RESULTS OF A JOINT U.S.A./U.S.S.R. HYDRODYNAMIC
AND TRANSPORT MODELING PROJECT
APPENDICES B, C, AND D
by
John F. Paul and William L. Richardson
Large Lakes Research Station
Environmental Research Laboratory-Duluth
Grosse lie, Michigan 48138
U.S.A.
Alexandr B. Gorstko
Institute of Mechanics and Applied Mathematics
Rostov State University
Rostov-on-Don
U.S.S.R.
and
Anton A. Matveyev
Hydrochemical Institute
Hydrometeorological Services
Novocherkassk,
U.S.S.R.
ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
DULUTH, MINNESOTA 55804
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DISCLAIMER
This report has been reviewed by the Large Lakes Research Station,
Environmental Research Laboratory-Duluth, Grosse lie, Michigan, U.S.
Environmental Protection Agency, and approved for publication. Mention of
trade names or commercial products does not constitute endorsement or
recommendation for use.
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CONTENTS
Appendices
B. Background on the Sea of Azov and Lake Baikal
Ecosystem B-l
Introduction B-2
The 'Sea of Azov1 Simulation System B-3
Ecological sketch of the Sea of Azov
Problems requirement the creation of a model B-3
Method of modeling of water exchange between different
regions of the sea and of the associated change in the
concentrations of solutes and suspensions B-88
Brief Characterization of Factors Affecting the Formation
of the Chemical Composition of Lake Baikal Water B-98
C. Results of Hydrodynamic and Dispersion Calculations for
Lake Baikal and Sea of Azov C-l
Lake Baikal C-3
Currents C-3
Material dispersion C-23
Sea of Azov C-47
Currents C-50
Material dispersion C-78
D. Meteorological, Hydrological, and Chemical Data for Selenga
Shallow D-l
Hydromet cruise, 28-29 May 1976 D-2
Hydromet cruise, 22-23 June 1976 D-9
Meteorology, 20 May to 20 June 1976 D-12
Wind data, June-July 1975 D-16
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APPENDIX B
BACKGROUND ON THE SEA OF AZOV AND LAKE BAIKAL ECOSYSTEMS
(Translation of the Russian text prepared by Alexander B. Gorstko and Anton
A. Matveyev).
B-l
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INTRODUCTION
The contacts between Soviet and American specialists engaged in under
the agreement for cooperation between the USSR and USA in the area of pre-
vention of pollution of natural waters have shown a considerable similarity
in the approaches to the mathematical modeling of the ecosystems of bodies
of water. However, existing differences in methodology lend special im-
portance to the problem of comparing results of modeling of the same objects
by different methods. The following three bodies of water were selected as
such objects:
(1) The Sea of Azov - an ecosystem model that can serve as a
reference standard has been worked out;
(2) Lake Baikal - a body of water under intensive study by the
USSR Hydrometeorological Service;
(3) Lake Michigan - a body of water under study by the U.S.
Environmental Protection Agency.
The present material forms the basis for constructing mathematical
models of the ecosystems of the first two bodies of water. It presents the
characteristics of these ecosystems, the necessary data on the catchment
basins, the existing information, and problems for whose solution the models
are created.
The Sea of Azov is used as an example for describing a model of water
exchange between different parts of a body of water.
B-2
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CHAPTER 1
THE "SEA OF AZOV" SIMULATION SYSTEM ("SEA OF AZOV" SS)
1. Ecological Sketch of the Sea of Azov. Problems Requiring the Creation
of a Model.
The construction of the "Sea of Azov" SS is based on extensive natural
scientific information on the object being modeled. It is not possible here
to give a detailed description of the processes and phenomena occurring in
the ecosystem, since this would take up too much space. We will, therefore,
confine ourselves to a fairly brief sketch, which will be completed with a
characterization of the problems for the solution of which the "Sea of Azov"
SS in intended.
The Sea of Azov is a comparatively small body of water located between
45° and 47° N and 35° and 39° E. Its area is 38,000 km2, and the seawater
3
volume * 320 km . The Sea of Azov is shallow; maximum depth is of the
order of 13 meters, and average depth, about 8 meters.
The sea is inhabited by:
332 species of phytoplankton
155 species of zooplankton;
180 species of benthos;
104 species of fish.
All the species are far from being of equal importance to the life of
the ecosystem as a whole. This made it possible to limit the modeling to
only the most important ones: :
20 species of phytoplankton comprising 95% of the phytoplankton biomass;
12 species of zooplankton comprising 92% of the zooplankton biomass;
6 species of benthos comprising 88% of the benthos biomass;
9 species of fish comprising 90% of the fish biomass.
B-3
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With time, under the action of various factors and processes, both
abiotic and biotic, a change in the biomasses of the enumerated species
takes place. In order to gain a correct understanding of the pattern of
these changes, we will give a more detailed description of the processes
taking place in the sea, and of the characteristics of the individual
trophic levels of the ecosystem.
External Factors
The rates of the processes in an ecosystem depend significantly on a
number of factors determining the state of the environment, the so-called
external factors, which include temperature conditions, wind activity over
the water area of the sea, solar activity, precipitation, evaporation, etc.
They can all be broken down into three groups: climate-governed factors,
hydrometeorological factors subjected to anthropogenic influence, and para-
meters of effective control of the ecosystem. The values of these factors
are available in the form of series of past observations, actual, and pre-
dicted values. When the processes in the ecosystem are simulated, the
possibility of their different realization for different values of external
factors is taken into consideration.
Dynamics of the Waters
One of the key processes in the Sea of Azov is the water exchange
between different parts of the sea and the associated redistribution of the
solutes, suspensions and organisms. The dynamics of the seawater are
essentially determined by the wind, and the horizontal water exchange is
determined by the wind-generated system of currents. Typical of the Sea of
Azov is the short time lag of the process. Because of the shallowness of
B-4
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the sea and unstable wind conditions, the speed and direction of currents
at any point of the water area change very rapidly.
According to the data of the Hydrometeorological Handbook for the Sea
of Azov, wind currents with speeds of 2-10 cm/sec have the highest fre-
quency (up to 60%). Currents with speeds of 10-20 cm/sec, corresponding to
winds of 5-10 m/sec, have a frequency of about 30%. The maximum current
speed does not exceed 60-80 cm/sec.
During the cold half of the year, winds of the eastern quarter of the
horizon prevail above the sea. Their frequency during this period amounts
to an average of 45-50%, and the frequency of westerly winds, about 30%.
The wind speed during the fall and winter periods reaches an average maxi-
mum of 6-7 m/sec. Storms with easterly winds of over 10-15 m/sec also
occur at that time.
In spring and summer, the directions of transport of the air masses
change; the frequency of western vectors increases to 38-45% and that of
eastern vectors decreases to 25-30%. Later (July, August), the wind speed
drops to the annual minimum, which amounts to a long-term average of 4.2
m/sec. In the course of a year, the frequency of northerly and southerly
winds does not usually exceed 10%, and the frequency of calms is approxi-
mately 7%.
Winds of the eastern quarter of the horizon raise the water level on
the western shores of the sea and lower,it on the eastern shores. The
effect of westerly winds is opposite. The level differences between regions
of the sea opposite in the latitudinal direction may reach 4-5 m. Lasting
winds lead to the establishment in the sea of a fairly stable profile of
the water surface with the maximum possible slope for a given wind pressure.
B-5
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In addition to wind, a role is also played in the level dynamics of the
sea, and hence in the displacement of water masses, by the specific propor-
tion of the elements of its water balance, primarily the runoff, atmospheric
precipitation, evaporation, and water exchange with the Black Sea through
the Kerch Straits.
Data on a long-term (1923-74) average water balance are listed in Table
1. Some characteristics of its component elements are given below.
TABLE 1. WATER BALANCE OF THE SEA OF AZOV (1923-74)
(km-Vyear)
Gain
Loss
River runoff 37.3
Precipitation 14.2
Inflow from Black Sea 32.9
Inflow from Sivash 0.3
TOTAL: 84.7
Evaporation 34.2
Runoff into Black Sea 48.6
Runoff into Sivash 1.4
TOTAL:
84.2
The main volume of the continental runoff into the Sea of Azov is due to
3
the inflow from the Don ( * km ; variation coefficient of annual run-
3
off, 0.30) and the Kuban" ( * km ; variation coefficient of annual
runoff, 0.19).
According to calculations of the State Institute of Oceanography (COIN),
the average annual precipitation on the sea surface is 14.2 km , and the
variation coefficient is 0.17.
The long-term average evaporation from the surface of the Sea of Azov
is 34.2 km^, and the variation coefficient is 0.06.
translator's Note: Figures missing in the original text.
B-6
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The water exchange of the Azov and Black Seas is the most dynamic com-
ponent of the water balance. During the period under consideration, the
maximum annual runoff of Azov waters was measured in 1932 and found to be
3 3
67.1 km , and the minimum, 38.8 km , was noted in 1950. The extremes of
3 3
annual inflow of Black Sea waters were 38.1 km (1950) and 28.9 km
(1932), respectively, and the extremes of the net water exchange were 38.1
3 3
km (1932) and 0.7 km (1950). The coefficient of variation of mean
annual values of water exchange through the Kerch Straits is 0.56.
The annual distribution of the main elements of the water balance is
presented in Table 2.'
Oxygen
Dissolved oxygen, which plays a decisive part in many processes, holds
a unique position among the abiotic parts of the ecosystem.
The chief sources of oxygen supplied to the water mass are its produc-
tion by photosynthesis and invasion from the atmosphere. During the cold
season, these incoming items are approximately equal, and in summer, photo-
synthesis is estimated to produce 60 to 90% of the total oxygen supply.
The dissolved oxygen is expended on the respiration of organisms and de-
gradation of organic matter of the pelagic zone and bottom. The latter
process is mainly due to the activity of the microflora, and is therefore
biochemical in nature. The Sea of Azov is characterized by a high rate of
biochemical oxygen consumption (demand) (BOD ); an average of 0.44-0.60
ml of 0?/£ day, and in the Don estuary, up to 0.70 ml of 0?/£ day.
This is chiefly determined by the substantial concentrations of organic com-
pounds accumulated in it. Since the consumption values cited are usually
lower than the total oxygen supply (about 0.9 ml of 0_/£ day in 1974-75),
B-7
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TABLE 2. ANNUAL DISTRIBUTION (%) OF MAIN ELEMENTS OF THE WATER BALANCE
OF THE SEA OF AZOV
Element of Balance
Jan Feb
Winter*
Mar Apr May
Spring
June July Aug
Summer
Sep Oct Nov
Fall
Dec
Winter
Don River runoff
Kuban1 River
runoff**
Precipitation
Evaporation
4.8 6.1 8.8 14.9 13.9 9.0 8.2. 7.5 7.2 7.6 7.2 4.8
5.0 4.9 7.9 9.0 13.5 13.3 12.5 9.3 5.0 4.5 5.7 9.4
25.4 20.3 28.9 25.4
7.3 10.7 53.9 28.1
w
1
DO
Runoff into
Black Sea
Inflow from
Black Sea
Net water
exchange
29.2 30.5 17.0 23
33.1 18.8 19.4 28
19.6 56.8 11.8 11
.3
.7
.8
*A11 data for winter are given for the Dec-Feb period.
**After the construction of the Krasnodar storage reservoir.
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there is practically never any oxygen deficit in the surface layers of the
sea. This however is not the case in the bottom layers. A very high rate
of oxygen consumption is observed in the "water-ground" contact zone. Thus,
BOD. for the bottom sediments of the sea during the warm period of the
2
year amounts to about 4 g of 0_/m day, while in Taganrog Bay this value
2
is 10.5 g of 0_/m day. For this reason, in the bottom layer, the
oxygen content often drops to zero, and so-called obstruction phenomena
take place.
It has been found that the oxygen consumption of the ground varies with"
the ground type. Tab,le 3 gives average values of oxygen consumption at 10°C
under optimum oxygen conditions.
TABLE 3. CONSUMPTION OF OXYGEN BY GROUNDS
Oxygen Consumption at 10°C
Type of Ground .- ( of 02/m^ day)
Clayed silt ; 3
Fine silt 2.5
Coarse silt 1
Sand with shells 0.7
However, the state of the oxygen regime of the sea is not determined
solely by the ratio of the gain and loss items of the balance. A very im-
portant role is played by regulating factors, i.e., temperature, quality of
organic matter, salinity, hydrodynamic activity of the period, and vertical
stratification of the waters. Their combined action determines the present
oxygen regime.
Since 1960, the phenomena of the summer oxygen deficit in the bottom
layers have become practically annual. On average, for 1960-75, the area
B-9
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bounded by the iso-oxidation line of 60% saturation (boundary of sublethal
2
oxygen content) amounted to about 10,000 km , or over 25% of the water
area of the sea. A complete absence of oxygen and consequent death of bot-
tom fauna were recorded over a considerable area. Among the reasons for
such a marked deterioration of the oxygen regime, the following may be
cited:
(1) A depression of wind activity in 1957-73 that was most
appreciable during the entire observation period and that
reduced the dynamic aeration of the water masses and es-
pecially of the bottom layers of the sea.
(2) A 0.5° increase in the mean annual temperature of the
waters of the Sea of Azov.
(3) A decrease in photosynthetic activity.
(4) An increase in the density stratification of the waters of
the sea.
The present oxygen deficiency of the Sea of Azov has well-defined nega-
o
tive ecological aftereffects.
Biogenic Elements
The concentration of nitrogen and phosphorus-containing compounds in
the sea is regulated by'both the proportion of their balance components and
the kinetics of the internal turnover. We will begin by considering the
components of the nitrogen balance.
On average, during the decade, 1966-75, the river runoff into the Sea
of Azov brought 67.43 thousand tons of nitrogen (Don - 37.67, Kuban' -
29.76 thousand tons) and 6.48 thousand tons of phosphorus (Don - 3.15,
B-10
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Kuban' - 3.33 thousand tons). It should be noted that these values are
unstable and depend on anthropogenic activity.
The average total concentration of mineral and organic compounds of ni-
3
trogen in precipitation falling on the sea surface amounts to 1400 mg/m ,
3
and that of phosphorus compounds, 45 mg/m . Since the mean annual pre-
3
cipitation on the sea surface is 14.2 km , it may be assumed that the in-
flow of nitrogen and phosphorus with this item of the balance will amount
to 19.9 and 0.6 thousand tons, respectively.
There is one more incoming item - the inflow of nitrogen and phoshorus
with materials from abrasion of the shores. Quantitative estimates are
given in Table 4.
TABLE 4. INFLOW OF TOTAL NITROGEN AND PHOSPHORUS INTO THE SEA OF AZOV
WITH MATERIALS FROM COASTAL ABRASION
Region of coastal zone
Amount of abra-
sion material, Average content Inflow, tons
million tons N P N P
Temryuk - Primorsko-
Aktarsk
Region of Primorosko-
Aktarsk
Genichesk - Belo-
sarayskaya sand bar
Northern shore of
Taganrog Bay
Southern shore of
Taganrog Bay !
Yeyskiy Peninsula
Taman and Kerch
Peninsulas
0.20
0.38
12.60
0.64
0.67
1.70
0.66
0.066 0.010 130 20
0.050 0.010 190 40
0.043 0.010 6000 1250
0.050 0.010 320 63
0.030 0.011 200 72
0.034 0.009 580 150
0.050 0.010 330 70
TOTAL
16.85
0.047 (sic)
7750 1665
B-ll
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Since phosphorus in coastal sediments is represented chiefly by
sparingly soluble compounds, its change to the dissolved state may be asumed
equal to 10% of the total inflow, i.e., 0.16 thousand tons/year. For nitro-
gen, this value reaches 50%, and the inflow into the water amounts to 3.88
thousand tons/year.
Another important item of the balance is the water exchange with the
Black Sea. Since the average concentration of nitrogen in Black Sea waters
is 350 mg/m , and that of phosphorus, 27 mg/m , their total inflows from
the Black Sea are 11.4 and 0.9 thousand tons, respectively. According to
12
the calculations of G^D. Makarova, the average content of nitrogen and
phosphorus in waters of the Sea of Azov region preceding the straits is
3 3
1110 and 80 mg/m . For a 49.8 km runoff from the Sea of Azov, the
annual loss of nitrogen and phosphorus-containing compounds from this
balance item amounts to 45.3 and 4.0 thousand tons, respectively.
We have examined the gain and loss balance items of biogenic compounds.
It should be noted, however, that the power of the producing system of a
sea depends not so much on the balance of biogenic compounds as on the rate
of their internal turnover. Therefore, information on the nitrogen and
phosphorus content is insufficient for estimating and predicting the state
of the ecosystem of a sea.
Basic diagrams of nitrogen and phosphorus turnovers in bodies of water
are known rather well, and we will not dwell on them here. Let us only
note that according to data pertaining to the period of the natural regime
of the Sea of Azov, the rate of its nitrogen and phosphorus turnover was 7
and 8 cycles per year, respectively. Of these, 4-5 were accomplished in
summer, 1-2 in spring, and 2-3 in fall.
B-12
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12 . .
Recent data indicate a significant reduction in the rates of inter-
nal turnover of nitrogen and phosphorus, which now amounts to 2.1 and 6.8
cycles per year, respectively. There is reason to assume that this reduc-
tion in rates is due to an increasing salinity of the sea.
Quality of the Waters
The chemical pollution of waters of the Sea of Azov is a significant
factor in its biological action, with a negative effect on the ecosystem of
the sea. The most common pollution components are petroleum products,
phenol compounds, detergents and pesticides. The content of heavy metal
salts in the pelagic zone of the sea are at the level of the natural geo-
chemical background.
Because of shallow waters, which provide for a high degree of aeration
of the water masses and their satisfactory progressiveness, and also be-
cause of its high biological productivity, the Sea of Azov has a high self-
purifying capacity. The chief role in self-purification eliminating
degradable pollutants is played by biological processes. Participants in
these processes are bacteria, fungi, infusoria, rotifers, etc.
In the la.st few years, considerable work has been done in the Azov
Basin to prevent the pollution of the sea and of the rivers emptying into
it. A number of water-protection measures have been implemented in plants
and population centers located along the Azov coast: Taganrog, Zhdanov,
Berdyansk, etc. An effective system of control and sanctions providing for
the necessary progress of water-protection measures has been created in the
Azov Basin.
B-13
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A resolution of the Central Committee of the Communist Party and USSR
Council of Ministers of 4 February 1976, entitled "Measures to Prevent the
Pollution of Black and Azov Basins", stipulates a set of measures providing
for the complete cessation by 1985 (and for many large plants, by 1980) of
the dumping of untreated household and industrial sewage into the bodies of
water of the Azov Basin.
Despite the relatively favorable situation with respect to water quality
in the Sea of Azov and the prevailing tendency toward its further improve-
ment, the Water Quality .unit, describing the dynamics of concentrations of
pollutants and the self-purification processes in the Sea of Azov, has been
introduced into the SS for testing different control variants and also for
retrospective analysis. ,
Phytoplankton
The phytoplankton of the Sea of Azov, consisting of 332 species, is the
chief producer of organic matter. It thereby largely determines the state
of the nutritive base and hence, the living conditions of food fish popula-
tions.
Analysis of observations of phytoplankton development has revealed a
seasonal rhythm of the production processes within the annual cycle. In the
Sea of Azov, one can distinguish two main ecological complexes of algae: a
cold-water and a warm-water complex.
In the course.of an \annual cycle, because of the fluctuation in water
temperature, a change in the prevalence of representatives of these two
types is observed. This change, combined with the dynamics of biogen-con-
taining compounds, usually determines the presence of three maxima - the
B-14
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spring and fall maxima (with the prevalence of cold-water algae) and summer
maximum (with the prevalence of warm-water ones).
The early spring period is characterized by a massive development of
temperate and cold-water species of diatoms - Sceletonema costatum,
Chaetoceros holsatucus, and in Taganrog Bay - Sceletonema costatum,
Chaetoceros rigidus.
The absence of competing algae at that time, low consumption by the
animals and a simultaneous high content of biogenic elements in the water
enable the cold-water species of algae to form a large biomass, on the order
3
of 14-27 g/m , or about 80% of the total phytoplankton biomass.
The reduction of the content of biogenic elements in the water because
of their intensive consumption is associated with a sharp reduction in the
biomass of algae and an almost complete elimination of algae of the cold-
water complex from the plankton. The total phytoplankton biomass decreases
3
to 1.0-0.2 g/m . The low level of the phytoplankton biomass lasts until
June.
As the seawater warms up to optimum temperatures for warm-water species
and as the biogenic elements return to mineral forms accessible to assimila-
tion by phytoplankton, the number of warm-water phytoplankton species, which
develop intensively, increases, and at 22-26° a second maximum in the phyto-
plankton biomass is observed. In the sea itself, phytoplankton is repre-
sented by marine and saltwater species of pyrophytic algae (Exuviaella
cordata, Prorocentrum tnicans, Peridinium sp., Goniaulax poliedra). In
Taganrog Bay, the summer complex is chiefly represented by saltwater and
genetically freshwater species of blue-green, green algae and diatoms. The
B-15
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highest specific value in the total biomass (about 90%) is formed by diatoms
(Coscinodiscus jonesianus, Thalassiosira parva) and the blue-green algae
(Aphanizomenon flos-aquae, Anabaena flos-aquae, and Microcystis sp.). The
3
phytoplankton biomass in July-August reaches an average of 1.0-3.8 g/m
in the sea and 3.3-8.5 g/m in the bay.
The third fall maximum is characterized by the attenuation of production
processes of warm-water species of algae and a new maximum in the develop-
ment of diatoms (Thalassionema nitzschiodis, Zeptoculindrus danicus,
Sceletonema costatum, Coscinodiscus jonesianus). The fall "flash" of dia-
toms is less intense'than the spring one.
In winter, the phytoplankton vegetation almost comes to a halt, and its
3
biomass amounts to 0.02-0.5 n/m . Seasonal variations in phytoplankton
composition and biomass are presented in Table 5.
The substantial phytoplankton biomass fluctuations are caused by
different responses of the leading types of phytoplankton to changing
environmental factors.
It may be considered established that the chief factors controlling the
state of phytoplankton populations are the illumination conditions, tempera-
ture, salinity, and concentrations of biogen-containing compounds in the
water.
For modeling purposes, we must know the ranges of variation of these
factors optimal for the species under consideration (Table 6), as well as
the chemical composition of the individual groups and species of phytoplank-
ton (Table 7).
B-16
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TABLE 5. SEASONAL VARIATIONS IN THE COMPOSITION AND BIOMASS (mg/m3)
OF PHYTOPLANKTON OF THE SEA OF AZOV
(Based on data for 1965-72
Name
Diatoms
Pyrophytic
Green
Blue-green
Other
Total Biomass
Total Biomass
Diatoms
Pyrophytic
Blue-green
Green
Other
April
a 1401
b 76
a 290
b 16
a 22
b 1
a 19..
b 1
b 6
1845
a 6446
b 100
a 5570
b 86
a 79
b 1
a 829
b 12
a 116
b 2
b 2
May
704
75
48
4
33
4
20
2
15
938
1501
100
844
56
103
7
120
8
100
7
2
June
SEA OF AZOV
554
58
132
14
14
1,5
4
0,4
26
961
TAGANROG BAY
3892
100
2372
61
90
2
375
10
256
7
0-,3
July
334
28
785
63
36
3
26
2
4
1247
3327
100
1856
56
260
8
923
28
243
7
1
August
1030
27
2600
68
251
6
58
1,5
• 0,5
3813
8511
100
1698
20
288
3
5941
70
139
2
0,3
October
6035
93
350
5
19
5
38
0,6
0,4
6500
7555
100
5734
76
72
1
2163
27
714
9
0,3
Note: a - biomass mg/m3
b - percent (%)
Translator's Note: Comma (,) represents a decimal point (.) here and in
other tables.
B-17
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TABLE 6. SOME CHARACTERISTICS OF Pitt TOPLANKTON SPECIES SELECTED FOR MODELING
Phase
vari-
able Name
X27
X28
X29
X30
X31
X32
W X33
£ X3"
X35
X36
X37
X38
X39
Xto
Sceletonema
Coskinodiskus
Thalassiasira
Ciclotella
Leptocylindrus
Chaetoeerus
Thalassionema
Rhizocolenia
Exuviaella
Paricebtryn
Gonianlox
Glenodinium
Peridinium
Microxystis
Aphanizomenon
Anabaena
Lynobia
Aakistrodesmus
Scenedesmus
Oocystis
costaium
fonesianus
decipiens
caspia
danicus
holsaticus
nitzschiodis
calcar-aris
cardaia
micans
v polyedra
centicula
orbiculare
aeruginosa
f los-aquae
f los-aquae
limnetica
Biological
form
Diatoms
Diatoms
Diatoms
Diatoms
Diatoms
Diatoms
Diatoms
Diatoms
Pyrophytic
Pyrophytic
Pyrophytic
Pyrophytic
Pyrophytic
Blue-green
Blue-green
Blue-green
Blue-green
Green
Green
Green
Salinity
(optimum
range (%)
10,5-13,2
10,5-12,3
12,5-13,1
5-14,3
10,5-12,3
7-13
5,2-12,8
11-12,9
9-20
9-20
9-20
9-20
9-20
10
10
10
10
8-9
8-9
8-9
Tempera-
ture
(optimum
range (%)
2-8
2,8-15
5,1-12,8
4-24,5
9,1-16,2
10-25
2-8
15-25
22-26
22-26
22-26
22-26
22-26
24-26
24-26
24-26
24-26
24-26
24-26
24-26
Nitrogen, opt.
cone, mg/1
NO 3 NHA,
0,01-0,4
0,01-0,4
0,01-0,4
0,01-0,4
0,01-0,4
0,01-0,4
0,01-0,4
0,01-0,4
0,5-0,8
0,5-0,8
0,5-0,8
0,5-0,8
0,5-0,8
0,6-0,2
0,6-0,2
0,6-0,2
0,6-0,2
5,0
5,0
5,0
0,01-0,4
0,01-0,4
On i n A
, U 1 U , f
On i c\ /.
, U 1 U ,4
0,01-0,4
0,01-0,4
0,01-0,4
0,01-0,4
0,01-0,4
0,01-0,4
0,01-0,4
0,01-0,4
0,01-0,4
0,06-0,2
0,06-0,2
0,06-0,2
0,06-0,2
0,2-0,5
0,2-0,5
0,2-0,5
Phosphorus
( optimum
concentra-
tion), mg/1
0,08-0,32
0,08-0,32
0,08-0,32
0,08-0,32
0,08-0,32
0,08-0,32
0,08-0,32
0,08-0,32
0,1-0,3
0,1-0,3
0,1-0,3
0,1-0,3
0,1-0,3
0,03-0,32
0,03-0,32
0,03-0,32
0,03-0,32
0,03-0,32
0,03-0,32
0,03-0,32
-------
TABLE 7. ELEMENTARY CHEMICAL COMPOSITION OF INDIVIDUAL GROUPS
AND SPECIES OF ALGAE
(% of dry weight)
Name of Algae Nitrogen Phosphorus
Diatoms 2.49 0.60
Pyrophytic 4.01 0.57
Blue-green 7.05 0.89
Blue-green 9.00 0.46
X
Microcvstis
aeruginosa 9.10 0.45
Nitrogen:
Phosphorus
4:1
7:1
8:1
20:1
20:1
Site of
Sampling
-
-
Sea of
Azov
Uchinskoye
storage
reservoir
Taganrog
Bay
Author
Vinogradov
1939
Vinogradov
1939
Vinogradov
1939
Guseva
1963
Aldakimova
Ka si nova
1962
Zonpl.ankton '
The zooplankton of the Sea of Azov consists of 185 species pertaining to
marine, saltwater relict and freshwater complexes. The sea itself is in-
habited mainly by marine forms and some saltwater forms. The copepods
Calanipeda aquae-dulcis, Ascartia clausi, Acartia latisetosa, Centropages
ponticus are widely distributed; Synchaeta sp. dominate among rotifera, and
among cladocerans, Podon polyphemoides. Until recently, the freshwater and
saltwater organisms Daphnia longispina, Bosmina longirostris, and Calanipeda
aquae-dulcis, etc., dominated in Taganrog Bay. At the present time, because
of the salinization of the waters of the sea and bay, the freshwater com-
plexes have lost their leading role.
B-19
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Despite the abundance of zooplankton species inhabiting the Sea of Azov,
the bulk of the zooplankton biomass (up to 80%) is made up of two to three
dominant species during each season. A definite seasonal change of dominate
groups is also observed.
The early-spring plankton of the sea is chiefly represented by rotifers
of the genus Synchaeta (76% of total biomass). Later in the season, Balanus
larvae, which account for up to 63% of the total biomass, dominate. The
start of massive development of copepods, whose biomass amounts to over 20%,
is attributed to that period.
In Taganrog Bay, the copepods comprise 50% of the total zooplankton in
spring.
Copepods predominate in the sea in summer, making up 56% of the zoo-
plankton biomass. In Taganrog Bay, the summer dominants are Cladocera
(46%), and also Calanipeda aquae-dulics (34%). By autumn, the fraction of
copepods in the open sea drops to 26%, whereas the amount of Balanus larvae
and rotifers increases. In the bay, a homogeneity of the zooplankton
composition, 80% of which is represented by Calanipeda aquae-dulcis is
observed at that time. :
In winter, a small number of species with a well-defined dominance of
copepods is observed in both the sea and bay. The annual variation of bio-
mass is shown in Table 8.
B-20
-------
TABLE 8. VALUES OF VARIOUS GROUPS AND SPECIES OF INVERTEBRATES IN
ZOOPLANKTON OF THE SEA OF AZOV
(% of mean biomass for 1969-73)
Months
Organisms
Synchaeta .
Calanipeda aquae-dulcis
Apr May July Oct
Taganrog Bay
32 5 61
35 34 52
Apr May July Oct
Sea of Azov
76 7 8 1.3
3-64
Acartia clausi
(Azov and Black Seas)
Centropages kroijeri
Balanus larvae
Other
47 15.4 24
_ _ _
18
21 26.6 36
30
0.7
5
21.3
10 19
- -
63
14 8
59
7
_
26
21
-
3.3
10.4
As is evident from the above, the dominant zooplankton species of the
Sea of Azov include: among copepods - Acartia clausi, Calanipeda aquae-
dulcis, Centropages kroijeri; among rotifers - Synchaeta sp.; among clado-
cerans - Podon polyphemoides, as well as the periodically appearing larvae
of the zoobenthos Balanus.
We will present some data on the ecology of these species, used below
for modeling purposes.
The most significant factors affecting the formation of a biocenosis are
salinity and temperature. The tolerance ranges and optimum ranges of the
values of these factors for various species are analyzed in Table 9.
B-21
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TABLE 9. RANGES OF ABIOTIC FACTORS AFFECTING THE SURVIVAL RATE
OF ZOOPLANKTON
Species
Acartia
clausi
Calanipeda
aquae-
dulcis
Centropages
kroi jeri
Synchaeta
sp.
