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TECHNICAL REPORTS OF THE
INSTITUTE OF CETACEAN RESEARCHTEREP-ICR
No. 1

The Institute of Cetacean Research (ICR)
Tokyo, 2017

Technical Reports of the Institute of Cetacean Research (2017)p. i

Foreword
It is a pleasure for me to introduce the ﬁrst issue of the Technical Reports of the Institute of Cetacean Research (TEREPICR). The main objective of the TEREP-ICR is to describe and report on the process, progress, or results of technical orscientiﬁc research, or the state of a technical or scientiﬁc research program conducted by the Institute of Cetacean
Research (ICR). To inform a wide audience of the ﬁeld and analytical research activities of the ICR, the TEREP-ICR will be
written in English and will be published in December of each year.
In principle the TEREP-ICR will include two kinds of articles: research articles and commentary articles. In addition,
the TEREP-ICR will publish in each annual issue a summary of international meetings in which ICR scientists have participated, and an updated list of peer reviewed publications based on ICR research. The main focus of the research articles
will be on biological, ecological, stock assessment and resource management research, but studies related to social science will be also included. Articles will be based on data collected by surveys under Special Permit Scientiﬁc research,and other surveys conducted by ICR.
TEREP-ICR is a non-peer reviewed journal, and articles included will be considered as ʻnon-archivalʼ publications, sothat the authors of articles published in the TEREP-ICR will be free to publish them elsewhere in peer-reviewed venues
with or without modiﬁcations.
I sincerely hope that the TEREP-ICR will contribute to increasing understanding of the technical and research activities
conducted by the ICR among the international scientiﬁc community.
Dr. Yoshihiro Fujise
Director General ICRTokyo, December 2017iTechnical Reports of the Institute of Cetacean Research (2017)

p. iii

Editorial
Welcome to the ﬁrst issue of the Technical Reports of the Institute of Cetacean Research (TEREP-ICR). TEREP-ICR is a nonpeer reviewed journal and therefore the contents of the articles published here will be primarily the responsibility of therespective authors. Work by the ICRʼs editorial team is limited to making suggestions of topics for articles and to keeping
editorial consistency among the diﬀerent articles. This ﬁrst issue contains eight research articles and one commentary
article. The ﬁrst research article is an overview of the research programs conducted at the ICR, which provides a generalbackground for the subsequent technical research articles focused this time on ICRʼs main research topics including
stock structure, abundance, biological parameters, feeding ecology and environmental pollutants, in both the Antarctic
and western North Paciﬁc. This ﬁrst issue also includes routine sections to outline the contribution of ICR scientists tointernational meetings in 2017 as well as their contribution in terms of peer reviewed publications up to 2017.
Dr. Luis A. Pastene
Head of Science ICR
Editor TEREP-ICR
Tokyo, December 2017iii

Technical Reports of the Institute of Cetacean Research (2017)

p. v

Contents
Forewordi

Editorialiii

Contentsv

Technical Reports
Tamura, T., Matsuoka, K. and Pastene, L.A. An overview of the research programs on large whales
conducted by the Institute of Cetacean Research

1

Taguchi, M., Goto, M. and Pastene, L.A. What do we know about the stock structure of Antarctic
minke whales in the Indo-Paciﬁc region of the Antarctic? A brief review of methodologies andresearch outputs
15
Bando, T. Laboratory and analytical approaches to estimate biological parameters in the Antarctic
minke whale and summary of results
22
Hakamada, T. and Matsuoka, K. Sighting survey procedures for abundance estimates of large whales
in JARPA and JARPAII, and results for Antarctic minke whales
28
Goto, M., Taguchi, M. and Pastene, L.A. Distribution and movement of ʻOʼ and ʻJʼ stock common
minke whales in waters around Japan based on genetic assignment methods
37
Konishi, K., Isoda, T. and Tamura, T. Overview of stomach content analyses for sei, Brydeʼs and common
minke whales under the oﬀshore component of JARPNII, and temporal changes in feeding habits
44
Yasunaga, G. and Fujise, Y. Temporal trend of total mercury levels in common minke, sei and Brydeʼswhales in the western North Paciﬁc in the period 1994–2014
58

Technical Reports-Note
Goto, M., Taguchi, M. and Oikawa, H. A summary of the genetic samples of large whales collected by
the Institute of Cetacean Research
68

Commentary
Goodman, D. Evolution of the IWC Scientiﬁc Committee

71International meetings

77

Peer-reviewed publications

81

Technical Reports of the Institute of Cetacean Research (2017)

pp. 1–14

Technical Report (not peer reviewed)

An overview of the research programs on large whales conducted by
the Institute of Cetacean Research
Tsutomu Tamura*, Koji Matsuoka and Luis A. Pastene
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: tamura@cetacean.jp

ABSTRACTThis paper summarizes the research programs and related activities conducted by scientists of the Instituteof Cetacean Research (ICR). ICR conducts biological and ecological research of whales and their ecosystemthrough diﬀerent research programs: special permit scientiﬁc programs involving lethal and non-lethal techniques; dedicated sighting survey programs; DNA register for large whales and market molecular monitoring
programs; and cetacean stranding record programs. This paper summarizes those research programs, including their objectives and methodologies. Outputs of speciﬁc studies based on data collected will be publishedin the annual series of the Technical Reports of ICR (TEREP-ICR).

INTRODUCTION
The Institute of Cetacean Research (ICR) was founded in
1987 as a foundational juridical person whose legal statusis authorized by the Minister of Agriculture, Forestry and
Fisheries of the Government of Japan. ICR has the purpose of contributing to the appropriate management andutilization of marine resources by conducting research on
marine mammals centered on whales, and investigationsof the international situation concerning large whales.
The Survey and Research Division of ICR is in charge ofthe biological and ecological research of whales and theirecosystem. The division has well-equipped laboratories
to study whale biology, environmental pollutants andmolecular ecology, and includes a number of national
and international scientists, who conduct speciﬁc studies
in the context of the objectives of the research programs
conducted by the institute.
Outputs of the research are available in a substantial
number of peer-reviewed publications and scientiﬁcdocuments presented to national and international meetings, mainly to meetings of scientiﬁc committees ofinternational organizations in charge of the conservationand management of marine resources including large
whales, for example working groups of the Convention
for the Conservation of Antarctic Marine Living Resources(CCAMLR) and the Scientiﬁc Committee (SC) of the International Whaling Commission (IWC).
The Technical Reports of the ICR (TEREP-ICR) will
publish outputs of speciﬁc studies conducted by ICR

scientists. As an introduction to such outputs, this paper
summarizes the research programs conducted by theinstitute, including their objectives and methodologies.

RESEARCH PROGRAMS
Special permit scientiﬁc research
ICR has been in charge of implementing some special
permit research programs under Article VIII of the International Convention for the Regulation of Whaling(ICRW). These research programs involve both lethal
and non-lethal components. Among the former component, a limited number of whales have been taken. The
research plans have been presented and commented onby the IWC SC, and data and results obtained have beenreviewed by workshops of specialists sponsored by the
IWC SC and by the IWC SC itself.
Antarctic
The ﬁrst program was the Japanese Whale Research Program under Special Permit in the Antarctic (JARPA), which
was conducted between the austral summer seasons of
1987/88 and 2004/05. The JARPA had four main objectives: a) estimation of biological parameters to improve
the stock management of the Southern Hemisphereminke whale; b) elucidation of the role of whales in the
Antarctic marine ecosystem; c) elucidation of the eﬀectof environmental changes on cetaceans; and d) elucidation of the stock structure of Southern Hemisphere minke
whales to improve stock management. The second phaseof JARPA, JARPAII, started with two feasibility surveys in1

Technical Reports of the Institute of Cetacean Research (2017)

the seasons 2005/06 and 2006/07. The ﬁrst full survey
started in the 2007/08 season. The objectives of the
JARPAII were the following: a) monitoring the Antarctic ecosystem (whale abundance trends and biologicalparameters; krill abundance and the feeding ecology ofwhales; eﬀects of contaminants on cetaceans; and cetacean habitat); b) modeling competition among whale
species and future management objectives (constructing
a model of competition among whale species; and new
management objectives including the restoration of thecetacean ecosystem); c) elucidation of temporal and spatial changes in stock structure; and d) improving the management procedure for Antarctic minke whale stocks. See
details of the objectives, methodology and outputs from
JARPAII in Pastene et al. (2014).
The current New Scientiﬁc Whale Research Programin the Antarctic Ocean (NEWREP-A), started in the austral summer season 2015/16 as a 12-year long research
program. NEWREP-A has two main objectives: a) improvement in the precision of biological and ecologicalinformation for the application of the Revised Management Procedure (RMP) to the Antarctic minke whales;
and b) investigation of the structure and dynamics of the
Antarctic marine ecosystem through building ecosystemmodels. In order to attain the ﬁrst objective, four subobjectives were set: (i) abundance estimates for Antarctic
minke whales taking into account of g(0) and additionalvariance; (ii) improvement of precision of biological andecological parameters; (iii) reﬁnement of stock structure
hypotheses of Antarctic minke whale in Areas III–VI for
the implementation of the RMP; and (iv) speciﬁcationof RMP Implementation Simulation Trials (ISTs) for the
Antarctic minke whales (GOJ, 2015). In order to attain thesecond objective, four sub-objectives were set: (i) ecological research (krill abundance estimate and oceanographic observation); (ii) abundance estimate of somecetacean species as input data for ecosystem modelling;(iii) estimation of prey consumption by the Antarctic

Figure 1.
2

minke whale and its nutritional condition; (iv) ecosystemmodelling (spatial interaction among baleen whales andconsideration of predators-prey system and allometricreasoning). See details of the objectives and methodology of NEWREP-A in GOJ (2015).
An outline of the research area, survey methodology
and data being obtained by NEWREP-A are given below.
Research area
The research area of NEWREP-A is shown in Figure 1. The
research area comprises the Indian and western South
Paciﬁc regions of the Antarctic, which involves IWC Management Areas III, IV, V and VI.
Research activities in the ﬁeld based on lethal techniques
The lethal part of NEWREP-A involves the sampling of alimited number of Antarctic minke whales (n=333 whales
annually).
Sampling methodology
Track-lines for sighting and sampling of Antarctic minke
whales are generally designed south of 60°S. Survey
courses are established in oﬀshore and ice edge watersof the research area by the line transect method. Twoor three sampling and sighting vessels advance along
parallel track-lines 7n. miles apart, at a standard speedof 11.5 knots. Basically, each of the sampling and sighting
vessels change the track-line order every day to avoid
possible sighting bias produced by ﬁxed positions. The
starting point each day is set at the most advanced position where one of the vessels ended the surveys on theprevious day. A maximum of two Antarctic minke whales
per school sighted is sampled randomly.
All whales are taken using explosive grenades to attaininstantaneous death in line with existing norms of whale
killing methods. If instantaneous death is not achieved by
the primary killing method, a suitable secondary method,such as a large caliber riﬂe or another grenade is chosen,

Research area of NEWREP-A.

An overview of the research programs on large whales conducted by the Institute of Cetacean Research

Figure 2.

Biological survey of Antarctic minke whale under the NEWREP-A.

depending on the condition of the whale.
Biological surveys
Sampled whales are immediately transported to theresearch base vessel, where biological measurements
and sampling are carried out in a systematic manner by
researchers (Figure 2). The following main data/samples
are obtained on board for each whale sampled (seealso Table 1). Samples and data collected are required
for the analyses related to the main objectives and subobjectives of NEWREP-A.
1. Morphometrics for studies on stock structure.
2. Body weight, blubber thickness and total fat
weight measurements for nutritional studies.
3. Reproductive organs (testis and ovaries) for determination of sexual maturity.
4. Earplugs for age determination.
5. Stomach contents (qualitative and quantitative)
for studies on feeding ecology.
6. Other biological samples such as ocular lenses forage determination and tissues for genetic studies
on stock structure.

Research activities in the ﬁeld based on non-lethal techniques
Dedicated sighting surveys
Data collected by these surveys are required for theabundance estimation of whales. Sighting surveys are
conducted by the Line Transect Method. Survey protocols
follow the IWC SCʼs Requirements and Guidelines for
Conducting Surveys and Analyzing Data within the Revised Management Scheme (IWC, 2012) and are conducted under the oversight of the IWC SC. Sighting protocols
are the same as those in the former International Decadefor Cetacean Research/Southern Ocean Whale and Ecosystem Research (IDCR/SOWER) (Matsuoka et al., 2003).
In general, the sighting surveys cover areas south of
60°S. Surveys are planned to cover one IWC Management
Area (one of the Areas III to VI) in a year. Cruise tracks aredesigned systematically in accordance with mathematicaland scientiﬁc calculation in the research area. The sighting survey is conducted using (1) Closing mode and (2)Passing with Independent Observer mode. Both survey
modes follow the protocol already endorsed for the
IDCR/SOWER surveys. Primary search eﬀort is conducted
only when weather conditions are acceptable (see details
in Matsuoka et al., 2003) (Figure 3).
3Technical Reports of the Institute of Cetacean Research (2017)

Biopsy and photo-ID (Figures 4 and 5)
Biopsy and photo-ID experiments are conducted routinely for large whales such as blue, ﬁn, humpback, southern
right and killer whales. Feasibility studies of biopsy sampling and telemetry for Antarctic minke whales are also
conducted. Photo-ID and DNA data obtained from biopsy
samples are useful for studies of distribution, movement
and stock structure of whales.

Krill survey (Figure 6)
The main objective of the krill surveys is to estimate therelative abundance of Antarctic krill acoustically, and toobtain the length frequency distribution and maturity
stage of Antarctic krill in the survey area. Information
on krill distribution and abundance is important as input
data for the development of ecosystem modelling. Acoustic data using quantitative echosounders EK80 and EK60
are recorded continuously. Net samplings using a small
ring net and an Isaacs-Kidd Midwater Trawl (IKMT) are
carried out to identify species and size compositions ofplankton echo signs. See details in GOJ (2015).
Oceanographic observations (Figure 7)
The conductivity-temperature-depth proﬁlers (CTD) areused to obtain water temperature and salinity data.
Oceanographic data are important to understand thephysical environment in which whales live. Changes inoceanographic conditions determine the distributionof krill, which is the main prey species of large baleen
whales.

Figure 3.

Figure 4.

Sighting activity by the dedicated sighting vessels.

Humpback whale biopsy sampling by the dedicatedsighting vessel.

Marine debris (Figure 8)
The observation and collection of debris, both in theenvironment and in the stomachs of the whales sampledprovide valuable information on the surrounding environment of whales. Such information is collected systematically during the sampling and sighting surveys.
Data and analyses
Table 1 shows the kinds of data and samples being collected by NEWREP-A. These data are analyzed in the context
of the objectives and sub-objectives of the program, withsome of the analyses of temporal trends incorporating
data from the previous research programs JARPA and JARPAII (see details of the data and samples collected by JARPA
and JARPAII in IWC, 2008 and IWC, 2015, respectively).

Figure 5. Morphological characteristics used for individual identiﬁcation in southern right (a) and humpback (b) whales.
4An overview of the research programs on large whales conducted by the Institute of Cetacean Research

Figure 6.

Figure 7.

Figure 8.

Small ring net (left) and an Isaacs-Kidd Midwater Trawl (IKMT) net (right).

Oceanographic survey by CTD.

Rope found in the stomach contents of an Antarctic
minke whale.

Research outputs
As in the cases of JARPA and JARPAII, the scientiﬁc outputs from NEWREP-A will be summarized as a) scientiﬁcreports to be presented to international meetings, mainly
to the IWC SC meetings; and b) as peer-reviewed publications. In the case of the previous JARPA, results were
presented to the IWC SC review workshops conducted
in 1997 (mid-term review) (IWC, 1998) and 2006 (ﬁnal
review) (IWC, 2008). The results of the JARPAII were presented to the IWC SC review workshops conducted in 2014
(IWC, 2015). Peer-reviewed publications based on JARPA
and JARPAII are presented in this issue of TEREP-ICR.

Western North Paciﬁc
The ﬁrst program was the Japanese Whale Research Program under Special Permit in the western North Paciﬁc(JARPN), which was conducted in the spring-autumn seasons between 1994 and 1999. The main objective was toelucidate the stock structure of common minke whales in
the Paciﬁc side of Japan. A second objective, ʻthe feasibility study on the feeding ecology of minke whales in the
research ground,ʼ was added in 1996. The second phaseof JARPN, JARPNII, started with two feasibility surveys in2000 and 2001. The ﬁrst full survey started in 2002. The
objectives of the JARPNII were the following: a) feeding
ecology and ecosystem studies; b) monitoring environmental pollutants in cetaceans and the marine ecosystem; and c) stock structure of large whales. See details of
the objectives, methodologies and outputs from JARPNII
in Tamura et al. (2016).
The current New Scientiﬁc Whale Research Program in
the western North Paciﬁc (NEWREP-NP) started in 2017as a 12-year long research program. NEWREP-NP has two
main objectives: a) contribution to optimizing the establishment of a sustainable catch limit for common minke
whales in the coastal waters of Japan; and b) contribution
to the RMP/IST for North Paciﬁc sei whales. In order toattain the ﬁrst objective, four secondary objectives are
set: (i) investigate the spatial and temporal occurrence ofJ stock common minke whales around Japan, by sex, age
and reproductive status; (ii) estimate the abundance of
the J and O stocks in coastal waters of Japan; (iii) verify
that there is no structure in the O stock common minke
whales in the Paciﬁc side of Japan; and (iv) improve RMP
trials by incorporating age data in their conditioning.
In order to attain the second objective, four secondary
objectives are set: (i) abundance estimates for North Paciﬁc sei whales taking account additional variance; (ii) estimation of biological and ecological parameters in North
Paciﬁc sei whales for RMP Implementation; (iii) study ofthe pattern of movement of whales of the ʻpelagic stockʼwithin the feeding grounds and between feeding and5Technical Reports of the Institute of Cetacean Research (2017)
Table 1
Data and samples collected under the NEWREP-A (from GOJ, 2015).
Data

SampleAbundance estimate*# Weather data*# Eﬀort data*# Sighting record of whales*# Angle and distance experiments*# Ice edge line
Environmental data
# Temp. Salin. (CTD)# Echo sound (krill distribution/abundance)
Marine debris (sea surface)
Antarctic minke whale*# Catching date and location
Photographic record of external character
Record of internal and external parasites*# Sex and body length* Body proportion for stock structure* Skull measurements (length and breadth) for stock structure* Satellite tracking for stock structure# Body weight for feeding ecology# Organ weight including fat weight for feeding ecology# Diatom ﬁlm record for feeding ecology# Blubber thickness for feeding ecology# Stomach content : freshness and weight for feeding ecology# Diving behaviour for feeding ecology*# Testis weight for reproductive study
Mammary grand : lactation status and measurement for
reproductive study
Fetal number, sex, length and weight for reproductive
study
Marine debris (stomach)
Gross pathological observation and sampling
Other large whales
Photo-ID

#
#
*#
*#
*#
*#
*#
*#
*#
#

Prey species in stomach for feeding ecology
Feces and colon contents for feeding ecology
Testis for reproductive study
Ovary for corpora counting and reproductive study
Mammary grand and endometrium for reproductive study
Earplug for age determination
Ocular lens for age determination
Baleen plates for age determination
Tissue samples for genetic study
Tissue and organ samples for chemical study
Tissue and plasma samples for physiological study
Vertebral epiphyses for physical maturity

Skin sample (biopsy)*: Data or samples to be used for Main Objective I; # : Data or samples to be used for Main Objective II (other items will be used
for other research purposes)

breeding grounds; and (iv) speciﬁcation of RMP ISTs forNorth Paciﬁc sei whales. See details of the objectives andmethodology of NEWREP-NP in GOJ (2017).
An outline of the research area, survey methodologies
and data being obtained by NEWREP-NP are given below.
Research area
The research area of NEWREP-NP is shown in Figures 9a
and 9b. The research area for lethal sampling comprises
the Paciﬁc side and the Okhotsk Sea side of Japan, which
involves IWC Management Sub-areas 7, 8, 9 and 11(Figure 10). The research area for the sighting surveys
6comprises the Paciﬁc side, the Sea of Japan side and the
Okhotsk Sea side of Japan, which involves IWC Management Sub-areas 6, 7, 8, 9, 10 and 11.
Research activities in the ﬁeld based on lethal techniques
The lethal part involves the sampling of a limited numberof common minke whales (n=80 whales annually in sub
areas 7CS and 7CN; n=47 whales annually in sub area 11;
and n=43 whales annually in sub areas 7WR, 7E, 8 and 9),
and of sei whales (n=134 whales annually in sub areas
7WR, 7E, 8 and 9).

An overview of the research programs on large whales conducted by the Institute of Cetacean Research

Sampling methodology (oﬀshore component)
Survey courses are established in the research area by
the Line Transect Method. Two sampling and sighting
vessels advance along parallel track-lines 7n. miles apart,at a standard speed of 10.5 knots. All common minke andsei whales sighted as primary and secondary sightings,
excluding cow and calf pairs, are targeted for sampling.
When a sighting consists of more than one animal, theﬁrst targeted animal is selected using tables of random
sampling numbers (TRS).
All whales are taken using explosive grenades to attaininstantaneous death in line with existing norms of whale
killing methods. If instantaneous death is not achieved by
the primary killing method, a suitable secondary method,such as a large caliber riﬂe or another grenade is chosen,
depending on the condition of the whale.
Sampling methodology (coastal component)
A land-based operation system which takes into accountoperational capacity, ability, and arrangements of thesmall boats is applied, and thus is diﬀerent from thesampling procedures adopted by the oﬀshore component. A predetermined course (direction from the port)
at an angle of regular intervals (usually 10–15 degreeintervals) is set up by the head oﬃce, and allocated to
the respective boats. The boats depart the port with theirrespective course, and start searching at a survey speedof 10–11 knots. All common minke whales sighted as
primary and secondary sightings, excluding cow and calf
pairs, are targeted for sampling. When a sighting consistsof more than one animal, the ﬁrst targeted animal is selected using tables of random sampling numbers (TRS).
All whales are taken using explosive grenades to attaininstantaneous death in line with existing norms of whale
killing methods. If instantaneous death is not achieved by
the primary killing method, another grenade is chosen asa suitable secondary method.
Biological surveys
Sampled whales are immediately transported to theresearch base vessel (oﬀshore component) or land base(coastal component), where biological measurements
and sampling are carried out in a systematic manner by
researchers (Figure 11). The kind of data and biologicalsampling is similar to those in NEWREP-A.

Figure 9a.

Research area of NEWREP-NP for lethal sampling(oﬀshore component).

Figure 9b.

Research activities in the ﬁeld based on non-lethal techniques
Dedicated sighting surveys
Sighting surveys are conducted by the Line Transect
Method and the survey protocols are the same as in the
Antarctic dedicated sighting surveys.

Research area of NEWREP-NP for lethal sampling (coastal component).
7

Technical Reports of the Institute of Cetacean Research (2017)

Figure 10.

Sub-areas to be covered by the dedicated sighting surveys under the NEWREP-NP (Sub-areas 6E, 10E, 11,
7CS, 7CN, 7WR, 7E, 8 and 9).

Figure 11.

Biological surveys of sei whales under the NEWREP-NP.

Provided that two dedicated sighting vessels are available, surveys are planned to cover sub-areas 7, 8 and 9
in summer once in three years. Sub-areas 6E, 10E and 11
would be surveyed once in the other three years (Figure 10).
Biopsy and photo-ID
Biopsy and photo-ID experiments are conducted routinely for large whales such as blue, ﬁn, humpback, North
8

Paciﬁc right, gray and killer whales. Feasibility studiesof biopsy sampling for common minke whales are also
conducted. As in the Antarctic, photo-ID and DNA dataobtained from biopsy samples are useful for studies of
distribution, movement and stock structure of thesewhales (Figure 12).

An overview of the research programs on large whales conducted by the Institute of Cetacean Research

Figure 12. Biopsy sampling of a sei whale under the NEWREP-NP.
Figure 14.

Figure 13.

Satellite tagging of sei whales under the
NEWREP-NP.

Satellite tagging
Satellite tagging experiments are conducted for common
minke and sei whales to elucidate movement within thefeeding grounds and the location of breeding grounds(Figure 13).
Oceanographic observations
In the oﬀshore component of NEWREP-NP, oceanographic conditions are investigated using data collectedby ocean circulation models such as FRA-ROMS (Okazaki et al., 2016). In the Sanriku region, the oceanographic surveys are conducted using a trawler-type R/V,
ʻMiyashioʼ (199 GT) by the Miyagi Prefecture Fisheries
Technology Institute. Vertical oceanographic observations are conducted using CTD. Subsurface (approximately 5 m water depth) temperature, salinity and chlorophylla index are recorded every minute along the track-lines.
Marine debris
As noted above, the observation and collection of debris,
both in the environment and in the stomachs of thewhales sampled, provide valuable information on thesurrounding environment of whales. Such information iscollected systematically during the sampling and sighting
surveys of NEWREP-NP (Figure 14).

Plastic bowl found in the stomach of a sei whale.

Data and analyses
Table 2 shows the kinds of data and samples being collected by NEWREP-NP. These data are analyzed in thecontext of the objectives and sub-objectives of the
program, with some of the analyses on temporal trends
incorporating data from the previous research programs
JARPN and JARPNII (see details of the data and samples
collected by JARPN and JARPNII in IWC, 2001 and IWC,
2016a, respectively).
Research outputs
As in the cases of JARPN and JARPNII, the scientiﬁc output
from NEWREP-NP is summarized as a) scientiﬁc reports
to be presented to international meetings, mainly to the
IWC SC meetings; and b) as peer-reviewed publications.
The results of the JARPN were presented to the IWC SC
review workshop conducted in 1999 (IWC, 2001). In thecase of the JARPNII, results were presented to the IWC SC
review workshops conducted in 2009 (mid-term review)(IWC, 2010) and 2016 (ﬁnal review) (IWC, 2016a). Peerreviewed publications based on JARPN and JARPNII arepresented in this issue of TEREP-ICR.
International dedicated sighting surveys
One example of international sighting surveys in which ICR
scientists participate is the IWC-Paciﬁc Ocean Whale andEcosystem Research (POWER) program. The IWC-POWER
program is an international eﬀort coordinated by the IWC
and designed by the IWC SC with special partnership of
the Japanese Government. The vessel is provided by theGovernment of Japan. The IWC-POWER surveys in the
North Paciﬁc follow the series of IWC IDCR/SOWER surveys that were conducted in the Antarctic since 1978. The
IWC POWER program has the following main objectives:(a) provide information for the proposed future in-depth
assessment of sei whales in terms of both abundance andstock structure; (b) provide information relevant to the9Technical Reports of the Institute of Cetacean Research (2017)
Table 2
Data and samples collected under NEWREP-NP, by research objective (from GOJ, 2017).
Data

SampleAbundance estimate
1,2,3
Weather data
1,2,3
Eﬀort data
1,2,3
Sighting record of whales
1,2,3
Angle and distance experiments
Common minke whale/sei whale
1,2,3,4Catching date and location
1
Photographic record of external character
1,2,3,4
Sex and body length
1,2,3Satellite tracking
3,4
Body weight
3,4
Blubber thickness and nutrition condition
3,4
Stomach content: freshness and weight
1,2,3,4
Testis weight
1,2
Fetal number, sex, length and weight4
Marine debris (in stomach)
Other large whales
5
Photo ID1

1,2,3,4
1,2,3,4
1,2,4
1,2,4
1,2,3,4
1,2,4
1,2,3,4
4
3,4

3,5

Testis
Ovary
Earplug
Ocular lens
Baleen plates
Tissue samples for genetic study (including fetus)
Tissue and organ samples for chemical study
Tissue and plasma samples for physiological study
Prey species in stomach

Skin sample (biopsy)

2: Data or samples to be used for Primary Objective I. : Data or samples to be used for Primary Objective II. 3: Data or samples to be used
for Ancillary Objective I. 4: Data or samples to be used for Ancillary Objective II. 5: Data or samples to be used for Ancillary Objective III

Implementation Reviews of whales in terms of both abundance and stock structure; (c) provide baseline information
on distribution and abundance for a poorly known area forseveral large whale species/populations (including thosethat were known to have been depleted in the past, butwhose status is unclear); (d) provide biopsy samples andphoto-identiﬁcation data to contribute to discussions ofstock structure for several large whale species/populationsand (e) provide essential information for the intersessional
workshop to plan for a medium to long term international
research programme in the North Paciﬁc (IWC, 2016b).
Research area
The research area was set north of 20°N, south of the
Aleutian Islands, between 170°E and 135°W in the period
2010–2016 (Figure 15). The research area for the 2017–19 period and agreed by the IWC SC is shown in Figure 16.

Figure 15.

Research area of the IWC POWER program in
2010–2016.

Figure 16.

Research area of the IWC POWER program in
2017–2019.

Research activities
Dedicated sighting surveys
Survey methodology is similar to that described above forthe dedicated sighting surveys in the Antarctic.
Other surveys
Photo-ID and biopsy experiments are conducted forNorth Paciﬁc right, blue, ﬁn, sei, Brydeʼs, gray, humpback,sperm and killer whales. Marine debris information is collected systematically. Acoustic studies using sonobuoys
10An overview of the research programs on large whales conducted by the Institute of Cetacean Research

Figure 17.

Flow chart of the DNA monitoring system for regulation of whale products in the market in Japan.

have also been conducted since 2017.
Data and analyses
The data and samples collected are analyzed in the context of the objectives of the program (see details of thedata and samples collected by IWC-POWER in Matsuoka
et al., 2011, 2012, 2013, 2014, 2015, 2016 and 2017).
Results of analyses are presented to the annual meetingsof the IWC SC and/or published in peer-reviewed journals(e.g. Kanda et al., 2013; 2015; Hakamada et al., 2017).
DNA register and market monitoring
BackgroundThe basic position of the Government of Japan is thatmatters related to regulation of the market for whale
products are outside the jurisdiction of the IWC. Therefore management and regulation of whale products inJapan is carried out by the Government.
As in the case of Norway and Iceland, Japan is usinga DNA-based system for tracking whale products in themarket, and this task has been assigned to the ICR. The
system involves two main components: establishment
and maintenance of a diagnostic DNA register for large
whales and molecular market monitoring through systematic surveys in the retail market (Figure 17).
Technical details of the DNA register for large whales
Source of tissue samples
In Japan there are two main sources of tissue samples oflarge whales: 1) special permit scientiﬁc whaling in the
North Paciﬁc (JARPN/JARPNII and NEWREP-NP) and theAntarctic (JARPA/JARPAII and NEWREP-A), and 2) coastal
by-catches in set nets.
In the case of special permit scientiﬁc whaling, samples
for genetic analysis are collected from each whale by researchers. These involve skin samples (two or three piec-

es of 5×5×5 mm kept in 99% ethanol). A large amountof information of each whale sampled is collected using
established protocols including species name, catch dateand location (longitude, latitude), body length and sex.
The Japanese regulation on by-catches (establishedfrom 1 July 2001) requires that all animals should be DNAregistered before whale meat can be sold in the market.
Details of the regulation and procedure can be found in
the following web page: http://www.icrwhale.org/pdf/
higekujira.pdf.
Skin or muscle samples (5×5×5 cm) are taken by theﬁsherman and sent to the laboratory at the ICR (as frozen
samples). Together with these samples, the ﬁshermen
should provide information following an established protocol including: species, date and location of the by-catch,
type of set net, body length and sex.
Genetic markers
The Japanese DNA register for large whales is composedof three parts: a) an approximately 500 bp fragmentof the 5ʼ-end of the mitochondrial DNA control region,
which is used for the purpose of species identiﬁcation of
unknown whale products, based on phylogenetic analyses; b) a set of nuclear DNA markers (microsatellites:
13–17 loci in each species), which is used for the purposeof individual identiﬁcation; and c) data from Y chromosome DNA, which is used for the purpose of sex identiﬁcation. See details in Pastene and Goto (2006).
Technical details of the market monitoring
Sampling procedure
One or two technicians, who are familiar with market operations, are appointed to carry out the sampling of whale
products in the retail market. In each year, a total of 350
samples have been collected between September and December, involving around 19 cities or towns. Table 3 shows11Technical Reports of the Institute of Cetacean Research (2017)
Table 3The number of whale products by sampling localities and tissue
type purchased in the 2016 survey.
City/Town

Meat

Blubber

Ventralgrooves

Total

SapporoSendai
Niigata
Kanazawa
NotoAnamizu
Nanao
ToyamaHimi
Nagoya
Kochi
Kobe
Osaka
Taiji
Nachikatsuura
Hiroshima
Shimonoseki
Fukuoka
Nagasaki

15
25
4
4
4
1
1
4
2
13
8
13
14
3
4
18
15
13
12

2
3
12
2
5
0
1
0
6
0
9
5
7
6
4
0
8
6
7

13
7
4
1
1
0
0
2
1
4
8
6
7
1
3
3
9
11
13

30
35
20
7
10
1
2
6
9
17
25
24
28
10
11
21
32
30
32

Total

173

83

94

350

an example of cities and whales products sampled in the2016 survey. The sampling attempts to cover the entire
Japanese archipelago but the method of sampling is not a
random procedure. The following information is collected
for each whale product sample: kind of whale product, sampling locality, date, and price. Once sampled, the products
are sent to the laboratory at the ICR for genetic analysis.
Genetic markers
The laboratory work for the whale product samples involves the same genetic markers used for the DNA register, which were explained above.
Outputs
Results of the comparisons between ʻtestʼ (sequencesand genotype of whaleʼs products) and ʻtypeʼ (sequencesand genotype in the register) samples are summarizedin an annual report to the Fishery Agency of the Government of Japan. An example of analyses is available inGoto and Pastene (2000).
Stranding record
Background
The ICR has been recording strandings of marine mam12

mals on the Japanese coast since 1986, with the purposeof obtaining information on their migration and distribution through the record and analysis of samples collectedfrom the stranded animal.
Record procedure
The ICR compiles information on stranding received fromresearchers, government oﬃcials or the general public who
send the information following a protocol and record sheet
developed and distributed by the ICR among Japanese
coastal prefectures, or from other sources such as newspapers. See details on the protocol and data sheet in the following link: (http://www.icrwhale.org/pdf/stranding.pdf).
Together with the stranding record sheet, people arerequested to send skin or muscle samples for genetic analysis in pieces of 5×5×5 mm kept frozen or in 99% ethanol.
The ICR corroborates species identity by DNA analysis.
Outputs
Information on stranding of large cetacean has beenreported to the IWC SC annual meetings on a voluntarybase as Progress Reports on Cetacean Research. Stranding records since 1996 are available in the following link:(http://www.icrwhale.org/zasho2.html).
Data and samples from strandings are available tointerested scientists under the data access protocol of
the ICR.

RESEARCH COLLABORATION
Several aspects of the research programs describedabove are conducted as research collaboration between
the ICR scientists and several Japanese and international
research organizations. Within Japan in particular the
ICR conducts research collaboration with the National
Research Institute of Far Seas Fisheries and with theTokyo University of Marine Science and Technology. A listof peer-reviewed publications derived from research collaborations is included in the relevant section of this issueof the TEREP-ICR. Protocols for data access and research
proposals are available at the ICR Home Page.

FINAL REMARKSThe ICR has been heavily involved in the design andimplementation of several research programs on large
whales and the ecosystem. The ICR will maintain thiseﬀort by continuing the ongoing surveys. A unique andvaluable data base of whale biology and whaleʼs environment has become available. Analyses of these data
have contributed and will continue contributing to theunderstanding of whale biology and ecology, and to theAn overview of the research programs on large whales conducted by the Institute of Cetacean Research

management of whaling on a sustainable basis.

REFERENCES
Goto, M. and Pastene, L.A. 2000. Results of molecular genetic
analyses of whale products collected from the Japanese retailmarkets in 1996 and 1999/2000 surveys. Paper SC/52/SD7
presented to the IWC Scientiﬁc Committee, May 2000 (unpublished). 32 pp.
Government of Japan. 2015. Research Plan for New Scientiﬁc
Whale Research Program in the Antarctic Ocean (NEWREP-A).
IWC.ALL.238, November 2015 (unpublished). 110 pp.
Government of Japan. 2017. Research Plan for New Scientiﬁc
Whale Research Program in the western North Paciﬁc(NEWREP-NP). IWC.ALL.295, June 2017 (unpublished). 190
pp.
Hakamada, T., Matsuoka, K., Murase, H. and Kitakado, T. 2017.
Estimation of the abundance of the sei whale Balaenoptera
borealis in the central and eastern North Paciﬁc in summer using sighting data from 2010 to 2012. Fish Sci. 83(6):887–895.
International Whaling Commission. 1998. Report of theIntersessional Working Group to review data and results from
special permit research on minke whales in the Antarctic,
Tokyo, 12–16 May 1997. Rep. int. Whal. Commn 48: 377–412.
International Whaling Commission. 2001. Report of theWorkshop to Review the Japanese Whale Research
Programme under Special Permit for North Paciﬁc Minke
Whales (JARPN), Tokyo, 7–10 February 2000. J. Cetacean Res.
Manage. (Suppl.) 3: 375–413.
International Whaling Commission. 2008. Report of theIntersessional Workshop to review data and results from special permit research on minke whales in the Antarctic, Tokyo,
7–8 December 2006. J. Cetacean Res. Manage. (Suppl.) 10:
411–445.
International Whaling Commission. 2010. Report of the Expert
Workshop to Review the Ongoing JARPNII Programme. J.
Cetacean Res. Manage. (Suppl. 2) 11: 405–449.
International Whaling Commission. 2012. Requirements
and Guidelines for Implementations under the Revised
Management Procedure (RMP). J. Cetacean Res. Manage.
(Suppl.) 13: 497–505.
International Whaling Commission. 2015. Report of the Expert
Workshop to Review the Japanese JARPAII Special Permit
Research Programme. J. Cetacean Res. Manage. (Suppl.) 16:
369–409.
International Whaling Commission. 2016a. Report of the Expert
Panel of the Final Review on the Western North PaciﬁcJapanese Special Permit Programme (JARPNII). J. Cetacean
Res. Manage. (Suppl.) 18: 527–592.
International Whaling Commission. 2016b. Report of the
Planning Meeting for the 2016 IWC-POWER Cruise, Paper
SC/66b/Rep02 presented to the IWC Scientiﬁc Committee,
May 2016 (unpublished). 15 pp.

