  The dependence of the diffractive nuclear shadowing and the nuclear pion
excess effect on the deuteron spin alignment leads to a substantial tensor
polarisation of sea partons in the deuteron. The corresponding tensor structure
function $b_2(x,Q^2)$ rises towards small $x$, and we predict the about one
percent tensor asymmetry $A_2(x,Q^2) =b_2(x,Q^2)/F_{2D}(x,Q^2)$. We calculate
the shadowing of the gluon distribution in the deuteron for two different
pomeron gluon-distributions. For a hard gluon dominated $\Pom$-structure
function, as advocated by H1, we find large gluon shadowing, which appears to
be in conflict with the DGLAP analysis of nuclear SF's.
