Lake Onega water per year, of which 46% are industrial and household water, 25% is stormwater runoff and 16% is melioration-related drainage. This drainage contains of phosphorus and of nitrogen; respectively of these elements are removed through the River Svir whereas the rest accumulates in the lake. Ships and motor boats (about 8,000 units) bring oil pollution at the level of about per navigation year, as well as phenols (), lead () and oxides of sulfur, nitrogen, and carbon. The lake basin is a major source of granite, marble and black schist in Russia which have been exploited in the area since
Onega stepanovi by an undivided zone. The surface of the undivided region of "Onega" is covered with small tubercles. "Onega" was originally described by Mikhail Fedonkin as a problematic organism, being grouped together with "Vendia", "Praecambridium" and "Vendomia" as possible stem-group arthropods due to a vague similarity with primitive Cambrian trilobites and arthropods. In 1985 Mikhail Fedonkin erected Phylum Proarticulata, in which he placed: "Onega", "Dickinsonia", "Palaeoplatoda", "Vendia", "Vendomia", "Praecambridium" and "Pseudovendia sp.", although he did not exclude the possibility that "Onega" may still be related to various lower Cambrian arthropods, such as "Skania". Andrey Yu. Ivantsov has proposed that "Onega" be