Bacterial diseases exacerbated by low water levels and warmer temperatures killed more than a dozen fish last week in the Ogeechee River, officials said Friday.“The fish are stressed, or were, because of a low water level and rising water temperatures,” Bulloch County Public Safety Director Ted Wynn said. “Those factors make them more susceptible to Columnaris, and Aeromonas, common bacteria found in the river that the fish did test positive for.”“EPD’s conclusions are that the low levels and rising water temperatures are stressing the fish and making them more vulnerable to these bacteria.”The directors of the Environmental Protection Division, Department of Natural Resources and Georgia Emergency Management revealed in a conference call Friday the results of tests conducted on several dead fish found in the Ogeechee River last week. Wynn said officials will require more time to interpret water samples also taken last week and have scheduled a conference call Tuesday to discuss those findings.