Having already read about a fair number of fish deaths this winter, caused by ice, I wonder what other area of ‘animal welfare’ would get away with what some fishery managers or owners do? Imagine keeping caged birds and having an aviary-full of perfectly healthy birds die from cold, or allowing a horse to die of thirst because its water supply was frozen. The RSPCA would never allow that to happen twice.
Any fairly basic knowledge of fish-keeping would lead fishery managers to know that a covering of ice on a land-locked stillwater prevents any oxygen from permeating into the water. That same knowledge should tell them that, beneath the water, the bacteria munching away on dead leaves, fish faeces, rotting bait and highly organic silt will be using up oxygen.
At the same time, although fish go into a state of torpor and their oxygen requirements drop, they still need to breathe, albeit more slowly.
Small waters, heavily but not necessarily densely stocked, will feel the effects in a few days. Any more than that and major trouble can be expected.
Waters that continue to run matches or club events will have anglers breaking the ice, but on some fisheries it’s just been left and fish have died. Most commercial fisheries are shallow as well as quite small, and oxygen is held in water volume, even if it is replaced by surface area.
What happens now is those same fisheries order more fish to replace those lost. Why is this allowed to happen? Is it time for the Fish Welfare Group to start baring a few gnashers and demanding some sort of say before any fish are stocked in any stillwater?
I don’t know how many times I have complained about the rapidity of pools being dug, filled with water, fish then anglers. It is nothing short of a disgrace. If those people digging pools can’t afford to wait before allowing angling, then they should not be allowed planning permission to dig the pool in the first place.