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TECHNICAL REPORTS OF THE
INSTITUTE OF CETACEAN RESEARCHTEREP-ICR
No. 2

The Institute of Cetacean Research (ICR)
Tokyo, 2018

Technical Reports of the Institute of Cetacean Research (2018)

p. i

Foreword
It is a pleasure for me to introduce the second issue of the Technical Reports of the Institute of Cetacean Research(TEREP-ICR). As explained in the presentation of the ﬁrst issue, the main objective of the TEREP-ICR is to describe andreport on the process, progress, or results of technical or scientiﬁc research, or the state of a technical or scientiﬁc research program conducted by the Institute of Cetacean Research (ICR).
I believe that the production of the ﬁrst issue of the TEREP-ICR was an important step toward achieving the aim statedabove. TEREP-ICR No. 1 was distributed widely among the scientiﬁc community. It was distributed among approximately
100 individual scientists from Japan and 30 foreign countries. It was also distributed to approximately 160 research
institutions (including universities, research institutes, public libraries, museums and aquariums) both in Japan andforeign countries. I am happy to report that positive comments were received from several colleagues about the highquality of TEREP-ICR No. 1. Some international colleagues noted that TEREP-ICR will contribute to increased researchcollaboration because it informs external scientists of the kind of data/samples collected and the kind of technical andscientiﬁc research conducted by ICR scientists. I appreciate these comments because they validate the main purpose of
the TEREP-ICR.
I sincerely hope that this second issue of the TEREP-ICR will continue contributing to an increased understanding of
the technical and research activities conducted by the ICR among the national and international scientiﬁc community.
Dr. Yoshihiro Fujise
Director General ICRTokyo, December 2018iTechnical Reports of the Institute of Cetacean Research (2018)

p. iii

Editorial
Welcome to the second issue of the Technical Reports of the Institute of Cetacean Research (TEREP-ICR).
This second issue contains nine research articles and one commentary article. The ﬁrst research article interprets theresults of several biological and ecological studies on large whales under the JARPA and JARPAII in the Antarctic ecosystem in the context of two hypotheses, the ʻkrill surplusʼ hypothesis at the middle of the past century and the hypothesisof recovery of large whales since the 1980ʼs. The second article explains the purposes and the progress of the ecosystemmodeling studies conducted by the ICR in both the Antarctic and western North Paciﬁc. The next article summarizes theinformation on spatial and temporal distribution of large whales in the Indo-Paciﬁc region of the Antarctic, emphasizing the importance of long-term monitoring research programs. Other articles summarize the biological information
obtained from Antarctic ﬁn and western North Paciﬁc Brydeʼs whales, two species for which biological information isvery limited for the period after the commercial whaling. This issue also contains an article explaining the criteria of the
ICR for evaluating novel non-lethal research techniques in whales. In relation to this, one article is included that explains
and summarizes the research being conducted to investigate the feasibility of novel non-lethal techniques for investigating the age and reproductive status of whales. Two articles deal with results of routine non-lethal research, the ﬁrst
summarizes the surveys on marine debris conducted by the ICR in the Antarctic, and the second summarizes the dataon photo-identiﬁcation of three Antarctic baleen whale species in the Antarctic. The commentary article deals with theissue of the ethics of whaling.
This second issue also includes sections to outline the contribution of ICR scientists to national and international
meetings in 2018 as well as their contribution in terms of peer reviewed publications up to December 2018.
I hope you will ﬁnd this second issue informative and useful.
Dr. Luis A. Pastene
Editor TEREP-ICR
Tokyo, December 2018iii

Technical Reports of the Institute of Cetacean Research (2018)

p. v

Contents
Forewordi

Editorialiii

Contentsv

Technical Reports
Fujise, Y. and Pastene, L.A. Cetaceans as indicators of historical and current changes in the Antarctic
ecosystem

1

Hakamada, T. and Tamura, T. An overview of the Institute of Cetacean Research work on ecosystemmodeling in the Antarctic and western North Paciﬁc
14
Matsuoka, K. and Hakamada, T. Geographical distribution of whales in the Indo-Paciﬁc region of the
Antarctic based on JARPA and JARPAII sighting data collected in the period 1987/88–2008/09
20
Bando, T. Earplug-based age determination and estimation of biological parameters inNorth Paciﬁc Brydeʼs whales based on samples collected by JARPNII
32
Mogoe, T. Biological observations of ﬁn whales sampled by JARPAII in the Indo-Paciﬁc region of
the Antarctic
38
Mogoe, T. Field and analytical protocol for the evaluation of novel non-lethal techniques in theJapanese whale research programs
50
Goto, M. and Inoue, S. Results of feasibility studies on novel non-lethal techniques to address themain objectives of NEWREP-A
56
Isoda, T., Tamura, T. and Pastene, L.A. Using JARPA and JARPAII platforms for investigating theoccurrence of marine debris in the Indo-Paciﬁc region of the Antarctic
64

Technical Reports-Note
Matsuoka, K. and Pastene, L.A. A summary of photo-id information of blue, southern right andhumpback whales collected by JARPA/JARPAII in the Indo-Paciﬁc region of the Antarctic
74

Commentary
Ohmagari, K. Ethics of Whaling: Is whaling truly immoral?

77

International meetings

79

National meetings

81

Peer-reviewed publications

83v

Technical Reports of the Institute of Cetacean Research (2018)

pp. 1–13

Technical Report (not peer reviewed)

Cetaceans as indicators of historical and current changes in the
Antarctic ecosystem
Yoshihiro Fujise* and Luis A. Pastene
Institute of Cetacean Research, Toyomi-cho 4–5, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: fujise@cetacean.jp

ABSTRACT
Changes in the Antarctic ecosystem are triggered by anthropogenic and natural factors. This paper reviews thescientiﬁc information on whales produced mainly by the Institute of Cetacean Research (ICR), that could be indicative of changes in the Antarctic ecosystem in the context of two hypotheses, the ʻkrill surplusʼ hypothesis in
the middle of the past century, and the hypothesis of recovery of krill-eater large whales since the 1980ʼs. The
information in the Indo-Paciﬁc region of the Antarctic (70°E–170°W) showed that the increased krill availability
in the middle of the past century could have been translated into better nutritional conditions for some krill
predators like the Antarctic minke whale, resulting in a decreasing trend in the age at sexual maturity and anincreasing trend in the recruitment rate and total population size of this species between approximately 1940
and 1970. The evidence available since the 1980ʼs showed a sharp increase in the abundance of some species
such as the humpback and ﬁn whales, which had been heavily exploited in the ﬁrst half of the past century.
The evidence also showed that, in parallel to this increase, the nutritional condition of Antarctic minke whales
has deteriorated as revealed by a decrease in energy storage and stomach content weight since the 1980ʼs.
This observation is consistent with the stable trend of age at sexual maturity, recruitment and abundance of
this species after the 1980ʼs. Therefore the historical demographic changes observed in the Antarctic minke
whale are consistent with the pattern expected under the ʻkrill surplusʼ hypothesis, while the demographic
and ecological changes observed in recent years are consistent with the changes expected under the reverseof the ʻkrill surplusʼ hypothesis.

INTRODUCTION
The Antarctic ecosystem is a very dynamic one withchanges in species composition and habitat occurring
through time. Within this ecosystem the Antarctic krill(Euphausia superba) is a key prey species supporting different species of baleen whales, pinnipeds, birds and ﬁsh.
Changes in the ecosystem can be derived from humaninterventions or from natural causes. One example ofthe former is the large-scale exploitation of whales in theﬁrst half of the 20th Century, which has been discussed
by several authors, notably by Laws (1977; 1985). Exploitation of large whales in the Antarctic Ocean started in
1904. Several species of krill-eater large whales such as
Antarctic blue (Balaenoptera musculus intermedia) andhumpback (Megaptera novaeangliae) whales were heavily depleted by commercial whaling by the ﬁrst half of thepast century. Other species such as the ﬁn (B. physalus)
whales were depleted during the second half of the 20th
Century. Large changes in the biomass of some whale

species had a strong eﬀect on the demography of otherkrill-eater predators in the Antarctic ecosystem (Laws
1977; 1985).
One example of the latter are the environmental
changes reported in recent years for some parts of the
Antarctic. For example Fraser et al. (1992) suggested
that the increase in chinstrap penguin populations in thelast four decades (1950ʼs–1990ʼs) were due to a gradualdecrease in the frequency of cold years with extensive
winter sea ice cover resulting from environmental warming. Their observation was supported by a multidisciplinary winter expedition to the Scotia and Weddell seas,satellite images of ocean ice cover, and the analysis of
long-term surface temperature records and penguin
demography. Less ice cover means wider open waters
available for penguinʼs feeding on krill. This observation
contradicted the hypothesis that the increases in the
penguin population resulted from an increase in preyavailability brought on by the decrease in baleen whale
stocks. They cited modeling work that predicted that the1Technical Reports of the Institute of Cetacean Research (2018)

Figure 1.

Schematic diagram of ecosystem perturbation in the Scotia Sea (after Trivelpiece et al., 2011).

Table 1
Biological and ecological parameters monitored from whales and their environment to investigate change in the ecosystem.
Research parameter2

How the information is obtained

Relevance of monitoring

Krill biomass

Echo-sounder and net surveys

Krill is a key species in the Antarctic ecosystem.
Changes in its abundance have eﬀects on predatorsand the whole ecosystem.

Whale abundance

Systematic sighting surveys

Fluctuation of abundance of whales through time isimportant for their management. Diﬀerent levels of
whale abundance have diﬀerent impacts on krill.

Whale distribution

Systematic sighting surveys

Distribution of whale species can change with time inresponse to changes in abundance and/or changes inoceanographic conditions/krill availability.

Whale recruitment

Population dynamic models
that use age and abundance
information from whales

Same as above. Index of young whale abundance.

Blubber thickness,
fat weight and girth

Direct measurements fromsampled whales

Index of body condition. Better nutritional condition(e.g. better availability of krill) will be reﬂected inthicker blubber, heavier fat and larger girth.

Stomach content weight

Direct measurements fromsampled whales

Index of body condition. Better nutritional condition
will be reﬂected in heavier stomach contents.

Age at sexual maturity (ASM)

Examination of transition
phase in earplugs; examination of ovaries and testis.

Better nutritional conditions will be reﬂected in a shiftof the ASM to younger ages e.g. whales will be able toreproduce at younger ages.

Pregnancy rate

Examination of ovaries anduterus

Better nutritional conditions will be reﬂected in higher
pregnancy rates.

Oceanographic conditions

Systematic oceanographic surveys based on CTD and XCTD

Changes in oceanographic conditions will aﬀect distribution and krill biomass and in turn the abundanceand distribution of whales. Changes in oceanographic
conditions might indicate an eﬀect of climate changes.

Cetaceans as indicators of historical and current changes in the Antarctic ecosystem

beneﬁts of a reduction in baleen whales would have been
most directly conferred to predators of similar size andbehavior, namely, other whales (Fraser et al., 1992). However more recent analyses in the Antarctic Peninsula andScotia Sea concluded that the chinstrap penguin instead
may be among the most vulnerable species aﬀected by awarming climate (Trivelpiece et al., 2011).
Trivelpiece et al. (2011) presented a very informative
diagram of ecosystem perturbation in West Antarctic(Scotia Sea) due to both, anthropogenic reasons suchas the commercial over-exploitation of marine resources (sealing from 1820 to the 1960ʼs, whaling from1900 to 1970; ﬁshing for ice ﬁshes and Notothenids
from 1960–1980), and natural reasons (climate-change
eﬀects from the 1970ʼs). They noted that a pelagic trawl
ﬁshery for krill also developed from the 1970ʼs, and thatin the 2000ʼs, the once-depleted marine mammal populations had recovered or were recovering, that the krill ﬁshery was expanding, that climate change was progressing
and that Adelie and chinstrap penguin populations weredecreasing (Figure 1). The causes of ecosystem changes
in the Antarctic are therefore complex, and to understandthose causes, long-term monitoring research programs
focused on collecting biological data of krill predators aswell as data on sea ice cover and environmental variables,
are important.
Previous studies have documented ecosystem changes
in West Antarctic, and have considered environmental
variables and demographic information of land-based
krill predators. The objective of this study was to review
the scientiﬁc evidence for expected changes in the IndoPaciﬁc region of the Antarctic, in the context of someestablished hypotheses. The evidence is based mainly
on biological and ecological data of baleen whales, seabased predators, collected by ICR. Table 1 shows the data
monitored in whales and their environment, which are
informative of changes in the ecosystem.

KEY BALEEN WHALES IN THE ANTARCTIC ECOSYSTEM
Baleen whale species, except the Brydeʼs whale, migrateseasonally between low latitude breeding areas in winterto high latitude feeding areas in the Antarctic in summer. The main prey of baleen whales such as Antarctic
blue, ﬁn, humpback and Antarctic minke (B. bonaerensis)
whales is the Antarctic krill therefore their summer migrations to the Antarctic are related to areas of krill concentrations as those shown in Figure 2. Breeding areas of
the humpback whales occurring in the Antarctic researcharea are located in both Western and Eastern Australia.

Figure 2.

Areas of krill distribution in the Antarctic associatedwith gyres (after Nicol, 2006).

Breeding areas for the other species are assumed to be
in low latitudes of the eastern Indian and western South
Paciﬁc Oceans.
Antarctic blue whale
This is the largest baleen whale species. The record for awhale killed in the Southern Hemisphere in the ﬁrst halfof the past century was a body length of more that 30 m
and weight of nearly 180 tons. During the austral summer
season blue whales are distributed mainly above the Antarctic Convergence to the ice edge. Current abundance inall of the Antarctic is approximately 3,000 animals.
Fin whale
This is the second largest baleen whale species witha maximum length of 27.1 m and weight of 120 tons.
During the austral summer season ﬁn whales are foundextensively south of 50°S, most commonly north of 60°S
(Branch and Butterworth, 2001). In the Antarctic ﬁnwhales feed on krill. The existing estimates from limitedparts of the range covered are of the order of several
thousand animals.
Humpback whale
This is a highly migratory species with a maximum bodylength of 17 m and weight of 40 tons. During the australsummer season it is distributed south of the Antarctic
Convergence to the ice edge but just north of the main3

Technical Reports of the Institute of Cetacean Research (2018)

distribution area of Antarctic minke whale. In the Antarctic, humpback whales feed on krill. The total current
Southern Hemisphere abundance is probably at least
60,000.
Antarctic minke whale
This is one of the smallest baleen whale species with amaximum body length of 10.7 m and weight of 10 tons.
During the austral summer season it is distributed mainly
around the pack-ice and feeds on krill. Abundance ofAntarctic minke whale in the Antarctic was estimated at
515,000 animals (IWC, 2013).

RESEARCH AREA
The review was focused on the Indo-Paciﬁc region of
the Antarctic, in the longitudinal sector between 70°E
and 170°W, south of 60°S, including both Indian (Area
IV according to International Whaling Commission (IWC)
terminology, 70°–130°E) and Paciﬁc (Area V according to
IWC terminology, 130°E–170°W) sectors. The researcharea includes Prydz Bay as its western boundary and theRoss Sea as the eastern boundary.

CHANGES IN THE ANTARCTIC ECOSYSTEM
The review of evidence of changes in the Indo-Paciﬁcregion of the Antarctic is treated in two periods, historicaland current. The former corresponds to the period approximately from the start of commercial whaling in the
Antarctica in 1904 until approximately 1970ʼs, which
Trivelpiece et al. (2011) characterized as ʻfavourable
climate conditions and reduced competition for krillʼ(Figure 1). The latter corresponds to the period from the1970ʼs–1980ʼs to recent years, which those authors char-

Figure 3.
4acterized as ʻunfavorable climate conditions and increasing competition for krillʼ (Figure 1).
Historical changes
The ecological eﬀect of the large-scale exploitation ofwhales in the ﬁrst half of the 20th Century has been discussed by several authors, notably by Laws (1977; 1985).
Exploitation of large whales in the Antarctic Ocean started in 1904. Several species of large whales such as blueand humpback whales were heavily depleted by the ﬁrst
half of the past century (Figure 3). Other species such as
the ﬁn and sei whales were depleted during the second
half of the 20th Century. Commercial exploitation of the
Antarctic minke whale started in the early 70ʼs when allother baleen whale species were already depleted. Table
2 shows the original and current (by 1980) abundanceof large whales exploited in the Southern Hemisphere(mainly Antarctic). In the Southern Hemisphere the abundance of large whale species such as the blue and humpback whales decreased to a minimal percentage of theoriginal abundance before exploitation. In the case of the
Antarctic minke whales, which were not exploited during
the ﬁrst half of the past century, the current abundance
has not changed with regard the original abundance.
As noted earlier, the Antarctic krill is a key prey species
in the Antarctic ecosystem supporting diﬀerent species ofbaleen whales, pinnipeds, birds and ﬁsh. Some researchers have suggested that following the main exploitation
period of large baleen whales in the Antarctic (approximately at the middle of the past century) some 150 million tons of ʻsurplusʼ annual production of Antarctic krill(Figure 4) became available for other krill predators, suchas Antarctic minke whales, crabeater seals, fur seals, pen-

Catches of baleen whales in the southern Hemisphere, 1910–1977 (after Allen, 1980).

Cetaceans as indicators of historical and current changes in the Antarctic ecosystem

Figure 4.

Initial and present (1970ʼs) biomass and annual krill consumption of exploited large baleen whale species
and other predators in the Antarctic (after Laws, 1977; Sahrhage, 1984).
Table 2
Original and current (by 1980) abundance of exploited large whales in the Southern
Hemisphere (modiﬁed of Allen, 1980).

guins and some albatrosses which took advantage of thisfood surplus to increase their abundance. This is the socalled ʻkrill surplusʼ hypothesis (Laws, 1977; 1985).
Inter-speciﬁc eﬀects of the surplus hypothesis
Antarctic minke whale
As shown in Table 2, Antarctic minke whales were notexploited in the ﬁrst half of the past century and thecommercial exploitation of this species only started in
the 1970ʼs at a moderate scale under management of
the IWC. The expectation here was that the krill surplus
by the middle of the past century translated to better
nutritional conditions, which should have been reﬂectedin changes in demographic parameters of this species.
In particular we focus here on the information on age atsexual maturity and total abundance.
Changes in the age at sexual maturity (ASM) indicate
change in nutritional conditions of the whales, which inturn could indicate less or more food availability in theenvironment. Better nutritional conditions will be reﬂected in a shift of the ASM to younger ages e.g. whales
will be able to reproduce at younger ages and as a consequence the populations will growth faster (Table 1). Oneof the methods for determining age at sexual maturity
in whales is examination of the ʻtransition phaseʼ in theearplugs. The earplugs of several baleen whale stocks exhibit seasonal growth layers which have been shown forsome species to indicate the age of the animals. A transition from early, irregular layers, to later, more regularlayers can be seen in these earplugs, and this is thought
to indicate the age at maturity of the whale (Thomson
et al., 1999). Historical changes in the age at sexual maturity can be investigated when the analyses are carriedout on cohorts (groups of whales born in the same year).
Earplugs of Antarctic minke whales were collected during the period of commercial whaling in the early 1970ʼs,
and during Japanese whale research in the Indo-Paciﬁcregion of the Antarctic (JARPA and JARPAII), for morethan 25 years. Thomson et al. (1999) showed a decline
in the average age at transition in Antarctic minke whalesin the Indian sector from roughly 11 for the cohorts of
the 1950ʼs to roughly 7 for those of the 1970ʼs, and thetrend was similar for females and males. This work was
updated by Bando et al. (2014) by using a large numberof samples, and analyses conducted on two biologicalstocks, one mainly distributed in the Indian Ocean sector
and the other in the Paciﬁc Ocean sector.
These results suggested that the nutritional conditions
were optimal for Antarctic minke whales after a period inwhich other krill-predators species such as the Antarctic
5Technical Reports of the Institute of Cetacean Research (2018)

blue and humpback whales were already depleted (Figure 3).
The Scientiﬁc Committee (SC) of the IWC has been
applying statistical catch-at-age (SCAA) analyses on Antarctic minke whales since 2005. A summary history of theapplication of SCAA to this species was presented by Punt(2014), and an assessment of Antarctic minke whales
using SCAA was reported by Punt et al. (2014).
The data used when conducting assessment by SCAA
on Antarctic minke whales consisted of catches, abundance estimates, length frequency data, and conditional
age-at-length data. Diﬀerent series of abundance estimates were used e.g. those from the IWC SCʼs International Decade of Cetacean Research/Southern Ocean
Whale and Ecosystem Research (IDCR/SOWER) as wellas those from Japanese dedicated sighting surveys in the
Indo-Paciﬁc region of the Antarctic. Biological data wereavailable from the period of commercial whaling (Japanand the former Soviet Union), and from Japanese whale
research in the Indo-Paciﬁc region of the Antarctic (JARPA
and JARPAII), for more than 25 years.
The SCAA assessment on Antarctic minke whale involved a ʻreferenceʼ case and several sensitivity tests.
These sensitivity tests explored sensitivity to the weightassigned to the various data sources and penalties, theassumptions related to vulnerability, natural mortality
and catchability, and to the use or otherwise of the Japanese researchʼs index data (Punt et al., 2014).
Results presented here refer to the ʻreferenceʼ casein Punt et al. (2014), which was robust to the sensitivity
tests conducted (Figure 6 for the Indian sector). As shownin Figure 6, the stock was estimated to have increased
from 1930 until the early 1970ʼs, with the stock having
declined subsequently thereafter. The increase in abundance was due primarily to an increase in recruitment
owing in turn to an increase in carrying capacity (Puntet al., 2014).

Figure 6.

6

For historical changes examined in this section, it isinteresting to note that the increase from 1930 to 1970ʼsroughly coincided with the period in which the age atsexual maturity decreased. Again these results suggested
that the nutritional conditions were optimal for Antarctic
minke whales after a period in which other krill-predator
species such as the Antarctic blue and humpback whales
were already depleted (Figure 3).
Summary
According to the ʻkrill surplusʼ hypothesis, the increased
krill availability was translated into better nutritional conditions for some krill predators like the Antarctic minke
whale. In the case of this species this resulted in some

Figure 5.

Changes in the age at sexual maturity of Antarctic
minke whale, by cohort (Indian Ocean sector). Ageat sexual maturity changed from around 11 years in
1950s cohorts to around 7 years in 1970s cohorts(middle curve) (after Thomson et al., 1999).

Time trajectories of total (1+) population size of Antarctic minke whales in the Indian sector (base-case).
The dotted lines indicate 95% asymptotic conﬁdence intervals (after Punt et al., 2014).

Cetaceans as indicators of historical and current changes in the Antarctic ecosystem

biological changes such as the observed decreasing trend
in the age at sexual maturity between approximately
1940 and 1970 (Figure 5), which coincide with the period
of depletion of some key krill-eater large whale species(Figure 3). A low age at sexual maturity favored an increase in the recruitment rate and total population size ina similar period (Figure 6).
The Antarctic minke whale perhaps reached the increased maximum carrying capacity by the late 1960s,
and then the stock responded by stabilizing the age atsexual maturity at 7–8 years old (Figure 5). This biologicalprocess should have resulted in a stable continuous highrate of newborns after 1970 since the recruitment was
rather stable after 1970 (Figure 6). The trend in recruitment is consistent with the trend in total abundance ofAntarctic minke whale estimated by sighting data which
has been broadly stable since the 1980ʼs.
Finally it should be noted that the period of demographic changes observed in Antarctic minke whales
coincides with the period 1900–70ʼs (ʻwhaling eraʼ) in
Trivelpiece et al. (2011), which they characterized as ʻfavorable climate conditions and reduced competition for
krillʼ (Figure 1). Such conditions allowed for rapid growthand increase in populations of the Antarctic minke whaleand other krill-eater predators in that period.

IWC SC (IWC, 2012). The IWC SC carried out three circumpolar sighting surveys under the IDCR/SOWER programs.
Japanese researchers also carried out dedicated sighting
surveys in the Indo-Paciﬁc region using the same methodology and guidelines.
Matsuoka et al. (2011) reported abundance estimatesand abundance trends for two populations of the humpback whales, stock D in the Indian sector (Area IV) andstock E in the Paciﬁc sector (Area V). Results showed thatthe abundance of both stocks has been increasing in thelast decades. Abundance and population growth rates of
humpback whale in the Indian sector and in the Paciﬁc
sector were 31,000 (16.4% increase by year with 95% CI:
9.5–23.3%) and 9,000 (12.1% increase by year with 95%
CI: 1.7–22.6%), respectively. The current abundance ofthe stock in the Indian sector is close to that at its preexploitation level. Figure 7 shows the abundance trend

Current changes
Commercial whaling of humpback, Antarctic blue and ﬁnwhales in the Antarctic was banned in 1963, 1964 and1976, respectively. As an eﬀect of these conservation
measures, the abundance of these species increased inrecent decades, which points toward a recovery frompast commercial exploitation. The speed of recovery varies among these species and among stocks within these
species. The increase in the abundance of large whale
species that feed on krill in the Antarctic means less foodavailable for species like the Antarctic minke whale thatonce beneﬁted from the surplus of krill. It was expectedthat these conditions, which correspond to the ʻreverseʼ
of the krill surplus hypothesis, should have some eﬀect
on the nutritional conditions and on demographic parameters of Antarctic minke whale and other species thatonce beneﬁted from the surplus of krill.
Evidence for the increase in abundance of large whales in
the Indo-Paciﬁc region of the Antarctic
To estimate abundance of large whales in the Antarctic,
systematic sighting surveys have been carried out under
the DISTANCE sampling method (Buckland et al., 2015),
and the guidelines for surveys and analyses agreed by the

Figure 7.

Abundance trend of humpback whale in the Indian
sector (Area IV) and Paciﬁc sector (Area V) based onJapanese dedicated sighting surveys. Black dots areabundance estimates based on the IDCR/SOWER
surveys, which are consistent with those from theJapanese surveys (after Matsuoka et al, 2011).
7

Technical Reports of the Institute of Cetacean Research (2018)of this stock in the Indian and Paciﬁc sectors for the period 1989/90–2003/04, and compares it with the trend
estimated using IDCR/SOWER sighting data (Matsuoka
et al., 2011). There is a clear increasing trend that is consistent between both Japanese and IDCR/SOWER surveys(see Figures 7).
The abundance and annual population growth rates ofﬁn whales in the Indian sector and Paciﬁc sector based onJapanese dedicated sighting surveys were estimated at
6,514 (16.0% CV: 0.78 increase rate) and 5,241 (12.8% CV:
0.60 increase rate) for the period 1989/90–2004/05, respectively (Matsuoka et al., 2005). It should be noted thatabundance estimates for ﬁn whales were made based ondata obtained south of 60°S because the Japanese dedicated sighting surveys did not cover the main distribution areaof ﬁn whales in the austral summer, which is north of 60°S.
The circumpolar abundance of the Antarctic blue
whales based on IDCR/SOWER surveys was estimatedat 1,700 (95% Bayesian interval 860–2,900) in 1996.
Although this ﬁgure corresponds to less than 1% of theoriginal levels, blue whales are increasing at 7.3% perannum (95% Bayesian interval 1.4–11.6%) (Figure 8)(Branch et al., 2004).

Figure 8.

Posterior abundance trajectory (and 95% interval)
from 1965, and the IDCR/SOWER abundance estimates for blue whales in the Antarctic (d) (after
Branch et al., 2004).

Figure 9.

8Possible inter-speciﬁc eﬀects of the recovery of large
whalesAntarctic minke whale
Trend in abundance
Hakamada et al. (2013) estimated abundance and abundance trends of Antarctic minke whale in the Indian sector (Area IV) and Paciﬁc sector (Area V) based on Japanese
dedicated sighting surveys (JARPA and JARPAII), under
the assumption of g(0)=1. Abundance estimates for the
Indian sector range from 16,562 (CV=0.542) in 1997/98
to 44,945 (CV=0.338) in 1999/00, while those for the Paciﬁc sector range from 74,144 (CV=0.329) in 2004/05 to
151,828 (CV=0.322) in 2002/03. Estimates of the annual
rates of increase in abundance are 1.8% with a 95% CI of[−2.5%, 6.0%] for the Indian sector and 1.9% with a 95%
CI of [−3.0%, 6.9%] for the Paciﬁc sector. Adjustments toallow for the g(0) being less than 1 were made by theapplication of a regression model, developed from theresults of the Okamura-Kitakado (OK) method estimateof minke whale abundance from the IDCR-SOWER surveys, which provides estimates of g(0) from the statisticsof the minke whale school size distribution in a stratum.
With this adjustment, abundance estimates increased byan average of 32,333 (106%) for the Indian sector and89,245 (86%) for the Paciﬁc sector, while the estimatesof annual rates of increase and their 95% CIs changedslightly to 2.6% [−1.5%, 6.9%] for the Indian sector and1.6% [−3.4%, 6.7%] for the Paciﬁc sector. See Figure 9 forthe abundance trends in the two sectors.
In 2012 the IWC SC agreed to a new best abundance
estimate for Antarctic minke whale in Antarctic open waters south of 60°S, based on IDCR/SOWER sighting data.
The estimates were 720,000 based on the sighting datacollected during the CPII (1985/86–1990/91) with 95% CI(512,000, 1,012,000), and 515,000 based on the sighting
data collected during the CPIII (1992/93–2003/04) with

The best case estimates of annual abundance of Antarctic minke whale in the Indian sector (Area IV) andPaciﬁc sector (Area V) together with their 95% CIs. The IDCR/SOWER estimates for a common northernboundary for CPII and CPIII are shown by the open triangles. Conﬁdence intervals include allowance for
additional variance. The dashed curves indicate the 95% Cis for the exponential model (after Hakamada
et al., 2013).

Cetaceans as indicators of historical and current changes in the Antarctic ecosystem

95% CI (361,000, 733,000). No signiﬁcant statistical diﬀerences were found between the CPII and CPIII estimates(IWC, 2013).
The estimates in the Indian sector (Area IV) were55,237 (CV: 0.17) in CPII and 59,677 (CV: 0.34) in CPIII. In
the Paciﬁc sector (Area V) were 300,214 (CV: 0.13) in CPII
and 183,915 (CV: 0.11) in CPIII.
By considering the 95% CIs of the estimates it can besuggested that the stocks of Antarctic minke whales arebroadly stable with at most a slight decline.
Changes in spatial distribution
Figures 10 and 11 show the temporal changes in whale
species composition in the Indian sector (Area IV) andPaciﬁc sector (Area V) based on Japanese dedicated sighting surveys. In the Indian sector, humpback whales weremore frequently observed than Antarctic minke whales
in recent years (Figure 10). In the Paciﬁc sector Antarctic
minke whale is still the predominant species (Figure 11).
The increase in abundance of the large whales once
depleted by commercial whaling implies changes in thespatial distribution of whale species. Murase et al. (2014)
examined Japanese dedicated sighting survey data to
study the spatial distribution of Antarctic minke whales
and humpback whales in the Indian sector (Area IV)
during three periods: early (1989/1990, 1991/1992
and 1993/1994), middle (1995/1996, 1997/1998 and1999/2000) and late (2001/2002, 2003/2004 and2005/2006). Spatial distribution was estimated using generalized additive models (GAM). Presence or absence ofwhales was used as the response variable while seaﬂoor
depth, distance from shelf break and longitude were used
as explanatory variables.
Mean probabilities of occurrence of Antarctic minke
whales in the survey area in early, middle and late periods were 0.41, 0.46 and 0.41 while those of humpback
whales were 0.14, 0.35 and 0.46. Occupied area indices(probabilities of occurrence of Antarctic minke whales
minus probabilities of occurrence of humpback whales)
were also calculated. If the index is 1, only Antarctic
minke whales were present in a grid cell while only humpback whales were present if the index is −1. If the index is0, probabilities of presence of Antarctic minke whales andhumpback whales in a grid cell were identical. Mean occupied area indices in early, middle and late periods were0.28, 0.11 and −0.07, respectively. The authors concluded
that the spatial distribution of humpback whales expanded during the period investigated while that of Antarctic
minke whales remained stable. The results suggested thepossibility that competition between humpback and Ant-

Figure 10.

Sighting composition of Antarctic minke, humpback and ﬁn whales in the Indian sector (AreaIV) for two Japanese dedicated sighting surveys,
1995/96 and 2005/06. Note that humpback
whales are more frequently observed than
Antarctic minke whales in recent years (see explanation of data source in Pastene et al., 2014).

Figure 11.

Sighting composition of Antarctic minke, humpback and ﬁn whales in the Paciﬁc sector (AreaV) for two Japanese dedicated sighting surveys,
1996/97 and 2006/07. Note that Antarctic minke
whale is still the predominant species. The composition of humpback whales in the total sighting
have increased but at a slower pace compared to
the Indian sector (see explanation of data source
in Pastene et al., 2014).

arctic minke whales for habitat in the Indian sector (AreaIV) during the period studied could have been intensiﬁed
as abundance of humpback whales increased. A summary of the results are presented in Figure 12.
It should also be mentioned here that Antarctic minke
9Technical Reports of the Institute of Cetacean Research (2018)

Figure 12.

Probability of occurrence of humpback (left) and Antarctic minke (right) whales in the Indian sector (AreaIV) in three periods: early, middle and late (after Murase et al., 2014). Red indicate high probability ofoccurrence.

whales have been observed more frequently in polynias within the pack-ice in recent years (Matsuoka, pers.
comm. 2016), reﬂecting perhaps a response to the geographical expansion of humpback whales.
Nutritional conditions
Nutritional condition in Antarctic minke whales has been
investigated through diﬀerent indices, blubber thickness
under the assumption that the amount of lipids increase
with the thickness of the blubber, girth and total fat.
These data have been collected for more than 25 years by
Japanese research (JARPA and JARPA II) in the Indo-Paciﬁcregion of the Antarctic (Areas IV and V).
Konishi et al. (2008) showed the results of the annual trend in energy storage in sexually mature Antarctic
minke whales based on data collected for a period of
18 years in the Indo-Paciﬁc region. Regression analyses
clearly showed that blubber thickness, girth and fat
weight have been decreasing for nearly two decades.
The decrease per year was estimated at approximately
10

0.02 cm for mid-lateral blubber thickness and 17 kg for
fat weight, corresponding to 9% for both measurements
over the 18-year period (Figure 13).
Konishi et al. (2014) reported the results of an analysisof temporal trend in stomach content weight in the Antarctic minke whale in a 20-year period. A linear mixedeﬀects analysis showed a 31% (95% CI 12.6–45.3%)
decrease in the weight of stomach contents over the 20
years since 1990/91. A similar pattern of decrease wasfound in both males and females, except in the case of
females sampled at higher latitude in the Ross Sea. These
results were consistent with the decline in energy storage reported above. Humpback whales are not found in
the Ross Sea, where both Antarctic krill and ice krill (E.
crystallorophias) are available, and where the authors
found no change in prey availability for Antarctic minke
whales.
These studies suggested a decrease in the availabilityof krill for Antarctic minke whales.

Cetaceans as indicators of historical and current changes in the Antarctic ecosystem

Figure 13.

Yearly trends in blubber thickness (a), fat weight (b) and girth (c) in Antarctic minke whale in the Indo-Paciﬁc region of
the Antarctic from 1987/88 to 2004/05 (after Konishi et al., 2008).

Figure 14.

Yearly age-related changes of hepatic Hg concentrations in the Antarctic minke whale (after Honda et al., 2006).

Pollutant loads
Honda et al. (2006) studied yearly age-related accumulations of Hg in the Antarctic minke whales collected in the
period 1980–1999 in the Indo-Paciﬁc region. One of therelevant results was that of Hg levels and growth rates
in young age-groups (1–5 years old): Hg levels and bodyweights for the 1997/99 season groups were signiﬁcantly
lower than those for the 1988/90 groups. On the other
hand they examined the Hg levels in krill from the whale
stomach, and no yearly signiﬁcant diﬀerences were
found. They concluded that the diﬀerences in Hg levels inyounger age groups was due to diﬀerences in the amountof food intake by the whale i.e. whale are consuming lessfood in recent years (Figure 14). These results are consistent with the decrease in stomach contents weight in
Antarctic minke whales in recent years.

arctic minke whales has stabilized or slightly increased
since the 1970ʼs and 1980ʼs. The recruitment has consistently been broadly stable since the 1970ʼs and the totalabundance estimated by SCAA has been stable or slightly
decreasing (Figure 6). These observations are consistent
with the observation of deteriorated nutritional conditions since the 1980ʼs.
Other species
A recent study showed that the regional population of
the krill-eater Adelie penguin have almost doubled inabundance since the 1980ʼs and have been increasing
since the earliest counts in the 1960ʼs. These results ofdecadal-scale change were based on a combination ofextensive new population survey data, new population
estimation methods, and re-interpretation of historicalsurvey data (Southwell et al., 2015).

Demographic parameters
As shown in Figure 5 the age at sexual maturity for Ant11

Technical Reports of the Institute of Cetacean Research (2018)

Summary
Evidence available since the 1980ʼs has shown that thenutritional conditions for Antarctic minke whales havenot been optimal as revealed by the decrease in energy
storage and stomach content weight since the 1980ʼs.
This observation is consistent with the observations thatage at sexual maturity has stabilized or slightly increasedin the 1970ʼs and that the recruitment was stable after
1970. The stable trend in recruitment is consistent withthe total abundance of Antarctic minke whale estimatedby sighting data which has been broadly stable since the1980ʼs.
The observations above suggest less availability of krill
for Antarctic minke whales. Less availability of krill for thisspecies could result from competition with other recovering krill-eater large whale species, e.g. the reversal ofLawsʼ ʻkrill surplusʼ hypothesis. The implication of theseʻdeterioratedʼ nutritional conditions is the possibility ofa decrease of Antarctic minke whale abundance in thenear future.
Southwell et al. (2015) provided two explanations forthe increase of the Adelie penguins in East Antarctica.
The ﬁrst was that harvesting of baleen whales, krill andﬁsh across East Antarctic waters through the 20th century
could have reduced competition between Adelie penguins and other predators for food, and improved preyavailability. The second was that a proposed reduction in
sea-ice extent in the mid-20 century may also have beneﬁted Adelie penguins by enabling better access to theocean for foraging. Since a strong recovery of krill-eater
large baleen whales has been reported since the 1980ʼs,
it can be suggested that environmental factors are moreplausible for explaining the increase of Adelie penguinssince the 1980ʼs. Probably environmental changes havestronger eﬀects on land-based predators such as the penguins than on sea-based predators such as whales.

CONCLUDING REMARKSThe review of scientiﬁc evidence for ecosystem changes
in the Indo-Paciﬁc region of the Antarctic has highlighted
the importance of long-time monitoring research programs focused on the collection of biological data of krill
predators (land-based and sea-based predators) as well
as data on sea ice cover and environmental variables.
Evidence of environmental changes are more marked inWest Antarctic than East Antarctic. An implication of thisis that in East Antarctic (Indo-Paciﬁc region), competition for space and food could better explain the patternof changes in biological and demographic parameters
observed among sea-based krill predators. However to12further investigate the plausibility of this hypothesis it
will be necessary to obtain information on krill biomass
trends in the research area. There is some partial information based on dedicated krill surveys in the past but
the information is scattered and needs to be combinedwith new surveys in a comprehensive and consistent way
so that time series data can be obtained.

ACKNOWLEDGEMENTS
We thank researchers and crew members of the JARPA/
JARPAII and IDCR/SOWER surveys that collected samples
and data used in many published studies, on which thisreview is based.

