Do not cite without written permission from the authors
SC/61/JR7

Further mitochondrial DNA analysis on stock structure in thewestern North Pacific common minke whales
Mutsuo Goto1, Naohisa Kanda1, Toshiya Kishiro2, Hideyoshi Yoshida2, Hidehiro Kato3 and Luis A. Pastene1

1 The Institute of Cetacean Research, 4-5 Toyomi-cho, Chuo-ku, Tokyo, 104-0055, Japan.
2 National Research Institute of Far Seas Fisheries, 2-12-4 Fukuura, Kanazawa, Yokohama Kanazawa, 236-8648,
Japan
3Tokyo University of Marine Science and Technology, 1-5-7 Konan, Minato-ku, Tokyo,
108-0075 Japan
Contact email:goto@cetacean.jp

ABSTRACTThis paper is the revised version of the mitochondrial DNA analysis presented in SC/J09/JR29 to cover therecommendations from the Expert Workshop to review the JARPNII Programme. Genetic variation at the mtDNA
control region in the western North Pacific common minke whales was analyzed to examine the plausibility of four
stock structure baseline scenarios adopted at the final stage of the Implementation Simulation Trials (ISTs) process
under the Revised Management Procedure by the IWC Scientific Committee in 2003. A total of 1,639 whales collectedduring JARPN and JARPNII surveys from 1994 to 2007 in the area from the Japanese coast to the offshore waters (to170°E) on the Pacific side, was used for the analyses. The samples from 2002 to 2007 (n= 1,124) were not used during
the previous ISTs process. Heterogeneity tests were based on the randomized chi-square test and Fst as recommended by
the review Workshop. Significant mtDNA heterogeneity was found in sub-areas 7W (for both chi-square test and Fst in
the sample of 2007) and 9W (for Fst in the sample of 1995). Additional analysis in sub-area 7W suggested that thesource of heterogeneity was due to the occurrence of J stock animals in this sub-area. Our updated analysis based on alarger data set confirmed that 1) whales from the J stock existed in the 7W with low but large enough number to cause
genetic heterogeneity observed in the 7W samples as well as between the 7W and other samples, 2) except the J stock
whales, the survey area was mainly occupied by O stock, and 3) the baselines C and D were not supported because noother genetically distinct stock was observed in the survey area, however the genetic heterogeneity found in sub-area 9
by the Fst analysis in a single year should be further investigated in the context of baseline scenario A.
KEY WORDS: COMMON MINKE WHALE, MTDNA, STOCK STRUCTURE, JARPN, JARPNII, NORTH PACIFICINTRODUCTION
The Implementation Simulation Trials (ISTs) for North Pacific common minke whale under the Revised Management
Procedure (RMP) was completed during the 2003 International Whaling Commission Scientific Committee (IWC SC)
meeting. At the final stage of the ISTs process the SC adopted the following four stock structure baseline scenarios(IWC, 2004):(1) Baseline A: three-stock scenario (‘J’, ‘O’, ‘W’) with the ‘W’ stock found only in part of sub-area 9 and only
sporadically.
(2) Baseline B: two stock scenario (‘J’ and ‘O’) with no W stock as a limiting case of Baseline A.
(3) Baseline C：four-stock scenario overall, with ‘OW’, ‘OE’ and ‘W’ to the east of Japan. Boundaries are fixed at
147°E and 157°E and there is no mixing between the stocks.
(4) Baseline D：three-stock scenario (‘J’, ‘O’, ‘W’), with ‘O’ and ‘W’ mixing over 147°E and 162°E, O being
dominant to the west and W to the east.
Unfortunately the SC did not examine plausibility of the stock structure scenarios. In order to get agreement among SC
members it gave the same ‘high’ plausibility to the four scenarios (IWC, 2004).

