  The dynamics of plasma can be formulated as a subalgebra of the Poisson
manifold of the Clebsch fields. In this work, we extend this formulation to a
Lorentz covariant form. We show that the generalized enstrophy, which means the
"charge" of the Clebsch field, is no longer conserved by the relativistic
effect, implying that the conservation of circulation is broken. Instead, we
formulate a relativistically modified generalized enstrophy that is conserved
in the relativistic model.
