Behaviour 2019
Do individual responses to anthropogenic noise spread throughout the community scale? 
Emilie Rojas1, Melanie Gouret1, Simon Agostini2, Gérard Lacroix2, Paulo J. Fonseca3, Vincent Médoc1. 1ENES / CRNL, CNRS UMR5292, INSERM UMR_S 1028, University of Lyon / Saint-Etienne, Saint-Etienne, Rhones-Alpes, France; 2Ecole Normale Supérieure (ENS), PSL Research University, CNRS, Centre for Research in Experimental and Predictive Ecology (CEREEP-Ecotron Ile de France), UMS 3194, Saint‐Pierre‐lès‐Nemours, Ile-De-France, France; 3Department of Animal Biology and cE3c - Centre for Ecology, Evolution and Environmental Changes, Faculty of Sciences, University of Lisbon, Lisbon, , Portugal

Anthropogenic noise in freshwater is considered to be a pervasive pollutant attributed to the development of trade, urbanization and recreational activities. It is known to induce alterations in physiology, behavior and anatomy, but the extent to which individual responses propagate to whole communities and disturb their ecological features remains under-documented. We did a six-week long mesocosm investigation to test whether boat noise influences the strength of the trophic cascade along a three-level chain including fish (roach, Rutilus rutilus), zooplankton and phytoplankton. Noise-induced alteration in fish behavior may release zooplankton from predation and have a negative indirect effect on phytoplankton. Whatever the noise condition, fish presence significantly increased the phytoplankton to zooplankton ratio, suggesting a trophic cascade. At the end of the experiment, fish from the control mesocosms (no noise) showed reduced predation under boat noise whereas those that experienced noise in the mesocosms did not, suggesting habituation. Our study illustrates how habituation to noise may prevent individual alterations to propagate to larger ecological scales.