"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”.