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In this study the plausibility of the four stock structure scenarios is examined through genetic analysis based on
mitochondrial DNA (mtDNA) and samples collected by JARPN and JARPNII from 1994 to 2007. The samples from2002 to 2007 were not used during the previous ISTs process.
This paper is a revised version of Document SC/J09/JR29 presented to the JARPN II review workshop, which covers
some of the recommendations of the Expert Workshop to review the JARPNII Programme held at Tokyo from 26-30 ofJanuary. Regarding to the mtDNA analysis, one of the recommendations by the panel was that a revised paper should
include estimates of genetic divergence in addition to probabilities of homogeneity tests.
MATERIALS AND METHODS
Samples
Table 1 shows the number of samples used in the present mtDNA analysis by year, sub-area and the offshore andcoastal components of JARPN II. Details of the surveys design and methodology in the offshore and coastal
components of JARPNII were described in Tamura et al. (2009) and in Kishiro et al. (2009), respectively. During the
IST specification conducted in 2003, eighteen sub-areas were set for management purpose of the western North Pacificcommon minke whale (Figure.1). Sub-areas 7, 8 and 9 were divided into western and eastern strata by 147°E, 157°E
and 162°E, 7W (140.01°E -147.00°E), 7E (147.01°E -150.00°E), 8W (150.01°E -153.00°E), 8E (153.01°E -157.00°E),
9W (157.01°E -162.00°E), and 9E (162.01°E -170.00°E). The sighting position of common minke whales used in thisstudy is shown in Figure 2. Whales were sampled by JARPN and JARPNII surveys during 1994-2007
Sequencing of the mtDNA control region
We followed the IWC guidelines for DNA data quality (IWC, 2009) as much as possible. Using established protocols(Sambrook et al., 1989), total-cell DNA was extracted from skin tissue samples. The extracted DNA was used for both
mtDNA and microsatellite (Kanda et al., 2009b) analyses. The first half of control region of the mitochondrial genome
was amplified using the polymerase chain reaction (PCR). In order to amplify an approximately 500 bp of the mtDNA
control region, primers light-strand MT4 (Árnason et al., 1993) and heavy-strand Dlp5R (5'-CCATCgAgATgTCTTATTTAAggggAAC-3'), were used. PCR products were purified by MicroSpin S-400HR columns (Pharmacia Biotech).
Cycle sequencing was performed with the same primers, using BigDye terminator cycle sequence Kit (Applied
Biosystems, Inc). The cycle sequencing products were purified by AutoSeq G-50 spin Columns (Pharmacia Biotech).
The labeled sequencing fragments were resolved by electrophoresis through a 5% denaturing polyacrylamide matrix on
an ABI 377™ and ABI3100 Automated DNA Sequencer (Applied Biosystems, Inc), following the protocols of the
manufacturer. For each sample both strands were sequenced.
Data analysis
The evolutionary distance between two nucleotide sequences was calculated according to Kimura’s two parameters
method (Kimura, 1980). The degree of genetic diversity within each locality was estimated using the nucleotide
diversity (Nei, 1987). The randomized chi-square Test of Independence (Roff and Bentzen, 1989) was used toinvestigate the temporal/spatial differentiation of mtDNA variation. FST was calculated using the software of Analysis of
Molecular Variance (AMOVA) (Excoffier et al. 1992). The strata with less than 5 individuals were excluded from thegenetic divergence analyses. In each test a total of 10,000 permutations of the original data were performed. A P-value
smaller than 0.05 was used as a criterion to reject the null hypothesis of panmixia.
The following steps were conducted: a) analysis of genetic differences between the coastal and offshore samples
collected in the same year from sub-area 7W; b) analysis of genetic differences among whales collected in different
years from a same sub-area; and c) analysis of genetic differences among whales grouped according to the geographic
divisions defining the four stock structure baseline scenarios used in previous ISTs.
Assignment for J or O stock types
Analyses were conducted with and without suspected J stock animals in the case of sub-area 7W. Individual assignment
to O and J stocks was based on analysis of microsatellite and the computer program STRUCTURE (Kanda et al.,2009a).
RESULTS
Kanda et al. (2009a) showed that there were suspected J stock individuals in the samples of common minke whales
from the Pacific side of Japan. On the basis of the individual identifications to the stocks in Kanda et al. (2009a), we

