SC/63/O4

SC/63/O4

Cruise report of the second phase of the Japanese Whale Research Program
under Special Permit in the Western North Pacific (JARPN II) in 2010
(Part III) - Coastal component off Kushiro.
HIDEYOSHI YOSHIDA1, NOBUYUKI ITO2, TOSHIYA KISHIRO1, TOMIO MIYASHITA1, TOSHIHIDE IWASAKI1,
SHINGO MINAMIKAWA1, YU KANAJI1, HIROYUKI OIKAWA3, SHIGEO TABATA2, SAEKO KUMAGAI2, GEN
NAKAMURA4, HIKARI MAEDA4, SATOKO INOUE4, NAOKO MIYAKAWA4, YUICHIRO ISHIKAWA4, KAORISHIMIZU4, YUTA YONEHARA4, KAZUYA KITAYAMA4, TAICHI TSUTSUMI4, AND HIDEHIRO KATO4.
1

National Research Institute of Far Seas Fisheries, 2-12-4 Fukuura, Kanazawa-ku, Yokohama,
Kanagawa 236-8648, Japan
2
Association for Community-Based Whaling, Hakata-Kaiseki Building 2F, Hakata-Eki-Higashi, Hakata-ku,
Fukuoka 812-0013, Japan
3
The Institute of Cetacean Research, 4-5, Toyomi-cho, Chuo-ku, Tokyo, 104-0055, Japan.
4
Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-0075, Japan

Contact e-mail:hideka@fra.affrc.go.jp
ABSTRACTThe eighth survey of the JARPN II coastal component off Kushiro, northeast Japan (middle part of the sub-area
7CN) was conducted from 7 September to 6 October 2010, using four small-type whaling catcher boats as
sampling vessels. Searching and sampling of common minke whales was conducted in coastal waters within 50
nautical miles from Kushiro port. All the whales collected were landed at the JARPN II research station forbiological examination. During the survey, a total of 4,151.6 nautical miles (385.0 hours) was searched, all the
125 schools (126 individuals) of common minke whales were detected, and 60 individuals were sampled.
Average body length of males was 5.80 m (SD=1.06, Range=4.05-7.70 m, n=41) and 5.44 m (SD=0.63,
Range=4.49-6.86 m, n=19) for females. Nine of the 41 males were sexually mature, but no mature animals were
found among the 19 females. Dominant prey species detected from whale forestomach was walleye pollock(Theragra chalcogramma, 60.0%), followed by Japanese anchovy (Engraulis japonicus, 36.7%) andunidentified fishes (3.3%). No other prey species were observed. The ratio of whales feeding on walleye pollock
was highest in the present survey, in comparison with the previous surveys in 2002-2009 (3.4-58.0%). Immatureand mature whales fed on different prey species, even if they were collected at close distance: immature
animals had walleye Pollock, while matures tended to take Japanese anchovy. These results indicate thedifference in feeding habit between immature and mature common minke whales off Kushiro in autumn season,
as suggested from the previous surveys.
KEYWORDS: COMMON MINKE WHALE; NORTH PACIFIC; COASTAL WATERS OF JAPAN; FOOD/PREY;ECOSYSTEM; SCIENTIFIC PERMITS.

BACKGROUND
The full-scale survey of the second phase of the Japanese Whale Research Program under Special Permit in
the Western North Pacific (JARPN II) was started in 2002. The survey mainly aimed at i) feeding ecology
and ecosystem studies, involving prey consumption by cetaceans, prey preferences of cetaceans andecosystem modeling, ii) monitoring environmental pollutants in cetaceans and the marine ecosystem, andiii) elucidation of stock structure of whales (Government of Japan, 2002a).
The full-scale JARPN II consists of two survey components, i.e., offshore and coastal components. The
JARPN surveys (1994-1999) and the JARPN II feasibility study (2000-2001) revealed that common minke
whales are widely distributed from offshore waters into coastal waters and feed on various prey species
such as Japanese anchovy, Pacific saury, and walleye pollock (Government of Japan 2002b; Tamura andFujise 2002). Both the waters are very important fishing grounds. Thus, it is thought that the waters are also
very important area for the full-scale JARPN II program. However, the Nisshin Maru research vessels can
not be operated in near shore areas, because of their movement restrictions in shallow waters and thepresence of fishing gear and many boats. Furthermore, the research vessels are not available from lateautumn to early spring. In order to cover the temporal and spatial gap of these vessels, in the full-scale

