Publications
Institute Of Oceanology
Vol. 1 Varna 1992
Bulgarian Academy of Sciences
MARINE PHYSICS:
Main principles for the creation of a new wind-wave atlas of the Bulgarian sector of the Black Sea Zdravko K. Belberov, Izrail N. Davidan, Dobrina R. Kostichkova, Igor V. Lavrenov, Leonid I. Lopatoukhin, Zhivelina Iv. Cherneva
The main features of the new atlas of the wind and the waves in the Bulgarian sector of the Black Sea have been described. Its main characteristic is that, together with the open sea data it will contain also detailed data about the wind and the waves in the coastal zone. The atlas will consist in two parts. The first, part will include a description of all methods that have been used for the calculation of the wind and the wave fields including the results of the calibration and the verification of the algorithms and the programs. The second part will include wind and wave maps and roses for the deep water and for separate typical points of the coastal zone, as well as tables of the one- and the two-dimensional distribution functions of the wave heights and periods throughout the various months of the year. In case there will be a possibility, a computer version of the atlas will be created which will allow to currently solve various tasks connected with the coastal protection and with the design of hydralic facilities.
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Mathematical simulation of wind-generated waves in the Bulgarian sector
of the Black Sea
Vladimir Iv.Dimov, Dobrina R. Kostichkova, Igor V. Lavrenov
The mathematical simulation of wind-generated waves is represented as successive determination of the barric field, the gradient and the generating winds, the wind-waves in the deep-water, the shallow-water and in the surf zone. The calculation of the wind-generated waves is based on the solution of the equation of the spectral density balance of the wave impact and, at absence of currents in the deep-water — on the spectral-parametric model created in LOGOIN.
The numerical results and their comparison with measured full-scale data in the coastal zone are shown for a concrete zone of the Bulgarian coast and for a concrete storm situation.
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Envelope of the wind waves in the coastal zone
Zhivelina Iv. Cherneva, Albena D. Velcheva
This paper describes a method for processing the experimental data in the coastal zone in order to obtain and examine the group properties of the wind waves. Using the method herein described, the wind waves envelope and the envelope of the auto correlation function have been obtained and compared for variuos depths as well as the spectra of the waves and of the envelope. The method and the software created, allow to include in the routine processing of the experimental data off wind-generated waves the obtaining of the main characteristics of the envelope.
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MARINE CHEMISTRY:
Hydrochemical features of the Black Sea coastal area
at Shkorpilovtsi in comnparison with data of monitoring the Bay of Varna
Alexander V. Rozhdestvenskiy
According to investigations carried out between 1982 — 1985 dynamical chamges of the most significant hydrochemical indicators as chlorinity, salinity, alkalinity, dissolved oxygen, hydrogen indicator, biogeenic elemetns, some microelements, biochemical necessity of oygen and oxydation of the Black Sea waters in the relatively open sea area at Shkorpilovtsi are discussed. Comparison with data from the northern and southern parts of the Bay of Varna is made. The results show close relationship between chemical composition of the waters in the region of Shkorpilovtsi and the waters along the northern coast of the Bay of Varna. On account of pollution caused by a current from the Lake of Varna the waters in the southern part of the Bay of Varna are noticeably different.
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Composition of the lipids on the Bulgarian Black Sea shelf
zone
Inna A. Nemirovskaya, Evgeny A. Romankevich, Alexander S. Stoyanov
Data of composition and content of lipids in water, suspended matter and the surfece layer of bottom sediments is cited. No increase of the concentration of alkanes and surfece active substance is found out at the coastal stations compared to the opensea stations. It is shown that the plankton and eath vegetation greatly affect the composition of lipids. Oil hydrocharbons appear to be secondary in significance in composition with biogenic hydrocarbons.
