These farmers are exploiting the higher margins of rare species, not scale, otherwise they would be looking after the highly productive species. Regulation would be enough to change the industry.
It's no different than cattle. We're used to red meat but it's actually a wasteful industry that has a huge impact on ecology. We only keep raising cattle because it sells for a premium (red meat is the most expensive source of protein).
The impact of fish farmers that grow carnivore fish is comparable to the impact of destroying native land to farm soy/corn used to feed cattle. We just got used to it. There are other ways though.
It's no different than cattle. We're used to red meat but it's actually a wasteful industry that has a huge impact on ecology. We only keep raising cattle because it sells for a premium (red meat is the most expensive source of protein).
The impact of fish farmers that grow carnivore fish is comparable to the impact of destroying native land to farm soy/corn used to feed cattle. We just got used to it. There are other ways though.