  We study 4-dimensional Riemannian manifolds equipped with a minimal and
conformal foliation $\mathcal F$ of codimension 2. We prove that the two
adapted almost Hermitian structures $J_1$ and $J_2$ are both cosymplectic if
and only if $\mathcal F$ is Riemannian and its horizontal distribution
$\mathcal H$ is integrable.
