TEREP‐ ICR
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―

「 CR

TECHNICAL REPORTS OF THE
INSTITUTE OF CETACEAN RESEARCHTEREP-ICR is published annually by the Institute of Cetacean Research.
ISSN: 2433-6084
Copyright© 2023, The Institute of Cetacean Research (ICR).

Citation
Entire issue:
Institute of Cetacean Research. 2023. Technical Reports of the Institute of Cetacean Research (TEREP-/CR) No. 7. The Institute of Cetacean Research, Tokyo,」apan, 00 pp.
Individual reports:'Author Name'. 2023.'Report title'. Technical Reports of the Institute of Cetacean Research (TEREP­/CR) No. 7:'pp'-' pp'.

Editorial correspondence should be sent to:
Editor, TEREP-ICR
The Institute of Cetacean Research,
4-5 Toyomi-cho, Chuo-ku, Tokyo 104-0055,」a pan
Phone: +81(3) 3536 6521
Fax: +81(3) 3536 6522
E-mail: webmaster@icrwhale.org
TEREP-ICR is available online at www.icrwh�le.org/_TEREP-ICR.html

Cover photo: A specialized multi-platform observation vessel in the Antarctic. This kind of vessel isused by the Institute of Cetacean Research for dedicated sighting surveys in both Antarctic andNorth Pacific (top). Satellite tagging (LIMPET-type SPLASHlO-F-333 fired with an Aerial Remote Tag
System) on an Antarctic minke whale. The tag can be observed on the right side of the body
(middle). Concurrent biopsy sampling (using a crossbow) and satellite-tag deployment (LIMPET-type
SPLASHlO-F-333 fired with a crossbow) of a fin whale in the southern Okhotsk Sea. The tag can beobserved on the right side of the dorsal fin (bottom). These satellite-linked tags can transmit infer­mation on the diving profile of the whales via ARGOS system.

Copyright© 2023, The Institute of Cetacean Research (ICR).

Technical Reports of the Ins�tute of Cetacean Research (2023)

p. i

Foreword
It is a pleasure for me to introduce the seventh issue of the Technical Reports of the Ins�tute of Cetacean Research(TEREP-ICR-7). As stated previously, TEREP-ICR describes and reports on the process, progress, and results of technical orscien�ﬁc research on whales and their environment, as well as the ﬁeld ac�vi�es and state of current research surveys
conducted by the ICR, both in the central-western North Paciﬁc and the Antarc�c.
The strict sanitary measures taken previously in response to the Covid-19 pandemic have been relaxed in 2023, which
can be considered as the post-pandemic year. This relaxa�on of sanitary measures has facilitated enormously the implementa�on of the several research ac�vi�es by the ICR, including prepara�on and implementa�on of sigh�ng surveys andpar�cipa�on in na�onal and interna�onal scien�ﬁc mee�ngs, which are now being conducted in-person or in a combina�on of in-person and online approaches. During 2023 the ICR has been able to conduct ﬁeld surveys, laboratory works
and analyses, write papers and par�cipates safely and successfully in na�onal and interna�onal mee�ngs. These eﬀorts
enabled the ICR to make signiﬁcant contribu�on to whale science during 2023 as shown in this issue of TEREP-ICR.
Similar as in previous TEREP-ICR issues, TEREP-ICR-6 was widely distributed in Japan and in foreign countries and I
feel TEREP-ICR is on course towards achieving its objec�ves. At the same �me, TEREP-ICR has been a good opportunity
for our scien�sts to compile and summarize their research conducted over the years, as a precursor to submi�ng theirworks for publica�on in peer-review journals.
I sincerely hope that this seventh issue of the TEREP-ICR will contribute further to an increased understanding amongna�onal and interna�onal scien�ﬁc communi�es of the technical and research ac�vi�es on whales and the ecosystem
conducted by the ICR.
Dr. Yoshihiro Fujise
Director GeneralIns�tute of Cetacean Research
Tokyo, December 2023iTechnical Reports of the Ins�tute of Cetacean Research (2023)

pp. iii

Editorial
Welcome to the seventh issue of the Technical Reports of the Ins�tute of Cetacean Research (TEREP-ICR-7).
This issue contains eight technical reports and one commentary ar�cle. In TEREP-ICR-7, we completed the series ofreports summarizing the research ﬁndings on whales and the ecosystem in the western North Paciﬁc Ocean. Yasunaga
and Fujise (Part 4) focused on the studies on chemical pollu�on in large baleen whale species and their prey. Tamura andcolleagues (Part 5) summarized the results of large whaleʼs ecology, including feeding habits and ecosystem modelling.
Results of three important dedicated sigh�ng surveys were presented in this issue: Isoda and colleagues summarized
the results of the 2022/23 austral summer season survey of the Japanese Abundance and Stock structure Surveys in the
Antarc�c (JASS-A) conducted in a Paciﬁc sector of the Antarc�c; Kim and colleagues summarized the results of sigh�ng
surveys conducted in the western North Paciﬁc in 2022; and Katsumata and Matsuoka summarized the results of the2022 Interna�onal Whaling Commission-Paciﬁc Ocean Whale and Ecosystem Research (IWC-POWER) survey conductedsouth of the western Aleu�an Islands.
Inoue and colleagues presented an update of the study on age at sexual maturity trends in the Antarc�c minke whale
and interpreted the results in the context of other biological and ecological results for this species and hypotheses on
Antarc�c marine ecosystem changes. Katsumata and colleagues examined the u�lity of data logger for obtaining diving �me data of Antarc�c minke whales for the es�ma�on of availability bias during dedicated sigh�ng surveys. Finally,
Konishi and Kleivane used the data logger techniques for studying the feeding ecology of ﬁn whales in the southern
Okhotsk Sea.
In the commentary ar�cle, Pastene presented his view on the current and future u�lity of data and samples fromformer Japanese whale research programs under special scien�ﬁc permit.
TEREP-ICR-7 issue also included sec�ons that outline the contribu�on of ICR scien�sts to interna�onal and na�onal
mee�ngs in 2023, as well as their contribu�on in terms of peer-reviewed publica�ons up to December 2023.
We trust that you will ﬁnd this seventh TEREP-ICR issue informa�ve and useful.
Dr. Luis A. Pastene
Dr. Satoko Inoue
Editorial Team, TEREP-ICR
Tokyo, December 2023

iii

Technical Reports of the Ins�tute of Cetacean Research (2023)

p. v

Contents
Forewordi

Editorialiii

Contentsv

Technical Reports
Yasunaga, G. and Fujise, Y. What do we know about whales and ecosystem in the western North
Paciﬁc Ocean? Part 4: Summary of results on chemical pollu�on

1

Tamura, T., Konishi, K., Isoda, T. and Hakamada, T. What do we know about whales and ecosystem in
the western North Paciﬁc Ocean? Part 5: Summary of results on whaleʼs ecology including feeding
habitat and ecosystem modelling

8

Isoda, T., Katsumata, T., Kim, Y. and Matsuoka, K. Results of the dedicated sigh�ng survey under theJapanese Abundance and Stock structure Surveys in the Antarc�c (JASS-A) in a part of Area VI inthe 2022/23 austral summer season
22
Kim, Y., Katsumata, T., Isoda, T. and Matsuoka, K. Report and highlights of the Japanese dedicated34sigh�ng surveys in the North Paciﬁc in 2022
Katsumata, T. and Matsuoka, K. Results of the IWC-Paciﬁc Ocean Whale and Ecosystem Research(IWC-POWER) dedicated sigh�ng survey in 2022—An overview—
47
Inoue, S., Bando, T. and Fujise, Y. An update of the study on age at sexual maturity trends in the Antarc�c minke whale
55
Katsumata, T., Isoda, T. and Matsuoka, K. U�lity of data logging for the es�ma�on of availability bias
in sigh�ng surveys
64
Konishi, K. and Kleivane, L. Using satellite-linked tags for studying the feeding ecology of ﬁn whalesin the southern Okhotsk Sea
69

Commentary
Pastene, L.A. The current u�lity of data and samples collected by former Japanese whale research
programs under special scien�ﬁc permit
74Na�onal mee�ngs and lectures

78

Interna�onal mee�ngs and lectures

79

Peer-reviewed publica�ons

82v

Technical Reports of the Ins�tute of Cetacean Research (2023)

pp. 1–7

Technical Report (not peer reviewed)

What do we know about whales and the ecosystem in the western
North Paciﬁc Ocean? Part 4: Summary of results on chemical pollu�on
Genta Yasunaga* and Yoshihiro Fujise
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: yasunaga@cetacean.jp

ABSTRACT

Three baleen whale species, common minke, sei and Brydeʼs whales were surveyed during the former Japanese whale research under special scien�ﬁc permit programs in the western North Paciﬁc Ocean. They wereconducted from 1994 to 2019. The Ins�tute of Cetacean Research collected and analyzed samples in order toinves�gate the concentra�on of chemical pollutants and the eﬀect of those pollutants on the health of thewhales. This paper summarizes the results found for mercury (Hg), Persistent Organic Pollutants (POPs) andradioisotope concentra�ons in the whales collected during the research programs. Whales are suited as biological indicators of environmental condi�ons because they are long-living animals with the ability to migrate
long-distances. In par�cular, the former JARPNII research program inves�gated pollutant concentra�ons of
the sampled baleen and toothed whales in rela�on to their sex and maturity. In addi�on, JARPNII inves�gatedpollu�on concentra�ons in prey species collected from the stomach contents of whales as well as those insamples of seawater and air obtained from the research area at the �me of survey. The results from direct
examina�ons of diﬀerent types of bio�c and abio�c sources revealed very important informa�on in furthering
our understanding of the bioaccumula�on process through the marine food chain.

INTRODUCTION
Pollutants such as Persistent Organic Pollutants (POPs)and mercury (Hg) are generally released from land andtransported to coastal and pelagic waters in run-oﬀs as
well as by atmospheric dissemina�on and other ways.
Higher trophic animals such as cetaceans generally accumulate POPs through the marine food web (Sanpera
et al., 1993; Borrell and Reijnders, 1999). The monitoringof pollutants concentra�ons in the marine environment
through the examina�on of biological �ssues of marine
mammals is important, since marine mammals can serveas biological indicators of environmental condi�ons.
Large cetaceans may be par�cularly useful as they are
long-living animals migra�ng long distances.
In 1995, the Interna�onal Whaling Commission (IWC)
decided to ʻgive priority to research on the eﬀects ofenvironmental changes on cetaceans …ʼ (IWC Resolu�on
1995/10), and its Scien�ﬁc Commi�ee (SC) decided totreat the adverse eﬀects of pollutants in cetaceans as oneof its highest priority issues.
Japanʼs whale research programs under special permit in the western North Paciﬁc were conducted forapproximately 25 years, from 1994 and 2019. The main

target species of the programs were the common minke(Balaenoptera acutorostrata), Brydeʼs (B. edeni) and sei(B. borealis) whales. During the surveys, the Ins�tute of
Cetacean Research (ICR) collected and analyzed samples
in order to inves�gate the concentra�on of chemical pollutants and the eﬀect of those pollutants on the health of
the whales.
At this point, it was considered important to summarize the knowledge on whales and their environment
accumulated so far by Japanʼs whale research in thewestern North Paciﬁc. The objec�ve of this paper is tosummarize the most relevant outputs of pollutant studies
based on samples and data collected during the former
whale research programs under special permit in thewestern North Paciﬁc.

SUMMARY OF POLLUTANT MONITORING IN
THREE BALEEN WHALE SPECIESThe ICR uses a cold-vapor atomic absorp�on spectrometry, ELISA, UPLC-MS/MS and UPLC-FDA for measurementsof pollu�on and biomarker concentra�ons in whales(Figure 1).
Table 1 shows the measurement systems and the standard procedures used at the ICR in recent chemical pol1

Technical Reports of the Ins�tute of Cetacean Research (2023)

lutant studies of North Paciﬁc baleen whales. Results on
chemical pollutants in whales presented in this paper are
based on those systems and procedures.
Laboratory and analy�cal procedures to determine
pollutant concentra�ons in baleen whales have been
described in previous documents (Yasunaga et al., 2016;
Yasunaga and Fujise, 2016a; b). Details of the procedures
are not repeated here for the sake of brevity. The main results are presented in this sec�on for three baleen whale
species, by type of chemical pollutant.
Mercury (Hg)
It is known that Hg is mainly released on land as elemental Hg from natural sources such as volcanic ac�vi�es
and anthropogenic sources, e.g. thermal power plants.
Once released, elemental Hg is transported to the pelagic
ocean and pelagic surface water (Fitzgerald et al., 1998).
In the pelagic ocean, elemental Hg is converted into

methyl Hg and bioconcentrated at moderate levels inanimals of high trophic level, such as cetaceans, throughthe food chain (Knauer and Mar�n, 1972). Therefore, inpredic�ng changes in Hg concentra�ons in baleen whales
and their environment, factors such as food habitat ofwhales and biological informa�on such as sex, age andpregnancy, are important.
Yasunaga et al. (2016) examined temporal changes
in Hg concentra�ons (including all chemical forms ofHg such as methyl Hg and inorganic Hg, i.e. total Hg) of
baleen whales using muscle samples of mature malesof common minke whales for the period 1994–2014, sei
whales for the period 2002–2014 and Brydeʼs whales forthe period 2002–2014 from the western North Paciﬁc.
The research areas surveyed are shown in Figure 2. The

Figure 2.
Figure 1.

UPLC-MS/MS and FDA system at the environmental
chemistry laboratory of the Ins�tute of Cetacean
Research.

Sub-areas surveyed by the former Japanese whale
research program under special permit. Sub-areas
are based on IWC (1994), and they have been usedby the IWC for the management of common minke
whales.

Table 1
Measurement systems and the standard procedures used at the Ins�tute of Cetacean Research in the recent chemical pollutant
studies of North Paciﬁc baleen whales.
Substances

Total Hg

Direct Thermal
Measurement
Decomposi�on-Goldsystems
Amalgama�on-CVAAS

Standard
procedures

2

Provisional regula�onlevels of Hg in ﬁsheries
by Ministry of Health andWelfare Japan (1972)

Total PCB

Legacy POPs fordetermina�on of each isomerRadioisotopes(the I131, Cs134 and Cs137)

Analy�cal methodof PCBs using
GC-ECD with apacked colomun

A sample decomposedwith alkaline solu�on andextracted with hexane aremeasured by GC/MS-SIM

Containers were placed in
0.04-mm thick polyethylenebags and a germanium semiconductor detector

The public analy�cal
method of Japan by
Ministry of Welfare
Japan (1973)

Analy�cal Manual for endocrine disrupter chemicals
by Japan Environmental
Agency (1998)

The analy�cal manual forradioac�ve materials in foods inemergency by Ministry of Health,Labour and Welfare (2002)

What do we know about whales and the ecosystem in the western North Pacific? Part 4

reason for using only mature males was to exclude theeﬀects of pregnancy in case of females and growth, andto be less suscep�ble to age-related Hg accumula�on(Braune et al., 2015).
Concentrations of Hg through the trophic chain
To understand the bioaccumula�on process, it is necessary to examine Hg concentra�ons not only in whales but
also in their prey species. Figure 3 shows the rela�onships
between Hg concentra�ons in common minke, sei and
Brydeʼs whales in the western North Paciﬁc, and those in
their main prey species (two zooplanktons and six pelagicﬁsh species) during the period 1995–2007. The Hg concentra�ons were in the order of:Common minke whales (0.22±0.07 ppm wetwt.)>sei whales (0.052±0.009)≒Brydeʼs whales(0.046±0.008).
The Hg concentra�ons in krill and copepods ranged
from <0.001–0.013 and 0.003–0.010 ppm dry wt.,
respec�vely. Mercury concentra�ons in the pelagicﬁshes were in the order of:
Paciﬁc pomfret (0.232±0.027)>walleye pollock(0.045)=Paciﬁc saury (0.039±0.016)=Japanese anchovy (adult) (0.037±0.025)>Japanese anchovy(larval ﬁsh) (0.005±0.003).
It is known that common minke whales selec�vely feed
on rela�vely higher trophic organisms, mainly pelagic ﬁshsuch as Paciﬁc saury and Japanese anchovy (Tamura andFujise, 2002). This is diﬀerent from sei and Brydeʼs whales
which feed mainly on krill and copepod (Tamura andFujise, 2002; Tamura et al., 2009). Diﬀerences in feeding
habitat among whale species and trophic levels of prey
would be one of the reasons for higher Hg concentra�ons
in common minke whales than in sei and Brydeʼs whales.
The Hg concentra�ons in common minke whales from

Figure 3.

oﬀshore, however, would be aﬀected by changes in thefood habitat during the research period.
Temporal trend in Hg concentrations
To examine yearly changes of Hg in common minke, sei
and Brydeʼs whales in the western North Paciﬁc, mul�ple
linear regression analyses were carried out including adjustment for confounders, i.e. sampling years, sampling
longitude, sampling la�tude, sampling date, body length,
blubber thickness and main prey item.
Results indicated that Hg concentra�ons observed in
the muscle of common minke whales oﬀ Kushiro andSanriku (part of sub-area 7) and sub-area 8, and Brydeʼswhales in sub-areas 8 and 9 were rela�vely stable in thewestern North Paciﬁc during the research periods.
On the other hand, the associa�on of Hg concentra�ons with sampling year was sta�s�cally signiﬁcant incommon minke whales from sub-areas 7 and 9, and sei
whales from sub-area 9. A slight ﬂexion point of yearly
trends of Hg was observed in 2008 for common minke
whales from sub-area 9, and in 2012 for sei whales fromsub-area 9 (Figure 4). The results of mul�ple linear regression analyses showed that the main prey items (subarea 7= walleye pollock, sub-aera 9= Paciﬁc pomfret and
Paciﬁc saury) were associated with Hg concentra�ons
in common minke whales. This associa�on was not observed in the case of sei whales. Hg concentra�ons in sei
whales, having sardine and saury in their stomachs, wereslightly lower than those in common minke whales fromsub-area 9. Therefore, Hg concentra�ons of sei whales
from sub-area 9 may be less aﬀected by Hg in the fooditems (Figure 4).
Thus, the yearly trend of Hg in sea surface water andthe baleen whales from the North Paciﬁc remain stable
for the research period. This is also supported by the

Rela�onships between Hg concentra�ons in muscle �ssues of common minke, sei and Brydeʼs whales in
the western North Paciﬁc, and those in their prey species.
3Technical Reports of the Ins�tute of Cetacean Research (2023)

Figure 4.

Simple plots (le� sides) and smoothing plots using the GAM (right sides) of Hg concentra�ons in muscle �ssues of common minke whales in sub-areas 7 (a: 1996–2012) and 9 (b: 1994–2013), sei whales in sub-area
9 (c: 2002–2014) and Brydeʼs whales in sub-areas 8 and 9 during research years.

results of monitoring studies on Hg concentra�ons from1980s in the nearby waters (Laurier et al., 2004; Sunderland et al., 2009).
POPs
POPs are organic compounds that are resistant to environmental degrada�on that occur through chemical andbiological processes. Therefore, they have the poten�al
to be transported over long distances. The manufacturing, use and import/export of the speciﬁed compounds
4

have been strictly restricted since the adop�on of theStockholm Conven�on on POPs by the United Na�ons Environment Programme in 2001 (Hagen and Walls, 2005).
Among them, polychlorinated biphenyls (PCBs), dichlorodiphenyl-trichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB) and chlordanes(CHLs) are commonly called ʻlegacy POPsʼ (French
et al., 2006). These legacy POPs had been produced andused in large quan��es worldwide in the middle of lastcentury. However, they remain a major environmental

What do we know about whales and the ecosystem in the western North Pacific? Part 4

Figure 5.

Composi�ons of a) DDTs and b) HCHs in the blubber of common minke, sei, Brydeʼs whales from the western North Paciﬁc and Antarc�c minke whales.

Figure 6.

Simple plots of PCB concentra�ons in blubber of common minke whales (mature males) in sub-areas 7(coastal) and 9 (oﬀshore).

challenge for human health and risk to wildlife due totheir toxicity and persistency.
Accumulation features
Yasunaga and Fujise (2020) examined accumula�on
features of PCB congeners and DDT, HCH, HCB and CHL
isomers in the blubber of common minke, sei and Brydeʼswhales from the western North Paciﬁc. DDT and HCH,
the main components contained in pes�cide products
released into the environment, were hardly present in
the samples. Concentra�on levels of ﬁve mature malesof common minke, sei and Brydeʼs whales taken by the
JARPNII in 2011 were compared with those in Antarc�cminke whales. Results showed that, among the legacy
POPs, concentra�on levels of PCBs were the highest in
the whales from the western North Paciﬁc, whereas in
Antarc�c minke whales from the Antarc�c Ocean, thelevels were lower than those of HCB and DDTs.
The average percentage of p,pʹ-DDT (which is primarily released into the environment) in the three whale
species from the western North Paciﬁc was lower thanthat of Antarc�c minke whales (Figure 5). The p,pʹ-DDT
has been used to control malaria (De Jager et al., 2006),
and is metabolized into p,pʹ-DDE in the animal body andthe environment over a long period of �me (Okonkwo
et al., 2008). The percentage of β-HCH accounted forover 90% of total HCHs in common minke, sei and Brydeʼswhales from the western North Paciﬁc, whereas thepercentage of γ-HCH was the dominant isomer of total
HCHs in Antarc�c minke whales (Figure 5). Technical HCH,
called Lindane, had been released into the environment.
Almost all of those consisted of γ-HCH from the 1950s
and 1970s (Walker et al., 1999). However, in Australia, it
was used a�er that period (Tanabe et al., 1982). These
results suggest that in the western North Paciﬁc, a great
deal of �me had passed from the release of DDTs andHCHs into the environment.
Yearly trend
Yasunaga and Fujise (2016a) examined yearly changes of
PCBs in the western North Paciﬁc. Mul�ple linear regression analysis was carried out, including adjustment for
confounders, i.e. sampling years, sampling longitude, la�tude, sampling date, body length, blubber thickness andmain prey species. Results indicated no signiﬁcant correla�ons between year and food items in all areas. It wassuggested that PCB concentra�ons in minke whales fromthe western North Paciﬁc were stable during 2002–2014.
Results for common minke whales in coastal and oﬀshore
waters are shown in Figure 6.

5

Technical Reports of the Ins�tute of Cetacean Research (2023)

Figure 7.

Concentra�ons of Cs 134+137 in muscle of common minke, sei and Brydeʼs whales taken from the western
North Paciﬁc from 2011 to 2015.

Radio Isotope
On 11 March 2011, the Great East Japan Earthquake andthe tsunami that followed destroyed the nuclear power
plant in Fukushima. This accident led to the release oflarge amounts of radioac�ve materials into the environment.
To monitor the impact of this incident on large whalesin the western North Paciﬁc, Yasunaga and Fujise (2016b)
inves�gated the I131, Cs134 and Cs137 concentra�ons inmuscle samples of 53 common minke, 16 Brydeʼs, 32 sei
and 3 sperm whales sampled in the period 2011–2015.
Results are shown in Figure 7. Iodine131 was not detected in Brydeʼs, sei and sperm whales, with the excep�on of two common minke whales taken from Kushiro
in 2012. The ranges of Cs134 + Cs137 concentra�ons incommon minke, sei, Brydeʼs and sperm whales were ND(not detected)-31, ND-9.8, ND-7.1 and ND-0.59 Bq/kg
wet wt., respec�vely. The radioisotope concentra�ons
in all four whale species examined have been decreasing
since 2011.

CONCLUDING REMARKS
It is important to monitor the concentra�ons of diﬀerent chemical pollutants in whale �ssues and their environment, and the possible eﬀect of such pollutants on
whales. The ICR has contributed to this monitoring by analyzing samples and data collected over a long period in
the western North Paciﬁc, not only from whales but also
from their prey species and their environment. Biological
data available from the whales are important for the in6

terpreta�on of the concentra�ons of chemical pollutants
found. The results from the direct analyses of samples
from bio�c and abio�c sources revealed very important
informa�on in furthering our understanding of the bioaccumula�on process through the marine food chain.
The Minamata Conven�on on Mercury is a global
treaty which aims to protect human health and the environment from the adverse eﬀects of mercury. The monitoring of the marine environment using bioindicatorsfrom marine mammals is encouraged by the Conven�on
as one of the recommended ac�ons in the Hg reduc�onplans (UNEP, 2019). Thus, the ﬁndings from this study
are expected to contribute directly to such monitoring
programs.

ACKNOWLEDGEMENTS
We thank Luis A. Pastene (ICR) for his assistance in preparing this document and the Editorial Team of TEREP-ICR
for editorial work.

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Ministry of Health and Welfare Japan. 1972. Provisional regula�on levels of Hg in ﬁsheries. Tokyo, Japan (in Japanese).
h�ps://www.mhlw.go.jp/web/t_doc?dataId=00ta5730&dat
aType=1&pageNo=1.
Ministry of Welfare Japan. 1973. The public analy�cal methodof Japan. Tokyo, Japan (in Japanese). h�ps://www.mhlw.
go.jp/web/t_doc?dataId = 00ta5729&dataType = 1&page
No=1.
Ministry of Health, Labour and Welfare. 2002. The analy�cal
manual for radioac�ve materials in foods in the emergency.
http://www.mhlw.go.jp/stf/houdou/2r9852000001558eimg/2r98520000015cfn.pdf.
Okonkwo, J.O., Mutshatshi, T.N., Botha, B. and Agyei, N. 2008.
DDT, DDE and DDD in human milk from South Africa. Bulletinof Environmental Contamination and Toxicology 81: 348–354.
Sanpera, C., Capelli, R., Mingan�, V. and Jover, L. 1993. Total andorganic mercury in North Atlan�c ﬁn whales: distribu�on pattern and biological related changes. Marine Pollution Bulletin

26 (3): 135–139.
Sunderland, E.M., Krabbenho�, D.P., Moreau, J.W., Strode, S.A.
and Landing, W.M. 2009. Mercury sources, distribu�on, andbioavailability in the North Paciﬁc Ocean: Insights from data
and models. Global Biogeochemical Cycles 23 (2).
Tamura, T. and Fujise, Y. 2002. Geographical and seasonal changes of the prey species of minke whale in the Northwestern
Paciﬁc. ICES Journal of Marine Science 59 (3): 516–528.
Tamura, T., Konishi, K., Isoda, T., Okamoto, R. and Bando,
T. 2009. Prey consump�on and feeding habits of common minke, sei and Brydeʼs whales in the western North
Paciﬁc. Paper SC/J09/JR16 presented to the JARPNII Review
Workshop, January 2009 (unpublished). 36 pp. [Available
from the IWC Secretariat].
Tanabe, S., Tatsukawa, R., Kawano, M. and Hidaka, H. 1982.
Global distribu�on and atmospheric transport of chlorinatedhydrocarbons: HCH (BHC) isomers and DDT compounds in thewestern Paciﬁc, eastern Indian and Antarc�c Oceans. Journalof the Oceanographical Society of Japan 38: 137–148.
UNEP. 2019. Minamata Conven�on on mercury - Text andAnnexes.
h�ps://mercuryconven�on.org/en/resources/
minamata-conven�on-mercury-text-and-annexes.
Walker, K., Vallero, D.A. and Lewis, R.G. 1999. Factors inﬂuencing
the distribu�on of lindane and other hexachlorocyclohexanes
in the environment. Environmental Science & Technology 33(24): 4373–4378.
Yasunaga, G., Hakamada, T. and Fujise, Y. 2016. Update of
the Analyses on Temporal trend of Total Hg levels in threebaleen whale species based on JARPN and JARPNII data forthe period 1994–2014. Paper SC/66b/E/08 presented to the
IWC Scien�ﬁc Commi�ee, June 2016 (unpublished). 18 pp.
[Available from the IWC Secretariat].
Yasunaga, G. and Fujise, Y. 2016a. Temporal trend of PCB levels
in common minke whales from the western North Paciﬁc
for the period 2002–2014. Paper SC/F16/JR31 presented to
the JARPNII Special Permit Expert Panel Review Workshop,
February 2016 (unpublished). 9 pp. [Available from the IWC
Secretariat].
Yasunaga, G. and Fujise, Y. 2016b. Status of I131, Cs134 andCs137 in baleen and sperm whales from the western North
Paciﬁc during 2011-2015. Paper SC/F16/JR35 presented to
the JARPNII Special Permit Expert Panel Review Workshop,
February 2016 (unpublished). 6 pp. [Available from the IWC
Secretariat].
Yasunaga, G. and Fujise, Y. 2020. Concentra�on of persistentorganic pollutants (POPs) in three species of baleen whalesin the western North Paciﬁc. Cetacean Population Studies 2:
39–53.

7

Technical Reports of the Ins�tute of Cetacean Research (2023)

pp. 8–21

Technical Report (not peer reviewed)

What do we know about whales and the ecosystem in the western
North Paciﬁc Ocean? Part 5: Summary of results on whaleʼs ecology
including feeding habitat and ecosystem modelling
Tsutomu Tamura*, Kenji Konishi, Tatsuya Isoda and Takashi Hakamada
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: tamura@cetacean.jp

ABSTRACTThe Ins�tute of Cetacean Research has conducted whale research under special scien�ﬁc permit in the western North Paciﬁc since 1994. The research was conducted systema�cally under diﬀerent research programs
such as JARPN and JARPNII, and ﬁnally, under the NEWREP-NP. These research programs employed both lethal
and non-lethal methods to study diﬀerent aspects of the biology and ecology of large whales in the western
North Paciﬁc. NEWREP-NP ceased a�er the 2019 summer season following Japanʼs decision to withdraw fromthe Interna�onal Conven�on for the Regula�on of Whaling and to start commercial whaling within its Exclusive Economic Zone. This paper summarizes the most relevant ecological research outputs from the Japanesewhaling under special scien�ﬁc permit in the western North Paciﬁc.

INTRODUCTION
Japan conducted systema�c research on whales and theecosystem in the western North Paciﬁc for more than 30
years (1994–2019). The ﬁrst research program was theJapanese Whale Research Program under Special Permit
in the North Paciﬁc (JARPN: 1994–1999), which was followed by JARPNII (2000–2016) and subsequently by the
New Scien�ﬁc Whale Research Program in the North Paciﬁc (NEWREP-NP: 2017–2019). The Ins�tute of Cetacean
Research (ICR) was the ins�tu�on in charge of designingand implemen�ng those research programs. Tamura
et al. (2017) provided details on the objec�ves, sampling
and analy�cal methodology of these research programs.
Several interna�onal review workshops (e.g. IWC,
2001; 2016) discussed and evaluated the large amount ofdata and results from those research programs.
Following the change in Japanʼs whaling policy, NEWREP-NP ceased from 30 June 2019, the date of Japanʼs
withdrawal from the Interna�onal Conven�on for the
Regula�on of Whaling (ICRW). At this point, it was considered important to summarize the knowledge on whales
and the western North Paciﬁc ecosystem accumulated so
far by the Japanese whale research in the North Paciﬁc
Ocean.
The objec�ve of this paper is to summarize the most
relevant ecological research outputs from the Japanesewhaling under special scien�ﬁc permit in the western
8

North Paciﬁc.

SURVEYS, DATA AND SAMPLES
Surveys were conducted in the western North Paciﬁc, inthe sub-areas used by the Interna�onal Whaling Commission (IWC) for the management of common minke whales(Balaenoptera acutorostrata) (Figure 1). The researcharea on the Paciﬁc side of Japan (e.g. Sanriku and Kushiro)
can be considered as Japanʼs richest ﬁshing grounds andFigure 1. Sub-areas in the western North Paciﬁc used by the
IWC for management purposes of the common minke
whale. These sub-areas were used for the Japanesewhale surveys under special scien�ﬁc permit.

What do we know about whales and the ecosystem in the western North Pacific? Part 5

provided an ideal area to study the interac�on between
cetaceans and ﬁsheries. This area can be considered as a
ʻhot-spotʼ area for cetacean/ﬁsheries interac�on.
Survey and sampling methodologies of the Japanesewhale research programs in the North Paciﬁc Ocean
regarding feeding ecology research were described in
Tamura et al. (2016). A list of relevant data and samples
collected by the Japanese whale research programs in the
North Paciﬁc Ocean is available in Tamura et al. (2016).

ABUNDANCE ESTIMATES OF LARGE BALEENWHALES
Apart from its applica�on for assessment and management, abundance es�mate informa�on is highly important for evalua�ng the impact of prey consump�onby whales on the ecosystem. Abundance es�mates are
obtained by analyzing sigh�ng data collected during
dedicated sigh�ng surveys. From the results of the feeding ecology studies, prey species of whales are diﬀerent
between the early (May–June) and late (July–September)seasons. For this reason, the abundances were es�matedfor the early and late seasons. Table 1 shows the abundance es�mates for each whale species studied in thewestern North Paciﬁc. Prey consump�on of whales werees�mated for the coastal areas of Sanriku and Kushiro as
well for the oﬀshore waters of sub-areas 7, 8 and 9. In thela�er, abundance was es�mated for the early and lateseasons as explained above (Table 1). With this informa�on, individual prey consump�on can be extrapolated toobtain the amount of consump�on by the total numberof whales in the area.

DISTRIBUTION OF LARGE WHALES
Analyses of seasonal and spa�al distribu�on of common
minke, sei (B. borealis) and Brydeʼs (B. edeni) whalesin the sub-areas of Figure 1 using Generalized Addi�ve
Models (GAM) indicated that all species shi�ed their distribu�on toward the north as the season progressed fromspring to summer. However, the extent of the shi� was
diﬀerent among whale species. While spa�al segrega�onoccurred among the three baleen whale species, someoverlaps occurred. Given this, the extent of direct interac�on among whale species could be minimal althoughindirect interac�on could occur as they share the same
prey species (Figure 2) (Murase et al., 2016a).

OVERVIEW OF OCEANOGRAPHY, PREY SPECIESDISTRIBUTION AND BIOMASS AND PREY PREFERENCE STUDIES
Oceanography
Oceanographic surveys are important in understanding
the pa�ern of distribu�on of prey species of whales. The
northern part of the survey area is under the inﬂuenceof the Oyashio (a subarc�c western boundary current
with cold, low-salinity water) whereas the southern partis under the inﬂuence of the Kuroshio and its extension(the subtropical western boundary current with warm,
high-salinity water). The area between the Oyashio andthe Kuroshio is called the Kuroshio–Oyashio or subarc�csubtropical transi�on (interferen�al) zone (Figure 3).
Oceanographic condi�ons in the research area were
examined using FRA-ROMs data. This is an ocean forecast
system developed by Fisheries Research Agency (FRA)
based on Regional Ocean Modeling System (ROMS). Annual mean PDO index from 1900 to 2015 was calculatedusing monthly data available from “h�p://research.jisao.
washington.edu/pdo/” [accessed on 6 October 2015].
Nega�ve values of annual mean PDO index were dominant in the period from 2000 to 2013 (Figure 4). It can beconsidered that JARPNII surveys from 2000 to 2013 wereconducted in the nega�ve phase of PDO index.
Prey distribu�on and prey preference
Prey distribu�on and prey preferences of common minke,
Brydeʼs and sei whales at meso-scale were es�matedusing data from the coopera�ve surveys of cetacean sampling and prey of cetaceans (using echosounder and several trawl nets). The surveys were conducted as a part ofthe oﬀshore component of JARPNII in the western North
Paciﬁc from 2002 to 2007 (Figure 5).
For example, in the post-stra�ﬁed block 1 in 2007, prey
distribu�on, sigh�ng posi�ons and stomach contents ofsampled common minke, Brydeʼs and sei whale, watertemperature at 100 m and 200 m are shown in Figure 6.
All blocks were examined for prey preference of whales.
The standardized form of Manlyʼs selec�on index called
Manlyʼs α, also known as Chessonʼs index, was used fores�ma�ng prey preference. Table 2 showed the average
Manlyʼs α of three baleen whale species in the JARPNII
oﬀshore component survey area in summer seasons from2002 to 2007. As a result, common minke whales showed
preference for Japanese anchovy and Paciﬁc saury while
they avoided krill. Brydeʼs whales showed preference
for Japanese anchovy while they also avoided krill. Sei
whales showed preference for copepods and Japanese9Technical Reports of the Ins�tute of Cetacean Research (2023)
Table 1Abundance es�mates for several large baleen whale species based on dedicated sigh�ng surveys in coastal and oﬀshore waters (fromTamura et al., 2019).
Area: Coastal Sanriku
Species: Common minke whale

Area: Coastal Kushiro
Species: Common minke whale

PeriodNumbers

CV

95% CI LL

95% CI ULPeriodNumbers

CV

95% CI LL

95% CI UL

2005
2006
2012

401
216
124

0.321
0.407
0.385

217
101
121

741
466
521

2002
2003
2004
2005
2006
2007
2012

551
888
338
290
221
130
433

0.350
0.406
0.352
0.350
0.351
0.553
0.542

283
413
173
149
113
47
160

1,073
1,908
660
564
431
358
1,171

Area: Oﬀshore sub area 7
Species: Common minke whale

Area: Oﬀshore sub area 8
Species: Common minke whale

PeriodNumbers

CV

95% CI LL

95% CI ULPeriodNumbers

CV

95% CI LL

95% CI UL

Early
2000–2007
2008–2014

4,969
269

0.934
0.951

1,052
56

23,457
1,297

Early
2000–2007
2008–2014

769
755

0.636
0.738

245
207

2,411
2,747

Late
2000–2007
2008–2014

665
—

0.667
—

203

2,182

Late
2000–2007
2008–2014

226
—

0.746
—

61

832

95% CI ULSpecies: Bryde's whale
PeriodSpecies: Bryde's whale
Numbers

CV

Early
2000–2007
2008–2016

804
2,595

1.593
0.445

Late
2000–2007
2008–2016

3,090
3,394

0.456
0.486

95% CI LL

95% CI ULPeriodNumbers

CV

95% CI LL

89
1,128

7,280
5,967

Early
2000–2007
2008–2016

535
—

1.296
—

76

3,742

1,318
1,376

7,245
8,369

Late
2000–2007
2008–2016

2,918
2,733

0.466
0.467

1,224
1,145

6,958
6,526

Species: Sei whale
PeriodSpecies: Sei whale
Numbers

CV

95% CI ULPeriodNumbers

CV

95% CI LL

95% CI UL

253
77

1,768
1,729

Early
2002–2007
2008–2016

2,341
614

0.334
0.683

1,237
182

4,431
2,064

1.148
1.130

40
10

1,452
353

Late
2002–2007
2008–2016

1,400
908

0.541
0.635

518
290

3,780
2,840

Numbers

CV

95% CI LL

95% CI UL

Early
2000–2007
2008–2014

1,600
2,605

0.577
0.701

560
754

4,574
9,000

Late
2000–2007
2008–2014

2,085
3,080

0.618
0.677

684
924

6,362
10,266

Early
2002–2007
2008–2016

668
364

0.529
0.938

Late
2002–2007
2008–2016

241
60

95% CI LL

Area: Oﬀshore sub area 9
Species: Common minke whale
PeriodSpecies: Brydeʼs whale
PeriodNumbers

CV

95% CI LL

95% CI UL

Early
2000–2007
2008–2016

338
363

0.732
0.441

93
159

1,220
828

Late
2000–2007
2008–2016

3,790
7,179

0.582
0.358

1,315
3,636

10,92014,173

Numbers

CV

95% CI LL

95% CI UL

Early
2002–2007
2008–2016

4,735
3,756

0.371
0.182

2,340
2,636

9,579
5,353

Late
2002–2007
2008–2016

3,765
4,119

0.352
0.444

1,928
1,793

7,352
9,460

Species: Sei whale
Period10

What do we know about whales and the ecosystem in the western North Pacific? Part 5

Figure 2.