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Hydrochemical characteristic of the Bulgarian Black Sea water area
for the period 1986-1990
Alexander V. Rozhdestvenskiy
During the period 1986 - 1990 the hydrochemical surveys of the Varna Bay and open sea waters having the characteristics of a multi-year monitoring were continued. The averaged five-year data confirmed the alternation of periods of decreased salinity and of increased contents of nutrates and phosphates which is probably connected with the solar activity. The eurofication of the water area is continuing. The increase of the percentage of oxygen contents in the water in the upper layers is accompanied by its decrease in the layers below 70 m. The hydrogen sulphide boundary does not show any considerable changes.
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The impact of anthropogenic factors on the hydrology and on the hydro-chemistry
of the Varna Lake
Alexander V. Rozhdestvenskiy
The Varna lake is a brackish lagoon located in the West direction of the Varna Bay. Until 1909 when the first channel connecting the lake with the sea was excavated, the lake was a fresh-water one. In connection with the density stratification and the weak water exchange with the sea, hydrogen sulphide appears periodically in the deep water layers (in the warm months mainly). Initially episodical, the lake surveys became since 1948.systematic monthly surveys having a character of a multi-year monitoring. After 1955 the lake is being considerably polluted (by industrial waters, domestic wastewater disposal, etc.). The period of the clean lake and the one after the beginning of its pollution have been considered in the previous papers (1957, 1962, 1967). During the last two decades the anthropogenic impact has increased, the lake waters are used for cooling in the Thermal Power Station - Varna, a second water-way channel to the sea had been excavated, wider and twice as deep as the first one. As a result, the thermal balance and the water exchange had been changed which payed a certain influence on the chemistry of the lake waters: the salinity, the dissolved oxygen, the hydrogen sulphide, the biogenic elements, etc. In sertain conditions the lake, which is a place where processes take place faster, might be used as a model for possible long-term changes in the Black Sea.
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MARINE GEOLOGY:
Structure and composition of Hologene sapropelitesein
the western part of the Black Sea
Venelin H. Velev, Petko S. Dimitrov, Maria M. Fayer
The sapropelites being deposited in the western part of the Black Sea are chracteristic of the continental slope and the abyssal bottom of the basin. Their structure is a result of two rival processes of sedimentation — nephelite sedimentation and overland flow. Chemical composition of the mineral fraction of the sapropelites is not qualitatively different from the composition of the well studied ancient clay-argillite formations which are used as a pattern in the facies analyses. Quantative differences are related to the content of some of the main lithophilous elements (silicon, calcium, sodium) and microelements (molybddenum, copper, zinc, uranium etc.). These indicators may have an informative value when comparison is made between different types of studied areas and also when decisions for classifications are taken. Organic substance in sapropelites amounts to 1/3 of their weight (dry substance). Its various components are at low degree of transformation state and possess high reaction ability. The content of hydrocarbons and alkali-soluble substances is relatively small. Attempts made for economical utilization of the sapropelites have given positive results but the quantity and variety of sapropelites are still quite limited.
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Analysis of type-profiles in the conditions of the coastal
zones ot Poland and Bulgaria
Zbygnew Prusak, Hristo Iv. Nikolov
The paper presents an analysis of various methods for describing the FORM OF THE CROSS-SECTION underwater profile and its variation in time and space. An analysis is made for two different sites located on the coasts of the Black and Baltic Sea wich have different hydro- and lithodynamic lithological and morphological specific features. As a result was obtained that the character and the type OF THE CROSS-SECTION profile is well described by Dean's model. the existence of a long-term oscillation was obtained for the mean inclination of the bottom profile for the conditions of the Polish coast line. According to the values of the coefficients the Polish coast has been classified as an inclined one and the Bulgarian — as a steep one. The period of long-term changes along the polish coast is about 20-25 years. The specification of this period for the Bulgarian coastal zone is at present impossible due to the short series of field observations.
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On the role of the biogenic factor in the resedimentation
of the sediment material on the shelf of the West Black Sea sector
Nikolay A. Ayboulatov, Petko S. Dimitrov, Leonid A. Simonenko
A characteristics feature of the Black Sea basin is its exclusive rate of biogenic sedimentation which finds its direct reflection in the sedimentation process. A speciaal role in the material transformation in the shelf conditions are playing the benthos flora and fauna.