Kanda, N., Matsuoka, K., Yoshida, H. and Pastene, L. A. 2013.
Microsatellite DNA analysis of sei whales obtained from the
2010–2012 IWC-POWER. Paper SC/65a/IA05 presented to
the IWC Scientiﬁc Committee, June 2013 (unpublished). 6 pp.
Kanda, N., Matsuoka, K., Goto, M. and Pastene, L. A. 2015.
Genetic study on JARPNII and IWC-POWER samples of sei
whales collected widely from the North Paciﬁc at the sametime of the year. Paper SC/66a/IA08 presented to the IWC
Scientiﬁc Committee, May 2015 (unpublished). 8 pp.
Matsuoka, K., Ensor, P., Hakamada, T., Shimada, H., Nishiwaki,S., Kasamatsu, F. and Kato, H. 2003. Overview of minke
whale sightings surveys conducted on IWC/IDCR and SOWER
Antarctic cruises from 1978/79 to 2000/01. J. Cetacean Res.
Manage. 5 (2): 173-201.
Matsuoka, K, Hakala, S., Kim, H.W., Aki, M. and Shinyasiki, Y.
2011. 2010 IWC/Japan Joint Cetacean Sighting Survey Cruisein the North Paciﬁc. Paper SC/63/O5 presented to the IWC
Scientiﬁc Committee, June 2011 (unpublished). 43 pp.
Matsuoka, K, Mizroch, S., and Komiya, H. 2012. Cruise report ofthe 2011 IWC-Paciﬁc Ocean Whale and Ecosystem Research(IWC-POWER). Paper SC/64/IA5 presented to the IWC
Scientiﬁc Committee, June 2012 (unpublished). 27 pp.
Matsuoka, K., Mizroch, S., An, Y.R., Kumagai, S. and Hirose, K.
2013. Cruise report of the 2012 IWC-Paciﬁc Ocean Whaleand Ecosystem Research (IWC-POWER). Paper SC/65a/IA8
presented to the IWC Scientiﬁc Committee, June 2013 (unpublished). 43 pp.
Matsuoka, K., Kim, H.W., Martinez-Aguilar, S., Kumagai, S.
and Sasaki, Y. 2014. Cruise report of the 2013 IWC-Paciﬁc
Ocean Whale and Ecosystem Research (IWC-POWER). Paper
SC/65b/IA05 presented to the IWC Scientiﬁc Committee, May2014 (unpublished). 24 pp.
Matsuoka, K., Mizroch, S., Taylor, J., Yoshimura, I. and Yamauchi,
Y. 2015. Cruise report of the 2014 IWC-Paciﬁc Ocean Whaleand Ecosystem Research (IWC-POWER). Paper SC/66a/IA5
presented to the IWC Scientiﬁc Committee, May 2015 (unpublished). 24 pp.
Matsuoka, K., Gilpatrick Jr, J. W., Taylor, J., Yoshimura, I.,
Katsumata, T. and Ohkoshi, C. 2016. Cruise report of the2015 IWC-Paciﬁc Ocean Whale and Ecosystem Research(IWC-POWER). Paper SC/66b/IA09 presented to the IWC
Scientiﬁc Committee, May 2016 (unpublished). 31 pp.
Matsuoka, K., Gilpatrick Jr, J. W., Kim, J. and Yoshimura, I. 2017.
Cruise report of the 2016 IWC-Paciﬁc Ocean Whale andEcosystem Research (IWC-POWER). Paper SC/67a/ASI09 presented to the IWC Scientiﬁc Committee, May 2017 (unpublished). 28 pp.
Okazaki, M., Masujima, M., Murase, H. and Morinaga, K. 2016.
Oceanographic conditions in the JARPNII survey area from2000 to 2013 using FRA-ROMS data. Paper SC/F16/JR5 presented to the JARPNII special permit expert panel review
workshop, Tokyo, February 2016 (unpublished). 25 pp.
Pastene, L.A. and Goto, M. 2006. Report of the Scientiﬁc

13

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Committee. Annex N. Report of the working group on stockdeﬁnition. Appendix 3. Status of the Japanese DNA register for large whales. J. Cetacean Res. Manage. (Suppl.) 8:
255–258.
Pastene, L.A., Fujise, Y. and Hatanaka, H. 2014. The Japanese
Whale Research Program under Special Permit in the
Antarctic - Phase II (JARPAII): origin, objectives, research
progress made in the period 2005/06-2010/2011 and relevance for management and conservation of whales andthe ecosystem. Paper SC/F14/J01 presented to the Expert
Workshop to Review the Japanese JARPAII Special Permit

14

Research Programme, February 2014 (unpublished). 76 pp.
Tamura, T., Kishiro, T., Bando, T., Yasunaga, G., Murase, H.,
Kitakado, T. and L. A Pastene. 2016. The Japanese Whale
Research Program under Special Permit in the western North
Paciﬁc Phase-II (JARPNII): results and conclusions in thecontext of the three main objectives, and scientiﬁc considerations for future research. Paper SC/F16/JR1 presented to
the workshop of the Expert Panel of the ﬁnal review on thewestern North Paciﬁc Japanese Special Permit programme(JARPNII), February 2016 (unpublished). 68 pp.

Technical Reports of the Institute of Cetacean Research (2017)

pp. 15–21

Technical Report (not peer reviewed)

What do we know about the stock structure of Antarctic minke whalesin the Indo-Paciﬁc region of the Antarctic? A brief review ofmethodologies and research outputs
Mioko Taguchi*, Mutsuo Goto and Luis A. Pastene
Institute of Cetacean Research, Toyomi-cho 4–5, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: taguchi@cetacean.jp

ABSTRACTThis paper presents a brief review of the studies on stock structure of the Antarctic minke whale conductedunder the Japanese Whale Research Program under Special Permit in the Antarctic (JARPA, austral summer
seasons 1987/88–2004/05) and the Second Phase of JARPA (JARPAII, 2005/06–2013/14), and summarizes themain research ﬁndings. The stock structure of the Antarctic minke whale was examined using genetic and nongenetic approaches. Both research programs were conducted in the International Whaling Commission (IWC)Management Areas IIIE (35°–70°E), IV (70°–130°E), V (130°E–170°W) and VIW (170°–145°W). Both genetics,
i.e., RFLP of the whole mitochondrial DNA (mtDNA), sequencing of mtDNA control region, microsatellite DNA,and non-genetic, i.e., morphometric and mean body length at physical maturity analyses were used. Thesestudies provided evidence for the occurrence of at least two stocks in the research area, which were calledʻeastern Indian Ocean stockʼ (I-stock) and ʻwestern South Paciﬁc stockʼ (P-stock), which overlap geographicallyin the central part of the research area. The results of a modelling approach incorporating genetic and morphometric data suggested that the two stocks have a soft boundary (or area of mixing) mainly in the westernpart of Area V (130°–165°E), which changes by year and sex.

INTRODUCTION
The Antarctic minke whale Balaenoptera bonaerensis(Figure 1), like all the other Southern Hemisphere baleen
whales species apart from the Brydeʼs whale (B. edeni),
was managed by the International Whaling Commission(IWC) on the basis of six geographical ʻAreasʼ (Figure 2).
The IWC established these Areas from the 1974/75 austral summer season, based mainly upon informationfrom Mackintosh (1942; 1966) on distribution of catchesof blue, ﬁn and humpback whales (see review by Donovan, 1991). These Areas were used by the IWC for the
implementation of the New Management Procedure(NMP) on baleen whale species.
However, biological evidence for the particular bound-Figure 1.

aries are weak, especially for those species such as the
Antarctic minke whale, whose data were not consideredwhen the original management Areas were established.
In this regard, important questions were formulated
originally by Hoelzel and Dover (1989): ʻAre the Antarctic
minke whales found in two geographically distinct management Areas from two diﬀerent genetic stocks?ʼ orʻAre individuals from more than one genetic stock present in a particular management Area? If so, what levelof interchange may have occurred between diﬀerent
genetic stocks?ʼ Several approaches were used in the past
to identify genetic stocks of this species in the Antarctic
feeding grounds and to determine to what extent genetic
stocks and IWC management Areas coincide.
Studies on stock structure of the Antarctic minke whale

Antarctic minke whale (Balaenoptera bonaerensis).
15

Technical Reports of the Institute of Cetacean Research (2017)

started at the end of the decade of the 1970ʼs, and resultsof genetic and non-genetic analyses were revised by the
IWC Scientiﬁc Committee (IWC SC) during the comprehensive assessment (CA) of the species in 1990. All theanalyses presented at the CA were based on samples anddata from commercial pelagic whaling in the Antarctic.
The genetic studies were based mainly on allozyme atthat time, although studies based on mitochondrial andnuclear DNA were also conducted, most of the analyses
involved small sample sizes from only Areas IV and V.
Non-genetic studies revised in the 1990ʼs CA involved
morphology, catch and sighting distribution pattern, analysis of Discovery marks and ecological markers. Resultsfrom the diﬀerent approaches failed to unambiguously
identify any isolated stock in the Antarctic (IWC, 1991).
Studies on stock structure under the Japanese Whale
Research Program under Special Permit in the Antarctic(JARPA) started after the CA. It was considered that JARPA
samples were more useful for studies on stock structure
than the commercial samples, given the wider geographi-

Figure 2.

16

IWC Antarctic Areas for the management ofbaleen whale species (except Brydeʼs whale)(Donovan, 1991).

cal coverage of the surveys and that samples were taken
along track-lines in a random mode design. Studies on
stock structure of Antarctic minke whale continued under
the second phase of JARPA (JARPAII).
This paper reviews the studies on stock structure conducted under the JARPA and JARPAII, emphasizing thetechnical aspects and main research outputs.

SAMPLING AND ANALYTICAL APPROACHESJARPAJARPA was conducted during the austral summer seasons
1987/88–2004/05 and the research area was composedof Areas IIIE (35°–70°E), IV (70°–130°E), V (130°E–170°W)
and VIW (170°–145°W) (Figure 2). The main analyticalprocedure used in the genetics and non-genetic studies was hypothesis testing under the null hypothesis of
panmixia.
Genetic approaches
Mitochondrial DNA (mtDNA)
In JARPA, restriction fragment length polymorphisms(RFLP; Box 1.1) was applied for the whole mtDNA (Pastene et al., 1993; 1996). The mtDNA is an extra-chromosomal genome in the cell mitochondria and is inherited
only from the mother. This marker is widely used in constructing intra- and related species phylogenies and inferring evolutionary history.
The mtDNA extracted from a total of 6,256 Antarctic
minke whales was digested with six-base sequence recognition endonucleases (AccI, BanI, EcoRV, HincII, HpaI and
SspI). Restriction fragments were separated by submarine
electrophoresis in 1% agarose gels. After electrophoresis,
the gels were stained with ethidium bromide and wereWhat do we know about the stock structure of Antarctic minke whales in the Indo-Pacific region of the Antarctic?

photographed using Polaroid ﬁlm under an UV irradiation. Distinctive restriction fragment patterns producedby each enzyme were assigned letters. Individuals wereassigned haplotypes consisting of a list of the letters designating the fragment proﬁles produced by each of the six
restriction enzymes. Then, the composite haplotype foreach individual comprises a string of six letters.
Haplotype frequencies were employed to determine
genetic relationships between the samples of the designed strata. Genetic relationships were ﬁrst quantiﬁed using the chi-square statistics for heterogeneity of
mtDNA haplotype frequencies (Roﬀ and Bentzen, 1989).
The level of signiﬁcance obtained by this method is referred to in this paper as the P-value. A P-value smaller
than 0.05 was used as a criterion to reject the null hypothesis of panmixia. Additionally, the quantiﬁcation of
the geographical diﬀerentiation of mtDNA was carriedout using the analysis of molecular variance (AMOVA) of
Excoﬃer et al. (1992).
More detailed descriptions of laboratory and analyticalprocedures were provided in Pastene et al. (1993; 1996).
Microsatellite DNA
In addition to the mitochondrial RFLP analysis, microsatellite analyses (Box 1.2) was also applied on JARPA
samples. Microsatellites are codominant and become apopular marker for many aspects of molecular ecology,
in particular for intraspeciﬁc studies, because of its highmutation rate and polymorphisms compared to othermarkers.
Microsatellite polymorphisms were examined at
six loci in samples from a total of 6,260 minke whales:
EV1, EV104 (Valsecchi and Amos, 1996), GT023, GT211,
GT4195 (Bérubé et al., 2000), and DlrFCB14 (Buchanan
et al., 1996). Polymerase chain reaction (PCR) ampliﬁcations at these loci were performed, which were run withan internal size standard (GENESCAN400HD, Applied Biosystems Japan) using BaseStation100 DNA fragment analyzer. Allelic sizes were determined manually in relation to
the internal size standard and Antarctic minke whale DNAof known size that were re-run on each gel.
The allele frequencies at the six microsatellite lociwere calculated and the departure from expected HardyWeinberg genotypic proportions was tested at each locus
as well as overall loci. The number of alleles per locus,
allelic richness and heterozygosity were also computed.
A conventional hypothesis testing procedure was performed using a heterogeneity test in allele frequencies.
The probability test or Fisherʼs exact test with the Markov chain method was used for the heterogeneity tests
among minke whales in the designed strata. Statisticalsigniﬁcance of the heterogeneity tests was determinedusing the chi-square value obtained from summing thenegative logarithm of P-values over the six microsatellite
loci (Sokal and Rohlf, 1995).
More detailed descriptions of laboratory and analyticalprocedures were provided in Pastene et al. (2006).
Non-genetic approaches
Morphometric analyses
The relationship between body length and longitudinal
strata for ten body measurements of Antarctic minke
whale was investigated using ANCOVA. A cluster analysis was also applied for an estimated average length ofmeasurements to examine the degree of relationships
among whales in six longitudinal strata. A more detailed
description of the analytical procedure was provided in
Hakamada (2006).
Mean body length at physical maturity
Mean body length at physical maturity was comparedamong whales in Areas IIIE, IV, V and VIW for males andfemales. Physically matured individuals were deﬁned as
those with epiphysis fusion occurring in the 6th thoracic
vertebrae. The t-test and ANOVA were used for testing
diﬀerences in mean body length among strata of the
JARPA survey. A more detailed description of the analytical procedure was provided in Bando et al. (2006).
17

Technical Reports of the Institute of Cetacean Research (2017)

JARPAII
JARPAII was conducted during the austral summer
seasons 2005/06–2013/14 in the same research area
covered by JARPA. The analyses on stock structure werereﬁned in two ways: by using additional genetic markers
and by applying new analytical approaches.
Genetic approaches
Mitochondrial DNA control region sequencing
In JARPAII, sequencing analysis (Box 1.3) was performed
instead of the mitochondrial RFLP used in JARPA, which
provides higher resolution.
A 338 bp-segment of the mtDNA control region was
sequenced for a total of 2,278 samples using the primers MT4 (Arnason et al., 1993) and Dlp 5R or P2 developed by the ICR. PCR and subsequent cycle sequencing
reaction for each sample were performed following the
manufactureʼs protocol. The nucleotide sequence of eachcycle sequencing product was determined using Applied
Biosystems 3500 Genetic Analyzer (Life Technology)
under standard conditions. Both strand samples weresequenced in their entirety for all samples.
The statistical approaches used for the RFLP analyses
in JARPA (hypothesis testing) were also adopted for the
mitochondrial control region sequence data analyses.
In addition to this, constructing haplotype network andmismatch distribution analysis were conducted.
More detailed descriptions of laboratory and analyticalprocedures were provided in Pastene and Goto (2016).
Microsatellite DNA
Genetic variation was analyzed at 12 microsatellite loci18

(instead of the six used in JARPA) in a total of 2,551
samples: AC045, AC082, AC087, AC137, CA234, GT129(Bérubé et al., 2005), DlrFCB14 (Buchanan et al., 1996),
EV1, EV104 (Valsecchi and Amos, 1996), GT023, GT195,
and GT211 (Bérubé et al., 2000). Laboratory protocols
were the same as in JARPA.
The statistical approaches used for microsatellite
analyses in JARPA were adopted for the JARPAII microsatellite analyses. In addition to this, the Bayesian clustering
approach using STRUCTURE (Pritchard et al., 2000) wasused to determine the number of genetically distinct
populations present in the samples based on informationon the individual genotypes.
More detailed descriptions of laboratory and analyticalprocedures were provided in Pastene and Goto (2016).
Modelling approach
Schweder et al. (2011) developed an integrated approachfor estimating longitudinal segregation of two stocks
using diﬀerent sources of data: morphometric, microsatellite and mtDNA data. Under this approach, areas ofoverlap between stocks were allowed to vary by year andsex. A joint likelihood function was deﬁned for the estimation of mixing proportions and statistical tests without assuming any baseline populations. The approach
was originally applied to the JARPA data (Schweder
et al., 2011) and subsequently to JARPA and JARPAII data.
More detailed analytical procedure was described in Kitakado et al. (2014).

What do we know about the stock structure of Antarctic minke whales in the Indo-Pacific region of the Antarctic?

SUMMARY OF RESULTS
JARPA
A summary of the results of the analyses on stock structure under the JARPA is shown in Table 1.
Taking all results together, Pastene (2006) suggested
that whales in the eastern part of Area III and westernpart of Area VI were more diﬀerentiated than they wereto whales in the Areas IV and V. Therefore, the author
concluded that the single stock scenario cannot be applied to Antarctic minke whales in the feeding grounds ofAreas IIIE–VIW, and proposed the occurrence of at least
two genetic stocks in the research area. The author alsosuggested that this observation is probably related to thebreeding areas in the eastern Indian Ocean and westernSouth Paciﬁc proposed by Kasamatsu et al. (1995). The
following names were proposed for these stocks by Pastene (2006): ʻEastern Indian Ocean Stockʼ (I-stock) andʻWestern South Paciﬁc Ocean Stockʼ (P-stock).
While the microsatellite and morphometric analyses

were unable to identify any boundary between them, the
mtDNA RFLP analyses suggested that the western part ofArea V was more related to the I-stock than the P-stock,
and a boundary in the sector 150°–160°E was proposed.
This was consistent with the results of mark-recapturethat showed movement of whales through 130°E (division between Areas IV and V). No western boundary of
the I-stock and eastern boundary of the P-stock were
proposed.
JARPAII
The main objective here was to test the stock structure
hypothesis derived from JARPA analyses by using a set of
new genetic samples obtained by JARPAII, and mitochondrial control region sequencing and microsatellite DNA
genotyping.
Results of the heterogeneity test for both markers
showed signiﬁcant genetic diﬀerences between whales
in two sectors, the western (35°–130°E) and eastern(165°E–145°W) research area, conﬁrming that diﬀerent

Table 1
Summary of the results on stock structure in JARPA.
Analytical approaches

mtDNA

Sex

Period of sampling

Pattern of geographical variation

References

F+M

1987/88–2004/2005

IIIE=IVW=IVE
VIW=VE
IIIE, IVW, IVE≠VE, VIW
Possible boundary in the sector 150°–160°E

Pastene et al. (2006)

F

1989/90–2003/2004

IVWN, IVWS≠VE, VIW
Some degree of diﬀerence in haplotype
frequency between Areas IIIE and IVW

M

1989/90–2004/2005

No signiﬁcant diﬀerence in haplotype frequency

F+M

1989/90–2004/2005

IVW≠ VE

F

1987/88–2004/2005

IIIE=IVW=IVE=VW
VIW=VE
IIIE, IVW, IVE, VW≠VE, VIW

M

1987/88–2004/2005

VEN≠VES
IIIE=IVW=IVE=VW
VIW=VEN, VES
IIIE, IVW, IVE, VW≠VEN, VES, VIW

F

1987/88–2004/2005

IIIE=IVW=IVE=VW
VIW=VE
IIIE, IVW, IVE, VW≠VE, VIW

1987/88–2004/2005

IIIE=IVW=IVE
VIW=VE
IIIE, IVW, IVE≠VW, VE, VIW

Microsatellites

MBLM

Morphometrics
M

Pastene et al. (2006)

Bando et al. (2006)

Hakamada (2006)

MBLM indicates mean body length of physically matured whales. A sign ʻ=ʼ means that the statistical test found no signiﬁcant difference at a=0.05
19

Technical Reports of the Institute of Cetacean Research (2017)

Figure 3.

Hypothesis on stock structure of the Antarctic
minke whale. The upper ﬁgure shows the encounter rates of Antarctic minke whales in 10° squaresof latitude and longitude in waters 0–30°S during
October (Kasamatsu et al., 1995). The high sighting
densities in the eastern Indian Ocean and westernSouth Paciﬁc could correspond to breeding groundsof this species. At least two stocks (I- and P-stocks)
occur in the research area of JARPA and JARPAII,
which mix through a transition area. The transitionarea and the mixing rate appears to change by year
and sex (Pastene and Goto, 2016).

stocks inhabit the Indian and Paciﬁc sectors of the Antarctic (I- and P-stocks) (Pastene and Goto, 2016). On theother hand, the STRUCTURE analysis for the microsatellites did not show genetic structuring of this species. Thisobservation is probably due to a very low level of genetic
diﬀerentiation. Microsatellite DNA analyses also showed
more dispersal in males than females, and also some degree of annual variation.
The results of the modelling approach conﬁrmed theoccurrence of at least two stocks (I- and P-stocks) in the
JARPA/JARPAII research area, which could be related tothe suggested breeding areas in the eastern Indian Ocean
and western South Paciﬁc Ocean (Figure 3). Furthermore,
the results indicated that the spatial distribution of thetwo stocks has a soft boundary (or area of mixing) mainly
in Area VW (130°–165°E) (Figure 3), which changes by
year. Results also suggested possible sex diﬀerences in
the pattern of distribution of the two stocks (Kitakado
et al., 2014).

CONCLUSION
In conclusion, stock structure analyses for the Antarctic
20

minke whale conducted under the JARPA and JARPAII
program indicated that the structure of Antarctic minke
whale in Areas IIIE–VIW is more complex than originally
thought: there are at least two stocks (I- and P-stocks),
which overlap geographically in a wide area locatedmainly at 130°–165°E, which changes with year and sex.
Pastene and Goto (2016) postulated that Antarctic
minke whales originating from breeding grounds in thewestern South Paciﬁc (P-stock) have some degree of ﬁdelity to the krill concentration associated with the Ross Sea
Gyre (120°W–180°) (ʻhomeʼ sector). On the other hand,whales originating in the Indian Ocean (I-stock) havesome ﬁdelity to the krill concentration associated withthe gyre located between 90°E and 120°E (ʻhomeʼ sector).
They also postulated that both stocks could expand longitudinally (depending on the particular oceanographic
conditions in a given year) and interact in the middle
sectors and that therefore any boundary (or proportionof the populations in areas with mixing) in the Antarctic
should be considered ʻsoftʼ probably changing annuallyaccording to changes in the oceanographic conditions.

ACKNOWLEDGEMENTS
We gratefully acknowledge the researchers and crew
members that participated in JARPA/JARPAII surveys forthe collection of genetic samples. We thank H. Oikawa(ICR) who collaborated in the process of DNA extraction.
We also thank N. Kanda (JANUS-Japan) for preparing the
microsatellite data set used in this study.

REFERENCES
Arnason, U., Gullberg, A. and Widegren, B. 1993. Cetacean
mitochondrial DNA control region: sequences of all extant
baleen whales and two sperm whale species. J. Mol. Biol.
Evol. 70: 960–970.
Bando, T., Zenitani, R. and Fujise, Y. 2006. A study on stock structure in the Antarctic minke whale from the JARPA researcharea based on analysis of body length of physically matured
whales. Paper SC/D06/J11 presented to the IWC Scientiﬁc
Committee JARPA review meeting, December 2006 (unpublished). 7 pp.
Beebee, T.J.C. and Rowe, G. 2008. An Introduction to Molecular
Ecology 2nd edition. Oxford University Press, New York. 400 pp.
Bérubé, M., Jørgensen, H., McEwing, R. and Palsbøll, P.J. 2000.
Polymorphic di-nucleotide microsatellite loci isolated fromthe humpback whale, Megaptera novaeangliae. Mol. Ecol.
9: 2181–2183.
Bérubé, M., Rew, M.B., Skaug, H., Jørgensen, H., Robbins, J.,Best, P., Sears, R. and Palsbøll, P.J. 2005. Polymorphic microsatellite loci isolated from humpback whale, Megaptera
novaeangliae and ﬁn whale, Balaenoptera physalus. Conserv.

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Genet. 6: 631–636.
Buchanan, F.C., Friesen, M.K., Littlejohn, R.P. and Clayton, J.A.
1996. Microsatellites from beluga whale Delphinapterus
leucas. Mol. Ecol. 5: 571–575.
Donovan, G.P. 1991. A review of IWC stock boundaries. Rep. int.
Whal. Commn (special issue 13): 39–68.
Excoﬃer, L., Smouse, P.E. and Quattro, J.M. 1992. Analysis ofmolecular variance inferred from metric distances among
DNA haplotypes: application to human mitochondrial DNA
restriction data. Genetics 131: 479–491.
Goldstein, D.B. and Schlotterer, C. (eds.). 1999. Microsatellites:
Evolution and Applications. Oxford University Press, Oxford.
368 pp.
Hakamada, T. 2006. Morphometric analysis on stock structurein the Antarctic minke whale based on JARPA samples. Paper
SC/D06/J10 presented to the IWC Scientiﬁc Committee JARPA
review meeting, December 2006 (unpublished). 8 pp.
Hoelzel, A.R. and Dover, G.A. 1989. Molecular techniques for
examining genetic variation and stock identity in cetacean
species. Rep. int. Whal. Commn (special issue 11): 81–120.
International Whaling Commission. 1991. Report of the
Scientiﬁc Committee. Rep. int. Whal. Commn 41: 51–89.
Kasamatsu, F., Nishiwaki, S. and Ishikawa, H. 1995. Breedingareas and southbound migrations of southern minke whales,
Balaenoptera acutorostrata. Mar. Ecol. Prog. Ser. 119: 1–10.
Kitakado, T., Schweder, T., Kanda, N., Pastene, L.A. and Walloe,
L. 2014. Dynamic population segregation by genetics andmorphometrics in Antarctic minke whales. Paper SC/F14/J29
presented to the IWC Scientiﬁc Committee JARPA review
meeting, February 2014 (unpublished). 20 pp.
Lowe, A., Harris, S. and Ashton, P. 2004. Ecological Genetics:
Design, Analysis, and Application. Blackwell Publishing,
Oxford. 326 pp.
Mackintosh, N.A. 1942. The southern stocks of whalebone
whales. Disc. Rep. 22: 197–300.
Mackintosh, N.A. 1966. The distribution of southern blue andﬁn whales. pp. 125–144. In: K.S. Norris (ed.) Whales, Dolphinsand Porpoises. University of California Press, Berkeley and Los
Angeles. xv+789 pp.

Pastene, L.A. 2006. What do we know about the stock structureof the Antarctic minke whale? A summary of studies and hypotheses. Paper SC/D06/J12 presented to the IWC Scientiﬁc
Committee JARPA review meeting, December 2006 (unpublished). 24 pp.
Pastene, L.A. and Goto, M. 2016. Genetic characterization andpopulation genetic structure of the Antarctic minke whale
Balaenoptera bonaerensis in the Indo-Paciﬁc region of theSouthern Ocean. Fish. Sci. 82: 873–886.
Pastene, L.A., Goto, M., Itoh, S. and Numachi, K. 1996. Spatial
and temporal patterns of mitochondrial DNA variation inminke whale from Antarctic Areas IV and V. Rep. int. Whal.
Commn 46: 305–314.
Pastene, L.A., Goto, M. and Kanda, N. 2006. Genetic analysis
on stock structure in the Antarctic minke whales from the
JARPA research area based on mitochondrial DNA and microsatellites. Paper SC/D06/J9 presented to the IWC Scientiﬁc
Committee JARPA review meeting, December 2006 (unpublished). 22 pp.
Pastene, L.A., Kobayashi, T., Fujise, Y. and Numachi, K. 1993.
Mitochondrial DNA diﬀerentiation in Antarctic minke whales.
Rep. int. Whal. Commn 43: 349–355.
Pritchard, J.K., Stephens, M. and Donnelly, P. 2000. Inferenceof population structure using multilocus genotype data.
Genetics 155: 945–959.
Roﬀ, D.A. and Bentzen, P. 1989. The statistical analysis of mtDNA
polymorphisms: chi-square and the problem of small samples. Mol. Biol. Evol. 6(5): 539–545.
Schweder, T., Kitakado, T., Kanda, N., Pastene, L. and Walloe,
L. 2011. Dynamic population segregation by genetics andmorphometrics in Antarctic minke whales. Paper SC/63/IA7
presented to the IWC Scientiﬁc Committee, May 2011 (unpublished). 20 pp.
Sokal, R.R. and Rohlf, F.J. 1995. Biometry: the Principles of
Statistics in Biological Research 3rd edition. Freeman andCompany, New York. 887 pp.
Valsecchi, E. and Amos, W. 1996. Microsatellite markers for the
study of cetacean populations. Mol. Ecol. 5: 151–156.

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Technical Reports of the Institute of Cetacean Research (2017)

pp. 22–27

Technical Report (not peer reviewed)

Laboratory and analytical approaches to estimate biologicalparameters in the Antarctic minke whale and summary of results
Takeharu Bando*
Institute of Cetacean Research, Toyomi-cho 4–5, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: bando@cetacean.jp

ABSTRACTLife history-related biological parameters in marine mammals such as age at sexual maturity and pregnancy
rate are known to change in response to changes in abundance, food availability or competition among species. Therefore, monitoring of biological parameters and investigations of how these parameters change withtime are important information for whale stock assessment and management. This paper presents an outlineof the laboratory and analytical approaches used to estimate biological parameters in large whales and a summary of biological parameters estimated for the Antarctic minke whales based on JARPA and JARPAII biologicalsamples.

INTRODUCTION
Biological parameters such as age at sexual maturity
and pregnancy rate are directly correlated to reproduction of whale stocks. Information on sex ratio and age
at sexual maturity is necessary to assess the proportionof whales which contribute to reproduction; fetus sex
ratio and litter size is information necessary to estimate
the composition of young whales which recruit into thestock. Some of these parameters are known to change
in response to changes in abundance, food availability orcompetition among whale species (Gambell, 1973; Kato,
1986a, 1986b, 1987; Kato and Sakuramoto, 1991; Masaki,
1979; Lockyer, 1972, 1979, 1984a). Therefore, monitoringof biological parameters is indispensable for assessment
and sustainable management of whale stocks (Ohsumi
et al. 1997).
The Antarctic minke whale Balaenoptera bonaerensis
is one of the smallest Balaenopterid species with bodylength generally less than 10 m. Antarctic minke whales
are widely distributed in the Southern Hemisphere, migrating seasonally between feeding grounds in the Antarctic in summer (south of 60°S) and breeding grounds
in the tropical or temperate regions in winter (Perrin
and Brownell, 2009). The Antarctic minke whale was
exploited by commercial whaling in the decades of the1970ʼs and 1980ʼs, until the moratorium on commercial
whaling was implemented in the 1987/88 austral summer season. Given their large abundance, this species is atarget of possible future commercial whaling operations
22

in the Antarctic.
Previous estimates of biological parameters of Antarctic minke whale were based on samples collected during
the commercial whaling period (Ohsumi et al., 1970;
Ohsumi and Masaki, 1975; Best, 1982; Kato, 1982, 1983,
1987; Masaki, 1979). However samples from commercial
whaling are not representative of the stock as whaling operations targeted large individuals concentrated aroundthe ice edge. Therefore biological parameters such as
the age at sexual maturity estimated from those samples
were thought to be biased (Kato, 1982, 1987).
The Japanese Whale Research Program under Special
Permit in the Antarctic (JARPA) was conducted between
the seasons 1987/88 and 2004/05. The main objectiveof JARPA was the estimation of biological parameters
to improve the management of Antarctic minke whales.
Relevant samples and data to estimate several biological parameters were collected systematically throughout
the 18-year research period. Under the JARPA, tracklines were designed in each stratum established in the
research area independently and random sampling was
conducted to ensure representativeness of samples toaccurately estimate biological parameters. Similar procedures were used in the second phase of JARPA (JARPAII).
The International Whaling Commissionʼs Scientiﬁc
Committee (IWC SC) had recommended previously arecalculation of biological parameters of Antarctic minke
whale by biological stock (IWC, 1998). Since then, stock
structure analyses of Antarctic minke whale were reﬁned, and a new stock structure hypothesis proposing an

Laboratory and analytical approaches to estimate biological parameters in the Antarctic minke whale and summary of results

ʻEastern Indian Ocean Stock (I-stock)ʼ (distributed mainly
between 35°–130°E) and a ʻWestern South Paciﬁc Stock(P-stock)ʼ (distributed mainly between 165°E–145°W) in
the Antarctic Ocean, was proposed. Pastene and Goto
(2016) presented the latest genetic analyses in support ofthis hypothesis.
This paper presents an outline of the laboratory andanalytical approaches to estimate biological parametersof large whales and a summary of biological parameters
estimated for the Antarctic minke whales.

MATERIALS AND METHODSThis section summarizes the sampling and analytical procedures used by diﬀerent authors for estimating several
biological parameters in the Antarctic minke whale.
Age determination based on earplugs
One of the most important information obtained by
JARPA and JARPAII was the age of the whales, which was
obtained by examining the internal earplugs of whales.
Sampling at the ﬁeld
The left and right earplugs were collected carefully byresearchers at the ﬁeld, which were immediately ﬁxed in
10% formalin.
Laboratory work
At the laboratory, individual age was determined bycounting growth layers appearing on the bisected surfaceof the earplug using a stereoscopic microscope, assuming
an annual deposition of growth layers (i.e. one pair ofdark and pale laminae accumulated per year) (Figure 1)(Lockyer, 1984b).
Calibration work
The inter-reader variability has been evaluated undersuggestions and guidance from the IWC SC. After such
evaluation, the estimated ages with this variability was in-

Figure 2.

corporated into the Statistical Catch-At-Age (SCAA) analysis (IWC, 2012; Kitakado et al., 2013; Punt et al., 2014),
which was conducted to estimate the historical andcurrent population trajectories of the stocks as well thenatural mortality rates by age classes in the Antarctic
minke whale (see below).
The ages of whales with unreadable earplugs havebeen estimated by applying an age-length-key for the
purposes of the SCAA. In more recent years the racemization technique was developed for the Antarctic
minke whale (Yasunaga et al., 2017) and therefore thistechnique can provide age estimation for unreadable earplugs, which in turn will improve the SCAA performance.
Sexual maturity determination
Sampling at the ﬁeld
Testes samples of about 1.5 cm square were collectedfrom testes from the right side and immediately ﬁxed in
10% formalin. Ovaries from both sides were collected andpreserved at −20°C for later analyses.
Laboratory work
Sexual maturity of males was determined by examinationof histological samples of testes stained by hematoxylineosin. Males with seminiferous tubules over 100 µm
diameter, spermatid or open lumen in the tubules were
determined as sexually mature (Figure 2) (Kato, 1986a;
Kato et al., 1990, 1991). Sexual maturity for females was

Figure 1.

Earplug of Antarctic minke whale.

Histological testis sample of immature (left) and mature (right) Antarctic minke whales.
23

Technical Reports of the Institute of Cetacean Research (2017)

determined by the presence of corpora luteum (CL) or
albicans (CA) in both ovaries (Lockyer, 1984a) (Figure 3).
Physical maturity
Sampling at the ﬁeld
Physical maturity status was identiﬁed by examinationof vertebrae. The fusion of the vertebral epiphysis to thecentrum was known to start at the anterior cervical, thenat the posterior caudal vertebrae, and is completed on
the middle or posterior dorsal vertebrae (Kato, 1988). A
part of the 6th dorsal vertebra which contains cartilage
between centrum and anterior epiphysis was collected
and ﬁxed in the 10% formalin solution.
Laboratory work
Physical maturity was determined by examination of thevertebrae stained by 0.25% toluidine blue-O solution.
Cartilage between epiphyses and centrum was observed
by naked eye or stereoscopic microscope. Whales withthe epiphyses fused to the centrum were deﬁned asphysically mature (Figure 4) (Kato, 1988).

Figure 3.

Y = 1+ e (aX +b ) −1

where Y is the proportion mature at age/body length X,
and a and b are empirical parameters. Age/body length at
50% maturity was calculated as −ba−1.
Age at physical maturity
Age at 50% physical maturity was estimated by logistic
regression analysis based on maximum likelihood. This is
the same as the method for estimation of the age at 50%

Ovary of Antarctic minke whales with corpora lutea (left) and corpora albicantia (right).

Figure 4.
24

Age/length at sexual maturity
Body length and age at sexual maturity was estimated by
two methods. The ﬁrst is the body length and age at ﬁrst
ovulation (Lmov, tmov) (Kato, 1987). Under this method
the mean body length and age were calculated for thewhales with one corpus luteum and no corpus albicans
in both ovaries.
The second method is the body length and age at 50%
sexual maturity (Lm50%, tm50%) (Kato, 1987). Under
this method the body length and age at 50% maturity
was estimated by logistic regression analysis based on
maximum likelihood. The logistic model was ﬁtted to age/body length and sexual maturity rate as:

Vertebra of physically immature (left) and mature (right) Antarctic minke whale.

Laboratory and analytical approaches to estimate biological parameters in the Antarctic minke whale and summary of results

sexual maturity (tm50%).
Growth curve
The von Bertalanﬀy growth model was ﬁtted to the bodylength and age as:(

Lt = L∞ 1 − e− K (t −t0 ))where Lt is the body length at age t, L ∞ is asymptotic
length, K is the growth rate coeﬃcient and t0 is the theoretical time at zero length.
Proportion of pregnant whales in matured females (PPF)
PPF is deﬁned as the proportion of pregnant females
within the sexually matured females.
Annual ovulation rate
Annual ovulation rate was estimated by applying linear
regression analysis between age and total number ofcorpora (CL and CA). Only individuals after the 1970 cohort were used because of the reported decline of age
at sexual maturity (determined from transition phase in
ear plug) from the 1940s to the 1960s cohorts (Kato and
Sakuramoto, 1991; Thompson et al., 1999). The regression line was ﬁtted to age 10 and 30 because almost all
animals are mature at the age of 10 and sample size was
not large enough for ages over 30.
Fetal sex ratio and litter size
Presence or absence of fetus was identiﬁed by cutting
both sides of the uterus horn. Fetus sex was identiﬁedby the appearance of the genital organ. Small fetuses ofwhich sex could not be identiﬁed were excluded from theanalysis.
Natural mortality via SCAA
Natural mortality was estimated by the Statistical Catchat-Age (SCAA) model (Punt et al., 2014). Individual age,abundance and catch history information were incorporated in the SCAA model and age dependent natural
mortality was estimated (Punt et al., 2014).

SUMMARY OF RESULTS
Biological parameters of Antarctic minke whales on stockbasis (Pastene and Goto, 2016) are presented in Table 1.
Both stocks presented similar values for age at sexual andphysical maturity. In both stocks the values were smaller
in males than females.
Remarkable diﬀerences between stocks were found inbody length at sexual maturity (Lmov, Lm50%) and in theasymptotic length calculated from growth curves, which
was about 20 cm larger in I-stock than P-stock for both
sexes. The PPF of both stocks was as high as about 0.9 andannual ovulation rate supported the high pregnancy rate
in both stocks. The fetus sex ratio is almost parity for bothstocks and multiplets are rare in this species.
Age dependent natural mortality was estimated from
SCAA. The pattern was similar between the two stocks
with natural mortality being higher in young and old animals. It was calculated as 0.048 (for age=15) to 0.107 (forage=35) for the I-stock and 0.046 (for age=15) to 0.103

Table 1
Summary of biological parameters of Antarctic minke whales estimated from 1987/88 to 2004/05 JARPA samples.
I-stock (35°E–130°E)

P-stock (165°E–145°W)

Male

FemaleMale

FemaleLt =8.60(1−e−0.272(t+1.97))

Lt =9.16(1−e−0.228(t+2.19))

Lt =8.44(1−e−0.269(t+2.08))

Lt =8.97(1−e−0.203(t+2.90))

16.9

20.8

16.9

20.6

GrowthGrowth curve
Age at physical maturity

50%mature

Sexual maturity
Age at sexual maturity

tmov
tm50%

Body length at sexual
maturity (m)

7.6
5.3

Lmov
Lm50%

7.6

8.5
5.4

8.39 m7.28 m8.20 m8.1
8.32 m

7.14 m

7.99 mReproductive characteristics
Proportion of pregnant inmatured female (%)

92.1%

Annual ovulation rate
Foetal sex ratio
Litter size

87.7%

0.989/year
52.1%

47.9%
1.002

1.005/year
46.8%

53.2%
1.013

25

Technical Reports of the Institute of Cetacean Research (2017)

Figure 5.