Number of sighted schools of common minke (a), sei (b) and Brydeʼs (c) whales in 1×1 longitude and la�tude grids from May to September. Total numbers from 2002 to 2013 are shown (from Murase et al., 2016a).

anchovy while they avoided krill and Paciﬁc saury.

Figure 3.

Schema�c map of oceanographic structure in thesurvey area (from Okazaki et al., 2016).

Overview of Prey Biomass Studies
In Japan, ﬁsh abundance and biomass for species such
as Japanese anchovy, Japanese sardine, mackerels andwalleye pollock have basically been es�mated by cohort
analysis. Es�ma�on of the biomass of prey species using
a quan�ta�ve echosounder in JARPNII were also used.
In oﬀshore waters, basin-scale distribu�on pa�ern andbiomass es�ma�on of Japanese anchovy, which was oneof the main prey species, were examined using a quan�ta�ve echosounder between 2004 and 2007. Taking
account of the spa�al coverage of the survey each year,
the most reliable biomass es�mate of Japanese anchovy
11

Technical Reports of the Ins�tute of Cetacean Research (2023)

for this region was 3.4 million tons (CV= 0.22) (Murase
et al., 2012). As an example, Figure 7 shows the distribu�on of Japanese anchovy in 2006 using a quan�ta�veechosounder.
In coastal waters oﬀ Sanriku, the prey surveys were
included in the coastal component of JARPNII. The survey
area for prey species was divided into ten blocks (A–J)
based on bo�om depth (20, 40, 100 and 200 m) andprefectural boundary (between Miyagi and Fukushima
prefecture) (Figure 8). The biomass of sand lance andJapanese anchovy were examined using a quan�ta�veechosounder between 2005 and 2009. The biomasses�ma�ons of sand lance were between 2,827 tons
and 28,340 tons. The biomass es�ma�ons of Japanese
anchovy were between 0.20 and 9,060 tons, respec�vely(Table 3) (Murase et al., 2009b; Wada et al., 2016).

FEEDING ECOLOGY OF LARGE BALEEN WHALES

Figure 4.

Annual mean of Paciﬁc Decadal Oscilla�on (PDO)
index from 1900 to 2015. Monthly PDO data
available from “h�p://research.jisao.washington.
edu/pdo/” (accessed on 6 October 2015) are used
to calculate annual mean. Climate regime shi� indicated in several published papers are also shown inthe ﬁgure (see Okazaki et al., 2016).

Figure 5.

12

Sampling and treatment of stomach contents
Baleen whales have a four chambered stomach system.
The stomach contents remain in the forestomach (ﬁrststomach) and fundus (second stomach). For the analyses,
and a�er capture, the stomach contents were removed
from each compartment and weighed to the nearest
0.1 kg on the shipʼs ﬂensing deck.
The analysis of prey consump�on was based on datacollected from the forestomach and fundus. A subsample (1–5 kg) of stomach contents was removed andfrozen and/or ﬁxed with 10% formalin water for later
analyses. The stomach contents were transferred toa system consis�ng of three sieves (20 mm, 5 mm and1 mm), which were applied in the Norwegian scien�ﬁcresearch to ﬁlter oﬀ liquid from the rest of the material(Haug et al., 1995). In the laboratory, prey species inthe sub-samples were iden�ﬁed to the lowest possible

Pre-deﬁned survey blocks for the coopera�ve whale and prey surveys in JARPNII oﬀshore component from2002 to 2007. Each color represents boundary of surveyed blocks. These blocks were post-stra�ﬁed basedon observed oceanographic condi�ons. Zigzag lines within each block represent planned track lines of preysurveys (from Murase et al., 2009a).

What do we know about whales and the ecosystem in the western North Pacific? Part 5

Figure 6.

Maps in block 1 in 2007: Distribu�on pa�erns of krill (a), Japanese anchovy (b), copepods (Neocalanus spp.
(Copepodite stage 5)) (c) and Paciﬁc saury (d). Sigh�ng eﬀort and sigh�ng posi�ons of common minke,
Brydeʼs and sei whales (e). Sampled posi�ons and stomach contents of common minke (f) and sei (g)whales. Water temperature at 100 m (h) and 200 m (i) water depth. Encircled areas by red and blue lines
are the post-stra�ﬁed area, E–N and E–S, respec�vely. Light blue and orange lines in maps (a)–(g) represent
4°C and 10°C isotherm at 100 m water depth, respec�vely (from Murase et al., 2009a).

Table 2Es�mated average values of Manlyʼs α of common minke, Brydeʼs and sei whales α in the JARPNII oﬀshore component survey area insummer from 2002 to 2007 using the log-likelihood func�on based on a mul�nomial distribu�on (from Murase et al., 2009a).
SpeciesCommon minke whale
Bryde's whale
Sei whale

Copepods

Krill

Japanese anchovy

Paciﬁc saury

Manlyʼs αSE

Manlyʼs αSE

Manlyʼs αSE

Manlyʼs α

SE

—
—
0.41

—
—
0.10

0.05
0.05
0.13

0.03
0.04
0.04

0.36
0.95
0.25

0.19
0.04
0.10

0.59
—
0.20

0.17
—
0.08

taxonomic level. The total weight of each prey species inthe stomach contents were es�mated by using the values
obtained from the sub-sample and the total weight ofstomach contents (see details in Tamura et al., 2019).
Data analyses
An es�mate of the daily prey consump�on by whales
requires the use of some addi�onal biological and morphometric data. For example, body length of the whales
was measured to the nearest 1 cm from the �p of theupper jaw to the deepest part of the ﬂuke notch in astraight line. Body weight was measured to the nearest
50 kg using large weighing machine. Furthermore, energy
requirements are diﬀerent for sexual maturity classes,

and therefore, es�ma�ons of the daily prey consump�ontook into considera�on informa�on on sexual maturity.
Sexual maturity of each whale was deﬁned by either tes�s weight or examina�on of ovaries.
The daily amount of prey consump�on consumed ises�mated using theore�cal energy requirement formulae. The total seasonal prey consump�on by whales wases�mated using the informa�on on abundance in Table
1, sexual maturity composi�on, daily prey consump�onand a seasonal feeding period of 150 days. The uncertain�es associated with the relevant parameters weretreated by Monte Carlo simula�ons (see details in Tamura
et al., 2019).

13

Technical Reports of the Ins�tute of Cetacean Research (2023)
Table 4Prey species of common minke, Brydeʼs and sei whales in thewestern North Paciﬁc during May and September in the years
1994–2022.
Prey species/Whale species

Figure 7.

Figure 8.

Distribu�on pa�erns of Japanese anchovy in 2006.
Bars Rela�ve densi�es of anchovy. Thin black lines
Surveyed track lines. Seasonal composite surface
seawater temperature (SST) data in the summer,
derived from the Moderate Resolu�on Imaging
Spectroradiometer (MODIS) aboard the satellite,
Aqua, are also shown (from Murase et al., 2012).

Ten blocks (A–J) surveyed for whalesʼ prey species inSanriku since 2005 (from Wada et al., 2016).

Table 3
Biomasses of sand lance and Japanese anchovy in B, C, E and F
blocks (surveyed in 2005 and 2006) and B, C blocks (surveyed in2008 and 2009). See Figure 8 for surveyed blocks (from Wadaet al., 2016).

14

Year

Sandlance (tons)

Japanese anchovy (tons)

2005
2006
2008
2009

7,610
28,340
9,310
2,827

1,320
9,060
0.2
0.6

Main prey species
Copepoda
Neocalanus cristatus
N. plumchrus
Krill
Euphausia paciﬁca
E. similis
E. gibboides
Thysanoessa gregaria
T. inermis
T. inspinata
T. longipes
Nematoscelis diﬃcilis
PiscesJapanese anchovy
Japanese sardine
Paciﬁc saury
Chub mackerel
Spo�ed mackerel
Walleye pollocke
Japanese pomfret
Pink salmon
Chum salmon
Atka mackerel
Sand lance
Vinciguerria nimbaria
Auxis rochei
SquidsJapanese common squid
Minimal armhook squid
Minor prey species
PiscesParalepis atlantica
Arothron ﬁrmamentum
Decapterus russelli
Diaphus theta
Tarletonbeania taylori
Starry toado
Nemichthys scolopaceus
Lestidiops jayakari
SquidsJapanese common squid

Common
minke

Sei

✔

✔
✔

✔

✔
✔

✔
✔
✔
✔

✔

Brydeʼs

✔
✔
✔
✔

✔
✔
✔
✔
✔

✔
✔
✔
✔
✔

✔

✔
✔

✔
✔
✔
✔
✔
✔
✔
✔
✔
✔

✔

✔
✔
✔
✔
✔
✔
✔
✔
✔

What do we know about whales and the ecosystem in the western North Pacific? Part 5

Summary of results for three baleen whale species
Prey species in stomach
Common minke whales (1994–2022)
A total of eighteen preys, including one species of copepod, ﬁve species of krill, ten species of ﬁshes and two
species of squids were iden�ﬁed in 3,036 stomachs ofcommon minke whales (Table 4).
Sei whales (2002–2022)
A total of eleven preys, including two species of copepods, three species of krill, ﬁve species of ﬁshes and one
species squid were iden�ﬁed in 1,722 stomachs of sei
whales (Table 4).
Brydeʼs whales (2000–2022)
A total of eighteen preys, including ﬁve species of krill,
twelve species of ﬁshes and one species squid were iden-

�ﬁed in 1,478 stomachs of Brydeʼs whales (Table 4).
Geographical and yearly changes of main prey species in
the oﬀshore area
Common minke whales (1994–2019)
Prey composi�on in the stomach of common minke
whales is shown for each season (early [May–June] andlate [July–September]), sub-area and year in Figure 9.
The composi�on of main prey species is highly variable
between years.
In sub-area 7, Japanese anchovy has been an important
prey in both seasons since 1994. A�er 2017, Japanesesardine and mackerels have become important preys.
In sub-area 8, krill and Japanese anchovy have been
important preys since 1994. A�er 2017, Japanese sardine
has been an important prey in the early season. In lateseason Paciﬁc saury has been an important prey since

Figure 9.

Prey composi�on in the stomach of common minke whales by season, sub-area and year, in the period
1994–2019 (par�ally from Konishi et al., 2017).

Figure 10.

Prey composi�on in the stomach of sei whales by season, sub-area and year, in the period 2002–2022(par�ally from Konishi et al., 2017).
15

Technical Reports of the Ins�tute of Cetacean Research (2023)

1994. A�er 2017, Japanese sardine has become an important prey.
In sub-area 9, Japanese anchovy and krill have been
important preys since 1994. A�er 2017, mackerels havebecome important preys in the early season. In late season, Paciﬁc saury has been an important prey since 1994.
A�er 2017, Paciﬁc saury and mackerels have become
important preys.
Sei whales (2002–2022)
Prey composi�on in the stomach of sei whales is shownfor each season, sub-area and year in Figure 10. The composi�on of main prey species is highly variable among
years.
In sub-area 7, krill and Japanese anchovy have been
important preys since 2003. A�er 2016, Japanese sardine
has become an important prey in the early season. In thelate season, krill and Japanese anchovy have been important preys since 2003. A�er 2019, Japanese sardine andkrill have become important preys.
In sub-area 8, krill, copepod, Japanese anchovy and16mackerels have been important preys since 2002 in bothseasons. A�er 2017, Japanese sardine has become an
important prey.
In sub-area 9, copepod has been an important preysince 2002 in both seasons. A�er 2015, Japanese sardine
and mackerels have become important preys.
Brydeʼs whales (2000–2022)
Prey composi�on in the stomach of Brydeʼs whales isshown for each season, sub-area and year in Figure 11.
In sub-area 7, krill and Japanese anchovy have been
important preys since 2000. A�er 2020, Japanese sardine
has become an important prey in the early season. In thelate season, krill and Japanese anchovy have been important preys since 2000.
In sub-areas 8 and 9, krill and Japanese anchovy
have been important preys since 2002 in both seasons.
Occasionally, high propor�ons of lantern ﬁshes wereobserved. A�er 2016, Japanese sardine has also been
observed as the main prey.

Figure 11.

Prey composi�on in the stomach of Brydeʼs whales, by season, sub-area and year, in the period 2000–
2022 (par�ally from Konishi et al., 2017).

Figure 12.

Yearly change of dominant prey species of common minke whales in Sanriku (A) and Kushiro (B), in the
period 2002–2022 (par�ally from Tamura et al., 2016).

What do we know about whales and the ecosystem in the western North Pacific? Part 5

Geographical and yearly changes of main prey species ofcommon minke whales in the coastal areas (2002–2022)
Sanriku
Figure 12 shows the yearly changes in prey composi�on based on data from commercial whaling and somescien�ﬁc surveys in Sanriku. A�er 2003, sand lance has
been the dominant prey species. Since 2016, the dominant prey species switched from sand lance to Japanesesardine.
KushiroLong term informa�on of prey composi�on is available
from past commercial whaling (Kasamatsu and Tanaka, 1992). Figure 12 shows the yearly changes in preycomposi�on based on data from commercial whaling andsome scien�ﬁc surveys in Kushiro. Un�l 1976, the dominant prey species of common minke whales was the chubmackerel. The dominant prey species switched from chubmackerel to Japanese sardine in 1977, from Japanesesardine to Paciﬁc saury or Japanese anchovy in 1996, andfrom Paciﬁc saury or Japanese anchovy to Japanese sardine and mackerels in 2012.
Daily and seasonal prey consumption by whales
Oﬀshore area
The es�mated daily prey consump�on by sex and repro-

duc�ve status is shown in Table 5 for the three species ofbaleen whales.
Es�mated prey consump�on (thousand tons) per year
over 150 days, from May to September, in two periods(2000–2007 and 2008–2016) by three baleen whale species is shown in Table 6. See details of this calcula�on in
Tamura et al. (2019). The consump�on per year of Japanese anchovy by three baleen whale species in the two
periods (2000–2007 and 2008–2016) were 754 thousand
tons and 565 thousand ton, respec�vely. The consump�on per year of mackerels by three baleen whale species
in the same two periods was 25 thousand tons and 74
thousand tons, respec�vely. The consump�on per yearof Paciﬁc saury by common minke and sei whales in thesame two periods was 38 thousand tons and 35 thousand
tons, respec�vely. Recently, Japanese sardine has been
the dominant prey species for three baleen whale species. The consump�on per year of Japanese sardine by
three baleen whale species in the 2008–2016 period was
54 thousand tons.
Coastal areas
For Sanriku, prey consump�on per year during midMarch to mid-June (90 days) by common minke whales isshown in Table 7. For Kushiro, seasonal prey consump�on
per year during September-October (60 days) by common

Table 5Es�mates of daily prey consump�on (kg) by three baleen whale species in the oﬀshore area, by sex and reproduc�ve status (fromTamura et al., 2019).
Male

SpeciesCommon minke whale
Bryde's whale
Sei whale

FemaleImmature

MatureImmature

Mature73–187
380–578
265–665

118–304
51–839341–878

69–179369–563294–727

140–359
619–943
405–1,021

Table 6Es�mates of prey consump�on (thousand tons) per year by common minke, Brydeʼs and sei whales in the oﬀshore area in two diﬀerent periods (from Tamura et al., 2019).
PeriodPrey species

2000–2007

Japanese anchovy
Paciﬁc saury
Mackerels
Japanese sardine
Other
Total

Consump�on(thousand tons)
754
38
25
0
349
1,166

Period2008–2016

Prey species
Japanese anchovy
Paciﬁc saury
Mackerels
Japanese sardine
Other
Total

Consump�on(thousand tons)
565
35
74
54
593
1,321
17

Technical Reports of the Ins�tute of Cetacean Research (2023)
Table 7Es�mates of prey consump�on (tons) by common minke whales in coastal areas of the western North Paciﬁc based on data collected
between 2002 and 2012 (from Tamura et al., 2019).
Year

Sanriku
Krill

KushiroSandlance Anchovy

Total

Krill

Anchovy Sardine

Saury Mackerels Pollock

Squid

Total

2002
2003
2004
2005
2006
2007
2012

—
—
—
1,533
758
—
356

—
—
—
2,338
1,033
—
472

—
—
—
606
363
—
269

—
—
—
4,477
2,154
—
1,097

453
—
41
241
8
27
217

733
—
1,171
170
907
292
2

0
—
0
0
0
0
669

635
—
878
20
118
125
0

0
—
0
0
0
0
178

815
—
76
1,562
378
227
902

1394
—
0
101
92
111
92

4,030
—
2,166
2,094
1,503
782
2,060

Average

882

1,281

413

2,576

165

546

112

296

30

660

298

2,106

Table 8Prey consump�on (tons) by common minke whales and ﬁsheries catch of sand lance in Sanriku in the period 2002 and 2012.
Fisheries catch data were obtained from Sta�s�cal Survey on
Marine Fishery Produc�on (h�ps://www.maﬀ.go.jp/j/tokei/
kouhyou/kaimen_gyosei/).
Year

Prey consump�on(tons)

Fisheries catch(tons)

Ra�o
(%)

2002
2003
2004
2005
2006
2007
2012

—
—
—
2,338
1,033
—
472

—
—
—
8,679
5,250
—
479

—
—
—
26.9
19.7
—
98.5

Average

1,281

4,803

26.7

minke whales is shown in the same table.
Amount of prey consumed by common minke whales incomparison with catch by ﬁsheries
The es�mated consump�on of sand lance by common
minke whales and ﬁsheries catch of sand lance in Sanriku
is shown in Table 8.
The es�mated consump�on of Paciﬁc saury andwalleye pollock by common minke whales and ﬁsheries
catch of those species in Kushiro is shown in Table 9. The
prey consump�on of Paciﬁc saury and walleye pollock
by common minke whales in Kushiro were calculated as
0–878 tons and 76–1,562 tons. Consump�on of them bycommon minke whales in Kushiro waters corresponded
to approximately 0–3% of the ﬁsheries catch of theseresources (Table 9).
To further evaluate the interac�on between whale and18

ﬁsheries, long-term informa�on of prey composi�on ofwhales, accurate abundance of prey species and eachwhale, and accurate resident period of each whale areneeded.

PROGRESS IN MODELLING WORKThis sec�on presents an overview of the objec�ves andprogress made in the research on ecosystem modelling in
the western North Paciﬁc. Whale abundance, prey composi�on and prey consump�on of whales have been used
as input data to the models. Those values were obtained
as described above.
Oﬀshore area
Mori et al. (2009) developed the EwE in the western
North Paciﬁc (north of 35°N and west of 170°E), where
JARPNII surveys were conducted. The model consistsof 31 species/groups ranging from detritus to whales(Table 10). Input data required for the model were biomass, produc�on, prey consump�on, diet composi�onand total ﬁshery catch of each predator in the target area.
When produc�on is not available, total mortality wasused in the Ecopath instead of produc�on per biomass.
Once the mass-balance model was constructed, possible eﬀect by ﬁsheries of the species in the model were
simulated by using Ecosim under the harves�ng scenarios
examined.
The work by Mori et al. (2009) was updated in the studies by Murase et al. (2016b) and Watari et al. (2019). They
have focused on the interac�ons between forage ﬁsh andtheir predators including target species of JARPNII (common minke, sei, Brydeʼs and sperm whales). They haveupdated the input data to the models by considering thedata available in the period 1994–2013 and made several
technical adjustments following recommenda�ons from

What do we know about whales and the ecosystem in the western North Pacific? Part 5
Table 9Prey consump�on (tons) by common minke whales and ﬁsheries catch of Paciﬁc saury and walleye pollock in Kushiro in the period
2002 and 2012. Fisheries catch data were obtained from Sta�s�cal Survey on Marine Fishery Produc�on (h�ps://www.maﬀ.go.jp/j/tokei/kouhyou/kaimen_gyosei/).
Prey species: Paciﬁc saury

Prey species: Walleys pollock

Year

Prey consump�on(tons)

Fisheries catch(tons)Ra�o (%)

Year

Prey consump�on(tons)

Fisheries catch(tons)Ra�o (%)

2002
2004
2005
2006
2007
2012

635
878
20
118
125
0

55,594
48,40358,52861,89569,62949,550

1.1
1.8
0.0
0.2
0.2
0.0

2002
2004
2005
2006
2007
2012

815
76
1,562
378
227
902

52,52465,18654,62856,582
51,08859,061

1.6
0.1
2.9
0.7
0.4
1.5

Average296

57,267

0.6

Average

660

56,512

1.2

Table 10
List of the species/groups used in the EwE model and Trophic Level (TL) es�mated by Ecopath (from Mori et al., 2009).
Species/Group

TL

Species/Group

TL

Species/GroupTL

Minke whale
Bryde's whale
Sei whale
Other baleen whales
Sperm whale
Baird's beaked whale
Short-ﬁnned pilot whale
Ziphidae
Other toothed whales
Northern fur seal
Marine birds

3.99
3.83
3.73
3.23
4.17
4.15
4.40
4.24
4.46
4.08
4.24

Albacore
Sword ﬁsh
Skipjack tuna
Blue shark
Samon shark
Lantern ﬁsh
Neon ﬂying squid
Large surface squid
Small surface squid
Mid-deep water sea squid
Mackerels

4.08
4.81
3.97
4.27
4.35
3.06
4.12
3.41
3.01
3.11
3.30

Paciﬁc ponfretSardineAnchovy (<8 cm)
Anchovy (>8 cm)
Paciﬁc saury
Phytoplankton
Euphausiids
Copepods eaten by whales
Other Copopods
Detritus

4.20
2.30
3.04
3.04
3.12
1.00
2.18
2.00
2.00
1.00

the IWC Scien�ﬁc Commi�ee. They have iden�ﬁed several poten�al future data and tasks required to progress
the development of ecosystem modelling in the western
North Paciﬁc.
Coastal areas
Okamura et al. (2009) examined the eﬀects of preda�on of common minke whales on sand lance stock oﬀ
Sanriku in order to inves�gate the eﬀect of preda�on by
the common minke whales in terms of MSY of sand lance
popula�on. Bayesian delay-diﬀerence model was used
to develop an ecosystem model. By using new data, Kitakado et al. (2016) updated the model work by Okamura
et al. (2009). The preda�on by the common minke whales
accounts for a certain propor�on of the current adult biomass of the sand lance popula�on, although the level ofpropor�on is sensi�ve to the model assump�on.
The results are s�ll preliminary because further valida-�on of consump�on of sand lance by predator species
and further modelling process for linking sand lance andseveral predators through simultaneous es�ma�on of
popula�ons dynamics are needed. Progress in the workon the MRM is presented in a diﬀerent paper to thismee�ng (Kawano et al., 2019).

CONCLUSIONSThe Japanese whale research programs under special
permit provided important informa�on on the ecology ofseveral baleen whale species in the western North Paciﬁc.
Such informa�on is key for the elucida�on of the role ofwhales in the ecosystem. There is a need to further evaluate the interac�on between prey consump�on by whales
and commercial ﬁsheries, either directly or indirectly,
using simula�on models for speciﬁc geographical regions.
The commercial whaling within Japanʼs Exclusive Economic Zone commenced in 2019. It is important to collect19

Technical Reports of the Ins�tute of Cetacean Research (2023)

addi�onal informa�on on the feeding ecology of baleen
whales from this source.

ACKNOWLEDGEMENTS
We thank Luis A. Pastene for his assistance in preparing
this document and the Editorial Team of TEREP-ICR for
editorial work.

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(unpublished). 135 pp. [Available from the IWC Secretariat].
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21

Technical Reports of the Ins�tute of Cetacean Research (2023)

pp. 22–33

Technical Report (not peer reviewed)

Results of the dedicated sigh�ng survey under the JapaneseAbundance and Stock structure Surveys in the Antarc�c (JASS-A) in apart of Area VI in the 2022/2023 austral summer season
Tatsuya Isoda*, Taiki Katsumata, Yujin Kim and Koji Matsuoka
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: isoda@cetacean.jp

ABSTRACTThe results of the sigh�ng survey of the Japanese Abundance and Stock structure Surveys in the Antarc�c(JASS-A) in the 2022/2023 austral summer season are reported. Two dedicated sigh�ng vessels were engaged
in the line transect method survey in a part of Antarc�c Area VI (145°W–130°W) for 28 days, from 10 January
to 6 February 2023. For the survey, the research area was divided into northern and southern strata. In addi�on, surveys were conducted successfully in coastal ice-free waters, south of 71°30ʹS, an area that is normallycovered by pack-ice and diﬃcult for vessels to access. The total searching distance in the research area was
2,168.6 n.miles (4,016.2 km). Four baleen whale species and at least two toothed whale species were sighted
in the research area. Other research ac�vi�es such as biopsy sampling, photo-ID, satellite tagging and oceanographic observa�ons were also conducted. The data and samples collected are required for the main andsecondary research objec�ves of JASS-A.

INTRODUCTION
Long-term systema�c surveys on whales and the ecosystem in the Antarc�c, such as the JARPA/JARPAII1,
NEWREP-A2 and IWC IDCR/SOWER3, obtained importantdata pertaining to the study of abundance and abundance trends of large whales and their biology as well as
the role of whales in the Antarc�c ecosystem. All theseresearch programs have been terminated. The last NEWREP-A survey was carried out in the 2018/2019 australsummer season.
The Japanese Abundance and Stock structure Surveys
in the Antarc�c (JASS-A) commenced in the 2019/2020
austral summer season because it was considered important to con�nue with the whale and ecosystem surveys
in the Indo-Paciﬁc region of the Antarc�c Ocean throughdedicated sigh�ng surveys and other non-lethal researchtechniques. JASS-A has two main research objec�ves,i) the study of the abundance and abundance trends oflarge whale species, and ii) the study of the distribu�on,
1

Japanese Whale Research Programs under Special Permit in
the Antarc�c, Phases I and II
2
New Scien�ﬁc Whale Research Program in the Antarc�c Ocean
3
Interna�onal Decade for Cetacean Research/Southern Ocean
Whale and Ecosystem Research
4Interna�onal Whaling Commission-Scien�ﬁc Commi�ee
22

movement and stock structure of large whale species.
JASS-A also has several secondary research objec�ves
related to oceanography, marine debris, gene�c data toes�mate abundance, whale biology and study on theu�lity of Unmanned Aerial Vehicle (UAV). The JASS-A
program was presented to the 2019 mee�ng of IWC SC4(GOJ, 2019a), the 2019 mee�ng of CCAMLR-EMM5 (GOJ,
2019b) and the 2019 mee�ng of NAMMCO SC6 (GOJ,
2019c).
The approach of JASS-A is systema�c vessel-basedsigh�ng surveys u�lizing the line transect method. Surveys are designed and conducted following the protocols
included in the ʻRequirements and Guidelines for Conduc�ng Surveys and Analysing Data within the Revised
Management Schemeʼ (IWC, 2012). Sigh�ng protocols
are the same as those used in the former IDCR/SOWER
surveys (Matsuoka et al., 2003; IWC, 2008). The JASS-A
surveys are conducted alterna�vely in IWC Management
Areas III, IV, V and VI by one or two specialized vessels,
over a tenta�ve period of eight austral summer seasons.
The ﬁrst to third JASS-A surveys were carried out in the5Commission for the Conserva�on of Antarc�c Marine Living Resources-Working Group on Ecosystem Monitoring andManagement
6
North Atlan�c Marine Mammal Commission-Scien�ﬁc Commi�eeResults of the dedicated sighting survey under the Japanese Abundance and Stock structure Surveys in the Antarctic (JASS-A)

2019/2020, 2020/2021 and 2021/2022 austral summer
seasons, respec�vely, and covered the sector 000°–035°E
of Antarc�c Area III West and 130°W–120°W of Antarc�c
Area VI East.
The fourth JASS-A survey was carried out in the2022/2023 season and covered the sector 145°W–130°W
of Antarc�c Area VI. This paper presents a summary of
the 2022/2023 JASS-A survey results.

SURVEY DESIGN
Research area
The research area of JASS-A is comprised of IWC Management Areas III, IV, V and VI, south of 60°S (Figure 1).
The research area in the 2022/2023 season was a partof Antarc�c Area VI (145°W–130°W), south of 60°S (Figure 1). The area was divided into northern and southern
strata. The boundary between these strata was deﬁned
by a line 45 n.miles from the northern edge of the packice (Figure 2). In addi�on, the sea ice on the coastal area
opened and formed ice-free waters in early January. The
ice-free waters (in the range of 145°W to 130°W) became
accessible to the vessel in early February. Details of theice conﬁgura�on are shown in Figure 3.

Figure 1.

Research area of JASS-A. The shaded area
(145°W–130°W) indicates the surveyed area in the2022/2023 austral summer season.

Figure 2.

Research area (145°W–130°W) indica�ng northern,southern strata, and coastal ice-free waters searching eﬀorts (red and blue lines for Yushin-Maru No.
2 (YS2) and Yushin-Maru No. 3 (YS3), respec�vely)of the JASS-A survey in the 2022/2023 austral summer season. The research commenced with YS2 at
65°41ʹS; 130°00ʹW and YS3 at 68°17ʹS; 130°00ʹW,
and ended with YS2 at 74°14ʹS; 130°00ʹW and with
YS3 at 72°59ʹS; 143°21ʹW. Note the ice-free waters
south of 71°30ʹS.

Research vessels
The dedicated sigh�ng vessels Yushin-Maru No. 2 (YS2)
and Yushin-Maru No. 3 (YS3) were engaged in the survey.
The speciﬁca�ons for both vessels are the same and areshown in Figure 4. Eight researchers par�cipated in thesurvey, four in YS2 and four in YS3. They had experiencein conduc�ng line transect surveys, biopsy sampling,
photo-iden�ﬁca�on (photo-ID), satellite tagging andoceanographic survey through the previous JARPA/JARPAII, NEWREP-A and previous JASS-A surveys.
Sigh�ng procedures and experiments
The procedures for sigh�ng and experiments were thesame as in previous JASS-A surveys. See Isoda et al.
(2023) for details of the procedures used for sigh�ng
surveys and other research ac�vi�es such as sigh�ng distance and angle experiment, photo-ID, biopsy sampling,satellite tagging, oceanographic survey, marine debris
observa�on and survey using UAV.

RESULTS OF THE SURVEY
Narra�ve of the survey
Table 1 shows the i�nerary of the survey. The dura�onof this cruise was 99 days (YS2) and 97 days (YS3). The
YS2 and YS3 departed Japan on 5 and 7 December 2022,
respec�vely. They arrived at the home port on 22 Decem-

ber. The YS2 and YS3 started the sigh�ng survey in Antarc�c Area VI at 65°41ʹS; 130°00ʹW on 11 January, and at23

Technical Reports of the Ins�tute of Cetacean Research (2023)

Figure 3.

Maps of the pack-ice distribu�ons in the research area for dates 5 January (upper le�), 15 January(lower le�), 25 January (upper right) and 1 February (lower right) 2023, constructed by Japan Aerospace
Explora�on Agency (JAXA), based on observa�onal data acquired by the Advanced Microwave ScanningRadiometer 2 (AMSR2). Note that the ice-free waters became accessible to the vessel in early February.

Figure 4.

Speciﬁca�ons of the dedicated sigh�ng vessel Yushin-Maru No. 2, which is similar to Yushin-Maru No. 3.

68°17ʹS; 130°00ʹW on 10 January 2023, respec�vely. The
YS2 and YS3 completed the surveys at posi�on 74°14ʼS;
130°00ʼW and 72°59ʹS; 143°21ʹW respec�vely, on 6 February. The YS2 and YS3 arrived at the home port on 22
February, and ﬁnally in Japan on 13 March.

24

Research eﬀort in the research area
Table 2 shows a summary of the searching eﬀort spent
during the survey. The YS2 and YS3 were engaged in
the research for 27 days and 28 days, respec�vely. The
total searching eﬀort of both vessels was 2,168.6 n.
miles (4,016.2 km); 1,051.1 n.miles in NSP mode duringResults of the dedicated sighting survey under the Japanese Abundance and Stock structure Surveys in the Antarctic (JASS-A)
Table 1
I�nerary of the 2022/2023 JASS-A dedicated sigh�ng survey.
Date (y/m/d)

Event2022/11/16
2022/12/2
2022/12/5
2022/12/7
2022/12/7
2022/12/8
2022/12/22
2023/1/10
2023/1/11
2023/2/6

Planning mee�ng at Tokyo, Japan
Pre-cruise mee�ng at Shiogama, JapanYS2 departed Shiogama, JapanYS3 departed Shiogama, JapanYS2 started transit survey at 31°20ʹN; 145°35ʹE (high sea)
YS3 started transit survey at 35°20ʹN; 143°20ʹE (high sea)
YS2 and YS3 arrived in the home port (Suva, Fiji)
YS3 ﬁnished transit survey and started survey in the research area at 68°17ʹS; 130°00ʹW
YS2 ﬁnished transit survey and started survey in the research area at 65°41ʹS; 130°00ʹW
YS2 and YS3 completed surveys in the research area (27 days and 28 days, respec�vely) and started transit survey at
74°14ʹS; 130°00ʹW and at 72°59ʹS; 143°21ʹW, respec�vely
YS2 and YS3 arrived in the home port (Suva, Fiji)
YS2 and YS3 ﬁnished transit survey at 31°05ʹN; 145°44ʹE and at 27°59ʹN; 138°11ʹE, respec�vely
YS2 and YS3 arrived in Japan and post cruise mee�ngs at Shiogama and Shimonoseki, Japan, were carried out respec�vely

2023/2/22
2023/3/10
2023/3/13

98 hours 2 minutes of research and 1,117.4 n.miles in IO
mode during 104 hours 33 minutes of research.
In the northern stratum, the total searching eﬀort was
1,295.8 n.miles (NSP: 637.8 n.miles; IO: 658.0 n.miles),and the searching eﬀort coverage was 76%. In the southern stratum, the total searching eﬀort was 393.3 n.miles(NSP: 209.3 n.miles; IO: 184.0 n.miles), and the searchingeﬀort coverage was 91%. In the coastal ice-free waters,
the total searching eﬀort was 479.4 n.miles (NSP: 203.8 n.
miles; IO: 275.6 n.miles), and the searching eﬀort coverage was 75%.
Therefore, a good distribu�on of eﬀort within all strata
and survey mode was achieved. The total experimental
�me for photo-ID, biopsy sampling, tagging and distanceand angle experiment was 45 hours 26 minutes.
Whale sigh�ngs in the research area
Four baleen whale species and at least two toothed whale
species were sighted in the research area. The dominant
whale species in the research area was the Antarc�cminke whale (242 schools/521 individuals) followed by
the ﬁn whale (59/137). Sigh�ngs of other species were as
follows; humpback (21/46), Antarc�c blue (20/31), sperm(7/7), killer (11/117, including Type A, Type B, Type C andundetermined type) and Ziphiidae (1/2) whales (Table 3).
Antarctic minke whales
Antarc�c minke whales were widely distributed in the
research area including in the coastal ice-free waters(Figure 4). This result is consistent with the interpreta�onof Fujise and Pastene (2021) that larger number of thisspecies are being distributed in polynyas within the pack-ice in recent years, possibly in searching of alterna�vefeeding areas in response to the increase in abundance
and geographical expansion of other large whale species(e.g. humpback and ﬁn whales). On the other hand, asigh�ng survey using an icebreaker vessel found no Antarc�c minke whales within coastal polynyas in a similar
loca�on to that surveyed in the present survey (Ainley
et al., 2007). However, this survey was conducted in 1994
and it was suggested that the distribu�on of this species
has changed in recent years.
The Amundsen Sea Coastal Polynya overlaps par�ally
with the eastern side of Antarc�c Area VI East. Here highdensi�es of the ice krill (Euphausia crystallorophias) wereobserved along the ice shelf and near the boundary between pack-ice and coastal polynya. These high densi�es
are an order of magnitude higher than recorded previously in the Ross Sea Polynya (La et al., 2015). The ice krill
is the predominant prey species on coastal (shallow) area
on con�nental shelf (Tamura and Konishi, 2009). The highdensity of Antarc�c mink whale in coastal ice-free waters
in the 2021/2022 and 2022/2023 seasons might be related to high densi�es of this prey species.
Fin whales
Fin whales were widely distributed only in the northern
stratum (Figure 4). The density was higher than that in
the previous 2000/2001 IWC-SOWER survey in the sector
140°W–120°W (Ensor et al., 2001). An increasing trend
in abundance of this species was already suggested forin the area adjacent to the west side: Areas V+ VI West
(Matsuoka and Hakamada, 2014).

