Unfortunately, they kind of already are, or at least with human pollution. The steliferas (the little cuttlefish people) once lived peaceful, knowledge-seeking lives in the oceans of their homeworld, until it was annexed by the humans of the powerful and bigoted Azlanti Star Empire. The rapid industrialization of the planet resulted in massive pollution that reduced the steliferas to near-extinction, at which point they revealed themselves to the Empire and begged for aid. The Empire's reply was a curt offer of citizenship in the Empire and a ticket off-world. Now the steliferas are refugees among the stars, living as second-class citizens in the Star Empire (as all non-humans are) and working to colonize and spread out so a single ecological disaster can't wipe them out again. They travel by using their psychic powers to telekinetically make spheres of water for them to survive in!