LAUSR

The distance of spawning migrations of semianadromous burbot spawners is reconstructed based on long-term (2000–2017) records characterizing the contribution of the Ural spawning tributaries of the Ob River (the Severnaya Sosva, Synya, Voikar, and Sob) to the generations of this species. It is shown that the Voikar River has played the dominant role in contributing to the total number of burbot generations over the observation period and that the migratory activity of spawners depends on the duration of flooding of the low floodplain. The dynamics of contributions from the northern and southern tributaries are evaluated in the context of possible climate change. It is concluded that burbot spawners have to skip the spawning season during long-distance migrations (over 1000 km) from wintering grounds to spawning grounds.