The results of hydroacoustic studies of the Baikal omul (Coregonus migratorius) in the fishing waters of Lake Baikal using domestic information developments

After many years of interruptions, sonar surveys of the main fishing areas of Lake Baikal were carried out: Selenginsky shallow water and Northern Baikal. When performing hydroacoustic research and data processing, a Simrad EY500 scientific echo sounder with a frequency of 70 kHz and with an ES 70-11 antenna (split beam), a domestic GIS "CartMaster" with a hydroacoustic database was used. In the area of the Selenginsky shallow water, accumulations of omul were recorded in the depth range from 70 to 300 meters. In the water area of 145,010 hectares, the number of omul was 11386970, and its biomass was 4108 tons. The maximum registrations of omul accumulations per unit of distance traveled on Northern Baikal were higher compared to the Selenga shallow water. The densest accumulations of omul were recorded in the depth range from 120 to 250 meters. In the water area of 14695 hectares, the number of omul was 6370,540, and its biomass was 992 tons.

The results of hydroacoustic surveys turned out to be comparable with the results of biological studies and on the basis of which it can be assumed that the decline in abundance and biomass has stopped. There is an increase in spawning herds and the number of larvae, which means that we can expect an increase in the total biomass in the foreseeable future.

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