Yes.
We do have marine conservation areas in the Great Lakes, and they actually count, strangely enough, towards the terrestrial target. For example, with the recent work in establishing Lake Superior national marine conservation area, it was for a short time the largest freshwater marine conservation area in the world, only to be bumped out, very closely, by a similar marine park area by the U.S. in Lake Superior.
They can actually contribute quite significantly to the terrestrial target.