Aswell as the Mute Swans that John mentioned, I remember lots of small fish called 'Sticklebacks' in the lakes. I've seen the odd crayfish aswell as Newts & frogs.
When we clambered amongst the rocks we often got a glimpse of what we called Water Rats, but Ive no idea if they were rats or water voles.
A common bird at the lakes was the 'Swift's we called 'swifties' flying around constantly catching midges.On summer nights those midges were a problem as there was thousands of them.