Sunlight modulates concentrations of culturable E. coli and enterococci in marine waters. However, the mechanism of photoinactivation is poorly understood. Additionally, little is known about photoinactivation of novel fecal indicator bacteria and human viruses in naturally impacted recreational waters. We conducted field work at Avalon Beach, California where we sampled nearshore waters hourly for 72 h for reactive oxygen species (ROS), traditional indicator bacteria (culturable E. coli and enterococci and QPCR-based detection of enterococci), F+ (DNA and RNA) and somatic coliphages, the human-specific marker in Bacteroidales (HF marker), human enterovirus, and human adenovirus. Results from the field study, as well as a modeling study are presented. Using the model, we determined field-relevant photoinactivation rates of culturable enterococci and E. coli, enterococci measured by QPCR, and somatic coliphage. Since hydrogen peroxide and singlet oxygen steady state concentrations were moderate and they have the potential for synergistic interactions with sunlight, we cannot rule out that the mechanism of photoinactivation is exogenous at Avalon.
Presenter:
Alexandria Bianca Boehm, Ph.D.
Assistant Professor
Civil and Environmental Engineering
Stanford University
Monday, June 22, 2009
10:30 a.m.
Pacific Ocean Science & Technology (POST) 723
The Pacific Research Center for Marine Biomedicine (PRCMB) is a newly established center at the University of Hawaii dedicated to trans-disciplinary research designed to gain new knowledge about the profound impacts of the ocean on human health. The Center is funded by the National Science Foundation and the National Institute of Environmental Health Sciences.
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