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Branch, T.A., Matsuoka, K. and Miyashita, T. 2004. Evidence forincreases in Antarctic blue whales based on Bayesian modelling. Mar. Mam. Sci. 20 (4): 726–754.
Buckland, S.T., Rexstad, E.A., Marques, T.A. and Oedekoven, C.S.
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Honda, K, Aoki, M. and Fujise, Y. 2006. Ecochemical approach
using mercury accumulation of Antarctic minke whale,
Balaenoptera bonaerensis, as tracer of historical change ofAntarctic marine ecosystem during 1980–1999. Bull. Environ.
Contam. Toxicol. 76: 140–147.
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Konishi, K., Tamura, T., Zenitani, R., Bando, T., Kato, H. andWalløe, L. 2008. Decline in energy storage in the Antarctic
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Polar Biol. 31: 1509–1520.
Konishi, K., Hakamada, T., Kiwada, H., Kitakado, T. and Walløe,
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Laws, R.M. 1977. Seals and whales of the Southern Ocean.
Philos. Trans. R. Soc. Lond. B 279: 81–96.
Laws, R.M. 1985. The Ecology of the Southern Ocean. Am. Sci.
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Trivelpiece, W.Z., Hinke, J.T., Miller, A.K., Reiss, C.S., Trivelpiece,
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Technical Reports of the Institute of Cetacean Research (2018)

pp. 14–19

Technical Report (not peer reviewed)

An overview of the Institute of Cetacean Research work on ecosystemmodeling in the Antarctic and western North Paciﬁc
Takashi Hakamada* and Tsutomu Tamura
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: hakamada@cetacean.jp

ABSTRACTThe development of ecosystem models has been an important research activity organized and promoted by
the Institute of Cetacean Research (ICR). This paper presents an overview of the objectives and progress madein the research on ecosystem modeling in the Antarctic and western North Paciﬁc. Whale abundance, preycomposition and prey consumption of whales have been some of the input data to the models, which wereobtained by ICR surveys. Several future research needs to progress the ecosystem modeling work have been
identiﬁed.

INTRODUCTION
The development of ecosystem models has been an
important research activity of the Institute of Cetacean
Research (ICR) in its whale research programs in the Antarctic and western North Paciﬁc. What is understood byʻecosystem modelsʼ? An ecosystem model is an abstract,usually mathematical representation of an ecologicalsystem, which is studied to better understand the realsystem (Hall and Day, 1990). Ecological relationships,
such as the relation between predators and preys, arederived using data gathered from the ﬁeld, and these are
combined to form ecosystem models. These model systems are studied in order to make predictions about the
dynamics of the real system.
Ecosystem models have applications in a wide variety
of disciplines including natural resource management.
Morishita (2008) provided a good summary of the various
interpretations of the ecosystem approach for ﬁsheries
management, one of them being the evolution from single-species management to multi-species management.
According to the FAO home page (Fisheries and Aquaculture Department), ecosystem models for ﬁsheries
management purposes have ranged in complexity fromenhanced single-species models to fully articulated food
web models including physiological, spatial and environmental processes.
Objectives of ecosystem modeling studies are diﬀerent according to the kind of model used. They could be,for example, 1) understanding structure, features andinteractions of an ecosystem, 2) identifying major causes
14

of changes in an ecosystem, 3) prediction of population dynamics for speciﬁc species, 4) assessment of the
impact of ﬁsheries and predation on an ecosystem, 5)
providing some scientiﬁc advice on management of astock or stocks.
Plagányi (2007) reviewed ecosystem modeling studies
and grouped the models into two groups: 1) whole ecosystem models, which are models taking into account all
trophic levels. This includes Ecopath with Ecosim (EwE)(Christensen et al., 2005); and 2) Minimum Realistic
Models (MRM), which are models restricted to represent
a limited number of species most likely to have important interactions with a target species of interest. This
includes MULTSPEC (Bogstad et al., 1997; Tjelmeland andBogstad, 1998) and BORMICON (Stefansson and Palsson, 1998).
This paper summarizes the studies on ecosystem modeling organized and promoted by the ICR in the Antarctic
and western North Paciﬁc Ocean.

ECOSYSTEM MODELING IN THE ANTARCTIC
BackgroundThe ecological background for the ecosystem modelingin the Antarctic is provided by Fujise and Pastene (thisissue). There are some hypotheses related to ecosystemchanges in the Antarctic. The ﬁrst is referred to as theʻkrill surplusʼ hypothesis. After the depletion of Antarctic
blue (Balaenoptera musculus intermedia), ﬁn (B. physalus) and humpback (Megaptera novaeangliae) whalesat the middle of the past century there was some 150
million tons of krill surplus. This surplus became available

An overview of the Institute of Cetacean Research work on ecosystem modeling in the Antarctic and western North Pacificfor other krill-eater species of penguins, seals and smallerwhales (e.g. Antarctic minke whale, B. bonaerensis)(Laws, 1977). The krill surplus implied better nutritional conditions in those species, which was reﬂected inchanges in some demographic parameters. For example
from 1940 to 1970, recruitment had been increasing for
Antarctic minke whales (Punt et al., 2014) reﬂecting better nutritional conditions for the species at the middle ofthe past century.
The second hypothesis is that the population dynamics
of Antarctic species is aﬀected by environmental changes.
A decrease in sea-ice cover by the middle of the twentyﬁrst century due to global warming has been predictedby several studies (Levitus et al., 2000; de la Mare, 1997).
Warming of the Southern Ocean appears to be occurring
faster than the warming of other oceans of the world(Gille, 2002).
It was therefore necessary to investigate and quantify
the interactions among krill predators such as some baleen whale species, and to examine the dynamics of the
Antarctic marine ecosystem. This would enable investigation of what has happened in the past and to predict
what is going to happen in the future in the context of
ecosystems in the Antarctic (GOJ, 2015). For this aim,
ecosystem modeling has been used.
One of the main objective of the ecosystem modeling study in the Antarctic was to determine whether
predator-prey interactions alone can broadly explain observed population trends without the need for recourse
to environmental change hypotheses (Mori and Butterworth, 2006).
MRM Models in the Antarctic
Objectives
The objective of the study by Mori and Butterworth(2006) was to determine whether predator–prey interactions alone can broadly explain the observed population
trends of four large baleen whale species, Antarctic blue,
ﬁn, humpback and Antarctic minke whales; two seal
species, Antarctic fur seal (Arctocephalus gazelle) andcrabeater seal (Lobodon carcinophagus); and Antarctic

Figure 1.

krill (Euphausia superba), without the need for recourse
to environmental change hypotheses.
Ecosystem model
Population dynamics models were developed to describe
predator–prey interactions among the four large baleen
whale species, the two seals species and krill (Figure 1).
Functional responses are generally classiﬁed into three
types, which are called Type I, II, and III (Holling, 1959).
In the model, two types of functional responses wereconsidered, Type II, which assumes that consumption
rate decreases as prey abundance increases and that prey
consumption is limited, and Type III, which assumes that
consumption rate increases as prey abundance increases
when prey abundance is lower than a threshold of prey
abundance, and it decreases as prey abundance increases when prey abundance is higher than the threshold(Holling, 1959). Mori and Butterworth (2006) ﬁtted theabundance estimates of these species to estimate parameters/coeﬃcients in the models by maximum likelihood
method.
Research area and data used
The predator-prey model was constructed in two sectorsof the Antarctic. One in the Atlantic/Indian sector (eastof 60°W and west of 130°E) and the other in the Paciﬁc
sector (east of 130°E and west of 60°W). Historical catch
data for all species considered in the model were used.
Abundance estimates of krill predators for the whole sectors were also used. Abundance trend estimates for blue,
humpback, Antarctic minke whales and crabeater seal
were made for a part of each sector, and were based on
independent data sources.
Results
The main results of Mori and Butterworth (2006) were
the following:(i) species interaction eﬀects alone can explain observed predator abundance trends;(ii) it is necessary to consider species other than baleen whales and krill, to explain observed trends—

Food web in the Antarctic modeled in Mori and Butterworth (2006) and Moosa (2017).
15

Technical Reports of the Institute of Cetacean Research (2018)crabeater seals seemingly play an important roleand constitute a particular priority for improved
abundance and trend information;(iii) the Atlantic/Indian Ocean sector shows majorchanges in species abundances, in contrast to the
Paciﬁc Ocean sector, which is much more stable;(iv) baleen whales have to be able to achieve relatively
high growth rates to explain observed trends; and(v) Laws (1977) estimate of some 150 million tons
for the krill surplus may be too high because his
calculations omitted consideration of densitydependent eﬀects in feeding rates.
Moosa (2017) reﬁned the ecosystem modeling work by
Mori and Butterworth (2006), mainly by incorporating/updating catch history and abundance estimates of species considered in the model, and by making some technical improvement to the model. Preliminary results supported the main ﬁndings of Mori and Butterworth (2006).
Moosa (2017) identiﬁed the following future work required: i) inclusion of a space limitation term for the fur
seals in the model so as not to increase their population
to unrealistically high values; ii) consideration of a set of
diﬀerently deﬁned regions as this might possibly better
represent the Antarctic minke whale abundance trends
and population trajectories; iii) further consideration of
the variation of the eﬀective annual natural mortality rateof krill, because this is likely causing the oscillations in the
krill dynamics; iv) further consideration of the variation of
the bounds imposed on carrying capacity of krill; and v)
further consideration of the variation in the proportion of
ﬁn whales assumed to feed south of 60°S.
This work is ongoing.

ECOSYSTEM MODELING IN THE WESTERN NORTHPACIFIC
Background
There were two main motivations for building ecosystemmodels in the western North Paciﬁc. The ﬁrst one was
the rapid decrease of Japanʼs ﬁsheries catch from 12,785
thousand tons in 1988 to 4,690 thousand tons in 2015
(GOJ, 2000; 2017). Ecosystem models including ﬁsheryresources can provide some insight to the reasons forchanges in stock status considering interaction among
species.
The second one was the possibility of competition
between marine mammals and ﬁsheries on prey speciesof economic importance. For example, common minke
whales (Balaenoptera acutorostrata) sightings occurred
close to the ﬁshing grounds of Paciﬁc saury (Cololabis
saira) oﬀ Kushiro. In fact, they fed mainly on Paciﬁc saury
16

near the ﬁshing ground of the Paciﬁc saury. This observation suggested a relationship between common minke
whales and Paciﬁc saury from summer to autumn in thewestern North Paciﬁc (Tamura and Fujise, 2002). Ecosystem models can be used to investigate whether competition exists, for example by comparing ecosystem models
with and without the assumption of competition.
EwE model in the western North Paciﬁc
Objectives
Mori et al. (2009) applied the EwE model to investigate
the possible impact of whaling on the catch of otherspecies in the western North Paciﬁc ecosystem. They
also compared single-species MSY and multi-species
MSY. If there were substantial diﬀerences between the
two MSYs, the stock status derived from the two models
could be quite diﬀerent. In such a situation, multi-species
model should be used rather than single-species model
for assessment of the stocks.
Ecosystem model used
Ecopath is a static, mass-balanced snapshot of the system and Ecosim is a time dynamic simulation module forpolicy exploration (Christensen et al., 2005). The model
consist of the species from detritus to top predators. Ecopath is used to model tropic ﬂow within a food chain ofan ecosystem. Ecosim can be used to simulate temporalchange from the steady state described by the Ecopath
model under some harvesting scenarios.
The scenarios examined in Mori et al. (2009) were: i)harvesting 4% of the common minke whale population;ii) harvesting 4% of the sei whale (B. borealis) population;iii) harvesting 4% of Brydeʼs whale (B. edeni) population;iv) harvesting 4% of the common minke, sei and Brydeʼswhale populations; v) harvesting 4% of the sperm whale(Physeter macrocephalus) population; and vi) harvesting
4% of the four whale species.
For an initial test run, the impact of no harvesting andharvesting 4% of the whales for the coming 50 years oncatch of the ﬁshes, was made. Uncertainty of the data
input to Ecopath, functional response and trophic ﬂow(top-down or bottom-up) were considered. Type I functional response, which assumes that prey consumption
is in proportion to prey abundance up to the maximum(Holling, 1959) was assumed as the reference case, andthe Types II and III functional responses were used forsensitivity analyses.
Research area and data used
Mori et al. (2009) developed the EwE in the westernAn overview of the Institute of Cetacean Research work on ecosystem modeling in the Antarctic and western North Pacific
Table 1
List of the species/groups used in the EwE model and Trophic Level (TL) estimated by Ecopath (Mori et al., 2009).
Species/Group

TL

Species/Group

TL

Species/GroupTL

Minke whale
Brydeʼs whale
Sei whale
Other baleen whales
Sperm whale
Bairdʼs beaked whale
Short-ﬁnned pilot whale
Ziphiidae
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
Salmon shark
Lanternﬁsh
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 pomfret
SardineAnchovy (<8 cm)
Anchovy (≧8 cm)
Paciﬁc saury
Phytoplankton
Euphausiids
Copepods eaten by whales
Other Copepods
Detritus

4.20
2.30
3.04
3.04
3.12
1.00
2.18
2.00
2.00
1.00

North Paciﬁc (north of 35°N and west of 170°E), where
JARPNII surveys were conducted. The model consistsof 32 species/groups ranging from detritus to whales(Table 1). Estimated trophic level (TL) for each species isshown in Table 1. Higher TL represents the species playing
a role closer to top predator in the ecosystem. Input datarequired for the model were biomass, production, prey
consumption, diet composition and total ﬁshery catch ofeach predator in the target area. When production is notavailable, total mortality was used in the Ecopath insteadof production per biomass (Christensen et al., 2005).
Biomass, prey consumption and diet compositions
for common minke, Brydeʼs, sei and sperm whales werebased on JARPNII surveys. Details of the input data were
provided in Mori et al. (2009). Once the mass-balance
model was constructed, possible eﬀect on ﬁsheries ofthe species in the model were simulated by using Ecosim
under the harvesting scenarios examined.
Results
Results of Mori et al. (2009) suggested the following:i) when minke whales are the only species that are
harvested by 4% of its biomass (catch of other species are kept constant at current catch rate), depending on the functional response form assumed
for the species, it is not certain whether catch ofsome Japanese ﬁsheries resources (e.g. anchovy(Engraulis japonicus), Paciﬁc saury, skipjack tuna
(Katsuwonus pelamis), mackerels (Scomber japonicus, S. australasicus) will increase or not;ii) when sei and Brydeʼs whales are each the only
species that are harvested by 4% of their biomass,
regardless of the functional response form assumed for the species, catch of anchovy, skipjack
tuna, and mackerels may increase;iii) when minke, sei and Brydeʼs whales are all harvested by 4% of their biomass, an increase in catchis expected for most of the ﬁsh resources (i.e. anchovy, skipjack tuna and mackerels), indicating theeﬀectiveness of harvesting several whale species
simultaneously; andiv) when sperm whales are the only species that are
harvested by 4% of its biomass, depending on thefunctional response form assumed for the species,
catch of anchovy, Paciﬁc saury, mackerels and skipjack tuna may decrease, but in contrast, catch ofneon-ﬂying squid may increase.
The work by Mori et al. (2009) is being updated in thestudies by Murase et al. (2016) and Watari et al. (2018).
Murase et al. (2016) have focused on the interactions
between forage ﬁsh and their predators including target species of JARPNII (common minke, sei, Brydeʼs andsperm whales). They have updated the input data to themodels by considering the data available in the period
1994–2013 and made several technical improvements
following recommendations from the International Whaling Commission Scientiﬁc Committee (IWC SC). Watari
et al. (2018) have improved Ecopath model focusing on
the small pelagic ﬁshes to investigate their role in theecosystem by using two ecological indices.
Murase et al. (2016) and Watari et al. (2018) have identiﬁed several future data and work required to progress
the development of ecosystem modeling in the western
North Paciﬁc. Some suggestions to improve input of EwE
were the following: (i) consistency of spatial resolutionof input data is required, (ii) regional models are to be
developed within the EwE area, (iii) collection of dietcomposition data at regular interval is required becausesome of the diet composition data were old or obtained
outside the research area, (iv) resolution (the numbers
17Technical Reports of the Institute of Cetacean Research (2018)of species/group) and quality of data on non-commercial
and lower trophic level species should be improved and(v) evaluation of the sensitivity of Ecopath models to
input data is required.
This work is ongoing.
MRM in coastal areas
Objectives
Okamura et al. (2009) examined the eﬀects of predationof common minke whales on sandlance (Ammodytesspp.) stock oﬀ Sanriku region to investigate the eﬀect of
predation by the common minke whales in terms of MSY
of the sandlance population.
Model used
A Bayesian delay-diﬀerence approach (Hilborn and Walters, 1992; Meyer and Miller, 1999) was used to develop
a MRM-type ecosystem model. They focused on interaction between sandlance and common minke whales (Figure 2), and constructed a population dynamics model ofsandlance taking into account predation by the common
minke whales. In the analysis, functional response Types
I, II and III (Holling, 1959) were considered.
Research area and data used
The research area was the coastal area oﬀ Sanriku. Data
used in this modeling were CPUE series of juvenile andadult sandlance ﬁsheries, abundance estimate for adultsandlance, age, length and weight time series of sandlance during 1999–2005, catch series of sandlance bylift net with light ﬁshery, dip nets, and trawl-net ﬁsheryfrom 1901 to 2006 and stomach contents of the common
minke whales oﬀ Sanriku in 2003 obtained from JARPNII
surveys (Tamura et al., 2004).

Results
Under the scenarios of the linear functional response
curve (Type I), the resultant impact was so great that themedian value of MSY was increased by 154%. Whereasusing the constant functional response scenario (mostextreme functional form), the impact was much smaller,
where there was only a 17% increase of the medianvalue of MSY. This suggested that estimating functional
response is important to assess the impact of predationby the common minke whales.
Kitakado et al. (2016) updated the model work by
Okamura et al. (2009) by using new data as follows: i)catch and CPUE series of juvenile sandlances by lift nets
with light ﬁshery (1994–2015); ii) catch and CPUE seriesof adult sandlances by dip nets ﬁshery (1994–2015); iii)
time series of age composition data of sandlances takenfrom summer sampling survey (2002–2014); iv) time series of density estimate of sandlances (in number) during
summer sampling survey (2002–2014); v) consumptionof sandlances by common minke whales in 2005, 2006
and 2012 (JARPNII surveys); and vi) time series of abundance estimates in Sanriku region for the common minke
whales in 2004, 2005, 2006 and 2012.
Further analyses should be conducted to examine sensitivities of the results to the assumption of prior distributions. Because only the Type II functional response wasassumed in Kitakado et al. (2016), other forms of functional response and multiple-prey functional responsewith krill and anchovy are worthy to investigate. The
weight allocated among the components of the likelihood(likelihood relevant to abundance of juvenile sandlance,
likelihood relevant to abundance of adult sandlance,and likelihood relevant to age composition of sandlance)
should be carefully considered in future analyses (Kitakado et al., 2016).
This work is ongoing.

CONCLUDING REMARKS

Figure 2.

18

Ecosystem model oﬀ Sanriku modeled in Okamura
et al. (2009) and Kitakado et al. (2016).

Progress has been made in the development of ecosystem modeling for some particular objectives related toﬁsheries management and ecosystem structure and dynamics, in both the Antarctic and western North Paciﬁc.
Biological and abundance data of the species consideredin the models are important. In the case of whale species
such data came from ICR surveys. Several research needs
were identiﬁed which should be addressed to progress
the work on ecosystem modeling work and potentiallycontribute to resources management taking into accountmulti-species considerations.

An overview of the Institute of Cetacean Research work on ecosystem modeling in the Antarctic and western North Pacific

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Barents Sea. J. N. Atl. Fish. Sci. 22: 317–341.
Christensen, V., Walters, C.J. and Pauly, D. 2005. Ecopath with
Ecosim: a userʼs guide. Fisheries Center, University of British
Columbia, Vancouver.
de la Mare, W.K. 1997. Abrupt mid-twentieth-century decline
in Antarctic sea-ice extent from whaling records. Nature 389:
57–60.
Gille, S.T. 2002. Warming of the Southern Ocean since the1950s. Science 295: 1275–1277.
Government of Japan. 2000. Research plan for cetacean studies
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presented to the IWC Scientiﬁc Committee, June 2000 (unpublished). 68 pp. [Available from the IWC Secretariat].
Government of Japan. 2015. Research Plan for New Scientiﬁc
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IWC.ALL.238, November 2015 (unpublished). 110 pp.
Government of Japan. 2017. Annual Statistics of Fishery and
Fish Culture 2015. Statistics Department of Ministry ofAgriculture, Forestry and Fisheries. 53 pp. (in Japanese).
Hall, C.A.S. and Day, J.W. 1990. Ecosystem Modeling in Theory
and Practice: An Introduction with Case Histories. University
Press of Colorado. 684 pp.
Hilborn, R. and Walters, C.J. 1992. Quantitative Fisheries Stock
Assessment. Chapman and Hall, London. xv+570 pp.
Holling, C. 1959. The Components of Predation as Revealed by
a Study of Small-Mammal Predation of the European Pine
Sawﬂy. The Canadian Entomologist 91 (5): 293–320.
Kitakado, T., Murase, H. and Tamura, T. 2016. Predation impacts
on sandlance population by consumption of common minke
whales oﬀ Sanriku region. Paper SC/F16/JR29 presented to
JARPNII ﬁnal review meeting. February 2016 (unpublished)
10 pp. [Available from the IWC Secretariat].
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Trans. R. Soc. Lond. B 279: 81–96.
Levitus, S., Antonov, J.I, Boyer, T.P. and Stephens, C. 2000.
Warming of the world ocean. Science 287: 2225–2229.
Meyer, R. and Millar, R.B. 1999. Bayesian stock assessment
using a state-space implementation of the delay diﬀerence
model. Canadian Journal of Fisheries and Aquatic Sciences
56: 37–52.
Moosa, N. 2017. An updated model of the krill-predator dynamics of the Antarctic ecosystem. MSc thesis, University of Cape

Town. 246 pp.
Mori, M. and Butterworth, D.S. 2006. A ﬁrst step towards modelling the krill–predator dynamics of the Antarctic ecosystem.
CCAMLR Science 13: 217–277.
Mori, M., Watanabe, H., Hakamada, T., Tamura, T., Konishi,K., Murase, H. and Matsuoka, K. 2009. Development of an
ecosystem model of the western North Paciﬁc. Paper SC/J09/
JR21 presented to JARPNII review meeting, January 2009 (unpublished) 49 pp. [Available from the IWC Secretariat].
Morishita, J. 2008. What is the ecosystem approach for ﬁsheries
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Kiyofuji, H., Yonezaki, S. and Kitakado, T. 2016. Ecosystemmodelling in the western North Paciﬁc from 1994 to 2013using Ecopath with Ecosim (EwE): some preliminary results.
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IWC Secretariat].
Okamura, H., Nagashima, H. and Yonezaki, S. 2009. Preliminary
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JR14 presented to JARPNII review meeting, January 2009
(unpublished). 20 pp. [Available from the IWC Secretariat].
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Kawahara, S. 2004. Preliminary analyses of interaction
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Ser. https://doi.org/10.3354/meps12508.

19

Technical Reports of the Institute of Cetacean Research (2018)

pp. 20–31

Technical Report (not peer reviewed)

Geographical distribution of whales in the Indo-Paciﬁc region of the
Antarctic based on JARPA and JARPAII sighting data collected in the
period 1987/88–2008/09
Koji Matsuoka* and Takashi Hakamada
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: matsuoka@cetacean.jp

ABSTRACTThis paper examined the geographical and temporal pattern of distribution of several whale species in the
Indo-Paciﬁc region of the Antarctic during the austral summer. The analyses were based on sighting data collected systematically by JARPA and JARPAII surveys in the longitudinal sector 35°E–145°W, south of 60°S, between 1987/88 and 2008/09. A total of 353,134n.miles was surveyed in these Areas. Density Index of Whales(No. of individuals sighted/100 n.miles) was calculated and its geographical distribution plotted for each individual species. Antarctic minke whale was the species most frequently sighted, followed by killer, humpback,unidentiﬁed beaked, ﬁn, sperm, southern bottlenose, blue, southern right and sei whales. The geographicalpattern of distribution was described for each whale species. The large sighting data set collected systematically by JARPA and JARPAII in the Indo-Paciﬁc region has made a substantial contribution to understanding thepattern of geographical distribution and habitat use of whales in the Antarctic ecosystem.

INTRODUCTION
One of the main sources of sighting data for assessing
the population status of whale species in the Antarctic is
the JARPA which was conducted between 1987/88 and2004/05, and its second phase JARPAII conducted between 2005/06 and 2008/09.
The sighting data collected during the JARPA have beenused for studying the distribution pattern and abundance
estimation of several large whale species (Kishino et al.,
1991; Kasamatsu et al., 2000; Matsuoka et al., 2003;
2011; Branch et al., 2004; Murase et al., 2002; 2014).

Figure 1.

20

The objective of this study was to investigate the pattern of geographical distribution of large whale species in
the Indo-Paciﬁc region of the Antarctic during the australsummer feeding season. The study was based on sighting data collected systematically by JARPA and JARPAII
surveys.

MATERIAL AND METHODS
Research area
The research area comprised the Indo-Paciﬁc regionof the Antarctic, speciﬁcally the International Whaling
Commission (IWC) Management Areas IIIE (35°E–70°E),

The IWC Antarctic Areas for the management of baleen whales (except Brydeʼs whale), and the research
Area of the JARPA and JARPAII surveys between 35°E and 145°W.

Geographical distribution of whales in the Indo-Pacific region of the Antarctic based on JARPA and JARPAII

IV (70°E–130°E), V (130°E–170°W) and VIW (170°W–
145°W), south of 60°S (Figure 1).
Sighting data
Primary sighting and eﬀort data were collected by JARPA
and JARPAII systematic surveys in the period 1987/88–
2008/09. Surveys were conducted by sighting and sampling vessels (SSV) and dedicated sighting vessels (SV).
Sighting procedure
The sighting procedure in JARPAII (2005/06–2008/09)
was not substantially changed with regard the procedures in JARPA (Nishiwaki et al., 2014). The research
vessels were equipped with top barrel, where three top
men conducted sightings. On the upper bridge, a captain,a gunner, a helmsman and a researcher also conducted
the sighting. The sighting activity was conducted under
acceptable weather conditions (see below), from 30 minutes after sunrise to 30 minutes before the sunset.
Survey modes
Searching was conducted under closing and passing
modes (Hakamada et al., 2006). These modes were used
under acceptable weather conditions (minke whale visibility of 2 n.miles or more and wind speed under 20
knots in the northern strata, and under 25 knots in thesouthern strata) (Nishiwaki et al., 2014).
Conﬁrmation of the sightings
When a sighting was made, the vessel closed to theschool immediately in order to identify the species, estimate the school size and get other biological information

Figure 2.

(number of calves, estimated body length, etc.).
Density Index of Whales
The Density Index of Whales (DIW) (the number of individual whales sighted by 100 n.miles) was calculated byeach Lat.1°× Long.1°grid squares.

RESULTS AND DISCUSSIONS
Searching eﬀorts
A total of 353,134 n.miles was surveyed in Areas IIIE, IV,
V and VIW, south of 60°S between 1989/90 and 2008/09.
Figure 2 shows the distribution of the primary searchingeﬀort.
Distribution pattern of whales
Tables 1a and 1b show a summary of primary sightings of baleen and toothed whales, respectively. Table
2 shows the number of calves, observed mean school
size and DIW, by species and month. Figures 3a–d show
the maps of the DIW for i) blue, ﬁn and sei whales; ii)
Antarctic minke, dwarf minke and humpback whales; iii)
southern right, sperm and southern bottlenose whales;
and iv) unidentiﬁed beaked (Ziphiidae) and killer whales,
respectively, by each Lat.1°× Long.1°grid squares. Figure
4 shows the monthly change in DIW for most of the species.
A description of the geographical distribution by whale
species is presented and discussed below.
Blue whale
Blue whale had the 8th rank of DIW among the ten species sighted in the research area (Table 2). They were

Searching eﬀorts (red line) by JARPA and JARPAII surveys in the period 1987/88–2008/09, including transit
sighting survey in middle latitude.
21

Technical Reports of the Institute of Cetacean Research (2018)
Table 1a
Summary of baleen whale species sighted in the Indo-Paciﬁc region of the Antarctic.
Eﬀort

Blue whale(n.miles)sch. ind. calfAnt. minke whale

Humpback whale

calf sch. ind. calf

sch.

ind.

calf

sch.

ind.

3
16

0
0

1
0

1
0

0
0

237
353

719
768

0
0

35
1

76
2

0
0

1
0

1
0

0
0

5
33
8
15
9
73
60
37
18
45
66
114
143
52
109
49

20
67
34
27
26
241
214
82
57
222
356
374
983
216
446
118

0
0
0
1
0
1
1
1
0
1
3
0
2
0
0
1

0
0
2
2
0
2
0
1
0
0
0
7
1
8
0
1

0
0
2
4
0
5
0
1
0
0
0
13
2
14
0
1

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

758
740
597
1,024
688
823
887
853
672
826
1,507
1,907
1,867
2,420
1,092
1,663

1,968
1,713
2,030
3,228
1,619
2,453
2,008
2,610
1,373
2,665
6,581
4,949
4,374
6,531
3,250
4,278

0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0

121
58
177
28
133
131
325
114
577
106
661
191
1219
145
1690
197

210
90
321
56
220
228
562
200
1,122
203
1,269
341
2,387
228
3,134
336

11
0
7
5
1
9
10
3
2
7
5
3
5
4
5
2

2
0
26
3
11
0
8
0
34
0
3
2
15
0
1
2

2
0
30
4
14
0
8
0
37
0
3
2
22
0
2
2

0
0
0
0
0
0
0
0
0
0
0
0
1
0
1
0

188
37
48
109

748
253
134
440

1
0
4
2

2
0
2
5

3
0
2
7

0
0
0
0

1,657
969
823
1,870

4,375
2,169
1,702
4,668

0
0
0
0

1702
160
1314
339

3,200
283
2,536
587

22
13
7
8

53
0
72
0

73
0
96
0

4
0
0
0

264 462 10 1,228 5,077 18

34

55

0

24,233 66,031

1

9,424 17,591 129 233 296

6No.

Season1
2

1987/88
1988/898,860.6
10,806.7

0
2

0
3

3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18

1989/90
1990/91
1991/92
1992/93
1993/94
1994/95
1995/96
1996/97
1997/98
1998/99
1999/2000
2000/01
2001/02
2002/03
2003/04
2004/05

16,423.2
14,660.0
17,844.1
13,924.9
17,957.3
14,047.7
21,466.7
17,783.2
21,594.4
8,066.5
16,341.5
20,421.3
19,767.4
18,126.2
19,287.4
18,486.7

5
4
3
7
5
13
9
7
16
4
25
10
17
5
32
12

19
20
21
22

2005/06
2006/07
2007/08
2008/09

16,372.7
11,968.8
14,575.3
14,351.4

24
7
43
14

Total

353,134

Fin whale
sch.

ind.

0
0

3
7

9
6
3
9
9
20
16
9
25
7
53
18
26
10
61
16

0
0
0
0
0
1
0
0
0
1
2
0
1
0
0
0

38
12
84
28

2
1
1
1

Sei whale

S. right whale

calf sch. ind. calf

Table 1b
Summary of toothed whale species sighted in the Indo-Paciﬁc region of the Antarctic.
S. bottlenose whale

Unid. beaked whales(n.miles)

sch.

ind.

calf

sch.

ind.

calf

sch.

ind.

calf

sch.

ind.

calf

1987/88
1988/898,860.6
10,806.7

6
81

6
91

0
0

3
2

5
4

0
0

87
65

218
143

0
0

20
31

194
189

0
0

3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18

1989/90
1990/91
1991/92
1992/93
1993/94
1994/95
1995/96
1996/97
1997/98
1998/99
1999/2000
2000/01
2001/02
2002/03
2003/04
2004/05

16,423.2
14,660.0
17,844.1
13,924.9
17,957.3
14,047.7
21,466.7
17,783.2
21,594.4
8,066.5
16,341.5
20,421.3
19,767.4
18,126.2
19,287.4
18,486.7

204
175
225
105
321
133
341
121
295
49
195
100
269
128
222
105

215
188
233
108
336
135
352
128
302
50
204
106
272
129
223
108

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

23
13
29
10
145
74
137
75
222
23
138
72
126
97
154
44

46
26
51
19
243
146
273
128
409
53
251
121
226
168
274
78

0
0
0
0
0
1
1
0
0
0
0
0
0
0
0
0

281
241
181
202
205
168
161
78
197
35
110
173
134
113
208
89

514
421
304
361
337
263
284
144
338
54
188
272
205
154
338
159

0
1
1
0
0
0
0
1
0
0
0
0
0
0
0
0

69
32
53
82
56
35
109
50
82
35
109
72
79
63
120
78

859
870
805
1,130
399
281
1,282
539
931
409
2,011
1,471
939
953
1,348
1,472

0
2
0
0
1
1
1
4
9
5
7
2
0
0
0
3

19
20
21
22

2005/06
2006/07
2007/08
2008/09

16,372.7
11,968.8
14,575.3
14,351.4

181
63
280
75

182
63
280
76

0
0
0
0

88
51
79
32

179
80
157
61

0
0
1
0

135
66
102
77

244
88
155
140

0
0
0
0

100
44
62
38

1,563
394
790
788

3
0
0
14

353,134.0

3,674

3,787

0

1,637

2,998

3

3,108

5,324

3

1,419

19,617

52

No.

Season

1
2

Total

22

Sperm whale

Eﬀort

Killer whale

Geographical distribution of whales in the Indo-Pacific region of the Antarctic based on JARPA and JARPAII

widely distributed in the research area in both northernand southern strata. High density values of this species
were observed in Areas IIIE, particularly between 45°E
and 65°E (Figure 3a). They were rarely found in the Prydz
Bay. Blue whales were sighted within the Ross Sea between 70°S and 77°S. A total of 286 schools (495 individuals) including eleven calves were sighted south of 60°S
(Table 2). Observed mean school size was 1.73 individuals. The DIW of this species was 0.140 for the whole period and the indices were almost stable from December
to March (Table 2 and Figure 4).
Two subspecies of blue whales exist in Southern Hemisphere: the Antarctic (or true) blue whale (Balaenoptera
musculus intermedia) and the pygmy blue whale (B.
m. brevicauda) (Mackintosh, 1966; Ichihara, 1966;
Rice, 1998). A complete review of spatial and seasonal
distribution, densities and movements of blue whales isprovided by Branch (2007) and Branch et al. (2007). Thesestudies indicated that there is little evidence that pygmy
blue whales migrate into high latitudes of the Antarctic.
Less than 1% of the records south of 52°S were of thissubspecies. There is no current evidence of population
structure in Antarctic blue whales. The latest abundance
estimate of this species (south of 60°S, 35°E–145°W) was
1,223 whales (CV=0.345) in 2007/08+2008/09 seasons,and the abundance trend was 8.2% (95% CI: 3.9%, 12.5%)
between 1995/96 and 2008/09 for combined Areas IIIE+
IV+V+VIW based on JARPAII data (Matsuoka and Hakamada, 2014). There is a need for continued monitoringof the abundance and abundance trend of this species,
especially because they provide an excellent opportunity

to improve our understanding of the dynamics of baleen
whale populations recovering from low levels.
Fin whale
Fin whale had the 5th rank of DIW among the ten species sighted in the research area. A total of 1,268 schools(5,209 individuals) including 20 calves, were sighted(Table 2). Observed mean school size was 4.11 individuals. This species was more frequently encountered in
Areas V and VIW than in Areas IIIE and IV in both northernand southern strata. High density areas were observedin Areas IIIE, particularly between 55°E and 65°E, VW,
between 140°E and 160°E and VE between 163°E and170°W (Figure 3a). The DIW of this species was 1.475 forthe whole period and the indices increased from December to March (Figure 4).
In the Antarctic feeding grounds, ﬁn whales occur yearround but higher density is found from November to May(Kasamatsu et al., 1996; Mackintosh, 1966). Whales canbe found as far south as 65°S–70°S, but the majority ofthe population seems to occur north of 60°S (Miyashita
et al., 1995). Catches occurred throughout the Antarctic,
but the majority of whales (∼73%) were taken in the IWC
Management Areas II and III. Sighting data suggest thatspatial distribution varies across ocean basins (Kasamatsu
et al., 1996).
Sei whale
Sei whale was rarely sighted in the research area. A totalof 36 schools (59 individuals) were sighted south of 60°S
(Table 2) and no calves were observed. Observed mean

Table 2
Summary of sighting information in the whole research area in the period 1987/88–2008/09, by whale species and month. Sch.:
number of primary sightings of schools; Ind.: number of primary sightings of individuals; Calf: number of calves; Mss: mean school
size (Ind./Sch.); DIS: Density Index (schools/100 n.miles); DIW: Density Index (individuals/100 n.miles).
SpeciesAll Areas(IIIE, IV, V and VIW; south of 60°S, 35°E–145°W)

Order of
DIW

Dec.
DIW

Jan.
DIW

Feb.
DIW

Mar.
DIW

Sch.

Ind.

Calf

Mss

DIS

DIW

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

286
1,268
36
25,507
10,036
235

495
5,209
59
69,076
18,770
298

11
20
0
0
137
6

1.73
4.11
1.64
2.71
1.87
1.27

0.081
0.359
0.010
7.223
2.842
0.067

0.140
1.475
0.017
19.561
5.315
0.084

8
5
10
1
3
9

0.281
1.323
0.002
10.173
3.425
0.001

0.092
0.794
0.004
14.301
4.842
0.014

0.101
1.760
0.020
33.331
7.337
0.156

0.102
3.059
0.044
19.4366.708
0.292

Sperm whale
S. bottlenose whale
Unid. beaked whale
Killer whale

3,810
1,666
3,175
1,472

3,926
3,045
5,457
20,569

0
3
3
59

1.03
1.83
1.72
13.97

1.079
0.472
0.899
0.417

1.112
0.862
1.545
5.825

6
7
4
2

1.500
0.932
1.864
1.935

1.272
0.974
1.594
5.692

0.992
0.787
1.123
9.303

0.292
0.570
1.209
6.624
23

Technical Reports of the Institute of Cetacean Research (2018)school size was 1.64 individuals. This species occurred
more frequently in Areas V and VIW than in Areas IIIE and
IV in the northern strata (Figure 3a). The DIW of this species was 0.017 for the whole period.
In summer, sei whales do not venture into higher

Figure 3a.

24latitude waters near the Antarctic continent as muchas some other baleen whales (Horwood, 1987; Miyashita et al., 1995). The majority of the population occurs
between 40°S and 60°S, usually north of the Antarctic
Convergence. Juveniles are found further north than

DIW of blue (top), ﬁn (middle) and sei (bottom) whales in the Indo-Paciﬁc region of the Antarctic, by
Lat.1°× Long.1°square (whole research period).

Geographical distribution of whales in the Indo-Pacific region of the Antarctic based on JARPA and JARPAII

mature individuals. Occurrence in low latitude wintering
grounds has been recorded from March to December, butabundance peaks from June/July to August/September(Horwood, 1987). In late spring and summer, abundance
peaks in November between 30°S and 50°S. As theseason progresses relatively more whales are observed

Figure 3b.

south of 40°S and abundance between 50°S and 60°S
increases consistently until March (Horwood, 1987). The
results in the present study are consistent with those ofprevious studies.