Time-trajectories of total (1+) population size
(upper panels), age-speciﬁc natural mortality(center panels), and total (1+) population size relative to carrying capacity (lower panels) for three
ways to model natural mortality (the Siler model,
autoregressive and piecewise linear) of two stocksof Antarctic minke whale (from Punt et al., 2014).
Biological data obtained from both JARPA and
JARPAII were used in the SCAA.

(for age=35) for P-stock (Figure 5) (Punt et al., 2014).
Time-trajectories derived from SCAA showed that total
population size of Antarctic minke whale increased until
1970ʼs and then declined until 2000ʼs for both stocks (Figure 5) (Punt et al., 2014).

DISCUSSION
At present examination of earplugs is the only practicablemeans to obtain age data at the annual scale. The earplug
has proved to be a valid and useful tool for age determination (Lockyer, 1984b), and is the only method providing
age data accurate enough for population-level analyses
such as the SCAA of Antarctic minke whales. Because
there are a number of whales sampled with unreadable
earplugs, the feasibility of other ageing techniques isbeing investigated by ICR scientists such as that based on
enantiomers of aspartic acid in eye lens, which are measured using high performance liquid chromatography (Yasunaga et al., 2017) and the DNA methylation approach
which was applied to humpback whale (Polanowski
et al., 2014). Potentially these techniques could complement the age information obtained from earplugs.
26

Age and other reproductive data obtained by JARPA
and JARPAII enabled the estimation of important biological parameters in the Antarctic minke whale, which
are signiﬁcant for assessment and management of thisspecies in the Antarctic. Of particular importance was
the estimate of age-speciﬁc natural mortality rate (Puntet al., 2014) in this species, which was one of the main
research objectives of JARPA.
Another important aspect was that the estimation of
biological parameters was made on the basis of biologicalstocks and not on the basis of politically-based geographical boundaries. It was found that some biological parameters diﬀered between stocks.
Some of the biological parameters are known tochange in response to changes in abundance, food availability or competition with other species (Gambell, 1973;
Lockyer, 1979; Kato, 1986b, 1987). Monitoring of biological parameters is useful for understanding of the present
status of stocks and to predict future trends, which areessential for sustainable management of whale stocks.
Moreover, information on biological parameters is useful
to improve the performance of the Revised Management
Procedure (RMP).

ACKNOWLEDGEMENTS
Sincere thanks are due to all researchers and crews who
participated in the JARPA/JARPAII surveys.

REFERENCES
Best, P.B. 1982. Seasonal abundance, feeding, reproduction,
age and growth in minke whales oﬀ Durban (with incidental
observations from the Antarctic). Rep. int. Whal. Commn 32:
759–786.
Gambell, R. 1973. Some eﬀects of exploitation on reproductionin whales. J. Reproduct. Fert. (Suppl.) 19: 533–553.
International Whaling Commission. 1998. Report of the
Scientiﬁc Committee. Rep. int. Whal. Commn 48: 53–127.
International Whaling Commission. 2012. Report of the
Scientiﬁc Committee. J. Cetacean Res. Manage. (Suppl.) 13:
1–73.
Kato, H. 1982. Some biological parameters for the Antarctic
minke whale. Rep. int. Whal. Commn 32: 935–945.
Kato, H. 1983. Some considerations on the decline in age atsexual maturity of the Antarctic minke whale. Rep. int. Whal.
Commn 33: 393–399.
Kato, H. 1986a. Study on changes in biological parameters andpopulation dynamics of southern minke whales. Doctoral
Thesis, Hokkaido University. 145 pp. (in Japanese).
Kato, H. 1986b. Changes in biological parameters of
Balaenopterid whales in the Antarctic, with special reference
to southern minke whale. Mem. Natl. Inst. Polar Res. (Special

Laboratory and analytical approaches to estimate biological parameters in the Antarctic minke whale and summary of results

Issue 40): 330–344.
Kato, H. 1987. Density dependent changes in growth parameters of the southern minke whale. Sci. Rep. Whales Res. Inst.
38: 47–73.
Kato, H. 1988. Ossiﬁcation pattern of the vertebral epiphyses
in the southern minke whale. Sci. Rep. Whales Res. Inst. 39:
11–19.
Kato, H. and Sakuramoto, K. 1991. Age at sexual maturity ofsouthern minke whales: a review and some additional analyses. Rep. int. Whal. Commn 41: 331–337.
Kato, H., Kishino, H. and Fujise, Y. 1990. Some analyses on age
composition and segregation of southern minke whales
using samples obtained by the Japanese feasibility study in
1987/88. Rep. int. Whal. Commn 40: 249–256.
Kato, H., Fujise, Y. and Kishino, H. 1991. Age structure and segregation of southern minke whales by the data obtained during
Japanese research take in 1988/89. Rep. int. Whal. Commn
41: 287–292.
Kitakado, T., Lockyer, C. and Punt, A.E. 2013. A statistical modelfor quantifying age-reading errors and its application to the
Antarctic minke whales. J. Cetacean Res. Manage. 13(3):181–190.
Lockyer, C. 1972. The age at sexual maturity of the southern ﬁnwhale (Balaenoptera physalus) using annual layer counts inthe ear plug. J. Cons. Int. Explor. Mer. 34(2): 276–294.
Lockyer, C. 1979. Changes in a growth parameter associatedwith exploitation of southern ﬁn and sei whales. Rep. int.
Whal. Commn 29: 191–196.
Lockyer, C. 1984a. Review of baleen whale (Mysticeti) reproduction and implications for management. Rep. int. Whal.
Commn (Special Issue 6): 27–50.
Lockyer, C. 1984b. Age determination by means of the earplug
in baleen whales. Rep. int. Whal. Commn 34: 692–696.
Masaki, Y. 1979. Yearly change of the biological parameters
for the Antarctic minke whale. Rep. int. Whal. Commn 29:

375–395.
Ohsumi, S. and Masaki, Y. 1975. Biological parameters of the
Antarctic minke whale at the virginal population level. J. Fish.
Res. Board Can. 32: 995–1004.
Ohsumi, S., Masaki, Y. and Kawamura, A. 1970. Stock of the
Antarctic minke whale. Sci. Rep. Whales Res. Inst. 22: 75–125.
Ohsumi, S., Tanaka, S. and Kato, H. 1997. A review of the studies on estimation of biological parameters conducted under
the Japanese Whale Research Program under Special Permit
in the Antarctic (JARPA). Paper SC/M97/2 presented to
the IWC Intersessional Working Group to Review Data andResults from Special Permit Research on Minke whales in the
Antarctic, May 1997 (unpublished). 25 pp.
Pastene, L.A. and Goto, M. 2016. Genetic characterization andpopulation genetic structure of the Antarctic minke whale
Balaenoptera bonaerensis in the Indo-Paciﬁc region of theSouthern Ocean. Fish. Sci. 82: 873–886.
Perrin, W.F. and Brownell Jr, R.L. 2009. Minke whales(Balaenoptera acutorostrata and B. bonaerensis). In: Perrin,
W.F. et al. (Ed.) Encyclopedia of marine mammals (2nd ed.).
Elsevier, New York, pp. 733–735.
Polanowski, A.M., Robbins, J., Chandler, D. and Jarman, S.N.
2014. Epigenetic estimation of age in humpback whales. Mol.
Ecol. Resour. 14: 976–987.
Punt, A.E., Hakamada, T., Bando, T. and Kitakado, T. 2014.
Assessment of Antarctic minke whales using statistical catchat-age analysis (SCAA). J. Cetacean Res. Manage. 14: 93–116.
Thomson, R.B., Butterworth, D.S. and Kato, H. 1999. Has the age
at transition of southern hemisphere minke whales declined
over recent decades? Marine Mammal Science 15: 661–682.
Yasunaga, G., Pastene, L.A., Bando, T., Hakamada, T. andFujise, Y. 2017. Age estimation of Antarctic minke whales
Balaenoptera bonaerensis based on aspartic acid racemization technique. Fish. Sci. 83: 947–954.

27

Technical Reports of the Institute of Cetacean Research (2017)

pp. 28–36

Technical Report (not peer reviewed)

Sighting survey procedures for abundance estimates of large whales
in JARPA and JARPAII, and results for Antarctic minke whales
Takashi Hakamada* and Koji Matsuoka
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: hakamada@cetacean.jp

ABSTRACTThis paper provides an overview of the sighting surveys and analytical procedures for abundance estimates oflarge baleen whales under the non-lethal component of JARPA/JARPAII. The paper also summarizes the abundance estimates and abundance trends for Antarctic minke whales based on sighting data collected by JARPA
and JARPAII surveys between 1989/90 and 2008/09.

INTRODUCTION
There are two main sources of sighting data for abundance estimates of large whales in the Antarctic. One
is the International Decade for Cetacean Research(IDCR)/Southern Ocean Whale and Ecosystem Research(SOWER) program (Matsuoka et al., 2003), and the otheris the sighting surveys conducted as part of the non-lethal
component of the Japanese Whale Research Programs in
the Antarctic (JARPA, JARPAII and NEWREP-A).
One of the features of the sighting surveys under theJapanese whale research programs is that, unlike the
IDCR/SOWER program, surveys are repeated in the same
area and in the same months every second austral summer season, over a long period. Therefore, those sighting
surveys facilitate both estimations of abundance trends
and the extent of inter-year variability in local abundance
in a particular area.
The objective of this paper was to outline the sighting procedures adopted during JARPA/JARPAII and theanalytical procedures used to estimate whale abundance
and abundance trends from sighting data. A summary of
the results for Antarctic minke whales based on the JARPA
and JARPAII sighting data is also presented. Surveys andanalytical procedures used took into consideration therecommendations from the Scientiﬁc Committee (SC) of
the International Whaling Commission (IWC) (see IWC
2008, pp. 349).

MATERIALS AND METHODS
Survey area and geographical stratiﬁcation
The main research areas were IWC Management Areas
IV (70°E–130°E) and V (130°E–170°W) until 1994/95.
28

Since 1995/96 the sighting surveys also covered Areas
IIIE (35°E–70°E) and VIW (170°W–145°W), south of 60°S.
Each of these Areas was divided into smaller strata as
shown in Figure 1. The surveys were conducted fromthe end of December to March in each austral summer
season, with the surveys in Areas IV and V concentrated
in January and February in most years, which coincides
with the peak period for migration of Antarctic minke
whales to their Antarctic feeding grounds (Kasamatsu
et al., 1996). The starting and ending dates in JARPA/JARPAII surveys are shown in Figure 2.
Research vessels
JARPA/JARPAII comprised a combination of sighting
and sampling surveys, and several specialized vessels
participated in the surveys as Sighting Sampling Vessels (SSVs) and Sighting Vessels (SVs). Kyo-Maru No. 1,
Toshi-Maru No. 25 and Toshi-Maru No. 18 operated from
1989/90. Kyoshin-Maru No. 2 operated since 1995/96.
Yushin-Maru operated since the 1998/1999 survey as thereplacement of Toshi-Maru No. 18. Yushin-Maru No. 2 operated since the 2001/2002 survey as the replacement ofToshi-Maru No. 25. Yushin-Maru No. 3 operated since the
2007/2008 survey as the replacement of Kyo-Maru No. 1.
Kaiko-Maru operated from 2005/06 to 2008/09 surveys.
Details of the vessels were provided in Matsuoka et al.
(2011) and Hakamada et al. (2013).
Line transect method
Tracklines are designed randomly or systematically sothat they are independent from distribution of the objects (e.g., whales). Tracklines consist of parallel lines orzigzag lines as shown in Figure 3. In shipboard or aerialSighting survey procedures for abundance estimates of large whales in JARPA and JARPAII, and results for Antarctic minke whales

Figure 1.

Research area for the sighting surveys under the JARPA/JARPAII. Dotted lines indicate 45n.mile lines fromthe ice edge lines.

Figure 2.

Starting and ending dates of JARPA/JARPAII sighting surveys for abundance estimation of large whales inAreas IV and V.

Figure 3.

Example of zigzag lines used during a line transect
survey.

surveys, there is signiﬁcant cost for travelling from one
transect to another. In such circumstance, zigzag lines(or saw-tooth line) are used to save costs (Buckland
et al., 2015).
During the line transect survey, observers on the
research vessels search for whale schools from the platforms on the research vessels (Figure 4). When a whale
school is detected, the distance between the school andFigure 4.

Platforms of observation of whale schools in specialized vessels used during JARPA and JARPAII.

the observer (r), and the angle from the track line (θ) arerecorded (Figure 5). Position of the research vessel andtime of the detection are also recorded.
After the detection of a whale school, in principle, thevessels approach the school to conﬁrm the species and29

Technical Reports of the Institute of Cetacean Research (2017)

school size. Activities of the research vessel are recorded
to calculate distance and time on-eﬀort. Weather (e.g.,
air temperature, sea surface temperature, Beaufort scale,visibility etc.) are recorded every hour during sighting
surveys to record the weather condition that could potentially aﬀect the detectability.
Trackline design and sighting procedures in JARPA/
JARPAII
Survey design and procedures used under JARPA and
JARPAII fundamentally followed the ʻRequirements
and Guidelines for Conducting Surveys and Analyzing
Data within the Revised Management Scheme (RMS)ʼ
(IWC, 2012). More details on trackline design and sighting
procedures in JARPA and JARPAII are found in Hakamada
et al. (2013) and Hakamada and Matsuoka (2014a). The
Sighting Vessels (SVs) conducted the surveys in closing

Figure 5.

Illustration of the detection of whales from observers on research vessels. Black hexagon indicatesa research vessel, white circle indicates a whale
school, horizontal line indicates a trackline, r is distance to the whale school from the research vessel,
θ is an angle from the track line and x is perpendicular distance from the trackline.

Figure 6.

30

mode (SVC) up to and including 1996/97. Surveys inpassing mode (SVP) started in 1997/98 because previous
studies (Butterworth and McQuaid, 1986; Haw, 1991)
had shown potential eﬀect on abundance estimate of thesurvey mode.
The trackline was designed to cover the whole research area and the design was consistent throughout
the JARPA and JARPAII surveys. The starting points wereselected at random from 1n.mile intervals on lines of longitude. Trackline way points (where the trackline changes
direction) were systematically allocated on the ice edge
and on the locus of points 45n.miles from that edge insouthern strata, and on this locus and the 60°S latitude
line in the northern strata.
There were two modiﬁcations in trackline design in
JARPAII surveys in relation to the previous JARPA, which
responded to recommendations from the IWC SC to
improve abundance estimation. One is that a saw-toothtype trackline for the southern strata was not used. The
other is that the northern and southern strata weresurveyed in the same period (Nishiwaki et al., 2014). As
noted above, JARPA/JARPAII comprised a combination ofsighting and sampling surveys using SSVs and SVs. SSVs
and SVs surveyed the area independently. An example
plot of sightings on tracklines actually surveyed is shownin Figure 6.
Smearing parameters and truncation distanceThe data recorded for radial distance and angle aresmeared using the Method II of Buckland and Anganuzzi(1988). The smearing parameter values were estimatedfor Antarctic minke (Hakamada et al., 2013; Hakamada
and Matsuoka, 2014a) whales. After the smearing, theperpendicular distances are truncated at 1.5n.miles for
Antarctic minke whales. This treatment is the same as

Primary searching eﬀort (thin lines) and associated primary sightings of Antarctic minke whales (pinkcircles) in Area IV together with the ice edge (dotted blue line) in the 2005/06 JARPAII survey.

Sighting survey procedures for abundance estimates of large whales in JARPA and JARPAII, and results for Antarctic minke whales

the one employed in abundance estimation from the IWC
IDCR/SOWER surveys (Branch and Butterworth, 2001a;
Branch, 2006). The number of sightings remaining aftersmearing and truncation includes sightings with both
conﬁrmed and unconﬁrmed school sizes.
Correction of observed angle and distance
To be able to correct for bias in distance and angle estimation, a distance and angle estimation experiment
was conducted on each vessel each year (Nishiwaki
et al., 2014). The correction factors estimated in Matsuoka et al. (2011) and Hakamada and Matsuoka (2014b)
were used for these analyses. More details of the methodology for the estimation of the correction factors arefound in Burt and Stahl (2000).
Abundance estimation
The methodology for abundance estimation used in thisstudy is described by Branch and Butterworth (2001a;
2001b) and Branch (2006), and has been termed theʻstandard methodologyʼ in the IWC SC terminology. The
program DISTANCE ver. 6.0 (Thomas et al., 2010) wasused to provide abundance estimates corresponding toeach trackline. The following equation was used for abundance estimation in each stratum:Pi =AE ( s)ni
2wLi

(1)

where Pi is the abundance in numbers as estimated fromthe i th trackline, A is the open ocean area of the stratum,
E(s) is the estimated mean school size, ni is the numbersof primary sightings of schools on the i th trackline,w isthe eﬀective search half-width for schools and Li is theprimary search eﬀort on the i th trackline.
For SSVs, the total abundance in each stratum is calculated as:

L P
i i

P=

i

(2)

L
where L is sum of the Li for each of the SSVs in the stratum.
The CV of the total abundance estimate P, is then calculated for each stratum using the equation:2 n 
2
2
CV ( P ) = CV    +{CV ( E ( s ))} +{CV ( w)} (3)
L





where n is the sum of ni for all the SSVs. Estimation of the
CV of n/L is as speciﬁed in equation (5) below.

Detection function
A hazard rate model with no adjustment terms was used
for the detection function:  y  − b g ( y ) = 1 − exp  −   a   (4)

where y is perpendicular distance, and a>0 and b≥1 areparameters of the model to be estimated. It is assumed
here that g(0)=1 (i.e. the detection probability of a schoolon the track line is 1). Detections with perpendiculardistances of more than 1.5 n.miles were truncated whenestimating eﬀective search half-width (ESW) w. More details of this detection function are given in Buckland et al.
(1993; 2001).
Stratiﬁcation of data to estimate ESW
In line with an IWC (2008) recommendation, ESWs were
estimated by stratum. In cases where the sample size wassmaller than 15, the sighting data were pooled among
strata to estimate the detection function in line withother IWC (2008) recommendations. In such cases, data
were pooled across West-East strata because sighting
conditions and school size distributions are expected tobe more similar than for North-South strata. In instanceswhere there were less than 15 detections in southern/
northern strata, data were aggregated over the whole ofeach Area.
Estimated mean school size
In line with an IWC (2008) recommendation, meanschool sizes were estimated by stratum. Only the primary sightings for which the school size was conﬁrmed
were used for the estimation. The method for estimation of the mean school size described in Buckland et al.
(1993; 2001) was used. More speciﬁcally, regressions of
the log of observed school size against f(y) was conducted
for this purpose. If the regression coeﬃcient was not signiﬁcant at the 15% level, the observed mean school sizefor sightings within the truncated distance was substituted instead in the equation (1). If the consequent meanschool size estimated was less than 1, then the observed
mean school size was substituted instead in the equation (1) even if the regression coeﬃcient was statisticallysigniﬁcant at this 15% level. Similarly to the analyses for
the IDCR/SOWER data (Branch and Butterworth, 2001a;
Branch 2006), for SVP the mean school size estimatedfrom SVC data was used instead of estimating this from
SVP data, for which school size estimates are known tobe negatively biased as a result of not approaching all31Technical Reports of the Institute of Cetacean Research (2017)

schools closely (Butterworth and McQuaid, 1986).
Combined encounter rate taking account of correlation
among two or three SSV track lines
The survey by the SSVs comprised two or three parallel tracklines. There may be a positive correlation in theencounter rates along these lines, which would cause anegative bias in the estimate of the CV of the overall encounter rate if the results from each vessel were assumed
to be independent. To take this possible covariance into
account, the CV of the encounter rate when combinedover the two or three SSVs with their parallel tracklines
was estimated as:n
Var  n
LCV   =
n
L
L

(5)

where
ni =

n , L =L
i, j

i

j

i, j

j

with ni,j and Li,j being the number of primary sightings ofminke whale schools and the primary eﬀort on the i thtransect as surveyed on the j th tracklines. The varianceof (n/L) is calculated as:2k1  Li   ninn
Var   =
 L  L − L
L
k
−
1
(
)
i
  i=1
  




2

(6)

where k is the number of transects on each trackline.
Estimating abundance trend
In order to examine the potential eﬀect of survey timing
and that of survey mode, the four models shown below
were considered.
Model i) log { Pobs ( y, a)} =log { ptrue (0, a )} + αy + ε y ,a + ηy ,a(7)Model ii) log { Pobs ( y, a)} =log { ptrue (0, a )} + αy + M + ε y ,a + ηy ,a(8)Model iii) log { Pobs ( y, a)} =log { ptrue (0, a )} + αy + M +T + ε y ,a + η y ,a(9)Model iv) log { Pobs ( y, a )} =log { ptrue (0, a )} + αy + M +T + a * T + ε y ,a + ηy ,a (10)where y is the year, a is the stratum, Pobs(y,a) is the observed abundance estimate in stratum a and in year y as
obtained from the line transect analyses, Ptrue(y,a) is the32

underlying abundance (i.e. free from the eﬀect of surveymode) which is to be estimated in year y and in stratum a,
M is the survey mode factor, T is the categorical variable
related to survey time as deﬁned below, a*T is an interaction between strata and survey timing, ε y,a is an error
reﬂecting the sampling error of the survey abundance
estimate in year y and stratum a and η y,a is a normally
distributed error with mean of 0 and variance of σ 2 associated with “model error.”
The middle day of the survey period in each stratum
was calculated and categorized into groups as a basis tospecify T. Because the estimate of trend α might be sensitive to the deﬁnition of T, four grouping were considered:
1) T=1: Dec 1–Jan 15, T=2: Jan 16–31, T=3: Feb 1–15,
T=4 Feb 16–Mar15 (Grouping T1)
2) T=1: Dec 1–Jan 15, T=2: Jan 16–Feb 15 and T=3: Feb
16–Mar 15 (Grouping T2)
3) T=1: Dec, T=2: Jan, T=3: Feb and T=4: Mar (Grouping T3)
4) T=1: Dec and Jan and T=2: Feb and Mar (Grouping T4)
The groups in bold letters were included in the intercept of the alternative models considered (i.e. the eﬀectof those groups is set to zero in the calculations). T1–T4
were used as categorical covariates in Models iii) and iv)(equations (9) and (10)) above. The best grouping wasselected by comparing the corrected AIC (AICc) (Sugiura,
1978; Hurvich and Tsai, 1989; 1991), which can be applied to linear models with normal errors, and is used instead of Akaike Information Criterion (AIC) (Akaike, 1973)
for each model.
Correction of nominal abundance estimates and theirvariance-covariance matrices
Using the estimated coeﬃcients of models i)–iv), nominal
abundance estimates for each survey mode can be corrected, and the weighted average of the corrected abundance estimates for each mode were calculated. Amongthe weighted average of the abundance estimates, thatusing correction factors based on the best model istreated as ʻBase case.ʼ Further details are provided in
Hakamada et al. (2013).
Sensitivity analyses
There are various possible sources of bias in abundance
estimates and their trends, the more important of whichwere discussed at the IWC SC meeting in 2007 (IWC,
2008; Table 1). In order to examine their possible magnitudes, sensitivity analyses to examine robustness ofabundance estimates and trend were conducted.

Sighting survey procedures for abundance estimates of large whales in JARPA and JARPAII, and results for Antarctic minke whales
Table 1
List of the factors for which the sensitivity of abundance estimates and/or trends is examined. Speciﬁcations are given for both thebase case and the sensitivities, with more details provided in Hakamada et al. (2013) and Hakamada and Matsuoka (2014a).
Sensitivity factors

Speciﬁcation for the base caseSpeciﬁcation for sensitivities

Estimation by stratum, except that For SSVs, ESW averaged over vessels concerned wasused. For SVs the detection function estimation
when sample size is less than 15,
takes account covariates.
strata are pooled.
Trackline following ice edge Complete tracklines used.
(1) Exclude trackline segments along the ice edge
contours(Option B). (2) Use only transects parallel to lines oflongitude (Option C).
Abundance in gaps between Assume same density as in stratum to (1) Assume the density is 0. (2) Assume the same dennorthern and southern strata
the north.
sity as in the stratum south.
Interpolation of density in the Estimated density assumed to apply Extrapolate based on average ratio of density in theto complete stratum for JARPA.
unsurveyed area within aunsurveyed to surveyed area as estimated in other
Interpolation using GLM was usedstratumyears with complete coverage for JARPA and JARPA II.
for JARPAII.
ʻSkippingʼ
Assumed not to introduce bias.
Exclude the abundance estimates for years when
ʻSkippingʼ occurred when estimating trends.
g(0)Assumed to equal 1.
Adjust for g(0) estimates provided by the regression
model.
Shoulder of detection function

RESULTSThis section presents the results of abundance estimate
for Antarctic minke whale.
Abundance estimate
Nominal abundance estimates by strata in Areas IIIE, IV, V
and VIW in each survey mode (SSV, SVC and SVP) during
JARPA/JARPAII were provided in Hakamada et al. (2013)and Hakamada and Matsuoka (2014a). Detection functions to estimate ESW for abundance estimation werealso provided by these authors. Hakamada and Matsuoka(2014a) shows interpolated abundance estimate for strata where survey coverage was incomplete. Abundance
estimates for Areas IV and V for SSV, SVC and SVP survey
modes during the JARPA period to apply log-linear models (7)–(10) were referred from Hakamada et al. (2013).
Log-linear models to estimate abundance trend
Model i) was selected for both Areas IIIE+IV and V+VIW.
These rates of increase (ROI) are 1.1% with a 95% CI of[−2.3%, 4.5%] for Area IIIE+IV and 0.6% with a 95% CI of[−2.2%, 3.3%] for Area V+VIW (Hakamada and Matsuoka,
2014a). The point estimates from the other models range
from 1.1% to 4.4% for Area IIIE+IV and from −2.1% to0.6% for Area V+VIW, so that all lie within the 95% CI for
the abundance trend estimate for the model selected(Hakamada and Matsuoka, 2014a).

Figure 7.

The base case estimates of annual abundance together with their 95% CIs are compared to exponential trend estimated by the AICc-selected model i) of
equation (7) for Areas IV (upper panel) and V (lower
panel) (from Hakamada and Matsuoka, 2014a).

Abundance estimates averaged over survey modes
The inverse variance weighted averages of abundance estimates over survey modes for Areas IV and V are shownin Figure 7 with their 95% CIs. The point estimates of theweighted average abundance and their CVs (taking into account model error) are shown in Table 2 for Areas IV and V.
The CVs for these abundance estimates are all higher than33

Technical Reports of the Institute of Cetacean Research (2017)
Table 2
The abundance estimates for the base case scenario for Area IV (left) and Area V (right) (from Hakamada and Matsuoka, 2014a).
Year

PWA

CV(PWA)

Year

PWA

CV(PWA)

1989/90
1991/92
1993/94
1995/96
1997/98
1999/00
2001/02
2003/04
2005/06
2007/08

29,99332,41827,59832,97016,562
44,94530,80732,97063,79415,088

0.527
0.720
0.473
0.458
0.542
0.338
0.402
0.682
0.509
0.645

1990/91
1992/93
1994/95
1996/97
1998/99
2000/01
2002/03
2004/05
2006/07
2008/09

100,745
78,919104,013
99,680118,779
106,769
151,072
74,03067,661109,173

0.445
0.371
0.458
0.461
0.515
0.524
0.326
0.336
0.308
0.523

of increase estimates range over [0.1%, 3.7%] for Area
IIIE+IV and [−1.7%, 0.6%] for Area V+VIW for the various
sensitivity tests.
When the abundance estimates are g(0)-adjusted, as
would be expected the estimates increase by an averageof 23,984 (88%) for Area IV and 105,906 (109%) for Area
V (Figure 8). The estimates of annual rates of increase
and their 95% CIs change to 2.5% [−1.3%,6.3%] for Area
IV and −0.6% [−3.9%,2.6%] for Areas V, reﬂecting 1.5%
increase for the former and 1% decrease for the latter,and slightly less precision (an increase in standard errorof about 0.02) than when g(0) is assumed to be 1 becauseof the further variance introduced in estimating the g(0)values (Hakamada and Matsuoka, 2014a).
Figure 8.

Same plots as for Figure 7, but with the abundance
estimates and associated exponential model forthe base case replaced by the corresponding g(0)adjusted results. The IDCR/SOWER estimates for acommon northern boundary for CPII and CPIII asagreed by the 2012 IWC SC meeting are shown by
the yellow triangles (IWC, 2013); their conﬁdence
intervals include allowance for additional variance,
as do those for the JARPA and JARPAII surveys. The
dashed curves indicate the 95% CIs for the exponential model (from Hakamada and Matsuoka, 2014a).

those from a previous analysis (Hakamada et al., 2006)
because model error is now taken into account.
Abundance estimates and trends for the sensitivity tests
Besides the g(0) adjusted scenario, abundance estimatesfor Areas IV and V do not change substantially for thesensitivities excluding scenarios models other than themodel i) (i.e. the best model in the base case) was selected as the best model (Hakamada et al., 2013; Hakamada
and Matsuoka, 2014a). These annual abundance rate
34

DISCUSSION
Comparison of the abundance estimates from JARPA
and JARPAII with those based on IDCR/SOWER
As shown in Figure 8, abundance estimates for Antarctic
minke whales for Areas IV and V based on JARPA and
JARPAII agree with the estimates of Okamura and Kitakado (2012) based on IDCR/SOWER (Hakamada et al.,2013; Hakamada and Matsuoka, 2014a).
Application of JARPA and JARPAII abundance trends
As noted earlier, one of the features of JARPA and JARPA
II is that, unlike for the IDCR/SOWER program, surveys
have been repeated in the same area and in the samemonths every second year over a long period. Therefore,
the JARPA and JARPAII surveys facilitate both estimationof trends and the extent of inter-year variability in local
abundance. These abundance series as well as thosefrom IDCR/SOWER can be used to estimate abundancetrends using population dynamics models which incorporate catch-at-age data and so integrate information froma number of diﬀerent sources (Punt et al., 2014; MoriSighting survey procedures for abundance estimates of large whales in JARPA and JARPAII, and results for Antarctic minke whales

et al., 2006).
Through their use in such population models, theabundance estimates and trends derived from JARPA and
JARPAII which are reported in this paper provide information to complement that available to estimate sustainable
catch levels for minke whales in Areas IIIE, IV, V and VIW.
It should be noted that the abundance estimates inthis study were made on the basis of geographical Areas.
These estimates should be made on the basis of biological stocks deﬁnition in the future, as such information isalready available (Pastene and Goto, 2016).

ACKNOWLEDGEMENTS
This work would not have been possible without the considerable and appreciable eﬀorts of all the researchers,
captains, oﬃcers and crew members who have participated in the JARPA and JARPAII surveys.

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Borchers, D.L. and Thomas, L. 2001. Introduction to DistanceSampling: Estimating Abundance of Biological Populations.
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2015. Distance Sampling: Methods and Applications. Springer
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Hakamada, T., Matsuoka, K. and Nishiwaki, S. 2006 Abundancetrend of Antarctic minke whales in Areas IV and V based on
JARPA data. Paper SC/58/IA7 presented to the IWC Scientiﬁc
Committee, May 2006 (unpublished). 4 pp.
Hakamada, T., Matsuoka, K., Nishiwaki, S. and Kitakado, T. 2013.
Abundance estimates and trends for Antarctic minke whales(Balaenoptera bonaerensis) in Antarctic Areas IV and V basedon JARPA sighting data. J. Cetacean Res. Manage. 13 (2):123–151.
Hakamada, T. and Matsuoka, K. 2014a. Estimates of abundance
and abundance trend of the Antarctic minke whale in Areas
IIIE–VIW, south of 60°S, based on JARPA and JARPAII sighting
data (1989/90–2008/09). Paper SC/F14/J3 presented to the
JARPA II review meeting, February 2014 (unpublished). 41 pp.
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(1989/90–2008/09). Paper SC/F14/J4 presented to the JARPA
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Technical Reports of the Institute of Cetacean Research (2017)

pp. 37–43

Technical Report (not peer reviewed)

Distribution and movement of ʻOʼ and ʻJʼ stock common minke whales
in waters around Japan based on genetic assignment methods
Mutsuo Goto*, Mioko Taguchi and Luis A. Pastene
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: goto@cetacean.jp

ABSTRACT
A total of 4,275 western North Paciﬁc common minke whales were examined with a set of 16 microsatellite
DNA loci and the program STRUCTURE to assign individuals to either O or J stocks. Samples were available
from JARPN/JARPNII (1994–2014; n=2,637), and by-catches (2001–2014; n=1,638), from waters around
Japan. Results of the Bayesian clustering analysis conﬁrmed that the whales came from two genetically differentiated stocks, O and J stocks. By using 16 loci, more than 90% of the individual whales were assigned toeither stock. Almost all of the individuals collected from the Sea of Japan side belonged to the J stock, whereas
almost all of the individuals from the oﬀshore North Paciﬁc belonged to the O stock. Intermediate areas contained individuals from both stocks. The southern part of the Paciﬁc side of Japan was mainly occupied by the
J stock, which predominated (around 80% in proportion) throughout the year. In the north part of the Paciﬁcside of Japan the proportion of the J stock animals increased in autumn/winter and decreased in spring/summer, and the O stock showed a reverse pattern.

INTRODUCTION
In the western North Paciﬁc at least two biological stocksof common minke whales Balaenoptera acutorostrata
are known to exist: the Okhotsk Sea-West Paciﬁc (Ostock) and the Sea of Japan-Yellow Sea-East China Sea (Jstock) (Omura and Sakiura, 1956; Ohsumi, 1977; 1983).
The two stocks are diﬀerentiated in morphological andreproductive characters (Omura and Sakiura, 1956;
Ohsumi, 1977; Kato, 1992), as well in genetics (Wada andNumachi, 1991 for allozymes; Goto and Pastene, 1997 for
mtDNA; and Kanda et al., 2009a; b for microsatellites),suggesting their reproductive isolation. The International
Whaling Commission (IWC) had proposed some boundaries for these stocks (Donovan, 1991, Figure 1).
Previous genetic studies showed that both stocks mix
with each other spatially and temporally in the southernpart of the Okhotsk Sea (northern Hokkaido) (Wada,
1991; Pastene et al., 1998). Since then, a substantial number of genetic samples of western North Paciﬁc common
minke whale became available, and modern and more
powerful genetic markers became available in recent
years. The application of such markers to the new samples made ﬁner studies of stock structure of this species
possible for this ocean basin (Pastene et al., 2016a; b).
There are several analytical approaches for estimating

Figure 1.

Historical IWC stock boundaries of western North
Paciﬁc common minke whale (Donovan, 1991).

the mixing proportion in areas where two or more stocks
overlap, based on genetic data. One of those is the frequency-based approach (e.g. Pastene et al., 1998). Under
this method the allele or haplotype frequency distribution for regions where only a single stock is considered to
be present is determined ﬁrst (ʻpure stockʼ frequencies).
Then the proportion of each stock is estimated in overlap
37Technical Reports of the Institute of Cetacean Research (2017)

areas by Maximum Likelihood Methods. The other is theindividual assignment-based approach, which does notneed ʻpure stockʼ assumptions and is based on minimizing departures from Hardy-Weinberg equilibrium (e.g.
Pritchard et al., 2000).
The objective of this study was to gain further understanding of the spatial and temporal distribution of the O
and J stocks around Japan by using an individual assignment-based approach on the large number of genetic
samples of this species collected in waters around Japan.

MATERIALS AND METHODS
Sample collections
To describe the distribution and movement of stocks atotal of six Areas were deﬁned for waters around Japan:
Areas A=southern part of the Okhotsk Sea; Ba=coastal in
the Paciﬁc side oﬀ Hokkaido; Bb=coastal in the northernpart of the Paciﬁc side of Japan; C=oﬀshore Area in the
Paciﬁc side; D=coastal in the southern part of the Paciﬁcside of Japan; and E=coastal Area in the Sea of Japan side
(Figure 2). Sample sizes used in this study are shown in
Table 1, by Area.
Oﬀshore samples were from the Japanese Whale
Research Program under Special Permit in the western
North Paciﬁc (JARPN/JARPNII) surveys from 1994 to 2013
in Areas A, Ba, Bb and C. Common minke whale samples
obtained from the coastal JARPNII survey between 2002
and 2014 were also used in this study, Kushiro in Area Ba
and Sanriku in Area Bb. Samples from bycaught whales in
set net ﬁsheries along the Japanese coast from 2001 to2014 were also used. The bycatches were from Areas A,
Ba, Bb, D and E year-round.

Figure 2.
38

DNA extraction
The IWC guidelines for DNA data quality (IWC, 2009) were
followed as much as possible (see Kanda et al., 2014).
Genomic DNA was extracted from 0.05 g of skin or muscle
tissues using standard proteinase K, phenol-chloroform
procedure described by Sambrook et al. (1989) or using
Gentra Puregene kits (QIAGEN). Extracted DNA was stored
in the TE buﬀer (10 mM Tris-HCl, 1 mM EDTA, pH 8.0).
Microsatellites
Microsatellite polymorphisms were analyzed using
16 loci: EV1, EV14, EV21, EV37, EV94, (Valsecchi andAmos, 1996), GT23, GT195, GT211, GT310, GT509, GT575(Bérubé et al., 2000), GATA28, GATA98, GATA417, TAA31(Palsbøll et al., 1997), DlrFCB14 (Buchanan et al., 1996).
EV1, EV14, EV21 were developed from sperm whale,
EV37, EV94, GT23, GT310, GT575, GATA28, GATA98,
GATA417, TAA31 from humpback whale, and DlrFCB14
from beluga whale. All GT, EV and DlrFCB primers are
Table 1
Sample size used in this study, by Area.
Area

Number of samples

A
Ba
Bb
C
D
E

128
1066
921
942
535
683

Total

4275

Geographical location of each Area deﬁned for this study.

Distribution and movement of ʻOʼ and ʻJʼ stock common minke whales in waters around Japan based on genetic assignment methods

dinucleotide repeats, TAA31 trinucleotide repeats, and all
GATA primers tetranucleotide repeats. Primer sequences
and PCR proﬁles follows those of the original authors
with slight modiﬁcations.
PCR ampliﬁcations were performed in 15 µl reaction
mixtures containing 10–100 ng of DNA, 5 pmole of eachprimer, 0.625 units of Ex Taq DNA polymerase (Takara
Shuzo), and 2 mM of each dNTP, and 10x reaction buﬀer
containing 20 mM MgCl2 (Takara Shuzo). PCR ampliﬁcations followed the manufacturerʼs instructions for theuse of Ex Taq DNA polymerase (Takara Shuzo). Ampliﬁed
products with internal size standard (GENESCAN400HD,
Applied Biosystems Japan) were run on a 6% polyacrylamide denaturating gel (Long Ranger™) using a
BaseStation TM100 DNA fragment analyzer (Bio-Rad) or
were electrophoresed on an Applied Biosystems 3500
Genetic Analyzer. Allele sizes were determined using a
600 LIZ size standard and GeneMapper v. 5.0 (ABI).
Data analysis
The Bayesian clustering approach was implemented withthe microsatellite data in the program STRUCTURE version
2.0 (Pritchard et al., 2000) to determine the most likely
number of genetically distinct stocks present in our samples. The program is a model-based clustering method for
inferring stock structure (K, the number of stocks in themodel) using multilocus genotype data with and without
information on sampling locations. STRUCTURE allowed
for the analyses of the samples without choosing sample
units that did not necessarily correspond to real biologicalstock boundaries. A conceptual diagram of individual assignment under STRUCTURE is shown in Figure 3.
Posterior probabilities for K were estimated from ten
independent runs for each value of K from one to ﬁvewith only genetic information. These data were calculated based on burn-in period of 10,000 iterations and runsof 100,000 iterations. Individual assignment was thenconducted for the most plausible K using the estimatedindividual proportion of membership probability (90%).
The ancestry model used for the simulation was the
admixture model, which assumes individuals may havemixed ancestry. The allele frequency model used was
the correlated allele frequencies model, which assumes
frequencies in the diﬀerent stocks are likely to be similar
due to migration or shared ancestry.

