There is actually a very good reason why many people have already replaced fish consumption with algal farms: bioamplified and persistent environmental pollutio

There is actually a very good reason why many people have already replaced fish consumption with algal farms: bioamplified and persistent environmental pollution, particularly mercury. The only unique nutritional value of fish is in long-chain omega-3 fatty acids, which the fish get from algae. This is commonly marketed as "Algae EPA DHA" at very large markups (I pay about $20 for two months' supply at my local rich people organic food store).