1Yoshida, et al.: Report of the JARPN II in 2010 - Coastal Component off Kushiro

JARPN II, sampling of common minke whales in coastal waters using small-type whaling catcher boats
was planned (Government of Japan, 2002a).
In the first two years of the full-scale JARPN II, feasibility studies were conducted, to examine the logistic
aspects of the methodology in the coastal component. The first feasibility study was conducted in coastal
waters off Kushiro in autumn 2002 and the second one was in coastal waters off Sanriku in spring 2003
(Kishiro et al. 2003, Yoshida et al. 2004). Since no logistic problem occurred in the studies, it was
concluded that the coastal survey could be continued as the component of the full-scale JARPN II, using
the same methodology (Government of Japan 2004b, Kato et al. 2004), while the survey was revised to be
conducted twice a year and to collect 60 common minke whales in each of spring and autumn (Governmentof Japan 2004a).
The first revised full-scale survey was carried out in coastal waters off Kushiro in autumn 2004 (Kishiro etal. 2005), then the coastal survey was conducted annually from 2005 to 2008 (Kishiro et al. 2006, 2008,
Yoshida et al. 2007, 2009). In January 2009, the JARPN II review workshop was carried out in Japan underthe IWC/SC, where the progress made in the first six years of the full-scale JARPN II (2002-2007) was
reviewed by the scientific specialists. Because there was no critical problem in the survey methodology, theseventh survey off Kushiro was carried out in 2009, under the original research plan (Kishiro et al. 2010).
Here, we show results of the eighth survey conducted off Kushiro, from 7 September to 6 October 2010.
The present survey, which was authorized by the Government of Japan in compliance with Article VIII of
the International Convention for the Regulation of Whaling, was also conducted under the original researchplan (Government of Japan 2004b). The National Research Institute of Far Seas Fisheries (NRIFSF) of theFisheries Research Agency planned and conducted the survey, under cooperation of the ICR, Tokyo
University of Marine Science and Technology, and the Association for Community-Based Whaling.
MATERIALS AND METHODS
Research area
Research area was set in the same waters where the previous JARPN II coastal surveys off Kushiro wereconducted in 2002-2009 (Kishiro et al. 2003, 2005, 2006, 2008, 2010, Yoshida et al. 2007, 2009): the area
was in coastal waters within 50 nautical miles from Kushiro port, southeastern Hokkaido (Fig. 1). The area
is included in the middle part of the sub-area 7CN, established by the IWC.
Research vessels, station, and period
Four small-type whaling catcher boats were used as sampling vessels: Taisho Maru No. 28 (hereinafterreferred as 28T; 47.3GT), Koei Maru No. 75 (75K; 46.0GT), Katsu Maru No.7 (7K; 32.0GT), andSumitomo Maru No.31 (31S; 32.0GT). All the common minke whales collected were landed at the JARPN
II research station established in the Kushiro port, for biological examination. Research period was set for
50 days, from 7 September to 26 October, 2010.
Searching and sampling methods
Searching and sampling methods were almost same with those for the first coastal survey off Kushiro in2002 (Kishiro et al. 2003). The research head office established in the research station controlled thesampling vessels during the survey. In order to avoid concentration of searching effort, the office
determined searching areas and routes of the vessels every day, from weather conditions, whale distribution,and information on fishing grounds of coastal fisheries. Searching was carried out in the daytime and thevessels returned to the port every night. A researcher was on board each of the vessels and recorded
sighting and sampling information, e.g., coordinates and time of common minke whale sighting andsampling made, weather conditions, and vessel activity. Sighting information was also recorded for otherbaleen whales and sperm whales. Searching was conducted by crews and researchers from the top barrel
and upper bridge of vessels running at around 10.5 knots. All common minke whales sighted were targeted
for sampling, except cow-calf pairs. When a school consisted of more than 1 animal, an individual was
selected randomly from the school and then collected. Once a vessel caught a whale, it returned to theKushiro port, to transport the animal to the research station. While returning to the port, other common
minke whales sighted were also targeted for sampling, if the situation allowed. At the port, animals werelifted from the vessel by the crane, using a wire net and then carried to the station by the 11-ton freighttrailer. At that time, body weight of animals was measured with the truck scale.

