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Full-Text Articles in Life Sciences
Vertical Distribution Of Estuarine Phytoplankton In The Surface Microlayer And At One Meter, And Fluctuations In Abundance Caused By Surface Adsorption Of Monomolecular Films, Victoria R. Gibson
Vertical Distribution Of Estuarine Phytoplankton In The Surface Microlayer And At One Meter, And Fluctuations In Abundance Caused By Surface Adsorption Of Monomolecular Films, Victoria R. Gibson
Dissertations, Theses, and Masters Projects
A quantitative comparison of the phytoplankton in the surface microlayer of an estuary and that a depth of one meter was made using a Garrett-type screen and a Frautschy bottle for sample collection. Results showed that the surface microlayer contained a significantly greater number of phytoplankton cells than the water at one meter. Species diversity at the surface tended to be somewhat lower than one meter, due to a greater number of individuals of the dominant species. Investigation revealed that the presence of a monomolecular film of slick material absorbed onto the water surface resulted in a decrease in the …
Age, Growth, And Mortality Of The White Perch, Morone Americana (Gmelin), In The James And York Rivers, Virginia, Richard Alan St. Pierre
Age, Growth, And Mortality Of The White Perch, Morone Americana (Gmelin), In The James And York Rivers, Virginia, Richard Alan St. Pierre
Dissertations, Theses, and Masters Projects
More than 750 white perch, Morone americana, were collected from each of two major tributaries of southern Chesapeake Bay to compare the age structures, growth rates, and mortality rates of the two populations.The James River is characterized by heavy domestic and industrial pollution, whereas the York River is only slightly polluted. Maximum ages determined by scale analysis were 7 and 10 years for males and females respectively in each river. Males and females from the James River were larger than those from the York up to ages IV and V, respectively. Older fish were larger in the York . Females …
The Effects Of Thermal Shock And Chlorine On The Estuarine Copepod Acartia Tonsa, David Michael Dressel
The Effects Of Thermal Shock And Chlorine On The Estuarine Copepod Acartia Tonsa, David Michael Dressel
Dissertations, Theses, and Masters Projects
Acute bioassays were conducted to determine the effects of thermal shock and chlorine exposure on the estuarine copepod Acartia tonsa. Laboratory conditions simulated power plant conditions using 8 C elevated temperatures and slug chlorination. A factorial design having temperatures at two levels and multiple chlorine additions, showed isolated effects of temperature and chlorine and their interaction. Adult Acartia tonsa withstood thermal shocks of 8 C above ambient summer temperatures of 20 to 25 C. No adverse effects were noted after 96 hours following an 8 ⃤ T over 5 seconds, holding at the elevated temperature for 5 minutes, and slowly …
Benthic Infauna Of Eelgrass, Zostera Marina, Beds, Robert Joseph Orth
Benthic Infauna Of Eelgrass, Zostera Marina, Beds, Robert Joseph Orth
Dissertations, Theses, and Masters Projects
The infauna of Zostera beds in the Chesapeake Bay-York River estuary and Chincoteague Bay was sampled in March and July using a corer. Sediments were fine sand or very fine sand. Sorting of sediments varied from poorly sorted to moderately well-sorted and was related to the density of Zostera at the respective stations. A total of 17 macroinvertebrate taxa was collected. Species abundance decreased up the estuary and there was a significant interaction in the number of species between stations and seasons. Faunal similarity of the areas sampled, as measured by three indices, indicated that the infauna of most Zostera …
Distribution And Structure Of Benthic Communities In A Gradient Estuary, Donald F. Boesch
Distribution And Structure Of Benthic Communities In A Gradient Estuary, Donald F. Boesch
Dissertations, Theses, and Masters Projects
No abstract provided.
Zoogeography And Host-Specificity Of The Superfamily Capsaloidea, Price, 1936 (Monogenea: Monopisthocotylea) An Evaluation Of The Host-Parasite Locality Records Of The Superfamily, Capsaloidea, Price, 1936, And Their Utility In Determinations Of Host-Specificity And Zoogeography, Adrian R. Lawler
Dissertations, Theses, and Masters Projects
No abstract provided.
Effects Of Thermal Shock On Larvae Of The Oyster, Crassostrea Virginica (Gmelin), Robert J. Diaz
Effects Of Thermal Shock On Larvae Of The Oyster, Crassostrea Virginica (Gmelin), Robert J. Diaz
Dissertations, Theses, and Masters Projects
Larvae of the American oyster Crassostrea virginica (Gmelin) were subjected to thermal shocks of varying magnitude at different larval ages. The effects were assessed in terms of mortality, growth, and setting success. Growth of larvae acclimated at 25 C and 20% salinity was not affected by a thermal shock of 10 C or 15 C, but a 20 C thermal shock had detrimental effect on growth. Mortality of oyster larvae increased significantly following thermal chocks of 10, 15, and 20 C, and was higher for older than for younger larvae. Setting rates of the control and 10 C shocked larvae …
The Feeding Of Cornstarch To Clams And Mussels, Kathleen Rapier Harleston
The Feeding Of Cornstarch To Clams And Mussels, Kathleen Rapier Harleston
Dissertations, Theses, and Masters Projects
Three concentrations of cornstarch, 0 . 6 ppm, l.l ppm, 4.0 ppm, were fed to clams and mussels during the spring, summer, and fall of 1970 . Parameters measured were shell length, shell thickness, total weight, wet meat weight, and percentage glycogen based on wet meat weight. Starch had no effect on size parameters but did influence glycogen content of meats . Mussels showed an increase of glycogen in all three seasons . Clams showed an increase only in the fall. This dissertation is from the Joint Program Degree from the College of William & Mary and University of Virginia …