Life Sciences Commons^™

Survival Of Juvenile Queen Conch, Strombus Gigas, In Natural Habitats: Impact Of Prey, Predator And Habitat Features, Livingston Sinclair Marshall Jr

Dissertations, Theses, and Masters Projects

In this dissertation, I experimentally examine predation-induced mortality upon juvenile queen conch, Strombus gigas, and assess the importance of select habitat predator and conch characteristics affecting predation intensity. Experiments were conducted during the summer and early fall of 1987, 1988, 1990 and 1991 in seagrass beds and adjacent sand flats near Lee Stocking Island, Exuma Cays, Bahamas. These experiments indicate that various factors act interactively to produce habitat-specific mortality rates in queen conch due to predation. These include (1) habitat type, whereby seagrass beds offer some protection; (2) local population dynamics, such that populated seagrass beds appear to enhance conch …

Modelling Of Zinc Accumulation In The American Oyster, Crassostrea Virginica (Gmelin), Cheol Mo

Dissertations, Theses, and Masters Projects

A model of zinc accumulation by the American oyster, Crassostrea virginica, is developed by relating in-situ zinc body burden to time-integration of uptake. Short-term uptake rates are estimated in laboratory by introducing &\sp{lcub}65{rcub}&Zn to oysters of various weights in aquaria with salinities of 18&\perthous& and 12&\perthous&. Uptake of &\sp{lcub}65{rcub}&Zn by an oyster: (1) varies as a power function of the body weight (soft tissue dry weight) of the oyster (&dy\over{lcub}dt{rcub}& = kW&\sp{lcub}\beta{rcub}&), (2) is inversely related to the salinity of ambient water, and (3) increases linearly with ambient concentration. Zinc body burdens of oysters of various weights from oyster beds …

Distribution, Abundance, And Behavior Of The Cownose Ray, Rhinoptera Bonasus (Mitchill 1815), In Lower Chesapeake Bay, Robert A. Blaylock

Dissertations, Theses, and Masters Projects

Aspects of the ecology of the cownose ray, Rhinoptera bonasus, in the lower Chesapeake Bay and its tributaries were studied using aerial surveys, biotelemetry, and examination of stomach contents. The Chesapeake Bay was surveyed by airplane during 1986-1989, to examine the distribution of cownose rays and estimate their abundance using line transect methods. Cownose rays resided in Chesapeake Bay throughout the summer months, entering in early June and emigrating in late September. They were usually absent, or nearly so, by late October. Mean monthly abundance ranged from none present in May and November, to a September average of 9.3 &\cdot& …

Foraging Ecology Of The Blue Crab, Callinectes Sapidus Rathbun, In Lower Chesapeake Bay, Randa A. Mansour

Dissertations, Theses, and Masters Projects

This study concurrently quantified blue crab feeding habits and preference, and examined the inter-relationships between diet, predator preference, and predator and prey abundance and distribution in three subestuaries of lower Chesapeake Bay--the James, York and Rappahannock Rivers, Virginia. Complementary laboratory investigations estimated the combined effect of the functional, aggregative and interference responses upon prey and predator survival and predator foraging rates for blue crabs and a common bivalve prey, Macoma balthica, in this system. Crab abundance, prey abundance and diet were correlated such that blue crabs aggregated in areas of highest preferred (i.e., bivalve) prey abundance, as determined through electivity …

Distribution Of Aeschynomene Virginica And Bacopa Innominata Along The Proposed Alternative Routes For The Sr629 Mattaponi River Crossing Upgrade Project, James E. Perry

Reports

Four wetland macrophytes of interest are found in the region of the proposed upgrade of the State Route 629 bridge crossing of the Mattaponi River. Two of these are State listed endangered or threatened species: the sensitive joint vetch (Aeschynomene virginica) and the mat-forming water-hyssop (Bacopa innominata). Two species, Long's bittercress (Cardamine longii) and Parker's pip~wort (Eriocaulon parkeri) are included on the Virginia watch list (Ludwig, 1992).

The purpose of this study was to locate and describe plant populations of the specified species (i.e. determine the size, spatial distribution, and density of extant populations) within a specified range of each …

The Effects Of Gull Predation On The Colony Reproductive Success Of Terns And Skimmers In Virginia, Timothy J. O'Connell

Dissertations, Theses, and Masters Projects

No abstract provided.

Shoreline Habitat Selection By Bald Eagles (Haliaeetus Leucocephalus) In A Non-Breeding Eagle Concentration-Area On The James River, Virginia, Kennedy H. Clark

Dissertations, Theses, and Masters Projects

No abstract provided.

A Vegetational Analysis Of Interdunal Swale Communities Of False Cape State Park, Currituck Spit, Virginia, Heather A. Jones

Dissertations, Theses, and Masters Projects

No abstract provided.

Hardwood Forest In The Coastal Plain Of Virginia East Of The Suffolk Scarp, Penelope Williams Cazier

Dissertations, Theses, and Masters Projects

No abstract provided.