^FISHERIES AND MARINE SERVICE Translation Seriesdfo-mpo.gc.ca/Library/111669.pdf · ^FISHERIES AND MARINE SERVICE Translation Series No. 3060 Translated by the Translation Bureau(EJI,)

^FISHERIES AND MARINE SERVICE

Translation Series No. 3060

Translated by the Translation Bureau(EJI,)Multilingual:,Services Divisior.

Department of the Secretary of State,of Canada

"and mèt.hod of predicting possib.l.e:`;,catches:'Thedynamiçs:-bf "the population of sprat in - the '°Black . Sea

Z:by C.S; Yuryev, and L.I. Starus'henko

Original title:. Dinamika chi,slennosti chornomorskogo shprota

Department Qf the Environment 1.

.;' Fisheries And Marine Service

Biôhoeical Station, Nanaimo, B.C.

,:i,metodika,prognozirovaniya yego vozmozhnogo ulova.,.

I

:rTrudy Vsesoyuzno'gô Nxùchno-Issledova.tel'skogo Instit'uta

Morakogo Rybnogo'Kh_â,i.yaistva,.i.,.Okeanop r a f i i (VNIRO)

(Proceedings of thé;;''All-Union Research Institute' of:''

Marine Fisher ies,"and-Oceanography), 83..: 212-21.9,'.,.-1972..

Marine E,cology Lafioratorv`, Dartmouth, N.S.

Biological Stâtion,.St. John's, Nfid.`

1 PUBLISHER - ÉDITEUR

Not available

DATE OF PUE3LICATION DATE DE PUBLICATION

YEAR ANNÉE

1972

PAGE NUMBERS IN ORIGINAL NUMÉROS DES PAGES DANS

L'ORICINAL

212-219 NUMBER OF TYPED PAGES

NOMEIRE DE PAGES

DACTYLOGRAPHIÉES

13

ISSUE NO. NUMÉRO

83

VOLUME

MI6

PLACE OF PUBLICATION LIEU DE PUBLICATION

(USSR)

YOUR 14UME3CR owe

VOTRE DOSSIER NO

DATE OF REQUEST DATE DE LA DEMANDE _ April 4, 1974

.t\ r-t ,-seN

DEPARTMENT OF THE SECRETARY OF STATE Plve; 4 SECRÉTARIAT D'ÉTAT

TRANSLATION i3UREAU BUREAU DES TRADUCTIONS '

MULTILINGUAL SERVICES DIVISION DES SERVICES CAN/WA

DIVISION , MULTILINGUES

fer4 (.3e) 1 S15L L., 1INTO - IN

Russian English

Yuryov and L. I. Starushenko :171T-L . :7IN ENGLISH --11 111 E ANGLAIS

TEE DYTAUCS OP TEE ropunnow or sPnAY IN THE mucK SEA. AND DETEOD OP PREDICTDG 120SIDIE CCOsif2S

TITLE IN FOREIGN LANC•UAGE (TRA/ISLITEFIAlE FOREIGN CHARACTERS) TITRE F.N LANGUE ÉTRANGE....RE (TRANSCRIPE Eli CARACri, Rus RomAiNs)

DIWIn CEISL=OSTI CEORNOFORSKOCO SUPROTA 1 METODIKA 2ROGKOZIROVANril .EGO VOnOZEUGO ULOVA

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Trudy VNIRO

REFER/71.1 , F 1 11 rNGLIgH - RiFÉRENCE EL APGLAIS

Treatises of the Ali-.Union Scientific Research Institute of Marine Fisheries and Oceanography (VUIRO)

7 84532 REQUESTING DEPARTMENT Environm TRANSLATION BUREAU NO.ent

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PERSON REQUESTING A. S. Hourston, Pacific Biological Station, DEMANDÉ PAR ra 119, 11110

soS•200-10-6 (REV. 2/013)

7030-21-02 1 -0133

• DEPARTMENT OF THE SECRETARY OF STATE

TRANSLATION BUREAU

SECRÉTARIAT D'ÉTAT

BUREAU DES TRADUCTIONS

DIVISION DES SERVICES

MULTILINGUES

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Office of the Editor/ Fisheries Service

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DEPARTMENT

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784552

Trudy VUTRO (T:ccatises of the A il—Union Scientific Rescu.rch 7.11Shtuï-(76f Marine Fisheries and Oceanography), Vol. 83, 1972, pp. 212-219 (USSR)

UDC 597-152.6 ; 597.55, - „\

THE DYNAMICS or THE POPULATION OP smiav.