DIW of Antarctic minke (top), dwarf minke (middle) and humpback (bottom) whales in the Indo-Paciﬁcregion of the Antarctic, by Lat.1°× Long.1°square (whole research period).
25

Technical Reports of the Institute of Cetacean Research (2018)

Antarctic minke whale
This was the most frequently sighted species throughout
the surveys. A total of 25,507 schools (69,076 individuals) were sighted south of 60°S (Table 2). No calves wereobserved. Observed mean school size was 2.71 individuals. High density areas were observed along the ice-edge,
especially the Ross Sea and Prydz Bay (Figure 3b). The
DIW of this species for the whole period was the highest(19.561). The indices increased from December to February and decreased in March (Figure 4).
In the austral summer the majority of Antarctic minke
whales congregate in the Southern Ocean, with greatest densities close to and within the pack ice, and lower
densities with increasing distance from the ice (Kasamatsu et al., 2000; Hakamada and Matsuoka, 2014a),
including some north of 60°S. Antarctic minke whales are
noticeably well adapted to living within the ice (Ainley
et al., 2007), but the exact proportion of Antarctic minke
whales found within the pack ice, and in polynyas, is currently a source of debate. It is possible that a large proportion of the population is found within the pack ice, outof reach of vessel-based sighting surveys (Murase et al.,2005; 2014; Shimada and Kato, 2007).

found within the Prydz Bay and the Ross Sea and no sighting occurred south of 73°S. High density values of thisspecies were observed between 85°E and 110°E (Figure3b). The DIW of this species was 5.315 for the whole period. Indices increased from December to February anddecreased in March (Figure 4).
IDCR/SOWER circumpolar surveys encountered humpback whales more frequently in the sectors 20–40°E,
80°E–100°E and 150°E–180°E (Branch, 2011). The current
distribution map of this species suggests that humpback
whales are encountered more frequently in the sector
80°E–100°E because of its high productivity. In the sector 80°E and 100°E, large scale distribution changes wereobserved (Matsuoka et al., 2011; Murase et al., 2014;
Hakamada and Matsuoka, 2014b). It has been suggested
that such changes are related to changing oceanographic
conditions such as the eﬀect of the regime shift in the
global sea-surface temperatures in relation to El Ninosouthern oscillation events (Watanabe et al., 2014; Naganobu et al., 2014). This should be further investigatedin the future.

Dwarf minke whale
Distribution of this species was limited within the research area. There are two separated areas of distribution, between 120°E and 147°E, and between 165°E and170°W in the northern stratum (mainly between 60°S and
63°S), south of Australia and New Zealand (Figure 3b). The
dwarf minke whale has a white band on the ﬂipper that
distinguishes it from the Antarctic minke whale, but was
only fairly recently identiﬁed as separate from Antarctic
minke whales (Best, 1985). On available information,
only a small percentage of minke whales in the Antarctic(south of 60°S) are dwarf minke whales. For example, in
the IDCR/SOWER surveys from 1993/94–1997/98 only
0.2% of the identiﬁed sightings were dwarf minke whales(2 out of 906). No formal analysis has been conducted
but it is probable that less than 1% of the minke whales
south of 60°S are dwarf minke whales (Branch and Butterworth, 2001).

Southern right whale
A total of 235 schools (298 individuals) involving six
calves were sighted (Table 2). Distribution area of thisspecies was limited to the sector 80°E and 135°E, southof Western Australia (Figure 3c). The DIW of this species was 0.084 for the whole period. Indices increased
from December to March (Figure 4). In summer southern right whales migrate south but generally not as
far south as other baleen whale species. They appear
to occur near the subtropical convergence in summer(January to March) at around 40°S–50°S (Ohsumi andKasamatsu, 1985), but there are records of animals muchfurther south (e.g. around 60°S–65°S south of Australia(Bannister et al., 1999; 2008). The present distribution
map of this species is consistent with these previous
studies. The population estimate for the coastal area ofWestern Australia was 2,400 in 2006 (Bannister, 2008).
A current estimate in Area IV south of 60°S is 1,557 individuals (95% CI: 871–2,783) in the 2007/08 season basedon JARPAII data (Matsuoka and Hakamada, 2014).

Humpback whale
Humpback whale had the 3rd rank among the ten species
sighted in the research area. A total of 10,036 schools(18,770 individuals) including 137 calves were sighted(Table 2). Observed mean school size was 1.87 individuals. They were widely distributed in the research area
in both northern and southern strata. They were rarely

Sperm whale
Sperm whale had the 6th rank among the ten species
sighted in the research area. A total of 3,810 schools(3,926 individuals) were sighted. No calves were observed (Table 2). Single large males were mainly sighted(96.5%) and consequently the observed mean school size
was 1.03. They were widely distributed in the research

26

Geographical distribution of whales in the Indo-Pacific region of the Antarctic based on JARPA and JARPAII

Figure 3c.

DIW of southern right (top), sperm (middle) and southern bottlenose (bottom) whales in the Indo-Paciﬁcregion of the Antarctic, by Lat.1°× Long.1°square (whole research period).

area. High density values of sperm whales were observedin Area IV (between 70°E and 100°E) and Area V (between
170°E and 170°W, in the mouth of the Ross Sea (Figure3c). They tended to be concentrated on the Antarctic
continental slope, on the southern Kerguelen Plateau,

and around the mouth of the Ross Sea, where most frequently the depth was between 1,000 m and 4,000 m.
They were rarely found within the Prydz Bay and the Ross
Sea (Figure 3c). There were no sightings south of 74°S in
the Ross Sea. The DIW of this species was 1.081 for the27Technical Reports of the Institute of Cetacean Research (2018)

whole period. The indices decreased from December toMarch (Figure 4).
Southern bottlenose whale
Southern bottlenose whale had the 7th rank among theten species sighted in the research area. A total of 1,666
schools (3,045 individuals) including three calves weresighted (Table 2). They were widely distributed in the
research area but were rarely sighted within the Prydz
Bay and the Ross Sea. High density values of this whale
were observed between 85°E and 130°E (Figure 3c). Observed mean school size was 1.83 individuals. The DIWof this species was 0.862 for the whole period. Indicesdecreased from December to March (Figure 4).
Unidentiﬁed beaked whales
Unidentiﬁed beaked whales had the 4th rank among theten species sighted in the research area. A total of 3,175
schools (5,457 individuals) including three calves were

Figure 3d.

28sighted (Table 2). The sightings were recorded as unidentiﬁed species of beaked whales. This ʻunidentiﬁed beaked
whalesʼ possibly included southern bottlenose whale (Hyperoodon planifrons), Arnouxʼs beaked whale (Berardius
arnuxii), strap-toothed whale (Mesoplodon layardii) andGreyʼs beaked whale (M. grayi). Distribution pattern of
the unidentiﬁed beaked whales was consistent with thatof southern bottlenose whales (Figure 3d).
Killer whale
Killer whale had the 2nd rank among the ten species
sighted in the research area. A total of 1,472 schools(20,569 individuals) including 59 calves were sighted(Table 2). Observed mean school size was 13.97 individuals. The DIW of this species was 5.825 for the whole period (Table 2). They were widely distributed in the researcharea and were more frequently sighted in the southern
stratum. High density areas were observed within the
Prydz Bay and the Ross Sea (Figure 3d).

DIW of unidentiﬁed beaked (top) and killer (bottom) whales in the Indo-Paciﬁc region of the Antarctic, by
Lat.1°× Long.1°square (whole research period).

Geographical distribution of whales in the Indo-Pacific region of the Antarctic based on JARPA and JARPAII

to March. It is necessary to further investigate the relationship between whale distribution and oceanographic
condition shifts such as the eﬀect of the regime shift
in the global sea-surface temperatures in relation to El
Nino-southern oscillation events (Matsuoka et al., 2003;
Watanabe et al. 2014; Naganobu et al., 2006; 2014).

ACKNOWLEDGEMENTS
We thank all researchers, captains, oﬃcers and crew
members that participated in the JARPA and JARPAII surveys from which the data used in the present study werecollected. We also thank S. Suzuki for help in drawing
some of the ﬁgures.

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Figure 4.

Monthly change of DIW for baleen (top) and toothed(bottom) whales in the whole research area andperiod.

Relationship between pattern of distribution and oceanographic conditions
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and porpoises. University of California Press, Berkeley, CA.
789 pp.
Matsuoka, K., Watanabe, T., Ichi, T., Shimada, H. and Nishiwaki,

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S. 2003. Large whale distributions (south of 60°S, 35°E–130°E)
in relation to the southern boundary of the ACC. pp. 26–30.
In: A.H.L. Huiske, W.W.C. Gieskes, J. Rozema, R.M.L. Schrno,
S.M. van der Vies and W.J. Wolﬀ (eds.) Antarctic Biology
in a Global Context. Backhuys Publishers, Leiden, The
Netherlands. 338 pp.
Matsuoka, K., Hakamada, T., Kiwada, H., Murase H. andNishiwaki, S. 2011. Abundance estimates and trends forhumpback whales (Megaptera novaeanglie) in the Antarctic
Areas IV and V based on JARPA sighting data. J. Cetacean Res.
Manage. (Special Issue) 3: 75–94.
Matsuoka, K. and Hakamada, T. 2014. Estimates of abundance
and abundance trend of the blue, ﬁn and southern rightwhales in Areas IIIE–VIW, south of 60°S, based on JARPA and
JARPAII sighting data (1989/90–2008/09). Paper SC/F14/J5
presented to the IWC/SC Review Workshop of the Japanese
Whale Research Program under Special Permit in the
Antarctic-Phase II (JARPAII), February 2014 (unpublished). 27
pp. [Available from the IWC Secretariat].
Miyashita, T., Kato, H. and Kasuya, T. (eds.) 1995. Worldwide
Map of Cetacean Distribution based on Japanese Sighting
Data (Volume 1). National Research Institute of Far Seas
Fisheries, Shimizu, Japan. 140 pp.
Murase, H., Matsuoka, K., Ichii, T. and Nishiwaki, S. 2002.
Relationship between the distribution of euphausiids andbaleen whales in the Antarctic (35°E–145°W). Polar Biol. 25:
135–145.
Murase, H., Shimada, H. and Kitakado, T. 2005. Alternative
estimation of Antarctic minke whale abundance taking account of possible animals in the unsurveyed large polynya
using GAM-based spatial analysis: A case study in Area II in
1997/98 IWC/SOWER. Paper SC/57/IA6 presented to the IWC
Scientiﬁc Committee, May–June 2005 (unpublished). 20 pp.
[Available from the IWC Secretariat].
Murase, H., Matsuoka, K., Hakamada, T. and Kitakado, T. 2014.
Preliminary analysis of changes in spatial distribution of
Antarctic minke and humpback whales in Area IV during
the period of JARPA and JARPAII from 1989 to 2006. Paper
SC/F14/J18 presented to the IWC/SC Review Workshop of theJapanese Whale Research Program under Special Permit in
the Antarctic-Phase II (JARPAII), February 2014 (unpublished).
17 pp. [Available from the IWC Secretariat].
Naganobu, M., 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., Murase, H.,
Matsuoka, K. and Ito, K. 2006. Interactions between oceanography, krill and baleen whales in the Ross Sea and Adjacent
Waters: An overview of Kaiyo Maru-JARPA joint survey in
2004/05. Paper SC/D06/J23 presented to the JARPA Review
Meeting, December 2006 (unpublished). 33 pp. [Available
from the IWC Secretariat].
Naganobu, M., Matsuoka, K. and Kutsuwada, K. 2014.
Consideration on the Kerguelen-Davis Oscillation IndexGeographical distribution of whales in the Indo-Pacific region of the Antarctic based on JARPA and JARPAII(KDOI) inﬂuencing variability on environmental ecosystem in
the Prydz Bay Region, east Antarctic: data exploration. Paper
SC/F14/J21 presented to the IWC/SC Review Workshop of theJapanese Whale Research Program under Special Permit in
the Antarctic-Phase II (JARPAII), February 2014 (unpublished).
12 pp. [Available from the IWC Secretariat].
Nishiwaki, S., Ishikawa, H., Goto, M., Matsuoka, K. and Tamura,T. 2014. Review of general methodology and survey procedure under the JARPAII. Paper SC/F14/J2 presented to the
IWC/SC Review Workshop of the Japanese Whale Research
Program under Special Permit in the Antarctic-Phase II(JARPAII), February 2014 (unpublished). 34 pp. [Available
from the IWC Secretariat].
Ohsumi, S. and Kasamatsu, F. 1985. Recent oﬀ-shore distribution of the southern right whale in summer. Rep. Int. Whal.
Commn (Special Issue) 10: 177–185.
Rice, D.W. (ed.) 1998. Marine mammals of the world: systematics and distribution. Society for Marine Mammalogy,
Lawrence, KS. 231 pp.

Shimada, H. and Kato, A. 2007. Population assessment of the
Antarctic minke whale within and out ice ﬁeld using a sighting data by the Ice Breaker and the IWC SOWER vessels in
2004/2005. Paper SC/59/IA16 presented to the IWC Scientiﬁc
Committee, May 2007 (unpublished). 8 pp. [Available fromthe IWC Secretariat].
Watanabe, T., Yabuki, T., Suga, T., Hanawa, K., Matsuoka, K. andKiwada, H. 2006. Results of oceanographic analyses conducted under JARPA and possible evidence of environmental
changes. Paper SC/D06/J30 presented to the JARPA Review
Meeting, December 2006 (unpublished). 13 pp. [Available
from the IWC Secretariat].
Watanabe, T., Okazaki, M. and Matsuoka, K. 2014. Results ofoceanographic analyses conducted under JARPA and JARPAII
and possible evidence of environmental changes. Paper
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the Antarctic-Phase II (JARPAII), February 2014 (unpublished).
10 pp. [Available from the IWC Secretariat].

31

Technical Reports of the Institute of Cetacean Research (2018)

pp. 32–37

Technical Report (not peer reviewed)

Earplug-based age determination and estimation of biologicalparameters in North Paciﬁc Brydeʼs whales based on samples
collected by JARPNII
Takeharu Bando*
Institute of Cetacean Research, Toyomi-cho 4–5, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: bando@cetacean.jp

ABSTRACTThis study summarizes the results of earplug-based age determination and estimation of biological parameters in the western North Paciﬁc Brydeʼs whales sampled by the JARPNII surveys between 2000 and 2016. A
total of 730 whales (314 males and 416 females) was sampled in the western North Paciﬁc north of 35°N andbetween the Paciﬁc coast of Japan and 170°E. Age information was obtained from earplugs of 476 (65.2%)
whales. Earplug readability was higher for mature (76.4%) than immature (43.8%) whales and no diﬀerence
between sexes was observed. The growth curves for males and females were Lt =12.63(1−e−0.208(t+4.266)), and
Lt =13.28(1−e−0.172(t+4.834)), respectively. The age at sexual maturity for males and females were 10.24 and 8.56
years, respectively. The annual ovulation rate was estimated as 0.526/year. It is concluded that substantial
biological information was obtained for the North Paciﬁc Brydeʼs whales during the 17 years of JARPNII. In
particular the readability of earplugs for age determination increased notably compared to that in the periodof commercial whaling. The analyses of biological data will contribute to the management of this whale species in the North Paciﬁc, for example by incorporating such data into the conditioning process of the RMP
Implementation Simulation Trials.

INTRODUCTION
Brydeʼs whales are widely distributed throughout theworld, especially in waters with temperature of 20°C
or more (Kato and Perrin, 2017). Two types of Brydeʼswhales are distributed around Japan, one in the southwestern part of Japan (coastal type) and the other inoﬀshore waters in the Paciﬁc side of Japan (oﬀshore type)(Kishiro, 1996; Yoshida and Kato, 1999).
Some authors (e.g., Wada et al., 2003) recognize these
Brydeʼs whale types as two separate species, the smaller
coastal one Balaenoptera edeni Anderson, 1879 (Edenʼswhale) and the larger oﬀshore one B. brydei Olsen, 1913
(Brydeʼs whale). Other authors (e.g., Kershaw et al. 2013)
assign these species a sub-speciﬁc status: B. edeni edeni
and B. edeni brydei, respectively. This study focused on
the larger, oﬀshore type Brydeʼs whale (Figure 1).
JARPNII started in 2000 with three research objectives,i) feeding ecology and ecosystem studies, ii) monitoringof environmental pollutants in cetaceans and marine
ecosystems and iii) elucidation of stock structure (GOJ,
2000; 2002). Brydeʼs whale (oﬀshore type) was selected
as one of the target species for sampling. The estima32

Figure 1.

North Paciﬁc Brydeʼs whale (oﬀshore type). Notethe three distinct ridges in the head, which are characteristic of this species.

tion of biological parameters of whales was not included
among the main objectives of JARPNII, however biological samples for such estimates were collected systematically during the surveys. The JARPNII was completed in2016, and a total of 730 Brydeʼs whales were sampledduring the 17 years survey period.
Age data is one of the most important information forEarplug-based age determination and estimation of biological parameters in North Pacific Brydeʼs whale

stock assessment and management of large whales. Ageestimation based on earplugs is considered the most reliable tool for age determination in whales (Lockyer, 1984;
Maeda et al., 2016). Earplug readability of North Paciﬁc
Brydeʼs whales was reported as 17.4% from commercial
whaling samples collected in the pelagic whaling groundof the North Paciﬁc from 1971 to 1974 (Ohsumi, 1977).
During the JARPNII, earplugs were collected carefully
from each whale sampled, and eﬀorts were made to increase the readability.
This study summarized the results of age determination in North Paciﬁc Brydeʼs whales based on earplugs
and some biological parameters based on age data. The
analyses were based on Brydeʼs whale samples collectedby JARPNII in the period 2000–2016 in the western North
Paciﬁc.

MATERIALS AND METHODS
Whale sampling
A total of 730 (314 males and 416 females) Brydeʼswhales were sampled by JARPNII during 2000–2016. The
geographical distribution of the sampled whales is shownin Figure 2. Whales were sampled between the Japanese
coast and 170°E, and between 35°N and approximately
42°N. Two biological stocks of Brydeʼs whales (oﬀshoretype) have been suggested for the western North Paciﬁc,one distributed between the Japanese coast and approximately 165°E and the other, east of 180°, with a transitionarea between 165°E and 180° (IWC, 2017). The analyses
in this study are mainly focused on the former stock.
Table 1 shows the number of sampled whales by year
and sexual maturity status.
Biological data
Body length was measured in a straight line from the tipof snout to the notch of ﬂukes using stainless steel measuring tapes. Sexual maturity of females was preliminarily
determined in the ﬁeld by the presence or absence ofcorpora lutea/albicantia in ovaries from both sides andconﬁrmed later by counting corpora number at the laboratory. If there was at least one corpora lutea or albicantia
in the ovaries, the female was determined as sexually mature. Maturity of males was determined by testis weight.
Testis weight (heavier side) of more than 560 g was regarded as sexually mature (Bando unpublished data).
Earplug sampling and age determination procedure
Earplugs were collected from all sampled animals, following the method developed for baleen whales (Omura,
1963; Maeda et al., 2016). The left and right earplugs

Figure 2.

Research area of JARPNII and sighting positions ofBrydeʼs whales sampled during the 2000–2016 surveys.

Table 1
Sex and sexual maturity status of Brydeʼs whales sampled during 2000 to 2016 JARPNII.
Male

FemaleImmature Mature Total Immature Mature Total

Total

2000

9

12

21

6

16

22

43

2001

13

4

17

12

21

33

50

2002

18

7

25

11

14

25

50

2003

10

9

19

9

22

31

50

2004

5

14

19

7

24

31

50

2005

10

11

21

13

16

29

50

2006

8

13

21

8

21

29

50

2007

13

10

23

5

22

27

50

2008

6

24

30

4

16

20

50

2009

9

9

18

14

18

32

50

2010

5

20

25

4

21

25

50

2011

10

10

20

11

19

30

50

2012

6

5

11

4

19

23

34

2013

3

10

13

3

12

15

28

2014

2

4

6

5

14

19

25

2015

3

11

14

2

9

11

25

2016

1

10

11

2

12

14

25

Total

131

183

314

120

296

416

730

were collected carefully, and immediately ﬁxed in 10%
formalin.
In the laboratory, the ﬂat along the central axis of theearplug was cut using a sharp blade, then it was placed ona wet stone to expose the neonatal line and growth layers (Figure 3). Growth layers were counted under waterusing a stereoscopic microscope. A growth layer group(GLG) was deﬁned as one pair of light and dark laminae inthe core and considered as one year of age. Age reading
was conducted in the following manner: i) earplug of the33

Technical Reports of the Institute of Cetacean Research (2018)

left side was read. If the growth layers were ambiguous,
earplug from the right side was also read. Reading fromthe less ambiguous side was adopted; ii) age reading was
conducted only once without any knowledge of biological information such as body length or sex; iii) when thereading of all sample was completed, age data was compared with biological data such as body length or sexual
maturity status, and some samples were re-read to check
outlier, incomplete sample or invalid reading. All earplugs
were read by a single reader (TB).
Estimation of biological parameters
Growth curve
To estimate growth curve, the von Bertalanﬀy growthmodel was ﬁtted to the body length and age as:(

Lt = L∞ 1 − e− K (t −t0 ))where Lt is the body length at age t, L ∞ is asymptotic
length, K is the growth rate coeﬃcient and t0 is the theoretical time at zero length.
Age at sexual maturity
Age at sexual maturity (tm) was estimated by the following equation (Cooke, 1984):
tm = l − 0.5 +Figure 3.

k Ia la  N var(tm) =

k
l

where
Ma is
Ia is
Na is
l is
k is

M a Ia N ( N − 1)2aanumber of mature animals in age anumber of immature animals in age atotal number of animals in age a
age of youngest mature animal in the sample
age of oldest immature animal in the sample.

Ovulation rate
Annual ovulation rate was estimated by applying linear
regression analysis between age and total number of corpora (corpora lutea and albicantia). The regression line
was ﬁtted to age 10 and older because almost all animals
mature at the age of 10.

RESULTS AND DISCUSSIONSAge readability
The readability of earplugs varied depending on the maturity status. Readability of sexually immature individuals
was 46.6% for males and 40.8% for females (Table 2).
Readability of earplugs in sexually mature animal was
higher, 76.5% and 76.4% for males and females, respectively (Table 2). Readability of all samples was 65.2%,
which was higher than that of western North Paciﬁc
common minke whales (44.1%) (Maeda et al., 2016), andBisected earplug surfaces of Brydeʼs whales (left: 5 GLGs, right: 20 GLGs). The scale shows 1 mm interval.
Table 2
Earplug-age readability of Brydeʼs whales by sex and sexual maturity status.

34

Male

FemaleTotal

Number of Readable
whalesearplugs

Readability Number of Readable(%)
whalesearplugs

Readability Number of Readable(%)
whalesearplugs

Readability(%)

Immature
Mature

131
183

61
140

46.6
76.5

120
296

49
226

40.8
76.4

251
479

110
366

43.8
76.4

Total

314

201

64.0

416

275

66.1

730

476

65.2

Earplug-based age determination and estimation of biological parameters in North Pacific Brydeʼs whale

Figure 4.

Figure 5.

Earplug age readability of Brydeʼs whales by body length class and sex.

Relationship between body length and age of Brydeʼs whales. The solid line shows the von Bertalanﬀygrowth curve.

was comparable to that of sei whales (63.0%) (Bandoet al., 2016), which were estimated based on samples
collected by JARPN/JARPNII.
Readability increased with body length for both sexes(Figure 4). An inter-reader calibration experiment, following the method of Kitakado et al. (2013), will be conducted in the near future.
Growth curve
For both sex, the growth rate was high at younger ages
and stabilized after 20 years old (Figure 5). The following
von Bertalanﬀy growth curves were estimated:
Male:
Female:(L = 13.28 (1 − e

Lt = 12.63 1 − e −0.208( t+4.266)
t− 0.172( t+4.834)))

Ohsumi (1977) estimated growth curves of Brydeʼswhales based on samples collected by the commercial
whaling in the North Paciﬁc, and estimated maximum
length as 12.8 m (42 ft) and 13.4 m (43.8 ft) for males andfemales, respectively. Similar values were obtained for
Brydeʼs whales sampled by JARPNII.
Age at sexual maturity
Sexually mature males ﬁrst appeared at the age of 8,
and from 16 years old all animals were sexually mature(Figure 6). Age at sexual maturity (tm) for males was esti-

mated as 10.24 years (SE=0.60).
Sexually mature females ﬁrst appeared at the age of 7,
and from 11 years old all animals were sexually mature(Figure 6). Tm was estimated as 8.56 years (SE=0.39).
Ohsumi (1977) reported age at 50% sexual maturityof Brydeʼs whales collected by the commercial whaling
in the North Paciﬁc in the 1970ʼs as 10 and 8 years formales and females, respectively. Consideration should begiven to the possibility of bias arising from legal size limit
and the selectivity of large animals during commercial
whaling. However similar estimates were obtained for
Brydeʼs whales collected during past commercial whaling
and JARPNII.
Annual ovulation rate
The corpora lutea/albicantia ﬁrst appeared at the age of
7 and the number of corpora increased linearly after theage of 10 (Figure 7). Annual ovulation rate was calculated
as 0.526. The estimated annual ovulation rate means thatthe majority of Brydeʼs whale in the North Paciﬁc givebirth (or ovulation occurs) every two years. The estimatedvalue was higher than the 0.455 estimated from the1970ʼs commercial whaling (Ohsumi, 1977).

CONCLUDING REMARKS
It is concluded that substantial biological information was
35Technical Reports of the Institute of Cetacean Research (2018)

Figure 6.

Figure 7.

Sexual maturity status by age and sex in the Brydeʼs whales. Numbers in the bar shows the number ofsamples examined.

Relationship between age and number of corpora in
Brydeʼs whales. Linear regression line was ﬁtted toages 10 and more.

obtained for the North Paciﬁc Brydeʼs whales during the17 years of JARPNII. In particular the readability of earplugs for age determination increased notably comparedto that in the period of commercial whaling. The analysesof biological data will contribute to the management of
this whale species in the North Paciﬁc for example byincorporating such data into the conditioning process of
the RMP Implementation Simulation Trials (Bando andKato, 2017).

ACKNOWLEDGEMENTS
Our sincere thanks are due to all researchers and crews
that collected data and samples during the JARPNII surveys. Kazuyoshi Nakai (ICR) helped in the preparation of
earplugs for age determination.

REFERENCES
Bando, T., Maeda, H., Ishikawa, Y., Kishiro, T. and Kato, H. 2016.
Preliminary report on progress in earplug-based age deter36

mination of sei whales collected during 2002 to 2013 JARPNII
survey. Paper SC/F16/JR55 presented to the JARPNII special
permit expert panel review workshop, Tokyo, February 2016
(unpublished). 3 pp. [Available from the IWC Secretariat].
Bando, T. and Kato, H. 2017. Report on progress in earplugbased age determination and estimation of biological parameters of Brydeʼs whales collected during 2000 to 2014
JARPNII surveys. Paper SC/MAR17/RMP/03 presented to theWorkshop on the RMP Implementation Review of oﬀshore
western North Paciﬁc Brydeʼs whales, Tokyo, March 2017
(unpublished). 9 pp. [Available from the IWC Secretariat].
Cooke, J.C. 1984. The estimation of mean ages at sexual maturity from age sample. Paper SC/36/O22 presented to IWC
Scientiﬁc Committee, 1984 (unpublished). 8 pp. [Available
from the IWC Secretariat].
Government of Japan. 2000. Research plan for cetacean studies
in the western North Paciﬁc under special permit (JARPNII)(Feasibility study plan for 2000 and 2001). Paper SC/52/O1
presented to the IWC Scientiﬁc Committee, 2000 (unpublished). 68 pp. [Available from the IWC Secretariat].
Government of Japan. 2002. Research plan for cetacean
studies in the western North Paciﬁc under special permit(JARPNII). Paper SC/54/O2 presented to the IWC Scientiﬁc
Committee, 2002 (unpublished). 115 pp. [Available from the
IWC Secretariat].
International Whaling Commission. 2017. Report of theWorkshop on the Implementation Review of western North
Paciﬁc Brydeʼs whales, 21–24 March 2017, Tokyo, Japan.
Paper SC/67a/REP/07 presented to the IWC Scientiﬁc
Committee, May 2017 (unpublished). 37 pp. [Available fromthe IWC Secretariat].
Kato, H. and Perrin, W.F. 2017. Brydeʼs whales Balaenoptera
edeni/brydei. pp. 158–163. In: B. Würsig, J.G.M. Thewissen
and K. Kovacs (eds.) Encyclopedia of marine mammals, Third
Edition. Academic Press, San Diego. 1190 pp.
Kershaw, F., Leslie, M.S., Collins, T., Mansur, R.M., Smith,B.D., Minton, G., Baldwin, R., LeDuc, R.G., Anderson, R.C.,
Brownell, R.L. and Rosenbaum, H.C. 2013. Population differentiation of 2 forms of Brydeʼs whales in the Indian andEarplug-based age determination and estimation of biological parameters in North Pacific Brydeʼs whale

Paciﬁc Oceans. J. Hered. 104 (6): 755–764.
Kishiro, T. 1996. Movements of marked Brydeʼs whales in thewestern North Paciﬁc. Rep. Int. Whal. Commn. 46: 421–428.
Kitakado, T., Lockyer, C. and Punt, E.A. 2013. A statistical modelfor quantifying age reading errors and its application to the
Antarctic minke whales. J. Cetacean Res. Manage. 13 (3):181–190.
Lockyer, C. 1984. Age determination by means of the earplug inbaleen whales. Rep. Int. Whal. Commn. 34: 692–696.
Maeda, H., Bando, T., Kishiro, T., Kitakado, T. and Kato, H. 2016.
Basic information of earplug as age character of common
minke whales in western North Paciﬁc. Paper SC/F16/JR53
presented to the JARPNII special permit expert panel re-view workshop, Tokyo, February 2016 (unpublished). 10 pp.
[Available from the IWC Secretariat].
Ohsumi, S. 1977. Brydeʼs whales in the pelagic whaling groundof the North Paciﬁc. Rep. Int. Whal. Commn. (Special Issue 1):
140–148.
Omura, H. 1963. An improved method for collection of earplugs
from baleen whales. Norsk Hvalfangst-Tidende 10: 279–283.
Yoshida, H. and Kato H. 1999. Phylogenetic relationships ofBrydeʼs whales in the western North Paciﬁc and adjacentwaters inferred from mitochondrial DNA sequences. Mar.
Mamm. Sci. 15: 1269–1286.
Wada, S., Oishi, M. and Yamada, T. 2003. A newly discovered
species of living baleen whale. Nature 426: 278–281.

37

Technical Reports of the Institute of Cetacean Research (2018)

pp. 38–49

Technical Report (not peer reviewed)

Biological observations of ﬁn whales sampled by JARPAII in the
Indo-Paciﬁc region of the Antarctic
Toshihiro Mogoe*
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: mogoe@cetacean.jp

ABSTRACT
A limited number of ﬁn whales (n=17) was sampled during the JARPAII surveys in the Indo-Paciﬁc region of the
Antarctic in the austral summer seasons between 2005/06 and 2010/11. This paper summarizes the biologicalinformation obtained from those whales such as body proportion, reproductive status, age/length relationship, body length/body weight relationship and ecological markers (external parasites). Some of the biologicalinformation was compared with data from the commercial whaling period. The main results were that bodyweights of whales in the JARPAII period are heavier than those reported in the 1950ʼs. Results suggested thepossibility that whales are reaching sexual maturity at younger ages, which is consistent with the reported
increase in the abundance in recent decades. Given the small sample size, these results should be considered
as preliminary.

INTRODUCTION
The ﬁn whale, Balaenoptera physalus (Linnaeus, 1758)
was one of the main target species of commercial whaling during the 20th century, and populations reachedcritical levels after overexploitation. The species was protected in 1976 (IWC, 1977).
More than 40 years have passed since the ban of commercial whaling of ﬁn whales in the Antarctic. As an eﬀectof the protection measures, in recent years abundanceof this species in the Indo-Paciﬁc region of the Antarctic
has been increasing at annual rates of 13–16% based on
JARPA sighting data obtained from the austral summer
season 1987/1988 (Matsuoka et al., 2005; Matsuoka
et al., 2006). Information on biological parameters is important for assessment and management but biological
data of this species have not been available since 1976.
Changes in biological parameters such as pregnancy rate,sexual maturity rate, and age at sexual maturity changes
are density-dependent (Gambell, 1973; Kato, 1986).
A limited number of ﬁn whales (n=17) was sampledduring the JARPAII surveys in the Indo-Paciﬁc region of
the Antarctic in the austral summer seasons between
2005/06 and 2010/11 (GOJ, 2005). Detailed biological examinations were conducted on these whales. The objective of this paper was to summarize the biological information collected. These are the only available biological
data from ﬁn whales in the Antarctic after the commercial
38

whaling operations stopped some 40 years ago. Some of
the biological information was compared with data in thecommercial whaling period.

MATERIALS AND METHODS
SamplesCatch records and biological data of the 17 whales sampled are shown in Table 1. The geographical distributionof the catches is shown in Figure 1. The body weight of
one individual (0506F001) was not obtained because ofsome technical reasons. Another individual (0607F001)
was lost before landing on the deck of the research basevessel and no measurements could be obtained.
Biological data
External measurements
The external measurements were conducted based on
previous protocols (Mackintosh and Wheeler, 1929;
Laws, 1961), modiﬁed by the Institute of Cetacean Research (ICR). Figure 2 shows the external measurements
obtained. Figure 3 shows a ﬁn whale being measured onboard the research base vessel. Body length was deﬁned
as the body axes length from the tip of snout to notch of
ﬂukes in parallel to the plane of the deck.
Ventral grooves
The number of ventral grooves was counted following
Williamson (1973).

Biological observations of fin whales sampled by JARPAII in the Indo-Pacific region of the Antarctic
Table 1
Catch records and biological data of the ﬁn whales sampled in the JARPAII.
Catch
date

LatitudeLongitude

0506F001
0506F002
0506F003
0506F004
0506F005
0506F006
0506F007
0506F008
0506F009
0506F010
0607F001
0607F002
0607F003
0809F001
0910F001
1011F001
1011F002

030206080206090206100206130206140206070306090306100306130306030107050107020207130309030210070111
20011165°44S
65°54S
65°48S
65°37S
65°22S
65°10S
64°34S
64°53S
64°48S
65°36S
63°53S
62°35S
68°46S
65°38S
66°08S
63°28S
66°39S

71°38E
78°06E
78°07E
78°13E
82°00E
81°59E
111°51E
114°06E
114°14E
120°30E
170°44W
174°17W
173°41W
165°08E
62°32E
175°40W
165°32E

Figure 1.

Sex

Sexualmaturity

Body
length(m)

Bodyweight
(t)

Age
(yrs)

M
F
F
M
M
F
F
F
M
F
F
M
F
F
M
M
M

Immature
MatureMatureMatureMatureImmature
MatureImmature
Immature
Immature—
MatureMatureImmature
Immature
MatureMature

19.17
20.05
19.47
18.73
19.14
19.15
20.22
18.22
18.30
19.35
—
20.67
21.15
14.79
17.61
19.05
18.99

—
53.48
52.05
41.87
47.28
47.04
61.52
41.06
42.27
47.24
—
51.62
65.02
22.26
34.20
39.63
43.78

9
11
12
22
11
9
7
7
6
8
—
11
10
6
6
12
10

Catch position

SerialNo.

Foetussex

Foetusbody length
(cm)

Male
Female

127.5
280.7

—

—

Male

243.4

Geographical distribution of ﬁn whales sampled during JARPAII surveys. Closed circle: female; open circle: male.

Body weight
Body weights were measured by summing all body parts
using an electronic hanging scale (maximum capacity of30t) and marine scale (M1100, Marel, Iceland).
Reproductive data
Three individuals (0506F002, 0506F003 and 0607F003)
were pregnant. Their foetuses were measured and sampled in the same manner as adult whales.
In females, both ovaries were removed and weighed
together. In males, testes were removed from both sides

and weighed separately. The gonads weight was measured by using the electronic marine scale (S-182, Marel,
Iceland).
The sexual maturity of females was determined by thepresence of corpus luteum or corpus albicans in either
ovary. In the case where no corpus luteum or corpus
albicans was observed in both ovaries, the female wascategorized as sexually immature. Conversely, if at least
one corpus luteum or corpus albicans was observed ineither or both ovaries, the female was categorized as
sexually mature. The counting of the corpus luteum and39

Technical Reports of the Institute of Cetacean Research (2018)

Figure 2.

Measurement points of external proportions of ﬁn whale in the JARPAII. 1: total length; 2: lower jaw, projection beyond tip of snout; 3: tip of snout to blowhole; 4: tip of snout to angle of gape; 5: tip of snout tocentre of eye; 6: tip of snout to tip of ﬂipper; 7: eye to ear; 8: notch of ﬂukes to posterior emarginationof dorsal ﬁn; 9: ﬂukes, width at insertion; 10: notch of ﬂukes to anus; 11: notch of ﬂukes to umbilicus; 12:
notch of ﬂukes to end of ventral grooves; 13: anus to reproductive aperture; 14: dorsal ﬁn, vertical height;
15: dorsal ﬁn, length of base; 16: ﬂipper, tip to axilla; 17: ﬂipper, tip to anterior end of lower border; 18:
ﬂipper, length along curve of lower border; 19: ﬂipper, greatest width; 20: not available; 21: skull, greatest
width; 22: skull length, condyle to tip of premaxilla; 23: ﬂipper, tip to head of humerus; 24: not available;
25: ﬂukes, notch to tip; 26: tip of snout to centre of ear; 27: tip of snout to centre of umbilicus; 28: tip ofsnout to end of ventral grooves; 29: tip of snout to centre of reproductive aperture; 30: tip of snout to anus;
31: notch of ﬂukes to centre of reproductive aperture; 32: tip of snout to posterior emargination of dorsal
ﬁn; 33: width of ﬂukes; 34: girth of chest, half; 35: girth of abdominal, half; 36: girth of buttock, half; 37:
not available; 38: body height of navel; 39: border length posterior end to tip of ﬂipper.

Age determination
The age was determined by counting of growth layers in
the earplugs (Purves, 1955; Ohsumi, 1964; Lockyer, 1972;
Maeda et al., 2013). The left and right earplugs were collected carefully using scalpel, and immediately ﬁxed in
10% formalin until age determination. After slicing thesurface of earplugs by use of whetstone, the layers werecounted using a stereoscopic microscope under low magniﬁcation (3.15–31.5x, Figure 5). One pair of the light anddark laminae in the core of the earplug corresponds to
one year, according to evidence from Ohumi (1964) and
optimized histochemical method of Maeda et al. (2013).
Figure 3.

Body measurements of ﬁn whale No. 1011F001 on
the deck of the research base vessel.

corpus albicans was not carried out because the ovary
samples were lost after the earthquake and tsunami on
11 March 2011.
The male sexual maturity was determined by theweight of testis. If one testis was over 2.5 kg, the whale
was determined as sexually mature (Ohsumi, 1964).
Figure 4 shows ovaries and testes of Antarctic ﬁnwhales examined in this study.