It has been noticed that the impact of the biogenic factor is reduced to a consolidating and destructuring influence on the bottom sediments. Besides, the bottom organisms can trnasfer particles in vertical and horizontaldirections. The thickness of the reprocessing layer varies from several mm up to 21 cm and is different for the shelf zones.
In conclusion, the considerable contribution of the bottom organisms is emphasized which paay influence on the physico-mechanical properties'of the sediments, determine the washout speeds and from specific structural and texture shapes. They to a great extent determine also the specific regimen in the bottom layerdirections. The thickness of the reprocessing layer varies from several mm up to 21 cm and is different for the shelf zones.
In conclusion, the considerable contribution of the bottom organisms is emphasized which paay influence on the physico-mechanical properties'of the sediments, determine the washout speeds and from specific structural and texture shapes. They to a great extent determine also the specific regimen in the bottom layer.
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Changes in the accumulation of heavy minerals on the South
Black Sea costal zone
Vendulka I. Tsvetkova - Goleva
Data presented characterizes the process of accumulation of heavy minerals within the limits of the shore prifile. It is gathered from regime observation over different types of coastal zones as zones of accretion, slide-accretion, erosion, mixed, river mouths, etc. Changes in accumulation of the heavy component for a 10 year period have been traced out. To obtain more detailed information of the process of accumulation different parts of the beach profile were sampled. Data acquired of the process of changes and the presence of minimums and maximums respectively give evidence of the periods of decrease and increase of accumulation according to different types of zones. It is also connected connected with the distribution of sediments in the coastal zone. An almost permanent tendency of increasing the quantity of the heavy element is observed.
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Formation of pseudoassociations among the Quaternary marine
Molluses
Vladimir L. Shopov
Under the influence of the sedimentogenic factors (redeposition and condensation) pseu-doassociations from the relics of organisms of different age are formed. Pseudoassociations are mixed communities of local organisms (autochthones) and redeposited organisms (allochthones) which are part of the bio-coenose characterizing the same biotope. During redeposition older sediments (together with their fauna contents) are mixed with younger deposits. Condensation occurs during delayed sedimentation and in the presence of current scour. Formation of pseudoassocitions under hte influence of these two factors is a common phenomenon in stratigraphy.
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MARINE BIOLOGY:
Palunological investigation of marine sediments from
the western sector of the Black Sea
Juliana R. Atanassova, Elissaveta D. Bozilova
Осноаноым методом реконструкции палеоэкологичееских условий черноморского побережья во время четвертичного периода является спорово-пыльцевой анализ морских осадков. Сочетание его с анализами динофлагеллятных цист и другими биостратиграфическими и литостратиграфическими методами позволяет сделать выводы о колебаниях уровня моря во время четвертичного периода, дает возможность осуществить достоверное стратиграфическое разчленение осадков, а также и другие заключения.
В настоящей работе представлены результаты спорово-пыльцевого анализа и анализов динофлагеллятных цист, взятых с трех морских скважин северного и южного континентального склона и южного черноморского шельфа с континентальной окраины болгарского берега. Обособлены две комплексные пыльцевые зоны. Отложение осадков комплексной пыльцевой зоны 1 происходило при сухом и холодном климате, и вероятнее всего, связано с поздним ледниковым периодом. Доказательством этому служит преобладание пыльцы травянистых видов, капример, из рода Artemisia (полыни) и представители семейства СЬепоросНасеае, а также высокие значения степно-горского индекса.
В осадках, отнесенных к комплексной пыльцевой зоне II, преобладает пыльца широколиственных древесных видов; степно-горский индекс значительно ниже, и сто дает основание отнести их к голоцену.
Граница между двумя комплексными пыльцевыми зонами ясно очертана повышением кривой древесных пыльцевых видов (АР) в начале комплексной пыльцевой зоны и сменой типов динофлагеллятных цист.