2

SC/63/O4

Biological research on common minke whales collected
All the whales sampled were examined by biological researchers at the research station. Research items arelisted in Table 2. The data and samples were collected for studies on feeding ecology, stock structure, life
history and pollutants.
RESULTS
Searching effort made by sampling vessels
Although the survey period was set for 50 days from 7 September to 26 October, the survey was finishedon 6 October. This is because sampling of 60 animals was completed on that day. Of a period of 30 days,
sampling vessels could conduct searching for 18 days (60.0%). Other days were not suitable for survey,
from bad weather conditions, e.g., low atmospheric pressure and thick fog. Cruise tracks made by thevessels are shown in Figure 2. Searching distance and time are given in Table 1. Here, searching distanceand time are defined as distance and time recorded under searching activity conducted by crews from the
top barrel of the vessels. During the survey, a total of 4,151.6 nautical miles (385.0 hours) was searched.
Sightings made by sampling vessels
All the 125 schools (126 individuals) of common minke whales were sighted during the searching (Table 1,
Fig. 2). No cow-calf pairs were observed. Cruise tracks were widely distributed in coastal waters ofKushiro port, whereas sightings of common minke whales concentrated in waters along 200m isobath,particularly on the continental slope southwest of Kushiro. Density index of common minke whales wascalculated as 2.34 for DI (the number of primary sightings of schools per 100 nautical miles searching) and
0.25 for SPUE (the number of primary sightings of schools per 1 hour searching). In the last 2009 survey,
sampling vessels often encountered large cetaceans in addition to common minke whales: the 41 sightingsof baleen whales (fin, sei, or humpback whales) were made. However, only one sighting of humpback
whale was recorded in the present survey.
Sampling of common minke whales
Of the 126 common minke whales encountered, 60 animals were collected for biological examination. In
the sampling process, struck and lost was not occurred. Sighting positions of animals collected are shownin Figure 2.
Body length, sex ratio, and maturity of animals caught
Research items of biological examination for the 60 common minke whales are summarized in Table 2,with the number of data and samples collected. The animals consisted of 41 males and 19 females. Sex
ratio of males to all animals was 68.3%, which is almost same with ratios recorded in the previous surveys
off Kushiro in 2002-2009 (61.0-79.7%). Average body length was 5.80 m (SD=1.06, range=4.05-7.70 m)
for males and 5.44 m (SD=0.63, range=4.49-6.86 m) for females (Table 3). In males, the most dominant
length class was 5.0 m (Fig. 3). For females, there were no animals with length of 7 m or more. Sexual
maturity of animals collected is shown in Table 4. In males, 9 of 41 animals were sexually mature (22.0%),
but no mature females were obtained. Male maturity ratio was lowest in the present survey, when it iscompared with the ratio recorded in the previous 2002-2009 surveys (31.3-68.1%).
Prey species found from common minke whale forestomach
Stomach contents of the 60 animals collected were examined. Following the same methods used in the
JARPN II feasibility survey conducted in 2001 (Fujise, et al., 2002), stomach contents were weighed to thenearest 0.1 kg, by each of four chambers. Weights were recorded both including and excluding liquid
contents. A small quantity of stomach contents was collected and frozen for laboratory analysis. Weight offorestomach contents including liquid ranged from 7.1 kg to 73.9 kg. Average weight was 27.9 kg.
Forestomach contents found from the 60 whales are listed in Table 5. Empty stomach was not observed.
Dominant prey species was walleye pollock (Theragra chalcogramma)(60.0%), followed by Japanese
anchovy (Engraulis japonicus)(36.7%). No other species including krill (Euphausia pacifica), common
squid, and Pacific saury were observed. The ratio of whales feeding on walleye pollock was highest in thepresent survey, in comparison with the previous Kushiro surveys (3.4-58.0%)(see, Fig. 4). In mature
animals, only two took walleye Pollock, while other seven animals had Japanese anchovy (Fig. 5). Sighting
positions of whales collected in the present survey are shown by their maturity stage and prey species (Fig.
6).