40

Marine diatom
Quantitative measurements of attached marine diatoms
on the whale body (ﬁve categories) were made following
Omura (1950).
Parasites
Observation of internal/external parasites was carriedout.
Analytical procedures
Fin whale data obtained by JARPAII were compared withpublished Japanese commercial whaling data obtained in
the Antarctic in the late 1940s and early 1950s. Table 2

Biological observations of fin whales sampled by JARPAII in the Indo-Pacific region of the Antarctic

Figure 4.

A pair of ovaries of ﬁn whale individual No. 0506F003 (left) and a pair of testes with epididymis of ﬁn whale
individual No. 0607F002 (right).

from Japanʼs commercial whaling data. These data were
calculated on mean (±SD) value in each class of 1 m bodylength.
In order to check whether there are diﬀerences in reproductive condition, we compared the relationship bodylength/gonad weight using the same data from bodyparts weight.

Figure 5.

Earplug of ﬁn whale individual No. 0506F001 after
slicing the surface.

shows the number of samples used for the comparative
analysis. The following biological data were used in thecomparison.
Body proportion
The mean values (±SD) of JARPAII were calculated andcompared through plotting data on the normalized axis
using Japanese commercial whaling data.
Relationship between body length and body weight/organ weight
The relationship between body length and body weight
was evaluated by applying single nonlinear regression.
The following formula was used (Lockyer, 1976):

Body weight (t) = a Body length (m)bThe coeﬃcient of a and b were estimated by the leastsquares method.
Comparison between body length and body partweights was carried out using samples from 34 ﬁn whales

Relationship between body length and sexual maturity,and between age and sexual maturity
We estimated the age and length at sexual maturity byﬁtting a logistic regression to the proportion of mature
female and male at age (length) x.
For body length and sexual maturity in JARPAII, there
was no signiﬁcant regression coeﬃcient in the logistic
model (p=0.09). Therefore estimates were based only
on commercial whaling data in seasons 1949/1950s,
1950/1951s, and 1951/1952s.
For age and sexual maturity the same approach as
described above was used. In this case the logistic model
was based on both JARPAII and commercial whaling(1956/1957 season; Nishiwaki et al., 1958). Each formulaof logistic regression model was used:p=e β1x1+β2 x2++β p x p+β0
1+ e β1x1+β2 x2++β p x p+β0

p: predicted value, x: independent variable, e: base ofnatural logarithm, β: parameter.

RESULTS
Biological information from JARPAII
Sex ratio and body weight
Of 17 whales sampled nine were females (male sex ratio:0.47). Mean body weight was 46.02t (SD: 10.47). The
maximum and minimum weights for females were 65.02t
41

Technical Reports of the Institute of Cetacean Research (2018)
Table 2
Number of samples, period of sampling and source of data used in the comparative analysis of ﬁn whales between JARPAII and pastcommercial whaling.
Items

JARPAII
SamplesCommercial whaling
Samples

SourceBody proportion

16

16
6
5

1948/1949
1949/1950
1950/1951

Fujino (1954)
Fujino (1954)
Fujino (1954)

Body length and weight

16

16
13
5

1947/1948
1948/1949
1950/1951

Nishiwaki (1950)
Nishiwaki (1950)
Ohno and Fujino (1952)

Organ weight

15

16
13
5

1947/1948
1948/1949
1950/1951

Nishiwaki (1950)
Nishiwaki (1950)
Ohno and Fujino (1952)

Body length and gonad weight

16

16
13
5

1947/1948
1948/1949
1950/1951

Nishiwaki (1950)
Nishiwaki (1950)
Ohno and Fujino (1952)

Body length and maturity

16

437
2,049
2,583

1949/1950
1950/1951
1951/1952

Mizue and Murata (1951)
Ohno and Fujino (1952)
Kakuwa et al. (1953)

Age and maturity

16

288

1956/1957

Nishiwaki et al. (1958)

Body length

16535,740

1930/1931–1975/1976

International Whaling
Statistics

and 22.26t, respectively. The maximum and minimum
weights for males were 51.62t and 34.20t, respectively(Table 1).
Sexual maturity
Sexual maturity rate was 50.0% (4/8) and 62.5% (5/8)
for female and males, respectively. The three pregnant
whales had a single foetus, and a single corpus luteum
existed on one ovary. During the dissection of all female
whales, no milk was found in the mammary glands. As
shown in Table 1, body lengths of foetuses were 280.7 cm(female), 127.5 cm (male) and 243.4 cm (male). Theirbody weights were 172.0 kg, 20.00 kg, and 141.0 kg,
respectively. No abnormalities were observed in the fetuses.
Ventral grooves
The mean number of ventral grooves was 67 (SD: 10) inmales and 69 (SD: 5) in females.
Marine diatom
In most cases diatom ﬁlm was recognized on the surfaceof the whale body (14 of 16 whales). Adhesions of diatom
ﬁlms were more densely observed in males than females
42

SeasonTable 3
The adhesion level of diatom ﬁlms of the body of ﬁn whales
sampled by JARPAII.
Classiﬁcation1

Female

Male

Total

−
±
+
++
+++

2
0
6
0
0

0
0
6
2
0

2
0
12
2
0

Total

8

8

16

1

−: not infected; ±: with thin ﬁlm; +: with patched; ++: withthick ﬁlm; +++: with thick ﬁlm on whole body.

(category ʻ++ʼ in Table 3).
Parasites
Table 4 shows the frequency of external parasites.
The most observed sessile organisms on the skin were
Cyamus (44.0%). 75.0% of males and 12.5% of females
had Cyamus on the ventral grooves. Chi-square test revealed that the percentage of attachments of Cyamus signiﬁcantly diﬀered by sex (p<0.05). Neither Pennella nor
Conchoderma were observed. Coronula sp. was observed

Biological observations of fin whales sampled by JARPAII in the Indo-Pacific region of the Antarctic

in males and females with the same percentage.
Internal parasites were not observed in the stomachs
of 16 ﬁn whales. Unidentiﬁed parasites were observed in
the Gastroepiploic.
Comparative analyses
Average body length
Mean body length for female whale sampled in JARPAII
was 19.05 m (SD: 1.92) (maximum and minimum lengths
were 21.15 m and 14.79 m, respectively). Mean bodylength for male whales sampled in JARPAII was 18.96 m(SD: 0.87) (maximum and minimum lengths were 20.67 m
and 18.61 m, respectively).
Body length (m) of each ﬁn whale sampled in JARPAII
is plotted in Figure 6 with annual mean length and ±SD of
ﬁn whales captured in Antarctic pelagic whaling during
the periods 1930/1931–1975/1976.
It is diﬃcult to compare the data between the commercial and JARPAII, because there was a regulation forsize limit of 70ft (21.34 m) for the ﬁn whale in pelagic
Table 4
Infection rate of external parasites and diatom ﬁlms in ﬁnwhales collected from JARPAII.
Species

Male1

Female1

Total1

CyamusCoronula sp
Conchoderma sp
Pennella sp
Diatom ﬁlm

6/8 (75.0)
1/8 (12.5)
0/8 (0.0)
0/8 (0.0)
8/8 (100.0)

1/8 (12.5)
1/8 (12.5)
0/8 (0.0)
0/8 (0.0)
6/8 (75.0)

7/16 (43.8)
2/16 (12.5)
0/16 (0.0)
0/16 (0.0)
14/16 (100.0)

1

infected/investigated (infected rate %)Figure 6.

commercial whaling. On the other hand, for technicalreasons it was not possible to take ﬁn whales of morethan 20 m in JARPAII. Notwithstanding these diﬃculties, adecreasing trend in the average body length is observed
for the years of commercial whaling (Figure 6).
Body proportion
The mean value and body proportion of the externalmeasurements of JARPAII is summarized in Table 5, bysex. As shown in this table, no diﬀerence in proportions
was observed between the sexes except for the reproductive aperture (e.g. measurement point 13).
In order to clarify the JARPAII properties of body proportions, a data chart was created using the mean value
and the standard deviation for 15 measurement locationsof Japanese commercial whaling data (Figure 7). JARPAII
data are smaller than Japanese commercial whaling data
in many parts in both sexes. In measurements points 7,
14, and 21 in JARPAII, males are larger than commercial
whaling data. Females are larger than males in many
points. Excepting for sex diﬀerence, dorsal ﬁn is higher,
and the skull is shorter than commercial whaling data.
This trend was particularly pronounced in males.
Relationship between body length and body weight
Figure 8 shows the relationship between body lengthand body weight for JARPAII and commercially caught ﬁnwhales. Calculated coeﬃcients a and b in the formula are
a=0.005394±0.005329 and b=3.068448±0.332619 in
JARPAII, and a=0.044530±0.027880 and b=2.315830±
0.205040 in commercial data. From the graph, predictedbody weights of ﬁn whale captured in JARPAII tend to beYearly change in average body length of ﬁn whale captured in Antarctic pelagic commercial whaling (opencircle: seasons 1930/1931–1975/1976) and the body lengths of ﬁn whale sampled in JARPAII (closed circle:
seasons 2005/2006–2010/2011). Vertical bars indicate plus/minus one standard error. The data used in
Antarctic pelagic commercial whaling were summarized from International Whaling Statistics.
43

Technical Reports of the Institute of Cetacean Research (2018)
Table 5The external body proportions of the ﬁn whales in the JARPAII (see Figure 2 for details).
Males

1. Body length (0.01 m)
2. Projection of snout (0.1 cm)
3. Snout-blow-hole (1 cm)
4. Snout-angle of gape (1 cm)
5. Snout-eye (1 cm)
6. Snout-tip of ﬂipper (1 cm)
7. Eye-ear (0.1 cm)
8. Notch of ﬂukes-dorsal ﬁn (1 cm)
9. Notch of ﬂukes-root of ﬂukes (1 cm)
10. Notch of ﬂukes-anus (1 cm)
11. Notch of ﬂukes-umbilicus (1 cm)
12. Notch of ﬂukes-ventral grooves (1 cm)
13. Anus-reproductive aperture (0.1 cm)
14. Height of dorsal ﬁn (0.1 cm)
15. Length dorsal ﬁn (0.1 cm)
16. Axilla-tip of ﬂipper (1 cm)
17. Flipper length (1 cm)
18. Border length ﬂipper (1 cm)
19. Width of ﬂipper (0.1 cm)
21. Skull width (0.1 cm)
22. Skull length (0.1 cm)
23. Flipper length (from humerus) (1 cm)
25. Notch of ﬂukes-ﬂukes (1 cm)
26. Snout-ear (1 cm)
27. Snout-umbilicus (1 cm)
28. Snout-ventral grooves (1 cm)
29. Snout-reproductive aperture (1 cm)
30. Snout-anus (1 cm)
31. Notch of ﬂukes-rep. aperture (1 cm)
32. Snout-dorsal ﬁn (1 cm)
33. Width of ﬂukes (1 cm)
34. Chest circumference, half (1 cm)
35. Abdominal circumference, half (1 cm)
36. Buttock circumference, half (1 cm)
37. Body height (0.1 cm)
38. Body height (0.1 cm)
39. Border leng. ﬂipper (posteroior) (1 cm)

Females

n

Mean

%BL

n

Mean

%BL

8
4
8
8
8
8
8
8
7
8
8
8
8
8
8
8
8
8
8
8
8
8
4
8
8
8
8
8
8
8
8
8
8
8
7
8
8

18.96
9.9
344
365
372
777
91.4
429
98
535
860
833
131.3
47.9
108.3
149
230
237
52.8
220.6
464.5
239
215
461
1032
1061
1227
1358
664
1460
407
436
345
260
182.6
246.6
154

100.0
0.5
18.2
19.2
19.6
41.0
4.8
22.6
5.1
28.2
45.4
44.0
6.9
2.5
5.7
7.9
12.1
12.5
2.8
11.6
24.5
12.6
11.3
24.3
54.5
56.0
64.7
71.6
35.0
77.0
21.5
23.0
18.2
13.7
9.6
13.0
8.1

8
6
8
8
8
8
8
8
9
8
8
8
8
8
8
8
8
8
8
6
8
5
3
8
8
8
8
8
8
8
8
8
8
8
8
8
8

19.05
7.2
353
371
382
779
91.1
435
100
532
860
835
59
45
102.1
151
230
236
52.3
205.4
475.6
245
226
470
1056
1055
1311
1370
589
1467
426
452
366
277
195.4
254.8
156

100.0
0.4
18.5
19.5
20.1
40.9
4.8
22.8
5.2
27.9
45.1
43.8
3.1
2.4
5.4
7.9
12.1
12.4
2.7
10.8
25.0
12.9
11.9
24.6
55.4
55.4
68.8
71.9
30.9
77.0
22.4
23.7
19.2
14.5
10.3
13.4
8.2

Remarks. n: number of samples; %BL: percentage to body length; Mean: mean length.

heavier than that of the commercial whaling for the same
body length.
Relationship between body length and organ weights
Figure 9 shows the relationship between body lengthand gonad weight. The relationship is very similar
between JARPAII and commercially caught ﬁn whale
samples.
44

Tables 6a–b and 7a–b, and Figure 10 show the mean
weights of each body part, by body length. Figure 10
shows that the body parts weight increase with bodylength. This increase is more pronounced in the case of
the JARPAII whales for blubber (Figure 10b) and meat
(Figure 10c). For bones and viscera the increasing pattern is similar between JARPAII and commercially caught
whales.

Biological observations of fin whales sampled by JARPAII in the Indo-Pacific region of the Antarctic

Relationship between body length and sexual maturity
Figure 11 shows the relationship between body lengthand maturity rate of ﬁn whales sampled by commercial
whaling during the seasons 1949/1950, 1950/1951,
and 1951/1952, for female and males. JARPAII samples

Figure 7.

Body proportions of the JARPAII sample (closed
circles and solid line: male; open circle and broken line: female). The data are plotted on thenormalized axis using the data of Japanese commercial whaling (seasons 1948/1949–1950/1951).
Measurement point key are shown in Figure 2. μ j:
mean value of JARPAII data; μ c: mean value of thecommercial whaling data; σ c: standard deviation of
the commercial whaling data.

Figure 9.

are plotted for both immature (0 rate) and mature (1.0rate) individuals. Immature individuals of JARPAII ranged
from 14.79 m to 19.35 m (17.61–19.17 m in males,
14.79–19.35 m in females). Mature individuals ranged
from 18.73 m to 21.15 m (18.73–20.67 m in male, 19.47–
21.15 m in female respectively).
It is estimated that the body length at 50% sexual maturity is 18.99 m (18.69 m in male and 19.90 m in female)in commercial whaling samples. Regression coeﬃcient

Figure 8.

Relationships between body length and bodyweight in ﬁn whales. Closed circles and solid line:
JARPAII; open circles and broken line: Japanesecommercial whaling (Nishiwaki, 1950; Ohno andFujino, 1952: seasons 1947/1948–1950/1951).

Relationship between body length and gonad weight. A: ovary weight; B: testis weight; closed circle:
JARPAII; open circle: Japanese commercial whaling (Nishiwaki, 1950; Ohno and Fujino, 1952: seasons
1947/1948–1950/1951).
45

Technical Reports of the Institute of Cetacean Research (2018)
Table 6a
Average body parts weight (kg) of the ﬁn whales in the JARPAII.
Class of bodylength (m)Samples(female/male)

Total parts
weightBlubber

Meat

Bone

Viscera andothers

14.0–
17.0–
18.0–
19.0–
20.0–
21.0–

1 (1/0)1 (0/1)4 (1/3)5 (3/2)3 (2/1)1 (1/0)21,982.0
33,996.0
41,837.1
46,090.3
54,992.7
63,999.3

5,505.8
7,779.1
10,317.3
11,678.0
13,587.8
16,745.8

10,700.8
17,080.4
20,463.3
22,318.7
27,499.9
31,439.0

2,783.2
4,879.5
5,370.9
5,918.1
7,195.1
7,287.7

2,992.2
4,257.1
5,685.6
6,175.5
6,709.9
8,526.8

Total

15 (8/7)

45,517.0

11,363.5

22,344.4

5,840.7

5,968.4

Table 6b
Percentage of body parts weight of the ﬁn whales in the JARPAII.
Class of bodylength (m)Samples(female/male)

Total parts
weightBlubber

Meat

Bone

Viscera andothers

14.0–
17.0–
18.0–
19.0–
20.0–
21.0–

1 (1/0)1 (0/1)4 (1/3)5 (3/2)3 (2/1)1 (1/0)

100.0
100.0
100.0
100.0
100.0
100.0

25.0
22.9
24.7
25.3
24.7
26.2

48.7
50.2
48.9
48.5
50.0
49.1

12.7
14.4
12.8
12.8
13.1
11.4

13.6
12.5
13.6
13.4
12.2
13.3

Total

15 (8/7)

100.0

25.0

49.1

12.8

13.1

Table 7a
Average body parts weight (kg) of the ﬁn whales in commercial whaling data during the seasons 1947/1948–1950/1951.
Class of bodylength (m)Samples(female/male)

Total parts
weightBlubber

Meat

Bone

Viscera andothers

17.0–
18.0–
19.0–
20.0–
21.0–
22.0–
23.0–

1 (1/0)1 (1/0)5 (0/5)
12 (6/6)
8 (8/0)6 (6/0)1 (1/0)33,817.0
37,367.0
43,712.0
48,652.7
55,629.7
60,966.0
57,487.6

6,953.0
8,270.0
10,263.8
11,289.8
12,761.0
15,897.7
13,319.0

16,875.0
18,391.0
19,473.6
21,971.2
25,914.0
27,398.5
24,093.0

4,899.0
5,906.0
7,760.2
8,264.3
8,856.8
10,284.7
9,132.0

5,123.04,800.0
6,214.4
7,127.5
8,098.0
7,385.1
10,943.6

Total

34 (23/11)

51,232.3

12,141.5

23,296.6

8,543.3

7,251.9

Table 7b
Percentage of body parts weight of the ﬁn whales in commercial whaling data during the seasons 1947/1948–1950/1951.

46

Class of bodylength (m)Samples(female/male)

Total parts
weightBlubber

Meat

Bone

Viscera and others

17.0–
18.0–
19.0–
20.0–
21.0–
22.0–
23.0–

1 (1/0)1 (1/0)5 (0/5)
12 (6/6)
8 (8/0)6 (6/0)1 (1/0)

100.0
100.0
100.0
100.0
100.0
100.0
100.0

20.5
22.1
23.5
23.2
22.9
26.1
23.2

49.9
49.3
44.5
45.2
46.6
44.9
41.9

14.5
15.8
17.8
17.0
15.9
16.9
15.9

15.1
12.8
14.2
14.6
14.6
12.1
19.0

Total

34 (23/11)

100.0

23.7

45.4

16.7

14.2

Biological observations of fin whales sampled by JARPAII in the Indo-Pacific region of the Antarctic

Figure 10.

Comparison of the relationship body parts weight/
body length between JARPAII (closed circle and solidline) and commercial whaling (open circle and broken
line: seasons 1947/1948–1950/1951). A: body weight;
B: blubber; C: meat; D: bones; E: viscera and others.

Figure 11.

Relationship between body length and sexual
maturity rate of the ﬁn whales sampled by JARPAII(closed circle), and comparison of that with thatfrom commercial whaling (broken line: female; dot
line: male; seasons 1949/1950–1951/1952).

Figure 12.

Relationship between age and sexual maturity rateof the ﬁn whales sampled by JARPAII (closed circle
and solid line), and comparison with that by commercial whaling (broken line: season 1956/1957).

between sexual maturity and body length of JARPAII did
not reach statistical signiﬁcance, possibly due to the small
sample size. From the plotting, JARPAII data were equallydistributed besides the rise of predicted probability ofmaturity rate in commercial whaling data except for immature one (body length=14.79 m).

47

Technical Reports of the Institute of Cetacean Research (2018)

Relationship between age and sexual maturity
Figure 12 shows the relationship between age and sexual
maturity rate of ﬁn whales sampled by JARPAII and commercial whaling during the season 1956/1957, for both
sexes combined. Immature individuals of JARPAII ranged
from 6 to 9 years old, and mature individuals ranged from
7 to 22 years old. It is estimated that the 50% sexual maturity age are 8.8 years old in JARPAII and 11.0 years oldin commercial whaling, respectively. The minimum age ofa pregnant whale obtained in JARPAII was 10 years old.
Age at 50% sexual maturity of JARPAII is 2.2 years younger
than Japanese commercial whaling data.

DISCUSSION
This study provided new biological information of ﬁnwhales in the Antarctic after 36 years of protection fromcommercial whaling. Although the number of whales
examined was small some new and interesting results
such as body proportion and parasites were obtained.
During the commercial whaling period only large whales
were taken. During the JARPAII survey there was the opportunity of sampling small animals for the ﬁrst time. Infact the smallest whale was a 14.79 m whale and several
biological data were obtained from this whale. The limitation of JARPAII, however, was for animals larger than
20.0 m which usually were not sampled because technicaldiﬃculties.
Body length/ body weight
It was found that Antarctic ﬁn whales collected by JARPAII
were heavier than those taken by commercial whaling in
the 1950s. This might suggest that the feeding condition
for the Antarctic ﬁn whale has improved in recent years.
It was also found that the relative weights of the blubber and the meat are heavier for ﬁn whales sampled by
JARPAII (Figure 10). The increase in body weight of ﬁnwhales, particularly in weight of meat and blubber, might
indicate faster growth which was derived from better nutritional condition in recent years.
Body length and age at sexual maturity
There is the possibility that the age at sexual maturity of
the ﬁn whale has decreased in the 2000s. Decline in theage at sexual maturity in whales in response to substantial decrease in the abundance (for example due to overexploitation) has been reported for sei and ﬁn whales inpart of the Indian Ocean and the Antarctic Ocean, andfor ﬁn whales in the northwest Paciﬁc Ocean (Gambell,
1973; Lockyer, 1979; Ohsumi, 1986). Our study provided
evidence that the age at sexual maturity of ﬁn whales
48

sampled by JARPAII has decreased about 2.2 years fromthe 1950s.
The number of pregnant whales among the ﬁn whales
sampled by JARPAII was three out of four matured whales(75.0%). This high pregnancy rate was similar to the1970s (Gambell, 1973).
All this evidence suggests improved nutritional conditions for ﬁn whales in recent years. The biological studies
based on JARPAII data were based on a small sample size.
Further biological samples and data from this species will
be needed to conﬁrm the results found in this study.

ACKNOWLEDGEMENTS
I express my gratitude to the crew members and researchers that participated in the JARPAII surveys forhard work and excellent technical assistance. I also thankseveral ICR colleagues for providing suggestions on theanalyses in this study.

REFERENCES
Fujino, K. 1954. On the body proportions of the ﬁn whales(Balaenoptera physalus (L)) caught in the northern Paciﬁc
Ocean (I) (Preliminary report). Sci. Rep. Whales Res. Inst. 9:
121–163.
Gambell, R. 1973. Some eﬀects of exploitation on reproductionin whales. J. Reprod. Fertil. (Suppl.) 19: 533–553.
Government of Japan. 2005. Plan for the second phase of theJapanese whale research program under special permit in the
Antarctic (JARPAII)—Monitoring of the Antarctic ecosystemand development of new management objectives for whale
resources. Paper SC/57/O1 presented to the IWC Scientiﬁc
Committee, June 2005 (unpublished). 99 pp. [Available fromthe IWC Secretariat].
International Whaling Commission. 1977. Chairmanʼs Reportof the Twenty-Eighth Meeting. Rep. int. Whal. Commn 27:
22–35.
Kakuwa, Z., Kawakami, T. and Iguchi, K. 1953. Biological investigation on the whales caught by the Japanese Antarctic whaling ﬂeets in the 1951–52 season. Sci. Rep. Whales Res. Inst.
8: 147–213.
Kato, H. 1986. Changes in biological parameters of Balaenopterid
whales in the Antarctic, with special reference to southernminke whale. Mem. Natl. Inst. Polar Res., Spec. Issue. 40:
330–344.
Laws, R.M. 1961. Reproduction, growth and age of southern ﬁnwhales. Discovery Reports 31: 327–486.
Lockyer, C. 1972. The age at sexual maturity of the Southern ﬁnwhale (Balaenoptera physalus) using annual layer counts inthe ear plug. ICES Journal of Marine Science 34 (2): 276–294.
Lockyer, C. 1976. Body weights of some species of large whales.
ICES Journal of Marine Science 36 (3): 259–273.
Lockyer, C. 1979. Changes in a growth parameter associatedBiological observations of fin whales sampled by JARPAII in the Indo-Pacific region of the Antarctic

with exploitation of southern ﬁn and sei whales. Rep. int.
Whal. Commn 29: 191–196.
Maeda, H. Kawamoto, T. and Kato, H. 2013. A study on the improvement of age estimation in common minke whales using
the method of gelatinized extraction of earplug. NAMMCO
Scientiﬁc Publications [Online] 10. doi: 10.7557/3.2609.
Mackintosh, N.A. and Wheeler, J.F.G. 1929. Southern blue andﬁn whales. Discovery Reports 1: 259–540.
Matsuoka, K., Hakamada, T., Kiwada, H., Murase, H. andNishiwaki, S. 2005. Abundance increases of large baleen
whales in the Antarctic based on the sighting survey during
Japanese whale research program (JARPA). Global Environ.
Res. 9 (2): 105–115.
Matsuoka, K., Hakamada, T., Kiwada, H., Murase, H. andNishiwaki, S. 2006. Distributions and standardized abundance
estimates for humpback, ﬁn and blue whales in the Antarctic
Areas IIIE, IV, V and VIW (35°E–145°W), south of 60°S. Paper
SC/D06/J7 presented to the JARPA Review Workshop, Tokyo(unpublished). 37 pp. [Available from the IWC Secretariat].
Mizue, K. and Murata, T. 1951. Biological investigation on thewhales caught by the Japanese Antarctic whaling ﬂeets season 1949–50. Sci. Rep. Whales Res. Inst. 6: 73–131.

Nishiwaki, M. 1950. On the body weight of whales. Sci. Rep.
Whales Res. Inst. 4: 184–209.
Nishiwaki, M., Ichihara, T. and Ohsumi, S. 1958. Age studies ofﬁn whale based on earplug. Sci. Rep. Whales Res. Inst. 13:
155–169.
Ohno, M. and Fujino, K. 1952. Biological investigation on thewhales caught by the Japanese Antarctic whaling ﬂeets, season 1950/51. Sci. Rep. Whales Res. Inst. 7: 125–190.
Ohsumi, S, 1964. Examination on age determination of the ﬁnwhale. Sci. Rep. Whales Res. Inst. 18: 49–88.
Ohsumi, S. 1986. Yearly change in age and body length at sexual
maturity of a ﬁn whale stock in the eastern North Paciﬁc. Sci.
Rep. Whales Res. Inst. 37: 1–16.
Omura, H. 1950. Diatom infection on blue and ﬁn whales in the
Antarctic Whaling Area V (the Ross Sea area). Sci. Rep. Whales
Res. Inst. 4: 14–26.
Purves, P.E. 1955. The wax plug in the external auditory meatusof the Mysticeti. Discovery Reports 27: 293–302.
Williamson, G.R. 1973. Counting and measuring baleen andventral grooves of whales. Sci. Rep. Whales Res. Inst. 25:
279–292.

49

Technical Reports of the Institute of Cetacean Research (2018)

pp. 50–55

Technical Report (not peer reviewed)

Field and analytical protocol for the evaluation of novel non-lethal
techniques in the Japanese whale research programs
Toshihiro Mogoe*
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: mogoe@cetacean.jp

ABSTRACTThis paper describes the ICR ﬁeld and analytical protocol used to evaluate novel non-lethal techniques, which
potentially can be used to respond to scientiﬁc questions related to NEWREP-A and NEWREP-NP. The protocol
includes four primary questions, which should be responded to in order to evaluate the techniques. This paper
also illustrates the use of this protocol to evaluate the use of faeces for studies of feeding ecology of whales(a non-lethal technique).

INTRODUCTION
The International Whaling Commission Scientiﬁc Committee (IWC SC) recommended that a ﬁeld and analytical
protocol should be developed to assist the evaluation of
the utility of novel non-lethal techniques (IWC, 2016).
Such techniques could potentially be used to respondto scientiﬁc questions related to the Japanese whale
research programs (see Goto and Inoue, this issue). In
response to this recommendation, scientists from theInstitute of Cetacean Research (ICR) developed a protocol
consisting of several questions that should be responded
to in order to evaluate novel non-lethal techniques (seeMogoe et al., 2015).
The objective of this paper is to describe this ﬁeld andanalytical protocol. The paper also illustrates the use ofthis protocol to evaluate the use of faeces for studies of
feeding ecology of whales, a non-lethal technique.

DESCRIPTION OF THE FIELD AND ANALYTICAL
PROTOCOL
The questions
The protocol consists of four questions, which are listed
and explained in this section.
The ﬁrst question (Q1) is whether a tissue or otherkinds of samples can be obtained by a non-lethal technique (for example whether or not faeces can be collected from the sea surface during a research period).
The second question (Q2) is whether a suﬃcient number of samples for statistical analysis can be obtained by
the non-lethal technique.
The third question (Q3) is whether the sample ob50

tained by the non-lethal technique can produce scientiﬁc information comparable to that produced by a lethal
sampling technique.
The fourth question (Q4) is whether the cost for obtaining the sample and for producing scientiﬁc information from the sample is reasonable.
Q1 and Q2 above are technical in nature. Q3 is analytical while Q4 is of a logistic nature.
Formulating the questions to evaluate a non-lethal
techniqueThe ﬂow chart of Figure 1 shows a systematic applicationof the protocol to evaluate a novel non-lethal technique.
The fundamental question to be responded to throughthis chart is whether a novel non-lethal technique canreplace the lethal-sampling.
The formulation of the four questions forms a basis
to objectively discuss the feasibility and practicability of
non-lethal techniques, particularly from a perspectiveof whether particular research objectives are achievablethrough non-lethal techniques.
Criteria for questions
The criteria for Q1 is simple. If at least one tissue or
sample can be taken during the research period by the
non-lethal technique, the answer is ʻyesʼ otherwise theanswer is ʻno.ʼ
For Q2 the sampling eﬃciency of a non-lethal technique needs to be compared with that of a lethal technique. For example in the case of faeces sampling (seebelow), the number of samples collected by some unit ofeﬀort is compared with the number of whales (stomachs)

Field and analytical protocol for the evaluation of novel non-lethal techniques in the Japanese whale research programs

Figure 1.

Systematic application of the four questions to evaluate the feasibility of novel non-lethal techniques.

sampled by the same unit.
In Q3 the key issue is whether the analysis of the tissue or samples obtained by the non-lethal technique
can respond to speciﬁc scientiﬁc questions by producing
scientiﬁc information of similar or better quality than that
produced by the lethal-technique. For example in thecase of faeces samples (see below), the key question will
be whether the analysis of faeces samples can produce
similar or better scientiﬁc information than the lethal
technique (stomach content analysis) to respond questions of prey consumption (qualitative and quantitative)
and prey preference, which are important input data forecosystem models.
Criteria for Q4 require further consideration but thesimplest approach for an evaluation could be dividing
the overall cost for research by the number of samples
obtained.

APPLICATION OF THE PROTOCOL TO EVALUATE
THE USE OF FAECES FOR FEEDING ECOLOGYSTUDIES
Currently reliable information on prey consumption andprey preferences of whales is obtained through the analyses of stomach contents. The fundamental question iswhether the analysis of faeces samples can provide suchreliable information.

Field and laboratory data were obtained, which are explained below. Data collected were the basis of responses
to the four questions in Figure 1.
Field data
The ﬁeld experiments on the evaluation of the faeces
sampling for studies of feeding ecology of North Paciﬁc common minke, Brydeʼs and sei whales were carriedout during the 2014 and 2015 JARPNII surveys. Yushin
Maru-type vessels were used for the experiments inthe oﬀshore component of JARPNII (Bando et al., 2016)(sighting and sampling vessels: SSVs, and sighting vessels:
SVs). Smaller vessels were used in the coastal component(Kishiro et al., 2016).
Table 1 shows a summary of the eﬀort (time) spent on
both whale observation and sampling (lethal) and faeces
observation and sampling (non-lethal).
Observation and sampling of faeces
Observation of excretion and sampling of faeces in identiﬁed individuals of common minke, sei and Brydeʼs whales
were made from the platforms of the survey vessels. The
eﬀort was deﬁned as the observation time from conﬁrmation of the whale species (0.2 n.miles) to the end ofobservation/sampling. If an observer found faeces near
the sea surface, the faeces were sampled by circle net
51

Technical Reports of the Institute of Cetacean Research (2018)
Table 1Eﬀort (hours) spent in whale observation and sampling (lethal)and faeces observation and sampling (non-lethal) surveys. See
text for details.
Oﬀshore Oﬀshore Coastal Coastal
SSVs
SVs
Sanriku Kushiro2014 JARPNII
Whale observationand sampling eﬀort 193.3
Faeces observationand sampling eﬀort 89.6
Total eﬀort
282.9
Rate (%) of
non-lethal eﬀort
31.7
2015 JARPNII
Whale observationand sampling eﬀort
Faeces observationand sampling eﬀort
Total eﬀort
Rate (%) of
non-lethal eﬀort

Figure 2.

—

510.3

250.9

262.4
262.4

60.8
571.1

58.6
309.5

100.0

10.6

18.9

61.5

—

596.4

521.7

99.5
161.0

547.5
547.5

54.6
650.9

65.4
587.1

61.8

100.0

8.4

11.1

Sampling of sei whale faeces in the 2015 JARPNII
oﬀshore survey.

with 100 µm mesh size (Figure 2). The sampled faeces
were stored using polyethylene bottles at −20°C.
Observation and sampling of whales
Whales were sighted and sampled along the predetermined track-lines. The eﬀort was deﬁned as the timefrom conﬁrmation of whale species to the time of theshooting.
Analytical procedures
The idea was to compare the results on prey species inthe stomach contents (direct observations) and in faeces
samples (DNA analyses). As this comparison was not pos52

sible for a same individual, the contents in intestine wasused as a proxy for faeces. Therefore prey species in thestomach (direct observation) and intestine (DNA analyses) was compared for a same individual. In addition,
prey species in the faeces samples collected were also
investigated by DNA analyses.
In the case of genetic analysis, total genomic DNA wasextracted using the standard phenol/chloroform extractions protocol of the GENTRA PUREGENE DNA extraction
kit (QIAGEN) following the companyʼs manual. Extracted
DNAs were stored in TE buﬀer. After PCR ampliﬁcation,
the products were analyzed using an Illumina MiSeq(next-generation DNA sequencers) to identify the preyspecies.
Analysis of stomach content followed standard procedure (Tamura et al., 2016).

RESULTS
Response to question 1
A total of 1,808 experiments were made (1,179 for sei,
393 for Brydeʼs and 236 for common minke whales), for377.2 h (Table 2). Excretion was observed in 38 individuals (30 sei, 6 Brydeʼs, and 2 common minke whales). Of
these, faeces was obtained successfully from ﬁve sei
whales. For Brydeʼs and common minke whales, faeces
could not be obtained due to sinking or spreading of faeces before sampling.
Therefore at the present, the answer to Q1 is ʻyesʼ
for sei whales and ʻnoʼ for common minke and Brydeʼswhales.
Response to question 2
Table 2 shows that the observation eﬀort and number of
excretions observed in the research period. The numberof faeces observed is extremely low, 38 cases in 1,808
individual experiments (2.1%) for all surveys and species
combined. These percentages were 2.5%, 1.5%, 0.0%
and 0.0% for sei, Brydesʼs, common minke (oﬀshore) andcommon minke (coastal), respectively.
These percentages contrast with those of the eﬃciencyof whale (stomach) sampling. For all surveys and species
combined there were 297 targeted individuals of which
151 were sampled (50.8%). The percentages by species
were 93.6%, 89.3% and 50.8% for sei, Brydeʼs and minke(coastal) whales, respectively.
Sampling eﬃciency of faecal sampling is substantially lower than the whale (stomach) sampling eﬃciency.
Therefore the response to Q2 is ʻnoʼ for sei, Brydeʼs andcommon minke whales.

Field and analytical protocol for the evaluation of novel non-lethal techniques in the Japanese whale research programs
Table 2
The results of faecal sampling in the 2014 and 2015 surveys.
Species2014 JARPNII
Sei
Brydeʼs
C. minke (Oﬀshore)
C. minke (Sanriku)
C. minke (Kushiro)
2015 JARPNII
Sei
Brydeʼs
C. minke (Oﬀshore)
C. minke (Sanriku)
C. minke (Kushiro)
Total
Sei
Brydeʼs
C. minke (Oﬀshore)
C. minke (Coastal)

Vesseltype

Number ofexperiments(school)

Number ofexperiments(individuals)

Observationeﬀort (hours)

Observation of
excretion(number)

Faecalsampling(number)

SSVs
SVs
SSVs
SVs
SSVs
SVs
SSVs
SSVs

192
134
94
30
2
2
49
89

346
333
116
42
2
2
49
89

75.1
5.9
25.4
12.7
0.1
0.2
44.8
60.6

11
10
1
2
0
0
0
1

3
0
0
0
0
0
0
0

SSVs
SVs
SSVs
SVs
SSVs
SVs
SSVs
SSVs

193
133
113
70
2
0
33
59

259
241
147
88
2
0
33
59

51.6
7.7
27.4
2.4
0.9
0.0
31.0
31.4

6
3
2
1
0
0
0
1

2
0
0
0
0
0
0
0

652
307
6
230

1,179
393
6
230

140.3
67.9
1.2
167.8

30
6
0
2

5
0
0
0

Response to question 3
Comparison between direct observation of stomach contents and DNA analysis of intestine
Table 3 shows a comparison of the prey species foundin the stomach (direct observation) and in the intestine(DNA analysis) of sei, Brydeʼs and common minke whales.
As indicated earlier, intestine was used as a proxy for
faeces.
There is no good correspondence between the preys
identiﬁed in the stomach and the intestine of the same
individuals. In several cases the species could not be
identiﬁed by the DNA analysis notwithstanding the fullstomach of the whales.
A prey of prey species was also observed. For example
Acartia clausii was identiﬁed by the DNA analysis in theindividual 14NPCS-M019. This species is known as amajor prey of sand lance, which is a known prey speciesof the common minke whale.
The results of prey identiﬁcation by the DNA analysis
was somewhat diﬀerent between the upper/middle partsof the small intestine and the large intestine.

DNA analysis of faeces
Table 4 shows the results of the DNA analysis for prey
identiﬁcation from faeces in three sei whales. The DNA
analysis could not detect the prey species from the faecesof other three sei whales, which suggest low eﬃciencyof this technique to identify prey species from faeces
samples.
Therefore the response to Q3 is ʻnoʼ for sei, Brydeʼs andcommon minke whales.
Respond to question 4This question is not addressed in the present study. However whale ﬁeld surveys are extremely expensive. Funding for some of the surveys involving sampling of whales
are provided in part by the sale of by-products.

