The distribution of Gonyostomum semen (Ehr.) Diesing in the lake Ladoga tributaries

The distribution of aphidophyte alga Gonyostomum semen in Ladoga Lake inflows is analyzed on the data of long-term researches. This species, which for the first time met in some Lake Ladoga inflows in the middle of the 90-th of the last century, now is found in summer-autumn plankton of almost all rivers of the basin. The largest number of Gonyostomum in period of 2000-2005 was noted in Tulema, Tuloksa, Morye, Iyyoki and Miynola. All these rivers are characterized by the low total ions content, high water colour and рН