Ｓｃ/MO5/ＢＲ２

AnexalninationofthecatchhistolyofWesternNorthPacific
StockofBryde1swhale
HiroshiHatanaka1andShigeyukiKawahara2
ｌｍｈｅ｣h８㎡ZuteQfCbmcean陸seazlchl4-Z8Zhymni麺ｑｍｕｏ士zz2b｣と、Ｚ“-OO53i
j2zpan２聴ｔｊｍａﾉ陸Sea２℃LMhS雄uteofnzrSbas雄hez…冠,Shimわu-Omib5choma
ShizzJoAz必4皀85a3lJZZpan
AＢＳＴＲＡＣＴ

Thedataofwhahngoperationshfoml965tol978ofaJapanesecoastalwhanngcompany
wereexammedandcomparedwithseveralkmdsofmfbrmationThemostcatchesmamIy
fbrthePacificcoastofnortllernJapanconsistedofspermandseiwhales，fbUowedby

Bryde，sandfinwhalesThemamspeciestakeｎａｎｄｔｈｅｗhannggroundschanged

seasonauyThecatChesofBryde'swhaleswerereportedmsomeParticularyearsusuaUy
underthecategoryofseiwhalesWhilesomereportedcatchesofseiwhalesmightbefbr
Bryde，swhales,ｔｈｅｍｉｓＳ－ｒｅｐｏｒｔｍｇｓｅｅｍｓｎｏｔｔｏｂｅｓｅrioustolmplementationSimulation

nials・ThetotalactualcatchesofftheOgasawaralslandsmightbel6timesthereported

catchesbuttheorigmalrecor曲havebeenlostandnotavaUable､Basedonseveralkmdsof
mfbrmation,itseemsthatthefbrmalUSSRcatchisrenablelnconclusion,thereported
catchescouldbeusedasthebasennecatchhistoryForsensitivitytestsalternativecatChhistoriescouldbeassumed,fbrexample,withthel6timescatchesfbrOgasawaralslands
IＮＴＲＯＤＵＣＴＩＯＮ

ForavarietyofreasonsqargelyrelatedtonewgeneticmfbrmationandqUestionsoverthehistoriccatchseries)itwasappropriatetoconsiderthatthelmplementationfbrwestern

NorthPacificBryde'swhaleswasmthepre-implementationassessmentstage(IWC,2003）

Gjventheconsiderableworkalreadb7undertakenmdevelopmgImplementationSimulation

Trials(IST)mpreviousyearstheScientificCommittee(Ｓｃ)hadagreedthatitshouldbe
possibletomovefastertowardslmplementationthanenvisagedmtheprocessdevelopedm
20020ntheqUestionsovertllehistoriccatchseries，uncertamtiesaboutJapancoastalcatcheswereraisedmamlybasedonthehistoricalcatchdataprovidedbyMrlKondowho
wasthedirectorofwhalingstationsfbrthefbrmerNihonKinkaiHogeiCoLtdqaterthe
NihonHogeiCoLtd）AstheKondo'sdataareprivateones,theauthorsofthisdocument
requestedthemfbrverificationbasedonProcedureAofDataAN7ailabilityProcedureTheobjectivewastoevaluatetherenabilityandaccuracyoftheKonddsdatatodevelop
hypothesesfbrcatchhistorytousemlmplementation．
MArITF】円JAT｣ＡＮＤＭＥＴＨＯＤTheKondo'ｓｄａｔａｈａｖｅａｈｅａｄｙｂｅｅｎｓｅｎｔｔｏｔｈｅＣｈａｉｒｍａｎｏｆＳＣｂｙＭＩＩＫｏｎｄｏａｎｄDrm
Kasuyaatthedateof28September2004toopentoauscientistsfbrfilrtherinvestigationandanalysesThedataarearchivedwithtlleseｃｒｅｔａｒｉａｔａｎｄｗｅｇｏｔｔｈｅｍａｓａＣＤ、１ｔ

contamedmanyphotographsofthesummary6monthly)chartsofwhahngoperationshFom

l965tol978SomeofthemwerembadconditiontoreadnlreeregionalChartsweremade

fbrwhalingstationsatAkkeshiandAyukawa(PacihccoastofnorthernJapan),Wakkanai(theSeaofJapanandOkhotskSea)andTblijiPacificcoastofcentralJapan),thelatter

