  We deal with a class of abstract nonlinear stochastic models, which covers
many 2D hydrodynamical models including 2D Navier-Stokes equations, 2D MHD
models and 2D magnetic B\'enard problem and also some shell models of
turbulence. We first prove the existence and uniqueness theorem for the class
considered. Our main result is a Wentzell-Freidlin type large deviation
principle for small multiplicative noise which we prove by weak convergence
method.
