SC/65b/IA06

Cruise report of the Japanese cetacean sighting survey inthe western North Pacific in 2013
KOJI MATSUOKA1, TAKAHIRO KONAGAI 2, TORU TAKAMATSU 2AND TOMIO MIYASHITA3
1

Institute of Cetacean Research, Toyomi 4-5, Chuo-ku Tokyo, 104-0055, JAPANKyodo Senpaku Co. Ltd., Toyomi 4-5, Chuo-ku Tokyo, 104-0055, JAPAN3
National Research Institute of Far Seas Fisheries, Fukuura 2-12-4, Kanazawa, Yokohama, Kanagawa
236-8648, JAPAN
2

Contact e-mail: matsuoka@cetacean.jp

ABSTRACT
A systematic vessel-based sighting survey was conducted in 2013 by Japan to examine the distribution andabundance of large whales in the western North Pacific. The research area was set between 35° N and 44° N
and between 140° E and 157° E (sub-areas 7W, 7E and 8 for common minke whale). Survey was conducted
between 18 May and 26 June. The research vessels Yushin-Maru and Yushin-Maru No.2 were engaged in thissurvey. A total of 3,470.1 n.miles was searched in this survey. Successful coverage of the searching efforts ofeach sub-area was 74% for sub-area 7W&7E and 73% for sub-area 8, respectively. In total, eight species
including seven baleen whales, blue (2 school / 2 individual), fin (26/35), sei (33/56), Bryde’s (39/55),
common minke (7/7), North Pacific right (1/1) and humpback (66/88) whales and sperm whale (75/225) weresighted during the survey. Concentration areas of sei, Bryde’s and humpback whales were observed. Photo-ID
photographs were successfully taken from blue (2 individuals), North Pacific right (1) and humpback (22)whales. Biopsy skin samples were also successfully collected from blue (1) and humpback (6) whales
including a mother and calf pair of humpback whale.

KEY WORD: BLUE WHALES, FIN WHALES, SEI WHALES, BRYDE’S WHALE, COMMON MINKEWHALES, SPERM WHALES, SURVEY VESSEL, NORTH PACIFICINTRODUCTION
In the western North Pacific dedicated cetacean sighting surveys based on the survey procedures of theInternational Whaling Commission/Southern Ocean Whale and Ecosystem Research (IWC/SOWER) have been
conducted since 1995 as a part of the Japanese Whale Research Program under Special Permit in the Western
North Pacific (JARPN/JARPNII). Based on the collected data the distribution patterns of large whales such as
blue, fin, sei, Bryde’s, common minke, humpback, North Pacific right and sperm whales, and abundance
estimates of common minke, sei and Bryde’s whales were investigated and reported to the IWC SC (IWC, 2001,
2010, Pastene et al., 2007, 2008, 2009, Hakamada et al., 2009, Matsuoka et al., 2009, Murase et al., 2009). The
National Research Institute of Far Seas Fisheries (NRIFSF) also conducts dedicated sighting survey forcetaceans in the North Pacific since the 1980s (Buckland et al., 1992; Miyashita and Kato, 2004; 2005, Kanaji,2011). In 2013 the Government of Japan planned to continue the sighting surveys in the North Pacific. The
collection of sighting data to estimate abundance and biopsy/photo-identification data to examine stock structure
will contribute to the work on management and conservation of large whales by the IWC SC (IWC, 2010). This
paper reports the result of the Japanese dedicated sighting surveys conducted in 2013. The plan of this survey
had been presented to the 2012 IWC/SC meeting (Matsuoka et al., 2013) and endorsed by the SC (IWC, 2012).

MATERIALS AND METHODS
The surveys were conducted in 2013 in the western North Pacific by the research vessel Yushin-Maru (YS1) andYushin-Maru No.2 (YS2). The vessels were equipped with a top barrel platform (TOP) and upper bridge.
Specifications of these vessels are shown in Table 1.
Research area and period
The research area was set between 35° N and 45° N and between 140° E and 157° E in May to June (Table 2 andFigure 1).

