title: Watershed Assessment with Beach Microbial Source Tracking and Outcomes of Resulting Gull Management.
abstract: Total maximum daily load (TMDL) implementation at a southern California beach involved ultraviolet treatment of watershed drainage that provided >97% reduction in fecal indicator bacteria (FIB) concentrations. However, this pollutant control measure did not provide sufficient improvement of beach water quality, prompting further assessment. Investigation included microbial source tracking (MST) for human, gull, and canine fecal sources, monitoring of enterococci and fecal coliform, and measurement of chemical and physical water quality parameters for samples collected from watershed, groundwater, and beach sites, including a beach scour pond and tidal creek. FIB variability remained poorly modeled in regression analysis. However, MST revealed correlations between FIB and gull source tracking markers, leading to recommendations to manage gulls as a pollutant source. Beach conditions were followed for three years after implementation of a best management practice (BMP) to abate gulls using a falconry program for the beach and an upland landfill. The gull abatement BMP was associated with improved beach water quality, and this appears to be the first report of falconry in the context of TMDL implementation. Overall, MST data enabled management action despite an inability to fully model FIB dynamics in the coupled watershed-beach system.
authors.affiliation: Atlantic Oceanographic & Meteorological Laboratory, Ocean Chemistry and Ecosystems Division, NOAA , 4301 Rickenbacker Causeway, Miami, Florida 33149, United States.
authors.forename: Kelly D
authors.initials: KD
authors.lastname: Goodwin
authors.affiliation: Weston Solutions, Inc. , 5817 Dryden Place, Suite 101, Carlsbad, California 92008, United States.
authors.forename: Steve
authors.initials: S
authors.lastname: Gruber
authors.affiliation: City of San Clemente , 910 Calle Negocio, Suite 100, San Clemente, California 92673, United States.
authors.forename: Mary
authors.initials: M
authors.lastname: Vondrak
authors.affiliation: Weston Solutions, Inc. , 5817 Dryden Place, Suite 101, Carlsbad, California 92008, United States.
authors.forename: Andrea
authors.initials: A
authors.lastname: Crumpacker
mesh_terms: D000818:Animals; D001493:Bathing Beaches; D002140:California; D046091:Charadriiformes / Q000382:microbiology*; D004285:Dogs; D016983:Enterococcus; D004784:Environmental Monitoring; D005243:Feces / Q000382:microbiology; D006801:Humans; D014871:Water Microbiology; D060753:Water Quality