Life Sciences Commons^™

The Magnitude And Persistence Of Soil No, N2o, Ch4, And Co, Fluxes From Burned Tropical Savanna In Brazil, M Poth, Iris C. Anderson, Et Al

VIMS Articles

Among all global ecosystems, tropical savannas are the most severely and extensively affected by anthropogenic burning. Frequency of fire in cerrado,a type of tropical savanna covering 25% of Brazil, is 2 to 4 years. In 1992 we measured soil fluxes of NO, N2O, CH4, and CO2 from cerrado sites that had been burned within the previous 2 days, 30 days, 1 year, and from a control site last burned in 1976. NO and N2O fluxes responded dramatically to fire with the highest fluxes observed from newly burned soils after addition of water. Emissions of N-trace gases after burning were of …

Status Of The Major Oyster Diseases In Virginia 1994 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson

Reports

No abstract provided.

Studies On Processes Controlling The Input Of Agricultural Chemicals In Groundwater To Surface Waters, Edward Laurence Libelo

Dissertations, Theses, and Masters Projects

This dissertation describes several studies of groundwater quality, the fate and transport of nutrients and atrazine in groundwater systems and physical processes at the sediment-water interface which impact on groundwater discharge. Groundwater monitoring wells were installed at the Goodwins Island and Catlett Island NERRS sites in Virginia and agricultural, suburban and forest land use sites in the York and James River Basins. Groundwater was analyzed for nutrients, pH, salinity and trace organics. Shoreline land use, associated nutrient loading and an estimate of total groundwater flux suggest that groundwater contributes up to 30% of the total nitrogen input to the Chesapeake …

A Study Of The Histozoic Oyster Parasite, Perkinsus Marinus: I. Disease Processes In American Oysters (Crassostrea Virginica). Ii. Biochemistry Of Perkinsus Marinus, Aswani K. Volety

Dissertations, Theses, and Masters Projects

Numerous studies have investigated the disease processes of Perkinsus marinus in the oyster, Crassostrea virginica. However, the transmission dynamics and factors affecting P. marinus infection are still unclear. The objectives of this study were to investigate: (1) the principal and most effective lifestage of P. marinus, (2) the synergistic effects of temperature, salinity and P. marinus dose on disease prevalence, (3) suppression of host reactive oxygen intermediates by P. marinus, (4) the localization of acid phosphatase in the parasite, (5) the effects of temperature and salinity on acid phosphatase secretion, and (6) the P. marinus lipid and fatty acid composition. …

Evidence For A Relation Between A White Perch Young-Of-The-Year Index And Indices Of Later Life Stages, Thomas C. Mosca Iii, Herbert M. Austin, David M. Plotner

VIMS Books and Book Chapters

Juvenile indices are employed in fisheries management to predict the future abundance of harvestable adults. Frequently, regulations on the utilization of the resource, and a lack of fishery independent abundance data, make verification of the prediction accuracy impossible. In the case of white perch in Virginia, this is not so. Using the weighting system developed for a Chesapeake Bay-wide index of juvenile striped bass abundance based on summertime beach seine data collected in nursery ground waters, we developed a similar index for white perch in the Virginia portion of the Bay. Regressions against Virginia Institute of Marine Science otter trawl …

The Precarious State Of The Chesapeake Public Oyster Resource, William J. Hargis Jr., Dexter S. Haven

VIMS Books and Book Chapters

The 243,000 acres of Virginia's public oyster reefs (a.k.a. the Baylor Grounds) have been extremely productive of usable and saleable (market .md seed) oysters (Crassostrea virginica), oyster shells and oyster shell by-products. Archaeological remains and historical records show that they have yielded great numbers of whole oysters, oyster meats, oyster "seed" and shell since the 01esapeake was formed some 3,000 years BP. In the last century their natural productivity, as indicated by commercial harvest records (the only long-term data available), has declined markedly. In 1904, Vrrginia's total market (adult) oyster harvest was about 7.6 million bushels (mostly from public grounds). …

Regulating The Blue Crab, Callinectes Sapidus, Fishery In Virginia : Biological And Economic Concerns, James E. Kirkley, William D. Dupaul, Michael J. Oesterling

Reports

The blue crab, Callinectes sapiclus, fishery has been one of the most important fisheries of Virginia. The importance of the fishery in terms of commercial activities has substantially increased in recent years in response to declining resource levels of American Oyster, Crassostrea virginica, and a growing international and domestic demand for soft crabs, female hard crabs, and crab meat.

The actual economic importance of the fishery, however, is not well known. For example, what are the employment and earning levels generated by the fishery? What portion of a waterman's household income is derived from crabbing? How much does crabbing contribute …