RESULTS
Genetic assignment
Bayesian clustering analyses conducted on the total
samples (4,275 individuals) without information on their

Figure 3.

Basic concept of individual assignment: (a) with allele frequency at single loci (bar plot in this ﬁgure)in each source population. In this case, it is highly
possible that individual A originates from population 1 since it has two alleles that are major in
population 1. In contrast, individual B is likely tocome from population 2 since it has two alleles
that are minor in population 1; (b) with no allele
frequency in each source population. In this case,genotypes at multiple loci in each individual enable estimation of allele frequency for the source
population and an assignment probability for eachindividual by repeating the following steps: (I) estimation of allele frequency from tentative clusteringin Hardy-Weinberg equilibrium, and (II) individualassignment based on the tentative allele frequency
according to the concept of Figure 3a.

geographic origins presented the highest likelihood probability at K=2 (Table 2). These results conﬁrmed that the
samples came from two genetically distinct stocks ofcommon minke whales (O and J stocks). In this study, theindividuals with the membership probability of over 90%
for either of the two stocks at each of the runs were assigned as pure individuals. All other individuals with themembership probability of less than 90% to the eithergroups were ʻunassignedʼ.
Spatial distribution of O and J stocks along the Japanese
coast
Both the stock-assigned and unassigned individuals were39Technical Reports of the Institute of Cetacean Research (2017)

Figure 4.

Spatial occurrence of O and J stocks common minke whale in waters around Japan.

Table 2
Results of the Bayesian clustering method analyzed for overall
samples.
K

Log P (k/x)

Variance

Pr (k/x)

1
2
3
4
5

−210753.0−202085.7−203026.1−202960.7−204283.6

85.2
873.1
3693.04761.08075.9

~0.0
~1.0
~0.0
~0.0
~0.0

grouped based on the deﬁned Areas (Figure 4). Almost
all of the individuals collected from the Sea of Japan side
(Area E) belong to the J stock, whereas almost all of theindividuals from the oﬀshore North Paciﬁc (Area C) belong to the O stock. Area D (southern part of the Paciﬁcside of Japan) was mainly occupied by the J stock. Areas A(northern Hokkaido) and Ba and Bb (northern part of the
Paciﬁc side of Japan) represent areas where both stocks
overlap geographically.
Temporal distribution of O and J stocks along the Paciﬁccoast of Japan
Figure 5 shows the temporal distribution of the O and J
stocks in Areas Ba, Bb and D in the Paciﬁc side of Japan,
expressed as three months moving average. In Area D, the J
stock was predominant (around 80% in proportion) throughout the year. In Areas Ba and Bb the proportion of the J
stock increased in autumn/winter and decreased in spring/summer. Conversely the proportion of O stock decreased inautumn/winter and increased in spring/summer.
40

Figure 5.

Monthly occurrence of O and J stocks in Areas Ba,
Bb and D in the Paciﬁc side of Japan. Each bar isexpressed as three months moving average. Sample
size is on the top of each bar. The sampling years in
Areas Ba and Bb were 1994–2014. In Area D sampling years were 2001–2014.

Distribution and movement of ʻOʼ and ʻJʼ stock common minke whales in waters around Japan based on genetic assignment methods

DISCUSSION
Assignment methods based on genetic data
There are several methods for assigning individuals tosource populations. Dawson and Belkhir (2001) developed a maximum likelihood method for assigning theindividuals in a sample to source populations, on thebasis of their genotypes at co-dominant marker loci.
Cornuet et al. (1999) used a partially Bayesian exclusion
test that uses an exclusion simulation method in the
Geneclass software. Mantel et al. (2002) showed that the
fully Bayesian assessment test of Prichard et al. (2000)
performed better than the partially Bayesian exclusion
test of Cornuet et al. (1999). However they recognizedthat the fully Bayesian method required the assumptionthat the true population origin was sampled. Given thisbackground the fully Bayesian clustering approach of
Pritchard et al. (2000), implemented in the STRUCTURE
program, was used in this study to assign individuals toeither O and J stocks, which are highly diﬀerentiatedgenetically.
Temporal and spatial distribution of O and J stocks
Results of the Bayesian clustering analysis conﬁrmedthat the whales came from two genetically diﬀerentiatedstocks, O and J stocks. By using 16 loci, more than 90% of
the individual whales were assigned to either stock. Almost all of the individuals collected from the Sea of Japanside (Area E) belonged to the J stock, whereas almost allof the individuals from the oﬀshore North Paciﬁc (Area C)
belonged to the O stock. Intermediate areas (Areas A, Ba
and Bb) contained individuals from both stocks. In Area D
the J stock was predominant (around 80% in proportion)
throughout the year. In Areas Ba and Bb the proportion of
the J stock increased in autumn/winter and decreased inspring/summer.
The fact that the J stock is distributed in Area D
throughout the year suggests that the Kuroshio Current,
which is one of the strongest west-boundary currents ofthe subtropical gyre, is working as the stock boundary
between O and J stocks.
It is important to note that the individuals from the
JARPN/JARPNII and those from the bycatch samples
diﬀer in their body length. Average body length of the
JARPN/JARPNII samples including both the oﬀshore andcoastal components was 6.67 m (SD=1.13) and that of
the all bycatch sample was 4.94 m (SD=0.99). Kato (1992)
estimated mean body length at sexual maturity of North
Paciﬁc minke whales to be 6.3 m for males and 7.1 m forfemales, so that the bycatch sample in the present study

Figure 6.

Assumed feeding migration route of O stock andJ stock animals (modiﬁed after Hatanaka andMiyashita, 1997 and Goto et al., 2010). Dark blue:
female of O stock animals, light blue: male of O
stock animals, red: J stock animals. Solid line: mature, dotted line: immature.

consisted mostly, if not all, of immature whales. The
observed diﬀerence in the maturity status between theindividuals from the bycatch and JARPN/JARPNII samples,
however, could indicate that the patterns of the temporaland spatial distributions illustrated with the bycatches
for the Areas Ba, Bb and D in this study may be diﬀerent
to some extent from those of adults. In regard to Area D,
common minke whales from the oﬀshore Area are notavailable. A related concern can be also seen in Area A.
The number of J stock individuals in Area A diﬀered between the bycatch and JARPN samples. This diﬀerence
could be due to the immature/mature, temporal, or bothfactors, but we were not able to distinguish among these
possibilities. Although we substantially increased our understanding of common minke whale distribution in thewaters around Japan from this study, our sample set isstill missing samples from some areas to depict the whole
picture of distribution and movement of the two stocks.
Genetic samples from the central and northern Okhotsk
Sea are therefore highly desirable.
The pattern described above conﬁrms the migration
pattern proposed by Hatanaka and Miyashita (1997) for
the O stock and that proposed by Goto et al. (2010) for
the J stock (see a summary of movements in Figure 6).
Possibility of additional structure with the O and J stocks
STRUCTURE has generated considerable discussion in the
IWC Scientiﬁc Committee (SC) (e.g. IWC, 2007; 2010).
One major concern is the well-documented diﬃcultythat STRUCTURE had in detecting weakly diﬀerentiated41Technical Reports of the Institute of Cetacean Research (2017)

populations/stocks, e.g. the approach could not detect
additional structure within the O and J stocks.
In this regard one of the issues discussed at the IWC
SC was the signiﬁcance of the unassigned individuals
that could not reliably be assigned to either O or J stocks(IWC, 2010). Some IWC SC members have argued thatsome if not all of the unassigned individuals, might belong to a diﬀerent stock. Alternatively, these unassigned
individuals could be the product of low statistical powerof the analysis. Taguchi et al. (2017) showed that the
proportion of unassigned individuals decreased with anincrease of the number of loci used. Therefore the most
likely explanation for the unassigned individuals is thelow power of the analysis due to a small number of lociused.
On the other hand, Pastene et al. (2016b) conductedhypothesis testing to examine the genetic population
structure of O stock common minke whales assigned by
STRUCTURE, and found no signiﬁcant heterogeneity inthe sample providing support for a single O stock in thewestern North Paciﬁc. A simulation exercise showed thatthe statistical power of the test was high.
More recently Tiedemann et al. (2017) investigated
the spatial distribution of parent/oﬀspring pairs based on
microsatellite genotype proﬁles. Several pairs were foundin which the parents were distributed in oﬀshore waters
and the oﬀspring in the coastal waters in the Paciﬁc sideof Japan, a pattern diﬃcult to reconcile with a multiple O
stocks scenario in the western North Paciﬁc.

ACKNOWLEDGEMENTS
We gratefully acknowledge the researchers and crew
members that participated in JARPN/JARPNII surveys forthe collection of genetic samples. We thank H. Oikawa(ICR) who collaborated in the process of DNA extraction.
We also thank N. Kanda (JANUS-Japan) for preparing the
microsatellite data set used in this study.

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Technical Reports of the Institute of Cetacean Research (2017)

pp. 44–57

Technical Report (not peer reviewed)

Overview of stomach content analyses for sei, Brydeʼs andcommon minke whales under the oﬀshore component of JARPNII,
and temporal changes in feeding habits
Kenji Konishi*, Tatsuya Isoda and Tsutomu Tamura
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: konishi@cetacean.jp

ABSTRACTThis study presents an overview of the stomach content analyses for sei, Brydeʼs and common minke whales
oﬀ the Paciﬁc coast of Japan based on data and samples collected by the oﬀshore component of JARPNII during 2000–2016. The three species were highly dependent on small pelagic ﬁsh, in addition to planktonic crustaceans. The prey species composition in sei whales drastically changed from Japanese anchovy in the early
2000s to Japanese sardine in 2014 to 2016, while copepods (Neocalanus spp.) steadily occurred throughout
the years in oﬀshore waters. Brydeʼs whale had a simple prey composition involving mainly Japanese anchovy,
but a lesser amount of this prey species was observed during the last three years. Prey composition in common minke whales in oﬀshore waters showed that Japanese anchovy and Paciﬁc saury are the main prey species, while in the vicinity of northern Japan, Japanese anchovy and walleye pollock were the dominant preyspecies. These three whale species showed diversities in their feeding habits reﬂecting changes in prey species
populations and availability through the years.

INTRODUCTION
The Japanese Whale Research Program in the western
North Paciﬁc, Phase II (JARPNII) started in 2000 with theprimary purpose to study the interactions between ﬁsheries and cetaceans through ecosystem modeling of the
Paciﬁc side of Japan, an area well known as a large ﬁsheries ground (GOJ, 2002; 2004). The goal of JARPNII wasto assist in the formulation of eﬀective ecosystem-based
ﬁsheries management in this research area.
This paper focuses on the study of the feeding ecologyof three baleen whale species, sei whale (Balaenoptera
borealis), Brydeʼs whale (B.edeni) and common minke
whale (B. acutorostrata) based on surveys under the oﬀshore component of JARPNII (whales sampled by the pelagic research vessels) . The baleen whales in oﬀshore waters are highly dependent on abundant pelagic ﬁshes andzooplankton which are important components of the food
web in the subarctic region of the western North Paciﬁc.
Eggs and larvae of pelagic ﬁsh, such as Japanese anchovy Engraulis japonicus and Japanese sardine Sardinops
melanostictus are transported by the Kuroshio Current
to oﬀshore waters (Itoh et al., 2009; 2011; Okunishi
et al., 2011), and these species are important prey items
for baleen whales, in addition to crustaceans such as krill.
44

In fact, the Japanese anchovy was found in the stomachof sei, Brydeʼs and common minke whales sampled in theearly half of the JARPNII (Konishi et al., 2009), in addition to mackerel (genus Scomber). Acoustic and trawlingsurveys during JARPNII (Murase et al., 2012) showed thatJapanese anchovy was distributed widely in the survey
area between 2004 and 2007. Because these pelagic ﬁsh
species are also commercially important, there are manystudies on the catch history (Yatsu et al., 2005; Yonezaki
et al., 2015), optimal environment (Takasuka et al., 2007)
and transportation to oﬀshore areas (Itoh and Kimura,2007; Itoh et al., 2009; 2011). These studies suggested
synchronized exchange of favorable environmental conditions between Japanese sardine and Japanese anchovy
caused by climate change, which can be deﬁned by Paciﬁc
Decadal Oscillation (PDO) (Mantua and Hare, 2002).
In the early 2000s, when sampling of sei and Brydeʼswhales started in the JARPNII, the sardine population had
already collapsed and the anchovy catch had increased(Yatsu et al., 2005; Takasuka et al., 2008; Itoh et al., 2009).
Since PDO ﬂuctuations occur in scale from 15–25 years
and 50–70 years (Mantua and Hare, 2002), the continuous sampling under the JARPNII for more than a decade isuseful to see changes in the feeding habits of sei, Brydeʼsand common minke whales.

Overview of stomach content analyses for sei, Brydeʼs and common minke

The main purpose of this study was to present an
overview of the studies of feeding ecology of sei, Brydeʼsand common minke whales based on stomach content
analyses, and to examine decadal changes in the feeding
habits of these three species.

MATERIALS AND METHODS
Study area
The JARPNII research area has a unique environment
under the eﬀect of both the cold Oyashio Current andthe warm Kuroshio Current and this transition region covers most of this research area (see Favorite et al., 1976).
High productivity is an important factor related to spring
blooming in the lower trophic level (Liu et al., 2004). Copepods (Neocalanus spp.) are the dominant zooplankton
in the Oyashio region during spring to summer in the surface layer, which depend on phytoplankton (see Kobari
and Ikeda, 1999; Tsuda et al., 2001).
The occurrence of subarctic gyres near the Kuroshio
Current is also important to marine mammals (Springer
et al., 1999). Basic oceanic features of oceanic fronts,
Kuroshio-current and eddies in July are illustrated as an

example (Figure 1). To examine positions of oceanic fronts,
Argo data were used for salinity and temperature proﬁles(http://www.argo.ucsd.edu, http://argo.jcommops.org). To
draw the Kuroshio-current and eddies, sea surface heightdata were obtained from the AVISO webpage (http://www.
aviso.altimetry.fr/duacs/). Another topographic feature associated with prey distribution in this area is the Emperor
Seamounts and the Shatsky Rise which cause upwellingand changing current stream (Figure 2). The northward
branch of the Kuroshio Extension Front near the Shatsky
Rise is located around 160°E (Mizuno and White, 1983).
Whale sampling
Data and samples used in this study were obtained by the
JARPNII oﬀshore component in the period 2002–2016
for sei whales; 2000–2016 for Brydeʼs whales; and2000–2013 for common minke whales. Sample sizes of
the whales examined are shown in Table 1. Details of thesurvey procedure under JARPNII are available in Bandoet al. (2016) and Tamura et al. (2016). During the sampling survey, information on catch date and location foreach whale sampled as well surface temperature where
the whales were ﬁrst sighted, was recorded.
Prey information
Prey information was obtained by examining stomach
content of the whales sampled. Most of the stomachs
were occupied by a single prey species. The methodology
for stomach content analysis was described in previous

Figure 1.

Geographical locations of oceanic fronts at western
North Paciﬁc in July during 2001–2013. Original datafrom Argo ﬂoat (JAMSTEC). Upper left: Subarctic
Front: 4°C isotherm at 100 m depth (Argo datafrom JAMSTEC). Upper right: Subarctic boundary.
Salinity of 34 psu at near surface (Argo data from
JAMSTEC). Bottom left: Kuroshio extension northern branch. Bottom right: Kuroshio extension fromsea surface height (AVISO absolute dynamic topography derived from sea surface height measured
by several satellites, AVISO, France, http://www.
aviso.altimetry.fr); estimated current eddies area
also drawn. Detail of oceanographic features in the
JARPNII area during 2000 to 2013 is well describedin Okazaki et al. (2016). Deﬁnition of boundary followed description in Kida et al. (2015).

Figure 2.

The locations of major geographic features at the
JARPNII research area with isobath to 4000 m depth.
The contours are from the GEBCO bathymetric atlas(Amante and Eakins, 2009). Survey Areas are shownwith thick black line. Shatsky Rise and Emperor
Seamounts are also drawn by 3000–4000 m isobathin depth in the eastern part of the research area at
155°E–160°E and around 170°E, respectively.
45

Technical Reports of the Institute of Cetacean Research (2017)
Table 1
Number of sei, Brydeʼs and common minke whales caught under the JARPNII, by area, month and year.
Area 7
Sei
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016

May

Minke
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013

46

Jul.

1

4

Aug.

Sep.

May

Jun.

Jul.

3

16
2
3
19
2
24
1
9
5
31

16
28
6
9
19
6
11
3

6

10
7
6

8
10
16

May

Jun.

Jul.

Aug.

4

12
1
2

4
4

16
11

10
1

Area 9
Sep.

Oct.

May

Jun.

Jul.

11
9
41
19
23
35
38
18
26
21

32
12
36
17
6
16
15
13
29
11
45

3

5
22
18
13
11

3
4

Bryde's May
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016

Jun.

Area 8

Jun.

Jul.

6

33

11

1

19

7

3

36
5
1
26

Aug.

Sep.

24

19

13

4

7

Sep.

Oct.

11
20
9

49

12

46

May

Jun.

23

14
13
8
6

26
3
16
9

27
5
3
13
21

4
14
1
10

22

4

Jul.

Aug.

Sep.

6

18

May

Jun.

54

2

Jul.
22
1

19

14

3

14
11
79

18
11

11

4

14

Aug.

7
9
5

54

Sep.

Oct. Total

6
13
2

4
4

4

Aug.

Sep.

16
Aug.

7

Sep.

Oct.

May

Jun.

10
1

26
14
5

1

Jul.
23
20

3

18

11
4
12

10
1

16

47
57

Jul.

17
1
2

16
16

26

4

6
22

29

5

9

28

39
50
100
100
100
100
100
100
100
95
100
100
90
90
90

49
32

Jun.

Oct. Total

28
28

7
44

5
8
15

Sep.

23

1

May

3
27
6
23
9
17

35
13

Aug.

Aug.

3

3
10
5
3
4
1

24
3
14

16
5
5
28
60
38

29

22

12

2
1

3
3

4

1

43
50
50
50
50
50
50
50
50
50
50
50
34
28
25
25
25

Oct. Total
40
100
100
100
100
100
100
100
59
43
14
49
74
3

Overview of stomach content analyses for sei, Brydeʼs and common minke

reports (e.g. Tamura et al., 1998; Konishi et al., 2009), andit involves the steps shown in Figure 3. Prey length distributions for pelagic ﬁsh in the stomachs of the sampledwhales are shown in the Appendix.

RESULTSSei whale
Figure 4 shows the geographical position (based on the ﬁrst
sighting) of sei whales sampled including information of theprey species found in the stomachs. Whales were widelydistributed in the survey area, but mostly from east of 150°E
and south of 46°N between north of the Kuroshio extension
and just north of the Subarctic Front (see also Figure 1).
The main prey species were copepod (Neocalanusspp.), euphausiid (Euphausia spp.), Japanese anchovy,
two mackerel species (Scomber japonicus and S. aus-Figure 3.

Figure 4.

tralasicus) and Japanese sardine. Paciﬁc saury (Cololabis
saira) was found in the eastern side of the research areain every year. Most of the copepods found in the stomachs were 5th copepodite stage of Neocalanus cristatus
and N. plumchrus (also see Konishi et al., 2009). Minimalarmhook squid (Berryteuthis anonychus) was also foundmainly in far eastern areas near the Emperor Seamounts.
The locations of whales feeding on Japanese sardine was
the most eastern in the survey area, overlapping withwhales feeding on Japanese anchovy and copepods.
Prey composition in the stomach of sei whales sampledduring 2002–2016 is shown for each Area in Figure 5.
Copepod and Paciﬁc saury were dominant preys in Area
9 than in western Area 8, while Japanese anchovy andeuphausiid were found widely in both Areas 8 and 9. In
the years 2002–2012, Japanese anchovy, copepod andA schematic diagram of the steps in the analyses on stomach contents.

The distribution of sampled sei whales (based on ﬁrst sighting), and information of prey species in theirstomachs (period 2002–2016). The contours are from the GEBCO bathymetric atlas.
47

Technical Reports of the Institute of Cetacean Research (2017)

Figure 5.

Figure 6.

Prey composition in the stomach of sei whales sampled in the period 2002–2016, by Area and year.

Surface temperature in which sei whales were sampled, and prey species in their stomachs (2002–2016).

euphausiid were major components with the exceptionof years 2005 and 2008. After 2007, mackerel became
one of the major preys which coincided with a decreasing occurrence of anchovy and copepod. In the years
2014–2016, Japanese sardine was the dominant prey
while some Japanese anchovy was found only in 2016.
Stomachs with no contents (NC) were also found widely
throughout the survey years. Japanese sardine was not
the main prey species until recently.
Figure 6 shows the surface temperature in which sei
whales were found, including information on prey species in their stomachs. Surface temperature in which sei
whales were found varied according the prey species. Japanese anchovy was found in a wider range of surface temperatures. Copepods and Paciﬁc saury tend to be found atlower temperatures (c.a. <15°C) than mackerel. Althougha variation of surface temperature is observed within
years, these are not consistent among years. Length dis48

tribution of main ﬁsh prey species in the stomachs of sei
whales had diﬀerent modes among years (see Appendix).
Brydeʼs whale
Figure 7 shows the geographical position (based on theﬁrst sighting) of Brydeʼs whale sampled including information of the prey species found in the stomach. Their
distribution is mainly south and west of the distributionof sei whales sampled. They were concentrated around
145°E–150°E and 155°E–160°E, south of 41°N. Japanese
anchovy and euphausiids were found in a wide longitudinal range. Mackerels and stomiiforms (Vinciguerria nimbaria and Maurolicus muelleri) occurred oﬀshore.
Prey composition in the stomachs of Brydeʼs whales
sampled during 2000–2016 is shown for each Area in
Figure 8. Japanese anchovy, stomiiforms and euphausiid
were the dominant prey species. Mackerels were occasionally found in some years. The composition of mainOverview of stomach content analyses for sei, Brydeʼs and common minke

Figure 7.

The distribution of sampled Brydeʼs whales (based on ﬁrst sighting), and information of prey species intheir stomachs (period 2000–2016). The contours are from the GEBCO bathymetric atlas.

Figure 8.

Prey composition in the stomach of Brydeʼs whales sampled in the period 2000–2016, by Area and year.

prey species is highly variable among years, however
there was no obvious variation among Areas and decadalchange in the prey composition. However, it should be
noted that lower occurrence of anchovy and high occurrence of ʻNCʼ stomachs were observed in the last two
years (2015–2016). Japanese sardine was not a main preyspecies and was just found occasionally.
Figure 9 shows the surface temperature in which
Brydeʼs whales were found, including information on preyspecies in their stomachs. Brydeʼs whales fed on prey inwarmer surface temperature areas compared to sei andcommon minke whales in JARPNII. No obvious variationof surface temperature among the prey species was observed. Length distribution of pelagic ﬁsh prey species
showed variation of mode among years (see Appendix).

Common minke whale
Figure 10 shows the geographical position (based on theﬁrst sighting) of common minke whales sampled including information of the prey species found in the stomach.
Figure 11 shows details of the coastal area in the westernside of the research area.
Paciﬁc saury is the key prey species in oﬀshore waters and common minke whales occurred mainly northcompared to the sei whales sampled. Japanese anchovy
was found widely through longitudinal sectors, and also
was intensively fed on by common minke whales in the
coastal area (Figure 11). Minimal armhook squid and Paciﬁc
pomfret (Brama japonica) were found in the far northeastern regions near and above the Emperor Seamounts (Figure 10). In coastal waters, walleye pollock (Theragra chalcogramma), which occurs at bottom or midwater depth, wascommonly found above shelf edge and slope oﬀ eastern49

Technical Reports of the Institute of Cetacean Research (2017)

Figure 9.

Surface temperature in which Brydeʼs whales were sampled, and prey species in their stomachs(2000–2016).

Figure 10.

The distribution of sampled common minke whales (based on ﬁrst sighting), and information of prey species in their stomachs (period 2000–2013). The contours are from the GEBCO bathymetric atlas.

Hokkaido (Figure 11). Japanese anchovy, Paciﬁc saury andeuphausiids were also common prey species in this area.
The Japanese ﬂying squid (Todarodes paciﬁcus) was also
found just on the continental slope but only in early years of
JARPNII (Figures 10 and 11). Feeding on Japanese anchovyand euphausiid by common minke whales was also foundabove the continental shelf oﬀ Hachinohe (Figure 11).
Prey composition in common minke whales diﬀers among
years, but not to the extent as in the case of the sei whale.
Recent transition of pelagic ﬁsh species was not found probably due to the absence of common minke whale samples
50

during 2014–2016 (see Table 1 and Figure 12).
Surface temperature varied in the range of 10°C–20°C,
and the range was small in the oﬀshore area (Figure 13).
Length distribution of Japanese anchovy, mackerel andPaciﬁc saury in the stomach of common minke whales
diﬀers within and among years (see Appendix).

DISCUSSION
This study showed a general overview of stomach content analyses and decadal changes in feeding habits forsei, Brydeʼs and common minke whales in the westernOverview of stomach content analyses for sei, Brydeʼs and common minke

Figure 11.

Ampliﬁed plots of Figure 10 to show details of the situation in areas near to the coast of the Paciﬁc sideof Japan and northern Honshu and Hokkaido.

Figure 12.

Prey composition in the stomachs of common minke whales sampled in the period 2000–2013, by Areaand year.

North Paciﬁc in terms of rather qualitative information based on data collected by JARPNII in the period
2000–2016. The Japanese anchovy was an important
prey for the three whale species across the entire survey
area, and it was also important in the coastal area forcommon minke whales. The results showed a remarkable
shift in prey species in the case of the sei whales late in
the JARPNII period (2015–2016), i.e. a limited occurrenceof Japanese anchovy and higher incidence of Japanesesardine as main prey in the last three years (2014–2016).
A similar decrease of Japanese anchovy as prey species ofBrydeʼs whales also supported the prey shift.
There is no doubt that prey composition in the baleen
whales reﬂected a pelagic ﬁsh shift from Japanese anchovy
to Japanese sardine and mackerel in the western North
Paciﬁc. Mechanisms of these decadal scale shifts of pe-

lagic ﬁsh composition in the western North Paciﬁc wereinﬂuenced by large-scale SST variability by the Aleutian
Low (Miller et al., 2004; Sasaki et al., 2012). The responses
to the SST in terms of growth rate in sardine, saury andanchovy diﬀer. For example, the patterns of spawning temperature clearly show ʻwarmʼ and ʻeurythermalʼ Japanese
anchovy and ʻcoolʼ and ʻstenothermalʼ Japanese sardine in
the western North Paciﬁc (e.g. Takasuka et al., 2007; 2008;
Oozeki et al., 2009; Watanabe, 2009; Itoh et al., 2011).
Locations where whales were found in JARPNII elucidated the site-speciﬁc feeding behaviors of the whales.
Sei whales occurred where both pelagic ﬁsh and copepod
were available which covers the oﬀshore research area
to mainly feed on copepod and small pelagic ﬁsh. Brydeʼswhales occurred from the near coastal area in sub-area
7 to around the Shatsky Rise in sub-area 9, where both
51

Technical Reports of the Institute of Cetacean Research (2017)

Figure 13.

Surface temperature in which common minke whales were sampled, and prey species in their stomachs(2000–2013).

pelagic ﬁsh from the Kuroshio Current and euphausiid
are both common. They possibly can feed on euphausiids
even if pelagic ﬁsh is not available. Common minke whales
showed unique feeding habits with occurrences at higher
latitude to ca. 48°N and high dependency on Paciﬁc sauryin the oﬀshore area and prey related to the continental
shelf in coastal areas. They feed on minimal armhook
squid near the Emperor Seamounts where the mature
minimal armhook squid occurs in summer (Konishi andTamura, 2007). Minke whales also feed on larger prey,such as walleye pollock, Paciﬁc pomfret and salmonids.
This study highlighted the fact that feeding ecology studies of sei, Brydeʼs and common minke whales in the western North Paciﬁc are beneﬁted by long-term systematicsurveys, which allow decadal-level variability be studied.

ACKNOWLEDGEMENTS
We would like to thank all researchers and crews involvedin the JARPNII surveys, who supported feeding habits
studies on board of Nisshin-Maru ﬂeet. Thanks are also
due to the members of the Institute of Cetacean Researchfor useful suggestions and helping to conduct stomach
contents treatment. We ﬁnally thank the Fisheries Agency of Japan for supporting the JARPNII program.

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Appendix
Length distribution of main pelagic ﬁsh in the stomachs of sei, Brydeʼs and common minke whales during
JARPNII period (2000–2016)
Length distributions of pelagic ﬁshes in the stomach ofsei, Brydeʼs and common minke whales are shown in Figs.
A1–A4. Mackerels include both Scomber japonicus andS. australasicus because these species were sometimes
found mingled in half digested stomach contents. The
length distributions diﬀer among years and whale species, suggesting that prey length, as also deﬁned as age
class, reﬂects the relative abundance and availability inthe feeding area for the baleen whales.
53Technical Reports of the Institute of Cetacean Research (2017)

Figure A1. Length distribution of Japanese anchovy in the stomach of sei, Brydeʼs and common minke whales during
JARPNII (2000–2016).

54

Overview of stomach content analyses for sei, Brydeʼs and common minke

Figure A2.

Fork length distribution of mackerels (including Scomber japonicus and S. australasicus) in the stomach of sei, Brydeʼsand common minke whales during JARPNII (2000–2016).

55

Technical Reports of the Institute of Cetacean Research (2017)

Figure A3. Length distribution of Japanese sardine in the stomach of sei, Brydeʼs and common minke whales during
JARPNII (2000–2016).

56

Overview of stomach content analyses for sei, Brydeʼs and common minke

Figure A4.

Knob length distribution of Paciﬁc saury in the stomach of sei, and common minke whales during JARPNII(2000–2016).

57

Technical Reports of the Institute of Cetacean Research (2017)

pp. 58–67

Technical Report (not peer reviewed)

Temporal trend of total mercury levels in common minke, sei and
Brydeʼs whales in the western North Paciﬁc in the period 1994–2014
Genta Yasunaga* and Yoshihiro Fujise
Institute of Cetacean Research, Toyomi-cho 4–5, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: yasunaga@cetacean.jp

ABSTRACTTo examine yearly changes of total mercury (Hg) concentrations in common minke (Balaenoptera
acutorostrata), sei (B. borealis) and Brydeʼs (B. edeni) whales in the western North Paciﬁc, total Hg concentrations were measured in muscle samples from whales collected between 1994 and 2014 by JARPN/JARPNII.
Averages and standard deviations of total Hg concentrations in the samples of mature male common minke
whales from coastal area oﬀ Kushiro and Sanriku were 0.22±0.05, 0.22±0.06, ppm wet wt, and from oﬀshore sub-areas 7, 8 and 9 were 0.22±0.05, 0.22±0.06 and 0.24±0.10 ppm, respectively. The concentrationin sei whales from sub-area 9 was 0.044±0.013 ppm, and that in Brydeʼs whales from sub-areas 8 and 9 was
0.044±0.013 ppm. Multiple robust linear regression analysis was carried out considering several variables:
sampling year, sampling location (longitude and latitude), sampling date, body length, blubber thickness andmain prey item observed in their stomach. Results of the analyses can be summarized as follow: no signiﬁcant
yearly changes of total Hg concentrations in muscle of common minke whales oﬀ Kushiro, Sanriku and subarea 8; no signiﬁcant yearly changes of total Hg concentrations in muscle of Brydeʼs whales in sub-areas 8 and
9; signiﬁcant yearly changes of total Hg concentrations in muscle of minke whales from sub-areas 7 and 9, andsigniﬁcant yearly changes of total Hg concentrations in muscle of sei whales from sub-area 9. Temporal trendsof total Hg concentrations have not been observed in environmental samples, lower trophic organisms andbaleen whales, except for those cases mentioned above. Temporal changes in total Hg concentrations in common minke whales (sub-areas 7 and 9) and sei whales (sub-area 9) may reﬂect changes in their food habitsrather than changes of background levels of total Hg in the marine environment. Consequently, it is concluded
that the temporal trend of total Hg concentrations in the marine habitat of baleen whales in the western North
Paciﬁc remained stable in the research period.

INTRODUCTION
Mercury (Hg) is one of the most neurotoxic chemicals
to human and wildlife in the environment. It is released
into the ocean from a variety of sources such as volcanic
emission, degassing from soil and combustion of coalfrom power plants. It is released in the form of elemental
mercury, and is accumulated into top predators throughthe food chain in the marine ecosystem. There is a needto monitor Hg in the oceans.
Cetaceans have been used to monitor spatial and temporal trends of Hg in the oceans (Sanpera et al., 1993;
Borrell and Reijnders, 1999). Pollutants can be monitoredin wide areas and integrated in some way over time byusing cetacean as indicators because they are located at
the top of the food chain in the marine ecosystem, andare mobile and long-lived animals.
58

The present study examines temporal changes of total
Hg concentrations in common minke, sei and Brydeʼswhales in the western North Paciﬁc. To understand thepattern of accumulation of total Hg in whales it is important to consider some biological information such assex and sexual maturity of the animals, and ecologicalinformation such as feeding habits of whales and indicators of body condition. The present study, which is basedon samples collected by the Japanese Whale Research
Program under Special Permit in the western North
Paciﬁc (JARPN) and its Second Phase, JARPNII in the period 1994–2014, considers such biological and ecologicalinformation to understand and interpret the pattern ofaccumulation of Hg in whales.

Temporal trend of total mercury levels in common minke, sei and Brydeʼs whales in the western North Pacific in the period 1994–2014

MATERIALS AND METHODS
Whale sampling
Common minke (1994–2014), sei (2002–2014) and
Brydeʼs (2002–2013) whales were sampled in sub-areas
7, 8 and 9 under the JARPN and JARPNII. In addition common minke whales were sampled in coastal areas oﬀ Sanriku (2003–2014) and oﬀ Kushiro (2002–2014) (Figure 1).
Details of the sampling procedures are given in Tamura
et al. (this TEREP-ICR issue).
For all sampled whales, biological sampling and measurements were conducted on the research base vessel, Nisshin-maru in the oﬀshore component (JARPN/
JARPNII), and at the land research stations in the case of
the coastal component (JARPNII).

Figure 1.

Sub-areas surveyed by the JARPN and the JARPNII
surveys, excluding the EEZ of foreign countries.

Figure 2.

Tissue sampling for Hg analysis
Figure 2 shows the overall process for Hg analysis fromthe tissue sampling at the ﬁeld to the laboratory work.
Muscle tissues were collected for total Hg analysis.
Biological information
The kind of biological information obtained from eachsampled whale was described by Bando (this TEREP-ICR
issue). In this study information on body length, blubber
thickness and reproductive status of whales was used.
Only mature male animals were used. Males of common
minke, Brydeʼs and sei whales were deﬁned as sexuallymature by testis weight of more than 290 g, 560 g and
1,090 g (heavier side), respectively. Only common minke
whales from the Okhotsk Sea-West Paciﬁc stock (O-stock)
as identiﬁed by the microsatellite DNA analysis (Gotoet al., this TEREP-ICR issue), were used.
The forestomach contents have proved suﬃcient for
determination of the common minke whale diet (seeKonishi et al., this TEREP-ICR issue). Data on prey composition and preyʼs Hg concentrations used in the present
study were based on contents from forestomach andanalyses conducted by Yasunaga and Fujise (2009) and
MHLW (2005).
Tables 1–3 show the number of samples by sub-areaand year, and the biological information used for common minke, sei and Brydeʼs whales in this study.
Measurement of total mercury concentration in muscle
of whales
Total Hg analysis was conducted at the laboratory of the Institute of Cetacean Research (ICR) in Tokyo and also at the

Schematic diagram of total Hg analysis in muscle tissue of whales.
59Technical Reports of the Institute of Cetacean Research (2017)
Table 1
Biological data and total mercury concentrations in muscle of common minke whales (mature males) from the western North Paciﬁcduring 1994 and 2014.
Sub areaYearnBody length(m)

Blubber thickness(cm)

Muscular Hg(ppm wet wt.)

7

1996
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2009
2011
2012
Total

18
35
31
6
27
33
11
6
17
16
41
11
23
19
294

(7.36±0.28)(7.50±0.27)(7.41±0.29)(7.30±0.25)(7.45±0.31)(7.52±0.27)(7.42±0.40)(7.56±0.21)(7.51±0.23)(7.39±0.39)(7.47±0.26)(7.71±0.26)(7.47±0.34)(7.37±0.34)(7.46±0.30)(3.1±0.4)(2.6±0.4)(3.6±0.8)(3.6±1.0)(2.4±0.5)(3.7±0.8)(2.4±0.5)(4.1±0.6)(3.3±0.9)(2.4±0.7)(3.0±0.7)(3.2±0.7)(3.5±0.6)(2.6±0.4)(3.1±0.8)(0.23±0.05)(0.20±0.05)(0.20±0.04)(0.24±0.04)(0.21±0.04)(0.22±0.03)(0.20±0.07)(0.22±0.02)(0.27±0.04)(0.22±0.05)(0.23±0.04)(0.21±0.06)(0.25±0.05)(0.24±0.08)(0.22±0.05)

Kushiro

2002
2004
2005
2006
2007
2008
2009
2010
2011 spring2011 autumn
2012
2013
2014
Total

14
23
25
10
14
5
6
3
4
10
5
23
10
152

(7.22±0.34)(7.43±0.24)(7.44±0.32)(7.52±0.29)(7.33±0.59)(7.26±0.21)(7.54±0.37)(7.49±0.21)(7.40±0.41)(7.26±0.37)(7.48±0.21)(7.33±0.35)(7.33±0.28)(7.38±0.35)(4.3±1.0)(4.2±0.6)(3.5±0.6)(4.4±0.8)(4.1±0.8)(4.3±1.0)(4.3±0.4)(3.8±0.4)(3.2±0.6)(4.4±1.0)(5.0±0.7)(5.0±0.9)(5.0±0.8)(4.3±0.9)(0.21±0.06)(0.20±0.03)(0.25±0.05)(0.22±0.03)(0.23±0.06)(0.25±0.01)(0.21±0.07)(0.23±0.02)(0.24±0.03)(0.23±0.02)(0.21±0.06)(0.19±0.04)(0.21±0.09)(0.22±0.05)

Sanriku

2003
2005
2006
2007
2008
2009
2010
2012
2013
2014
Total

8
3
6
10
3
1
5
2
2
2
42

(7.10±0.35)(7.27±0.13)(7.24±0.32)(7.50±0.30)(7.49±0.32)(6.85±)(7.32±0.24)(7.31±)(7.52±)(7.38±0.39)(7.32±0.32)(2.9±0.5)(2.5±0.3)(2.8±0.2)(2.5±0.4)(3.2±0.3)(2.8± )
(3.1±0.6)(3.4± )
(3.5± )
(2.7±0.3)(2.8±0.5)(0.18±0.04)(0.29±0.02)(0.19±0.05)(0.25±0.08)(0.19±0.03)(0.21±)(0.20±0.05)(0.18±)(0.30±)(0.31±0.04)(0.22±0.06)

ﬁeld research stations of the coastal and oﬀshore components. The muscle sample was stripped externally to avoid
contamination before analysis, approximately 100 mg oftissue was weighed, and set on the total Hg analyser (Nippon Instruments Co., MA-3000) which applies a thermal
60

decomposition system (Figure 2). To increase the accuracyof the determination, triplicate analyses were performedon each sample. Accuracy and precision of the present
system were conﬁrmed using standard reference materials, DORM-3 (NRCC, muscle of dogﬁsh).

