Results of resource hydroacoustic surveys of the Baikal omul in the fishing waters of Lake Baikal in the spring-summer period of 2022

Abstract

The purpose of the work carried out is to quantify the abundance of the Baikal omul within the four fishing areas of Lake Baikal (Selenginsky shallow water, Northern Baikal, the Small Sea, Barguzin Bay), to build maps of the spatial distribution of fish concentrations in the surveyed waters.The data collection and processing method is based on hydroacoustic survey, during which echo signals are recorded in the vertical direction along the route of the ship along a pre-planned transects. To calculate the values of surface densities along the survey transects, the echo integration method was used. When calculating surface density values, data from control catches are used. The Kriging geostatistical interpolator was used to numerically estimate the stocks of omul and its distribution within the surveyed water areas.New data have showed that in the main fishing area of Lake Baikal, the Selenginsky shallow water, there was a high abundance of juvenile omul, less than 22 cm in size of the 2018 generation and younger. In the areas of the Small Sea and the Barguzin Bay, no significant accumulations of fish were recorded. In Northern Baikal, the abundance and biomass of the omul was comparable to the results of 2021.The practical significance of the research results is the quantitative assessment of the omul stocks and its distribution in the fishing areas of Lake Baikal in order to predict its stocks.