Coming as it does on the heels of yesterday's sea level warning - https://news.ycombinator.com/item?id=9927099 this makes me wonder what it takes to take a large chunk of water, maintain a traditional pH, cleanliness and temperature, and grow stuff (fish, algae, seaweed). It seems this is going to be an area with increasing demand, even just betting on the growing population. Anyone interested in doing an aquaculture startup? I have had some ideas in the area (I think fundamentally different to others) already.