CONCLUDING REMARKS
Discussions on the feasibility of novel non-lethal techniques in whale research have so far been controversial
and inconclusive. This is due a lack of an objective protocol guiding these discussions. The ICR has developed
53

Technical Reports of the Institute of Cetacean Research (2018)
Table 3Results of detected prey species in enteral content using next generation DNA sequencers.
Species
Sei

Brydeʼs

C.minke

ID NumberPrey species observedby stomach contents

Prey species estimatedPrey species estimatedby NGS—Middle part ofby NGS—Large intestine
small intestine

14NPSE001

Mackerels (90%) andMackerels and Japanese Mackerels and Japanese No identiﬁed
Japanese anchovy (10%) anchovyanchovy

14NPSE006

Copepods (99%) andkrill (1%)

Krill

No identiﬁed

Krill

14NPSE018

Mackerels

Mackerels and Paciﬁcsaury

Paciﬁc saury

No identiﬁed

14NPSE044

Japanese sardine (50%), Japanese sardine andJapanese anchovy (40%) Japanese anchovy
and Mackerels (10%)

No identiﬁed

No identiﬁed

14NPSE048

Copepods (80%) andPaciﬁc saury (20%)

Paciﬁc saury

Paciﬁc saury

Krill

14NPSE052

Copepods

Paciﬁc saury

Paciﬁc saury

Paciﬁc saury

14NPSE067

Copepods

No identiﬁed

No identiﬁed

No identiﬁed

14NPSE070

Mackerels

Mackerels and Paciﬁcsaury

Mackerels

No identiﬁed

14NPB005

Japanese anchovy

Japanese anchovy

Japanese anchovy

No identiﬁed

14NPB006

Mackerels

Japanese anchovy

No identiﬁed

Light ﬁsh
(Maurolicus muelleri)

14NPB009

Japanese anchovy
Japanese anchovy(90%), Japanese sardine(8%) and Mackerels (2%)

Japanese anchovy

Japanese anchovy,
Japanese sardine andkrill

14NPB010

Japanese anchovy

Japanese anchovy

No identiﬁed

No identiﬁed

14NPB016

Japanese anchovy

Japanese anchovy

Japanese anchovy

Krill

14NPB019

Japanese anchovy (99%) Japanese anchovy
and mackerels (1%)

Japanese anchovy

No identiﬁed

14NPCS-M013

Sand lance——

Sand lance

14NPCS-M019

Sand lance——

Copepoda(Acartia clausii)

14NPCS-M021

Sand lance——

No identiﬁed

14NPCK-M013

Japanese sardine——

No identiﬁed

14NPCK-M015

Japanese sardine——

No identiﬁed

14NPCK-M016

Japanese sardine——

Japanese sardine

14NPCK-M017

Walleye pollock andJapanese sardine——

No identiﬁed

14NPCK-M019

Japanese sardine——

Japanese anchovy

14NPCK-M027

Walleye pollock andJapanese common squid——

Japanese common squidand krill

NGS: next-generation sequencing.

54

Prey species estimatedby NGS—Upper part ofsmall intestineField and analytical protocol for the evaluation of novel non-lethal techniques in the Japanese whale research programs
Table 4Prey species in faeces of sei whales identiﬁed by the NGS.
Species

ID Number

Results

Sei
Sei
Sei

140527SEI
140528SEI
150529SEI

Copepoda (Oithona similis)
Copepoda (Oithona similis)
Euphausiacea, Calanoida

a protocol with four questions that should be responded
to in order to evaluate the feasibility of novel non-lethal
techniques. An objective evaluation of the available datain the context of the four questions will make possible
more useful discussions and conclusions on the feasibility of a given novel non-lethal technique. In this study
the protocol was used to evaluate the feasibility of theanalysis of whale faeces in studies on feeding ecology
speciﬁcally to respond to questions on prey consumption
and prey preferences. Results of the evaluation following
the protocol suggest that at this stage of knowledge, suchtechnique is not feasible and therefore cannot replace
the analysis of stomach content to respond the samequestions.

ACKNOWLEDGEMENTS
The author would like to thank all captains, crews andresearchers, who were involved in the JARPNII surveys.

REFERENCES
Bando, T., Isoda, T., Nakai, K., Sato, H., Okitsu, Y., Tsunekawa, M.,
Fujii, K., Yamasaki, M., Honma, H. and Eguchi, K. 2016. Cruise
Report of the Second Phase of the Japanese Whale Research
Program under Special Permit in the Western North Paciﬁc(JARPNII) in 2015 (part I)—Oﬀshore component—. Paper
SC/66b/SP2 presented to the IWC Scientiﬁc Committee,
May 2016 (unpublished). 14 pp. [Available from the IWC

Secretariat].
International Whaling Commission. 2016. Report of the Expert
Panel of the ﬁnal review on the western North PaciﬁcJapanese Special Permit Programme (JARPNII). Paper SC/66b/
Rep06 presented to the IWC Scientiﬁc Committee, June 2016
(unpublished). 96 pp. [Available from the IWC Secretariat].
Isoda, T., Kawabe, S., Ohkoshi, C., Mogoe, T. and Matsuoka, K.
2016. Results of the NEWREP-A dedicated sighting survey in
Area IV during the 2015/16 austral summer season. Paper
SC/66B/IA5 presented to the IWC Scientiﬁc Committee,
June 2016 (unpublished). 25 pp. [Available from the IWC
Secretariat].
Kishiro, T., Yoshida, H., Ito, N., Mogoe, T., Nakamura, G., Maeda,
H., Miyakawa, N., Hirose, A., Ota, M., Kato, K., Hayashi, R.,
Yoshii, K., Kim, Y., Miyashita, T., Kumagai, S., Sato, H., Kimura,Y., Hiruda, H., Katsumata, T., Nakai, K. and Kato, H. 2016.
Cruise Report of the Second Phase of the Japanese Whale
Research Program under Special Permit in the western North
Paciﬁc (JARPNII) in 2015 (Part III)—Coastal component oﬀ
Kushiro. Paper SC/66b/SP3 presented to the IWC Scientiﬁc
Committee, June 2016 (unpublished). 12 pp. [Available fromthe IWC Secretariat].
Mogoe, T., Tamura, T., Yoshida, H., Kishiro, T., Yasunaga, G.,
Bando, T., Konishi, K., Nakai, K., Kanda, N., Kitamura, T.,
Nakano, K., Katsumata, H., Handa, Y. and Kato, H. 2015.
Preliminary report of eﬃciency and practicability of biopsy
sampling, faecal sampling and prey species identiﬁcationfrom genetic analyses in 2014, and work plan for non-lethal
research in JARPNII. Paper SC/66a/SP11 presented to the
IWC Scientiﬁc Committee, May 2015 (unpublished). 11 pp.
[Available from the IWC Secretariat].
Tamura, T., Konishi, K. and Isoda, T. 2016. Updated estimation of
prey consumption by common minke, Brydeʼs and sei whalesin the western North Paciﬁc. Paper SC/F16/JR15 presented
to the Expert Panel of the Final Review on the western North
Paciﬁc Japanese Special Permit programme (JARPNII), Tokyo,
February 2016 (unpublished). 58 pp. [Available from the IWC
Secretariat].

55

Technical Reports of the Institute of Cetacean Research (2018)

pp. 56–63

Technical Report (not peer reviewed)

Results of feasibility studies on novel non-lethal techniques toaddress the main objectives of NEWREP-A
Mutsuo Goto* and Satoko Inoue
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: goto@cetacean.jp

ABSTRACTThis paper presents the progress made in the research conducted to evaluate the feasibility of some novel
non-lethal techniques. The techniques are DNA methylation for age determination and progesterone analysis
for determining the reproductive status of whales. Age and reproductive status of whales are key information
for addressing one of the main objectives of the NEWREP-A. Potentially both techniques can be used on biopsy
samples collected from free ranging whales. Regarding the former technique, eﬀort was spent to investigate
diﬀerences in methylation rates between Antarctic minke and humpback whales. Regarding the latter technique, eﬀort was made to examine progesterone from blubber of female Antarctic minke whales for whichhigh qualitative reproductive data was already available. A ﬁnal evaluation of both techniques will be made in
the near future considering the protocol developed for evaluating novel non-lethal techniques (Mogoe, thisissue).

INTRODUCTION
The Institute of Cetacean Research (ICR) conducts whale
research using both lethal and non-lethal techniques. Lethal techniques are required for key research objectivesof NEWREP-A such as the estimation of biological parameters based on age and reproductive data, and feeding
ecology based on qualitative and quantitative analyses ofstomach contents.
Routine non-lethal techniques used by ICR include systematic sighting surveys for abundance estimates, oceanographic surveys for ecological studies and photo-id andbiopsy sampling for studies on movement, distribution
and stock structure in blue, humpback and right whales.
These routine non-lethal techniques have been used by
ICR for many years in its whale research programs in the
Antarctic and western North Paciﬁc.
More recently some novel non-lethal techniques havebeen proposed, which potentially could be used to address some key objectives of NEWREP-A. For example,
DNA methylation in skin to investigate the age of theanimals, analysis of progesterone level in blubber to investigate the reproductive status of female whales, andstable isotopes in skin/blubber to study the feeding ecology of whales. These techniques can potentially be usedwith skin/blubber samples obtained by biopsy sampling.
ICR started the evaluation of the feasibility of using the56

non-lethal techniques mentioned above. The evaluation
involves two aspects, the ﬁrst is whether biopsy sampling(source of the samples) is feasible in the target species of
the research programs. The other aspect is the analyticalone, which involves laboratory and statistical analyses(see Mogoe, this issue).
The degree of diﬃculty of biopsy sampling is diﬀerent
among whale species, being more diﬃcult for smallerand fast swimming species such as the minke whale. Biopsy sampling was considered feasible in the case of large
whales such as sei and Brydeʼs whales in the North Paciﬁc
however it was considered not feasible for the case of
North Paciﬁc common and Antarctic minke whales (Yasunaga et al., 2017; 2018).
This paper summarizes the laboratory and statisticalprocedures to investigate the feasibility of using nonlethal techniques to determine age and reproductive status in Antarctic minke whale, the target species for lethal
sampling under the NEWREP-A. Tissue samples from thesampled Antarctic minke whale individuals were used
as a proxy for biopsy sampling of skin and blubber. The
outputs of these studies will be used for a ﬁnal evaluationof non-lethal techniques based on some speciﬁed criteria(see Mogoe, this issue).

Results of feasibility studies on novel non-lethal techniques to address the main objectives of NEWREP-A

DNA METHYLATION FOR AGE DETERMINATION
IN WHALES
DNA methylation as a tool for age determination
Chronological age is an important factor in animal ecology
because many biological characteristics change with time
(Jarman et al., 2015). Biological ageing is a combinationof programmed processes (Berdasco and Esteller, 2012;
Horvath, 2013) and accumulated changes caused byunrepaired environmental damage (Kujoth et al., 2005).
Recent evidence suggests that epigenetic changes areboth directing the process of ageing and being caused byit (Maegawa et al., 2010; Koch et al., 2011; Winnefeld andLyko, 2012; Hannum et al., 2013; Horvath, 2013).
The best studied class of epigenetic change in vertebrates is the methyl group presence or absence at the C5
position of Cytosine residues that are adjacent to Guanidine residues (ʻCpG sitesʼ) (Figure 1). CpG methylationlevels play an important role in control of gene expression, where higher methylation levels (ʻhypermethylationʼ) generally reduce gene transcription rate.
Methylation changes at speciﬁc CpGs have been
linked to age in mice (Maegawa et al., 2010) and humans (Christensen et al., 2009; Grönniger et al., 2010;
Bocklandt et al., 2011; Koch and Wagner, 2011; Hannum
et al., 2013). For the cetacean species, the DNA methylation approach was recently developed and applied to
humpback whales with the aim of age determination inthis species (Polanowski et al., 2014).

ed DNA, which was used in the case of the humpback
whale (Polanowski et al., 2014) and in the present study
for Antarctic minke whales. This method implies the useof bisulﬁte treatment of DNA to determine its patternof methylation. In animals it predominantly involves the
addition of a methyl group to the carbon-5 position of cytosine residues of the dinucleotide CpG, and is implicatedin repression of transcriptional activity. Treatment of DNA
with bisulﬁte converts cytosine residues to uracil, but
leaves 5-methylcytosine residues unaﬀected. Therefore,
DNA that has been treated with bisulﬁte retains only
methylated cytosines. The percentage of DNA mismatchis recorded, this gives the user a percentage methylation
per CpG site.
Research on DNA methylation at ICR
As a ﬁrst step to evaluate the DNA methylation for age
determination purpose, the same method used for
humpback whale was applied to Antarctic minke whale.
The purpose in this ﬁrst step was to compare DNA methylation rates between two baleen whale species. The
work conducted on Antarctic minke whale is explained in
the sections below.
Samples
A total of 100 Antarctic minke whale samples taken during the JARPAII were used for the study. Each sample
had good age information obtained by earplug reading.
Details of the samples are shown in Table 1. DNA was extracted from each sample using standard protocols.

Detection methods
DNA methylation can be detected by several methods,
one of them being the pyrosequencing of bisulﬁte treat-

Figure 1.

Methylation of cytosine to form 5-methylcytosine occurs at the same C5 position on the pyrimidine ring
(upper right), the same position distinguishes thymine from the analogous RNA base uracil after bisulﬁteconversion (lower right), and then methylation rate is estimated by the ratio of thymine and cytosine.
57

Technical Reports of the Institute of Cetacean Research (2018)
Table 1The sample sizes of Antarctic minke whales used for DNA methylation analysis by pyrosequencing method by sampling season,sex and age classes.
SeasonSex

2010/2011

F
M
F
M

2011/2012
Total

Figure 2.

–10 11–20 21–30 31–40 41–

Total

10
7
1
1

16
8
8
3

9
8
11
1

3
2
6
1

3
1
1

41
25
27
7

19

35

29

12

5

100

PYROMARK 24 Pyrosequencing System used in thisstudy.

Figure 3.

58

Age

Identiﬁcation of age-related epigenetic markers in
Antarctic minke whale
The procedure for identiﬁcation of age-related DNA
methylation sites and measurement of methylation levels
followed Polanowski et al. (2014). The following sevenCpG sites in three genes were selected for this study because they showed signiﬁcant correspondence between
CpG methylation levels and age in humpback whales.
Gene TET2 (three sites: CpG+16; CpG+21 and CpG+31)
Gene CDKN2A (three sites: CpG+297; CpG+303 andCpG+309)
Gene GRIA2 (one site: CpG+202)
Measurement of cytosine methylation levels and correlation with age
Cytosine methylation levels were measured with Qiagen PyroMark assays. The pyrosequencing assays were
designed using PYROMARK Assay Design Software (Version 2.0.1, Qiagen). Pyrosequencing was performed on
a PYROMARK 24 Pyrosequencing System (Qiagen) (Figure 2). The PYROMARK Q24 software gave percentage
methylation values for each CpG site (Figure 3).
DNA methylation rates in the seven sites were scoredsuccessfully, and regressions of each CpG methylation
rate against age determined by earplug reading weremade (Figure 4).
Correlations of all seven CpG sites in three loci withage based on earplug reading were lower than in the caseof the humpback whale study (Table 2). The standard
deviation for Antarctic minke whale by the Leave One

An Example of output of CpG Pyrogram report by PYROMARK 24 Pyrosequencing System of three CpG
sites in TET2 gene. Methylation rate of each CpG site is estimated by the ratio of the integral of Thymine
to Cytosine in gray shadow.

Results of feasibility studies on novel non-lethal techniques to address the main objectives of NEWREP-A

Figure 4.

Regressions between CpG methylation and age determined by earplug at seven sites (n=100). CpG sites
are: (A) GRIA2_CpG+202, (B) TET2_CpG+16, (C) TET2_CpG+21, (D) TET2_CpG+31, (E) CDKN2A_CpG+297,(F) CDKN2A_CpG+303 and (G) CDKN2A_CpG+309.

Table 2Comparison of the coeﬃcient of determination (R2) between
methylation rates of seven CpG sites and age determined from
earplug reading in humpback (Polanowski et al., 2014) andAntarctic minke (this study) whales.
Gene and CpG position

Humpback whale

This study

GRIA2_CpG+202
TET2_CpG+16
TET2_CpG+21
TET2_CpG+31
CDKN2A_CpG+297
CDKN2A_CpG+303
CDKN2A_CpG+309

0.469
0.174
0.189
0.409
0.409
0.211
0.344

0.01610.06040.06830.1874>0.0001
0.01480.0784Out Cross Validation (LOOCV) method was estimated at
8.865 years (Goto et al., 2018), while that for the humpback whale was estimated at 2.991 years using the same
method (Polanowski et al., 2014). Therefore the main
conclusion of this study is that the methylation rates fora same gene and sites are diﬀerent between the two baleen whale species.
Future works
The ICR is planning investigation of additional informative methylation sites. Such investigation should include
analyses on how the methylation rates changes among
body tissues as well among body parts of the whale,
among other factors.
With all information at hand the feasibility of using the
DNA methylation technique for age determination in Ant59

Technical Reports of the Institute of Cetacean Research (2018)arctic minke whale can be further evaluated.

HORMONE ANALYSIS FOR DETERMINATION OF
REPRODUCTIVE STATUS IN WHALES
Progesterone analysis for determination of reproductive
status in female whales
In cetacean species female reproductive status has been
determined by direct observation of reproductive organs
such as ovaries and uteruses. Progesterone is one of thesex hormones produced from ovaries and placenta (whenan individual gets pregnant) and it has role in ovulationand maintaining pregnancy.
Previous studies suggested that an elevation in theconcentration of progesterone in serum can be indicativeof ovulation and pregnancy diagnosis in captive cetaceans (Sawyer-Steﬀan et al., 1983; Schroeder and Keller,
1990; Kirby, 1990). Recently, the relationship between
progesterone and reproductive status has been studied
based on samples which potentially can be obtainedby non-lethal approach from free ranging cetaceans(Table 3). Several of those studies reported that progesterone can be detected from the samples used, and thatits concentration was substantially higher in pregnant
than immature females.
Methods
There are two main groups of methods to measure progesterone level, one is liquid chromatography (e.g. HPLC
and LC-MS in Table 3) and the other is immunoassay. The
latter has been used in the studies conducted by the ICR.
Immunoassay
Immunoassay is a method that measures the presenceor concentration of target analytes (like hormones) in
solution using antigen-antibody reactions. The antigenantibody reaction is a speciﬁc binding between an anti-

gen and an antibody. The reaction can be used for thedetection of antigens or antibodies speciﬁc for analytes.
Immunoassay measures the formation of antigenantibody complexes by labeling or labeling-free format.
There are several types of immunoassays depending onlabeling material, for example, labeling by radioisotope
is called radioimmunoassay (RIA), labeling by enzyme iscalled enzyme immunoassay (EIA) or enzyme-linked immunosorbent assay (ELISA). The immunoassay used at
the ICR is the latter one (ELISA) (Figure 5).
Research on progesterone at ICR
In the ICR, the relationship between concentration ofprogesterone in blubber and reproductive status in the
Antarctic minke whale was investigated by examining
female Antarctic minke whales. The main question waswhether or not progesterone concentration in blubber
can be used as an indicator of the reproductive status offemale whales.
Samples
Antarctic minke whales used in this study were collected
between December 2015 and February 2016 by NEWREPA in the Paciﬁc sector of the Antarctic Ocean. Whales
were sampled randomly from a predetermined zigzag
track line designed to cover the whole research area. A
total of 333 Antarctic minke whales (103 males and 230
females) were sampled during the survey. All sampled
females (230) were used in this study. The blubber tissues were obtained from the lateral side of each whale byresearchers on board the research base ship. The tissues
were stored at −20°C until analyses at the laboratory.
Determination of reproductive status
Reproductive status was determined by standard procedures (Lockyer 1984; 1987). The sexual maturity of

Table 3
Summary of the non-lethal studies to measure sex hormones in whales.
Species
MysticetiBlue whale Balaenoptera musculus
North Atlantic right whale Eubalaena glacialis
Humpback whale Megaptera novaeangliae

Odontoceti
Beluga Delphinapterus leucas
60

Samples

Methods

References

Feces
Feces
Blow
Blubber
Blubber
Blow

RIA, HPLC
RIA
LC-MS
EIA
EIA
LC-MS

Valenzuela-Molina et al. (2018)
Corkeron et al. (2017)
Hogg et al. (2009)
Clark et al. (2016)
Pallin et al. (2018)
Hogg et al. (2009)

Blow

ELISA

Richard et al. (2017)

Results of feasibility studies on novel non-lethal techniques to address the main objectives of NEWREP-A

Figure 5.

Schematic representation of ELISA. An antibody speciﬁc for a target protein is immobilized on the surfaceof microplate wells. Then it is incubated with samples containing the target protein and a known amount of
enzyme-labeled target protein. After the reaction, the substrate is added and the activity of the microplate
well-bound enzyme is measured. When the antigen level in the sample is high, the level of antibody-boundenzyme-labeled antigen is lower and the color is lighter. Conversely, when it is low, the level of antibodybound enzyme-labeled antigen is higher and the color is darker.

Figure 6.

Flow from collection of blubber sample to measurement of progesterone concentration.

females was determined by the presence of at least one
corpus luteum or corpus albicans in either ovary. In thecase where no corpus luteum and corpus albicans wasobserved, the female was categorized as immature. Reproductive status of mature female whales was classiﬁed
into three categories (resting, ovulating and pregnant),
based upon observation of the ovary and uterus.
Extraction and measurement of progesterone
The procedures for progesterone extraction and defatting treatment were performed according to Kellar et al.
(2013) and Nagata et al. (1996), respectively. Progesterone concentrations were determined by a commerciallyavailable ELISA kit, using the Crocodile Mini Workstation(Titertek Berthold, Germany). All samples were processed and quantiﬁed in triplicate. Figure 6 shows thesteps followed in the progesterone concentration study.
Results
Table 4 shows the results of the reproductive status determined by direct observation of reproductive organs,progesterone concentrations by reproductive status andother biological data for the total sample of 230 female
whales.
Seventy-six percent of the samples were mature females, and 90% of the mature females were pregnant.
About 73% of the immature whales were below the detection limit of the assay for progesterone concentration(0.2 ng/g). The pregnant females had the highest medianof 72 ng/g (range: 13–740 ng/g), with wider concentrations of progesterone. All pairwise comparisons apartfrom the ovulating-pregnant comparison, resulted in61Technical Reports of the Institute of Cetacean Research (2018)
Table 4
Biological data, determined reproductive status and progesterone concentration in the female Antarctic minke whales.
Immature

Resting

OvulatingPregnant

Body length (m)Median
7.37
8.81
9.01
8.78
Range
5.17–8.51 7.65–9.32 8.45–9.40 7.71–10.06
Ovary
total CL
Mean
0
0
1
1
Range
0
0
1–1
1–2
total CA
Mean
0
18
16
13
Range
0
1–44
0–45
0–40
Progesterone Concentration (ng/g)
Median
<0.2
15
26
72
Range
<0.2–2.6 <0.2–34
24–150
13–740
N
56
11
6
157

signiﬁcant statistical diﬀerences (Steel-Dwass post-hoc
test, p<0.05). However, overlap of progesterone concentrations was observed between each reproductive status
with the exception of the cases immature/ovulating andimmature/pregnant.
Summary
In this study, signiﬁcant diﬀerences were found in medianprogesterone concentration between all reproductive
categories except in the case between ovulating andpregnant females. However, the ranges of progesterone
concentration overlapped between each reproductive
category with the exception of the cases immature/ovulating and immature/pregnant. The results of this study
indicated that the progesterone concentration in blubber,which potentially can be obtained by biopsy sampling,cannot be used as an accurate diagnostic index to determine the reproductive status in the Antarctic minke
whale.

CONCLUDING REMARKS
Progress has been made in the work to evaluate novel
non-genetic techniques that potentially could be used toaddress some important objectives of NEWREP-A. The
degree of progress is diﬀerent among the speciﬁc technique examined and obviously further reﬁnement work
is required. Stable isotopes are also being examined toelucidate the feeding habits of some large baleen whale
species in the Antarctic. As stated earlier a ﬁnal evaluation of the feasibility of those techniques will be madein the near future following speciﬁc criteria (see Mogoe,
62

this issue).

ACKNOWLEDGEMENTS
We thank crew members and researchers that participated in the 2010/11 and 2011/12 JARPAII, 2015/16 and2016/17 NEWREP-A surveys in Antarctic for collecting
data and samples of the Antarctic minke whale used inthis study. We thank Natsumi Endo (Tokyo University ofAgriculture and Technology) for providing ELISA assay.

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Technical Reports of the Institute of Cetacean Research (2018)

pp. 64–73

Technical Report (not peer reviewed)

Using JARPA and JARPAII platforms for investigating the occurrence ofmarine debris in the Indo-Paciﬁc region of the Antarctic
Tatsuya Isoda*, Tsutomu Tamura and Luis A. Pastene
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: isoda@cetacean.jp

ABSTRACT
Records of marine debris and entanglements of whales in Antarctic waters are very limited. In this study, theinformation on marine debris and entanglements collected during JARPA/JARPAII and Japanese dedicatedwhale sighting surveys in the period 1987/88–2014/15, is summarized. The surveys were conducted in the
Indo-Paciﬁc sector, south of 60°S. Marine debris on the sea surface was recorded during systematic sighting
surveys. A total of 163 pieces were found with buoys/ﬂoats being the most abundant (69% of all marine debris
recorded). The highest density index (DI: number of marine debris observed per 100 n.miles) was recordedin Areas IV (70°E–130°E) and V (130°E–170°W) (DI: 0.15). The stomachs of 10,660 Antarctic minke whales, 16
dwarf minke whales and 17 ﬁn whales caught under JARPA/JARPAII were also examined for the presence ofdebris. A total of 71 pieces were found in the stomachs of the three species. The number of plastic debris per
100 Antarctic minke whales was estimated at 0.08. Four cases of entanglement in a total of 10,660 Antarctic
minke whales examined, were found. Given these low indices, the negative eﬀects of marine debris on whalesin the Antarctic is expected to be limited at present.

INTRODUCTION
The Antarctic is one of the most isolated places on earth,and the eﬀects of human activities in this area is limited.
However in recent years marine debris has been recordedin sub-Antarctic and Antarctic islands, but the information is limited (Barnes et al., 2010; Ivar do Sul et al., 2011).
JARPA/JARPAII conducted systematic monitoring of
the Antarctic ecosystem for a long period of time, which
included observation of marine debris in whales and theirenvironment. The present study summarizes the observations on marine debris collected by JARPA/JARPAII andJapanese dedicated whale sighting surveys in the IndoPaciﬁc region of the Antarctic, over a period of morethan 20 years. The relevance of this kind of survey is thatmarine debris could aﬀect whales through ingestion andentanglements.

MATERIALS AND METHODS
Surveys
JARPA was conducted during the austral summer seasons(December–March) from 1987/88 to 2004/05 seasons,while JARPAII was conducted from 2005/06 to 2013/14.
These long-term programs included sighting surveys andoceanographic surveys for management and monitoring64

purposes concurrently with whale sampling to study biological parameters (GOJ, 2005).
The present study on marine debris and entanglements
was based on data collected by the JARPA/JARPAII and by
a Japanese dedicated whale sighting survey conducted in
the 2014/15 season. Details of the general methodology
and survey procedures can be found in Nishiwaki et al.
(2006) and Nishiwaki et al. (2014).
Research area
The research area comprised the Indo-Paciﬁc regionof the Antarctic, speciﬁcally the International Whaling
Commission (IWC) Antarctic management Areas III (East)(35°E–70°E), IV (70°E–130°E), V (130°E–170°W) and VI(West) (170°W–145°W), south of 60°S.
Observation of marine debris on the sea surface
Marine debris (macro debris) observations on the sea
surface were made from dedicated sighting vessels (Figures 1 and 2).
For each debris found, sighting date, sighting position
and types of marine debris were recorded. Marine debris
data was roughly sorted into three types of debris: metal,
petrochemical products and others. The density index(DI: number of marine debris per 100 n.miles) was also

Using JARPA and JARPAII platforms for investigating the occurrence of marine debris in the Indo-Pacific region of the Antarctic

Figure 1.

Sighting vessel from where the observations were made (left) and sighting activity of whale schools andmarine debris (right).

Figure 2.

Example of marine debris found on the sea surface. The buoy was observed at 67°S; 179°W during the
2013/14 season.

Figure 3.

Examination of marine debris in whale stomachs onboard the research base vessel.

calculated in the period 1995/96–2014/15. No independent sighting surveys were conducted in the 2010/11,
2011/12 and 2013/14 seasons due to external interferences.
Observation of marine debris in whaleʼs stomach
The stomachs of 10,660 Antarctic minke whales(Balaenoptera bonaerensis), 16 dwarf minke whales (B.
acutorostrata subsp.) and 17 ﬁn whales (B. physalus)
were examined for the occurrence of debris.
The examination of whale stomachs was conductedonboard the research base vessel as shown in Figure 3.
The three stomach chambers and the duodenal ampulla

were examined macroscopically during the JARPA. Only
the fore and main stomachs were examined during the
JARPAII. Marine debris and objects other than preys weretabulated by ﬁve categories: feather, stone, wood, plastic
and other. The sizes of solid objects (stone, wood andplastic) were estimated from photographic records.
The relationship between body length and body weightof Antarctic minke whales was compared between whales
with and without debris in their stomachs (n=8,705). Thiswas made to examine the body condition of the whales
with debris in their stomachs.

65

Technical Reports of the Institute of Cetacean Research (2018)

Figure 4.

Observation of entanglements onboard the research base vessel.

Table 1
Summary of the sightings of marine debris on the sea surface in Areas III (East), IV, V and VI (West) during the JARPA (1991/92–
2004/05), JARPAII (2005/06–2013/14) and Japanese dedicated whale sighting (2014/15) surveys.
Other

Metal

Petrochemical products (Total number=148)(Total number=14)
Type of marine debris
Drum

Can
AREA / Type of searching eﬀort
AREA III (East)
AREA IV
AREA VAREA VI (West)
Total

on

oﬀ

2
2

0

(Totalnumber=1)

Other(≦200 L)buoy
/ﬂoat*

Bottle

on

on

oﬀ

1

1

oﬀ

Container

FenderNet

plastic
products

oﬀ

on

1
2
1
1

4
3

4
37
35
7

10
14
5

3

5

7

83

29

4

on

oﬀ

1
2
1

3

0

on

oﬀ

on

5

3

1
2

5

3

3

oﬀ

0

on

Styrofoam

Otherproducts products*

oﬀ

on

1
1

1

1
8
1

oﬀ

on

4

1

2

1

10

4

1

oﬀ

0

Sub total

Total

on

oﬀ

7
51
52
8

1
19
20
5

8
70
72
13

118

45

163

Buoys/ﬂoats /fenders were ﬂoating as single object, however, at least in six cases, several buoy/fenders were observed; those cases were counted as a single observation.
Other plastic products were rope and ball. Other products were unknown material square boxes.
*Material of buoys/ﬂoats was considered to be plastic, in addition to Styrofoam and rubber.

Entanglements
Observations of the external part of the bodies of thewhales were made onboard the research base vessel asshown in Figure 4. All cases of entanglements (attachedobjects) in Antarctic minke whales sampled by the JARPA
and JARPAII (n=10,660) were recorded. Furthermore
scars and marks in the body of whales possibly produced
by entanglements was examined for whales sampled
under the JARPAII (n=3,883). The latter analysis was
based on JARPAII surveys, when more detailed bodyobservations, supported by the use of digital cameras,
started.
The relationship between body length and bodyweight of Antarctic minke whales was compared between
whales with and without entanglements (n=8,705). Thiswas made to examine the body condition of the whales
with entanglements.

66

RESULTS
Marine debris on the sea surface
A total of 163 records of marine debris were made (14metals, 148 petrochemical products and one other) on
the sea surface (Table 1). Buoys/ﬂoats (petrochemical)
accounted for 69% of all marine debris. Debris was foundthroughout all research areas; however, the DI was higher
in Areas IV and V particularly during the JARPAII period(Table 2, Figures 5a and 5b). The most southerly debris
was a buoy found in area V (Ross Sea) at 74°S, 176°W.
The highest DI was recorded in Area IV and V (DI: 0.15).
The average DI in the four Areas was 0.13 (Table 2). DI
for buoys/ﬂoats ranged from zero to 0.35 and theseincreased suddenly in Areas IV and V after the 2005/06
season and it peaked at the 2007/08 season and thendecreased (Figure 6).

Using JARPA and JARPAII platforms for investigating the occurrence of marine debris in the Indo-Pacific region of the Antarctic

Figure 5a.

Figure 5b.

Distribution of marine debris found during the JARPA surveys (1987/89–2004/05).

Distribution of marine debris found during the JARPAII (2005/06–2013/14) and Japanese dedicated whalesighting (2014/15) surveys.

Table 2The density indices (DI, number of marine debris per 100 n.
miles) during JARPA (1995/96–2004/05), JARPAII (2005/06–
2013/14) and Japanese dedicated whale sighting survey(2014/15).

Area (95/96–14/15)

Searching
distance(n.miles)Density index
Number of(number of mamarine debris
rine debris per(on eﬀort)
100 n.miles)

Area III (East)

14,5707

0.05

Area IV

34,63851

0.15

Area V34,55452

0.15

Area VI (West)10,096

8

0.08

Total

93,857118

0.13

Observation of debris in whaleʼs stomachs
A total of 69 out of the 10,660 Antarctic minke whales
examined had ingested marine debris and objects otherthan prey (Table 3). Feathers accounted for 44 cases,stones in six cases, pieces of wood in eight cases and plastics in nine cases. In 36 cases, debris and objects otherthan prey was found in the fore and main stomach.
The occurrence of plastic debris in body of whales per
100 Antarctic minke whales examined was calculated
at 0.08. The size of solid objects (stone, wood, plastic)
was less than 100×100 mm (Figure 7). There were two

Figure 6.

Density indices by season/area of sighted buoys/
ﬂoats during JARPA (1995/96–2004/05), JARPAII(2005/06–2013/14) and Japanese dedicated whalesighting (2014/15) surveys.

occurrences (one plastic bag and one small wood scantling) in which the size of the objects was more than
100×100 mm.
There were no diﬀerences in the relationship between
body length and body weight of Antarctic minke whales
with or without debris in their stomachs (Figure 8).
No debris and objects other than prey was found in
the stomachs of the 16 dwarf minke whales examined. In
the case of the ﬁn whales, only one animal had ingested
objects other than prey (two pieces of feathers).
67Technical Reports of the Institute of Cetacean Research (2018)
Table 3
Marine debris and objects other than prey ingested by the Antarctic minke whales sampled by JARPA and JARPAII surveys (1987/88–
2013/14).
Antarctic minke whale

Marine debris and objects other than prey
Total

ResearchseasonSample size

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
2009/102010/112011/122012/132013/14

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

—
—
—
—
—
2
—
—
—
8
4
1
—
—
1
2
4
8
11
—
—
—
2
—
1
—
—

—
—
—
—
—
(2)
—
—
—
(7)
(0)
(0)
—
—
(0)
(1)
(3)
(3)
(11)
—
—
—
(2)
—
(1)
—
—

—
—
—
—
—
—
—
—
—
1
—
1
—
—
1
—
1
1
—
—
—
1
—
—
—
—
—

—
—
—
—
—
—
—
—
—
(0)
—
(1)
—
—
(0)
—
(0)
(0)
—
—
—
(1)
—
—
—
—
—

—
—
—
—
1
1
1
—
—
—
—
1
1
2
—
—
—
1
—
—
—
—
—
—
—
—
—

—
—
—
—
(0)
(0)
(0)
—
—
—
—
(0)
(0)
(2)
—
—
—
(0)
—
—
—
—
—
—
—
—
—

1
—
—
—
1
1
1
—
—
—
—
1
2
1
—
1
—
—
—
—
—
—
—
—
—
—
—

(0)
—
—
—
(0)
(0)
(0)
—
—
—
—
(0)
(0)
(0)
—
(1)
—
—
—
—
—
—
—
—
—
—
—

—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
1
1
—
—
—
—
—
—
—
—
—
—

—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
(0)
(1)
—
—
—
—
—
—
—
—
—
—

1
—
—
—
2
4
2
—
—
9
4
4
3
3
2
4
6
10
11
—
—
1
2
—
1
—
—

(0)
—
—
—
(0)
(2)
(0)
—
—
(7)
(0)
(1)
(0)
(2)
(0)
(2)
(4)
(3)
(11)
—
—
(1)
(2)
—
(1)
—
—

Total

10,660

44

(30)

6

(2)

8

(2)

9

(1)

2

(1)

69

(36)

Feather

Stone

Wood

Plastic

OthersAll items were found in the stomach and duodenal ampulla except for three feathers, one small stone and one plastic piece foundin the oral cavity, small intestine and anus respectively. The ʻOthersʼ includes one small rubber piece and one small mineral mattersuch as coal. (Number in parentheses): number of marine debris and objects other than prey found in the fore stomach and main
stomach.

Entanglements
Only four cases of entanglements were found in a totalof 10,660 Antarctic minke whales examined (Table 4,
Figure 9). Those involved ﬁshing hooks, monoﬁlamentﬁshing lines, ropes and packing bands. There were nodiﬀerences in the relationship between body length andbody weight of Antarctic minke whales with or without
entanglements (Figure 8). At least ﬁve out of 3,883 Antarctic minke whales examined in JARPAII had scars presumably derived from entanglements (Figure 10).

68

DISCUSSION
Evidence from remote oceanic islands suggested asouthward-decreasing, strong latitudinal gradient in litter
densities from subtropical and temperate waters throughthe subtropical convergence to polar front and beyond(i.e. there is a clear trend in marine debris accumulation
with latitude) (Barnes, 2005; Gregory and Ryan, 1997).
Matsumura and Nasu (1997) reported the results ofsighting surveys showing the distribution of ﬂoating marine debris in the North Paciﬁc Ocean and its adjacent

Using JARPA and JARPAII platforms for investigating the occurrence of marine debris in the Indo-Pacific region of the Antarctic

Figure 7.

Size of marine debris ingested by Antarctic minke
whales sampled by JARPA and JARPAII surveys(1987/88–2013/14).

Figure 8.

Relation of body length and body weight in Antarctic
minke whales (n=8,705) for whales with and without debris in their stomachs (or entanglements).

waters in the period 1987–1991. These surveys covered
approximately 926,000 n.miles and counted 136,338
pieces of marine debris (including natural objects). About
60% of marine debris accounted for petrochemical debris(e.g. ﬁshing gear, styrofoam, other plastic products). Total
debris densities in coastal waters were 20–40 objects per
square n. mile, while the density in the north equatorial
current area (5° to 15°N, across the central Paciﬁc) was
about 0.2 objects per square n. mile, and 1–3 objects
per square n. mile in the subarctic boundary area (35° to45°N) (Matsumura and Nasu, 1997).
The DI in our study (Table 2) was compared with theresults by Matsumura and Nasu (1997). The DI in the
Antarctic is lower by two orders of magnitude in comparison with the North Paciﬁc Ocean and its adjacentwaters. Thus our observations prove that the Antarctic
waters have a very low density of marine debris on thesea surface.
Sources of marine debris in the Antarctic include ﬁshing, and research/tourism vessels, but also global oceanic
debris drifting across the Polar Front. Fishing operations
are important sources of marine debris in the Antarctic,
contributing not only with direct ﬁshing-related debris
but also miscellaneous items (Ivar do Sul et al., 2011). According to our results, ﬁshing buoys/ﬂoats accounted forabout 69% of all sighted marine debris on the sea surface.
Barnes et al. (2010) recorded three pieces of marine debris in the Durmont DʼUrville and Davis Seas (i.e. Areas IV
and V): a plastic cup and two ﬁshing buoys.
The assumption that all buoys/ﬂoats observed in
the Antarctic were transported from lower latitudes isunreasonable in consideration of the barrier eﬀects of
the Polar Frontal Zone, even if it is weak. Webber andParker (2012) showed ﬁshing gear loss of bottom longline ﬁsheries targeting Antarctic toothﬁsh (Dissostichus
mawsoni). Since 2004/05, licensed longline vessels haveconducted exploratory ﬁshery for Dissostichus spp. (target species is Antarctic toothﬁsh) in CCAMLR division
subarea 58.4.1 (which overlaps with Areas IV and V), andTable 4
List of entangled whales observed during JARPA and JARPAII surveys (1987/88–2013/14).
ResearchseasonSpecimenNo.