Temporal trend of total mercury levels in common minke, sei and Brydeʼs whales in the western North Pacific in the period 1994–2014
Table 1
Table 1 minke whales (mature males) from the western North Paciﬁc
Biological data and total mercury concentrations in muscle of common
Continued.
during 1994 and 2014.
Sub areaYearnBody length(m)

Blubber thickness(cm)

Muscular Hg(ppm wet wt.)

8

1996
1997
1998
2001
2002
2003
2005
2006
2007
2008
2009
Total

11
26
28
13
5
27
2
24
10
3
6
155

(7.44±0.33)(7.44±0.36)(7.54±0.25)(7.78±0.34)(7.71±0.21)(7.50±0.24)(7.54±)(7.51±0.26)(7.55±0.26)(7.52±0.05)(7.23±0.34)(7.52±0.30)(2.6±0.5)(3.5±0.6)(2.6±0.4)(2.3±0.4)(3.2±0.6)(2.4±0.4)(2.2± )
(2.9±0.6)(2.3±0.4)(2.7±0.4)(3.2±0.6)(2.8±0.6)(0.25±0.04)(0.27±0.06)(0.23±0.05)(0.21±0.05)(0.20±0.11)(0.18±0.06)(0.16±)(0.21±0.05)(0.22±0.06)(0.23±0.02)(0.20±0.06)(0.22±0.06)

9

1994
1995
1997
2000
2001
2002
2003
2004
2005
2006

16
68
39
12
19
21
28
50
25
16

(7.42±0.27)(7.45±0.31)(7.41±0.32)(7.51±0.23)(7.69±0.29)(7.55±0.21)(7.50±0.32)(7.47±0.21)(7.49±0.29)(7.56±0.30)(3.5±0.7)(3.1±0.5)(3.1±0.5)(2.6±0.5)(2.5±0.4)(2.9±0.6)(2.9±0.6)(3.9±0.7)(3.5±0.6)(3.4±0.6)(0.36±0.16)(0.27±0.06)(0.25±0.11)(0.16±0.03)(0.19±0.05)(0.20±0.05)(0.18±0.05)(0.20±0.07)(0.17±0.05)(0.28±0.08)

2007
2008
2009
2010
2013
Total

4
36
5
9
3
351

(7.56±0.20)(7.45±0.26)(7.41±0.41)(7.66±0.23)(7.59±0.22)(7.49±0.28)(2.2±0.3)(3.1±0.7)(3.0±0.8)(3.2±0.5)(4.0±1.3)(3.2±0.7)(0.18±0.09)(0.30±0.15)(0.19±0.06)(0.22±0.03)(0.19±0.06)(0.24±0.10)

Table 2Biological data and mercury concentrations in muscle of sei whales (mature males) from the western North Paciﬁc during 2002 and 2014.
Sub area
9

Total

Year

n

Body length(m)

Blubber thickness(cm)

Muscular Hg(ppm wet wt.)

2002
2003
2004
2005
2006
2007
2011
2012
2013
2014
2002–2014

5
5
5
5
5
5
15
21
26
21
113

(13.60±0.16)(13.80±0.43)(13.61±0.04)(13.54±0.38)(13.84±0.51)(13.92±0.08)(13.82±0.42)(13.74±0.45)(13.76±0.50)(13.80±0.36)(13.76±0.41)(4.7±0.5)(4.7±0.7)(4.1±0.6)(4.8±0.6)(4.9±0.6)(5.8±0.7)(4.8±0.8)(5.0±0.5)(5.6±0.8)(4.8±0.5)(5.0±0.8)(0.050±0.012)(0.057±0.007)(0.050±0.009)(0.049±0.011)(0.052±0.006)(0.058±0.010)(0.039±0.009)(0.030±0.011)(0.040±0.009)(0.053±0.009)(0.044±0.013)

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Technical Reports of the Institute of Cetacean Research (2017)
Table 3
Biological data and mercury concentrations in muscle of Brydeʼs whales (mature males) from the western North Paciﬁc during 2002 and 2013.
Sub area
8, 9

Total

Year

n

Body length(m)

Blubber thickness(cm)

Muscular Hg(ppm wet wt.)

2002
2004
2006
2007
2011
2012
2013
2002–2013

5
5
5
5
3
6
9
38

(12.67±0.43)(12.59±0.36)(12.36±0.47)(12.63±0.35)(12.31±0.27)(12.85±0.48)(12.79±0.38)(12.64±0.41)(4.5±0.6)(4.4±0.7)(4.5±0.5)(3.9±0.7)(3.6±0.5)(4.8±1.0)(4.7±0.8)(4.4±0.8)(0.051±0.008)(0.045±0.008)(0.040±0.011)(0.049±0.008)(0.022±0.005)(0.046±0.019)(0.047±0.010)(0.044±0.013)

Statistical analysis
The yearly changes of total Hg concentrations in muscle
of whales were assessed by multiple robust linear regression in the context of several variables (R Development
Core Team, 2006). The following independent variables
were considered: ʻYear,ʼ ʻDate,ʼ ʻLatitude,ʼ ʻLongitude,ʼʻBody length,ʼ ʻBlubber thicknessʼ and ʻMain prey itemʼ.
All variables except the main prey item, were logarithmically transformed.
Categorical parameters of main prey items used in theanalyses were the following: minke whale and sub-area
7 (Japanese anchovy: Engraulis japonicus, Euphausiids, Japanese ﬂying squid: Todarodes paciﬁcus, mackerel: Scomber japonicus, Japanese sardine: Sardinops
melanostictus, Paciﬁc saury: Cololabis saira and walleye
pollock: Theragra chalcogramma); minke whale andsub-area 8 (anchovy, copepods, Euphausiids, Japanese
ﬂying squid, mackerel and Paciﬁc saury); minke whaleand sub-area 9 (anchovy, Atka mackerel: Pleurogrammus monopterygius, Copepods, Euphausiids, mackerel,minimal armhook squid: Berryteuthis anonychus, oceanic lightfish: Vinciguerria nimbaria, Paciﬁc pomfret:Brama japonica, salmonids, Paciﬁc saury); sei whale andsub-area 9 (Japanese anchovy, Copepods, Euphausiids,
mackerel, minimal armhook squid, Japanese sardine
and Paciﬁc saury); Brydeʼs whale and sub-areas 8 and 9(Japanese anchovy, Euphausiids and mackerel). Anchovyis the baseline prey item in sub-areas 7–9 so the eﬀects
of anchovy being the main prey item are included in themodel intercepts. Categorical parameters of main prey
items were not used in the case of Sanriku and Kushiro. In
Sanriku the prey items of common minke whales were almost all sand lance. In Kushiro the diversity of prey items
was too high in relation to the number of whale samples.
The cases of whales with empty stomach and damageby harpoon were excluded from the analysis. Furthermore, a generalized additive model (GAM) was used to62

examine the ﬂexion point in the yearly changes of total Hgconcentrations in muscle of whales. A p value of less than
0.05 was considered to indicate statistical signiﬁcance inall tests. These statistical analyses were performed using
the free software R, version 3.3.0.

RESULTS
Tables 1–3 show the total Hg concentrations in muscle ofcommon minke, sei and Brydeʼs whales, respectively.
The results of multiple robust linear regression to examined yearly changes in the context of several variables
are given in Tables 4–10. F statistics showed that theoverall regression was statistically signiﬁcant in all cases(p<0.05). Only in the cases of minke whales from subareas 7 and 9 (Tables 4, 8), and sei whales from sub-area
9 (Table 9), the total Hg concentrations were signiﬁcantly
associated with sampling year. In these cases the simple
and GAM plots against research year are shown in Figures
3 and 4 for minke whales in sub-areas 7 and 9, respectively, and in Figure 5 for sei whale in sub-area 9.
Slight ﬂexion points of yearly trends of muscular total
Hg were observed in minke whales from sub-area 9 in2008 and in sei whales from sub-area 9 in 2012.

DISCUSSION
Results of the analyses can be summarized as follows:
no signiﬁcant yearly changes of total Hg concentrations
in muscle of common minke whales oﬀ Kushiro, Sanriku
and sub-area 8; no signiﬁcant yearly changes of total Hgconcentrations in muscle of Brydeʼs whales in sub-areas
8 and 9; signiﬁcant yearly changes of total Hg concentrations in muscle of minke whales from sub-areas 7 and 9,
and signiﬁcant yearly changes of total Hg concentrations
in muscle of sei whales from sub-area 9.
It should be noted here that no signiﬁcant trends oftotal Hg concentrations were found in prey species suchas the krill, Japanese anchovy and Paciﬁc saury from 1994

Temporal trend of total mercury levels in common minke, sei and Brydeʼs whales in the western North Pacific in the period 1994–2014
Table 4
Results of multiple robust linear regression analysis with ʻtotal
Hg levels in muscle of common minke whales from subarea 7ʼ as
the dependent variable.

Table 6
Results of multiple robust linear regression analysis with ʻtotal
Hg levels in muscle of common minke whales from oﬀ Sanrikuʼ
as the dependent variable.

a) Analysis of Variancea) Analysis of Variance

SourceSourceRobust residual SE

0.20

Robust residual SE

0.2543

R2

0.135

R2

0.2374

Adjusted R2

0.0969Adjusted R2

0.1067b) Variablesb) Variables

Model
Intercept

p value

Model

B

SE

−198.59771 53.16048 −3.736 p<0.05

Intercept

−50.2

286.8

−0.175 0.862

Year

31.50

44.65

0.71

0.485

B

SE

T

Year

26.054

6.788

3.84

p<0.05T

p value

Body length−0.138

0.237

−0.58

0.559

Body length−0.029

0.025

−1.15

0.257

Blubber thickness

0.059

0.060

0.98

0.328

Blubber thickness−0.400

0.274

−1.46

0.153

Latitude−0.156

0.541

−0.29

0.773

Latitude23.79217.674

1.35

0.187

Longitude−0.064

0.568

−0.11

0.911

Longitude−56.288

43.990

−1.28

0.209

Date

0.038

0.017

2.21

p<0.05

Date

1.079

0.569

1.90

0.066

MainPrey_Euphausiids

0.076

0.045

1.70

0.089

MainPrey_JFSquid

0.062

0.054

1.15

0.250

MainPrey_Mackerel

0.372

0.026

14.53

p<0.05

MainPrey_Sardine−0.294

0.036

−8.25

p<0.05

MainPrey_Saury

0.097

0.047

2.07

p<0.05

MainPrey_WalleyePollock

0.138

0.049

2.83

p<0.05

Table 7
Results of multiple robust linear regression analysis with ʻtotal
Hg levels in muscle of common minke whales from subarea 8ʼ as
the dependent variable.
a) Analysis of Variance

Table 5Results of multiple robust linear regression analysis with ʻtotal
Hg levels in muscle of common minke whales from oﬀ Kushiroʼ
as the dependent variable.
a) Analysis of Variance

SourceRobust residual SE

0.2439R20.3021

Adjusted R2

0.2473b) Variables

Source

Model

B

SE

T

p value

Robust residual SE

0.2834R2Intercept

163.35009

95.2101.716 0.088

0.3472Adjusted R2

Year−17.288

13.636

−1.27

0.207

0.3176

Body length

1.219

0.534

2.29

p<0.05

Blubber thickness

0.288

0.108

2.67

p<0.05Latitude−0.281

1.628

−0.17

0.863

Longitude−7.181

2.778

−2.59

p<0.050.481b) Variables
SET

p value

Model

B

Intercept

63.6

98.2

0.648

0.518

Date

0.495

0.699

0.71

Year

−2.14

10.61

−0.20

0.840

MainPrey_Copepods−0.020

0.080

−0.25

0.805

Body length

0.904

0.843

1.07

0.285

MainPrey_Euphausiids−0.104

0.144

−0.72

0.471

Blubber thickness−0.322

0.077

−4.15

p<0.05

MainPrey_JFSquid−0.137

0.101

−1.36

0.175

Latitude

5.384

6.941

0.78

0.439

MainPrey_Mackerel

0.309

0.170

1.82

0.072

Longitude−14.215

13.618

−1.04

0.298

MainPrey_Saury

0.180

0.063

2.84

p<0.05

Date

0.119

0.149

0.80

0.424

to 2008 (Yasunaga and Fujise, 2009), and that total Hgconcentrations in surface water of the North Paciﬁc did
not change from the 1980ʼs to 2000ʼs (Laurier et al., 2004;
Sunderland et al., 2009).
Firstly those cases where signiﬁcant yearly trend wasobserved, are discussed.

In sub-area 7, total Hg concentrations in muscle ofcommon minke whales (period 1996–2012) were signiﬁcantly associated with Intercept (−), Year (+), Date (+),
Main prey items (mackerel, sardine, saury and Walleye
pollock) (Table 4). A comparison of total Hg concentrations in muscle of common minke whale and in the whole63

Technical Reports of the Institute of Cetacean Research (2017)
Table 8Results of multiple robust linear regression analysis with ʻtotal
Hg levels in muscle of common minke whales from subarea 9ʼ as
the dependent variable.
a) Analysis of Variance

Table 9Results of multiple linear regression analysis with ʻtotal Hg levels
in muscle of sei whales from subarea 9ʼ as the dependent variable.
a) Analysis of Variance
SourceSourceRobust residual SE

0.2526

Robust residual SE

0.2834R2

0.3344R2

0.3472Adjusted R2

0.2293

2

Adjusted R

0.3176b) Variablesb) Variables
B

SE

Intercept

330.3

55.7

5.932 p<0.05

Year−43.74

7.31

−5.99

Body length

0.150

0.441

T

p value

Model

0.34

T

p value

Model

B

SE

Intercept

405.9

137.4

2.954 p<0.05

Year−54.46

18.35

−2.97

p<0.05p<0.05

Body length

3.579

1.029

3.48

p<0.05

0.735

Blubber thickness

0.024

0.262

0.09

0.927

Blubber thickness

0.164

0.092

1.78

0.076

Latitude

0.910

1.188

0.77

0.446

Latitude

1.809

0.672

2.69

p<0.05Longitude−1.233

1.431

−0.86

0.392
0.215

Longitude−0.784

0.899

−0.87

0.384

Date

−0.602

0.481

−1.25

Date

−1.424

0.301

−4.73

p<0.05

MainPrey_Copepods−0.182

0.096

−1.90

0.061

MainPrey_AtkaMackerel−0.368

0.076

−4.86

p<0.05

MainPrey_Euphausiids−0.259

0.159

−1.63

0.107

MainPrey_Copepods

0.044

0.224

0.20

0.843

MainPrey_Mackerel−0.064

0.097

−0.66

0.510

−0.012

0.105

−0.12

0.906

MainPrey_Euphausiids−0.177

0.159

−1.12

0.266

MainPrey_Min.arm squid

MainPrey_Mackerel

0.050

0.139

0.36

0.722

MainPrey_Sardine

0.193

0.104

1.85

0.069

MainPrey_MAFSquid−0.386

0.209

−1.84

0.066

MainPrey_Saury−0.136

0.096

−1.41

0.164

MainPrey_OceanicLightfish−0.439

0.060

−7.30

p<0.05

MainPrey_PaciﬁcPomfret

0.930

0.335

2.78

p<0.05

MainPrey_Salmonids

0.213

0.132

1.61

0.108

MainPrey_Saury

0.188

0.050

3.73

p<0.05body of the main prey species in the stomachs is shownin Table 11. Total Hg concentrations in minke whales having mackerel in the stomach were the highest while thosehaving sardine in stomach was the lowest. The numberof minke whales having mackerel and sardine in theirstomach were only one and two whales, respectively.
These observations indicate that total Hg concentrationsof common minke whales from sub-area 7 may be lessaﬀected by total Hg in the prey species.
In sub-area 9, total Hg concentrations in muscle ofcommon minke whales (period 1996–2012) were signiﬁcantly associated with Intercept (+), Year (−), Latitude (+),
Date (−) and Main prey items (Atka mackerel, oceanic
lightfish, Paciﬁc pomfret and saury) (Table 8). A comparison of total Hg concentrations in muscle of minke whale
and in the whole body of the main prey species in thestomachs is shown in Table 12. Total Hg concentrations
in common minke whales having Paciﬁc pomfret in theirstomach were the highest, and total Hg concentrationsin Paciﬁc pomfret were one or two orders of magnitude
higher than those in the other prey items. Also total
Hg concentrations in common minke whales having
zooplankton such as copepods and euphausiids were
64

Table 10
Results of multiple robust linear regression analysis with ʻtotal
Hg levels in muscle of Bryde's whales from subareas 8 and 9ʼ as
the dependent variable.
a) Analysis of Variance
SourceRobust residual SE

0.2025R2

0.3592Adjusted R2

0.1029b) Variables
Model

B

SE

InterceptTp value−101.1

162.8

Year

9.93

22.02

−0.621 0.541
0.45

0.657

Body length

2.431

1.453

1.67

0.110

Blubber thickness−0.320

0.317

−1.01

0.325

Latitude

1.693

1.534

1.10

0.283

Longitude

1.933

2.810

0.69

0.499

Date

0.503

0.376

1.34

0.196

MainPrey_Euphausiids−0.106

0.071

−1.51

0.148

MainPrey_Mackerel−0.240

0.274

−0.88

0.391

lower than the others. Total Hg concentrations in thezooplankton were one or two orders of magnitude lower
than those in the other prey items. Furthermore, yearlychanges were observed in food items of the common
minke whales in the same period (Konishi et al., 2016).

Temporal trend of total mercury levels in common minke, sei and Brydeʼs whales in the western North Pacific in the period 1994–2014

Figure 3.

Simple plots and smoothing plots using the generalized additive model of total Hg concentrations inmuscle of common minke whales (mature males, O-stock) in sub-area 7 against research years during theperiod 1996–2012.

Figure 4.

Simple plots and smoothing plots using the generalized additive model of total Hg concentrations inmuscle of common minke whales (mature males, O-stock) in sub-area 9 against research years during theperiod 1994–2013.

Figure 5.

Simple plots and smoothing plots using the generalized additive model of total Hg concentrations inmuscle of sei whales (mature males) in sub-area 9 against research years during the period 2002–2014.

A peak of total Hg concentration was observed in 2008
(Figure 4), and Paciﬁc pomfret was observed in the stomach contents of common minke whales from sub-area 9in that year (Tamura et al., 2009). These results indicatethat changes of total Hg concentrations in common minke
whales in sub-area 9 reﬂect changes in food habits of thiswhale species rather than changes of background levelsof total Hg in the marine environment.
In sub-area 9, total Hg concentrations in sei whales (period 2002–2014) were signiﬁcantly associated with Intercept (+), Year (−) and Body length (+) (Table 9), whereas

those in 2012 were lower than the others in the GAM
plots (Figure 5). A comparison of total Hg concentrations
in muscle of sei whale and in the whole body of the main
prey species in the stomachs are shown in Table 13. Total
Hg concentrations in sei whales having anchovy and sardine in the stomach were slightly higher than the othertwo whale species from sub-area 9. These results indicatethat total Hg concentrations of sei whales from sub-area
9 may be less aﬀected by total Hg in the food items.
Temporal trends of total Hg concentrations have notbeen observed in environmental samples, lower trophic
65

66

Ave.±SDn
Ave.±SDn( 0.21±0.051)
238(0.037±0.025)
20*( 0.22±0.049)
33(0.005±0.003)
19*

Euphausiids

Copepods

Euphausiids( 0.17±2(0.018±66**

Sardine

)

)

Saury

Mackerel(0.19±0.12)
5MAFSquid( 0.11±1

Oceanic
Lightfish

Ave.±SDn
Ave.±SDn(0.049±0.013)
11(0.037±0.025)
20*

Anchovy(0.043±0.014)
48(0.005±0.003)
5*

Copepods(0.045±0.016)
9(0.005±0.003)
19*

Euphausiids(0.045±0.016)
9(0.020±0.002)
5*

MackerelSaury( 0.24±0.056)
28(0.045±)2*

Walleye Pollock(0.040±0.005)
3

Min.arm squid(0.052±)2(0.018±)66**

Sardine(0.041±0.015)
7(0.038±0.015)
41*

Saury

) ( 0.44±0.26 ) ( 0.32±0.08 ) ( 0.24±0.09 )65257( 0.23±0.03 ) (0.027±) (0.038±0.015)
3*
41**
41*

Paciﬁc PomfretSalmonids( 0.23±0.043)
26(0.038±0.015)
41*

Table 13Comparison between Hg concentrations in muscle of sei whales and in the whole body of prey species in sub-area 9.

*: Yasunaga and Fujise (2009); **: Ministry of Health, Labour and Welfare (2005)

Whole of prey spp.

Muscle of whales

Mackerel( 0.33±)
1(0.020±0.002)
5*) ( 0.17±0.07 ) ( 0.18±0.09 ) ( 0.19±0.04 )615
3) (0.005±0.003) (0.005±0.003) (0.020±0.002)
5*
19*
5*

Atka Mackerel( 0.22±0.10 ) ( 0.13±
83
1(0.037±0.025) (0.086±
20*
61**

Anchovy*: Yasunaga and Fujise (2009); **: Ministry of Health, Labour and Welfare (2005)

Ave.±SDnWhole of prey spp. Ave.±SDnMuscle of whales( 0.22±0.03)
8(0.058±)57**

JFSquid

Table 12Comparison between Hg concentrations in muscle of common minke whales and in the whole body of prey species in sub-area 9.

*: Yasunaga and Fujise (2009); **: Ministry of Health, Labour and Welfare (2005)

Whole of prey spp.

Muscle of whales

Anchovy

Table 11Comparison between Hg concentrations in muscle of common minke whales and in the whole body of prey items in sub-area 7.

Technical Reports of the Institute of Cetacean Research (2017)

Temporal trend of total mercury levels in common minke, sei and Brydeʼs whales in the western North Pacific in the period 1994–2014

Figure 6.

Schematic diagram showing total Hg ﬂow in the western North Paciﬁc food web.

organisms and baleen whales, except for common minke
whales collected from sub-areas 7 and 9, and sei whales
from sub-area 9 from 1990ʼs to 2000ʼs. Total Hg concentrations in these exceptions may reﬂect changes in food habits rather than changes of background levels of total Hg in
the marine environment. This phenomenon is illustrated
in Figure 6, which shows that diﬀerences in food habitat
explain the pattern of Hg accumulation of baleen whales.
Consequently, it is concluded that temporal trend of
total Hg concentrations in the marine habitat of baleen
whales in the western North Paciﬁc remained stable in
the research period. In future, other variables such asage of the animals, should be included in the analyses toinvestigate yearly trend of Hg concentrations in baleen
whales.

ACKNOWLEDGEMENTS
We gratefully acknowledge the researchers and crew
members that participated in JARPN/JARPNII surveys forthe collection of data and samples.

REFERENCES
Borrell, A. and Reijnders, P.J.H. 1999. Summary of temporal
trends in pollutant levels observed in marine mammals. J.
Cetacean Res. Manage. (Special Issue 1): 149–155.
Konishi, K., Isoda, T. and Tamura, T. 2016. Decadal change of
feeding ecology in sei, Brydeʼs and common minke whales in
the oﬀshore of the Western North Paciﬁc. Paper SC/F16/JR23
presented to the JARPNII Review Workshop, Tokyo, February
2016 (unpublished). 19 pp.

Laurier, F.G.J., Mason, R.P., Gill, G.A. and Whalin, L. 2004.
Mercury distribution in the North Paciﬁc Ocean: 20 years ofobservations. Mar. Chem. 90: 3–19.
Ministry of Health, Labour and Welfare. 2005. Survey results ofmercury levels in ﬁsheries. http://www.mhlw.go.jp/topics/
bukyoku/iyaku/syoku-anzen/suigin/dl/050812-1-05.pdf
R Development Core Team 2006. R: A language and environment for statistical computing. R Foundation for StatisticalComputing, Vienna, Austria. ISBN 3-900051-07-0, URL
http://www.R-project.org.
Sanpera, C., Capelli, R., Minganti, V. and Jover, L. 1993. Totaland organic mercury in North Atlantic ﬁn whales: distribution
pattern and biological related changes. Mar. Pollut. Bull. 26:
135–139.
Sunderland, E.M., Krabbenhoft, D.P., Moreau, J.W., Strode, S.A.
and Landing, W.M. 2009. Mercury sources, distribution, andbioavailability in the North Paciﬁc Ocean: Insights from data
and models. Global Biogeochem. Cycles 23: GB2010.
Tamura, T., Otani, S., Isoda, T., Wada, A., Yonezaki, S., Mori, M.,
Tsunekawa, M., Fukutome, K., Nakai, K., Satoh, H., Nomura,I., Nagatsuka, S., Umatni, M., Koyanagi, T., Takamatsu, T.,
Kawabe, S., Kandabashi, S., Watanabe, H, Kumagai, S., Sato,H. and Ogawa, T. 2009. Cruise Report of the second phaseof the Japanese Whale Research Program under Special
Permit in the Western North Paciﬁc (JARPN II) in 2008 (partI)—Oﬀshore component—. Paper SC/61/O4 presented to the
IWC Scientiﬁc Committee, May 2009 (unpublished). 49 pp.
Yasunaga, G. and Fujise, Y. 2009. Temporal trends and factors aﬀecting mercury levels in common minke, Brydeʼs
and sei whales and their prey species in the western North
Paciﬁc. Paper SC/J09/JR23 presented to the JARPNII Review
Workshop, Tokyo, January 2009 (unpublished). 14 pp.

67

Technical Reports of the Institute of Cetacean Research (2017)

pp. 68–70

Technical Report-Note (not peer reviewed)

A summary of the genetic samples of large whales collected by theInstitute of Cetacean Research
Mutsuo Goto*, Mioko Taguchi and Hiroyuki Oikawa
Institute of Cetacean Research, Toyomi-cho 4–5, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: goto@cetacean.jp
Biological samples of whales for genetic analyses are collected through diﬀerent kinds of surveys conducted by
the Institute of Cetacean Research (ICR) as well as fromby-caught and stranded animals and from past commercial whaling samples. The objective of this note is to summarize the number of samples/data collected to date.
The sources of samples are the following:• Skin samples from whales taken under special permit
scientiﬁc whaling. See details in GOJ (2015; 2017).
• Skin samples obtained by biopsy sampling under
the non-lethal component of the special permit
scientiﬁc programs. See details in Mogoe et al.
(2017).
• Skin samples obtained by biopsy sampling during
dedicated sighting surveys (national and international). See details in Isoda et al. (2017) and Matsuoka et al. (2017).
• Skin and muscle samples obtained from by-caught
whales (such samples are provided to ICR from 1
July 2001 following a national-established protocol). See details in the link: http://www.jfa.maﬀ.
go.jp/j/whale/w_document/pdf/041012tsuuchi.
pdf.
• Skin and muscle samples obtained from stranded
whales. Systematic record and sampling fromstranding are conducted by ICR since 2004. See
details in the link: http://www.jfa.maﬀ.go.jp/j/whale/w_document/pdf/manyuaru2012kaisei.
pdf.
• Historical samples from past commercial andspecial permit scientiﬁc whaling (e.g., baleen andblood samples).
Table 1 summarizes the genetic samples available in
ICR, which were collected from the above describedsources. This data set is one of the largest and mostcomprehensive in the world. Samples are used mainly for
genetic analyses on population structure and phylogenyof baleen whales, and to a lesser extent, for analyses on
pollutants and feeding ecology.
Several genetic studies based on these samples have68

been presented to international meetings (e.g., Pastene
et al. 2016; Taguchi et al. 2017), and others have been
published in peer-reviewed journals (e.g., Pastene andGoto, 2016; Malde et al. 2017).
Samples and data in Table 1 are available for cooperative studies under established ICR protocol for data
access and collaboration. See details in the following link:
http://www.icrwhale.org/pdf/appendix2.pdf.

REFERENCES
Government of Japan. 2015. Research Plan for New Scientiﬁc
Whale Research Program in the Antarctic Ocean (NEWREP-A).
Circular Communication IWC.ALL.238, November 2015 (unpublished). 110 pp.
Government of Japan. 2017. Research Plan for New Scientiﬁc
Whale Research Program in the western North Paciﬁc(NEWREP-NP). Circular Communication IWC.ALL.295, June2017 (unpublished). 190 pp.
Isoda, T., Konishi, K., Yamaguchi, F., Kawabe, S., Moriyama, R.,
Kasai, H., Igarashi, Y., Mogoe, M. and Matsuoka, K. 2017.
Results of the NEWREP-A dedicated sighting survey during
the 2016/17 austral summer season. Paper SC/67a/ASI07
presented to the IWC Scientiﬁc Committee, May 2017 (unpublished). 27 pp.
Malde, K., Seliussen, B.B., Quintela, M., Dahle, G., Besnier, F.,
Skaug, H.J., Øien, N., Solvang, H.K., Haug, H., Skern-Mauritzen,
R., Kanda, N., Pastene, L.A., Jonassen, I. and Glover, K.A. 2017.
Whole genome resequencing reveals diagnostic markers forinvestigating global migration and hybridization between
minke whale species. BMC Genomics 18: 76–86.
Matsuoka, K., Gilpatrick Jr. J.W., Kim, J.H. and Yoshimura, I.
2017. Cruise report of the 2016 IWC-Paciﬁc Ocean Whaleand Ecosystem Research (IWC-POWER). Paper SC/67a/ASI09
presented to the IWC Scientiﬁc Committee, May 2017 (unpublished). 28 pp.
Mogoe, T., Isoda, T., Yoshida, T., Nakai, K., Kanbayashi, J., Ono,
K., Yoshimura, I., Ueda, Y., Mure, H., Ueta, E., Wada, A.,
Eguchi, H. and Tamura, T. 2017. Results of the second biological ﬁeld survey of NEWREP-A during the 2016/17 australsummer season. Paper SC/67a/SCSP05 presented to the IWC
Scientiﬁc Committee, May 2017 (unpublished). 21 pp.
Pastene, L.A. and Goto, M. 2016. Genetic characterization andA summary of the genetic samples of large whales collected by the Institute of Cetacean Research

population genetic structure of the Antarctic minke whale
Balaenoptera bonaerensis in the Indo-Paciﬁc region of theSouthern Ocean. Fish Sci. 82: 873–886.
Pastene, L.A., Goto, M., Taguchi, M. and Kitakado, T. 2016.
Updated genetic analyses based on mitochondrial and microsatellite DNA indicated no sub-structure of the ʻOʼ stock common minke whale in the western North Paciﬁc. Paper SC/F16/
JR40 presented to the JARPNII special permit expert panel re-view workshop, Tokyo, February 2016 (unpublished). 14 pp.
Taguchi, M., Goto, M. and Pastene, L.A. 2017. A synthesis of thework conducted on stock structure of western North Paciﬁc
common minke whale in response to recommendations
from the IWC Scientiﬁc Committee. Paper SC/67a/SDDNA05
presented to the IWC Scientiﬁc Committee, May 2017 (unpublished). 5 pp.

69

70

Common minke whale
Blue whale
Fin whale
Sei whale
Brydeʼs whale
Humpback whale
Right whale
Sperm whale
Killer whale

11,011 (9,777: 4,096)

Antarctic minke whale
Blue whale
Fin whale
Sei whale
Humpback whale
Southern right whale

56 (56: 56)

1,354 (1,354: 1,350)
730 (730: 727)

2,680 (2,672: 2,672)

18 (18: 18)

A

Species9 (5: 9)17 (0: 17)
10 (10: 10)
55 (55: 55)
87 (87: 87)
15 (9: 15)
8 (3: 8)20 (18: 20)
2 (0: 2)35 (0: 35)
54 (39: 42)
3 (3: 3)488 (483: 488)
73 (73: 73)

B

58 (58: 58)
9 (9: 9)14 (14: 14)

4 (0: 4)5 (5: 5)20 (20: 20)
40 (40: 40)

10 (0: 10)
16 (16: 16)

C

9 (0: 1)27 (2: 2)
82 (82: 82)
84 (84: 84)
1 (0: 0)115 (115: 113)
61 (61: 61)

D

1 (1: 1)63 (63: 63)
3 (2: 3)2 (2: 2)

11 (11: 11)

2,008 (1,980: 2,008)

—
—
—
—
—
—

E

18 (0: 18)
4 (0: 4)5 (3: 5)

—
—
—
—
—
—

F

5 (0: 5)303 (302: 303)323 (323: 287)G

1994–2016
2001–2015
1997–2016
1972–2016
1977–2016
1997–2016
1958–2016
2000–20102016

1987/88–2015/16
1994/95–2015/16
1998/99–2015/16
2000/2001
1993/94–2015/16
1993/94–2015/16

Period

A: Samples from recent special permit scientiﬁc whaling. Tissue samples collected before the 2011 tsunami in Japan are not available. B: Biopsy samples obtained from sighting/sampling vessels of the surveys under recent special permit scientiﬁc whaling. C: Biopsy samples obtained from Japanese dedicated sighting surveys (conducted under or outside the special permit scientiﬁc
whaling). D: Biopsy samples obtained from international dedicated sighting surveys e.g., IWC IDCR/SOWER in the Antarctic and IWC POWER in the North Paciﬁc. E: Samples from by-catches.
Tissue samples collected before the 2011 tsunami in Japan are not available. F: Samples from stranding. G: Historical samples from past commercial whaling in the North Paciﬁc (sei whale); past
special permit scientiﬁc whaling in the North Paciﬁc (right whales); past commercial whaling in the western North Paciﬁc and eastern South Paciﬁc, and past special permit scientiﬁc whaling
in other oceanic basins (Brydeʼs whale).

North Paciﬁc

Antarctic

Table 1
Number of genetic samples of several cetacean species available at the ICR. The numbers on the left and right sides in parenthesis indicate the available microsatellite and mtDNA data, respectively.

