Winter fish kills!!!

December 3, 2025

Fish, like other animals, cannot live without oxygen. A fish kill can occur in a body of water as a result of low oxygen content or its complete absence.

A fish kill is the mass death of fish due to a lack of oxygen (suffocation) in the water. This happens due to natural phenomena (e.g., hot weather and algal blooms in summer or ice cover in winter) or anthropogenic impact.

Signs of a fish kill include agitated fish behavior, rapid breathing, and frantic attempts to find clean water. Fish populations are mostly invisible to us, but during a fish kill, a large number of fish float to the surface of the water and are sometimes washed ashore.

For the conditions in Belarus, fish kills are most common in the late winter period. During winter, water bodies and watercourses are covered with a thick layer of ice, which stops atmospheric air from reaching the water, and the oxygen content in the water sharply decreases.

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.

The first to perish are fish species more sensitive to oxygen deficiency (salmonids, sturgeons, perches), as well as crayfish, mollusks (pearl mussels, swan mussels), and some species of water bugs.

According to the methodological recommendations, a set of measures aimed at preventing fish kills in water bodies consists of:

- clearing water bodies of snow, installing ice holes and openings;

- creating continuous forest and shrub belts along river banks to prevent the washout of organic and fine dispersed substances;

- clearing tributaries, organizing additional water exchange in water bodies.

- water aeration;

- liming of water bodies.

The Glubokoye District Inspectorate for Natural Resources and Environmental Protection strongly urges amateur anglers, who spend a lot of time in fishing grounds and possess unique information about the conditions therein, to report any instances of fish kill, early pre-anoxic phenomena, or pollution of water bodies that may lead to the death of their inhabitants. This information facilitates the prompt adoption of necessary measures to identify the causes of fish kill and prevent their recurrence in the future.

Do not remain indifferent to the barbaric treatment of the nature surrounding us.

 

Chief Specialist A.V. Gapanyenok