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Full-Text Articles in Fresh Water Studies

Phytoplankton In Lake Drummond And Two Drainage Ditches In The Great Dismal Swamp, Virginia, Christine Gregory Phillips Jul 1990

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.


Population Dynamics Of Young-Of-The-Year Striped Bass, Morone Saxatilis, Populations, Based On Daily Otolith Increments, Lisa L. Kline Jan 1990

Population Dynamics Of Young-Of-The-Year Striped Bass, Morone Saxatilis, Populations, Based On Daily Otolith Increments, Lisa L. Kline

Dissertations, Theses, and Masters Projects

Validation of daily increment deposition in otoliths of juvenile striped bass up to 80 days of age was provided through sequential sacrifice of known age hatchery-reared fish in 1987 and 1989, and through tetracycline marking of otoliths of cage-cultured striped bass in 1989. Ages of fish between 80-110 days old were consistently underestimated by 1-3 growth increments. Known age juvenile striped bass were raised in the laboratory in 1989 under controlled environmental conditions. These experiments provided evidence of an endogenous circadian rhythm controlling daily increment deposition in juvenile striped bass otoliths. Juvenile striped bass were collected in the 4 Virginia …


Stock Identification Of Weakfish, Cynoscion Regalis, By Discriminant Function Analysis Of Morphometric Characters, Daniel R. Scoles Jan 1990

Stock Identification Of Weakfish, Cynoscion Regalis, By Discriminant Function Analysis Of Morphometric Characters, Daniel R. Scoles

Dissertations, Theses, and Masters Projects

No abstract provided.


Comparative Community Structure Of Surf-Zone Fishes In The Chesapeake Bight And Southern Brazil, Cassiano Monteiro-Neto Jan 1990

Comparative Community Structure Of Surf-Zone Fishes In The Chesapeake Bight And Southern Brazil, Cassiano Monteiro-Neto

Dissertations, Theses, and Masters Projects

The structure of surf-zone fish communities at Cassino (western South Atlantic, WSA) and the Chesapeake Bight (western North Atlantic, WNA) is described using historical beach seine data, to examine similarities between geographically isolated fish communities. Numerical classification, ANCOVA, Shanon-Wiener diversity and its components, and species rarefaction are used to describe fish community structure: (a) within habitat (Cassino); (b) within region (Chesapeake Bight); (c) within the western Atlantic (comparison between Cassino and the Chesapeake Bight). The surf-zone fish community at Cassino had a low diversity and was dominated by a few species. Seasonal periods identified by cluster analysis correlated well with …


An Investigation Of Impediments To Commercial Shellfish Mariculture In Virginia, Robert Charles Neikirk Jan 1990

An Investigation Of Impediments To Commercial Shellfish Mariculture In Virginia, Robert Charles Neikirk

Dissertations, Theses, and Masters Projects

A nationwide survey of shellfish mariculturists was used in conjunction with a literature review and review of state and federal laws and regulations, to identify impediments to commercial shellfish mariculture development. The results of the survey and reviews were utilized to identify likely impediments to commercial shellfish mariculture in Virginia and to develop recommendations to address the identified impediments, should Virginia wish to pursue efforts to enhance development of this industry. This study suggests there are state laws, regulations, and policies which act as impediments to commercial shellfish mariculture development in Virginia. Mar,y of the identified regulatory impediments result from …


Characterization Of Minchinia Sp Spores (Ascetospora: Haplosporidiidae) Infecting Teredo Navalis L And Placopecten Magellanicus Von Martens (Mollusca: Teredinidae) In The Western North Atlantic, Elizabeth Robinson Mcgovern Jan 1990

Characterization Of Minchinia Sp Spores (Ascetospora: Haplosporidiidae) Infecting Teredo Navalis L And Placopecten Magellanicus Von Martens (Mollusca: Teredinidae) In The Western North Atlantic, Elizabeth Robinson Mcgovern

Dissertations, Theses, and Masters Projects

No abstract provided.


Effects Of Low Dissolved Oxygen On The Macrobenthos Of The Lower Rappahannock River, Chesapeake Bay, Roberto Javier Llanso Jan 1990

Effects Of Low Dissolved Oxygen On The Macrobenthos Of The Lower Rappahannock River, Chesapeake Bay, Roberto Javier Llanso

Dissertations, Theses, and Masters Projects

The lower Rappahannock River, a subestuary of the Chesapeake Bay, is affected by seasonal low dissolved oxygen events that are intermittent and vary in intensity. Overall, macrobenthic abundance and species number were low, decreasing towards the channel and upriver, where dissolved oxygen concentrations were lowest. Mortality of macrobenthos in early summer was attributed to hypoxia. Species abundances and number declined with the onset of hypoxia, and did not recover in the deep channel until the fall. Tolerance of macrobenthos to hypoxia appeared to be species-specific. Recruitment of hesionid polychaetes occurred in summer during normoxia, but mortality followed during hypoxia, suggesting …


Patterns Of Habitat Utilization In 0-Age Summer Flounder (Paralichthys Dentatus), David M. Wyanski Jan 1990

Patterns Of Habitat Utilization In 0-Age Summer Flounder (Paralichthys Dentatus), David M. Wyanski

Dissertations, Theses, and Masters Projects

No abstract provided.