The operation to saturate the water with oxygen in order to prevent a mass fish freeze was held today in Zaimishche village of Zelenodolskiy district. The environmental campaign was attended by the employees of the Central Territorial Administration of the Ministry of Ecology and Natural Resources of the Republic of Tatarstan, the Department of the Ministry for Emergency Situations of the Republic of Tatarstan and the Department of the Federal Agency for Fisheries in the Republic of Tatarstan.