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Track line design
The Survey blocks and pre-determined track lines are shown in Figures 1. The Latitudinal start point of the tracklines are decided at random using the “Distance program (ver.6.0) ” and the number of the line (width in thelongitude) is decided by the research schedule based on the IWC survey guideline (IWC, 2005).
Sighting procedure
Passing mode with closing during the abeam was used, which followed the protocol endorsed for the
IWC/SOWER cruise (IWC, 2008). There were two primary observers in the top barrel (TOP) and the upper
bridge (captain and helmsman), respectively. On the TOP, two observers conducted searching for cetaceans byusing scaled binoculars (7x). On the upper bridge, two primary observers also searched for cetaceans andrecorded sighting information. The survey was conducted 12 hours per day from 7:00 a.m. to 7:00 p.m. basicallywhen the weather conditions were suitable for observations: visibility better than 2.0 n.miles and wind speed lessthan 21 knots. The vessel searching speed was planned to be 11.5 knots with slight adjustment to avoid vibrationof vessel.
Research personnel
One researcher was on board of each research vessel. The researchers had considerable experience on whale linetransect surveys in the North Pacific, Antarctic and West Africa as well as experience conducting photo-id andbiopsy experiments through participation in the IWC/IDCR-SOWER and JARPN II Programs. Koji Matsuoka(Institute of Cetacean Research) was the oversight persons on behalf of the IWC/SC.
Experiments
Distance and angle experiments were conducted earlier in the Surveys. The experiment to evaluate measurement
error was conducted late in the survey following the protocol of the IWC/SOWER cruise (IWC, 2008). Whenlarge cetaceans such as blue, humpback and North Pacific right whales were found, photo-id experiments wereconducted. Biopsy skin sampling of blue, fin, Bryde’s, humpback, North Pacific right and sperm whales was
opportunistically collected.

RESULT AND DISCUSSION
Brief narrative of the Surveys
Research vessels (YS1 and YS2) departed from Shimonoseki, Japan on 18 May and started survey in the
research area on 21 May. The vessel finished research area on 21 June and arrived at Shiogama on 26 June
(Table 2).
Searching effort
A summary of the period covered and sighting effort in each Survey is shown in Table 2. A total of 3,470.1
n.miles were searched (73.5% covered).
Sightings
Sightings made are summarized in Table 3. Figures 2, 3 and 4 show the location of these sightings.
Blue Whale
Two schools and two individuals of blue whales were sighted in the northern part of sub-area 8 (Table 3 andFigure 2). Estimated body lengths of blue whales confirmed were 20.5 and 20.7 meters, respectively. The sea
temperatures of the sighting position of these whales were 12.0°C and 16.6 °C, respectively. One mother andcalf pair was observed. It was known that there were some sightings of this species in this area during July toAugust between 1964 and 1990 (Miyashita et al., 1995). It is recognized that this area is still important area of
this species in July. These information are important and useful for the future sighting survey planning in the
North Pacific.
Fin Whale
Fin whales were mainly sighted in the northern part of sub-area 7E and 8 (Figure 2). A total of 26 schools (35individuals) of this species were sighted (Table 3). High density was observed between 147°E- 150°E(38°N-41°N). Observed mean school size was 1.35 (n=26). No mother and calf pair was observed. Range of theestimated body length confirmed was 11.7 – 23.0 meters. Range of the sea temperature of the sighting position
was 4.9°C – 18.1°C.

