Coley, T. L. Horn Point Laboratory, tcoley@hpl.umces.edu
Cornwell, J. C. Horn Point Laboratory, cornwell@hpl.umces.edu

 
THE EFFECT OF HYDROLOGICAL FLOW ON THE FLUX OF NUTRIENTS AND GASES ACROSS THE SEDIMENT-WATER INTERFACE
 
An experiment was conducted to test the hypothesis that increased flow at the sediment surface enhances the flux of nutrients and gases across the sediment-water interface. Using homogenized sediment, free of macrofauna, 3 consecutive incubations were performed during which the fluxes of dinitrogen gas, oxygen and nitrate were measured. Only flow rate was varied in Incubation I. Both flow rate and sediment carbon loading were varied in Incubation II, while flow rate, sediment carbon loading and water column nitrate were manipulated in Incubation III. Increases in the fluxes of dinitrogen gas, oxygen and nitrate were observed with increased flow rates in all three incubations. Changes in the direction of fluxes between cores with flow and cores without flow also occurred. Flow rate effect on flux was enhanced with increased carbon loading and with increased water column nitrate concentration. The greatest effect of flow on flux was seen for oxygen, which increased 2-fold and 30-fold, at low and high carbon loading levels, respectively. These results suggest that not only does flow rate enhance the flux of nutrients and gases across the sedimnet-water interface, but also interacts with other environmental variables such as organic carbon loading and water column nutrient concentration.
 
Day: Thursday, Feb. 4
Time: 12:00 - 12:15pm
Location: Hilton of Santa Fe
 
Code: SS30FR1200S