  Correlations between different regions of a quantum many-body system can be
quantified through measures based on entropies of (reduced) subsystem states.
For closed systems, several analytical and numerical tools, e.g., hydrodynamic
theories or tensor networks, can accurately capture the time-evolution of
subsystem entropies, thus allowing for a profound understanding of the unitary
dynamics of quantum correlations. However, so far, these methods either cannot
be applied to open quantum systems or do not permit an efficient computation of
quantum entropies for mixed states. Here, we make progress in solving this
issue by formulating a dissipative quasi-particle picture -- describing the
dynamics of quantum entropies in the hydrodynamic limit -- for a general class
of noninteracting open quantum systems. Our results show that also in
dissipative many-body systems, correlations are generically established through
the propagation of quasi-particles.
