捕鯨とクジラ保護

・「増加率」については

プラスからマイナスにまたがっている、つまり

増加しているのか減少しているのか維持しているか

よくわからないってこと。

つまり「ほとんど解明されてはいない」ってこと。

・「自然死亡率」については

実質、未定である、

つまり「ほとんど解明されてはいない」ってこと。

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科学委員会報告書(2007年5月)
http://www.iwcoffice.org/_documents/sci_com/SCRepFiles2007/59-Rep1.pdf

1. ABUNDANCE AND TRENDS 　 「増加率」
Estimates of population trend arising from JARPA are
summarised in table 2 of SC/59/Rep1. Current confidence
intervals for the estimates of trend are relatively wide.
These results are, therefore, consistent with a substantial
decline, a substantial increase, or approximate stability in
Antarctic minke whale abundance in these geographic areas
over the period of JARPA (SC/59/Rep1, p.11).
Considerable progress has been made in addressing the
issues related to Antarctic minke whale abundance and
trends and provided the recommendations given under item
2 of SC/59/Rep1 are followed, the Committee may be able
to agree estimates. This issue was discussed in detail in at
this meeting (see Item 10.2.1.2) and a summary in Annex
G, item 6.
The abundance estimates provided in Matsuoka et al.
(2005) for humpback whales represented useful steps
forward in working towards acceptable estimates of
abundance. Further discussion of this issue is reported in
Annex H.

Area ―――― Estimate ―――― 95%CI ―――――――― Period

Area IV ―― -0.42% ――― (-4.02%, 4.59%) ――― 1989/90 to 2003/04

Area V ―― -1.54% ―――― (-4.91%, 2.18%) ――― 1990/91 to 2004/05

Area IIIE+IV+VW (35°E to 165°E)
―――――― 7.93% ―――― (-0.05%, 11.45%) ―― 1989/90/91 to 2003/04/05

Area VE+VIW (165°.E to 145°W)
―――――― -5.88% ―――― (-12.19%, 0.18%) ―― 1989/90/91 to 2003/04/05

3. ESTIMATION OF NATURAL MORTALITY RATE 　 「自然死亡率」
The estimation of this parameter was the main objective of
JARPA when the programme was initiated. The natural
mortality rate estimates from JARPA data alone (Tanaka et
al., 2006) (SC/D06/J13), were, at around 0.04, within the
plausible range, but the confidence limits (from below zero
to above 0.10) spanned such a wide range that the
parameter is still effectively unknown.
The ADAPT-VPA provided estimates of natural mortality
rates with a CV of about 0.15 but these depend on the use
of commercial catch-at-age data, about which, as discussed
in SC/59/Rep1, there are some problems (and see Item 10.2.3).