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Mussel Mytilus galloprovincialis L a m. (Bivalia) natural
resources along the northern Bulgarian Black Sea coast in relation to Rapana
thomasiana G r o s s e (Gastropoda) distribution
Tsenka H. Konsulova
В тази статия се интерпретират резултатите от 55 драгирания в района между нос Калиакра и Варна за изследване разпределението, количествената характеристика и размерния състав на естествената популация миди и рапани. Установено е, че количеството и размерният състав на мидите зависят основно от наличието и гъстотата на рапаните, които са разпростраиени предимно в по-плитките участъци на района и имат средна дължина 71,1 мм. В дълбочина се наблюдава постепенно възстановяване на мидите и изчезване на рапана.
В сравнение с данни от 1976 г. за същия район резултатите от тези изследвания показват, че процесът на деструктиране на мидените полета и на редуциране на запасите на основния вид в тази зооценоза — Mystilus galloprovincialis, се е осъществява ло с много по-бързи темпове, отколкото нарастването числеността на рапана.
Развитието на взаимоотношенията хищник-жертва навлиза във фаза на установяване на динамично равновесие между тях, но някои характерни белези дават основание да се допусне, че в близките години рапанът ще се окаже в следващата фаза — угнетено състояние, главно поради недостатъчната трофична обезпеченост.
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Dinamics of the condition factor of the Black Sea Sprat
(Sprattus sprattus L.)
Lyudia St. Ivanov, Georgy A. Marinov
The monthly dinamics of the condition factor by Fulton (K have been determined by linear classes and in general for 1978 - 1988, as well as, by sex and age for 1983 - 1988. The date has been collected from vessel catches and partially from trap net catches in the Bulgarian Black Sea water area.
The monthly values of K show its variation diring the pre-reproductionq the post-reproduction and the nursery periods, as well as the deviations from the mean trend for the various years. For an absolut length of 6,0 - 9,0 cm the values of K did not seem to have any definite trend of change while at length of 9,5 - 12,5 cm a trend of decrease m K was noticed. At the end of May 1987 large Sprat had been caught by trap nets (L = 11,0 - 14,5 cm age - 3 - 5 years) with a very high K (average values 0,802 versus 0,560 - 0,597 for ordinary Sprat) which had been given a separate statistical processing.
Minimum values of K for the 11-year period had been registered once in January. 7 times in March and 3 times in April. The lowest annual values of K have been observed in 1979 and in 1988.
In the range of the well-represented linear classes as well as in age groups, the values of K are higher for the female fish compared to those of the male ones the differences being significant (P = 0,97 - 1,0).
The annually averaged values of K are increasing with the increase of the zooplanctone biomass (x) and the 1-hour trawled catch (y). The same regressnon is observed for y depending on x and K. The coefficients of correlation and of regression for one and for two factors proved to be insignificant (P = 0,82 - 0,91 - 0,93 < 0,95). The values of K are dependent on other biotic and abiotic factors. The condition is assumed to be an important integral monitoring characteristic of the Sprat.
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Sexual composition dynamics of Sprattus sprattus L. catched
along the Bulgarian Black Sea coast
Lyudia S. Uvanov, Georgy A. Marinov
On monthly based investigation of the total o$$ interrelation and linear subclasses for the period 1978—1987, including the age exmanination for the period 1983 — 1987, the following trends and patterns in the sexual conposition dynamics of 5. sprattus L. along the bulgarian Black Sea coast are evaluated:
Commercial trau! During breeding migration and breeding (october — february) the percentage of increases (total: 42,1—42,6; by age groups: 1 year aged — 46,2; 2 years aged — 44,7; 3 years aged — 33,4; 4 years aged — 29,9), while during the period of nutritional migration and fatness (march — September) it decreases (total: 31,9 — 34,8; by age groups: 1 + - 35,4; 2 + - 33,6; 3 + - 28,0 and 4 + — 11,7). The mean perannual percentage (october — September) of d"o" comprises:
total 36,3 - 38,0; hy age groups: 0+ - 1 + - 39,3; 1+ - 2+ - 38,2; 2+ - 3+ -30,5 and 3+ - 4+ - 16,7. The sexual composition of linear classes during October—march is characterized by convergence in the lenghts 6,5 — 10 cm and divergence in the lenght exceeding 10,5 cm, as well in april — September — by a shift in the curves cros —point towards the smaller linear classes, due to the increasing share of $$ with the increase in lenght and age of the sprat.