Date

LatitudeLongitude

Body
Body
length (m) weight (t)1995/96
2003/04065
046

22/12/1995
10/12/2003

62°48ʹS
63°10ʹS

68°55ʹE
54°56ʹE

7.5
5.7

2005/06
2005/06

190
765

6/1/2006
5/3/2006

64°26ʹS
63°56ʹS

72°40ʹE
103°46ʹE

7.8
5.7

Sex

Stomachcontents

Entanglement
Figure 9
objects

4.7
2.1

M
M

Empty
Krill

NA
NA

F
M

Krill
Krill

Fishing hook
Monoﬁlamentﬁshing line
Rope
Packing band

a
b
c
d
69

Technical Reports of the Institute of Cetacean Research (2018)

Figure 9.

Four entangled Antarctic minke whales observed during JARPA and JARPAII surveys (1987/88–2013/14).
(a) Fishing hook, (b) Monoﬁlament ﬁshing line, (c) Rope, (d) Packing band, (d) Loose packing band when awhale was being transported on the way to research base vessel.

there are high levels of IUU (illegal, unreported and unregulated) ﬁshing conducted outside CCAMLR regulations(SC-CAMLR, 2011). The number of licensed vessels in the
exploratory ﬁshery in subarea 58.4.1 was four to seven in
2004/05 to 2007/08 seasons, however it was decreased
to one to three in 2008/09 to 2014/15 seasons (SCCAMLR, 2012a; CCAMLR, 2013; 2014; 2015). The numberof sighted buoys/ﬂoats suddenly increased in Areas IV
and V after the 2005/06 season and peaked at 2007/08
seasons, and then decreased. This pattern coincides with
the ﬂuctuation of longline ﬁsheries operations (include
IUU ﬁshing).
In Iceland, six of 82 examined ﬁn whales (commercial
whaling) and in the New York area, three of 19 examined
mysticetes (stranding) contained synthetics in the gut(Sadove and Morreale, 1990). The occurrence rates ofmarine litter ingestion obtained from stranded animals
examined in the UK were 2.2% in the harbour porpoise(Phocoena phocoena) and 2.3% in the short-beakedcommon dolphin (Delphinus delphis) (Deaville and Jepson, 2010). We found 60 individuals with 69 pieces ofmarine debris and objects other than prey out of 10,660
Antarctic minke whales sampled in the Antarctic (0.56%).
Among them, there were only nine cases of plastics,
which is an extremely low frequency (0.08%) in comparison with other oceanic basins. Given this low frequency
the eﬀect of marine debris on whales is expected to be70

low.
Entanglement of Antarctic fur seals (Arctocephalus
gazella) was caused mostly by loop shaped debris suchas packing bands (Croxall et al., 1990; Arnould andCroxall, 1995). CCAMLR has prohibited and restricted
the use of packing bands on ﬁshing vessels in Conservation Measure 26-01. In this study, some entangled
whales strapped with packing bands around their upper
rostrums were found (Figures 9-d). Similar cases werereported in common minke whales (B. acutorostrata) in
the Atlantic (Gill et al., 2000). It has been indicated thatloop shaped debris causes the entanglement of whales aswell pinnipeds.
Fishing gear is the most signiﬁcant source of entanglements for whales and those entanglements were reported in various waters (Laist, 1997; Simmonds, 2012).
Documented interaction between whales and ﬁsheries
in the Southern Ocean included killer (Orcinus orca) andsperm whales (Kock et al., 2006), however entanglement
mortalities recorded in the case of sperm whales and possibly minke whales (SC-CAMLR, 2004; 2012b) were low. In
this study, only three cases of entanglements (probably
by ﬁshing gear) were found among the 10,660 Antarctic
minke whales examined.
At least ﬁve out of 3,883 Antarctic minke whales examined in JARPAII had scars presumably derived fromentanglements (see Figure 10). Those scars suggested

Using JARPA and JARPAII platforms for investigating the occurrence of marine debris in the Indo-Pacific region of the Antarctic

Figure 10.

Five cases of Antarctic minke whales with scars probably derived from entanglements observed during
JARPAII surveys (2005/06–2013/14). In the middle right-hand picture the wire rope used in the processing
is also shown.

that the entanglements occurred in previous cases, butthat they escaped from the obstructive objects and survived. Entanglements along the eastern seaboard of theUnited States and Canada during a ﬁve year period werereported as 27 cases of minke whales and 77 of humpback whales (Glass et al., 2008). In Iceland, ﬁve of 95 ﬁnwhales examined showed signs of previous entanglement(Sadove and Morreale, 1990). The entanglements of Antarctic minke whales are less frequent. Therefore the levelof impact of entanglements on Antarctic minke whales
would be low in comparison with other oceanic basins.

CONCLUSIONSThis study provided the ﬁrst comprehensive quantitative
approach of examining marine debris on the sea surface
and ingestion of marine debris and entanglement of
whales in the Antarctic. Given the low frequencies andindices, the impact of marine debris on whales in the
Antarctic is expected to be limited. Our study provides
some evidence that some degree of interaction between
whales and ﬁshery exist in the Antarctic. Webber andParker (2012) recommended that ﬁshing vessels and/or
the CCAMLR observer should record the detailed gear
loss, for estimating unaccounted ﬁshing mortality and to
reduce the loss of ﬁshing gear. That information is alsoessential to understand the interaction between whales
and ﬁsheries and marine debris. Long-term surveys conducted by JARPA and JARPAII proved very useful for examining the occurrence of marine debris and entanglementsin the Antarctic.

ACKNOWLEDGEMENTS
We would like to thank all of the captains, crew members,
cruise leaders and researchers onboard the research
71Technical Reports of the Institute of Cetacean Research (2018)vessels of JARPA, JARPAII and Japanese dedicated whalesighting survey for their contributions in collecting thedata used in this study.

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and Campos, L. 2011. Plastics in the Antarctic environment:
Are we looking only at the tip of the iceberg? Oecologia
Australis 15 (1): 150–170.
Kock, K.H., Purves, M.G., and Duhamel, G. 2006. Interactions
between cetacean and ﬁsheries in the Southern Ocean. Polar
Biol. 29: 379–388.
Laist, D.W. 1997. Impacts of marine debris: entanglement ofmarine life in marine debris including a comprehensive listof species with entanglement and ingestion records. pp.
99–139. In: J.M. Coe and D.B. Rogers (eds.) Marine Debris,sources, Impacts, and solutions. New York. Springer-Verlag.
432 pp.
Matsumura, S. and Nasu, K. 1997. Distribution of ﬂoating debris
in the North Paciﬁc Ocean: sighting surveys 1986–1991. pp.
15–24. In: J.M. Coe and D.B. Rogers (eds.) Marine Debris,sources, Impacts, and solutions. New York. Springer-Verlag.
432 pp.
Nishiwaki, S., Ishikawa, H. and Fujise, Y. 2006. Review of general
methodology and survey procedure under the JARPA. Paper
SC/D06/J2 presented to the JARPA review meeting called by
the IWC, December 2006 (unpublished). 47 pp. [Available
from the IWC Secretariat].
Nishiwaki, S., Ishikawa, H., Goto, M., Matsuoka, K. and Tamura,T. 2014. Review of general methodology and survey procedure under the JARPAII. Paper SC/F14/J2 presented to the
JARPAII review meeting called by the IWC, February 2014
(unpublished). 34 pp. [Available from the IWC Secretariat].
Sadove, S.S. and Morreale, S.J. 1990. Marine mammal and sea
turtle encounters with marine debris in the New York Bight
and the northeast Atlantic. pp. 562–570. In: R.S. Shomura and
M.L. Godfrey (eds.) Proceedings of the Second International
Conference on Marine Debris, 2–7 April 1989, Honolulu,
Hawaii. NOAA Tech. Memo. NMFS-SWFSC-154. 1274 pp.
SC-CAMLR. 2004. Report of the Working Group on Fish Stock
Assessment. In: Report of the twenty-third Meeting of the
Scientiﬁc Committee (SC-CAMLR-XXIII), Annex 5. CCAMLR,
Hobart, Australia: 338–657.
SC-CAMLR. 2011. Report of the Working Group on Fish Stock
Assessment (APPENDIX N: Fishery Report: Exploratory ﬁsheryfor Dissostichus spp.in Division 58.4.1). In: Report of the thirtieth Meeting of the Scientiﬁc Committee (SC-CAMLR-XXX),
Annex 7. CCAMLR, Hobart, Australia. 14 pp.
SC-CAMLR. 2012a. Report of the Working Group on Fish Stock
Assessment (APPENDIX Q: Fishery Report: Exploratory
ﬁshery for Dissostichus spp. (TOT) in Division 58.4.1). In:
Report of the thirty-ﬁrst Meeting of the Scientiﬁc Committee(SC-CAMLR-XXXI), Annex 7. CCAMLR, Hobart, Australia. 12
pp.
SC-CAMLR. 2012b. Report of the Working Group on Fish Stock
Assessment. In: Report of the Thirty-ﬁrst Meeting of the
Scientiﬁc Committee (SC-CAMLR-XXXI), Annex 7. CCAMLR,
Hobart, Australia: 265–377.
Simmonds, M.P. 2012. Cetaceans and Marine Debris: The Great

Using JARPA and JARPAII platforms for investigating the occurrence of marine debris in the Indo-Pacific region of the Antarctic

Unknown. Journal of Marine Biology. Vol. 2012 Article ID
684279, doi:10.1155/2012/684279. 8 pp.
Webber, D.N. and Parker, S.J. 2012. Estimating unaccountedﬁshing mortality in the Ross sea region and Amundsen Sea(CCAMLR subareas 88.1 and 88.2) bottom longline ﬁsheries
targeting Antarctic toothﬁsh. CCAMLR Science 19: 17–30.

73Technical Reports of the Institute of Cetacean Research (2018)

pp. 74–76

Technical Report-Note (not peer reviewed)

A summary of photo-id information of blue, southern right andhumpback whales collected by JARPA/JARPAII in the
Indo-Paciﬁc region of the Antarctic
Koji Matsuoka* and Luis A. Pastene
Institute of Cetacean Research, Toyomi-cho, 4–5 Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: matsuoka@cetacean.jp
The IWC Scientiﬁc Committee (IWC SC) conducted assessments of Antarctic blue (Balaenoptera musculusintermedia), southern right (Eubalaena australis) andhumpback (Megaptera novaeangliae) whales. One of thetechniques used by the IWC SC to investigate distribution, movement and abundance is photo-identiﬁcation(photo-id) of whales. Photo-id data obtained by JARPA
and JARPAII surveys have the potential to contribute to
the assessments of those species.
During the JARPA and JARPAII austral summer surveys
in the Indo-Paciﬁc region of the Antarctic, which include
IWC Management Areas IIIE (35°E–70°E), IV (70°E–130°E),
V (130°E–170°W) and VIW (170°W–145°W), photo-id experiments on blue, southern right and humpback whales
were conducted on an opportunistic basis. Photo-id
experiments were conducted in conjunction with biopsy
experiments. The dedicated sighting (SV) and the sighting
and sampling (SSV) vessels conducting line transect surveys under JARPA and JARPAII approached the whales for
obtaining pictures of natural marks, which can be used
for individual identiﬁcation e.g. scars, shape of dorsal ﬁnor mottled pigmentation pattern in the case of the blue
whale (Figure 1); scars, head callosities pattern in thecase of the southern right whale (Figure 2); scars, shapeof dorsal ﬁn, lateral marking and ventral ﬂuke colorationin the case of the humpback whale (Figure 3).
Between the austral summer seasons 1992/93 and2004/05 (JARPA), photographs were taken using 35 mm
SLR databack cameras equipped with 70-up to 300 mm
lenses and motor drive. Black and white 400 ASA ﬁlms (Ilford HP5) were used. From the 2005/06 season (JARPAII),
digital Nikon 70D cameras equipped with 100–300 mm
lens were used.
After each austral summer season, the best pictures
were selected (LAP for the pictures taken between
1989/90 and 2004/05 and KM for the pictures taken from2005/06), and these pictures were entered into the Institute of Cetacean Research (ICR)ʼs catalogue.
Tables 1a, 1b and 1c summarize the number of pic74

tures for blue, southern right and humpback whales,
respectively, by survey. Table 2 shows the total numberof pictures in the ICR catalogue. A total of 3,108 photographs (529 for blue, 914 for southern right and 1,665
for humpback whales) were collected and selected from
1989/90 to 2010/11 seasons (22 seasons). The number

Figure 1.

Example of dorsal ﬁn shape and mottled pigmentation as natural marks for photo-id of Antarctic blue
whales.

Figure 2.

Example of head callosities as natural marks forphoto-id of southern right whales.

A summary of photo-id information of blue, southern right and humpback whales collected by JARPA/JARPAII
Table 1b
Number of southern right whale photographs taken during
JARPA and JARPAII surveys by IWC Management Areas and austral summer season.
SurveyFigure 3.

Example of ventral ﬂuke pigmentation pattern as
natural marks for photo-id of humpback whales.

Table 1a
Number of Antarctic blue whale photographs taken during
JARPA and JARPAII surveys by IWC Management Areas and austral summer season.
SurveyJARPAJARPAII

IWC Areas
IIIE

IV

V

VIW

Number ofphotographs

1987/88

—

—

—

—

0

1988/89

—

—

—

—

0

1989/90

—

—

—

—

0

1990/91

—

—

—

—

0

1991/92

—

—

—

—

0

1992/93

—

—

33

—

33

1993/94

—

9

—

—

9

1994/95

—

—

16

—

16

1995/96

7

3

—

—

10

1996/97

—

—

6

2

8

1997/98

1

4

—

—

5

1998/99

—

—

21

0

21

1999/00

22

6

—

—

28

2000/01

—

—

0

0

0

2001/02

0

5

—

—

5

2002/03

—

—

0

6

6

2003/04

5

4

—

—

9

2004/05

—

—

0

3

3

Sub-total

35

31

76

11

153

2005/06

59

113

0

—

172

2006/07

—

—

18

0

18

2007/08

60

10

0

—

70

2008/09

—

—

24

39

63

2009/10

21

32

0

—

53

2010/11

—

—

0

0

0

Sub-total 140 155

42

39

376

175 186 118

50

529

Season

Total

JARPA

JARPAII

IWC Areas
IIIE

IV

V

VIW

Number ofphotographs

1987/88

—

—

—

—

0

1988/89

—

—

—

—

0

1989/90

—

—

—

—

0

1990/91

—

—

—

—

0

1991/92

—

39

—

—

39

1992/93

—

—

24

—

24

1993/94

—

9

—

—

9

1994/95

—

—

0

—

0

Season1995/96

—

12

—

—

12

1996/97

—

—

0

—

0

1997/98

—

94

—

—

94

1998/99

—

—

0

—

0

1999/00

—

9

—

—

9

2000/01

—

—

2

—

2

2001/02

—

33

—

—

33

2002/03

—

—

10

—

10

2003/04

—

6

—

—

6

2004/05

—

—

5

—

5

Sub-total

0

202

41

0

243

2005/06

—

495

—

—

495

2006/07

—

—

0

—

0

2007/08

—

144

18

—

162

2008/09

—

—

0

—

0

2009/10

—

14

—

—

14

2010/11

—

—

0

—

0

Sub-total

0

653

18

0

671

Total

0

855

59

0

914

of photographs for blue whales were 140, 155, 42 and 39
in Areas IIIE, IV, V and VIW, respectively. The numbers ofphotographs for southern right whales were 653 and 18
in Areas IV and V, respectively. The numbers of photographs for humpback whales were 12, 903, 235 and 51 in
Areas IIIE, IV, V and VIW, respectively.
Analyses of photographs collected during the JARPA/
JARPAII have the potential to contribute to a better understanding of the pattern of movement and residenceof these species in the feeding grounds. It could assist
the interpretation of abundance trends and quantitative
distribution studies south of 60°S.
75

Technical Reports of the Institute of Cetacean Research (2018)
Table 1c
Number of humpback whale photographs taken during JARPA
and JARPAII surveys by IWC Management Areas and australsummer season.
SurveyJARPAJARPAII

IWC Areas

Species

JARPA

JARPAII

Total

153
243
464

376
671
1,201

529
914
1,665

860

2,248

3,108

IIIE

IV

V

Number of
VIW photographs

1987/88

—

—

—

—

0

Blue whale
Southern right whale
Humpback whale

1988/89

—

—

—

—

0

Total

1989/90

—

19

—

—

19

1990/91

—

—

8

—

8

1991/92

—

26

—

—

26

1992/93

—

—

69

—

69

1993/94

—

51

—

—

51

1994/95

—

—

43

—

43

Seasonresearch collaboration with several foreign scientists
and several photo-id matches between diﬀerent regions
have been reported (e.g. Bannister et al., 1999; Rocket al., 2006). Further collaboration is being conductedwith members of the IWC SC (e.g. Olson et al., 2018).
Pictures are available for cooperative studies under established ICR protocols for data access and collaboration.
See details in the home page of the ICR.

1995/96

3

31

—

—

34

1996/97

—

—

4

15

19

1997/98

7

52

—

—

59

1998/99

—

—

—

—

0

1999/00

14

37

—

—

51

2000/01

—

—

13

17

30

2001/02

3

14

—

—

17

2002/03

—

—

7

0

7

2003/04

9

11

—

—

20

2004/05

—

—

11

—

11

REFERENCES

Sub-total

36

241

155

32

464

2005/06

0

328

—

—

328

2006/07

—

—

62

34

96

2007/08

12

78

—

—

90

2008/09

—

—

165

17

182

2009/10

—

497

—

—

497

2010/11

—

—

8

—

8

Sub-total

12

903

235

51

1201

Total

48

1,144 390

83

1,665

Bannister, J.L., Pastene, L.A. and Burnell, S.R. 1999. First recordof movement of a southern right whale (Eubalaena australis)between warm water breeding grounds and the Antarctic
Ocean, south of 60°S. Mar. Mammal Sci. 15 (4): 1337–1342.
Olson, P.A., de Boer, M., Kennedy, A., Double, M.C., Matsuoka,
K., Pastene, L.A. and Findlay, K. 2018. Photo-identiﬁcationof Antarctic blue whales: new data from 1998 and 2015–2018. Paper SC/67b/PH/02 presented to the IWC Scientiﬁc
Committee, May 2018 (unpublished). 5 pp. [Available fromthe IWC Secretariat].
Rock, J., Pastene, L.A., Kaufman, G., Forestell, P., Matsuoka, K.
and Allen, J. 2006. A note on East Australia Group V Stockhumpback whale movement between feeding and breeding areas based on photo-identiﬁcation. J. Cetacean Res.
Manage. 8 (3): 301–305.

Further information on movement and distribution
can be optimized if these photographs are examined inconjunction with photographs from other surveys andregions. In fact, scientists from the ICR have conducted

76

Table 2
Summary of the number of pictures for each species during
JARPA and JARPAII surveys (1987/88–2010/11).

ACKNOWLEDGEMENTS
We acknowledge the captains, crew members andresearchers for their eﬀort in collecting photo-id data
during the JARPA and JARPAII surveys. We thank Hitomi
Sato for her assistance in constructing the ICRʼs photo-id
database.

Technical Reports of the Institute of Cetacean Research (2018)

pp. 77–78

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

Ethics of Whaling: Is whaling truly immoral?
Kayo Ohmagari
Institute of Cetacean Research, Toyomi-cho 4–5, Chuo-ku, Tokyo 104–0055, JapanINTRODUCTION
In recent years, the impact of human activities on theenvironment, in particular habitat degradation and destruction, and resource over-exploitation, have been ofincreasing concern which led to a rise of environmentalism. As a result, the relationship between humans, thenatural environment, and other living organisms is being
reconsidered. This has led to examining alternatives to
traditional consumptive use-oriented relationships between humans and nature, as well as moral and ethicalresponsibilities toward future generations.
A part of this debate relates to whaling, where the international community is split primarily along two opposing sides. One view denies the conventional consumptive
use-oriented relationship between humans and whales,
and claims that the only acceptable whale use in the 21st
century is non-consumptive use, such as whale watching.
According to this view, whales are an international common heritage which must be ʻpreserved,ʼ as opposed toʻconserved,ʼ for future generations. Moreover, whaling
should not be permitted because it is against ethics that
ʻthere are certain cultural norms, like cannibalism, thatare in violation of our basic approach to maintaining ourcivilizationʼ (Wetson cited in Eilperin, 2006).
In contrast, the other view supports the maintenanceof a traditional relationship between humans and whales,
where hunting and dietary use should be allowed as longas such use is sustainable. Since whales are used forfood, the claim that whaling and eating whale products
are immoral/unethical is not acceptable. Solely nonconsumptive use of whales is simply not justiﬁable aslong as resources are abundant. This view acknowledges
traditional usersʼ right to the resource, and opposes antiutilization when it is based strictly on sentiment.
This brief paper attempts to clarify moral/ethical arguments against whaling, their meanings, and if such claim
is indeed justiﬁable.

PHILOSOPHICAL DEBATETo understand the claim that whaling is unethical andimmoral, two philosophical concepts, namely ethics andmorality should be deﬁned and discussed. Singer (2018)
deﬁnes that ʻethics, also called moral philosophy, thediscipline concerned with what is morally good or bad,right or wrong.ʼ Furthermore, he states that ethicʼs ʻmajor
concerns include the nature of ultimate value and thestandards by which human actions can be judged right orwrong.ʼ In other words, ethics or morality implies something of objective and normative value to be accepted by
all people.
However, there is an opposing view, moral relativism,
which argues that such objective or universal morality
does not exist, but is only relative to a group, person, or
society/culture. This school of thought was largely inﬂuenced by anthropology (Gowans, 2018), such as ʻ…moral
values are relative to culture and that there is no way ofshowing that the values of one culture are better thanthose of anotherʼ (American Anthropological Association
Executive Board, 1947). Reﬂecting these varied viewson ethics, morality deﬁned by Gert and Gert (2017) is
more comprehensive: ʻ1. descriptively to refer to a codeof conduct put forward by a society or a) some othergroup, such as religion, or b) accepted by an individualfor his/her own behavior or 2. normatively refer to a codeof conduct that, given speciﬁed conditions, would be put
forward by all rational persons.ʼ As there are two opposing views of moral/ethics, the possibility of an objective
morality has become one of the constant themes of ethics (Singer, 2018).

DISCUSSION
When someone claims that whaling is immoral/unethical,
which morals does he/she refers to, universal or speciﬁc
to a society/culture? Universal moral or ethical argument
against whaling is persuasive only if the population or
resource cannot be sustainably used, and such use would
lead the species to go extinct, with nothing left for the
future generations. However, many whale populations
have recovered and a risk averse resource management
tool to ensure calculation of safe quotas, Revised Management Procedure (RMP), has been developed. There77

Technical Reports of the Institute of Cetacean Research (2018)is therefore no sound scientiﬁc basis to oppose whaling
because whales can be sustainably harvested and utilized
for human consumption.
Conservation of biological diversity is a globally sharedconcern and a part of newly emerging normative values,
however, the concern here is the conservation of thestock or species but not the protection of an individual
animal. As long as survival of species is not at risk, themoral argument against whaling is diﬃcult to justify as
it is a matter of animal rights or animal welfare but notconservation.
There are a wide variety of edible plant and animals
around the world, but somehow lines are drawn concerning what to eat or good to eat and ignore the rest as inedible, disgusting or sacred. Some people eat whales whileothers do not. The claim that whaling is immoral basedon the lack of shared food habits is merely a reﬂection ofa speciﬁc value. Nevertheless, provocative words, suchas bloodbath, barbaric and cruel practice, are often used
to criticize whaling and to justify their position against
whaling.
An attempt to convince the other side by claiming thatits own morality is superior to the othersʼ can be regarded
as ʻethical egoismʼ (Gert and Gert, 2017). Arguments ofimmorality against whaling may be a good example ofthis phenomenon. To be convincing, the claim is often
enforced with an evolutionary twist. Attitudes towards
whales are frequently used as a measurement stick forthe progress of animal rights discourse: liberation fromracism, sexism, and ﬁnally to speciesism (Kalland, 1993).
Compassion for whales is considered by some as anindicator of personal as well as social maturity (Scheffer, 1991) and being considerate to whales has becomea prerequisite for membership in the ʻworld communityʼ
(Fuller, 1991,). In other words, for those arguing against
whaling, advanced civilized society and its citizenry
should exempt whales from the universally accepted
principle of sustainable use because whales are special magniﬁcent creatures, ʻthe humans of the oceanʼ(Gylling-Nielsen, 1987). Thus, personiﬁed whales deserve
certain rights and exemption from dinner tables.

CONCLUSION
Do you perceive whaling as immoral and is this position78

justiﬁable? The word moral/ethic has strong connotations
that such values have to be absolute and universal. However, there is a philosophical debate between normativevs. speciﬁc which is manifested in the whaling debate. On
one hand, those who claim whaling immoral assert theirmorality has evolved to be normative and superior to theothers so that the rest should embrace this norm. On
the other hand, others consider such claim to be invalid
because such position is a mere reﬂection of a speciﬁcvalue only acceptable to certain groups and people, andconsider their argument to be ethical egoism. An answer
to the question whether whaling is immoral or not lies inoneʼs personal belief. Whaling is immoral for some, but it
is not for others.

REFERENCES
American Anthropological Association Executive Board. 1947.
Statement on Human Rights. American Anthropologist 49:
539–543.
Eilperin, J. 2006. Whaling Agency Faces a Possible Shift.
Washington Post, June 2.
Singer, P. 2018. Ethics. Encyclopedia Brinannica. Available at
http://www.britannica.com (Membership required). Accessdate: September 20, 2018.
Fuller, K.S. 1991. Letter to the Ambassadors of Whaling Nations,
dated May 24. Washington, WWF.
Gert, B. and Gert, J. 2017. The Deﬁnition of Morality. Stanford
Encyclopedia of Philosophy. (Fall 2017 Edition), Edward N.
Zalta (ed.). Available at http://plato.stanford.edu/archives/
fall 2017entries/morality-deﬁnition/. Access date: September
21, 2018.
Gowans, C. 2018. Moral Relativism. Stanford Encyclopedia of
Philosophy. (Summer 2018 Edition).
Edward N. Zalta (ed.). Available at ‹http://plato.stanford.edu/
archives/sum2018/entries/moral-relativism/›. Access date:
September 21, 2018.
Gylling-Nielsen, M. 1987. Havets Mennesker. Greenpeace
Magasinet, no. 1.
Kalland, A. 1993. Management by Totemization: Whale
Symbolism and the Anti-Whaling Campaign. Arctic 46 (2):
124–133.
Scheﬀer, V. 1991. Why Should We Care About Whales? pp.
17–19. In: N. Davies, A.M. Smith, S.R. Whyte, and V. Williams(eds.) Why Whales? The Whale and Dolphin Conservation
Society, Bath, U.K. 23 pp.

Technical Reports of the Institute of Cetacean Research (2018)

pp. 79–80

International meetings

Participation of scientists of the Institute of Cetacean Research inInternational Meetings in 2018
Annual meeting of the International Whaling
Commission Scientiﬁc Committee (IWC SC)
The International Whaling Commission (IWC) is an international body set up by the terms of the International Convention for the Regulation of Whaling (ICRW), which was signed
in Washington, D.C., United States, on 2 December, 1946 toʻprovide for the proper conservation of whale stocks andthus make possible the orderly development of the whaling
industry.ʼ One of the important components of the IWC is
the Scientiﬁc Committee (SC), which meets annually.
The 2018 meeting of the IWC SC was held at the Rikli
Balance Hotel, Bled, Slovenia, from 21 April to 6 May. A
total of ten scientists from the Institute of Cetacean Research (ICR) participated in the meeting (Fujise, Kato, Pastene, Tamura, Matsuoka, Goto, Yasunaga, Konishi, Taguchi
and Inoue). They presented seven documents at plenary
sessions, nine documents at the Ad hoc Working Groupon Abundance Estimates, Stock Status and International
Cruises, one document at the Working Group on Ecosystem Modelling, two documents at the Working Group on
Stock Deﬁnition and DNA Testing, one document at the
Sub-Committee on Northern Hemisphere Whale Stocks,
and one document at the Sub-Committee on Other Southern Hemisphere Whale Stocks.

Paciﬁc Brydeʼs whales, held at the FAJʼs Crew House, Tokyo,
Japan from 14-16 February (Pastene, Hakamada and Inoue);c) Fourth workshop on large whale entanglement issues,
held at the Center for Coastal Studies, Provincetown, USAfrom 5-7 June (Kato and Matsuoka); d) TAG and Planning
Meetings for the 2019 IWC-POWER Cruises in the North Paciﬁc, held at the FAJʼs Crew House, Tokyo, Japan from 12-16
October (Kato, Matsuoka, Hakamada and Takahashi).

Marine Ecosystem Assessment for the Southern
Ocean 2018 (MEASO18)—Assessing Status andTrends of Habitats, Key Species and Ecosystems
in the Southern Ocean
The MEASO18 was held at the C3 Convention Center,
Hobart, Australia from 9-13 April. One scientist from
ICR participated in the meeting (Pastene). He presented
a document titled ʻSite-ﬁdelity, movement ranges andabundance of southern right whales in the Antarctic Indoregion inferred from genetic tagging.ʼ The presentation
was made under Theme 1 of MEASO18, ʻAssessment.ʼ

C3 Convention Center, Hobart, Australia.

Rikli Balance Hotel, Bled, Slovenia.

In 2018, ICR scientists also participated in several intersessional meetings of the IWC SC: a) Workshop on Western
North Paciﬁc common minke whale stock structure in preparation for the start of the Implementation Review, held at the
Fisheries Agency of Japan (FAJ)ʼs Crew House, Tokyo, Japan,
from 12-13 February (Pastene, Goto, Taguchi and Inoue); b)
Second Implementation Review Workshop on western North

Annual meeting of the Convention on the Conservation of Antarctic Marine Living Resources—Working Group on Ecosystem Monitoring andManagement (CCAMLR-EMM)
The Convention on the Conservation of Antarctic Marine
Living Resources (CCAMLR) is part of the Antarctic Treaty
System. The Convention was opened for signature on
1 August 1980 and entered into force on 7 April 1982
thereby establishing the Commission for the Conservationof Antarctic Marine Living Resources. The goal is to preserve marine life and environmental integrity in and near
79

Technical Reports of the Institute of Cetacean Research (2018)

Antarctica. It was established in large part in response toconcerns that an increase in krill catches in the Southern
Ocean could have a serious impact on populations of othermarine life which are dependent upon krill for food. The
CCAMLR has a Scientiﬁc Committee and several Working
Groups including the Working Group on Ecosystem Monitoring and Management (EMM), which meet annually.
The 2018 meeting of the CCAMLR-EMM was held at
the British Antarctic Survey, Cambridge, UK from 9-13
July. One scientist from ICR participated in the meeting(Pastene). He presented a document titled ʻPopulation
identity, site-ﬁdelity, movement ranges and preliminary
estimates of abundance of southern right whales in the
Antarctic Indian sector inferred from genetic marker.ʼ The
presentation was made under the agenda item ʻEcosystem monitoring and observations.ʼ

British Antarctic Survey, Cambridge, UK.

Annual meeting of the North Paciﬁc Marine Science Organization (PICES)The North Paciﬁc Marine Science Organization (PICES) isan intergovernmental organization that promotes andcoordinates marine scientiﬁc research in the North Paciﬁc
Ocean and provides a mechanism for information anddata exchange among scientists in its member countries.
The 2018 meeting of the PICES was held at the Workpia
Yokohama Convention Facility, Yokohama, Japan from 25
October-4 November. One scientist from ICR participated in
the meeting (Tamura). He presented the study titled ʻEstimation of prey consumption by marine mammals in the PICES
regions-Update to Hunt et al. (2000)ʼ as an oral presentation
at the session ʻDiets, consumption, and abundance of marine birds and mammals in the North Paciﬁc.ʼ He was also
co-author of another study titled ʻSpatial estimation of prey
consumption by Brydeʼs whales in the western North Paciﬁcduring the summers of 2008-2009: Density surface model
approach,ʼ that was also presented to the meeting.

80

Workpia Yokohama Convention Facility, Yokohama, Japan.

Annual meeting of the North Atlantic Marine Mammal Commission (NAMMCO) Scientiﬁc
Committee (SC)The North Atlantic Marine Mammal Commission(NAMMCO) is an international body for cooperation on
the conservation, management and study of marine
mammals in the North Atlantic. The NAMMCO Agreement
was signed in Nuuk, Greenland on 9 April 1992 by Norway,
Iceland, Greenland and the Faroe Islands, and enteredinto force 90 days later on 8 July 1992. The agreement
focuses on modern approaches to the study of the marine
ecosystem as a whole, and to better understanding therole of marine mammals in the ecosystem. NAMMCO hasa Scientiﬁc Committee (SC) which meets annually.
The 2018 NAMMCO SC meeting was held on board the
MS Polarlys, between Bergen and Tromsø, Norway from
13-16 November. Three scientists from ICR participated in
the meeting (Pastene, Konishi and Takahashi) as observers
from Japan. They presented the 2016-2018 Japan progress
report on cetacean research as well a presentation on thewhaleʼs satellite tracking work by the ICR.

MS Polarlys, Norway.

Technical Reports of the Institute of Cetacean Research (2018)

pp. 81–82

National meetings

Participation of Scientists of the Institute of Cetacean Research in
National Meetings in 2018
Annual meeting of the Japanese Society of Fisheries Science (JSFS)
The Japanese Society of Fisheries Science (JSFS) was established in 1932. It is a non-proﬁt registered society dedicated to the promotion of all aspects of ﬁsheries science.
The society fulﬁlls its global commitment by promoting
science, striving to achieve sustainable development
while recognizing crucial need of preserving the natural
aquatic resources. It also strives to forego relationships
with the industry comprising both capture and cultureﬁsheries, the ﬁshing environment, and the concerned
trade. The main events organized by the society are thebiannual meetings held in spring and autumn in one of
the main cities of Japan. In this forum the members present their research activities, exchange information, andcreate partnerships in vital areas of research. Over 1,500
presentations are given during the meeting and a compendium of the abstracts is promptly published.
The 2018 spring meeting of the JSFS was held at theTokyo University of Marine Science and Technology,
Tokyo from 26 to 30 March, 2018. Three scientists fromthe Institute of Cetacean Research (ICR) participated in
the meeting (Goto, Konishi and Isoda). Goto presented
the study titled ʻEstimation of stock structure and migratory pattern of common minke whales around Japanesewatersʼ (co-authors Taguchi and Pastene). Konishi presented the study titled ʻTracking sei whales by satellite
tags at the foraging area in the western North Paciﬁcʼ (coauthors Isoda and Bando). Isoda presented the study titled ʻObservation of marine debris in the Antarctic basedon the Japanese Whale Research Program under Special
Permitʼ (co-authors Tamura and Pastene). Other scientists
from the ICR were co-authors in other presentations by
scientists external to ICR, on topics related to estimationof abundance of sei whales (Matsuoka and Hakamada),
and estimation of the feeding period of Antarctic minke
whales in the Antarctic through stable isotope analyses(Tamura, Konishi and Bando).

Tokyo University of Marine Science and Technology, Tokyo.

The 2018 autumn meeting of JSFS was held at the
School of Applied Biological Science, Hiroshima University, Hiroshima, from 15 to 18 September, 2018. Twoscientists from the ICR participated as co-authors inpresentations made to the meeting on topics related topopulation dynamics of sandlance in Sendai Bay (Tamura)and operating models for the North Paciﬁc common
minke whales (Goto).

Hiroshima University, Hiroshima.

Annual Meeting of the Mammal Society of Japan(MSJ)
The Mammal Society of Japan (MSJ) was established in
1987 by uniting two academic organizations, the Mammalogical Society of Japan and the Research Group of
Mammalogists, which were founded in 1949 and 1955,
respectively. The MSJ currently has an enrollment of over
1,100 members including students and non-professionals. The annual meeting of the society consists of academic sessions (symposia, oral presentations, and poster
papers), workshops, and a business meeting.
The 2018 autumn meeting of MSJ was held at the81Technical Reports of the Institute of Cetacean Research (2018)

School of Applied Biological Science, Shinshu University,
Nagano, from 7 to 10 September, 2018. Three scientists
from the ICR participated as co-authors in presentations
made to the meeting. The topics of the presentations
were on abundance estimation of blue whales in the
Antarctic (Matsuoka), estimation of spatial distributionof humpback whales in the North Paciﬁc (Matsuoka),morphological comparison of ﬁnless porpoises (Kato) andskull variation among stocks of common minke whales in
the western North Paciﬁc (Fujise and Kato).
Shinshu University, Nagano.

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pp. 83–100

Peer-reviewed publications

List of peer-reviewed publications based on the Institute of
Cetacean Research (ICR)ʼs surveys up to 2018
This section presents a list of peer-reviewed publications
based on data collected by surveys conducted under
special scientiﬁc permit (JARPA/JARPAII and JARPN/
JARPNII), including both lethal and non-lethal techniques.
Peer-reviewed publications based on these surveys arefocused mainly on topics related to assessment and management of large whales. However samples and data collected by the surveys have also been useful to carry out
studies of a more academic-oriented nature. Publications
based on such studies are also listed here.
This section also includes a list of peer-reviewed publications resulting from other surveys and research activities, diﬀerent from special scientiﬁc permit surveys.
Publications having as a ﬁrst author a non-ICR scientist commonly followed a data request or collaboration
research agreement with ICR. In a few cases, externalscientists used published data from ICR surveys in theiranalyses and publications, without a formal agreementwith ICR. These cases are indicated by an asterisk (*).