Podon poly-
phemoides
Balanus
larvae
Salinity
range for
survival
rate
5.0-14.5
1.0-13.0
8.5-14.0,.
0.5-12.0
6.5-12.4
5-30
Temperature
range where
the species Optimum Seasons when the
Optimum develops Tempera- species is pre-
salinity normally tures sent in plankton
10.0-12.0 10°-25° 23°-25° year round
4.0-7.0 9°-25° - year round
11.5-12.4 10°-25° 16.5°-17° heat-loving form
5-6 months
8.0-11.0 - 5°-10° April-May and
Septebmer-
October
11.5 ll°-25° 14°-16° April and
October
10-12 - 14° -16° April-May and
September-
October
During their development, the zooplankton organisms go through three
successive age stages: nauplii (the smallest young individuals), more
mature ones - copepodites, and finally, imagoes - adults. For modeling
purposes, it was found useful to distinguish three age groups for copepods,
since different processes take place in them at different rates. For the
remaining zooplankton species, however, whose lifetimes are much shorter,
the age structure is not considered. The times spent by the zooplankton
organisms in the various age groups are indicted in Table 10.
B-22
-------
TABLE 10. DEVELOPMENT TIME OF VARIOUS STAGES OF ZOOPLANKTON
Species
Acartia clausi
Calanipeda aquae-dulcis
Centropages kroijeri
Synchaeta sp.
x
Podon polyphemoides '
Balanus larvae
Stage
nauplii
copepodites
adults
nauplii
copepodites
adults
nauplii
copepodites
adults
Lifetime at 20°
8
20
60
12
11
21
10
17
59
20
20
14
The duration of these periods depends on temperature, and is consistent
with Krog's curve. ;
Another index - the reproduction rate - is closely related to the ther-
mal regime of a body of water. The zooplankton of the Sea of Azov repro-
duces over the course of the entire warm period (from April through
October). The rate of this process also depends on the organisms' food
supply, but it may be assumed as a first approximation that the food factor
is not the most important one, and the influence of thermal conditions on
the reproduction rate can be taken into account by means of Krog's tempera-
ture corrections.
Table 11 gives values of reproduction rate coefficients calculated from
the data of Ref. 3.
A key role in the process of zooplankton biomass variation is played by
the nutrition process.
B-23
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TABLE 11. REPRODUCTION RATE COEFFICIENTS
Reproduction rate coefficient (kR) at t = 20°
Species of the region
Acartia clausi Sea 5(Taganrog Bay) 6(Taganrog Bay) 7(Taganrog Bay)
0.02 0.05 0.07 0.07
Calanipeda
aquae-dulcis at t° > 9°
24°, 0.03 otherwise 0.01
Centropages
kroijeri 0.04 0.05 0.05 0.05
Podon poly-
phemoides 0.04 0.01 0.01 0.01
Synchaeta sp. at t° > 18°
0.01
Balanus
larvae -
Phytoplankton and detritus form the basis of zooplankton's ration. From
the phytoplankton, small cells up to 100 microns in size are consumed. In
spring and autumn, their deficiency is compensated by detritus, which amounts
to 70-80% of the weight of a food particle. In summer, when the development
of small algae reaches a maximum, they dominate in the ration of the zoo-
plankton, but the role of detritus is a major one, as before. The consump-
tion of live feed by the zooplankton is insignificant.
The amount of feed consumed by the zooplankton is calculated on the basis
of data on the amount of energy required to cover expenditures on the energy
metabolism (respiration and search for food), and also for the formation of
new biomass at the expense of both the growth of the organism and reproduc-
tion.
If one knows the food assimilability coefficients, which are listed in
Table 12 on the basis of Ref. 5, and coefficients of food utilization for
B-24
-------
TABLE 12. EXPENDITURES ON METABOLISM AND COEFFICIENTS OF ASSIMILABILITY (u)
AND FOOD UTILIZATION FOR GROWTH (K2)*
Species,
stage of
Development
Acartia
Calanipedo
Centropages
Synchaeta
Copepoda
nauplii
Copepoda
copepodites
Balanus
larvae
Weight of
one specimen
yg
12 , 9
13,4
14,5
54,7
54,7 .,
54,7
19,5
6,2 .!
8,8
M :
1,4
1,2
3,6
3,6
3,6
15,5
15,5
15,5
Temperature
°C
13-14
18-20
21-23
8-11
13-15
22-23
21-23
14-16
23-24
13-15
.14-16
22-24
9-11
14-16
23-24
11-13
21-22
24-25
Expenditures by days
one specimen
Ug %
5,31
6,63
7,09
17,9
20,2
15,2
6,5
2,69
5,33
0,96
1,08
1,39
1,56
4,98
2,50
2,43
4,61
6,54
41,2
49,5
48,9
32,7
36,9
27,8
33,3
43,4
60,5
68,4
77,1
115,8
43,3
138,3
69,3
16,0
29,7
48,9
K2
0,11 0,77
0,11 0,77
0,08 0,77
0,11-0,28
0,77
0,23-0,36
0,77
0,3 0,8
0,4 0,48
*Data kindly supplied by Ye. I. Studenikina.
B-25
-------
growth (Table 13) for each age froup of the zooplankton, then by using the
relations given in Ref. 5 and 14, one can formulte the maximum rations, i.e.,
the maximum amount of food (in calories) that can be consumed by the corre-
sponding zooplankton group.
TABLE 13. FUEL VALUE AND DRY SUBSTANCE CONTENT OF VARIOUS
SPECIES OF ZOOPLANKTON (5)
Calorific value of
1 mg of dry
Species substance
Acartia clausi
Calanipeda aquae-dulcis
Centropages kroijeri
Synchaeta sp.
Podon polyphemoides
Balanus larvae
5,6
5,6
4,86
5
5,6
5
% content of dry
substance in
the organism
12,6
15,8
17,9
10,2
20,0
15,0
Benthos
Up to 180 species of zoobenthos are counted in the Sea of Azov. In the
last few years, the dominant species have been Cerastoderma (Carium), Abra
(Syndesmya), Hydrobia, Mytilaster, Corbulomya, Balanus, Nephthys, Nereis.
The principal ecological factors determining the character of distribu-
tion of the bottom fauna and subsequently considered in the model are the
following: '
(1) Salinity of the water
(2) Oxygen regime
(3) Status of ground
(4) Food availability
(5) Temperature regime
B-26
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Tables 14-16 give information on the influence of the first three fac-
tors on benthos organisms.
TABLE 14. FAVORABLE SALINITY CONDITIONS FOR ZOOBENTHOS SPECIES
OF THE SEA OF AZOV (salinity in 0/00)
Species
Cerastoderma
Abra
Mytilaster
Corbulomya
Balanus
Hydrobia
Nephthys
Nereis
Tolerant
7,5
9,9
8
9
7.5
5
8
5
- 30
- 25
- 20
- 17,5
- 17,5
- 30
- 30
Optimum development
conditions
8.5 -
9 -
10 -
10 -
10 -
7.5 -
10 -
7 -
10.5
10
11
11
12
9
12
10
TABLE 15. LOWER OXYGEN THRESHOLD FOR THE MASS OF BOTTOM INVERTEBRATES OF
THE SEA OF AZOV UNDER SALINITY CONDITIONS FAVORABLE TO EACH SPECIES
Species
Cerastoderma
Abra
Corbulomya
Hydrobia
Nereis
Mytilaster
Balanus
Nephthys
Salinity
0/00
10-20
10-15
10-15
10-20
12-14
Lower oxygen
threshold
(ml/1 of 02)
1,5
1,5
3
1
0
0
- 2,0
0
0
_ 2*
- 3,5*
_ 2*
Length of survival
in oxygen-free
water (hours)
33-58
96-168
0 (18-34%
per day die)
150-170
360
240-288
*Experimental data for these species are lacking, the table gives data for
the corresponding genus of hydrobionts.
B-27
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TABLE 16. GROUND TYPES FAVORABLE TO THE LIFE OF BENTHOS ORGANISMS
OF THE SEA OF AZOV
Type of Ground
Liquid gray
with no
shelly
admixture Slurry
Species
Stones Shells Sand Mudstone
Cerastoderma
Abra
Corbulomya
Hydrobia
Nereis
Nephthys
Mytilaster
Balanus
Note: ++ preferred types of soil.
Benthos organisms feed mainly on detritus and to a lesser extent on phy-
toplankton and bacteria. As a rule, animal food comprises a very minor part
of the ration, since there are no predators among the bottom fauna of the
Sea of Azov.
TABLE 17. COMPOSITION OF FOOD OF THE MAIN SPECIES OF BENTHOS IN THE
SEA OF AZOV
Species
Cerastoderma
Abra
Mytilaster
Nereis
Nephthys
Algae
2,0
15,4
4,2
12,0
0,4
Type of food in % by weight
Animal Food Detritus
97,7
84 , 3
95,4
1,2 86,5
0,7 98,0
Bacteria
0,3
0,3
0,35
0,5
B-28
-------
The temperature regime of a body of water determines the irate of many
biological processes: growth, development, basal metabolism, nutrition, re-
production, etc. As the temperature increases to 25°, the rate of these
processes increases, and as the temperature rises further, the vital func-
tions of zoobenthos are depressed. The amount of food consumed is deter-
mined by the presence of feed and by the water temperature. To calculate
the maximum rations, it .is necessary to have information on expenditures on
energy metabolism and coefficients of food utilization for growth and
assimilability of the food, as given in Tables 18-20.
TABLE 18. OXYGEN CONSUMPTION Q BY BOTTOM INVERTEBRATES FOR
THE SEA OF AZOV
Species
Cerastoderma
Abra
Corbulomya
Mytilaster
Hydrobia
Balanus
Nereis
Nephthys
Tempera- Salinity
ture (°) 0/00
24 10-20
10-15
19 10-15
19 10-20
25 ; 12-14
Consumption of
02, m//h per 1
g of weight
0,050
0,08
0,068-0,076
0,072
0,06
Dependence of Q£
consumption (ml/h)
as a function of
weight (w) in g
at 20°C
=0,105
=0,041
=0,078
=0,095
=0,980
0,63
0,610
0,754
0,4
0,81
B-29
-------
TABLE 19. COEFFICIENTS OF FOOD UTILIZATION FOR GROWTH (K2) AND FOOD
ASSIMILABILITY (u) FOR VARIOUS BENTHOS GROUP
Organisms
Mollusks (Cerastodenna, Abra,
Corbulomya, Mytilaster, Hydrobia)
Crustaceans (Balanus)
Worms (Nereis, Nephthys)
K2(for average population)
0.3-0.4
0.3-0.4
0.54-0.73
u
0.4-0.6
0.4-0.8
0.64
To calculate the production of zoobenthos at the expense of nutrition,
information is also necessary on the average fuel value of benthos inverte-
brates given in the table below.
TABLE 20. FUEL VALUE OF MAIN REPRESENTATIVES OF ZOOBENTHOS IN
THE SEA OF AZOV (green weight)
Species Fuel value, kcal/g
Cerastoderma 0,216
Abra 0,684
Corbulomya 0,240
Mytilaster
Hydrobia 0,580
Balanus 0,486
Nereis 0,700
Nephthys
In contrast to the zooplankton discussed in the preceding section, ben-
thos information on periods and rates of reproduction and on fluctuations of
various characteristics for age groups is much less complete.
In this connection, despite the fact that the lifetime of. benthos
organisms is only a few years (Table 21), no age division was introduced
B-30
-------
into the model. This rough approximation is substantially attenuated by the
fact that the seasonal change of species is not related to age, but is
determined by the aforementioned ecological factors.
TABLE 21. LIFETIME AND DATA ON THE REPRODUCTION CYCLES OF THE MAIN
REPRESENTATIVES OF BENTHOS ORGANISMS IN THE SEA OF AZOV
Species
Lifetime,
years
Data on reproduction character
Cerastoderma
Abra
Hydrobia
Mytilaster
Corbulomya
Balanus
Nephthys
Nereis
1.5-2
8
3
2-3
3 times a year starting at age 2 years,
most intensively by 3-4 year olds. In
May, over 70% of individuals.
Starting with age 3 years, twice a year;
in June and August-September.
In March-April - individuals older than 2
years; in May-June - one year olds; in
autumn - 2-3 year olds.
In the first and second year of life, for
10-12 days:
(1) from 16 to 20 June (t > 17°)
(2) from 10 to 23 July
(3) from July to August.
Year round, most intensively at t = 14-16'
in May-June and October.
In the seasonal dynamics of the biomass of bottom invertebrates in the
Sea of Azov, an increase in population and biomass is observed from spring
to autumn. The spring biomass usually amounts to 1/3 - 1/2 of the autumn
biomass of the previous year. The decrease in biomass in the course of the
winter season is chiefly due to the natural death rate of the individuals
which reached their age limit. In particularly unfavorable years, the loss
B-31
-------
of benthos biomass from autumn to the following spring may reach 48-71%,
but on average, 40% of the zoobenthos biomass dies off.
TABLE 22. SEASONAL VALUES OF DAILY PRODUCTIVITY COEFFICIENT (P/B)
P/B - coefficient (daily)
Species
Spring
Au tumn
Average
P/B-Annual
Cerastoderma
Abra
Hydrobia
Mytilaster
Corbulomya
Balanus
Nephthys
Nereis
0,0018
(t° = 10°)
0,0064
(t° = 15°)
0,.005
0,014
0,006
0,09
0,0022
0,03-0,19
0,03-0,19
3,9
2,05
3,22
1,1-2,8
1-4,76
Fish Populations
The Sea of Azov is inhabited by 104 species of fish. Since there is de-
finitely no point in working out a separate model for each of these species,
the following scheme was adopted: some of the populations were modeled in-
dividually, and the others were combined into a single unit for more ap-
proximate modeling. In accordance with this breakdown, we will present the
necessary information on the ecology of the fish populations.
ROUND GOBY
The round goby is indigenous to the Sea of Azov and a typical repre-
sentative of the saltwater Pontian faunistic complex. It is capable of
tolerating a fairly wide range of salinity, occurring in both freshwater
B-32
-------
and waters with 18-20 /oo mineralization. The optimum salinity interval
for its reproduction is 10-13 /oo. The concentrations of the round goby
in any given zone are also determined by other factors: nature of ground
(it prefers dense, muddy, sandy and shelly grounds), content of oxygen dis-
solved in the water, water temperature, and composition and quantity of
available food. The population's habitats do not remain constant owing to
seasonal migrations.
Most round goby individuals reach an age of 3-4 years, and only some, 5
years. The population structure of the round goby is determined by the
proportions of the age' groups, and primarily by the yield of its young. As
a rule, the generation of the current year's young is the most numerous one
(Table 23). With increasing age, the population of the age groups de-
creases, and by the 4th year the death rate reaches 95% (Table 24).
TABLE 23. CHARACTERISTICS OF THE ROUND GOBY POPULATION
Periods
Index
1957-1962
1963-1969
1970-1973
Biomass, thousand
tons
Total population,
billions
Area, percent of
sea area
Age groups
Population of
groups, °/0
Length, mm
Weight, g
102,6
7270
86
1+ 2+ 3+
65 31 4
81 104 112
15 32 39
78,8
4488
72
1+ 2+ 3+
62 35 3
75 97 105
12 24 29
25,8
2173
60
1+ 2+ 3+
79 19 2
78 91 101
13 19 25
B-33
-------
TABLE 24. CHARACTERISTICS OF THE DEATH RATE OF THE ROUND GOBY (%) IN
THE COURSE OF A LIFE CYCLE (according to data for 1961-75)
Index
Total loss, including:
Fishing
Natural
1+ - 2+
61,7
14,8
46,9
Years
2+ - 3+
89,9
17,4
72,5
of Life
3+ - 4+
94,2
14,9
79,3
4+ - 5+
100
5,7
94,3
The round goby reaches sexual maturity at the age of 2-3 years. The
entire sexually mature part of the stock spawns. Approaches of the fish to
the spawning grounds begin with the warming of the water in the coastal
zone to 7°, which usually occurs in April, and the migration to the spawning
grounds becomes massive in April-May, when the water temperature reaches
10-12°. Spawning begins in April and continues until the end of August,
which corresponds to a water temperature from 10 to 25°. The spawning is
heaviest in May-June at a water temperature of 15-18°. The roe is laid in
*
several batches, as many as 5 to 6. The entire maturation cycle of the egg
batch and its casting last 15-20 days. Between castings of the egg batches,
the females travel to the spawning grounds and feed in the coastal band of
the sea. The fertility of the round goby changes according to the size and
age of the fish, amounting to an average of 1.5 for one-year olds, 2.2 for
two-year olds, 3.0 for three-year olds, and 2.0 thousand eggs for four-year
olds.
The reproduction efficiency of the round goby is determined by a com-
bination of factors: content of oxygen dissolved in the water, sea state,
silting of spawning grounds, consumption of fish eggs by predators, and
status of nutritive base. ' A very essential condition is the propor-
tion of the sexes in the spawning stock.
B-34
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After spawning, the round goby leaves the coastal zone and begins to
pasture actively.
About 85% of the stock pastures in the northeastern part of the Sea of
Azov. At the same time, it is the object of fishing. From 15 September to
1 December, up to 30% of the stock is caught. The round goby winters in the
same area where it pastures in autumn.
The principal food items of the round goby are zoobenthic organisms -
mollusks (87.8%), worms (4%) and bottom crustaceans (6.2%). The young feed
mainly on bottom crustaceans - mysids, ostracods, copepods, etc., whose
fraction decreases from 100% for a body length of 20 mm to 40% for a body
length of 50 mm as the size of the individuals increases. The round goby
becomes a typical benthophage after reaching a length of 5 cm, when the
mollusks in its ration are already as high as 60%. Individuals over 7-8 cm
in size feed mainly on various mollusks, which make up 75-90% of their
ration. For a food factor of 22.5-23, the round goby population can consume
up to 60% of the production of feed benthos on the water area of the Sea of
Azov.
TABLE 25. VARIATION IN THE COMPOSITION OF THE FOOD OF THE ROUND GOBY
WITH ITS SIZE (% of frequency of occurrence)
Organisms 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Mollusks 27 38 51 71 75 80 82 84 83 83 85 82 81 67 83 87
Crustaceans 100 78 57 46 25 18 14 9, 8 8 9 6 8 12 13 7 6
Worms 534657 5 5 3 2 5 3 8
Fish : 112345754 12 10 7
B-35
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The feeding intensity decreases with increasing size and age of the fish
(Table 26) and substantially depends on the water temperature in the pasture
regions.
TABLE 26. MEAN DAILY RATION OF THE ROUND GOBY AT DIFFERENT AGES
(% of body weight)
One-year olds - 5.4 Two-year olds - 4.11 Three-year olds - 3.9
The minimum rations are observed in winter (hundredths of one percent),
and the maximum ones, in summer (7.8-10.3% of body weight).
Azov round gobies' are subjected to wide temperature fluctuations, from
0 to 28°. At a water temperature above 5-6°, they lead a mobile life,
wandering in search of food. When the water temperature is below 5-6°, they
become sluggish and practically stop feeding.
An intensive growth of the round goby is observed at the end of spring
and the beginning of summer, and the growth slows down drastically in July-
August. The growth rate of the round goby also changes with increasing age:
it grows most intensively during the first years of life.
TABLE 27. LINEAR AND WEIGHT GROWTH OF THE ROUND GOBY
Age, Years
Sex
FEMALES
MALES
Parameter
Length, mm
Increase, mm
Weight, g
Gain, g
Length, mm
Increase, mm
Weight, g
Gain, g
0+
65
65
3.4 ,
3.4
65
65
3,5
3,5
1+
95
30
14.5
11.1
109
41
26,1
22,6
2+
111
16
21.7
7,2
132
23
41,5
15,4
3+
121
10
33.8
6,1
151
19
51,8
10,3
4+
125
4
36.8
3,0
_
-
-
B-36
-------
ANCHOVY (Azov Type)
The anchovy is one of the most numerous fishes of the Sea of Azov,
second only to the sardelle in population numbers. The mean annual quanti-
tative indices of the anchovy stock fluctuate over wide limits: a popula-
tion of 9 to 107 billion individuals and a biomass of 30 to 560 thousand
tons. Such a wide amplitude in population and biomass variations is due to
a clear-cut dependence of the anchovy's vital activity processes on external
factors, primarily the temperature regime.
The Azov anchovy - Engraulis encrasicholus macoficus - is one of two
9
subspecies of the European anchovy inhabiting the Azov-Black Sea Basin.
This is a typically marine, pelagic, heat-loving fish found at water
temperatures from 6 to 28°. When cooled to 5-6°, it grows torpid and dies.
For this reason, the anchovy inhabits the Sea of Azov only during the warm
period of the sea, migrating to the Black Sea for the winter. Thus, the
Azov anchovy is characterized by well-defined migrations, which constitute
an adaptation to the temperature regime within the confines of its range.
The change in sea regime and the establishment of a new level of biolo-
gical productivity, reduced in comparison with 1931-51, which have occurred
in the last few decades, have caused corresponding changes in the size, bio-
mass and structure of the anchovy population (Table 28).
All this - a large size of the stock, substantial fluctuations in num-
bers and biomass caused by the population's sensitivity to external condi-
tions, and identified negative changes in anchovy stock due to the change in
the sea regime - determines the important role of the ANCHOVY block in the
SS.
B-37
-------
TABLE 28. BIOLOGICAL CHARACTERISTICS OF AZOV ANCHOVY POPULATION
Periods
1931-1951
Indices
Biomass ,
thousand tons
Population,
billions
Total, including
young
Total, including
young
From
80
20
30
12
To
420
140
117
56
Av.
220
60
64
31
1952-1959
From
30
10
9
1
To
220
50
59
45
Av.
100
20
30
14'
1960-1969
From
30
5
11
3
To
540
110
89
42
Av.
220
40
46
21
1970-1975
From
163
6
33
3
To
376
108
75
64
Av.
297
51
60
18
Total, including
young
Production in Sea
of Azov during Apr-Oct *
thousand tons
Ratio of production to biomass
(P/B coefficient)
0+
1+ - 4+
Average population
of age groups, %
Average body length, mm
Average body weight, g
50 290 170
30 170 70
0,78
2 100 60
3 60 25
0,64
2 290 150
7 130 60
0,67
118 235 184
10 110 56
0,62
54,6
45,4
69,4
3,83
44,0
56,0
75,0
4,25
46,9
53,1
69,2
3,90
47,0
53,0
80,4
5,2
-------
We will describe the annual cycle of the anchovy, placing particular
emphasis on the dependence of its vital activity processes on the variation
in water temperature, which is its most important ecological factor.
The anchovy hibernates in relatively immobile assemblages, practically
without feeding. As soon as the Black Sea waters begin to warm up, the
anchovy becomes mobile and begins migrating in the direction of the Kerch
Straits. The anchovy's migration through the straits into the Sea of Azov
usually begins as the temperature passes 8°, although it can also begin at
6 (late March - early April) and, depending on the character of spring,
last from 18 to 52 days. The mass movement of the fish through the strait,
lasting an average of 22 days, is observed at an average water temperature
of 10-15° and ends when the waters of the strait and adjacent regions of
the sea warm up to 16-16.5° (most frequently in late April and the first 20
days in May). During the period of mass movement, 58-99.8% of the spawning
population, or an average of 84.6%, penetrates into the Sea of Azov. During
migration in the Black Sea and the zone of the Kerch Straits, the anchovy's
feeding rate is extremely low.
After passing the Kerch Straits, the anchovy becomes distributed over
the water area of the Sea of Azov. The anchovy's distribution is determined
by the warming patter of the water and location of the isotherms: the fish
avoids regions where the water is colder than 10-14°. In the second half
of May, the anchovy is ually found over the entire water area of the sea;
it also penetrates into Taganrog Bay, where its distribution is determined
by the mineralization of the water to a greater extent than in the other
regions of the sea: the anchovy avoids freshened regions (where the
salinity is below 7-8 /oo).
B-39
-------
The process of prespawning pasturing occurs simultaneously with the
distribution over the water area. The anchovy feeds actively, consuming
phytoplankton and plankobenthos organisms (Table 29).
TABLE 29. COMPOSITION OF THE FOOD OF THE AZOV ANCHOVY
(% by weight of food particle)
Organisms
Zoop lank ton
Phy toplankton
Benthos
April-May
35,7
19,5
44,8
June
39,8
31,0
29,2
July
60,9
31,3
7,8
August
46,3
18,9
34,8
September
33,6
48,3
18,1
Since the anchovy feeds by filtering out food items present in the
water, the organisms prevailing in its ratin are of species whose density
in the pelagic zone is highest at that time. The food factor of the anchovy
9
amounts to 8-11 weight units of feed per unit gain.
Reproduction of the anchovy begins when the water warms up to 16-18°
(usually in the second half of May). An intensive spawning of the anchovy
can take place over a wide temperature range, form 18 to 24°. According to
observational data, the most intensive spawning takes place in late May -
June. In July, the amount of eggs in the plankton drops abruptly, and in
August it is found only rarely.
Since all the anchovies mature at the age of one year, and their life-
time is short, the structure of the spawing population is determined by the
productivity of two successive generations, one of which matures in the
current year. According to long-term data, the age structure of the
spawning population is as follows: one-year olds - 60.1%, two-year olds -
37.1%, three-year olds - 2.8%, four-year olds and older - 0.01%. The age
composition of the spawning population undergoes substantial changes every
B-40
-------
year. Thus the relative population of one-year olds changed from 25.9 to
89.1% in the course of the last decade. The size-weight parameters of the
population are also subject to a similar variability (Table 30).
TABLE 30. SIZE AND WEIGHT OF SPAWNING ANCHOVY POPULATION
(Based on June estimated data)
Average lenght at age, mm
Year
1967
1968
1969
1970
1971
1972
AVERAGE
1+
80.0
91.5
82.4
82.6
88.7
86.0
86.2
2 +
98.5
98.1
97.8
98.2
97.0
101.1
98.5
3+
109.7
103.9
106.7
111.0
120.9
116.6
110.0
4+
125.0
113.9
117.3
123.8
128.5
-
123.3
Weight at age, g
1+
5.3
6.7
5.1
5.3
6.3
5.4
5.8
2+
8.2
8.1
8.3
8.3
8.0
8.9
8.3
3+
10.6
9.3
9.3
13.3,
11.9
13.6
11.3
4+
16.4
11.6
13.3
13.3
20.0
-
15.7
Anchovy fry, feeding mainly on young copepods have a high growth rate:
their length increases by approximately 1 mm in 24 h. By autumn, the young
anchovies may already have grown to 65-75 mm. By that time, the feeding of
the young is practically the same as that of sexually mature fish.
After completing its reproduction, the anchovy begins to feed inten-
sively, and usually manages to accumulate considerable energy reserves in a
short period of time.
Pasturing of the stock is determined by the status of the feed base and
the length of time elapsed from the completion of spawning to the autumn
cooling of waters of the Sea of Azov, when the migration of the anchovy to
the 1st and 2nd regions of the sea and the exodus to the Black Sea through
the Kerch Straits begin. The migration dates are determined not only by
the temperature regime of the waters, but also by the fatness of the stock.
B-41
-------
However, the influence of this factor has been inadequately studied and is
slight in comparison with the importance of cooling of the water, and there-
fore in the modeling, the process of autumn migration may be assumed to be
dependent solely on temperature. The water temperature varies from 9 to 15°
during the period of the mass migration, which ends most frequently at 7-
10°. It can be stated fairly definitely that as the temperature in the
area of the sea before the straits drops to 15°, the process of accumulation
of the anchovy in this region and its further migration through the strait
begin.
The dates of egress of the young and sexually mature anchovy from the
Sea of Azov differ. Observational data for the autumn migration of the
anchovy are summarized in Table 31.
TABLE 31. DATES OF AUTUMN MIGRATION OF THE AZOV ANCHOVY THROUGH THE
KERCH STRAITS
Young
Sexually mature fish
Duration
Days
Dates Start
Earliest 19 Jul
Latest 28 Sep
Average 12 Aug
Mass
migration
16 Aug -
16 Sep
13 Oct -
20 Nov
16 Sep -
19 Oct
Mass
Start migration end Total
20 Sep 3 Oct - 1 Nov 28
19 Oct
6 Nov 15 Nov - 9 Dec 62
3 Dec
10 Oct 19 Oct - 19 Nov 42
6 Nov
migra-
tion
3
35
19
Fishing for the anchovy is done during the autumn migration and to a
lesser extent at hibernation sites in the Black Sea.
Table 32 gives an idea of the average level of fishing and its fluctua-
tions in different periods.
B-42
-------
TABLE 32. REMOVAL OF ANCHOVY BY FISHING ACCORDING TO PERIODS OF FISHING
DEVELOPMENT IN THE AZOV BASIN
Period
1946-1955
1955-1973
Index
1930-1940
From To Av. From To Av. From To Av.
Biomass, thousand tons
Reserve, thousand tons
Production
Catch
Total of
portion of
stock,.-caught
Thousand tons
% of biomass
% of total
production
116 288 184,2 47 330 208,0 32 562 178,5
32 324 122,4 26 400 168,0 16 545 143,4
63 242 158,4 22 290 138,4 30 292 123,0
3,4 169 86,3 15 233 84,8 8 262 71,3
14,6 83,1 48,8 3,5 80,5 45,3 5,9 141,7 62,1
11,1 35,5 26,5 7,5 63,8 21,8 15,5 68,5 31,2
12 66
31
16
77 33
13 75 46
B-43
-------
The structure of the catch of the Azov anchovy is determined by the
character of its autumn migration. Each year at the start of fishing
(October), the young and adult anchovies migrate simultaneously, causing
substantial catches of young. At the present time, the fraction of young
in the catches (in numbers of fish) amounts to an average of 24%.
Average death rate indices of the anchovy for the same "average" genera-
tion, including removal by fishing, shows that the highest natural death
rate of the anchovy (about 50% of the numbers of the generation) is ob-
served during the 3rd and 4th years of life, and the largest removal by
fishing is observed during the lst-2nd year of life (Table 33).
To estimate the natural death rate during the winter-spring period, use
was made of material on the difference in the data of an absolute estimate
of anchovy of the same generation in August and June of consecutive years
without removal by fishing, expressed in % (Table 34).
SARDELLE
Sardelle - Clupeonella delicatula delicatula (Nordmann) - the most
numerous species in the Sea of Azov, is a short-cycle fish. As a rule, its
lifetime does not exceed 3-4 years, and only isolated individuals attain
the age of 5-6 years. Fluctuations in generation productivity are well-
defined, and strong generations surpass weak ones in numbers by a factor of
over 10.
The quantities and biomass of the safdelle in the Sea of Azov have been
determined from 1931 to the present time. During this period, numerous
changes in sea regime occurred which were reflected in the status of the
sardelle population (Table 35).