IN THE BLACK SEA AND METHOD OF PREDICTING POSSIBLE CATCHES

By G. S. Yuryev and L. :.. Starushenko, AzchorKIRO (Sea of Azov and Black Sea

Scientific Research Institute of Marine Fisheries and Oceanography)

Black Sea sprat (Sprattus sprattus phalericus russo) 212*

is one of the most numerous of commercial fishes to be

found in. the Black Sea s; Originally a native of the North

Atlantic /11/, sprat adapted itself to the Black Sea, never-

theless remaining a cold—loving fish. Sprat inhabits the

entire area of seawater. In winter it retains its presence

throughout the 100—metre depth of water, while in summer it

occupies the lapr below the thermocline.

Sprat spawns most intensively in the cold periods of

the year (December through March), although eggs of the fish

Numbers in the right—hand margin indicate the corresponding pages in the original.

S 05 -200.- I 0-31

40

20

10

m 1 14 2. (11 bi

are encountered the year around.

The northwest is the only region of the Black Sea

(within the limits of the waters of the USSR) where commer-

cial accumulations of sprat are regularly observed both in

spring and summer. Constant fishing has been developed in

this region, accounting for approximately 9 5 of the total

yield of sprat in the Black Sea basin. Sprat is caught

mainly with trap nets. The fishing season lasts 7 to 9

months, from March-April to October-November. A distribu-

tion of catches of sprat on a monthly average for 1946-69

is provided in Pig.l.

2

PacnpegexeHme plo)3o13 sep-HomopeKoro wipoTa -1K) ne-cluem B ope,o;uem sa I:k6- 1969 rr.

Fig.'. Distribution of catches of Black Sea sprat on a monthly average for 1946-69.

1 - Months; 2 - Catches, %

The dynamics of ahuri-

dance of Black Sea sprat is

determined by its short life

cycle, early maturing, leng-

thy spawning and spawning

intermittence. The abun-

dance of sprat is subjected

to considerable annual fluc-

tuations: This is reflect-

ed in the size of catches

changing from 40,200 cent-

ners (1954) to 2,500 cent-

ners (1961).

A study of the age structure of the commercial

stock of Black Sea sprat showed that the stock consists of

3

four to five age-groups: fingerlings, yearlings, two-year-

-olds, three-year--olds and four-year-olds (Table 1).,,r.: •

The bulk of the commercial stock.of sprat is com-

posed of yearlings (87.0-44-5M. It is precisely the abun-

dance of this age-group that determines the size of the

catch. As a result of a high natural mortality rate, the

abundance of the older age-groups is, in effect, exhausted

in the four-th year of life and therefore cannot substan-

tially influence either the stock or the amount of fish

caught.

Table 1

. Ta 6j, .^ a x

1 - Bo:ZpacrHO.`^ c:oc^^,ll, ttpo!•::,ac.ôvo^ro c a°^^,â uepFIOr,:opcicor. o i ^.c 1̂ T'a.0 -- 1569 rr.B cezêpc,-JànÛr^.:c•: Liûca:. ^^cC^rJ r.apz :^ Zr6

U ^)

-3os ^f^c'li^^l r^,vnzr4 -" BnôB;3oi1^ .r ç Y0+ T+ ,^ r 3+ +

1960 Z,O* 71,5 27,4 160 ^ 12,1

1961 0,1- 64,4 33,4 2,2 - 3,0

1962 0,1 86,4 13,1 015 - 18,5

1963 0,1 72,1 26,9 1,0 - 10,3

1964 0,1 87,0 12,9 0,1 - 36,9

1965 35,0 51;8 12,6 0,6 -- 39,4

1966 35,3 60,4 4,2 0,I - 19,4

1967 17,9 64,5 16,4 1,2 - 13,1

1968 31,0 56,5 12,5 - - 17,5

I969._ _X, I `^45 439 6.._ I0, 7_...._..._.__p+.I... 5,2

1- Age composition of the commercial stock ofBlack Sea sprat in the northwestern region ofthe Black Sea in 1960-69 (in per cent);

2 Year; 3 - Age-groups; 4-- Annual catch, inthousands of centners.

^Here, as in all the following numerical values in this

table, the comma is to be read as a decimal point.