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conducted the tests on two different grouping: 1) one that included all the individuals and 2) one that excluded thesuspected J stock individuals (samples contained individuals of unknown origin and the O stock).
Genetic diversity within samples
Sequence variations in a 487bp segment of the mtDNA control region resulted in 123 unique haplotypes in the total
sample of 1,632 whales. Forty-one polymorphic sites were detected, 37 of which were transitions, three transversion
and one insertion/deletion event.
Table 2 shows the nucleotide (π) and haplotype (H) diversities in each sample. Nucleotide diversities and its standard
error of JARPN (1994-1999), JARPNII offshore component (2000-2007) and JARPNII coastal component (2002-2007)
were 0.0079 (0.0002), 0.0081(0.0002) and 0.0089 (0.0002), respectively. Haplotype diversities were 0.9522, 0.9529 and0.9624, respectively. For both indices these values are higher in the JARPNII coastal whales. For nucleotide diversity
the difference was statistically significant between JARPN and JARPNII coastal component.
Genetic divergence between samples
Genetic differences between offshore and coastal samples in sub-area 7W
Table 3 shows the results of the heterogeneity tests for the comparison between samples taken in 7W by coastal andoffshore components of JARPN II, by year and with and without suspected J stock animals. None of the comparison
showed significant mtDNA differences except the 2007 samples for the chi-square analysis. We conducted theheterogeneity tests for this year excluding suspected J stock animals. In these cases no significant differences were
found. Therefore significant differences found were most likely due to the inclusion of whales from the J stock in thesample. For the subsequent analyses, we conducted the heterogeneity tests with and without suspected J stock animals
in the 7W sample.
Yearly genetic differences within sub-areas
Table 4 shows the results of the heterogeneity tests for yearly differentiation in each sub-area. No significant yearly
differences were found in the sub-areas. In subsequent analyses samples from different years were combined in the subareas.
Plausibility of hypotheses
Baseline A
In order to test the heterogeneity within sub-area 9, we compared the samples collected in the western and eastern sidesof sub-area 9, by year (Table 5). Regarding to the Chi-square statistics, no significant differences were found and there
was no significant difference between western and eastern sides of sub-area 9 using total samples. Significant difference
was detected in the 1995 samples in the analysis of Fst, and also significant difference was detected between westernand eastern sides of sub-area 9 using total samples. However this significant difference for total samples was notdetected when samples from western side of sub-area 9 in 1995 were excluded (Table 5).
Baseline B
We examined the genetic differences among all sub-areas (7W, 7E, 8W, 8E, 9W and 9E). No significant differenceswere found among all sub-areas with (P= 0.0595) and without (P=0.6106) suspected J stock animals in the sub-area 7W.
Statistically tests in the sub-area 9 for the scenario B are same as those for the baseline A shown above.
Baseline C
Table 6 shows the results of heterogeneity tests for samples divided according to scenario C (e.g. samples divided by thelongitudinal boundaries at 147°E and 157°E). We conducted the heterogeneity tests with and without the westernsamples in sub-area 9 in 1995. First heterogeneity test was conducted among samples from 7E, 8W and 8E, and no
significant differences were found on both statistics. Therefore these samples were combined into one as 7E-8E for thefollowing analyses. For the chi-square analysis no significant differences were found among samples from 7W, 7E-8E
and 9W-9E with and without suspected J stock animals in the 7W samples and with or without samples from 9W in
1995. For the Fst analysis no significant differences were observed when the samples from the western side of sub-area
9 in 1995 were excluded from the analysis.
Baseline D
We examined the genetic differences among three groups divided by the longitudinal boundaries at 147°E and 162°E
Table 7). We also conducted the heterogeneity tests with and without the western samples in sub-area 9 in 1995.
Regarding to the Chi-square statistics no significant differences were found among samples from 7E, 8W, 8E and 9W,
and. These samples were combined into one as 7E-9W for the following analyses. We then conducted the heterogeneity3

