.-------------~ ." • '"i ., ( '., \,~

Not to be cited without prior refe;ence to the author

Iriternational Couricil for theExploration of the Seil

C.M. 1997!EE: . (J; 13',Environmental Factors

.,RECENT VARIATIONS OF HYDROLOGICAL REGIME IN THE SOUTH~ .EASTERN BALTIC SEA AND.THEIR IMPACT UPON COO SPA\VNING. CONDITIONS, I

b',.,"," y, .. ,~~.S., ZeZeril E.S.

Atlantic Scie~tific Research InSiitÜt~ofManne Fishenes arid Oceanogfaphy (AtlantNII~.O) 5;", Dm.Donskoy Sir... Kalinirigriid 236000 Russia .

. .: .. -. ' '.

, .ABSTRACT

. ,The workS in the frames of South-EaStem BaItic Sea monitoring, änriiiliüy perfonriedby AtlantNIRO from 1992, have beencOntinued in the end of 1996. MiintrendS of deep

"vater hydrology vw:iations were analysed in Gcf3nsk and s~uthem GotIand Deeps from,1992to. 1997. SpaWriing eonditions in leES SubdiVisiori 26 for the latest years were charilCterizedon, the base ,ofadopted 'bouridaIy envirooni~ritäl coriditions,' ,which ~efirie success ~f cOdspawning (saliriity > 11%0. oxYgeri ::> 2ml/l, teinperatw-e >1.5°). In Gdansk spaWnirig arearetrospective data on Station PI were analySed from 1980 to the present

.2

.after, a series of weak iIillows With ilie st}ongeSt one in i993, abiotic roriditions in thc .Southern BaItic Sea improvoo (Hiriiichseß, 1996)... . ," ".

Plikshs (1996), Hinrichsen (1996), MacKenzie (1996), Wieland (1996), Bagge(1996) and others corisideroo vanous aspectS,of cOd reproduction during the latestdecades on the basis of long-terin data series. We suppOse the most imporiani result ofthose researches are as folIows: low spawrung stock of cod With young fish (firstmaturity) predominance; shirt ofspawning peak from mid-May - earlyJune (1986-1989)to mid-June - mid-July (1990-1995), occurence ofprolongoospaviniI1g without any peakby time; more significant decrease of rcprodüctive volumes from spring to sunuileiduring the latest decade, i.e. apparent negative trend of iritraannuaI decreaSe of thepenOd favoumble to spaWning; retain'ofthe leading role ofcod from thc Southem Batticspawning grounds (mainly. that of Bofnholni) in reproduction, i.e., no reCovery of thc,Gotland spawnirig ground after iIlfIows in 1993-1994 has beeri obserV~. .

In the paper 'presentoo the characterlStic of hydrological conditio~ in GdanSk, basin arid Southern Gotland Deep is piovidoo from 1992 to 1997 taking in account thc

above said, and another approach to RV estimation in the South-Eastem Baltic Sea ispropoSed. On the basis of 15-year obServation data at station PI (CentrnJ Gdarisk Deep)

, reproductive volumes in rectärigle 3864., (ICES StibdiVision 26) are· estimated ' andspawning conditions in GdanSk spawning ground ace anaIysed from ,1980 to 1997. This 'research continue thc eacliei works by ZCzerd (1993), Feldman et al., (1995, 1996).,

MATERIAL AND METHODS ,

, AßaIysis of hydrologieal regime h~ beeil eamed 'out öriihe basis of,materialS .obtäined in 14,cmises of AtiantNIRO in, 'the Baltic Sea (May 1992-March 1997). ,Tocharacterize deep water hydrology during' spritig-summer 1996 the, data of RJV"Alkor"of Kiel Institute ofMaririe Researches were usOO. '. .

, Hydrological"researches were perfonnoo using CTD-iooo probe arid Neil Brownwith temperature und salinity recording by 1-5 m intervaIs. Ai registration point stations >ci>mplex hydrocheinical 'feSearches were proVided. Water sampieS were collected with' _

',Nanseri bathometers; oxygen level was estimated using inethod by \Virikler. ', .

Spatial-temporal variability oftemperature, &'1linity and oxygen level was reveaJedby inean of, monitoring ai stations PI (Ceniral Giliillsk oecp) and BY9 (SOuthemGotland Deep).' ,. ".

