system
Given the following post, respond as if you're commenting on Reddit:
human
[The Little Mermaid] Where do mermaids get their protein?

The fish don't seem to be frightened of mermaids, so I assume they aren't chowing down on their intelligent subjects, Lion King style. So how do they get all muscle-y without eating fish?
gpt
Who said they don't eat fish?

It may seem like they live in a world where no one eats each other, but that just isnt true. There are still predators and scavengers and they do eat meat, the people on land have and continue to observe it.

It would seem that the Merfolk and sentient creatures that we see don't eat THEIR fellow residents, the ones that live in their small realm. Outside that little area it would seem as if it is nature as normal. Perhaps it is only those that were given sentience in Triton's kingdom that are off limits to eat, and the rest of the sea whose fish act as normal are considered food.