What we have found in the research from around the world that we have read on this is that MPAs have to be extremely large to have the spillover effect you're discussing. None of them in the Bay of Fundy would be large enough for that. Even in places where they are that large, those places are finding that the increase of activity around the MPAs from kicking all the fishing out is causing some problems too. The spillover effect is something that, in theory, was expected to happen, but it's not panning out in most of the MPAs around the world.
On November 23rd, 2017. See this statement in context.