SC/63/RMP10SATELLITE TRACKING OF A COMMON MINKE WHALE IN THE COASTAL
WATERS OFF HOKKAIDO, NORTHERN JAPAN IN 2010
Toshiya Kishiro and Tomio Miyashita
National Research Institute of Far Seas Fisheries,
2-12-4 Fukuura, Kanazawa-ku, Yokohama, Kanagawa 236-8648, Japan

Contact e-mail: kishiro@affrc.go.jp
ABSTRACT
Using a research vessel, Shonan-maru No.2, the sighting and satellite tagging survey for common
minke whales was conducted in the coastal waters off Kushiro, southeastern coast of Hokkaido,
northern Japan in 2010 autumn season. The period of survey was from 6 September to 4 October.
During the survey, a total of 878.2 n. miles was searched with the restricted closing mode, and 28
schools/ 30 individuals of common minke whales were sighted (primary sightings: 20/21, secondly
sightings: 8/9). Using a handy air gun, a satellite tag (Argos transmitter) was attached on one
common minke whale in the 15 n. miles offing of Kiritappu on 13 September. The estimated bodylength of the whale was 7.8m. The electric wave reception by the satellite was started on 15
September, and the movement of the whale was tracked for a period of 27 days. Estimated positionof the tagged whale was located in the west coast off the cape of Erimo, and moved to east –west
courses along the coastline. These results suggested that the tagged whale stayed in the coastal
waters off Kushiro, for at least four weeks in autumn season. The tracking results were notcontradicted with the expected migration routes of the whales. The increasing of the tagging
success rate and the extension of the tracking period could bring further information on migratoryroute and the southern breeding area of common minke whales.
KEYWORDS: COMMON MINKE WHALE, NORTH PACIFIC, COASTAL, SATELLITE TRACKING,SIGHTING SURVEY, MIGRATIONINTORODUCTION
Common minke whale, Balaenoptera acutorostrata, is a main target species for the past Japanese coastal
small-type whaling, and the second phase of the Japanese whale research program under special permit in thewestern North Pacific (JARPN II) coastal component. Coastal waters off Kushiro, southeastern part of the
Pacific coast of Hokkaido, northern Japan is one of the major grounds of common minke whales in autumn
season (Miyashita and Hatanaka, 1997), and the JARPN II coastal component off Kushiro had been
conducted annually since 2005 (Kishiro et. al., 2009). During those surveys, the independent dedicatedsighting surveys were often conducted for collecting data related to the distribution and abundance of thecommon minke whales (Kiwada et. al., 2009). However, individual migration manner such as the residence
time of the whales in those waters, and wintering routes and grounds is almost unknown. The former aspect
is important in the ecosystem modeling work in the JARPN II through the estimation of the prey
consumption, and the later aspect is important in considering the stock structure.
The satellite telemetry is an efficient way to investigate the migratory routes and wintering grounds of1

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marine mammals, and recent development of the tagging techniques have given the opportunity toinvestigate them (Mate et.al., 2007; Heide-Jorgensen et al., 2001). In Japan, some satellite tags had beensuccessfully attached using air guns for the coastal Bryde’s whales (Kishiro and Minamikawa, 2006) and theoffshore Bryde’s whales (Nishiwaki et.al. 2009), but common minke whales had not been attached, becauseof the difficulties in approaching them in the western North Pacific, and tagging activity had been a low or
medium priority in the existent sighting survey programs.
In autumn 2010, a dedicated sighting and satellite tagging survey for common minke whales was conductedin the coastal waters off Kushiro. In this program, tagging activity was allocated to even priority with thesighting survey, and one Argos transmitter could be attached on a common minke whale. The present reportsummarizes this cruise and result of the tracking by the Argos satellite-based data collection and location
system.
MATERIAL AND METHODS
Sighting survey
The research area was set in the coastal waters off southeastern Hokkaido from Cape Erimo (143°15’E) to
Cape Nosappu (about 146°00’E) and north of 41°00’N. In the area, three survey blocks (CW, CE, OF
blocks) were established and systematically designed track line were settled in the respective blocks (Fig.1).
The research vessel, Shonan-maru No.2 (712GT, 4,045KW) with a top barrel elevated 20 m above the sea
surface was used. The period of survey was from 6 September to 4 October in 2010. The restricted closing
mode survey was carried out, in which closing was made only for common minke whales, though opportunistic
closing was sometimes carried out. Two observers on the top barrel of the vessel conducted searching by
naked eyes. Species identification was conducted using binocular. Two observers on the upper-bridge also
searched for cetaceans and recorded sighting information. The survey was conducted from 6:00 a.m. to 6:00
p.m. basically when the weather conditions were suitable for observations: visibility better than 1.5 nautical
miles and the wind speed less than 7.5m/s. The vessel speed was 11.5 knots with slight adjustment to avoid
vibration of the vessel.