In spring trap-nets catches (march — may) the percentage of $$ is greater than that of commercial trauls. The trend discovedred by Stoyanov (1965) is confirmed. In spring $$ migrate to a greater extend towards the trap-net areas, decreasing in share from march to may with advantage of the season.
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MARINE ENGINEERING:
Choice of a crystal for piezoceramic transducer
Atanas Al. Atanasov
On the basis of the characteristic D = F(E) of an acoustic crystal and the imput voltage amplitude of piezoceramic transducer a method for choice of an acoustic crystal has been devised. It allows to define the structural elemetns of the traditional equivalent scheme of a piezoceramic transducer. Estimate of these elements present satisfactory data for the practical application of piezoceramic transducers.
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A program package for graphical presentation of the result
from oceanologic investigations
Atanas V. Palazov
The graphic presentation of the result from research investigations is a highly informative and easy-to-assimilate way of presentation and, it is for this reason, preferred in a number of cases to other types of presentation. The automation of the computer-aided plotting widens its applicability but requires the corresponding graphic software. The developed software package for graphic presentation contains 52 programs providing for plotting of elementary as well as of the most frequently used types of graphic presentations.
The package operation takes place in two stages: first — generating the graphic image and Us storing in a drawing file; and second — plotting the image by choosing one of the four types of plotters supported. The developed graphic software is functionally compatible with the graphic package of CALCOMP which gives a possibility to use existing applied graphic programs. It has been tested during the international experiment "WAVE 90", where it was used for representing the result of oceanologic investigations.
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Expirimental study of the hydrodynamical characteristics
of a free floating carriers of oceanographic tools
Trayan K. Trayanov
As a result of investigations conducted in the test-channel of the Institute of Ship Hydrodynamics in Varna estimates of the hydrodynamical characteristics of a free submerging and emerging autonomous carrier of of oceanographic tools are made. Forse and coefficients of resistance obtained may be used to define submerging and emerging speed of the carrier ant its drift from the point of launching.
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Prediction of the motion of autonomous automatic free
sinking and surfacing carriers of oceanographic instrumentation
Atanas V. Palazov, Trayan K. Trayanov
The advantage of the use of autonomous automaatic free sinking and surfacing carriers of oceanographic instrumentation is reduced to the considerable saving of vessel-time for carrying out the research. The utilization of this advantage would be possible only if the surfaced carriers would be idscovered in time, this problem becomes much more serious in simultaneous use of several carriers when the vessel is at a considerable distance from them. the predicting of the place of surfacing allows to direct beforehard the vessel to the necessary place and thus to shorten time for discovering.
The movement of the autonomous free sinking and surfacing carrier of oceanographic instrumentation is divided into four phases: sinking, release of balast, surfacing and drifting. The sinking and the surfacing of the carrier is described by ordinary differential equations. The solution of these equations allows to determine the current position of the carrier in the aqutic space.
On the basis of the solutions obtained, a computer program has been developed which allows to simulate the movement of the carrier and to predict its current positions.
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Acoustic receiving-transmitting unit of digital information
Atanas Al. Atanasov, Petar T. Draganov
An acoustic receiving-transmitting unit of digital information with reduced consumption has been proposed. The block-diagram and the main electric circuits of the attacking and of the receiving blocks are shown. Experimental tests have been carried out to estimate the operation ability and the reliability of the acoustic receiving-transmitting unit.
A demonstration is made of the deviations of the trasported units as well as of their "earring" pulses of a 32-bit code combination in the range from 25 to 400 m.
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An estimation of the data streams and the amount of
data in automated acquisition of oceanographic information
Atanas V. Palazaov
When determining the hard- and the software necessary for completing the systems intended for automation og the scientific research in oceanology, it is of major importance to know the streams and the amount of data which have to be processed.
