I'm not sure I can agree with the statement without knowing the parameters of the fishery of which you speak, what the species is that is being protected, and what the elements are. If you're talking about an MPA, in the context of an MPA, MPAs are established for different reasons. Often when we talk about the fishery being restricted, although it tends to be visualized as commercial or recreational, the reality is that it's about the gear type or whether or not that fishery will have an impact.
If you're talking about sensitive benthic areas or corals and this type of stuff, as long as the fishing activity does not impact the bottom, then in theory, that should be okay.