Fig. 1 - Valamo Island
Valamo Island is situated at the North-West of the Ladoga Lake
(Fig.1). There are 11 lakes at the island, among them two are
semi-closed (connected with the Ladoga by narrow streams). The lake
Leshevoe - the subject of the present study (Fig. 2)- is the second in the
total size among them.
The lake Leshevoe (Fig. 2) is connected with the Ladoga from the one side and
with another semi-closed lake - Sisjarve from another. However, the
water exchange is not sufficient. During the hot summer seasons the streams,
connecting lakes, are nearly dried-up, making them actually closed.