"Three"Three LargeLarge LakesLakes ofof RussiaRussia NorthNorth--

WestWest:: LakeLake Ladoga,Ladoga, LakeLake PskovskoPskovsko--

ChudskoeChudskoe andand LakeLake IlmenIlmen asas thethe objectsobjects

ofof longlong--termterm investigationinvestigation andand waterwater

resourcesresources management"management"..

Izmaylova A., Kudersky L., Rumyantsev V., Kondratiev S.,Izmaylova A., Kudersky L., Rumyantsev V., Kondratiev S.,

Limnology Institute of the Russian Academy of Sciences, Limnology Institute of the Russian Academy of Sciences,

St. Petersburg, Russia St. Petersburg, Russia

Savenkova T. Asanova T.Savenkova T. Asanova T.

State Scientifically Research Institute of the Fish State Scientifically Research Institute of the Fish

Facilities, the Novgorod branch, Novgorod, Russia.Facilities, the Novgorod branch, Novgorod, Russia.

Three large lakes of the North -West of Russia Lake Ladoga,Lake Ilmen and Lake Pskovsko-Chudskoe (Peipsi) are situatedin industrial, densely populatedregion. About 4 mln people livein Lake Ladoga catchment andmore 1 mln in Lake Pskovsko-Chudskoe catchment.

Due to theirs high sociallyeconomic importance the LakeLadoga together with connected

St. Petersburg

Lake Ladoga

Gulf of Finland

Ladoga together with connectedby water drain large LakesOnega, Saimaa, Ilmen andseparately located LakePskovsko-Chudskoe arefrequently called the Great NorthEuropean Lakes.

Lakes were the results of thelast Valdai congelation activitycovering this territory from 80up to 10 thousand B.C.

Velikiy

Novgorod

Pskov

Tartu

L. Peipsi

Pskovskoe L.

L. Ilmen

In a natural condition the water of three considered lakes is characterized

high quality. Active economic development happened in XX century resulted

in 1960 – 70-th in increase of trophical level and in substantial growth of

pollutant contains in the lakes. With the purpose of improvement of water

quality a number of the measures directed on restoration of a

normal ecological

condition of water

bodies and

prevention theirs

negative

infringements in the

future has beenfuture has been

undertaken.

Since the end of XX

century on L.

Ladoga, L.

Pskovsko-Chudskoe

and L. Ilmen the

regular monitoring

researches are

carried out.

L. Ladoga is the largest water body of Europe and the second fresh water

lake in Russia. L. Ladoga accumulates the water drain formed both in

Russia, Finland and Belarus. Its catchment area is 258.6 th. km2.

Till 1970th L. Ladoga was

characterized as coldwater

low productivity

oligotrophical water body. At

the beginning of 1960-th the

oxygen concentration in open

part of the lake did not fallpart of the lake did not fall

below 90-120% of saturation.

Concentration of biogenic

elements and first of all

phosphorus was low. It was

estimated in 10 µg/l for total

phosphorus averaged for a

year. Predominating groups

in phytoplankton was

Diatoma.

Because of active anthropogenous development on a watershed taking place

since the second half of XX century the quality of L. Ladoga water began to be

decreased quickly. By the beginning of 1980s ecological state of lake had

sharply worsened, the water body had changed to a mesotrophic status.

Concentration of phosphorus has increased by 3-5 times and in 1976-1980 it

increased up to 26 µg/l. Concentration of oxygen during the winter period in

deep-water areas went down not only near the bottom, but also in the surface

waters. In the connection with sharp increase of phosphorus load the biomass

of phytoplankton in littoral zone at the end of 1970s has grew up by 4-5 times

in comparison with 1960s, zooplankton by 2.5 times, and bacterioplankton by 3

times.

The species mostlyThe species mostly

sensitive to pollution

began to drop out

from the structure of

planktonic and

benthic communities.

Also the water quality

essentially decreased

because of significant

reception of toxic

substances.

With the purpose of overcoming an unfavorable condition formed on Lake

Ladoga the acceptance of some measures directed on restoration of its natural

ecological state took place. The most radical measures have followed as a

result of acceptance of 2 special decisions of Ministerial Council of USSR (in

1984 and 1987) about protection and rational use of natural resources of L.

Ladoga basin.