bemgfbundonlyml976TYlｅｃａｔｃｈｄａｔａｍｔｈｅＳｅａｏｆＪａｐａｎａｎｄＯｋｈotskSeawerenot
exammedasBryde'swhalesarenotdistributedmthosewaters・Onthechartsthelines
mdicatmgthedirectionanddistancebfomthelandmarksnearthewhalingstationsaredrawnandtllepositionsofcatCheｓｏｆｍｄｉｖｉdualwhalesareplottedwiththespeciesanddate(Fig.１).Thecatchesofthemonthandthecumulativecatchesarealsowrittenby
sｐｅｃｉｅｓＷｅｅｘａｍｍｅｄｔｈｅｄａｔａａｎｄｃｏｍｐａredwithseveralkmdsofcatchesfbrthe
JapanesecoastalfisheryandthatbasedontheOgasawaraのon、)islandsandfbrthe
USSRUeet．

ＲＥＳＵＩｎＳＡＮＤＤＩＳＣＵＳＳＩＯＮ

1nl999itwasagreedthatmitialtrialswouldbebasedonthebase･casecatchseries(Ihblel）usedfbrthel996ComprehensiveAssessment・Ｉｔｌｂｌｅ２ｓｈｏｗｓｔｈｅｌＷＣｑＵＯｔａａｎｄ
ｒeportedcatcheshoml969whenthequotawasmtroducedbylWOForcoastalwhaling，
however,ｔｈｅｄｏｍｅｓｔｉｃｑｕｏｔａｗａｓｓｅｔａｓｓｅｉｐｌｕsBryde'ｓwhales,ａｎｄ10-15％ofquotawas
transfCrabletothoseoffinwhalesSmgleBryde'squotawasmtroducedhoml976

IntheKondo)sdatamamlyfOrthePacificcoastofnorthernJapan,mostcatchesconsisted

ofspermandseiwhales,fbuowedbyBryde/sandfinwhales・Themalnspeciestakenand
thewhalinggroundschangedseasonanyFromApriltoJunethecatChesmamlyconsisted
ofseiwhaleS,whichwhahnggroundslocatedmtheoffShoreareasatlatitudesbetween36

to42degreesNmovlngnorthwardswithseason､Thecatchesofspermwhalesmcreased
fifomaroundJUlyThewhalinggroundslocatedmtheoEfShoreareasatthestart,movedgraduaUytowardthemshoreareaandconcentratedmthenarrowareasalongthecoast
nearAyukawamDecembem

IntheKondo'ｓdata,thecatChesofBryde,swhaleswerereportedmsomeparticularyears
suchasl969，l971andl976usuauyunderthecategoryofseiwhalesThenorthernlimits
ofthecatchesmovedseasonauytothenorth,fbrexample,３６．５ｄｅｇｒｅｅｓＮｍＪＵｎｅｍｌ９７１

ａｎｄ３８ｄｅｇｒｅｅｓＮｍＪｕｌｙｍｌ９７６Ｊｕｄｇｍｇｈｏｍｔｈｅｐｏｓitions,somereportedcatchesofsei
whalesmightbefbrBryde'swhaIesasKondoandKasuya(2002)pomtedoutRelative]bllargercatchesreportedasseiwhalesmMay-Juneml974andl975(２９ａｎｄ３９ａｎｉｍａｌｓ，respectively)mightbeBryde'swhalesNocatcheswerereportedmthoseyears(Iblble3）
Howeverthemiss-reportmgseemsnottobeserioustolmplementationSimuIationnials

Kondo（2001）reportedthecatchesofBryde'swhalesofftheOgasawaraIslandsm

l981-1987TheyareshownmTnble4KasuyaandBrowneu(2001)notedthetotalactual
catchesofftheOgasawaralslandsarel6timesthｅｃａｔｃｈｅｓｒｅｐｏｒｔｅｄｔｏｔｈｅｌＷＣ・The
origmalrecordshavebeenlostandfUrtherdetausofthestatisticsarenotavanable．
Kondo(2001)mentionedthetakeofthreeBryde'swhalesonl6Junel976at40nauticalmnessouth-eastoftheShionomisakiPomtnearTaijiFromthebiologicalmfbrmation

thosewhalesseemnottobelongtotheordinalBryde'swhalesBIyde,swhaleswereusuanytakenfarhfomthecoastalljnesasshownmthesummarycharts,themostcatchesoffthe
PacificcoastofcentralJapancanberegardedasthewestemNorthPacificstock．

