Fresh Water Studies Commons^™

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 …

Systematics Of The Freshwater Amphipod Genus Crangonyx (Crangonyctidae) In North America, Jun Zhang

Biological Sciences Theses & Dissertations

The systematics of the amphipod genus Crangonyx of North America (north of Mexico) is revised, based on available collections (ca. 2240) and literature dealing with the genus. A grand total of 42 North America species of Crangonyx are recognized in the present study, 24 of them new to science. All species are described or redescribed and figured, utilizing external morphological features. Keys to both species groups and individual species are given. Phylogenetic trees are built using computer programs (PAUP, Hennig86, MacClade) based on 26 characters. Wagner parsimony produced 18 parsimonious trees and Fitch parsimony produced 45 trees. The consensus tree …

Seasonal Composition Of Mesozooplankton In The Pagan River, A Nutrient Enriched Virginia Estuary, Lillian Norman Davis

Biological Sciences Theses & Dissertations

A two year study of the mesozooplankton composition and seasonal distribution was conducted in the Pagan River, a nutrient rich tidal estuary and tributary to the lower James River. The mesozooplankton was dominated by calanoid copepods (80%), with the total zooplankton abundance peaks occurring during spring and fall. The total mean abundance, 3008/m', was somewhat lower than those found by other authors, however the mean abundance at one station approximated those means. Seventy-eight percent of the calanoid copepods were Acartia spp. that were primarily responsible for the fall increase in mesozooplankton abundance. The spring increase was primarily due to increases …

Mat Movement In Coastal Louisiana Marshes: Effect Of Salinity And Inundation On Vegetation And Nutrient Levels, Christopher Martin Swarzenski

Biological Sciences Theses & Dissertations

The present research compared and contrasted the physical structure of floating and rooted marshes, their differing responses to open-water salinities and inundation, as well as the nutrient distribution in the porewaters and sediment. The effects of the physical differences in the two marsh types on the ocurrence of the dominant emergent vegetation was discussed.

The main difference in physical structure of the two marsh types was the presence of a mineral, non-buoyant layer at 25-45 cm depth in the rooted marsh, which could serve as an anchor for the overlying highly organic mat layer found in both marsh types. Porewater …

Phytoplankton In Lake Drummond And Two Drainage Ditches In The Great Dismal Swamp, Virginia, Christine Gregory Phillips

Biological Sciences Theses & Dissertations

A twelve month study was conducted on the phytoplankton of Lake Drummond and Washington and Jericho Ditches from December 1988 to November 1989. Surface water samples were collected for nutrient and chlorophyll analysis from June 1989 to November 1989. The dominant phytoplankton component was the pico-nanoplankton (< 3 micron) category. A total of 57 species were identified from Lake Drummond, 51 species from Washington Ditch, and 31 species from the Jericho Ditch. Three major phytoplankton groups were identified at these sites: bacillariophyceans, cyanophyceans and cryptophyceans. The dominant species was the diatom Asterionella formosa. Nutrient and chlorophyll concentrations increased from summer to fall. Based on nutrient and chlorophyll g concentrations and species diversity indices, Lake Drummond is classified as eutrophic.

An Annual Study Of Phytoplankton Composition And Associated Environmental Conditions Of Lake Trashmore, Virginia Beach, Virginia, Seba B. Sheavly

Biological Sciences Theses & Dissertations

A 12 month study of Lake Trashmore was conducted on phytoplankton composition, inorganic nutrients and their seasonal associations. The dominant phytoplankton groups observed were diatoms, chlorophyceans and cyanobacteria. Phytoplankton assemblage patterns were coupled with pH, temperature, dissolved oxygen, nitrites and silicates. Diatoms dominated during periods of high nutrient concentrations, cooler temperatures and an unstable water column. Cyanobacteria forms dominated during periods of warmer temperatures, higher pH and decreased nitrogen and dissolved oxygen concentrations. A seasonal community shift occurred from cyanobacterial dominance to chlorophycean dominance when pH levels decreased. The lake is eutrophic based on indices of chlorophyll a concentrations, transparency …

Environmental Factors Affecting Nocturnal Migrations Of Macrobenthos, C. Timothy Morris

