There is this problem that farming is cruel. It’s improving, but the improvements may never be really enough to make farming ethical.
Seafood farming is worse. The hunting of fish is devastating to ecology. But farming fish is already difficult and probably cannot be done humanely.
Instead, farmers can provide a habitat for the target animals, without fences. The habitat must be humane to ensure the animals stay. Those that do can be slaughtered regularly for food.
This farm is a net benefit for the environment, providing a habitat and thus helping the wild population. It meets the highest standard of ethics, in that the animals are leading their normal wild lives. It is more expensive than enclosed farming, but in the long run cheaper and more sustainable than hunting.
It would enhance the human diet and health by enabling farming of animals which cannot today be farmed, like octopus, shark. So it effectively stops exploitation of the oceans for these foods.
The only extra requirement is ensuring that wild animals don’t all congregate there to be slaughtered, leading to extinction. This is tricky. Maybe a requirement to build two identical habitats, provide the same amount of food and shelter in each, but only slaughter from one. The population can be checked by a regulator the day before slaughter, and only the more sparse habitat is culled.
And of course species-specific restrictions are needed like, for migratory birds, no slaughters during nesting season.