Chu Y., Tournoud M. G., Salles C., Got P., Perrin Jean-Louis, Rodier C., Caro A., Troussellier Marc. (2014). Spatial and temporal dynamics of bacterial contamination in South France coastal rivers : focus on in-stream processes during low flows and floods. Hydrological Processes, 28 (8), p. 3300-3313. ISSN 0885-6087.
Titre du document
Spatial and temporal dynamics of bacterial contamination in South France coastal rivers : focus on in-stream processes during low flows and floods
Chu Y., Tournoud M. G., Salles C., Got P., Perrin Jean-Louis, Rodier C., Caro A., Troussellier Marc
Source
Hydrological Processes, 2014,
28 (8), p. 3300-3313 ISSN 0885-6087
Faecal indicator bacteria (thermotolerant coliform and faecal streptococci) were enumerated in a Mediterranean coastal river to evaluate bacterial contamination levels in relation to hydrological conditions, to estimate delivery of bacterial loads to transitional and coastal waters (Thau lagoon) and to identify bacterial sources of pollution and their contribution to the bacterial flow. Results showed that (1) in low flow conditions, mean bacterial concentrations were higher than EU guidelines for bathing waters; (2) floods had higher concentrations of indicator bacteria than low flows; (3) low flow conditions represented a negligible proportion of bacterial loads compared with high flow and flood periods; (4) during medium and low flow conditions, bacteria were stored in riverbed fine sediments forming in-stream stores that may be flushed during floods; (5) the first flush effect was highlighted during an early autumn flood as was the role of in-stream stores during the course of the flood; and (6) point sources that continuously feed the river are contributing to the pool of bacteria accumulated in the riverbed sediment.