A time-diagram is proposed of the measured data acquisition, in accordance with the method applied for carrying the research investigations. On the basis of this time-diagram, formulae have derived for estimating the data streams and the amount of data.
The method for the estimation of the data streams and the amount of data includes the creation of the research time-diagram, the estimation of the time for each element of the time-diagram and the calculation of the streams and the amount of data.
By means of the formulae obtained an estimation was made of the streams and of the amount of data received from the scientific instrumentation of the RV "Aicademuc".
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Bridge-type measuring circuit with a non-linear parametric
convertor
Atanas Al. Atanasov
A bridge measuring circuit with a non-linear parametric converter switched in one of its arms has been alalysed. The analytic expression of its normed characteristic of conversion has been derived.
For a known value of the linearizing reistance, the conversion characteristic of the non-linear parametric converter, the optimum value of the resistances in the nonbalanced bridge circuit has been determine.
The graphic characterictics of the nonbalanced bridge circuit with a non-linear parametric converter have been shown without a linearizing resistance and with optimum choice of elements of the non-balanced bridge.
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Fiber optics telemetry for marine coastal research
Atanas V. Palazov, Dimitar D. Slavov
A description is made of the fiber optics telemetry line for data transfer during marine coastal researches, created in the Institute of Oceanology of the Bulgarian Academy of Sciences — Varna. The line has been developed with an experimental purpose and is installed in SRB "Shkorpilovtsy". It was designed for data transfer between the field sensors and the laboratory. Totally made up to Bulgarian elements the line consists of receiving transmitting blocks and of fiber optics cable.
After laboratory tests the line was installed in the SRB "Shkorpilovtsy" site and pute into operation. After one-year field tests, the performance and usability of the line for marine coastal researches will be estimated.
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Main results of the Joint Soviet - Bulgarian Research
voyage with the RV "Prof.Kolesnikov" - voyage No XVIII
Alexey A. Bezborodov, Atanas D. Vasilev, Spartak D. Chochov, Alexander S. Romanov,
Stanislav B. Kramarenko
Results from the geothermal, lithological-stratigraphic, engineering-geological, hydro-physical and hydrochemical investigations have been presented.
Thee physical-mechanical properties of the separate contemporary, ancient Black Sea and New-Euxinian sediments have been determined on a geological site covering the anticline "Yurii Godin" structure. A thermal anomaly of the "thermal depression" type has been registered.
New data about the distribution of the physical-chemical parameters in the waters of the Bulgarian shelf and in its adjacent deep-water region have been obtained during their restructuring to the summer type.
New data has been presented about the distribution of the suspended substance in the waters of the Bulgarian shelf.
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Method for measuring of wind wave by an autonomous
wave-recording gauge of buoy type
Victor Y. Seryh, Hristo D. Slabakov, Trayan K. Trayanov, Leonid F. Brodetskiy
The experience in wind wave measuring by an autonomous wave-recording gauge of buoy type (designed by specialists from both Institutes of Oceanology in Bulgaria and USSR) has been summaried. A method for measuring wind wave under specific meteorological conditions is devised and a manner of calibration of the wave gauge is shown.
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Sex maturation of the young-of-the year anchovy, English
encrasicolus (L.)in Varna Bay (Black Sea, Bulgaria) in August 1987
Konstantin R. Mikhailov
Отразени са резултатите от изследванията върху размножаването на хамсията през българския бряг през 1987 г. Пробите са събирани с крайбрежни риболовни уреди през втората половина на август, т.е. в края на размножителния период. Устанононо е, че половите жлези на най-ранните генерации, достигнали в края на август до 70 - 92 мм дължина, са в III, III-IV и IV стадий на зрелост. Такова ранно полово съзряване на 0+ годишнн риби се констатира за първи път в Черно море. Вероятно това е свързано с условията на околната среда и рязкото понижаване на размножителната биомаса на хамсията.
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