Natural water bodies with surface area exceeding 100 km2 refer to the big lakes. Currently there are 141 such lakes in Europe. According to the given estimation, nearly 2310 km3 of fresh water are concentrated there. The large lakes are situated almost in all the landscape zones, from tundra in the North up to the Mediterranean in the South-West and steppe in the South-East, however, the majority of them (about 80 %) is concentrated in Boreal zone that occupies nearly 40 % of Europe. The difference in origin of the beds and the variety of natural and climatic factors determine a wide variety of lake ecosystems. Due to high population density on the most part on the European continent and to active development of industry and agriculture, water bodies are under the significant anthropogenic load. The greatest anthropogenic impact on the lakes fell at the second half of the XXth century, during this period the increasing of biogenic load was especially high. Many lakes have changed their status from oligotrophic to meso- and eutrophic. Measures on the improvement of lakes' ecological state being taken since 1970s in the number of European countries (change of agricultural practice, sewage treatment, removing the especially dangerous part of the wastewater outside the basin and a severe legislative policy) have led to the first positive results as early as by 1980. The clearest examples are the prealpine lakes Bode see, Geneva, Como and Maggiore, where the phosphorus load for the period of 1975-2010 decreased by 3-8 times. However, the measures taken on many large were insufficient to reduce the concentration of biogenic substances in the water, the role of environmental factors in the formation oflake ecosystems and its response to anthropogenic influence, and, above all, to biogenic loads, is shown in the paper. The results of taken restoration measures are also revealed.
Seismic and tectonic setting in the construction area of North-European gas-pipeline on the Baltic Sea bottom is not completely studied, though the earthquakes with magnitudes up to M = 7 are registered and strong paleo-eart-hquakes are described in the region. The role of submeridian system of disjunctive breaches in contemporary geodynamic processes is noted. This system is produced by the fragments of great transcontinental lineaments of Europe. Some fragments, subordinated to Fennoscandia-Mediterranean geoid's lineament (Bothnia-Vistula «un-der-developed» rift), are active. But the question of seismicity of the Eastern part of the Gulf of Finland remains open. The Chudskoye-Hogland region attracts the special attention. On the Hogland island it is represented by the tectonic fault with the amplitude of tens and, possibly, up to hundred meters. According to trees' thickness, the age of tectonic fault is not more than 100 years. The sharp blocks near the foot (up to 10 m in diameter) and the «fresh-ness» of its edges also show its neanic age. The «immediate» foundation of such a displacement could cause a destructive earthquake that couldn't escape being noticed (N. I. Nikolaev). So the prospects are given that either the displacement was forming gradually or it happened during the armed conflicts of XXth century. The activity of Bothnia-Ladoga rift doesn't allow to refer the route of the North-European gas-pipeline and the whole Saint-Petersburg region to the aseismic area. So the following necessities are noted: 1) to initiate the International scientific programme of complex investigation of the geodynamic activity of the gas-pipeline area and the whole region; 2) to renew the surveys on Saint-Petersburg geodymamic polygon; 3) to expand the network of seismic and geophysic stations; 4) to create the forecast geodetic networks designed by the method of A. K. Pevnev to reveal the focuses of an upcoming earthquake.