2Sei Whale
Sei whales were mainly sighted (33 schools, 56 individuals) in sub-area 8 (Table 3 and Figure 3). Six mother andcalf pairs were observed. Observed mean school size was 1.70 (n=33). Range of the estimated body length was
9.5 - 14.6 meters except calves. Range of the sea temperature of the sighting position was 13.0°C - 20.4°C.
Bryde’s Whale
Bryde’s whales were most second sighted frequently for baleen whales and widely distributed in the southernpart of the whole research area (Figure 3). A total of 39 schools (55 individuals) were observed (Table 3).
Observed mean school size was 1.41 (n=39). 10 schools were mother and calf pairs. Range of the estimated bodylength was 8.0 – 13.4 meters except calves. Range of the sea temperature of the sighting position was 16.0°C 21.5°C. Bryde’s whales are widely distributed in summer in the western North Pacific south of 40ºN based on
the recent Japan/NRIFSF and JARPN/JARPN II catches ((Shimada, 2004; Pastene et al., 2009).
Common minke whale
Common minke whales were sighted (7 schools and 7 individuals) in the northern part of the research area
(Figures 3). No mother and calf pair was observed. Range of the sea temperature of the sighting position was
7.9°C – 17.1°C. In general, common minke whales were tended to distribute in the coastal area as surveyed in2012 surveys (42 schools and 52 individuals sighted during 44 days coastal survey area, Matsuoka et al., 2012).
The few encounters were attributed to insufficient allocation of searching effort in these waters and anomalous
condition of the ocean (high swell due to storms and heavy fogs).
North Pacific right whale
North Pacific right whale was most rare species for baleen whales in the research area (1 school and 1
individual). This was sighted in the western part of sub-area 8 (Figure 2). Estimated body length was 11.6 meters.
Range of the sea temperature of the sighting position was 13.4°C. Head of this animal was photographed as
Photo-ID data. Biopsy sampling was also conducted but no sample was collected.
Humpback whale
Humpback whales were most sighted frequently for baleen whales in the research area (66 schools and 88
individuals). They were mainly sighted in the western part of sub-area 8 (Figure 2). Observed mean school size
was 1.33 (n=66). Five mother and calf pairs were observed. Range of the estimated body length was 11.2 – 14.3
meters except calves. Range of the sea temperature of the sighting position was 5.6°C – 16.7 °C.
Sperm Whale
Sperm whales were most frequently sighted and widely distributed in the whole research are (Table 3 and Figure4). A total of 75 schools (225 individuals) were observed during the Survey. Observed mean school size was
3.00 (n=75). At least one mother and calf pair was observed. Because of limited closing to the schools, there was
no information for body length and calves. Range of the sea temperature of the sighting position was 3.7°C 21.4°C.
Experiments
Estimated Angle and Distance
The Estimated Angle and Distance Training Exercise were conducted earlier in the Surveys. During the exercise
the observers familiarized themselves with distance estimates from the TOP and Upper Bridge. The EstimatedAngle and Distance Experiment were conducted on 4 June by YS1, and 5 June by YS2.
Photo-ID experiments
Photographs were taken from 1 blue and 11 humpback whales by YS1, from 1 blue whale, 1 North Pacific rightwhale and 11 humpback whales by YS2. A total of 2 individual of blue, 1 individual of North Pacific right and
22 individuals of humpback whales were photographed (Table 4 and 6). All photographs were stored at the ICR
catalogue.
BiopsyAll of the biopsy attempts were made using the compound crossbow system. Allocation of research time tobiopsy attempts was initially restricted with the aim of maximizing the searching effort to cover the research area.
A total of 7 biopsy samples were collected from 1 blue and 6 humpback whales including one mother and calf
pair (Table 5 and 6). All samples were stored at the ICR laboratory.

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Report of the IWC oversight
The plan of the Surveys was presented to the 2012 IWC/SC meeting (Matsuoka et al., 2012) and endorsed by the
Scientific Committee (IWC, 2012). Koji Matsuoka carried out the oversight work through the planning and theexecution of this sighting survey conducted by the Institute of Cetacean Research (ICR) in May-June 2013 onbehalf of the SC. The research vessels, Yushin-Maru and Yushin-Maru No.2 were used for the cruises. All
equipment and the survey method were the same as in the past sighting surveys. The design of the survey blocks
and track lines was improved to cover each survey block with uniform probability. The planned sighting
procedure was in accordance with the guideline agreed by the SC (IWC, 2005). Objectives and procedure of thesurvey were explained to the captains, officers, crew and researcher in advance. Sighting data was already sent to
the IWC secretary and confirmed on 24 April.

ACKNOWLEDGEMENT
We acknowledge the Government of Japan for the assistance in the research permit and funding for this cruise.
We also thank the captain and his officers and crew of the Yushin-Maru and Yushin-Maru No.2 for their hard
work and dedication which led to the successful execution of this cruise. We acknowledge Drs. Yoshihiro Fujise,
Hiroshi Hatanaka, Seiji Ohsumi, Shigetoshi Nishiwaki, Tsutomu Tamura, Bando Takeharu and the staff of theInstitute of Cetacean Research (Tokyo) and Kyodo Senpaku Co. Ltd. for their assistance in arrangements andsupport for the cruise. We thank to Luis Pastene for his constructive suggestions to improve the draft of thispaper.