Satellite tagging
Basically, all common minke whales encountered were targeted for tagging except for the whales sighted in
the survey area of the JARPN II coastal component off Kushiro (area within about 30 nautical miles radiusfrom the Kushiro port). The time for chasing was usually limited to a maximum of 120 minutes against one
animal. The Wildlife Computers Spot-5 implantable tags were used as the Argos transmitter. The tagging dart
system and methods of attachment were followed to the methods developed for the coastal Bryde’s whales
by the NRIFSF (Kishiro and Minamikawa, 2006). A handy air gun with a 40mm-caliber (Miroku Machinery
Co. Ltd) was used for attachment (Fig.2). The filling pressure was set to 110kgf/cm2, and firings were madefrom the forecastle deck when the vessel could adequately approach the whale during the chasing. The
tagging dart consists of a dart with 3-bladed tip, an Argos transmitter, and retrievable float (Fig.3). The float
was connected with dart by aqueous rope. When the whale is hit, the dart becomes embedded in the blubber
and muscle, the float is come off, and antenna of the transmitter is exposed on the body surface. When thewhale is missing, the dart with float can be retrieved. The dart was coated with povidone iodine to mitigate2

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physical damage and potential infection caused by tagging.
RESULTS
Scientists on board
Two scientists were onboard during the survey:
Shigeru Noji (Chief scientist, NRIFSF), Noriko Funasaka (Scientist, NRIFSF)
Cruise itinerary
6 September: The vessel left the Shiogama port, Miyagi Prefecture.
7 September: The vessel arrived at the reseach area, started the survey.
19 September: The vessel arrived at the Kushiro port, Hokkaido.
21 September: The vessel left the Kushiro port, resumed the survey.
2 October: The vessel ended the survey, left the research area.
4 October: The vessel arrived at the Shiogama port.
Sighting results
During the survey, a total of 878.2 nautical miles was searched with the restricted closing mode. Cruise
tracks and sighting positions of common minke whales are shown in Figure 4. Although some track lines
were not searched in southern part of the offshore block (OF block) due to the bat weather condition, the restof all predetermined track lines was searched. Sighting positions of Common minke whales wereconcentrated in the coastal blocks (CW and CE blocks) and no sightings was made in the OF blocks.
Numbers of sightings are given in Table 1. A total of 28 schools/ 30 individuals of common minke whales
were sighted (primary sightings: 20/21, secondly sightings: 8/9). In addition, two schools/ two individuals of
sei whales, six schools/ ten individuals of fin whales, eight schools/ ten individuals of humpback whales, andtwo schools/ six individuals of sperm whales were sighted. Although some humpback whales were sighted in
the coastal blocks, almost all of sightings of large whale species were made in the offshore OF block (Fig. 5).
Tagging activity
Among 30 individuals of common minke whales sighted, only three schools/ three individuals of the whales(10% of all 30 sightings) could be approached within the maximum firing range of the equipment (30m orless). Results of the firings for each individual are shown in Table 2. Among three shots made for thesewhales, one animal was missed with the firing distance of 25m, one animal was ricocheted with the firing
distance of 22m, and one animal was hit with the firing distance of 15m. The time for chasing was ranged
from 47 minutes to 1 hour 18 minutes. One tag was successfully attached on the left side of the dorsal bodysurface anterior to the dorsal fin with near the mid-line of the animals (Fig. 6). The estimated body length of
the tagged whale was 7.8m. The candidate whale swam fast during the chasing, and no behavioral change
was observed during and after the tagging operation.
Signal reception and movements of the tagged whale
The tag was attached on the whale in around 15 nautical miles offing of Kiritappu, southeastern coast of
Hokkaido (42°48.9’N, 145°17.9’ E) on 13 September. The electric wave reception by the Argos satellite
was started on 15 September, and a total of 61 signals were received during the periods from 15 September3SC/63/RMP10

