The researchers studied the types of small creatures living in Vozhe and Lacha lakes and nearby rivers. They found that chironomids were the most common in the lakes, while oligochaetes and a gastropod were dominant in the rivers. The lakes had similar types of creatures, mainly oligochaetes and chironomids, making up most of the population. In the rivers, oligochaetes and mollusks were important. The lakes showed signs of pollution and eutrophication, with fewer types of creatures and more pollution-tolerant species. Overall, the changes in the types and numbers of creatures in the lakes may be due to environmental factors and pollution.