3

Yoshida, et al.: Report of the JARPN II in 2010 - Coastal Component off Kushiro

DISCUSSION
In the present survey, bad weather conditions, e.g., low atmospheric pressure and thick fog, often prevented
sampling vessels from research activities, as similar to the past surveys. During a survey period of 30 days,
the vessels conduct searching for 18 days. Of these, there were only 10 days, on which the vessels could
conduct the survey throughout the day. Nevertheless, sampling of 60 animals was completed successfully.
Density index of common minke whales recorded by the vessels was higher in the present survey (2.34)
than that of the 2009 survey (1.89)(Kishiro et al., 2010), which suggests more whales migrating off
Kushiro in the present season. The index was, furthermore, much higher in the first two weeks in 2010. In
the period, weather condition was also suitable for searching. It is thought that, from these, sampling of 60
animals was completed.
In the present survey, the most dominant prey species found from whale forestomach was walleye pollock,followed by Japanese anchovy. No other species were found. Most of mature animals had Japanese
anchovy: only two animals took walleye Pollock (Fig. 5). Immature and mature animals fed on different
prey species, even if they were collected at close distance. Animals having walleye pollock were collectedalong the 200 m isobath (Fig. 6). On the isobath, however, most of mature animals had Japanese anchovy.
These results indicate difference in feeding habit between immature and mature common minke whales off
Kushiro in autumn season, as suggested by Kishiro et al. (2009).
The number of sightings of baleen whales other than common minke whales was much lower in the present
survey: there was only one sighting of humpback whale, while baleen whales (fin, sei, or humpback
whales) were detected 41 occasions in the 2009 survey (Kishiro et al. 2010). At the survey, the second
dominant prey species of common minke whales was krill. Common minke whales collected close tosighting positions of the large cetaceans had krill. From these, Kishiro et al. (2009) discussed that krill wasabundant around Kushiro during the 2009 survey and hence local migration of large cetaceans into thewaters occurred for krill concentration. In the present survey, however, krill was not observed from whale
stomach: krill may not have been so abundant off Kushiro and hence only one sighting of the humpback
whale was obtained.
There was no serious practical problem in conducting the surveys. The 2010 coastal survey off Kushiro wascompleted successfully.
ACKNOWLEDGMENTS
We acknowledge Dr. Hiroshi Hatanaka (ICR), Dr. Seiji Ohsumi (ICR), and Mr. Shigeki Takaya (theFisheries Agency of Japan), for their guidance in the survey design and support. Dr. Hikaru Watanabe gave
us valuable comments and suggestions. Crew of research vessels, staff of the research station in Kushiro,
and the Association for Community-Based Whaling assisted in important aspects of the survey. We also thankthe Kushiro fisheries cooperative association, the municipal office of Kushiro, Hokkaido government
Kushiro sub-prefectural office, and Hokkaido government office, for their kind assistance.
REFERENCES
Fujise, Y., Tamura, T., Bando, T., Watanabe, H., Kiwada, H., Otani, S., Kanda, N., Yasunaga, G., Mogoe, T.,
Konishi, K., Inamori, M., Shigemune, H. and Tohyama, D. 2002. Cruise report of the feasibility study of
the Japanese Whale Research Program under Special Permit in the western North Pacific-Phase II(JARPN II) in 2001. Paper SC/54/O16 submitted to the 54th IWC Scientific Committee, 51pp.
Government of Japan, 2002a. Research plan for cetacean studies in the western North Pacific under special
permit (JARPN II). Paper SC/54/O2 submitted to the 54th IWC Scientific Committee.
Government of Japan (Fujise, Y., Kawahara, S., Pastene, L.A. and Hatanaka, H. eds.), 2002b. Report of2000 and 2001 feasibility study of the Japanese Whale Research Program under Special Permit in thewestern North Pacific-Phase II (JARPN II). Paper SC/54/O17 submitted to the 54th IWC ScientificCommittee, 202pp.
Government of Japan, 2004a. Revised research plan for cetacean studies in the western North Pacific under
special permit (JARPN II). Paper SC/56/O1 submitted to the 56th IWC Scientific Committee, 14pp.
Government of Japan (Fujise, Y., Tamura, T., Kato, H. and Kawahara, S. eds.), 2004b. Some considerationsof the feasibility components of the JARPN II research plan. Paper SC/56/O2 submitted to the 56th IWC
Scientific Committee, 36pp.
Kato, H., Kishiro, T., Yoshida, H. and Kawahara, S. 2004. Feasibility of coastal surveys in the JARPN II,