B-44
-------
TABLE 33. CHANGE (%) IN THE RESTOCKING OF ANCHOVY DURING ITS LIFE CYCLE
(Based on data for 1932-72)
Popu- Remain- Popu- Remain- Popu-
lation der of lation der of lation
of 1st
year
1st-
year
of 2nd
year
2nd-
year
of 3rd
year
Index
fish on fishing fish on fishing fish on
1 Sept season 1 Sept season 1 Sept
Remain-
der of
3rd-
year
fishing
season
Popu-
lation
of 4th
year
fish on
1 Sept
Remain-
der of
4th-
year
fishing
season
Popu-
lation
of 5th
year
fish on
1 Sept
Remarks
Population of generation 100.0 87.9 70.8 54.2
Removal 12.1 29.2 45.8
Including:
Fishing industry 12.1 16.6
Natural loss 17.1
w
I Number of observation
w years
Population of generation
Removal
Including:
Fishing industry
Natural loss
27.6
72.4
27.4
72.6
0.2
26.6
2.0 2.0 0
98.0 98.0 100.0 For entire ob-
servation
series
25.4 2.0
36
100.0
36
87.9
12.1
35
69.0
31.0
35
40.6
59.4
34
24.1
75.9
31
23.1
76.9
31
1.7
98.3
22
1.6
98.4
22
0
100.0
12.1 29.4
18.9
1.0
16.5
Number of observation
years 36 36 22 22
14
22.4
14
0,1
14
1.6
12
Series ne-
glecting years
with entries
of Black Sea
anchovy and in
wliich the gen-
erations are
not adequately
considered.
-------
TABLE 34. NATURAL DEATH RATE OF ANCHOVY FROM SEPTEMBER TO JUNE
ACCORDING TO AGE GROUPS (%)
Years
1968-1969
1969-1970
1970-1971
1971-1972
TABLE 35.
Years
1930-1940
1945-1951
1952-1958
1964-1975
0+ - 1+
45,0
18,0
17,3
14,2
SARDELLE STOCK AND
DEVELOPMENT
Stock
thousand tons
465
463
412
454
1+ - 2+
42,5
17,0
23.0
18.3
CATCHES ACCORDING TO PERIODS
OF AZOV FISHING
Catch
Thousand tons %
59,3
63.2
66.8
62.0
2+ - 3+
66,6
77,5
72.0
OF
of stock
12,8
13.7
18.2
13.7
In the last two years (1974 and 1975), the sardelle biomass is at the
lowest level for the observation period, i.e., 200-230 thousand tons.
In the sardelle population, three age groups with different ecological
characteristics are distinguished: fry (up to 4-5 months), young fish (up
to 2 years) and sexually mature individuals.
Hibernation of the sardelle - young and sexually mature individuals -
takes place in central regions of the Sea of Azov at depths of 10 m or
more. Fishing for the sardelle is usually carried out at that time. Fairly
accurate data are available on the size o'f removal by fishing for 1931-75.
Hibernation assemblages are usually formed in December, when the water
temperature is 2-4°. The better the fish are prepared for hibernation and
the lower the wind activity above the sea surface, the earlier and the
higher the water temperature at which the sardelle concentrates in an
B-46
-------
assemblage. During cold winters, when the sea surface becomes covered with
stationary solid ice, the sardelle is characterized by a high natural death
rate.
In late winter and early spring, the hibernation assemblages begin to
break up, indicating the start of spawning migration.
Spawners first begin to approach the spawning grounds at a water
temperature of 4-5°. As the water warms up, the strength of the spawning
run increases, reaching a maximum at 10-15° (second half of April -
beginning of May).
The sardelle spawns in freshened regions of the sea (with a salinity up
to 7-9%). However, its main spawning ground, where practically the entire
population is reproduced, is Taganrog Bay.
Reproduction of the sardelle takes place over a fairly wide temperature
range, from 6-8 to 25°. It is most intense in late April-May at a water
temperature of 14-19°. The reproduction period of the sardelle lasts mainly
from April to July.
The fertility of sardelle spawners varies over wide limits. In 1963-69,
it ranged from 3.9 to 28.2 thousand eggs in fish of different size, and
in 1973-75, from 2.3 to 19.9 thousand. All of the eggs are usually cast
forth in three batches.
In most cases, the development of sardelle larvae (less than 10 mm long)
takes place in slightly saline water (1-7%). Large larvae are more euryha-
line and live at a salinity up to 10-12%.
Data on the distribution of the Azov sardelle for the past decade and a
half show that in spring, up to 80% of the population lives in water areas
with a salinity up to 7-9%, in August - 9-14%, and in October - 10-13%.
B-47
-------
The majority of the young fish remain within the confines of freshened
zones of Taganrog Bay during the summer period.
The fastest growth rate characterizes the sardelle during its first
year of life, when its size reaches 45-55 mm in the course of the vegetation
period. The weight growth of the sardelle is appreciable during the first
two years of life, particularly at the age of 2 years (Table 36). At the
age of 4 years, the sardelle reaches a size of 80-90 mm and a weight of 6-7
g-
TABLE 36. QUANTITATIVE CHARACTERISTICS OF THE SARDELLE ACCORDING
TO AGE GROUPS IN AUGUST
Body length,
Years
1967
1968
1969
1970
1971
1972
1973
1974
1975
AVERAGE
0+
48
48
36
46
45
47
43
40
48
45
1+
71
66
58
63
66
62
61
59
61
63
2+
73
71
66
68
72
72
70
68
68
70
rnm
3+
74
77
75
73
75
77
77
78
77
76
Body weight,
0+
1.4
1.2
0.7
1.1
1.0
1.0
0.9
0.7
1.3
1.0
1+
4.2
3.4
2.3
3.3
3.9
3.2
2.9
2.6
2.9
3.2
2+
4.8
4.1
3.1
4.0
5.0
4.1
4.5
3.6
4.2
4.2
g
3+
5.0
4.9
4.2
4.6
5.5
4.7
5.7
5.7
5.3
5.0
Fat content, up to
60 mm
19.6
23.3
19.6
8.5
9.5
17.9
13.7
13.5
11.6
15.2
80-70
27.3
23.8
16.9
23.8
20.8
22.2
25.4
22.4
22.8
22.8
71 mm
25.5
20.6
15.9
24.1
23.9
18.5
27.4
18.6
23.4
22.0
The reproduction efficiency of the sardelle is determined by the popula-
tion of the spawning school (see Table 37).
TABLE 37. CHARACTERISTICS OF THE REPRODUCTION EFFICIENCY OF THE SARDELLE
AS A FUNCTION OF THE BIOMASS OF THE SPAWNING POPULATION
Biomass of spawners Number of first-year
Generation (thous. tons) B fish (units) per spawner
High-yield
Medium-yield
Low-yield
330
250 < B < 330
B < 250
0.8
1.3
2.7
B-48
-------
The preferred food during the summer-autumn periods includes water fleas
and crustaceans, mysids and other zooplankton organisms.
The sardelie's ration is determined by the age of the individuals and
the temperature regime of the body of water. The sardelle population is
the chief consumer of the Azov zooplankton. The main food competitors of
the sardelle are the Azov anchovy, the goby, friar, three-spined stickle-
back, as well as the young of other fish species (Table 38).
The sardelle's pasturing rate decreases with the autumn cooling of the
seawater, and the fish assembles in small schools and moves to open regions
of the sea. In late November-December, it concentrates in hibernation
areas, where its hibernation assemblages are formed and are subjected to
fishing.
All age groups of the sardelle are found in the catches, an appreciable
part of which consists of young fish.
PIKE-PERCH
The pike-perch - Lucioperca lucioperca (Linn.) - is the most abundant
predator of the Sea of Azov. The maximum biomass and size of its population
was 260 thousand tons and 535 million, respectively (1933-34). At the pre-
sent time, the population of the Azov pike-perch is in a depressed state
(the biomass slightly exceeds 10.0 thousand tons, and the population, 9
million) due to a deterioration of reproduction and habitation conditions
as a result of the anthropogenic activity in the basin.
The pike-perch stock level is determined by the yield of the generations
and conditions of their habitation in the sea.
The maximum catches, observed in 1936 and 1937, reached 73.6 and 72.0
thousand tons, for a mean annual value of 31.9 thousand tons for the period
B-49
-------
I
Ln
O
TABLE 38. COMPOSITION OF SARDELLE'S FOOD IN THE SEA OF AZOV
(Percent by weight of food particle)
Components
Copepoda
of Cirripedia
Ostracoda
Cladocera
Mysidacea
of Crabs ^nd Shrimp
Rotifers
of Mo Husks
Phy top lank ton
Month
Jan-Feb March Apr-May June
75,2 58,9 62,6 17.6-45
0,1 0,1 - 10.5-68
- - - 29,8
1,9
18.9 17.6 15.4 19.2
0,1
1.8 23.2 21.0 2.4
0,5 10.0-12.3
4.0 0.1 - 1.0
July
13.3-58
6.0-11.4
1.3
-
62.5-48
6,6
5.1
6.0-16.0
0.1
Aug Nov
50.4 47.9
2.2
0,8
-
6.9 21.9
0,4
6.0
33.3 0,6
0.1-0.7 -
Dec
83.3
-
-
-
16.7
-
- ,
-
-
-------
of the natural runoff regime of the Don River (up to 1952). In the last two
decades, its largest catches did not exceed 15.0 thousand tons, and in the
last few years (1973-76), 5 thousand tons.
The pike-perch is a semi-migratory fish which spends the major part of
its life (except for brief reproduction periods and the period of fry
development) in the subsaline regions of the Sea of Azov. The area of its
inhabitation is bounded by the 11.5 /oo isohaline, and the young and
first-year fish usually prefer regions with a water salinity up to 10.5
/oo. ' Two stocks of pike-perch are distinguished in the Azov basin -
/
the Don and the Kuban* stocks. Earlier, when the freshening of the sea was
sufficient, the Don pike-perch inhabited mainly Taganrog Bay, and the Kuban1
pike-perch favored the eastern part of the sea proper. In the last few
years, as the salinity of the basin has sharply increased, a definite ten-
dency has been observed on the part of the pike-perch, including the Kuban1
stock, to dwell primarily in Taganrog Bay, from which it migrates to the
spawning areas.
The pike-perch inhabiting the sea grows faster than the one in Taganrog
Bay, owing to the long period of active feeding and the composition of the
food organisms. Differences in the size and weight characteristics, parti-
cularly in average weight, between the pike-perch inhabiting the bay and
the sea are detected as early as the age of two years, but most clearly
manifested in fish 3-5 years old (Table 39).
B-51
-------
TABLE 39. LENGTH AND WEIGHT OF PIKE-PERCH OF DIFFERENT AGES
ACCORDING TO REGIONS OF HABITATION
Taganrog Bay
Weight, kg
Age
1
2
3
4
5
6
7
8
9
10
12
Length, cm
18
35
40
47
54
• 60
62
64
65
66
69
1945-1958
0,08
0,5
0,8 •
1,2
1,8 ;
2,6
3,2
4,0
4,1 •
4,5
5,2
1958-1973
0,07
0,40
0,75
1,17
1,67
2,26
2,73
3,14
4,35
4,85
Length, cm
18
36
43
50
57
61
63
64
65
65
66
Sea Proper
Weight, kg
1945-1958
0,08
0,6
1,1
1,8
2,6
3,3
3,8
3,9
4,4
4,8
5,2
1958-1973
0,07
0,46
0,95
1,54
2,25
3,06
3,80
4,11
5,17
5,13
5,42
The growth of the pike-perch young takes place fairly uniformly with the
seasons, and sexually mature individuals gain weight most rapidly during the
autumn-winter period, when about 75% of the annual gain occurs. The largest
gains among the first-year and young fish and the sexually mature pike-perch
are observed at 23-18°, 18-12° and 5-18°, respectively.
The lifetime of the pike-perch reaches 16 years, but because of elimina-
tion due to natural causes and heavy fishing, fish more than 10 years old
are seldom found in the population. Fish up to five years old predominate
in the population in number and biomass (Tables 40, 41 and 42).
TABLE 40. PROPORTION OF PIKE-PERCH OF DIFFERENT AGE GROUPS (%)
ACCORDING TO REGIONS OF HABITATION
Age Group
Region
Sea Proper
Taganrog Bay
0+
22 ;
78
1+
11
89
2+
28
72
3+
53
47
4+
72
28
5+
82
18
6+
61
39
7 +
100
0
8+ and
100
0
older
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TABLE 41. AGE COMPOSITION OF PIKE-PERCH CATCHES IN 1975
Age Group 2+ 3+ 4+ 5+ 6+ 7+ 8+ 9+ 10+ 11+ 12+ and older
Size of
genera- 13,4 30,6 17,6 9,3 2,9 15,7 5,0 2,0 0,5 1,4 1,6
tions, T%
TABLE 42. MEAN BIOMASS OF PIKE-PERCH AGE GROUPS (thousand tons)
Age Group 0+ 1+ 2+ 3+ 4+ 5+ 6+ 7+ 8+ 9+ 10+ and older
1926-1951 7,7 36,1 32,5 31,7 15,5 5,8 3,0 1,4 0,7 0,3 0,3
1952-1973 2,9 11,9 11,2 8,2 4,9 2,2 0,9 0,4 0,3 0,1 0,3
The pike-perch reaches its sexual maturity in 3 to 5 years. After
maturing, the pike-perch participates in spawning every year. The matura-
tion rate of the individual generations varies with the conditions of habi-
tation and growth, and the population of mature fish may vary from 12 to 54%
in the three-year age group and from 48 to 93% of the population of the
generations in the four-year age group (Table 43).
TABLE 43. MATURATION RATES OF THE AZOV PIKE-PERCH IN 1958-75
(After T.M. Avedikova, 1975)
Age 1+ 2+ 3+ 4+ 5+ 6+ 1+ 8+ 9+
Population 1 34 70 90 97 99 100 100 100
The mature pike-perch engages in spawning migrations and enters rivers
of the northern Azov coastal region, the Don, the Kuban", and limans on the
eastern shore of the Sea of Azov, where it reproduces. The chief reproduc-
tion sites of the Azov pike-perch are the Don River and Chelbas, Beysug and
Kuban1 limans.
The run of the Don pike-perch begins in autumn, usually at the end of
September. A small part of the population enters the lower course of the
B-53
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river, where it passes the winter. However, the majority hibernate in
Taganrog Bay and in the eastern regions of the sea. After the Don ice
breaks up, or even during the spring ice drift, the main run of the pike-
perch begins, and it reaches its maximum intensity in April.
In the Kuban', the spawning run begins in late winter and early spring.
The dates of the mass run depend on the time when spring begins.
Spawning of the pike-perch takes place at a water temperature of 8.5-
24°, which determines its period and duration. The spawning of the Don
pike-perch usually starts when the water has warmed to 12°, and that of the
Kuban' pike-perch, 9-11°.
Mass spawning of the Don pike-perch takes place in the second half of
April and early May at a water temperature of 12-15°, and that of the Kuban'
pike-perch, in mid-April and early May at 12-19°.
The pike-perch is characterized by a fertility ranging from 82 to 2500
thousand eggs. Usually, an average-size female contains several hundred
thousand eggs. The individual fertility of the pike-perch is highly vari-
able with the age, size and weight of the individuals and is determined by
the habitation conditions of the fish in each specific year (Table 44).
TABLE 44. AVERAGE FERTILITY OF THE PIKE-PERCH (thousand of eggs)
(After A. Ye. Landyshevskaya, 1973)
Years
1966-1969
1973
30
114
103
35
163
136
40
229
181
Size of
45
315
309
Females, cm
50
430
392
55
584
377
60 65
661 660
617
70
The survival rate of the pike-perch during the embryonic-larval period
of development is considerably affected by the water temperature and
B-54
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salinity level of the spawning grounds. The eggs develop normally at a
water temperature of 9.3° to 27.2°. The lower lethal temperature for pike-
perch larvae is 6.0-6.5°. A sharp drop in water temperature from 17 to 7°
causes the larvae to die. The upper lethal temperature for pike-perch
larvae is 30-32°.
A water salintiy up to 3 /oo is favorable to the spawning of the
pike-perch and normal development of the eggs. The survival rate of the
eggs during the development in water with a salinity of 3.4-4.5 /oo is
only 1.2%.
The seaward run from the egg-laying areas on the Don and from the limans
of the Kuban1 takes place when the individuals are 19 to 50 mm long in late
May-June, and in smaller numbers in July. During the first period of habit-
ation in the sea, the pike-perch takes up residence in the coastal zone,
and in July-Septeber migrates to the open regions. :
The character of feeding of the pike-perch in ontogeny changes from
planktonic in the early stages of larval development to predatory in the
following period of life. The young fish feed on tiny plankton organisms,
chiefly Copepoda and Cladocera, then Mysidae. The plankton period of
feeding ends when the pike-perch reaches a length of about 33 mm. From the
age of one month, the pike-perch leads a predatory mode of life. As the
growth continues, the fraction of fish food continuously increases. Thus,
for young fish 41-58 mm long, fish food'is already as high as 97.5%
The chief nourishment of the adult pike-perch is the goby (56.5-59.5).*
*The first figure refers to Taganrog Bay, and the second, to the sea proper.
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The species composition of the pike-perch's feed items varies consider-
ably with the season and the location - in the sea proper or in Taganrog
Bay.
Thus, in the latter spring, the pike-perch feeds primarily on the
sardelle (81%), and in summer and autumn, on gobies (65.7% in summer and
94.1% in autumn). In the sea in spring, it eats mainly the sardelle
(53.4%) and gobies (43.1%), and in the autumn, primarily gobies (74.7% of
the weight of a food particle).
There are seasonal differences not only in the species composition of
the food consumed by the pike-perch, but also in the rate of feeding. In
the sea, the highest rate is observed in spring and autumn (respectively
61.8% and 46.9% of feeding individuals, and in summer, 25.2%).
The annual ration of the pike-perch is estimated at 7 body weights, and
the daily ration, 2-9% of the individual's weight.
The distribution of the pike-perch over a range is affected by both the
advent of a given stage of the biological cycle and abiotic factors. The
maturing pike-perch executes spawning migrations, and the young fish
arriving from the spawning grounds adopt a range whose size is limited by
the salinization level of the seawater. On the range, important factors
determining the distribution of the pike-perch are the density and accessi-
bility of food organisms and the oxygen regime. The pike-perch is not found
in regions of the basin where the content of oxygen dissolved in water is
less than 5-6 mg/1, and dies if the oxygen concentration drops to 2 mg/1.
Pike-perch fishing is done during the autumn-winter and spring seasons
in Taganrog Bay and the Don.
B-56
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STURGEONS
Sturgeons are the most valuable food fish of the Sea of Azov and are
represented by three species: beluga, huso huso (Linn.), sturgeon,
Acipenser guldenstadtii (Brandt), and starred sturgeon, Acipenser stellatus
(Pallas), which are fairly similar in ecological characteristics.
Although sturgeons range throughout the Sea of Azov, their distribution
in it is uneven. The young, whose areas are bounded by isohalines, stay
mainly in Taganrog Bay and along the northern seashore, and also in the
freshened coastal region of the Kuban' River. Adult individuals inhabit
,'
the entire sea. Most of the stock hibernates in the western part of the
sea (3rd and 4th regions).
All three species of sturgeons are typically migratory, traveling to
spawn in the middle and upper reaches of the Don and Kuban1 Rivers. Before
the runoff of the rivers was regulated, the size of the stock and large
catches of sturgeons were maintained exclusively through natural reproduc-
tion. At the present time, because of the construction of dams, which have
almost completely barred access to the reproduction areas of sturgeons, the
spawning grounds of the Don and Kuban1 have become largely inaccessible.
Because of the complete disruption of the conditions for natural repro-
duction of sturgeons, a system of fish breeding plants has been -created in
the Azov basin to ensure their reproduction.
Artificial breeding of sturgeons is'being conducted at seven fish
breeding plants, including three plants on the Don (Rogozhkino, Aksay-Don
and "Vzmor'ye") and four plants in the Kuban1 River basin (Temryuk,
Achuyevo, Grivenskaya and Krasnodar). As shown by observational data, the
efficiency of sturgeon breeding is high, and the size of the sturgeon stock
B-57
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in the Sea of Azov increases in proportion to the plants' production of
young fish (Tables 45 and 46).
TABLE 45. VARIATION IN THE POPULATION OF AZOV STURGEONS WITH THE
DEVELOPMENT OF FISH BREEDING
Quantity of young fish
produced (yearly average)
Increase in sturgeon
population in the sea
Years
1964-65
1967-69
1970-72
1973-75
Millions
7.3
13.4
15.3
27.0
%
100
184
210
370
Thousands
185
354
466
736
%
100
191
252
400
1967
1968
1969
1970
1971
1972
1973
1974
TABLE 46. PRODUCTION OF YOUNG STURGEONS BY FISH BREEDING PLANTS
OF THE DON AND KUBAN'
Year
Quantity (millions
Starred
Beluga Sturgeon sturgeon Total
Weighed portion (g)
Starred
Beluga Sturgeon sturgeon
Don plants
38
74
0
0.04
1.71
0.45
1.21
0.55
44
48
0
35
62
44
49
2.74
2.80
2.81
3.37
1.62
6.36
4.32
6.81
09
07
7.
7,
7.
7.
77
95
96
78
5.56
3.51
9.62
4.46
3.55
1.97
3.7
3.
3.5
3.9
3.0
2.8
2.81
.57
.39
2.6
1.
2.
54
25
28
2.6
2.6
1.0
1.6
1.7
1.7
1970
1971
1972
1973
1974
2.17
1.86
1.39
3.93
6.85
Kuban
4.3
5.97
4.22
8.59
11.67
' plants
6.47
7.83
6.61
12.52
18.52
3.9
3.7
3.4
3.7
3.1
2.1
2.2
2.21
2.8
2.38
Table 46 presents data on the production of spawners and young fish by
Don and Kuban' fish plants, used in the modeling.
The populations of all species of sturgeons have a similar structure.
The presence of this structure, which is more complex than that of the fish
B-58
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populations discussed above, is due to a long lifetime, late maturation
(Table 47), and the fact that sturgeons do not reproduce annually; the
intervals between spawnings last 4-5 years. Therefore, the sexually mature
part of the stock is divided into the spawning population and a reserve,
i.e., individuals not particpating in spawning in a given year. Although
the effect of natural reproduction is very slight and there is no point in
considering it in the model, it is necessary to distinguish the spawning
population in order to describe ecological characteristics such as the
spawning migration.
The data of Table 47 reflect the structure of the stock (in % by weight
and population) for each species of sturgeons.
TABLE 47. STRUCTURE OF THE STOCK OF STURGEONS
Time of advent of
sexual maturity
(average number
Species of ^ears) Young fish
Beluga 12
Sturgeon 9
Don Starred Sturgeon 8
Kuban" Starred Sturgeon 7
30*
60
28
62
27
60
28
58
Spawning
populations
17
9
31
12
30
13
33
19
Reserve
53
31
41
26
43
27
39
23
*Note: Numerator - in % by weight of total stock:
Denominator - according to the number of individuals.
Table 48 summarizes data on average weights of individuals in different
age groups of sturgeons, used in the modeling.
B-59
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TABLE 48. AVERAGE WEIGHTS OF AGE GROUPS OF STURGEONS (kg)
Species
Beluga
Sturgeon
Don starred
Average weight
of young in
Taganrog Bay
2,2
3,4
sturgeon 2
Average weight of
young in the sea
2,7
3,5
4
Average weight of
adult individuals
95
16
8,5
Kuban1 starred
sturgeon
2
2,05
7,5
Sturgeons are characterized by a mixed feeding type (predators and ben-
thophages). Table 49 contains data on the sizes of rations and feeding
efficiency of sturgeons.
TABLE 49. COMPOSITION OF STURGEON FOOD (in % by weight of
food particle), YEARLY AVERAGE '.
Species
Beluga
Sturgeon
Starred
sturgeon
fry
young
adult
fry
young
adult
fry
young
adult
Type of
Fish
Round goby, Benthophilus,
monkey goby, knipowitchia
goby
3.1
97.6
98.52
1.1
57.65
61.72
-
43.57 '
34.18
Food
Zoobenthos
(mysids, shrimps, crabs,
kerophiids, Cumacea, mol-
lusks, chironomids, poly-
chaetous worms)
96.9
2.4
1.48
98.9
42.35
38.28
100
56.43
65.82
Sturgeons poorly tolerate high temperatures, and kills are observed at
25". Sturgeon fishing is carried on in three fishing regions: (1) Azov-
Don, (2) Azov-Kuban1 and (3) Azov-Ukraine.
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It is well known that adult individuals and young fish are found in the
catches. Data on the percentage of young in the catches are given in Table
50.
TABLE 50. PERCENTAGE OF YOUNG IN CATCHES (average for 1970-72)
Region Starred sturgeon Sturgeon Beluga
Kuban' 28.2 68.5 40.3
Don 27 30 33
We will now turn to a brief presentation of data on spawning migrations
and pasturing of the young of individual species.
To reproduce, the beluga enters mainly the Don River, and only a small
portion of the run enters the Kuban1 River. The beluga run to spawn
earlier than other sturgeons, and the first sexually mature individuals
appear in the Don as early as January, when the water temperature is 0.1-
1.0°. The spawning run is stretched out, and several waves are observed.
The heaviest run is noted in March-April at a water temperature of 6-10°.
During the entire period of spring migration, 29% of the spawning beluga
population runs to spawn, while the majority (71%) of spawning individuals
run to spawn during the summer-autumn run, which begins in June and reaches
its peak in September. : This beluga will spawn in the spring of the
following year after hibernating in the Don. The production of fry from
fish breeding plants in the Don and Kuban" Rivers is carried out during the
months of June-August. . As a rule, the seaward run of the young ends at the
end of August. The young belugas pasture in Taganrog Bay for one year, then
migrate to the sea.
B-61
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Like the beluga, the sturgeon travels to the Don to reproduce, and only
isolated individuals wander into the Kuban'. The start of the sturgeon's
spawning run is observed in March at a water temperature of 1-3°, and the
sturgeon enters the Don en masse in April, at a water temperature of 9-15°.
In spring, 82-90% of the sturgeon's spawning stock goes to spawn, and the
remainder goes during the autumn run from the beginning of September, with a
maximum during the end of September and the first 10 days of October.
After spawning, the spawning population runs into the sea. The young
sturgeons stay in Taganrog Bay for up to 4-5 years.
The spawning migration of the starred sturgeon takes place later than
those of the other sturgeons. The Don portion of the run enters the Don at
a temperature of 5-9°, and the maximum of the run occurs at 12-16° (which
corresponds to the end of April-May).
The Kuban' sturgeon goes to spawn in may at a temperature of 8-12°, and
its maximum run is observed in June at 18-25°. The seaward run of starred
sturgeon young in the Don and Kuban1 begins at the end of May and is
heaviest in June-July. It ends in the Kuban" in August, and isolated speci-
mens of the young remain in the mouth of the Don until November. In
Taganrog Bay, the young pasture for 4-5 years.
BREAM ':
The bream, Abramis brama (Linn.) is a freshwater fish and is also a
valuable and abundant benthophage among semi-migratory fishes. During the
maximum development of Azov fishing, among valuable fishes, its catches
were second only to those of the pike-perch and reached 46.4 thousand tons
(1936), the average catches for the period of the natural regime of the Don
River being at the 20-thousand ton level. After the runoff of the rivers
B-62
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became regulated, owing to the deterioration of the reproduction conditions,
the size of its populations decreased sharply, so that the catches were re-
duced almost 6-fold. In the last 20 years, they have been practically at
the same level, 2.5-3.0 thousand tons.
Fluctuations in the catches of the bream, like those of the pike-perch,
are determined by the yield of its generations and its habitation conditions
in the sea.
The size of bream generations is determined by the water supply of the
spawning grounds (mainly floodplains) and the spring temerature regime. '
After the Don River became regulated, the floodplains were flooded very sel-
dom (3 times in the last 25 years), and this led to a sharp decline of their
quality. All this, coupled with the salinization of the sea, has caused a
14
low level of bream reserves and catches during the present period.
Among semi-migratory Azov fishes, the bream is the least resistent to
water salinity. Its young prefer regions with a salinity up to 7-8 /oo,
and sexually mature individuals, up to 10.5 /oo. During sea freshening
2
periods, the range of the bream amounted to 10.1 thousand km , or 30% of
the water area of the basin, and in some years (1930-35), up to 70%. During
the last decade, the bream has not been found beyond the confines of
Taganrog Bay, and with increasing salinization, its range contracts toward
the central and eastern parts of the bay. During the present period, the
bream inhabits the eastern part of Taganrog Bay, covering only 3-5% of the
water area of the sea.
The salinization of the basin and the associated decrease in range lead
to a reduction of the reserve and growth rate, decline in the quality of the
spawning population, and other negative biological aftereffects.
B-63
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For the indicated reasons, the depression of bream reserves in the last
20 years has become permanent (Table 51), and the growth rate of fish of
the same age has been cut almost in half (Tables 52 and 53).
TABLE 51. FREQUENCY (%) OF YEARS WITH DIFFERENT LEVELS OF BREAM RESERVE
Level of reserve, thousand tons Number of
Period up to 100 150 200 250 300 observations
1930-1951 5 58 5 27 5 22
1952-1976 78 24 25
TABLE 52. AVERAGE WEIGHT OF BREAM (g) IN THE 5th AND 6th YEARS OF LIFE
IN DIFFERENT PERIODS OF SALINIZATION OF THE SEA
Years of growth
1935-1938
1955-1958
1973
1974
Salinity
°/oo
9,8
12,1
12,6
12j9
Five-year
882
688
650
650
Age Groups
olds Six-year olds
1275
872
740
720
TABLE 53. RATE OF WEIGHT GROWTH OF THE BREAM (g) DURING ONE-TIME REGIME
OF THE AZOV SEA (Data of T.M. Avedikova)
Age
Period 123456789 10
1934-1952 10 122 371 527 712 927 1146 1402 1953 1620
1955-1975 12 130 400 526 646 751 831 1009 1123 1261
In the period of the natural runoff regime of the rivers, the lifetime
of the bream was as long as 20 years, and 17-year old specimens used to be
found in the catches. A considerable rejuvenation of the bream population
has now occurred, and fish older than 10-12 years are rarely found, this
being clear from the example of the 1975 spawning population (Table 54).
The maximum size of the bream during the present period does not exceed 51
cm, and its weight, 3.5 kg.
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TABLE 54. AGE COMPOSITION OF SPAWNING BREAM POPULATION IN 1975
(Data of G.P. D'yakova, 1975)
Age, years 3 4 5 6 7 8 9 10 11 12
Size of gen-
erations, % 0,9 21,4 34,4 19,7 19,5 3,1 0,5 0,1 0,2 0,2
The distribution of the bream over the area is determined, in addition
to the salinity, by the biological cycle of the fish, and also by the nutri-
tive base. The sexually mature beam pastures in spring, summer and fall,
and with the advent of autumnal cooling, the stock begins to concentrate in
the eastern part of Taganrog Bay and areas of the Don before the straits. A
certain part of the population, and when the latter is low, sometimes a
significant part, may enter the Don delta in November-December and remain
there to hibernate.
