  The detection of narrow channels of accretion toward protostellar disks,
known as streamers, have increased in number in the last few years. However, it
is unclear if streamers are a common feature around protostars that were
previously missed, or if they are a rare phenomenon. Our goals are to obtain
the incidence of streamers toward a region of clustered star formation and to
trace the origins of their gas, to determine if they originate within the
filamentary structure of molecular clouds or from beyond. We used combined
observations of the nearby NGC 1333 star-forming region, carried out with the
NOEMA interferometer and the IRAM 30m single dish. Our observations cover the
area between the IRAS 4 and SVS 13 systems. We traced the chemically fresh gas
within NGC 1333 with HC3N molecular gas emission and the structure of the
fibers in this region with N2H+ emission. We fit multiple velocity components
in both maps and used clustering algorithms to recover velocity-coherent
structures. We find streamer candidates toward 7 out of 16 young stellar
objects within our field of view. This represents an incidence of approximately
40\% of young stellar objects with streamer candidates when looking at a
clustered star forming region. The incidence increases to about 60\% when we
considered only embedded protostars. All streamers are found in HC3N emission.
Given the different velocities between HC3N and N2H+ emission, and the fact
that, by construction, N2H+ traces the fiber structure, we suggest that the gas
that forms the streamers comes from outside the fibers. This implies that
streamers can connect cloud material that falls to the filaments with
protostellar disk scales.