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

Kasamatsu, F., Kishino, H. and Hiroyama, H. 1990. Estimation of the number of minke whale (Balaenoptera
acutorostrata) schools and individuals based on the
1987/88 Japanese feasibility study data. Rep. int. Whal.
Commn 40: 239–247.
Kato, H., Fujise, Y., Yoshida, H., Nakagawa, S., Ishida, M.
and Tanifuji, S. 1990. Cruise report and preliminary
analysis of the 1988/89 Japanese feasibility study ofthe special permit proposal for southern hemisphereminke whales. Rep. int. Whal. Commn 40: 289–300.
Kato, H., Kishino, H. and Fujise, Y. 1990. Some analyses on
age composition and segregation of southern minke
whales using samples obtained by the Japanese feasibility study in 1987/88. Rep. int. Whal. Commn 40:
249–256.
Nagasaki, F. 1990. The Case for Scientiﬁc Whaling. Nature
334: 189–190.
Tanaka, S. 1990. Estimation of natural mortality coeﬃcient of whales from the estimates of abundance andage composition data obtained from research catches.
Rep. int. Whal. Commn 40: 531–536.
1991 (9)Bergh, M.O., Butterworth, D.S. and Punt, A.E. 1991. Further examination of the potential information content
of age-structure data from Antarctic minke whale
research catches. Rep. int. Whal. Commn 41: 349–361.
Ichii, T. and Kato, H. 1991. Food and daily food consumption of southern minke whales in the Antarctic. Polar
Biol 11 (7): 479–487.
Kasamatsu, F., Kishino, H. and Taga, Y. 1991. Estimationof southern minke whale abundance and school size
composition based on the 1988/89 Japanese feasibility
study data. Rep. int. Whal. Commn 41: 293–301.
Kato, H., Fujise, Y. and Kishino, H. 1991. Age structure andsegregation of southern minke whales by the data obtained during Japanese research take in 1988/89. Rep.
int. Whal. Commn 41: 287–292.
Kato, H. and Miyashita, T. 1991. Migration strategy ofsouthern minke whales in relation to reproductive
cycles estimated from foetal lengths. Rep. int. Whal.
Commn 41: 363–369.
Kato, H., Zenitani, R. and Nakamura, T. 1991. Inter-reader
calibration in age readings of earplugs from southernminke whale, with some notes of age readability. Rep.
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Technical Reports of the Institute of Cetacean Research (2018)

int. Whal. Commn 41: 339–343.
Kishino, H., Kato, H., Kasamatsu, F. and Fujise, Y. 1991.
Detection of heterogeneity and estimation of population characteristics from the ﬁeld survey data: 1987/88
Japanese feasibility study of the Southern Hemisphereminke whales. Ann. Inst. Statist. Math. 43 (3): 435–453.
Nakamura, T. 1991. A new look at a Bayesian cohortmodel for time-series data obtained from researchtakes of whales. Rep. int. Whal. Commn 41: 345–348.
Wada, S., Kobayashi, T. and Numachi, K. 1991. Genetic
variability and diﬀerentiation of mitochondrial DNA
in minke whales. Rep. int. Whal. Commn (special
issue 13): 203–215.
1992 (2)Nakamura, T. 1992. Simulation trials of a Bayesian cohortmodel for time-series data obtained from researchtakes of whales. Rep. int. Whal. Commn 42: 421–427.
Tanaka, S., Kasamatsu, F. and Fujise, Y. 1992. Likely precision of estimates of natural mortality rates fromJapanese research data for Southern Hemisphereminke whales. Rep. int. Whal. Commn 42: 413–420.
1993 (7)Fujise, Y., Ishikawa, H., Saino, S., Nagano, M., Ishii, K.,
Kawaguchi, S., Tanifuji, S., Kawashima, S. and Miyakoshi H. 1993. Cruise report of the 1991/92 Japanese research in Area IV under the special permit for Southern
Hemisphere minke whales. Rep. int. Whal. Commn 43:
357–371.
Hasunuma, R., Ogawa, T., Fujise, Y. and Kawanishi,
Y. 1993. Analysis of selenium metabolites in urine
samples of minke whale (Balaenoptera acutorostrata)
using ion exchange chromatography. Comp. Biochem.
Physiol. 104C (1): 87–89.
Itoh, S., Takenaga, F. and Tsuyuki, H. 1993. Studies onlipids of the Antarctic minke whale. II. The fatty acidcompositions of the blubber oils of minke whale anddwarf minke whale caught on 1988/89 and 1989/90
seasons. Yukagaku 42 (12): 1007–1011 (in Japanese).
Iwata, H., Tanabe, S., Sakai, N. and Tatsukawa, R. 1993.
Distribution of persistent organochlorines in the oceanic air and surface seawater and the role of ocean on
their global transport and fate. Environ. Sci. Technol.
27: 1080–1098.
Kasamatsu, F., Yamamoto, Y., Zenitani, R., Ishikawa, H.,
Ishibashi, T., Sato, H., Takashima, K. and Tanifuji, S.
1993. Report of the 1990/91 southern minke whale
research cruise under scientiﬁc permit in Area V. Rep.
int. Whal. Commn 43: 505–522.
84

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

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2018of catch-at-age information for Southern Hemisphereminke whales. Rep. int. Whal. Commn 46: 349–359.
Fukui, Y., Mogoe, T., Jung, Y.G., Terawaki, Y., Miyamoto, A.,
Ishikawa, H., Fujise, Y. and Ohsumi, S. 1996. Relationships among morphological status, steroid hormones,
and post-thawing viability of frozen spermatozoa ofmale minke whales (Balaenoptera acutorostrata).
Marine Mammal Science 12 (1): 28–37.
Iga, K., Fukui, Y., Miyamoto, A., Ishikawa, H. and Ohsumi,
S. 1996. Endocrinological observations of female minke
whales (Balaenoptera acutorostrata). Marine Mammal
Science 12 (2): 296–301.
Matsuoka, K., Fujise, Y. and Pastene, L.A. 1996. A sightingof a large school of the pygmy right whale, Caperea
marginata in the southeast Indian Ocean. Marine
Mammal Science 12 (4): 594–597.
Pastene, L.A., Goto, M., Itoh, S. and Numachi, K. 1996.
Spatial and temporal patterns of mitochondrial DNA
variation in minke whale from Antarctic Areas IV and V.
Rep. int. Whal. Commn 46: 305–314.
1997 (3)Aono, S., Tanabe, S., Fujise, Y., Kato, H. and Tatsukawa,R. 1997. Persistent organochlorines in minke whale(Balaenoptera acutorostrata) and their prey species
from the Antarctic and the North Paciﬁc. Environmental Pollution 98: 81–89.
Fukui, Y., Mogoe, T., Ishikawa, H. and Ohsumi, S. 1997a.
Factors aﬀecting in vitro maturation of minke whale(Balaenoptera acutorostrata) follicular oocytes. Biology of Reproduction 56: 523–528.
Fukui, Y., Mogoe, T., Ishikawa, H. and Ohsumi, S. 1997b.
In vitro fertilization of in vitro matured minke whale(Balaenoptera acutorostrata) follicular oocytes. Marine Mammal Science 13 (3): 395–404.
1998 (7)
Ichii, T., Shinohara, N., Fujise, Y., Nishiwaki, S. and Matsuoka, K. 1998. Interannual changes in body fat conditionindex of minke whales in the Antarctic. Mar. Ecol. Prog.
Ser. 175: 1–12.
Ito, S., Takenaga, F. and Tsuyuki, H. 1998. Lipids in Antarctic minke whales III. Site and sexual diﬀerences ofmuscle lipids. J. Jpn. Oil Chem. Soc. 47 (2): 191–194 (inJapanese).
Kida, M.Y. 1998. Morphology of the tracheobronchial
tree and the route of the pulmonary artery in the fetal
minke whale (Balaenoptera acutorostrata). Okajimas
Folia Anat. Jpn.75 (5): 251–258.
Mogoe, T., Fukui, Y., Ishikawa, H. and Ohsumi, S. 1998a.

Morphological observations of frozen-thawed spermatozoa of Southern minke whales (Balaenoptera acutorostrata). Journal of Reproduction and Development 44(1): 95–100.
Mogoe, T., Fukui, Y., Ishikawa, H. and Ohsumi, S. 1998b.
Eﬀects of diluent composition and temperature on
motility and viability after liquid storage and cryopreservation of minke whale (Balaenoptera acutorostrata) spermatozoa. Marine Mammal Science 14(4): 854–860.
Nagasawa, K., Yamada, T.K. and Ishikawa, H. 1998. Measurements of the skeleton of a minke whale (Balaenoptera acutorostrata) from the Antarctic Ocean. Bulletinof the Yamagata Prefectural Museum 20: 1–19.
Terabayashi, T. and Kawanishi, Y. 1998. Naturally occurring ganglioside lactones in minke whale brain. Carbohydrate Research 307 (3): 281–290.
1999 (4)Bannister, J.L., Pastene, L.A. and Burnell, S.R. 1999.
First record of movement of a southern right whale(Eubalaena australis) between warm water breeding
grounds and the Antarctic Ocean, South of 60°S. Marine Mammal Science 15 (4): 1337–1342.
Butterworth, D.S., Punt, A.E. Geromont, H.F., Kato, H. andFujise, Y. 1999. Inferences on the dynamics of Southern
Hemisphere minke whales from ADAPT analyses ofcatch-at-age information. J. Cetacean Res. Manage. 1(1): 11–32.
Ishikawa, H., Amasaki, H., Dohguchi, H., Furuya, A. andSuzuki, K. 1999. Immunohistological distributions ofﬁbronectin, tenascin, type I, III and IV collagens, andlaminin during tooth development and degeneration infetuses of minke whale, Balaenoptera acutorostrata. J.
Vet. Med. Sci. 61 (3): 227–232.
Thomson, R.B., Butterworth, D.S. and Kato, H. 1999. Has
the age at transition of southern hemisphere minke
whales declined over recent decades? Marine Mammal Science 15 (3): 661–682.
2000 (5)Asada, M., Horii, M., Mogoe, T., Fukui, Y., Ishikawa, H.
and Ohsumi, S. 2000. In vitro maturation and ultrastructural observation of cryopreserved minke whale(Balaenoptera acutorostrata) follicular oocytes. Biology of Reproduction 62 (2): 253–259.
Kasamatsu, F., Matsuoka, K. and Hakamada, T. 2000. Interspeciﬁc relationships in density among the whale
community in the Antarctic. Polar Biol 23 (7): 466–473.
Mogoe, T., Suzuki, T., Asada, M., Fukui, Y., Ishikawa, H. and85

Technical Reports of the Institute of Cetacean Research (2018)

Ohsumi, S. 2000. Functional reduction of the Southernminke whale (Balaenoptera acutorostrata) testis during the feeding season. Marine Mammal Science 16(3): 559–569.
Rosenbaum, H.C., Brownell, R.L., Brown, M.W., Schaeﬀ, C.,
Portway, V., White, B.N., Malik, S., Pastene, L.A., Pateneude, N.J., Baker, C.S., Goto, M., Best, P.B., Clapham,
P.J., Hamilton, P., Moore, M., Payne, R., Rowntree, V.,
Tynan, C.T., Bannister, J.L. and DeSalle, R. 2000. Worldwide genetic diﬀerentiation of Eubalaena: questioning
the number of right whale species. Molecular Ecology
9: 1793–1802.
Wei, H. and Fukui, Y. 2000. Fertilizability of ovine, bovine
or minke whale (Balaenoptera acutorostrata) spermatozoa intracytoplasmically injected into bovine oocytes. Zygote 8 (3): 267–274.
2001 (3)Asada, M., Tetsuka, M., Ishikawa, H., Ohsumi, S. andFukui, Y. 2001. Improvement on in vitro maturation,
fertilization and development of minke whale (Balaenoptera acutorostrata) oocytes. Theriogenology 56 (4):521–533.
Asada, M., Wei, H., Nagayama, R., Tetsuka, M., Ishikawa,
H., Ohsumi, S. and Fukui, Y. 2001. An attempt at intracytoplasmic sperm injection of frozen-thawed minke
whale (Balaenoptera bonaerensis) oocytes. Zygote 9(3): 299–307.
Suzuki, T., Mogoe, T., Asada, M., Miyamoto, A., Tetsuka,
M., Ishikawa, H., Ohsumi, S. and Fukui, Y. 2001. Plasmaand pituitary concentrations of gonadotropins (FSHand LH) in minke whales (Balaenoptera acutorostrata)
during the feeding season. Theriogenology 55 (5):1127–1141.
2002 (6)Abe, H. and Goto, M. 2002. The application of microsatellite DNA for determining population structure of minke
whale. pp. 109–113. In: Nishimura, A. (Ed). Technical
Reports of the Hokkaido National Fisheries ResearchInstitute No.5. Hokkaido National Fisheries ResearchInstitute, Hokkaido.
Kunito, T., Watanabe, I., Yasunaga, G., Fujise, Y. and Tanabe, S. 2002. Using trace elements in skin to discriminate the populations of minke whale in southern hemisphere. Marine Environmental Research 53: 175–197.
Murase, H., Matsuoka, K., Ichii, T. and Nishiwaki, S. 2002.
Relationship between the distribution of euphausiids
and baleen whales in the Antarctic (35°E–145°W).
Polar Biol 25 (2): 135–145.
86

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

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2018

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

incubator. Journal of Reproduction and Development
51 (1): 69–75.
Matsuoka, K., Pitman, R. and Marques, F. 2005. A note ona pigmy right whale (Caperea marginata) sighting inthe southwestern Paciﬁc Ocean. J. Cetacean Res. Manage. 7(1): 71–73.
Matsuoka, K., Hakamada, T., Kiwada, H., Murase, H. andNishiwaki, S. 2005. Abundance increases of large baleen whales in the Antarctic based on the sighting survey during Japanese Whale Research Program (JARPA).
Global Environmental Research 9 (2): 105–115.
Nikaido, M., Sasaki, T., Makino, H., Goto, M., Kanda, N.,
Pastene, L.A. and Okada, N. 2005. Phylogenetic reconstruction of baleen whales and detection of their pastextensive radiation event by the SINE insertion analysis. Fossils 77: 22–28 (in Japanese).
Sasaki, T., Nikaido, M., Hamilton, H., Goto, M., Kato, H.,
Kanda, N., Pastene, L.A., Cao, Y., Fordyce, R.E., Hasegawa, M. and Okada, N. 2005. Mitochondrial phylogenetics and evolution of mysticete whales. Systematic
Biology 54 (1): 77–90.
2006 (9)Fujihira, T., Kobayashi, M., Hochi, S., Hirabayashi, M.,
Ishikawa, H., Ohsumi, S. and Fukui, Y. 2006. Developmental capacity of Antarctic minke whale (Balaenoptera bonaerensis) vitriﬁed oocytes following in vitro
maturation, and parthenogenetic activation or intracytoplasmic sperm injection. Zygote 14 (2): 89–95.
Honda, K., Aoki, M. and Fujise, Y. 2006. Echochemical approach using mercury accumulation of Antarctic minke
whale, Balaenoptera bonaerensis, as tracer of historical change of Antarctic marine ecosystem during 1980–
1999. Bull. Environ. Contam. Toxicol. 76: 140–147.
Iwanami, K., Mita, H., Yamamoto, Y., Fujise, Y., Yamada,T. and Suzuki, T. 2006. cDNA-derived amino acid sequences of myoglobins from nine species of whales
and dolphins. Comparative Biochemistry and Physiology, Part B 145: 249–256.
Kobayashi, T., Amemiya, K., Takeuchi, K., Tsujioka, T.,
Tominaga, K., Hirabayashi, M., Ishikawa, H., Fukui,
Y. and Hochi, S. 2006. Contribution of spermatozoal
centrosomes to the microtubule-organizing centre in
Antarctic minke whale (Balaenoptera bonaerensis).
Zygote 14 (1): 45–51.
Konishi, K. 2006. Characteristics of blubber distribution
and body condition indicators for Antarctic minke
whale (Balaenoptera bonaerensis). Mammal Study 31(1): 15–22.
Mori, M. and Butterworth, D.S. 2006. A ﬁrst step towards
87Technical Reports of the Institute of Cetacean Research (2018)

modelling the krill–predator dynamics of the Antarctic
ecosystem. CCAMLR Science 13: 217–277.
Nikaido, M., Hamilton, H., Makino, H., Sasaki, T., Takahashi, K., Goto, M., Kanda, N., Pastene, L.A. and Okada,N. 2006. Baleen whale phylogeny and a past extensive
radiation event revealed by SINE insertion analysis.
Mol. Biol. Evol. 23 (5): 866–873.
Rock, J., Pastene, L.A., Kaufman, G., Forestell, P., Matsuoka, K. and Allen, J. 2006. A note on East Australia
Group V Stock humpback whale movement between
feeding and breeding areas based on photo-identiﬁcation. J. Cetacean Res. Manage. 8 (3): 301–305.
Yabuki, T., Suga, T., Hanawa, K., Matsuoka, K., Kiwada, H.
and Watanabe, T. 2006. Possible source of the Antarctic bottom water in the Prydz Bay Region. Journal of
Oceanography 62 (5): 649–655.
2007 (7)Asada, M., Tetsuka, M., Ishikawa, H., Ohsumi, S. andFukui, Y. 2007. Ultrastructural changes during maturation and cryopreservation of follicular oocytes of Antarctic minke whales (Balaenoptera bonaerensis). Jpn. J.
Zoo. Wildl. Med. 12 (1): 51–66.
Branch, T.A., Staﬀord, K.M., Palacios, D.M., Allison, C.,
Bannister, J.L., Burton, C.L.K., Cabrera, E., Carlson, C.A.,
Galletti Vernazzani, B., Gill, P.C., Hucke-Gaete, R., Jenner, K.C.S., Jenner, Mn. M., Matsuoka, K., Mikhalev,
Y.A., Miyashita, T., Morrice, M.G., Nishiwaki, S., Sturrock, V.J., Tormosov, D., Anderson, R.C., Baker, A.N.,
Best, P.B., Borsa, P., Brownell Jr, R.L., Childerhouse,
S., Findlay, K.P., Gerrodette, T., Ilangakoon, A.D., Joergensen, M., Kahn, B., Ljungblad, D.K., Maughan, B.,
Mccauley, R.D., Mckay, S., Norris, T.F., Oman Whaleand Dolphin Research Group, Rankin, S., Samaran, F.,
Thiele, D., Van Waerebeek, K. and Warneke, R.M. 2007.
Past and present distribution, densities and movements of blue whales in the Southern Hemisphere andadjacent waters. Mammal Rev. 37 (2): 116–175.
LeDuc, R.G., Dizon, A.E., Goto, M., Pastene, L.A., Kato,
H., Nishiwaki, S. and Brownell, R.L. 2007. Patterns ofgenetic variation in southern hemisphere blue whales,
and the use of assignment test to detect mixing on
the feeding grounds. J. Cetacean Res. Manage. 9 (1):73–80.
Nagai, H., Mogoe, T., Ishikawa, H., Hochi, S., Ohsumi, S.
and Fukui, Y. 2007. Follicle size-dependent changes
in follicular ﬂuid components and oocyte diameter in
Antarctic minke whales (Balaenoptera bonaerensis).
Journal of Reproduction and Development 53 (6):1265–1272.
88

Nishida, S., Goto, M., Pastene, L.A., Kanda, N. and Koike,
H. 2007. Phylogenetic relationships among cetaceansrevealed by Y-chromosome sequences．Zoological Science 24 (7): 723–732．
Onbe, K. Nishida, S., Sone, E., Kanda, N., Goto, M., Pastene, L.A., Tanabe, S. and Koike, H. 2007. Sequence variation in the Tbx4 gene in marine mammals．Zoological
Science 24 (5): 449–464.
Pastene, L.A., Goto, M., Kanda, N., Zerbini, A.N., Kerem,D., Watanabe, K., Bessho, Y., Hasegawa, M., Nielsen,
R., Larsen, F. and Palsbøll, P.J. 2007. Radiation andspeciation of pelagic organisms during periods ofglobal warming: the case of the common minke whale,
Balaenoptera acutorostrata. Molecular Ecology 16:1481–1495.
2008 (4)Ishikawa, H. and Shigemune, H. 2008. Comparative experiment of whaling grenades in the Japanese Whale
Research Program under Special Permit (JARPA and
JARPN). Jpn. J. Zoo Wildl. Med. 13 (1): 21–28.
Konishi, K., Tamura, T., Zenitani, R., Bando, T., Kato, H. andWalløe, L. 2008. Decline in energy storage in the Antarctic minke whale (Balaenoptera bonaerensis) in theSouthern Ocean. Polar Biol 31 (2): 1509–1520.
Ohishi, K., Fujise, Y. and Maruyama, T. 2008. Brucella spp.
in the western North Paciﬁc and Antarctic cetaceans: areview. J. Cetacean Res. Manage. 10 (1):67–72.
Yunoki, K., Ishikawa, H., Fukui, Y. and Ohnishi, M. 2008.
Chemical properties of epidermal lipids, especiallysphingolipids, of the Antarctic minke whale. Lipids 43(2): 151–159.
2009 (2)Ono, N., Yamaguchi, T., Ishikawa, H., Arakawa, M.,
Takahashi, N. Saikawa, T. and Shimada, T. 2009. Morphological varieties of the Purkinje ﬁber network inmammalian hearts, as revealed by light and electron
microscopy. Arch Histol Cytol 72 (3): 139–149.
Tamura, T. and Konishi, K. 2009. Feeding habits and prey
consumption of Antarctic minke whale (Balaenoptera
bonaerensis) in the Southern Ocean. J. Northw. Atl.
Fish. Sci. 42: 13–25.
2010 (15)
Fujise, Y., Nishiwaki, S. and Ishikawa, S. 2010. Overview of
the Japanese Whale Research Program under Special
Permit in the Antarctic (JARPA). Bull. Jpn. Soc. Fish.
Oceanogr. 74: 43–44 (in Japanese).
Fujise, Y., Hatanaka, H. and Ohsumi, S. 2010. Changes

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2018

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

Jpn. Soc. Fish. Oceanogr. 74: 46–47 (in Japanese).
Yabuki, T., Noiri,Y., Murase, H., Kiwada, H., Matsuoka, K.
and Naganobu, M. 2010. Physical and chemical studyof hydrographic feature based on the R/V Kaiyo Maru
cruise and JARPA in the Ross Sea, Antarctica. Bull. Jpn.
Soc. Fish. Oceanogr. 74: 35–36 (in Japanese).
Zenitani, R. and Kato, H. 2010. The growth of baleen
plates in Antarctic 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 estimates and trends
for humpback whales (Megaptera novaeangliae) in
Antarctic Areas IV and V based on JARPA sighting data.
J. Cetacean Res. Manage. (Special Issue 3): 75–94.
2012 (1)*Sremba, A.L., Hancock-Hanser, B., Branch, T.A., LeDuc,
R.L. and Baker, C.S. 2012. Circumpolar diversity andgeographic diﬀerentiation of mtDNA in the criticallyendangered Antarctic blue whale (Balaenoptera musculus intermedia). PLoS ONE 7 (3): e32579.
2013 (6)Glover, K.A., Kanda, N., Haug, T., Pastene, L.A., Øien, N.,
Seliussen, B.B., Sørvik, A.G.E. and Skaug, H.J. 2013.
Hybrids between common and Antarctic minke whales
are fertile and can back-cross. BMC Genetics 14: 25.
Hakamada, T., Matsuoka, K., Nishiwaki, S. and Kitakado,
T. 2013. Abundance estimates and trends for Antarctic
minke whales (Balaenoptera bonaerensis) in Antarctic
Areas IV and V for the period 1989/90–2004/05. J. Cetacean Res. Manage. 13 (2): 123–151.
Kitakado, T., Lockyer, C. and Punt, A.E. 2013. A statisticalmodel for quantifying age-reading errors and its application to the Antarctic minke whales. J. Cetacean Res.
Manage. 13 (3): 181–190.
Murase, H., Kitakado, T., Hakamada, T., Matsuoka, K.,
Nishiwaki, S. and Naganobu, M. 2013. Spatial distribution of Antarctic minke whales (Balaenoptera bonaerensis) in relation to spatial distributions of krill in theRoss Sea, Antarctica. Fish. Oceanogr. 22 (3): 154–173.
Sasaki, M., Amano, Y., Hayakawa, D., Tsubota, T., Ishikawa,
H., Mogoe, T., Ohsumi, S., Tetsuka, M., Miyamoto, A.,
Fukui, Y., Budipitojo, T. and Kitamura, N. 2013. Structure and steroidogenesis of the placenta in the Antarctic minke whale (Balaenoptera bonaerensis). Journal of89

Technical Reports of the Institute of Cetacean Research (2018)

Reproduction and Development 59 (2): 159–167.
Shibata, Y., Matsuishi, T., Murase, H., Matsuoka, K.,
Hakamada, T., Kitakado, T. and Matsuda, H. 2013. Effects of stratiﬁcation and misspeciﬁcation of covariates
on species distribution models for abundance estimation from virtual line transect survey data. Fish Sci 79(4): 559–568.
2014 (3)Konishi, K., Hakamada, T., Kiwada, H., Kitakado, T. andWalløe, L. 2014. Decrease in stomach contents in the
Antarctic minke whale (Balaenoptera bonaerensis) in
the Southern Ocean. Polar Biol 37 (2): 205–215.
Punt, A.E. 2014. A summary history of the applicationof statistical catch-at-age analysis (SCAA) to Antarctic
minke whales. J. Cetacean Res. Manage. 14: 81–92.
Punt, A.E., Hakamada, T., Bando, T. and Kitakado, T. 2014.
Assessment of Antarctic minke whales using statisticalcatch-at-age analysis (SCAA). J. Cetacean Res. Manage.
14: 93–116.
2015 (2)Konishi, K. and Walløe, L. 2015. Substantial decline inenergy storage and stomach fullness in Antarctic minke
whales (Balaenoptera bonaerensis) during the 1990ʼs.
J. Cetacean Res. Manage. 15: 77–92.
Yasunaga, G., Fujise, Y., Zenitani, R., Tanabe, S. and Kato,
H. 2015. Spatial and temporal variation of PCBs and organochlorine pesticides in the Antarctic minke whales,
Balaenoptera bonaerensis, in the period 1987–2005.
Chemosphere 126: 11–17.
2016 (2)Pastene, L.A. and Goto, M. 2016. Genetic characterization and population genetic structure of the Antarctic
minke whale Balaenoptera bonaerensis in the IndoPaciﬁc region of the Southern Ocean. Fish Sci 82 (6):873–886.
Wada, N., Yamanaka, S., Shibato, J., Rakwal, R., Hirako, S.,
Iizuka, Y., Kim, H., Matsumoto, A., Kimura, A., Takenoya,F., Yasunaga, G. and Shioda, S. 2016. Behavioral andomics analyses study on potential involvement of
dipeptide balenine through supplementation in dietof senescence-accelerated mouse prone 8. Genomics
Data 10: 38–50.
2017 (3)Isoda, T. and Tamura, T. 2017. Report of a White Adélie
Penguin Pygoscelis adeliae in the Antarctic Ocean. J.
Yamashina Inst. Ornithol. 48 (2): 74–77.
90*Leduc, R.G., Archer, F.I., Lang, A.R., Martien, K.K., Hancock-Hanser, B., Torres-Florez, J.P., Hucke-Gaete, R.,
Rosenbaum, H.C., VanWaerebeek, Bownell, R.L. andTaylor, B.L. 2017. Genetic variation in blue whales inthe eastern paciﬁc: implications 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 estimation of Antarctic minke
whales Balaenoptera bonaerensis based on aspartic
acid racemization technique. Fish Sci 86 (6): 947–954.

JARPN/JARPNII surveys
1996 (3)Butterworth, D.S., Geromont H.F. and Wada S. 1996.
Further analysis of allele frequency data to provide
estimates of the extent of mixing between the various
North Paciﬁc minke whale stocks, and their implications for the status of the “O”stock. Rep. int. Whal.
Commn 46: 443–451.
Kuramochi, T., Machida, M., Araki, J., Uchida, A., Kishiro,
T. and Nagasawa, K. 1996. Minke whales (Balaenoptera acutorostrata) are one of the major ﬁnal hosts ofAnisakis simplex (Nematoda: Anisakidae) in the Northwestern North Paciﬁc Ocean. Rep. int. Whal. Commn
46: 415–419.
Miyashita, T. and Fujise, Y. 1996. Abundance estimate of
the western North Paciﬁc minke whale in sub-area 9
with notes on the results of dedicated surveys. Rep. int.
Whal. Commn 47: 543–551.
1997 (6)Aono, S., Tanabe, S., Fujise, Y., Kato, H. and Tatsukawa,R. 1997. Persistent organochlorines in minke whale(Balaenoptera acutorostrata) and their prey species
from the Antarctic and the North Paciﬁc. Environmental Pollution 98: 81–89.
Araki, J., Kuramochi, T., Machida, M., Nagasawa, K. andUchida, A. 1997. A note on the parasite fauna of thewestern North Paciﬁc minke whale (Balaenoptera acutorostrata). Rep. int. Whal. Commn 47: 565–567.
Goto, M. and Pastene, L.A. 1997. Population structureof western North Paciﬁc minke whale based on an
RFLP analysis of mtDNA control region. Rep. int. Whal.
Commn 47: 531–537.
Hatanaka, H. and Miyashita, T. 1997. On the feeding migration of the Okhotsk Sea-West Paciﬁc stock of minke
whales, estimates based on length composition data.
Rep. int. Whal. Commn 47: 557–564.
Hatanaka, H. 1997. A short review of hypotheses onList of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2018minke whale stock structure in the Northwesternpart of the North Paciﬁc. Rep. int. Whal. Commn 47:
553–555.
Pastene, L.A., Goto, M., Itoh, S., Wada, S. and Kato, H.
1997. Intra- and inter-oceanic patterns of mitochondrial DNA variation 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 estimateof mixing proportion of ʻJʼ and ʻOʼ stocks minke whales
in sub-area 11 based on mitochondrial DNA haplotype
data. Rep. int. Whal. Commn 48: 471–474.
Tamura, T., Fujise, Y. and Shimazaki, K. 1998. Diet of minke
whales Balaenoptera acutorostrata in the Northwestern part of the North Paciﬁc in summer 1994 and 1995.
Fish Sci 64 (1): 71–76.
Uchida, A., Kawakami, Y., Yuzu, S., Kishikawa, S., Kuramochi, T., Araki, J., Machida, M. and Nagasawa, K.
1998. Prevalence of parasites and histopathology ofparasitisation in minke whales (Balaenoptera acutorostrata) from the western North Paciﬁc Ocean andSouthern Sea of Okhotsk. Rep. int. Whal. Commn 48:
475–479.
1999 (2)Le, T.H.L., Takahashi, S., Saeki, K., Nakatani, N., Tanabe,S., Miyazaki, N. and Fujise, Y. 1999. High percentage ofbutyltin residues in total tin in the livers of cetaceansfrom Japanese coastal waters. Environmental Science& Technology 33 (11): 1781–1786.
Martinez, I. and Pastene, L.A. 1999. RAPD-typing ofcentral and eastern North Atlantic and western North
Paciﬁc minke whales, Balaenoptera acutorostrata. ICES
Journal of Marine Science 56 (5): 640–651.
2000 (2)Punt, A.E., Butterworth, D.S. and Wada, S. 2000. On theuse of allele frequency data within a Bayesian framework: evaluation of relative probabilities of alternative
stock structure hypotheses for North Paciﬁc minke
whales. J. Cetacean Res. Manage. 2 (2): 151–158.
Uchida, A. and Araki, J. 2000. The ectoparasites and endoparasites in the minke whale, Balaenoptera acutorostrata from the western North Paciﬁc Ocean. J. Jpn.
Vet. Med. Assoc. 53 (2): 85–88 (in Japanese).

2001 (1)Okamura, H., Matsuoka, K., Hakamada, T., Okazaki, M.
and Miyashita, T. 2001. Spatial and temporal structureof the western North Paciﬁc minke whale distribution
inferred from JARPN sightings data. J. Cetacean Res.
Manage. 3 (2): 193–200.
2002 (5)Abe, H. and Goto, M. 2002. The application of microsatellite DNA for determining population structure of minke
whale. pp. 109–113. In: Nishimura, A. (Ed). Technical
Reports of the Hokkaido National Fisheries ResearchInstitute No.5. Hokkaido National Fisheries ResearchInstitute, Hokkaido.
Cui, G., Punt, A.E., Pastene, L. A. and Goto, M. 2002.
Bayes and Empirical Bayes approaches to addressing
stock structure questions using mtDNA data, with anillustrative application to North Paciﬁc minke whales. J.
Cetacean Res. Manage. 4 (2): 123–134.
Ohsumi, S. and Tamura, T. 2002. Dietary studies on baleen whales in the North Paciﬁc. Fish Sci 68 (Supp. I):
260–263.
Pastene, L.A., Goto, M. and Kanda, N. 2002. The utility of
DNA analysis for the management and conservation oflarge whales. Fish Sci 68 (Supp. I): 286–289.
Tamura T. and Fujise Y. 2002. Geographical and seasonalchanges of the prey species of minke whale in the
Northwestern Paciﬁc. ICES Journal of Marine Science59 (3): 516–528.
2003 (4)Hayashi, K., Nishida, S., Yoshida, H., Goto, M., Pastene,
L.A. and Koike, H. 2003. Sequence variation of the DQB
allele in the cetacean MHC. Mammal Study 28 (2):89–96.
Nishida, S., Pastene, L.A., Goto, M. and Kanda, N. 2003.
SRY gene structure and phylogeny in the cetacean species. Mammal Study 28 (1): 57–66.
Nishida, S., Hayashi, K., Pastene, L.A., Goto, M., Kanda, N.
and Koike, H. 2003. Polymorphic analysis of cetacean
MHC - A case study on the minke whales -. Mammalian
Science 3: 75–78 (in Japanese).
Ohishi, K., Zenitani, R., Bando, T., Goto, Y., Uchida, K.,
Maruyama, T., Yamamoto, S., Miyazaki, N. and Fujise, Y. 2003. Pathological and serological evidence of
Brucella-infection in baleen whales (Mysticeti) in thewestern North Paciﬁc. Comp. Immun. Microbiol. Infect.
Dis 26 (2): 125–136.

91

Technical Reports of the Institute of Cetacean Research (2018)2004 (5)Kim, E.Y., Iwata, H., Fujise, Y. and Tanabe, S. 2004. Searching for novel CYP members using cDNA library from aminke whale liver. Marine Environmental Research 58:
495–498.
Ohishi. K., Takishita, K., Kawato, M., Zenitani, R., Bando,T., Fujise, Y., Goto, Y., Yamamoto, S. and Maruyama,
T. 2004. Molecular evidence of new variant Brucellain North Paciﬁc common minke whales. Microbes andInfection 6: 1199–1204.
Ohishi, K., Takishita, K., Kawato, M., Maruyama, T.,
Zenitani, R., Bando, T., Fujise, Y., Goto, Y. and Yamamoto, S. 2004. Molecular characterization of Brucellafrom North Paciﬁc common minke whale. Oceans'04:
499–504.
Watanabe, H., Mogoe, T., Asada, M., Hayashi, K., Fujise,Y., Ishikawa, H., Ohsumi, S., Miyamoto, A. and Fukui,
Y. 2004. Relationship between serum sex hormone
concentrations and histology of seminiferous tubulesof captured baleen whales in the western North Paciﬁcduring the feeding season. Journal of Reproduction andDevelopment 50 (4): 419–427.
Zharikov, K., Fujise, Y., Tamura, T., Kiwada, H., Bando, T.,
Konishi, K. and Isoda, T. 2004. Distribution and feedingof large cetaceans based on the data of JARPN II - 2003
May, 17-July, 9. Marine Mammals of the Holarctic
2004: 207–210.
2005 (5)Birukawa, N., Ando, H., Goto, M., Kanda, N., Pastene, L.A.,
Nakatsuji, H., Hata, H. and Urano, A. 2005. Plasma andurine levels of electrolytes, urea and steroid hormones
involved in osmoregulation of cetaceans. Zoological
Science 22 (11): 1245–1257.
Nikaido, M., Sasaki, T., Makino, H., Goto, M., Kanda, N.,
Pastene, L.A. and Okada, N. 2005. Phylogenetic reconstruction of baleen whales and detection of their pastextensive radiation event by the SINE insertion analysis. Fossils 77: 22–28 (in Japanese).
Niimi, S., Watanabe, M.X., Kim, E.Y., Iwata, H., Yasunaga,G., Fujise, Y. and Tanabe, S. 2005. Molecular cloning
and mRNA expression of cytochrome P4501A1 and
1A2 in the liver of common minke whales (Balaenoptera acutorostrata). Marine Pollution Bulletin 51 (8):784–793.
Ohishi, K., Takishita, K., Kawato, M., Zenitani, R., Bando,T., Fujise, Y., Goto, Y., Yamamoto, S. and Maruyama,
T. 2005. Chimeric structure of omp2 of Brucella from
North Paciﬁc common minke whales (Balaenoptera
acutorostrata). Microbiol. Immunol. 49 (8): 789–793.
92

Sasaki, T., Nikaido, M., Hamilton, H., Goto, M., Kato, H.,
Kanda, N., Pastene, L.A., Cao, Y., Fordyce, R.E., Hasegawa, M. and Okada, N. 2005. Mitochondrial phylogenetics and evolution of mysticete whales. Systematic
Biology 54 (1): 77–90.
2006 (5)
Iwanami, K., Mita, H., Yamamoto, Y., Fujise, Y., Yamada,T. and Suzuki, T. 2006. cDNA-derived amino acid sequences of myoglobins from nine species of whales
and dolphins. Comparative Biochemistry and Physiology, Part B 145: 249–256.
Kanda, N., Goto, M. and Pastene, L. A. 2006. Genetic
characteristics of western North Paciﬁc sei whales,
Balaenoptera borealis, as revealed by microsatellites.
Marine Biotechnology 8: 86–93.
Mitani, Y., Bando., T., Takai., N. and Sakamoto, W. 2006.
Patterns of stable carbon and nitrogen isotopes in thebaleens of common minke whale Balaenoptera acutorostrata from the western North Paciﬁc. Fish Sci 72(1): 69–76.
Nikaido, M., Hamilton, H., Makino, H., Sasaki, T., Takahashi, K., Goto, M., Kanda, N., Pastene, L.A. and Okada,N. 2006. Baleen whale phylogeny and a past extensive
radiation event revealed by SINE insertion analysis.
Molecular Biology and Evolution 23 (5): 866–873.
Ohishi, K., Maruyama, T., Ninomiya, A., Kida, H., Zenitani,
R., Bando, T., Fujise, Y., Nakamatsu, K., Miyazaki, N. and
Boltunov, A.N. 2006. Serologic investigation of inﬂuenza a virus infection in cetaceans from the western
North Paciﬁc and the Southern Oceans. Marine Mammal Science 22 (1): 214–221.
2007 (11)
Fukui, Y., Iwayama, H., Matsuoka, T., Nagai, H., Koma,
N., Mogoe, T., Ishikawa, H., Fujise, Y., Hirabayashi, M.,
Hochi, S., Kato, H. and Ohsumi, S. 2007. Attempt at
intracytoplasmic sperm injection of in vitro matured
oocytes in common minke whales (Balaenoptera acutorostrata) captured during the Kushiro coast survey.
Journal of Reproduction and Development. 53 (4):945–952.
Kanda, N., Goto, M., Kato, H., McPhee, M.V. and Pastene,
L.A. 2007. Population genetic structure of Brydeʼswhales (Balaenoptera brydei) at the inter-oceanic andtrans-equatorial levels. Conservation Genetics 8 (4):853–864.
Konishi, K. and Tamura, T. 2007. Occurrence of the minimal armhook squids Berryteuthis anonychus (Cephalopoda: Gonatidae) in the stomachs of common minke

