The paper presents the results of research carried out into the state of rivers and lakes in the region of Lake Ladoga in Karelia. The research took the form of observations of the components of the water ecosystem of Lake Surrin spring and summer, a survey of the lake in summer, and occasional observations of 10 lakes around Kuznechnoye and in Lekhmalakhti bay in Lake Ladoga. The study investigated the state of the biocoenosis and the biotope and the bottom deposits of the lakes.