CS34 River Dynamics
Date: Wednesday, June 12, 2002
Location: Poster Session - VCC
 
WheelerK, Joseph W. Jones Ecological Research Center, Newton, USA, kwheeler@jonesctr.org
Opsahl, S, P, Joseph W. Jones Ecological Research Center, Newton, USA, sopsahl@jonesctr.org
 
INVESTIGATING THE RELATIONSHIPS BETWEEN SOURCE WATER CHEMISTRY AND MICROBIAL ACTIVITY IN A SMALL COASTAL PLAIN STREAM
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Relationships between water chemistry and microbial activity were examined in Chickasawhatchee Creek, a small coastal plain stream in southwestern Georgia. Microbial activity in the creek was gauged by determination of respiration rates and growth-limiting substrates through oxygen consumption experiments. Important water chemistry parameters (nitrate, phosphate, ammonium, dissolved organic and inorganic carbon, major cation and anion species) were also measured in order to evaluate introduction and removal of various compounds and to identify groundwater contributions. Results indicate that there are substantial differences in water chemistry between the northern and southern reaches of the creek. One possible explanation for the observed differences is streamflow variation. During low flow periods, the upper reach of the creek was dominated by surface runoff while the lower stretch had considerable groundwater inflow. Conversely, during periods of high flow, surface water runoff dictated streamflow for the entire system. The level of microbiological activity was also important in determining stream water chemistry. There is strong evidence that organic matter always served as the growth-limiting substrate and that microbial activity was governed by hydrologic regime.