Technical Reports of the Institute of Cetacean Research (2017)

Technical Reports of the Institute of Cetacean Research (2017)

pp. 71–75

Commentary
The views expressed here are those of the author and do not necessarily reﬂect the views of the Institute of
Cetacean Research

Evolution of the IWC Scientiﬁc Committee
Dan Goodman1
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, JapanINTRODUCTION
The Scientiﬁc Committee is one of four Committees
established by the International Whaling Commission(hereafter, the Commission), the others being the Financeand Administration Committee, the Technical Committee
and the Conservation Committee. The Scientiﬁc Committee was established by the IWC in 1950. This in part is areﬂection of Article IV of the International Convention
for the Regulation of Whaling (hereafter, the Convention)that refers to scientiﬁc research and the publication of
results, statistics and reports2 and in part a reﬂection of
Article V2 of the Convention that states inter alia that
Schedule amendments ʻ…shall be based on scientiﬁcﬁndings…ʼ3. The Scientiﬁc Committee has met each year
since its establishment (Donovan and Hammond, 2017).
The Scientiﬁc Committee was established in accordance with the IWCʼs Rules of Procedure M1 and its
terms of reference are given in Rule M4. The duties of the
Scientiﬁc Committee are further elaborated in the Rulesof Procedure for the Scientiﬁc Committee which were signiﬁcantly amended by the Commission at its meeting in2016 (see details below). Scientiﬁc Committee priorities
and the initial agenda for the next meeting together withwork plans for the intersessional period are approved atmeetings of the Commission.
Just as the Commission has moved away from its core
responsibilities related to the management of whaling ina manner prescribed by Article IV of the Convention (seefootnote 2), the Scientiﬁc Committee has, to a signiﬁcantdegree evolved away from providing advice on sustainable catch levels for large whales to that of providing
advice on non-direct catch related threats to all cetacean
stocks. This paper describes some of the major factors
and events related to or responsible for this evolution.
The Committee of Three (Four)
Evolution of the Scientiﬁc Committee essentially began
in 1961 with the establishment by the Commission of
the Committee of Three, later Four, scientists who wereexperts in population dynamics. They were tasked withassessing the whale stocks, reporting on the sustainable
yield of these stocks and advising on any conservation
measures that would increase yield. This new focus whichdeveloped and extended the mathematical techniques as
used in ﬁsheries assessments to the science of managing
whale stocks led to recommendations for reduced catches and that the regulation of catches should be on an

1

The author is a Councillor at the Institute of Cetacean Research in Tokyo and a former Visiting Researcher at the Government ofJapanʼs Fisheries Agency. The author has been involved in all aspects of the work of the International Whaling Commission for morethan 30 years. He is a former Senior Advisor in the Government of Canadaʼs Department of Fisheries and Oceans and represented theGovernment of Canada at meetings of the IWC from 1979 to 1996. He is a member of the IWC Scientiﬁc Committee and has been amember of the Government of Japanʼs delegation to the IWC since 1998.
2
Article IV
The Commission may either in collaboration with or through independent agencies of the Contracting Governments or other public
or private agencies, establishments, or organizations, or independently(a) encourage, recommend, or if necessary, organize studies and investigations relating to whales and whaling;(b) collect and analyze statistical information concerning the current condition and trend of the whale stocks and the eﬀects of whaling activities thereon;(c) study, appraise, and disseminate information concerning methods of maintaining and increasing the populations of whale stocks.
3
Article V(2)These amendments of the Schedule (a) shall be such as are necessary to carry out the objectives and purposes of this Convention
and to provide for the conservation, development, and optimum utilization of the whale resources; (b) shall be based on scientiﬁcﬁndings; ….
71

Technical Reports of the Institute of Cetacean Research (2017)individual species basis rather than in the combined Blue
Whale Unit (BWU) system (Gambell, 1977; Allen, 1980).
The New Management Procedure (NMP)
The next major development to impact the work of the
Scientiﬁc Committee was the Commissionʼs adoption of
the New Management Procedure (NMP) in 1974. This followed: (i) the adoption of a resolution at the 1972 United
Nations Conference on the Human Environment thatcalled for a 10-year moratorium on all commercial whaling; a demand for greatly increased scientiﬁc research
into the status of the worldʼs whale stocks; and a call forthe strengthening of the IWC secretariat and its capabilities (Gambell, 1977) and, (ii) the consensus agreement by
the Scientiﬁc Committee that a blanket moratorium could
not be scientiﬁcally justiﬁed (IWC, 1973). With the adoption of the NMP the focus of the Scientiﬁc Committee
became classifying whale stocks into three categories
according to their relative abundance (IWC, 2016a). Alsoin response to the 1972 United Nations Conference on
the Human Environment resolution, the IWC Scientiﬁc
Committee compiled a large-scale program for an International Decade of Cetacean Research (Gambell, 1977).
The Moratorium and the Revised Management
Procedure (RMP)
Between 1972 and 1982, a total of 29 proposals for a
moratorium on commercial whaling were proposed.
The Commission rejected all of them except 1 of the 5
proposals proposed in 1982.4 The proposal that was adopted is paragraph 10(e) of the Schedule (IWC, 2016a)—
commonly referred to as ʻthe Moratoriumʼ. It was (atleast on its face) intended as a temporary measure(Morishita, 2013) based on the view that there was toomuch uncertainty in the scientiﬁc knowledge to ensure
safe harvest levels (Morishita and Goodman, 2005; IWC,
2017a). There was however, no advice from the Scientiﬁc
Committee that such a measure was required for conservation (Morishita and Goodman, 2005).
Following the moratorium decision, the Commission
asked the Scientiﬁc Committee to develop a new approach to providing advice on the setting of catch limits
that was both safe and practical. This was a complex task
and formed a major part of the work of the Scientiﬁc
Committee during the eight years it took to complete.
4

Details of the proposals and the manner in which they weredealt with by the Commission are recorded in the Chairʼs reports of the Annual Meetings. Available at: https://archive.iwc.
int/pages/search.php?search=%21collection49&k=

72

The new process was called the Revised Management
Procedure (RMP). It was adopted by the Commission
in 1994 and set a new standard in scientiﬁc management advice for marine and other living resources (IWC,
2017a).
Scientiﬁc Committee membership and agenda
Referencing IWC reports, Morishita and Goodman (2005)
recorded that in 1976, 29 scientists representing elevencountries and one intergovernmental organization participated in the Annual Meeting of the Commissionʼs
Scientiﬁc Committee. They note that the agenda for thismeeting consisted of 21 items primarily focused on thestatus of stocks and providing advice to the Commission
on quotas for whaling. They further note that in contrast
to this, the 2004 meeting of the Scientiﬁc Committee wasattended by 202 scientists from 30 member countries
and eight international organizations, and included 41
ʻinvited participantsʼ and one representative from a nongovernmental organization and that the 26-item agenda
included numerous items which are regarded by approximately half of the IWC member countries as outside of
the Commissionʼs mandate such as small cetaceans, DNA
testing, environmental concerns, whalewatching, bycatch in ﬁsheries and ship strikes.
This drastic change in the Scientiﬁc Committee took
place over a number of years beginning in the late 1970ʼswith the recruitment of additional Commission memberswith an anti-whaling position in order to obtain the 3/4
majority vote required to adopt the moratorium. Importantly, the additional membership also provided antiwhaling members with the means to change to focus of
the Scientiﬁc Committeeʼs work away from the provisionof management advice for the regulation of commercial
whaling through the adoption of resolutions and changes
to the Rules of Procedure of the Scientiﬁc Committee that
only require a simple majority for adoption. The following
examples elaborate this point.
The Berlin Initiative
At its 55th Annual Meeting the Commission adopted
resolution 2003-1 titled ʻThe Berlin Initiative on Strengthening the Conservation Agenda of the International
Whaling Commissionʼ. This resolution references what
are referred to as ʻmore than 100 conservation-oriented
resolutionsʼ and notes that ʻthe Commission has graduallydeveloped an extensive conservation-oriented agendaʼ.
The resolution established the ʻConservation Committeeʼ and, inter alia ʻrequests the Scientiﬁc Committee toadvise the Conservation Committee in the performanceEvolution of the IWC Scientific Committeeof the tasks entrusted to it in this Resolution, and toensure that the appropriate scientiﬁc research items,
including inter alia, whalewatching, environmental issues
and behavioural research, under the responsibility of the
Scientiﬁc Committee, are incorporated in the Conservation Agendaʼ (IWC, 2004). This major shift in the focus of
the Scientiﬁc Committee agenda has been enhanced byadditional resolutions since 20035 and, approval of the
Scientiﬁc Committee agenda is a speciﬁc agenda item at
each meeting of the Commission.
Resolution 2014-4: Resolution on the Scientiﬁc
Committee
Resolution 2014-4 that was adopted by consensus recallsʻmore than 50 resolutions of the International Whaling
Commission addressing the work of the Scientiﬁc Committee, particularly regarding the increase and evolving
work over decades on conservation aspects, including
small cetaceansʼ. Further, the resolution notes ʻthat thework of the Scientiﬁc Committee oriented towards issues
related to other threats than direct takes, has increased
over the last decades…ʼ, ʻconsolidates the mandate of
the Small Cetaceans Standing Sub-Committeeʼ and establishes ʻa working group between the Conservation Committee and the Scientiﬁc Committee in order to propose aprocedure to facilitate the implementation and follow-up
of conservation recommendationsʼ. Annex 1 of Resolution 2014-4 is a ʻCompiled list of IWC resolutions addressing the work of the Scientiﬁc Committee 1976–2012ʼ
(IWC, 2016b).
As with the Berlin Initiative described above, this resolution adds emphasis to those aspects of the Scientiﬁc
Committeeʼs work that are unrelated to its core responsibility of providing advice on the regulation of commercial
whaling as provided for by the Convention.
Amendments to the Commissionʼs Rules of Procedureand Financial Regulations and to the Rules of Procedureof the Scientiﬁc Committee.
Resolution 2014-4 proposed a number of amendments
to the Commissionʼs Rules of Procedure and Financial
Regulations and to the Rules of Procedure of the Scientiﬁc Committee. The Resolution including proposed
amendments to the Commissionʼs Rules of Procedureand Financial Regulations (Annex II of the Resolution)
were adopted by consensus while, in accordance with5

See for example Resolution 2009-1, 2012-1, 2016-3, and2016-4. Available at: https://archive.iwc.int/pages/search.php?
search=%21collection72&k=

the Resolution, proposed amendments to the Rules ofProcedure of the Scientiﬁc Committee (Annex III of the
Resolution) were referred to the Scientiﬁc Committee for
their advice.
Changes to the Commissionʼs Rules of Procedureincluded references to ʻcetaceansʼ rather than ʻwhalesʼ
and the addition of the words ʻshall review current andpotential threats and methods to mitigate them in orderto maintain cetacean populations at viable levels…ʼ tothe duties of the Scientiﬁc Committee contained in Ruleof Procedure M. 4 (a). Changes to the Financial Regulations established a Research Fund and prescribed that the
Research Fund ʻshall have a balanced distribution among
activities … including small cetaceans…ʼ.
Proposed amendments to the Rules of Procedure of
the Scientiﬁc Committee also referred to ʻcetaceansʼand ʻsmall cetaceansʼ rather than ʻwhalesʼ and proposed
signiﬁcant changes to the items listed under the headingʻSPECIFIC TOPICS of current concern to the Commissionʼ
(IWC, 2016b).
Proposed amendments to the Rules of Procedure for
the Scientiﬁc Committee included in resolution 2014-4
were considered by the Scientiﬁc Committee at its meeting in 2015. Their recommendations together with some
additional proposed amendments were incorporated
in its Annex R (IWC, 2016c). These additional proposed
amendments included deletion of the section titled ʻSpeciﬁc Topics of current concern to the Commissionʼ. The
Scientiﬁc Committee proposed that this section would be
more eﬀectively located in the introduction to its workplanʼ. Annex R of the 2015 Scientiﬁc Committee report
was then considered by the Finance and Administration
Committee and adopted by the Commission at its 2016
meeting (IWC, 2016d).
In summary, amendments to the Commissionʼs Rulesof Procedure and Financial Regulations and to the Rulesof Procedure of the Scientiﬁc Committee that resulted
from the adoption of Resolution 2014-4 provide strong
support for the view of anti-whaling Commission members that the Scientiﬁc Committee and the Commissionthat approves the work plan and agenda of its Scientiﬁc
Committee have a mandate concerning the managementof small cetaceans as well as a broad mandate related tothreats to cetacean populations.
Whalewatching
The IWC adopted its ﬁrst resolution on whalewatchingin 1993 at IWC45, and the following year, at IWC46, afurther resolution requested advice from the Scientiﬁc
Committee on whalewatching and established what has
73Technical Reports of the Institute of Cetacean Research (2017)

in practice now become an ongoing program of work. In
1998, a standing Whale Watching Sub-Committee was set
up under the Scientiﬁc Committee (IWC, 2011).
OthersOther records that document or demonstrate the shift in
the activities of the Commission and its Scientiﬁc Committee away from their core responsibilities provided by
the Convention to a focus on threats to cetaceans fromissues other than direct takes include:(i) The list of issues on the IWC website under the tabtitled ʻConservation and Managementʼ. Items on
this list include 3 items related to whaling and 11
non-whaling issues including animal welfare issue,
bycatch, entanglement of large whales, strandings,
ship strikes, environmental concerns, conservation
management plans, sanctuaries and MPAs and,whalewatching (IWC, 2017b).
(ii) The 60 correspondence groups established by the
Scientiﬁc Committee (IWC, 2017c) of which almost
one half are not related to Commissionʼs primary
responsibility.
(iii) The agenda for the 2017 meeting of the Scientiﬁc
Committee that includes: cooperation with otherorganizations, bycatch, ship strikes, environmental
concerns, small cetaceans, whalewatching andwhale sanctuaries (IWC, 2017d). At the meeting, anumber of Sub-committees and Working Groups
were established to address some of these issues
even though many members of the Commission
view these as outside of the Commissionʼs mandate.

CONCLUSIONS
While the above has clearly documented the increase in
the work of the Scientiﬁc Committee oriented towards
issues related to other threats than direct takes, it should
be noted that the Scientiﬁc Committee has continued
work related to the management of whale stocks. In thisregard, the agenda for the 2017 meeting of the Scientiﬁc
Committee includes: General assessment issues related
to the Revised Management Procedure (RMP); RMP implementation matters related to North Atlantic common
minke whales, Western North Paciﬁc common minke
whales; Aboriginal Subsistence whaling; In-depth assessments of whale stocks not subject to directed takes; and,cetacean abundance estimates and stock status (IWC,
2017d). However, three aspects of the context of thiscontinuing work need emphasis:(i) Changes to the Financial Regulations adopted aspart of Resolution 2014-4 added the following:
74

ʻThe Research Fund shall have a balanced distribution among activities, deﬁned according to conservation priorities and the work of the Commission,
including small cetaceans (IWC, 2016b)ʼ.6(ii) Resolution 1997-5 that ʻInstructs the Scientiﬁc
Committee not to consider Southern Hemisphereminke whales in the context of implementation of
the RMP unless advised to do so by the Commissionʼ remains in eﬀect (IWC, 1998).
(iii) The current politicized nature of the Scientiﬁc
Committee means that it is highly unlikely that its
work on RMP related matters would result in recommendations to the Commission for the settingof quotas for the resumption of commercial whaling (Morishita and Goodman, 2005).
These aspects of the context of the Scientiﬁc Committeeʼs work lend strong support for the following conclusions reached by Morishita and Goodman (2005).
(i) ʻThe deep philosophical and political divisions
between the International Whaling Commission(IWC) member countries that support managed
whaling activities and those opposed to any harvesting of whales has caused a seriously dysfunctional situation in the IWCʼ.
(ii) ʻStrong personal positions on the issues related towhaling, the inﬂuence of national government positions on scientists and advocacy have polarized
the debates within the Scientiﬁc Committeeʼ.
(iii) ʻUnless the Commission and its member governments change their institutionalized discourse andprocedures, it is naïve to expect outputs from the
Scientiﬁc Committee that are useful for the sustainable use and management of whale resourcesin accordance with the objectives of the ICRWʼ.

REFERENCES
Allen, K.R. 1980. Conservation and Management of Whales.
Washington Sea Grant distributed by University of Washington
Press Seattle, Washington.
Donovan, G. and Hammond, P. 2017. Scientiﬁc Committee
Handbook. [Available at https://iwc.int/scientiﬁc-committeehandbook Last accessed Sept. 1, 2017].
Gambell, R. 1977. Whale Conservation—Role of the International
Whaling Commission. Marine Policy, October 1977.
International Whaling Commission. 1973. Report of the
Scientiﬁc Committee Rep. int. Whal. Commn 23: 28–263.

6This is a not so subtle attempt to reduce funding for the Commission and Scientiﬁc Committee work related to the provisionof management advice.

Evolution of the IWC Scientific Committee

International Whaling Commission. 1998. Report of the Forty-Ninth
Annual Meeting. Appendix 5. IWC Resolution 1998-4 Resolution
on Whaling under Special Permit. 1998: 43. [Available athttps://iwc.int/private/downloads/egGQwtdRPDuv-4v_2ezJsA/
IWCRES49_1997.pdf Last accessed Sept. 5, 2017].
International Whaling Commission. 2004. Report of the Fifty-Fifth
Annual Meeting. Annex C. Resolution 2003-1 Adopted during the 55th Annual Meeting. IWC Resolution 2003-1. The
Berlin Initiative on Strengthening the Conservation Agendaof the International Whaling Commission. Ann. Rep. Int.
Whal. Commn. 2003: 58–60. [Available at https://archive.iwc.
int/pages/search.php?search=%21collection72&k= Last accessed Sept. 5, 2017].
International Whaling Commission. 2011. Five Year Strategic Plan
for Whalewatching 2011–2016. [Available at https://iwc.int/
private/downloads/ZibAR4HShR6wjYdH9C8NRw/AC-002s3%20
IWC%20Whale%20Booklet_HR.pdf Last accessed Sept. 5,
2017].
International Whaling Commission. 2016a. Paragraph 10 of the
Schedule to the International Convention for the Regulationof Whaling. [Available at https://archive.iwc.int/pages/view.
php?ref=3606&k= Last accessed Sept. 1, 2017].
International Whaling Commission. 2016b. Report of the
Sixty-Fifth Annual Meeting. Annex E Resolutions Adopted
at the 65th Meeting. IWC Resolution 2014-4 Resolution on
the Scientiﬁc Committee. 2014: 50–53. [Available at https://archive.iwc.int/pages/search.php?search=%21collection72&
k= Last accessed Sept. 1, 2017].
International Whaling Commission. 2016c. Report of the
Scientiﬁc Committee. Annex R. Proposed Amendments to
the Scientiﬁc Committee Rules of Procedure. J. Cetacean Res.

Manage. (Suppl.) 17: 423–430. [Available at https://archive.
iwc.int/pages/search.php?search = %21collection73&k =Last accessed Sept. 1, 2017].
International Whaling Commission. 2016d. Chairʼs Report of the
Sixty-sixth Meeting of the International Whaling Commission
2016: 43 pp. [Available at https://archive.iwc.int/pages/
search.php?search=%21collection49&k= Last accessed Sept.
5, 2017].
International Whaling Commission. 2017a. The Revised
Management Procedure - a detailed account [Available athttps://iwc.int/rmp2 Last accessed Sept. 1, 2017].
International Whaling Commission. 2017b. Conservation &Management at the IWC website. [Available at https://iwc.
int/home Last accessed Sept. 5, 2017].
International Whaling Commission. 2017c. CorrespondenceGroups of Scientiﬁc Committee at the IWC website. [Available
at https://iwc.int/correspondence-groups Last accessed Sept.
5, 2017].
International Whaling Commission. 2017d. Report of the Scientiﬁc
Committee 2017. Annex B. Agenda. [Available at https://archive.iwc.int/pages/search.php?search=%21collection73&k=
Last accessed Sept.5, 2017].
Morishita, J. and Goodman, D. 2005. Role and Problems of
the Scientiﬁc Committee of the International Whaling
Commission in terms of Conservation and Sustainable
Utilization of Whale Stocks. Global Environ. Res. 9(2): 157–
166.
Morishita, J. 2013. The Truth about the Commercial Whaling
Moratorium. Senri. Ethnol. Stud. 84: 337–353. In: Kishigami,N., Hamaguchi, H. and Savelle, J.M. (eds). AnthropologicalStudies of Whaling.

75

Technical Reports of the Institute of Cetacean Research (2017)

pp. 77–79

International meetings

Participation of Scientists of the Institute of Cetacean Research inInternational Meetings in 2017
Annual meeting of the International Whaling
Commission Scientiﬁc Committee (IWC SC)
The International Whaling Commission (IWC) is an international body set up by the terms of the International
Convention for the Regulation of Whaling (ICRW), which
was signed in Washington, D.C., United States, on 2 December, 1946 to ʻprovide for the proper conservation ofwhale stocks and thus make possible the orderly development of the whaling industry.ʼ One of the importantcomponents of the IWC is the Scientiﬁc Committee (SC),which meets annually. The 2017 meeting of the IWC SC
was held at the Golf Hotel, Bled, Slovenia, from 9–21 May.
A total of ten scientists from the Institute of Cetacean Research (ICR) participated in the meeting (Yoshihiro Fujise,
Luis A. Pastene, Tsutomu Tamura, Koji Matsuoka, Mutsuo
Goto, Takashi Hakamada, Genta Yasunaga, Kenji Konishi,
Tatsuya Isoda and Mioko Taguchi), who presented eight
documents at plenary sessions, one document at the
Sub-Committee on Revised Management Procedure, ﬁve
documents at the Ad hoc Working Group on Abundance
Estimates, Stock Status and International Cruises, two
documents at the Working Group on Ecosystem Modelling, two documents at the Working Group on StockDeﬁnition and DNA Testing, one document at the SubCommittee on In-Depth Assessments, and two at the SubCommittee on Conservation Management Plans.

Hotel Golf, Bled, Slovenia.

In 2017 ICR scientists also participated in several
intersessional meetings of the IWC SC: a) Review Workshop for the New Scientiﬁc Whale Research Programin the western North Paciﬁc (NEWREP-NP), held at the
Toyomi Center Building, Tokyo, Japan, from 30 January-3 February (Seiji Ohsumi, Yoshihiro Fujise, Luis A.
Pastene, Tsutomu Tamura, Koji Matsuoka, Mutsuo Goto,

Takeharu Bando, Takashi Hakamada, Genta Yasunaga,
Satoko Inoue, Mioko Taguchi and Megumi Takahashi);b) Workshop on the Implementation Review of western
North Paciﬁc Brydeʼs Whales held at the Fisheries Agencyof Japan (FAJ)ʼs Sanban-cho, Tokyo, Japan from 21–24
March (Luis A. Pastene, Tsutomu Tamura, Mutsuo Goto,
Mioko Taguchi, Takashi Hakamada and Koji Matsuoka); c)
Workshop on the Comprehensive Assessment of North
Paciﬁc Humpback Whales held at the Marine Mammal
Laboratory, Seattle, USA from 18–21 April (Koji Matsuoka); d) Planning Meeting for the 2018 and 2019 IWCPOWER Cruises in the North Paciﬁc held at the FAJʼs Crew
House, Tokyo, Japan from 15–18 October (Koji Matsuoka
and Takashi Hakamada).

Annual meeting of the Convention on theConservation of Antarctic Marine Living Resources—Working Group on Ecosystem Monitoringand Management (CCAMLR-EMM)
The Convention on the Conservation of Antarctic Marine
Living Resources (CCAMLR) is part of the Antarctic Treaty
System. The Convention was opened for signature on
1 August 1980 and entered into force on 7 April 1982
thereby establishing the Commission for the Conservation of Antarctic Marine Living Resources. The goal is topreserve marine life and environmental integrity in andnear Antarctica. It was established in large part in response to concerns that an increase in krill catches in theSouthern Ocean could have a serious impact on populations of other marine life which are dependent upon krill
for food. The CCAMLR has a Scientiﬁc Committee andseveral Working Groups including the Working Group on
Ecosystem Monitoring and Management (EMM), whichmeet annually. The 2017 meeting of the CCAMLR-EMM
was held at the Palacio San Martin, Buenos Aires, Argentina from 10–14 July. One scientist from ICR participatedin the meeting (Tsutomu Tamura) presenting a document
titled ʻFeeding habits and prey consumption of Antarctic
minke whale Balaenoptera bonaerensis in the IndoPaciﬁc region of the Southern Oceanʼ relevant to themeeting agenda item ʻEcological interactions: predators.ʼ

77

Technical Reports of the Institute of Cetacean Research (2017)

Annual meeting of the North Paciﬁc Marine Science Organization (PICES)

Palacio San Martin, Buenos Aires, Argentina.

XIIth Scientiﬁc Committee for Antarctic Research(SCAR) Biology Symposium
The Scientiﬁc Committee on Antarctic Research (SCAR) is
an interdisciplinary body of the International Council for
Science (ICSU). It was established in February 1958. SCAR
is charged with initiating, developing and coordinating
scientiﬁc research in the Antarctic region. The scientiﬁcbusiness of SCAR is conducted by its Standing Scientiﬁc
Groups. SCAR also provides scientiﬁc advice to the Antarctic Treaty Consultative Meetings and other organizations on issues of science and conservation aﬀecting themanagement of Antarctica and the Southern Ocean. The
XIIth SCAR Biology Symposium was held at the Universityof Leuven, Leuven, Belgium from 10–14 July 2017. One
scientist from ICR participated in the meeting (Luis A.
Pastene) who presented the study titled ʻCetacean as
indicators of historical and current changes in the Antarctic ecosystemʼ as an oral presentation at the session
ʻDistribution and trends of top predators.ʼ He was also coauthor of the study titled ʻChanges in circumpolar spatial
distribution of baleen whales in the Antarctic from 1980s
to 2000s,ʼ which was presented as a poster at the session
ʻLarge scale analyses of spatial diversity pattern.ʼ

Leuven University, Leuven, Belgium.
78

The North Paciﬁc Marine Science Organization (PICES) isan intergovernmental organization that promotes andcoordinates marine scientiﬁc research in the North Paciﬁc Ocean and provides a mechanism for informationand data exchange among scientists in its member countries. The 2017 meeting of the PICES was held at the Far
Eastern Federal University, Vladivostok, Russia from 22
September-1 October. One scientist from ICR participatedin the meeting (Tsutomu Tamura) presenting the study titled ʻEstimation of prey consumption by cetaceans in thewestern North Paciﬁc-Update of Hunt et al. (2000)ʼ as anoral presentation at the session ʻSeasonal and climatic inﬂuences on prey consumption by marine birds, mammals
and predatory ﬁshes.ʼ He was also co-author of anotherstudy titled ʻSpatial estimation of prey consumption by
sei whales in the western North Paciﬁc during the summers of 2008–2009: Density surface model approach,ʼ
also presented to the meeting.

Far Eastern Federal University, Vladivostok, Russia.

22nd Biennial Meeting of the Society for Marine
Mammalogy (SMM)
The Society for Marine Mammalogy (SMM) was founded
in 1981 and is the largest international association ofmarine mammal scientists in the world. The mission of
the SMM is to promote the global advancement of marine mammal science and contribute to its relevance andimpact in education, conservation and management. The
22nd Biennial meeting of the SMM was held at the Halifax
World Trade and Convention Centre, Halifax, Nova Scotia,
Canada from 23–27 October 2017. One scientist from ICR
participated in the meeting (Kenji Konishi) presenting thestudy ʻMovements of satellite monitored Antarctic minke
whales inside and along the ice edge at the feeding areain the Paciﬁc sector of the Antarctic Circle,ʼ as a poster at

Participation of scientists of the Institute of Cetacean Research in International Meetings in 2017

the session ʻHabitat and Distribution.ʼ He and other ICR
members were co-authors of another study titled ʻEstimation of feeding records in pregnant Antarctic minke
whales using stable isotope analysis of carbon and nitrogen of baleens,ʼ which was also presented as a poster.

ment was signed in Nuuk, Greenland on 9 April 1992
by Norway, Iceland, Greenland and the Faroe Islands,
and entered into force 90 days later on 8 July 1992. The
agreement focuses on modern approaches to the studyof the marine ecosystem as a whole, and to better understanding the role of marine mammals in the ecosystem.
NAMMCO has a Scientiﬁc Committee (SC) which meetsannually. The 2017 NAMMCO SC meeting was held at
the Marine Research Institute, Reykjavik, Iceland from
14–17 November. One scientist from ICR participated in
the meeting (Genta Yasunaga) as an observer for Japanand presented the Japan progress report on cetacean
research in 2016.

Halifax World Trade and Convention Centre, Halifax, Nova
Scotia, Canada.

Annual meeting of the North Atlantic Marine Mammal Commission (NAMMCO) Scientiﬁc
Committee (SC)The North Atlantic Marine Mammal Commission(NAMMCO) is an international body for cooperation on
the conservation, management and study of marine
mammals in the North Atlantic. The NAMMCO Agree-

Marine Research Institute, Reykjavik, Iceland.

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Technical Reports of the Institute of Cetacean Research (2017)

pp. 81–97

Peer-reviewed publications

List of peer-reviewed publications based on the Institute of
Cetacean Research (ICR)ʼs surveys up to 2017
This section presents a list of peer-reviewed publications
based on data collected by surveys conducted under
special scientiﬁc permit (JARPA/JARPAII and JARPN/
JARPNII), including both lethal and non-lethal techniques.
Peer-reviewed publications based on these surveys arefocused mainly on topics related to assessment and management of large whales. However samples and data collected by the surveys have also been useful to carry out
studies of a more academic-oriented nature. Publications
based on such studies are also listed here.
This section also includes a list of peer-reviewed publications resulting from other surveys and research activities, diﬀerent from special scientiﬁc permit surveys.
Publications having as a ﬁrst author a non-ICR scientist commonly followed a data request or collaboration
research agreement with ICR. In a few cases, externalscientists used published data from ICR surveys in theiranalyses and publications, without a formal agreementwith ICR. These cases are indicated by an asterisk (*).

JARPA/JARPAII surveys
1989 (2)Kato, H., Hiroyama, H., Fujise, Y. and Ono, K. 1989.
Preliminary report of the 1987/88 Japanese feasibility study of the special permit proposal for Southern
Hemisphere minke whales. Rep. int. Whal. Commn 39:
235–248.
Nakamura, T., Ohnishi, S. and Matsumiya, Y. 1989. A
Bayesian cohort model for catch-at-age data obtained
from research takes of whales. Rep. int. Whal. Commn
39: 375–382.
1990 (8)Butterworth, D.S. and Punt, A.E. 1990. Some preliminary
examinations of the potential information content
of age-structure data from Antarctic minke whale research catches. Rep. int. Whal. Commn 40: 301–315.
Ichii, T. 1990. Distribution of Antarctic krill concentrations
exploited by Japanese krill trawlers and minke whales.
Proc. NIPR Symp. Polar Biol. 3: 36–56.
Itoh, S., Takenaga, F. and Tsuyuki, H. 1990. Studies on lipidsof the Antarctic minke whale. I. The fatty acid compositions of the minke whale blubber oils caught on 1987/88
season. Yukagaku 39 (7): 486–490 (in Japanese).

Kasamatsu, F., Kishino, H. and Hiroyama, H. 1990. Estimation of the number of minke whale (Balaenoptera
acutorostrata) schools and individuals based on the
1987/88 Japanese feasibility study data. Rep. int. Whal.
Commn 40: 239–247.
Kato, H., Fujise, Y., Yoshida, H., Nakagawa, S., Ishida, M.
and Tanifuji, S. 1990. Cruise report and preliminary
analysis of the 1988/89 Japanese feasibility study ofthe special permit proposal for southern hemisphereminke whales. Rep. int. Whal. Commn 40: 289–300.
Kato, H., Kishino, H. and Fujise, Y. 1990. Some analyses on
age composition and segregation of southern minke
whales using samples obtained by the Japanese feasibility study in 1987/88. Rep. int. Whal. Commn 40:
249–256.
Nagasaki, F. 1990. The Case for Scientiﬁc Whaling. Nature
334: 189–190.
Tanaka, S. 1990. Estimation of natural mortality coeﬃcient of whales from the estimates of abundance andage composition data obtained from research catches.
Rep. int. Whal. Commn 40: 531–536.
1991 (9)Bergh, M.O., Butterworth, D.S. and Punt, A.E. 1991. Further examination of the potential information content
of age-structure data from Antarctic minke whale
research catches. Rep. int. Whal. Commn 41: 349–361.
Ichii, T. and Kato, H. 1991. Food and daily food consumption of southern minke whales in the Antarctic. Polar
Biol 11 (7): 479–487.
Kasamatsu, F., Kishino, H. and Taga, Y. 1991. Estimationof southern minke whale abundance and school size
composition based on the 1988/89 Japanese feasibility
study data. Rep. int. Whal. Commn 41: 293–301.
Kato, H., Fujise, Y. and Kishino, H. 1991. Age structure andsegregation of southern minke whales by the data obtained during Japanese research take in 1988/89. Rep.
int. Whal. Commn 41: 287–292.
Kato, H. and Miyashita, T. 1991. Migration strategy ofsouthern minke whales in relation to reproductive
cycles estimated from foetal lengths. Rep. int. Whal.
Commn 41: 363–369.
Kato, H., Zenitani, R. and Nakamura, T. 1991. Inter-reader
calibration in age readings of earplugs from southernminke whale, with some notes of age readability. Rep.
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Technical Reports of the Institute of Cetacean Research (2017)

int. Whal. Commn 41: 339–343.
Kishino, H., Kato, H., Kasamatsu, F. and Fujise, Y. 1991.
Detection of heterogeneity and estimation of population characteristics from the ﬁeld survey data: 1987/88
Japanese feasibility study of the Southern Hemisphereminke whales. Ann. Inst. Statist. Math. 43 (3): 435–453.
Nakamura, T. 1991. A new look at a Bayesian cohortmodel for time-series data obtained from researchtakes of whales. Rep. int. Whal. Commn 41: 345–348.
Wada, S., Kobayashi, T. and Numachi, K. 1991. Genetic
variability and diﬀerentiation of mitochondrial DNA
in minke whales. Rep. int. Whal. Commn (special
issue 13): 203–215.
1992 (2)Nakamura, T. 1992. Simulation trials of a Bayesian cohortmodel for time-series data obtained from researchtakes of whales. Rep. int. Whal. Commn 42: 421–427.
Tanaka, S., Kasamatsu, F. and Fujise, Y. 1992. Likely precision of estimates of natural mortality rates fromJapanese research data for Southern Hemisphereminke whales. Rep. int. Whal. Commn 42: 413–420.
1993 (7)Fujise, Y., Ishikawa, H., Saino, S., Nagano, M., Ishii, K.,
Kawaguchi, S., Tanifuji, S., Kawashima, S. and Miyakoshi H. 1993. Cruise report of the 1991/92 Japanese research in Area IV under the special permit for Southern
Hemisphere minke whales. Rep. int. Whal. Commn 43:
357–371.
Hasunuma, R., Ogawa, T., Fujise, Y. and Kawanishi,
Y. 1993. Analysis of selenium metabolites in urine
samples of minke whale (Balaenoptera acutorostrata)
using ion exchange chromatography. Comp. Biochem.
Physiol. 104C (1): 87–89.
Itoh, S., Takenaga, F. and Tsuyuki, H. 1993. Studies onlipids of the Antarctic minke whale. II. The fatty acidcompositions of the blubber oils of minke whale anddwarf minke whale caught on 1988/89 and 1989/90
seasons. Yukagaku 42 (12): 1007–1011 (in Japanese).
Iwata, H., Tanabe, S., Sakai, N., and Tatsukawa, R. 1993.
Distribution of persistent organochlorines in the oceanic air and surface seawater and the role of ocean on
their global transport and fate. Environ. Sci. Technol.
27: 1080–1098.
Kasamatsu, F., Yamamoto, Y., Zenitani, R., Ishikawa, H.,
Ishibashi, T., Sato, H., Takashima, K. and Tanifuji, S.
1993. Report of the 1990/91 southern minke whale
research cruise under scientiﬁc permit in Area V. Rep.
int. Whal. Commn 43: 505–522.
82

Nakamura, T. 1993. Two-stage Bayesian cohort modelfor time-series data to reduce bias in the estimate ofmean natural mortality rate. Rep. int. Whal. Commn
43: 343–348.
Pastene, L.A., Kobayashi, T., Fujise, Y. and Numachi, K.
1993. Mitochondrial DNA diﬀerentiation in Antarctic
minke whales. Rep. int. Whal. Commn 43: 349–355.
1994 (3)Kimoto, H., Endo, Y. and Fujimoto, K. 1994. Inﬂuence ofinteresteriﬁcation on the oxidative stability of marine
oil triacylglycerols. JAOCS 71 (5): 469–473.
Pastene, L.A., Fujise, Y. and Numachi, K. 1994. Diﬀerentiation of mitochondrial DNA between ordinary anddwarf forms of southern minke whale. Rep. int. Whal.
Commn 44: 277–281.
Yoshioka, M., Okumura, T., Aida, K. and Fujise, Y. 1994. A
proposed technique for quantifying muscle progesterone content in the minke whales (Balaenoptera acutorostrata). Can. J. Zoo. 72: 368–370.
1995 (3)
Fukui, Y., Mogoe, T., Terawaki, Y., Ishikawa, H., Fujise,
Y. and Ohsumi, S. 1995. Relationship between physiological status and serum constituent values in minke
whales (Balaenoptera acutorostrata). Journal of Reproduction and Development 41 (3): 203–208.
Ishikawa, H. and Amasaki, H. 1995. Development andphysiological degradation of tooth buds and development of rudiment of baleen plate in Southern minke
whale, Balaenoptera acutorostrata. J. Vet. Med. Sci. 57(4): 665–670.
Kasamatsu, F., Nishiwaki, S. and Ishikawa, H. 1995. Breeding areas and southbound migrations of southernminke whales Balaenoptera acutorostrata. Mar. Ecol.
Prog. Ser. 119: 1–10.
1996 (7)Bakke, I., Johansen, S., Bakke, O. and El-Gewely, M.R.
1996. Lack of population subdivision among the minke
whales (Balaenoptera acutorostrata) from Icelandic
and Norwegian waters based on mitochondrial DNA
sequences. Marine Biology 125: 1–9.
Butterworth, D.S. and Geromont, H.F. 1996. On the provision of advice on the eﬀect on stock(s) of scientiﬁc
permit catches, with particular reference to proposed
research catches of minke whales from Antarctic Area
IV. Rep. int. Whal. Commn 46: 653–655.
Butterworth, D.S., Punt, A.E., Geromont, H.F., Kato, H. andMiyashita, T. 1996. An ADAPT approach to the analysis

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2017of catch-at-age information for Southern Hemisphereminke whales. Rep. int. Whal. Commn 46: 349–359.
Fukui, Y., Mogoe, T., Jung, Y.G., Terawaki, Y., Miyamoto, A.,
Ishikawa, H., Fujise, Y. and Ohsumi, S. 1996. Relationships among morphological status, steroid hormones,
and post-thawing viability of frozen spermatozoa ofmale minke whales (Balaenoptera acutorostrata).
Marine Mammal Science 12 (1): 28–37.
Iga, K., Fukui, Y., Miyamoto, A., Ishikawa, H. and Ohsumi,
S. 1996. Endocrinological observations of female minke
whales (Balaenoptera acutorostrata). Marine Mammal
Science 12 (2): 296–301.
Matsuoka, K., Fujise, Y. and Pastene, L.A. 1996. A sightingof a large school of the pygmy right whale, Caperea
marginata in the southeast Indian Ocean. Marine
Mammal Science 12 (4): 594–597.
Pastene, L.A., Goto, M., Itoh, S. and Numachi, K. 1996.
Spatial and temporal patterns of mitochondrial DNA
variation in minke whale from Antarctic Areas IV and V.
Rep. int. Whal. Commn 46: 305–314.
1997 (3)Aono, S., Tanabe, S., Fujise, Y., Kato, H. and Tatsukawa,R. 1997. Persistent organochlorines in minke whale(Balaenoptera acutorostrata) and their prey species
from the Antarctic and the North Paciﬁc. Environmental Pollution 98: 81–89.
Fukui, Y., Mogoe, T., Ishikawa, H. and Ohsumi, S. 1997a.
Factors aﬀecting in vitro maturation of minke whale(Balaenoptera acutorostrata) follicular oocytes. Biology of Reproduction 56: 523–528.
Fukui, Y., Mogoe, T., Ishikawa, H. and Ohsumi, S. 1997b.
In vitro fertilization of in vitro matured minke whale(Balaenoptera acutorostrata) follicular oocytes. Marine Mammal Science 13 (3): 395–404.
1998 (7)
Ichii, T., Shinohara, N., Fujise, Y., Nishiwaki, S. and Matsuoka, K. 1998. Interannual changes in body fat conditionindex of minke whales in the Antarctic. Mar. Ecol. Prog.
Ser. 175: 1–12.
Ito, S., Takenaga, F. and Tsuyuki, H. 1998. Lipids in Antarctic minke whales III. Site and sexual diﬀerences ofmuscle lipids. J. Jpn. Oil Chem. Soc. 47 (2): 191–194 (inJapanese).
Kida, M.Y. 1998. Morphology of the tracheobronchial
tree and the route of the pulmonary artery in the fetal
minke whale (Balaenoptera acutorostrata). Okajimas
Folia Anat. Jpn.75 (5): 251–258.
Mogoe, T., Fukui, Y., Ishikawa, H. and Ohsumi, S. 1998a.