Assessrrient· of RV in the South-Eastein Baitic Sea during spring' 1992-1995 waspeiformed by ICES rectangles using average thickriess of reproductive layer in euchrectangle. In ihe case of large heterogeneity of- hydrological conditions withiri onerectangle, the urea of the latter was divided into' subdivisions; , RV. was 'estiniated'individually by subdivisioiis arid the total value was suinmed. To obtairi ihe latter results~the' area with adopted Jimitirig conditions was preliminary contoured for euch sui-Vey.·Further, it was overhipped by a bathymetfic map with isobathcs corresponding to ihc: .depth of reproductive layer upper boundary within each ICES rectangle. 11 allows toestimate represeniability of average vahie adopted for t11c spa\l.ming laycr, and 10 excludethe areas which meet no requiremeriis for limiting conditions relevant to salinity andoxygen, from assessments. "

~ , .. 3 .

, .Analy~is of abiotic coridiiions in Gdarisk Decp from 1980 \6 thc prescn(tirri6 \~ascarried out against RV in rectangle 3864 (leES Subdivisiön 26).' Lirie-ar regresSion'analysis shows high correlation between the spa\\'J1irig layer at registraÜon point station(PI) and RV in rectangle 3864 (R2=0.96). Regression .model obtairicd was usoo' tocstimat.c retrospectivc RV.. ,\Vater volumcs v.;th charactcristics sclecicd wcrc. cstirmitcdusing the programme "DalthyPsogrnph'" by \Volf and Aridersori from StockhohnUniversity.

. '

, . , ,..~ , .

. ',' : " I •

RESULTS AND DIS~USSION.. '

••

R~ehrches in the Sohth-Eastem Baltic Sea in March ,1996 au'ows to d~fin'e severnlfeaturesof hydrological regime, caused by rather, scvere' wiriter of 1995/96 arid advectiveprocesseS. .In March the rise of temperature v.'as observed in deep water layers (belowhalocline) inspitc of cohsidcrablc cooling of the earth sunacc iri Yt'inter, l>CSidcs. inGrlansk Deep positive anomalies approached 1.5-i.0°c aS oomparcit to October 1995while maximum occured in the layer of 80-90 m and 2.0-3.5°(;' as oompared to March1995. Temperature increase in the active layer of decp water was found also in SouthemGotIand Deep. Opposit temperature variations in thc surface layer imd in \Vater columneVidencethe: advective' pattern of procesSes, observed in deep water laYer. Appareritpositive background of, rinomalies fourid, allows tö· identify warm deep waters 'astiinsforrried Noi1h-sea inflow of the fall 1995. Teinperature in the: core of ihese water

'niasses approaches 7°(:,. Satiriity of these water masSes was relatively l~w (i Ö.6- i0.9 %0 );. which in couple with high tcmperaturc resulied in relativcly low dcnsity arid distributionover the area at" iriterinediate levels.. ", ' . " .',

• , .'Aflother aspect of March obserVations is fixation 'of high~saIiriitywaters (saIinity

12.6-13.3%0, oxygen 2.4-3.2 mlll) in the near-böttom layer southwards of Gotlarid oeep.Distribution of thesewater maSses was followOO northwards up t056°N, Le. besideSadvection in Winter 1995/96 in the äctive layer, advective waters of the fall genesis was~rririspoited a~~o into the ~ear-bottom laycr. •

, . .'.. In'late May-early. itine iiillow pf another portion. of highly aerated .'(oxygen

conieni above 3-4 mlfl), saline (above 12%0) arid cold (2.:3°C) water maSscs was observeclin the area. Water temperature in the near-b~ttom layer decreasoo by'more'th~n 3.5-4°Cas crimpared to March. further imj>rovemenl of abiotic coriditioris (6ip~ially of oxygenregime) was observed in deep near-boUorillaYer. ..' .

• .' '. • ~ • • • . ' \ e 0 •

"_ Obse~ai'ioris iriOc'tober 1996 alSo evidence prerlominanceof advcctive procCsses..In GdUriSk Deep absolute valueS of such indices as isohiiline 10%0 depth, area of waterswith l1igh salinity (above 10 %0' ),- salinity änomalies' in' the ncar~boitom layer wereromparable to the similar indices in "adveCtive" 1994 (Fig. I,' 2, 3). Therefore. transportoftwo ..portions....ofNorth Sea watcr masscs irito the area was the mairi feiltim~ of 1996:-The first infiow was dunng wiriter hydrological seasOn~ the secorid in'laie sp~ing-summer..In general eritire Soüthem Baltic Sea was covered with advection, including Gdansk aridSouthem Gotland Deeps (up to 56°30N). . '. ...., . . .: .