• • , ..^. ,.^, ..,.,..^_.w............^..,., .i -,^. ... ......:^.. .â .... .^ . ... .• . ^^..i.. .1 a ..n1.{i^...atEC-Jr,.a..YLF....u.r. . 3itix?.^f.. uL..'.; ...... -.. ..»...u':Ÿ.il^â.•i:iy,i'a.-d ..e ^+kw.^r ?

.....

4

4

The preponderance of one age-group (1+) of Black Sea 214

sprat in the commercial stock makes it possible to establish

the relation between,the abundance of certain year-classes

and various environmental factors*

Research work of recent years has established that the

principal causes of fluctuations in the catches of commerci-

al fishes lie in the conditions of the reproduction and sur-

vival of juveniles in the early stages of development. Let

us attempt to find how the water temperature during the

spawning s ea so n and the availab il it y of fo o d to the j uveniles

of sprat affect the abundance of year-classes of sprat.

In order to establish the relation between the

yield of sprat and temperature conditions we compared the

average monthly temperature of the water for December-March

(the main spawning season) with the catches made in the

period between 1946 and 1969 (the catches are displaced by

one year, Fig. 2). The water temperature measured near the

coast of Odessa reflects the character of temperature change

in the other regions of the northwest of the sea, since the

Black Sea is characterized by a uniformity of processes

taking place in it /`7/• As a result of such a comparison

we establish a direct relation between the magnitude of the

yield of sprat and the temperature conditions of the main

spawning season.

After cold winters (194-4/45, 1946/4-7, 1948/49, 215

1953/54, 1959/60.) the catches of sprat were low, whereas

after mild winters (194.7/48, 1952/53, 1954/55) 1957/58)

5

they were high.

Thus, after severe winters the year-classes of sprat

are found of a low yield, which is subsequently reflected

in lovi catches the following year. Mild winters with con-

siderable precipitation provide the most favourable condi-

tions for the survival of year-classes of sprat.

1 . 31-imm

1944/45 i946/47 IM49 1g50)51 1952/53 1954/55 1956/S7 i553[59 1950/61 19463 i91;4/65 1966/57 t

cC • t___.-- + --e ---4 . --4 ---)----t--4 --4,---1-- --4-,-.1 -i----4-L- -4---t- 4 4,----e--f t f

. .5

A . i \ S zi • , ■ e

•‘ ‘ /' .

4

1 -30

/ \ x- i\ ---' \ . •3 ---...,

, 20 .;

._... j\„ . ...--. .2 10 re/ •,,,/ \ : — \ I

L...._.— ....._ ,. — I .. . • 21 --- — _.__—_— _,_— . 0 . I 1966 194G 19 50 1952 1954 1955 1956 i9G0 1962 1964 1946 I9S 6,

.. cv 3 — ro Aid

Pic. 2. CRUX, ypozzaa U11.1p0Ta co coe,Tunaul TemepaTy-pawl BON B nepuog liopecTa (y.uoul.ogemyTu Ra 1 rog):

yzoB, .11; TeunepaTypa, °C .

Pig.2. Relation between yield of sprat and average water temperatures during spawning season. (catches are shifted by 1 year):

- catch, in thousands of cent-ners; - - temperature, in ° C.

1 - Winters; 2 - Catches, in thousands of centners; 3 - Years.

The relation between the abundance of year-classes

of BlackSea sprat and the water temperature in winter is

also confirmed by other researchers /12, 13/.

