Abstract. 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, knowledge of 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 versions of the Regional Ocean Modeling System (ROMS) to
study the deep-bottom connectivity between submarine canyons and to compare
their influence on the particle transport. From a biological point of view,
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 continental slope and drifted less than
200 km considering a pelagic larval duration (PLD) of 31 d. Two of the
submarine canyons were connected by more than 27 % of particles if they were
released at sea bottom depths above 600 m. The vertical advection of
particles depended on the depth where particles were released and the
circulation influenced by the morphology of each submarine canyon.
Therefore, the impact of contiguous submarine canyons on particle transport
should be studied on a case-by-case basis and not be generalized. Because
the flows were strongly influenced by the bottom topography, the
hydrodynamic model with finer bathymetric resolution data, a less smoothed
bottom topography, and finer sigma-layer resolution near the bottom should
give more accurate simulations of near-bottom passive drift. Those results
propose that the physical model parameterization and discretization have to
be considered for improving connectivity studies of deep-sea species.
Influence of the summer deep-sea circulations on passive drifts among the submarine canyons in the northwestern Mediterranean Sea