.I~ Ma;ch:i997 no iiidicationS of "new"water iriflow into leES Subdivision 26 was

observed.· Hydrological .situation waS, mainly similar to that iri, March 1995,' with "relatively hig~ location of isohalirie lO%O(79m) .arid oxygen dificiency in the most .

4

Gdarisk .Dccp area (0.2-0.5. mui in the ~entre. and bclow i ~lfl northwards). In theSoutllem. Gotland Deepoxygen conditions near .boUom was more favourable with

"oxygen content ~bove 1 nilfl and maxüiiuin 2.5 mlfl southwards. . , .. ".

General dynamics of temperature. Salinity and oxygen vanability by time atregistered point stations from 1992 to 1997 is presentCd in Fig. 4,5. .

At present reproductive volurries becorrie a gerier~ly adopted' charucteristie ofabiotic conditions. Many authors (MacKenzie. John, Bagge. ete.) used in iheir researchesof various factors affecting srawnirig sücceSS, RV by. Plikshs (1993) who estimates RV at

"major cod spaWning grounds on the, basis of observations at one (registerCd point)station for different areas: BY5, PI, BY9. stA3, BYIS respectively (Plikshs et al., 1993).Representability of' this approach when spawnirig layer thickneSs in one point isextrapolated to significant areas, has been checked on the basis of AtlantNIRO springsurveys in leES Subdivision 26 in 1992-1?95. "'. . ~ . . . . ' .

Depths of isohaline 11%0 and isooxygeri 2m1Jl (temperature' "Yas not a limiting , .,.factor) revealed oonsiderable nirige of those features variations ,over the are3~ Thus, in ...Gdansk Deep thickness ofihe hiyer with high salinity (above 11%0) rind oxygen content •2 inlfl und more vaned froin I ni to 14 ci in 1992 ,( at station PI - -3 m), and from 2 mto21 in . (at station PI '-12 m), from 1 m to 25 m (at station PI - 25 m) arid from -2(isooxygene 2"mllI was locäted above isOhrilme 11%0 ) io 21 rii ( at sÜition PI - 15 m) in1993-1995. respeciively, Le. riciually, assessment of real RV ( in Olir case for Gdrinskspawnirig groimd) on'the basis of one station includinginternritional station PI. is ratherproblematic. Evidently, RV values, obtairied on the basis of averaged thicknesS of thelayer studied, will be more repreSentalive. BeSides. it is important. thaUhe urea to whichthat "ridopted" layeris extrapolated, is relativeIy small. Appropriate choise ofthe area iseSpecially important for RV eStiination iri Gotlarid Deep which is char.lcterized by ri laf!~erange of depths variations from the South to the North. Since the depth of waters,v.:ithhigh salinity and oxygen regime of the latter, depends both.on· the .volume of advected

.. ' water intlow, periodicity 01' their transport and the deplh of the area. selection of statioris. for assessment of average reproductive layer thickncss and the urea' to where it is .extrapolated in Gotland Decp should oe more strict. In the laUer area the "routiries"ofadvective flows movement from. the South to the North' are more important. Forexample, observationS in April 1993 arid March 1996 show; that intrusion of advectivewaters northwards" to" 56°30 N occures westwards of st. BY9, i.e. during iridividüa) e,penods the above rcgistration poirit should not be uscd 10 cstimatc RV in' SouthcrnGotländ', Deep, since it reflci:ls no hydfological situation. in the area. Besidcs. in theprocess of RV. estimation" by one station; inchiding the international station BY9 'imdstation 43 (56°42 N. 19°52 E) wiih extrapolation io rectangles; proposcd by Plikshs(1993), sigilifiearif"överestifnation of RV is nted caused by more deep nothern parts ofrectangles whil~ InOre shallow southern parts (as eompareä to tllt 'rcgistralion poilli)' areexcluded from estimation. It reflects no vertical and horizontal stnieturcof,deep waters•

.observed in appropriatc hydrological survey. Besidcs; actual distribution pattern ofwaters favourable to cod reproduction was almost opposite; Le. ihose watcr inassesoccured mostly, in the souihern part of" rectangles \vhile northward of the registraiion '.point thcy werc totally absent.· . .'