4

SC/63/O4

from the viewpoint of logistics. Appendix 1, pp4-12. In: Government of Japan (Fujise, Y., Tamura, T.,
Kato, H. and Kawahara, S. eds.), Some considerations of the feasibility components of the JARPN II
research plan. Paper SC/56/O2 submitted to the 56th IWC Scientific Committee, 36pp.
Kishiro, T., Kato, H., Ohizumi, H., Yoshida, H., Saito, T., Isoda, T., Tabata, S., Sakakibara, M., Saino, S.,
Hara., T., Hayashi, T., Miyashita, T., Fukudome, K., Kiwada, H., and Kawahara, S. 2003. Report of the2002 JARPN II survey in the western North Pacific. Part II: Coastal component - Coastal Survey off
Kushiro, northeast Japan. Paper SC/55/O8 submitted to the 55th IWC Scientific Committee, 26pp.
Kishiro, T., Kato, H., Yoshida, H., Miyashita, T., Ryono, T., Tabata, S., Okamoto, R., Yasui, K., Sato, H.,
Morita, Y., Saino, S., Hara, T., Ebisui, T., Kuroishi, H., Nishiwaki, S., and Kawahara, S. 2005. Cruise
report of the coastal survey on common minke whales off Kushiro, northeast Japan: the 2004 JARPN II
survey (Part II) - Coastal component. Paper SC/57/O4 submitted to the 57th IWC Scientific Committee,
37pp.
Kishiro, T., Kato, H., Yoshida, H., Miyashita, T., Ryono, T., Tabata, S., Yasui, K., Sato, H., Morita, Y.,
Kumagaya K., Tokuda, D., Nakai, K., Funabashi, N., Ebisui, T., Wakatsuki, T., Sakaguchi, M., Houhana,T., Nishiwaki, S., and Kawahara, S. 2006. Cruise report of the second phase of the Japanese Whale
Research Program under Special Permit in the Western North Pacific - Coastal component off Kushiro in2005. Paper SC/58/O10 submitted to the 58th IWC Scientific Committee, 32pp.
Kishiro, T., Kato, H., Yoshida, H., Miyashita, T., Iwasaki, T., Kanaji, Y., Ryono, T., Tabata, S., Morita, Y.,
Okamoto, R., Maeda, H., Nagatsuka, S., Ogawa, N., Nakai, K., Ebisui, T., Matsumoto, A., Gokita, A.,
Kiwada, H. and Kawahara, S. 2008. Cruise report of the Second phase of the Japanese Whale Research
Program under Special Permit in the western North Pacific (JARPN II) in 2007 - Coastal component off
Kushiro. Paper SC/60/O7 submitted to the 60th IWC Scientific Committee, 33pp.
Kishiro, T., Yoshida, H., Tamura, T., Konishi, K., Kanda, N., Okamoto, R., and Kato, H. 2009. Relationshipbetween body size, maturity, and feeding habit of common minke whales off Kushiro in autumn season,
from 2002-2007 whale sampling surveys under the JARPN II coastal components off Kushiro. Paper
SC/J09/JR13 submitted to the JARPN II Review Workshop, Tokyo, January 2009, 25pp.