As a result Priozersk pulp-and-paper factory

and the similar enterprise in Harlu have been

closed, the plant for biological clearing of

sewage was constructed, technology of

preparation of raw materials at the Volkhovpreparation of raw materials at the Volkhov

aluminium factory was changed and the

outputs of sewage in Pitkaranta was moved.

Besides this the control of nature protection

standards operated during this period has

been strengthened. In spite of the fact that it

was only the first step in the solution of

environmental problems, they have soon

yielded positive results. The concentration of

phosphorus was decreased in lake water.

The decrease of industrial and agricultural production, occured in the country

in 1990-s in connection with economic recession, has promoted to lake

returning to normal ecological state. As a result of the undertaken nature

protection measures the phosphorus concentration in lake decreased to 20-21

µg/l in 1990-s and to 16-18 µg/l in 2000-s. Decrease of eutrophication level in

various parts of the lake was observed, the increase of water transparency and

oxygen saturation has taken place. In the structure of benthos the relict

crustacean species almost extinct during eutrophication period appeared

again. Researches of the present time show the different trophic status of a

lake by its area. The lake changes from oligotrophic in the central part to

oligotrophic-mesotrophic

and up to mesotrophic inand up to mesotrophic in

southern bays.

Problems of restoration

of biological resources

remain actual. Therefore

the problem of

continuation and

strengthening of works

on restoration and

protection of ecological

state of lake continues to

be urgent.

LakeLake IlmenIlmen is located in South-West of Novgorod region in the center of vast

Priilmen Lowland. It is shallow water body with flat bottom covered by 9-10 m

thick silt layer. The distinctive feature of the lake is significant variability of its

water area because of high interannual and long-term oscillations of its water

level under conditions of flat low-lying flood-lands.

WATER

LEVEL

WATER

LEVEL,M

VOLUME, KM3 WATER

AREA, KM2

AVERAGE

DEPTH, M

MAX.

DEPTH, M

Low 16.00 1.01 660 1.55 2.25

Average 18.00 2.85 1100 2.60 4.25

High 23.50 12.07 2230 5.40 9.75

level under conditions of flat low-lying flood-lands.

Due to shallowness Lake Ilmen is characterized as fast warmed and high

productivity water body. Water transparency is sufficiently low, about 1 m.

During the second half of XX century the lake was characterized with high

trophic content, explained both natural features of a water body, and

economic development on a catchment. By the beginning of 1980-th the

significant deterioration of lake water caused by the anthropogenous reasons

has been observed.

Chemical parameters distribution

is very non-uniformly over the

lake water area. Total phosphorus

concentration varies within 20 -

110 µg/l, total nitrogen - 160 -

1270 µg/l. Predominating groups

in phytoplankton are Chlorophyta

(158 species) and Diatoma (120

species).

Distinctive features of L. Ilmen is its water undersaturation with oxygen.

Oxygen saturation is 73-95% at surface level and 9-30% near the bottom.

species).

In 1990-th due to decrease of

anthropogenous press,

connected with recession in

economy, the tendency of

reduction of water contamination

in L. Ilmen was observed.

In 1990-2000 some growth of zooplankton biomass and decrease of benthos

biomass was marked. The qualitative structure of zooplankton improved at

the end of XX century due to increase of Crustacea in total biomass.

For the improvement

of quality of Lake

Ilmen water it is

necessary the

acceptances of

additional measures

on restriction of

polluting load at the

catchment and the

introduction of new

systems of clearing

Lake Ilmen

systems of clearing

because the systems

existing today work

insufficiently

effectively.

L. Pskovsko-Chudskoe (Peipsi) – is the

4th largest (by its area) freshwater lake

in Europe with water surface of 3555

km2. It is located on the boundary of

Russia and Estonia. The lake has a

complex configuration and it is divided

into three main parts: north part with

the biggest water area of 2611 km2 – L.

Chudskoe (Peipsi järv), south part with

water area of 708 km2 – L.Pskovskoe

(Pihkva järv) and L. Teploe (Lämmijärv;)

connected them - 236 km2. Theconnected them - 236 km2. The

outflowing river is the R. Narva which

flows into the Gulf of Finland.

As the lake is shallow and it warms up

fast, it is one of the most productive

lakes with high level of fish population

reproduction in the Baltic Sea region.

Trophic status of main lake parts is

different: L. Chudskoe is eutrophic, L.

Teploe – transitional to hypereutrophic

and L. Pskovskoe is regarded as

hypereutrophic.

