the wikipedia article also states that they have a more varied diet than the native turtles and could be applying pressure on species that previously didnt have

the wikipedia article also states that they have a more varied diet than the native turtles and could be applying pressure on species that previously didnt have that predator like the mentioned frogs. In the same way that humans didnt go out and kill/eat most big predators, we just ate all their food first and they died that way