Redalje, D. G. The University of Southern Mississippi, Donald.Redalje@usm.edu
Shiller, A. M. The University of Southern Mississippi, Alan.Shiller@usm.edu
Ivey, J. E. University of South Florida, jivey@seas.marine.usf.edu
Bivens, J. R. The University of Southern Mississippi, jbivens@sunfish.ssc.usm.edu
Grembowicz, K. P. The University of Southern Mississippi, kpgrem@sunfish.ssc.usm.edu

 
ABSORPTION SPECTRA OF CDOM ALONG A SALINITY GRADIENT IN ST. LOUIS BAY, MISSISSIPPI, A SHALLOW, TURBID ESTUARY
 
St. Louis Bay, Mississippi, is a shallow (<2 m.), turbid estuary with freshwater input from two rivers (Wolf and Jourdan Rivers) and several bayous. The bay is bounded by the Mississippi Sound, a shallow shelf region separated from the open Gulf of Mexico by barrier islands. Salinities in the bay range from 0 at the river to about 20 at the bay mouth. A set of stations were occupied from the mouth of the bay to the Jourdan River. We examined absorption spectra of CDOM (400-750 nm) for surface samples filtered through GF/F and through 0.2 micrometer Poretics filters. Absorption maxima at 400 nm for river samples were 3-fold greater than those at the bay mouth. Absorption maxima at 400 nm were greater for samples filtered through a GF/F filter than those filtered through the 0.2 micrometer filter, with values 30% greater at the river station and only 3% greater for the bay mouth. We are using Field-Flow Fractionation to size-fractionate samples collected at each station and filtered through 0.8 micrometer Poretics filters to characterize the nature and concentrations of colloidal materials contained in St. Louis Bay waters. We are comparing sample colloids to observed differences in CDOM absorption spectra.
 
Day: Thursday, Feb. 4
Time: 04:15 - 04:30pm
Location: Eldorado Hotel
 
Code: CS61TH0415E