Long-term monitoring of molecular markers can distinguish different seasonal patterns of fecal indicating bacteria sources

Timothy E Riedel; Vanessa Thulsiraj; Amity G Zimmer-Faust; Rosi Dagit; Jenna Krug; Kaitlyn T Hanley; Krista Adamek; Darcy L Ebentier; Robert Torres; Uriel Cobian; Sophie Peterson; Jennifer A Jay

doi:10.1016/j.watres.2014.12.037

Long-term monitoring of molecular markers can distinguish different seasonal patterns of fecal indicating bacteria sources

Water Res. 2015 Mar 15:71:227-43. doi: 10.1016/j.watres.2014.12.037. Epub 2014 Dec 30.

Authors

Affiliations

¹ Department of Civil and Environmental Engineering, University of California Los, Angeles, Los Angeles, CA 90095, USA. Electronic address: triedel@utexas.edu.
² Department of Civil and Environmental Engineering, University of California Los, Angeles, Los Angeles, CA 90095, USA.
³ Department of Civil and Environmental Engineering, University of California Los, Angeles, Los Angeles, CA 90095, USA; Institute of the Environment and Sustainability, University of California Los, Angeles, Los Angeles, CA 90095, USA.
⁴ Resource Conservation District of the Santa Monica Mountains, PO Box 638, Agoura Hills, CA 91301, USA.
⁵ UCLA High School Summer Research Program, The Henry Samueli School of Engineering & Applied Science, Office of Academic & Student Affairs, Room 6426, Boelter Hall, Los Angeles, CA 90095, USA.

PMID: 25618519
DOI: 10.1016/j.watres.2014.12.037

Abstract

Elevated levels of fecal indicator bacteria (FIB) have been observed at Topanga Beach, CA, USA. To identify the FIB sources, a microbial source tracking study using a dog-, a gull- and two human-associated molecular markers was conducted at 10 sites over 21 months. Historical data suggest that episodic discharge from the lagoon at the mouth of Topanga Creek is the main source of bacteria to the beach. A decline in creek FIB/markers downstream from upper watershed development and a sharp increase in FIB/markers at the lagoon sites suggest sources are local to the lagoon. At the lagoon and beach, human markers are detected sporadically, dog marker peaks in abundance mid-winter, and gull marker is chronically elevated. Varied seasonal patterns of FIB and source markers were identified showing the importance of applying a suite of markers over long-term spatial and temporal sampling to identify a complex combination of sources of contamination.

Keywords: FIB; Long-term; MST; Molecular markers; Topanga; qPCR.

MeSH terms

Animals
Bacteroides / isolation & purification
Bathing Beaches
California
Charadriiformes
Dogs
Enterobacteriaceae / isolation & purification
Enterococcaceae / isolation & purification
Environmental Monitoring
Feces / chemistry
Feces / microbiology*
Humans
Rivers / microbiology
Seasons
Water Microbiology*
Water Pollutants / isolation & purification*

Substances

Water Pollutants