title: Widespread detection of human- and ruminant-origin Bacteroidales markers in subtidal waters of the Salish Sea in Washington State.
abstract: Rising populations around coastal systems are increasing the threats to marine water quality. To assess anthropogenic fecal influence, subtidal waters were examined monthly for human- and ruminant-sourced Bacteroidales markers at 80 sites across six oceanographic basins of the Salish Sea (Washington State) from April through October, 2011. In the basins containing cities with individual populations>190,000, >50% of sites were positive for the human marker, while in the basins with high densities of dairy and cattle operations, ∼30% of sites were positive for the ruminant marker. Marker prevalence was elevated in spring (April and May) and fall (October) and reduced during summer (June through September), corresponding with seasonal precipitation. By logistic regression, the odds of human marker detection increased with percentage of adjacent catchment impervious surface, dissolved nitrate concentration, and abundance of low nucleic acid bacteria, but decreased with salinity and chlorophyll fluorescence. The odds of ruminant marker detection increased with dissolved ammonium concentration, mean flow rate for the nearest river, and adjacent shoreline length. These relationships are consistent with terrestrial to marine water flow as a transport mechanism. Thus, Bacteroidales markers traditionally used for identifying nearby sources can be used for assessing anthropogenic fecal inputs to regional marine ecosystems.
authors: Joint Institute for the Study of the Atmosphere and Ocean, University of Washington, PO Box 355672, Seattle, WA 98195, USA Current address: Hawaii Institute of Marine Biology, University of Hawaii at Manoa, PO Box 1346, Kaneohe, HI 96744, USA.
authors: Zack S
authors: ZS
authors: Oyafuso
authors: Northwest Fisheries Science Center, National Marine Fisheries Service, NOAA, 2725 Montlake Boulevard East, Seattle, WA 98112, USA E-mail: linda.rhodes@noaa.gov.
authors: Anne E
authors: AE
authors: Baxter
authors: Northwest Fisheries Science Center, National Marine Fisheries Service, NOAA, 2725 Montlake Boulevard East, Seattle, WA 98112, USA E-mail: linda.rhodes@noaa.gov.
authors: Jason E
authors: JE
authors: Hall
authors: Frank Orth and Associates, Under Contract to Northwest Fisheries Science Center, National Marine Fisheries Service, NOAA, 2725 Montlake Boulevard East, Seattle, WA 98112, USA Current address: Department of Zoology, University of British Columbia, #4200-6270 University Boulevard, Vancouver, BC, Canada V6T 1Z4.
authors: Sean M
authors: SM
authors: Naman
authors: Northwest Fisheries Science Center, National Marine Fisheries Service, NOAA, 2725 Montlake Boulevard East, Seattle, WA 98112, USA E-mail: linda.rhodes@noaa.gov.
authors: Correigh M
authors: CM
authors: Greene
authors: Northwest Fisheries Science Center, National Marine Fisheries Service, NOAA, 2725 Montlake Boulevard East, Seattle, WA 98112, USA E-mail: linda.rhodes@noaa.gov.
authors: Linda D
authors: LD
authors: Rhodes
mesh_terms: D000818:Animals; D041963:Bacteroidetes / Q000235:genetics* / Q000302:isolation & purification*; D002417:Cattle; D005243:Feces / Q000382:microbiology; D005819:Genetic Markers / Q000235:genetics*; D006801:Humans; D014861:Washington; D014871:Water Microbiology; D014876:Water Pollution / Q000032:analysis*
chemical_list: D005819:Genetic Markers