was observed between phylogenetic groups within each station, but less variability was noted for phylogenetic categories at different stations.

Little difference …

Seasonal Phytoplankton Assemblages In The Nansemond River, Virginia, Cindy Eleanor Shomers

Biological Sciences Theses & Dissertations

A monthly phytoplankton study was conducted on the Nansemond River from November 1984 to October 1985. Light microscopy was utilized to characterize the resident populations, their cell concentrations and to provide a general comparison to other regional studies of river systems considered more polluted. The results divided the flora into two major categories. The first group was a pico-nanoplankton component composed of Cyanobacteria and Chlorophycean cells 1-10 um in diameter. The second group was a microplankton assemblage of Bacillariophyceae, Dinophyceae, Cryptophyceae, Chlorophyceae, Cyanobacteria and Euglenophyceae. The pico-nanoplankton had a unimodal abundance pattern with peak concentrations occurring in spring. The microplankton …

Microbial Food Resources Of The Macrofaunal-Deposit Feeder Ptychodera Bahamensis (Hemichordata: Enteropneusta), Fred C. Dobbs, James B. Guckert

OES Faculty Publications

Biochemical and traditional analyses were used to characterize the microbial food resources and digestive efficiency of Ptychodera bahamensis, an enteropneust hemichordate. Sediment was collected from freshly extruded fecal casts and adjacent feeding depressions. There were no significant differences between casts and depressions in median grain size, percent silt-clay, density of total meiofauna and of nematodes, and concentrations of chlorophyll a and phaeophytin. Nematodes in casts had a median diameter greater than those in depressions. Measures of total, viable microbial biomass were 30% (total phospholipid, ester-linked fatty acids) and 49% (extractible phospholipid phosphate) lower in casts. Concentrations of 33 fatty …

Callianassa Trilobata (Crustacea: Thalassinidea) Influences Abundance Of Meiofauna And Biomass, Composition, And Physiologic State Of Microbial Communities Within Its Burrow, Fred C. Dobbs, James B. Guckert

OES Faculty Publications

Biochemical and traditional methods were used to determine the influence of Callianassa trilobata on microbiological and meiofaunal communities within its large, highly consolidated burrow. Sediment was collected from the lining of the shrimp's burrow, the burrow matrix, and ambient, subsurface sediment. The lining and matrix were composed of poorly sorted, fine-grained material compared to sandy ambient sediment. Meiofauna, predominantly nematodes, were most abundant in ambient sediment, not in the burrow as has been found for other species of macrofauna. Concentrations of chlorophyll a were very high in the lining, consistent with the suggestion that C. trilobata lines its burrow walls …

Age And Growth Of The Tautog, Tautoga Onitis (Pisces: Labridae), From Lower Chesapeake Bay And Coastal Waters Of Virginia, E. Brian Hostetter

Biological Sciences Theses & Dissertations

The tautog, Tautoga onitis (Pisces: Labridae), is rapidly gaining popularity in Virginia by anglers, spearfishermen and specialized commercial interests. In Virginia, tautog are seasonally abundant on hard bottom substrates in nearshore (ca. 2-10 m) habitats and inhabit offshore wrecks and reef areas (ca. 10-30 m) year round. Habitat restriction and slow growth of the species coupled with recent technological advances in marine electronics which simplify locating tautog populations by user groups may contribute to overexploitation of tautog within the region.

Tautog were collected over a two year period from the lower Chesapeake Bay and nearshore waters of the Atlantic Ocean …

A Biochemical And Genetic Analysis Of The American Shad Alosa Sapidissima Migrating Into The Chesapeake Bay, Edward Norbert Sismour

Biological Sciences Theses & Dissertations

Seven enzymes extracted from heart and liver tissues of American shad Alosa sapidissima captured during migrations into the Chesapeake Bay and Nansemond River were electrophoretically surveyed. Malate dehydrogenase and nonspecific esterase displayed polymorphic loci. The esterase polymorphism was used as a biochemical genetic marker to analyze the shad migration through the southern Chesapeake Bay. The genetic composition of the shad migration changed significantly over time indicating that this migration is probably composed of multiple, genetically divergent spawning populations. Results of this study are subject to differing interpretations. Observed temporal heterogeneity may result from separation of northern and James River stocks …

The Distribution Of Ceratia Over The Mid-Atlantic Bight, Paul V. Zimba

Biological Sciences Theses & Dissertations

The distribution and concentration of Ceratium species, between Cape Hatteras, North Carolina and Long Island, New York ls discussed in relation to specific physical factors and the development of a phytoplankton bloom. The progression of high Ceratium counts Is discussed for the Bight areas of New York, Delaware, and the Chesapeake Bay (April through June). The concentration of Ceratium species declined after June, with highest concentrations along the New York and Delaware coast-lines. Coastal regions (less than 12 km from shore) were associated with high concentrations of several species. Path and regression analysis were used to relate physical factors and …

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 Effects Of The Mud Snail Ilyanassa Obsoleta (Say) Upon The Benthic Community Of Broad Bay, Virginia, Wick Timothy Harlan

Biological Sciences Theses & Dissertations

The effects of the presence of the mud snail Ilyanassa obsoleta (Say) upon the benthic community of Broad Bay, Virginia were examined through artificial removal and exclusion of the snail and artificial increase of the snail population. The enclosure treatment exhibited a significantly higher number of macrofaunal individuals than the control. The control had a significantly higher number of meiofaunal individuals than either treatment. There were no significant differences for the chlorophyll a. The increase in macrofauna and corresponding decrease in meiofauna were probably due to cage effects and not snail densities. The presence of the fences can act as …

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.

Feeding Behavior Of Three Species Of Spionid Polychaetes, Thomas Lane Stokes Jr.

Biological Sciences Theses & Dissertations

Observations of feeding behavior of three species of spionid polychaetes (Paraprionospio pinnata, Polydora ligni, and Streblospio benedicti) were performed in currents ranging from 0 to 10 cm/sec over fine and coarse sediments and in high and low suspended particle loads. These interface feeders may suspension feed, deposit feed, or both simultaneously using a pair of anterior tentaculate feeding palps. P. ligni and S. benedicti were found to alter their palp behaviors in response to experimental manipulations. P. ligni reacted strongly to currents by suspension feeding with coiled palps. S. benedicti reacted strongly and complexly to food particle type and availability. …

A Structural Analysis Of Phytoplankton In The Chesapeake Bay Plume And Adjacent Shelf Waters, Charles K. Rutledge

Biological Sciences Theses & Dissertations

Community structures of phytoplankton populations from the southern portion of the Chesapeake Bight were examined and associated to real and environmental spaces. The sampling design was specifically intended to examine the small scale three dimensional structure of the Chesapeake Bay plume as characterized by its phytoplankton populations. The phytoplankton were sampled at 101 stations, non-synoptically, over a five day period in mid-June, 1980.

Several multivariate numerical techniques were used to determine the relationships between the phytoplankton species distributions and pattern the low salinity plume distribution. A pattern of distribution which approximated the salinity plume resulted from several clustering procedures. Environmental …