How do I go about writing aquatic humans as an allegory (or w/e the right word is) for Indigenous people?

I’m considering writing the merfolk in my story as a sort of metaphor for indigenous peoples, as well as other sea-dwelling or otherwise aquatic humans. Is this inherently problematic in and of itself, or is there a way to write this that works and is respectful to actual indigenous folks? If it’s inherently disrespectful, I can nix the idea, but as of current I don’t have any other equivalents to write them in with. I’m sure I could figure something out easily enough, though.