The spawning migration of the bream into the Don begins during the first
ten days of February, and the mass run lasts from the second ten-day period
of March to the beginning of May. Usually, two heavy approaches are distin-
guished: at the end of March and in mid-April. The bream spawns at a water
temperature of 11-24°, usually from mid-April through the end of July, and
massive spawning takes place at a water temperature of 14-18°. After
spawning, the spawners migrate to Taganrog Bay, where they pasture.
The majority of bream individuals reach sexual maturity at the age of 3
years.
The fertility of the bream, like that of other fishes, varies widely
with the size, weight and age of the females and ranges from 42 to 605
thousand eggs, with an average of 154 thousand. Spawning takes place in
two batches, the second batch being spawned 10-15 days after the first and
amounting to 1/4-1/5 of the breeding performance. In the last few years,
because of the limited number of bream spawning areas, partial or complete
B-65
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resorption of the eggs in the females has been frequently observed. This
has a highly unfavorable effect on the size of the generation being born,
as well as on the next reproduction and population, since females with
resorbed eggs do not participate in the following year's spawning.
The development of bream eggs last 10-11 days at a water temperature of
11-16°, 6-7 days at 18°, and 2-3 days at 23°.
The survival rate of bream eggs depends to a large extent on the dura-
tion of flooding of the floodplains, and also on the spring temperatures:
marked temperature fluctuations, particularly lows of 6-7°, results in a
mass destruction of the laid eggs.
After the resorption of the yoke sac, the hatched larvae begin to feed
on zooplankton. On reaching a length of 2.5-3.0 cm, the bream young
partially switch to feeding on bottom organisms. The bream becomes a typi-
cal benthophage when its length reaches about 10 cm.
A mass migration of the young to Taganrog Bay takes place from mid-June
until the end of July. , The average size of the individuals changes from
22-25 cm for an initial weight of 0.24-0.42 g to 70 mm for a weight of 5.2 g
at the end of the mass migration. The bream young which have migrated to
Taganrog Bay first occupy regions adjacent to the outer delta of the Don,
as well as coastal regions, spreading over the entire water area of the
eastern bay by autumn.
In Taganrog Bay, the bream feeds on'benthic organisms, consuming bottom
crustaceans (mainly ostracods), worms, and mollusks. The young bream (1-2
years old) sometimes consumes appreciable amounts of planktobenthos forms,
mainly mysids.
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The bream's competitors in feeding include: during the freshwater
period of life - the young and sexually mature individuals of fishes of
litte value inhabiting the river, and during the marine period of life -
gobies, sturgeon young, roaches, etc.
The catching of bream is based on fishing in its assemblages in Taganrog
Bay during the autumn and spring periods, and also in the spawning popula-
tion in the Don. Catches in the Don constitute 60-80% of the annual take.
ROACH
The Azov roach, Rutilus rutilus (Heckeli) is one of the most important
food fishes of the Azov basin. In size of the population and catches, among
semi-migratory fish, the roach is only behind the pike-perch and bream, and
in the last few years has been only second to the pike-perch. The maximum
roach catches occurred in 1935-36 (23.5 and 18.1 thousand tons), the
averages for the period from the early 1930's were close to 5 thousand tons,
and only in the last few years (173-76) have the takes been low, at the
level of 1-2 thousand tons.
The roach is a gregarious fish, widely distributed over the Sea of Azov.
However, its chief concentrations are observed in the eastern half of the
sea and Taganrog Bay. Of greatest importance in its reproduction is the
Azov-Kuban' region.
Of all semi-migratory fish, the roach is the most resistant to water
mineralization. The upper limit of favorable salinity for its first-year
young is 11 /oom fir sexually mature fish, 12 °/oo, and the highest
fish density is usually observed inzones with a salinity of 9-10 loo.
In this connection, and also in view of the extensive measures to develop
the Kuban' limans, where most of the roach spawning takes place, the size
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of its population in the sea was at a high level up until the early 1970's.
It dropped sharply only in the last five years because of unsatisfactory
salt conditions in the Kuban1 region of the Sea of Azov. In addition, as
the average salinity of the Sea of Azov increased, a definite trend was ob-
served whereby the area of the roach contracted and the main roach concen-
trations shifted from the eastern part of the Sea of Azov into Taganrog Bay
(Table 55). The maximum size of the roach exceeds 50 cm, and its weight is
3.5 kg. The maximum age under present conditions does not exceed 9 years,
but fish older than 6-7 years are very rare in the population. Dominant in
age group populations are one and two-year olds, and in biomass, three and
four-year olds (Table 56). By the age of two years, the population of the
generations decreases by 30% owing to natural loss, and by the age of three
years, by another 10%. When fishing is involved (at the age of 3-4 years),
the natural death rate amounts to less than 10%, and removal by fishing
14
amounts to 23 to 44%.
TABLE 55. DISTRIBUTES OF FOOD ROACH (%) IN RELATION TO THE SALINITY
LEVEL OF AZOV SEA WATERS
Year
1965
1966
1967
1968
Salinity
°/oo
11,1
10,9
11,3
11,1
Sea
95,9
90,0
92,5
93,1
Bay
4,1
10,0
7,5
6,9
Year
1970
1971
1972
1973
1974
Salinity
°/oo
11,7
11,8
12,3
12,6
12j8
Sea
77,3
40,5
30,2
45,0
16^4
Bay
22,7
59,5
69,8
55,0
83^6
TABLE 56. STRUCTURE OF THE POPULATION OF THE AZOV ROACH
Age Groups, %
Period
Index
Average level
Thousand
Millions tons
1932- Population 55,9 22,2 14,0 6,4 1,4 0,1 464
1953 Biomass 7,4 16,0 37,2 30,0 8,4 1,0 - 222
1953- Population 56,7 23,1 13,2 5,6 1,3 0,1 761
1972 Biomass 9.0 20,0 34,1 27,2 8,3 1,2 - 328
B-68
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The roach characteristically engages in spawning and pasturing migra-
tions, and therefore its distribution over the range in the Azov basin de-
pends on the season, population status and nutritive base. During the
autumn-winter period, particularly in February, the roach moves from open
regions of the sea and bay into the coastal zone, from which the sexually
mature portion of the population begins to migrate toward the spawning
grounds.
The Azov roach becomes sexually mature at the age of two to three years,
when about 83% of the females and 94% of the males mature.
The spawning population of the roach is represented by 2-6-year olds,
and 3-4-year old fish usually predominate (Table 57). The ratio of the
sexes in the spawning population is close to 1:1.
TABLE 57. AGE COMPOSITION OF SPAWNING ROACH POPULATION
Population of age groups, %
Period 2 3 4 5 6
1945-1968 1,9 44,1 39,4 12,6 2,0
1969-1975 0.9 57,6 35,2 5,4 0,7
The entry of the roach into limans takes place at a water temperature of
3-10° from the end of February to May, and is massive in March - early
April. Spawning of the roach begins when the water warms up to 8-10° and is
observed from the end of March to mid-May, and massive spawning takes place
at a temperature of 12-14° (April - beginning of May). After spawning, the
roach spawners migrate into the sea. The fertility of the females varies
from 2 to 200 thousand eggs (average, 50 thousand eggs). In some of the
fish, particularly those remaining in limans, resorption of the reproductive
products takes place.
B-69
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The optimum conditions for spawning and egg development are as follows:
(1) Water temperature in the spawning areas, 12-14°; no marked
daily fluctuations of this temperature.
(2) Salinity of water no higher than 3 /oo, since a 3-5 /oo
mineralization of water causes a marked loss of the developing
eggs.
(3) Saturation of water with oxygen in the spawning areas not
under 35%.
(4) Absence of strong wind waves, which cause the water to
/
become turbid.
Infringement of even one of these conditions causes a marked decrease in
the number of hatching larvae, sharp temperature fluctuations being parti-
cularly harmful. Thus, lowering the temperature from 12.7 to 9.3° causes an
unproductive generation, and lowering it to 3-5° leads to the complete loss
of the laid eggs. The duration of egg development depends on the water
temperature and amounts to 13 days at 8.7° and 1 day at 15-16°.
The yield of roach young is greatly affected by the temperature during
the period of embryonic-larval development, and also by the availability of
food to the larvae during the period of change to active feeding, and the
presence of predator and competitor pressure in the breeding areas. The
size of the spawning population is not a decisive factor in the formation
of the size of a new generation.
In contrast to the sexually mature fish, which immediately after
spawning leave the limans for the sea, the young remain in the breeding
areas. Usually, their migration to the sea begins in June, and after
reaching a maximum in July, ends in August.
B-70
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The size and weight of the migrating individuals are 21-37 mm and
140-800 mg, respectively; at the end of summer, they may be 2 to 3 times as
much. Roach fry which have entered the sea initially dwell in the shallows
of the coastal zone (at a depth of less than 1 m), and subsequently also mi-
grate to Taganrog Bay; the rate of this phenomenon has sharply increased in
the last few years.
The roach in ontogeny feeds on various complexes of food organisms.
Thus, larvae in the early stages of development consume zooplankton (roti- .
fers, copepods, cladocerans), and in later stages switch to feeding on
crustaceans. In feeding, the roach young in limans now dominate benthic
forms of chironomid larvae. When they reach the sea, young of the current
year consume bottom crustaceans, worms, and mollusks, and from the age of
two years, switch to feeding exlusively on mollusks.
The feeding rate of the roach is substantially affected by the water
temperature in the region of habitation. The fish feeds most actively at a
temperature above 15°, so that during the summer season (May-August), up to
90% total ration required by the roach during one year is consumed. In
spring (April) and autumn (October-November), 5-7% of the total amount
ration is consumed.
The roach becomes edible at the age of three years, when it reaches
>
14-16 cm. Data on its average weight are given in Table 58. It is caught
in September-December and February-April', when it approaches the coastal
zone and executes spawning migrations. Until recently, the main fishing
region was the Azov-Kuban' region, where up to 70% of the annual catch was
taken.
B-71
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TABLE 58. AVERAGE WEIGHT OF ROACH OF DIFFERENT AGE GROUPS (g)
Period
1945-1969
1973-1975
3
185
110
Age Groups
4
210
130
5
280
160
OTHER FISHES
It goes without saying that the characteristics of the other 97 unmen-
tioned fish species of the Sea of Azov will not be cited here. What we are
interested in is to consider in some way, for modeling purposes, the total
influence which other fishes exert on the populations of edible fishes and
on the ecosystem as a whole, with the understanding that many populations
cannot and should not be considered. The classification of a population in
3-8
the OTHER FISH class was decided on the basis of reported data and ex-
pert estimates based on the following system of criteria:
Cl. The average size and biomass of a population should not be
smaller in order of magnitude than the size and biomass of
the population selected for "individual" modeling.
C2. The commercial significance of a population (if the fish in
question has any commercial significance at all) should be
much less than that of the population discussed in Sec. 7.1-
7.7.
C3. A given population should be in trophic or competing rela-
tionships with the populations of the "main" fishes, and
these relationships should be significant for the latter.
C4. It is necessary to have either quantitative estimates of the
vital activity parameters of the fishes, or at least fairly
B-72
-------
precise qualitative notions permitting the formulation of
plausible hypotheses concerning the significance of such
parameters.
Each of the selected populations must satisfy C2 and C4 and either Cl or C3.
From the multitude of fish species in the Sea of Azov, eight populations
were selected - five fish species hibernating in the Black Sea (referred to
below as the "Black Sea species") and three species dwelling permanently in
the Sea of Azov (the "Azov species").
(1) Friar, Atherina nochon pontica (Eichwold)
(2) Three-spined stickleback, Gasterostens
aculeatus (Linn.)
Black Sea
fishes
(3) Black-Azov Sea migratory herring,
Alosa kessleri pontica (Eichwold)
(4) Azov Sea herring,
Alosa caspia tanaica (Grimm)
(5) Red mullet,
Mullus barbatus ponticus (Essipo)
(6) Percarina, Percarina domendofii
(7) Syrman goby,
Gobius syrman (Nordmann)
(8) Goby-knipowitschia,
Knipowitschia longicandati (Kessler)
It is possible that if necessary, this number of populations can be
I
increased later on.
Table 59, compiled on the basis of Refs. 6, 7, 8 and expert estimates,
give the principal biological characteristics of the above species. Here
Azov Sea
fishes
B-73
-------
and in all the remaining Tables 60-62, a large proportion of the data were
obtained by means of expert estimates.
TABLE 59. PRINCIPAL BIOLOGICAL CHARACTERISTICS OF FISHES (1-8) BASED ON
DATA OF NATURAL OBSERVATIONS AND EXPERT ESTIMATES
Species
Average
biomass
( thous.
tons)
Average
popula-
tions
(millions)
Average weight
(g)
Adults Young
Length
(cm)
Adults Young
Friar
Three-spined
stickleback
30-60
8000
6,0
1,5
8,0
1
Sea herring 12
Azov Sea herring 0,35
Red mullet 1,75
Percarina 8
Syr-man goby 7
Goby-
knipowitschia 0,1-0,3
200
4000
20
70
30000
2
2,5
141
48
10,7
2,5
17,0
0,5
3,6
5,5
5,3
0,7
3,6
6
22,4
15
14,5
4,5
14,5
1,5
6,7
4,5
5,0
1,2
6,0
12
0,3
0,17
2,8
2,0
TABLE 60. CERTAIN PARAMETERS ADOPTED IN MODELING
(number of five-day period)
Start of
spawning
25
18
19
19
28
28
25
27
End of
spawning
49
42
45
32
37
43
36
42
Entry from
Black Sea
19
19
14
14
17
-
-
-
Departure
for
Black Sea
66
66
69
70
71
-
-
-
Start of
spawning
run
19
19
14
14
17
16
16
16
End of stages in
breakdown of
spawning period
36
24
27
25
30
28
25
28
42
42
35
32
36
35
36
35
49
-
45
-
-
43
-
42
B-74
-------
We will enumerate the principal effects of the selected populations on
the ecosystem.
Friar - one of the most abundant fishes of the Sea of Azov, serves as food
for the pike-perch, herring, and is also a feeding competitor of the
anchovy, sardelle, and young of the goby.
Three-spined stickleback - consumes the eggs and larvae of the pike-perch
and roach, is a feeding competitor of the young and larvae of valuable fish
breeds as well as sexually mature planktophages.
Black-Azov Sea migratory herring - is a competitor and to a lesser extent,
/
consumer of the young of valuable fish breeds as well as planktophages.
Azov Sea herring - serves as food for the pike-perch and is also a feeding
competitor of the young of the pike-perch, roach, golden shiner, and stur-
geons during the period of their feeding on planktobenthos.
Red mullet - is a food object for sturgeons and gobies and to a lesser ex-
tent, anchovy.
Percarina - is a competitor of the young of valuable fish breeds and to a
lesser extent, a consumer of their larvae as well as a food object for the
pike-perch.
Syrman goby - eats the sardelle and anchovy, serves as food for the pike-
perch and sturgeon and is a feeding competitor of the round goby.
Knipowitschia goby - serves as food for edible fishes and competes in
feeding with planktophages.
Tables 60, 61 and 62 give data on the feeding, breeding and regions of
habitation of the fishes modeled in the unit.
It is evident from the data cited that our knowledge of the vital pro-
cesses of the above fishes is very limited.
B-75
-------
TABLE 61. FEEDING AND BREEDING CHARACTERISTICS
Feeding Spectrum
Zoo- Phyto-
plank- plank- Ben-
Species ton ton thos Fishes
Friar + - +
Three-spine + - - +
stickleback
Sea herring + - + +
Azov Sea + -
herring
Red mullet - - + +
Percarina + ' - + +
Synnan goby - + +
Knipowitschia + - - -
Spawning
Fertility Time
Av. 592 May-Aug
782-1381 end March
end April
Av. 49000 April-mid
August
12000- April-
39000 early
July
3650 end May
end June
up to end May-
3000 early
August
Av. 820 May to
June
274-804 Mid-May-
August-
September
Place
coastal
zone, 7 /OO
Kerch
Straits,
Kuban1
estuaries
Don R. in
June-
partly in
Taganrog
Bay
lower
course of
Don
southern
part of
Sea, Kerch
Straits
eastern
part of
Taganrog
Bay
Taganrog
Bay,
coastal
zone
Taganrog
Bay
B-76
-------
TABLE 62. CHARACTERISTICS OF REGIONS OF HABITATION AND MIGRATION
w
i
Species
Season
Winter
Spring
Summer
Au tumn
1
Black
Sea
Coast
of Sea
of Azov,
Sivash
Coast
of Sea
of Azov
2
Black
Sea
Sea of
Azov,
Kub an '
limans
Coast
of Sea
of Azov
3
Black
Sea
Tagan-
rog
Bay,
Don
River
North-
eastern
part of
Sea of
Azov
4
Black Sea,
Kerch
Straits
Taganrog
Bay,
lower
part of
Don,
Kuban1
limans
North-
eastern
part of
Sea of
Azov
5
Black
Sea
Southern
part of
Sea of
Azov,
Kerch
Straits
Southern
part of
Sea of
Azov
6
Eastern
and Cen-
tral
parts of
Sea of
Azov
Taganrog
Bay
Eastern
part of
Sea of
Azov,
Taganrog
Bay
7
Central
part of
Sea of
Azov
Coast of
Sea of
Azov,
Taganrog
Bay
Sea of
Azov
8
Eastern
part of
Sea of
Azov
Taganrog
Bay
East Coast
of Sea of
Azov
-------
We have beome acquainted with the life of the ecosystem of the Sea of
Azov. Before turning to its modeling, it will be useful to recall that it
is desirable to obtain a model, not of the system in general, but of a
problem in the system. Only then can the model be expected to prove really
useful, and in particular necessary for solving a specific problem.
What problems of the Sea of Azov are of most interest to us? Do they
exist at all? yes, they unquestionably do, and furthermore, are of vital
importance.
A considerable portion of the catchment basin of the Sea of Azov is
located in a zone of insufficient humidification, where the coefficient of
runoff from the territory of the catchment is equal to 0.13. For this rea-
14
son, the river runoff is very limited and amounts to an average of 41
3 23
km (according to other data, 43.4 km ). The bulk of the runoff is
3
due to two rivers - the Don and Kuban1 (27.9 and 13.9 km , respectively).
3
The exceptional variability of the Don River runoff with time (52 km in
3
1942 and 11.8 km in 1950) causes large fluctuations of the total water
3 3
reserves of the basin (25% availability - 50.7 km ; 75% - 33.0 km ).
The river runoff of the Azov Basin is used for the needs of industry,
agriculture, power engineering, water transport, municipal water supply and
fisheries. The Sea of Azov is the closing link in the utilization of the
Q
water. It follows from general ecological considerations that the
effects of anthropogenic action in the basin should accumulate in the eco-
system of the Sea of Azov. This is indeed the case.
We will examine in more detail the mechanism of the pressure exerted on
the ecosystem of the Sea of Azov by the continental part of the basin and
will attempt to determine the extent to which the ecological system is
B-78
-------
stable to this pressure, and the conditions and planning prospects for the
development of the national economy on the territory of the basin.
The principal negative effects exerted at the present time by the con-
tinental part of the basin on the marine part should be assumed to be the
following:
(1) Irreversible removal of a considerable part of the runoff. At the
3
1975 level, the total water consumption in the basin was already 23 km ,
and the irreversible consumption, 15 km , or about 35% of the river runoff
norm. Despite the planned measures of efficient utilization of water in
s
industry, heat and power engineering and agriculture, the water consumption,
including nonrecoverable consumption, will continue to grow at a rapid pace.
In 1980, the total planned water consumption will be 33 km , and nonre-
3 3
coverable, 20 km ; in 1985, 38 and 22 km , respectively, and in the
3
2000, 60 and 38 km , i.e., by the end of the century, practically all of
the runoff will be irretrievably consumed by participants in the hydroecono-
mic complex. Of these, the largest water consumer is irrigation (total
3
water consumption in 1975, 9.22 km ; nonrecoverable, 8.69), and the rates
of its presumed growth are the most substantial (in the year 2000, 27 and
3
25.5 km ). The industry, heat and power engineering, and population of
towns and urban-type settlements consume quantities of water comparable to
3
irrigation (in 1975, 10.65, and in the year 2000, 21.22 km is antici-
pated), but the fraction of nonrecoverable water consumption is much
3 3
smaller (in 1975, 2.24 km , and in the year 2000, 5.09 km ). The re-
maining sectors of the hydroeconomic complex (fisheries will be discussed
separately) make a comparatively small contribution to the nonrecoverable
removal of water.
B-79
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(2) Seasonal leveling of runoff. In 1952, the Tsimlyansk storage re-
servoir, one of the largest in the USSR, was built in the lower course of
the Don, and in 1975, the filling of the Krasnodar storage reservoir on the
Kuban1 was completed. The seasonal leveling of the runoff sharply reduced
the frequency, area and duration of the flooding of floodplain spawning
grounds in the tailraces of the hydrosysteins (Table 63).
TABLE 63. MEAN MONTHLY RUNOFF OF THE DON RIVER BEFORE AND AFTER
CONSTRUCTION OF TSIMLYANSK HYDROELECTRIC POWER PLANT
(Village of Razdory)
Month
I
II
III
IY
Y
YI
YII
YIII
IX
X
XI
XII
Flow rate
mVsec
286
412
951
2730
3600
899
373
289
244
241
271
243
1881-1951
Runoff
km3
0,8
1,1
2,5
7,2
9,6
2,3
1,0
0,8
0,6
0,6
0,7
0,6
Runoff in
% of annual
2,9
4,0
9,1
25,7
34,4
8,3
3,6
2,9
2,2
2,2
2,5
2,2
Flow rate
m-Vsec
405
557
727
1347
1247
767
650
601
599
612
610
411
1953-1971
Runoff
km3
1,1 :
1,3
1,9
3,5
3,3
2,0
1,7
1,6
1,8
1,6
1,6
1,1
Runoff in
% in annual
4,9
5,9
8,6
15,8
14,9
9,0
7,7
7,2
6,7
7,2
7,2
4,9
The above table illustrates the radical changes in the annual runoff of
the Don River. As a result of these changes, the flooding frequency of
spawning grounds of the Lower Don dropped from 84 to 18% years, the area,
from 95 to 30 thous. ha, and the duration, from 49 to 12 days.
(3) Reduction in the breeding areas of migratory and semi-migratory
fishes due to the difficult access of spawning grounds. This effect is also
a result of the construction of dams, and its impact on sturgeons is parti-
cularly strong. Thus, 80% of the spawning grounds have proven practically
B-80
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inaccessible to the sturgeon, over 95% to the beluga, and 50% to the starred
sturgeon.
(4) Change in biogenic and mineral runoff. A change in the qualitative
composition of the waters flowing into the sea.
After the regulation of the Don River runoff, the biogenic river runoff
decreased substantially. The proportions of different biogenic elements in
the runoff, to which the ecosystem was adjusted, changes. Since modern
methods of purification of waste waters from industrial plants and return
waters of irrigation systems are inadequate, and the self-purifying capacity
of rivers is limited, a certain amount of pollutants fall within the eco-
system of the sea.
Thus, the negative effects of the continental part of the basin on the
Azov ecosystem are very appreciable. At the same time, the ecosystem is
distinguished by an extremely low inertia of development and stability to
external forces. This is due to the following factors:
(1) Exceptionally small dimensions of the sea (see above).
(2) Short period of chemical and biological cycles.
(3) Minimum variety of species, resulting in a particularly
high degree of potential vulnerability of the ecosystem.
(4) Intensive water exchange with the Black Sea, permitting
rapid introduction into the Azov ecosystem of representa-
tives of Black Sea flora and fuana in the presence of
conditions favorable to them in the Sea of Azov.
Under the prevailing conditions, the ecosystem of the sea has been
thrown out equilibrium, and the changes taking place in it may be estimated
as unfavorable. Catches of fish, particularly of valuable breeds, have de-
B-81
-------
creased. The bioproductivity of the most valuable species of ichthyofauna
has shrunk from an average of 90 thousand tons for 1927-51 to 20 thousand
tons. The total catches of migratory and semi-migratory fishes have now
dropped to an extremely low level, 5-10 thousand tons.
The extremely rapid development of negative aftereffects of anthropo-
genic reduction of the river runoff and its annual leveling renders parti-
cularly important the problem of examining the fundamentally new phenomena
directly in the sea and their relationships. We will try to trace the
direct and more remote aftereffects of the change in runoff regime.
One of the chief factors responsible for the unique fish productivity
of the sea should be considered a low water salinity, thanks to which the
populations of saltwater and generatively freshwater fishes have been able
to utilize the food resources over practically the entire water area of the
sea.
The average long-term salinity of the Sea of Azov during the 1912-51
period was 10.6 loo. This average level correspond to an equilibrium be-
tween the large masses of Black Sea salt water arriving through the Kerch
Straits and the continental runoff. The water exchange between the Black
and Azov Seas is mainly determined by the wind conditions in the Kerch
Straits, and hence as the river runoff decreased, the equilibrium should
have been disturbed. The anthropogenic reduction of the river runoff
coincided in time with the climate-caused depression of the total humidi-
fication of the basin, leading to an appreciable intensification of advec-
tion of Black Sea waters with an accompanying yearly accumulation of about
60 million tons of salts in the Sea of Azov. By 1976, the average salinity
of the sea had increased to 13.8 /oo, and in Taganrog Bay, to 10.8 /oo
B-82
-------
(versus 6.5 /oo in 1912-51). Changes in the salinity field of the Sea
of Azov are illustrated in Figure .*
The fastest and most noticeable consequence of such salinization of the
sea has been a sharp reduction the areas of saltwater and relicit species,
amounting to up to 10% of the sea area and 5% of the sea volume. The va-
cated ecological niches are rapidly snapped up by Mediterranean immigrants.
, ]_]_ 12
The latest studies ' have made it possible to establish a number of
new characteristics, whose appearance and development had never before been
directly or indirectly correlated with the transformation of the river run-
off. They include:
(1) Accentuation of the salt stratification and hence, tempera-
ture stratification of the water masses of the sea.
(2) Accelerated sedimentation of suspended organic matter and
its accumulation in the bottom sediments of the sea.
(3) Increase in the size of bacterial populations of the bottom,
caused by an increase in the mass of organic substrate.
(4) Increase in the biochemical consumption of oxygen by the
surface layer of the ground.
(5) Stable formation of anaerobic or similar situations in the
bottom layer. So-called oxygen kills are observed almost
constantly in the summertime.
(6) Large-scale death of benthos arid benthic fishes due to
oxygen kills. Obviously, this promotes the phenomena des-
cribed in items (2), (3), and (A).
translator's note: Number of figure missing in the original text.
B-83
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(7) Self-pollution of the sea as a result of oxygen deficiency.
This involves a periodic production in the Sea of Azov of
toxic products due to anaerobic decay of soil organic mat-
ter (hydrogen sulfide, methane, phenols, carbolic acids,
etc.).
(8) Reduction in the potential capacity of the Sea of Azov for
self-purification involving the removal of organic pollutants.
(9) Transformation of the qualitative composition of the organic
matter of the Sea of Azov.
s
(10) Slowing down of biogeochemical cycles of the main biogenic
elements. In comparison with 1956-60, by 1971-75 the average
rate of nitrogen turnover had decreased from 4.3 to 1.9 cycles/
year, and that of phosphorus turnover, from 12.1 to 0.7 cycles/
year.
The net result of the above transformations of the chemical aspects of
the sea has been a sharp decrease in the amount of primary organic matter
synthesized therein. In the last five years, the annual phytoplankton
production has been in the range of 13-20 million tons, vs. a natural norm
of 34 million tons. As a result, a curtailment of production is also ob-
served in the higher links of the trophic pyramid.
The principal chains of the cause-effect relationships formed in the
sea as a result of the anthropogenic re'duction of the river runoff are
illustrated by the diagram shown in Figure .*
translator's note: Number of figure missing in the original text.
B-84
-------
The data presented in this figure make it possible to draw an important
conclusion, i.e., the reduction in river runoff leads to not partial, but
total damage of the ecosystem of the sea, detectable at the most diverse
levels of its organization. Also visible on the diagram is the coordinating
role of salinity change in the dynamics of all new processes taking place
in the sea.
Thus, the Azov ecosystem has already been thrown out of the state of
equilibrium and in now in some intermediate state. The problem of the Sea
of Azov is one of the directions of further anthropogenic activity within
the confines of the Azov Basin with due regard for these undesirable
changes.
Serval alternative approaches are possible:
(1) Consider as necessary measures that would provide for the
restoration of conservation of natural conditions, to halt
the negative processes taking place in the sea and restore
the Azov ecosystem as much as possible (for example, con-
struction of the Azov Dam).
(2) Aim at the elaboration and creation of a set of natural
conditions and economic measures that would create in the
Azov Sea an "artificial" ecosystem that is sufficiently
productive from the standpoint of fishery (for example,
transformation of the sea into 'a "nursery" of sturgeons
with artificial breeding).
(3) Treat the changes in the Azov ecosystem as a natural conse-
quence of a highly efficient utilization of the water for
other needs in the continental part of the basin.
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(The negative significance of the rearrangement of the ecosystem caking
place in the sea must not be exaggerated. The importance of the Sea of Azov
in fishing will undoubtedly decrease if no steps are taken, but the salini-
zation of the sea has no negative effects on such species as the anchovy,
sardelle, etc.).
At the same time, however, one should realize that such control can be
adopted only if it is certain that such a rearrangement will not lead to a
complete degradation of the ecosystem and destruction of the natural object.
Within the framework of each of these approaches, a number of variants
of specific measures are possible that can both preclude each other and
prove mutually complementary. Approaches that effectively reconcile these
three points are possible, as are fundamentally new views of this problem.
In any event, it should be recalled that the problem of the Sea of Azov
cannot be considered separately from the general problem of utilization of
the water resources in the Azov Basin. At the present time, there exist
several projects for diverting the runoff from other regions. In the pre-
paration of general long-term plans, a diversion of the runoff from the
Volga has bee proposed in volumes that by the end of this century would in-
3
crease from 5 to 20 km /year. However, in view of the continuing drop in
the Caspian Sea level, the Volga itself requires runoff assistance. In
this situation, diversions of part of its waters to the Azov Basin create
the necessity of appropriate compensations in the same amount and Volga's
replenishment with the runoff of northern rivers. Specific proposals for
such major hydroeconomic measures are already in the stage of constructive
discussion. Thus, the problems of water distribution in the Azov Basin are
exceeding the scope of their territorial boundaries and becoming a part of
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the overall program for transforming the river runoff of the European part
of the USSR. There is still another extension of the problem on a country-
wide scale, i.e., an economic one: the comparative rates of economic
development of the regions included territorially in the Azov Sea Basin de-
pends on all the resources, in particular, the water resources. It should
also be noted at this point that the fishing economy is more closely deter-
mined by the necessary set of natural conditions than are most industrial
and agricultural sectors.
