Influence of the summer deep-sea circulations on passive drifts among the submarine canyons in the northwestern Mediterranean Sea

Marine biophysical models can be used to explore the displacement of individuals in and between submarine canyons. Mostly, the studies focus on the shallow hydrodynamics in or around a single canyon. In the northwestern Mediterranean Sea, the knowledge on the deep-sea circulation and its spatial variability in three contiguous submarine canyons is limited. We used a Lagrangian framework with three-dimensional velocity fields from two hydrodynamics models to study the deep bottom connectivity between submarine canyons and to compare their influences on the particle transport. The particles represented eggs and larvae spawned by the deep-sea commercial shrimp Aristeus antennatus along the continental slope in summer. The passive particles mainly followed a southwest drift along the slope and drifted less than 200 km within 31 days. Two of the sub-marine canyons were connected by more than 27 % particles if they were released at sea bottom depths above 600 m. The vertical displacement of particles was depending on the submarine canyons, the depth and the can-yon wall where particles were released and it encouraged the analyses of the particle transport by canyons in-stead of generalizing the dynamics. In the two hydrodynamic models tested in this study, passive drift simulation differed depending on topography. Despite being run on a coarser grid, the hydrodynamic model using finer bathymetric resolution data and adjusted to the topography seemed to better model the passive drift of particles. Those results promote that the physical model parameterization has to be considered for improving the transport studies of deep-sea species.