I tested it in survival and creative. Once you feed the baby turtles sea grass they won't despawn anymore. It doesn't matter if they are adults. It also works on other mobs as well, once you feed them they won't despawn. hope it helps .-.
Edit: although I'm not sure if it would stay that way for a long time or not, but it works.
its a secret
Date: October 17 2020
PE version 1.16.20.54
I tested it in survival and creative. Once you feed the baby turtles sea grass they won't despawn anymore. It doesn't matter if they are adults. It also works on other mobs as well, once you feed them they won't despawn. hope it helps .-.
Edit: although I'm not sure if it would stay that way for a long time or not, but it works.