25

Technical Reports of the Ins�tute of Cetacean Research (2023)
Table 2
Summary of searching eﬀort and �me spent by YS2 and YS3 during the 2022/2023 JASS-A survey.
Vessel: YS2

Date and �me

Searching eﬀort (distance [n.miles] and �me[hours: minutes: seconds])

Es�mated angle anddistance training/
experiment

Start

End

Transit survey(Shiogama-Equator)

2022/12/07
07 : 052022/12/15
12 : 46473.1

40 : 57 : 38——

02 : 54 : 49—

Transit survey(Equator-Research area)

2022/12/15
12 : 472023/1/10
18:00

519.7

45 : 42 : 44——

04 : 13 : 33—

Research area
(Area VIE 145°W-130°W)

2023/1/11
06 : 00

2023/2/1
12 : 15347.5

31 : 48 : 56342.7

31 : 36 : 47

16 : 27 : 28

05 : 27 : 16

Coastal ice-free waters, southof 71°30'S (145°W-130°W)

2023/2/1
12 : 162023/2/6
16 : 1999.1

09 : 31 : 03

122.9

12 : 00 : 45

01 : 38 : 25—

Transit survey(Research area-Equator)

2023/2/6
16 : 202023/3/2
09 : 20709.7

60 : 53 : 25——

01 : 35 : 15—

Transit survey(Equator-Shiogama)2023/3/3
06 : 00

2023/3/10
16 : 20305.9

25 : 33 : 15——

00 : 42 : 28—

2455.0214 : 27 : 01465.6

43 : 37 : 32

27 : 31 : 58

05 : 27 : 16

Vessel: YS3

Date and �me

IO

Photo-ID,
Biopsy,Satellite
tagexperiment

Survey Sec�ons

Total

NSP

Experiments �me (hours: minutes:
seconds)

Searching eﬀort (distance [n.miles] and�me [hours: minutes: seconds])

Es�mated angle anddistance training/
experiment

Start

End

Transit survey(Shiogama-Equator)

2022/12/8
07 : 25

2022/12/16
14:00

436.3

36 : 25 : 34——

00 : 46 : 01—

Transit survey(Equator-Research area)

2022/12/16
14:01

2023/1/9
18:00

472.5

40 : 20 : 53——

01 : 20 : 18—

Research area
(Area VIE 145°W-130°W)

2023/1/10
06 : 00

2023/1/31
16 : 42499.7

46 : 11 : 38499.2

46 : 23 : 09

14 : 10 : 21

01 : 29 : 12

Coastal ice-free waters, southof 71°30'S (145°W-130°W)

2023/1/31
16 : 422023/2/6
17 : 10104.8

10 : 30 : 23

152.7

14 : 32 : 19

02 : 00 : 09

04 : 12 : 48

Transit survey(Research area-Equator)

2023/2/7
06 : 00

2023/3/2
15 : 20794.8

67 : 29 : 11——

03 : 01 : 48—

Transit survey(Equator-Shimonoseki)

2023/3/3
06 : 00

2023/3/10
16 : 50295.5

24 : 46 : 55——

00 : 00 : 00—

2,603.6

225 : 44 : 34651.9

60 : 55 : 28

21 : 18 : 37

05 : 42 : 00

Humpback whales
Humpback whales were widely distributed in the northern stratum with higher concentra�ons observed in thenorthern part of this stratum (Figure 4). The density wasslightly higher than that in the 2000/2001 IWC-SOWER
cruise in the same sector (Ensor et al., 2001). This result
suggests that abundance of this species is rela�vely
stable in this area.

26

IO

Photo-ID,
Biopsy,Satellite tag
experiment

Survey Sec�ons

Total

NSP

Experiments �me (hours: minutes:
seconds)

Antarctic blue whales
Antarc�c blue whales were sighted in the northern andsouthern strata with higher densi�es in the former stratum (Figure 4). Four mother and calf pairs were observed.
There were only two schools (four individuals) in the
2000/2001 IWC-SOWER cruise in the same sector (Ensor
et al., 2001). This informa�on is crucial for monitoring theAntarc�c blue whale popula�on recovery.

Results of the dedicated sighting survey under the Japanese Abundance and Stock structure Surveys in the Antarctic (JASS-A)
Table 3
Number of sigh�ngs made during the 2022/2023 JASS-A survey in the research area, by stratum and species.
Western part of Area VIE (145°W–130°W)
SpeciesSouthern stratum

Northern stratum

Prim.

Prim.

Second.

Second.

Ind.

Sch.

Sub-total

Coastal ice-free waters,south of 71°30'S

Ind.

Prim.
Sch.

Second.

Sch.

Ind.

Sch.

Ind.

Sch.

Ind.

Sch.

Ind.

Antarc�c blue whale

2

2

0

0

17

27

1

2

0

0

0

0

Fin whale

0

0

0

0

50

117

9

20

0

0

0

0

Prim.
Sch.

Total

Second.

Ind.

Sch.

Ind.

Sch.

19

29

50

117

Ind.

1

2

20

31

9

20

59

137

Antarc�c minke whale

48

85

17

31

48

101

6

9

102

238

21

57

198

424

44

97

242

521

Like minke whale

3

3

1

10

2

3

1

1

8

8

2

3

13

14

4

14

17

28

Like Antarc�c minke whale

0

0

0

0

1

1

0

0

0

0

0

0

1

1

0

0

1

1

Humpback whale

0

0

0

0

20

36

1

10

0

0

0

0

20

36

1

10

21

46

Baleen whales

2

2

0

0

9

9

1

1

2

2

0

0

13

13

1

1

14

14

Sperm whale

1

1

0

0

6

6

0

0

0

0

0

0

7

7

0

0

7

7

Killer whale (Undetermined)

1

3

0

0

1

9

0

0

2

7

0

0

4

19

0

0

4

19

Killer whale (Type A)

0

0

0

0

1

8

0

0

0

0

0

0

1

8

0

0

1

8

Killer whale (Type B)

0

0

0

0

1

13

0

0

2

21

1

9

3

34

1

9

4

43

Killer whale (Type C)

0

0

0

0

0

0

0

0

2

47

0

0

2

47

0

0

2

47

Ziphiidae

0

0

0

0

1

2

0

0

0

0

0

0

1

2

0

0

1

2

Uniden�ﬁed whales

1

1

0

0

4

4

0

0

3

3

0

0

8

8

0

0

8

8

Prim.: Primary sigh�ng, Second.: secondary sigh�ng, Sch.: Schools, Ind.: individuals

Figure 4.

Geographical distribu�on of primary sigh�ngs of Antarc�c blue, ﬁn, humpback, and Antarc�c minke whales
during the 2022/2023 JASS-A survey.

Duplicate sightings
Duplicates sigh�ngs were those sigh�ngs made concurrently by both the IOP and TOP barrel observers during
the IO mode survey. These data will be used to es�mate
g(0), which in turn will be used to adjust es�mates ofabundance. There was a total of 63 duplicates involving
several whale species.
Other research ac�vi�es
Table 4 shows a summary of results of diﬀerent experiments.

Sighting distance and angle experiment
The sigh�ng distance and angle experiment was conducted in order to evaluate the accuracy of sigh�ng distanceand angle provided by primary observers. The results ofthis experiment will be used for the calcula�on of abundance es�mates. The actual experiments were successfully completed on 1 February for 120 trials in YS2, and on
4 February for 128 trials in YS3.
Photo-ID
Photo-ID data is used for individual matching exercise toinves�gate distribu�on and movement of large whales.
A total of 26 Antarc�c blue, 11 humpback and 37 killer
27

Technical Reports of the Ins�tute of Cetacean Research (2023)
Table 4
Summary of the results of experiments conducted during the 2022/2023 JASS-A survey.
Experiments

Results and descrip�ons

Sigh�ng distance and angle experiment 248 trials completed
Photo-ID

Obtained from 26 Antarc�c blue, 11 humpback and 37 killer whales

Biopsy sampling

Collected from 8 Antarc�c blue, 20 ﬁn, 28 Antarc�c minke, 6 sei, 16 humpback, 2 pygmy
right and 9 killer whales

Satellite tagging

Deployed on 8 ﬁn, 25 Antarc�c minke, 2 sei, 2 humpback and 1 pygmy right whales

Oceanographic survey

137 XCTD casts

Marine debris observa�on

8 ﬁshing buoy and 1 plas�c tank were observed in the research area

UAV

Aerial images collected from 6 Antarc�c blue, 7 Antarc�c minke and 1 pygmy right whales

whales were successfully photo-iden�ﬁed during the en�re survey. These data will be registered into the Ins�tuteof Cetacean Research (ICR) database (see Matsuoka andPastene, 2014).
Biopsy sampling
Biopsy samples are used for gene�c studies on stock
structure of large whales and for other feasibility studies
related to the speciﬁc objec�ves of the JASS-A. For theen�re survey, a total of 89 biopsy samples were collectedfrom 8 Antarc�c blue, 20 ﬁn, 28 Antarc�c minke, 6 sei,
16 humpback, 2 pygmy right and 9 killer whales, using
the Larsen system (Larsen, 1998). Biopsy samples werestored at −20°C.
Satellite tagging
Satellite tagging is used for the study of movement,
distribu�on and stock structure of whales. The satellitemonitored tags (SPOT and SPLASH-types, Wildlife Computers, Redmond, Washington, USA) were deployed with
the Air Rocket Transmi�er System (ARTS) (LK-ARTS, Skutvik, Norway). The detail of deployment system, protocols
and research results to date were described in Konishi
et al. (2020). During the whole survey, 8 ﬁn, 25 Antarc�cminke, 2 sei, 2 humpback and 1 pygmy right whales were
tagged.
Oceanographic survey
Oceanographic observa�ons are important to understandthe rela�onship of whales and the physical environment.
The ver�cal distribu�on of water temperature and salinity were recorded from sea surface to 1,850 m water
depth using XCTD system (eXpendable Conduc�vity,
Temperature and Depth proﬁler, Tsurumi-Seiki Co., Ltd.,
Yokohama, Japan; probe type: XCTD-4N) with Digital Converter MK-150P (YS2) and MK-150N (YS3) at 137 sta�ons(Figure 5a).
The ver�cal structure of temperature and salinity be28

Figure 5a.

Oceanographic sta�ons (XCTD cas�ng points) at
the 2022/2023 JASS-A survey. Red circle: sta�ons
at the research area; black circle: sta�ons at thetransit area.

tween 5 m and 800 m were illustrated in Figure 5b. In theoﬀshore area, cold water was distributed at 50 to 150 m,
while in the coastal area cold water was distributed at
100 to 300 m. Oceanographic data will be analysed to
study the oceanographic structure of the research area
and the rela�onship with whale distribu�on.
Marine debris observation
Studies on marine debris in the Antarc�c are very scarce.
It is therefore important to con�nue with this kind of survey in order to monitor future trends in the occurrenceof marine debris. Eight ﬁshing buoys and one plas�c tankwere observed in the research area. These data will be
registered into the ICR database and reported in the fu-

Results of the dedicated sighting survey under the Japanese Abundance and Stock structure Surveys in the Antarctic (JASS-A)

Figure 5b.

Preliminary analysis of the la�tude-depth sec�ons of temperature (°C) (A) and salinity (PSU) (B), along
a track line between 60°00' and 74°45'S (C) using data obtained during the 2022/2023 JASS-A survey.
Figures were generated using Ocean Data View (Schlitzer, 2020).

ture (e.g. Isoda et al., 2021).
Feasibility study on the utility of UAV
UAV will be used to reﬁne observa�ons related withwhale abundance and distribu�on, e.g. determine thenumber of individuals in the schools. The technique canbe used also for photogrammetry studies. Aerial images
were collected for a total of 6 Antarc�c blue, 7 Antarc�c minke and 1 pygmy right whales, using a small UAV,
Inspire 2 Pro and DJI phantom 4 Pro (video clips can beaccessed at h�ps://www.youtube.com/channel/UCz3c9IIMiQPVeryAogmJIig). These data will be registered into
the photo-ID catalogue of ICR.
This UAV ASUKA is being developed to collect informa�on on whales in areas of diﬃcult access to the vessels
e.g. ice-bound seas in the Antarc�c (Matsuoka and Yoshida, 2021; Katsumata and Yoshida, 2023). In this survey,
the UAV ASUKA departed and arrived using the pla�ormof the research vessel. UAV ASUKA operated for an approximate �me of 32 h during the day�me. Basic datafor improving UAV ASUKA ﬂight performance in the polar
regions were obtained.
Sigh�ng survey in low-middle la�tude area
Sigh�ng surveys in low-mid la�tude areas have thepoten�al to collect data on seasonal movement andpossible breeding grounds of whale species. JASS-A has
been collec�ng informa�on on cetaceans by conduc�ngsigh�ng surveys in the low-middle la�tude area using
the opportunity of a round-trip cruise to the Antarc�c,
excluding waters of foreign countries EEZs. In transit
from Japan to the equator, the total searching eﬀort was
909.3 n.miles (Table 2). Bryde's (3/3), sei (4/6), ﬁn (2/2),
sperm (10/17), Ziphiidae (6/16) and Mesoplodon (2/4)
whales were sighted. Biopsy samples were collected fromfour sei whales and satellite tags were a�ached on two
sei whales.
In transit from the equator to the star�ng posi�on in
the Antarc�c research area, the total searching eﬀort
was 992.2 n.miles (Table 2). Fin (30/61), sei (5/6), Brydeʼs(1/1), Antarc�c minke (7/9), humpback (4/7), sperm(3/3), Ziphiidae (1/1) and Mesoplodon (5/10) whales
were sighted. Biopsy samples were collected from 4 ﬁn, 1sei, 3 Antarc�c minke and 1 humpback whale, and satellite tags were a�ached on 3 Antarc�c minke whales.
In transit from the ending posi�on in the Antarc�cresearch area to the equator, the total searching eﬀort
was 1,504.4 n.miles (Table 2). Fin (2/3), Antarc�c minke(30/45), humpback (1/2), sei (1/1), pygmy right (2/2),
sperm (1/3), southern bo�lenose (1/2), killer (Type A)
29

Technical Reports of the Ins�tute of Cetacean Research (2023)(1/13), Ziphiidae (10/22) and Mesoplodon (5/13) whales
were sighted. Biopsy samples were collected from 1 ﬁn, 3Antarc�c minke, 1 sei, 2 humpback and 2 pygmy right and2 killer whales. Satellite tags were a�ached to 3 Antarc�cminke whales and 1 pygmy right whale.
In transit from the equator to Japan, the total searching eﬀort was 601.4 n.miles (Table 2). Fin (1/1) and Ziphiidae (1/1) whales were sighted.

HIGHLIGHTS OF THE SURVEY
The 2022/2023 JASS-A survey covered a part of Area VI(145°W–130°W) and succeeded in collec�ng sigh�ng
data necessary for the abundance es�ma�on of cetaceans in this area. Of par�cular importance was the survey conducted in ice-free waters south of 71°30'S, sameas in the 2021/2022 season. Several other data necessary
for understanding stock structure, movement and theenvironment of whales were collected during the survey.
The data collected through the JASS-A will be analysedin conjunc�on with the data collected by the previous
JARPA/JARPAII, NEWREP-A and IDCR/SOWER surveys inthe same region so that the analyses can be based on along and consistent data set.

ACKNOWLEDGEMENTS
We thank the captains, crew members and researchers
who par�cipated in the 2022/2023 JASS-A survey for
their eﬀort in the collec�on of data and samples. We also
thank the Fisheries Agency of Japan for the funding andlogis�c support for the JASS-A program. We appreciate
Yoshihiro Fujise, Tsutomu Tamura (ICR), Hiroto Murase(Tokyo University of Marine Science and Technology),
Takashi Hakamada, Mioko Taguchi (ICR) and the steering group of JASS-A for their guidance in the design andimplementa�on of the research. Kyodo Senpaku Co., Ltd.
is acknowledged for their arrangements and support forthis cruise. ICR colleagues for support survey ac�vity. We
are grateful to Luis A. Pastene (ICR) for his assistance inpreparing this report and to the Editorial Team of TEREPICR for editorial work.

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org/_documents/sci_com/SOWER/Guide%20%20for%20
Researchers%202008-09.pdf. [Available from the IWC
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Interna�onal Whaling Commission. 2012. Requirements andguidelines for conduc�ng surveys and analysing data within
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Spa�al and temporal distribu�on of ﬂoa�ng marine macrodebris in the Indo-Paciﬁc region of the Antarc�c. Cetacean
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Isoda, T., Katsumata, T., Kim, Y., Omukai, C., Teruya, S., Miyagi,
M., Nagata, R., Kasai, H., Abe, N. and Matsuoka, K. 2023.
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Survey in the Antarc�c (JASS-A) during the 2022/2023 australsummer season. Paper SC/69A/ASI/13 presented to the IWC
Scien�ﬁc Commi�ee, April–May 2023 (unpublished). 31 pp.
[Available from the IWC Secretariat].
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Konishi, K., Isoda, T., Bando, T., Minamikawa, S. and Kleivane,
L. 2020. Antarc�c minke whales ﬁnd ice gaps along the iceedge in foraging grounds of the Indo-Paciﬁc sector (60°E and140°E) of the Southern Ocean. Polar Biol 43 (4): 343–357.
La, H.S., Lee, H., Fielding, S., Kang, D., Ha, H.K., Atkinson, A.,
Park, J., Siegel, V., Lee, S. and Shin, H.C. 2015. High density of ice krill (Euphausia crystallorophias) in the Amundsen
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Matsuoka, K., Ensor, P., Hakamada, T., Shimada, H., Nishiwaki,S., Kasamatsu, F. and Kato, H. 2003. Overview of minke
whale sigh�ngs surveys conducted on IWC/IDCR and SOWER
Antarc�c cruises from 1978/79 to 2000/01. J. Cetacean Res.
Manage. 5 (2): 173–201.
Matsuoka, K. and Hakamada, T. 2014. Es�mates of abundance

and abundance trend of the blue, ﬁn and southern rightwhales in the Antarc�c Areas IIIE–VIW, south of 60°S, basedon JARPA and JARPAII sigh�ng data (1989/90–2008/09).
Paper SC/F14/J05 presented to the IWC Scien�ﬁc Commi�ee,
February 2014 (unpublished). 27 pp. [Available from the IWC
Secretariat].
Matsuoka, K. and Pastene, L.A. 2014. Summary of photoiden�ﬁca�on informa�on of blue, southern right and humpback whales collected by JARPA/JARPAII. Paper SC/F14/J34
presented to the IWC Scien�ﬁc Commi�ee, February 2014
(unpublished). 11 pp. [Available from the IWC Secretariat].
Matsuoka, K. and Yoshida, T. 2021. Development of an
Unmanned Arial Vehicle (UAV) and u�lity for the research
work of the Ins�tute of Cetacean Research. Technical Reportsof the Institute of Cetacean Research (TEREP-ICR) No. 5:
64–67.
Schlitzer, R. 2020. Ocean Data View, h�ps://odv.awi.de.
Tamura, T. and Konishi, K. 2009. Feeding habits and prey consump�on of Antarc�c minke whale (Balaenoptera bonaerensis) in the Southern Ocean. J. Northw. Atl. Fish. Sci. 42: 13–25.

31

Technical Reports of the Ins�tute of Cetacean Research (2023)

Appendix 1.
Photographs from the 2022/2023 JASS-A survey in Antarc�c Area VI

Photo 1.

Antarc�c blue whale.

Photo 3.

Photo 5.
32

Fin whale.

Humpback whale.

Photo 2.

Photo 4.

Antarc�c blue whale mother and calf.

A large school of Antarc�c minke whales observed in
the coastal ice-free waters.

Photo 6.

Killer whales (type A).

Results of the dedicated sighting survey under the Japanese Abundance and Stock structure Surveys in the Antarctic (JASS-A)

Photo 7.

Pigmy right whale sighted during the low-middle
la�tude area survey.

Photo 9.

Sigh�ng ac�vity at top barrel pla�orm.

Photo 11.

Biopsy and satellite tagging experiments.

Photo 8.

Photo 10.

Naviga�ng within the pack-ice.

Buoy used in the angle and distance experiment.

Photo 12.

VTOL-UAV ASUKA takes oﬀ from the vessel.
33

Technical Reports of the Ins�tute of Cetacean Research (2023)

pp. 34–46

Technical report (not peer reviewed)

Report and highlights of the Japanese dedicated sigh�ng surveys
in the North Paciﬁc in 2022
Yujin Kim*, Taiki Katsumata, Tatsuya Isoda and Koji Matsuoka
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: kim@cetacean.jp

ABSTRACTThis paper presents the results of vessel-based sigh�ng surveys conducted in 2022 by the Ins�tute of Cetacean
Research in the North Paciﬁc. The research area was set between 35°N–46°N and 140°E–175°W. The surveys
were conducted between 7 April and 10 November involving three seasons: spring, late summer and autumn.
The spring and late summer surveys were conducted to examine the distribu�on and abundance of whales,
and the autumn survey was conducted to inves�gate the migra�on of sei whales using satellite tags. The research vessels Yushin-Maru, Yushin-Maru No. 2 and Kaiyo-Maru No. 7 were engaged in the surveys. A totalof 8,340.9 n.miles was searched in the research area. Coverage of the searching eﬀorts on the planned cruise
track line was 81.1%. In total, eight large whale species, including blue (3 schools/3 individuals), ﬁn (105/165),sei (32/44), Brydeʼs (248/274), common minke (151/172), humpback (52/62), North Paciﬁc right (1/1) andsperm (198/375) whales were sighted during the whole research. Photo-ID images were collected from blue(n=2), humpback (n=7), North Paciﬁc right (n=1) and killer (n=2) whales. Biopsy skin samples using a Larsen
system were collected from ﬁn (n=1), sei (n=16), Brydeʼs (n=6), common minke (n=6) and North Paciﬁc right(n=1) whales. Satellite tags were a�ached on ﬁn (n=1), sei (n=16), Brydeʼs (n=5) and common minke (n=1)
whales. Data collected during these surveys will be used in studies on abundance, distribu�on, movement andstock structure of several whale species.

INTRODUCTION
Dedicated cetacean sigh�ng surveys in the western North
Paciﬁc were conducted in the late summer season since1995 as a part of the Japanese Whale Research Program
under Special Permit in the western North Paciﬁc (JARPN/
JARPNII) and the New Scien�ﬁc Whale Research Programin the western North Paciﬁc (NEWREP-NP) based on thesurvey procedures of the Interna�onal Whaling Commission/Southern Ocean Whale and Ecosystem Research(IWC/SOWER) (IWC, 2008). Based on the collected data,
the distribu�on pa�erns of large whales such as blue,
ﬁn, sei, Brydeʼs, common minke, humpback, North Paciﬁc right and sperm whales, and abundance es�matesof common minke, sei, and Brydeʼs whales were inves�gated and reported to the IWC Scien�ﬁc Commi�ee (SC)(IWC, 2001; 2010; 2016).
The Fisheries Resources Ins�tute (FRI) has also conducted dedicated sigh�ng surveys for cetaceans in the
North Paciﬁc since the 1980s (Buckland et al., 1992;
Miyashita et al., 1995; Miyashita and Kato, 2004; 2005;
Shimada, 2004; Kanaji et al., 2012). In 2019 the Govern34

ment of Japan decided to con�nue the sigh�ng surveys
in the North Paciﬁc (IWC, 2019) under the ra�onal thatthe collec�on of sigh�ng data to es�mate abundanceand biopsy/photo-iden�ﬁca�on data to examine stock
structure have contributed in the past to the work on
management and conserva�on of large whales by the
IWC SC (IWC, 2016).
This paper reports the results of the Japanese dedicated sigh�ng surveys conducted during 7 April and 10
November 2022 involving three seasons: spring, latesummer and autumn.

SURVEY DESIGN
Research period and area
In 2022, the surveys were conducted in three seasons:spring, late summer and autumn. The objec�ve of spring
and late summer surveys was the study of distribu�on
and abundance of large whales from poorly documented
seasons. Autumn survey aimed to study the movement
and southern migra�on of sei whales using satellite tags.
Figure 1 illustrates the research areas covered in eachseason.

Report and highlights of the Japanese dedicated sighting survey in the North Pacific in 2022

Figure 1.

Research areas covered by the 2022 dedicated sigh�ng surveys in each season. Upper le�: springsurvey. Kaiyo-Maru No. 7 (KY7) covered the yellow area, Yushin-Maru (YS1) covered the green area, andYushin-Maru No. 2 (YS2) covered the blue area. Upper right: late summer survey. KY7 covered the orange
area, and YS1 covered the pink area. Lower le�: autumn survey. YS2 covered the purple area. The autumn
survey did not have a pre-determined track line.

In spring (April to June), the research area was set up
between 35°N–46°N and 140°E–146°E. In late summer(August to September), the research area was set up
between 35°N–44°N and 140°E–154°E. Finally, in autumn
season (October to November), the research area was set
up between 38°N–46°N and 141°E–175°W.

program ver. 7.3ʼ (Thomas et al., 2010) and the numberof the line (width in the longitude) was decided by the
research schedule based on the IWC survey guidelines(IWC, 2012). The autumn survey did not set track lines
because the objec�ve in this season was not abundancees�mates but satellite tagging of sei whales.

Research vessels
The sigh�ng surveys in 2022 were conducted by the
research vessels Yushin-Maru (YS1), Yushin-Maru No. 2(YS2) and Kaiyo-Maru No. 7 (KY7) (Figure 2). The vessels
were equipped with a top barrel pla�orm (TOP), IO barrelpla�orm (IOP) and upper bridge.

Sigh�ng procedure
The sigh�ng surveys were conducted using (1) Normal
Passing mode (NSP), (2) Normal Closing mode (ASP)
and (3) Passing with Independent Observer mode (IO)
in order to es�mate whale abundance considering es�mated g(0). The survey modes adopted for each survey
are shown in Table 1. Three survey modes followed theprotocol endorsed for the SOWER surveys (e.g. Matsuoka
et al., 2003; IWC, 2008; 2012). As data from late summer survey are used to es�mate the abundance of large
whales, the IO mode was also adopted for this survey, as

Track line design
The pre-determined track lines in spring and late summer surveys are shown in Figure 1. The start points of the
track lines were decided randomly using the ʻDistance35

Technical Reports of the Ins�tute of Cetacean Research (2023)

Figure 2.

Research vessels par�cipa�ng in the 2022 dedicated sigh�ng surveys: Yushin-Maru (YS1) (upper le�),
Yushin-Maru No. 2 (YS2) (upper right) and Kaiyo-Maru No. 7 (KY7) (lower le�).

Table 1
Summary of the survey modes and searching condi�ons by each seasonal survey during the 2022 dedicated sigh�ng surveys.
Searching condi�ons
SeasonVesselSpring

KY7, YS1, YS2

Late summer

KY7, YS1

AutumnYS2

Survey mode
Normal Passing mode
Normal Passing mode
Passing with Independent Observer mode
Normal Closing mode

this survey can provide important data to calculate g(0).
For NSP and ASP mode, there were two primary observers in the top barrel (TOP) and two in the upper
bridge (captain and helmsman). All primary observers
conducted searching for cetaceans by using angle board
and scaled binoculars (7x).
For IO mode, there were two primary observers on
the TOP and two in the independent observer pla�orm(IOP). These observers conducted searching for cetaceans
by using angle board and scaled binoculars (7x). There
was no open communica�on between the IOP and theTOP. The observers and researchers on the upper bridge
communicated to the TOP (or IOP) independently, only toclarify informa�on and did not distract the top-men fromtheir normal searching procedure. These primary observers report sigh�ng-informa�on to researchers and otherobservers on the upper bridge for data recording.
The survey eﬀort began 60 minutes a�er sunrise and36

Visibility(n.miles)Wind speed(kt)

Searchingspeed (kt)

≥2.0

17.0>

10.0≥

≥2.0

17.0>

10.0≥

≥2.0

21.0>

11.5≥

ended 60 minutes before sunset, with a maximum of 12hours per day (maximum 06:00–19:00, including 30 minutes for meal�me for lunch and supper, when surveying
in IO mode) when the weather condi�ons were acceptable for observa�ons. Detailed search condi�ons for eachsurvey are shown in Table 1.
Experiments
Table 2 describes the details of the planned experiments
for each survey. Distance and angle experiments wereconducted in the middle of the survey period. The experiment was conducted to evaluate measurement error
and followed the protocol of the IWC/SOWER and IWCPOWER surveys (IWC, 2012).
When large cetaceans such as blue and humpback
whales were found, photo-id images were obtained using
Canon EOS 7D Mark II (with 100–400 mm lens) from thebow or upper deck. Further, biopsy skin sampling usingReport and highlights of the Japanese dedicated sighting survey in the North Pacific in 2022

the Larsen system (Larsen, 1998) was conducted when
blue, ﬁn, sei and humpback whales were sighted. The satellite tagging experiment using the Air Rocket Transmi�er
System (LK-ARTS) was also conducted for ﬁn, sei, Brydeʼsand common minke whales.

RESULTS
Brief narra�ve of the surveys
Spring (April–June)
KY7 departed Hakodate, Hokkaido, Japan on 7 April, andstarted the survey in the research area on 8 April. KY7
paused the survey on 4 May for a scheduled port call, andentered Hakodate, on 6 May for refueling and disembarka�on of researchers. On 11 May, KY7 departed Hakodate, and resumed the survey on 12 May. The survey wascompleted on 7 June. KY7 arrived in Hakodate on 9 June.
YS1 and YS2 departed Shiogama, Miyagi, Japan on 14
April. YS1 and YS2 started the survey in the research areaon 15 April and completed it on 21 May. YS1 and YS2 arrived in Shiogama on 23 May.

Late summer (August–September)
YS1 and KY7 departed Shiogama on 2 August and 3 August, and started the surveys on 3 and 4 August, respec�vely. On 24 August, KY7 suspended the survey and entered Hakodate for refueling. KY7 departed Hakodate andrecommenced the survey on 25 August. KY7 completed
the survey on 16 September and arrived in Shiogama on
17 September. YS1 completed the survey on 22 September and arrived in Shiogama on 30 September.
Autumn (October–November)
The YS2 departed Shiogama on 17 October and began thesurvey on 18 October. The vessel completed the survey
on 9 November and arrived in Shiogama on 10 November.
Searching eﬀort
A summary of searching eﬀort and coverage in each seasonal survey is shown in Table 3. A total of 8,340.9 n.miles(15,447.3 km) were searched in all seasonal surveys.

Table 2
Experiments planned in each seasonal survey during the 2022 dedicated sigh�ng surveys.
SeasonVesselSpringLate summer
AutumnKY7, YS1, YS2
KY7, YS1
YS2

Planned experiments
Photo-ID, biopsy, satellite tagging, distance and angle experiments
Photo-ID, biopsy, satellite tagging, distance and angle experiments
Photo-ID, biopsy, satellite tagging

Table 3
Summary of the survey periods and searching eﬀort by each seasonal survey in the 2022 dedicated sigh�ng surveys.
SeasonResearch period

Plannedcruise track(n.miles)Searchingeﬀort NSP
(n.miles)Searchingeﬀort IO
(n.miles)Searchingeﬀort Total(n.miles)Coverage ofeﬀort (%)

2022/04/08–05/04

1,019.2

781.9

–

781.9

76.7

2022/05/12–06/07

1,019.2

607.9

–

607.9

59.6

YS1

2022/04/15–05/21

1,298.1

1,139.7–

1,139.7

87.8

YS2

2022/04/15–05/21

1,317.4

936.1

–

936.1

71.1

Sub total—

4,653.9

3,465.6–

3,465.6

74.5

2022/08/04–08/24

1,122.3

484.9

463.1

948.0

84.5

2022/08/25–09/16

965.7

439.4

407.9

847.3

87.7

YS1

2022/08/03–09/22

3,060.8

1,351.2

1,339.2

2,690.4

87.9

Sub total—

5,148.8

2,275.5

2,210.2

4,485.7

87.1

YS2

2022/10/18–11/09—

389.6*

—

389.6

—

—

9,802.7

6,130.7

2,210.2

8,340.9

81.1

VesselKY7
SpringLatesummerAutumn

KY7

Total* Searching eﬀort ASP (n.miles).

37

Technical Reports of the Ins�tute of Cetacean Research (2023)

Sigh�ngs
SpringTables 4a and 4b show the total sigh�ngs for large andsmall cetacean species, respec�vely, made in spring
season 2022. The sigh�ng loca�ons of each species areshown in Figure 3 together with sea surface temperature(SST).

4.48 and 8.39, respec�vely while the DIs of YS1 and YS2
were 0.09 and 0.11, respec�vely.
Sei whale
This species was not sighted in the spring season.
Brydeʼs whale
A total of 14 schools (19 individuals including one motherand calf pair) were sighted south of 38°N (Figure 3). The
range of SST at the sigh�ng posi�ons was 8.8°C–21.0°C(mean SST: 18.6°C). Observed mean school size was 1.36.
The DI of YS1 was 0.44.

Blue whale
This species was not sighted in the spring season.
Fin whale
A total of 96 schools (153 individuals including three mother and calf pairs) were sighted north of 40°N (Figure 3).
The range of SST in the sigh�ng posi�ons was 1.8°C–9.2°C(mean SST: 5.2°C), and the mean school size was 1.59.
One biopsy sample was collected from one individual.
The Density Index (DI: schools of primary sighted/100 n.
miles searching distance) of KY7 in April and May were

Common minke whale
This species was the most frequently sighted species
in the spring season (149 schools and 170 individuals)(Figure 3). One mother and calf pair was sighted at posi�on 42°40ʹN, 145°03ʹE. The mean school size was 1.14
and the range of SST at the sigh�ng posi�ons was 1.3°C–

Table 4aTotal number of sigh�ngs of large whales made in spring 2022, by research vessel and species.
KY7 (Apr.)

Species

KY7 (May)

YS1

YS2

Total

Sch.

Ind.

Sch.

Ind.

Sch.

Ind.

Sch.

Ind.

Sch.

Ind.

39
0
59
1
0
0

46
0
67
1
0
0

55
0
84
1
0
2

105
0
96
1
0
4

1
14
2
32
0
30

1
19
2
38
0
59

1
0
4
12
1
3

1
0
5
15
1
3

96
14
149
46
1
35

153
19
170
55
1
66

Fin whale
Brydeʼs whale
Common minke whale
Humpback whale
North Paciﬁc right whale
Sperm whale
Sch.: Schools, Ind.: Individuals.

Table 4b
Total number of sigh�ngs of small cetaceans made in spring 2022, by research vessel and species.
Species
Bairdʼs beaked whale
Common dolphin
Northern form short-ﬁnned pilot whale
Southern form short-ﬁnned pilot whale
Rissoʼs dolphin
Killer whale
True type Dallʼs porpoise
Dalli type Dallʼs porpoise
Uniden�ﬁed type Dallʼs porpoise
Ziphiidae
Mesoplodon spp.
Sch.: Schools, Ind.: Individuals.
38

KY7 (Apr.)

KY7 (May)

YS1

YS2

Total

Sch.

Ind.

Sch.

Ind.

Sch.

Ind.

Sch.

Ind.

Sch.

Ind.

10
0
0
0
0
11
0
0
0
0
0

36
0
0
0
0
89
0
0
0
0
0

9
0
0
0
0
7
0
1
11
0
0

46
0
0
0
0
73
0
7
30
0
0

2
1
6
0
2
7
17
1
18
5
4

11
25
66
0
18
19
114
8
150
9
5

0
0
0
1
0
1
16
0
8
3
0

0
0
0
30
0
3
90
0
32
5
0

21
1
6
1
2
26
33
2
37
8
4

93
25
66
30
18
184
204
15
212
14
5

Report and highlights of the Japanese dedicated sighting survey in the North Pacific in 2022

Figure 3.

