265 Marta Segura 1 , Chiara Romano 1 , Joan Batista Company 2 & Daniel Martin 1 1 Centre d’Estudis Avançats de Blanes. Consejo Superior de Investigaciones Científicas. 2 Institut de Ciències del Mar. Consejo Superior de Investigaciones Científicas. Abstract The purpose of this work was to assess the effect of the extreme event of St Esteve’s storm 2008 on swimmers fluxes on the Blanes Canyon as recorded by in situ measurements during winter 200809. Sediment traps were deployed at 1200 m depth inside the Blanes Canyon and in the adjacent open slope. Average swimmers fluxes were one order of magnitude higher inside the canyon (21.5 ind. m 2 d 1 ) than outside (0.7 ind. m 2 d 1 ). Results suggest that the storm had a stronger effect on the Blanes Canyon than at the open slope as showed by the collapse of swimmers during and after the extreme event. Inside the canyon significant differences were recorded in taxa composition of swimmers between samples collected before and after the storm. Image: Map of the Catalan Coast showing submarine canyons, by GRC Geociències Marines, UB Deepsea fauna. Blanes Canyon CHAPTER 18