Date of Award

Fall 2010

Degree Type

Masters Thesis

Degree Name

Master of Science (MS)


Marine Science

Committee Chair

Donald Redalje

Committee Chair Department

Marine Science

Committee Member 2

Karen Orcutt

Committee Member 2 Department

Marine Science

Committee Member 3

Kjell Gundersen

Committee Member 3 Department

Marine Science


The Bay of St. Louis (BSL) is a shallow and vertically well-mixed estuary on the Gulf Coast of Mississippi and supports the recreational and commercial activities of the surrounding towns of Bay St. Louis, Diamondhead, DeLisle, and Pass Christian. In addition to residential communities, various industrial and commercial sites inhabit the watershed and coastline. The Hollywood casino, DuPont titanium dioxide plant, and multiple sew_age treatment plants, as well as nonpoint sources of pollution, contribute to poor water quality. To evaluate spatial and temporal changes in BSL water quality, freeliving and attached bacterioplankton concentrations were enumerated by epifluorescence microscopy. Nine stations were sampled during outgoing tidal cycles from March to September 2007 to determine how the water quality changed as it is flushed out of BSL. Environmental parameters, inorganic and organic nutrients, hydrologic parameters, and weather condition were measured or collected to explain bacterioplankton variability in BSL. Stations included the mouths of two rivers, the entrance to a bayou, and along a longitudinal transect out of the bay to the adjacent Mississippi (MS) Sound. Attached . bacteria, cells removed from particles, were found in the range of 0.92 x 108 cells L-1 to 13.20 x 108 cells L-1 • Free-living bacteria (7.22 x 108 cells L-1 to 52.98 x 108 cells L-1 ), cells that were plank.tonic and not associated with particles, accounted for the majority