【日本/豪州】ラッド首相、外交官を捕鯨問題使節に[05/02]

＞http://www.sydney.au.emb-japan.go.jp/Whaling2J.html
＞【捕鯨問題における日本の立場】
＞ １９９０年、ＩＷＣ科学委員会は、鯨資源包括的評価の結果、南氷洋のミンククジラは７６万頭と認め、
＞現在の管理方式に基づけば、１００年間に毎年最低２，０００頭から４，０００頭を捕獲することが
＞資源に何の問題も及ぼさず可能であるということを示しました。

の根拠：
国際捕鯨委員会・科学委員会（1990年6月10日―ノルトウィカーホウト、オランダ
1990年REPORT OF THE SCIENTIFIC COMMITTEE
第41回国際捕鯨委員会年報　REP. INT. WHAL. COMMN 41, （1991）51−82ページ
．．．．．．．．．．．以下62-63ページ
7. COMPREHENSIVE ASSESSMENT -　PRIORITY STOCKS
7.1 Southern Hemisphere minke whales
7.1.2 Management advice

_Effect of zero catches for commercial whaling_

The Committee noted that its ability to provide advice on
the effects of the zero catch limit for Southern Hemisphere
minke whales, which came into effect in the 1985/1986
pelagic season, was influenced by; the length of time for
which the decision of 1982 had been in effect; the general
population biology of large whales; the precision and
frequency of abundance surveys; and the reliability of the
population models used for prediction.
It noted that the slow growth rate of whale populations
meant that there was no possibility that there had been a
substantial change in minke whale numbers since the
1985/1986 whaling season. In addition, attempts to
compare the results of IDCR sighting cruises in the same
management Area had indicated that only major changes
in abundance could be detected because of the size of the
coefficient of variation associated with the individual
estimates.

_Other management advice_

SC/42/SHMi15（大隅清治論文） argued that, on the basis of estimates of
current population size, observed changes in CPUE and
age at sexual maturation and indirect evidence on the
relationship between krill as prey (the main food of minke
whales) and its predators in the Antarctic, there was no
longer any reason to protect the Southern Hemisphere
stocks of minke whales from exploitation. The author
believed a catch limit of 1% of the exploitable population
in sub-areas of the six management Areas was appropriate,
as an interim management measure, even in the most
conservative case.

It had been noted during earlier discussions in the
Committee that, in the absence of an agreed revised
management procedure, it would not be out of order to
attempt to formulate advice on catch limits in accordance
with the provisions of the Schedule paragraphs 10(a)-(c).
Some members considered that such catch limits could be
calculated from the results of the HITTER runs and the
classifications described above, if an appropriate value of
MSYR could be chosen. Some of these members believed
that a value of 2% for MSYR would provide a conservative
estimate for interim catch limits. Others considered that
there was no objective basis for such a choice but agreed
that a value of 2% could be used in such calculations for
illustrative purposes. The calculated catch limits based on
the 'best estimates' with a 60% MSYL, 2% MSYR and
taking 90% of the MSY values from Table 1 of Appendix 6
of Annex E, with no allowance for the sex ratio of the
catch, are: Area I: 456; Area II: 792; Area III: 650; Area
IV: 583; Area V: 1,746; Area VI: 626.

Those members who considered 2% as a conservative
interim measure were of the opinion that until such a time
as the Schedule was revised, management advice still was
based on the existing paragraphs 10(a)-(c) of the Schedule.
Further, regardless of uncertainties about the dynamics of
minke whale 'stocks', a catch limit at an MSYR of 2%
would not result in appreciable reduction in stock
abundance in the short term (5 years) no matter what
assumptions are made, nor would it affect the development
of revised management procedures.

Other members stated that it is now generally recognised
that the management procedure incorporated in
paragraphs 10(a)-(c) of the Schedule is inadequate.
Accordingly they believed that offering advice on catch
limits under this procedure was no longer appropriate. For
the specific case of minke whales in the Southern
Hemisphere they drew attention to the reasons they gave
earlier for believing that the application of the HITTER
routine to these stocks was inappropriate and pointed out
that there is great uncertainty about stock identity and
boundaries, most importantly for the more heavily
exploited Indian Ocean sector (present Areas III and IV).

REP. INT. WHAL. COMMN 41, 1991 63ページ

Thus the problems which made impossible the application
of paragraphs 10(a)-(c) remain unresolved. They believed
that the Committee does not at this time have instructions
from the Commission, or any other basis, for providing
advice on catch limits. They anticipated that the revised
management procedures now being developed would be
able to avoid the problems described above. However,
they noted that SC/42/Rep2（第３回管理方式包括アセス
メント作業部会オスロ会議報告） had indicated that the success
of these procedures was likely to depend largely on their
ability to cope with uncertainty about stock identity.