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SC/61/JR7
tests among 7W, 7E-9W, and 9E with and without suspected J stock individuals in the 7W sample (7W x 7E-9W x 9E.
7W* x 7E-9W x 9E). For the chi-square test there are no significant differences among these samples with and withoutsuspected J stock individuals in the 7W sample and with or without samples in 9W in 1995. For the Fst analysis no
significant differences were found when the samples from sub-area 9 in 1995 were excluded from the analysis.
DISCUSSION
Level of genetic diversity
Genetic diversity at the mtDNA control region in common minke whales used in this study was similar to that of otherlarge baleen whales in the North Pacific, such as Bryde’s (Kanda et al., 2009c) and sei whales (Kanda et al., 2009d).
Diversities in the common minke whale in the JARPNII coastal component samples are slightly higher than in the othersamples. This could be caused by the occurrence of J stock animals distributed around the coastal area in the Pacificside of Japan described by Kanda et al. (2009a).
Genetic divergence
Overall our study based on a larger data set than used previously failed to find any evidence of significant genetic
heterogeneity in sub-areas 7, 8 and 9 other than in sub-areas 7W(2007 sample) and 9W (1995 sample). Significant
mtDNA heterogeneity was found in sub-area 7W in the 2007 sample for the chi-square analysis, and in the sub-area 9 in1995 for the Fst analysis. Additional analysis in sub-area 7W suggested that the source of heterogeneity was due to theoccurrence of J stock animals. Heterogeneity in sub-area 9W in a particular year should be further investigated in thecontext of stock structure baseline scenario A (see below).
These results based on mtDNA and a larger data set are valuable to re-evaluate the plausibility of the four stock
structure scenarios defined by the IWC SC in 2003. Results constitute a very strong demonstration that the underlying
hypothesis of scenario C, e.g. three stocks with hard boundaries at 147°E and 157°E, has no independent support asthere are no genetic evidences for multiple O stocks as proposed by this scenario. Genetic differentiation among stocks
is facilitated by some geographical or ecological ‘barrier’, which acts restricting the gene flow among them. Minke
whales in sub-areas 7, 8 and 9 have been described as opportunistic feeders. Distribution of these whales is related tothe distribution and dynamics of prey species and the distribution of prey species is defined by oceanographic
conditions in the area, which are variable. There is no evidence for ecological barriers at 147°E or 157°E.
Further common minke whales were taken by the Japan’s small-type coastal whaling in sub-area 7W for more than 40
years. The annual catches of minke whales were in the range 200-300 (IWC, 2004). If the occurrence of a small coastal
Ow stock, as proposed by the Baseline C stock scenario, is true, such stock could have been extinct under such catchlevels. Kawahara (2002) reviewed the small-type whaling and two types of CPUE analyses. Judging from the corrected
CPUE1 trend for about 35 years, the drastic decline of abundance seems unlikely. And CPUE2 analysis in 1977-1987
with operation hours by area also does not suggest that O stock has declined. Consequently no considerable decline was
detected in either CPUE series. These results are consistent with result of the present genetic analysis and show that theplausibility of Baseline C is low.
Regarding to the Scenario D, results of our genetic analysis are also difficult to reconcile with the underlying hypothesisof scenario D. This hypothesis establishes that O and W stocks mix with each other between 147°E and 162°E. The O
stock is predominant to the west and the W stock to the east of this range. Under this scenario only O stock occur
between the Japanese coast and 147°E and only W stock from 162° to the east. One of the inconsistencies is that the
mtDNA haplotype frequency in samples from sub-area 9E (scenario D assume that only W stock is distributed in this
sector) is genetically similar to those in sub-areas 7 and 8 (O stock). Furthermore analysis of microsatellite indicated nosignificant departure from the Hardy-Weinberg equilibrium in the sector 147°-162°E (Kanda et al., 2009b). A
significant departure from equilibrium could indicate a situation of mixing between different stocks as suggested by the
scenario D. Scenario D is therefore inconsistent with genetic data.
One of the objectives of the JARPNII was to look for any evidence of existence of the W stock in sub-area 9 (Stockscenario A). We did not find the genetic heterogeneity in 9W in the present study based on the Chi-square test but
analysis of Fst revealed significant heterogeneity in sub-area 9W in a particular year (1995) same as in past analyses(e.g., Goto et al., 2000). The microsatellite analysis found some degree of heterogeneity in sub-area 9E (Kanda et al.,2009b).
The situation in sub-area 9 is difficult to interpret from the biological point of view. In the case of 1995 the mtDNA
heterogeneity was observed in the western part of sub-area 9. However the eastern part was genetically homogeneous4

