Even though they're having some results, I suspect that it's in Europe in the Mediterranean and then some of the more northern European protected areas. To be frank, their responses are not as strong as one would hope, in part I think because they were not designed as a network.
The history of creating protected areas is of haphazard efforts of making one here and making one there, not thinking of them as a system or a network. As a consequence, they don't create the benefits that a network does. The idea of a network is that the whole is greater than the sum of the separate MPAs. The product of these haphazard MPAs is just how well each one of those does individually. They don't contribute to one another the way a network does.
It's that history of creating MPAs without a broader context, a spatial planning approach, that has led to a lower conservation value.