GreenMind Project: About the natural environment of the Estonian-Russian transboundary Peipsi/Chudskoye Lake region

About the Project

This website was developed by NGO “Lake Peipsi Project (Pskov)” (Russia) in cooperation with the Peipsi Center for Transboundary Cooperation (Estonia) in 2020 as part of the project “Raising Environmental Awareness in Estonian-Russian Border Area” (ER101 GreenMind).

The main purpose of the website is to consolidate information about the unique nature of the Peipsi region, an area covering Estonian and Russian lands around Peipsi/Chudskoye lake.

The website operates in 2 languages — Russian and Estonian in parallel and tells about the biodiversity of the region, the state of the environment, environmental organizations, current environmental challenges, nature protected areas and environmental initiatives implemented on both the Russian and Estonian sides of the lake.

Use the available language of the website to read more: RUS, EST.

About the Peipsi/Chudskoye lake

Peipsi/Chudskoye lake is one of the largest freshwater bodies of Europe and the biggest transboundary lake of the continent. In the list of European water bodies it is the fifth by the water-surface area (3 555 km2) and the water mass volume (25.1 km3). The bigger ones are the Ladoga (18 390 km2) and Onega (9 840 km2) in Russia, Vänern (5 545 km2) in Sweden and the Saimaa Lake system (4 400 km2) in Finland (although Saimaa is not one lake, but rather a chain of several linked lakes.).

The common Russian name for Peipsi/Chudskoye Lake is Chudskoye. The name derives from the word “chud”, that is, the Old Slavic name of the Finno-Ugric tribe residing on the lakeshore.

The water area is shared by Estonia (44%) and Russia (56%). The lake plays a big role in the economies of the two countries. Yet, it is not merely used for fishing purposes, but also as an energy resource, a waterway and recreation asset. Geographically, most of the Russian share belongs to the Pskov Region and a part to the Leningrad Region.

About 240 rivers, streams and brooks are tributaries to the lake, with just one river — the Narva (77 km) — having it as its source, and connecting the lake to the Gulf of Finland. The area of the lake watershed comprises 47800 km2,and is oblong and elongated, stretching north to south for 370 km. About one third of the watershed belongs to Estonia and two thirds to Russia. The territory includes around 45 00 lakes — all of them small (under 1 km2) — except for the Võrtsjärv, connected to the Peipsi Lake by the Emajõgi river. The largest waterways in the basin are: in Russia – the Velikaya (430 km long) and the Zhelcha (107 km), and in Estonia – the Emajõgi (101 km) and the Võhandu (162 km), inflowing into the Tyoploye Lake.

The lake bed can be conventionally split into 3 parts: the northern – the Chudskoye or Peipsi (from Estonian) Lake of 2 680 km2; the southern – the Pskov Lake (Pihkva järv) of 716 km2 and the Tyoploye Lake (Lämmijärv) connecting them like a strait, with the area of 170 km2. The total length of Peipsi/Chudskoye Lake is 152 km, and the maximum width is 47 km.

Main environmental challenges of the region

Overgrowing of fields with the hogweed

Sosnovsky’s hogweed, as a plant species, was described in 1944 by the Soviet botanist Ida Mandenova. It was named after another botanist, Dimitri Sosnovsky, a researcher of Caucasian flora.

A study of Sosnovsky’s hogweed during the first post-war (WWII) years showed that the plant is extremely undemanding and can be used for feeding livestock after ensiling, i.e. after fermenting/conserving the shredded green mass without air access. Since after the war there was an urgent problem of livestock regeneration, the hogweed quickly found its application and began to march across Russia.

Toxicity, tenacity and speed of spreading of the hogweed were established later than its introduction into agricultural practice, and the time for its containment was lost. Particularly actively the hogweed displayed itself in cold and moderate climate, in connection with what the North-West of Russia, as well as the territories of Estonia, Latvia, Lithuania and Byelorussia, where the hogweed began to cultivate since 1947.

The sap of the hogweed is dangerous, especially in sunny weather. The sap may contact the skin on a cloudy day and a person may not even notice it, but once the sun goes out, the sap residue on the skin will result in a chemical burn. This is because the juice contains furanocoumarins, light-sensitive substances that, when exposed to ultraviolet light, become active and attack skin cells. Recovery takes a long time and burn marks may remain on the body. Damage to the mucous membranes (eyes, mouth, etc.) can lead to more serious health consequences.

Due to the photosensitivity of the sap of the hogweed, the first “antidote” is not even washing the poison off with water, but isolating the affected area from the light – you should cover the body with impermeable material – clothes, etc. Only then, once you are in a dark place, should you bathe the affected area with soap and water. And even after these procedures, it is advisable to avoid exposing the skin to sunlight for a couple of days. If you have any suspicion of contact with hogweed, you should consult a doctor.