JapanesepelagicwhahngtoBryde，swhalestartedml971andthelnternationalObserver
SystemqOS)wasmtroducedml972Asunder-reportmgwasseldomoccurredunderlOS，
thepossibilityisonlyml971・Therewasnoinfbrmationonunder-reportmgtothe
Japanesepelagicwhaljng．

UncertamtyaboutthefbrmerUSSRcatcheswasdiscussedseveraltimesafterl996(RIWC

47）mble5showsthreekmdsofcatchstatisticsfbrthefbrmerUSSRNoBrydeiswhale

catchwasmademland-baseoperationmKurillslands（Ohsumi，1998)．No
under-reportmgcouldbemadeunderlOS(Shigemuneetal,1999)Catcheswerelessthanthequota(Ohsumi,1998)NonewinfbrmationisprovidedBasedontheabove-mentioned
mfbrmation,itseemstothatthefbrmalUSSRcatchisreuable．

lnconclusion，thereportedcatchescouldbeusedasthebasehnecatchhistoryFor
sensitivitytestsalternativecatchhistoriescouldbeassumed,fbrexample，withthel6
timescatchesfbrOgasawaralslands．
REFUDRF】ＮＣＥＳ

BrowneU,Ｊｒ.,ＲＬ.（1999):USSRpelagiccatchesofBryde'swhalesmtheNorthPacificlWC/Ｓｃ/51/ＲＭＰ２５

１ＷＣ(2003):ReportoftheScientificCommitteeJCetaceanResManagexk）
Kasuya,mandBrowneU,Ｊｒ.,ＲＬ（2001):ＩⅡegalJapanesecoastalwhalingandothermanipulationofcatchrecordslWC/Sc/53/RMP24

Kondo,Ｌ(2001):RiseandfbluofJapanesecoastalwhaljngSanyo-sha,Tbkyo,449ｐｐ(mJapanese1
Kondo,IandKasuya,、（2002):nuecatchstatisticsfbraJapanesecoastalwhaling
companyml965-1978.1ＷC/SＣ/54/O1a
Ohsumi,Ｓ(1998):AreviewofthecatchhistoryofBryde'swhalesbySovietwhaljngmthe
NortｈＰａｃｉｆｉｃＲＩＷＣ４８:l39-142

Shigemune,Ｓ,Yblmamura,Ｋ,Ohsumi,SandHatanaka,Ｈ（1999):Theplausibilityof
catchrecordsofBryde'swhalesreportedbythefbrmerUSSRGovernment・
ＩＷＣ/Sc/51/ＲＭＰ2．

ＦｉｇｌＡｐｈｏｔｏｇｒａｐｈｏｆｏｎｅｏｆｔｈｅｓｕｍｍａrychartsofwhaljng
operations(Septemberl969offAkkeshiandAyukawa）

TablelCatchstatisticsofNorthPacihicBryde1swhalesmpost-warperiod

WesternNorthPacificStock

ＥａｓｔＣｈｍａＳｅａＳｔｏｃｋ

YearKoreaJapanTotal

４５＊
９２＊２７＊

１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７
５５５５５５５５５６６６６６６６６６６７７７７７７７７７７８８８８８８８８９９９９９９９９９９９９９９９９９９９９９９９９９９９９９９９９９９９９９２４＊270５７篭
７０＊
２３４７２２５４４２３４７２２５４４８９２４３９２５４２６３４０４
１６７５０４２１０６６８

８５５

１６８８８
１８４５８９１７２２１４７５２２１１６６８８１１９８３５７８１７１７６４２４２００５２１７５４８６307485482
９７０４４536481
３１７３１７３１７１３０２３０３９６２１１１８５７４，ｙＪ

１５４０１１１１１０４３４１１０１１０９８４６８１６４９９５６７６３７５５２７７１２６６６６６２２２７３

１１９１６３４４９５０７４４５５３３３

１７１４３４Total

７５費

197
231

４６７０９４９４３４７４０８８５５１９９９０８３３９６６８３５２５８７７７
０８５７８２３５６０６０１６５４７８３１６９２３５４９２９８８４２５１１
２２４１５２1950

