In this paper we use invariant theory to develop the notion of cohomological detection for Type I classical
Lie superalgebras. In particular we show that the cohomology with coefficients in an arbitrary module can
be detected on smaller subalgebras. These results are used later to affirmatively answer questions, which
were originally posed in Boe et al. (2010) [5] and Bagci et al. (2008) [2], about realizing support varieties
for Lie superalgebras via rank varieties constructed for the smaller detecting subalgebras.