Nuclear phenomena at HERA energies

We argue that current data on nuclear shadowing confirm expectations of the color singlet models of nuclear shadowing. We demonstrate that unitarity constrains require nuclear shadowing for gluons to be very significant already for $x \le 10^{-3}$ . Physics of coherent diffraction production of vector mesons off light nuclei is also discussed.
Talk at the Workshop on Deep Inelastic Scattering and QCD, Paris, April 1995, 5 pages LATEX, uses "qcdparis.sty" (appended at end), no figures