Morphological observations of frozen-thawed spermatozoa of Southern minke whales (Balaenoptera acutorostrata). Journal of Reproduction and Development 44(1): 95–100.
Mogoe, T., Fukui, Y., Ishikawa, H. and Ohsumi, S. 1998b.
Eﬀects of diluent composition and temperature on
motility and viability after liquid storage and cryopreservation of minke whale (Balaenoptera acutorostrata) spermatozoa. Marine Mammal Science 14(4): 854–860.
Nagasawa, K., Yamada, T.K. and Ishikawa, H. 1998. Measurements of the skeleton of a minke whale (Balaenoptera acutorostrata) from the Antarctic Ocean. Bulletinof the Yamagata Prefectural Museum 20: 1–19.
Terabayashi, T. and Kawanishi, Y. 1998. Naturally occurring ganglioside lactones in minke whale brain. Carbohydrate Research 307 (3): 281–290.
1999 (4)Bannister, J.L., Pastene, L.A. and Burnell, S.R. 1999.
First record of movement of a southern right whale(Eubalaena australis) between warm water breeding
grounds and the Antarctic Ocean, South of 60°S. Marine Mammal Science 15 (4): 1337–1342.
Butterworth, D.S., Punt, A.E. Geromont, H.F., Kato, H. andFujise, Y. 1999. Inferences on the dynamics of Southern
Hemisphere minke whales from ADAPT analyses ofcatch-at-age information. J. Cetacean Res. Manage. 1(1): 11–32.
Ishikawa, H., Amasaki, H., Dohguchi, H., Furuya, A. andSuzuki, K. 1999. Immunohistological distributions ofﬁbronectin, tenascin, type I, III and IV collagens, andlaminin during tooth development and degeneration infetuses of minke whale, Balaenoptera acutorostrata. J.
Vet. Med. Sci. 61 (3): 227–232.
Thomson, R.B., Butterworth, D.S. and Kato, H. 1999. Has
the age at transition of southern hemisphere minke
whales declined over recent decades? Marine Mammal Science 15 (3): 661–682.
2000 (5)Asada, M., Horii, M., Mogoe, T., Fukui, Y., Ishikawa, H.
and Ohsumi, S. 2000. In vitro maturation and ultrastructural observation of cryopreserved minke whale(Balaenoptera acutorostrata) follicular oocytes. Biology of Reproduction 62 (2): 253–259.
Kasamatsu, F., Matsuoka, K. and Hakamada, T. 2000. Interspeciﬁc relationships in density among the whale
community in the Antarctic. Polar Biol 23 (7): 466–473.
Mogoe, T., Suzuki, T., Asada, M., Fukui, Y., Ishikawa, H. and83

Technical Reports of the Institute of Cetacean Research (2017)

Ohsumi, S. 2000. Functional reduction of the Southernminke whale (Balaenoptera acutorostrata) testis during the feeding season. Marine Mammal Science 16(3): 559–569.
Rosenbaum, H.C., Brownell, R.L., Brown, M.W., Schaeﬀ, C.,
Portway, V., White, B.N., Malik, S., Pastene, L.A., Pateneude, N.J., Baker, C.S., Goto, M., Best, P.B., Clapham,
P.J., Hamilton, P., Moore, M., Payne, R., Rowntree, V.,
Tynan, C.T., Bannister, J.L. and DeSalle, R. 2000. Worldwide genetic diﬀerentiation of Eubalaena: questioning
the number of right whale species. Molecular Ecology
9: 1793–1802.
Wei, H., and Fukui, Y. 2000. Fertilizability of ovine, bovine or minke whale (Balaenoptera acutorostrata)
spermatozoa intracytoplasmically injected into bovine
oocytes. Zygote 8 (3): 267–274.
2001 (3)Asada, M., Tetsuka, M., Ishikawa, H., Ohsumi, S. andFukui, Y. 2001. Improvement on in vitro maturation,
fertilization and development of minke whale (Balaenoptera acutorostrata) oocytes. Theriogenology 56 (4):521–533.
Asada, M., Wei, H., Nagayama, R., Tetsuka, M., Ishikawa,
H., Ohsumi, S. and Fukui, Y. 2001. An attempt at intracytoplasmic sperm injection of frozen-thawed minke
whale (Balaenoptera bonaerensis) oocytes. Zygote 9(3): 299–307.
Suzuki, T., Mogoe, T., Asada, M., Miyamoto, A., Tetsuka,
M., Ishikawa, H., Ohsumi, S. and Fukui, Y. 2001. Plasmaand pituitary concentrations of gonadotropins (FSHand LH) in minke whales (Balaenoptera acutorostrata)
during the feeding season. Theriogenology 55 (5):1127–1141.
2002 (6)Abe, H. and Goto, M. 2002. The application of microsatellite DNA for determining population structure of minke
whale. pp. 109–113. In: Nishimura, A. (Ed). Technical
Reports of the Hokkaido National Fisheries ResearchInstitute No.5. Hokkaido National Fisheries ResearchInstitute, Hokkaido.
Kunito, T., Watanabe, I., Yasunaga, G., Fujise, Y. and Tanabe, S. 2002. Using trace elements in skin to discriminate the populations of minke whale in southern hemisphere. Marine Environmental Research 53: 175–197.
Murase, H., Matsuoka, K., Ichii, T. and Nishiwaki, S. 2002.
Relationship between the distribution of euphausiids
and baleen whales in the Antarctic (35°E–145°W).
Polar Biol 25 (2): 135–145.
84

Pastene, L.A., Goto, M. and Kanda, N. 2002. The utility of
DNA analysis for the management and conservation oflarge whales. Fish Sci 68 (Supp. I): 286–289.
Suzuki, M., Ishikawa, H., Otani, S., Tobayama, T., Katsumata, E., Ueda, K., Uchida, S., Yoshioka, M. and Aida,
K. 2002. The characteristics of adrenal glands and its
hormones in cetacean. Fish Sci 68 (Supp. I): 272–275.
Urashima, T., Sato, H., Munakata, J., Nakamura, T., Arai, I.,
Saito, T., Tetsuka, M., Fukui, Y., Ishikawa, H., Lyndersen,
C. and Kovacs, K.M. 2002. Chemical characterization of
the oligosaccharides in beluga (Delphinapterus leucas)
and minke whale (Balaenoptera acutorostrata) milk.
Comparative Biochemistry and Physiology Part B 132:
611–624.
2003 (5)Hayashi, K., Nishida, S., Yoshida, H., Goto, M., Pastene,
L.A. and Koike, H. 2003. Sequence variation of the DQB
allele in the cetacean MHC. Mammal Study 28 (2):89–96.
Matsuoka, K., Watanabe, T., Ichii, T., Shimada, H. andNishiwaki, S. 2003. Large whale distributions (south of
60°S, 35°E–130°E) in relation to the Southern Boundary of the Antarctic Circumpolar Current. pp. 26–30.
In: Antarctic Biology in a Global Context. Proceedingsof the VIIIth SCAR International Biology Symposium, 27
August-1 September 2001. Vriji Universiteit, Amsterdam, The Netherlands, Backhuys Publisheres, Leiden.
Nishida, S., Hayashi, K., Pastene, L.A., Goto, M., Kanda, N.
and Koike, H. 2003. Polymorphic analysis of cetacean
MHC - A case study on the minke whales -. Mammalian
Science 3: 75–78 (in Japanese).
Nishida, S., Pastene, L.A., Goto, M. and Kanda, N. 2003.
SRY gene structure and phylogeny in the cetacean species. Mammal Study 28 (1): 57–66.
Ohishi, K., Zenitani, R., Bando, T., Goto, Y., Uchida, K.,
Maruyama, T., Yamamoto, S., Miyazaki, N. and Fujise, Y.
2003. Pathological and serological evidence of Brucella-infection in baleen whales (Mysticeti) in the western
North Paciﬁc. Comp. Immun. Microbiol. Infect. Dis. 26(2): 125–136.
2004 (8)Amemiya, K., Iwanami, Y., Kobayashi, T., Terao, T., Fukui,Y., Ishikawa, H., Ohsumi, S., Hirabayashi, M. and Hochi,
S. 2004. Acquirement of oocyte-activating factor in
Antarctic minke whale (Balaenoptera bonaerensis)
spermatogenic cells, assessed by meiosis resumptionof microinseminated mouse oocytes. J. Mamm. Ova
Res. 21: 149–156.

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2017

Branch, T.A., Matsuoka, K. and Miyashita, T. 2004.
Evidence for increase in Antarctic blue whales basedon Bayesian modeling. Marine Mammal Science 20(4):726–754.
Fujihira, T., Kinoshita, M., Sasaki, M., Ohnishi, M., Ishikawa, H., Ohsumi, S. and Fukui, Y. 2004. Comparative
studies on lipid analysis and ultrastructure in porcine
and southern minke whale (Balaenoptera bonaerensis)
oocytes. Journal of Reproduction and Development 50(5): 525–532.
Fukui, Y., Togawa, M., Abe, N., Takano, Y., Asada, M.,
Okada, A., Iida, K., Ishikawa, H. and Ohsumi, S. 2004.
Validation of the sperm quality analyzer and the hypoosmotic swelling test for frozen-thawed ram and minke
whale (Balaenoptera bonarensis) spermatozoa. Journal of Reproduction and Development 50 (1): 147–154.
Ikumi, S., Sawai, K., Takeuchi, Y., Iwayama, H., Ishikawa,
H., Ohsumi, S. and Fukui, Y. 2004. Interspecies somatic
cell nuclear transfer for in vitro production of Antarctic
minke Whale (Balaenoptera bonaerensis) Embryos.
Cloning and Stem Cells 6 (3): 284–293.
Iwayama, H., Hochi, S., Kato, M., Hirabayashi, M., Kuwayama, M., Ishikawa, H., Ohsumi, S. and Fukui, Y. 2004.
Eﬀects of cryodevice type and donorʼs sexual maturity
on vitriﬁcation of minke whale (Balaenoptera bonaerensis) oocytes at germinal vesicle-stage. Zygote 12 (4):333–338.
Muranishi, Y., Sasaki, M., Hayashi, K., Abe, N., Fujihira, T.,
Ishikawa, H., Ohsumi, S., Miyamoto, A. and Fukui, Y.
2004. Relationship between the appearance of preantral follicles in the fetal ovary of Antarctic minke whales(Balaenoptera bonaerensis) and hormone concentrations in the fetal heart, umbilical cord and maternal
blood. Zygote 12 (2): 125–132.
Tetsuka, M., Asada, M., Mogoe, T., Fukui, Y., Ishikawa, H.
and Ohsumi, S. 2004. The pattern of ovarian development in the prepubertal Antarctic minke whale (Balaenoptera bonaerensis). Journal of Reproduction andDevelopment 50 (4): 381–389.
2005 (6)Ishikawa, H. and Shigemune, H. 2005. Improvements
in more humane killing methods of Antarctic minke
whales, Balaenoptera bonaerensis, in the Japanese
Whale Research Program under Special Permit in the
Antarctic Sea (JARPA). Jpn. J. Zoo Wildl. Med. 10 (1):
27–34.
Iwayama, H., Ishikawa, H., Ohsumi, S. and Fukui, Y. 2005.
Attempt at in vitro maturation of minke whale (Balaenoptera bonaerensis) oocytes using a portable CO2

incubator. Journal of Reproduction and Development
51 (1): 69–75.
Matsuoka, K., Pitman, R. and Marques, F. 2005. A note ona pigmy right whale (Caperea marginata) sighting inthe southwestern Paciﬁc Ocean. J. Cetacean Res. Manage. 7(1): 71–73.
Matsuoka, K., Hakamada, T., Kiwada, H., Murase, H. andNishiwaki, S. 2005. Abundance increases of large baleen whales in the Antarctic based on the sighting survey during Japanese Whale Research Program (JARPA).
Global Environmental Research 9 (2): 105–115.
Nikaido, M., Sasaki, T., Makino, H., Goto, M., Kanda, N.,
Pastene, L.A. and Okada, N. 2005. Phylogenetic reconstruction of baleen whales and detection of their pastextensive radiation event by the SINE insertion analysis. Fossils 77: 22–28 (in Japanese).
Sasaki, T., Nikaido, M., Hamilton, H., Goto, M., Kato, H.,
Kanda, N., Pastene, L.A., Cao, Y., Fordyce, R.E., Hasegawa, M. and Okada, N. 2005. Mitochondrial phylogenetics and evolution of mysticete whales. Systematic
Biology 54 (1): 77–90.
2006 (9)Fujihira, T., Kobayashi, M., Hochi, S., Hirabayashi, M.,
Ishikawa, H., Ohsumi, S. and Fukui, Y. 2006. Developmental capacity of Antarctic minke whale (Balaenoptera bonaerensis) vitriﬁed oocytes following in vitro
maturation, and parthenogenetic activation or intracytoplasmic sperm injection. Zygote 14 (2): 89–95.
Honda, K., Aoki, M. and Fujise, Y. 2006. Echochemical approach using mercury accumulation of Antarctic minke
whale, Balaenoptera bonaerensis, as tracer of historical change of Antarctic marine ecosystem during 1980–
1999. Bull. Environ. Contam. Toxicol. 76: 140–147.
Iwanami, K., Mita, H., Yamamoto, Y., Fujise, Y., Yamada,T. and Suzuki, T. 2006. cDNA-derived amino acid sequences of myoglobins from nine species of whales
and dolphins. Comparative Biochemistry and Physiology, Part B 145: 249–256.
Kobayashi, T., Amemiya, K., Takeuchi, K., Tsujioka, T.,
Tominaga, K., Hirabayashi, M., Ishikawa, H., Fukui,
Y. and Hochi, S. 2006. Contribution of spermatozoal
centrosomes to the microtubule-organizing centre in
Antarctic minke whale (Balaenoptera bonaerensis).
Zygote 14 (1): 45–51.
Konishi, K. 2006. Characteristics of blubber distribution
and body condition indicators for Antarctic minke
whale (Balaenoptera bonaerensis). Mammal Study 31(1): 15–22.
Mori, M. and Butterworth, D.S. 2006. A ﬁrst step towards
85

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modelling the krill–predator dynamics of the Antarctic
ecosystem. CCAMLR Science 13: 217–277.
Nikaido, M., Hamilton, H., Makino, H., Sasaki, T., Takahashi, K., Goto, M., Kanda, N., Pastene, L.A. and Okada,N. 2006. Baleen whale phylogeny and a past extensive
radiation event revealed by SINE insertion analysis.
Mol. Biol. Evol. 23 (5): 866–873.
Rock, J., Pastene, L.A., Kaufman, G., Forestell, P., Matsuoka, K. and Allen, J. 2006. A note on East Australia
Group V Stock humpback whale movement between
feeding and breeding areas based on photo-identiﬁcation. J. Cetacean Res. Manage. 8 (3): 301–305.
Yabuki, T., Suga, T., Hanawa, K., Matsuoka, K., Kiwada, H.
and Watanabe, T. 2006. Possible source of the Antarctic bottom water in the Prydz Bay Region. Journal of
Oceanography 62 (5): 649–655.
2007 (7)Asada, M., Tetsuka, M., Ishikawa, H., Ohsumi, S. andFukui, Y. 2007. Ultrastructural changes during maturation and cryopreservation of follicular oocytes of Antarctic minke whales (Balaenoptera bonaerensis). Jpn. J.
Zoo. Wildl. Med. 12 (1): 51–66.
Branch, T.A., Staﬀord, K.M., Palacios, D.M., Allison, C.,
Bannister, J.L., Burton, C.L.K., Cabrera, E., Carlson, C.A.,
Galletti Vernazzani, B., Gill, P.C., Hucke-Gaete, R., Jenner, K.C.S., Jenner, Mn. M., Matsuoka, K., Mikhalev,
Y.A., Miyashita, T., Morrice, M.G., Nishiwaki, S., Sturrock, V.J., Tormosov, D., Anderson, R.C., Baker, A.N.,
Best, P.B., Borsa, P., Brownell Jr, R.L., Childerhouse,
S., Findlay, K.P., Gerrodette, T., Ilangakoon, A.D., Joergensen, M., Kahn, B., Ljungblad, D.K., Maughan, B.,
Mccauley, R.D., Mckay, S., Norris, T.F., Oman Whaleand Dolphin Research Group, Rankin, S., Samaran, F.,
Thiele, D., Van Waerebeek, K. and Warneke, R.M. 2007.
Past and present distribution, densities and movements of blue whales in the Southern Hemisphere andadjacent waters. Mammal Rev. 37 (2): 116–175.
LeDuc, R.G., Dizon, A.E., Goto, M., Pastene, L.A., Kato,
H., Nishiwaki, S. and Brownell, R.L. 2007. Patterns ofgenetic variation in southern hemisphere blue whales,
and the use of assignment test to detect mixing on
the feeding grounds. J. Cetacean Res. Manage. 9 (1):73–80.
Nagai, H., Mogoe, T., Ishikawa, H., Hochi, S., Ohsumi, S.
and Fukui, Y. 2007. Follicle size-dependent changes
in follicular ﬂuid components and oocyte diameter in
Antarctic minke whales (Balaenoptera bonaerensis).
Journal of Reproduction and Development 53 (6):1265–1272.
86

Nishida, S., Goto, M., Pastene, L.A., Kanda, N. and Koike,
H. 2007. Phylogenetic relationships among cetaceansrevealed by Y-chromosome sequences．Zoological Science 24 (7): 723–732．
Onbe, K. Nishida, S., Sone, E., Kanda, N., Goto, M., Pastene, L.A., Tanabe, S. and Koike, H. 2007. Sequence variation in the Tbx4 gene in marine mammals．Zoological
Science 24 (5): 449–464.
Pastene, L.A., Goto, M., Kanda, N., Zerbini, A.N., Kerem,D., Watanabe, K., Bessho, Y., Hasegawa, M., Nielsen,
R., Larsen, F. and Palsbøll, P.J. 2007. Radiation andspeciation of pelagic organisms during periods ofglobal warming: the case of the common minke whale,
Balaenoptera acutorostrata. Molecular Ecology 16:1481–1495.
2008 (4)Ishikawa, H. and Shigemune, H. 2008. Comparative experiment of whaling grenades in the Japanese Whale
Research Program under Special Permit (JARPA and
JARPN). Jpn. J. Zoo Wildl. Med. 13 (1): 21–28.
Konishi, K., Tamura, T., Zenitani, R., Bando, T., Kato, H. andWalløe, L. 2008. Decline in energy storage in the Antarctic minke whale (Balaenoptera bonaerensis) in theSouthern Ocean. Polar Biol 31 (2): 1509–1520.
Ohishi, K., Fujise, Y. and Maruyama, T. 2008. Brucella spp.
in the western North Paciﬁc and Antarctic cetaceans: areview. J. Cetacean Res. Manage. 10 (1):67–72.
Yunoki, K., Ishikawa, H., Fukui, Y. and Ohnishi, M. 2008.
Chemical properties of epidermal lipids, especiallysphingolipids, of the Antarctic minke whale. Lipids 43(2): 151–159.
2009 (2)Ono, N., Yamaguchi, T., Ishikawa, H., Arakawa, M.,
Takahashi, N. Saikawa, T. and Shimada, T. 2009. Morphological varieties of the Purkinje ﬁber network inmammalian hearts, as revealed by light and electron
microscopy. Arch Histol Cytol 72 (3): 139–149.
Tamura, T. and Konishi, K. 2009. Feeding habits and prey
consumption of Antarctic minke whale (Balaenoptera
bonaerensis) in the Southern Ocean. J. Northw. Atl.
Fish. Sci. 42: 13–25.
2010 (14)Fujise, Y., Nishiwaki, S. and Ishikawa, S. 2010. Overview of
the Japanese Whale Research Program under Special
Permit in the Antarctic (JARPA). Bull. Jpn. Soc. Fish.
Oceanogr. 74: 43–44 (in Japanese).
Fujise, Y., Hatanaka, H. and Ohsumi, S. 2010. Changes

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2017

in the Antarctic marine ecosystem as revealed by the
JARPA research: What has happened to the Antarctic
minke whale stocks? Ottar (Tromsø Museum) 280:
29–34 (in Norwegian).
Glover, K.A., Kanda, N., Haug, T., Pastene, L.A., Øien, N.,
Goto, M., Seliussen, B.B. and Skaug, H.J. Migration of
Antarctic minke whales to the Arctic. PLoS ONE 5 (12):e15197.
Ishikawa, H. 2010. Animal Welfare - Introduction -. Jpn. J.
Zoo. Wildl. Med. 15 (1): 1–3 (in Japanese).
Ishikawa, H. 2010. Lethal Research for Wildlife. Jpn. J.
Zoo. Wildl. Med. 15 (1): 9–14 (in Japanese).
Kokubun, N., Yasuma, H., Murase, H. and Naganobu, M.
2010. Distribution of seabirds in the Ross Sea, Antarctica. Bull. Jpn. Soc. Fish. Oceanogr. 74: 42–43 (inJapanese).
Matsuoka, K., Kiwada, K., Murase, H. and Nishiwaki, S.
2010. Whale species composition and their distribution patterns in the Ross Sea, Antarctica. Bull. Jpn. Soc.
Fish. Oceanogr. 74: 44–45 (in Japanese).
Murase, H., Matsuoka, K., Hakamada, T., Nishiwaki, S.,
Naganobu, M. and Kitakado, T. 2010. Estimation of
spatial distribution pattern of cetacean using environmental covariates in the Ross Sea, Antarctica. Bull. Jpn.
Soc. Fish. Oceanogr. 74: 47–48 (in Japanese).
Naganobu, M. and Murase, H. 2010. Ecological linkage
between oceanographic environment and distributionof top predators and their preys in the Ross Sea region.
Bull. Jpn. Soc. Fish. Oceanogr. 74: 48–49 (in Japanese).
Naganobu, M., Murase, H., Nishiwaki, S., Yasuma, H.,
Matsukura, R., Takao, Y., Taki, K., Hayashi, T., Watanabe,Y., Yabuki, T., Yoda, Y., Noiri, Y., Kuga, M., Yoshikawa, K.,
Kokubun, N., Iwami, T., K., Itoh, K., Goto, M., Isoda, T.,
Matsuoka, K., Tamura, T. and Fujise, Y. 2010. Structureof marine ecosystem of the Ross Sea, Antarctica—overview and synthesis of the results of the Japanese multidisciplinary study by Kaiyo-Maru and JARPA—. Bull.
Jpn. Soc. Fish. Oceanogr. 74: 1–12.
Naganobu, M., Nishiwaki, S., Nagai, N. and Tohyama, D.
2010. Multidisciplinary ecological survey by the R/V
Kaiyo Maru and JARPA in the Ross Sea, Antarctica. Bull.
Jpn. Soc. Fish. Oceanogr. 74: 34–35 (in Japanese).
Pastene, L. A., Acevedo, J., Goto, M., Zerbini, A.N., Acuna,
P. and Aguayo-Lobo, A. 2010. Population structure andpossible migratory links of common minke whales,
Balaenoptera acutorostrata, in the Southern Hemisphere. Conserv Genet 11 (4): 1553–1558．
Tamura, T., Konishi, K., Nishiwaki, S., Taki, K., Hayashi, T.
and Naganobu, M. 2010. Feeding ecology of the Antarctic minke whales in the Ross Sea, Antarctica. Bull.

Jpn. Soc. Fish. Oceanogr. 74: 46–47 (in Japanese).
Yabuki, T., Noiri,Y., Murase, H., Kiwada, H., Matsuoka, K.
and Naganobu, M. 2010. Physical and chemical studyof hydrographic feature based on the R/V Kaiyo Maru
cruise and JARPA in the Ross Sea, Antarctica. Bull. Jpn.
Soc. Fish. Oceanogr. 74: 35–36 (in Japanese).
2011 (1)Matsuoka, K., Hakamada, T., Kiwada, H., Murase, H. andNishiwaki, S. 2011. Abundance estimates and trends
for humpback whales (Megaptera novaeangliae) in
Antarctic Areas IV and V based on JARPA sighting data.
J. Cetacean Res. Manage. (Special Issue 3): 75–94.
2012 (1)*Sremba, A.L., Hancock-Hanser, B., Branch, T.A., LeDuc,
R.L. and Baker, C.S. 2012. Circumpolar diversity andgeographic diﬀerentiation of mtDNA in the criticallyendangered Antarctic blue whale (Balaenoptera musculus intermedia). PLoS ONE 7 (3): e32579.
2013 (6)Glover, K.A., Kanda, N., Haug, T., Pastene, L.A., Øien, N.,
Seliussen, B.B., Sørvik, A.G.E. and Skaug, H.J. 2013.
Hybrids between common and Antarctic minke whales
are fertile and can back-cross. BMC Genetics 14: 25.
Hakamada, T., Matsuoka, K., Nishiwaki, S. and Kitakado,
T. 2013. Abundance estimates and trends for Antarctic
minke whales (Balaenoptera bonaerensis) in Antarctic
Areas IV and V for the period 1989/90–2004/05. J. Cetacean Res. Manage. 13 (2): 123–151.
Kitakado, T., Lockyer, C. and Punt, A.E. 2013. A statisticalmodel for quantifying age-reading errors and its application to the Antarctic minke whales. J. Cetacean Res.
Manage. 13 (3): 181–190.
Murase, H., Kitakado, T., Hakamada, T., Matsuoka, K.,
Nishiwaki, S. and Naganobu, M. 2013. Spatial distribution of Antarctic minke whales (Balaenoptera bonaerensis) in relation to spatial distributions of krill in theRoss Sea, Antarctica. Fish. Oceanogr. 22 (3): 154–173.
Sasaki, M., Amano, Y., Hayakawa, D., Tsubota, T., Ishikawa,
H., Mogoe, T., Ohsumi, S., Tetsuka, M., Miyamoto, A.,
Fukui, Y., Budipitojo, T. and Kitamura, N. 2013. Structure and steroidogenesis of the placenta in the Antarctic minke whale (Balaenoptera bonaerensis). Journal of
Reproduction and Development 59 (2): 159–167.
Shibata, Y., Matsuishi, T., Murase, H., Matsuoka, K.,
Hakamada, T., Kitakado, T. and Matsuda, H. 2013. Effects of stratiﬁcation and misspeciﬁcation of covariates
on species distribution models for abundance estima87

Technical Reports of the Institute of Cetacean Research (2017)tion from virtual line transect survey data. Fish Sci 79(4): 559–568.
2014 (3)Konishi, K., Hakamada, T., Kiwada, H., Kitakado, T. andWalløe, L. 2014. Decrease in stomach contents in the
Antarctic minke whale (Balaenoptera bonaerensis) in
the Southern Ocean. Polar Biol 37 (2): 205–215.
Punt, A.E. 2014. A summary history of the applicationof statistical catch-at-age analysis (SCAA) to Antarctic
minke whales. J. Cetacean Res. Manage. 14: 81–92.
Punt, A.E., Hakamada, T., Bando, T. and Kitakado, T. 2014.
Assessment of Antarctic minke whales using statisticalcatch-at-age analysis (SCAA). J. Cetacean Res. Manage.
14: 93–116.
2015 (2)Konishi, K. and Walløe, L. 2015. Substantial decline inenergy storage and stomach fullness in Antarctic minke
whales (Balaenoptera bonaerensis) during the 1990ʼs.
J. Cetacean Res. Manage. 15: 77–92.
Yasunaga, G., Fujise, Y., Zenitani, R., Tanabe, S. and Kato,
H. 2015. Spatial and temporal variation of PCBs and organochlorine pesticides in the Antarctic minke whales,
Balaenoptera bonaerensis, in the period 1987–2005.
Chemosphere 126: 11–17.
2016 (2)Pastene, L.A. and Goto, M. 2016. Genetic characterization and population genetic structure of the Antarctic
minke whale Balaenoptera bonaerensis in the IndoPaciﬁc region of the Southern Ocean. Fish Sci 82 (6):873–886.
Wada, N., Yamanaka, S., Shibato, J., Rakwal, R., Hirako, S.,
Iizuka, Y., Kim, H., Matsumoto, A., Kimura, A., Takenoya,F., Yasunaga, G. and Shioda, S. 2016. Behavioral andomics analyses study on potential involvement of
dipeptide balenine through supplementation in dietof senescence-accelerated mouse prone 8. Genomics
Data 10: 38–50.
2017 (3)Isoda, T. and Tamura, T. 2017. Report of a White Adélie
Penguin Pygoscelis adeliae in the Antarctic Ocean. J.
Yamashina Inst. Ornithol. 48 (2): 74–77.
*Leduc, R.G., Archer, F.I., Lang, A.R., Martien, K.K.,
Hancock-Hanser, B., Torres-Florez, J.P., Hucke-Gaete,R., Rosenbaum, H.C., VanWaerebeek, Bownell, R.L.
and Taylor, B.L. Genetic variation in blue whales in theeastern paciﬁc: implications for taxonomy and use of88

common wintering grounds. Molecular Ecology 26:
740–751.
Yasunaga, G., Pastene, L.A., Bando, T., Hakamada, T. andFujise, Y. 2017. Age estimation of Antarctic minke
whales Balaenoptera bonaerensis based on aspartic
acid racemization technique. Fish Sci 86 (6): 947–954.

JARPN/JARPNII surveys
1996 (3)Butterworth, D.S., Geromont H.F. and Wada S. 1996.
Further analysis of allele frequency data to provide
estimates of the extent of mixing between the various
North Paciﬁc minke whale stocks, and their implications for the status of the “O”stock. Rep. int. Whal.
Commn 46: 443–451.
Kuramochi, T., Machida, M., Araki, J., Uchida, A., Kishiro,
T. and Nagasawa, K. 1996. Minke whales (Balaenoptera acutorostrata) are one of the major ﬁnal hosts ofAnisakis simplex (Nematoda: Anisakidae) in the Northwestern North Paciﬁc Ocean. Rep. int. Whal. Commn
46: 415–419.
Miyashita, T. and Fujise, Y. 1996. Abundance estimate of
the western North Paciﬁc minke whale in sub-area 9
with notes on the results of dedicated surveys. Rep. int.
Whal. Commn 47: 543–551.
1997 (6)Aono, S., Tanabe, S., Fujise, Y., Kato, H. and Tatsukawa,R. 1997. Persistent organochlorines in minke whale(Balaenoptera acutorostrata) and their prey species
from the Antarctic and the North Paciﬁc. Environmental Pollution 98: 81–89.
Araki, J., Kuramochi, T., Machida, M., Nagasawa, K., andUchida, A. 1997. A note on the parasite fauna of thewestern North Paciﬁc minke whale (Balaenoptera acutorostrata). Rep. int. Whal. Commn 47: 565–567.
Goto, M. and Pastene, L.A. 1997. Population structureof western North Paciﬁc minke whale based on an
RFLP analysis of mtDNA control region. Rep. int. Whal.
Commn 47: 531–537.
Hatanaka, H. and Miyashita, T. 1997. On the feeding migration of the Okhotsk Sea-West Paciﬁc stock of minke
whales, estimates based on length composition data.
Rep. int. Whal. Commn 47: 557–564.
Hatanaka, H. 1997. A short review of hypotheses onminke whale stock structure in the Northwesternpart of the North Paciﬁc. Rep. int. Whal. Commn 47:
553–555.
Pastene, L.A., Goto, M., Itoh, S., Wada, S. and Kato, H.
1997. Intra- and inter-oceanic patterns of mitochon-

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2017

drial DNA variation in the Brydeʼs whale, Balaenoptera
edeni. Rep. int. Whal. Commn 47: 569–574.

inferred from JARPN sightings data. J. Cetacean Res.
Manage. 3 (2): 193–200.

1998 (4)
Lindstrøm, U., Fujise, Y., Haug, T. and Tamura, T. 1998.
Feeding habits of western North Paciﬁc minke whales,
Balaenoptera acutorostrata, as observed in JulySeptember 1996. Rep. int. Whal. Commn 48: 463–469.
Pastene, L.A., Goto, M. and Kishino, H. 1998. An estimateof mixing proportion of ʻJʼ and ʻOʼ stocks minke whales
in sub-area 11 based on mitochondrial DNA haplotype
data. Rep. int. Whal. Commn 48: 471–474.
Tamura, T., Fujise, Y. and Shimazaki, K. 1998. Diet of minke
whales Balaenoptera acutorostrata in the Northwestern part of the North Paciﬁc in summer 1994 and 1995.
Fish Sci 64 (1): 71–76.
Uchida, A., Kawakami, Y., Yuzu, S., Kishikawa, S., Kuramochi, T., Araki, J., Machida, M. and Nagasawa, K.
1998. Prevalence of parasites and histopathology ofparasitisation in minke whales (Balaenoptera acutorostrata) from the western North Paciﬁc Ocean andSouthern Sea of Okhotsk. Rep. int. Whal. Commn 48:
475–479.

2002 (5)Abe, H. and Goto, M. 2002. The application of microsatellite DNA for determining population structure of minke
whale. pp. 109–113. In: Nishimura, A. (Ed). Technical
Reports of the Hokkaido National Fisheries ResearchInstitute No.5. Hokkaido National Fisheries ResearchInstitute, Hokkaido.
Cui, G., Punt, A.E., Pastene, L. A., and Goto, M. 2002.
Bayes and Empirical Bayes approaches to addressing
stock structure questions using mtDNA data, with anillustrative application to North Paciﬁc minke whales. J.
Cetacean Res. Manage. 4 (2): 123–134.
Ohsumi, S. and Tamura, T. 2002. Dietary studies on baleen whales in the North Paciﬁc. Fish Sci 68 (Supp. I):
260–263.
Pastene, L.A., Goto, M. and Kanda, N. 2002. The utility of
DNA analysis for the management and conservation oflarge whales. Fish Sci 68 (Supp. I): 286–289.
Tamura T. and Fujise Y. 2002. Geographical and seasonalchanges of the prey species of minke whale in the
Northwestern Paciﬁc. ICES Journal of Marine Science59 (3): 516–528.

1999 (2)Le, T.H.L., Takahashi, S., Saeki, K., Nakatani, N., Tanabe,S., Miyazaki, N. and Fujise, Y. 1999. High percentage ofbutyltin residues in total tin in the livers of cetaceansfrom Japanese coastal waters. Environmental Science& Technology 33 (11): 1781–1786.
Martinez, I. and Pastene, L.A. 1999. RAPD-typing ofcentral and eastern North Atlantic and western North
Paciﬁc minke whales, Balaenoptera acutorostrata. ICES
Journal of Marine Science 56 (5): 640–651.
2000 (2)Punt, A.E., Butterworth, D.S. and Wada, S. 2000. On theuse of allele frequency data within a Bayesian framework: evaluation of relative probabilities of alternative
stock structure hypotheses for North Paciﬁc minke
whales. J. Cetacean Res. Manage. 2 (2): 151–158.
Uchida, A. and Araki, J. 2000. The ectoparasites and endoparasites in the minke whale, Balaenoptera acutorostrata from the western North Paciﬁc Ocean. J. Jpn.
Vet. Med. Assoc. 53 (2): 85–88 (in Japanese).
2001 (1)Okamura, H., Matsuoka, K., Hakamada, T., Okazaki, M.
and Miyashita, T. 2001. Spatial and temporal structureof the western North Paciﬁc minke whale distribution

2003 (4)Hayashi, K., Nishida, S., Yoshida, H., Goto, M., Pastene,
L.A. and Koike, H. 2003. Sequence variation of the DQB
allele in the cetacean MHC. Mammal Study 28 (2):89–96.
Nishida, S., Pastene, L.A., Goto, M. and Kanda, N. 2003.
SRY gene structure and phylogeny in the cetacean species. Mammal Study 28 (1): 57–66.
Nishida, S., Hayashi, K., Pastene, L.A., Goto, M., Kanda, N.
and Koike, H. 2003. Polymorphic analysis of cetacean
MHC - A case study on the minke whales -. Mammalian
Science 3: 75–78 (in Japanese).
Ohishi, K., Zenitani, R., Bando, T., Goto, Y., Uchida, K.,
Maruyama, T., Yamamoto, S., Miyazaki, N. and Fujise, Y. 2003. Pathological and serological evidence of
Brucella-infection in baleen whales (Mysticeti) in thewestern North Paciﬁc. Comp. Immun. Microbiol. Infect.
Dis 26 (2): 125–136.
2004 (5)Kim, E.Y., Iwata, H., Fujise, Y. and Tanabe, S. 2004. Searching for novel CYP members using cDNA library from aminke whale liver. Marine Environmental Research 58:
495–498.
89

Technical Reports of the Institute of Cetacean Research (2017)

Ohishi. K., Takishita, K., Kawato, M., Zenitani, R., Bando,T., Fujise, Y., Goto, Y., Yamamoto, S. and Maruyama,
T. 2004. Molecular evidence of new variant Brucellain North Paciﬁc common minke whales. Microbes andInfection 6: 1199–1204.
Ohishi, K., Takishita, K., Kawato, M., Maruyama, T.,
Zenitani, R., Bando, T., Fujise, Y., Goto, Y. and Yamamoto, S. 2004. Molecular characterization of Brucellafrom North Paciﬁc common minke whale. Oceans'04:
499–504.
Watanabe, H., Mogoe, T., Asada, M., Hayashi, K., Fujise,Y., Ishikawa, H., Ohsumi, S., Miyamoto, A. and Fukui,
Y. 2004. Relationship between serum sex hormone
concentrations and histology of seminiferous tubulesof captured baleen whales in the western North Paciﬁcduring the feeding season. Journal of Reproduction andDevelopment 50 (4): 419–427.
Zharikov, K., Fujise, Y., Tamura, T., Kiwada, H., Bando, T.,
Konishi, K. and Isoda, T. 2004. Distribution and feedingof large cetaceans based on the data of JARPN II - 2003
May, 17-July, 9. Marine Mammals of the Holarctic
2004: 207–210.
2005 (5)Birukawa, N., Ando, H., Goto, M., Kanda, N., Pastene, L.A.,
Nakatsuji, H., Hata, H. and Urano, A. 2005. Plasma andurine levels of electrolytes, urea and steroid hormones
involved in osmoregulation of cetaceans. Zoological
Science 22 (11): 1245–1257.
Nikaido, M., Sasaki, T., Makino, H., Goto, M., Kanda, N.,
Pastene, L.A. and Okada, N. 2005. Phylogenetic reconstruction of baleen whales and detection of their pastextensive radiation event by the SINE insertion analysis. Fossils 77: 22–28 (in Japanese).
Niimi, S., Watanabe, M.X., Kim, E.Y., Iwata, H., Yasunaga,G., Fujise, Y. and Tanabe, S. 2005. Molecular cloning
and mRNA expression of cytochrome P4501A1 and
1A2 in the liver of common minke whales (Balaenoptera acutorostrata). Marine Pollution Bulletin 51 (8):784–793.
Ohishi, K., Takishita, K., Kawato, M., Zenitani, R., Bando,T., Fujise, Y., Goto, Y., Yamamoto, S. and Maruyama,
T. 2005. Chimeric structure of omp2 of Brucella from
North Paciﬁc common minke whales (Balaenoptera
acutorostrata). Microbiol. Immunol. 49 (8): 789–793.
Sasaki, T., Nikaido, M., Hamilton, H., Goto, M., Kato, H.,
Kanda, N., Pastene, L.A., Cao, Y., Fordyce, R.E., Hasegawa, M. and Okada, N. 2005. Mitochondrial phylogenetics and evolution of mysticete whales. Systematic
Biology 54 (1): 77–90.
90

2006 (5)
Iwanami, K., Mita, H., Yamamoto, Y., Fujise, Y., Yamada,T. and Suzuki, T. 2006. cDNA-derived amino acid sequences of myoglobins from nine species of whales
and dolphins. Comparative Biochemistry and Physiology, Part B 145: 249–256.
Kanda, N., Goto, M. and Pastene, L. A. 2006. Genetic
characteristics of western North Paciﬁc sei whales,
Balaenoptera borealis, as revealed by microsatellites.
Marine Biotechnology 8: 86–93.
Mitani, Y., Bando., T., Takai., N. and Sakamoto, W. 2006.
Patterns of stable carbon and nitrogen isotopes in thebaleens of common minke whale Balaenoptera acutorostrata from the western North Paciﬁc. Fish Sci 72(1): 69–76.
Nikaido, M., Hamilton, H., Makino, H., Sasaki, T., Takahashi, K., Goto, M., Kanda, N., Pastene, L.A. and Okada,N. 2006. Baleen whale phylogeny and a past extensive
radiation event revealed by SINE insertion analysis.
Molecular Biology and Evolution 23 (5): 866–873.
Ohishi, K., Maruyama, T., Ninomiya, A., Kida, H., Zenitani,
R., Bando, T., Fujise, Y., Nakamatsu, K., Miyazaki, N. and
Boltunov, A.N. 2006. Serologic investigation of inﬂuenza a virus infection in cetaceans from the western
North Paciﬁc and the Southern Oceans. Marine Mammal Science 22 (1): 214–221.
2007 (11)
Fukui, Y., Iwayama, H., Matsuoka, T., Nagai, H., Koma,
N., Mogoe, T., Ishikawa, H., Fujise, Y., Hirabayashi, M.,
Hochi, S., Kato, H. and Ohsumi, S. 2007. Attempt at
intracytoplasmic sperm injection of in vitro matured
oocytes in common minke whales (Balaenoptera acutorostrata) captured during the Kushiro coast survey.
Journal of Reproduction and Development. 53 (4):945–952.
Kanda, N., Goto, M., Kato, H., McPhee, M.V. and Pastene,
L.A. 2007. Population genetic structure of Brydeʼswhales (Balaenoptera brydei) at the inter-oceanic andtrans-equatorial levels. Conservation Genetics 8 (4):853–864.
Konishi, K. and Tamura, T. 2007. Occurrence of the minimal armhook squids Berryteuthis anonychus (Cephalopoda: Gonatidae) in the stomachs of common minke
whales Balaenoptera acutorostrata in the western
North Paciﬁc. Fish Sci 73 (5): 1208–1210.
Murase, H., Tamura, T., Kiwada, H., Fujise, Y., Watanabe,
H., Ohizumi, H., Yonezaki, S., Okamura, H. and Kawahara, S. 2007. Prey selection of common minke (Balaenoptera acutorostrata) and Brydeʼs (Balaenoptera

