  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 measures for Markov operator cocycles and
establish the mean ergodic theorem for generalized linear operator cocycles
over arbitrary Banach spaces. The advantage of the result is that we show the
implication of weak precompactness for almost every environments to strong
convergence in the global sense.
