  A gauge-invariant reformulation of QCD in three spacetime dimensions is
presented within a Hamiltonian formalism, extending previous work to include
fermion fields in the adjoint and fundamental representations. A priori there
are several ways to define the gauge-invariant versions of the fermions; a
consistent prescription for choosing the fermionic variables is presented. The
fermionic contribution to the volume element of the gauge orbit space and the
gluonic mass-gap is computed exactly and this contribution is shown to be
closely related to the mechanism for induction of Chern-Simons terms by
parity-odd fermions. The consistency of the Hamiltonian scheme with known
results on index theorems, Landau Levels and renormalization of Chern-Simons
level numbers is shown in detail. We also comment on the fermionic contribution
to the volume element in relation to issues of confinement and screening.
