Holden Laboratory

Coastal Microbiological Water Quality

Ning Jiang, Laurie Van De Werhorst, Jared Ervin, Photo by P.A. Holden
Ning Jiang, Laurie Van De Werhorst, Jared Ervin, Photo by P.A. Holden
Tracking Tools for Human Pollution in Urban Settings

In coastal urban settings, what are the occurrences of pathogen-containing fecal material in freshwaters that discharge into coastal oceans, and what are the origins?  Worldwide, human activities related to development result in periodically high levels of disease indicators in coastal waters. Conventional indicators of fecal contamination are insufficient for unequivocally relating human sources in watersheds to coastal contamination. Estuaries and wetlands may attenuate pollution that is transported from upstream by dry weather flow and stormwater runoff. Biotic markers of human waste are subject to decay, as well as accumulation or growth, but the patterns may differ from those observed for pathogens. Our research is towards understanding human fecal contamination in drains and surface waters, and the implications for human health in a systems context. Methods include comparatively quantifying conventional waste indicators, quantitative PCR-based markers specific to human waste, abundances of select pathogens, and sewage-related chemical indicators. Mathematical modeling is used to interpret results of quantiative sample analysis relative to the physical system. Culture-independent techniques in whole community analysis are also of interest, to the degree that patterns of human fecal contamination can be discerned from indigenous microbial communities. One longstanding collaboration has been with the City of Santa Barbara, Creeks Division, which provides context and access to urban creek systems in researching origins of human fecal pollution in coastal cities. Funded by Proposition 50 in the State of California Clean Beaches Initiative, the work with Dr. Jill Murray of the City Creeks Division culminated in a user-friendly guide for tracking human fecal pollution in urban drains, creeks, and at beaches (cover image, right), available on the City of Santa Barbara website (https://www.santabarbaraca.gov/civicax/filebank/blobdload.aspx?BlobID=16722).  The research during dry weather (AB411 period of April through October) is currently supported by the Clean Beach Initiative in the State of California, building from the Source Identification Protocol Project (SIPP) that delivered the manual for Microbial Source Tracking for the State of California (http://www.swrcb.ca.gov/water_issues/programs/beaches/cbi_projects/docs/...). The study during dry weather, when upstream catchments are hydrologically disconnected from surf zones, regards determining sources of low levels of human fecal pollution at beaches. As of January 18th, 2018, we are responding to the need for more understanding of the public health consequences related to sediment disposal to Goleta Beach following the January 9th debris flow in Montecito, CA.