Dynamics of catches and state of stocks the common dace Leuciscus leuciscus in the Middle Ob basin (in the Tomsk region)

Abstract

Common dace Leuciscus leuciscus is a medium-sized representative of the Cyprinidae. It distributed in temperate latitudes of Eurasia and inhabits mainly of rivers. In the Tomsk region, it is numerous both in the Ob itself and in its tributaries. Previously, common dace was a significant fishery object — during the Great Patriotic War, its production volumes reached 2,514 tons per year and accounted for up to 20,1% of all fish catches in the region. Fishing of dace in the Middle Ob basin can be carried out 1. by special traps “atarma” in the spring during the migration of fish from the tributaries to the main channel of the Ob; 2. by lake seines in the summer-autumn period; 3. by constipation during the migration of fish from the main channel of the Ob to the tributaries for wintering grounds in the late autumn period. Previously, the main volume of dace was caught in the spring, by atarma fishing — the number of rivers on which atarmas were placed reached 128. In the last decade (2013–2022), the number of exhibited atarma does not exceed 10. The dace is fished mainly by small fishers with lake seines and using fixed networks, in the late summer — early autumn periods. The average catch of dace is 131,5 tons per year (4,6% of all fish production). Dace stocks are currently in a relatively stable state, the estimated biomass of the species ranges from 901,4 to 1539,8 tons, but it is significantly underutilized — the development of the recommended catch volumes averages only 67,5%. First of all, this is due to the low consumer demand of dace, which leads to a lack of interest among fishers in specialized fishing by atarma.