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2017

edeni) whales in the western North Paciﬁc in 2000 and
2001. Fish. Oceanogr. 16 (2): 186–201.
Niimi, S., Kim, E.Y., Iwata, H., Watanabe, M.X., Yasunaga,G., Fujise, Y. and Tanabe, S. 2007. Identiﬁcation andhepatic expression proﬁles of cytochrome P450 1–4
isozymes in common minke whales (Balaenoptera acutorostrata). Comparative Biochemistry and Physiology,
Part B 147: 667–681.
Nishida, S., Goto, M., Pastene, L.A., Kanda, N. and Koike,
H. 2007. Phylogenetic relationships among cetaceansrevealed by Y-chromosome sequences. Zoological
Science 24 (7): 723–732.
Onbe, K. Nishida, S., Sone, E., Kanda, N., Goto, M., Pastene, L.A., Tanabe, S. and Koike, H. 2007. Sequencevariation in the Tbx4 Gene in marine mammals. Zoological Science 24 (5): 449–464.
Pastene, L.A., Goto, M., Kanda, N., Zerbini, A.N., Kerem,D., Watanabe, K., Bessho, Y., Hasegawa, M., Nielsen,
R., Larsen, F. and Palsbøll, P.J. 2007. Radiation andspeciation of pelagic organisms during periods ofglobal warming: the case of the common minke whale,
Balaenoptera acutorostrata. Molecular Ecology 16:1481–1495.
Urashima, T., Kobayashi, M., Asakuma, S., Uemura, Y.,
Arai, I., Fukuda, K., Saito, T., Mogoe, T., Ishikawa, H. andFukui, Y. 2007. Chemical characterization of the oligosaccharides in Brydeʼs whale (Balaenoptera edeni) andSei whale (Balaenoptera borealis) milk. Comparative
Biochemistry and Physiology, Part B 146: 153–159.
Watanabe, H., Tateno, H., Kusakabe, H., Kamiguchi, Y.,
Fujise, Y., Ishikawa, H., Ohsumi, S. and Fukui, Y. 2007.
Fertilizability and chromosomal integrity of frozenthawed Brydeʼs whale (Balaenoptera edeni) spermatozoa intracytoplasmically injected into mouse oocytes.
Reproduction, Fertility and Development 19 (1): 306.
Watanabe, H., Tateno, H., Kusakabe, H., Matsuoka, T.,
Kamiguchi, Y., Fujise, Y., Ishikawa, H., Ohsumi, S. andFukui, Y. 2007. Fertilizability and chromosomal integrityof frozen-thawed Brydeʼs whale (Balaenoptera edeni)
spermatozoa intracytoplasmically injected into mouse
oocytes. Zygote 15 (1): 9–14.
2008 (3)Birukawa, N., Ando, H., Goto, M., Kanda, N., Pastene,
L.A. and Urano, A. 2008. Molecular cloning of urea
transporters from the kidneys of baleen and toothed
whales. Comparative Biochemistry and Physiology,
Part B 149: 227–235.
Ishikawa, H. and Shigemune, H. 2008. Comparative experiment of whaling grenades in the Japanese Whale

Research Program under Special Permit (JARPA and
JARPN). Jpn. J. Zoo Wildl. Med. 13 (1): 21–28.
Ohishi, K., Fujise, Y. and Maruyama, T. 2008. Brucella spp.
in the western North Paciﬁc and Antarctic cetaceans: areview. J. Cetacean Res. Manage. 10 (1): 67–72.
2009 (9)Bhuiyan, M.M.U., Suzuki, Y., Watanabe, H., Hirayama, H.,
Matsuoka, K., Fujise, Y., Ishikawa, H., Ohsumi, S. andFukui, Y. 2009. Attempts at in vitro fertilization andculture of in vitro matured oocytes in sei (Balaenoptera
borealis) and Brydeʼs (B. edeni) whales. Zygote 17 (1):19–28.
Fujita, H., Honda, K., Hamada, N., Yasunaga, G and Fujise,
Y. 2009. Validation of high-throughput measurement
system with microwave-assisted extraction, fully automated sample preparation device, and gas chromatography-electron capture detector for determinationof polychlorinated biphenyls in whale blubber. Chemosphere 74: 1069–1078.
Hiwasa, M., Suzuki, Y., Watanabe, H., Bhuiyan, M.M.U.,
Matsuoka, K., Fujise, Y., Ishikawa, H., Ohsumi, S., andFukui, Y. 2009. Eﬀects of semen extenders and storage temperatures on characteristics of frozen-thawed
Brydeʼs (Balaenoptera edeni) whale spermatozoa. Journal of Reproduction and Development 55: 599–606.
Konishi, K., Tamura T., Isoda, T. Okamoto, R., Hakamada,T., Kiwada, H. and Matsuoka, K. 2009. Feeding strategies and prey consumption of three baleen whale species within the Kushiro-Current Extension. J. Northw.
Atl. Fish. Sci. 42: 27–40.
Lee, E., Bhuiyan, M.M.U., Watanabe, H., Matsuoka, K.,
Fujise, Y., Ishikawa, H. and Fukui. Y. 2009. Production ofcloned sei whale (Balaenoptera borealis) embryos byinterspecies somatic cell nuclear transfer using enucleated pig oocytes. J. Vet. Sci. 10 (4): 285–292.
Matsukura, R., Yasuma, H., Murase, H., Yonezaki, S., Funamoto, T., Honda, S. and Miyashita, K. 2009. Measurements of density contrast and sound-speed contrast
for target strength estimation of Neocalanus copepods(Neocalanus cristatus) in the North Paciﬁc Ocean. FishSci 75 (6): 1377–1387.
Murase, H., Ichihara, M., Yasuma, H., Watanabe, H., Yonezaki, S., Nagashima, H., Kawahara, S. and Miyashita, T.
2009. Acoustic characterization of biological backscatterings in the Kuroshio-Oyashio inter-frontal zone andsubarctic waters of the western North Paciﬁc in spring.
Fish. Oceanogr. 18 (6): 386–401.
Murase, H., Nagashima, H., Yonezaki, S., Matsukura, R.
and Kitakado, T. 2009. Application of a generalized ad91

Technical Reports of the Institute of Cetacean Research (2017)ditive model (GAM) to reveal relationships between
environmental factors and distributions of pelagic ﬁsh
and krill: a case study in Sendai Bay, Japan. ICES Journalof Marine Science 66 (6): 1417–1424.
Tsuki, K., Sato, A., Kaneko, H., Yasunaga, G., Fujise, Y. and
Nomata, H. 2009. Comparison of physiologically signiﬁcant imidazole dipeptides in cetaceans sampled inJapanese whale research (short paper). Sci. Rep. Hokkaido Fish. Exp. Stn. 74: 25–28 (in Japanese).
2010 (7)Bhuiyan, M.M.U., Suzuki, Y., Watanabe, H., Lee, E.,
Hirayama, H., Matsuoka, K., Fujise, Y., Ishikawa, H.,
Ohsumi, S. and Fukui, Y. 2010. Production of sei whale(Balaenoptera borealis) cloned embryos by inter- andintra-species somatic cell nuclear transfer. Journal of
Reproduction and Development 56: 131–139.
Funakasa, N., Yoshioka, M. and Fujise, Y. 2010. Featuresof the Ocular Harderian Gland in three Balaenopterid
species based on anatomical, histological and histochemical observations. Mammal Study 35 (1): 9–15.
Ogawa, G., Ishida, M., Kato, H., Fujise, H. and Urano, N.
2010. Identiﬁcation of facultative anaerobic bacteria
isolated from the intestine of the minke whale Balaenoptera acutorostrata by 16S rRNA sequencing analysis. Fish Sci 76 (2): 177–181.
Pastene, L.A., Fujise, Y. and Hatanaka, H. 2010. JARPNII: achallenging multidiscipline research program focusedon whales in the western North Paciﬁc. Ottar (TromsøMuseum) 280: 23–28 (in Norwegian)．
Shishido, R., Ohishi, K., Suzuki, R., Takishita, K., Ohtsu,
D., Okutsu, K., Tokutake, K., Katsumata, E., Bando, T.,
Fujise, Y., Murayama, T. and Maruyama, T. 2010．Cetacean Toll-like receptor 4 and myeloid diﬀerentiation
factor 2, and possible cetacean-speciﬁc responses
against Gram-negative bacteria．Comp. Immun. Microbiol. Infect. Dis. 33 (6): 89–98．
Suzuki, Y., Umatani, M., Bhuiyan, M.M.U., Watanabe,H., Mogoe, T., Matsuoka, K., Fujise, Y., Ishikawa, H.,
Ohsumi, S., Sasaki, M. and Fukui, Y. 2010. Eﬀects ofequilibration steps, type of sugars and addition ofwhale follicular ﬂuid on viability and in vitro maturation of vitriﬁed whale oocytes．Jpn. J. Zoo Wildl. Med
15 (2): 65–72．
Tojo, N., Matsukura, R., Yasuma, H., Yonezaki, S., Watanabe, H., Kawahara, S., Murase, H., and Miyashita, K.
2010．Spatial analysis of isada krill (Euphausia paciﬁca)
distribution in frontal environments in the North Pacific Ocean．GIS/spatial analyses in ﬁsheries and aquatic
science．4．International Fishery GIS Society: 115–138.
92

2011 (20)
Hakamada, T. and Matsuoka, K. 2011. Abundance estimate for common minke, Brydeʼs and sei whales in theoﬀshore region of the western North Paciﬁc. Bull. Jpn.
Soc. Fish. Oceanogr. 75 (3): 173–174 (in Japanese).
Kanda, N., Goto, M. and Pastene, L. A. 2011. Genetic stock
structure of baleen whales. Bull. Jpn. Soc. Fish. Oceanogr. 75 (3): 191 (in Japanese).
Kato, H. and Fujise, Y. 2011. General discussion: Symposium on “Marine ecosystem of the western North Paciﬁc with special interest in cetaceans.” Bull. Jpn. Soc.
Fish. Oceanogr. 75 (3): 194–195 (in Japanese).
Kishiro, T., Yoshida, H., Tamura, T., Konishi, K., Kanda, N.,
Okamoto, R. and Kato, H. 2011. Relationship between
maturity and feeding ecology of common minke whales
oﬀ Kushiro in autumn. Bull. Jpn. Soc. Fish. Oceanogr. 75(3): 175–176 (in Japanese).
Maehara, T., Aoki, I., Yonezaki, S., Watanabe, H., Murase,
H. and Yamaguchi, A. 2011. Feeding ecology of theJapanese anchovy in the oﬀshore area east of Honshu,
Japan in summer. Bull. Jpn. Soc. Fish. Oceanogr. 75 (3):187 (in Japanese).
Matsuoka, K., Kiwada, H., Fujise, Y. and Miyashita, T. 2011.
Distribution of baleen whales in the western North Paciﬁc based on the JARPN and JARPN II sighting surveys(1994 to 2007). Bull. Jpn. Soc. Fish. Oceanogr. 75 (3):178–179 (in Japanese).
Miyashita, K., Matsukura, R., Tojo, N., Minami, K.,
Yasuma, H., Nagashima, H., Onodera, K., Watanabe, H.,
Yonezaki, S. and Murase, H. 2011. Monitoring of preyof cetaceans by using quantitative echosounders. Bull.
Jpn. Soc. Fish. Oceanogr. 75 (3): 183–184 (in Japanese).
Mori, M., Watanabe, H., Hakamada, T., Tamura, T., Konishi, K., Murase, H. and Matsuoka, K. 2011. Development of an ecosystem model of western North Paciﬁcusing Ecopath with Ecosim. Bull. Jpn. Soc. Fish. Oceanogr. 75 (3): 189 (in Japanese).
Murase, H., Kawabata, A., Kubota, H., Nakagami, M.,
Amakasu, K., Abe, K., Miyashita, K. and Oozeki, Y. 2011.
Eﬀect of depth-dependent target strength on biomass
estimation of Japanese anchovy. Journal of Marine
Science and Technology 19: 267–272.
Murase, H., Tamura, T., Isoda, T., Okamoto, R., Kato, H.,
Yonezaki, S., Watanabe, H., Tojo, N. Matsukura, R.,
Miyashita, K., Kiwada, H., Matsuoka, K., Nishiwaki, S.,
Inagake, D., Okazaki, M., Okamura, H. and Fujise, Y.
2011. Prey selection of common minke, Brydeʼs andsei whales in the oﬀshore region of the western North
Paciﬁc. Bull. Jpn. Soc. Fish. Oceanogr. 75 (3): 180–181(in Japanese).

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2017

Nishiwaki, S., Otani, S. and Tamura, T. 2011. The satellite
tracking of the western North Paciﬁc. Bull. Jpn. Soc.
Fish. Oceanogr. 75 (3): 193–194 (in Japanese).
Onodera, K., Nagashima, H., Matsukura, R., Miyashita,K., Yonezaki, S. and Murase, H. 2011. Cetacean preyspecies and oceanographic surveys in Sendai Bay. Bull.
Jpn. Soc. Fish. Oceanogr. 75 (3): 184–185 (in Japanese).
Pastene, L.A., Hatanaka, H., Fujise, Y., Kanda, N., Murase,
H., Tamura, T., Miyashita, T. and Kato, H. 2011. Whale
research program under special permit in the western
North Paciﬁc—Phase II (JARPNII): origin and objectives. Bull. Jpn. Soc. Fish. Oceanogr. 75 (3): 172–173 (inJapanese).
Pastene, L.A., Hatanaka, H., Fujise, Y., Kanda, N., Murase,
H., Tamura, T., Yasunaga, G., Kishiro, T., Yoshida, H.,
Miyashita, T. and Kato, H. 2011. The Japanese Whale
Research Program under Special Permit in the western
North Paciﬁc Phase-II (JARPNII): origin, objectives andresearch progress made in the ﬁrst six years period(2002–2007), including scientiﬁc considerations for the
next research period. Aquabiology 33 (2): 171–185 (inJapanese).
Sasaki, Y., Saito, S., Matsuoka, K., Murase, H. and Kiwada.,
H. 2011. Spatial distribution patterns of sei and Brydeʼswhales. Bull. Jpn. Soc. Fish. Oceanogr. 75 (3): 179–180(in Japanese).
Tamura, T., Konishi, K., Isoda, T., Hakamada, T., Kiwada, H.,
Okamoto, R. and Matsuoka, K. 2011. The food habitat,
relation of habitat factor and prey consumption of
three baleen whale species in the oﬀshore region of
the western North Paciﬁc. Bull. Jpn. Soc. Fish. Oceanogr. 75 (3): 174–175 (in Japanese).
Watanabe, H., Kiwada, H., Kumagai, S., Yonezaki, S.,
Kishiro, T., Konishi., K. and Yoshida, H. 2011. Habitatand prey selection of common minke whale oﬀ Kushiro
in autumn—Estimation of distribution and migrationof common minke whale using environmental information—Bull. Jpn. Soc. Fish. Oceanogr. 75 (3): 182–183 (inJapanese).
Yamaguchi, A., Hanamiya, Y., Murase, H. and Watanabe,
H. 2011. Vertical ﬂux of materials by diel vertical migration of macrozooplankton. Bull. Jpn. Soc. Fish. Oceanogr. 75 (3): 185–186 (in Japanese).
Yasunaga, G. and Fujise, Y. 2011. Monitoring of pollutants in the baleen whales and their prey species in thewestern North Paciﬁc. Bull. Jpn. Soc. Fish. Oceanogr. 75(3): 190 (in Japanese).
Yoshida, H., Kishiro, T., Goto, M., Bando, T., Tamura, T.,
Konishi, K., Okamoto, R. and Kato, H. 2011. Feeding
ecology of common minke whales in coastal waters oﬀ

Sanriku in spring. Bull. Jpn. Soc. Fish. Oceanogr. 75 (3):
177–178 (in Japanese).
2012 (4)Maeda, H. and Kato, H. 2012. Technical improvementsof the age character (earplug) collections in common
minke whales. Bull. Jpn. Soc. Fish. Oceanogr. 76 (2):59–65 (in Japanese).
Murase, H., Kawabata, A., Kubota, H., Nakagami, M.,
Amakasu, K., Abe, K., Miyashita, K. and Oozeki, Y. 2012.
Basin-scale distribution patterns and biomass estimation of Japanese anchovy Engraulis japonicus in thewestern North Paciﬁc. Fish Sci 78 (4): 761–773.
Nakamura, G., Kato, H. and Fujise, Y. 2012. Relative
growth of the skull of the common minke whale Balaenoptera acutorostrata from the North Paciﬁc in comparison to other Balaenoptera species. Mammal Study
37 (2): 105–112.
Watanabe, H, Okazaki, M., Tamura, T., Konishi, K., Inagake, D., Bando, T., Kiwada, H. and Miyashita, T. 2012.
Habitat and prey selection of common minke, sei, andBrydeʼs whale in mesoscale during summer in the
sub-arctic and transition regions of the western North
Paciﬁc. Fish Sci 78 (3): 557–567.
2013 (5)*Kershaw, F., Leslie, M.S., Collins, T., Mansur, R.M., Smith,B.D., Minton, G., Baldwin, R., LeDuc, R.G., Anderson,
R.C., Brownell, R.L. and Rosenbaum, H.C. 2013. Population diﬀerentiation of 2 forms of Brydeʼs whales in the
Indian and Paciﬁc Oceans. Journal of Heredity 104 (6):755–764.
Maeda, H., Kawamoto, T. and Kato, H. 2013. A study on
the improvement of age estimation in common minke
whales using the method of gelatinized extraction of
earplug. NAMMCO Scientiﬁc Publications 10: 17pp.
Matsukura, R., Sawada, K., Abe, K., Minami, K., Nagashima, H., Yonezaki, S., Murase, H. and Miyashita,
K. 2013. Comparison of measurements and model
calculations of target strength of juvenile sandeel in
Sendai Bay. Nippon Suisan Gakkaishi 79 (4): 638–648(in Japanese).
Sasaki, H., Murase, H., Kiwada, H., Matsuoka, K., Mitani, Y.
and Saitoh, S. 2013. Habitat diﬀerentiation between sei(Balaenoptera borealis) and Brydeʼs whales (B. brydei)
in the western North Paciﬁc. Fish. Oceanogr. 22 (6):496–508.
Shimizu, Y., Ohishi, K., Suzuki, R., Tajima, Y., Yamada, T.,
Kakizoe, Y., Bando, T., Fujise, Y., Taru, H., Murayama, T.
and Maruyama, T. 2013. Amino acid sequence varia93

Technical Reports of the Institute of Cetacean Research (2017)

tions of signaling lymphocyte activation molecule andmortality caused by morbillivirus infection in cetaceans. Microbiol Immunol 57: 624–632.
2014 (6)Inoue, S., Kishiro, T., Fujise, Y., Nakamura, G. and Kato,
H. 2014. Seasonal changes in the testis of the North
Paciﬁc common minke whale. Nippon Suisan Gakkaishi
80 (2): 185–190 (in Japanese).
Murase, H., Hakamada, T., Matsuoka, K., Nishiwaki, S.,
Inagake, D., Okazaki, M., Tojo, N. and Kitakado, T. 2014.
Distribution of sei whales (Balaenoptera borealis) in
the subarctic–subtropical transition area of the western North Paciﬁc in relation to oceanic fronts. Deep
Sea Research Part II: Topical Studies in Oceanography
107: 22–28.
Nakamura, G., Kadowaki, I., Nagatuka, S., Fujise, Y.,
Kishiro, T. and Kato, H. 2014. Variation in a color pattern of white patch on the ﬂippers of North Paciﬁc
common minke whales: potential application for theirinteroceanic diﬀerence. La mer 52: 31–47.
Nakamura, G. and Kato, H. 2014. Developmental changes
in the skull morphology of common minke whales
Balaenoptera acutorostrata. Journal of Morphology
275: 1113–1121.
Niimi, S., Imoto, M., Kunisue, T., Watanabe, M.X., Kim,
E.Y., Nakayama, K., Yasunaga, G., Fujise, Y., Tanabe, S.
and Iwata, H. 2014. Eﬀects of persistent organochlorine exposure on the liver transcriptome of the common minke whale (Balaenoptera acutorostrata) fromthe North Paciﬁc. Ecotoxicology and Environmental
Safety 108: 95–105.
*Rosel, P.E. and Wilcox, L.A. 2014. Genetic evidence reveals a unique lineage of Brydeʼs whales in the northern Gulf of Mexico. Endang Species Res. 25 : 19–34.
2015 (1)Kitayama, C., Sasaki, M., Ishikawa, H., Mogoe, T., Ohsumi,
S., Fukui, Y., Budipitojo, T., Kondoh, D. and Kitamura, N.
2015. Structure and functions of the placenta in common minke (Balaenoptera acutorostrata), Brydeʼs (B.
brydei) and sei (B. borealis) whales. Journal of Reproduction and Development 61 (5): 415–421.
2016 (5)Hirako, S., Suzuki, M., Kim, H., Iizuka, Y., Matsumoto,A., Wada, N., Okabe, M., Takenoya, F., Yasunaga, G.,
Yamanaka, S., Miyazaki, A. and Shioda, S. 2016. Hepatic
lipid accumulation is ameliorated in obese KK mice by
dietary sei whale oil. Fish Sci 82 (3): 509–517.
94

Miyakawa, N., Kishiro, T., Fujise, Y., Nakamura, G. andKato, H. 2016. Sexual Dimorphism in Pelvic Bone
Shape of the North Paciﬁc Common Minke Whales(Balaenoptera acutorostrata). Open Journal of Animal
Sciences 6: 131–136.
Murase, H., Tamura, T., Otani, S. and Nishiwaki, S. 2016.
Satellite tracking of Brydeʼs whales Balaenoptera edeni
in the oﬀshore western North Paciﬁc in summer 2006
and 2008. Fish Sci 82 (1): 35–45.
Nakamura, G., Kadowaki, I., Nagatsuka, S., Hayashi, R.,
Kanda, N., Goto, M., Pastene, L.A. and Kato, H. 2016.
White Patch on the Fore-Flipper of Common Minke
Whale, as a Potential morphological Index to Identify
Stocks. Open Journal of Animal Sciences 6: 116–122.
Ohishi, K., Bando, T., Abe, E., Kawai, Y., Fujise, Y. andMaruyama, T. 2016. Long-term and large-scale epidemiology of Brucella infection in baleen whales andsperm whales in the western North Paciﬁc and Antarctic Oceans. J. Vet. Med. Sci. 78 (9): 1457–1464.
2017 (2)Bando, T., Nakamura, G., Fujise, Y. and Kato, H. 2017.
Developmental changes in the morphology of western
North Paciﬁc Brydeʼs whales (Balaenoptera edeni).
Open Journal of Animal Sciences 7: 344–355.
Ishii, M., Murase, H., Fukuda, Y., Sawada, K., Sasakura,T., Tamura, T., Bando, T., Matsuoka, K., Shinohara, A.,
Nakatsuka, S., Katsumata, N., Okazaki, M., Miyashita,
K. and Mitani, Y. 2017. Diving behavior of sei whales
Balaenoptera borealis relative to the vertical distribution of their potential prey. Mammal Study 42: 1–9.

Other surveys
1993 (1)Fujise, Y., Ishikawa, H., Saino, S. and Kawasaki, M. 1993.
Catch and struck-and-lost rate in the Japanese Dallʼs
porpoise hand-harpoon ﬁshery. Rep. int. Whal. Commn
43: 453–457.
1995 (1)Shimada, H. and Pastene, L.A. 1995. Report of a sightings survey oﬀ the Solomon Islands with comments on
Brydeʼs whale distribution. Rep. Int. Whal. Commn 45:
413–418.
1997 (4)Kimura, T., Ozawa, T. and Pastene, L.A. 1997. Sample
preparation and analysis of mitochondrial DNA fromwhale baleen plates. Marine Mammal Science 13 (3):495–498.

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2017

Ljungblad, D.K., Staﬀord, K.M., Shimada, H. and Matsuoka, K. 1997. Sounds attributed to blue whales recorded
oﬀ the southwest coast of Australia in December 1995.
Rep. int. Whal. Commn 47: 435–439.
Ohmagari, K. and Berkes, F. 1997. Transmission of indigenous knowledge and bush skills among the WesternJames Bay Cree Women of Subarctic Canada. Human
Ecology 25 (2): 197–222.
Shimamura, M., Yasue, H., Ohshima, K., Abe, H., Kato, H.,
Kishiro, T., Goto, M., Munechika, I. and Okada, N. 1997.
Molecular evidence from retroposons that whales
form a clade within even-toed ungulates. Nature 388:
666–670.
1998 (2)Miyazaki, N., Fujise, Y. and Iwata, K. 1998. Biologicalanalysis of a mass stranding of melon-headed whales(Peponocephala electra) at Aoshima. Japan. Bull. Natn.
Sci. Mus., Tokyo, Ser. A 24 (1): 31–60.
Otani, S., Naito, Y., Kawamura, A., Kawasaki, M., Nishiwaki, S. and Kato, A. 1998. Diving behavior and performance of harbor porpoises, Phocoena phocoena,
in Fukuoka bay, Hokkaido, Japan. Marine Mammal
Science 14 (2): 209–220.
1999 (4)Iino, Y. 1999. Treaty Implementation: the 1946 International Convention for the Regulation of Whaling.
System Compliance in Ocean Management. Southeast
Asian Programme in Ocean Law. Policy and Management: 189–193.
Pastene, L.A. and Shimada, H. 1999. Report of a sighting
survey in Chileʼs Exclusive Economic Zone with comments on sei whale distribution. Anales Instituto Patagonia, Serie Cs. Nat. 27: 51–62.
Shimamura, M., Abe, H., Nikaido, M., Ohshima, K. andOkada, N. 1999. Genealogy of families of SINEs in cetaceans and artiodactyls: the presence of a huge superfamily of tRNAGlu-derived families of SINEs. Mol. Biol.
Evol. 16 (8): 1046–1060.
Yoshida, H. and Kato, H. 1999. Phylogenetic relationshipsof Brydeʼs whales in the Western North Paciﬁc andadjacent waters inferred from mitochondrial DNA sequences. Marine Mammal Science 15 (4): 1269–1286.
2000 (3)Goto, M. and Ohsumi, S. 2000. Response to “Scientiﬁc
Whaling Source of illegal Products for Market” By Baker
et al. Science 290: 1695–1696.
Otani, S., Naito, Y., Kato, A. and Kawamura, A. 2000. Div-ing behavior and swimming speed of a free-ranging
harbor porpoise, Phocoena phocoena. Marine Mammal Science 16 (4): 811–814.
Takahashi, S., Le, L.T.H., Saeki, H., Nakatani, N., Tanabe,S., Miyazaki, N. and Fujise, Y. 2000. Accumulation ofbutyltin compounds and total tin in marine mammals.
Water Science and Technology 42 (7–8): 97–108.
2001 (2)Abe, H., Goto, M., Pastene, L.A., Dewa, K. and Naito, E.
2001. Practical use of multiplex ﬂuorescent PCR for
cetacean sex identiﬁcation. Marine Mammal Science
17 (3): 657–664.
Yoshida, H., Yoshioka, M., Shirakihara, M. and Chow, S.
2001. Population structure of ﬁnless porpoises (Neophocaena phocaenoides) in coastal waters of Japan
based on mitochondrial DNA sequences. Journal of
Mammalogy 82 (1): 123–130.
2002 (1)Konishi, K. and Sakurai, Y. 2002. Geographical variations ininfection by larval Anisakis simplex and Contracaecum
osculatum (Nematoda, Anisakidae) in walleye pollock
Theragra chalcogramma stocks oﬀ Hokkaido, Japan.
Fish Sci 68 (3): 534–542.
2003 (1)Matsuoka, K., Ensor, P., Hakamada, T., Shimada, H., Nishiwaki, S., Kasamatsu, F. and Kato, H. 2003. Overview
of the minke whale sighting survey in IWC/IDCR and
SOWER cruises from 1978/79 to 2000/01. J. Cetacean
Res. Manage. 5 (2): 173–201.
2004 (5)Branch, T.A., Matsuoka, K. and Miyashita, T. 2004. Evidence for increases in Antarctic blue whales based on
Bayesian modelling. Marine Mammal Science 20 (4):726–754.
Escorza-Trevino, S., Pastene, L.A. and Dizon, A.E. 2004.
Molecular analyses of the Truei and Dalli morphotypes of Dallʼs porpoise (Phocoenoides dalli). Journal of
Mammalogy 85 (2): 347–355.
Ikemoto, T., Kunito, T., Watanabe, I., Yasunaga, G., Baba,N., Miyazaki, N., Petrov, E.A. and Tanabe, S. 2004.
Comparison of trace element accumulation in Baikal
seals (Pusa sibirica), Caspian seals (Pusa caspica) andnorthern fur seals (Callorhinus ursinus). Environmental
Pollution 127: 83–97.
Murase, H., Matsuoka, K., Nishiwaki, S., Hakamada, T. andMori, M. 2004. Eﬀect of observed covariates (school95

Technical Reports of the Institute of Cetacean Research (2017)

size, sighting cue, latitude and sea state) on the Antarctic minke whale abundance estimation parameters in
the IWC/IDCR-SOWER surveys. J. Cetacean Res. Manage. 6 (3): 283–292.
Yanagimoto, T. and Konishi, K. 2004. Acanthochondria priacanthi (Copepoda: Chondracanthidae) as a biologicalindicator for stock identiﬁcation of sandﬁsh Arctoscopus japonicus (Steindachner). Fish Sci 70 (2): 336–338.
2005 (5)Agusa, T., Matsumoto, T., Ikemoto, T., Anan, Y., Kubota, R.,
Yasunaga, G., Kunito, T., Tanabe, S., Ogi, H. and Shibata,Y. 2005. Body distribution of trace elements in blacktailed gulls from Rishiri Island, Japan: age-dependentaccumulation and transfer to feathers and eggs. Environ. Toxicol. Chem. 24 (9): 2107–2120.
Agusa, T., Kunito, T., Yasunaga, G., Iwata, H., Subramanian, A., Ismail, A. and Tanabe, S. 2005. Concentrationsof trace elements in marine ﬁsh and its risk assessment in Malaysia. Marine Pollution Bulletin 51 (8–12):
896–911.
Fukui, Y., Ishikawa, H. and Ohsumi, S. 2005. Diﬃculties
in publishing research results from scientiﬁc whaling.
Marine Mammal Science 21 (4): 781–783.
Prudente, M., Tanabe, S., Kunisue, T., Yasunaga, G., Watanabe, I. and Miyazaki, N. 2005. Accumulation of traceelements and persistent organochlorines in resident
and migratory waders from Calatagan Bay, Philippines.
Coastal Marine Science 29 (2): 133–140.
Sanino, G.P., Waerebeek, K.V., Van Bressem, M. andPastene, L.A. 2005. A preliminary note on population
structure in eastern South Paciﬁc common bottlenose
dolphins, Tursiops truncatus. J. Cetacean Res. Manage.
7 (1): 65–70.
2006 (6)Acevedo, J., Aguayo-Lobo, A. and Pastene, L.A. 2006.
Filopatria de la ballena jorobada (Megaptera novaeangliae Borowski, 1781), al area de alimentacion delEstrecho de Magallanes. Revista de Biologia Marina y
Oceanograﬁa 41 (1): 11–19.
Acevedo, J., Aguayo-Lobo, A., Acuna, P. and Pastene, L.A.
2006. A note on the ﬁrst record of the dwarf minke
whale (Balaenoptera acutorostrata) in Chilean waters.
J. Cetacean Res. Manage. 8 (3): 293–296.
Hayashi, K., Yoshida, H., Nishida, S., Goto, M., Pastene,
L.A., Kanda, N., Baba, H. and Koike, H. 2006. Genetic
Variation of the MHC DQB locus in the ﬁnless porpoise(Neophocaena phocaenoides). Zoological Science 23(2): 147–153.
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Mori, M. and Butterworth, D.S. 2006. A ﬁrst step towards
modelling the krill–predator dynamics of the Antarctic
ecosystem. CCAMLR Science 13: 217–277.
Sekiguchi, K., Olavarria, C., Morse, P., Olson, P., Ensor,
P., Matsuoka, K., Pitman, R., Findlay, K. and Gorter, U.
2006. The spectacled porpoise (Phocoena dioptrica)
in Antarctic waters. J. Cetacean Res. Manage. 8 (3):265–271.
Takahashi, Y., Ohwada, S., Watanabe, K., Ropert-Coudert,Y., Zenitani, R., Naito, Y. and Yamaguchi, T. 2006. Does
elastin contribute to the persistence of corpora albicantia in the ovary of the common dolphin (Delphinusdelphis). Marine Mammal Science 22 (4): 819–830.
2007 (2)Acevedo, J., Rasmussen, K., Felix, F., Castro, C., Llano, M.,
Secchi, E., Saborio, M.T., Aguayo-Lobo, A., Haase, B.,
Scheidat, M., Dalla-Rosa, L., Olavarria, C., Fosestell, P.,
Acuna, P., Kaufman, G. and Pastene, L.A. 2007. Migratory destinations of humpback whales from the Magellan Strait feeding ground, Southeast Paciﬁc. Marine
Mammal Science 23 (2): 453–463.
Branch, T.A., Staﬀord, K.M., Palacios, D.M., Allison, C.,
Bannister, J.L., Burton, C.L.K., Cabrera, E., Carlson, C.A.,
Galletti Vernazzani, B., Gill, P.C., Hucke-Gaete, R., Jenner, K.C.S., Jenner, Mn. M., Matsuoka, K., Mikhalev,
Y.A., Miyashita, T., Morrice, M.G., Nishiwaki, S., Sturrock, V.J., Tormosov, D., Anderson, R.C., Baker, A.N.,
Best, P.B., Borsa, P., Brownell Jr, R.L., Childerhouse,
S., Findlay, K.P., Gerrodette, T., Ilangakoon, A.D., Joergensen, M., Kahn, B., Ljungblad, D.K., Maughan, B.,
Mccauley, R.D., Mckay, S., Norris, T.F., Oman Whaleand Dolphin Research Group, Rankin, S., Samaran, F.,
Thiele, D., Van Waerebeek, K. and Warneke, R.M. 2007.
Past and present distribution, densities and movements of blue whales in the Southern Hemisphere andadjacent waters. Mammal Rev. 37 (2): 116–175.
2009 (1)Nambu, H., Tokutake, K., Ishikawa, H., Ohta, M., Fujita, K.
and Yamada, T.K. 2009. Observation of a gray whale, Eschrichtius robustus, in Tokyo Bay in 2005. Japan Cetology
19: 17–22 (in Japanese).
2010 (3)Nambu, H., Ishikawa, H. and Yamada, T. 2010. Recordsof the western gray whale Eschrichtius robustus: its
distribution and migration. Japan Cetology 20: 21–29(in Japanese).
Pastene, L.A. and Quiroz, D. 2010. An Outline of the His-

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2017

tory of Whaling in Chile. pp. 73–98. In: International
Center for Folk Culture Studies (Ed). Human Culture
from the Perspective of Traditional Maritime Communities, International Symposium Report No. 1. Kanagawa
Shimbun Press, Kanagawa. 199pp.
Taguchi, M., Ishikawa, H. and Matsuishi, T. 2010. Seasonal
distribution of harbour porpoise (Phocoena phocoena)
in Japanese waters inferred from stranding and bycatchrecords．Mammal Study 35 (2) : 133–138．
2011 (2)Acevedo, J., Olavarría, C., Plana, J., Aguayo-Lobo, A., Larrea, A. and Pastene, L.A. 2011. Occurrence of dwarf
minke whales (Balaenoptera acutorostrata subsp.)
around the Antarctic Peninsula. Polar Biol 34 (2):313–318.
Acevedo, J., Plana, J., Aguayo-Lobo, A. and Pastene, L.A.
2011. Surface feeding behavior of humpback whalesin the Magellan Strait. Revista de Biologia Marina y
Oceanograﬁa. 46 (3): 483–490.
2013 (4)Acevedo J., Haro D., Dalla R.L., Aguayo-Lobo A., HuckeGaete R., Secchi E., Plana J. and Pastene L.A. 2013.
Evidence of spatial structuring of eastern South Paciﬁchumpback whale feeding grounds. Endang Species Res
22 (1): 33–38.
Kitamura, S., Matsuishi, T., Yamada, K., Tajima, Y., Ishikawa, H., Tanabe, S., Nakagawa, H., Uni, Y. and Abe, S.
2013. Two genetically distinct stocks in Bairdʼs beaked
whale (Cetacea: Ziphiidae). Marine Mammal Science
29 (4): 755–766.
Murase, H., Temoai, I., Kirata, T., Finkaso, S., Yasunaga, G.
and Pastene, L.A. 2013. A note on cetaceans oﬀ Kiribati
and Tuvalu from a research cruise in October 2010. J.
Cetacean Res. Manage. 13 (2): 153–158.
Sugino, T., Yasunaga, G. and Fukuda, M. 2013. Eﬀect ofwhale meat extract on fatigue induced by physical load
and by daily activities in humans. Jpn. Pharmacol. Ther
41 (9): 879–893 (in Japanese).
2014 (3)Pastene, L.A. 2014. Macaya Hermanos y Compania.
Notas sobre las actividades de la empresa ballenerade más larga historia en Chile. Colección Mocha Dick
pp 255–274.
Quiroz, D. and Pastene, L.A. 2014. Norwegian whaling inChile in the 20th Century and its inﬂuence on Chilean
local communities. pp. 61–70. In: Jan Erik Ringstad(Ed). Whaling and History IV. Commander Chr. Christensenʼs Whaling Museum, part of Vestfoldmuseene
IKA, Sandefjord. 192pp.
Quintela, M., Skaug, H.J., Øien, N., Haug, T., Seliussen,
B.B., Solvang, H.K., Pampoulie, C., Kanda, N., Pastene,
L.A. and Glover, K.A. 2014. Investigating population genetic structure in a highly mobile marine organism: theminke whale Balaenoptera acutorostrata acutorostrata in the North East Atlantic. PLoS ONE 9 (9): e108640.
2015 (3)Funasaka, N., Kirihata, T., Kato, H. and Ohsumi, S. 2015.
The ﬁrst record of a true albino common bottlenose
dolphin Tursiops truncatus from Japan. Mammal Study
40 (1): 19–22.
Pastene, L.A., Acevedo, J., Siciliano, S., Sholl, T.G.C., de
Moura, J.F., Ott, P.H. and Aguayo-Lobo, Anelio. 2015.
Population genetic structure of the South American
Brydeʼs whale. Revista de Biologia Marina y Oceanograﬁa 50 (3): 453–464.
Sakamoto, M., Itai, T., Yasutake, A., Iwasaki, T., Yasunaga,G., Fujise, Y., Nakamura, M., Murata, K., Chan, H.M.,
Domingog, J.L. and Marumoto, M. 2015. Mercury
speciation and selenium in toothed-whale muscles.
Environmental Research 143: 55–61.
2017 (2)Hakamada, T., Matsuoka, K., Murase, H. and Kitakado, T.
2017. Estimation of the abundance of the sei whale
Balaenoptera borealis in the central and eastern North
Paciﬁc in summer using sighting data from 2010 to2012. Fish Sci 83 (6): 887–895.
Malde, K., Seliussen, B.B., Quintela, M., Dahle, G., Besnier,F., Skaug, H.J., Øien, N., Solvang, H.K., Haug, T., SkernMauritzen, R., Kanda, N., Pastene, L.A., Jonassen, I. andGlover, K.A. 2017. Whole genome resequencing reveals diagnostic markers for investigating global migration and hybridization between minke whale species.
BMC Genomics 18: 76.

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