Coots, pike, swans, geese and ducks.
I've seen how otters will grab a swan by the neck, and bite in until it dies.
I did see on on the lake going into a rabbit warren, rabbit numbers are very low around the lake this year. The roadside warren has been wiped out. It was 20metres from a copse alongside the lake, where the otter hid. The warren on the house side has less rabbits than usual, but that is right next to the main car park and track, so may get regularly disturbed.