Nevertheless, there exist anthropogenic actions in the Azov Sea Basin
whose positive effect is unquestionable. They should be carried out as
rapidly and effectively as possible.
They include primarily the construction of purification installations,
the design of recycling water supply systems and latest waste water purifi-
cation systems for plants now under construction and those being recon-
structed, the creation of irrigation systems in which the evaporation loss
would be minimal, and steps toward utilizing the water transport and pre-
venting the pollution of waters with petroleum products. All these mea-
sures are stipulated in the Resolution concerning measures to prevent the
pollution of the Black and Azov Basins (Pravda of 4 February 1976).
In any event, to select the control of a natural-technical system as in-
tricate as the hydroeconomic complex of the Azov Basin, it is necessary to
be able to predict with an adequate degree of reliability and detail the
state of the Azov ecosystem for different variants of anthropogenic
activity. However, the complexity of the processes taking place in the sea
and their interdependence are such that no scientific group is able to pre-
dict the reactions of the ecosystem on the basis of only qualitative or
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basically qualitative ideas. To obtain even one prediction variant, it is
necessary to perform many calculations, and an effective prediction implies
that different paths of the system have been obtained, each of which is ran-
dom to some degree. That is to say, a new tool for obtaining predictions
is required. Selected to be such a tool was a mathematical model of the
Azov ecosystem, a model realized in the form of a set of computer programs.
And, although strictly speaking, the solution of the Azov problem requires
a general model of water utilization in the Azov Basin, the model of the
Azov ecosystem is its principal part, which simulates the processes taking
place in the most complex and closing link of the water consumption of the
Azov Basin.
2. Method of Modeling of Water Exchange Between Different Regions of the
Sea and of the Associated Change in the Concentration of Solutes and
Suspensions
The solution of the problems listed above requires the creation of a
mathematical model of the entire ecosystem of the Sea of Azov. In this sec-
tion, we will consider only one but very important part of this model - a
model of water exchange between different regions of the sea. Its impor-
tance is due to the fact that water exchange determines to a considerable
degree the changes in the concentration of solutes and of the phytoplankton,
zooplankton, etc. inhabiting the water mass. These changes are very sub-
stantial for the ecosystem as a whole.
The most accurate and universal means of solving such problems involves
the use of hydrodynamic equations for calculating the currents in a body of
water, and the subsequent calculation, by means of the turbulent diffusion
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equation, of the dynamics of concentrations of the substances on the basis
of the flow pattern obtained. This equation is
^ = - div(x-u) + div(E, grad x) (1)
dt
In practical calculations, exact differential relations are replaced by
their finite-difference analogs, and the computations (usually done with a
computer) are performed for discrete instants of time on a discrete grid
approximately the body of water.
The necessity of changing to discrete time and space steps when des-
cribing the dynamics of concentrations of a substance in a body of water by
exact hydrodynamic equations renders competitive the methods of description
of this dynamics whereby the discreteness, although usually fairly rough,
is established in space and time. If instead of the vertices of the grid
one represents individual regions of the body of water, and the currents in
the latter are described in terms of water exchanges between its neighboring
regions, the finite-difference analog of the turbulent diffusion equation
can be integrated as a relation describing for each region the balance of
the substance entering it from neighboring regions (or from the outside)
and carried out neighboring regions (or participating in certain chemical
transformations). The basic idea, which we wish to repeat once again, con-
sists in the fact that models based on balance relations should never be
compared with exact hydrodynamic models. ' Both types of models describe,
perhaps with different degrees of accuracy, the same physical laws of the
real world.
Let us turn to a more detailed description of the calculations of the
concentration dynamics of a substance in a body of water. Let the latter
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be divided into n regions, which may be assumed internally homogeneous in
the concentration of this substance. The following notation is introduced:
x. - concentration of sbustance at time t in region of number i;
v. - volume of region i at time t;
y. - entry of the substance into region i at time t;
q.. - volume of flow from region i to region j at time t;
K. - decay coefficient of the substance.
The equation for the concentration dynamics of the substance is
t+1 r t,.. t _ t, . „ t t t _, „ t t,,_. t+1 ...
= [x. (V. - Z q.. ) + I q.. x. + y. - K. V._ x._ J/V.^ (2)
i = 1, 2,>", n
Xi '11 7 'ij ; 'ji j 'i i i i
J J
The terms of the right member of Equation (2) have a clear physical meaning:
x. v. - amount of substance in region i at time t;
x. Iq . . - amount of substance carried out of the region to neighboring
j 1J regions;
Zq.. *x. - amount of substance•entering region i from neighboring regions;
j J1 J
y. - inflow into region i from the outside;
K.v. x. - consumption of substance in-region i caused by chemical
decomposition.
In conformity with the two terms in the right member of the turbulent
diffusion equation (1), the quantities q.. are assumed to consist of two
terms:
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The first term corresponds to the water exchange between regions i and j,
related to dominant currents, and the. second terras describe diffusion or
random disturbances relative to the dominant currents durint the selected
time step. ]
Accordingly, q.. > 0 and q.. = 0 only for regions with no common
boundary. Since the second term in Equation (2) describes the interpenetra-
tion of water at the boundary of the regions, we have the conditions q..
= q.. , i.e., the second terms are the same for oppositely traveling
currents. A different condition, q.. «q .. = 0, holds for the first
HiJ 4Ji '
terms, i.e., at least one of these two terms is equal to zero. This is a
reflection of the fact that the directional flow between two contiguous
regions can take place in only one of two possible directions.
The equation of concentration dynamics (2) makes it possible to compute
the concentrations x only if the values of all the variables in the
right member of the equation are known. The values of concentration x in
the preceding step are assumed to have been computed or specified as initial
conditions. The values y of inflows of the substance into the regions of
the body of water are exogenous factors and should be specified. The decay
constants KI of the substance may be different for different regions of
the body of water because of possible differences in physicochemical condi-
tions of the region, and should also be specicified exogenously. The re-
maining values of the volumes v. , v. of each of the regions and
flows q.. depend on the hydrological regime of the body of water. They
may also be either specified or computed as a result of the application of
a special procedure describing the hydrology of the body of water.
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In accordance with these various possibilities, formula (2) can be used
for different purposes. If the situation in the body of water is suffi-
ciently stable, one can calculate the steady state of the concentrations,
assuming that the quantities entering into formula (2) remain unchanged when
the substitution t -»• t + 1 is made. This leads to the relation
x. = x.(l - ~ I q..) + ~ I q.. x. + y. - K. x. (3)
i i V. . ij V. . ji i 'i 11
1 J * J
i = 1,2, •••, n
Simple transformation reduce the system of equations (3) to the standard
form ;
Ax = 6,
where A is a square matrix of order n with coefficients
K. + ~, I q. . for i = j
.1 v£ j 1J
/
A.
J
vT z qij for
i j '
and y is a column vector with components y..
The steady state of the concentrations of the substance in the body of
water is obtained as the solution of the linear system
x = A y;
hence, if the volumes of flow q.. between the regions of the body of water
are specified or estimated in some manner, and the concentrations of the
substance may be considered to be in a steady state, then from a given in-
flow (removal) y of the substance one can compute the distribution of its
concentrations in all the regions of the body of water, the dependence of
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vector x, or steady-state concentrations, on vector y, or losses of the sub-
stance, being linear.
The second method of using Equation (3) consists in computing the non-
stationary concentrations x. The nonstationary values of volumes v.
and flows between regions q.. can be computed with the aid of a suit-
able hydrological model. For a shallow body of water characterized by a
predominance of level fluctuations due to the raising and lowering of water
by the effect of wind, this can be done by means of a model analogous to the
one used for simulating the hydrological regime of the Sea of Azov.
s
s
In this model, a time step of 5 days was chosen. It was assumed that to
the 5-day average of the wind velocity vecotr there corresponds a certain
slope of the water surface, which to a first approximation was assumed to be
an ideal plane. These assumptions were based on data from natural observa-
tions and level fluctuations of the Sea of Azov.
The sequence of the calculations in the model is as follows: first, the
average levels of each of the regions are calculated from the average wind
velocity vector above the water area of the sea. From the level of the re-
gion, its volume v. is calculated. Comparison of v. and
v. shows what additional (or excess)' amount of water is required by
region i. From the relative arrangement of the regions, one determines from
where this amount of water enters this region. Also considered are inflows
of water with river runoffs and from other sources, and also the balance of
evaporation from the sea surface and precipitation on the latter.
A systematic study of the hydrometeorological regime of the Sea of Azov
began in 1922. Up to that time, only irregular measurements of the hydro-
meteorological characteristics of this sea had been taken from several
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coastal stations, as well as sporadic measurements of water temperature and
salinity in the open part of the sea. By the early 1930's, the network of
hydrometeorological stations and posts conducting regular measurements num-
bered 31 observation points. the data of hydrometeorological observations
during the period from their inception to 1935 were classified and corre-
lated in Ref. 15. During World War II, systematic observations in the Sea
of Azov were discontinued, but as early as 1947, all formerly active sta-
tions and posts began systematic observations. At the same time, hydrolo-
gical and biological studies in the open part of the sea were resumed.
In 1949, in connection with projects to regulate the runoff of the Don
and Kuban" Rivers, a number of scientific and planning institutes carried
out additional studies that made it possible to prepare forecasts of pos-
sible changes in the hydrological regime of the sea.
Observations made up to 1959 were classified and correlated in the
Hydrometeorological Handbook for the Sea of Azov.
In addition to the results of measurements of hydrometeorological
characteristics, this handbook presents conclusions of topical investiga-
tions conducted under special programs. As a result, the handbook consti-
tutes a complete and conprehensive description of the hydrometeorological
regime of the sea.
At the present time, systematic observations of hydrometeorological
characteristics such as atmospheric pressure, wind speed and direction,
temperature of air and water, absolute and relative humidity, amount of
precipitation, duration of solar radiance, etc. are being conducted at
thirteen weather stations arranged in a fairly regular patter along the
entire coastline. For measurements in the open part of the sea, the Azov
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Scientific Research Fishery Institute, which is the chief organization
engaging comprehensive investigations of the Azov ecosystem, conducts four
cruises per year: in April, July, August and October. The research ship
takes water and ground samples at 33 points arranged in a fairly regular
pattern over the water area of the sea. The water samples are taken at two
or three levels, depending on the depth in the region of the sampling site.
If the preliminary analysis performed on the spot aboard the ship indicates
the presence of a temperature stratification or a bottom deficit of oxygen,
additional samples are taken at 0.5-m intervals from the water surface to
the bottom.
Under laboratory conditions, the samples are subjected to a thorough
chemical and biochemical analysis. In particular, such indices as total
mineralization, dissolved oxygen content, iron content, pH analysis, alka-
linity, concentrations of nitrogen and phosphorus in organic and inorganic
state, silicon content, etc. are determined.
In addition to taking the samples, the expedition ship also measures the
wind speed and direction, air and water temperature at various levels, at-
mospheric pressure, current speed and direction by means of independent
printing current meters, and water transparency by means of a Secchi disk.
These measurements and observations do not exhaust the entire range of
studies performed on the expedition ship. During each cruise, special
studies aimed at more thorough and compfehensive investigations or certain
individual ingredients of the ecosystem are carried out. The;programs of
these additional observations are prepared by considering the suggestions
of specialists who investigate and simulate the Azov ecosystem for the pur-
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pose of a more accurate description of the key components or processes
taking place in the Azov ecosystem.
REFERENCES
1. A.B. Gorstko and F.A. Surkov. Mathematics and Problems of Conserva-
tion, Moscow, 1975.
2. A.M. Bronfman. The present hydrological-hydrochemical regime of the
Sea of Azov and its possible variations. Trudy azNIIRKh, Issue 10,
1972.
3. A.B. Gorstko and F.A. Surkov. Dynamic model of the functioning of
water communities of the Sea of Azov, In: "Methods of Systems Analysis
in Problems of Rational Utilization of Water Resources." International
Institute of Applied Systems Analysis, Austria, 1974.
4. A.B. Gorstko and F.A. Surkov. Dynamic model of functioning of water
communities in the Sea of Azov, In: "Simulation and Ecology." Nauka,
Moscow, 1975. I
5. A.B. Gorstko, £t al. The "Sea of Azov" simulation model, In: "Methods
of Systems Analysis in Problems of Effective Utilization of Water
Resources." Moscow, 1976.
6. V.G. Dubinina and Yu. M. Gargona. Fisheries of the Azov Basin under
conditions of intensive utilization of water resources. Trudy VNIRO,
Issue 103, 1974.
7. N.I. Revina, S.P. Volovik and N.K. Fil'chagin. Status of the reserves
of Azov food fishes (gobies, anchovies, sardelles) and their possible
changes in the presence of certain water management measurements, Tr.
azNIIRKh, Issue 10; 1972.
8. M.K. Spichak. Hydrological regime of the Sea of Azov in 1951-57 and
its influence on certain chemical and biological processes. Tr.
AzNIIRKh, Issue 1, 1960.
9. N.F. Taranenko. Population dynamics of the Azov anchovy. Tr.
AzCherNIRO, Issue 24, 1966.
10. E.N. Altman and D.M. Tolmazin. Method of calculation of currents and
water exchange in the Kerch Straits. Okeanologiya, Vol. 10, Issue 3,
1970. I
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11. A.M. Bronfman. Salinity of the Sea of Azov and its forthcoming
changes. Izvestiya Severo-Kavkazskogo nauchnogo tsentra Vysshey
shkoly. Seriya Yestestvennyye nauki, No. 1, 1973.
12. A.M. Bronfman, G.D. Makarova and M.G. Romova. Present climate-caused
changes in the composition of organic matter in the Sea of Azov.
Izvestiya AN SSSR, seriya geografiya, No. 6, 1973.
13. A.P. Zhilyayev. Calculation of level fluctuations of the Sea of Azov.
Okeanologiya, Vol. 12, Issue 1, 1972.
14. A.B. Gorstko. Mathematical modeling and problems of utilization of
water resources, RGU, 1976.
15. Hydrometeorological Handbook for the Seas of the USSR, Vol. 3, Issues
1, 2, 3, Gidrometeoizdat, Leningrad, 1937.
16. Hydrometeorological Handbook for the Sea of Azov, Gidrometeoizdat,
Leningrad, 1962.
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CHAPTER 2
BRIEF CHARACTERIZATION OF FACTORS AFFECTING THE FORMATION OF THE
CHEMICAL COMPOSITION OF LAKE BAIKAL WATER
(Material pertaining to the US-USSR cooperation in the area of
"Mathematical Modeling of Lake Ecosystems)
GENERAL CHARACTERISTICS OF THE LAKE
The basin of Lake Baikal is located almost at the center of Asia, in a
very rugged mountain province of the south of Siberia - the Baikal region.
The characteristics geomorphological feature of the region are medium and
high mountains extending over 1500 km in the southwest to northwest direc-
tion, and an alternation of ridges and trenches, the largest of which is
filled with waters of the lake.
Baikal is the oldest and deepest intracontinental body of water in the
world. The formation of the Baikal trench began about 30 million years ago.
2
The watershed area of the lake is 0.54 million km , and the area of the
2
lake itself, 31.5 thousand km . The length of the lake is 636 km, maxi-
mum width 79 km, minimum width 25 km, maximum depth 1620 m, and volume of
3
the water mass, about 23 thousand km . The trench of Lake Baikal is
divided into three basins, of which the middle one is the deepest; it is
separated from the southern basin by the Selenga shallows, in the region of
which the largest tributary, the Selenga River, flows into the lake. The
runoff of the Selenga amounts to about 50% of the total runoff into the
lake.
Baikal concentrates approximately 4/5 of the total surface water re-
serves of the USSR. . However, the importance of the lake does not end there.
During the past approximately 1 million years, when this body of water was
formed in it present boundaries, some species properties arose in the waters
B-98
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of the lake: low solute content, high transparency, low temperature and
high saturation with dissolved oxygen.
Baikal's biological community is specific and closely balanced. In
the course of its evolution, its organisms have adapted to conditions
varying little with time, and .have reacted very sensitively to changes in
these conditions. Suffice it to indicate that Baikal organisms of the open
deepwater parts of the lake do not dwell in the shallow regions near the
delta, which are subjected to the action of the river runoff.
PROSPECTS FOR THE ECONOMIC DEVELOPMENT OF THE BAIKAL REGION
In planning the basic aspects of the development of the territory adja-
cent to Baikal, a lake that is a unique water reservoir on the earth, an in-
admissible approach would be one in which the desired rapid progress in
economic development might lead to a change in the quality of the water and
atmosphere. This basic principle - to preserve the lake's ecosystem, the
result of processes that took thousands of years - is used in formulating
all the special requirements for developing the economics and changing the
size of the population in the region, and intensifying the monitoring of
the environment.
The organization and implementation of management measures in the
Baikal Basin will be accomplished in the near future with consideration for
setting the lake region apart as an area with special levels of requirements
as regards the problems of conservation and reconstruction of the environ-
ment.
Important elements of this concept include a gradual change to a
directed control of the environment and simultaneous improvement of its
quality.
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The increased amount of attention given to the basin of Lake Baikal in
the past 10 to 15 years has been related to a certain inevitable confronta-
tion of attempts to combine the principles of conservation of the lake's
natural properties with the possibilities of development of various areas
of the region. In this connection, a series of resolutions were passed by
the government, various ministries, Academy of Sciences, Hydrometeorological
Service and other organizations.
The planned development of the industrial-territorial complex in the
lake basin up to the year 2000 will be coordinated mainly with the in-
dividual regions - iii the basin of the middle course of the Selenga River,
on the itinerary of the Baikal-Amur highway under construction in the north.
These limitations are determined by the aforementioned necessity of pre-
serving the purity of the lake's waters.
Considering the further industrial development in the Selenga River
Basin, it was deemed appropriate to design plants with a circulating water
supply and to centralize the repurification of the waste waters.
The total volume of capital investments in the development of produc-
tion facilities in the basin of Lake Baikal during the period from 1971
through 2000 will amount to over 10 billion rubles, approximately 6% of
which will be spent on measures to protect the purity of the water re-
sources and other natural facilities.
As an estimated level, during the next 30 years, a 4 to 5-fold in-
crease in the volume of gross industrial production, 3-fold increase in the
volume of agricultural production, and 1.5-fold increase in timber produc-
tion are envisaged. The expected size of the population will increase by a
factor of 1.5 during the same period.
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DEVELOPMENT OF BAIKAL AS A RESORT AREA
Considerable shifts in the utilization of recreation resources are
planned for the Baikal region. The presence of favorable types of weather
will permit a vigorous growth of many aspects of tourism in this region.
Also promising is the development of medical treatment in sanatoriums and
of resorts and recreation, based on mineral sources and state parks.
A 1971 government resolution stipulates a broad development of recrea-
tion and treatment areas as well as foreign tourism on the shores of Baikal.
At the present time, during the navigation season, over 100 thousand people
visit the lake. It is predicted that by the year 2000, the flow of visitors
will be 2.5 million per year, including 100 thousand foreign tourists. It
is planned to create six natural parks with an area of 150-300 thousand
hectares each, mainly in the southern and middle parts of the lake's basin.
The planned expansion of rest areas will cause an increase in the popu-
lation's employment and will attract visitors to tourist services, rest
houses, etc. Modern construction of numerous boarding houses and campsites
in such tourist centers as peschanaya Bay and other places will also be re-
quired. These measures and processes will inevitably lead to an increased
role of so-called unorganized and inadequately organized residential and in-
dustrial sewage systems. Thus, the requirements for their purification and
isolation from the lake will be raised.
Specialists in recreational development are already pointing out the
difficulties involved in the water supply and utilization of waste, since
the self-purifying capacity of the rivers flowing into the lake is practi-
cally nil and their discharge is low.
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Factors hampering the development of the Baikal area such as the seis-
micity of the regions and the potential danger of specific diseases (tick
encephalitis, etc.) must also be considered.
On the whole, it may be hoped that intelligent efforts and sound mea-
sures to prevent the undesirable influence of the anthropogenic factor will
permit a positive solution of the problem of combining conservation and
economic development in the Baikal region.
BASIC FEATURES OF THE CLIMATE FROM THE STANDPOINT OF FORMATION OF CONCENTRA-
TION FIELDS OF SUBSTANCES IN THE ATMOSPHERE
The formation of the climate in the Baikal depression and adjacent
territory is determined by the large-scale transport of the air masses,
thermal conditions of the lake, mountain relief, and other local factors.
The humidification of the basin is related to the westward transport
of the air masses. During the warm part of the year, the cyclonic activity
is activated here, resulting in 80-90% of the total annual precipitation,
including 50% in July-August alone. In winter, a powerful anticyclone which
blocks westerly winds develops in the lake region.
The distribution of precipitation above the lake is nonuniform and
varies from 200 to 1200 mm for individual regions. The average long-term
total precipitation for the water area is about 400 mm per year. The
largest amount of precipitation falls on the southern shore of the lake; in
the region of the Selenga shallows, it is most commonly in the range of
300-400 mm per year. Approximately 15% of the total precipitation is due
to evaporated local moisture.
The nonuniformity of the annual distribution of precipitation coupled
with the characteristics of the temperature regime and dissected topography
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accounts for the fact that rainfall floods are the main phase of the rivers'
water regime. They occur from May to September, the period when 80-90% of
the annual runoff is formed. In the wintertime, the rivers are low.
The distribution of impurities in the atmosphere and in the surface
layer of the lake is greatly affected by the temperature regime and the
wind direction and speed.
Stable and strong temperature inversions, often with a complex multi-
stage structure, are very frequent above the lake, especially during the
warm season. During these periods, the self-purification of the air reser-
/
voir is minimal, since the impurities concentrate in local regions. In
situations where breeze and mountain-valley circulations interact in the
Baikal trench, the impurities penetrate intensively in the direction of both
the dry land and water areas. During these periods, pollutants become dis-
tributed over small areas of the territory and retain relatively high con-
centrations. Subsequently drawn into the local wind system, they may spread
over considerable distances.
FORMATION OF CURRENTS IN THE LAKE
The chief source of motion of Baikal's water masses are the winds in
its basin. In limited areas, an appreciable influence is exerted by iner-
tial jets formed by large inflows. Above the water area of the lake and
particularly above the central and southern parts, the northwesterly type
of wind fields predominate during the course of the year (frequency, 31%).
Strong winds of southeasterly direction are frequently observed near the
eastern shore of southern Baikal. Another characteristic feature of the
entire region is the simultaneous presence of northwesterly wind currents
on the western shore and southwesterly ones on the eastern shore.
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The frequency of winds of different velocities is approximately the
same for all directions during the annual cycle. The wind speed is in the
5-10 m/sec range most of the time, but it may reach 16-20 m/sec during the
spring-summer period.
Wind-generated currents form several types of circulation of water
masses in the lake.
Large-scale cyclone-type circulations cover all three parts (basins)
of the lake, the number of such circulation being 6-7. Inside, mesoscale
eddies and secondary circulation, particularly in regions with a hetero-
geneous bottom and shore, exist along the -coastal macrocirculations.
Insofar as it has been studied, the wind regime above Baikal makes it
possible to estimate the duration of water-lowering (raising) circulation
18
processes in the lake at 40 to 80 hours.
Currents are observed in the lake everywhere, including deepwater
areas. The current speed has an annual variation; it increases with an
intensification of the winds after the lake is cleared of ice in May-June,
declines during the summer period of scarce winds, and increases during the
autumn storm period.
The horizontal structure of the current fields is fairly complex,
particularly in the coastal regions.
The average speed of large-scale circulations is around 2-3 km per day
(2.3-3.5 cm/sec) during the navigation season and 1-1.5 km per day (1.1-
1.8 cm/sec) during the ice period, but individual large-scale gusts can be
an order of magnitude higher. The gusts last an average of 20-30 h.
Among other circulatory formations, the highest frequency is displayed
by eddies 1-2 km in size. Late in autumn, in the presence of strond wind
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and when the temperature stratification is practically absent, eddies from
6-7 to 5-10 km occur.
Hydrochemical surveys made in the coastal strip revealed finer turbu-
lent structures 0.5-1 km in size. It is possible that these eddies have a
local character related to the inhomogeneity of the shoreline.
A characteristic feature of currents in the 8-10 km shore strip is
their practically identical direction over the entire thickness of the layer
from the surface to the bottom.
However, within this area there exist several characteristic features
/•
in the transport of thie water masses. The current speeds at a distance of
0.4-0.6 km from the shore are 1.5-2 times lower than at 1.5-2 km. Slight
eddylike circulations of different types and sizes frequently appear in this
strip. The transport in the strip up to 1.5 km is much less than in the
zone located at a distance of 1.5-3 km. Steady and strong alongshore cur-
25
rents begin to appear at approximately the same distance (1.5-2.5 km).
At a distance up to 2-3 km, the current speed is 1.5-2 times lower
than at 3-5 km from the shore.
In the deepwater part of the lake, the observed maximum of current
speeds ranges from 25 to 50 m, then the speeds slow down, and below 100 m
toward the bottom become almost homogeneous in magnitude and direction.
According to observations in southern Baikal during the open period, the
average current speeds for the navigation season are in the 12-18 cm/sec
range at a depth of 15 m and 4-8 cm/sec range at 50 m and lower. The
speeds increase everywhere from summer to autumn.
The vertical structure of the current speed profile is determined to a
considerable degree by the temperature stratification of the water masses.
B-105
-------
When the latter is constantly present, the speed values averaged over
several days and the directional stability decrease from the surface to the
thermocline layer. Below the latter, they increase, then the speed de-
creases smoothly with depth.
In deepwater parts of the lake, according to the character of the
vertical distribution of currents, the upper (dynamically active), deep and
bottom zones are distinguished. The upper zone covers 0.3 of the depth,
and contains high values of maximum speeds and an inhomogeneous distribu-
tion of average values during periods of temperature stratification. In
the deep zone, the currents are more stable and change little with time and
in speed. The bottom zone (without the layer of bottom friction) is
characterized by a certain increase in current speeds.
During the cold season, the currents remain, but their speed is much
lower. A major part of the time (60%), the speeds under the ice are less
than 2 cm/sec. On the western shore, they were observed during 30-45% of
the observation time, and on the eastern shore, speeds above 2-3 cm/sec
were not observed. In winter, in areas located far from the shore, speeds
of 5-9 cm/sec were recorded that remained almost constant in magnitude and
direction for up to 5-12 days.
The vertical current speed profile in the upper 3 m layer under the
ice is characterized by very low values. Below 3 m, the speed increases,
then decreases somewhat in the area of the first thermocline layer (at
approximately 25 m), reintensifies, then decreases again. At the bottom,
the current speed increases slightly.
In the southern Baikal at the 15-20 m level, a cylonic circulation
similar to the one observed during the navigation season was observed in
Winter' B-106
-------
TRANSPORT OF MATTER IN THE LAKE
As was indicated earlier, the main transport of water masses in the
lake takes place in the upper layer, whose thickness amounts to approxi-
mately 0.3-0.4 of the lake's depth.
Observations of the distribution of water temperature, aquatic or-
ganisms and certain substances in the water of the lake showed that during
all seasons, local formations (separate water masses) exist according to
one or several indices. The dimensions of the heterogeneous structures
amount to 0.5-1 to 5-10 km, but "spots" of smaller size, distinguished by
X
' 18 22
means of hydrochemical indices, were also found. '
The coefficients of horizontal turbulent exchange (K), calculated from
data on currents and dimensions of heterogeneities of hydrochemical and
252
hydrobiological fields, are of the order of 10 -10 cm /sec.
In the near-shore zone of southern Baikal, for eddies 0.5-1 km in size,
4 42
they were found to be 10 -5'10 cm /sec, and at a depth of 13 m, 350 m
2 32
from the shore, 5-10 - 6«10 cm /sec.
Data obtained after studying the distribution of fluorescent matter in
2 32
the shore zone showed values of 10 - 10 cm /sec; according to obser-
4.
vations of another tracer, for the summer-autumn period, (3-5)«10
9 o ^
cm /sec, and for winter (across the flow), 10 cm /sec.
The average values (K) for the November-December season on the Selenga
4 2
shallows were found to be in the (2-8) -10 cm /sec range for eddies of
approximately the same size.
A study of the structure of current fields in southern Baikal showed
that macroturbulent eddies in the shore strip have an anisotrophic character
B-107
-------
which decreases with increasing distance from the shore. The isotropy
remains only in small formations up to 100 m in size.
It was also found that the mean daily exchange coefficients are highly
variable and do not always obey the accepted laws in the case of large-scale
macroturbulent eddies.
According to the water temperature and optical characteristics of the
water masses, a near-shore zone of deepwater Baikal having a width of 1-2 km
is distinguished in the lake. Extending through it are turbid floodwaters,
and it contains the highest values of gradients of the indicated para-
23 24
meters. ' The permanent differences manifested here between the
values of many indices indicate the existence of a transverse component of
the velocity of the alongshore cyclonic circulation, directed toward the
2 -3
shore in the surface layers and having a value of 10 - 10 cm/sec for
20
the warm period. The velocity of the reverse process (horizontal tur-
bulent diffusion) at the boundary between the near-shore zone and the waters
of the open lake has approximately the same value, but on the average, the
transport processes have a stronger influence on the distribution of impuri-
ties.
The pulling of the surface waters of the lake toward the shores by the
transverse component of the alongshore flow interferes with the inflow of
wash products from the shores and with the runoffs into the pelagic zone of
the lake. These substances will dissolve slowly in a comparatively narrow
strip and be transported over long distances. The localization of impuri-
ties in a comparatively small volume is most pronounced in summer and winter
during periods of vertical stratification.
B-108
-------
Analysis of data on the seasonal variation in water temperature and in
the concentrations of chemical elements in deep layers of the lake makes it
possible to assert the existence of a vertical circulation. The latter
develops with particular intensity above underwater slopes in a near-shore
strip 3 to 9 km wide. On the average, such circulations with speeds of
-1 -2
10 - 10 cm/sec are most frequent directed downs lope.
According to hydrochemical data, the processes of ascent of water
masses in the central part of the lake (~10 cm/sec) and descent near
the shore promote the aeration of deep waters. These processes take place
intensively in autumn', when the intensification of wind activity raises the
horizontal current speeds, and the temperature stratification attenuates.
According to preliminary estimates, the substitution time of deep
waters by surface ones is approximately 20 years at a rate of descent of
-2
10 cm/sec.
A strong mechanism of vertical mixing of the water masses is thermal
convection. Calculations of vertical thermal diffusivity showed a fluctua-
2
tion of the values from unts to thousands of cm /sec during the course of
a year. During the period of stable summer stratification, the diffusivity
2
is equal to approximately 7 cm /sec, and during the autumn isothenny,
2 23
over 1000 cm /sec. The contribution of thermal convection to the
vertical mixing is many times greater than that of turbulent diffusion. We
calculated the average vertical turbulent exchange coefficient from data on
2 2
current speed fields to be of the order of 10 cm /sec.
