That depends on the MPA and the fisheries that it impacts. For something like the Hecate sponge reefs, the main impact is on the bottom-contact fisheries, so you're talking about longline, trap, and crab fisheries. The trawl fisheries are certainly impacted there. Then, because of the way the MPA has been put in, it will also impact mid-water fisheries there. So yes, you can identify them.
One of the other issues, though, is that fish move. If you lock off an area now, what happens when another fish moves into that area? In terms of the impact with mid-water, the hake are moving further north, so that area there will become more important as we move forward in the global warming of our oceans that we're encountering.