REFERENCES
Buckland, S.T., Cattanach, K.L. and Miyashita, T. 1992. Minke whale abundance in the northwest Pacific andthe Okhotsk Sea, estimated from 1989 and 1990 sighting surveys. Rep. int. Whal. Comn 42: 387-92.
Hakamada, T., Matsuoka, K. and Miyashita, T., 2009. Distribution and the number of western North Pacificcommon minke, Bryde's, sei and sperm whales distributed in JARPNII Offshore component survey area.
SC/J09/JR15. 18pp. [Paper available at the IWC Office].
IWC, 2001. Report of the Workshop to Review the Japanese Whale Research Program under special permit for
North Pacific minke whales (JARPN). J. Cetacean Res. Manage. 3 (Supp.):377-413.
IWC. 2005. Report of the Scientific Committee. Annex D. Report of the sub-committee on the Revised
Management Procedure. Appendix 3. Requirements and Guidelines for Conducting Surveys andAnalysing Data within the Revised Management Scheme. J. Cetacean Res. Manage. 7 (Supp.):92-101.I
IWC,
2008.
IWC
SOWER
Cruise2008/09,
InformationforResearchers.
http://iwcoffice.org/_documents/sci_com/SOWER/Guide%20%20for%20Researchers%202008-09.pdf
IWC, 2010. The Report of the Expert Workshop to review the ongoing JARPN II Programme. J. Cetacean Res.
Manage. 11 (Supp.2):405-450.
IWC, 2012. Report of the Scientific Committee, Annex G. J. Cetacean Res. Manage. 13 (Supp.):xxxx.
Kanaji, Y., Iwasaki, T., Kishiro, T. and Miyashita, T., 2012. Cruise report of the sighting and satellite tagging
survey for common minke whales in the sub-area 7 in 2011. SC/64/O9. 10pp. [Paper available at the IWC
Office].
Matsuoka, K., Kiwada, H., Fujise, Y. and Miyashita, T., 2009. Distribution of blue (Balaenoptera musculus), fin(B. physalus), humpback (Megaptera novaeangliae) and north pacific right (Eubalaena japonica) whales in
the western North Pacific based on JARPN and JARPN II sighting surveys (1994 to 2007). SC/J09/JR35.
12pp. The IWC/SC JARPNII review meeting, Yokohama, 26-30, January. [Paper available at the IWC
Office].
Matsuoka, K., Hakamada, T. and Miyashita, T., 2012. Research plan for a cetacean sighting surveys in theWestern North Pacific in 2012. SC/64/IA6. 5pp. [Paper available at the IWC Office].
Matsuoka, K., Hakamada, T. and Miyashita, T., 2013. Research plan for a cetacean sighting surveys in theWestern North Pacific in 2013. SC/65a/IA. 4pp. [Paper available at the IWC Office].
Miyashita, T., Kato, H. and Kasuya, T., 1995. Worldwide Map of Cetacean Distribution based on Japanese
Sighting Data (Volume 1). pp43-56.
Miyashita, T. and Kato H. 2004. Plan for the North Pacific minke whale sighting surveys in 2004. SC/56/RMP3.
3pp. [Paper available at the IWC Office].
Miyashita, T. and Kato H. 2005. Plan for the minke whale sighting surveys in the North Pacific in 2005.
SC/57/NPM2. 5pp. [Paper available at the IWC Office].
Murase, H., Hakamada, T., Kiwada, H., Inagake, D., Okazaki, M., Tojyo, N. and Matsuoka, K., 2009.
Preliminary results of estimation of sei whale (Balaenoptera borealis) distributuion and abudnace in thewhole North Pacific basin. Appendix 2. 11pp. In: Hakamada, T., Examination of the effects on whale4

stocks of future JARPN II catches. SC/J09/JR36. 56pp.
Pastene, L.A, Kawahara, S. and Hatanaka, H. 2007. concepts for a research program on north pacific Bryde’s
whale -RMP VARIANT 2 WITH RESEARCH-. SC/59/PFI2 5pp. [Paper available at the IWC Office].
Pastene, L.A, Kitakado, T. and Hatanaka, H. 2008. Research proposal accompanying management variant 2 of
the RMP Implementation for western North Pacific Bryde’s whale. SC/60/PFI9 10pp. [Paper available atthe IWC Office].
Pastene, L,A., Hatanaka, H., Fujise, Y., Kanda, N., Murase, H., Tamura, T., Miyashita, T. and Kato, H., 2009.
The Japanese Whale Research Program under Special Permit in the western North Pacific Phase-II(JARPN II): origin, objectives and research progress made in the period 2002-2007, including scientificconsiderations for the next research period. SC/J09/JR1 (Rev 1). 73pp.
Shimada, 2004. Abundance estimate of the western North Pacific stock of Bryde’s whales using sighting datafrom 1998 to 2002. SC/56/PIF6. 8pp.