In addition to its harm to human and animal health, the hogweed is also dangerous on an ecosystem level. It replaces other plants, takes over large territories, cuts natural biocenoses by impassable thickets, and withdraws lands from agricultural turnover.

It is extremely difficult, but not impossible, to control the hogweed. There are different approaches: mapping the growing areas and destroying the plants before seeds appear, digging up and burning the roots, cutting off the inflorescences with seeds, spot application of general herbicides such as glyphosphate, irrigation with a flammable liquid and incineration, ploughing and discing the land several times per season, replacing it with other plants – e.g. by sowing topinambur and fast-growing plants with a large number of seeds, e.g. bromegrass and legumes (goatweed, galena). The ground surface can also be covered with a light-tight material to suppress the growth of the hogweed. The borage moth, the only known natural pest of borage to date, is artificially bred.

The main problem of beetle moth control is haphazard local initiatives. The control of the beech moth can only be carried out at the macro-regional level with mutual consolidation of efforts of many municipalities and regions over several years. In the Baltic States, for example, where the national programmes of cowberry control are in place, the plant is virtually extinct (it seems impossible to speak of a complete “victory” over such a tenacious plant, therefore, the situation is constantly monitored in order to prevent new outbreaks of the plant).

Abandoned fishing nets

One of the most serious environmental problems in recent decades, including in the Pskov Oblast, has been abandoned fishing nets. In the recent past the nets were industrially or manually made of natural fibres – which could take weeks or months of work. Such nets were expensive for the owner – literally and figuratively. Today, the market is flooded with synthetic nets, mainly made in China, which pay for themselves in one catch. If such net gets torn, entangled or caught by the fish guards, it is easier for an unscrupulous fisherman to abandon it and buy a new one than to retrieve it.

When left in water, such a net, of course, continues to perform its functions: fish get into it and then die. The net also collects other water inhabitants – diving ducks and other waterfowl, crayfish, aquatic mammals die in it, it poses a serious threat to navigation and especially to the life of swimmers. Over time, such a net will inevitably sink to the bottom due to currents, gained weight, and rips, covering it with a dense layer. According to estimates of officially operating fishing companies, conducting fishery in the water area of Lake Peipsi, the bottom of the reservoir in some places is covered literally by a solid carpet of abandoned nets for many square kilometres. Thus, additional serious problem appears: nets, having sunk to the bottom, block migration ways and spawning places of valuable commercial fish. The decaying remains in the nets drastically deteriorate water quality, further spoiling the water body. Finally, another negative factor is synthetics used in the manufacture of modern nets; remaining in the water reservoir for years, it is a direct threat to water quality.

At present regional and municipal authorities throughout the country are sounding the alarm. For example, the administration of the Pskov Oblast tries to regularly announce tenders for cleaning up the lake from nets within the framework of the state programme “Sustainable Development of the Fisheries Sector for 2014-2020”. In general, the cleaning of Pskov reservoirs from nets has been carried out since 2006; more than 1,000 cubic metres! of nets have been caught.

Retrieving a heavy abandoned net from a water body is also a major technical challenge. Contrary to popular belief, it is not enough to sweep the area with an anchor; such trawling most often acts like a plough and simply rips up the lying net. Fishing companies interested in clearing their fisheries tend to use manual, extremely labour-intensive work: A person standing in the stern holds the trawl in his hands, in order to feel the tension of the rope, and slowly and carefully pulls the “catch” towards the vessel in order to avoid tearing it off.

However, these undoubtedly important measures are still fighting the symptoms of the disease, the cause of which is the trade in extremely cheap manufactured nets and the lack of environmental culture of many users of such products. And even a total ban on the trade/export of synthetic nets on the national scale will make it much easier – at least for the time being – but will not fundamentally improve the situation. After all, an unscrupulous fisherman can weave such a net from ordinary fishing line – progress never stands still and automatic machines for binding fishing nets are not getting more expensive either.

For the time being, there is no question of a complete ban on sales. Measures proposed include the following: (1) registration of sold nets (the net is “tied” to the owner; such a net can no longer be abandoned, but the burden on controlling authorities, who will have to check the conditions of keeping nets in place – whether they are missing – literally like firearms, is extremely increased); (2) significant increase in fines for poaching (an important measure, although, unfortunately, it does not solve the problem of easy “parting” of a poacher with his net – rather the opposite – the poacher may become even more cautious); and (3) increasing the environmental culture of the population (an effective measure, but long implemented, which is one of the main objectives of the Russian-Estonian CBC project “GreenMind”).

Eutrophication (aging of water bodies and algae blooms)

One of the most important environmental challenges of the Pskov Oblast is eutrophication of water bodies. Under natural conditions, eutrophication is a natural process of aging of water bodies, characteristic of the entire geological past of the planet and usually lasting for centuries. However, in recent times, due to increased anthropogenic impact, the rate of aging has increased dramatically, turning lakes into swamps in just a few decades. The Peipsi Lake has also been affected.

