Restoration of macrozoobenthos after dredging on Lake Manzherokskoe (Republic of Altai, Russia)

Dredging is the activity of excavating soil and performing other soil operations in order to expand and increase the depth of water bodies. Under conditions of increased pollution, dredging operations may cause certain damage to aquatic ecosystems in general and to particular aquatic species. The changes in the composition and structure of benthic invertebrate communities have been studied in Lake Manzherokskoe in different periods: before dredging (2007), two weeks after the dredging has been started (2018), and 3 years after the dredging activities have been finished (2021). In 2021, there was an increase in species diversity and quantitative indicators of the development of benthic communities comparing to the period of dredging completion. Our data indicated the restoration of macrozoobenthos community in the lake to a certain extent. Later, this process may end in complete restoring with an increase in the water level in the lake and a significant decrease in the technogenic load on bottom communities.