As a result of the lack of oxygen in Razna lakes, fish are killed

Dead fish are found in the coastal zone of Razna Lake - wedges and eels. The National Security Administration Latgale Regional Administration (administrative) employees carried out survey of the territory. The management specialists explain that the death of fish is due to untypical hot summer, water flowering and lack of oxygen. Water droughts are reduced during the flowering of water and blowing processes begin in the environment. Blowing causes rapid oxygen consumption and a lack of water in water, followed by poisoning and death of other aquatic organisms in the environment through blowing products. Algae breeding is facilitated by warm water (above 16 °C), calm time and sufficient concentration of nutrients in water. 

Keepers and eels are very sensitive to changes in oxygen. In addition, they stay closer to the bottom layer, the lower layer of the water body where the quantity of dissolved oxygen is relatively low. The amount of oxygen consumed depends on the age, size, feeding, etc. – the small need more oxygen than the large salmonids, more than the carp family. The quantity of dissolved oxygen in the Razna lake ~ 7 m deep on 1 September is 2.03 mg/l and is even lower at depths. If the level of oxygen dissolved in water is less than 5 mg/l, it is a negative environment for fish, but the oxygen concentration of less than 2 mg/l results in a loss of fish.   

As the hot weather has stopped and the rain has fallen, the situation is normalised.     

The administrative inspectors have collected samples of fatalities and delivered to the laboratory for food safety, animal health and environmental scientific institute “BIOR”. After receiving the results, the Authority will provide additional information.   

More Information: Government Latgale Regional Administration Nature Protection Officer Dainis Tuch, 26528739