Kishiro, T., Kato, H., Yoshida, H., Yasunaga, G., Tabata, S., Nakamura, G., Maeda, H., Inoue, S.,
Miyagawa, N., Okamoto, R., Oikawa, H., Watanabe, H., Iwasaki, T., Kanaji, Y., Minamikawa, S., Otani,
S., Ishikawa, H., Kanda, N., Gokita, A., Yamazaki, K., and Yonehara, Y. 2010. Cruise report of theSecond phase of the Japanese Whale Research Program under Special Permit in the western North
Pacific (JARPN II) in 2009 - Coastal component off Kushiro. Paper SC/62/O6 submitted to the 60th IWC
Scientific Committee, 13pp.
Tamura, T. and Fujise, Y. 2002. Geographical and seasonal changes of the prey species on minke whale in
the Northwestern Pacific. ICES Journal of Marine Science, 59:516-528.
Yoshida, H., Kato, H., Kishiro, T., Iwasaki, T., Miyashita, T., Ryono, T., Tabata, S., Sakakibara, M., Saino,
S., Hara, T., Hayashi, T., Tomizawa, Y., Tamai, K., Okamoto, R., Fukuoka, M., Watanabe, H., Tsunekawa,
M. and Kawahara, S. 2004. Report of the coastal survey on common minke whales off Sanriku coast,
northeast Japan: the Japanese whale research program under special permit in the western North Pacific– Phase II (JARPN II) in 2003 (Part II) – Coastal component. Paper SC/56/O14 submitted to the 56th
IWC Scientific Committee, 31pp.
Yoshida, H., Kato, H., Kishiro, T., Miyashita, T., Iwasaki, T., Minamikawa, S., Ryono, T., Tabata, T.,
Morita, M., Sato, H., Okamoto, R., Toyoda, Y., Nakamura, G., Ebisui, T., Nakai, K., Matsumoto, A.,
Nishiwaki, S., and Kawahara, S. 2007. Cruise report of the second phase of the Japanese Whale Research
Program under Special Permit in the Western North Pacific (JARPN II) in 2006 - Coastal component off
Kushiro. Paper SC/59/O7 submitted to the 59th IWC Scientific Committee, 43pp.
Table 1. Searching days, distances, hours, and number of cetacean sightings made during the 2010 JARPN II
coastal survey off Kushiro.
Number of sightings*
PeriodDays Distances Hours
SpeciesPrimary
Secondary
Total(n. miles)(Ind/Sch)(Ind/Sch)（Ind/Sch）
9/7-10/6
184151.6385.0
Common minke whale
98/97
28/28
126/125
Like minke whale
18/18
2/2
20/20
Humpback whale
1/1
0/0
0/0
Unknown large whale
15/15
0/0
15/15
*: The number probably includes some duplicated sightings made by plural vessels.

5

Yoshida, et al.: Report of the JARPN II in 2010 - Coastal Component off Kushiro6

SC/63/O4

Table 3. Statistics of body length (m) of common minke whales sampled during the 2010 JARPN II
coastal survey off Kushiro.
PeriodMale
FemaleMean S.D. Min. Max.
n
Mean S.D.
Min. Max. n
9/7 – 9/12
6.06
1.14
4.05
7.57
20
5.12
0.56
4.49
6.27
8
9/13 – 9/18

