Leveraging molecular methods to improve water quality monitoring at beaches


Thursday, December 8, 2011
Redfield Auditorium - 12:00 Noon
Ms. Elizabeth Halliday
JPh.D. Candidate, Joint Program in Biological Oceanography

Decades ago, limits on the amounts of fecal indicator bacteria in recreational waters were recommended by the EPA in order to monitor and close beaches when contact with waters was likely to cause illness.  Since then, the nature of pollution at our country’s beaches and lakes has changed, and technology has advanced – but the monitoring standards have remained the same.  One serious problem with the current standards is the long time delay between testing waters, ascertaining results, and closing beaches.  Molecular methods, such as monitoring indicator bacteria DNA via quantitative PCR, could potentially produce rapid results and same-day closures, but the implementation of qPCR for routine monitoring comes with a suite of challenges.  Additionally, a more comprehensive understanding of the fecal indicator bacteria and their ability to survive for extended periods in the environment, including on wrack and in sands and sediments, has also challenged the indicator paradigm.  In this seminar I will be discussing insights from my work comparing culture-based and molecular monitoring of the fecal indicator bacteria Enterococcus in the surf-zone environment.  Going beyond the traditional fecal indicator paradigm, I will also share results from a pyrosequencing project comparing the impact of water quality exceedance events and environmental conditions on the bacterial communities of surf-zone waters and sands.