But what is “healthy”? Do we even know? Humans have been part of the “ecosystem” for an immensely long time. Certainly, it’s possible for people to overfish, overhunt, overcultivate, etc. But that does not mean complete absence of human exploitation is somehow perfection or even a “state of nature”.
If no fishing of any kind occurs in that area, does anybody really know what the outcome will be, or that it will even be stable? Will certain species take over and exclude others that have been there or migrated through for centuries?
I’m not very familiar with how things work in the sea, but on land if you completely remove the hand of man, it often turns unproductive, diseased or even desertified. Much of the nationalized lands in the west have become deserts precisely because grazing is prohibited there. Some semi-arid place require hooved animals to fill a niche in the ecosystem or it goes off kilter, or at least the “kilter” it has had for millennia. What it would have been like before hooved animals, no one knew until it turned into a desert in recent years.
And one thing we certainly don’t know is the degree to which human intervention replaces something that was there before and needed but is now gone; like cattle replacing buffalo on some semi-arid parts of the west.
That’s not to say the government could not improve anything by, say, limiting endangered catches. It could, all but for the migratory species like swordfish and tuna. Setting aside a reserve will do nothing for those kinds of species. And some of the protected species are predators. Can an overabundance of predators perhaps cause some food species to disappear entirely?
I recall reading that there is not a single place in the habitable zone of the earth that has not been forever altered by humans. One would think it would be less so in the oceans, but again, humans have fished the oceans for centuries, if not millennia. What’s “natural”, then?