Frozen lakes can prevent fish feeding and make them more susceptible to parasites, and can lead to oxygen dissolved in the water being replaced by harmful by-products of decomposing food and organic matter. Shallow lakes (less than 1.5 metres deep) are particularly at risk.
Experts at the Angling Trust recommend using sub-surface air diffusers to maintain oxygen levels and to keep water moving as a preventative measure. In emergencies, fishery managers should consider dropping water levels by a few inches and employing a specialist to inject hydrogen peroxide into the water. The Trust advises against trying to break the ice because it can cause lethal shock waves and would be unlikely to help the fish.
The Trust also offers guidance on the steps that fishery managers should take in future to prepare for harsh winters.
Angling Trust Chairman Mike Heylin, said: “still water fisheries require careful management, based on sound science and a detailed knowledge of specialist techniques to maintain high standards of fish welfare at all times. There are far too many examples of lakes being managed by people with little or no experience of fisheries management.”
The 1,400 angling clubs and fisheries who are members of the Angling Trust are eligible for a 10% discount on aerators at www.aquacultureequipment.co.uk. They can call Mark Stockton on 07715 007 964 and quote their membership number to qualify for the discount.