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with sub-area 7 and 8. The mtDNA heterogeneity observed in the western part of sub-area 9 could be due to additional
stock structure other than the O stock (e.g. W stock) or could be due to sampling bias.
If the first explanation is correct then we have a scenario in where a different stock distributes in part of sub-area 9 atleast in one or some year(s) (stock scenario A). The sub-area 9 has been surveyed in several years (Table 1) and the
mtDNA heterogeneity has been detected only in 1995 survey and in only a western part of sub-area 9. For the second
explanation further analysis on possible relative in the sample from sub-area 9 should be conducted. This will be donein the near future using microsatellite in the context of a recommendation from the JARPN II review workshop (IWC,
2009)
Therefore we should further evaluate stock scenario A in the context of results from other genetic analysis based on
microsatellites (e.g. Kanda et al., 2009b) as well from other non-genetic approach (e.g., morphometric) that use thesame samples. Continued monitoring of common minke whales migrating to sub-area 9 is also necessary.
ACKNOWLEDGEMENTS
We thank researchers and crewmembers participating in the 2002 to 2007 JARPNII surveys for their effort in collecting
the samples used in this study. Our sincere gratitude also goes to H. Oikawa and S. Azumi for their assistance in DNA
extraction, and H. Hatanaka for his valuable comments on the manuscript.
REFERENCES
Árnason, Ú., Gullberg, A. and Widegten, B. 1993. Cetacean mitochondrial DNA control region: Sequences of all extant
baleen whales and two sperm whale species. Mol. Biol. Evol., 10, 960-970.
Excoffier, L., Smouse, P.E. and Quattro, J.M. 1992. Analysis of molecular variance inferred from metric distancesamong DNA haplotypes: application to human mitochondrial DNA restriction data. Genetics 131: 479-91.
Goto, M., Abe, H. and Pastene, L.A. 2000. Additional analyses of mtDNA control region sequences in the western
North Pacific minke whales using JARPN samples. Paper SC/F2K/J32 presented to the IWC Scientific Committee
Workshop to Review the Japanese Whale Research Programme under Special Permit for North Pacific Minke
Whales (JARPN), Tokyo, 7-10 February 2000. 5pp.
Hakamada, T. and Bando, T. 2009. Morphometric analysis on stock structure in the western North Pacific common minke whale (Balaenoptera acutorostrata)Paper SC/J09/JR27 presented to the JARPN II Review Workshop, Tokyo,
January 2009 (unpublished). 13pp
International Whaling Commission. 2004. Report of the Scientific Committee, Annex D. Report of the sub-committee
on the revised management procedure. J. Cetacean Res. Manage. (Suppl) 6:75-184.
International Whaling Commission. 2009. Report of the Scientific Committee, Annex I. Report of the working
group on stock definition. J. Cetacean Res. Manage. (Suppl) 11:75-184.
Kanda, N., Goto, M., Kishiro, T., Yoshida, H., Kato, H. and Pastene, L.A. 2009a. Individual identification and mixing of
the J and O stocks around Japanese waters examined by microsatellite analysis. Paper SC/J09/JR26 presented to the
JARPN II Review Workshop, Tokyo, January 2009 (unpublished). 9pp.
Kanda, N., Goto, M., Kishiro, T., Yoshida, H., Kato, H. and Pastene, L.A. 2009b. Further microsatellite analysis ofminke whales in the western North Pacific. Paper SC/61/JR8 presented to this meeting. 14pp
Kanda, N., Goto, M. and Pastene, L.A. 2009c. Stock structure of Bryde’s whales in the western North Pacific as
revealed by microsatellites and mitochondrial DNA. Paper SC/J09/JR31 presented to the JARPN II Review
Workshop, Tokyo, January 2009 (unpublished). 8pp
Kanda, N., Goto, M., Yoshida, H. and Pastene, L.A. 2009d. Stock structure of sei whales in the North Pacific as revealedby microsatellites and mitochondrial DNA analyses. Paper SC/J09/JR32 presented to the JARPN II Review
Workshop, Tokyo, January 2009 (unpublished). 14pp
Kawahara, H. 2002. A review of Japanese small-type whaling and CPUE analyses to address the relative plausibility oftrials on western North Pacific minke whale. Paper SC/55/IST16 presented to the IWC/SC, May, 2002,(unpublished). 9pp.
Kimura, M. 1980. A simple method for estimating evolutionary rates of base substitutions through comparative studies
of nucleotide sequences. J. Mol. Evol. 16: 111-120.
Kishiro, T., Yoshida, H., Goto, M., Bando, T., and Kato, H. 2009. Methodology of whale sampling surveys in the
2002-2007 coastal components under the JARPNII. Paper SC/J09/JR3 presented to the JARPN II Review
Workshop, Tokyo, January 2009 (unpublished). 27pp
Nei, M. 1987. Molecular Evolutionary Genetics. Columbia University Press, New York.
Roff, D.A., and Bentzen, P. 1989. The statistical analysis of mtDNA polymorphisms: χ2 and the problem of small

