Thanks for the compliment.
There can be different viable farming system. The most important is to review thoroughly all parameters, environmental as well as financial and as well short as long term, before making a decision.
Further, it has been written nowhere that we have to farm everything. We must limit ourselves to what we can manage properly.

It would seem to me that the commercially viable fish farming method would be land based in areas with mild climate.

This would limit the species that could be farmed but modern advertising can sell almost anything I suppose.

Bob