Biological Sciences Theses & Dissertations

Nocturnally dispersing macrobenthic invertebrates of the Lafayette River, Norfolk, Virginia were collected from September 4 to October 4, 1982 to determine environmental factors affecting migrations. A total of 55 taxa were identified from 325 surface and bottom nocturnal plankton tows. Peracaridan crustaceans were the dominant (99.0% of the total density) group collected. Six of the commonly collected species showed a significant (P

Macrobenthic Communities Of An Industrialized Seaport Ecosystem: The Southern Branch Of The Elizabeth River, Virginia, Steven D. Hawthorne

Biological Sciences Theses & Dissertations

Macrobenthic invertebrates of an industrialized seaport ecosystem were studied seasonally from October, 1977 through July, 1978. Five stations were selected along the Southern Branch of the Elizabeth River, Virginia. The stations ranged from an area of heavy industrialization to a non-urbanized environment. At each station, bottom water was measured for salinity, temperature, dissolved oxygen, and pH. Within each sampling area, macrobenthic infauna! invertebrates were collected from in and out of channel sites along with sediment samples for various types of physicochemical analysis.

Community structure was spatially homogeneous at station sites and throughout the stations along the River. Slightly acidic pH …

The Comparative Ecology Of Two Populations Of The Troglobitic Isopod Crustacean Lirceus Usdagalun (Asellidae), James Alexander Estes

Biological Sciences Theses & Dissertations

Aquatic communities of two caves in Lee Co., Virginia, were compared, and an examination was made of the life history phenomena of the troglobitic isopod Lirceus usdagalun. Measurements of physical and biological parameters were made in Thompson Cedar Cave and Gallohan Cave No. l. A contagious distribution was exhibited by populations of L. usdagalun in both caves and also by the population of another troglobitic isopod, Caecidotea recurvata, in Gallohan Cave No. 1. This distribution was attributed to aggregations of individuals which were considered to occur in areas of preference or optimal habitat patches. Lirceus usdagalun exhibited a …

Genetic Studies Of Cave And Spring Populations Of The Freshwater Amphipod Crustacean Gammarus Minus Say, Steven Wolf Hetrick

Biological Sciences Theses & Dissertations

The amphipod Gammaru. minus has three morphotypes in its Appalachian range : (1) a spring form with well-developed eyes, (2) an intermediate cave form with slightly reduced eyes, and (3) an extreme cave form with greatly reduced eyes. This study compares the genetic structure of populations in two karst areas and analyzes the genetics of populations of the three morphotypes.

Genetic data were collected from populations in the Ward's Cove, Virginia and Greenbrier Valley, West Virginia karst areas using zone electrophoresis zymograms. One hundred percent of the Ward's Cove populations are polymorphic at both MDH-1 and PEP 1 loci …

Observations On The Distribution And Composition Of Zooplankton In Portions Of The Intracoastal Waterway, Virginia, O. Clair Hillard Jr.

Biological Sciences Theses & Dissertations

Five stations were established in the Southern Branch of the Elizabeth River, the Dismal Swamp Canal, the Albemarle and Chesapeake Canal and the North Landing River. Representative samples of zooplankton were taken from October 1971 to June 1972. A. total of 57 species were identified and discussions regarding seasonal distribution in relation to physical factors and circulation are presented.

The composition of the zooplankton was found to fluctuate greatly due to the variables characteristic of the study area. The combined effect of tidal flow with freshwater input in conjunction with drainage from the Great Dismal Swamp, results in isolated populations …

A Zooplankton Study Of Stumpy Lake, Virginia Beach, Virginia, Jose E. Hernandez

Biological Sciences Theses & Dissertations

A one year study was made of the zooplankton composition in Stumpy lake, a reservoir in the city of Virginia Beach, Virginia. Quantitative and qualitative -parameters were investigated under field conditions. The analysis of the data presents information on the monthly dynamics or the zooplankton and other fluctuations in the lake environment. It is the intention or this study to emphasize the seasonal changes in the zooplankton community and their relationship to the ecological factors responsible for these variations.

Diurnal Studies At A Station On An Urban Estuary In Norfolk, Virginia, Burton Marc Golue

Biological Sciences Theses & Dissertations

No abstract.

Phytoplankton Composition At Lake Drummond In The Dismal Swamp, Virginia, William Howard Poore Jr.

Biological Sciences Theses & Dissertations

Abstract unavailable.