Takirig in aecount the above said. estimation of RV for eod iri the Eastern BalticSca was carried out by leES reciangles using average thickness 01' reproductivc layer foreach rectangles. The results of RV estimation in Sub~ivisiori 26 are shown in Table.".

•

.. , ..5

. ,. . " , ", . ' ' , , .. . More .det~il~ ~pproach' to; fq>rodtictive layer estimaiion Wiihin spaWning.

grou~ds provIdes;~?re accurate abso~u~~ v~ueof~Ywhich is the most important factor .(Jf th,lS co~ple~ envI.r?mllC?nt~1 parameter m various physic~l models. The problem is to .s~lect r~~lstrat.19n P~)I~t .st~tlOns fo,r, eachICES rt~ctangle which appropriatelY. reflectshrd~oJoglCal sltu~tlOn:WltJun the area to which' ~he ,reproductive,layer is extrapohited.SImllar problem In Bomholm spawning groimd was solvCd by Hinrichsen (1996). Thefir:st attempt to subsÜmtiate theabove niethoG for the South-Eastem Briltic area is RY'~.ti~a~ion in r,ectangJ~. 3864 (Subdivision 26) where sigi1ificant part of Gdansk' codspawnmg ground 10cates. "

, . 111 Figure 6 the follo~g linear "relations are shoWn: A) bet~~~ 'spawriing layerthiekness in the Central Gdansk Deep(54Ö50N, i9°2iE) and reproductive volumeS irirectangle 3864 (on the basis,of 10 cruises of AiIantNIRO from 05.1992 to 10.1996); B)1>etween RY arid - R Y, estimated by regression 'model obtairied.. ." ,'" Figure 7 sh~ws 'the variable dYn~ics of the layer favo~rabic to'ood spawning'and reprooucÜve voltirries in rectangle 3864 from 1980 to 1997. . .. "}

" Asis seen from Figure 7, spawning eonditions in Gdansk Dcep during 1980s wereextremely unfavourable. Slight improvement which covers also Gotland basin (PlikShs,1996), waS observed in 1983 arid 1985. In other years formation 01' the hiyer lavourableto spawning occurroo orily during short period while from 1988 to 1991, no such layerwas formed in Gdansk spawning area. Actually during entire 1980s Bornholm basin wasthe major spaWning grourid of cod; while extremeJy poor conditions were observed therefrom laie 1980s (Hinrichsen, 1996). From erirly 19905 in the South-Westem' BaIti

6

REFERENCES. . . . . .' .

, Bagge O. 1996. Inflows to the Baltic. predation on eod eggs and )'cur-etass strcIlgth 'in, Subdivisions 25-28. ICES C.M. 1996/C+J:9. .

Feldman V.N.• Nazarov N.A.• Zczcra A.S.~ lizcra E.S. i995. Salinit)'/oxygcn regime of, water in South-Eastem part of Baltic proper iri 1992-199)and demcrsal living

eonditipns. ICES C.M.1995/J:21.. '

Feldman V.N.• Naiarov N.A., Zezera A.S.• Zezera E.S. 1996. saJinity/oxygen regime ofwater in, South-Eastempart of Baltic proper in 1992-/996 and its impact on codspawning conditions and distri.bution. ICES C'~~ 1996/C+J:8.

Hinrichseri N.-H. 1996. Reprorluction 'v'oi~me of BaJtic ead i~ theBomholm Basin, estimated fromsingJe point measurements..ICES C.M. 1996/C+J:7. .

MacKenZie B.R., Stjohn M.A.• Plikshs M., Hinrichsen H.-H.; Wieland K.· 1996...Oceariogmphic processes influencing seasonal and interannual variability in cod .iIspawning habitat inthe ~terri Baltic S61. ICES C.M. 1996/C+J:4.' .

Matthüus 'V. i995. Natural variability and human impactS reflecied in Ing term changesin the Baltic Deep water C(mditiorls. A bnef review. Deutsche HydrographischeZeitschnft. Vol. 47, No.l:47-65.· , .'

Plikshs M.• Kalejs M.• Grauman.G: i99i The infiüence oferiVironmentafeon'ditions a~dspawning 'stock sire on the year-elass strength' of the eiistem Briltic cod. ICESC.M. 1993/1:22.

