On winter fish kills

Winter fish kills are mass fish deaths caused by suffocation due to a lack of oxygen in a water body.

During the winter period, water bodies and watercourses are covered with a thick layer of ice, which prevents atmospheric air from reaching the water, leading to a sharp decrease in the oxygen content in the water.

Fish kills are observed both as a result of the cessation of oxygen supply from the air and a sharp limitation of plant life under the ice.

In accordance with the Rules for conducting fishery and fishing, approved by Decree of the President of the Republic of Belarus of July 21, 2021 No. 284, measures to prevent fish kill phenomena and eliminate their consequences are carried out by local executive and administrative bodies, or legal entities specially authorized by them, and in water bodies leased or used free of charge – by lessees or users of such water bodies.

In order to prevent fish kill phenomena, measures aimed at increasing the dissolved oxygen content in water can be carried out:

creation of ice holes in water bodies prone to fish kill phenomena;

liming of water bodies, which promotes the decomposition and acceleration of the mineralization of organic matter, as well as improves the gas regime and neutralizes the acidic reaction of water;

aeration of water bodies – the use of special equipment (compressors, pumps) for artificial oxygenation of water;

suspension of bags with salt in ice holes.