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2018

whales Balaenoptera acutorostrata in the western
North Paciﬁc. Fish Sci 73 (5): 1208–1210.
Murase, H., Tamura, T., Kiwada, H., Fujise, Y., Watanabe,
H., Ohizumi, H., Yonezaki, S., Okamura, H. and Kawahara, S. 2007. Prey selection of common minke (Balaenoptera acutorostrata) and Brydeʼs (Balaenoptera
edeni) whales in the western North Paciﬁc in 2000 and
2001. Fish. Oceanogr. 16 (2): 186–201.
Niimi, S., Kim, E.Y., Iwata, H., Watanabe, M.X., Yasunaga,G., Fujise, Y. and Tanabe, S. 2007. Identiﬁcation andhepatic expression proﬁles of cytochrome P450 1–4
isozymes in common minke whales (Balaenoptera acutorostrata). Comparative Biochemistry and Physiology,
Part B 147: 667–681.
Nishida, S., Goto, M., Pastene, L.A., Kanda, N. and Koike,
H. 2007. Phylogenetic relationships among cetaceansrevealed by Y-chromosome sequences. Zoological
Science 24 (7): 723–732.
Onbe, K. Nishida, S., Sone, E., Kanda, N., Goto, M., Pastene, L.A., Tanabe, S. and Koike, H. 2007. Sequencevariation in the Tbx4 Gene in marine mammals. Zoological Science 24 (5): 449–464.
Pastene, L.A., Goto, M., Kanda, N., Zerbini, A.N., Kerem,D., Watanabe, K., Bessho, Y., Hasegawa, M., Nielsen,
R., Larsen, F. and Palsbøll, P.J. 2007. Radiation andspeciation of pelagic organisms during periods ofglobal warming: the case of the common minke whale,
Balaenoptera acutorostrata. Molecular Ecology 16:1481–1495.
Urashima, T., Kobayashi, M., Asakuma, S., Uemura, Y.,
Arai, I., Fukuda, K., Saito, T., Mogoe, T., Ishikawa, H. andFukui, Y. 2007. Chemical characterization of the oligosaccharides in Brydeʼs whale (Balaenoptera edeni) andSei whale (Balaenoptera borealis) milk. Comparative
Biochemistry and Physiology, Part B 146: 153–159.
Watanabe, H., Tateno, H., Kusakabe, H., Kamiguchi, Y.,
Fujise, Y., Ishikawa, H., Ohsumi, S. and Fukui, Y. 2007.
Fertilizability and chromosomal integrity of frozenthawed Brydeʼs whale (Balaenoptera edeni) spermatozoa intracytoplasmically injected into mouse oocytes.
Reproduction, Fertility and Development 19 (1): 306.
Watanabe, H., Tateno, H., Kusakabe, H., Matsuoka, T.,
Kamiguchi, Y., Fujise, Y., Ishikawa, H., Ohsumi, S. andFukui, Y. 2007. Fertilizability and chromosomal integrityof frozen-thawed Brydeʼs whale (Balaenoptera edeni)
spermatozoa intracytoplasmically injected into mouse
oocytes. Zygote 15 (1): 9–14.
2008 (3)Birukawa, N., Ando, H., Goto, M., Kanda, N., Pastene,

L.A. and Urano, A. 2008. Molecular cloning of urea
transporters from the kidneys of baleen and toothed
whales. Comparative Biochemistry and Physiology,
Part B 149: 227–235.
Ishikawa, H. and Shigemune, H. 2008. Comparative experiment of whaling grenades in the Japanese Whale
Research Program under Special Permit (JARPA and
JARPN). Jpn. J. Zoo Wildl. Med. 13 (1): 21–28.
Ohishi, K., Fujise, Y. and Maruyama, T. 2008. Brucella spp.
in the western North Paciﬁc and Antarctic cetaceans: areview. J. Cetacean Res. Manage. 10 (1): 67–72.
2009 (9)Bhuiyan, M.M.U., Suzuki, Y., Watanabe, H., Hirayama, H.,
Matsuoka, K., Fujise, Y., Ishikawa, H., Ohsumi, S. andFukui, Y. 2009. Attempts at in vitro fertilization andculture of in vitro matured oocytes in sei (Balaenoptera
borealis) and Brydeʼs (B. edeni) whales. Zygote 17 (1):19–28.
Fujita, H., Honda, K., Hamada, N., Yasunaga, G and Fujise,
Y. 2009. Validation of high-throughput measurement
system with microwave-assisted extraction, fully automated sample preparation device, and gas chromatography-electron capture detector for determinationof polychlorinated biphenyls in whale blubber. Chemosphere 74: 1069–1078.
Hiwasa, M., Suzuki, Y., Watanabe, H., Bhuiyan, M.M.U.,
Matsuoka, K., Fujise, Y., Ishikawa, H., Ohsumi, S. andFukui, Y. 2009. Eﬀects of semen extenders and storage temperatures on characteristics of frozen-thawed
Brydeʼs (Balaenoptera edeni) whale spermatozoa. Journal of Reproduction and Development 55: 599–606.
Konishi, K., Tamura T., Isoda, T. Okamoto, R., Hakamada,T., Kiwada, H. and Matsuoka, K. 2009. Feeding strategies and prey consumption of three baleen whale species within the Kushiro-Current Extension. J. Northw.
Atl. Fish. Sci. 42: 27–40.
Lee, E., Bhuiyan, M.M.U., Watanabe, H., Matsuoka, K.,
Fujise, Y., Ishikawa, H. and Fukui. Y. 2009. Production ofcloned sei whale (Balaenoptera borealis) embryos byinterspecies somatic cell nuclear transfer using enucleated pig oocytes. J. Vet. Sci. 10 (4): 285–292.
Matsukura, R., Yasuma, H., Murase, H., Yonezaki, S., Funamoto, T., Honda, S. and Miyashita, K. 2009. Measurements of density contrast and sound-speed contrast
for target strength estimation of Neocalanus copepods(Neocalanus cristatus) in the North Paciﬁc Ocean. FishSci 75 (6): 1377–1387.
Murase, H., Ichihara, M., Yasuma, H., Watanabe, H., Yonezaki, S., Nagashima, H., Kawahara, S. and Miyashita, T.
93

Technical Reports of the Institute of Cetacean Research (2018)2009. Acoustic characterization of biological backscatterings in the Kuroshio-Oyashio inter-frontal zone andsubarctic waters of the western North Paciﬁc in spring.
Fish. Oceanogr. 18 (6): 386–401.
Murase, H., Nagashima, H., Yonezaki, S., Matsukura, R.
and Kitakado, T. 2009. Application of a generalized additive model (GAM) to reveal relationships between
environmental factors and distributions of pelagic ﬁsh
and krill: a case study in Sendai Bay, Japan. ICES Journalof Marine Science 66 (6): 1417–1424.
Tsuki, K., Sato, A., Kaneko, H., Yasunaga, G., Fujise, Y. and
Nomata, H. 2009. Comparison of physiologically signiﬁcant imidazole dipeptides in cetaceans sampled inJapanese whale research (short paper). Sci. Rep. Hokkaido Fish. Exp. Stn. 74: 25–28 (in Japanese).
2010 (7)Bhuiyan, M.M.U., Suzuki, Y., Watanabe, H., Lee, E.,
Hirayama, H., Matsuoka, K., Fujise, Y., Ishikawa, H.,
Ohsumi, S. and Fukui, Y. 2010. Production of sei whale(Balaenoptera borealis) cloned embryos by inter- andintra-species somatic cell nuclear transfer. Journal of
Reproduction and Development 56: 131–139.
Funakasa, N., Yoshioka, M. and Fujise, Y. 2010. Featuresof the Ocular Harderian Gland in three Balaenopterid
species based on anatomical, histological and histochemical observations. Mammal Study 35 (1): 9–15.
Ogawa, G., Ishida, M., Kato, H., Fujise, H. and Urano, N.
2010. Identiﬁcation of facultative anaerobic bacteria
isolated from the intestine of the minke whale Balaenoptera acutorostrata by 16S rRNA sequencing analysis. Fish Sci 76 (2): 177–181.
Pastene, L.A., Fujise, Y. and Hatanaka, H. 2010. JARPNII: achallenging multidiscipline research program focusedon whales in the western North Paciﬁc. Ottar (TromsøMuseum) 280: 23–28 (in Norwegian)．
Shishido, R., Ohishi, K., Suzuki, R., Takishita, K., Ohtsu,
D., Okutsu, K., Tokutake, K., Katsumata, E., Bando, T.,
Fujise, Y., Murayama, T. and Maruyama, T. 2010．Cetacean Toll-like receptor 4 and myeloid diﬀerentiation
factor 2, and possible cetacean-speciﬁc responses
against Gram-negative bacteria．Comp. Immun. Microbiol. Infect. Dis. 33 (6): 89–98．
Suzuki, Y., Umatani, M., Bhuiyan, M.M.U., Watanabe,H., Mogoe, T., Matsuoka, K., Fujise, Y., Ishikawa, H.,
Ohsumi, S., Sasaki, M. and Fukui, Y. 2010. Eﬀects ofequilibration steps, type of sugars and addition ofwhale follicular ﬂuid on viability and in vitro maturation of vitriﬁed whale oocytes．Jpn. J. Zoo Wildl. Med
15 (2): 65–72．
94

Tojo, N., Matsukura, R., Yasuma, H., Yonezaki, S., Watanabe, H., Kawahara, S., Murase, H. and Miyashita, K.
2010．Spatial analysis of isada krill (Euphausia paciﬁca)
distribution in frontal environments in the North Pacific Ocean．GIS/spatial analyses in ﬁsheries and aquatic
science．4．International Fishery GIS Society: 115–138.
2011 (20)
Hakamada, T. and Matsuoka, K. 2011. Abundance estimate for common minke, Brydeʼs and sei whales in theoﬀshore region of the western North Paciﬁc. Bull. Jpn.
Soc. Fish. Oceanogr. 75 (3): 173–174 (in Japanese).
Kanda, N., Goto, M. and Pastene, L. A. 2011. Genetic stock
structure of baleen whales. Bull. Jpn. Soc. Fish. Oceanogr. 75 (3): 191 (in Japanese).
Kato, H. and Fujise, Y. 2011. General discussion: Symposium on “Marine ecosystem of the western North Paciﬁc with special interest in cetaceans.” Bull. Jpn. Soc.
Fish. Oceanogr. 75 (3): 194–195 (in Japanese).
Kishiro, T., Yoshida, H., Tamura, T., Konishi, K., Kanda, N.,
Okamoto, R. and Kato, H. 2011. Relationship between
maturity and feeding ecology of common minke whales
oﬀ Kushiro in autumn. Bull. Jpn. Soc. Fish. Oceanogr. 75(3): 175–176 (in Japanese).
Maehara, T., Aoki, I., Yonezaki, S., Watanabe, H., Murase,
H. and Yamaguchi, A. 2011. Feeding ecology of theJapanese anchovy in the oﬀshore area east of Honshu,
Japan in summer. Bull. Jpn. Soc. Fish. Oceanogr. 75 (3):187 (in Japanese).
Matsuoka, K., Kiwada, H., Fujise, Y. and Miyashita, T. 2011.
Distribution of baleen whales in the western North Paciﬁc based on the JARPN and JARPN II sighting surveys(1994 to 2007). Bull. Jpn. Soc. Fish. Oceanogr. 75 (3):178–179 (in Japanese).
Miyashita, K., Matsukura, R., Tojo, N., Minami, K.,
Yasuma, H., Nagashima, H., Onodera, K., Watanabe, H.,
Yonezaki, S. and Murase, H. 2011. Monitoring of preyof cetaceans by using quantitative echosounders. Bull.
Jpn. Soc. Fish. Oceanogr. 75 (3): 183–184 (in Japanese).
Mori, M., Watanabe, H., Hakamada, T., Tamura, T., Konishi, K., Murase, H. and Matsuoka, K. 2011. Development of an ecosystem model of western North Paciﬁcusing Ecopath with Ecosim. Bull. Jpn. Soc. Fish. Oceanogr. 75 (3): 189 (in Japanese).
Murase, H., Kawabata, A., Kubota, H., Nakagami, M.,
Amakasu, K., Abe, K., Miyashita, K. and Oozeki, Y. 2011.
Eﬀect of depth-dependent target strength on biomass
estimation of Japanese anchovy. Journal of Marine
Science and Technology 19: 267–272.
Murase, H., Tamura, T., Isoda, T., Okamoto, R., Kato, H.,

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2018

Yonezaki, S., Watanabe, H., Tojo, N. Matsukura, R.,
Miyashita, K., Kiwada, H., Matsuoka, K., Nishiwaki, S.,
Inagake, D., Okazaki, M., Okamura, H. and Fujise, Y.
2011. Prey selection of common minke, Brydeʼs andsei whales in the oﬀshore region of the western North
Paciﬁc. Bull. Jpn. Soc. Fish. Oceanogr. 75 (3): 180–181(in Japanese).
Nishiwaki, S., Otani, S. and Tamura, T. 2011. The satellite
tracking of the western North Paciﬁc. Bull. Jpn. Soc.
Fish. Oceanogr. 75 (3): 193–194 (in Japanese).
Onodera, K., Nagashima, H., Matsukura, R., Miyashita,K., Yonezaki, S. and Murase, H. 2011. Cetacean preyspecies and oceanographic surveys in Sendai Bay. Bull.
Jpn. Soc. Fish. Oceanogr. 75 (3): 184–185 (in Japanese).
Pastene, L.A., Hatanaka, H., Fujise, Y., Kanda, N., Murase,
H., Tamura, T., Miyashita, T. and Kato, H. 2011. Whale
research program under special permit in the western
North Paciﬁc—Phase II (JARPNII): origin and objectives. Bull. Jpn. Soc. Fish. Oceanogr. 75 (3): 172–173 (inJapanese).
Pastene, L.A., Hatanaka, H., Fujise, Y., Kanda, N., Murase,
H., Tamura, T., Yasunaga, G., Kishiro, T., Yoshida, H.,
Miyashita, T. and Kato, H. 2011. The Japanese Whale
Research Program under Special Permit in the western
North Paciﬁc Phase-II (JARPNII): origin, objectives andresearch progress made in the ﬁrst six years period(2002–2007), including scientiﬁc considerations for the
next research period. Aquabiology 33 (2): 171–185 (inJapanese).
Sasaki, Y., Saito, S., Matsuoka, K., Murase, H. and Kiwada.,
H. 2011. Spatial distribution patterns of sei and Brydeʼswhales. Bull. Jpn. Soc. Fish. Oceanogr. 75 (3): 179–180(in Japanese).
Tamura, T., Konishi, K., Isoda, T., Hakamada, T., Kiwada, H.,
Okamoto, R. and Matsuoka, K. 2011. The food habitat,
relation of habitat factor and prey consumption of
three baleen whale species in the oﬀshore region of
the western North Paciﬁc. Bull. Jpn. Soc. Fish. Oceanogr. 75 (3): 174–175 (in Japanese).
Watanabe, H., Kiwada, H., Kumagai, S., Yonezaki, S.,
Kishiro, T., Konishi., K. and Yoshida, H. 2011. Habitatand prey selection of common minke whale oﬀ Kushiro
in autumn—Estimation of distribution and migrationof common minke whale using environmental information—Bull. Jpn. Soc. Fish. Oceanogr. 75 (3): 182–183 (inJapanese).
Yamaguchi, A., Hanamiya, Y., Murase, H. and Watanabe,
H. 2011. Vertical ﬂux of materials by diel vertical migration of macrozooplankton. Bull. Jpn. Soc. Fish. Oceanogr. 75 (3): 185–186 (in Japanese).

Yasunaga, G. and Fujise, Y. 2011. Monitoring of pollutants in the baleen whales and their prey species in thewestern North Paciﬁc. Bull. Jpn. Soc. Fish. Oceanogr. 75(3): 190 (in Japanese).
Yoshida, H., Kishiro, T., Goto, M., Bando, T., Tamura, T.,
Konishi, K., Okamoto, R. and Kato, H. 2011. Feeding
ecology of common minke whales in coastal waters oﬀ
Sanriku in spring. Bull. Jpn. Soc. Fish. Oceanogr. 75 (3):
177–178 (in Japanese).
2012 (4)Maeda, H. and Kato, H. 2012. Technical improvementsof the age character (earplug) collections in common
minke whales. Bull. Jpn. Soc. Fish. Oceanogr. 76 (2):59–65 (in Japanese).
Murase, H., Kawabata, A., Kubota, H., Nakagami, M.,
Amakasu, K., Abe, K., Miyashita, K. and Oozeki, Y. 2012.
Basin-scale distribution patterns and biomass estimation of Japanese anchovy Engraulis japonicus in thewestern North Paciﬁc. Fish Sci 78 (4): 761–773.
Nakamura, G., Kato, H. and Fujise, Y. 2012. Relative
growth of the skull of the common minke whale Balaenoptera acutorostrata from the North Paciﬁc in comparison to other Balaenoptera species. Mammal Study
37 (2): 105–112.
Watanabe, H, Okazaki, M., Tamura, T., Konishi, K., Inagake, D., Bando, T., Kiwada, H. and Miyashita, T. 2012.
Habitat and prey selection of common minke, sei, andBrydeʼs whale in mesoscale during summer in the
sub-arctic and transition regions of the western North
Paciﬁc. Fish Sci 78 (3): 557–567.
2013 (5)*Kershaw, F., Leslie, M.S., Collins, T., Mansur, R.M., Smith,B.D., Minton, G., Baldwin, R., LeDuc, R.G., Anderson,
R.C., Brownell, R.L. and Rosenbaum, H.C. 2013. Population diﬀerentiation of 2 forms of Brydeʼs whales in the
Indian and Paciﬁc Oceans. Journal of Heredity 104 (6):755–764.
Maeda, H., Kawamoto, T. and Kato, H. 2013. A study on
the improvement of age estimation in common minke
whales using the method of gelatinized extraction of
earplug. NAMMCO Scientiﬁc Publications 10: 17pp.
Matsukura, R., Sawada, K., Abe, K., Minami, K., Nagashima, H., Yonezaki, S., Murase, H. and Miyashita,
K. 2013. Comparison of measurements and model
calculations of target strength of juvenile sandeel in
Sendai Bay. Nippon Suisan Gakkaishi 79 (4): 638–648(in Japanese).
Sasaki, H., Murase, H., Kiwada, H., Matsuoka, K., Mitani, Y.
95Technical Reports of the Institute of Cetacean Research (2018)

and Saitoh, S. 2013. Habitat diﬀerentiation between sei(Balaenoptera borealis) and Brydeʼs whales (B. brydei)
in the western North Paciﬁc. Fish. Oceanogr. 22 (6):496–508.
Shimizu, Y., Ohishi, K., Suzuki, R., Tajima, Y., Yamada, T.,
Kakizoe, Y., Bando, T., Fujise, Y., Taru, H., Murayama, T.
and Maruyama, T. 2013. Amino acid sequence variations of signaling lymphocyte activation molecule andmortality caused by morbillivirus infection in cetaceans. Microbiol Immunol 57: 624–632.
2014 (6)Inoue, S., Kishiro, T., Fujise, Y., Nakamura, G. and Kato,
H. 2014. Seasonal changes in the testis of the North
Paciﬁc common minke whale. Nippon Suisan Gakkaishi
80 (2): 185–190 (in Japanese).
Murase, H., Hakamada, T., Matsuoka, K., Nishiwaki, S.,
Inagake, D., Okazaki, M., Tojo, N. and Kitakado, T. 2014.
Distribution of sei whales (Balaenoptera borealis) in
the subarctic–subtropical transition area of the western North Paciﬁc in relation to oceanic fronts. Deep
Sea Research Part II: Topical Studies in Oceanography
107: 22–28.
Nakamura, G., Kadowaki, I., Nagatsuka, S., Fujise, Y.,
Kishiro, T. and Kato, H. 2014. Variation in a color pattern of white patch on the ﬂippers of North Paciﬁc
common minke whales: potential application for theirinteroceanic diﬀerence. La mer 52: 31–47.
Nakamura, G. and Kato, H. 2014. Developmental changes
in the skull morphology of common minke whales
Balaenoptera acutorostrata. Journal of Morphology
275: 1113–1121.
Niimi, S., Imoto, M., Kunisue, T., Watanabe, M.X., Kim,
E.Y., Nakayama, K., Yasunaga, G., Fujise, Y., Tanabe, S.
and Iwata, H. 2014. Eﬀects of persistent organochlorine exposure on the liver transcriptome of the common minke whale (Balaenoptera acutorostrata) fromthe North Paciﬁc. Ecotoxicology and Environmental
Safety 108: 95–105.
*Rosel, P.E. and Wilcox, L.A. 2014. Genetic evidence reveals a unique lineage of Brydeʼs whales in the northern Gulf of Mexico. Endang Species Res. 25 : 19–34.
2015 (1)Kitayama, C., Sasaki, M., Ishikawa, H., Mogoe, T., Ohsumi,
S., Fukui, Y., Budipitojo, T., Kondoh, D. and Kitamura, N.
2015. Structure and functions of the placenta in common minke (Balaenoptera acutorostrata), Brydeʼs (B.
brydei) and sei (B. borealis) whales. Journal of Reproduction and Development 61 (5): 415–421.
96

2016 (6)Hirako, S., Suzuki, M., Kim, H., Iizuka, Y., Matsumoto,A., Wada, N., Okabe, M., Takenoya, F., Yasunaga, G.,
Yamanaka, S., Miyazaki, A. and Shioda, S. 2016. Hepatic
lipid accumulation is ameliorated in obese KK mice by
dietary sei whale oil. Fish Sci 82 (3): 509–517.
Miyakawa, N., Kishiro, T., Fujise, Y., Nakamura, G. andKato, H. 2016. Sexual Dimorphism in Pelvic Bone
Shape of the North Paciﬁc Common Minke Whales(Balaenoptera acutorostrata). Open Journal of Animal
Sciences 6: 131–136.
Murase, H., Tamura, T., Otani, S. and Nishiwaki, S. 2016.
Satellite tracking of Brydeʼs whales Balaenoptera edeni
in the oﬀshore western North Paciﬁc in summer 2006
and 2008. Fish Sci 82 (1): 35–45.
Nakamura, G., Kadowaki, I., Nagatsuka, S., Hayashi, R.,
Kanda, N., Goto, M., Pastene, L.A. and Kato, H. 2016.
White Patch on the Fore-Flipper of Common Minke
Whale, as a Potential morphological Index to Identify
Stocks. Open Journal of Animal Sciences 6: 116–122.
Nakamura, G., Takahashi, M., Hirose, A., Hayashi, R.,
Fujise, Y., Miyakawa, N., Inoue, S. and Kato, H. 2016.
Presence of an interparietal bone and morphologicalvariation 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 infection in baleen whales andsperm whales in the western North Paciﬁc and Antarctic Oceans. J. Vet. Med. Sci. 78 (9): 1457–1464.
2017 (2)Bando, T., Nakamura, G., Fujise, Y. and Kato, H. 2017.
Developmental changes in the morphology of western
North Paciﬁc Brydeʼs whales (Balaenoptera edeni).
Open Journal of Animal Sciences 7: 344–355.
Ishii, M., Murase, H., Fukuda, Y., Sawada, K., Sasakura,T., Tamura, T., Bando, T., Matsuoka, K., Shinohara, A.,
Nakatsuka, S., Katsumata, N., Okazaki, M., Miyashita,
K. and Mitani, Y. 2017. Diving behavior of sei whales
Balaenoptera borealis relative to the vertical distribution of their potential prey. Mammal Study 42 (4):
191–199.
2018 (2)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.
Population structure of North Atlantic and North Paciﬁc sei whales (Balaenoptera borealis) inferred from

List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2018

mitochondrial control region DNA sequences and microsatellite genotypes. Conserv Genet 19: 1007–1024.
Watari, S., Murase, H., Yonezaki, S., Okazaki, M., Kiyofuji,
H., Tamura, T., Hakamada, T., Kanaji, Y. and Kitakado,
T. 2018. Ecosystem modeling in the western North
Paciﬁc using Ecopath, with a focus on small pelagicﬁshes. Mar. Ecol. Prog. Ser.: https://doi.org/10.3354/
meps12508.

Other surveys
1993 (1)Fujise, Y., Ishikawa, H., Saino, S. and Kawasaki, M. 1993.
Catch and struck-and-lost rate in the Japanese Dallʼs
porpoise hand-harpoon ﬁshery. Rep. int. Whal. Commn
43: 453–457.
1995 (1)Shimada, H. and Pastene, L.A. 1995. Report of a sightings survey oﬀ the Solomon Islands with comments on
Brydeʼs whale distribution. Rep. Int. Whal. Commn 45:
413–418.
1997 (4)Kimura, T., Ozawa, T. and Pastene, L.A. 1997. Sample
preparation and analysis of mitochondrial DNA fromwhale baleen plates. Marine Mammal Science 13 (3):495–498.
Ljungblad, D.K., Staﬀord, K.M., Shimada, H. and Matsuoka, K. 1997. Sounds attributed to blue whales recorded
oﬀ the southwest coast of Australia in December 1995.
Rep. int. Whal. Commn 47: 435–439.
Ohmagari, K. and Berkes, F. 1997. Transmission of indigenous knowledge and bush skills among the WesternJames Bay Cree Women of Subarctic Canada. Human
Ecology 25 (2): 197–222.
Shimamura, M., Yasue, H., Ohshima, K., Abe, H., Kato, H.,
Kishiro, T., Goto, M., Munechika, I. and Okada, N. 1997.
Molecular evidence from retroposons that whales
form a clade within even-toed ungulates. Nature 388:
666–670.
1998 (2)Miyazaki, N., Fujise, Y. and Iwata, K. 1998. Biologicalanalysis of a mass stranding of melon-headed whales(Peponocephala electra) at Aoshima. Japan. Bull. Natn.
Sci. Mus., Tokyo, Ser. A 24 (1): 31–60.
Otani, S., Naito, Y., Kawamura, A., Kawasaki, M., Nishiwaki, S. and Kato, A. 1998. Diving behavior and performance of harbor porpoises, Phocoena phocoena,
in Fukuoka bay, Hokkaido, Japan. Marine Mammal

Science 14 (2): 209–220.
1999 (4)Iino, Y. 1999. Treaty Implementation: the 1946 International Convention for the Regulation of Whaling.
System Compliance in Ocean Management. Southeast
Asian Programme in Ocean Law. Policy and Management: 189–193.
Pastene, L.A. and Shimada, H. 1999. Report of a sighting
survey in Chileʼs Exclusive Economic Zone with comments on sei whale distribution. Anales Instituto Patagonia, Serie Cs. Nat. 27: 51–62.
Shimamura, M., Abe, H., Nikaido, M., Ohshima, K. andOkada, N. 1999. Genealogy of families of SINEs in cetaceans and artiodactyls: the presence of a huge superfamily of tRNAGlu-derived families of SINEs. Mol. Biol.
Evol. 16 (8): 1046–1060.
Yoshida, H. and Kato, H. 1999. Phylogenetic relationshipsof Brydeʼs whales in the Western North Paciﬁc andadjacent waters inferred from mitochondrial DNA sequences. Marine Mammal Science 15 (4): 1269–1286.
2000 (3)Goto, M. and Ohsumi, S. 2000. Response to “Scientiﬁc
Whaling Source of illegal Products for Market” By Baker
et al. Science 290: 1695–1696.
Otani, S., Naito, Y., Kato, A. and Kawamura, A. 2000. 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. Accumulation ofbutyltin compounds and total tin in marine mammals.
Water Science and Technology 42 (7–8): 97–108.
2001 (2)Abe, H., Goto, M., Pastene, L.A., Dewa, K. and Naito, E.
2001. Practical use of multiplex ﬂuorescent PCR for
cetacean sex identiﬁcation. Marine Mammal Science
17 (3): 657–664.
Yoshida, H., Yoshioka, M., Shirakihara, M. and Chow, S.
2001. Population structure of ﬁnless porpoises (Neophocaena phocaenoides) in coastal waters of Japan
based on mitochondrial DNA sequences. Journal of
Mammalogy 82 (1): 123–130.
2002 (1)Konishi, K. and Sakurai, Y. 2002. Geographical variations ininfection by larval Anisakis simplex and Contracaecum
osculatum (Nematoda, Anisakidae) in walleye pollock
97Technical Reports of the Institute of Cetacean Research (2018)

Theragra chalcogramma stocks oﬀ Hokkaido, Japan.
Fish Sci 68 (3): 534–542.
2003 (1)Matsuoka, K., Ensor, P., Hakamada, T., Shimada, H., Nishiwaki, S., Kasamatsu, F. and Kato, H. 2003. Overview
of the minke whale sighting survey in IWC/IDCR and
SOWER cruises from 1978/79 to 2000/01. J. Cetacean
Res. Manage. 5 (2): 173–201.
2004 (5)Branch, T.A., Matsuoka, K. and Miyashita, T. 2004. Evidence for increases in Antarctic blue whales based on
Bayesian modelling. Marine Mammal Science 20 (4):726–754.
Escorza-Trevino, S., Pastene, L.A. and Dizon, A.E. 2004.
Molecular analyses of the Truei and Dalli morphotypes of Dallʼs porpoise (Phocoenoides dalli). Journal of
Mammalogy 85 (2): 347–355.
Ikemoto, T., Kunito, T., Watanabe, I., Yasunaga, G., Baba,N., Miyazaki, N., Petrov, E.A. and Tanabe, S. 2004.
Comparison of trace element accumulation in Baikal
seals (Pusa sibirica), Caspian seals (Pusa caspica) andnorthern fur seals (Callorhinus ursinus). Environmental
Pollution 127: 83–97.
Murase, H., Matsuoka, K., Nishiwaki, S., Hakamada, T. andMori, M. 2004. Eﬀect of observed covariates (school
size, sighting cue, latitude and sea state) on the Antarctic minke whale abundance estimation parameters in
the IWC/IDCR-SOWER surveys. J. Cetacean Res. Manage. 6 (3): 283–292.
Yanagimoto, T. and Konishi, K. 2004. Acanthochondria priacanthi (Copepoda: Chondracanthidae) as a biologicalindicator for stock identiﬁcation of sandﬁsh Arctoscopus japonicus (Steindachner). Fish Sci 70 (2): 336–338.
2005 (5)Agusa, T., Matsumoto, T., Ikemoto, T., Anan, Y., Kubota, R.,
Yasunaga, G., Kunito, T., Tanabe, S., Ogi, H. and Shibata,Y. 2005. Body distribution of trace elements in blacktailed gulls from Rishiri Island, Japan: age-dependentaccumulation and transfer to feathers and eggs. Environ. Toxicol. Chem. 24 (9): 2107–2120.
Agusa, T., Kunito, T., Yasunaga, G., Iwata, H., Subramanian, A., Ismail, A. and Tanabe, S. 2005. Concentrationsof trace elements in marine ﬁsh and its risk assessment in Malaysia. Marine Pollution Bulletin 51 (8–12):
896–911.
Fukui, Y., Ishikawa, H. and Ohsumi, S. 2005. Diﬃculties
in publishing research results from scientiﬁc whaling.
98

Marine Mammal Science 21 (4): 781–783.
Prudente, M., Tanabe, S., Kunisue, T., Yasunaga, G., Watanabe, I. and Miyazaki, N. 2005. Accumulation of traceelements and persistent organochlorines in resident
and migratory waders from Calatagan Bay, Philippines.
Coastal Marine Science 29 (2): 133–140.
Sanino, G.P., Waerebeek, K.V., Van Bressem, M. andPastene, L.A. 2005. A preliminary note on population
structure in eastern South Paciﬁc common bottlenose
dolphins, Tursiops truncatus. J. Cetacean Res. Manage.
7 (1): 65–70.
2006 (6)Acevedo, J., Aguayo-Lobo, A. and Pastene, L.A. 2006.
Filopatria de la ballena jorobada (Megaptera novaeangliae Borowski, 1781), al area de alimentacion delEstrecho de Magallanes. Revista de Biologia Marina y
Oceanograﬁa 41 (1): 11–19.
Acevedo, J., Aguayo-Lobo, A., Acuna, P. and Pastene, L.A.
2006. A note on the ﬁrst record of the dwarf minke
whale (Balaenoptera acutorostrata) in Chilean waters.
J. Cetacean Res. Manage. 8 (3): 293–296.
Hayashi, K., Yoshida, H., Nishida, S., Goto, M., Pastene,
L.A., Kanda, N., Baba, H. and Koike, H. 2006. Genetic
Variation of the MHC DQB locus in the ﬁnless porpoise(Neophocaena phocaenoides). Zoological Science 23(2): 147–153.
Mori, M. and Butterworth, D.S. 2006. A ﬁrst step towards
modelling the krill–predator dynamics of the Antarctic
ecosystem. CCAMLR Science 13: 217–277.
Sekiguchi, K., Olavarria, C., Morse, P., Olson, P., Ensor,
P., Matsuoka, K., Pitman, R., Findlay, K. and Gorter, U.
2006. The spectacled porpoise (Phocoena dioptrica)
in Antarctic waters. J. Cetacean Res. Manage. 8 (3):265–271.
Takahashi, Y., Ohwada, S., Watanabe, K., Ropert-Coudert,Y., Zenitani, R., Naito, Y. and Yamaguchi, T. 2006. Does
elastin contribute to the persistence of corpora albicantia in the ovary of the common dolphin (Delphinusdelphis). Marine Mammal Science 22 (4): 819–830.
2007 (2)Acevedo, J., Rasmussen, K., Felix, F., Castro, C., Llano, M.,
Secchi, E., Saborio, M.T., Aguayo-Lobo, A., Haase, B.,
Scheidat, M., Dalla-Rosa, L., Olavarria, C., Fosestell, P.,
Acuna, P., Kaufman, G. and Pastene, L.A. 2007. Migratory destinations of humpback whales from the Magellan Strait feeding ground, Southeast Paciﬁc. Marine
Mammal Science 23 (2): 453–463.
Branch, T.A., Staﬀord, K.M., Palacios, D.M., Allison, C.,List of peer-reviewed publications based on the Institute of Cetacean Research (ICR)ʼs surveys up to 2018

Bannister, J.L., Burton, C.L.K., Cabrera, E., Carlson, C.A.,
Galletti Vernazzani, B., Gill, P.C., Hucke-Gaete, R., Jenner, K.C.S., Jenner, Mn. M., Matsuoka, K., Mikhalev,
Y.A., Miyashita, T., Morrice, M.G., Nishiwaki, S., Sturrock, V.J., Tormosov, D., Anderson, R.C., Baker, A.N.,
Best, P.B., Borsa, P., Brownell Jr, R.L., Childerhouse,
S., Findlay, K.P., Gerrodette, T., Ilangakoon, A.D., Joergensen, M., Kahn, B., Ljungblad, D.K., Maughan, B.,
Mccauley, R.D., Mckay, S., Norris, T.F., Oman Whaleand Dolphin Research Group, Rankin, S., Samaran, F.,
Thiele, D., Van Waerebeek, K. and Warneke, R.M. 2007.
Past and present distribution, densities and movements of blue whales in the Southern Hemisphere andadjacent waters. Mammal Rev. 37 (2): 116–175.
2009 (1)Nambu, H., Tokutake, K., Ishikawa, H., Ohta, M., Fujita, K.
and Yamada, T.K. 2009. Observation of a gray whale, Eschrichtius robustus, in Tokyo Bay in 2005. Japan Cetology
19: 17–22 (in Japanese).
2010 (3)Nambu, H., Ishikawa, H. and Yamada, T. 2010. Recordsof the western gray whale Eschrichtius robustus: its
distribution and migration. Japan Cetology 20: 21–29(in Japanese).
Pastene, L.A. and Quiroz, D. 2010. An Outline of the History of Whaling in Chile. pp. 73–98. In: International
Center for Folk Culture Studies (Ed). Human Culture
from the Perspective of Traditional Maritime Communities, International Symposium Report No. 1. Kanagawa
Shimbun Press, Kanagawa. 199pp.
Taguchi, M., Ishikawa, H. and Matsuishi, T. 2010. Seasonal
distribution of harbour porpoise (Phocoena phocoena)
in Japanese waters inferred from stranding and bycatchrecords．Mammal Study 35 (2) : 133–138．
2011 (2)Acevedo, J., Olavarría, C., Plana, J., Aguayo-Lobo, A., Larrea, A. and Pastene, L.A. 2011. Occurrence of dwarf
minke whales (Balaenoptera acutorostrata subsp.)
around the Antarctic Peninsula. Polar Biol 34 (2):313–318.
Acevedo, J., Plana, J., Aguayo-Lobo, A. and Pastene, L.A.
2011. Surface feeding behavior of humpback whalesin the Magellan Strait. Revista de Biologia Marina y
Oceanograﬁa. 46 (3): 483–490.
2013 (4)Acevedo J., Haro D., Dalla R.L., Aguayo-Lobo A., Hucke-

Gaete R., Secchi E., Plana J. and Pastene L.A. 2013.
Evidence of spatial structuring of eastern South Paciﬁchumpback whale feeding grounds. Endang Species Res
22 (1): 33–38.
Kitamura, S., Matsuishi, T., Yamada, K., Tajima, Y., Ishikawa, H., Tanabe, S., Nakagawa, H., Uni, Y. and Abe, S.
2013. Two genetically distinct stocks in Bairdʼs beaked
whale (Cetacea: Ziphiidae). Marine Mammal Science
29 (4): 755–766.
Murase, H., Temoai, I., Kirata, T., Finkaso, S., Yasunaga, G.
and Pastene, L.A. 2013. A note on cetaceans oﬀ Kiribati
and Tuvalu from a research cruise in October 2010. J.
Cetacean Res. Manage. 13 (2): 153–158.
Sugino, T., Yasunaga, G. and Fukuda, M. 2013. Eﬀect ofwhale meat extract on fatigue induced by physical load
and by daily activities in humans. Jpn. Pharmacol. Ther
41 (9): 879–893 (in Japanese).
2014 (3)Pastene, L.A. 2014. Macaya Hermanos y Compania.
Notas sobre las actividades de la empresa ballenerade más larga historia en Chile. Colección Mocha Dick
pp 255–274.
Quiroz, D. and Pastene, L.A. 2014. Norwegian whaling inChile in the 20th Century and its inﬂuence on Chilean
local communities. pp. 61–70. In: Jan Erik Ringstad(Ed). Whaling and History IV. Commander Chr. Christensenʼs Whaling Museum, part of Vestfoldmuseene
IKA, Sandefjord. 192pp.
Quintela, M., Skaug, H.J., Øien, N., Haug, T., Seliussen,
B.B., Solvang, H.K., Pampoulie, C., Kanda, N., Pastene,
L.A. and Glover, K.A. 2014. Investigating population genetic structure in a highly mobile marine organism: theminke whale Balaenoptera acutorostrata acutorostrata in the North East Atlantic. PLoS ONE 9 (9): e108640.
2015 (3)Funasaka, N., Kirihata, T., Kato, H. and Ohsumi, S. 2015.
The ﬁrst record of a true albino common bottlenose
dolphin Tursiops truncatus from Japan. Mammal Study
40 (1): 19–22.
Pastene, L.A., Acevedo, J., Siciliano, S., Sholl, T.G.C., de
Moura, J.F., Ott, P.H. and Aguayo-Lobo, Anelio. 2015.
Population genetic structure of the South American
Brydeʼs whale. Revista de Biologia Marina y Oceanograﬁa 50 (3): 453–464.
Sakamoto, M., Itai, T., Yasutake, A., Iwasaki, T., Yasunaga,G., Fujise, Y., Nakamura, M., Murata, K., Chan, H.M.,
Domingog, J.L. and Marumoto, M. 2015. Mercury
speciation and selenium in toothed-whale muscles.
99Technical Reports of the Institute of Cetacean Research (2018)

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. Estimation of the abundance of the sei whale
Balaenoptera borealis in the central and eastern North

100

Paciﬁc in summer using sighting data from 2010 to2012. Fish Sci 83 (6): 887–895.
Malde, K., Seliussen, B.B., Quintela, M., Dahle, G., Besnier,F., Skaug, H.J., Øien, N., Solvang, H.K., Haug, T., SkernMauritzen, R., Kanda, N., Pastene, L.A., Jonassen, I. andGlover, K.A. 2017. Whole genome resequencing reveals diagnostic markers for investigating global migration and hybridization between minke whale species.
BMC Genomics 18: 76.