title: Evaluating short-term changes in recreational water quality during a hydrograph event using a combination of microbial tracers, environmental microbiology, microbial source tracking and hydrological techniques: a case study in Southwest Wales, UK.
abstract: Quantitative assessment of multiple sources to short-term variations in recreational water quality, as indexed by faecal indicator organism (FIO) concentrations, is becoming increasingly important with adoption of modern water quality standards and catchment-based water quality management requirements (e.g. the EU Water Framework Directive, Article 11 'Programmes of Measures' and the US Clean Water Act, 'Total Maximum Daily Loads'). This paper describes a study combining microbial tracers, intensive FIO measurement, open channel hydrology and molecular microbial source tracking (MST) to enhance understanding of recreational water quality at Amroth in southwest Wales, UK. Microbial tracers were released from four stream inputs during a moderate hydrograph event. Tracers from two local streams impacted simultaneously with a period of maximum FIO concentrations at the near-shore compliance monitoring site. Connection between these inputs and this site were rapid (9-33 min). Water quality impairment from a more remote stream input followed, 12.85 h after tracer release, sustaining FIO concentrations above desired compliance levels. MST analysis showed dominance of ruminant Bacteroidales genetic markers, associated with agricultural pollution. This integration of tracers and MST offers additional information on the movement and individual sources causing water quality impairment.
authors.affiliation: Centre for Research into Environment and Health, River Basin Dynamics and Hydrology Research Group, Institute of Geography and Earth Sciences, Aberystwyth University, Penglais, Aberystwyth, Ceredigion SY23 3DB, UK. mark@crehwyer.demon.co.uk
authors.forename: Mark D
authors.initials: MD
authors.lastname: Wyer
authors.forename: David
authors.initials: D
authors.lastname: Kay
authors.forename: John
authors.initials: J
authors.lastname: Watkins
authors.forename: Cheryl
authors.initials: C
authors.lastname: Davies
authors.forename: Chris
authors.initials: C
authors.lastname: Kay
authors.forename: Rod
authors.initials: R
authors.lastname: Thomas
authors.forename: Jonathan
authors.initials: J
authors.lastname: Porter
authors.forename: Carl M
authors.initials: CM
authors.lastname: Stapleton
authors.forename: Heather
authors.initials: H
authors.lastname: Moore
mesh_terms: D001435:Bacteriophages / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D041963:Bacteroidetes / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D001493:Bathing Beaches / Q000592:standards; D001681:Biological Assay; D016972:Enterobacter cloacae / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D004783:Environmental Microbiology; D005069:Evaluation Studies as Topic; D005243:Feces / Q000382:microbiology; D017909:Levivirus / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D011998:Recreation; D018570:Risk Assessment; D013171:Spores, Bacterial / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D013997:Time Factors; D006113:United Kingdom; D014852:Wales; D014871:Water Microbiology; D014876:Water Pollution / Q000032:analysis*; D014881:Water Supply / Q000032:analysis* / Q000592:standards