Biofilm development in a hotspot of mixing between shallow and deep groundwater in a fractured aquifer: field evidence from joint flow, chemical and microbiological measurements

Olivier Bochet1,2, Alexis Dufresne3, Mathieu Pédrot4, Eliot Chatton4, Thierry Labasque4, Sarah Ben Maamar4, Luc Burté5, Jérôme de La Bernardie6, Nicolas Guihéneuf7, Nicolas Lavenant8, Christophe Petton9, Olivier Bour6, Luc Aquilina10 and Tanguy Le Borgne4, (1)University of Rennes, Rennes Cedex, France, (2)University of Rennes 1 / ADEME, Géosciences Rennes UMR 6118, Rennes, France, (3)CNRS, Ecobio UMR 6553, Rennes, France, (4)University of Rennes 1, Géosciences Rennes UMR 6118, Rennes, France, (5)University of Rennes 1 / ANTEA GROUP, Géosciences Rennes UMR 6118, Rennes, France, (6)Univ Rennes, CNRS, Géosciences Rennes, UMR 6118, Rennes, France, (7)Géosciences Rennes, Rennes, France, (8)Geosciences Rennes, CNRS, Rennes Cedex, France, (9)Univ Rennes, CNRS, Géosciences Rennes – UMR 6118, Rennes, France, (10)UMR CNRS 6118, University of Rennes 1, Géosciences Rennes, Rennes, France