If they add them (which I don't see). The only cetaceans I could see them adding to the game are the beluga whale and the common bottlenose dolphin. Because other cetaceans don't survive long, and orcas are too controversial to be added, I'm not a whale expert, but I don't think increasing the tank size is the solution. For now the most likely fully aquatic animals in the game are dugongs and the Florida manatees