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samples. Mol. Biol. Evol., 6, 539-545
Sambrook, J., Fritsch, E.F., and Maniatis, T. 1989. Molecular cloning: A laboratory manual. 2nd Ed., Cold Spring
Harbor, NY: Cold Spring Harbor Laboratory.
Taylor, B.L. and Chivers, S.J. 2000. Evaluating the performance of different statistics to detect population subdivision.
Paper SC/F2K/J5 presented to the IWC Scientific Committee Workshop to Review the Japanese Whale Research
Programme under Special Permit for North Pacific Minke Whales (JARPN), Tokyo, 7-10 February 2000. 10pp.
Tamura, T., Matsuoka, K., and Fujise, Y. 2009. General methodology and survey procedure under the JARPNII,
offshore component. Paper SC/J09/JR4 presented to the JARPN II Review Workshop, Tokyo, January 2009
(unpublished). 16pp
Table 1. Sample sizes used in this study by year, sub-area in offshore (A) andCoastal (B) components.
A) Offshore
Y

7W

7E

9W

9E

Total

1994

7

14

21

1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007

78

22

31
1
25
50
24
43
60
17
16
32
36
79

19

48

14
42
33
1
4

100
47
100
100
50
40
100
100
100
100
100
100
100

Total

414

178

1158

1
31

8W

1
1
44

8E

15
30

7

21

21
8
16

2

7
10
2

7
28
13

16
29
32
25
42
21
23
2

48

86

138

294

7

(B) Coastal
Year

7W

2002
2003
2004
2005
2006
2007

50
50
59
120
95
107

Total

481

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Table 2. Nucleotide (π) and haplotype (H) diversities in each sample.
samples

N

π

SE

H

JARPN（1994-1999）

418

0.00790.00020.9522JARPNII (2000-2007)
Offshore component

734

0.00810.00020.9529

2000
2001
2002
2003
2004
2005
2006
2007

40
100
100
100
100
94
100
100

0.00780.00860.00790.00780.00870.00830.00770.00820.00070.00040.00040.00040.00040.00050.00040.00040.9321
0.94890.95350.94910.95940.95200.95820.9590JARPNII (2002-2007) Coastal
component

480

0.00890.00020.9624

Kushiro260

0.00910.00030.9656

Sanriku

220

0.00860.00030.95841632

0.00830.00010.9561

Sum

Table 3. Statistical comparison between offshore and coastal samples in sub-area 7W by year, and with and withoutsuspected J stock animals.

