Temporal variations in fecal indicator bacteria in bathing water and sediment in a coastal ecosystem (Aytré Bay, Charente-Maritime, France)

• Published in: Marine pollution bulletin 2022-02, Vol.175, p.113360-113360, Article 113360
• Main Authors: Ndione, Méry, Ory, Pascaline, Agion, Tony, Treilles, Michaël, Vacher, Luc, Simon-Bouhet, Benoit, Le Beguec, Maëlig, Pineau, Philippe, Montanié, Hélène, Agogué, Hélène
• Format: Article
• Language: English
• Subjects: Abundance; Bacteria; Bacteria - classification; Bacteria - isolation & purification; Bathing; Bathing water; Bays; Biodiversity and Ecology; Chlorophyll; Chlorophyll a; Coastal beaches; Coastal ecosystems; Coliforms; Contamination; E coli; Earth Sciences; Ecosystem; Environmental drivers; Environmental Monitoring; Environmental Sciences; Fecal coliforms; Fecal indicator bacteria; Feces; Feces - microbiology; France; Geologic Sediments - microbiology; Microbiological quality; Mineral nutrients; Nitrogen dioxide; Nutrients; Oceanography; Parameters; Phosphates; Rain; Rainfall; Salinity; Salinity effects; Sciences of the Universe; Seasonal variation; Seasons; Seawater - microbiology; Sediment; Sediment samplers; Sediment samples; Silica; Silicon Dioxide; Summer; Surveying; Temporal variations; Water Microbiology; Water quality; Water temperature; Winter
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2022.113360

This study presents the fecal contamination dynamic at the two bathing sites of Aytré Bay (Charente Maritime, France). We quantified fecal indicator bacteria (FIB) abundances (Escherichia coli and enterococci) from water and sediment samples over one-year survey. Then we measured biological (bacterial abundance, chlorophyll-a), physico-chemical (dissolved nutrients and oxygen, salinity, pH …) and climatic (temperatures, rainfall and tidal coefficient) parameters. Results showed that FIB abundances were occasionally higher than the European regulatory threshold during winter, summer and fall. The “poor quality” of the bathing water was due to high enterococci abundance. We found negative significant correlations between FIB and water temperature and salinity, and positive significant correlations between FIB and rainfall, PO4, NO3, NO2, and SiO2 mainly in water. Relationships between parameters showed that during summer and spring the main environmental drivers were temperature and salinity, while in fall and winter they were rainfall and dissolved nutrients. •This study investigates fecal indicators bacteria dynamic at a contaminated beach.•Kinetics of fecal indicators bacteria are different between water and beach sediment.•In summer and spring, environmental drivers of FIB dynamics are water temperature.•In winter and fall, environmental drivers of FIB dynamics are rainfall and nutrients.