Within the second half of XX

century ecological conditions of

the lake have considerably

worsened. The majority of

parameters testified the increase

of trophic level in 1980-90.

Permanent increase of biomass

of phytoplankton in L. Pskovsko-

Chudskoe occurred from 1987 till

1996.

A v e r a g e s a s o n a l b i o m a s s ( M a y - O c t o b e r ) o f p h y t o p l a n k t o n

i n L a k e P e i p s i - P s k o v

0

3

6

9

1 2

1 5

1 8

2 1

2 4

2 7

3 0

1 9 7 0 -

1 9 7 4

1 9 7 5 -

1 9 7 9

1 9 8 0 -

1 9 8 4

1 9 8 5 -

1 9 8 9

1 9 9 0 -

1 9 9 4

1 9 9 5 -

1 9 9 9

2 0 0 0 -

2 0 0 3

Y e a r s

g/m

3

L a k e P s k o v

L a k e P e i p s i

о

Since 1988 in L. Pskovskoe a

tendency of decreasing the numbersAve ra g e s e a s o na l (ma y - o c to be r) bioma s s o f zo o pla nk to n

in L ak e Pe ips i - P s k o v

0

0 .5

1

1 .5

2

2 .5

3

3 .5

4

4 .5

1 9 7 0 -

1 9 7 4

1 9 7 5 -

1 9 7 9

1 9 8 0 -

1 9 8 4

1 9 8 5 -

1 9 8 9

1 9 9 0 -

1 9 9 4

1 9 9 5 -

1 9 9 9

2 0 0 0 -

2 0 0 3

Y e a rs

g/m

3

L a k e P sk o v

L a k e P e ip s i

tendency of decreasing the numbers

of peaks of phytoplankton biomass

was observed within the vegetation

period from two-three units to two.

This is one of the features of a water

body shifting to hypereutrophic

stage. Annually in summer-autumn

period the water bloom of various

intensity due to cyanobacteria

propagation is observed in Lake

Pskovsko-Chudskoe.

The situation with receipt of pollution in L. Pskovsko-Chudskoe has changed

after disintegration of Soviet Union. The deterioration of an economic

situation in Estonia, Latvia and the Russian Federation led to significant

reduction of pollution receipt from the agriculture. Since the second half of

1990-th the improvement of clearing constructtions on the majority of point

sources of pollution became the other favorable factor of the reduction of

pollution. As a result since 1997 phytoplankton biomass in the lake tended to

decrease and the two blue-green algae species (Planktothrix agardhii and

Limnothrix redekei), actively distributed at the end of 1980 and typical for

hypereutrophic water bodies, are not among the mass forms already.

Now the main course of joined

Assessment of total phosphorus load on Chudskoe and Pskovskoe Lakes from Estonia (1)

and Russia (2 – re-calculated from PO4 data, 3- based on direct measurements).

Now the main course of joined

actions in preventing further

eutrophication is the reduction of

phosphorus content in urban and

rural sewages. Moreover, the

complex of measures for decrease

of phosphorus load on the lake from

agricultural activity in the catchment

is under realization.

Due to high social and economic importance Lakes Ladoga, Ilmen and

Pskovsko-Chudskoe are the objects of long-term investigation. Observed at

the second part of XX century the essential decrease of water quality has

demanded the acceptance of a complex measures for restoration of lakes

ecosystems. Alongside with the lines of prohibitive measures and the closing

of several most harmful manufactures, in 1990 – 2000-th the mechanism of

rational wildlife management and the program of regular monitoring of a

condition of water objects are developed.

The control over water use of all organizations and enterprises in Lake

Ladoga basin and Lake Ilmen basin is carried out by Neva-Ladoga BasinLadoga basin and Lake Ilmen basin is carried out by Neva-Ladoga Basin

Water Department. From the beginning of 2000-th the exploitation of aquatic

resources in the catchment of Lake Pskovsko-Chudskoe is regulated by some

international conventions. The control of a condition of water objects is

carried out by all water-users, and by agencies of the state control according

their competence.

Despite of stabilization of ecological conditions on considered lakes of North-

West of Russia observed in last decades, the problem of restoration of water

quality continues to remain actual. The principal step in the field of protection

of water resources of North-West of Russia should become the acceptance of

the special Law “about protection of Lake Ladoga”.

Thanks for your attentionThanks for your attention