Harwood considered that, in the light of the estimates of
abundance and associated variance given in Table 1, and
the catches which these stocks had experienced, it should,
in principle, be possible to give advice on catches which
would not have an adverse effect on the stocks. The use of
the HITTER routine, with a suitably wide range of input
parameters, was a crude but useful method for evaluating
the effect of past catches. The application of Schedule
paragraphs 10(a)-(c) to these results, as described above,
gave a broad indication of the magnitude of catches which
might be sustained. He noted that, in essence, this
methodology forms the basis of many of the revised
management procedures being considered. However, he
cautioned that such a procedure was, as yet, insufficiently
developed, and that calculations using uncertain point
estimates were not an appropriate basis for interim
management. Reilly, Stokes and Zeh associated
themselves with this view.

Holt and Cooke expressed the view that in offering
management advice on classifications and catch limits a
consistent approach should be adopted in the sense that
either 'best estimates' should be used in both cases or
'conservative' ones.

Ohsumi believed that the 'best estimates' were
conservative, because they were based on negatively
biased population estimates, as detailed earlier in the
report. He considered that using results for MSYR = 0%
for classification purposes was also conservative.

61ページより
______Table 2________________________________________
HITTER results using the inputs shown in IWC/42/4 Annex E, Table
2. Results are given as exploitable female stock/female stock in 1972.

____________________________________________________I+II+III+
MSYR_______I____ II_____III_____IV_____V______VI____IV+V+VI

'Best estimate'
0% ______0.85___0.80___0.67___0.62___0.93___0.96___0.94
4% ______0.92___0.87___0.74___0.70___0.95___0.96___0.95

Lower 95% CL
0%_______0.73___0.71___0.46___0.43___0.90___0.91___0.90
4%_______0.83___0.79___0.51___0.48___0.93___0.94___0.93
_____________________________________________________

科学委員会レポートだと、要するに意見が割れているということなんだけど、
この部分、総会のほうの議長総括ではどう記述されているかというと；

1990年7月2−6日第42回年次総会、ノルトウィク（オランダ）
CHAIRMAN'S REPORT OF THE FORTY-SECOND MEETING
第42回総会議長総括
REP. INT. WHAL. COMMN 41, 1991. p.11-50
国際捕鯨委員会年報41号（1991年）11-50頁

以下当該部分
19−20ページ
The Scientific Committee had noted that, in the absence
of an agreed revised management procedure, it would not
be out of order to attempt to formulate advice on catch
limits in accordance with the NMP. Some members
（19／20頁）
considered that such catch limits could be calculated from
the results of the HITTER runs and the classifications
described above, if an appropriate value of MSYR could
be chosen. Some of these members believed that a value of
2% for MSYR would provide a conservative estimate for
interim catch limits. Others considered that there was no
objective basis for such a choice but agreed that a value of
2% could be used in such calculations for illustrative
purposes. The calculated catch limits based on the 'best
estimates' with a 60% MSYL, 2% MSYR and taking 90%
of the MSY values from the Scientific Committee Report
(Annex E, Appendix 6, Table 1) with no allowance for the
sex ratio of the catch, are given in Table 3.

Table 3

Area_ Catch limit 2% MSYR___Area__Catch limit 2% MSYR
_________________________________________________
I_____456___________________IV___583
II____792____________________V__1,746
III___650____________________VI___626
__________________________________________________

議長総括つづき
Those members of the Scientific Committee who
considered 2% as a conservative interim measure were of
the opinion that until such time as the Schedule was
revised, management advice should still be based on the
NMP. Further, regardless of uncertainties about the
dynamics of minke whale 'stocks', a catch limit at an
MSYR of 2% would not result in appreciable reduction in
stock abundance in the short term (5 years) no matter what
assumptions are made, nor would it affect the development
of revised management procedures.

Other members of the Scientific Committee stated that it
is now generally recognised that the NMP is inadequate
and thus that offering advice on catch limits under the
NMP was inappropriate. They reiterated their view that
application of the HITTER routine to these stocks was
inappropriate and pointed out that there is great
uncertainty about stock identity and boundaries, most
importantly for the more heavily exploited Indian Ocean
sector (present Areas III and IV). Thus the problems
which made impossible the application of the NMP remain
unresolved. They believed that the Scientific Committee
had no instructions from the Commission, or any other
basis, for providing advice on catch limits. Although they
anticipated that the revised management procedures now
being developed would be able to avoid the above
problems, they noted that the success of these procedures
was likely to depend largely on their ability to cope with
uncertainty about stock identify.

REP. INT. WHAL. COMMN 41, 1991. p19-20
国際捕鯨委員会年報41号（1991年）19-20頁

一応、全体の総頭数はこの時点で約76万頭と合意されたけれど、捕獲可能枠
については意見が割れている。
一部のメンバーは南氷洋全体、総計すると4,853頭捕獲可能という算出法を
支持しているけれど、他のメンバーはこの旧方式を支持していないということのようだ。

HITTER routine というのは、新管理方式の算定基礎をつくるHITTER/FITTER
というコンピュータ・プログラムの一部で、南半球ミンククジラの場合、過去データ
が無いので、ごく一部しか使えないということですね。したがってこの算定法は
特に不適切、という意見が強かったようです。