Good news this morning, the ramshorn snails are still alive and well and feeding on green algae on stones. There's a strange milky coloured slime that is settling to the bottom of the pond, which I can now see is really clogged up with bamboo leaves (that explains the rotting vegetation, then).
I don't want to disturb the leaf litter just in case something is overwintering and has survived the freeze, but in the summer I'll do a proper clear-out.
I don't want to disturb the leaf litter just in case something is overwintering and has survived the freeze, but in the summer I'll do a proper clear-out.