The loca�ons of large and small cetaceans sighted during the spring season 2022. Rolling 32 days averagesea surface temperature data from 23 April to 23 May 2022 and 9 May to 9 June obtained by MODIS-Aqua(Original data: Ocean color web, from h�ps://oceancolor.gsfc.nasa.gov/ (Accessed 2023-4-20)), are also
shown.

15.9°C (mean SST: 5.2°C). The DIs of KY7 in April and May
were 2.05 and 3.62, respec�vely. The DI of YS2 was 0.21.
Six biopsy samples were collected, and one satellite tag
was a�ached to one individual.
Humpback whale
A total of 46 schools (55 individuals including one motherand calf pair) were sighted (Figure 3). The mother and calf
pair was sighted at 36°48ʹN, 142°02ʹE. Observed meanschool size was 1.20. The range of SST in the sigh�ng posi�ons was 2.9°C–21.0°C (mean SST: 9.1°C). The DI of KY7
in May was 0.33. The DIs of YS1 and YS2 were 2.19 and
0.21, respec�vely. Seven individuals were photographed.
North Paciﬁc right whale
One school (one individual) of es�mated body length of
12.1 m was sighted at 42°16ʹN, 143°57ʹE (Figures 3 and 4).
The SST in the sigh�ng posi�on was 5.3°C. This individual
was photographed and a biopsy sample was obtained.

Figure 4.

A North Paciﬁc right whale sighted in spring 2022 (17May) during the 2022 dedicated sigh�ng surveys.

The DI of YS2 was 0.11.
Sperm whale
A total of 35 schools (66 individuals) were sighted (Figure 3).
The range of SST in the sigh�ng posi�ons was 1.5°C–
39Technical Reports of the Ins�tute of Cetacean Research (2023)

21.1°C (mean SST: 9.6°C). Because the opportunity toapproach the schools was limited, there was li�le informa�on on school size, body length and calves. The meanschool size was 1.89 when the school size was conﬁrmed.
The DIs diﬀered markedly between seasonal surveys,
0.33 for KY7, 2.19 for YS1 and 0.21 for YS2.

Late summer
Tables 5a and 5b show the total sigh�ngs for large andsmall cetacean species, respec�vely, made in late summer season 2022. The sigh�ng loca�ons of each species
are shown in Figure 4 together with SSTs.
Blue whale
This species was not sighted in the late summer season.

Small cetaceans
Five species of the the family Delphinidae, three speciesof the family Phocoenidae and three species of the family
Ziphiidae were sighted (Table 4b). The most common species sighted was the Dallʼs porpoise (72/431), followedby killer whale (26/184). Dallʼs porpoises were sighted
primarily at the 37°N–41°N la�tudinal band in April–May,and north of 44°N in May–June. Killer whales and Bairdʼsbeaked whales were mainly sighted north of 44°N.

Fin whale
Four schools (four individuals) were sighted north of
39°N (Figure 5). Mean school size was 1.00. The SST in thesigh�ng posi�on was 18.9°C–22.2°C (mean SST: 21.2°C).
The DIs were 0.11 and 0.11 by KY7 (August) and YS1,
respec�vely.

Table 5aTotal number of sigh�ngs of large whales made in late summer 2022, by research vessel and species.
KY7 (Aug.)

Species
Fin whale
Brydeʼs whale
Common minke whale
Humpback whale
Sperm whale

KY7 (Sep.)

YS1

Total

Sch.

Ind.

Sch.

Ind.

Sch.

Ind.

Sch.

Ind.

1
18
2
2
16

1
18
2
3
73

0
23
0
0
10

0
24
0
0
24

3
190
0
0
130

3
210
0
0
203

4
231
2
2
156

4
252
2
3
300

Sch.: Schools, Ind.: Individuals.
Table 5b
Total number of sigh�ngs of small cetaceans made in late summer 2022, by research vessel and species.
Species
Bairdʼs beaked whale
Common dolphin
Northern form short-ﬁnned pilot whale
Southern form short-ﬁnned pilot whale
Rissoʼs dolphin
Paciﬁc white-sided dolphin
Killer whale
Melon-headed whaleSpo�ed dolphin
Striped dolphinBo�lenose dolphin
True type Dallʼs porpoise
Dalli type Dallʼs porpoise
Uniden�ﬁed type Dallʼs porpoise
Ziphiidae
Mesoplodon spp.
Sch.: Schools, Ind.: Individuals.
40

KY7 (Aug.)KY7 (Sep.)

YS1

Total

Sch.

Ind.

Sch.

Ind.

Sch.

Ind.

Sch.

Ind.

7
0
1
0
1
5
0
0
0
0
1
3
0
4
0
0

35
0
18
0
45
293
0
0
0
0
10
29
0
38
0
0

17
0
1
0
3
0
0
1
0
0
2
0
0
1
7
3

103
0
95
0
70
0
0
15
0
0
20
0
0
3
23
9

3
13
0
2
7
0
1
0
1
22
0
0
0
2
57
2

28
787
0
89
59
0
8
0
45
1,273
0
0
0
22
117
5

27
13
2
2
11
5
1
1
1
22
3
3
0
7
64
5

166
787
113
89
174
293
8
15
45
1,273
30
29
0
63
140
14

Report and highlights of the Japanese dedicated sighting survey in the North Pacific in 2022

Figure 5.

The loca�ons of large and small cetaceans sighted during the late summer. Rolling 32 days average sea
surface temperature data from 21 August to 21 September 2022 obtained by MODIS-Aqua (Original data:
Ocean color web, from h�ps://oceancolor.gsfc.nasa.gov/ (Accessed 2023-4-20)), are also shown.

Sei whale
This species was not sighted in the late summer season.
Brydeʼs whale
Brydeʼs whales were the most frequently sighted species in this season (Figure 5). A total of 231 schools (252individuals) were sighted. Mean school size was 1.09. The
range of SST at the sigh�ng posi�ons was 16.2°C–27.4°C(mean SST: 23.0°C). The DIs were 1.90, 2.71 and 6.91 by
KY7 (August), KY7 (September) and YS1, respec�vely.
Common minke whale
Two schools (two individuals) were sighted north of 42°N
(Figure 5). The SSTs in the sigh�ng posi�on were 14.4°C
and 21.7°C. The DI of KY7 (August) was 0.21.
Humpback whale
Two schools (three individuals) were sighted (Figure 5).
Mean school size was 1.50. The SST at the sigh�ng posi�on were 16.4°C and 21.4°C. The DI of KY7 (August) was

0.21.
Sperm whale
A total of 156 schools (300 individuals including one
mother and calf pair) were sighted in this season (Figure 5).
A school consis�ng of 22 sperm whales was sighted at
42°15ʹN, 144°16ʹE. Mean school size was 1.92. The rangeof the SST in the sigh�ng posi�on was 16.0°C–29.6°C(mean SST: 22.2°C). The DIs were 1.69, 1.18 and 4.68 for
KY7 (August), KY7 (September) and YS1, respec�vely.
Small cetaceans
In this season, ten species of the family Delphinidae,
three species of the family Phocoenidae and three species of the family Ziphiidae, were sighted (Table 5b). The
most common sighted species was the striped dolphins(22/1,273), followed by the common dolphins (13/787).
Paciﬁc white-sided dolphins and Dallʼs porpoises weremainly sighted north of 40°N. Common dolphins andstriped dolphins were sighted primarily east of 145°E.
41Technical Reports of the Ins�tute of Cetacean Research (2023)

Bairdʼs beaked whales were sighted mainly west of 143°E.
The species of the family Ziphiidae were sighted east of
143°E.
Duplicate sigh�ngs
A total of 26 and 104 re-sigh�ngs of large cetaceans wererecorded during IO mode throughout this season involving several species.
AutumnTables 6 shows the total sigh�ngs for large and small cetacean species, made in autumn 2022. The sigh�ng loca�onof each species is shown in Figure 6 together with SSTs.
Blue whale
Three schools (three individuals) with body lengths of
17.8 m, 23.8 m and 24.1 m were sighted west of 150°E(Figure 6). The range of SST was 9.7°C–17.2°C (mean SST:
12.5°C). Two individuals were photographed.

Figure 6.

42

Fin whale
Five schools (eight individuals) were sighted (Figure 6).
Mean school size was 1.60, and the range of SST at thesigh�ng posi�ons was 11.7°C–14.8°C (mean SST: 13.6°C).
Table 6
Total number of sigh�ngs of large whales and small cetaceansmade in autumn 2022, by research vessel and species.
SpeciesBlue whale
Fin whale
Sei whale
Brydeʼs whale
Humpback whale
Sperm whale
Northern right whale dolphin
Rissoʼs dolphin

YS2
Sch.

Ind.

3
5
32
3
4
7
1
1

3
8
44
3
4
9
6
8

Sch.: Schools, Ind.: Individuals.

The loca�ons of large and small cetaceans sighted during autumn 2022. Rolling 32-days average sea
surface temperature data from 16 October to 16 November 2022 obtained by MODIS-Aqua (Original data:
Ocean color web, from h�ps://oceancolor.gsfc.nasa.gov/ (Accessed 2023-4-20)), are also shown.

Report and highlights of the Japanese dedicated sighting survey in the North Pacific in 2022

Sei whale
A total of 32 schools (44 individuals) were sighted (Figure 6).
The range of SST at the sigh�ng posi�ons was 10.1°C–
17.8°C (mean SST: 13.4°C). Mean school size 1.38. Biopsy
samples were collected from 16 individuals, and satellite
tags were a�ached on 16 individuals.

Small cetaceans
In this season, two species of the family Delphinidae weresighted (Table 6): Rissoʼs dolphin (1/8) and northern rightwhale dolphin (1/6).
Experiments
Sighting distance and angle experiment
In spring, the Es�mated Angle and Distance Experiment
was conducted by KY7 on 26 April and 28 May. It was
conducted on 5 May by YS1 and on 11 May by YS2. Inlate summer, the experiment was conducted on 15 September by KY7 and on 3 September by YS1. The results ofthis experiment will be used for calibra�ng the sigh�ng
distances and angle data used for the calcula�on of abundance es�mates.

Brydeʼs whale
Three schools (three individuals) were sighted (Figure 6)
with es�mated body lengths of 11.3 m, 11.8 m, and 12.8 m.
SST at the sigh�ng posi�on were 14.6°C, 14.9°C and
18.5°C.
Common minke whale
This species was not sighted in the autumn season.
Humpback whale
Four schools (four individuals) were sighted (Figure 6).
The range of SST in the sigh�ng posi�on was 10.4°C–
12.9°C (mean SST: 11.6°C).

Photo-ID
The number of individual photographed is shown in Table 7,
by species. All photographs were stored in the ICR catalogs and will be used for inves�ga�ng the stock structure
and movement of those cetacean species in the future.

Sperm whale
In total, seven schools (nine individuals) were sighted(Figure 6). Mean school size was 1.29. The range of SST
was 10.7°C–15.0°C (mean SST: 13.7°C).

Biopsy sampling
A total of 30 biopsy samples were collected during the2022 dedicated sigh�ng surveys. Table 8 shows the number of biopsies, by seasonal survey, research vessels andTable 7
Numbers of individuals photographed during the 2022 dedicated sigh�ng surveys, by seasonal survey, research vessel and species.
Species

Spring
KY7 (Apr.) KY7 (May)Late summer
YS1

YS2

KY7 (Aug.) KY7 (Sep.)

Autumn
YS1

YS2

Total

Blue whale
Humpback whale
North Paciﬁc right whale
Killer whale

0
1
0
0

0
1
0
2

0
4
0
0

0
1
1
0

0
0
0
0

0
0
0
0

0
0
0
0

2
0
0
0

2
7
1
2

Total

1

3

4

2

0

0

0

2

12

Table 8
Numbers of biopsy samples collected during the 2022 dedicated sigh�ng surveys, by seasonal survey, research vessel and species.
Species

Spring
KY7 (Apr.) KY7 (May)Late summer
YS1

YS2

KY7 (Aug.) KY7 (Sep.)

Autumn
YS1

YS2

Total

Fin whale
Sei whale
Brydeʼs whale
Common minke whale
North Paciﬁc right whale

0
0
0
0
0

0
0
0
3
0

0
0
6
2
0

1
0
0
1
1

0
0
0
0
0

0
0
0
0
0

0
0
0
0
0

0
16
0
0
0

1
16
6
6
1

Total

0

3

8

3

0

0

0

16

30
43

Technical Reports of the Ins�tute of Cetacean Research (2023)

species. All samples were stored at the ICR laboratory andwill be used in gene�c analyses for inves�ga�ng the stock
structure of those species in the future.

A large number of ﬁn and common minke whales weresighted in April–June in the Japanese side of the Sea of
Okhotsk. Common minke whales were mainly sighted
east coast of the Shiretoko Peninsula and west coast of
144°E. On the other hand, ﬁn whales were sighted east of
144°E which suggests that these species were separated
in distribu�on at the western coast of the Sea of Okhotsk.
Direct feeding behavior was not observed, but seabirds
were concentrated close to the sigh�ng posi�ons of ﬁnand common minke whales. From this, it is possible thatthese two species were distributed in this area for feeding
during this season.
A large number of humpback whales were sighted
in April–June in the southern part of the Paciﬁc side ofJapan. Most of humpback whales were sighted south of
40°N probably during their northward migratory path.
At the same �me, it was conﬁrmed that Brydeʼs whales
were also distributed south of 37°N, although in small
numbers.
The August-September survey covered the North
Paciﬁc from the coast of Japan to 154°E, providing important late summer sigh�ng data for Brydeʼs and sperm
whales. At the same �me, several sigh�ng data for ﬁn,
common minke and humpback whales were obtained inSatellite tagging
Satellite tag a�achments were a�empted during eachseasonal survey, but a�achments only occurred during
spring and autumn. The number of individuals taggedis shown in Table 9, by seasonal survey, research vessel
and species. A total of 16 sei whales were tagged, all inautumn. These were evenly a�ached among the sigh�ngs(Figure 7). Tracking data obtained from satellite tags willcontribute to the elucida�on of the movement of whales
in each season and the �ming of the start of migra�on
between high la�tude feeding areas and low la�tude
breeding areas.

HIGHLIGHTS OF THE SURVEY
The sigh�ng surveys conducted in 2022 were completed
successfully. They provided unique data obtained not
only in the late summer, but also in the spring and autumn seasons for which informa�on on cetacean distribu�on and abundance have been very scarce. Some main
characteris�cs of the surveys are summarized below.

Table 9Numbers of individuals a�ached with satellite tags, by each season and research vessel in 2022.
SpringSpecies

YS1

YS2

KY7 (Aug.) KY7 (Sep.)

Autumn
YS1

YS2

Total

Fin whale
Sei whale
Brydeʼs whale
Common minke whale

0
0
0
0

0
0
0
0

0
0
5
0

1
0
0
1

0
0
0
0

0
0
0
0

0
0
0
0

0
16
0
0

1
16
5
1

Total

0

0

5

2

0

0

0

16

23

Figure 7.

44

KY7 (Apr.) KY7 (May)Late summer

The loca�ons of tagged sei whales during autumn 2022. Loca�ons were obtained from photographs taken
at the �me of the tagging.

Report and highlights of the Japanese dedicated sighting survey in the North Pacific in 2022

this season. These three species were sighted north of
40°N. Compared to previous surveys conducted during
the same seasons and same research area (Katsumata
et al., 2021), Brydeʼs whales in 2022 were more northernly distributed. The northward exten�on of this species
could have been inﬂuenced by higher monthly mean SSTs
between 41°N–43°N than in 2020 (Figure 8). The monthly
mean SST between 41°N–43°N was higher than in 2020,
which could explain the northward migra�on of this species.
Consistent with previous surveys in 2020 (Katsumata
et al., 2021), no common minke whales were sighted in
the pelagic part. Murase et al. (2023) reported the mean
SST for sigh�ng posi�on of this species over the past four
years (2002, 2004, 2005, 2006) was 15.5°C. In this season,
the monthly mean SST at the research area was higher
than 16°C, and cold water below 16°C formed north of
43°N. From this, it is considered that common minke
whales distribu�on was shi�ed to the north in 2022.
In October–November, a large number of sei whales
were sighted in the northwest side of the Paciﬁc. Sei
whales were distributed in high density near 180°, andthe SST in this area was in the 10°C range. Although justa single feeding behavior was observed, this area could
be a feeding area for this species because seabirds wereconcentrated around the sigh�ng posi�ons. Satellite tags
were successfully a�ached on 16 individuals to study the
movement and southern migra�on of sei whales. The

study of the migra�on will contribute to resource management by assis�ng the interpreta�on of the gene�canalyses on stock structure. Several blue, ﬁn, humpbackand sperm whales were also sighted in this area.
As in the previous surveys, the 2022 surveys collected
data on small cetaceans in the same way as large cetaceans. The analyses of these data will provide valuable
informa�on on the distribu�on and abundance of small
cetaceans in diﬀerent seasons.

ACKNOWLEDGEMENTS
We acknowledge the Government of Japanʼs assistancein providing the research permits and funding for thesecruises. We also thank the Captains Koji Maki, Chikamasa
Okoshi, Hidenori Kasai, Yasuaki Sasaki, and their oﬃcers
and crew of the Yushin-Maru, Yushin-Maru No. 2 andKaiyo-Maru No. 7 for their hard work and dedica�onthat led to the successful execu�on of these surveys. We
express our deep gra�tude to Takashi Hakamada and
Megumi Takahashi of the Ins�tute of Cetacean Research(Tokyo) for expert support in planning survey design. We
thank Yoshihiro Fujise and Tsutomu Tamura and the staﬀ
of the Ins�tute of Cetacean Research (ICR) and Kyodo
Senpaku Co., Ltd. for their assistance in arrangements
and support for the cruise. We also thank Kenji Konishi
of ICR for satellite tagging and Mioko Taguchi of ICR forbiopsy sample management. Finally, we thank Luis A. Pastene for his assistance in preparing this report and to the
Editorial Team of TEREP-ICR for editorial work.

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Figure 8.

Sigh�ng posi�on of Brydeʼs whales and monthly
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Technical Reports of the Ins�tute of Cetacean Research (2023)

pp. 47–54

Technical Report (not peer reviewed)

Results of the IWC-Paciﬁc Ocean Whale and Ecosystem Research(IWC-POWER) dedicated sigh�ng survey in 2022—An overview—
Taiki Katsumata* and Koji Matsuoka
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: katsumata@cetacean.jp

ABSTRACTThis paper outlines the main results of the 2022 dedicated sigh�ng survey of the Interna�onal Whaling Commission-Paciﬁc Ocean Whale and Ecosystem Research (IWC-POWER). The IWC-POWER surveys are designed
and implemented by the IWC Scien�ﬁc Commi�ee, in special partnership with the Government of Japan. The
surveys have been conducted since 2010 as the ﬁrst phase with the long-term objec�ve: ʻ(to) provide informa�on to allow determina�on of the status of popula�ons (and thus stock structure is inherently important) oflarge whales that are found in the North Paciﬁc waters and provide the necessary scien�ﬁc background forappropriate conserva�on and management ac�onsʼ. The 2022 survey was conducted between 2 August and
30 September, south of the western Aleu�an Islands, within the U.S. Exclusive Economic Zone. This area wasalso surveyed in 2010 on the ﬁrst IWC-POWER cruise. The current survey was conducted aboard the Japanese
R/V Yushin-Maru No. 2. The acous�c survey was conducted for monitoring the presence of marine mammals,with par�cular emphasis on North Paciﬁc right whales. Sixty-two percent of the planned survey track line wascovered (917.3 n.miles of a planned distance of 1,486.4 n.miles). During the survey, blue (20 schools/21 individuals), ﬁn (36/54), sei (21/23), common minke (3/3), humpback (12/12), sperm (38/38) and killer (14/63)
whales were observed in the research area. No North Paciﬁc right whales were seen or acous�cally detectedduring the en�re cruise. Photo-iden�ﬁca�on data were collected for 16 blue, 7 ﬁn, 8 sei, 6 humpback and 8
killer whales. A total of 16 biopsy samples were collected from 4 blue, 4 ﬁn, 6 sei and 2 humpback whales. A
total of 34 sonobuoys were deployed, of which 33 were successful, for a total of over 210 monitoring hours.
Data collected during this survey will be used mainly for abundance es�ma�on and stock structure research
purposes.

INTRODUCTION
The Interna�onal Whaling Commission-Paciﬁc Ocean
Whale and Ecosystem Research (IWC-POWER) programis an interna�onal research eﬀort in the North Paciﬁc coordinated by the IWC and designed by the IWC Scien�ﬁcCommi�ee (SC) in special partnership with the Government of Japan. Scien�sts from the Ins�tute of Cetacean
Research (ICR) and coopera�ng ins�tutes such as Tokyo
University of Marine Science and Technology par�cipate
regularly in the IWC-POWER program, both in designingand implemen�ng the surveys.
The IWC-POWER surveys in the North Paciﬁc follow
the series of IWC Interna�onal Decade for Cetacean Research/Southern Ocean Whale and Ecosystem Research(IDCR/SOWER) surveys that were conducted in the Antarc�c between 1978/79 and 2009/10. The long-term
objec�ve of the IWC-POWER is to ʻprovide informa�on

to allow determina�on of the status of popula�ons (andthus stock structure is inherently important) of large
whales that are found in the North Paciﬁc waters and provide the necessary scien�ﬁc background for appropriate
conserva�on and management ac�onsʼ.
The past IWC-POWER surveys provided cri�cal informa�on on rare whale species such as North Paciﬁc rightwhale (Matsuoka et al., 2022). The ﬁrst survey of thisprogram was conducted in 2010 and the most recent one
in 2022 (IWC, in press). The IWC SC is close to completing the ﬁrst phase of the IWC-POWER, which focuses on
its short-term priori�es. The IWC SC is preparing for thesecond phase which relates to medium-term priori�es,
based on the results of the ﬁrst phase (see Matsuoka, 2020).
The objec�ve of this document is to summarize theresults of the 2022 IWC-POWER survey based on Morseet al. (2023). For a general background of the IWC47

Technical Reports of the Ins�tute of Cetacean Research (2023)

Figure 1.

Research area and survey track lines with start and end points for the 2022 IWC-POWER survey.

Table 1The 2022 IWC-POWER survey i�nerary.
Date

Event

2022/08/01

Pre-cruise mee�ng at Shiogama

2022/08/02

Vessel departed Shiogama

2022/08/10

Vessel arrived at Dutch Harbor2022/08/15

Cruise leader and US researcher came on
board and vessel departed Dutch Harbor2022/08/20

Survey commenced in the research area

2022/09/13

Survey ﬁnished in the research area

2022/09/15

Vessel arrived at Dutch Harbor2022/09/18

Vessel departed Dutch Harbor2022/09/30

Vessel arrived at Shiogama

POWER including objec�ves, research area, and general
methodology, see Matsuoka (2020).

RESULTS OF THE 2022 IWC-POWER SURVEY
The main results of the 2022 IWC-POWER survey in thisdocument were based on Morse et al. (2023). All researchac�vi�es (i.e. approaching cetaceans for species iden�ﬁca�on, school size es�mates, digital photography, andbiopsy sample collec�on) that were carried out within the
U.S. EEZ were permi�ed under U.S. Na�onal Marine Fisheries Service (NMFS) Permit no. 25563 (issued to AFSC,
Marine Mammal Laboratory). Cetacean research ac�vi�es conducted on the high seas in interna�onal waters by
Japanese researchers aboard the R/V Yushin-Maru No. 2
were authorized under permit SUIKAN 4-1112 (dated 12
July 2022) issued by the Fisheries Agency, Governmentof Japan.
I�nerary
The 2022 survey was conducted between 2 August and48

Figure 2.

The R/V Yushin-Maru No. 2 in Dutch Harbor (date:
15 August 2022).

30 September by the Japanese R/V Yushin-Maru No. 2.
The i�nerary is shown in Table 1.
Research area
The research area was oﬀ the southern Aleu�an Islands
bounded by the US Exclusive Economic Zone (EEZ), between 167°38ʹE and 170°00ʹW (Figure 1).
Research vessel and scien�ﬁc personnel
The R/V Yushin-Maru No. 2 (747GT) was contracted forthis cruise (Figure 2 and Table 2). The vessel is a sister
ship of the Yushin-Maru No. 3 which was contracted
in previous years. Four interna�onal researchers were
nominated by the IWC SC for this survey.
Laura Morse (USA) – Cruise Leader/Chief Scien�st;sigh�ng and photo-ID
Jessica Crance (USA) – acous�cs and photo-ID
Taiki Katsumata (Japan) – sigh�ng, photo-ID data
management and marine debris
Isamu Yoshimura (Japan) – sigh�ng data, marine debris and biopsy sample management

Results of the IWC-Pacific Ocean Whale and Ecosystem Research (IWC-POWER) dedicated sighting survey in 2022

Searching eﬀort
Survey track line coverage in the research area was 62%(917.3 n.miles of a planned distance of 1,486.4 n.miles),with a total of 491.2 n.miles in Passing with abeam closing
mode (NSP) and 426.1 n.miles in Independent Observer
passing mode (IO). The eﬀort spent on the sigh�ng survey
is shown in Table 3.

Table 2
Speciﬁca�ons of the R/V Yushin-Maru No. 2.
Call sign

JPPV

Length overall [m]69.61

Molded breadth [m]11.5Gross tonnage (GT)

747

Barrel height [m]19.5

IO barrel height [m]13.5

Upper bridge height [m]11.5

Bow height [m]6.5

Engine power [PS/kW]

Summary of the sigh�ngs
During the survey in the research area, the followingsigh�ngs were made: blue (20 schools/21 individuals),ﬁn (36/54), sei (21/23), common minke (3/3), humpback (12/12), sperm (38/38) and killer (14/63) whales(Table 4). The sea surface temperature (SST) of each species on the sigh�ng posi�on is summarized in Table 5.
Geographical distribu�on by species
Blue whale (Balaenoptera musculus)
Blue whales were widely distributed and mainly sighted
in the western part of the research area (Figure 3a). They
appeared to be spa�ally separated from sei whales with

5303/3900

Table 3
Summary of the searching eﬀort in the research area conducted during the 2022 IWC-POWER survey. NSP: Normal Passing withabeam Closing Mode, IO: Independent Observer Mode.

Area

Western Stratum(167°38ʹE–180°)
Eastern Stratum(180°–170°00ʹW)

Leg No.

Start

End

Start

Date

Date

End

Time

Time

87

134

20-Aug. 5-Sep.

US EEZ

114

6:40

86

112

5-Sep. 13-Sep.

US EEZ

101

11:49

Area
Code

NSP

11:49

17:35

20-Aug. 13-Sep.

Total

6:40

17:35

IO

NSP+IOTime

Dist.
(n.m.)

TimeDist.
(n.m.)

TimeDist.
(n.m.)

25:09:19

287.4

23:05:16

265.2

48:14:35

552.6

17:32:14

203.8

13:46:41

160.9

31:18:55

364.7

42:41:33

491.2

36:51:57

426.1

79:33:30

917.3

Table 4
Number of sigh�ngs (schools and individuals) for all species observed in the research area (original and transit track lines in the research area) by eﬀort mode. NSP: Normal Passing with abeam Closing Mode, IO: Independent Observer Mode, OE: Top Down (TD)and Dri�ing (DR), Sch.: schools, Ind.: individuals.
Species

NSP

IO

OE

Total

Sch.

Ind.

Calf

Sch.

Ind.

Calf

Sch.

Ind.

Calf

Sch.

Ind.

Calf

Blue whale

12

13

0

7

7

0

1

1

0

20

21

0

Fin whale

18

28

2

17

25

1

1

1

0

36

54

3

Sei whale

10

11

0

10

11

0

1

1

0

21

23

0

Common minke whale

2

2

0

1

1

0

0

0

0

3

3

0

Humpback whale

6

6

0

5

5

0

1

1

0

12

12

0

Sperm whale

22

22

0

14

14

0

2

2

0

38

38

0

Killer whale

3

15

0

10

47

1

1

1

0

14

63

1
49

Technical Reports of the Ins�tute of Cetacean Research (2023)
Table 5
Minimum, maximum, range and 25th to 75th quar�les of sea surface temperatures (SSTs) in degrees Celsius for each species sighted
in the research area (original track line). Also noted are the number of sigh�ngs for each species.
SpeciesNumber of sigh�ngs

Minimum SST

Maximum SST Temperature range

25th to 75th Quar�leBlue whale

20

6.8

10.8

4.0

7.9–10.1

Fin whale

36

5.4

11.2

5.8

8.7–9.6

Sei whale

21

9.3

12.0

2.7

10.0–11.6

Common minke whale

3

8.0

9.9

1.9

8.7–9.6

Humpback whale

12

6.5

12.0

5.5

7.2–9.3

Sperm whale

38

5.7

11.2

5.5

8.9–10.2

Killer whale

14

3.4

11.9

8.5

6.8–10.1aBlue whale

Figure 3a.

The searching eﬀort (thin line) and sigh�ng posi�ons (blue circles) of blue whales during the 2022
IWC-POWER survey (le�) and surfacing blue whales photographed in the research area (right).

b

Fin whale

Figure 3b.

The searching eﬀort (thin line) and sigh�ng posi�ons (red circles) of ﬁn whales during the 2022
IWC-POWER survey (le�) and a surfacing ﬁn whale photographed in the research area (right).

c

Sei whale

Figure 3c.

50

The searching eﬀort (thin line) and sigh�ng posi�ons (orange circles) of sei whales during the 2022
IWC-POWER survey.

dCommon minke whale

Figure 3d.

The searching eﬀort (thin line) and sigh�ng posi�ons (pink circles) of common minke whales during the 2022 IWC-POWER survey.

Results of the IWC-Pacific Ocean Whale and Ecosystem Research (IWC-POWER) dedicated sighting survey in 2022e

Humpback whale

Figure 3e.

The searching eﬀort (thin line) and sigh�ng posi�ons (black circles) of humpback whales during the 2022
IWC-POWER survey (le�) and ﬂuke of a humpback whale photographed in the research area (right).

fg

Sperm whale

Killer whale

Figure 3f. The searching eﬀort (thin line) and sigh�ng posi�ons (brown circles) of sperm whales during the2022 IWC-POWER survey.

Figure 3g.

associated SSTs at the sigh�ng posi�ons ranging between
6.8°C and 10.8°C (25th to 75th quar�les: 7.9–10.1°C)
which was lower than the range for sei whales (Table 5).

of 180° (Figure 3d). A total of 3 schools (3 individuals)
were observed. SSTs at the sigh�ng loca�ons ranged
from 8.0°C to 9.9°C (25th to 75th quar�les: 8.7–9.6°C)(Table 5). During this survey, sea states averaged 4–5 on
the Beaufort scale, which is assumed to be too rough forsigh�ng common minke whales.

Fin whale (Balaenoptera physalus)
Fin whales were widely distributed throughout the survey area. Several high-density areas were observed along
the most east transect and through Samalga Pass during
the transit to Dutch Harbor from the survey area (Figure3b). Sea temperatures ranged from 5.4°C to 11.2°C (25thto 75th quar�les: 8.7–9.6°C) (Table 5).
Sei whale (Balaenoptera borealis)
Sei whales were the second most frequently encounteredbaleen whale species through this survey. Sei whales
were widely distributed but appeared to be spa�ally
separated from blue whales with associated SST diﬀerences (Figure 3c). SSTs ranged from 9.3°C to 12.0°C (25thto 75th quar�les: 10.0–11.6°C), which was higher than
the range for blue whales (Table 5).
Common minke whale (Balaenoptera acutorostrata)
Common minke whales were the rarest baleen whale
species in the research area and were only sighted west

The searching eﬀort (thin line) and sigh�ng posi�ons (white circles) of killer whales during the2022 IWC-POWER survey.

Humpback whale (Megaptera novaeangliae)
Humpback whales were sporadically distributed in the
research area (Figure 3e). SSTs at the sigh�ng posi�ons
ranged from 6.5°C to 12.0°C (25th to 75th quar�les:7.2–9.3°C) (Table 5).
Sperm whale (Physeter macrocephalus)
Sperm whales were widely distributed throughout the
research area, with the highest densi�es observed between 175°E and 175°W (Figure 3f). All schools wereobserved as solitary individuals (probably large males).
Sperm whales were recorded in waters with SSTs ranging
from 5.7°C to 11.2°C (25th to 75th quar�les: 8.9–10.2°C)(Table 5).
Killer whale (Orcinus Orca)
Killer whales were widely distributed in the research area
51

Technical Reports of the Ins�tute of Cetacean Research (2023)
Table 6
Iden�ﬁca�on of duplicate sigh�ngs (main species) observed during the Independent Observer (IO) mode survey (original track line).
Duplicate status was based on the number of sigh�ngs made by the Independent Observer Pla�orm (IOP) that were observed also
by the Topmen in the Standard TOP Barrel. Status codes D: Deﬁnite duplicate, P: Possible duplicate, R: Remote duplicate, N: Not duplicate.
Species

Duplicate Status

Number of all schoolssighted by TOP and IOP

Number of all schoolssighted by IOP

D

P

R

N

12
21
10
1
3
21
13

5
10
5
0
3
11
4

5
6
2
0
0
7
4

0
0
0
0
0
0
0

0
0
0
0
0
0
0

0
4
3
0
3
4
0

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

Table 7a
Summary of the informa�on on photo-ID experiments during the 2022 IWC-POWER survey, by species.
Photo-IDBlue whale

Fin whale

Sei whale

Humpback whale

Killer whale

Total

Research area
Transit

14
2

7
0

7
1

2
4

8
0

38
7

Total

16

7

8

6

8

45

Table 7b
Summary of the number of biopsy samples collected during the 2022 IWC-POWER survey, by species.
Biopsy samples

Blue whale

Fin whale

Sei whale

Humpback whale

Total

Research area
Transit

4
0

4
0

5
1

2
0

15
1

Total

4

4

6

2

16

(Figure 3g). They were sighted in waters with SSTs ranging
from 3.4°C to 11.9°C (25th to 75th quar�les: 6.8–10.1°C)(Table 5).
Summary of Acous�c monitoring
A total of 34 sonobuoys were deployed during the cruise.
Of these, 33 were deployed and transmi�ed successfully
for an overall success rate of 97.05%. A total of 211.46
hours of acous�c monitoring occurred during the survey.
The most common species detected were sperm andﬁn whales, both detected on 31 of 33 buoys (93.9%),
followed by killer whales (23, 69.6%), blue whales (18,
54.5%) and humpback whales (7, 21.2%). More detailed
results are described in Morse et al. (2023).
Iden�ﬁca�on of duplicated sigh�ngs
Resight data were recorded for a total of 68 sigh�ngs
during IO Mode involving several baleen whale species(Table 6). These data will be used to es�mate g(0), which
52

in turn will be used to adjust abundance es�mates.
Photo-ID experiments
Photo-ID experiments were conducted on blue (16 individuals), ﬁn (7), sei (8), humpback (6) and killer (8) whales(Table 7a).
Biopsy sampling
Biopsy samples were collected from 4 blue, 4 ﬁn, 6 sei
and 2 humpback whales (Table 7b). Every biopsy encounter was documented photographically. All biopsy samples
were catalogued and stored on the vessel in cryo-vials
frozen at a temperature of −30°C.
Es�mated Angle and Distance Experiment
The Es�mated Angle and Distance Experiment was conducted on 1 September for 7 hours 51 minutes whilst
in the research area. A total of 84 trials were conducted
for each pla�orm (TOP and IO barrels and upper bridge).

Results of the IWC-Pacific Ocean Whale and Ecosystem Research (IWC-POWER) dedicated sighting survey in 2022
Table 8The diving and surfacing dura�ons of a sei whale tagged during the 2022 IWC-POWER survey.
PTT ID

Number of days
with data obtained

type

n

dura�onmean (sec.)

SD

207833

4.6

Dive
Surfacing

573
570

83.48
60.60

144.57185.28Figure 4.

Dura�onDura�onDura�on range
minimum (sec.) maximum (sec.)(sec.)
4
2

772
2728

768
2726

Interna�onal researchers and crew of the 2022 IWC-POWER survey with Yushin-Maru No. 2. The picture
was taken at the end of the survey in Dutch Harbor (date: 18 September 2022).

Both the Es�mated Angle and Distance Training Exercises
and Experiments were performed using the improved
protocol (IWC, 2017).
Marine debris observa�ons
A total of eight marine debris were observed. A total ofseven items were recorded ʻon eﬀortʼ (i.e. during the ﬁrst
15 minutes of each hour) and one item was recorded
during ʻoﬀ eﬀortʼ. Marine debris were scarce and sparsely
distributed in the survey area, compared to previous
years (Matsuoka et al., 2013; 2014).
Satellite tagging studies
During the transit survey on the high sea, satellite-linked
dive behavior tags were experimentally deployed as afeasibility study at the discre�on of Japan. The tag wasa�ached to one sei whale on 24 September. The diving
and surfacing dura�on obtained by 1 October are summarised in Table 8. The obtained data could be used tocorrect availability bias in future abundance es�ma�onwork.