" \i/ / V

1963 1965 196? 1961

/

70 „

GO So zi 40 J.4

20

101

T69 -

6

The annually varying stocks of Black Sea sprat, a

relative idea of which is provided by commercial catches,

also depend on the food supply of the body of water. The

Survival of the juveniles of sprat is conditioned bythe

amount of food available during the given year and varies in

proportion to the biogenic flow of Black Sea basin rivers /71

Comparing the catches of sprat in the northwestern

region of the Black Sea with the flow of the Dnieper River

for 1946-69 (the catches are displaced by 1 year), we find

that a pronounced direct correlative relation exists between

them (Pig. 3).

1 - 1 0 Abt

1946 1948 1950 052 1954 1956 1950 1960 1962..

1964 1966 1968 „ • . 4e. . . t. • . .

A /4\ / \ - / ■

(j50 • .,"" --"\ / \ / \ 1 1•

\ / .j

\ P-....

1 i-'s ■ -:-..../ \ /..- ,

,/ A\ i't . \ \ ./

e4; 30 0 20 u., 10

I . cm 1977 1949 1951 1953 1955 195? 1959

3 roAbt

• Pac.3. Cagn ypo.mn impoTa CO CTOKOM Menpa (yaoBu UBMIVT11 Ha I roz):

- plop, Tuc.I.1; CTOK ÂHenpa, ra43 . • Pig.3. Relation between catch of sprat and

flow of Dnieper River (catches are shifted by 1 year):

- catch, in thousands of centners4 - flow of Dnieper River, in km,

1.- Years; 2 - Catch, in thousands of cent-ners; 3 — Years; 4 — Flow of Dnieper River, km3.

7

Great biogenic flows of the Dnieper River are the 216

condition of an increased yield of plankton, resulting in

favourable feeding conditions for the survival of the juven-

iles of sprat, which consequently influences the size of the

catch.

Thus, after considerable flows of the Dnieper River

in 1948, 1953, 1955, 1956 and 1964, a year later, respect-

ively, the yields of sprat were high, and, conversely, small

flows of the Dnieper in 1954 and 1960 were followed by low

yields of sprat in 1955 and 1961, respectively.

The revealed relations between the yield of sprat

and the mean temperature of the main spawning season and

- the availability of food make it possible to use them for

predicting purposes.

Pigs: 2 and 3 show that, for several years, the

established relations were not observed. Evidently, during

that time the take of sprat was decisively influenced by

other factors.

When a passive method of catching sprat is used

(trap nets) the amount of fish caught depends not only on

the condition of the stock (abundance of yearlings), but

also on the hydrometeorological conditions, primarily

temperature conditions. Long—terni observations have estab-

lished that the sprat approaches the coastal zone of the

mea at water temperatures ranging from 8 to 180 0, when,

however, the water temperature rises to 200 0, it leaves the

8

coastal zone and descends to the colder layers of rater. In

effect / the water temperature determines when the approaches

occur, the amount of time the growing concentration of sprat

stays in the coastal zone of the sea (trap-net fishing zone),

and, consequently, the amount of fish caught.

The most favourable temperature conditions for the

approaches of the sprat into the coastal zone arise in

April-May and September-October. The water temperature is

at its highest--20-25 0 0--from June to August. During these

months the sprat can make the approach only in the period

of the accumulation of very large schools, which causes the

water temperature in the coastal zone to drop to 10-120 0.

, Therefore, in predicting the possible catch of sprat, a

correction should be made for the expected temperature con-

ditions in this zone of the sea.

Continuing our study of the regularities governing

the dynamics of the population of sprat, in 1967 we worked

out and applied a method of direct estimation of the abun-

dance of yearlings of sprat in the sea. A quantitative

estimate was carried out in April-May throughout the area

of the Black Sea in accordance with a standard layout of

the station using a fingerling trawl.

The results of an estimate conducted from 1967 to

1969 indicated an irregular distribution of yearlings of

sprat in the sea. The greatest concentrations of sprat, up

to 1,500,000 in 30 minutes' trawling, were noted in the pro-

9

-estuarine regions of large rivers and in the region lying

just off the Kerch Strait, that 3.s, those regions of the

sea where the greatest amount of food is available.

The average catches of yearl:ings, according to the

estimate data, indicate a fluctuation of their abundance in

the period between 1967 and 1969 (Table 2).

