Just to add a quick point - it is perfectly legal in this part of the world not only to touch turtles, but to kill them, take them home and eat them (endangered status notwithstanding).
I think playfully interacting with them is preferable. It might be a little bit alarming for them, but I don't see any liklihood of irreperable damage to the ecosystem.
I think playfully interacting with them is preferable. It might be a little bit alarming for them, but I don't see any liklihood of irreperable damage to the ecosystem.