  For an island-like distribution of matter the gravitational energy-momentum
tensor is defined according to Weinberg as a source of metric. If this source
is formed by self-interactions of gravitons, so that nonphysical degrees of
freedom are excluded, then this source is a reasonable candidate for the
energy-momentum tensor of gravitational field. The disastrous influence of the
nonphysical degrees of freedom is demonstrated by comparing the gravitational
energy-momentum tensors in the harmonic, isotropic and standard frames for the
Schwarzschild solution. The harmonic frame is clearly preferable for defining
the gravitational energy-momentum tensor.