Plikshs M. 1996; Reeent changes in cOd spawnirig stock abundarice and reproductionsucccss in the G~tland area: is the 00d recovery possible? ICES C.M. 1996/1:23.

si. iohn M.A.; Lehmarui~A.• Hinrlchsen H.-H.• MacKerizie B.R. 1996. Oxygen iri' theDeep Basins of the Baltic Sea:' Thc influenee of, win~er m,ixing. ICES C.M..I996/C+J:2.

W~tin L. and Nissling A. i991. Errect of~inity on'sperinatozoa ritobility. percentage ~f' .,fertilizoo eggsdevelopmeni of Baltic cod (Gadus morlzua) and implications for C?d"

, stock ßuctuationS in the BaItic. Marine Biology. 108:5-9.

Wieland k. and Horbowa K:.1996. Re:Cent changes in Peak spawning time und loeationI ofspawIling of rod in the Bomholm Basin, Baltic Sea. leES C~M. 199611:15.

Wieland K.• Waller U.• ScJlriack D. 1994. Deveiopment of Baltic cod eggs 3t differentlevels of temperature imd oxygencontent. Dana 10: 163-177. '

ZeZera A.S. and Zezera E.S. 1993. Recent chariges of saliniiy and its anomalies insoutheastem Baltic (1992-1993).ICES C.M. 1993/C:14 Sess.Y.

I, I

Tab1e

92-1995

1995

36.93

70.29

107.22

1994

95.36

67.39

162.75

1993

69.52

76.66

146.18

1992

Reproductive vo1umes (cub.km.) in Subdivision 26 in Apri1-May 19

7

Gdansk basin (rectangles 3863,3864,3963,3964) 15.07

Southern Gotland Deep (rectangles4063,4064,4163,4164) 0

Total Subdivision 26 15.7

Depth location of 10%0 isohaline in the central partof Gdansk Deep.

N N CO> CO> (") ~ ~ ~ .... .... on .., .., .., .., r-CJ) CJ) CJ) CJ) co co co co 0> co 0> 0> co 0> 0> 0>0> 0> 0> 0> 0> 0> 0> 0> 0> 0> 0> 0> co 0> co 0>.... "": "": .... "": "": "": "": "": "": ,... "": ,.... "": "": "":on 00 .., ..j 00 ~ .... 00 .., .... 00 .., ." r- C> ..,00 .... C> 00 ,.... 00 C> .... 0 0 ,... C> C> 00 ,... 00

60

70

80

90

100

110

Fig. 1.

Salinity anomaly in various layers in the central partof Gdansk Deep.

N N ... ... ... ~ ~ ." .... on 0> 0> 0> 0> 0> 0> 0> 0> 0> 0> 0>0> 0> 0> 0> co 0> 0> 0> 0> 0> 0> 0> 0> 0> 0>"":

,..."": .... ,... "": "": "": ,... ,... ..... "": "": ""': ""':

on C> .., ..j 00 on C> ... on 00 .., on r- C> C")C> .... 00 C> .... C> ..... 00 00 ,... 00 C> C> .... 00

Fig. 2.

-Oepth 10 0/00

--Average

1,5

1,0

0,5 -6-0·100 M--80·100 M

0,0

-0.5

-1,0

-1.5

-2,0

-2.5

-3,0

-3.5

_.

•

2000 ...••...•.•••.......••..............

Fig. 3.

ra Russian zone

DSD 26

........................................................................_..- _ _ _ ... .

-.Variability of areas (sq.miles) occupied by water with salinity

( above 10 %0'(50 26). .

500

1000

2500

1500

0 .... .... .., .., ... .. .. ... .... .... on co co Cl> Cl> Cl> • Cl> Cl> Cl> Cl>

.,. Cl> Cl> .,. .,. Cl>

• Cl> Cl> Cl> ... ... ... ... ... Cl> Cl> Cl> Cl> Cl> Cl>... ... ... ... ... ... ... ... ... ~ ~ ... ... ......; 0 ... .; 0 .; ...; o' ... on ~ ... 0 ...Ct .... Ct Ct ... Ct Ct ... C> Ct .... Ct ..... C>

Spatial-temporal variability of temperature. salinity and oxygentrom 1992 to 1997 (st. P-1).

•

•

TCW

5%0

02

"-\

- - -

\

/" "-I

II

/\

- \/

\-..