This accelerated or “anthropogenic” eutrophication is mainly caused by increased removal (washing out) of biogenic (nutrient) elements from land to water bodies due to increased economic activity in catchments. For example, it has been established that a considerable part (up to 20-30%) of nitrogen, potassium and phosphorus fertilizers can be washed away from the fields and get into water bodies.
However, the main sources of pollution of water bodies in Pskov Oblast are, nevertheless, the housing and utilities sector, accounting for 95% of the gross discharge of pollutants. The impact of anthropogenic eutrophication is primarily manifested in lakes, as the relative immobility of water contributes to the accumulation of biogenic elements. The waters of a lake receiving these effluents constitute a fertile environment for the development of hydrobionts. A direct consequence of the increased input of nutrients into the lake is the intensification of the growth of algae, phyto- and then zooplankton.

The main result of this increased fertility of the water body is an increase in its biomass, which at the initial stage is beneficial as the lake becomes more productive. Later, the productivity becomes so great that it causes a deterioration of water quality, manifesting itself in several forms. The abundance of biomass eventually results in a large volume of dead plants and animals (detritus) settling to the bottom. There this matter is oxidised by aerobic (oxygen using bacteria) bacteria, causing a severe reduction in the concentration of dissolved oxygen, as the bacterial decomposition of organic matter consumes oxygen intensively.

The rate of oxygen depletion is highest in summer because, on the one hand, summer is the temperature optimum for life activity of hydrobionts (it is summer when we observe “water blooms” in our reservoirs), on the other hand, with increasing temperature there is a natural reduction of oxygen solubility in water. At very high biomass density, oxygen deficit can be so great that it causes death of fish. Thus, mass death of fish in Peipsi Lake has also been observed on several occasions. Under conditions of low oxygen concentrations the decomposition of dead residues begins to be carried out by anaerobic bacteria (they carry out processes similar to fermentation, without the use of oxygen). Although these bacteria are still able to oxidise detritus, they metabolise significant amounts of gases such as methane and hydrogen sulphide.

Naturally, the water quality in this case is extremely poor and such water bodies should not be used not only for drinking, but also for recreational or irrigation purposes. Eutrophication of water bodies deteriorates not only the physical characteristics of the water body, but also its appearance and affects its beauty.

Intensive growth of aquatic vegetation overloads water bodies, making them inconvenient for swimming, boating or fishing. Clusters of decomposing aquatic plants along the shoreline, and sometimes even fish, further degrade the water and attract many insects and vermin. As the decomposition process intensifies, the water takes on an unpleasant smell. Naturally, the use of such water areas for recreational purposes is fraught with obvious difficulties and ultimately leads to economic losses.

The difficulty in solving the issue of eutrophication is related not only to increasing urbanisation, but also to the problems of wastewater treatment from nitrogen and phosphorus pollution. In recent years the Pskov Oblast’s wastewater treatment plants have been undergoing active modernisation, including with the help of the EU-Russia Cross-Border Cooperation Programmes, which have enabled a significant improvement in the quality of discharged wastewater.

Siltation of rivers

Siltation of rivers and brooks is not the most pressing, but still a notable environmental challenge in Pskov Oblast. The problem is caused by several main reasons: natural ageing of water bodies, monotonous flat topography, overgrowing of watercourses, littering (in particular – fallen trees across the watercourse), cutting of forests in river basins (which disturbed water balance and increased temperature / reduced watercourse speed due to lack of shade from riparian trees), beaver damming and reclamation works carried out in Soviet times. The latter were often associated with straightening of natural channels and the construction of artificial straight canals, resulting in a lower flow velocity in the straight sections and, consequently, a greater sedimentation of suspended solids. One of the results of the abovementioned combination of reasons has been the reduction of navigability of a number of rivers and flooding.

By the beginning of the new millennium, several problem areas of this kind have emerged in the region. Over the last decade and a half the Pskov Oblast Administration has been consistently increasing its efforts to prevent and eliminate the consequences of floods, increase water availability and navigability, strengthen the banks, and dredge silted watercourses. Thus, by now, the situation has generally been brought under control, timely monitoring of the situation by federal, regional and municipal authorities has been ensured, and new hydraulic engineering solutions are being actively developed and implemented.

This website has been produced with the financial assistance of the Estonia–Russia Cross Border Cooperation Programme 2014-2020. The content of this website is the sole responsibility of NGO “Lake Peipsi Project (Pskov)” (Russia) and the Peipsi Center for Transboundary Cooperation (Estonia) and can under no circumstances be regarded as reflecting the position of the Programme, Programme participating countries alongside with the European Union.

Estonia-Russia Cross Border Cooperation Programme 2014-2020 aims to foster crossborder cooperation across the borders between the Republic of Estonia and the Russian Federation to promote socio-economic development in the regions on both sides of the common borders. The Programme web-site is

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