  We use dynamical systems approach and Lagrangian tools to study surface
transport and mixing of water masses in a selected coastal region of the Japan
Sea with moving mesoscale eddies associated with the Primorskoye Current.
Lagrangian trajectories are computed for a large number of particles in an
interpolated velocity field generated by a numerical regional multi-layer
eddy-resolving circulation model. We compute finite-time Lyapunov exponents for
a comparatively long period of time by the method developed and plot the
Lyapunov synoptic map quantifying surface transport and mixing in that region.
This map uncovers the striking flow structures along the coast with a mesoscale
eddy street and repelling material lines. We propose new Lagrangian diagnostic
tools --- the time of exit of particles off a selected box, the number of
changes of the sign of zonal and meridional velocities --- to study transport
and mixing by a pair of strongly interacting eddies often visible at
sea-surface temperature satellite images in that region. We develop a technique
to track evolution of clusters of particles, streaklines and material lines.
The Lagrangian tools used allow us to reveal mesoscale eddies and their
structure, to track different phases of the coastal flow, to find inhomogeneous
character of transport and mixing on mesoscales and submesoscales and to
quantify mixing by the values of exit times and the number of times particles
wind around the eddy's center.
