In order to help with oxygen levels in the pond water below the ice, snow has been removed
Pond Conservation has undertaken some research into the standard advice given about iced over ponds. In normal garden ponds frog or fish kill by ice is a real concern. Pond Conservation sent out a survey to investigate this during the beginning of the year in the snow – their results showed that melting holes within the ice layer made no difference to the survival of frogs or fish. Removing snow cover from the ice though helped increase Oxygen within the water column – thus potentially helping organisms which over winter within the depths of the pond.
Small shallow ponds it seems would be best at retaining their oxygen at a reasonably high level compared to deep and dark ponds which do not allow photosynthesis during the daytime.
Under the ice (which is around 3inches thick approx) I could see the white ghosts of mayfly larvae resting upside down –
Mayfly larvae rest underneath the ice
Eventually when the snow and ice has melted I will be able to count any invertebrate deaths – a few died between the two snow falls and thaw but there were quite a few still very much alive and kicking
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