to 31 October (Fig. 7). Among them, a total of nine locations were obtained by the Argos satellite-based datacollection and location system with the accuracy location class of A or B (A; two times, B; seven times). The
movement of the whale was tracked for a period of 27 days until 9 October. At first, estimated position of thewhale was located in the west coast off the cape of Erimo on 3 October (42°05.40’N, 142°14.7’ E; about
262.7km west of the tagging site, and the average daily movement was 13.1km). Then, the whale moved tothe east coast off the cape of Erimo on 6 October, and moved to the coastal waters off Kushiro. After that, it
turned to west to the cape of Erimo, and turned to east to the coastal waters off Kushiro again (Fig. 8). The
total distance travelled was 667.1km, and the average daily movement for the whole period was 25.7km.
DISCUSSION
The present study indicated a first result of the satellite tracking of a common minke whale in the western
North Pacific. Results of the tacking suggested that the whale dose not moved for long distances, andpossibly stayed in the coastal waters off Kushiro, for at least four weeks in autumn season, though sample
size was too small. These results were not contradicted with the expected migration routes of the whales. The
coastal waters off Japan is thought to be located in the migration corridor of north-south migration of maturecommon minke whales, and in general, mature females off Kushiro in autumn is thought to be on the way tothe southward migration from the northern feeding areas to the southern unknown breeding areas. Sex oftagged whale was unknown, but estimated body length (7.8m) suggested the whale was mature. In the waters
off Kushiro, common minke whales frequently take a lot of prey such as walleye pollock, Japanese anchovy,
krill, Pacific saury, and common squid, and distribution of those prey species may attract the whales in thiswaters (Kishiro et. al., 2010). The concentrated distribution of the sightings of common minke whales in the
coastal regions observed in this study (Fig. 4) also implies these aspects, and it is thought that an abundant
prey supply possibly contribute the short residence of the whales in this waters.
During the tracking period, there were only 61 signals received by the satellite, and reception was
sporadic. Low uplink frequency may be caused by low surfacing time of the whale or some mechanicalproblems of the tag at firing or hitting on the whale body. After 1 November or a periods of 49 days from theattachment, no signal has been received by the satellite, and the tag was thought to be fallen out.
In this study, we revealed that a large vessel such as Shonan-maru No.2 could be used as atagging vessel for common minke whales, but the success rate was low. The increasing of the tagging
success rate and the extension of the tracking period could bring further information on migratory route andthe southern breeding area of common minke whales. In addition, simultaneous biopsy sampling will be alsovaluable in considering the migratory route and stock structure of the whales.
ACNOWLEDGEMENTS
We would like to thank all crews and researchers on board R/V Shonan-maru No.2 for their excellent
effort and cooperation during the 2010 sighting and tagging survey cruise off Kushiro.
REFERENCES
Heide-Jorgensen, M.P., Kleivane, L., Oien, N., Laidre, K.L. and Jensen, M.V. 2001. A new technique for
deploying satellite transmitters on baleen whales: Tracking a blue whale (Balaenoptera musculus) in the
North Atlantic. Mar. Mammal. Sci. 17(4): 949-954
Kishiro, T. and Minamikawa, S. 2006. Satellite tracking of Bryde’s whales in the coastal waters of southwestern4

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Japan. Abstract for 2nd Japan Bio-logging symposium in 2006. 11-13p.[in Japanese].
Kishiro, T., Yoshida, H., Goto, M., Bando, T. and Kato, T. 2009. Methodology and survey procedure under the
JARPN II-coastal component of Sanriku and Kushiro-, with special emphasis on whale sampling
procedures. Paper SC/J09/JR3 presented to the JARPN II Review Workshop, Tokyo, January 2009
(unpublished). 27pp.
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, H., Kanaji, Y., Minamikawa, S., Otani, S., Ishikawa,
H., Kanda, N. Gokita, A., Yamazaki, K. and Yonehara, Y. 2010. Cruise report of the second phase of theJapanese Whale Research Program under Special Permit in the western North Pacific (JARPN II) in
2009 (Part II)-Coastal component off Kushiro. Paper SC/62/O6 presented to the IWC ScientificCommittee, May 2010 (unpublished). 13pp.
Kiwada, H., Kumagai, S. and Matsuoka, K. 2009. Methodology and procedure of the dedicated sighting surveys
in JARPN II-Offshore and coastal component of Sanriku and Kushiro-. Paper SC/J09/JR2 presented to
the JARPN II Review Workshop, Tokyo, January 2009 (unpublished). 16pp.
Mate, B., Mesecar, R. and Lagerquist, B. 2007. The evolution of satellite-monitored radio tags for large whales:
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IWC Scientific Committee, May 2009 (unpublished). 7pp.

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Table 1. Number of sightings made by the Shonan-maru No.2 sighting and tagging survey off Kushiro in 2010.

Table 2. Results of the firing of the satellite tags for common minke whales off Kushiro in 2010.

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Fig. 1. Research area and pre-determined track line for Shonan-maru No.2 sighting and tagging survey off
Kushiro in 2010.The satellite tagging was not tried on the dotted track lines (way points 9-15) becauseof the overlap with the survey area of the whale sampling survey of the coastal component JARPN II
survey off Kushiro.

Fig. 2. Air gun used for attachment of the satellite tags.

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Fig. 3. The satellite tag used in this study. Upper photograph indicates the tag with a retrievable float at firing.
Lower photograph indicates the tag without the float.

Fig. 4. Cruise tracks and sighting positions of commom minke whales by the Shonan-maru No.2 sighting andtagging survey off Kushiro in 2010. Open circles: primary sightings; closed circles: secondly sightings.
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Fig.5. Sighting positions of sei, fin, humpback, and sperm whales by the Shonan-maru No.2 sighting and tagging
survey off Kushiro in 2010.

Fig. 6. Common minke whale with the satellite tag attached (White circle) on 13 September
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Fig.7. The electric wave receptions by the Argos satellite

Fig.8. Movements of a common minke whale tagged on 13 September 2010 and tracked until 9 October (27 days).
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