HIGHLIGHT OF THE SURVEY
The 2022 annual IWC-POWER survey was successfully
conducted by a group of interna�onal scien�sts using theJapanese R/V Yushin-Maru No. 2 (Figure 4), and valuable
data were collected for several cetacean species. Suchdata will allow for further studies on the distribu�on,abundance and stock structure of large cetaceans in thispar�cular area of the North Paciﬁc.
This survey provided cri�cal informa�on on seasonal
distribu�on and abundance of baleen whales. The research area of the 2022 survey was also surveyed in 2010
(Matsuoka et al., 2011). Some diﬀerences were noted
between the two surveys. Sei whales are moving northward, indica�ng they are distributed at higher la�tudes
in August–September. In addi�on, the 2010 survey had
poor coverage of 34% due to bad weather. On the other
hand, the coverage was 62% in 2022, which provides sufﬁcient data for abundance es�ma�on. Furthermore, it
should be noted that biopsy samples were collected forthe ﬁrst �me in this area. These samples will be used formolecular gene�cs analyses on stock iden�ﬁca�on.

53

Technical Reports of the Ins�tute of Cetacean Research (2023)

ACKNOWLEDGEMENTS
We acknowledge the Governments of the United Statesof America as well as Japan (Fisheries Agency of Japan)
for their assistance in the research permit and funding
for this cruise and Iain Staniland and the Secretariat ofthe IWC for their support and funding for this cruise. We
express our deep gra�tude to the cruise leader Laura
Morse (IWC) and the interna�onal researchers Jessica
Crance (NOAA/AFSC) and Isamu Yoshimura (IWC) for theirexper�se in contribu�ng to a highly successful survey.
We also acknowledge the steering group of this cruise,
the Technical advisory group of this cruise and Takashi
Hakamada, Tatsuya Isoda and Megumi Takahashi the staﬀ
of the Ins�tute of Cetacean Research (ICR) and Kyodo
Senpaku Co., Ltd., for their arrangements and support forthis cruise, especially in acquiring an interna�onal licenseof the vessel. We also thank the crew of the R/V YushinMaru No. 2 for their hard work and dedica�on. Alaska
Fisheries Science Center provided acous�c equipment
and organized the port arrangement at Dutch Harbor.
Mioko Taguchi (ICR) arranged biopsy CITES permit issues
and loaned materials for biopsy processing and storage.
We thank Luis A. Pastene for his assistance in preparing
this manuscript and to the Editorial Team of TEREP-ICR
for editorial work.

REFERENCES
Interna�onal Whaling Commission. 2017. Report of the
Planning Mee�ng for the 2016 IWC-POWER Cruise in the

54

North Paciﬁc. J. Cetacean Res. Manage. (Suppl.) 18: 477–488.
Interna�onal Whaling Commission. (in press). Report of Scien�ﬁcCommi�ee (SC69A, 2023). J. Cetacean Res. Manage. (Suppl.).
Matsuoka, K. 2020. An outline of the IWC-Paciﬁc Ocean Whaleand Ecosystem Research (IWC-POWER) including resultsof the 2019 survey. Technical Reports of the Institute of
Cetacean Research (TEREP-ICR) No. 4: 23–34.
Matsuoka, K., Hakala, S., Kim, H.W., Aki, M. and Shinyasiki,Y. 2011. 2010 IWC/Japan Joint Cetacean Sigh�ng Survey
Cruise in the North Paciﬁc. Paper SC/63/O5 presented to the
IWC Scien�ﬁc Commi�ee, June 2011 (unpublished). 40 pp.
[Available from the IWC Secretariat].
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 Scien�ﬁc Commi�ee, June 2013 (unpublished). 43 pp. [Available from the IWC Secretariat].
Matsuoka, K., Kim, H.W., Mar�nez-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 Scien�ﬁc Commi�ee, May 2014
(unpublished). 24 pp. [Available from the IWC Secretariat].
Matsuoka, K., Crance, J.L., Taylor, J.K.D., Yoshimura, I., James,
A. and An, Y.R. 2022. North Paciﬁc right whale (Eubalaena
japonica) sigh�ngs in the Gulf of Alaska and the Bering Sea
during IWC-Paciﬁc Ocean Whale and Ecosystem Research(IWC-POWER). Marine Mammal Science 38 (2): 822–834.
Morse, L., Crance, J., Yoshimura, I., Katsumata, T. and Kasai, H.
2023. Cruise report of the 2022 IWC-Paciﬁc Ocean Whaleand Ecosystem Research (IWC-POWER). Paper SC/69a/ASI09
presented to the IWC Scien�ﬁc Commi�ee, April–May 2023
(unpublished). 48 pp. [Available from the IWC Secretariat].

Technical Reports of the Ins�tute of Cetacean Research (2023)

pp. 55–63

Technical Report (not peer reviewed)

An update of the study on age at sexual maturity trends in the
Antarc�c minke whale
Satoko Inoue*, Takeharu Bando and Yoshihiro Fujise
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: inoue@cetacean.jp

ABSTRACTAn update of the analysis of age at sexual maturity in the Antarc�c minke whale based on the transi�on phase
was carried out by using all samples available from former Japanese whale research programs under special
permit in the Antarc�c (JARPA, JARPAII, NEWREP-A) from the 1987/88 to the 2018/19 austral summer seasons.
These research programs and surveys, designed and implemented by the Ins�tute of Cetacean Research,were conducted in the Indo-Paciﬁc sector of the Antarc�c (0°–120°W, south of 60°S). The updated analyses
conﬁrmed that the age at sexual maturity of this species declined from 10–12 years old in the mid-1940s year
classes to 7–8 years old in the early 1970s year classes. The age at sexual maturity remained stable at thatlevel un�l the 2000s year classes. Although some signiﬁcant sta�s�cal trends were found for the recent year
classes (from the 1970s), the extent of such changes, when conﬁrmed, is very small in comparison with theextent of the changes observed in the middle of the past century. These results for the age at sexual maturity
are interpreted and discussed in conjunc�on with changes observed in other ecological and biological parameters of the Antarc�c minke whale, in the context of some established hypotheses on changes of the Antarc�cecosystem.

INTRODUCTION
Since the moratorium on commercial whaling was implemented in 1988, the Ins�tute of Cetacean Research (ICR)
undertook diﬀerent whale research programs in the Antarc�c Ocean under Ar�cle VIII of the Interna�onal Conven�on for the Regula�on of Whaling (ICRW). The Japanese Whale Research Program under Special Permit in the
Antarc�c (JARPA) was conducted in the austral summers
from 1987/88 to 2004/05 and in a second phase (JARPAII) from 2005/06 to 2013/14. The New Scien�ﬁc Whale
Research Program in the Antarc�c Ocean (NEWREP-A)
was conducted from 2015/16 to 2018/19. These programs carried out systema�c surveys in the Indo-Paciﬁc
sector (0°–120°W, south of 60°S) of the Antarc�c using
both lethal (biological sampling of a limited number ofAntarc�c minke whales [Balaenoptera bonaerensis]) andnon-lethal (biopsy sampling and photo-iden�ﬁca�on ofseveral whale species, oceanographic and marine debris
surveys, dedicated sigh�ng surveys) approaches.
Data and samples obtained from the Antarc�c minke
whales were analyzed in regard to several objec�vesof the research programs related to both assessment(e.g. stock structure, biological parameters, abundancees�mates) and ecological (e.g. feeding ecology, environmental pollutants) aspects of this species (see Tamura
et al., 2017). The long �me series of data allowed scien�sts to inves�gate and interpret the temporal trend inseveral biological and demographic parameters of the
Antarc�c minke whale in the context of some establishedhypotheses on changes in the Antarc�c ecosystem. Fujise
and Pastene (2021) discussed the historical and current ecosystem changes in the Indo-Paciﬁc sector of the
Antarc�c through the examina�on of the informa�on
on biological and demographical parameters of mainly
Antarc�c minke whales and other whales, which are seabased predators.
Regarding historical changes, Fujise and Pastene (2021)
concluded that the increased krill availability in the middle of the past century as a result of the heavy harves�ngof the larger baleen whale species could have translated
into be�er nutri�onal condi�ons for the Antarc�c minke
whale, resul�ng in a decreasing trend in the age at sexual
maturity and an increasing trend in recruitment rate andhence total popula�on size between approximately 1940
and 1970. Regarding current changes, Fujise and Pastene(2021) concluded that the nutri�onal condi�ons of the
Antarc�c minke whale have deteriorated more recently,
55

Technical Reports of the Ins�tute of Cetacean Research (2023)

as conﬁrmed by a decrease in energy storage and stomach content weight observed since the 1980ʼs. Thesechanges coincide with appreciable increases in the abundance of humpback (Megaptera novaeangliae) and ﬁn(B. physalus) whales, which are also krill-eaters and wereheavily harvested in the ﬁrst half of the past century.
Fujise and Pastene (2021) suggested that the historicalchanges were consistent with the pa�ern to be expectedunder the krill surplus hypothesis and that the mostrecent scenario shows the Antarc�c minke whale again

compe�ng with other (recovering) baleen whale species for krill. Furthermore, these authors suggested that
Antarc�c minke whales could be using alterna�ve feedingareas (e.g. polynyas within the pack-ice) in response to
the increase in abundance and geographical expansion ofother large whale species.
One of the biological parameters discussed in the review by Fujise and Pastene (2021) was the age at sexual
maturity, which is considered a good indicator of changes
in the environment of whales. Previous studies used data

Table 1
Number of Antarc�c minke whales sampled by Japanese surveys in the Antarc�c during 1987/88 to 2018/19, and number of whales
examined for age at transi�on phase (TP).
FemaleSurvey year

Male

n

Number of TP*
determinednNumber of TP*
determinednNumber of TP*
determined

1987/88
1988/89
1989/90
1990/91
1991/92
1992/93
1993/94
1994/95
1995/96
1996/97
1997/98
1998/99
1999/00
2000/01
2001/02
2002/03
2003/04
2004/05
2005/06
2006/07
2007/08
2008/09
2009/102010/112011/122012/132013/142015/162016/172017/18
2018/19

119
151
142
159
123
160
130
130
167
234
159
142
206
182
239
205
240
263
391
351
278
304
269
108
167
53
125
230
178
181
147

41
48
34
56
31
69
32
51
59
137
27
46
77
64
76
80
96
131
156
152
114
129
104
52
82
13
26
103
79
54
44

153
85
184
164
165
167
200
200
273
206
279
247
233
258
201
235
200
177
462
154
273
375
237
62
99
50
125
103
155
152
186

81
18
76
51
52
87
81
106
137
124
119
114
112
136
88
104
68
89
225
75
100
148
87
32
50
16
35
45
69
40
93

272
236
326
323
288
327
330
330
440
440
438
389
439
440
440
440
440
440
853
505
551
679
506
170
266
103
250
333
333
333
333

122
66
110
107
83
156
113
157
196
261
146
160
189
200
164
184
164
220
381
227
214
277
191
84
132
29
61
148
148
94
137

total

5,933

2,263

6,060

2,658

11,993

4,921*TP: age at which transi�on phase layer was formed in the earplug.
56

Total

An update of the study on age at sexual maturity trends in the Antarctic minke whaleand samples collected from 1987/88 to 2010/11 surveys(Bando et al., 2014). Addi�onal samples and data are
available up to the 2018/19 season.
The objec�ve of this study was to update the analysesof the age at sexual maturity of Antarc�c minke whale byusing all the available samples and data. The results ofthese analyses will contribute further to the interpreta�on of current changes in the ecosystem of the IndoPaciﬁc sector of the Antarc�c.

SAMPLES
Biological samples were collected under the surveys of
JARPA (1987/88–2004/05), JARPAII (2005/06–2013/14)
and the New Scien�ﬁc Whale Research Program in the
Antarc�c Ocean (NEWREP-A) (2015/16–2018/19). A totalof 11,993 Antarc�c minke whales were sampled in thewhole period. Previous analyses included samples from1987/88 to 2010/11. The present study included samples
collected from 1987/88 to 2018/19, which incorporates
new samples collected by NEWREP-A surveys. Table 1
shows the number of Antarc�c minke whales sampled
and the number of whales examined for age at transi�onphase, which is considered as the age at sexual maturity(see Bando, 2017 and the next sec�on).

used in the present analysis.
Trunca�on bias
It is known that the age at sexual maturity in recent age
classes will be underes�mated when using the transi�on phase analysis, due to the under-representa�on oflate maturing individuals (Figure 1). This is known as thetrunca�on eﬀect. This can be addressed by combining
samples from diﬀerent year classes (Kato, 1985; Zenitani, 2011). Furthermore, in considera�on of the informa�on in Figure 2, only transi�on phase data for individuals
older than certain ages were used as shown below:
Year classes 1971–1975: 15 years
Year classes 1976–1980: 12 years
Year classes 1981–1985: 12 years
Year classes 1986–1990: 12 years
Year classes 1991–1995: 12 years
Year classes 1996–2000: 12 years
Year classes 2001–2010: 12 years
Data for these age values and older should therefore be
free of trunca�on bias, however the sample size will be
reduced.

ANALYTICAL PROCEDURES
Age at sexual maturity by transi�on phase
The age of baleen whales was es�mated by coun�ng
growth layers accumulated in the earplug (Lockyer, 1984).
The layer at which the spacing changed abruptly from
irregular early younger layers in the earplug is called thetransi�on phase (Lockyer, 1972). It is generally known
that the transi�on phase in earplugs of baleen whales
indicates the age at sexual maturity (Lockyer, 1972).
Therefore, the age at the transi�on layer was recorded, if
it was present, when observing the earplug.
Year of birth
The year of birth (=year class) in each individual was deﬁned as: (star�ng year of an austral survey season, e.g.
1987 in the case of 1987/88 season)−(age at capture).
Evalua�on of age data reading
Age and transi�on phase in earplugs were read by three
diﬀerent readers during the period of study. A test toevaluate the consistency and comparability of reading
among readers was required. Results of the test indicatedthat the data from diﬀerent readers were consistent andcomparable (see details of the test in Bando et al., 2014).
Therefore, the whole data set for the whole period was

Figure 1.

Schema�c illustra�on of the rela�onship between
distribu�on of age at transi�on phase and age at
capture in certain year classes with trunca�on bias(a�er Zenitani, 2011).
57

Technical Reports of the Ins�tute of Cetacean Research (2023)

Figure 2.

58

Distribu�on of age at transi�on phase against age at capture in each year class group. The triangle corresponds to trunca�on bias. Maximum age for trunca�on bias is indicated by the corner of the triangle.

An update of the study on age at sexual maturity trends in the Antarctic minke whale

Figure 3.

Temporal trend of mean age at sexual maturity by a transi�on phase of Antarc�c minke whales by year
class and sex, for the whole area.

A�er considering trunca�on bias, this study used a
total of 4,417 (2,078 females and 2,339 males) age andtransi�on phase data for temporal trend analysis.

y=0.0085x−9.3362 in males (y is mean age at sexual maturity and x is year of birth). In both cases the trend wassta�s�cally signiﬁcant (p<0.05).

Sta�s�cal analysis
Linear regression analysis was applied to examine longterm trends in the age at sexual maturity from the year
in which the trend had stabilized, e.g. 1970ʼs (Bandoet al., 2014). For the sta�s�cal test on trend, p values < 0.05 were considered to be sta�s�cally signiﬁcant.

Temporal trend of sexual maturity by stocks
At least two stocks of Antarc�c minke whales occur in the
Indo-Paciﬁc sector of the Antarc�c (I- and P-stocks) (Pastene and Goto, 2016; Murase et al., 2020). The boundary
between these two stocks is variable and changes by year
and sex (Kitakado et al., 2014). Figure 4 shows the temporal trend of age at sexual maturity for the main areas
occupied by the two stocks, 0°–130°E for the I-stock and165°E–120°W for the P-stock. Table 2 shows the data on
age at sexual maturity by year class, sex and stock.
The regression equa�ons for the recent trend for eachcase in Figure 4 were:

RESULTS
Temporal trend of age at sexual maturity for the wholearea
The analysis involved samples from 4,417 Antarc�cminke whales (2,078 females and 2,339 males) takenfrom 0°–120°W of the Indo-Paciﬁc region, south of 60°S.
The mean age at sexual maturity by year class and sex isshown in Figure 3, and detailed values are available in
Table 2. Age at sexual maturity in the most recent year
class was es�mated to be about 7–9 years old in 2005 forfemales and about 7–9 years old in 2006 for males.
The sta�s�cal examina�on of the trend of age at sexual
maturity from 1970 to 2005 in females and from 1970
to 2006 in males (e.g. recent changes) revealed resultsof interest. The age at sexual maturity increased slightly
for year class a�er the 1970s in both sexes. The regression equa�ons were y=0.0084x−8.8299 for females, andI-stock, female: y = 0.0051x − 2.3859

I-stock, male: y = 0.0113x − 14.8503
P-stock, female: y = 0.0082x − 8.5696
P-stock, Male: y = 0.0019 x +3.7597
The sta�s�cal test for temporal trend indicated that only
the age at sexual maturity for males of the I-stock wassigniﬁcant (p<0.05).

59

Technical Reports of the Ins�tute of Cetacean Research (2023)
Table 2Age at sexual maturity of Antarc�c minke whales derived from a transi�on phase in earplugs by year class, sex and stock.
Year
of
class

0°–120°W as “All area”
Female0°–130°E as “Indian sector”
Male

Female165°E–120°W as “Paciﬁc sector”

Male

Female

Male

Mean

SD

Range

n

Mean

SD

Range

n

Mean

SD

Range

n

Mean

SD

Range

n

Mean

SD

Range

n

Mean

SD

Range

n

1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006

—
—
—
—
—
13.00
—
—
13.00
13.00
13.00
11.00
11.75
11.20
11.33
11.00
11.20
11.00
10.63
11.00
11.00
10.67
10.15
9.50
9.60
9.04
8.92
8.92
8.59
8.53
8.40
8.23
7.95
7.55
7.39
7.22
7.49
7.20
7.42
7.73
7.52
7.63
7.63
7.77
7.91
7.89
7.79
8.19
7.88
7.86
7.92
7.89
7.80
7.63
7.86
7.94
7.91
7.93
7.96
7.56
7.89
7.50
7.81
7.78
7.73
7.90
7.40
8.00
7.64
6.86
8.00
8.25
—

—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
0.83 11–13
0.98 10–12
0.47 11–12
0.00 11–11
1.17 10–13
1.41 9–13
1.22 8–12
0.63 10–12
1.00 9–13
1.05 8–12
0.57 9–11
0.76 8–11
0.92 8–12
0.86 7–11
0.69 8–10
0.81 7–10
0.89 7–10
0.92 6–10
0.88 6–10
0.98 5–10
0.87 6–10
0.85 6–10
0.93 6–9
1.06 5–10
1.40 4–11
0.90 5–9
0.94 6–11
1.24 6–10
1.02 6–10
0.91 6–9
1.14 6–10
1.27 5–10
1.18 5–11
1.07 5–11
1.26 5–11
0.95 6–11
1.00 5–10
1.12 5–11
1.14 5–10
1.18 5–10
1.08 5–10
1.27 5–10
1.13 6–11
1.12 6–10
1.44 5–11
1.09 6–10
1.07 5–10
0.89 5–9
1.05 5–10
1.27 5–10
0.96 6–10
1.07 6–11
1.11 6–10
1.27 6–10
1.36 6–10
0.58 7–9
0.88 6–9
0.83 5–8
1.20 6–9
0.83 7–9
—
—

—
—
—
—
—
1
—
—
1
1
1
1
4
5
3
2
5
4
8
5
12
18
20
12
20
23
25
24
29
34
30
43
37
38
41
36
49
49
60
49
48
40
51
53
55
55
48
53
76
81
64
83
64
54
72
53
44
54
54
52
44
32
26
27
33
21
10
12
11
7
7
4
—

14.00
—
—
11.00
—
12.00
—
11.00
11.00
12.00
11.00
11.17
12.00
11.00
11.67
11.00
11.00
11.00
10.07
10.25
10.13
9.67
9.33
9.59
9.47
8.84
8.76
8.76
8.26
8.50
8.03
7.67
7.48
7.32
7.22
7.18
7.14
7.15
7.16
7.33
7.39
7.48
7.62
7.53
7.85
7.55
7.73
7.63
7.77
7.60
7.65
7.45
7.52
7.64
7.43
7.38
7.70
7.53
7.72
7.27
7.37
7.55
7.79
7.33
7.58
7.47
7.11
8.00
8.09
7.62
7.54
7.50
7.6

—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
0.00 12–12
1.00 10–12
1.21 9–13
0.82 11–13
0.82 10–12
0.47 11–12
1.41 9–12
0.89 10–12
1.10 10–13
2.02 7–15
1.30 8–12
0.96 9–12
1.07 7–11
0.87 8–11
0.97 8–12
0.93 7–12
1.32 6–11
0.97 6–10
0.71 8–10
0.84 6–10
0.92 7–10
0.91 6–10
1.11 5–10
0.91 6–10
1.11 5–10
1.00 5–10
0.92 5–9
1.12 5–10
1.02 5–10
0.95 5–9
0.98 4–10
1.08 5–11
0.95 5–9
1.19 5–10
1.13 5–10
0.84 6–9
1.04 5–9
0.94 5–9
1.06 6–11
0.90 6–10
1.06 5–10
1.14 5–11
1.03 6–10
0.92 5–9
1.26 5–11
1.10 5–10
1.20 5–10
1.05 6–11
0.93 6–10
0.90 5–10
1.12 5–9
0.93 6–9
0.94 6–10
0.77 7–9
1.11 6–10
1.23 5–10
0.99 5–9
0.87 6–9
1.04 6–9
1.16 6–10
1.08 6–10
0.84 6–9
1.50 5–9
0.80 7–9

1
—
—
1
—
1
—
1
1
3
2
6
6
3
3
3
5
10
15
16
15
15
15
17
32
25
29
37
31
44
37
42
62
41
51
49
57
74
68
67
67
71
61
60
52
62
62
63
82
88
71
66
60
78
58
52
47
45
46
45
38
31
19
24
19
19
9
13
11
13
13
4
5

—
—
—
—
—
13.00
—
—
—
13.00
—
—
—
12.00
11.33
11.00
10.50
12.00
10.25
11.33
10.75
9.80
10.29
10.00
9.60
8.57
9.09
8.92
8.73
8.56
8.42
8.48
8.06
7.53
7.21
7.11
7.53
7.22
7.45
7.59
7.53
7.67
7.80
8.25
7.86
7.84
7.95
8.05
8.03
7.85
8.00
8.00
7.81
7.74
7.75
8.21
7.53
8.08
7.83
7.27
7.68
7.36
7.85
8.50
8.11
7.22
7.20
8.00
8.00
7.50
8.00
8.33
—

—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
0.47 11–12——
0.50 10–11
1.00 11–13
1.48 8–12
0.47 11–12
0.43 10–11
1.17 8–11
0.45 10–11
0.82 9–11
0.49 9–10
0.90 7–10
0.79 8–10
0.86 7–10
0.93 7–10
1.00 6–10
0.86 7–10
1.14 5–10
0.87 7–10
1.09 6–10
1.01 6–9
0.94 5–9
1.61 4–10
0.97 5–9
0.80 6–9
1.24 6–10
1.20 6–10
0.79 6–9
1.11 6–9
1.30 6–10
0.91 6–9
1.23 5–11
1.43 5–11
0.64 7–9
1.02 5–10
1.00 6–10
1.02 5–10
1.05 6–10
0.96 6–10
1.29 5–10
0.97 6–10
0.89 7–10
1.53 5–11
1.15 6–10
0.90 7–9
1.01 5–9
1.13 5–10
0.81 6–9
1.10 6–10
1.20 7–11
0.87 7–9
1.13 6–9
1.47 6–10
0.00 8–8——
0.50 7–8
1.00 7–9
0.94 7–9
—
—

—
—
—
—
—
1
—
—
—
1
—
—
—
1
3
1
2
2
4
3
4
5
7
3
5
7
11
12
15
16
12
21
17
17
14
18
17
18
20
17
15
15
15
16
14
19
20
22
30
39
21
36
21
27
40
19
19
24
12
22
19
14
13
10
9
9
5
5
1
2
4
3
—

14.00
—
—
11.00
—
12.00
—
—
11.00
12.00
11.00
10.67
12.00
10.00
12.00
11.00
11.00
10.80
9.89
10.00
10.40
9.60
9.33
9.40
9.37
8.92
8.59
8.72
8.06
8.65
7.94
7.96
7.55
7.30
7.21
6.86
7.00
7.12
7.27
7.20
7.29
7.38
7.81
7.69
8.10
7.48
7.65
7.48
7.88
7.70
7.96
7.46
7.38
7.61
7.57
7.48
7.53
7.33
7.83
7.38
7.31
7.57
7.83
7.64
8.50
7.22
7.25
8.17
8.11
8.00
7.54
7.50
7.60

—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
1.00 10–12
1.25 9–12
0.89 11–13————
1.41 9–12
1.00 10–12
1.17 10–13
2.18 7–15
1.13 8–12
0.92 9–12
1.02 8–11
0.94 8–11
0.66 8–10
1.04 7–12
1.33 6–11
1.14 6–10
0.72 8–10
0.85 6–9
0.96 7–10
0.97 6–9
0.89 6–10
0.94 6–10
1.19 5–10
1.05 5–10
0.74 6–8
1.15 5–9
1.02 6–10
0.93 5–9
1.23 4–10
0.98 5–9
1.03 5–9
1.33 5–10
1.05 5–10
0.77 7–9
1.06 5–9
0.90 6–9
0.93 6–9
0.90 6–10
1.00 5–10
0.98 7–11
1.18 6–10
0.90 5–9
1.28 5–11
1.28 5–10
1.13 5–10
0.92 6–9
0.90 6–9
1.07 5–10
1.11 5–9
0.85 6–9
0.73 6–9
0.90 7–9
0.88 6–9
1.12 7–10
1.13 5–9
0.83 6–9
1.07 6–9
1.29 6–10
1.00 7–10
0.84 6–9
1.50 5–9
0.80 7–9

1
—
—
1
—
1
—
—
1
1
2
3
5
1
1
3
2
5
9
11
10
5
9
10
19
13
17
25
18
23
16
24
31
20
28
14
27
43
33
25
21
34
26
29
20
23
31
29
34
40
24
28
24
33
23
27
30
24
24
24
16
14
6
11
4
9
8
6
9
8
13
4
5

—
—
—
—
—
—
—
—
—
—
13.00
11.00
13.00
12.00
—
11.00
11.67
10.00
10.50
11.00
11.00
11.13
10.50
9.50
9.11
9.18
9.00
8.86
8.33
8.36
8.36
8.00
7.81
7.63
7.55
7.21
7.56
7.26
7.52
7.79
7.46
7.64
7.55
7.52
7.94
7.80
7.74
8.35
7.91
7.91
7.82
7.84
7.63
7.40
7.96
7.83
8.14
7.84
8.06
7.88
8.18
7.56
7.73
7.38
7.58
8.42
7.60
8.00
7.56
6.60
8.00
8.00
—

—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
1.25 10–13
1.00 9–11
0.50 10–11——
0.71 10–12
0.78 10–12
0.50 10–11
0.50 9–10
0.74 8–10
0.72 8–10
0.47 8–10
0.83 8–10
0.75 7–9
0.77 7–9
1.07 6–10
0.69 7–9
0.73 6–9
0.60 7–9
0.89 6–9
1.26 5–10
1.26 6–11
0.85 6–9
1.01 6–11
1.21 6–10
0.89 6–9
1.02 6–9
1.19 6–10
1.16 5–10
1.32 5–11
1.02 6–10
1.25 5–10
1.13 6–11
0.95 6–10
1.11 6–10
1.17 6–10
1.18 5–10
1.07 5–10
1.32 5–10
1.34 6–11
1.34 6–10
1.36 6–10
1.05 6–10
1.20 5–10
0.65 6–9
0.92 7–10
1.46 5–10
0.86 7–9
0.70 6–8
1.15 6–10
1.11 6–10
1.20 6–9
0.76 7–9
0.96 6–9
0.80 5–7
1.41 6–9
—
—
—
—

—
—
—
—
—
—
—
—
—
—
1
1
1
1
—
1
3
2
2
1
4
8
4
6
9
11
9
7
6
11
11
17
16
16
22
14
27
23
31
28
26
22
31
31
33
25
19
23
34
33
34
38
35
20
26
23
21
25
32
25
17
16
11
16
24
12
5
7
9
5
3
1
—

—
—
—
—
—
—
—
—
—
—
—
11.00
12.00
11.00
—
—
10.00
10.67
9.75
12.00
10.00
9.88
9.00
9.67
9.20
8.43
8.83
8.67
8.67
8.08
8.25
7.33
7.53
7.50
7.33
7.17
7.65
7.05
7.26
7.53
7.36
7.67
7.42
7.56
7.59
7.57
8.00
7.81
7.84
7.68
7.34
7.48
7.85
7.57
7.38
7.11
8.07
8.07
7.63
7.08
7.25
7.78
7.75
7.17
7.36
7.78
6.00
7.86
8.00
7.00
—
—
—

—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
0.94
1.48
—
0.82
0.60
0.82
1.70
0.75
1.50
0.69
0.75
0.47
0.86
0.66
1.25
0.88
1.12
1.11
0.90
1.13
0.97
0.96
0.72
1.11
0.77
0.95
1.12
0.84
0.94
0.62
1.26
0.83
1.07
1.21
0.94
0.79
1.12
0.90
1.15
1.24
0.85
0.70
1.14
0.90
1.23
0.72
1.21
0.98
0.79
—
0.99
0.00
0.89
—
—
—

—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
10–12
8–12
—
9–11
9–11
8–10
8–12
8–10
6–11
8–10
8–10
8–9
7–9
7–9
5–9
6–9
6–9
6–10
5–9
6–10
5–9
6–9
6–9
6–11
6–9
6–9
5–10
6–9
6–9
7–9
6–11
6–10
6–10
5–9
6–9
6–9
5–11
6–9
5–9
6–11
7–10
6–9
5–9
6–9
6–10
7–9
6–10
6–9
7–9
—
6–9
8–8
6–8
—
—
—

—
—
—
—
—
—
—
—
—
—
—
1
1
1
—
—
1
3
4
1
3
8
3
3
5
7
6
6
6
12
8
9
15
14
12
18
17
20
19
30
28
27
24
18
17
28
21
21
32
28
29
25
20
30
21
18
15
15
16
13
16
9
12
12
11
9
1
7
2
5
—
—
—

total

8.00

1.31 4–13

2,078

7.78

1.30 4–15

2,339

8.01

1.29 4–13

814

7.85

1.35 4–15

1,118

7.93

1.27 5–13

975

7.69

1.15 5–1276360

An update of the study on age at sexual maturity trends in the Antarctic minke whale

Figure 4.

Temporal trend of sexual maturity by transi�on phase of Antarc�c minke whales by year class, sex andstock (le�: I-stock; right: P-stock).

SUMMAY AND INTERPRETATION OF RESULTS
The previous study by Bando et al. (2014) examined theage at sexual maturity (based on a transi�on phase) un�lthe 1998ʼs year class. This study updated the analyses
by examining seven addi�onal year classes (1999–2006).
The updated analyses conﬁrmed that the age at sexual
maturity of this species declined from 10–12 years old in
the mid-1940s year classes to 7–8 years old in the early
1970s year classes, and that has remained stable at thatlevel �ll the 2000s year classes. There were no substan�aldiﬀerences when the analyses were conducted by stock.
Although some signiﬁcant sta�s�cal trends were found
for the recent year classes (from the 1970ʼs), the extent
of such changes, when conﬁrmed, is very small in comparison with the extent of the changes observed in the
middle of the past century. In general, the age at sexual
maturity in recent year classes (from the 1970ʼs) has remained stable at around 7–9 years old.
The results of stable age at sexual maturity in this study
should be examined in conjunc�on with the informa�on on recent trends in other biological and ecologicalaspects. In recent years the Antarc�c minke whale has
maintained a high apparent pregnancy rate of over 90%(Bando et al., 2006); the recruitment es�mated by Sta�s�cal Catch-At-Age (SCAA) analysis has not increased
and has remained somewhat constant at a level that is
not as high as that observed between 1940 and 1970
(Punt et al., 2014); and a decrease in blubber thickness
and average stomach contents weight has been reported(blubber thickness: Konishi et al., 2008; stomach contents: Konishi et al., 2014). In addi�on, Antarc�c minke
whales have been observed in polynyas in recent years
while an increase in the abundance of other large whale
species has been reported (e.g. humpback whale: Haka-

mada and Matsuoka, 2014; ﬁn whale: Matsuoka andHakamada, 2014). These results are consistent with thefollowing two hypotheses:
Hypothesis 1: interspeciﬁc compe��on for krill resources
Under this hypothesis, the deteriora�ng nutri�onal condi�ons of the Antarc�c minke whale are a consequenceof limited krill availability, which in turn is due to theincrease in the abundance of other krill-eater whale species. The distribu�on of Antarc�c minke whales in polynyas is part of this hypothesis as the increasing abundance(and expanded distribu�on) of other large whale species
has pushed the Antarc�c minke whale to ﬁnd other areas
for feeding. The observa�ons that the recruitment has
not increased in recent years and remaining somewhat
constant at a level but not as high as that observed
between 1940 and 1970, and that the abundance ofAntarc�c minke whale has remained constant/slightly
decreased are consistent with this hypothesis. The apparent contradic�on between low age at sexual maturity/high pregnancy rates and current recruitment rates are
due to a temporal phenomenon in which the responseof biological parameters to environmental changes (foodlimita�on) may be subjected to �me lags (Bjerke and Walløe, in press).
Hypothesis 2: the environmental condi�ons for Antarc�cminke whale remain op�mal
Low age at sexual maturity and high pregnancy rates are
consistent with this hypothesis. Although the nutri�onal
condi�ons have deteriorated slightly, such condi�ons are
not cri�cal for the popula�on. The observa�ons that therecruitment has not increased and has remained somewhat constant at a level but not as high as that observed
61

Technical Reports of the Ins�tute of Cetacean Research (2023)

between 1940 and 1970, and that the abundance trends
have remained constant are a reﬂec�on of the constraintsof the surveys, which cannot cover new areas of distribu�on of the Antarc�c minke whale such as the polynyas.
Colonizing of new areas by the Antarc�c minke whale has
been facilitated by environmental changes such as theincrease of surface temperature, which are opening newroutes into the pack ice.
Further monitoring of biological and ecological parameters of the Antarc�c minke whale is required to discern
between the two proposed hypotheses. Also, addi�onal
analy�cal procedures are required. For example, in thecase of the age at sexual maturity based on transi�onphase, model-based analysis (e.g. Thomson et al., 1999),
should be used in the future to further address the trunca�on bias and the fringe eﬀect of age data at the transi�on phase in earplugs.

ACKNOWLEDGEMENTS
We are grateful to all the researchers and crews whocollected data and samples during the JARPA, JARPAII
and NEWREP-A surveys. We thank the members of theIns�tute of Cetacean Research (ICR) for their useful sugges�ons and assistance in the laboratory work. We also
thank Luis A. Pastene (ICR) for his assistance in preparing
this report, and the Editorial Team of TEREP-ICR for editorial work.

REFERENCES
Bando, T. 2017. Laboratory and analy�cal approaches to es�mate biological parameters in the Antarc�c minke whaleand summary of results. Technical Reports of the Institute of
Cetacean Research (TEREP-ICR) No. 1: 22–27.
Bando, T., Zenitani, R., Fujise, Y., Hakamada, T. and Kato, H. 2006.
Biological parameters of the Antarc�c minke whale basedon materials collected by the JARPA survey in 1987/88 to
2004/05. Paper SC/D06/J17 presented to the Intersessional
Workshop to Review Data and Results from Special Permit
Research on Minke Whales in the Antarc�c, December 2006
(unpublished). 28 pp. [Available from the IWC Secretariat].
Bando, T., Kishiro, T. and Kato, H. 2014. Yearly trend in the age atsexual maturity of Antarc�c minke whales examined by transi�on phase in earplugs collected during JARPA and JARPAII
surveys. Paper SC/F14/J08 presented to the Expert Workshop
to Review the Japanese JARPAII Special Permit Research
programme, February 2014 (unpublished). 10 pp. [Available
from the IWC Secretariat].
Bjerke, S-M.H. and Walløe, L. (in press). Natural regula�onof popula�on size in large mammals by means of delayed
density-dependent fer�lity mechanisms—a model study. J.
Integrative Zoology.