The highest values of the thermal diffusivity coefficient corresponds
to periods of development of intensive convection in the lake and periods
of spring warming and autumn cooling.
B-109
-------
The combination of complex horizontal and vertical displacements of
the lake's water masses as a result of steadily acting large-scale
circulations and periodically forming smaller eddies related mainly to
seasonal phenomena leads to the transport of waters in the upper layer from
the center of the lake to the shores, their descent along the shore slopes
into the bottom region, and ascent of deep waters at the center of the
i i 20
lake.
WATER EXCHANGE BETWEEN INDIVIDUAL PARTS OF THE LAKE - WATER BALANCE
According to the data of the Limnological Institute, the water exchange
s
accomplished by large-scale horizontal circulations within each of the three
main parts of Baikal takes place most intensively in the upper 40% of the
water mass.
Table 1 gives long-term average water balances of individuals parts of
20
the lake for a year.
The water balance of Lake Baikal, according to the calculation of the
State Hydrological Institute based on observations for the period from 1901
to 1970 and Limnological Institute for approximately the same period, is
21
presented in Table 2.
BASIC ECOLOGICAL IMPORTANCE OF THE SELENGA REGION
In connection with the prospect of economic development of certain re-
gions in the Selenga River basin, augmentation of the river load with
treated waste as well as particles of soil cover washed into the river is a
possibility.
The importance for Baikal of the chemical runoff of the Selenga and of
the processes taking place in the river, especially its lower course, delta
B-110
-------
TABLE 1. AVERAGE LONG-TERM WATER BALANCES OF PARTS OF BAIKAL IN ONE YEAR, km
(Verbolov and Shimarayev, 1972)
Elements of Balance
Northern part
of lake
Central part
of lake
Southern part
of lake
GAIN
Inflow (surface and under-
ground)
Precipitation
Inflow from neighboring
part of lake (runoff)
TOTAL
13.8
3.7
17.5
23.7
2.8
13.9
(from northern
part)
40.4
23.4
2.8
36.2
(from southern
part)
62.4
LOSS
Evaporation
Outflow into neighboring
part and Angara River
TOTAL
Inflow when water level
is raised*
3.6
13.9
3.5
36.2
(into central (into southern
part)
part)
17.5
20
39.7
20 from south
10 from north
2.3
60.1
(into Angara
River)
62.4
10
Outflow when water level .
is lowered*
Volume of waters in part
of trench
Conventional time of water
exchange (loss + wind
tides) volume = years
10
7020
225
20 from north
10 from south
20
9200
5450
132
66
*The longitudinal profile of the lake level was assumed to be the same as in
a uninodal seiche.
B-lll
-------
TABLE 2. WATER BALANCE OF LAKE BAIKAL DURING THE PERIOD 1901-70
Elements of Balance mm/year m^/sec km^/sec %
(1) As calculated by the State Hydrometeorological Institute
GAIN
Surface inflow 1914 1910 60,28
Precipitation 405 404 12,76
Total 2319 2314 73,04
LOSS
Runoff through Angara River 1888 1884 59,46
Evaporation 416 415 13,10
Accumulation 15 15 0,48
Total 2319 2314 73,04
(2) After A.N. Afanas'yev
GAIN
Precipitation 296 9,29 13,1
Condensation on surface of
lake
Inflow of river waters
Inflow of ground waters
Total
Runoff from lake
Evaporation
Total
27
1870
(68)
2261
LOSS
1916
331
2261
0,82
58,75
2,30
71,16
60,39
10,33
71,16
1,2
82,7
3,0
100
84,8
14,6
100
B-112
-------
and contiguous region of the lake, consists in the fact that the Selenga is
a principal tributary which actively participates in the formation of the
ecosystem of this body of water. The value of the Selenga delta region and
of the shallow zone encircling it also lies in the growth and development
of the Selenga whitefish young exclusively in this area. Initially, after
its larvae have hatched, in April-May, the whitefish remains in the delta
for 35-45 days, and in shallows, until mid-August. Hence, until the end of
June, the whitefish young are under the direct action of the substances
entering the delta with the river runoff and during the subsequent period
are exposed to the influence of the waters diluted in the shallows. If the
level of toxic pollutants in the water of the Selenga from April to August
is an active one for fish, there is no doubt that it can have an even
stronger influence on the remaining trophic links of the Selenga shallows.
An essential role in all seasons is played by the runoff of suspended
matter and waters of the Selenga in the formation of bottom sediments of
the shallows. The studies performed also indicate that the suspended
material is affected by the processes of pollution and self-purification of
the reservoir.
TEMPERATURE REGIME OF WATER IN THE SOUTHERN PART OF THE LAKE
Baikal is a cold-water lake with water temperatures changing little in
the course of the year at depths of over 150 m. While in the surface layer
of water in different seasons, the temperature ranges from 0.3°C in February
to 15°C in August, starting at a depth of 150-200 m it is approximately con-
stant at 3.3-3.9°C the year round.
At least 40-50 days pass after the ice of the lake breaks before the
upper 20-meter layer of water warms up to 3.3-4°C and the spring homothermy
B-113
-------
sets in. In southern Baikal, it usually corresponds to the third ten-day
period in June. At the start of the warming period (May - early June), the
isothermal layer is thin and its water temperature low. During the first
two to three weeks after the ice break, the water temperature in southern
Baikal remains at the 0.5-1°C level in a layer of water only a few meters
thick.
The summer warming of open waters of southern Baikal lasts from the
spring isothery (end of June) to the middle and end of August. By that
time, the surface layer of water has warmed up to 12-15°C, and occasionally
higher.
During the period of summer warming, the temperature stratification of
the water mass is well-defined, especially after long periods of calm.
During this time, one distinguishes a layer of increased temperatures
(epilimnion) with a low gradient of their decrease with increasing depth,
an intermediate layer with a sharp temperature drop - the discontinuity or
thennocline layer, and hypolinmion - a layer with lower water temperatures
and small gradients of their decrease with depth.
At the start of the period of summer warming, the thermocline layer is
established at a depth of only 2-5 m, and toward the end of August descends
96
to 4-5 m in northern Baikal and 10-25 m in central and southern Baikal.
BRIEF CHARACTERIZATION OF CLIMATIC CONDITIONS OF THE SELENGA REGION
Expeditionary studies in the area of the Selenga delta and shallows and
observations at stationary weather stations in this region offer convincing
evidence of the presence here of conditions and seasonal meteorological pro-
cesses common for Baikal and its littoral atmosphere.
B-114
-------
The climate of the delta area is continental, but, like on the entire
shore, milder than in regions distant from the lake.
The mean annual air temperature is -0.7°C, the July temperature is
+17.5°, and the January temperature, -21.1°. The duration of the period
with air temperatures above 0° is 170-180 days.
The total annual atmospheric precipitation is 250-400 mm, and the mean
long-term precipitation is about 315 mm. The major part of the precipita-
tion occurs during the warm season. The maximum is observed in July and
August, and the heaviest precipitation occurs in the second half of June.
Evaporation in the Selenga region changes appreciably from one year to
2
the next. The total absorbed radiation is approximately 90 kcal/cm year.
DISTRIBUTION OF SELENGA WATERS IN THE LAKE - INFLUENCING FACTORS
The Selenga is the most substantial tributary of Lake Baikal. The area
of its basin amounts to 83.4% of the territory of the lake's water runoff,
and the water runoff amounts to 50% of the total runoff into the lake. The
Selenga waters flowing into the lake annually introduce an average of about
4 million tons of solutes and 2 million tons of suspended matter (75% of
the annual inflow of salts and 70% of suspensions brought into the lake
with all river waters).
The distribution o,f the Selenga waters in the lake takes place via a
system of numerous delta branches (Figure 1).
2
The delta area is over 600 km , the outer edge being about 70 km
long. During the period of highest water content in the river, approxi-
mately 30 branches are counted in the delta. During the period without ice
cover, about 90% of the Selenga River runoff is carried from the north and
B-115
-------
Fig. 1. Delta of Selenga River and its branches
1 - Shamanka, 2 - Kharauz, 3 - Galutay,
A - Srednyaya, 5 - Krivaya, 6 - Kolpinnaya,
7 - Severnaya, 8 -'Lobanovskaya,
A - Kharauz weather station
B-116
-------
1000
Fig. 2. Diagram of depths in the region of Selenga shallows
26
B-117
-------
southern parts of the delta through 8-10 main branches.* The entry of
river waters into the lake through branches of the central part of the delta
. . . .c. 8,9
is insignificant.
The largest navigable branch, Kharauz, located in the southern part of
the delta, usually gives less than 20% of the total runoff, with the re-
maining large branches giving no more than 5-10%.
When the river discharges in the section before the delta are close to
average (1500 m /sec), 50-60% of the runoff enters the southern part of
the delta and 35-45% enters the northern part, of which 30% goes into
Proval Bay. At discharges of 1500-2000 m /sec, the runoff is approxi-
mately evenly distributed between the southern and northern parts of the
delta. If the discharges exceed 2000 m /sec, 50-60% of the runoff enters
the lake through branches of the northern part of the delta.
In winter, 90-95% of the river waters located at the apex of the delta
3
enter the lake through one branch.
According to the data of hydrological observations, the penetration of
river flows into the lake depends on the water content of the branches and
speed of the flows at the exit to the lake. In the main branches, the speed
of the currents most commonly fluctuates between 30 and 60 cm/sec. At an
average speed of about 30 cm/sec in one of the main branches, the Selenga
water extends over a distance of 3 km into the lake, expanding by a factor
of more than 4-6 in this stretch. At the maximum speed of flow, 70 cm/sec,
observed mainly during the passage of a flood, it extends over 9 km into
the lake, and at the minimum speed, 6 cm/sec, over 0.3-0.4 km.
*According to some estimates, through 6-7 branches,
B-118
-------
Further, distribution of the Selenga waters in the lake is very com-
plex, and judging from available data, is explained in different ways by
some of the investigators. This pertains primarily to the directions and
magnitudes of water exchange between the individual parts of the lake, and
hence, to the transport of the solutes and suspended matter present in the
water.
The size of the water area over which the Selenga waters are distri-
buted as a function of hydrometeorological conditions can apparently vary
from tens to a thousand or more square kilometers. There are as yet no
sufficiently precise comprehensive criteria to permit one to determine from
generalized indices the boundaries of the zone of penetration of river
waters into the interior of the lake. If, for example, the average current
speed in the open lake, 5 cm/sec, is used as the only citerion for a con-
2 .
tact boundary, the size of the area is about 500 km , with the principal
direction of elongation of the zone along the northeastern shore.
During the period of flooding, when the flow of the Selenga water is
heaviest, it can reach the western shore and, entering the system of macro-
circulation currents penetrate into southern Baikal. At low discharges,
the northward distribution of the Selenga waters into central Baikal is
more probable. As is evident from the comparison, these data'almost contra-
dict the above conclusions that the river runoff is distributed over the
branches as a function of the water content (see p. ).
The formation of currents and zones of propagationof substances in the
Selenga shallows, in addition to being affected by the penetration of river
flows from the delta branches, is also dependent on the characteristics of
the local wind field above the lake.
B-119
-------
The principal directions of the wind in the region of the Selenga
shallows are southwesterly and northeasterly. The wind of NE direction is
observed with particular frequency on the western shore, opposite the
Selenga delta. During the navigation season, the frequency of winds of
these directions amounts to approximately 20% each. The highest wind speeds
are usually observed slightly to the north of the delta.
As an example, Figure 3 (Table 3) shows the principal wind directions
and average speeds recorded by observations on ships in June-August.
Owing mainly to the constancy of the wind directions (with the preva-
lance of northeasterly ones), horizontal currents which retain their direc-
tion the year round are created in the lake. One of them, the Selenga cur-
rent, was observed back in the 1920's. According to the observations, in
calm weather the waters of the Selenga flow into Baikal in two branches:
to the northeast and southwest in the direction of the head of the Angara
River. The main flow, hugging the western shore of Baikal, travels to the
southwest in a band a few kilometers wide. The Selenga River waters, mixed
with the lake waters, can be easily distinguished by their reduced trans-
parency and color index, as well as hydrobiological and hydrochemical in-
dices. It has been found that in the area of the head of the Angara River,
the Selenga waters are observed to a depth of 5 m in summer and 20-50 or
even 100 m in winter. The current speed in a stable flow in winter is 2.7
cm/sec.26'27 .:'
During SW winds, waters of the Selenga River are detected along the
eastern and northeastern shore of the lake over 120-130 km. When the band
is 3-5 km (occasionally up 7-8 km) wide, they occupy an area of 500-600
2
km in the central part of the lake. In the presence of NE winds, the
B-120
-------
Fig. 3. Average wind speeds (m/sec) in June-August and wind roses
on the Selenga shallows
B-121
-------
TABLE 3. AVERAGE WIND SPEED (m/sec) IN JUNE-AUGUST BASED ON DATA OF SHIP
OBSERVATIONS ON THE SELENGA SHALLOWS, AND FREQUENCY OF WINDS
OF DIFFERENT DIRECTIONS AND CALMS (in %)16
Average
Stations Speed N NE E SE S SW W NW Calm
16 3,5 9,4 13,0 8,0 9,4 4,3 13,7 11,6 14,5 16,1
17 4,1 9,8 15,7 - 7,8 3,9 13,7 23,5 15,7 9,1
14 2,7 10,6 10,6 10,6 7,6 1,5 16,7 10,6 4,5 24,6
15 3,1 8,9 25,9 4,5 7,1 7,1 21,4 7,1 9,8 8,2
10 2,7 2,9 17,6 4,4 10,3 13,2 26,5 7,4 5,9 11,8
11 2,7 11,9 23,8 8,3 6,0 10,7 16,7 2,4 9,5 10,7
B-122
-------
Selenge waters spread over approximately the same area to the south of the
delta. Having a higher temperature and lower density, the waters of the
Selenga River spread mainly through the surface layers of the lake to a
depth of 10-20 m.
An essential role in the further mixing of the water masses is played
by the vertical motion of the flows, which leads to an equalization of the
properties of the water masses, formation of an epilimnion, thermocline,
and hypolimnion. According to the data of the Limnological Institute, the
contribution of the thermal convection mechanism to vertical mixing is many
times greater than that of turbulent diffusion. A special role is played
in the spring separation of shallows and estuaries by the formation of
thermal bars.
In addition to the thermobar phenomenon, the thermocline present in the
upper layers of the lake during 75-80% of the year is also important. By
isolating waters of the most biologically active upper layer (epilimnion)
from the main water mass, the thermocline raises the concentration of im-
purities inthe upper trophogenic zone of Baikal. Both of these phenomena
promote the accumulation of impurities around the areas of the lake near
estuaries. In the summertime, warm river waters containing matter not
characteristic of the natural lake water background, spread mainly along
the shores in a comparatively thin surface layer.
Hydrological observations made during the cold season lead to the as-
sumption that the system of currents formed under the action of wind during
the navigation season remains essentially unaffected for a long time. This
is confirmed by studies made during the period of November-March. However,
with time, the speed and stability of the currents may decrease.
B-123
-------
It may be assumed that the mechanisms of transformation of currents
consists in a steady transfer of energy from macroturbulent formations to
smaller structures. This also leads to the conclusion that the role of
such structures in the migration of impurities present in the water masses
increases during the cold season.
As a result of the combined action of runoff and wind currents, the
maximum area over which the Selenga waters differing in color were detected
2
during the open season apparently amounts to 1500 km in the portion of
the lake adjacent to the delta.
According to the data of aerial visual surveys, a zone of heavier tur-
bidity exists inside this region. During period of medium runoff, its area
2
is no smaller than 150 km at the outer edge of the delta and of approxi-
mately the same size in Proval Bay, located north of the delta.
2
In the shallow-water Proval Bay, whose total area is 150 km , the mo-
tion of the waters is chiefly determined by the wind active above the bay.
The runoff current is manifested here only in the southern portion of the
bay, into which empties the most heavily flowing of the northern tributaries
of the Selenga River. The speed of the total current in the bay is 5-18
cm/sec less than in the adjoining open regions of the lake, but in the pre-
sence of strong winds, it values reach 60-65 m/sec. The water exchange of
Proval Bay with the open lake under calm and weak wind conditions is slight
and caused by the inflow of river waters-.
Studies on models of runoff currents of the Selenga and Angara Rivers
and wind currents do not give definite answers concerning the spread of
Selenga water.
B-124
-------
One laboratory study of a hydraulic model of Lake Baikal* confirmed
field observations of hydrochemical indices and turbidity, which indicated
penetration of Selenga waters to the western shore.
The modeling revealed the development, near the northwestern shore in
South Baikal, of a cyclonic circulation and a transit current promoting the
transport of Selenga waters into the southern basin.
The time taken by the Selenga waters to reach the flow of the Angara
amounts to an average of about a year and a half, according to calculations
2
made with this model.
Because of the characteristics of the wind regime of the Selenga
region, the transport of waters to the north predominates in spring-summer
near the southeastern shore, and to the south in autumn.
At the same time, .the distribution of current speed fields with time
remains complex. A sharp change in current directions can take place here
in one or two days. The average current speeds during the navigation season
in the central part of the shallows at a depth of 15 m are 15 cm/sec, and
at 150 m, cm/sec. At a distance of 150 m from the lake edge of the delta,
opposite one of the large estuaries, the speed in the surface layer in
different parts of the ^stream was 7-19 cm/sec, and at a distance of 300 m,
13 cm/sec. Thus, it is apparent that in addition to alongshore currents
with speeds of 20-30 cm/sec, a circulatory formation with low speeds, 2-10
cm/sec, exists in the central part of the region.
*According to field studies, 40% of the discharge of the Selenga River was
supplied to the northern branches and 30% each to the central and southern
branches.
B-125
-------
During the winter season, currents to the shallows are attenuated and
clearly observed only across from the active branches of the delta. No cur-
rents are observed at distances of 3 km.
During the ice period, in the region adjacent to the Selenga River
delta, if currents along the shore are present, they are under 2 cm/sec.
The speeds of deep current (below 150 m) during this period are more appre-
ciable than those of surface currents. Speeds of 5-7 cm/sec or even 10
cm/sec have been observed, although 60% of them did not exceed 3 cm/sec.
In the northern part of the Selenga shallows, the current speeds are
low in all seasons, and according to observations during the navigation sea-
son, they are of a pulsed character that duplicates the wind regime.
It has been noted above that the surface currents on the Selenga shal-
lows are marked by a considerable complexity and inhomogeneity.
Because of frequent changes in wind directions and sometimes even in
the presence of stable winds, the current fields in the shallows may vary
considerably during a short time interval. As an example, Figure 4 shows a
current pattern recorded in the surface layer over the course of two days.
Preservation of current fields as long as ten days was observed less fre-
quently, despite the variability of the wind conditions. As a rule, cur-
rents of deepwater circulation are more stable and begin to be manifested
in the shallow-water region at depths of over 40-50 m.
During the navigation season, the net transport of water masses in the
Selenga shallows near the southeastern shore is directed eastward, and near
the northwestern shore, westward. The average transport speeds for the
entire cross section of the flow are 1-3 cm/sec, and lower in summer than
in autumn (particularly in November-December). In the central region of
B-126
-------
Fig. 4. Diagram of surface currents in the Selenga region in the
0
presence of various winds
1 - prevailing southwesterly wind (30 August 1972);
2 - prevailing northwesterly wind (31 August 1972);
3 - steady lasting northwesterly wind (8 September 1972)
B-127
-------
the shallows, a turn of the current across the lake is observed (most fre-
quently) in the upper layers.
The average duration of a current in a single direction, based on
autumn data at a station located 7 km from the delta at a depth of 13 m, was
42 hours (maximum, 5 days), and at depths of 25 and 47 m, 45 hours (maximum,
7 and 5 days). The average current speeds at these depths were 28, 17 and
24 cm/sec. The macroeddies were 1-4 km in size, and the time of action
(existence of the eddies) was 10-40 hours.
WATER EXCHANGE IN THE REGION OF THE SELENGA SHALLOWS
The predominance in the Selenga region of SW, NE and in part, NNW winds
makes it possible here to distinguish several types of water mass transport:
the equilibrium type, in which one or several macroeddies are located
between the southern Baikal and central Baikal circulations; wind tide type,
whereby waters of southern Baikal intrude into the shallows over approxi-
mately 1/3 of the extent of the region or, coversely, 1/3 intrudes from cen-
tral Baikal; and a transition state characterized by a high turbulence of
the currents.
The duration of the intrusion of waters of southern or central Baikal
into the shallows usually does not exceed 30-40 hours, and the return to
the state (level) of equilibrium takes place in 1-1.5 hours. Calculations
show that about 10 km flows into the southern part of the lake when the
3
water level is raised by the effect of wind, and 20 km flows out into
the central part when the water level is lowered. Observations established
that during the annual cycle, water transport northward takes place near
the eastern shore, and southward, primarily along the northwestern shore.
B-128
-------
Tests on the model showed that under conditions of stormy winds
directed along the lake, water exchange in the basins is approximately 3-4
times greater than between them through the Selenga shallows.
RUNOFF REGIME AND CHARACTERISTICS OF SUSPENDED MATTER OF THE SELENGA RIVER
AND SHALLOWS
In comparison with other rivers of the lake basin, the Selenga river
has the greatest turbidity. During the medium low-water level in May, the
river waters may contain 350-400 mg of particles per liter, the average
long-term concentration maximum in May being in excess of 100 mg/£. The
transparency of Selenga waters during the spring-summer period does not ex-
ceed 0.15-0.20 m and increases to 1.5 m by autumn.
The chief causes of the higher content of suspended and dragged
material in the river water are the shower character of the rains and the
intense management activity on the territory of the river's watershed. How-
ever, the rate of chemical denudation in the Selenga basin - 0.0021
mm/year - is less than for the basin of the entire lake - 0.0052 mm/year.
The latter rate in turn amounts to approximately 1/2 of the average chemical
12
denudation of the earth, equal to 0.01 mm/year.
The annual distribution of the runoff of suspended matter (in % of the
mean annual value) is irregular:
Winter Spring Summer Autumn
1.2 23.2 57.8 17.6
The (mean long-term) particle size distribution of suspended detritus
of the Selenga River is as follows (in %):
particles of size greater than 0.5 mm 3.2
from 0.5 to 0.2 mm 8.1
<0.2to O.lmm ;9.5
less than 0.1 mm 80
B-129
-------
In the last fraction, 75-90% of the particles are 0.05 mm in size.
During the last decade (1965-74), the mean annual transport of sus-
pended matter into Lake Baikal by the Selenga River, according to measure-
ments in the cross section before the delta, amounted to 1.9 million tons,
with extreme values of 0.8 and 3.8 million tons (in 1972 and 1973, respec-
tively) in individual years of the period. Measurements of the runoff of
suspended matter during previous extended time periods up to 1965 showed
approximately the same values. For example, the average removal of suspen-
sions in 1947-62 amounted to 2.3 million tons.
s
The coefficients of variation of the runoff of suspended matter during
these two consecutive periods were practically the same: 0.52 and 0.54.
In terms of concentrations of suspended matter, it was determined that
in 1947-62, the Selenga carried an average of 80 mg/& into the delta, versus
62 mg/Jt in 1965-74.
In the view of specialists of the Limnological Institute, the present
regime of transport of suspended matter (which has been in existence for at
least 30 years) substantially exceeds the mean annual runoff of suspensions
into the lake during the entire period of formation of the deltaic cone in
the Selenga delta, equal to 0.9 million tons per year.*
During the period of rainfall floods, 50% of the suspensions are com-
posed of particles smaller than 0.01 mm and 40%, 0.01-0.05 mm. During the
winter low-water period, the particle size is above 0.05 mm.
The average sedimentation rate in the region of the delta shallows is
approximately 150 cm per 1000 years, which is 25 times faster than the
*The value was obtained from the age of the cone, 2 million years, its
volume, 1.2 thousand km^, and the density of the detritus, 1.5 g/cm^.
B-130
-------
average rate for the entire lake. The volume of deposits on the bottom of
3
the lake has now reached 46000 km , i.e., the Baikal trench is now two-
12
thirds filled with sediment.
With increasing'distance from the delta, the suspended material is
sorted out, and the types of bottom sediments change from sands to clayed
silt.
In the near-shore sands of the outer delta, over 75% consist of the
0.25-0.05 mm particle size fraction. This fraction and a finer one, 0.05-
0.01 mm, predominate in the coarse silts (48%). In fine and clayed silts,
approximately 60% consist of particles 0.05-0.005 mm in size.
The content of organic matter is lowest in sands, less than 1%, and
maximum, 2.4%, in pelitic silts. In comparison with other regions of
Baikal, the bottom sediments of the Selenga shallows are depleted or organic
matter.
In the surface layer of the bottom sediments of the shallows, the
closer to the delta, the more active the diagenesis of organic matter. As
a result, the content of organic matter (in terms of organic carbon) in-
creases from 0.35% at depths of 0-5 m to 2.5% at 100-250 m.
Allochthonous organic matter is observed in bottom sediments at a
distance of 3-5 km from .the shore.
According to individual observations, the distribution of organic
nitrogen in the bottom sediments of the shallows has a spotty structure.
In the southern region near the delta, the relative concentration N
equals 0.15-0.20%, and in the northern region, 0.05-0.15%.
The relative phosphorus content of the bottom sediments remains at
approximately the same level, -0.1%, over a wide range of depths (0-250
<> 13
m)' B-131
-------
A large portion of the organic matter of bottom sediments of the sur-
face layer is represented by readily hydrolyzable compounds.
It is difficult at the present time to draw conclusions regarding the
annual dynamics of the chemical composition of the suspensions. An analysis
of suspended substances sampled in May give the following results (in % of
air-dried residue):
C ~2; P - 0.1; Fe ~ 3; Mn ~ 0.05; SiO ~ 60.
DISTRIBUTION OF SUSPENDED MATTER OVER THE SELENGA SHALLOWS
On the average, a complete exchange of the lake's waters can take place
only in the course of over 400 years. However, owing to the existing system
of circulation currents, the Selenga waters can reach the Angara River in
2-3 months. On the other hand, river waters flowing into central and pos-
sibly northern Baikal can remain in the lake for a long time.
In the deepwater region of the lake, water exchange is slow in compari-
son with the border regions, pelagic zone, and near-shore strip. As a re-
sult, in the open deepwater region of the lake, the water transparency can
reach 40 m and decrease to 5-10 mm during the period of maximum plankton
development.
Turbid waters of the Selenga River, particularly floodwaters, differ
markedly in color and optical characteristics from the transparent lake
waters. The zone of visible propagation of the Selenga water usually
occupies a shore strip 1.5-3 km wide and crosses the 4-5 m isobath. At
these depths, the water mass is always homogeneous according to optical
observations.
At the same time, hydrochemical observations in the region of Selenga
shallows in August-October detected currents promoting the transport of
B-132
-------
suspensions 20 km into the interior of the lake and along the eastern shore
60 km to the south and 20 km to the north. Most frequently, in summer, the
water transparency in the region before the mouth, even far from the
shores, is mainted in the 2-3 m range, and after storms it may decrease to
a few centimeters. The southern branch, as the larger one, is traced to a
depth of over 30 m (particularly in calm weather). The main index is the
vertical homogeneity of the stream based on the water temperature and trans-
parency. The northern stream apparently nmoves under the surface waters of
Baikal. According to certain observations, for example, of 20 July
1962, turbid river waters extended over approximately 50 km in the northern
direction and 15 km (farthest distance) into the interior of the lake. The
water transparency in the zone at the outlet of the branches was up to 2 m,
and at a distance of 1-2 km, up to 9-17 m. In 1963-64, on the western
shore of southern Baikal near the southwestern end of the Selenga shallows,
in a region through which pass the dilute Selenga waters, the water trans-
parency at a distance of 1-1.5 km from the shore ranged from 4-5 m in
August-October to 18-21 m in June. In late May and early July, the trans-
r\r
parency in this area was in the 8-14 m range.
The very frequently observed sharp propagation boundary of the Selenga
waters is related to the particular character of the turbulent diffusion
processes involved and to the thermobar phenomenon arising at the inter-
face of the shore waters and the colder lake waters.
The dilution in the strip is very indefinite, not more than 3-4-fold,
the dimensions of the region being as follows: length, 10 km; width, 2 km;
layer thickness, about 20 m. The turbulent diffusion coefficients, cal-
culated for this layer for a speed of alongshore current of about 5 cm/sec,
B-133
-------
42 2
are K " 10 cm /sec and K ~ 10 cm /sec. The clear-cut interface
X X
of the water masses and low dilution indicate that the course of the im-
purity propagation process cannot be described by the parabolic equation of
18
turbulent diffusion. The propagation of the impurity has a flow charac-
18
ter with fairly well-defined boundaries.
The content of suspended matter in the water of the Selenga shallows
varies appreciably in the course of a year. As one moves a considerable
distance away from the delta branches, the concentration of suspensions
usually decreases by a factor of 10-15, and as a rule, reaches its maximum
throughout the shallows in August-September.
In May-June, when the concentration of suspended matter in the Selenga
River at the exit from the delta is most often only 23-26 mg/£, the average
concentrations of suspended matter in the region of the lake adjacent to
the delta are also high in comparison with the mean annual values. At a
distance of 1.5 km opposite the branches, the level of suspended matter is
13-20 mg/£, and at a distance of 21 km 0.8-1.2 mg/&.
During this period, the water temperature in the river and 21 km from
the outlet of a branch is 12° and 4°C, respectively. >
The high level of suspension concentrations in the water of the shal-
lows in May-June is also characterized by a high degree of homogeneity from
the surface to the bottom over a considerable distance from the branches,
up to 7.5 km. The average concentration, level at this boundary is 2-4
times the mean annual level. Tables 4-7 present data characterizing in de-
tail the state of the aqueous medium in terms of the May-June parameters
discussed.