Year
2002
2003
2004
2005
2006
2007

All animals
ChiN
squareOffshore Coastal
P value
60
50
0.173
17
50
0.137
16
59
0.281
32
119
0.233
36
95
0.382
79
107
0.019

Fst
-0.001
0.008
0.000
0.004
0.006
0.004

P
0.543
0.253
0.583
0.148
0.173
0.075

7

Without suspected J stock animals
ChiN
squareOffshore Coastal
P value
Fst
56
43
0.281
-0.003
16
44
0.167
0.009
13
34
0.127
0.000
29
94
0.280
0.005
34
78
0.307
0.007
75
88
0.124
0.002

P
0.434
0.187
0.363
0.246
0.101
0.305

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Table 4. Results of the heterogeneity test for yearly differences within each sub-area
All animals
Sub-area

7W

8W

8E

9W

9E

Chi-square
P value

Without suspected J stock animals

Year

N

1996

31

30

1998

25

25

1999

50

48

2000

24

21

2001

43

42

2002

110

2003

67

60

2004

75

68

2005

151

123

2006

131

112

2007

186

163

1998

44

2003

21

2006

10

1996

15

1997

30

2001

21

2003

16

2006

28

2007

13

1995

78

1997

19

2000

16

2001

29

2002

32

2003

24

2004

42

2005

19

2006

23

1994

14

1995

22

1997

48

2003

14

2004

42

2005

30

0.360

Fst

0.002

P

0.067

0.181

0.012

0.289

0.368

-0.004

0.774

0.370

0.004

0.130

0.410

0.002

0.287

8

N

99

Chi-square
P value

Fst

P

0.393

0.001

0.201

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Table 5.Results of the statistical comparison between 9W and 9E by year and total
samples.
Sample size
Chi-square
9W
9E
P value
Fst
P
1994
7
14
0.543
-0.029
0.767
1995
78
22
0.103
0.029
0.013
1997
19
48
0.858
-0.007
0.656
2003
25
14
0.063
0.031
0.114
2004
42
42
0.347
0.002
0.355
2005
19
30
0.456
-0.002
0.456
Total
292* 175*
0.419
0.004
0.016
Total**
214* 175*
0.427
0.003
0.090
*: including 2000, 2001, 2002, 2006 and 2006 samples**: exclude 1995 samples from the 9W.
Table 6. Results of the heterogeneity tests for the baseline C.
Chi-square
Combination of samples
P value
7E x 8W x 8E
0.366
9W x 9E
0.419
9W** x 9E
0.427

Fst
0.003
0.004
0.003

P
0.153
0.016
0.090

7W x 7E-8E x 9W-9E
0.193
0.001
7W* x 7E-8E x 9W-9E
0.890
0.000
7W* x 7E-8E x 9W**-9E
0.985-0.001*: suspected J stock individuals were excluded from the 7W sample.
**: exclude 1995 samples from the 9W.

0.023
0.778
0.967

Table 7.Results of the heterogeneity tests for the baseline D.
Combination of samples

Chi-square
P value

Fst

P

7E x 8W x 8E x 9W
7E x 8W x 8E x 9W**

0.234
0.330

0.003
0.002

0.022
0.119

7W x 9E
7W* x 9E

0.357
0.562

0.002
0.000

0.078
0.352

7W x 7E-9W x 9E
7W* x 7E-9W x 9E
7W x 7E-9W** x 9E
7W* x 7E-9W** x 9E

0.165
0.781
0.281
0.889

0.001
0.000
0.001
0.000

0.007
0.595
0.075
0.757

*: suspected J stock individuals were excluded from the 7W sample.
**: exclude 1995 samples from the 9W.

9

Do not cite without written permission from the authors
SC/61/JR7

Fig. 1. The 18 sub-areas used for the Implementation Simulation Trials for North Pacific minke whales.

50N

50N

45N

45N

40N

40N

35N

35N

30N
135E

30N
140E

145E

150E

155E

160E

165E

170E

Fig.2. Geographic distribution of sighting position of common minke whale used in this study taken by JARPN and
JARPNII surveys during 1994-2007.

10