Table 2

jyi 2^SG j7

l w y11on-; ce_Pojie xzcoi3 itti.po^ra B jl.en,,ion nope aa 30 t.+, xMyT'.CpaAG37YA B RIIPC'a:G-•.:.,'AC: Iz'. ( D LIT- 1

.......^.•^^^^...,..^...V,_^,..........,.^...._,..^._......_.

l'ou - 2 3.. BocTo'i-'i_iGsI 4 3aâon^.5- Cpe91UIeT ac) 5"1Jf^ ti v;c TT, -

1967 3347 903:2 6858

1968 TG6T5 GI^^ 11400

1969 3584 5123 4 888

1 - Catches of yearlings of sprat in the BlackSea in 30 minutes' trawling in April-Mayfor 1967-69 (number of fish caught);

2 - Year; 3 - T^.asterh region; 4 - Western;region; 5 - Average.

Proceeding from the results of the direct estimate

of yearlings we attempted to estirnate the total stock of

sprat in the sea. It was found close to the stocks of

Black Sea anchovy and constituted approximately two to

three million centners. The maximum removal of sprat by

fisheries of all the countries on the Black Sea constitutes

only 2-3ô of the stock. If our calculations are correct,

the considerable stocks of sprat make it possible to inorease

10

by several times the catches of the fish by employing an

active fishing method.

, It is no novelty that the stocks of Black Sea sprat

are immense and that the organization of active fishing is

necessary /1-6, 8-10/. However, the proposal to exploit

the stock of sprat in the open sea has not as yet been

realized, since active fishing gear enabling the seining

of rarified concentrations has not been found.

In 1968, the Sea of Azov and Black Sea Scientific

Research Institute of Marine Fisheries and Oceanography

(AzchorNIRO) ben research work directed at finding sprat

concentration forming methods for the organization of active

fishing of sprat in the open sea.

1. Aleev Yu. G .. The Biology and Economio Importance

of Black Sea Sprat (Sprattus sprattus phalericus Risso).

Trudy Sevastopollskoi Biologicheskol Stantsil. Vol. 10,1958.

2. Aslanova N. E. Black Sea Sprat. Trudy VNIRO.

Vol. 28, 1954.

3. Aslanova N. E. The Distribution and Prospects

of Catching Black Sea Sprat. Annotations for research papers

executed by VNIRO in 1955. Collection 1. Moscow, publish-

ing house of the USSR Ministry of the Fishing Industry, 1956.

4: Vodyanitskii V. A., Kazanova I. I. Key for Pelagic Eggs and Larvae of Black Sea Fishes: Trudy VNIRO.

11

Vol. 28, 1954.

5. Golenchenko A. P. Sprat in the Black Sea. Rybnoe

Khozyaistvo, 1940, No. 6.

6 , Golencheriko A. P. Black Sea Fish Resources and

Prospects of Exploiting Them. Rybnoe Khozyaistvo, 1 948 ,

No. 4.

7. Izhevskii G. K. Oceanological Principles of the

Fishing Productivity of Seas. Moscow, Pischepromizdat,

1961.

8. Iyublmova T. G. The Distribution of Sprat in the

Northwestern Region of the Black Sea. Rybnoe Khozyaistvo,

1957, No. 12.

9. Pilyavskaya A. E. Unexplolted Sprat Resources

in the Northwestern Region of the Black Sea. Rybnoe Khoz-

yaistvo, 1937, No. 8.

10. Rass T. S. Ichthyofauna of the Black Sea and

Its Exploitation. Trudy IOAN. Vol. 4, 1949.

11. Svetividov A. N. Black Sea Fishes. Moscow.

Publishing house Nauka, 1964.

12. Stoyanov St. A. The Condition of the Stock of

Black Sea Sprat Caught Along the Bulgarian Coast In the

Periods 1945-1950 and 1955-1959. Treatises of the Central

Scientific Research Institute of Fish Breeding and Fisheries.

Vo].. 3, Varna, 1960. 13. Cautis ilena, Migratiile sprotului la litoralul Românesc

si'causele care le determinâ, Buletinul institutului

de cercetâri si proiectâri pisciole, anul XXVII,

N 4, 1968.