B-134
-------
TABLE 4. WATER TEMPERATURE INTERVALS IN LATE MAY - EARLY JUNE ON THE
; SELENGA SHALLOWS
(Based on observations in individual years)
Distance from
delta, km 1,5 3 5
Depth, m
0 10,0-12,5 3,6-5,9 2,8-4,2
5 6,0-10,3 3,2-7,4 2,7-6,6
10 ; 3,4-6,4 2,7-6,4
25 3,7-6,7 2,7-5,8
50 2,8-4,2
100
200
400
600
10 21 27
2,1-3,2 2,6-2,9 2,0-2,8
1,9-3,5
1,7-3,8 1,6-2,9
1,7-4,1 2,7-3,2
1,7-4,8 2,7-3,4
2,9-3,5
3,5
3,4-3,5 3,5
3,4-3,5
B-135
-------
TABLE 5. WATER TRANSPARENCY (m) IN MAY-JUNE ON THE SELENGA SHALLOWS
(Based on observations in individual years)
Distance from
delta, km
Interval
of values
observed
Average
0 1,5 3
0,5-1,2 0,5-2,5 0,8-5
0,5 1,3 3
5 7,5
1,5-7 2-10
5 7
10 21 27
8-12 15-22 15-22
10 17 18
TABLE 6. CONCENTRATION OF SUSPENDED MATTER IN WATER (mg/&) ON THE SELENGA
SHALLOWS IN JUNE 1969; SURVEY OF ONE SECTION
Distance
delta,
Depth, m
from
km
0
5
10
25
50
200
400
600
1,5 3 5 7,5 10 21
8 1,8 0,6 0,5 0,6 0,5
10 1,8 0,7 0,5 0,5 0,5
1,5 0,6 0,6 0,5 0,5
1,5 0,6 0,8 0,5 0,5
0,8 0,6 0,5
0,6
0,6
0,6
27
0,5
0,6
0,6
0,5
0,5
0,5
0,6
B-136
-------
TABLE 7. CONCENTRATION OF SUSPENDED MATTER IN WATER (mg/&) ON THE SELENGA SHALLOWS ON 18-20 JUNE 1971
(Concentration ranges and average of 5 sections)
Distance from
delta, km
Depth, m 0
10
td
L 25
U)
50
100
200
1-1,5 3-4
Concen- Concen
tration Aver- tration Aver-
range age range age
5,9- 12,3 0,7- 5,6
22,6 12,3
5,4- 7,6 0,5- 5,3
9,7 10,7
0,3- 2,4
3,7
5
Concen-
tration Aver-
range age
3,3- 5,8
8,3
2,4- 5,0
7,6
2,3- 2,5
2,7
2,6- 2,6
3,1
6,
Concen-
tration
range
1,0-
2,2
0,8-
4,1
0,9-
1,9
0,8-
1,6
0,8-
1,2
5-9
Aver-
age
1,3
2,2
1,4
1,2
1,3
12,5 18-19
Concen- Concen-
tration Aver- tration
range age range
1,2 1,2 0,9-
1,0
0,8 0,8 0,8-
1,0
0,9-
1,2
0,9-
1,4
0,7 0,7 0,7-
2,0
0,6 0,0 0,6-
1,0
Aver-
age
1,0
0,9
1,0
1,1
1,3
0,8
-------
REFERENCES
1. M.M. Aybund, V.P. Kratsov, Ye. N. Podozerov and Yu. B. Chegurov. Mo-
tion of waters in large bays and their water exchange with open parts
of Lake Baikal, Trudy GGI, Issue 231, Gidrometeoizdat, Leningrad, 1976,
p. 231.
2. V.A. Znamenskiy. Study of runoff and wind currents on a hydraulic
model of Lake Baikal. Trudy GGI, Issue 231, Gidrometeoizdat,
Leningrad, 1976, p. 231.
3. M.M. Aybund. Characteristics of runoff distribution in the Selenga
River delta at different water contents. Abstracts of reports at
Third All-Union Hydrometeorological Service Conference-Seminar on the
Hydrology of Estuarine Areas of Rivers. Moscow, 31 March - 3 April,
1976. COIN, 1976, p. 38.
4. V.W. loganson. Role of mountain forests in the formation of the runoff
and water regime in the basin of Lake Baikal. Voprosy geografii, 102,
pp. 115-121. Mysl1, Moscow, 1976, p. 207.
5. V.I. Verbolov. Variability of water currents and temperature. Trudy
Limnologicheskogo instituta Vol. 12 (32), Nauka, Lenigr. Sec.,
Leningrad, 171, p. 293.
6. M.N. Shimarayev. Certain features of long-term variation of hydro-
meteorological elements. Trudy Limnolog. in-ta Vol. 12 (32), Nauka,
Leningrad, 1971, p. 293.
7. B.A. Bogoyavlenskiy. Natural boundaries of the Selenga River delta.
Productivity of Baikal and anthropogenic changes of its character.
Irkutsk, 1974, p. 320.
8. M.M. Aybund, A.I. Babkov and Ye. D. Yegorikhin. Results of study of
surface currents in the Selenga region of Lake Baikal by means of
aviation. Trudy GGI, Issue 205, Gidrometeoizdat, Leningrad, 1975, p.
131.
9. B.F. Lut. Basic features and genesis of bottom relief. Tr. LINa Vol.
12 (32). Nauka, Leningrad Sec., Leningrad, 1971, p. 293.
10. P.O. Sherstyankin. Dynamics of the waters of the Selenga shallows in
early summer based on data of distribution of optical characteristics
and water temperature. Nauka, Moscow-Leningrad, 1964, p. 193.
11. L.K. Vlasova. Runoff of suspended detritus of Baikal rivers. In:
Bottom Sediments of Baikal. Nauka, Moscow, 1970, p. 160.
12. K.K. Votintsev. Chemical denudation in the Baikal basin and role of
its products in sedimentation in the lake (pp. 64-68). In: Bottom
Sediments of Baikal. Nauka, Moscow, 1970, p. 160.
B-138
-------
13. I.E. Mizandrontsev. Chemical composition of ground solutions and
waters of the bottom layer. In: Limnology of Near-Delta Areas of
Baikal. The Selenga Region. Nauka, Leningrad, 1971, p. 293.
14. G.S. Goldyrev, L.A. Vykhristyuk and F.I. Lazo. Bottom sediments of
the outer delta of the Selenga River, In: Limnology of Near-Delta
Areas of Baikal. The Selenga Region. Nauka, Leningrad, 1971, p. 293.
15. V. Ya. Zyul'kina. Importance of suspended detritus and bottom sedi-
ments in the self-cleansing of Selenga River waters of volatile
phenols. In: Productivity of Baikal and Anthropogenic Changes of its
Character. Irkutsk, 1974, p. 320.
16. M.N. Shimarayev. Some characteristics of wind conditions above the
surface of Baikal during the navigation season. Trudy Limn, in-ta
Vol. V (XXV), Nauka, Moscow-Leningrad, 1964, p. 193.
17. I.V. Lebedev. Principal results of a study of the winter hydrological
regime of the Selenga shallows of Lake Baikal. In: Raboty Irkutskoy
gidromet. observatorii, Issue 5, Irkutsk, 1970.
18. V.I. Verbolov. Coefficients of horizontal macroturbulent exchange in
the near-shore zone of southern Baikal. Tr. Limnol. in-ta 14 (34).
Nauka, Leningrad Sec., Leningrad, 1970, p. 213.
19. L.A. Vykhristyuk. Organic matter and its transformation in bottom
sediments. Tr. Limnol. in-ta, Issue 21 (41). Nauka, Siberian Sec.,
Novosibirsk, 1975, p. 287.
20. V.I. Verbolov and M.N. Shimarev. Water exchange in Baikal. Dokl.
inst. geografii Sibiri i Dal'nego Vostoka, Issue 36, Irkutsk, 1972.
21. Z.A. Vikulina and T.D. Kashinova. Water balance of Lake Baikal. Tr.
GGI Issue 203, Gidrometeoizdata, Leningrad, 1973, p. 268.
22. A.V. Znamenskiy. Concerning processes of internal water exchange and
turbulence on Lake Baikal. Trudy GGI, 203, Gidrometeoizdata,
Leningrad, 1973, p. 268.
23. V.I. Verbolovm V.M. Sokol'nikov and M.N. Shimarev. The hydrometeoro-
logical regime and heat balance of Baikal. Nauka, Moscow-Leningrad,
1965.
24. L.M. Galkin, V.M. Sokol'nikov and M.N. Shimarev. Distribution of
floodwaters in southern Baikal. Tr. Limn, in-ta, Vol. 14 (34), Nauka,
Leningrad, 1970. -i
25. M.M. Aybund. Results of full-scale studies of currents in southern
Baikal. Tr. GGI, 203, Gidrometeoizdat, Leningrad, 1973.
26. M.M. Kozhov. An outline of Baikal limnology. Vostochno-Sibirskoye
knizhnoye izdatel'stvo, 1972, p. 254.
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27. V.M. Sokol'nikov. Currents and water exchange in Baikal. Tr. Limnol.
in-ta SO AN SSSR, Vol. 5 (XXV). Moscow-Leningrad, Nauka, 1964.
28. L.M. Knyazeva. Present precipitation in the southern part of Lake
Baikal. Tr. Bayk. Limnol. stantsii Vol. XV, AN SSSR, Moscow-
Leningrad, 1957, p. 464.
B-140
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APPENDIX C
RESULTS OF HYDRODYNAMIC AND DISPERSION CALCULATIONS FOR LAKE BAIKAL
AND SEA OF AZOV
Figure Number Page
C-l Steady-state hydrodynamic model calculation for
Lake Baikal with southwest wind C-3
C-2 Steady-state hydrodynamic model calculation for
Lake Baikal with northeast wind C-7
C-3 Steady-state hydrodynamic model calculation for
Lake Baikal with northwest wind C-ll
C-4 Steady-state hydrodynamic model calculation for
Lake Baikal with southeast wind C-15
C-5 Steady-state hydrodynamic model calculation for
Lake Baikal with southwest wind and northern
basin ice covered C-19
C-6 Dispersion model calculation for Lake Baikal after
28 days with steady southwest wind C-23
C-7 Dispersion model calculation for Lake Baikal after
28 days with steady northeast wind C-29
C-8 Dispersion model calculation for Lake Baikal after
28 days with steady northwest wind C-35
C-9 Dispersion model calculation for Lake Baikal after
28 days with steady southeast wind C-41
C-10 Case 1 winds used in hydrbdynamic model calculation
for Sea of Azov C-47
C-ll Case 2 winds used in hydrodynamic model calculation
for Sea of Azov C-48
C-12 Case 3 winds used in hydrodynamic model calculation
for Sea!of Azov C-49
C-l
-------
Figure Number Page
C-13 Case 1 hydrodynamic model calculation for Sea of
Azov after 2 days C-50
C-14 Case 2 hydrodynamic model calculation for Sea of
Azov after 2 days C-57
C-15 Case 3 (variable wind) hydrodynamic model calcula-
tion for Sea of Azov after 2 days C-64
C-16 Case 3 (constant wind) hydrodynamic model calcula-
tion for Sea of Azov after 2 days C-71
C-17 Case 1 dispersion model calculation for Sea of Azov
after 28 days C-78
C-18 Case 3 (variable wind) dispersion model calculation
for Sea of Azov after 28 days C-84
C-2
-------
N
WIND
0
SCflLE:
100
KM
200
15 CM/SEC
o
UJ
SURFACE VELOCITIES
Figure C-la. Steady-state hydrodynamic model calculation
for Lake Baikal with southwest wind.
-------
N
WIND
n
JS
100
KM
SCRLE
200
15 CM/SEC
VELOCITIES AT 200 METERS
Figure C-lb. Steady-state hydrodynamic model calculation
for Lake Baikal with southwest wind.
-------
o
N
WIND
SCRLE:
100
KM
200
NEAR BOTTOM VELOCITIES
30 CM/SEC
Figure C-lc. Steady-state hydrodynamic model calculation
for Lake Baikal with southwest wind.
-------
N
WIND
o
—i—
100
KM
SCRLE
200
n
i
VERTICflLLY INTEGRflTED VELOCITIES
Figure C-ld. Steady-state hydrodynamic model calculation
for Lake Baikal with southwest wind.
-------
o
i
N
WIND
SCRLE:
100
KM
200
SURFACE VELOCITIES
CM/3EC
Figure C-2a. Steady-state hydrodynamic model calculations
for Lake Baikal with northeast wind.
-------
o
i
oo
N
WIND
100
KM
SCRLE
200
15 CN/S
VELOCITIES AT 200 METERS
Figure C-2b. Steady-state hydrodynamic model calculations
for Lake Baikal with northeast wind.
-------
N
WIND
0
100
KM
SCflLE:
30 CM/SEC
o
i
NEAR BOTTOM VELOCITIES
Figure C-2c. Steady-state hydrodynamic model calculations
for Lake Baikal with northeast wind.
-------
N
WIND
0
100
KM
SCRLE
200
n
i
VERTICRLLY INTEGRflTED VELOCITIES
Figure C-2d. Steady-state hydrodynamic model calculations
for Lake Baikal with northeast wind.
-------
N
V
WIND
SCflLE:
100
KM
200
15 CM/SEC
o
i
SURFACE VELOCITIES
Figure C-3a. Steady-state hydrodynamic model calculations
for Lake Baikal with northwest wind.
-------
o
i
N
WIND
SCRLE:
o
100
KM
200
15 CM/SE
VELOCITIES AT 200 METERS
Figure C-3b. Steady-state hydrodynamic model calculations
for Lake Baikal with northwest wind.
-------
N
V
WIND
SCRLE:
o
100
KM
200
30 CM/SEC
o
i
NEAR BOTTOM VELOCITIES
Figure C-3c. Steady-state hydrodynamic model calculations
for Lake Baikal with northwest wind.
-------
N
V
WIND
—l—
100
KM
SCRLE:
200
n
i
VERTICflLLY INTEGRRTED VELOCITIES
Figure C-3d. Steady-state hydrodynamic model calculations
for Lake Baikal with northwest wind.
-------
N
\
c
1 1
100 2C
KM
SCRLE:
UIND
15 CM/&E.C
SURFACE VELOCITIES
Figure C-4a. Steady-state hydrodynamic model calculations
for Lake Baikal with southeast wind.
-------
N
A
WIND
0
SCflLE:
—i—
100
KM
200
IS Ch/S
o
i
VELOCITIES AT 200 METERS
Figure C-4b. Steady-state hydrodynamic model calculations
for Lake Baikal with southeast wind.
-------
N A
WIND
SCRLE:
100
KM
200,
30 CM/SEC
n
i
NEAR BOTTOM VELOCITIES
Figure C-4c. Steady-state hydrodynamic model calculations
for Lake Baikal with southeast wind.
-------
N
WIND
SCRLE
100
KM
200
o
i
co
VERTICRLLY INTEGRRTED VELOCITIES
Figure C-4d. Steady-state hydrodynamic model calculations
for Lake Baikal with southeast wind.
-------
N
WIND
0
—I—
100
KM
SCRLE:
200
15 CM/SEC
n
i
SURFACE VELOCITIES
Figure C-5a. Steady-state hydrodynamic model calculations
for Lake Baikal with southwest wind and
northern basin ice covered.
-------
N
SCRLE:
o
WIND
100
KM
200
15
ec
o
i
ro
o
VELOCITIES AT 200 METERS
Figure C-5b. Steady-state hydrodynamic model calculations
for Lake Baikal with southwest wind and
northern basin ice covered.
-------
N
SCflLE:
o
WIND
—I—
100
KM
200
30 CM/SEC
o
i
NJ
NEAR BOTTOM VELOCITIES
Figure C-5c. Steady-state hydrodynamic model calculations
for Lake Baikal with southwest wind and
northern basin ice covered.
-------
N
7!--
WIND
0
100
KM
SCflLE
200
n
i
ro
N3
\'ERT!CflLLY INTEGRRTED VELOCITIES
Figure C-5d. Steady-state hydrodynaralc model calculations
for Lake Baikal with southwest wind and
northern basin ice covered.
-------
N
;.if m r:
10!)
KM
r ONir.KNTRfiMON TPFR VOl I.JME
H 1 -0000
Fi .'000
C -0100
D .0010
L -0001
n
NJ
-r-L.r"
D \ F rlZZ
_r
s
SURFACE CONCENTRATIONS - NO SETTLING
Figure C-6a. Dispersion model calculation for Lake Baikal
after 28 days with steady southwest wind.
-------
N
"1
of HI i:
ton
KM
( MNQ NTR(,TION fPf K VOI ilMI
fi
B
r;
n
I
1 .0000
- I USC.
.0100
.0001
o
N5
\
;j
, .J-
n C ; ' -
I >_J 1 R
I r-
CONrt.NTRRTlON.j - NO SETTLING
Figure C-6b. Dispersion model calculation for Lake Baikal
after 28 days with steady southwest wind.
-------
I I , . I
o inrj '/no
KM
(.HNCE NTRfiTION (PFR VOl UMt~
R I -OOfJO
B -l000
c -oino
n -OHIO
b .000!
1
E ID/ c
ix-- ~
-J B
C\D\
>_.\ )
-1 " /P.
f £
J
_J
B
T
vTRTIClHLLY HVERRGED CONCf.NTRRT I ON3 - NO SETTLING
Figure C-6c. Dispersion model calculation for Lake Baikal
after 28 days with steady southwest wind.
-------
N
1 1 J
0 100 200
KM
t.ONCENTRf)f ION (PER VOI UMM
fi 1 -0000
B -i000
c oi no
D ,-nuiti
L -0001
o
-I—
r
SURFACE CONCENTRATIONS - SETTLING, 10 M/DAY
Figure C-6d. Dispersion model calculation for Lake Baikal
after 28 days with steady southwest wind.
-------
N
I
100
KM
f/JNr.f NTRfniON fl'FR VOIUMt" 1
fi 1 -0000
H -'000
C -0100
t) -0010
t .0001
n
i
to
,.r~
_..r
J-H7
-..,-A>
W
-A\B]CQL^->AE
j ) cr/z / //v \A
1 / /E/D/ ;-
1 LjLr—i ",
.--i
^
i..._.J
__j'
BOTTOh CONCENTRATIONS - SETTLING, 10 M/DAY
Figure C-6e. Dispersion model calculation for Lake Baikal
after 28 days with steady southwest wind.
-------
N
fiCHLF :
I 1 .
o i no
KM
I
LONCtNTRHTION (P[R VOUJME I
H 1 -CKJOO
B -1000
c -nino
U .0010
t -0001
o
to
oo
v'FRTICHLLY RVERRGf.D CONCf.NTRRT 1ONS - SETTLING, 10 M/DAY
Figure C-6f. Dispersion model calculation for Lake Baikal
after 28 days with steady southwest wind.
-------
N
7
i
100
KM
'•fjQ
NIRfiTlQN (PFR VOI UML
f) 1 -0000
B .1000
C -0100
D -0010
L -0001
n
I
N>
VO
D
'"I-
....r
J-
SURFACE CONCENTRATIONS - NO SETTLING
Figure C-7a. Dispersion model calculation for Lake Baikal
ater 28 days of steady northeast wind.
-------
N
OCfll t-
I
too
KM
3N HTR V01
fi 1 .OGOli
15 -1000
c; -oiorj
n -ooio
t .0001
n
I
U)
o
-i—v--, s
BOTTOM CONCF.NTRRTIONS - NO SETTLING
Figure C-7b. Dispersion model calculation for Lake Baikal
after 28 days of steady northeast wind.
-------
N
I I
0 100
KM
1
CQNCTNTRMION CPFR VOLUME)
H 1 .0000
u .1000
C .0100
0 -0010
t .0001
o
I
OJ
_._.;
~r
D\(
_i
\
i
E/ ( s^\ 1
~V
Bl
E.J
.-I
VF.RT1CRLLY RVFRRCF.D CONCLNTF^Hl IONS - NO SETTLING
Figure C-7c. Dispersion model calculation for Lake Baikal
after 28 days of steady northeast wind.
-------
r;')Nr;i NrRMiON IITR voi
N
1—
100
KM
200
i
. ocor;
. ' 000
.0100
no 10
.0001
o
u>
u>
BOTTOM CONCF.NTRflTlON'j - SETTLING, 10 M/DAY
Figure C-7e. Dispersion model calculation for Lake Baikal
after 28 days of steady northeast wind.
-------
N
-1
I
If 10
KM
200
I HNCl-NfRfiT ION (I'FR VOl UMM
fi i.ocnr;
« -ioca
c .rn no
17 .0010
e -oooi
o
VERTICflLir RVERHGF.D CONCf.NTRHT [ QNS - SETTLING, 10 M/DAY
Figure C-7f. Dispersion model calculation for Lake Baikal
after 28 days of steady northeast wind.
-------
N
100
KM
CONCt NTRHTFON (PF!\ VOI
» 1 -0000
B -1UOO
C -0100
D .0010
t. -0001
O
to
Ul
SURFACE CONCENTRATIONS - NO SETTLING
Figure C-8a. Dispersion model calculation for Lake Baikal
after 28 days with steady northwest wind.
-------
N
•HI r.-
„ I
100
KM
I.ONf.'l N1l\f,TI ON (I'FK V:)l
ri i.oor;!)
n . i o:;r;
r .0100
o o;;io
h .1)001
o
U)
~L
L
L~l-, \ l-l B
>C!D/E
L
L.
r-r~
E
n
'N
J
_J'
BOTTOM CONCr.NTRfHTlONo ~ NO SETTLING
Figure C-8b. Dispersion model calculation for Lake Baikal
after 28 days with steady northwest wind.
-------
N
i-
o
100
KM
f UNrt NTKfiMON ff'FR VOI UMf 1
fl 1 -0000
13 .1 UCO
C -0100
n .0010
t -0001
n
I
U)
—J
k
.-J"
9-'
y/FRTK (41.LY RVFRHGEU CONCF NTKHT 1 ONS - NO SETTLING
Figure C-8c. Dispersion model calculation for Lake Baikal
ater 28 days with steady northwest wind.
-------
N
:>rmr
_ ... -..-I —
1UCI
KM
'00
lONCtNTKTiTlON (PFR VOl Jflf
f\ l.OOOC
B .' OCK)
C .0100
D .0010
t -OCOt
n
I
oo
SURFACE CONCENTRATIONS - SETTLING, 10 M/DAY
Figure C-8d. Dispersion model calculation for Lake Baikal
after 28 days with steady northwest wind.
-------
I';NI:I
100
KM
ON (rn\ voi urn ;
i .ooon
.> or;r;
.coir,
-OGGl
o
I
CO
ff
J"
E \ ^ r
...J
CONCLNTRHTlClNb - SETTLING, 10 M/DAY
Figure C-8e. Dispersion model calculation for Lake Baikal
after 28 days with steady northwest wind.
-------
(/jNtKMTRfiTtON 'I'f R VCH JMl
N
•/I
i-
o
. 1 .
100
KM
—i
'/•.-GO
H - 1 one;
t: .r;iOG
u MO in
L -ODC1
O
VF.R1ICHLLY flVF.RWGF.U CONCFNTRR T t ONS - SETTLING, 10 M/DAY
Figure C-8f. Dispersion model calculation for Lake Baikal
after 28 days with steady northwest wind.
-------
N
100
KM
\
CONCENTRHT10N (TfR VOl UflE )
H 1. 0000
B .1000
C .0100
200
D
.0010
.0001
n
i
SURFACE CONCENTRATIONS - NO SETTLING
Figure C-9a. Dispersion model calculation for Lake Baikal
after 28 days with steady southeast wind.
-------
N
i
o
100
KM
C'JNCl NTRliTION (TfK VOIUMF)
fi i.oono
B .1000
C .0100
n -onto
t .0001
n
LT_
k
_H-'" <
HyA'c"
x_r
E/ yv^ToL
J B / /
I..
:_-^ \E
_j~
LJ~
\
I J
J
J
_J
._J~
B
BOTTOM CONCF.NTRflTIONo - NO SETTLING
Figure C-9b. Dispersion model calculation for Lake Baikal
after 28 days with steady southeast wind.
-------
N
oCHLF
too
KM
1
f.'ONCl NTRtiTlON f n R V'Jl UMt' I
n t.rjcino
B .'DUO
C -0100
0 -OG10
t .0001
o
VFRTlfRl.Lr HVF.RRCr.D CONCI NTRR r 1 QMS - NO SETTLING
Figure C-9c. Dispersion model calculation for Lake Baikal
after 28 days with steady southeast wind.
-------
N
t-
0
100
KM
I
200
I'UNCt NTRfiTlON (TFK VOl UMF )
H 1 -CKJOG
13 .1000
C .0100
0 .U01Q
I .0001
O
SURFACE CONCENTRATIONS - SETTLING, 10 M/DAY
Figure C-9d. Dispersion model calculation for Lake Baikal
after 28 days with steady southeast wind.
-------
NTRHTION rrn< VOUME
N
SCHLF •
1 ._.. - ..... I
100 20
Kh
i .occc
• i ooo
- 0 1 DC
-or; in
.0001
o
i
BO IT 011 CONCF.NTf\HTirjN'-j ~ SETTLING, 10 M/DAY
Figure C-9e. Dispersion model calculation for Lake Baikal
after 28 days with steady southeast wind.
-------
UffiLF.
N
100
KM
-H
200
l NTRfiHON (TFR VOLUMF )
ft l.OOCO
B .t 000
C .0100
D .0010
L -OCOl
n
vT.RTlfRLLr RVF.RRGF.D CONCF.NTRRT 1 ONb - SETTLING, 10 M/DAY
Figure C-9f. Dispersion model calculation for Lake Baikal
after 28 days with steady southeast wind.
-------
N
t
SCBLEi
0 25 SO
8 tn/sec
4 m/sec
Figure C-10. Case 1 winds used in hydrodynamic
model calculation for Sea of Azov.
C-47
-------
N
t
SCRLEi
25 50
Kfl
8 m/sec
Figure C-ll. Case 2 winds used in hydrodynamic
model calculation for Sea of Azov.
C-48
-------
N
t
SCRtEi
25 60
KM
7 m/sec
10 m/sec
Figure C-12. Case 3 winds used in hydrodynamic
model calculation for Sea of Azov.
C-49
-------
N
A
WIND
SCRLE-
0 25 50 15 Ch/SEC
KM
;; r
SURFACE VELOCITIES
Figure C-13a. Case 1 hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-5D
-------
25
KM
SCfiLE"
—-1 —>
50 15 Cn/SEC
WIND
•*?i?r7''ffs' ^ »t......... —r
/ > • •
\ \ \ - »«•<•-
, \ x v i ^ v ^
- •;>,..-'"
; ^ _ i
L' .'.''. _
VELOCITIES AT 1 METER
Figure C-13b. Case 1 hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-51
-------
N
A
WIND
SCflLE :
0 25 50 15 CM/SEC
KM
strrfffttttitt
/ f t f t *
f t t t i t •
r
VELOCITIES AT 2 METERS
Figure C-13c. Case 1 hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-52
-------
N
A
i
0
SCRLE
25 50 15
KM
HIND
VELOCITIES AT 3 METERS
iFigure C-13d. Case 1 hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-53
-------
N
A
SCRLE:
0 25 50 15 CM/SEC
KM
WIND
VELOCITIES AT 5 METERS
Figure C-13e. Case 1 hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-54
-------
N
A
SCflLE :
C 25 50 2-25 M**2/SEC
Kh
WIND
. .,fffttttttt1<<
VERT]CRLLY INTEGRflTED VELOCITIES
Figure C-13f. Case 1 hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-55
-------
N
A
WIND
SCRLE:
( i 1
0 25 50
KM
SALINITY(mg/kg)
12.5
r
SURFACE SALINITY CONCENTRATIONS
Figure C-13g. Case 1 hydrodynamic model
. calculation for Sea of Azov
after 2 days.
C-56
-------
SCfiLE :
0 25 50 15 CH/SEC
Kh
WIND
SURFACE VELOCITIES
Figure C-lAa. Case 2 hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-57
-------
N
A
WIND
SCRLE:
0 25 50 15 CM/SEC
KM
VELOCITIES AT 1 METER
Figure C-lAb. Case 2 hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-58
-------
N
SCflLE :
25 50 15
KM
KIND
* V^T-r -.Xj^-g-*- - -
^g-<-
VV-t-^_
L -
^^
^ •- • ^-£*
\
* if
S
***ttSS/J
SJJSJ^'^
VELOCITIES AT 2 METERS
Figure C-14c. Case 2 hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-59
-------
N
A
I-
WIND
SCRLE
^
0 25 50 15 CM/SEC
KM
VELOCITIES AT 3 METERS
Figure C-14d. Case 2 hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-60
-------
N
A
t-
o
25
KM
SCRLEc
50 15 Ch/SEC
HIND
VELOCITIES AT 5 METERS
Figure C-14e. Case 2 hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-61
-------
N
A
25
KM
SCRLE :
50 2.25 M**2/SEC
WIND
VERTICRLLY 1NTEGRRTED VELOCITIES
Figure C-14f. Case 2 fiydrodynamic model
calculation for Sea of Azov
after 2 days.
C-62
-------
N
A
WIND
SCRLE:
0 25 50
KM
SALINITY(mg/kg)
12.5
SURFACE SALINITY CONCENTRATIONS
Figure C-14g. Case 2 hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-63
-------
I-
0
25
Kh
SCfiLE;
50 15 CM/SEC
WIND
SURFACE VELOCITIES
Figure C-15a. Case 3 (variable wind) hydrodynamic model
calculations for Sea of Azov
after 2 days.
C-64
-------
N
t-
o
SCRLE:
25 50 15 CM/SEC
KM
WIND
^-:;
VELOCITIES AT 1 METER
Figure C-15b. Case 3 (variable wind) hydrodynamic model
calculations for Sea of Azov
after 2 days.
C-65
-------
N
A
SCRLE :
0 25 50 15 Ch/SEC
KM
WIND
VELOCITIES AT 2 METERS
Figure C-15c. : Case 3 (variable wind) hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-66
-------
N
A
h-
0
25
KM
SCRLE:
50 15 CM/SEC
WIND
- ' ' « *» " - " ' ' « * " - V f f M \ -
--,-,. i;v^- v -^,x^- f /•,,,.;. r
-,-".n ^^»^:;^M^^////^ J
VELOCITIES AT 3 METERS
Figure C-15d. Case 3 (variable wind) hydrodynamic model
calculations for Sea of Azov
after 2 days.
C-67
-------
N
A
WIND
SCRLE :
—I 1
25
KM
50 15 CM/SEC
VELOCITIES AT 5 METERS
Figure C-15e. Case 3 (variable wind) hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-68
-------
N
A
h-
o
SCflLE'
25 50 2-25>i**2/SEC
KM
WIND
r
VERTICflLLY INTEGRflTED VELOCITIES
Figure C-15f. Case 3 (variable wind) hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-69
-------
N
A
WIND
SCRLE:
0 25 50
Kn
SALINITY (mg/kg)
12.5
r
SURFACE SALINITY CONCENTRATIONS
Figure C-15g. Case 2 (variable wind) hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-70
-------
N
A
SCflLE :
C 25 50 15 Ch/SEC
KM
WIND
SURFACE VELOCITIES
Figure C-16a. Case 3 (constant wind) hydrodynamic model
calculation for Sea of Azov
; after 2 days.
C-71
-------
N
A
WIND
t-
0
25
Kh
SCflLEc
50 15 Cn/SEC
VELOCITIES AT 1 METER
Figure C-16b.
Case 3 (constant wind) hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-72
-------
N
A
I 1 1 —>
0 25 50 15 CM/SEC
KM
WIND
' - , i-" ' -»- - -, x „
VELOCITIES AT 2 METERS
Figure C-16c. Case 3 (constant wind) hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-73
-------
N
i-
0
25
KM
SCflLE :
50 15 CM/SEC
WIND
. ' • - . LJ < - , . , •
• . . ,—I f ' ' -»-»-•-'• • • ' • % "
VELOCITIES AT 3 METERS
Figure C-16d.