62

Fujise, Y. and Pastene, L.A. 2021. Whales as indicators of historical and current changes in the marine ecosystem of
the Indo-Paciﬁc sector of the Antarc�c. pp. 85–103. In: M.
Kanao, D. Godone and N. Dema�eis (eds.). Glaciers and Polar
Environment. IntechOpen, London. 200 pp.
Hakamada, T. and Matsuoka, K. 2014. Es�mates of abundance
and abundance trend of the humpback whale in Areas
IIIE-VIW, south of 60°S, based on JARPA and JARPAII sighting data (1989/90–2008/09). Paper SC/F14/J04 presented
to the Expert Workshop to Review the Japanese JARPAII
Special Permit Research Programme, February 2014. 36 pp.
[Available from the IWC Secretariat].
Kato, H. 1985. Further examina�on of the age sexual maturity of
the Antarc�c minke whale as determined from earplug studies. Rep. int. Whal. Commn 35: 273–277.
Kitakado, T., Schweder, T., Kanda, N., Pastene, L.A. and Walløe,
L. 2014. Dynamic popula�on segrega�on by gene�cs andmorphometrics in Antarc�c minke whales. Paper SC/F14/
J29rev presented to the IWC Scien�ﬁc Commi�ee, May 2014
(unpublished). 25 pp. [Available from the IWC Secretariat].
Konishi, K., Tamura, T., Zenitani, R., Bando, T., Kato, H. andWalløe, L. 2008. Decline in energy storage in the Antarc�cminke whale Balaenoptera bonaerensis in Southern Ocean.
Polar Biol 31: 1509–1520.
Konishi, K., Hakamada, T., Kiwada, H., Kitakado, T. and Walløe,
L. 2014. Decline in stomach contents in the Antarc�c minke
whale (Balaenoptera bonaerensis) in the Southern Ocean.
Polar Biol 37: 205–215.
Lockyer, C. 1972. The age at sexual maturity of southern ﬁnwhale (Balaenoptera physalus) using annual layer counts inthe earplug. ICES Journal of Marine Science 34 (2): 276–294.
Lockyer, C. 1984. Review of baleen whale (Mys�ce�) reproduc�on and implica�ons for management. Rep. int. Whal.
Commn (special issue) 6: 27–50.
Matsuoka, K. and Hakamada, T. 2014. Es�mates of abundance
and abundance trend of the blue, ﬁn and southern rightwhales in the Antarc�c Areas IIIE-VIW, south of 60°S, basedon JARPA and JARPAII sigh�ng data (1989/90–2008/09). Paper
SC/F14/J05 presented to the Expert Workshop to Review
the Japanese JARPAII Special Permit Research Programme,
February 2014. 36 pp. [Available from the IWC Secretariat].
Pastene, L.A. and Goto, M. 2016. Gene�c characteriza�on andpopula�on gene�c structure of the Antarc�c minke whale
Balaenoptera bonaerensis in the Indo-Paciﬁc region of theSouthern Ocean. Fish Sci 82 (6): 873–886.
Punt, A.E., Hakamada, T., Bando, T. and Kitkado, T. 2014.
Assessment of Antarc�c minke whales using Sta�s�cal
Catch-at-age Analysis (SCAA). J. Cetacean Res. Manage. 14:
93–116.
Tamura, T., Matsuoka, K. and Pastene, L.A. 2017. An overview
of the research programs on large whales conducted by
the Ins�tute of Cetacean Research. Technical Reports of theInstitute of Cetacean Research (TEREP-ICR) No. 1: 1–14.

An update of the study on age at sexual maturity trends in the Antarctic minke whaleThomson, R.B., Bu�erworth, D.S. and Kato, H. 1999. Has theage at transi�on of Southern Hemisphere minke whales declined over recent decades? Marine Mammal Science 15 (3):661–682.

Zenitani, R. 2011. Long-term changes in the age of sexual maturity in Antarc�c minke whales and their ecological analysis.
Doctoral thesis, Tokyo University of Marine Science andTechnology. 118 pp. (in Japanese).

63Technical Reports of the Ins�tute of Cetacean Research (2023)

pp. 64–68

Technical Report (not peer reviewed)

U�lity of data logging for the es�ma�on of availability bias in sigh�ng
surveys
Taiki Katsumata*, Tatsuya Isoda and Koji Matsuoka
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: katsumata@cetacean.jp

ABSTRACTThis paper describes the progress of the work by the Ins�tute of Cetacean Research on satellite-based data
logging experiments conducted with the aim of obtaining diving and surfacing dura�on data of the Antarc�cminke whale for es�ma�ng availability bias. The paper is organized to provide informa�on on ﬁeld equipment
for tagging, the data obtained on Antarc�c minke whale and results of preliminary es�ma�on of availability
bias. Tags were successfully a�ached to Antarc�c minke whales, and some diving and surfacing dura�on data
were obtained. Based on these data, es�mates of availability bias are presented. However, such es�matesshould be considered as preliminary and further experiments to obtain addi�onal behavioral data are recommended.

INTRODUCTION

FIELD EQUIPMENT FOR TAGGING EXPERIMENTS

Abundance es�mates of whales based on sigh�ng data
and the distance sampling method are aﬀected by anega�ve bias called ʻavailability biasʼ (McLaren, 1961;
Marsh and Sinclair, 1989). To address this point, Laakeet al. (1997), Okamura et al. (2012) and Borchers et al.
(2013) presented analy�cal methods that used whale diving and surfacing dura�on data to correct for availability
bias. These studies were based on diving and surfacing
dura�on data from visual observa�ons or from archival
tags. However, visual observa�on is not ideal for obtaining data on diving and surfacing behavior par�cularly inelusive species such as the Antarc�c minke whale. Also,
retrieving archival tags over several days while conducting the sigh�ng survey is not a prac�cal approach.
Satellite tagging provides a new and useful alterna�ve
to in obtaining data on diving and surfacing behavior.
Satellite tags were deployed on Antarc�c minke whales
during the 2021/22 and 2022/23 Japanese Antarc�c
Sigh�ng and Stock structure Survey (JASS-A) surveys witha par�cular aim to obtain diving and surfacing dura�ondata. Such data could be used to es�mate availability bias
following some of the methods indicated above.
This paper brieﬂy reports the details of ﬁeld equipment
for tagging, the data obtained on the Antarc�c minke
whale and the results of preliminary es�ma�on of availability bias.

The following equipment was used in the tagging experiment:– Satellite tags (SPLASH10-f-333, Wildlife Computers,US) in the Low-Impact Minimally Percutaneous External electronics Tag (LIMPET) with two 6.8 cm darts
and six petals;– Aerial Rocket Transmi�er System (LK-ARTS, Skutvik,
Norway); and– Deployment arrows (originally developed by Wildlife
Computers and modiﬁed by the Ins�tute of Cetacean
Research [ICR]) (Figure 1).
The deployment arrows and tag were a�ached using
adhesive (Aron Alpha Jelly, TOAGOSEI Co., LTD., Japan).
The tags were shot from the bow deck (8 m above thesea) using an LK-ARTS, with air pressure set at 14 bar. The
video of the experiment in the Antarc�c Ocean can beseen at the following URL: h�ps://www.youtube.com/
watch?v=_wlSpleQEM8.
The SPLASH 10-f-333 can be conﬁgured to deﬁne speciﬁc ranges of diving and the types of data sought using
the so�ware Mk10 Host (Wildlife Computers, 2023). Datasuch as the maximum depth of each dive and the dura�on of diving and surfacing are received, rather than afull-resolu�on diving behavior.
In this study, the tags were conﬁgured to provide data
for each diving and surfacing event as behavior message.
A whale was considered diving when it penetrated deeper

64

Utility of data logging for the estimation of availability bias in sighting surveys

Figure 1.

Equipment for satellite tagging: the satellite tags (SPLASH10-f-333) and the cup of the deployment arrow(a); original arrows developed by Wildlife Computers for a crossbow (b); and aerial rocket transmi�er system (LK-ARTS) (c).

Figure 3. Antarc�c minke whale with a SPLASH10-f-333 tag attached on 2 February 2022, at 71°16ʹS, 132°10ʹW. The
red circle indicates the a�ached posi�on of the tag.

Figure 2.

Mote Enclosure mounted on the upper bridge(upper le�), and Yagi and omnidirec�onal antenna
mounted on the top barrel of the research vessel(upper right). By connec�ng an USB memory s�ck
to the Mote Enclosure, the data received by theantenna can be retrieved (the retrieved data must
be decoded by Wildlife Computers portal).

than 4 m. The start and end of the recording were basedon a depth of 1 m, and the sampling interval was one
second. The percentages of �me spent in arbitrary depthbins (0; 1; 3; 5; 10; 30; 50; 100; 150; 200; 250; 300; 400;
>400 m) were obtained, and the diving dura�on bins (10;20; 30; 40; 50 sec; 1; 2; 3; 4; 5; 10; 15; 20; >20 min) wererecorded 12 �mes a day at two-hour intervals star�ng at
00:00 UTC. Tags were programmed to transmit 24 hours a
day and were limited to 3,000 transmissions per day.

Mote (Wildlife Computers, US) is a sta�onary listening sta�on and can con�nuously log telemetry datafrom satellite tags on animals within the recep�on range(Jeanniard-du-Dot et al., 2017). Mote was installed on
the research vessel (Yushin-Maru No. 2, YS2), and Yagi
and omnidirec�onal antenna were equipped on the
top barrel (approximately 20 m above the sea level)(Figure 2). The Yagi antenna has direc�vity and about a
60° beamwidth within which distant signals (about 8.5
nau�cal miles when placed at 20 meters) were received.
The omnidirec�onal antenna can receive signals from all
direc�ons, but the distance will be shorter.

DATA OBTAINEDIn the 2021/22 JASS-A survey, two Antarc�c minke
whales were tagged. Figure 3 shows the tag a�ached to
the whaleʼs body (PTT 207827). The vessel tracked this65Technical Reports of the Ins�tute of Cetacean Research (2023)
Table 1
Details of diving and surfacing dura�on data of an Antarc�c minke whale tagged in the 2021/22 JASS-A survey. Data obtained from 6
February 00:01:00 (UTC) to 17 February 13:33:24 (UTC) 2022.
PTT ID

Number of days withdata obtained

Type

n

dura�on mean
(sec)

SD

Dura�on min(sec)

Dura�on max(sec)

Dura�on range(sec)

207827

11.6

Dive
Surfacing50
50

196.5239.12

145.91
65.55

6
2

680
348

674
346

Figure 4.

Percentage of behavioral data recorded by satelliteand Mote from an Antarc�c minke whale tagged in
the 2022/23 JASS-A survey.

was tracked on 18 January 2023, from 11:13 to 13:40(UTC+ 14 hours) and data were received via Mote. There
were 35 dives recorded during the tracking. Of these, 30
dives were recorded by the Mote, indica�ng its usefulness (Figure 4). The �me dura�on of the a�ached tag on
the water surface may be too short to transmit behavior
messages to a satellite.
The Mote is suited for acquiring a large amount of dataand can obtain each diving and surfacing dura�on of awhale, which is challenging to collect by satellite alone.
Figure 5 shows the diving behavior of the same whale
recorded for 60 minutes a�er the tag was a�ached. The
�me period during which data could not be received,
even when the Mote was running, suggests that it is par�cularly diﬃcult to receive data from this species.

ESTIMATION OF AVAILABILITY BIAS

Figure 5.

The diving behavior of an Antarc�c minke whale(PTT 224705) tagged during the 2022/23, and recorded for 60 min a�er tag a�achment. This whale
repeatedly dived at depths shallower than 15 m.
There were periods when data was not received
even while the Mote was tracking the individual.

individual and stayed more than 0.5 n.miles away fromthe whale during the tracking. During the tracking diving and surfacing dura�on data were received via Mote
consecu�vely for 26 min, but no data were received via
satellite. The diving and surfacing dura�on of this whale
are summarized in Table 1. Although the tag was a�achedto the whale for more than 10 days, only 50 dives wererecorded in total. This is possibly because the tag was not
suﬃciently out of the water and the signal was weak.
In the 2022/23 survey, two Antarc�c minke whales weresuccessfully tagged. Antarc�c minke whale (PTT 224705)
66

Table 2 summarizes the Antarc�c minke whaleʼs diving
and surfacing dura�on data (PTT 224705) obtained during the 2022/23 JASS-A survey. Using the values of surfacing dura�on of 4.54 s and diving dura�on of 60.03 s, apreliminary es�ma�on of availability bias was conductedbased on the rela�vely simple method of Laake et al.
(1997) under the following two survey cases: the ﬁrst
case is the ICR's vessel-based visual survey (see Isoda
et al., 2020), and the second is the ICR's planned UAVbased aerial survey (see Matsuoka and Yoshida, 2021;
Katsumata and Yoshida, 2023).
Laake et al. (1997)ʼs formula to es�mate availability
bias is: t ( ymax ) E (d ) 1 − exp −E (s) E (d ) +a=
E ( s ) + E (d )E ( s) + E (d )where a is the probability of a single whale being available on the transect line, E(s) is the mean dura�on of
surfacing, E(d) is the mean dura�on of diving, and t(ymax)
is the amount of �me the ocean is in the observerʼs viewon the transect line.

Utility of data logging for the estimation of availability bias in sighting surveys
Table 2
Details of diving and surfacing dura�on from behavior messages on an Antarc�c minke whale in the 2022/23 JASS-A cruise. Data wereobtained from January 18, 2023, 11:13:24 (UTC+14h) to 13:40:09 (UTC+14h).
PTT IDTypen

Dura�on
mean
(sec)

SD

Dura�onmin(sec)

Dura�onmax(sec)

Dura�on
range
(sec)

224705

Dive
Surfacing

35
35

60.03
4.54

37.54
1.79

1
2

162
12

161
10

Case 1: Vessel-based visual survey
Here it is assumed that the survey speed is 11.5 knots (approx. 21 km/h) and that an Antarc�c minke whale can besighted up to 2 n.miles ahead. Under these assump�ons,
the value of t (ymax) is 626.1 seconds; that of a is 1.00. Thissuggests that there are no missing Antarc�c minke whalein the vessel-based survey due to diving.
Case2: UAV-based aerial survey
Here it is assumed that the survey speed is 43 knots(approx. 80 km/h), and that the UAV ﬂies at an al�tude
at 100 m above the sea and that the camera captures arange 0.1 n.miles directly below the aircra�. Under theseassump�ons the value of t(ymax) is 8.4 seconds; that of
a is 0.19. This suggests that more than 80% of Antarc�cminke whales are not sighted due to diving.

DISCUSSION
This study presented the results of the ﬁrst tagging experiment using SPLASH10-f-333 on Antarc�c minke whales
during Japanese whale surveys in the Antarc�c. Tags werea�ached and data were obtained. Thus, this ﬁrst a�empt
can be considered successful. This approach proved to be
useful to obtain diving and surfacing dura�on data froman elusive species as is the case with the Antarc�c minke
whale. However, a data gap was observed in the behavior
message even while Mote was ac�ve (Figure 5). In thecase of animals that repeatedly make short diving, it ispossible that too many behavior messages were created
and transmi�ed. Since SPLASH10-f-333 can set the diving
deﬁni�on and types of data produced in a ﬂexible way,
it is important to set it to a conﬁgura�on that maximizes
the data collec�on relevant to the es�ma�on of availability bias.
Laake's method has been applied to vessel-based visual surveys previously (e.g. Weir et al., 2021). However,this method assumes that whales above the sea surface
will always be sighted regardless of forward distance.
However, the Antarc�c minke whale has small blows
and some�mes only the body is visible. Therefore, theassump�on that these whales are always sighted up to

2 n.miles ahead is unlikely to be met. As a consequence,
availability bias could be overes�mated with this method,
leading to an underes�ma�on of abundance es�ma�on.
As for the vessel-based visual survey, the detec�on probability should be considered for the forward distance, as
was described in Borchers et al. (2013).
For the aerial survey, the value a 0.19 is consideredreasonable, because it is similar to Hansen et al. (2018),
which es�mates availability bias on aerial surveys using
Laakeʼs method for common minke whales in the North
Atlan�c Ocean. However, in the case of the aerial survey,
the availability bias changes depending on the depth towhich whales can be detected. The data in this study assumed that it can be detected when shallower than one
meter, but this assump�on also needs to be examined in
the future. In both cases, the sample size of the diving
and surfacing dura�on is s�ll small, so it is necessary toaccumulate more data to accurately correct the availability bias of abundance es�mates using the distancesampling method.
In the 2022/23 JASS-A surveys, one ﬁn whale and two
humpback whales were successfully tagged and data on
diving and surfacing dura�on were obtained. These data
will be used to es�mate the availability bias for these species in the near future.

ACKNOWLEDGEMENTS
We acknowledge Yong Huang (Enfotran Corpora�on) and
Kevin Lay (Wildlife Computers) for their technical advice
regarding the tagging of the SPLASH10-f-333, Mote, andrelated data processing. We also acknowledge Hiroto Murase (Tokyo University of Marine Science and Technology)
for his advice on opera�ng SPLASH10-f-333 and installing
Mote on the JASS-A cruise. We appreciate Yoshihiro Fujise and Takashi Hakamada (ICR) for suppor�ng the experiments and the preliminary analysis. We thank Captains
Hidenori Kasai and Nobuo Abe, and their crew members,
and the researchers who par�cipated in the 2021/22 and2022/23 JASS-A surveys for their eﬀort in the tagging
experiment. We are grateful to Luis A. Pastene (ICR) for
his assistance in preparing this report and to the Editorial
67

Technical Reports of the Ins�tute of Cetacean Research (2023)

Team of TEREP-ICR for editorial work.

REFERENCES
Borchers, D.L., Zucchini, W., Heide-Jorgensen, M.P., Canadas, A.
and Langrock, R. 2013. Using hidden Markov models to deal
with availability bias on line transect surveys. Biometrics 69:
703–713.
Isoda, T., Katsumata, T., Tamura, T., Matsuoka, K. and Pastene,
L.A. 2020. An outline of the Japanese Abundance and Stockstructure Surveys in the Antarc�c (JASS-A) including results of
the ﬁrst survey under this new research program. Technical
Reports of the Institute of Cetacean Research (TEREP-ICR) No.
4: 12–22.
Hansen, R.G., Boye, T.K., Larsen, R.S., Nielsen, N.H., Tervo, O.,
Nielsen, R.D., Rasmussen, M.H., Sinding, M.H.S. and HeideJørgensen, M.P. 2018. Abundance of Whales in West and East
Greenland in Summer 2015. NAMMCO Scientiﬁc Publications
11.
Jeanniard-du-Dot, T., Holland, K., Schorr, G.S. and Vo, D. 2017.
Motes enhance data recovery from satellite-relayed biologgers and can facilitate collabora�ve research into marine
habitat u�liza�on. Anim. Biotelemetry 5 (1): 1–15.
Katsumata, T. and Yoshida, T. 2023. Development progress of along-range ver�cal takeoﬀ and landing UAV for the improvement of ship-based cetacean sigh�ng surveys. Cetacean
Population Studies 4: 45–47.

68

Laake, J.L., Calambokidis, J.C., Osmek, S.D. and Rugh, D.J. 1997.
Probability of detec�ng harbor porpoise from aerial surveys:
es�ma�ng g(0). Journal of Wildlife Management 61: 63–75.
Matsuoka, K. and Yoshida, T. 2021. Development of an
Unmanned Aerial Vehicle (UAV) and u�lity for the research
work of the Ins�tute of Cetacean Research. Technical Reportsof the Institute of Cetacean Research (TEREP-ICR) No. 5:
64–67.
Marsh, H. and Sinclair, D.F. 1989. Correc�ng for visibility bias
in strip transect aerial surveys of aqua�c fauna. Journal of
Wildlife Management 53: 1017–1024.
McLaren, I.A. 1961. Methods of determining the numbers andavailability of ringed seals in the eastern Canadian Arc�c.
Arctic 14 (3): 162–175.
Okamura, H., Minamikawa, S., Skaug, H.J. and Kishiro, T. 2012.
Abundance es�ma�on of long-diving animals using line transect methods. Biometrics 68: 504–513.
Weir, C.R., Taylor, M., Jelbes, P.A.Q., Stanworth, A. andHammond, P.S. 2021. Distribu�on and abundance of sei
whales oﬀ the west coast of the Falkland Islands. Marine
Mammal Science 37 (3): 919–933.
Wildlife Computers. 2023. SPLASH10 (-F, -BF, -FL, -X, -L, -LX,
-FX) TDR10 (-F, -BF, -X, -L, FL, -FX, -LX, -BX) with host version
1.26.3002 User Guide (v.202306). 70 pp. h�ps://sta�c.wildlifecomputers.com/SPLASH10-TDR10-User-Guide-3.pdf.

Technical Reports of the Ins�tute of Cetacean Research (2023)

pp. 69–73

Technical Report (not peer reviewed)

Using satellite-linked tags for studying the feeding ecology of ﬁnwhales in the southern Okhotsk Sea
Kenji Konishi1, * and Lars Kleivane2
12

Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, JapanLKARTS-Norway, 8290 Skutvik, Norway*Contact e-mail: konishi@cetacean.jp

ABSTRACTThis paper reports the tagging of satellite transmi�ers on ﬁn whales in the southern Okhotsk Sea to simultaneously collect data on their diving and movement behaviors during the spring season. This informa�on isessen�al for understanding the feeding ecology of the species. Transdermal and LIMPET-type tags (a�ached tothe ﬁn with anchors) were deployed using a whale-watching boat in spring 2021 and 2022, and two ﬁn whales(one tagged with transdermal and the other with LIMPET) were tracked for 40 and 50 days, respec�vely. The
transdermal tag was deployed with a newly developed tether-type carrier using a pneuma�c air launcher,while the LIMPET tag was deployed with a crossbow. The tracking data revealed that ﬁn whales repeat foraging
in waters shallower than 150 m. This marks the ﬁrst instance of tagging a TDR-installed satellite transmi�er by
the Ins�tute of Cetacean Research.

INTRODUCTION
Understanding the ecology of large whales has beenchallenging owing to their massive size and oﬀshore
distribu�on. In par�cular, informa�on about their longrange movement and diving proﬁles, important forunderstanding their feeding habits, has been diﬃcult
to obtain through tradi�onal techniques such as vessel
observa�ons.
The development of satellite-linked tags has maderemarkable progress in studying the spa�o-temporal distribu�on and diving behavior of baleen whales without
recovering the tags (Ainley et al., 2020; Andrews et al.,2019; Heide-Jørgensen et al., 2001; Mate et al., 2007;
Palacios et al., 2022). These electronic tags can monitor
whale behavior over �me and transmit data via satellite
systems. Tracking records are also valuable for deciphering the mechanisms behind whale distribu�on in speciﬁc
ecosystems, helping us to understand their movement
and feeding behaviors.
The Ins�tute of Cetacean Research (ICR) has been planning satellite-linked biologging experiments since 2015 aspart of the surveys conducted under NEWREP-A (the New
Scien�ﬁc Whale Research Program in the Antarc�c Ocean;h�ps://www.jfa.maﬀ.go.jp/j/whale/pdf/151127newrep-a.
pdf). These experiments aim to gain insights into the feeding
behavior and movements of Antarc�c baleen whales. This

non-lethal technique was developed in collabora�on witha Norwegian tagging specialist and has been u�lized in ICR
surveys in both the Antarc�c and western North Paciﬁc.
For successful tracking of whales, the development oftags and suitable tagging equipment is crucial. This paper
provides technical insights into tagging experiments designed to monitor the concurrent movement and diving
behavior of ﬁn whales (Balaenoptera physalus) in thesouthern Okhotsk Sea during the spring season, with theobjec�ve of enhancing our understanding of their feeding
behavior in this region.

MATERIALS AND METHODS
Tags
Streamlining the deployment procedure and tag arrangement for each whale species and survey pla�orms is acri�cal aspect for ensuring successful deployments andtracking. In our eﬀorts, we tested a transdermal tag, designed for large whales, with a tether-type carrier using
the pneuma�c air launcher ARTS (Kleivane et al., 2022).
Addi�onally, we introduced the LIMPET-type tag from
Wildlife Computers Inc., a compact tag that can be deployed on the dorsal ﬁn with two anchors inserted into
the whaleʼs body to stabilize the transmi�er. These tags
enable tracking of whales over an extended period compared to recovery-type tags, which usually capture a large
volume of data but over rela�vely short period (Cade69Technical Reports of the Ins�tute of Cetacean Research (2023)

Figure 3.
Figure 1.

Figure 2.

Research area for the satellite tagging experiments.
Tagging was conducted in the area within 40 nau�cal miles of Abashiri port in the southern Sea of
Okhotsk.

Whale-watching boat “Chipashiri” (4.9 t; 10.45 m).
A safety fence was installed at the bow during thesurvey. The height of bow deck is 130 cm from thewater.

et al., 2023; Friedlaender et al., 2013; Savoca et al., 2021).
Survey area and boat
The tagging experiments took place oﬀ the coastof Abashiri, Hokkaido, in the southern Okhotsk Sea(Figure 1). Recently, ﬁn whales have been observed in
the vicinity of the Abashiri area, enabling us to conduct
experiments using a small boat that can closely approach
the whales. We u�lized the vessel “Chipashiri” (10.45 m)
70

Simultaneous shoo�ngs of a tag with ARTSTBC using
LK-ARTS (le�) and a biopsy dart with a crossbow on
the bow of a boat, Chipashiri.

for these tagging experiments and made prepara�ons
for safety, including the installa�on of a safety fence anda small deck at the bow of the boat during the survey(Figure 2). Two highly skilled crew members with exper�se in spo�ng and approaching marine mammals were
present. In most instances, two shooters were responsible for tagging and conduc�ng biopsy sampling within
the conﬁnes of the safety fence (Figure 3).
Tags and equipment
We deployed two types of tags—a transdermal tag
SPLASH10-302B (300 ∗ 24 mm; 390 g) and a ﬁn mount
LIMPET (Low Impact Minimally Percutaneous Electronic
Transmi�er) tag SPLASH10-F-333 (56 ∗ 50 ∗ 27 mm; 69 g)(Wildlife Computers; Redmond, WA, USA)—on adultsized ﬁn whales during the spring feeding season. The
former tag has a long ba�ery life and is larger, while
the la�er is a compact GPS posi�oning LIMPET tag withanchors designed to be a�ached to the dorsal ﬁn (www.
wildlifecomputers.com). All experiments oﬀ Abashiri
were approved by Fisheries Agency of Japan under thepermit SUIKAN3-367.
Tagging results
Case1 (transdermal tag SPLASH10-302B)
To launch the transdermal tags, we u�lized a carrier
known as ARTSTBC (the tethered ARTS carrier for Wildlife Computer tags in the 300 series, with simultaneous biopsy sampling), which was developed during the
project (LKARTS-Norway; Figure 4). During the carrierʼsdevelopment, numerous tests were conducted in both
Norway and Japan to enhance deployment procedures
and address safety concerns (Figure 5 and 6). A tag was

Using satellite-linked tags for studying the feeding ecology of fin whales in the southern Okhotsk Sea

Figure 4.

Wildlife Computers SPOT303 SPLASH302B-type tag
connected to ARTSTBC.

Figure 6.

Figure 5.

Test shoo�ng of a dummy tag with ARTSTBC in
Norway.

Test of releasing tag from ARTSTBC in the manufacturerʼs laboratory in Japan.

Figure 7.

Transdermal SPLASH10-302B (Wildlife Computers Inc.) tag was deployed at the base of the dorsal ﬁn oﬀ
the coast of Abashiri on May 20, 2021. This picture was taken by a drone.

deployed on a ﬁn whale on 20 May 2021, and trackedun�l 30 June, covering a period of 40 days (Figure 7).
The shoo�ng angle was set at 20 degree with a distanceof 20 m. The ARTS pressure used was 16 bar, and the tag
penetrated to a depth of 4–5 cm anterior to the triangle
stopper. The ARTSTBC was released upon impact during deployment and subsequently recovered. This 2021
deployment marks the ﬁrst use of TDR-installed satellitelinked tags for monitoring loca�on and diving behavior at
the ICR.
Case2 (LIMPET-type SPLASH10-F-333)
To deploy the LIMPET tag, we employed a combina�on of
a 150lb compound crossbow and an arrow-type carrier(Figure 8). These anchors are designed to a�ach securely
to hard ﬁbrous �ssues, such as the dorsal ﬁn. The LIMPET

Figure 8.

A set of SPLASH10-F-333 and its carrier are designed for a crossbow manufactured by Wildlife
Computers.

tag was placed beneath the dorsal ﬁn of the ﬁn whale on
May 10, 2022, and tracking was conducted un�l July 29,
covering a period of 50 days (Figure 9).
Diving proﬁles
Fin whales in the southern Okhotsk Sea predominantly
71Technical Reports of the Ins�tute of Cetacean Research (2023)

Figure 9.

Figure 10.

LIMPET-type SPLASH-F-333 (Wildlife Computers Inc.) was a�ached to the dorsal ﬁn of a ﬁn whale oﬀ thecoast of Abashiri on 10 May 2022. The arrow-type carrier is also visible in the image.

Diving proﬁle of the ﬁn whale (PTT ID 54121)
tracked in May–June 2021. The record is depicted
at ten-minute intervals using the Ethographer program (Sakamoto et al., 2009) within the IGOR Pro
6.3.6 so�ware.

feed at water depths shallower than 150 m (Figure 10
and 11). However, itʼs worth no�ng that their diving
behaviors exhibit temporal varia�ons on a daily andweekly basis. These tags also recorded posi�onal data
during their transmissions. The data collected from thesetwo data loggers provides a substan�al dataset thatwill enable us to gain a comprehensive understandingof their feeding behaviors. We plan to analyze this datain conjunc�on with environmental informa�on, biopsy
samples, and tracking records from other loca�on-only
tags to elucidate the feeding ecology of ﬁn whales in the
study area.

ACKNOWLEDGEMENTS
We thank crews of Chipashiri M. Maeda and S. Maeda
and the staﬀ of the Tokyo University of Agriculture, B.
Kobayashi, S. Ikuta, H. Kobayashi, and K. Kikuchi, for their
72

Figure 11.

Diving proﬁle of the ﬁn whale (PTT ID 212345)
tracked in June and July 2022. The record is plo�ed
at ten-minute intervals.

assistance during the ﬁeld works. Thanks are also due to
T. Isoda (ICR) for his par�cipa�on to the ﬁeld work and
T. Tamura (ICR) for his useful sugges�ons. We also thankLuis A. Pastene for his assistance in preparing this report
and the Editorial Team of TEREP-ICR for the editorial work .

REFERENCES
Ainley, D.G., Joyce, T.W., Saenz, B., Pitman, R.L., Durban, J.W.,
Ballard, G., Daly, K. and Kim, S. 2020. Foraging pa�erns
of Antarc�c minke whales in McMurdo Sound, Ross Sea.
Antarctic Science 32 (6): 454–465.
Andrews, R.D., Baird, R.W., Calambokidis, J., Goertz, C.E.C.,
Gulland, F.M.D., Heide-Jørgensen, M.P., Hooker, S.K.,
Johnson, M., Mate, B.R., Mitani, Y., Nowacek, D.P., Owen, K.,
Quakenbush, L.T., Raverty, S., Robbins, J., Schorr, G.S., Shpak,
O.V., Townsend, F.I.Jr., Uhart, M., Wells, R.S. and Zerbini,
A.N. 2019. Best prac�ce guidelines for cetacean tagging. J.
Cetacean Res. Manage. 20: 27–66.
Cade, D.E., Kahane-Rapport, S.R., Gough, W.T., Bierlich, K.C.,

Using satellite-linked tags for studying the feeding ecology of fin whales in the southern Okhotsk Sea
Linsky, J.M.J., Calambokidis, J., Johnston, D.W., Goldbogen,
J.A. and Friedlaender, A.S. 2023. Minke whale feeding rate
limita�ons suggest constraints on the minimum body size forengulfment ﬁltra�on feeding. Nature Ecology & Evolution 7 (4):535–546.
Friedlaender, A.S., Tyson, R.B., S�mpert, A.K., Read, A.J. and
Nowacek, D.P. 2013. Extreme diel varia�on in the feeding
behavior of humpback whales along the western Antarc�c
Peninsula during autumn. Mar. Ecol. Prog. Ser 494: 281–289.
Heide-Jørgensen, M.P., Kleivane, L., Øien, N., Laidre, K.L. andJensen, M.V. 2001. A new technique for deploying satellite transmi�ers on baleen whales: Tracking a blue whale(Balaenoptera musculus) in the North Atlan�c. Marine
Mammal Science 17: 949–954.
Mate, B., Mesecar, R. and Lagerquist, B. 2007. The evolu�on ofsatellite-monitored radio tags for large whales: One laboratoryʼs experience. Deep. Res. Part II Top. Stud. Oceanogr. 54:

224–247.
Palacios, D.M., Irvine, L.M., Lagerquist, B.A., Fahlbusch, J.A.,
Calambokidis, J. and Tomkiewicz, S.M. 2022. A satellite-linked
tag for the long-term monitoring of diving behavior in large
whales. Anim. Biotelemetry 10: 26.
Savoca, M.S., Czapanskiy, M.F., Kahane-Rapport, S.R., Gough,W.T., Fahlbusch, J.A., Bierlich, K.C., Segre, P.S., Di Clemente,J., Penry, G.S., Wiley, D.N., Calambokidis, J., Nowacek, D.P.,
Johnston, D.W., Pyenson, N.D., Friedlaender, A.S., Hazen, E.L.
and Goldbogen, J.A. 2021. Baleen whale prey consump�onbased on high-resolu�on foraging measurements. Nature
599: 85–90.
Sakamoto, K.Q., Sato, K., Ishizuka, M., Watanuki, Y., Takahashi,A., Daunt, F. and Wanless, S. 2009. Can ethograms be automa�cally generated using body accelera�on data from freeranging birds? PLoS ONE 4: e5379.