12

Jl II T C U a 1 y 3

I. A.rleeB I0.1'. 0 dnonorl.:i 1-1 e:taa.elilLil qeplta-

;dopt..rOro IMp0'a : prattus sprattus rhalericus

R i ; ;3U) .. Z`pgAU Ccracfi. G;ô:'ÙQr. cT. T.X, I:358.

2. la.cnaF-ora H. É. IünpoT liepiioro nopR.

I95 .̂^. .3. Aexmopa ti.D. PacnpzelieiTrre J.1 ÎCpcIIûx^^Ta^^ .uoLa. Llnr1a-

.L.SOpOiiorO L!3IIpo`S`Fi. Iz paC)o`S`r>"lr F1ÎI01ZIi`:^'klkiiQ

BIMPO B 1955 r. Cd. Z. tL,m3z. 121I CCCP, Dâ6,

4. ^30^^^1?^cl^`^ D.b., I{î3^lFi0IIA ^1.11. Onpe;nersl^2'c:^ ne^âz'n--

uecitnx iucpliilaz: 1.1 .nxtmxai-t plid Iieplloro mopi. ìj?yxu.

BHIIPO. T.XXYI[f, 1951.

5. l'onenremtio A.H. LWpaa.^ B qepxor:a rsope. "PHdR.ao3-ro" ,1940, ib 6.

6. I'o.uexueU;.co A.II. PHdln.ae doraxc^.'l.lA qepHOI'a I.ICpA Ii lIep-

cnel:l^s^^ lix ocxOeHjlx. "P>A6H. Xal--)ao" , 19,48, J^ 4.01C(:Etl3o:,I01'111i!Ïcx.T.iG' OcllOBht l1?0jî:tiîpUl3Fi.kis353

IIpQIÎCJI0B0^[ Ilpo,^ÎÎôcû ô^^^s. r}l. ,I33â^, 1961.

8. JIIOdw-ioaaa T.I. 0 pacIIpeîUeIIIIIi Eiupoa'a B ceBepo-3zW,Û-x9^'7,:ai2.xo^ uacx°n 'qepilora Mops. "PxdH.Zoc-DO",

9. IIui^t$clcaq A.E. HeXeno.zb3yexUle pecypclZ rJupoTa n caBa-

pa-3A17.31Îi0:^ Llac rA 'lPpHoro biOp:i.

1937, 9 8.,I0: Pace T.C. YLxTnoâyFla qepxoro mapx a ee xcIIoûsoLaxlre.

7'pyru,,i FIOAB. T.4, 1949.

XZ. CgeTozalY,ti,oB A. H. PON lqepxoro ?,4ôpR.1â. ,^t3;^T1Âa"Hn3rxa" , 1564.

12. C,oÎioa C^r.A. CIcToRHI:e Iia 3uIIaccZ HA tiepuot:iopcl;aTa

TplMoliR, JI0I3e1ia IIo dMrApcl'%oTo xpe: ¢6;?eê ?i^?03 ue-pIIOu,.^xe 194-5-1950 n I955-1559 rr. TpY,^Rone xa Lt, UT-- .pa1IIII1x âytllô^^ cne,ô$al^c^cxr^ nncT;STyT Aa pNda-nagc TBC m p^dojianc Èuo. T. II, }3aplla, 1960.

3

THE DYNAMICS OF THE POPULATION OF SPRAT IN THE BLACK SEA AND 'METHOD OF PREDICTING POSSIBLE CATCHES

G.S.Yuryev, L.LStarushenko

SUMMARY

A direct relation between the yield of sprat and the temperature of water during the spawning setSon has been ascertained. Mild winter with abundant precipitation makes the most favourable conditions for the surv.ival of year-classes of sprat.

The fluctuations in the abundance of sprat are also governed by the avàilability of food in the Black Sea, which is connected with the biogenic runoff of rivers entering the Black Sea.

Regular assessment of the abundance of the pelaele young of sprat made by the method suggested will contribute to predictions of fluctuations in the stock of sprat and, thus, possible catches. •

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^FISHERIES AND MARINE SERVICE Translation Seriesdfo-mpo.gc.ca/Library/111669.pdf · ^FISHERIES AND MARINE SERVICE Translation Series No. 3060 Translated by the Translation Bureau(EJI,)