Microbial response to a uranium mine discharge into the Kern River

Summary

The Kern River rises in a group of glacial lakes near Mount Whitney in Southern California, flows south through the Sierra Nevadas, passes through a 46 km² lake (Lake Isabella), and then flows past Bakersfield into several lakes in the Buena Vista Recreation Area. Approximately 10 km downstream from Lake Isabella, a uranium mine has been developed. Ore is mined and transported to Colorado for processing. The effect of the mine discharge on several bacterial groups was studied. Notable decreases in the Standard Plate Count, total coliform, fecal coliform, fecal streptococcus, vibrio, Pseudomonas and staphylococcus were seen at 1 km and at approximately 8 km downstream of the discharge. Bacterial recovery did not occur until about 15 km downstream. Decreases in chlorophylllevels were also noted. Degradation products appeared to decrease as the result of reduced bacterial numbers. Primary production studies were made to simultate the effect of different mine discharge rates.