Distribution omul map
Hydroacoustic measurement of the Baikal omul resources
In 2011, the assessment of the number and biomass of the Baikal omul Coregonus migratorius was carried out using the hydroacoustic method [1].
The results of the assessment are shown in Tables 1 and 2. The distribution of the number and biomass of the Baikal omul in the water area of Lake Baikal is uneven. Amassments with the density above average take less than a quarter of the examined area. However, they contain almost two thirds of the Baikal omul reserves. A general picture of the spatial distribution of the omul in the lake's water area corresponds with trawling and acoustic measurements. Our work confirmed the necessity of conducting such measurements immediately after ice clearance, but before the start of feeding migrations of the Baikal omul. During this period, the omul forms dense shoals that are easy to register using the hydroacoustic technique, which improves the accuracy of measurements. The derived number and biomass figures of the Baikal omul, especially in the Selenga shallow water area and Northern Baikal, correspond quite well with the forecast of the long-term dynamics based on the peculiarities of the size- and age-related composition of the fish population[2].
We confirmed the findings about the presence of a significant part of the omul population in the deep-water zones of the lake.
References:
Makarov, M. M., Degtev, A. I., Kucher, K. M., Mamontov, A. M., Nebesnykh, I. A., Khanaev, I. V. & Dzyuba, E. B. (2012). Assessment of the number and the biomass of the Baikal omul using trawling and acoustic techniques. DAN, 447(3). p 343-346.
Melnik, N. G., Smirnova-Zalumi, N. S., Smirnov, V. V., et al. (2009). Hydroacoustic measurement of the Baikal omul resources. Novosibirsk: Nauka. p 244.