/

/

rI

CD(:)

O-+---+rrmTT-'-r~"'''''''''''''TTTT1crr'-"TT"f"~-r---L.,-rrmrr'.--.''---....L..,...--.-~.......--,-~---l.-,.----.--__f_-f=~,__---j

O-+r---L--r-.L,--l--..,-~-r-r_,__'_~_+_-r--,J,-_,__--L--.L.-,._L-.,--+_r_-...L_,__-L-.....L-_,___+_

-10

-20

-30

-40

-50

-60

-79-80

-90

-100r---"-~.:>....U.-'-+----""-_,__L.....J.......L,--l--.--------L,....-"

-~-- ........

Spatial-temporaJ variabili~ of temperature, salinity and oxygentrom 1992 to 1997 (st SY 9).

8%0

02

V. 92 O-+---L-,-----,..L----r-J.-,---,-JL--,-.l--,--"--,---'----'-,---'--,---,--'-,-y->-r-r-

-10

-20

-30

-40

-50

-60

-70

-801------

-90

-100

-110

OI-t--........L...,....,.-y-L,r-r--r-',rTTT......-'L-.,-nrttr.J..--.rTTT+-~~TTTr-l----,-,-,-..,...,..-l.;-----'-.m~L.,

-10

-20

-30

-40

-50

-60

-70

-80

-90

-100

-110

OI-l----_..J........._-L-_...L-_.L.-_.L.-_L-----lL-.----l:....-----'._----L_---'--_--'-_--r

-1

-20

-30

-40

-50

-60

-70

-80

-90

-100

-110

•

X.92 111.93 IV.93 X.93 IV.94 V.94 X.94 11/95 V.95 X.95 111.96 X.96 111.97

Fig. 5.

50

Linear relations: A) between the thickness of the spawning layerat station P-1 and RV in rectangle 3864; B) between RVand -RV,

estimated by regression model obtained.

I

"II

40

'f =1,2264)(· 1,5324R2 =0,9597 •

M 30E

.JI:

>0:: 20

10

45

40

35

30

P)25E

.:..:->0:: 20I

15

10

5

00 5

5

10

10

."

15

15 20

Thickness (m)

20 . 25RV (km3)

Fig. 6.

30

25

35

30

40

A)

35

45

e.

(61Xt'1 -

-

Depth (m)~ . . . . . . .o 0 ~ w _ ~ ~ ~ ~

~ 0 ~ 0 ~ 0 ~ 0 ~

~"I~'~~ ool9>lO~ 08.1980~ 10.1980

02.1981

05.1981

08.1981

10.19(11

02.1982

05.1982

08.1982

10.1982

02.1983

.............~ l05.1983

091983 c; -I10.1983 ... ::TD) _02.1984 ~ C)

05.1984 0""~ ~ 08.1984 :::J ~

10.1984 " CI)02.1985 ~ CI)

-----~ L05.1985 ::::: ~08.1985 » ~

-I»101985 D) =02.1986 :::J 005.1986 Co :::J091986 ., CI)

. (D

10.1986 't:' S.02.1987 0"'"

- ::T05.1987 ...a. Co (D~ 1091987 !e ~ --nD)

10.1987 9 ~ '<fJ] 1988 ...a. 0 (D

.,.. :J .,05.1988 _ ....

00.1988 ~ ~ 1»37 . ;

1)9 1987 :

:::j :OS 1m f(el~

11 If188

02 lf039

l)51'~

OOI~

l",·'i"

- ----------------------...........

Approximate boundaries of areas favourable to cod spawning in April-May 1992-1996.

20°

I

'1 Ir - - T

• I I

_ 1.. -l

I I

I Ir - - TI I1.. -lI II Ir TI I

__1.. __ -l_

" ~I---'Ip

-\- r - 0 - -199~~ I

18°

I

1

TI

-l

I

I

TI

..LI

I

TI

..L _

I

19"

"1

1• I

_ 1.. __

I

I- - I - -

'I.\17 - -

" fr" ; '.,

1..

II

- - r -

1995 I

20°19°

I'" Ir--T--

, I I

_.1- __ -l __

I I

I I.- - r T -

I· I:fi __ -l _

.. 2~~'1"': II I

-·-.t ":':>:"j,T - -;. ".;r I

-.:. _ 1- ....;",._ -l _{~ '-J'

~~ I1994 I

18°19°

I

I I1 - - T

, I I

_ 1.. -l __

I I

i I- -:r;,>1' - T - -

.1)"/' I__ -l

I

I