Case 3 (constant wind) hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-74
-------
N
A
WIND
SCfiLE;
i-
0
H 1
25
KM
50 15 CM/SEC
r
VELOCITIES AT 5 METERS
Figure C-l6e. Case 3 (constant wind) hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-75
-------
N
A
WIND
I-
G
SCRLE;
2S 50 2.25 M**2/SEC
KM
' T"
' —— - * • • h
• jr *• ' *
k . - " - ^ •
VERTICALLY INTEGRATED VELOCITIES
Figure C-16f. Case 3 (constant wind) hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-76
-------
N
A
SCRLE:
0 25 50
KM
WIND
SALINITY(mg/kg)
12.5
SURFACE SALINITY CONCENTRATIONS
Figure C-16g. Case 3 (constant wind) hydrodynamic model
calculation for Sea of Azov
after 2 days.
C-77
-------
N
/K
;-5i: HI r :
KM
n
i
00
CONCtNTRFiTlON IPFR VOl UMF )
0 l.OGOOC
B -30000
C .10000
D .0.3000
t -oinoo
F -00300
G -00100
H -OU030
I -00010
J .00003
K .00001
SURFACE CONCENTRATIONS - NO SETTLING
Figure C-17a. Case 1 dispersion model calculation for
Sea of Azov after 28 days.
-------
N
A
KM
o
i
VO
CONCt NTRdT 1 ON (IT.R VOl UMF J
H l.OCQOC
u . lonou
C - 10UOO
n .03000
f .01000
^ .00300
G .00100
H -OL1C30
I .00010
J .001)03
K .00001
1 I
B'JTIMM l.ril-ir. I UTI.-IV i'mo - NO SETTLING
Figure C-17b. Case 1 dispersion model calculation for
Sea of Azov after 28 days.
-------
N
A
oCHt.f :
I 1 1
u
Kf1
o
oo
o
CONCtNTRhTION (PFK VOLUMF
fl 1.00000
B .30DOO
C .10000
D .03000
B .01000
f .011300
0 .00100
H -00030
1 .00010
J .00003
K -OU001
VERTICALLY HVF.RRGF.U CONCKNTRflT 1QN5 - NO SETTLING
Figure C-17c. Case 1 dispersion model calculation for
Sea of Azov after 28 days.
-------
N
A
ot Ml
KM
n
i
oo
CONCE.NTRRT10N (PFR VOl UMF )
ft 1.00000
B .30000
C .10000
D -03000
I. -OIOOU
K -00300
G .00100
H -00030
I .00010
J .00003
K .00001
SURFACE CONCENTRATIONS - SETTLING, 10 M/DAY
Figure C-17d. Case 1 dispersion model calculation for
Sea of Azov after 28 days.
-------
N
A
„ I
r> ;>(3
o
i
c»
NJ
J i H \ G \ F \ E \ ,
CONCENTRATION (PER VOLUME.)
H 1.00000
8 .30000
C .1.0000
D .03000
I .01000
t -00300
G .OU100
H .00030
I -00010
J -00003
K .00001
BOTTOM CONCENTRATIONS - SETTLING, 10 M/DAY
Figure C-17e. Case 1 dispersion model calculation for
Sea of Azov after 28 days.
-------
N
A
r;i. HI
KM
n
00
U)
CQNCtNTK'fmON (PFR VOl UMF )
U 1.00000
B .3UOOO
C -10000
D .03000
t. -01000
F .00300
G -00100
H .00030
I -00010
J .00003
K .00001
VF.RTICHLLr HVF.RROF.D CONCENTRflT IONS - SETTLING, 10 M/DAY
Figure C-17f. Case 1 dispersion model calculation for
Sea of Azov after 28 days.
-------
N
A
:.-,c. m
K h
r>
i
CD
CQNCE.NTRHnON (PER VOLUME)
H I .00000
B .30000
C -10000
D .03000
t' .01000
f .00300
G -00100 .
H .00030
I .00010
J .00003
K .00001
SURFACE CONCENTRATIONS - NO SETTLING
Figure C-18a. Case 3 (variable wind) dispersion model calculation
for Sea of Azov after 28 days.
-------
N
A
i i
KM
o
i
o>
r
CONCENTRfiTION ( PFR VOLUME)
fl t .00000
B .30000
C -10000
0 .03000
e .01000
f .00100
G .00100
H .00030
I .00010
J -00003
K .00001
BOTTOM CONCf.NTRRTlONS - NO SETTLING
Figure C-18b. Case 3 (variable wind) dispersion model calculation
for Sea of Azov after 28 days.
-------
N
A
HLf. :
KM
r
o
i
CO
ON
CONCENTRFiTION ( IT !\ VOl UMF )
fi I .00000
B .10000
C .10000
D -03000
t: .01000
I .00300
G -001 00
H .00030
t -00010
J -00003
K .00001
VERTICRLLY RVF.RROr.D CONCKNTRRTIONS - NO SETTLING
Figure C-18c. Case 3 (variable wind) dispersion model calculation
for Sea of Azov after 28 days.
-------
N
A
hi Ml. I
_.)..... . I
<•!> r-0
Kh
n
00
C \B
CONCFNTRRTION (PFR VOLUMF)
fi UC1COOG
8 - 30000
C .10000
D -03000
t .01000
F .00300
G .00100
H .00030
I .00010
J .00003
K .00001
SURFACE CONCENTRATIONS - SETTLING, 10 M/DAY
Figure C-18d. Case 3 (variable wind) dispersion model calculation
for Sea of Azov after 28 days.
-------
N
A
:-.rHl.r
;•.>
Kh
n
i
00
00
1 F
r
_-.•_:_ _T
C /B
_jj~
CONCtNTRRTlON (TFR VOLUME)
fi I.00000
B .30000
C .1.0000
0 .03000
I
f
G
H
I
J
.01000
.00300
-00100
.00030
.00010
.00003
K .00001
i;'JNL( MllvH1 ION', - SETTLING, 10 M/DAY
Figure C-18e. Case 3 (variable wind) dispersion model calculation
for Sea of Azov after 28 days.
-------
N
A
KM
o
i
oo
r
C B
CONCtNTRRTION (PFK VOlUME)
fi 1.00000
e .30000
C -10000
D .03000
F. -01000
r .00300
G .00100
H .00030
I -00010
J .00003
K .00001
VERTICALLY HVERRGf !) CONCfNTRRT [ QMS - SETTLING, 10 M/DAY
Figure C-18f. Case 3 (variable wind) dispersion model calculation
for Sea of Azov after 28 days.
-------
APPENDIX D
METEOROLOGICAL, HYDROLOGICAL, AND CHEMICAL DATA FOR
SELENGA SHALLOWS IN MAY-JUNE 1976.
Figure Number Page
D-l Hydromet sampling stations in Selenga Shallows
region of Lake Baikal ................ D-2
D-2 Near surface concentration of suspended material
for Hydromet cruise of 28-29 May 1976 ........ D-6
D-3 Near surface concentration of P04~ for Hydromet
cruise of 28-29 May 1976 .............. D-7
D-4 Near surface concentrations of Cl~ and 804"^
Hydromet cruise of 28-29 May 1976 .......... D-8
D-5 Location of meteorological stations ...... ... D-12
Table Number Page
D-l Hydrochemistry data for Hydromet cruise on
May 28-29, 1976 D-3
D-2 Hydrology data taken by Hyromet on
June 22-23, 1976 D-9
D-3 Wind data at meteorological station no. 1 D-13
D-4 Wind data at meteorological station no. 2 D-14
D-5 Solar radiation data . .' . . D-15
D-6 Wind information in June-July 1975 D-16
D-7 Number of occurances of wind velocity gradations
for June-July 1975 D-17
D-l
-------
Selenga
River
• Cruise Station
^Meteorological Station
Figure D-l. Hydromet sampling stations in Selenga Shallows Region
of Lake Baikal.
D-2
-------
Table D-l
DAT* FOR MYOROHpT CRUISE 0* MAY 28«29, 1976
STATION
06
07
OS
09
DEPTH AT STATION SAMPLE DEPTH
(METERS) (METERS)
1150 0,5
35
85
200
1150
700 0,5
35
85
200
700
aOO 0,5
35
85
200
uoo
lao 0,5
35
85
* /i n
WATER COLOR
i
i
i
9
16
13
13
9
5
9
9
0
U
0
5
0
2
0
i
SUSPENDED SOLIDS
(HC/L)
2.1
0,8
0,9
2,0
•
1.3
2,8
•
1.2
3,2
1.1
•
0.1
0,1
0,5
0,1
0,8
0,7
< •*
09 IflO 0,5
35
85
lao
10 25 0,5
25
j 11 600 0,5
! 35
85
200
600
12 300 .0,5
35
85
200
3«0
0
2
0
1
0
0
4
0
0
0
0
0
0
0
0
0
0,1
0,8
0,7
1,2
3.2
0.7
0,2
0,0
0.2
0.1
l.o
O.U
0.5
1.5
0.5
0.1
D~3
-------
Table D-l (continued)
OAT* FOR HYOROMCT CRUISE ON MAY 26«29, 1976
STATION
13
la
15
17
IS
1"
2fl
25
DEPTH AT STATION SAMPLE DEPTH
(DETERS) (METERS)
365 0.5
35
85
200
365
200 0.5
35
85
200
12 0,5
12
600 0.5
35
85
200
fcOO
195 0.5
35
85
1"5
9 0,5
9
300 0,5
35
85
200
300
100 0,5
35
100
MATER COLOR
0
3
0
0
•
0
0
0
0
0
0
0
1
0
3
0
1
0
3
0
0
0
0
3
0
4
0
3
0
a
SUSPENDED SOLIDS
(MG/L)
0,1
0,1
0,1
t,2
•
0,5
0,7
0,1
0,1
3.9
2.6
0.9
0.8
0.6
0.5
0,6
0,1
0,3
0.2
0,2
2.2
7,0
1.2
0,2
o,t
0,6
0,1
0,3
o.s
0,0
D-4
-------
Table D-l (continued)
WYD»OCHtMI3TRY DATA rOR HYDROMET CRUISE ON HAY 28«29, 1976
STATION
26
21
29
30
31
32
DEPTH AT STATION SAMPLE DEPTH
(METERS) (METERS)
15 0.5
IS
300 0,5
55
85
200
300
180 0,5
35
85
180
50 0,5
25
50
16 0,5
16
185 0,5
35
85
* a c
HATER COLOR
21
10
0
0
0
0
0
13
0
0
0
6
5
29
17
21
1
0
0
A
SUSPENDED SULlOS
(MG/U
3,3
3,3
O.o
0,2
3,5
1,2
0,6
1,0
0,6
0,6
1,0
0,6
l.a
2,5
0.7
0.9
2,7
1.2
0,7
32 185 0,5
35
85
185
33 5a 0,5
25
5<*
30 30 0.5
30
37
-------
o
Concentration (mg/liter)
Implied flow of material
Figure D-2. Near surface concentrations of suspended material
for Hydromet cruise of 28-29 May 1976.
-------
G
Concentration (mg/liter)
Implied flow of material
_3
Figure D-3. Near surface concentrations of PC>4 for
Hydromet cruise of 28-29 May 1976.
-------
Selenga ' River
Concentration (mg/liter)
Implied flow of material
Figure D-4. Near surface concentrations of Cl and
for Hydromet cruise of 28-29 May 1976.
-2
D-8
-------
Table D-2
HYO*ULOGY DATA TAKEN BY HTUROET ON JUKE 22»2Jr 1»76
STATION
oi
UIMH AT STATION
(METERS)
SECC»1 DEPTH
("ITEHS)
1050
02
1400
• 50
O
VD
0«
T50
16.0
SAMPLE DEPTH
(METERS)
«tl
i.
10.
20.
JO,
so.
100,
200.
0,1
i,
10.
20,
JO,
so,
100,
200,
O.I
5,
10,
20,
JO,
50.
100,
200,
0.1
*.
10.
20,
JO.
50,
too.
200.
kATtR TtMPEHATUHfc MIND DIRECTION AND SPEtO "AVE DIRECTION SEA STATt
(CbNTIGHADt) (M/SLC)
3.70 Hi 1,8 NE J
S.78
J.TT
J.7S
J.TJ
J.78
J.TJ
J.66
J.TO Nt J,7 NE J
J.76
,1»
.75
.70
.77
.67
J.b5
J.TO NE J.7 NE J
J.7«
J.7«
J.72
J.68
J.72
J.66
J.61
J.70 NNE a, 2 NNE a
J.76
J.75
J.7a
J.71
J.72
J.71
J.6»
-------
Table D-2 (continued)
HVORUIDGY OAT* TAKEN HY HYUHUHET UN JUNF 22«2i> 1976
o
1
o
STATION DEPTH AT STATION StCCHI OfPTM SAMpLE nEPTM
(METERS) (KfTEHS) (MfTERS)
05 60 7,5 0.1
5,
10,
20.
10,
. 50,
16 550 17,8 0,1
5,
10,
20,
10,
50,
too.
200,
20 650 16.5 U.I
S,
'o'
10,'
50.
100,
200,
21 15 2,4 0.1
b.
10.
15.
20,
10.
22 21 1.2 0,1
5,
to.
15.
20,
21 13 2,8 0,1
5.
to.
NATtR TEMPERATUNE KIND, DI»fCTIUN AND
(CfNTICRAOE)
8.70 NE
4.64
1.911
1,90
1,91
1.92
1.90 N
1.86
.88
. 74
.70
.77
,69
1,64
1.90 NE
1,88
1,80
1J70
1.75
1.69
1.59
12.1 NE
10.95
5.24
4.70
4,46
4,21
9,40 NE
8.66
7.69
7.22
5.U
11.2 NE
7.48
6.67
(M/SEC)
4.1
1,6
NE
1,7
1,1
3.1
1,6
NE
-------
Table D-2 (continued)
DATA T»«EN BY HYOHUMET ON JUNf. 22- (MFTEN3) IMFTER3)
15 «SO 21.5 O.I
b,
10,
20,
-10,
50,
100.
200,
Ik • 950 14.5 0,|
5.
10.
20.
10.
50,
100.
200
18 400 19.5 0,1
5.
10.
20,
10,
50,
100.
200.
00 120 20.5 0.1
10!
JO,
10,
50,
100,
«1 22 11.5 0.1
5.
10.
15.
"ATtH TFMPtRATUHE "IND DIRECTION AND SPEtO "AVE DIRECTION SEA STATt
(CENTIUHADE) (H/SEC)
•>,8 NE 2.8 NE 1
5.29
4,16
1.95,
1.90
1.9U
1.84
1.72
5.8 NE 2,7 NE 1
5.21
4.01
1.97
1.91
1.95
1.84
1.61
4.20 NE 1,4 NE t
4.20
4.10
4.02
1.92
1.97
3.85
1.60
1.80 NE 1.5 NE 1
JJ76
1.71
1.61
1.71
1.76
5.10 NE 1,8 Nt 1
5.2
4.98
4.62
-------
Angara
Selenga River
Meteorological Station No. 1
Meteorological Station No. 2
C.\ Solar Radiation Station
Figure D-5. Location of Meteorological Stations.
D-12
-------
NINO DIRECTION *ND SPEtD («/3K) AT SPICIFIEO MUuR
o
I-1
U)
DATF
05/20/76
OS/21/7*
OS/22/7*
05/21/7*
05/24/7*
OS/25/7*
05/2*/7*
05/27/7*
05/28/7*
05/29/7*
05/10/7*
05/11/7*
0*/Ol/7*
06/02/76
06/01/76
06/04/7*
06/05/7*
06/06/76
06/07/76
06/08/76
06/09/76
06/10/76
06/11/76
06/12/7*
06/11/76
06/11/7*
06/15/76
06/16/7*
06/17/76
06/18/7*
06/19/7*
06/20/76
NOTE 1)
2)
1800
SN 10
SE OS
SN 01
MSN Ot
3M OS
NE 01
00
SN 10
E Ot
SSN OS
E 01
SN 05
N 01
SM 01
NM 01
IN 05
E OS
NM 07
SM 01
SSN 01
SN OS
Nt 01
SN OS
SSN OS
IN to
M 05
8 OS
NNE Ot
00
NF ot
SN OS
IM OS
A '00' FOR MIND SPEED
HEADINGS STAMT AT 1800
2100
SSN 08
SSN 01
00
NN 01
SN 02
NE 02
00
SSH 07
E 01
S 01
E 01
SN 02
SN 01
00
NN 01
SM 01
NE 04
NM 04
00
00
M 07
00
S 01
NN 07
HNN 18
SN 01
S 01
00
00
NE 01
SSN 08
3 04
INDICATES
HOUR Of
oooo
SH 06
SN OS
SSN 01
M U4
SSE U2
NE 01
0 0
SH 07
E 01
SSE 02
SN 01
SH 05
SN 01
N 01
u> ft K
M 05
SH 04
NE 07
NNM U5
8SN 01
ft n
U w
S 02
SH 01
n n
U 0
SSN 05
MSN 10
1 04
SSN 01
n ft
00
E8E 02
SSN 01
SSN U4
8 01
CALM CONDITIONS
PREVIOUS DAY
0100
SN 08
SN 09
SN 05
nSH 07
I 01
NE OS
MSN 04
SN 08
SSN 10
SE 01
00
SN 08
MSN 07
NNt Ot
8N 01
NSN 05
SE 04
N 05
SSN 01
SN 04
NSN 01
SSN 01
SSE 01
SSN 01
NNH 08
SN 05
S 01
SSN OS
E 02
3N 05
SM 06
SSN 02
0600
NSN 04
HSM 07
N OS
M 07
SSE 07
NNM 08
SSN 04
SM 08
M 05
NNM 05
Nt 05
NSM 05
SN 09
NE 14
SN 05
SM US
SSM 01
SN 10
M 01
M 04
NH 01
N OS
NNE tO
SN 10
N 05
SM U5
M 02
SSN OS
Nt 05
SN 09
SM 08
SN 06
0900
SN 08
SN 07
N 04
MSN 05
a os
N 08
M OS
SH 08
NNM 04
-N 05
Ht 07
M 06
SSN 05
NSN 14
SM 05
N 04
SSM OS
|H 09
M OS
NSN 07
NH 05
NM OS
N 10
IM os
SN 07
NSN 10
M 01
M Ot
NNE 07
SM 08
SH 09
SIM 05
1200
BH 01
SH 07
N 04
SN 04
ESE OS
N 08
NN 05
SN 04
SH 07
N 05
NE 09
M 05
NNH 02
MJN 06
SN OS
N OS
SM 10
SM 09
SH 01
SH os
N 05
N OS
N 08
SM OS
8H 09
NSN |0
M Ot
NNM OS
NNE 06
SM 07
SN 07
IN o*
1500
NN 02
SN OS
SH 08
SN 06
Nt 10
NNt 05
NNM 05
NNN 01
SN 05
Nt 04
SN 02
SM 01
NSN 02
NNH 08
SN OS
Nt OT
NM OT
SM OT
8SN 01
M Ol
Nt 01
N 01
SN OS
SH 09
33N 07
SSN tO
N Ot
Nt Ot
NNE 0*
SH 0*
H8N 07
SH OS
Table D-3. Wind data at meteorological station No. 1.
-------
NINO DIRECTION »NO SPEtO (H/SEC) »T SPECIFIED nUUR
O
I
OATF
05/20/76
05/21 /76
05/22/76
05/21/76
05/21/76
05/25/76
05/26/76
05/27/76
05/28/76
05/29/76
05/10/76
05/11/76
06/01/76
06/02/76
06/01/76
06/01/76
06/05/76
06/06/76
06/07/76
06/08/76
06/09/76
06/10/76
06/11/76
06/12/76
06/11/76
06/10/76
06/15/76
06/16/76
06/17/76
06/18/7*
06/19/76
06/20/76
NOTE J)
2)
.
1800
S3*
SE
SE
ESC
3
NNE
NE
8
8SE
NC
NE
8E
H3N
SM
IE
NE
SM
esE
NE
NM
NNE
(
ESE
S
8
* '00' FOR
06
01
02
06
01
06
01
00
02
02
06
01
01
02
02
01
01
02
00
01
oa
00
02
02
0«
00 v
01
00
01
00
05
00
NINO SPEED
READINGS START AT tnoo
2)00
S3* 0%
SE 01
SE m
SH 01
St 01
HI 06
SE 01
S 01
SE 01
SE 01
NE 05
ESE 01
SE 01
SSE 02
SN 07
00
NE 05
SSE 01
00
00
S 01
NE 01
00
00
S 05
3S« 04
St 01
IH 02
8 01
00
S 05
00
INDICATES
HOUR OF
OOOU
33"
S
SE
3"
33E
NE
SE
3E
NE
SSE
SE
SE
SE
NNE
NNM
M
SE
S
NE
sse
s
8
M
SE
8N
3
3E
S3"
SE
01
01
01
01
Ul
07
00
02
00
01
05
01
01
01
00
02
07
05
Ul
01
02
01
02
05
0)
01
02
02
01
01
01
01
- •
o loo
3 01
3" 05
S3* 01
3" 05
SE 0|
NE 01
H3M 01
N 01
33" 01
St Ul
NE 01
SSE 01
00
S3" 01
S** 02
SE 01
NNE 05
SW 01
00
00
NNt 01
00
NNE Ou
SSE 01
00
00
SM 01
H 01
NNE 02
SSE 01
3 01
E 01
.
' ~
0600
M3H
M
NS»
3»
NE
NNE
M
M3M
N3H
NNE
NE
N
MS*
N8H
N3K
SM
SH
SM
NM
NN
NNE
NUN
N
SM
M3M
»8N
MSN
NX
NE
MSH
HSH
NE
05
05
01
07
OB
07
02
06
07
02
10
01
06
06
06
01
08
05
02
02
06
01
05
05
OK
05
05
01
01
05
06
02
0900
S
N
UN*
SH
NE
NNE
M
MSH
33M
NNE
ENE
\ NNE
W8M
SM
MSN
Nt
N
M3M
NM
MNN
NNE
NNM
NNE
SM
H8M
M
N
NNE
NNE
N
N
MSN
U6
06
01
05
07
Ob
02
Ob
01
04
01
05
06
08
to
04
05
01
00
05
05
01
07
05
04
04
05
02
04
05
06
06
1200
NN
SM
NNE
M8H
NE
NNE
N>H
SM
NNE
NNE
N
H
SM
8M
NE
SM
NNN
N
M8M
NE
NE
NNE
MSM
N8M
MNM
NNE
NNE
NSN
N
NNE
01
01
01
01
10
06
00
04
07
04
10
01
02
04
10
04
01
01
01
01
07
04
07
00
01
05
02
02
08
06
05
05
15UO
ENt 02
SM 02
Nt OJ
Si 0|
Nt 08
NNE 05
00
St 01
MSN 06
Nt 08
NE 10
Nt 05
MNM 06
MNN 04
NE 06
SM 01
NM 04
00
SN 0|
00
NNE 06
N 05
00
3SM 04
8M 05
NNH 04
NNt 01
NNt 07
SM 07
00
00
CALM CONDITIONS
PREVIOUS DAY
Table D-4. Wind data at meteorological station No. 2.
-------
SOLAH RADIATION (C»L/CM«»2-MJN) AT SPECIFIED «UvjH
I
M
Ul
DATE
05/20/76
05/21/76
05/?2/76
05/21/76
05/24/76
05/25/76
05/26/76
05/27/76
05/28/76
05/29/76
05/10/76
05/11/76
06/01/76
06/02/76
06/01/76
06/0«/76
06/05/76
06/06/76
06/07/76
06/08/76
06/09/76
06/10/76
06/11/76
06/12/76
06/11/76
06/14/76
06/15/76
06/16/76
06/17/76
06/18/76
06/19/76
06/20/76
NOTE THAT
0610
DIRECT ~ TOTAL
0.10
0,«l
0.11
0.10
0.17
0.10
0.16
0.15
0.15
0.17
0.17
0.16
0.27
0.28
0.12
0.04
0.44
0.10
0.13
0.11
0.52
0.01
O.S2
0.10
0.46
0.48
0.26
0.15
0.47
0.50
0,46
0.47
O.M
0.49
0.21
0.16
0,49
0,15
0.45
0.47
0.45 v
0.19
0.11
0.08
0.16
0.22
0,10
0.54
0.17
0.11
A BLANK INDICATES NO
0910
DIRtCT
0.17
0,16
0.17
0.9S
0.76
(1,96
0,61
0,98
0.95
0.58
0.97
O.B5
0.1H
O.BH
0,6«
0,84
0.86
0.25
0,21
1.05
TOTAL"
0,88
0,09
1.00
0.09
0.78
MO
1.26
»,t*
0.41
0.17
1.01
1.11
Ml
0.91
0.2«
1.13
0.55
l.l»
0.58
1,07
0,96
1.08
1.04
0.16
0,24
0.79
0.22
0,51
0.67
».1T
0.65
0.25
DATA AVAILABLE
12
Ul«ECT
0,6}
0. 17
0.21
I. 10
0.15
1,11
l.ll
1,02
LIB
1.20
1.15
1.09
1,02
1,04
0.99
0.1S
I. I*
1.14
JO
153
TOUl UMECT
1.22
n.12
O.T8
0,19
i.oe
0,58
0,07
1.27
0.11
0,47
.01
.15
,2a
.26
.67
.11
.16
.1"
.12
.27
.25
,26
.25
0,19
0,4}
0,85
0.66
0,58
0.30
1.29
1.29
O.J9
0.69
0.66
0.76
U.71
0,76
0.22
0.50
0.67
0,56
0.1}
0.7S
0.76
0,74
0,56
0.64
0,71
0.22
0,51
o.Bi
0.45
0.67
0
TOT»t
0.9}
0.10
0,51
0,94
0.14
o.ee
o.oa
0,86
0,92
0,40
0.66
0,77
1.0
0.7B
0,74
0.89
0.06
0,91
0,89
0.76
0.85
0,89
0,51
0,07
0.11
0,37
0,}9
0.9J
0,18
0,95
0,»1
1.01
1«
OIHtCT
0,08
0.11
0,1)
0,01
v 0,04
^0.15
0,00
0.09
0,0|
0,09
0.16
0,08
0,15
0.9
0,15
0.1)
0.14
0.17
0.15
0.18
30
TOTAL
0.24
0,19
0,08
0,26
0,01
0,10
0,01
0.17
0,21
0,11
0.11
0,18
0,11
1.01
0,17
0.12
0,02
0,11
0,18
0,24
0.18
0,24
0.2«
0,01
0,08
0.1J
0.14
0,09
0.15
O.Z5
0.24
0.26
table D-5. Solar Radiation Data.
-------
TABLE D-6. WIND INFORMATION IN JUNE-JULY 1975
Month
Frequency (Z) of wind directions (P) and average wind velocity (m/sec) (S)
N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW Average Maximum
Frequency
Wind velocity of calm
(m/sec) periods
U)
June (P) 1 21 7 2 0
(S) 2.0 4.2 5.5 3.5
July (P) 1 22 12 0 0
(S) 3.0 3.3 3.2
Sukhaya Station x
12 6 6 19 10 17 4 1 0 2
1.0 1.8 2.5 2.6 4.2 4.0 4.7 2.4 3.7 3.0 2.6
1 3 12 8 11 5 12 7 1 2 3
1.0 1.7 2.2 2.6 3.9 3.7 4.5 3.2 1.7 2.2 2.5
3.4
2.8
14
10
14
13
Babushkin Station
June (P)
(S)
July (P)
1
1.3
2
1.0
4
1.8
1
1.5
3
V1.3
3
1.5
1
1.7
4
1.4
1
1.5
2
1.2
3 5
1.8 2.5
1 9
1.5 2.6
1
3.0
3
2.7
1
1.0
2
2.2
0
1
2.0
5
2.5
6
1.4
24
4.1
28
4.2
39
4.9
30
4.1
5
2.3
6
1.7
4
1.4
4
1.0
0
1
1.5
3.1
2.5
16
18
16
20
Note: Results are presented at two meteorological stations which are located on the eastern shore of Lake Baikal.
Babushkin station is located south of the Selenga River mouth and Sukhaya station is north of Proval Bay.
For each month, the upper line is the percent frequency of wind directions and the lower line is the average
wind velocity.
-------
o
TABLE D-7. NUMBER OF OCCURANCES OF WIND VELOCITY GRADATIONS FOR
JUNE-JULY 1975.
Gradation of wind velocity (m/sec)
Month
June
July
June
July
0-1
62
76
78
106
2-3
75
93
70
72
4-5
54
55
46
46
6-7
Sukhaya
38
20
Babushkin
35
13
8-9
Station
5
3
Station
8
5
10-11
5
1
3
6
12-13
\ 1
0
0
0
14-15
0
0
0
0
Note: Station locations ame as in Table D-6.
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
REPORT NO.
2.
3. RECIPIENT'S ACCESSION-NO.
TITLE AND SUBTITLE
RESULTS OF A JOINT U.S.A./U.S.S.R. HYDRODYNAMIC AND
TRANSPORT MODELING PROJECT, APPENDICES B, C, AND D.
5. REPORT DATE
6. PERFORMING ORGANIZATION CODE
j0hn F. Paul, William L. Richardson, Alexandr
B. Grostko (Rostov State University, USSR), Anton A.
Matveyev (Hydrochemical Institute, Hydromet.
8. PERFORMING ORGANIZATION REPORT NO.
PERFORMING ORGANIZATION NAME AND ADDRESS
Large Lakes Research Station
Environmental Research Laboratory-Duluth
Grosse He, Michigan 48138
10. PROGRAM ELEMENT NO.
1BA769
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
Environmental Research Laboratory-Duluth
Office of Research and. Development
U.S. Environmental Protection Agency
Duluth, Minnesota 55804
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA/600/03
15. SUPPLEMENTARY NOTES
Performed as part of project 02.02-12 (Water Quality in Lakes and Estuaries) of
U.S.A./U.S.S.R. Environmental Agreement.
16. ABSTRACT
A joint modeling project with scientists from the U.S.A. and U.S.S.R. has been
accomplished. The three geographical areas investigated include Lake Baikal and
the Sea of Azov in the U.S.S.R. and Saginaw Bay, Lake Huron in the U.S.A. The
modeling approaches ranged from those employing material and mass conservation to
describe water movement to those involving solution of the complete three-dimensional
hydrodynamic equations. The model calculations were compared to available data and,
in all cases, reasonable agreement was obtained.
This portion of the report includes Appendices B, C, and D for the main study,
published as EPA-600/3-79-015.
This report covers a period from May 1977 to December 1977, and work was completed
as of April 1978.
KEY WORDS AND DOCUMENT ANALYSTS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
COSATI Field/Group
Hydrodynamics
Mathematical models
Circulation
Lakes
Lake Baikal
Sea of Azov
Saginaw Bay
Wind Driven Circulation
U.S.A/U.S.S.R. Environ-
mental Agreement
08/H
20/D
13. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (This Report)
UNCLASSIFIED
21. NO. OF PAGES
250
20. SECURITY CLASS (This page)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
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