Microbial Source Tracking in California Watersheds

Human impact, in the form of increased urbanization, agricultural practices, wildlife management and decaying infrastructure has resulted in a marked decrease in water quality in California.  This impacts anyone who would kneel down and take a drink from a cool stream or a lake as they hike or otherwise take advantage of California’s abundant outdoor recreational activities. Significant increases in illnesses have been reported for those who swim in our beaches compared to those that never venture into the water.  The surfing community has been aware of this phenomenon for years and organizations such as the Surfrider Foundation have created reporting tools to identify how and where they get sick to help identify pollution hotspots.  My laboratory is interested in identifying sources of fecal pollution as a first step towards control and mitigation.  We are far more at risk of getting sick from water contaminated with sewage, septic wastes and other human sources compared to non-human fecal sources such as birds or grazing animals.  To accurately differentiate sources we have developed a technology to comprehensively identify the total microbial community composition in water samples including the hundreds of source-specific microbes from each fecal source.  We are using this method to assess risks at contaminated beaches, develop Total Maximum Daily Load (TMDL) to calculate the maximum amount of pollution that a recreational beach can receive and still meet water quality standards and, finaly, determine how the fecal-specific species signals change over time in water.

watershed image?