Here is an article about robotic dolphins, considering them as an alternative to displaying live animals: Robotic dolphins could replace live creatures at theme parks | blooloop
Found myself stopping at this: “'In terms of a 10-year business operating period and a two million annual visitor capacity, the overall investment and maintenance costs for a decent animatronics entertainment portfolio only accounts for about one quarter or no more than one-third of what a traditional aquarium spends,' Edge Innovation’s Li Wang told the South China Morning Post." Does anyone else feel like one quarter to one third of an aquarium's expenditures for animatronics is more financially significant than Wang seems to suggest...? While I'm not sure about all of the benefits and drawbacks here, I do think this technology is interesting and definitely worth consideration - especially given that in some countries dolphins are still routinely captured in the wild for sale to aquariums.
I actually remember seeing an article proposing this, launched by some french zoo. I learnt about it by googling future zoo back in the day.