141195

３４１１５*,

１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１

1949

９０５６３０１
２５０１４８１
１１１２２４

1948

１１２＊

００３
４１００３４１

1946
1947

9６１，４６８７，１５４４，０３７４，１１１１６８６６

識Estimatedusingratio(26%)｡fBryde'swhalesinthecatchof､sei'whalesinSanrikuarea

Table2QuotaandreportedcatChesfroml969whenquotawasmtroduced
JapaneseCatchlWCQuota

Ｙｅａｒ

SeiBrydeis

BIyde1s

Sei+Bryde1s

１

２８７２０７
５６５４２１

175

７８８１４５６
１３０７０１０
３４５４３３３３１

聾★
★★
窪蓋

＊IntroductionofIOS*＊StartofOgasawara-basecoastalwhalingandthequotaswerewithmcoastalones…Japanesenationalquotaandcatchunderobjection

Table３.Bryde1swhalecatchesoff
Akkeshi,AyukawaandTaiji，Pacificcoastofnorthernand
弓ａＴＲｅＤｏｒｔｅＣ

1967

1970
1971

1972
1973

1974
1975

２２1969２１２１

1968

００００４４４００００

1966

２８４７３４８１５７８1965

FromAppendixTable6-3ofKondoandKasuya(2002）

９５２２８８４０５200

０424

１１

★
★

３６２２００７６６７７７
０７６５６１０３３５１１
１
４５５５５３３３578

Pelag

１

3,591
3,235
2,529
2,046
１，７１２
１，７１２
１，１４２

５７８０４５６
５５４４１３４
５５４３１２１

７７４９５５３
５５７７０００

５５４３３３２★

で１壹刃几１几學ＴＬイーｌ－１Ｌ－１ユイ１－１几１ユ１ユー１ユニＴＬ１上１１二Ⅵユ１１Ｔ几篁１Ｌ（ｕＵ〈Ⅱ）１ＬＯ△９Ｊ・加五戸〔Ｕ〈【Ｕ【●Ｉ（×〕（ｕＵｎＵ．ⅦＬＯ△ｎベリ●几五戸〔リハｈ）庁●ＩｎｎＵ［Ｊ１序１円，０円－万’０円，！▽０円〃Ｉ▽０［，Ｉ（ｘ）（ｘ〉（ｘＵ（ｘ〉（ｘ〕（ｘ〕（×）（ｘ）（ｕＵ（ｕ〉〈ｕＪＱＪ（ｕＵ〈ｕＪ（ｕＵ（ｕＪ〈ｕＵ〈ｕＵ（ｕＪ〈ｕＵ〈ｕ〉（ｕ〉（ｕ〉（ｕＵ（ｕ〉（ｕ〉〈ｕ〉

3,474
3,127
2,658
２，１２７
１，７１２
１’７１２
１，１４２

９３２４０７６３６２２７７４７０３２１
８７７８４４１８７６５０６４２１１１

Coast・Pela日，Coast・Pela質．Coast・Pelag・Coast．Ｏgas

able4Brvde1swhalecatchesoffBc
ＹｅａｒReported*＊Reported**＊（Bonin）（WNPstock）

True＊(Bonin）
４５４

１９８２６６５

１９８３５８６

１９８４７４７

１９８５５５３

Total

4.162４８２５３６４８１３１７３１７3172935■

６２０537
２

１９８６
１９８７

４８５

７８８１４５６９
１３０７０１０５３４５４３３３６1９８１*:FromTable62ofKondo(2001）**:FromTable2ofki員him(1995）***:FromTableloflWC(1996）

IｃａｔｌＢｈｆｂｒＢｒｖｄｅｌｓｗａｈｌｅ
mＴｍａｌＢｒｏｗｎＥ

catch

１９７２

＊

１９７３

１９７４
１９７５
１９７６
１９７７
１９７８
１９７９

totaI

４，１１１４

Calculated

４

Ｔｏｔａｌ

６８１５４９９５６７９６３７２５２７７１２６６６６６６２２２０

１９７１

６８１６４９９５６７１
６３７５５２７７１２１
６６６６６２２２１'９７０

ReportedBA

Scientist1sC
６６４５０

4,080

６７６２１
６５２６２９６７９２７４２１６

［227］
3.885

3,881

*IntroductionoflnternationalObserverScheme

A:IWCfbrmalstatistics(threemothervesseles）

B:ReportedcatchofUSSR(twomothervesseles）
OBerzin1sdata(twomothervesseles）