73

Technical Reports of the Ins�tute of Cetacean Research (2023)

pp. 74–77

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

The current u�lity of data and samples collected by former Japanesewhale research programs under special scien�ﬁc permit
Luis A. Pastene
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan
Japan, through the Ins�tute of Cetacean Research(ICR), designed and implemented several whale research
programs under special permits based on Ar�cle VIII of
the Interna�onal Conven�on for the Regula�on of Whaling (ICRW). Those programs were implemented in boththe Indo-Paciﬁc sector of the Antarc�c and in the western
North Paciﬁc as follow:
Antarc�c
1. Japanese Whale Research Program under Special
Permit in the Antarc�c (JARPA): 1987/88–2004/05
2. Japanese Whale Research Program under Special
Permit in the Antarc�c-Phase II (JARPAII): 2005/06–
2013/14
3. New Scien�ﬁc Whale Research Program in the Antarc�c Ocean (NEWREP-A): 2015/16–2018/19
Western North Paciﬁc
4. Japanese Whale Research Program under Special
Permit in the western North Paciﬁc (JARPN): 1994–
1999
5. Japanese Whale Research Program under Special Permit in the western North Paciﬁc-Phase II(JARPNII): 2000–2016
6. New Scien�ﬁc Whale Research Program in the western North Paciﬁc (NEWREP-NP): 2017–2019
Japan also conducted dedicated sigh�ng surveys,
which were independent from those research programs
under special scien�ﬁc permit. For example, a dedicatedsigh�ng survey was conducted in the Antarc�c in the austral summer 2014/15.
Those six former whale research programs under
special permits (FWRPs) above had research objec�ves
related with the assessment and management of whale
resources as well as to the role of whales in the ecosystem. The target species of the lethal sampling in the
Antarc�c FWRPs were the Antarc�c minke whale (JARPA),
Antarc�c minke and ﬁn whales (JARPAII) and Antarc�c
74

minke whale (NEWREP-A). In the western North Paciﬁc,the target species of the lethal sampling were the common minke whale (JARPN), common minke, Brydeʼs, sei
and sperm whales (JARPNII) and common minke and sei
whales (NEWREP-NP).
An important characteris�c of the Japanese FWRPs
was the combina�on of lethal and non-lethal sampling.
Among the former, a limited number of whales weretaken as indicated above for the objec�ve of collec�ng
informa�on on age, reproduc�ve status, and stomach
contents mainly. Among the la�er, techniques such assystema�c sigh�ng surveys, photo-iden�ﬁca�on, and biopsy sampling were conducted for all large whale species
distributed in the research area. Oceanographic and marine debris surveys were also conducted to understandthe whaleʼs physical environment.
The Japanese FWRP programs were duly reviewed
by interna�onal specialists in workshops organized by
the Interna�onal Whaling Commissionʼs Scien�ﬁc Commi�ee (IWC SC). Reports of the review workshops areavailable in IWC (2008) for JARPA; IWC (2015) for JARPAII;
IWC (2001) for JARPN and IWC (2017) for JARPNII. These
programs le� behind unique data and sample sets that
represent around 30 years of systema�c research in both
the Antarc�c and western North Paciﬁc. See IWC (2015)
and IWC (2017) for examples of lists of samples and dataobtained in the Antarc�c and western North Paciﬁc, respec�vely. All those samples and data were collected in aconsistent and systema�c way for the objec�ves of eachresearch program.
Scien�ﬁc outputs from the Japanese FWRPs are available in a substan�al number of peer-reviewed publica�ons (see the last sec�on of this TEREP-ICR issue)
and in scien�ﬁc documents presented to na�onal andinterna�onal mee�ngs, mainly to mee�ngs of scien�ﬁccommi�ee of interna�onal organiza�ons in charge of theconserva�on and management of marine resources including large whales.
In 2018, Japan announced its withdrawal from theThe current utility of data and samples collected by former Japanese whale research programs under special scientific permit

ICRW, which came into eﬀect on 30 June 2019 (seePastene, 2019). Because the Japanese FWRPs were conducted under Ar�cle VIII of the ICRW, Japan had to cease
the NEWREP-A and NEWREP-NP from that same date.
Instead, Japan, through the ICR started dedicated sigh�ng
surveys in the Antarc�c and western North Paciﬁc. These
new surveys collect informa�on like that obtained by
the non-lethal component of the FWRP informed above.
The most important data collected by recent non-lethal
surveys are the sigh�ng data for abundance es�mate
purposes.
Given the new whaling policy by Japan, a ques�onemerges about the current u�lity of the exis�ng samples1and data collected by the completed FWRPs (JARPA,
JARPAII, JARPN, JARPANII) and by the FWRPs that ceased
in 2019 (NEWREP-A and NEWREP-NP). To my view thesamples and data collected by the Japanese FWRP haveimportant future u�li�es on the following research topics:i)

Assessment and management of whale resources
in Japanese watersii) Assessment of whale resources in the Antarc�ciii) Role of whales in the marine ecosystemiv) Calibra�on of non-lethal techniquesi) Assessment and management of whale resources inJapanese waters
From 1 July 2019, Japan started commercial whaling oncommon minke, Brydeʼs and sei whales within its territorial sea and Exclusive Economic Zone (EEZ). Catch limits
were calculated in line with the IWC-endorsed Revised
Management Procedure (RMP) and the uncertain�es
evaluated through the process known as Implementation
Simulation Trials (ISTs). The applica�on of the RMP and
ISTs are based on the best available scien�ﬁc informa�on for the target whale species. Relevant informa�on isrevised from �me to �me so that future catch limits canbe adjusted by taking into considera�on the most recent
scien�ﬁc informa�on.
The most relevant informa�on for the applica�on of
the RMP and ISTs are stock structure (important for deﬁning management areas), catch history (available from1

Not all samples are s�ll available. A substan�al number ofsamples collected by the FWRPs were lost because of theearthquake and tsunami that occurred in Japan in February
2011. The tsunami destroyed the marine research sta�on of
Ayukawa where most of the samples collected un�l that year
were stored.

the IWC database), abundance series, and reproduc�ve
informa�on of the relevant whale species.
The analysis of gene�c samples obtained during theJapanese FWRPs is essen�al for the applica�on of the
RMP and ISTs for two main reasons. The ﬁrst is that,though valuable, gene�c analysis of gene�c samples collected by biopsy sampling during recent dedicated sighting surveys is not suﬃcient to elucidate stock structure.
This is because the sample size is small, and the samplingis limited in geographical distribu�on. These new gene�csamples should be analyzed in conjunc�on with gene�csamples from the FWRPs to provide sound stock structure hypothesis for management purposes. Second, thegene�c analysis on stock structure should be conductedconsidering the temporal factor as distribu�on and stock
structure of a species can change with �me due to environmental factors. In this context, gene�c samples from
FWRPs can be used as a reference in future studies on
stock structure of the relevant whale species.
In the same way, sigh�ng data obtained through theJapanese FWRPs should be analyzed in conjunc�onwith sigh�ng data from more recent dedicated sigh�ng
surveys to get �me series abundance es�mates for use
in RMP and ISTs. Under the RMP a larger �me series ofabundance is preferred as it will increase the precisionof the es�mates and therefore will op�mize the use of
the RMP for calcula�ng catch limits. In this context, theabundance es�mates from the Japanese FWRPs havebeen and will be important for the Japanese RMP domes�c process.
Informa�on on natural mortality and age at sexual maturity is par�cularly important for the ISTs. Because suchinforma�on cannot be obtained by the current dedicatedsigh�ng surveys, the use of parameters es�mated fromthe Japanese FWRPs will con�nue in the future.
It should be noted here that the domes�c applica�on of the RMP and ISTs in Japan is responsibility of an
ad-hoc group from diﬀerent research organiza�on. The
Terms of Reference (TORs) and main works of this groupwere explained in Pastene (2019). One of the TORs of thisgroup is ʻthe iden�ﬁca�on of biological data (e.g. age,
reproduc�ve data) and the process required to improve/op�mize the use of the current RMPʼ. The research objec�ves of the NEWREP-NP were directly related to this TOR
and therefore the samples and data from that program
related to common and sei whales are relevant to fulﬁll
this TOR in the near future.
ii) Assessment of whale resources in the Antarc�c
The monitoring of the abundance and abundance
75Technical Reports of the Ins�tute of Cetacean Research (2023)

trends of large whales in the Antarc�c is very important.
For the cases of species that were heavily exploited by
the middle of the 20th century, it is important to monitor
their recovery and how this recovery is aﬀec�ng othercomponents of the marine ecosystem including thosewhale species that were not exploited substan�ally inthe past.
Long-term abundance series can be obtained whensigh�ng data collected by past surveys associated and notassociated with FWRPs are analyzed in conjunc�on withmore recent sigh�ng data collected by current dedicatedsigh�ng surveys in the Antarc�c, e.g. by the JapaneseAbundance and Stock structure Surveys in the Antarc�c(JASS-A) program.
Also, gene�c samples from diﬀerent baleen whale species collected by biopsy sampling under the FWRPs canbe analyzed with those obtained by the JASS-A and contribute in this way to understand the stock structure ofthose species, which is essen�al to interpret abundancees�mates.
iii) Role of whales in the marine ecosystem
Apart from the samples and data directly relevant for
management under the RMP, the Japanese FWRPs collected important data to study the role and health ofwhales in the marine ecosystem in both the Antarc�cand western North Paciﬁc. For example, qualita�ve andquan�ta�ve data on stomach content, surveys of the preyspecies of whales, oceanographic surveys to understandthe environment of whales, samples to examine the concentra�on of diﬀerent chemical pollutants in both whales
and prey species, and surveys on marine debris on bothseas surface and whales, were collected systema�cally.
Only the informa�on collected by the non-lethal
component of the FWRPs can be obtained by recent
dedicated sigh�ng surveys, e.g. sigh�ng, oceanographic
and marine debris surveys. The �me series of such data,
constructed by combining FWRPs and recent sigh�ng surveys, are very important to inves�gate changes in the environment surrounding the whales. This is very importantin �mes of climate change. Changes in the oceanographic
condi�ons will imply changes in whaleʼs prey distribu�on
and by implica�on, changes in the distribu�on of whales.
Informa�on already obtained on feeding ecology andchemical pollu�on from the Japanese FWRPs will be
important for compara�ve purposes when new data on
those topics emerge in the future.
iv) Calibra�on of non-lethal techniques
Several non-lethal research techniques are being de76

veloped by the ICR. For example, the poten�al use of biopsy samples for epigene�c es�ma�on of age, analysis ofprogesterone in biopsy samples to obtain informa�on of
reproduc�ve status of female whales and stable isotope
to obtain informa�on on the feeding ecology of whales.
The samples and data from Japanese FWRPs can be used
to calibrate non-lethal methodologies, e.g. Goto et al.
(2020) for epigene�c analyses, Takahashi et al. (2022) for
stable isotope analyses and Inoue et al. (2019) for progesterone analyses.
Also, results on non-lethal techniques such as photoiden�ﬁca�on and satellite tracking of whales used forstudying the movement and distribu�on of whales, canbe be�er interpreted in the context of the stock structure
analyses conducted using gene�c samples obtained during the Japanese FWRPs.

CONCLUSION
The samples and data collected under the Japanese
FWRPs have been and will be important for studies on
assessment and management of whales targeted by Japanese commercial whaling, assessment of large whales in
the Antarc�c, role of whales in the marine ecosystem andin studies of calibra�on of new non-lethal techniques. In
addi�on, samples and data from the FWRPs can be usedin worldwide compara�ve studies of a more academic nature, for example on taxonomy e.g. Milmann et al. (2021).

REFERENCES
Inoue, S., Yasunaga, G. and Pastene, L.A. 2019. Comparison ofprogesterone concentra�ons in blubber and plasma amongfemale Antarc�c minke whales of known reproduc�ve status.
Fish Sci 85 (6): 971–977.
Interna�onal Whaling Commission. 2001. Report of the workshop to review the Japanese Whale Research Programme
under Special Permit for North Paciﬁc minke whales. J.
Cetacean Res. Manage. (Suppl.) 3: 375–413.
Interna�onal Whaling Commission. 2008. Report of the intersessional workshop to review data and results from special
permit research on minke whales in the Antarc�c. J. Cetacean
Res. Manage. (Suppl.) 10: 410–445.
Interna�onal Whaling Commission. 2015. Report of the expert
workshop to review the Japanese JARPAII special permit
research programme. J. Cetacean Res. Manage. (Suppl.) 16:
368–409.
Interna�onal Whaling Commission. 2017. Report of the expert panel of the ﬁnal review on the western North PaciﬁcJapanese special permit programme. J. Cetacean Res.
Manage. (Suppl.) 18: 527–592.
Goto, M., Kitakado, T. and Pastene, L.A. 2020. A preliminary
study of epigene�c es�ma�on of age of the Antarc�c minke

The current utility of data and samples collected by former Japanese whale research programs under special scientific permit
whale Balaenoptera bonaerensis. Cetacean Population
Studies 2: 5–14.
Milmann, L., Taguchi, M., Siciliano, S., Baumgarten, J.E., Oliveira,L.R., Valia�, V.H., Goto, M., O�, P.H. and Pastene, L.A. 2021.
New gene�c evidence for dis�nct popula�ons of the common
minke whale (Balaenoptera acutorostrata) in the Southern
Hemisphere. Polar Biol 44 (8): 1575–1589.
Pastene, L.A. 2019. Withdrawal of Japan from the Interna�onal

Conven�on for the Regula�on of Whaling: implica�ons forthe whale research conducted by the Ins�tute of Cetacean
Research. Technical Reports of the Institute of Cetacean
Research (TEREP-ICR) No. 3: 55–58.
Takahashi, M., Tamura, T., Bando, T. and Konishi, K. 2022.
Feeding habits of Brydeʼs and sei whales in the western North
Paciﬁc inferred from stomach contents and skin stable isotope ra�os. Journal of Sea Research 184: 102204.

77

Technical Reports of the Ins�tute of Cetacean Research (2023)

pp. 78National meetingsPar�cipa�on of scien�sts from the Ins�tute of Cetacean Research inNa�onal Mee�ngs in 2023
The 2023 mee�ng of the Japanese Society ofFisheries Science (JSFS)
The Japanese Society of Fisheries Science (JSFS) wasestablished in 1932. It is a non-proﬁt, registered society
dedicated to the promo�on of all aspects of ﬁsheriesscience. The society fulﬁlls its global commitment bypromo�ng science, striving to achieve sustainable development in the ﬁeld of ﬁsheries, while recognizing the
crucial need to preserve the natural aqua�c resources. It
also strives to forge rela�onships with the ﬁshing industry, comprising both capture and culture ﬁsheries. The
main events organized by the society are the biannual
mee�ngs held in spring and autumn in one of the mainci�es of Japan. This forum is where members present
their research ac�vi�es, exchange informa�on and foster
collabora�ve research in areas of common interest.
The 2023 spring mee�ng of the JSFS was held in-person
and online from 28 to 31 March at Tokyo University ofMarine Science and Technology. Katsumata from theIns�tute of Cetacean Research (ICR) par�cipated in themee�ng as co-author of the studies ʻSite ﬁdelity of hump-78

back whales around Hachijo-Jima water and interchangewith Ogasawara waterʼ and ʻAge es�ma�on of humpback
whales migra�ng to Hachijo-Jima water in 2018–21 using
DNA methyla�on analysisʼ. Matsuoka from the ICR par�cipated in the mee�ng as co-author of the study ʻTrialof cetacean vocaliza�on monitoring survey by the Sea
Explorer Gliderʼ.

The 2023 mee�ng of the Marine Acous�c Societyof Japan (MASJ)
The Marine Acous�c Society of Japan (MASJ) was established in 1973. This society implements projects
related to academic survey research, dissemina�on andenlightenment, and encouragement of research and development related to ocean acous�cs for people who arewidely interested in this ﬁeld. MASJ aims to spread ocean
acous�cs and ocean acous�c technology through Japan.
The 2023 mee�ng of the MASJ was held in-person
and online from 25 to 26 May at Kanagawa University.
Matsuoka from the ICR par�cipated in the mee�ng as coauthor of the study ʻDevelopment of ultra-low frequency
underwater recording deviceʼ.

Technical Reports of the Ins�tute of Cetacean Research (2023)

pp. 79–81

International meetingsPar�cipa�on of scien�sts from the Ins�tute of Cetacean Research inInterna�onal Mee�ngs in 2023
Annual mee�ng of the Interna�onal Whaling
Commission Scien�ﬁc Commi�ee (IWC SC)
The Interna�onal Whaling Commission (IWC) is an interna�onal body set up by the terms of the Interna�onal
Conven�on for the Regula�on of Whaling (ICRW), which
was signed in Washington, D.C., United States, on 2 December 1946, to ʻprovide for the proper conserva�on ofwhale stocks and thus make possible the orderly development of the whaling industryʼ. One of the important
subsidiary bodies of the IWC is its Scien�ﬁc Commi�ee(SC), which meets annually.
The 2023 mee�ng of the IWC SC (SC69A) was heldfrom 24 April to 6 May in Bled, Slovenia. This was the ﬁrst
in-person Commi�ee mee�ng since 2019 (SC68A). Fourscien�sts from the Ins�tute of Cetacean Research (ICR)
par�cipated in the mee�ngs (Pastene, Tamura, Matsuoka
and Katsumata). They presented a total of 10 documents:
six documents at the Standing Working Group on Abundance Es�mates, Stock Status and Interna�onal Cruises(ASI), one document at the Working Group on StockDeﬁni�on and DNA tes�ng (SDDNA), one document at
the Sub-Commi�ee on Conserva�on Management Plans(CMP) and two general documents (O: PICES Observer
Report and Japanʼs Scien�ﬁc Progress Reports).
The 2024 IWC SC mee�ng (SC69B) will be held in Bled,
Slovenia from 22 April to 4 May.
The report of the IWC SC mee�ng can be found on theMee�ng of the Interna�onal Whaling Commission (IWC)
Scien�ﬁc Commi�ee (SC69A) held at the Rikli Hotel, Bled,
Slovenia.

website of the IWC (h�ps://archive.iwc.int/pages/view.
php?ref= 20108&k=).

Annual mee�ng of the Conven�on on the Conserva�on of Antarc�c Marine Living Resources–
Working Group on Ecosystem Monitoring andManagement (CCAMLR-EMM)
The Conven�on on the Conserva�on of Antarc�c Marine
Living Resources (CCAMLR) is part of the Antarc�c Treaty
System. The Conven�on was opened for signature on
1 August 1980 and entered into force on 7 April 1982,
thereby establishing the Commission for the Conserva�on of Antarc�c Marine Living Resources. Its goal is topreserve marine life and environmental integrity in andnear Antarc�ca. 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 popula�ons of other marine life, which are dependent upon
krill for food. The CCAMLR has a Scien�ﬁc Commi�ee
and several Working Groups. One of these is the Working Group on Ecosystem Monitoring and Management(EMM), which meets annually.
The 2023 mee�ng of the EMM Working Group washeld from 3 to 14 July in Kochi, India. The main itemson the mee�ng agenda were krill ﬁshery management,spa�al management and ecosystem monitoring. Under
the spa�al overlap analysis approach, several papers onmonitoring of krill-dependent predators including whales

The mee�ng of the Conserva�on of Antarc�c Marine Living
Resources (CCAMLR)- Ecosystem Monitoring and Management(EMM) Working Group in Kochi, India.
79

Technical Reports of the Ins�tute of Cetacean Research (2023)

in western Antarc�c were presented. Isoda from the ICR
par�cipated in the mee�ng, presen�ng the documenten�tled ʻSummary of the dedicated sigh�ng survey under
the Japanese Abundance and Stock structure Surveys in
the Antarc�c (JASS-A) in four austral summer seasons(2019/2020–2022/2023)ʼ.
The report of the mee�ng can be found on the websiteof the CCAMLR (h�ps://mee�ngs.ccamlr.org/en/wg-emm2023).

Scien�ﬁc Commi�ee on Antarc�c Research(SCAR) Biology Symposium 2023
The Scien�ﬁc Commi�ee on Antarc�c Research (SCAR)
is a thema�c organiza�on of the Interna�onal Science
Council (ISC), and it was created in 1958. SCAR is charged
with ini�a�ng, developing and coordina�ng high quality
interna�onal scien�ﬁc research in the Antarc�c region(including the Southern Ocean), and on the role of the
Antarc�c region in the Earth system. SCAR provides objec�ve and independent scien�ﬁc advice to the Antarc�c
Treaty Consulta�ve Mee�ngs and other organiza�ons
such as the United Na�ons Framework Conven�on on
Climate Change (UNFCCC) and the Intergovernmental
Panel on Climate Change (IPCC) on issues of science andconserva�on aﬀec�ng the management of Antarc�ca
and the Southern Ocean and on the role of the Antarc�cregion in the Earth system.
The XIII SCAR Biology Symposium was held from 31
July to 4 August 2023 in Christchurch, New Zealand.
Katsumata from ICR par�cipated in the mee�ng. He madean oral presenta�on of the study ʻWide range distribu�onof baleen whales in the Antarc�c based on the data fromthe Japanese long-term ship-based monitoringʼ.

Presenta�on at the Scien�ﬁc Commi�ee on Antarc�c Research(SCAR) Biology Symposium in Christchurch, New Zealand.
80

The 13th Interna�onal Mammalogical Congress(IMC-13)The IMC-13 mee�ng was co-hosted by the American Society of Mammologists and the Interna�onal Federa�onof Mammologists. This mee�ng was held from 14 July to
20 July 2023 in Anchorage, Alaska, USA. Bando and Kuno
from the ICR were co-authors of a poster presenta�onto the mee�ng en�tled ʻSexual dimorphism of the laryngeal sacs of Bryde's whales and its rela�onship with theirsexual statusʼ.

Poster presenta�on at the Interna�onal Federa�on of Mammologists (IMC-13) mee�ng in Alaska, USA.

Annual mee�ng of the North Atlan�c Marine Mammal Commission (NAMMCO) Scien�ﬁcCommi�ee (SC)The North Atlan�c Marine Mammal Commission(NAMMCO) is an interna�onal body for coopera�on on
the conserva�on, management and study of marine
mammals in the North Atlan�c. The NAMMCO Agreement was signed in Nuuk, Greenland on 9 April 1992 by
Norway, Iceland, Greenland and the Faroe Islands, andentered into force on 8 July 1992. The agreement focuseson modern approaches to the study of the marine ecosystem as a whole, and to be�er understanding the roleof marine mammals in the ecosystem. NAMMCO has a
Scien�ﬁc Commi�ee (SC), which meets annually.
The 2023 NAMMCO SC (SC29) mee�ng was heldfrom 23 to 26 January in Copenhagen, Denmark. Fourscien�sts from ICR par�cipated in the mee�ng (Pastene,
Tamura, Konishi and Inoue) as observers from Japan.
They presented the following documents: the 2021–2022
Japan progress report on large cetacean research, the2019–2020 Japan progress report on small cetacean re-Participation of scientists from the Institute of Cetacean Research in International Meetings in 2023

search, proposal for star�ng a collabora�ve study to further understand the role of baleen whales in the western
North Paciﬁc ecosystem and the 2021–2022 report on
satellite tagging experiments at the Ins�tute of Cetacean
Research. The report of the mee�ng can be found on thewebsite of NAMMCO (h�ps://nammco.no/wp-content/
uploads/2023/02/report-sc29_16022023_rev.pdf).

ing as members of the Steering Group. The 6th MINTAG
mee�ng was held on 10 October 2023 online and two
scien�sts from ICR (Pastene and Konishi) par�cipated themee�ng. Konishi presented an update of the Japaneseeﬀorts for tagging ﬁve ﬁn whales in June 2023. The ac�vi�es of the MINTAG project can be found on the website(h�ps://mintag-project.com/).

Annual mee�ng of the North Paciﬁc Marine Science Organiza�on (PICES)

Scien�sts par�cipa�ng in the 2023 North Atlan�c Marine
Mammal Commission (NAMMCO) Scien�ﬁc Commi�ee meeting (SC29) in the Greenlandic Representa�on, Copenhagen,Denmark.

NAMMCO-Japan MINTAG project mee�ng
NAMMCO and Japan have agreed on a collabora�ve
project to develop a new satellite tag suited for use on
fast-swimming baleen whales which are of most interest
to NAMMCO countries and Japan (MINTAG). The project
started in 2022 and will run for ﬁve years. The project isdivided into phases: development phase, tes�ng phase,
deployment-data collec�on-analyses phase, and publica�on-ﬁnal repor�ng- workshop phase. The project is led by
a Steering Group composed of scien�sts from NAMMCO
countries and Japan, the Secretariat of NAMMCO and theFisheries Agency of Japan (FAJ).
The mee�ng of the MINTAG Steering Group was heldon 24 January 2023 during the NAMMCO SC mee�ng in
Copenhagen. The main topics of the mee�ng were thetender material for tags, the web blog and the schedule
for the test tagging experiments. Two scien�sts fromthe ICR (Pastene and Konishi) par�cipated in the meet-

The North Paciﬁc Marine Science Organiza�on (PICES) isan intergovernmental science organiza�on established in
1992. It aims to promote and coordinate marine scien�ﬁcresearch in the North Paciﬁc Ocean and its adjacent seas,
and to provide a mechanism for informa�on and dataexchange among scien�sts in its member countries. Itspresent members are Canada, Japan, People's Republic ofChina, Republic of Korea, the Russian Federa�on, and theUnited States of America.
The 2023 mee�ng of the PICES was held in Sea�le,
USA from 23 to 27 October. The business mee�ng of the
Marine Bird and Mammals (S-MBM) sec�on was held on
24 September 2023. One scien�st from ICR par�cipatedin the mee�ng (Tamura) introducing the observer reportof IWC SC mee�ng. The report of the PICES mee�ng canbe found on the website of PICES (h�ps://mee�ngs.pices.
int/).

The mee�ng of the 2023 North Paciﬁc Marine Science Organiza�on(PICES) in Sea�le, USA.

81

Technical Reports of the Ins�tute of Cetacean Research (2023)

pp. 82–102

Peer-reviewed publications

List of peer-reviewed publica�ons based on the Ins�tute of
Cetacean Research (ICR)ʼs surveys up to 2023
This sec�on presents a list of peer-reviewed publica�ons
based on data collected by surveys conducted underformer special scien�ﬁc permit programs (JARPA/JARPAII/
NEWREP-A and JARPN/JARPNII/NEWREP-NP), including
both lethal and non-lethal techniques. Peer-reviewed
publica�ons based on these surveys are focused mainly
on topics related to assessment and management oflarge whales. However samples and data collected by
the surveys have also been useful to carry out studies ofa more academic-oriented nature. Publica�ons based onsuch studies are also listed here.
This sec�on also includes a list of peer-reviewed publica�ons resul�ng from other surveys and research ac�vi�es, diﬀerent from special scien�ﬁc permit surveys.
Publica�ons having as a ﬁrst author a non-ICR scien�st commonly followed a data request or collabora�onresearch agreement with ICR. In a few cases, externalscien�sts used published data from ICR surveys in theiranalyses and publica�ons, without a formal agreementwith ICR. These cases are indicated by an asterisk (*).

JARPA/JARPAII/NEWREP-A 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)Bu�erworth, D.S. and Punt, A.E. 1990. Some preliminary
examina�ons of the poten�al informa�on content
of age-structure data from Antarc�c minke whale research catches. Rep. int. Whal. Commn 40: 301–315.
Ichii, T. 1990. Distribu�on of Antarc�c krill concentra�ons
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 Antarc�c minke whale. I. The fa�y acid composi�ons of the minke whale blubber oils caught on 1987/88
82

season. Yukagaku 39 (7): 486–490 (in Japanese).
Kasamatsu, F., Kishino, H. and Hiroyama, H. 1990. Es�ma�on 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 composi�on and segrega�on 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 Scien�ﬁc Whaling. Nature
334: 189–190.
Tanaka, S. 1990. Es�ma�on of natural mortality coeﬃcient of whales from the es�mates of abundance andage composi�on data obtained from research catches.
Rep. int. Whal. Commn 40: 531–536.
1991 (9)Bergh, M.O., Bu�erworth, D.S. and Punt, A.E. 1991. Further examina�on of the poten�al informa�on content
of age-structure data from Antarc�c minke whale
research catches. Rep. int. Whal. Commn 41: 349–361.
Ichii, T. and Kato, H. 1991. Food and daily food consump�on of southern minke whales in the Antarc�c. Polar
Biol 11 (7): 479–487.
Kasamatsu, F., Kishino, H. and Taga, Y. 1991. Es�ma�onof southern minke whale abundance and school size
composi�on 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 andsegrega�on 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. Migra�on strategy ofsouthern minke whales in rela�on to reproduc�ve
cycles es�mated from foetal lengths. Rep. int. Whal.
Commn 41: 363–369.
Kato, H., Zenitani, R. and Nakamura, T. 1991. Inter-reader
calibra�on in age readings of earplugs from southern

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2023

minke whale, with some notes of age readability. Rep.
int. Whal. Commn 41: 339–343.
Kishino, H., Kato, H., Kasamatsu, F. and Fujise, Y. 1991.
Detec�on of heterogeneity and es�ma�on of popula�on characteris�cs 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 �me-series data obtained from researchtakes of whales. Rep. int. Whal. Commn 41: 345–348.
Wada, S., Kobayashi, T. and Numachi, K. 1991. Gene�cvariability and diﬀeren�a�on of mitochondrial DNA in
minke whales. Rep. int. Whal. Commn (special issue)
13: 203–215.
1992 (2)Nakamura, T. 1992. Simula�on trials of a Bayesian cohortmodel for �me-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 es�mates 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 Antarc�c minke whale. II. The fa�y acidcomposi�ons 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.
Distribu�on 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 scien�ﬁc permit in Area V. Rep.

int. Whal. Commn 43: 505–522.
Nakamura, T. 1993. Two-stage Bayesian cohort modelfor �me-series data to reduce bias in the es�mate ofmean natural mortality rate. Rep. int. Whal. Commn
43: 343–348.
Pastene, L.A., Kobayashi, T., Fujise, Y. and Numachi, K.
1993. Mitochondrial DNA diﬀeren�a�on in Antarc�cminke whales. Rep. int. Whal. Commn 43: 349–355.
1994 (3)Kimoto, H., Endo, Y. and Fujimoto, K. 1994. Inﬂuence ofinteresteriﬁca�on on the oxida�ve stability of marine
oil triacylglycerols. JAOCS 71 (5): 469–473.
Pastene, L.A., Fujise, Y. and Numachi, K. 1994. Diﬀeren�a�on 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 quan�fying muscle progesterone content in the minke whales (Balaenoptera acutorostrata). Can. J. Zool. 72 (2): 368–370.
1995 (3)
Fukui, Y., Mogoe, T., Terawaki, Y., Ishikawa, H., Fujise,
Y. and Ohsumi, S. 1995. Rela�onship between physiological status and serum cons�tuent values in minke
whales (Balaenoptera acutorostrata). Journal of Reproduction and Development 41 (3): 203–208.
Ishikawa, H. and Amasaki, H. 1995. Development andphysiological degrada�on 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 migra�ons 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 popula�on subdivision among the minke
whales (Balaenoptera acutorostrata) from Icelandic
and Norwegian waters based on mitochondrial DNA
sequences. Marine Biology 125: 1–9.
Bu�erworth, D.S. and Geromont, H.F. 1996. On the provision of advice on the eﬀect on stock(s) of scien�ﬁcpermit catches, with par�cular reference to proposed
research catches of minke whales from Antarc�c Area
IV. Rep. int. Whal. Commn 46: 653–655.
Bu�erworth, D.S., Punt, A.E., Geromont, H.F., Kato, H. and83

Technical Reports of the Ins�tute of Cetacean Research (2023)

Miyashita, T. 1996. An ADAPT approach to the analysis
of catch-at-age informa�on 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. Rela�onships 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 observa�ons of female minke
whales (Balaenoptera acutorostrata). Marine Mammal
Science 12 (2): 296–301.
Matsuoka, K., Fujise, Y. and Pastene, L.A. 1996. A sigh�ng
of 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.
Spa�al and temporal pa�erns of mitochondrial DNA
varia�on in minke whale from Antarc�c 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 Antarc�c and the North Paciﬁc. Environmental Pollution 98: 81–89.
Fukui, Y., Mogoe, T., Ishikawa, H. and Ohsumi, S. 1997a.
Factors aﬀec�ng in vitro matura�on 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 fer�liza�on 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 condi�onindex of minke whales in the Antarc�c. Mar. Ecol. Prog.
Ser. 175: 1–12.
Ito, S., Takenaga, F. and Tsuyuki, H. 1998. Lipids in Antarc�c 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.
84

Mogoe, T., Fukui, Y., Ishikawa, H. and Ohsumi, S. 1998a.
Morphological observa�ons 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 composi�on and temperature on
mo�lity and viability a�er liquid storage and cryopreserva�on 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 Antarc�c 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 Antarc�c Ocean, South of 60°S. Marine Mammal Science 15 (4): 1337–1342.
Bu�erworth, 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 informa�on. J. Cetacean Res. Manage. 1(1): 11–32.
Ishikawa, H., Amasaki, H., Dohguchi, H., Furuya, A. andSuzuki, K. 1999. Immunohistological distribu�ons ofﬁbronec�n, tenascin, type I, III and IV collagens, andlaminin during tooth development and degenera�on infetuses of minke whale, Balaenoptera acutorostrata. J.
Vet. Med. Sci. 61 (3): 227–232.
Thomson, R.B., Bu�erworth, D.S. and Kato, H. 1999. Has
the age at transi�on 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 matura�on and ultrastructural observa�on of cryopreserved minke whale(Balaenoptera acutorostrata) follicular oocytes. Biology of Reproduction 62 (2): 253–259.
Kasamatsu, F., Matsuoka, K. and Hakamada, T. 2000. Interspeciﬁc rela�onships in density among the whale
community in the Antarc�c. Polar Biol 23 (7): 466–473.

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2023

Mogoe, T., Suzuki, T., Asada, M., Fukui, Y., Ishikawa, H. andOhsumi, S. 2000. Func�onal reduc�on of the Southernminke whale (Balaenoptera acutorostrata) tes�s 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 gene�c diﬀeren�a�on of Eubalaena: ques�oning
the number of right whale species. Molecular Ecology
9: 1793–1802.
Wei, H. and Fukui, Y. 2000. Fer�lizability 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 matura�on,
fer�liza�on 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 a�empt at intracytoplasmic sperm injec�on 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 concentra�ons 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 applica�on of microsatellite DNA for determining popula�on structure of minke
whale. pp. 109–113. In: A. Nishimura (Ed.). Technical
Reports of the Hokkaido National Fisheries ResearchInstitute No.5. Hokkaido Na�onal Fisheries ResearchIns�tute, Hokkaido.
Kunito, T., Watanabe, I., Yasunaga, G., Fujise, Y. and Tanabe, S. 2002. Using trace elements in skin to discriminate the popula�ons of minke whale in southern hemisphere. Marine Environmental Research 53: 175–197.
Murase, H., Matsuoka, K., Ichii, T. and Nishiwaki, S. 2002.
Rela�onship between the distribu�on of euphausiids
and baleen whales in the Antarc�c (35°E–145°W).

Polar Biol 25 (2): 135–145.
Pastene, L.A., Goto, M. and Kanda, N. 2002. The u�lity of
DNA analysis for the management and conserva�on oflarge whales. Fish Sci 68 (Suppl. I): 286–289.
Suzuki, M., Ishikawa, H., Otani, S., Tobayama, T., Katsumata, E., Ueda, K., Uchida, S., Yoshioka, M. and Aida,
K. 2002. The characteris�cs of adrenal glands and its
hormones in cetacean. Fish Sci 68 (Suppl. 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 characteriza�on 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 varia�on 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 distribu�ons (south of
60°S, 35°E–130°E) in rela�on to the Southern Boundary of the Antarc�c Circumpolar Current. pp. 26–30.
In: Antarctic Biology in a Global Context. Proceedingsof the VIIIth SCAR Interna�onal 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 (Suppl.) 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-infec�on in baleen whales (Mys�ce�) 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-ac�va�ng factor in
Antarc�c minke whale (Balaenoptera bonaerensis)
spermatogenic cells, assessed by meiosis resump�onof microinseminated mouse oocytes. J. Mamm. Ova
85Technical Reports of the Ins�tute of Cetacean Research (2023)

Res. 21: 149–156.
Branch, T.A., Matsuoka, K. and Miyashita, T. 2004. Evidence for increase in Antarc�c blue whales based on
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. Compara�vestudies 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.
Valida�on of the sperm quality analyzer and the hypoosmo�c 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 soma�ccell nuclear transfer for in vitro produc�on of Antarc�cminke 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 vitriﬁca�on 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. Rela�onship between the appearance of preantral follicles in the fetal ovary of Antarc�c minke whales(Balaenoptera bonaerensis) and hormone concentra�ons 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 pa�ern of ovarian development in the prepubertal Antarc�c 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 Antarc�c minke
whales, Balaenoptera bonaerensis, in the Japanese
Whale Research Program under Special Permit in the
Antarc�c Sea (JARPA). Jpn. J. Zoo Wildl. Med. 10 (1):
27–34.
Iwayama, H., Ishikawa, H., Ohsumi, S. and Fukui, Y. 2005.
A�empt at in vitro matura�on of minke whale (Balae86

noptera 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) sigh�ng 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 Antarc�c based on the sigh�ng 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. Phylogene�c reconstruc�on of baleen whales and detec�on of their pastextensive radia�on event by the SINE inser�on 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 phylogene�cs and evolu�on of mys�cete 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 Antarc�c minke whale (Balaenoptera bonaerensis) vitriﬁed oocytes following in vitro
matura�on, and parthenogene�c ac�va�on or intracytoplasmic sperm injec�on. Zygote 14 (2): 89–95.
Honda, K., Aoki, M. and Fujise, Y. 2006. Echochemical approach using mercury accumula�on of Antarc�c minke
whale, Balaenoptera bonaerensis, as tracer of historical change of Antarc�c 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. Contribu�on of spermatozoal
centrosomes to the microtubule-organizing centre in
Antarc�c minke whale (Balaenoptera bonaerensis).
Zygote 14 (1): 45–51.
Konishi, K. 2006. Characteris�cs of blubber distribu�on
and body condi�on indicators for Antarc�c minke
whale (Balaenoptera bonaerensis). Mammal Study 31(1): 15–22.

