Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Marine Biology
Nitrogen Fixation In Virginia Salt Marshes And The Effects Of Chronic Oil Pollution On Nitrogen Fixation In The Mobjack Bay Marshes, Alyce Diane Thomson
Nitrogen Fixation In Virginia Salt Marshes And The Effects Of Chronic Oil Pollution On Nitrogen Fixation In The Mobjack Bay Marshes, Alyce Diane Thomson
Dissertations, Theses, and Masters Projects
N2 fixation rates for several Virginia salt marshes were determined using in situ acetylene-reduction assays. A control and a chronically polluted oil marsh of the mesohaline Mobjack Bay area were sampled over a 1975-76 annual cycle. N2 fixation occurred in all transects which extended from upper mudflat to the Spartina patens zone. An isolated blue-green algal mat exhibited some of the highest N2 fixation rates. Intertidal sediment N2 fixation was patchy, both spatially and seasonally. However average rates (91.45 μg N/m2/h) compared to the estimated N requirement of the graminoid vegetation indicated a significant contribution to the N budget. Vegetation …
The Effects Of Pollution On Benthic Communities Of The Tidal James River, Virginia, Robert J. Diaz
The Effects Of Pollution On Benthic Communities Of The Tidal James River, Virginia, Robert J. Diaz
Dissertations, Theses, and Masters Projects
Benthic communities in the estuarine portion of the James River are controlled mainly by salinity. Pollution effects are localized and difficult to assess because of the rigorous physical environment. Mesohaline and oligohaline communities were very similar to those in other east coast estuaries. except for the dominance of Rangia cuneata in the oligohaline zone. Communities of the tidal freshwater zone are most affected by pollution. In the areas of Richmond and Hopewell, where the major portion of the pollution load enters the river, communities are most severely depressed. Separate multivariate analyses of species distributional patterns, and pollution and physical parameters …