  In the present paper, we consider random invariant densities and the mean
ergodic theorem for Markov operator cocycles which are applicable to quenched
type random dynamical systems. We give necessary and sufficient conditions for
the existence of random invariant densities for Markov operator cocycles and
establish the mean ergodic theorem for generalized linear operator cocycles
over a weakly sequentially complete Banach space. The advantage of the result
is that we show the implication of weak precompactness for almost every
environment to strong convergence in the global sense.
