Those Koi have really grown. At 2 meters your pond should be deep enough to have them survive over winter. Any idea what the lifespan of a Koi is? I have 2 ponds, one smaller and the other large enough to raise tilapia. Not sure what I will put in the smaller one. Right now I have three turtles that just showed up in the pond and an enormous amount of tadpoles.
I have read reports where a Koi was 200 years old, but I believe that's rare. 20 - 30 years perhaps?
We don' have turtles in the wild here in the UK. We get newts and one shows up sometimes.