Factors controlling variability in nearshore fecal pollution: The effects of mortality

TitleFactors controlling variability in nearshore fecal pollution: The effects of mortality
Publication TypeJournal Article
Year of Publication2013
AuthorsRippy MA, Franks PJS, Feddersen F, Guza RT, Moore DF
JournalMarine Pollution Bulletin
Date Published2013/01
Type of ArticleArticle
ISBN Number0025-326X
Accession NumberWOS:000315543500035
Keywordsadvection; california; diffusion; enteric bacteria; enterococcus-faecalis; escherichia-coli; Fecal indicator bacteria; indicator bacteria; marine beach; mortality; solar-radiation; sunlight inactivation; surf zone; Surfzone; zone water-quality

A suite of physical-biological models was used to explore the importance of mortality and fluid dynamics in controlling concentrations of fecal indicator bacteria (FIB) at Huntington Beach, CA. An advection-diffusion (AD) model provided a baseline to assess improvements in model skill with the inclusion of mortality. Six forms of mortality were modeled. All mortality models performed better than the AD model, especially at offshore sampling stations, where model skill increased from <0.18 to >0.50 (Escherichia colt) or <-0.14 to >0.30 (Enterococcus). Models including cross-shore variable mortality rates reproduced FIB decay accurately (p < 0.05) at more stations than models without. This finding is consistent with analyses that revealed cross-shore variability in Enterococcus species composition and solar dose response. No best model was identified for Entero coccus, as all models including cross-shore variable mortality performed similarly. The best model for E. colt included solar-dependent and cross-shore variable mortality. (C) 2012 Elsevier Ltd. All rights reserved.

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