Table 1. Specification of the research vessels.
Vessel nameYushin-Maru

Yushin-Maru No.2

Call sign

JLZS

JPPV

Length overall [m]

69.61

69.61

Gross tonnage (GT)

720

747

Barrel height [m]

19.5

19.5

Upper bridge height [m]

11.5

11.5

Bow height [m]

6.5

6.5

Engine power [PS / kW]

5,280 / 3,900

5,280 / 3,900

Table 2. Summary of the survey periods and searching effort (n.miles).
Research
vessels

Cruise period

Research area
periodPlanned cruise
track (n.miles)

Searchingeffort (n.miles)

Coverage ofeffort (n.miles)

YS1
YS2
Total

2013.5.18-6.26
2013.5.18-6.26
2013.5.18-6.26

2013.5.21- 6.21
2013.5.21- 6.21
2013.5.21- 6.21

2,231.2
2,491.2
4,722.4

1,646.2
1,823.9
3,470.1

73.8%
73.2%
73.5%

Table 3. Number of sightings by species and vessel.
SurveyYS1

YS2

Primary

Secondary

sch.

sch.

Primary

Total
SecondaryPrimary

SecondarySpecies
ind.

ind.

sch.

ind.

sch.

ind.

sch.

ind.

sch.

ind.

Blue whale

1

1

0

0

1

1

0

0

2

2

0

0

Fin whale

10

14

0

0

15

20

1

1

25

34

1

1

Sei whale

7

12

1

2

23

40

2

2

30

52

3

4

Bryde's whale

21

29

1

1

16

24

1

1

37

53

2

2

Common minke whale

1

1

0

0

5

5

1

1

6

6

1

1

North Pacific right whale

1

1

0

0

0

0

0

0

1

1

0

0

Humpback whale

13

17

1

2

47

61

5

8

60

78

6

10

Sperm whale

44

166

2

2

29

57

0

0

73

223

2

2

5

Table 4. Number of individuals photographed, by species and vessel.
Photo-IDBlue whale
North Pacific right
Humpback whale

YS1

YS2

Total

1
0
11

1
1
11

2
1
22

Table 5. Number of biopsy samples collected, by species and Survey.
BiopsyBlue whale
Humpback whale

YS1

YS2

Total

0
4

1
2

1
6

Table 6. Summary of the photo-ID and biopsy experiments. LD: Left dorsal; LL: Left lateral; RD: Right dorsal;
RL: Right lateral; HD: Head; OT: Other.
Photo-ID
resultNumberof biopsy

21
1
1

Number ofindividuals
photographed
21
1
1

LD, RD, FL
LD
LD, RD, FL
RD

0
0
0
0

Humpback

2

2

RD, LD

2

10

Humpback

2

2

LD, RD, FL

2

14
4
6
20
16

Humpback
Blue
North Pacific right
Humpback
Humpback
Humpback

2
1
1
4
1

2
1
1
3
1

RD, LD
RD, LD
HD, OT
RD, LD
FL

0
0
0
0
0

2

2

LD, RD1

HumpbackBlue
Humpback
Humpback

1
1
1
2

1
1
1
2

FL, OTLD
FL, RDFL01
00

Vessels

Date

Sighting
No.

Species

Schoolsize

YS1

21-May12-June12-June13-June1
11
13
1

Humpback
Humpback
Humpback
Humpback

13-June413-June17-June21-June21-June26-May27-May27-May27-May14-June15-June18-June

25
4
5
1

YS2

24

6

Remarks/Sample ID
Mother & calf pair/
J13NYS1H01 (Mother),
J13NYS1H02 (Calf)
J13NYS1H03,
J13NYS1H04
Mother & calf pair/Mother & calf pair/
J13NYS2H01(Mother)
J13NYS2B01-

Figure 1. Pre-determined track line and survey directions for each sub-area (7W, 7E and 8) for this survey.

Figure 2. Positions of blue (blue square), fin (red triangle), North Pacific right (purple circle) and humpback(white circle) whale sightings including searching effort (black line).

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Figure 3. Positions of common minke (pink circle), sei (yellow triangle) and Bryde’s (green square) whalesightings including searching effort (black line).

Figure 4. Positions of sperm (brown triangle) whale sightings including searching effort (black line).

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