Physical Sciences and Mathematics Commons^™

Trichodesmium Spp.: Numerical Studies Of Resource Competition, Carbohydrate Ballasting, And Remote-Sensing Reflectance, Tonya Denise Clayton

OES Theses and Dissertations

In recent years, a new appreciation for the role of diazotrophy in the oceans has emerged. This dissertation reports on three modeling studies designed to investigate ecological processes associated with Trichodesmium spp., the most conspicuous marine diazotroph: (1) characterization of a generalized model Trichodesmium and issues of macronutrient resource competition; (2) carbohydrate ballasting by Trchodesmium and implications for the formation of surface accumulations; and (3) the vertical distribution of Trichodesmium and implications for detection from space.

The first study focuses on issues of nitrogen and phosphorus competition and ecosystem structure. It utilizes a simple ecosystem model that includes dissolved nitrogen …

The Implications Of The Target-Area Hypothesis On The Population Dynamics Of The Spotted Spiny Lobster, Panulirus Guttatus, Denice N. Robertson

Biological Sciences Theses & Dissertations

The target-area hypothesis, based on the theory of island biogeography, predicts that larger islands are more effective at intercepting passive immigrants. Most marine invertebrates have meroplanktonic larvae and open population dynamics, so immigration to populations in isolated benthic habitats is primarily by pelagic larval recruits. Thus, recruitment to isolated habitat “islands” may be more continuous and predictable on large islands than on small ones. Consequently, populations on large islands should not only be larger than those on small islands, but should also have more evenly distributed size structures. These differences in size structure among populations in isolated habitats of differing …

A Comparison Of Phytoplankton Communities In Lake Prince And The Western Branch Reservoir, Suffolk, Virginia, Cara Marie Muscio

Biological Sciences Theses & Dissertations

Lake Prince and the Western Branch Reservoir are two eutrophic bodies of water located in Suffolk, Virginia. Lake Prince and its two small tributaries join the Western branch via a constructed spillway. This lake system is a source of water for the surrounding municipalities, and a recreational area for community citizens. In the past, these bodies of water had repeated incidents of low oxygen and nuisance algal blooms, particularly cyanobacteria species. As a result aerators have been installed in the main body of both Lake Prince and the Western Branch Reservoir. In addition, a pipeline has been installed from North …

Effects Of Human Disturbances On The Behavior Of Dabbling Ducks, Melissa Lynn Pease

Biological Sciences Theses & Dissertations

Disturbance of wintering and migrating birds by human activities can cause birds to expend energy in avoidance of humans and reduces the time available for resting and feeding at a time in the annual cycle when fat deposition and energy conservation are important. Also, human disturbances can effectively cause habitat loss by displacing birds from feeding or resting habitat. Managers of natural resources are increasingly faced with decisions about the types and amounts of public use that should be allowed without lowering the value of the resource for wildlife. In order for managers to make decisions about how to minimize …