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2023

Mori, M. and Bu�erworth, D.S. 2006. A ﬁrst step towards
modelling the krill–predator dynamics of the Antarc�cecosystem. 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
radia�on event revealed by SINE inser�on 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-iden�ﬁca�on. 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 Antarc�c bo�om 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 matura�on and cryopreserva�on of follicular oocytes of Antarc�c 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.,
Galle� 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., Gerrode�e, 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 distribu�on, densi�es 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. Pa�erns ofgene�c varia�on 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
Antarc�c minke whales (Balaenoptera bonaerensis).
Journal of Reproduction and Development 53 (6):1265–1272.
Nishida, S., Goto, M., Pastene, L.A., Kanda, N. and Koike,
H. 2007. Phylogene�c rela�onships 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 varia�on 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. Radia�on andspecia�on 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. Compara�ve 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 Antarc�c 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 Antarc�c cetaceans: areview. J. Cetacean Res. Manage. 10 (1): 67–72.
Yunoki, K., Ishikawa, H., Fukui, Y. and Ohnishi, M. 2008.
Chemical proper�es of epidermal lipids, especiallysphingolipids, of the Antarc�c 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 varie�es 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
consump�on of Antarc�c minke whale (Balaenoptera
bonaerensis) in the Southern Ocean. J. Northw. Atl.
Fish. Sci. 42: 13–25.
2010 (15)
Fujise, Y., Nishiwaki, S. and Ishikawa, S. 2010. Overview of
the Japanese Whale Research Program under Special
Permit in the Antarc�c (JARPA). Bull. Jpn. Soc. Fish.
Oceanogr. 74: 43–44 (in Japanese).
87Technical Reports of the Ins�tute of Cetacean Research (2023)

Fujise, Y., Hatanaka, H. and Ohsumi, S. 2010. Changes
in the Antarc�c marine ecosystem as revealed by the
JARPA research: What has happened to the Antarc�cminke 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. Migra�on of
Antarc�c minke whales to the Arc�c. PLoS ONE 5 (12):e15197.
Ishikawa, H. 2010. Animal Welfare—Introduc�on—. 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. Distribu�on of seabirds in the Ross Sea, Antarc�ca. Bull. Jpn. Soc. Fish. Oceanogr. 74: 42–43 (inJapanese).
Matsuoka, K., Kiwada, K., Murase, H. and Nishiwaki, S.
2010. Whale species composi�on and their distribu�on pa�erns in the Ross Sea, Antarc�ca. Bull. Jpn. Soc.
Fish. Oceanogr. 74: 44–45 (in Japanese).
Murase, H., Matsuoka, K., Hakamada, T., Nishiwaki, S.,
Naganobu, M. and Kitakado, T. 2010. Es�ma�on of
spa�al distribu�on pa�ern of cetacean using environmental covariates in the Ross Sea, Antarc�ca. Bull. Jpn.
Soc. Fish. Oceanogr. 74: 47–48 (in Japanese).
Naganobu, M. and Murase, H. 2010. Ecological linkage
between oceanographic environment and distribu�onof 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, Antarc�ca—overview and synthesis of the results of the Japanese mul�disciplinary study by Kaiyo-Maru and JARPA—. Bull.
Jpn. Soc. Fish. Oceanogr. 74: 1–12.
Naganobu, M., Nishiwaki, S., Nagai, N. and Tohyama, D.
2010. Mul�disciplinary ecological survey by the R/V
Kaiyo Maru and JARPA in the Ross Sea, Antarc�ca. 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. Popula�on 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 Ant88

arc�c minke whales in the Ross Sea, Antarc�ca. 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, Antarc�ca. Bull. Jpn.
Soc. Fish. Oceanogr. 74: 35–36 (in Japanese).
Zenitani, R. and Kato, H. 2010. The growth of baleen
plates in Antarc�c minke whales, with special reference to the V-shape notch appearing at the outer edgeof the plates. Nippon Suisan Gakkaishi 76 (5): 870–876(in Japanese with English abstract).
2011 (1)Matsuoka, K., Hakamada, T., Kiwada, H., Murase, H. andNishiwaki, S. 2011. Abundance es�mates and trends
for humpback whales (Megaptera novaeangliae) in
Antarc�c Areas IV and V based on JARPA sigh�ng 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 diﬀeren�a�on of mtDNA in the cri�callyendangered Antarc�c 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 Antarc�c minke whales
are fer�le and can back-cross. BMC Genetics 14: 25.
Hakamada, T., Matsuoka, K., Nishiwaki, S. and Kitakado,
T. 2013. Abundance es�mates and trends for Antarc�cminke whales (Balaenoptera bonaerensis) in Antarc�c
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 sta�s�cal
model for quan�fying age-reading errors and its applica�on to the Antarc�c minke whales. J. Cetacean Res.
Manage. 13 (3): 181–190.
Murase, H., Kitakado, T., Hakamada, T., Matsuoka, K.,
Nishiwaki, S. and Naganobu, M. 2013. Spa�al distribu�on of Antarc�c minke whales (Balaenoptera bonaerensis) in rela�on to spa�al distribu�ons of krill in theRoss Sea, Antarc�ca. 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 Antarc-

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2023

�c 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 stra�ﬁca�on and misspeciﬁca�on of covariates
on species distribu�on models for abundance es�ma�on from virtual line transect survey data. Fish Sci 79(4): 559–568.
2014 (4)Konishi, K., Hakamada, T., Kiwada, H., Kitakado, T. andWalløe, L. 2014. Decrease in stomach contents in the
Antarc�c minke whale (Balaenoptera bonaerensis) in
the Southern Ocean. Polar Biol 37 (2): 205–215.
Punt, A.E. 2014. A summary history of the applica�onof sta�s�cal catch-at-age analysis (SCAA) to Antarc�cminke whales. J. Cetacean Res. Manage. 14: 81–92.
Punt, A.E., Hakamada, T., Bando, T. and Kitakado, T. 2014.
Assessment of Antarc�c minke whales using sta�s�cal
catch-at-age analysis (SCAA). J. Cetacean Res. Manage.
14: 93–116.
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. 2014. Areolaeof the placenta in the Antarc�c minke whale (Balaenoptera bonaerensis). Journal of Reproduction andDevelopment 60 (1): 62–67.
2015 (2)Konishi, K. and Walløe, L. 2015. Substan�al decline inenergy storage and stomach fullness in Antarc�c 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. Spa�al and temporal varia�on of PCBs and organochlorine pes�cides in the Antarc�c minke whales,
Balaenoptera bonaerensis, in the period 1987–2005.
Chemosphere 126: 11–17.
2016 (2)Pastene, L.A. and Goto, M. 2016. Gene�c characteriza�on and popula�on gene�c structure of the Antarc�cminke 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 poten�al involvement of
dipep�de balenine through supplementa�on 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 Antarc�c Ocean. J.
Yamashina Inst. Ornithol. 48 (2): 74–77.
*Leduc, R.G., Archer, F.I., Lang, A.R., Mar�en, K.K., Hancock-Hanser, B., Torres-Florez, J.P., Hucke-Gaete, R.,
Rosenbaum, H.C., VanWaerebeek, Bownell, R.L. andTaylor, B.L. 2017. Gene�c varia�on in blue whales inthe eastern paciﬁc: implica�ons for taxonomy and useof common wintering grounds. Molecular Ecology 26:
740–751.
Yasunaga, G., Pastene, L.A., Bando, T., Hakamada, T. andFujise, Y. 2017. Age es�ma�on of Antarc�c minke
whales Balaenoptera bonaerensis based on aspar�cacid racemiza�on technique. Fish Sci 86 (6): 947–954.
2019 (1)Inoue, S., Yasunaga, G. and Pastene, L.A. 2019. Comparison of progesterone concentra�ons in blubber
and plasma among female Antarc�c minke whales ofknown reproduc�ve status. Fish Sci 85 (6): 971–977.
2020 (6)Cunen, C., Walløe, L. and Hjort, N.L. 2020. Focused model
selec�on for linear mixed models with an applica�on
to whale ecology. Ann. Appl. Stat. 14 (2): 872–904.
Goto, M., Kitakado, T. and Pastene, L.A. 2020. A preliminary study of epigene�c es�ma�on of age of the
Antarc�c minke whale Balaenoptera bonaerensis. Cetacean Population Studies 2: 5–14.
Konishi, K., Isoda, T., Bando, T., Minamikawa, S. and Kleivane, L. 2020. Antarc�c minke whales ﬁnd ice gaps along
the ice edge in foraging grounds of the Indo-Paciﬁc sector (60°E and 140°E) of the Southern Ocean. Polar Biol
43 (4): 343–357.
Matsuoka, K. and Hakamada, T. 2020. Density distribu�on of several major whale species in the Indo-Paciﬁcregion of Antarc�c using JARPA and JARPAII sigh�ng
data obtained through 1987/88–2008/09 seasons. Cetacean Population Studies 2: 15–38.
Murase, H., Palka, D., Punt, A.E., Pastene, L.A., Kitakado,T., Matsuoka, K., Hakamada, T., Okamura, H., Bando,T., Tamura, T., Konishi, K., Yasunaga, G., Isoda, T. andKato, H. 2020. Review of the assessment of two stocksof Antarc�c minke whales (eastern Indian Ocean andwestern South Paciﬁc). J. Cetacean Res. Manage. 21:
95–122.
89

Technical Reports of the Ins�tute of Cetacean Research (2023)

Tanabe, A., Shimizu, R., Osawa, Y., Suzuki, M., Ito, S.,
Goto, M., Pastene, L.A., Fujise, Y. and Sahara, H. 2020.
Age es�ma�on by DNA methyla�on in Antarc�c minke
whales. Fish Sci 86 (1): 35–41.
2021 (13)Cunen, C., Walløe, L., Konishi, K. and Hjort, N.L. 2021.
Decline in body condi�on in the Antarc�c minke whale(Balaenoptera bonaerensis) in the Southern Ocean
during the 1990s. Polar Biol 44 (2): 259–273.
Fujise, Y. and Pastene, L.A. 2021. Whales as indicators ofhistorical and current changes in the marine ecosystemof the Indo-Paciﬁc sector of the Antarc�c. pp. 85–103.
In: M. Kanao, D. Godone and N. Dema�eis (Eds.).
Glaciers and Polar Environment. IntechOpen, London.
200 pp.
Isoda, T., Matsuoka, K., Tamura, T. and Pastene, L.A. 2021.
Spa�al and temporal distribu�on of ﬂoa�ng marine
macro debris in the Indo-Paciﬁc region of the Antarc�c.
Cetacean Population Studies 3: 198–211.
Isoda, T., Tamura, T. and Pastene, L.A. 2021. Inges�on ofmarine debris and evidence of entanglements involving Antarc�c minke whales (Balaenoptera bonaerensis)
sampled in the Indo-Paciﬁc sector of the Antarc�c.
Cetacean Population Studies 3: 286–294.
Kato, H., Fujise, Y., Nakamura, G., Hakamada, T., Pastene,
L.A. and Best, P.B. 2021. Dwarf minke whales: morphology, growth and life history based on samples collectedfrom the higher la�tudes in the Southern Hemisphere.
Cetacean Population Studies 3: 93–128.
Kim, Y., Nishimura, F., Bando, T., Fujise, Y., Nakamura, G.,
Murase, H. and Kato, H. 2021. Fetal development in tailﬂukes of the Antarc�c minke whale. Cetacean Population Studies 3: 231–238.
Konishi, K. and Tamura, T. 2021. Preliminary use of nearinfrared spectroscopy to es�mate the biochemicalcomponents of the muscles of the Antarc�c minke
whale Balaenoptera bonaerensis. Cetacean Population
Studies 3: 281–285.
Nakamura, G., Zenitani, R., Bando, T., Fujise, Y., Yamamoto, R., Nishimura, F., Hirose, A., Kim, Y. and Kato, H.
2021. Skeletal measurements on some large cetacean
species done by scien�sts of TUMSAT and ICR. Cetacean Population Studies 3: 215–230.
Nishimura, F., Kim, Y., Bando, T., Fujise, Y., Nakamura,G., Murase, H. and Kato, H. 2021. Morphological differences in skulls and feeding apparatuses between
Antarc�c (Balaenoptera bonaerensis) and common(Balaenoptera acutorostrata) minke whales, and theimplica�on for their feeding ecology. Can. J. Zool. 99
90(12): 1067–1079.
Ohashi, Y., Goto, M., Taguchi, M., Pastene, L.A. and Kitakado, T. 2021. Evalua�on of a paternity method basedon microsatellite DNA genotypes for es�ma�ng theabundance of Antarc�c minke whales (Balaenoptera
bonaerensis) in the Indo-Paciﬁc region of the Antarc�c.
Cetacean Population Studies 3: 139–151.
Pastene, L.A., Goto, M., Taguchi, M. and Matsuoka, K.
2021. Gene�c matches of southern right whales in the
Indian sector of the Antarc�c: a contribu�on towards
understanding their movement and site-ﬁdelity. Cetacean Population Studies 3: 129–138.
Uchida, M., Suzuki, I., Ito, K., Ishizuka, M., Ikenaka, Y.,
Nakayama, S.M.M., Tamura, T., Konishi, K., Bando, T.
and Mitani, Y. 2021. Es�ma�on of the feeding recordof pregnant Antarc�c minke whales (Balaenoptera
bonaerensis) using carbon and nitrogen stable isotope
analysis of baleen plates. Polar Biol 44 (3): 621–629.
*Yamazaki, K., Aoki, S., Katsumata, K., Hirano, D. andNakayama, Y. 2021. Mul�decadal poleward shi� of thesouthern boundary of the Antarc�c Circumpolar Current oﬀ East Antarc�ca. Sci. Adv. 7 (24): eabf8755.
2022 (3)Ishikawa, H., Otsuki, M., Tamura, T., Konishi, K., Bando,
T., Ishizuka, M., Ikenaka, Y., Nakayama, S.M.M. and Mitani, Y. 2022. Foraging ecology of mature male Antarc�c minke whales (Balaenoptera bonaerensis) revealed
by stable isotope analysis of baleen plates. Polar Science 31: 100785.
Pastene, L.A., Goto, M., Taguchi, M. and Fujise, Y. 2022.
Phylogeny and popula�on gene�c structure of minke
whales worldwide: a review of recent studies. pp.
11–37. In: H.A.E. Kaoud (Ed.). Marine Mammals. IntechOpen, London. 126 pp.
Ten, S., Konishi, K., Raga, J.A., Pastene, L.A. and Aznar, F.J.
2022. Epibio�c fauna of the Antarc�c minke whale asa reliable indicator of seasonal movements. Sci. Rep.
12: 22214.
2023 (3)Hamabe, K., Matsuoka, K. and Kitakado, T. 2023. Es�ma�on of abundance and popula�on dynamics of the
Antarc�c blue whale in the Antarc�c Ocean south of
60°S, from 70°E to 170°W. Marine Mammal Science
39 (2): 671–687.
Yasunaga, G., Inoue, S., Bando, T., Hakamada, T. and Fujise,
Y. 2023. Aspar�c acid enan�omer quan�ﬁca�on using
ultraperformance liquid chromatography–tandem
mass spectroscopy combined with deuterium-chlorideList of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2023

hydrolysis to improve age es�ma�on in Antarc�cminke whale Balaenoptera bonaerensis. Marine Mammal Science 39 (2): 368–386.
Yasunaga, G., Inoue, S., Bando, T., Hakamada, T. and Fujise,
Y. 2023. Yasunaga et al. (2022) meets the ethics code ofMarine Mammal Science, and the journalʼs decision to
publish the paper is correct. Marine Mammal Science
39 (2): 709–711.

JARPN/JARPNII/NEWREP-NP surveys
1996 (3)Bu�erworth, D.S., Geromont H.F. and Wada S. 1996.
Further analysis of allele frequency data to provide
es�mates of the extent of mixing between the various
North Paciﬁc minke whale stocks, and their implica�ons 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 es�mate 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 Antarc�c 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. Popula�on 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 migra�on of the Okhotsk Sea-West Paciﬁc stock of minke
whales, es�mates based on length composi�on 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 pa�erns of mitochondrial DNA varia�on in the Brydeʼs whale, Balaenoptera
edeni. Rep. int. Whal. Commn 47: 569–574.
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 es�mateof mixing propor�on 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 ofparasi�sa�on in minke whales (Balaenoptera acutorostrata) from the western North Paciﬁc Ocean andSouthern Sea of Okhotsk. Rep. int. Whal. Commn 48:
475–479.
1999 (2)Le, T.H.L., Takahashi, S., Saeki, K., Nakatani, N., Tanabe,S., Miyazaki, N. and Fujise, Y. 1999. High percentage ofbutyl�n residues in total �n in the livers of cetaceansfrom Japanese coastal waters. Environmental Science& Technology 33 (11): 1781–1786.
Mar�nez, I. and Pastene, L.A. 1999. RAPD-typing ofcentral and eastern North Atlan�c and western North
Paciﬁc minke whales, Balaenoptera acutorostrata. ICES
Journal of Marine Science 56 (5): 640–651.
2000 (2)Punt, A.E., Bu�erworth, D.S. and Wada, S. 2000. On theuse of allele frequency data within a Bayesian framework: evalua�on of rela�ve probabili�es of alterna�ve
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.
91Technical Reports of the Ins�tute of Cetacean Research (2023)

and Miyashita, T. 2001. Spa�al and temporal structureof the western North Paciﬁc minke whale distribu�oninferred from JARPN sigh�ngs data. J. Cetacean Res.
Manage. 3 (2): 193–200.
2002 (5)Abe, H. and Goto, M. 2002. The applica�on of microsatellite DNA for determining popula�on structure of minke
whale. pp. 109–113. In: A. Nishimura (Ed.). Technical
Reports of the Hokkaido National Fisheries ResearchInstitute No.5. Hokkaido Na�onal Fisheries ResearchIns�tute, Hokkaido.
Cui, G., Punt, A.E., Pastene, L. A. and Goto, M. 2002.
Bayes and Empirical Bayes approaches to addressing
stock structure ques�ons using mtDNA data, with anillustra�ve applica�on 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 (Suppl. I):
260–263.
Pastene, L.A., Goto, M. and Kanda, N. 2002. The u�lity of
DNA analysis for the management and conserva�on oflarge whales. Fish Sci 68 (Suppl. 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.
2003 (4)Hayashi, K., Nishida, S., Yoshida, H., Goto, M., Pastene,
L.A. and Koike, H. 2003. Sequence varia�on 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 (Suppl.) 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-infec�on in baleen whales (Mys�ce�) 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 a92minke whale liver. Marine Environmental Research 58:
495–498.
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 characteriza�on 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. Rela�onship between serum sex hormone
concentra�ons 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. Distribu�on 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 osmoregula�on 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. Phylogene�c reconstruc�on of baleen whales and detec�on of their pastextensive radia�on event by the SINE inser�on 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 phyloge-

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2023

ne�cs and evolu�on of mys�cete whales. Systematic
Biology 54 (1): 77–90.
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. Gene�ccharacteris�cs 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.
Pa�erns 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
radia�on event revealed by SINE inser�on 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 inves�ga�on of inﬂuenza a virus infec�on 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. A�empt at
intracytoplasmic sperm injec�on 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. Popula�on gene�c 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: Gona�dae) 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 selec�on of common minke (Balaenoptera acutorostrata) and Brydeʼs (Balaenoptera
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. Iden�ﬁca�on andhepa�c 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. Phylogene�c rela�onships 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. Sequencevaria�on 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. Radia�on andspecia�on 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 characteriza�on 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.
Fer�lizability 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. Fer�lizability 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,
93

Technical Reports of the Ins�tute of Cetacean Research (2023)

Part B 149: 227–235.
Ishikawa, H. and Shigemune, H. 2008. Compara�ve 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 Antarc�c 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. A�empts at in vitro fer�liza�on 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. Valida�on of high-throughput measurement
system with microwave-assisted extrac�on, fully automated sample prepara�on device, and gas chromatography-electron capture detector for determina�onof 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 characteris�cs 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 consump�on 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. Produc�on ofcloned sei whale (Balaenoptera borealis) embryos byinterspecies soma�c 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 es�ma�on 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. Acous�c characteriza�on of biological backscatterings in the Kuroshio-Oyashio inter-frontal zone andsubarc�c waters of the western North Paciﬁc in spring.
94

Fish. Oceanogr. 18 (6): 386–401.
Murase, H., Nagashima, H., Yonezaki, S., Matsukura, R.
and Kitakado, T. 2009. Applica�on of a generalized addi�ve model (GAM) to reveal rela�onships between
environmental factors and distribu�ons 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 dipep�des 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. Produc�on of sei whale(Balaenoptera borealis) cloned embryos by inter- andintra-species soma�c 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 observa�ons. Mammal Study 35 (1): 9–15.
Ogawa, G., Ishida, M., Kato, H., Fujise, H. and Urano, N.
2010. Iden�ﬁca�on of faculta�ve anaerobic bacteria
isolated from the intes�ne 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 mul�discipline 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 diﬀeren�a�on
factor 2, and possible cetacean-speciﬁc responses
against Gram-nega�ve 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 ofequilibra�on steps, type of sugars and addi�on ofwhale follicular ﬂuid on viability and in vitro matura�on 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．Spa�al analysis of isada krill (Euphausia paciﬁca)

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2023

distribu�on in frontal environments in the North Pacific Ocean．GIS/spatial analyses in ﬁsheries and aquatic
science．4．Interna�onal Fishery GIS Society: 115–138.
2011 (20)
Hakamada, T. and Matsuoka, K. 2011. Abundance es�mate 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. Gene�c 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. Rela�onship 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.
Distribu�on of baleen whales in the western North Paciﬁc based on the JARPN and JARPN II sigh�ng 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 quan�ta�ve 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 biomasses�ma�on 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 selec�on 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).
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 objec�ves. 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, objec�ves andresearch progress made in the ﬁrst six years period(2002–2007), including scien�ﬁc considera�ons for the
next research period. Aquabiology 33 (2): 171–185 (inJapanese).
Sasaki, Y., Saito, S., Matsuoka, K., Murase, H. and Kiwada.,
H. 2011. Spa�al distribu�on pa�erns 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,rela�on of habitat factor and prey consump�on 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 selec�on of common minke whale oﬀ Kushiro
in autumn—Es�ma�on of distribu�on and migra�onof common minke whale using environmental informa�on—. Bull. Jpn. Soc. Fish. Oceanogr. 75 (3): 182–183(in Japanese).
Yamaguchi, A., Hanamiya, Y., Murase, H. and Watanabe,
H. 2011. Ver�cal ﬂux of materials by diel ver�cal migra�on 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
95

Technical Reports of the Ins�tute of Cetacean Research (2023)(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) collec�ons 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 distribu�on pa�erns and biomass es�ma�on of Japanese anchovy Engraulis japonicus in thewestern North Paciﬁc. Fish Sci 78 (4): 761–773.
Nakamura, G., Kato, H. and Fujise, Y. 2012. Rela�ve
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 selec�on of common minke, sei, andBrydeʼs whale in mesoscale during summer in the
sub-arc�c and transi�on 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. Popula�on diﬀeren�a�on 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 es�ma�on in common minke
whales using the method of gela�nized extrac�on of
earplug. NAMMCO Scientiﬁc Publications 10: 17 pp.
Matsukura, R., Sawada, K., Abe, K., Minami, K., Nagashima, H., Yonezaki, S., Murase, H. and Miyashita,
K. 2013. Comparison of measurements and model
calcula�ons 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 diﬀeren�a�on between sei(Balaenoptera borealis) and Brydeʼs whales (B. brydei)
in the western North Paciﬁc. Fish. Oceanogr. 22 (6):96496–508.
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 varia�ons of signaling lymphocyte ac�va�on molecule andmortality caused by morbillivirus infec�on 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 tes�s 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.
Distribu�on of sei whales (Balaenoptera borealis) in
the subarc�c–subtropical transi�on area of the western North Paciﬁc in rela�on to oceanic fronts. Deep
Sea Research Part II: Topical Studies in Oceanography
107: 22–28.
Nakamura, G., Kadowaki, I., Nagatsuka, S., Fujise, Y.,
Kishiro, T. and Kato, H. 2014. Varia�on in a color pattern of white patch on the ﬂippers of North Paciﬁc
common minke whales: poten�al applica�on 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. Gene�c 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 func�ons 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 (6)Hirako, S., Suzuki, M., Kim, H., Iizuka, Y., Matsumoto,List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2023

A., Wada, N., Okabe, M., Takenoya, F., Yasunaga, G.,
Yamanaka, S., Miyazaki, A. and Shioda, S. 2016. Hepa�clipid accumula�on is ameliorated in obese KK mice by
dietary sei whale oil. Fish Sci 82 (3): 509–517.
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 poten�al morphological index to iden�fy
stocks. Open Journal of Animal Sciences 6: 116–122.
Nakamura, G., Takahashi, M., Hirose, A., Hayashi, R.,
Fujise, Y., Miyakawa, N., Inoue, S. and Kato, H. 2016.
Presence of an interparietal bone and morphologicalvaria�on in the vertex of the skull in North Paciﬁc common minke whale. La mer 54 (1): 1–10.
Ohishi, K., Bando, T., Abe, E., Kawai, Y., Fujise, Y. andMaruyama, T. 2016. Long-term and large-scale epidemiology of Brucella infec�on in baleen whales andsperm whales in the western North Paciﬁc and Antarc�c Oceans. J. Vet. Med. Sci. 78 (9): 1457–1464.
2017 (3)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 rela�ve to the ver�cal distribu�on of their poten�al prey. Mammal Study 42 (4):
191–199.
Maeda, H., Fujise, Y., Kishiro, T. and Kato, H. 2017. U�lityof the transi�on phase in earplugs of the North Paciﬁc
common minke whale as an indicator of age at sexual
maturity. Open Journal of Animal Sciences 7: 414–424.
2018 (3)Hirose, A., Kishida, T. and Nakamura, G. 2018. Nasal mucosa resembling an olfactory system in the common
minke whale (Balaenoptera acutorostrata). Cetacean

Population Studies 1: 25–28.
Huijser, L.A.E., Bérubé, M., Cabrera, A.A., Prieto, R., Silva,
M.A., Robbins, J., Kanda, N., Pastene, L.A., Goto, M.,
Yoshida, H., Vikingsson, G.A. and Palsbøll, P.J. 2018.
Popula�on structure of North Atlan�c and North Paciﬁc sei whales (Balaenoptera borealis) inferred frommitochondrial control region DNA sequences and microsatellite genotypes. Conserv Genet 19: 1007–1024.
Nakamura, G., Ryeng, K.A., Kadowaki, I., Hayashi, R.,
Nagatsuka, S., Hirose, A., Fujise, Y. and Haug, T. 2018.
Comparison of shapes of the white ﬂipper patch
between two sub-species of common minke whales(Balaenoptera acutorostrata). Cetacean Population
Studies 1: 15–24.
2019 (1)
Watari, S., Murase, H., Yonezaki, S., Okazaki, M., Kiyofuji,
H., Tamura, T., Hakamada, T., Kanaji, Y. and Kitakado, T.
2019. Ecosystem modeling in the western North Paciﬁcusing Ecopath, with a focus on small pelagic ﬁshes. Mar
Ecol Prog Ser 617–618: 295–305.
2020 (1)Yasunaga, G. and Fujise, Y. 2020. Concentra�on of persistent organic pollutants (POPs) in three species ofbaleen whales in the western North Paciﬁc. Cetacean
Population Studies 2: 39–53.
2021 (8)Bando, T. 2021. Improved es�mates of some life-history
parameters of the pelagic subspecies of Brydeʼs whalein the western North Paciﬁc. Cetacean Population
Studies 3: 239–245.
Gomes, T.L., Quiazon, K.M., Kotake, M., Fujise, Y., Ohizumi, H., Itoh, N. and Yoshinaga, T. 2021. Anisakis spp.
in toothed and baleen whales from Japanese waters
with notes on their poten�al role as biological tags.
Parasitology International 80: 102228.
Maeda, H. and Kato, H. 2021. Seasonal changes in theearplug germinal layers of North Paciﬁc common minke
whales. Cetacean Population Studies 3: 246–251.
Matsuoka, K., Hakamada, T. and Miyashita, T. 2021. A
note on recent surveys for right whales Eubalaena japonica in the western North Paciﬁc. Cetacean Population Studies 3: 252–257.
Nakamura, G., Zenitani, R., Bando, T., Fujise, Y., Yamamoto, R., Nishimura, F., Hirose, A., Kim, Y. and Kato, H.
2021. Skeletal measurements on some large cetacean
species done by scien�sts of TUMSAT and ICR. Cetacean Population Studies 3: 215–230.
97

Technical Reports of the Ins�tute of Cetacean Research (2023)

Nishimura, F., Kim, Y., Bando, T., Fujise, Y., Nakamura,G., Murase, H. and Kato, H. 2021. Morphological differences in skulls and feeding apparatuses between
Antarc�c (Balaenoptera bonaerensis) and common(Balaenoptera acutorostrata) minke whales, and theimplica�on for their feeding ecology. Can. J. Zool. 99(12): 1067–1079.
Suyama, S., Yanagimoto, T., Nakai, K., Tamura, T., Shiozaki,
K., Ohshimo, S. and Chow, S. 2021. A taxonomic revision of Pennella Oken, 1815 based on morphology andgene�cs (Copepoda: Siphonostomatoida: Pennellidae).
Journal of Crustacean Biology 41 (3): ruab040.
Taguchi, M., Goto, M., Milmann, L., Siciliano, S., Tiedemann, R. and Pastene, L.A. 2021. New insights into thegene�c structure of sei whales (Balaenoptera borealis)at the inter-oceanic scale. Cetacean Population Studies
3: 152–163.
2022 (3)Pastene, L.A., Goto, M., Taguchi, M. and Fujise, Y. 2022.
Phylogeny and popula�on gene�c structure of minke
whales worldwide: a review of recent studies. pp.
11–37. In: H.A.E. Kaoud (Ed.). Marine Mammals. IntechOpen, London. 126 pp.
Takahashi, M., Tamura, T., Bando, T. and Konishi, K. 2022.
Feeding habits of Brydeʼs and sei whales in the western North Paciﬁc inferred from stomach contents andskin stable isotope ra�os. Journal of Sea Research 184:
102204.
Zhu, Y., Mizutani, K., Minami, K., Shirakawa, H., Kawauchi, Y., Shao, H., Tomiyasu, M., Iwahara, Y., Tamura,T., Ogawa, M., Tatsuyama, K. and Miyashita, K. 2022.
Target strength measurements of free-swimming
sandeel species, Ammodytes spp., in a large indoor
experimental aquarium. Journal of Marine Science andEngineering 10 (7): 966.
2023 (3)Murase, H., Matsuoka, K. and Watanabe, K. 2023. Eﬀect
of sea surface temperature on the distribu�on of common minke whales oﬀ southeastern Hokkaido, Japan,
between 2002 and 2006, with notes on the forma�onof Paciﬁc saury ﬁshing grounds. Cetacean Population
Studies 4: 7–18.
Saito, R., Bando, T., Kotaniguchi, M., Tamura, T., Kuno,
T., Watanabe, K., Mizukami, Y., Kitamura, S. and Kadokawa, H. 2023. Ethanolamine plasmalogens derived
from whale brain s�mulate both follicle-s�mula�ng
hormone and luteinizing hormone secre�on by bovine
gonadotrophs. Animal Science Journal 94 (1): e13839.
98

Taguchi, M., Goto, M., Matsuoka, K., Tiedemann, R. andPastene, L.A. 2023. Popula�on gene�c structure of
Brydeʼs whales (Balaenoptera brydei) on the central
and western North Paciﬁc feeding grounds. Can. J. Fish.
Aquat. Sci 80: 142–155.

Other surveys
1993 (2)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.
Taga, Y. 1993. Generaliza�on of HT strategy and its
applica�on. Yokohama Mathematical Journal 40 (2):
163–173.
1995 (1)Shimada, H. and Pastene, L.A. 1995. Report of a sightings survey oﬀ the Solomon Islands with comments on
Brydeʼs whale distribu�on. Rep. int. Whal. Commn 45:
413–418.
1997 (4)Kimura, T., Ozawa, T. and Pastene, L.A. 1997. Sample
prepara�on and analysis of mitochondrial DNA fromwhale baleen plates. Marine Mammal Science 13 (3):495–498.
Ljungblad, D.K., Staﬀord, K.M., Shimada, H. and Matsuoka, K. 1997. Sounds a�ributed 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 Subarc�c 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

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2023

Science 14 (2): 209–220.
1999 (5)Corkeron, P.J., Ensor, P. and Matsuoka, K. 1999. Observa�ons of blue whales feeding in Antarc�c waters. Polar
Biol 22 (3): 213–215.
Iino, Y. 1999. Treaty Implementa�on: the 1946 Interna�onal Conven�on for the Regula�on 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 sigh�ng
survey in Chileʼs Exclusive Economic Zone with comments on sei whale distribu�on. 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 ar�odactyls: 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. Phylogene�c rela�onshipsof 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 “Scien�ﬁc
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. Diving 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. Accumula�on ofbutyl�n compounds and total �n 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. Prac�cal use of mul�plex ﬂuorescent PCR for
cetacean sex iden�ﬁca�on. Marine Mammal Science
17 (3): 657–664.
Yoshida, H., Yoshioka, M., Shirakihara, M. and Chow, S.
2001. Popula�on 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 varia�ons ininfec�on 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 sigh�ng 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 Antarc�c 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 accumula�on 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 (school
size, sigh�ng cue, la�tude and sea state) on the Antarc�c minke whale abundance es�ma�on 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 iden�ﬁca�on 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 distribu�on of trace elements in blacktailed gulls from Rishiri Island, Japan: age-dependentaccumula�on 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. Concentra�onsof trace elements in marine ﬁsh and its risk assess99

Technical Reports of the Ins�tute of Cetacean Research (2023)

ment in Malaysia. Marine Pollution Bulletin 51 (8–12):
896–911.
Fukui, Y., Ishikawa, H. and Ohsumi, S. 2005. Diﬃcul�es
in publishing research results from scien�ﬁc whaling.
Marine Mammal Science 21 (4): 781–783.
Prudente, M., Tanabe, S., Kunisue, T., Yasunaga, G., Watanabe, I. and Miyazaki, N. 2005. Accumula�on 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 popula�on
structure in eastern South Paciﬁc common bo�lenose
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. Gene�c
Varia�on of the MHC DQB locus in the ﬁnless porpoise(Neophocaena phocaenoides). Zoological Science 23(2): 147–153.
Mori, M. and Bu�erworth, D.S. 2006. A ﬁrst step towards
modelling the krill–predator dynamics of the Antarc�cecosystem. 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 Antarc�c 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. Doeselas�n contribute to the persistence of corpora albican�a 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. Migra100

tory des�na�ons 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.,
Galle� 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., Gerrode�e, 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 distribu�on, densi�es 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. Observa�on 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
distribu�on and migra�on. Japan Cetology 20: 21–29(in Japanese).
Pastene, L.A. and Quiroz, D. 2010. An Outline of the History of Whaling in Chile. pp. 73–98. In: Interna�onal
Center for Folk Culture Studies (Ed.). Human Culture
from the Perspective of Traditional Maritime Communities, International Symposium Report No. 1. Kanagawa
Shimbun Press, Kanagawa. 199 pp.
Taguchi, M., Ishikawa, H. and Matsuishi, T. 2010. Seasonal
distribu�on 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 Antarc�c 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List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2023

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 spa�al 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 gene�cally dis�nct 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 Kiriba�
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 fa�gue induced by physical load
and by daily ac�vi�es in humans. Jpn. Pharmacol. Ther
41 (9): 879–893 (in Japanese).
2014 (3)Pastene, L.A. 2014. Macaya Hermanos y Compania.
Notas sobre las ac�vidades 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 communi�es. pp. 61–70. In: J.E. Ringstad (Ed.).
Whaling and History IV. Commander Chr. Christensenʼs
Whaling Museum, part of Ves�oldmuseene IKA, Sande�ord. 192 pp.
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. Inves�ga�ng popula�on gene�c structure in a highly mobile marine organism: theminke whale Balaenoptera acutorostrata acutorostrata in the North East Atlan�c. 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 bo�lenose
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., O�, P.H. and Aguayo-Lobo, Anelio. 2015.
Popula�on gene�c 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
specia�on and selenium in toothed-whale muscles.
Environmental Research 143: 55–61.
2017 (3)Funasaka, N., Kirihata, T., Hosono, M., Kato, K. andOhsumi, S. 2017. Three Cases of Anomalously White
Rissoʼs Dolphins Grampus griseus in Japan. Mammal
Study 42 (3): 173–178.
Hakamada, T., Matsuoka, K., Murase, H. and Kitakado, T.
2017. Es�ma�on of the abundance of the sei whale
Balaenoptera borealis in the central and eastern North
Paciﬁc in summer using sigh�ng 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 diagnos�c markers for inves�ga�ng global migra�on and hybridiza�on between minke whale species.
BMC Genomics 18: 76.
2019 (1)Takahashi, M., Kato, H. and Kitakado, T. 2019. Sex predic�on by machine learning methods for small sample
sizes: a case study of cranial measurements of killer
whales (Orcinus orca). Mammalian Science 59 (1):67–78 (in Japanese).
2020 (2)Kawasaki, K., Mikami, M., Goto, M., Shindo, J., Amano,
M. and Ishiyama, M. 2020. The evolu�on of unusuallysmall amelogenin genes in cetaceans; pseudogeniza�on, X–Y gene conversion, and feeding strategy. Journal of Molecular Evolution 88 (2): 122–135.
Pastene, L.A., Acevedo, J. and Branch, T.A. 2020. Morphometric analysis of Chilean blue whales and implica�ons
for their taxonomy. Marine Mammal Science 36 (1):
116–135.
2021 (4)Diallo, S.T., Sane, A., Nelson, T., Katsumata, T. and Hakamada, T. 2021. Cetaceans oﬀ Gabon based on a 2011sigh�ng survey, with a preliminary density es�mate of
the humpback whale Megaptera novaeangliae. Cetacean Population Studies 3: 258–264.
Katsumata, T., Hirose, A., Nakajo, K., Shibata, C., Murata,
H., Yamakoshi, T., Nakamura, G. and Kato, H. 2021.
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Evidence of winter migra�on of humpback whales tothe Hachijo island, Izu Archipelago oﬀ the southerncoast of Tokyo, Japan. Cetacean Population Studies 3:
164–174.
Milmann, L., Taguchi, M., Siciliano, S., Baumgarten,
J.E., Oliveira, L.R., Valia�, V.H., Goto, M., O�, P.H.
and Pastene, L.A. 2021. New gene�c evidences fordis�nct popula�ons of the common minke whale(Balaenoptera acutorostrata) in the Southern Hemisphere. Polar Biol 44 (8): 1575–1589.
Takahashi, M., Nakamura, G. and Kato, H. 2021. Growthrelated changes in the cranium of killer whales in thewestern North Paciﬁc. Cetacean Population Studies 3:
175–188.
2022 (6)Cabrera, A.A., Schall, E., Bérubé, M., Anderwald, P.,
Bachmann, L., Berrow, S., Best, P.B., Clapham, P.J.,
Cunha, H.A., Dalla Rosa, L., Dias, C., Findlay, K.P., Haug,
T., Heide-Jørgensen, M.P., Hoelzel, R., Kovacs, K.M.,
Landry, S., Larsen, F., Moreira Lopes, X., Lydersen, C.,
Ma�la, D.K., Oos�ng, T., Pace III, R.M., Pape�, C., Paspa�, A., Pastene, L.A., Prieto, R., Ramp, C., Robbins, J.,
Sears, R., Secchi, E.R., Silva, M.A., Simon, M., Víkingsson, G., Wiig, Ø., Øien, N. and Palsbøll, P.J. 2022. Strong
and las�ng impacts of past global warming on baleen
whales and their prey. Global Change Biology 28 (8):2657–2677.
Dolar, L., Barbieri, M., Crespo, E.A., Palacios, D.M., Pastene, L.A., Ponnampalam, L.S., Rajamani, L., Reyes,
J.C., Rojas-Bracho, L., Secchi, E., Segniagbeto, G.H.,
Siciliano, S., Sutaria, D.N., Urbán, J., Wang, J.Y., Yamada,
T.K. and Van Waerebeek, K. 2022. William Fergus Perrin—a marine mammalogist ʻfor all seasonsʼ: 20 August
1938–11 July 2022. Latin American Journal of Aquatic
Mammals 17 (2): 133–141.
Hirose, A., Kodera, R., Uekusa, Y., Katsumata, H., Katsu-

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The institute of cetacean Research′
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