5.51

0.92

4.62

7.48

11

5.53

0.27

5.10

5.78

5

9/19 – 9/24

6.62

1.53

5.53

7.70

2

6.86

-

6.86

6.86

1

9/25 – 9/30

5.03

0.23

4.82

5.28

3

-

-

-

-

0

10/1 – 10/6

5.53

0.93

4.49

6.98

5

5.56

0.65

4.80

6.30

5

Total (9/7 – 10/6)

5.80

1.06

4.05

7.70

41

5.44

0.63

4.49

6.86

19

Table 4. Composition of sex and sexual maturity of common minke whales sampled during the 2010 JARPN II
coastal survey off Kushiro.
PeriodMale
FemaleIm M Total Maturity(%)
Im R P Total Maturity(%) Pregnancy(%)*
9/7 - 9/12
14
6
20
30.0
8
0 0
8
0.0
9/13 - 9/18

10

1

11

9.1

5

0

0

5

0.0

-

9/19 - 9/24

1

1

2

50.0

1

0

0

1

0.0

-

9/25 - 9/30

3

0

3

0.0

-

-

-

0

0.0

-

10/1 - 10/6

4

1

5

20.0

5

0

0

5

0.0

-

0.0

-

Total (9/7 - 10/6)
32
9
41
22.0
19 0 019
Im: Immature; M: Mature; R: Resting; P: Pregnant; *: Apparent pregnancy ratio.

Table 5. Number of common minke whales by major prey species found in forestomach, sampled during
the 2010 JARPN II coastal survey off Kushiro.
Number of whales (%)
PeriodJapanese
Pacific
Walleye
Krill
Common Unidentified Total
anchovysaury
Pollock
squid
species
9/7 - 9/12
13 (46.4)
0 (0.0)15 (53.6)
0 (0.0)0 (0.0)0 (0.0)28
9/13 - 9/18

5 (31.3)

0 (0.0)9 (56.3)

0 (0.0)0 (0.0)2 (12.5)

16

9/19 - 9/24

2 (66.7)

0 (0.0)1 (33.3)

0 (0.0)0 (0.0)0 (0.0)3

9/25 - 9/30

0 (0.0)0 (0.0)3 (100.0)

0 (0.0)0 (0.0)0 (0.0)3

10/1 - 10/6

2 (20.0)0 (0.0)8 (80.0)0 (0.0)0 (0.0)0 (0.0)10

Total (9/7 - 10/6)

22 (36.7)

0 (0.0)36 (60.0)

0 (0.0)0 (0.0)2 (3.3)

60

7

Yoshida, et al.: Report of the JARPN II in 2010 - Coastal Component off Kushiro

Kushiro50n. miles

Figure 2. Cruise tracks (upper) and sighting positions (lower) ofcommon minke whales made by sampling vessels during
the 2010 JARPN II coastal survey off Kushiro. Blackcircles are sighting positions of common minke whales
collected. Isobaths are 100m, 200m, and 1000m.

Figure 1. Research area set for the 2010 JARPN II coastal survey off
Kushiro. Isobaths are 100m, 200m, 1000m, and 2000m.

8Number of individuals

SC/63/O4

Body length (m)Figure 3. Body length frequency of common minke whales sampled during the 2010 JARPN II
coastal survey off Kushiro, with comparison to results of the previous 2002-2009 surveys.

9

Yoshida, et al.: Report of the JARPN II in 2010 - Coastal Component off Kushiro

Figure 4. Composition of prey species of common minke whales sampled during the 2010 JARPN II
coastal survey off Kushiro, with comparison to results of the previous 2002-2009surveys.

Figure 5. Sexual maturity and body length frequency of common minke whales by their prey species
found in forestomach in the 2010 JARPN II coastal survey off Kushiro.

Walleye pollock(Immature)

Walleye pollock(Mature)Japanese anchovy (Immature)
Japanese anchovy (Mature)

Figure 6. Sighting positions of common minke whales collected during the 2010 JARPN II coastal survey off
Kushiro, shown by their maturity stage and prey species. Isobaths are 100m, 200m, and 1000m.

10