Technical Reports of the Ins�tute of Cetacean Research (2022)

pp. 46–51

Technical Report (not peer reviewed)

Results of the IWC-Paciﬁc Ocean Whale and Ecosystem Research(IWC-POWER) dedicated sigh�ng survey in 2021—An overview—
Hiroto Murase*
Tokyo University of Marine Science and Technology, 4–5–7 Konan, Minato-ku, Tokyo 108–8477, Japan*Contact e-mail: hmuras0@kaiyodai.ac.jp

ABSTRACTThis paper outlines the main results of the 2021 dedicated sigh�ng survey of the Interna�onal Whaling Commission-Paciﬁc Ocean Whale and Ecosystem Research (IWC-POWER). The IWC-POWER surveys are designed
and implemented by the IWC Scien�ﬁc Commi�ee, in special partnership with the Government of Japan. The
surveys have been conducted since 2010 as the ﬁrst phase with the long-term objec�ve: ʻ(to) provide informa�on to allow determina�on of the status of popula�ons (and thus stock structure is inherently important) oflarge whales that are found in the North Paciﬁc waters and provide the necessary scien�ﬁc background forappropriate conserva�on and management ac�onsʼ. The 2021 survey was conducted successfully between 2
August and 30 September 2021 in the eastern North Paciﬁc by the Japanese R/V Yushin-Maru No. 2. The following whale species were sighted in the survey area: blue (6 schools / 7 individuals), ﬁn (77/113), sei (23/37),
Brydeʼs (20/22), sperm (14/14) and killer (1/4) whales. Photo-iden�ﬁca�on data were collected from 7 blue,
31 ﬁn, 15 sei 13 Brydeʼs and 3 killer whales. A total of 19 biopsy samples were collected from 3 blue, 9 ﬁn, 4sei, 2 Brydeʼs and 1 killer whales. A total of 88 objects of marine debris were observed and recorded. Data collected during this survey will be used mainly for abundance es�ma�on and stock structure purposes.

INTRODUCTION
The Interna�onal Whaling Commission-Paciﬁc Ocean
Whale and Ecosystem Research (IWC-POWER) programis an interna�onal research eﬀort in the North Paciﬁccoordinated by the IWC and designed by the IWC Scien�ﬁc Commi�ee (SC) in special partnership with theGovernment of Japan. Scien�sts from the Ins�tute of Cetacean Research and coopera�ng ins�tutes such as Tokyo
University of Marine Science and Technology par�cipate
regularly in the IWC-POWER program, both in designingand implemen�ng the surveys. The IWC-POWER surveys
in the North Paciﬁc follow the series of IWC Interna�onal
Decade for Cetacean Research/Southern Ocean Whaleand Ecosystem Research (IDCR/SOWER) surveys conducted in the Antarc�c since 1978.
The long-term objec�ve of the IWC-POWER is to ʻprovide informa�on to allow determina�on of the statusof popula�ons (and thus stock structure is inherently
important) of large whales that are found in the North
Paciﬁc waters and provide the necessary scien�ﬁc background for appropriate conserva�on and management
ac�ons.ʼ The ﬁrst survey of this program was conducted
in 2010 and the most recent one in 2021 as the ﬁrst phase46(IWC, 2021).
The IWC SC is close to comple�ng the ﬁrst phase of theIWC-POWER, which is related to its short-term priori�es.
The IWC SC is preparing for the second phase related tomedium-term priori�es, based on the results of the ﬁrst
phase (see Matsuoka, 2020).
Originally, the 2021 IWC-POWER was planned to beconducted in the region east of the Kuril archipelago
within the Russian EEZ, and Japan submi�ed the research
applica�on to the Russian Federa�on. However, Russia
sent a note verbale to Japan sta�ng that the government
could not accept the applica�on. No reason was given. Asa result, the 2021 IWC-POWER was conducted following
the back-up plan in the eastern North Paciﬁc waters.
The objec�ve of this document is to present an overview of the results of the 2021 IWC-POWER survey.
Details can be found in Murase et al. (2022). For generalbackground of the IWC-POWER including objec�ves, research area and general methodology, see Matsuoka(2020).

RESULTS OF THE 2021 IWC-POWER SURVEY
The main results of the 2021 IWC-POWER survey aresummarized here based on Murase et al. (2022).

Results of the IWC-Pacific Ocean Whale and Ecosystem Research (IWC-POWER) dedicated sighting survey in 2021—An overview—
Table 1The 2021 IWC-POWER survey i�nerary.
DateEvent

1 August 2021

Pre-cruise mee�ng in Shiogama

2 August

Vessel departs Shiogama

17 August

Vessel starts the survey in the researcharea

18 September

Vessel completes the survey in the research area

30 September

Vessel arrives in Shiogama

1 OctoberPost-cruise mee�ng in Shiogama

Table 2Speciﬁca�ons of the R/V Yushin-Maru No. 2 used in the 2021
IWC-POWER survey.
Call sign

JPPV

Length overall [m]69.61

Molded breadth [m]11.5Gross tonnage (GT)

747

Barrel height [m]19.5

IO barrel height [m]13.5

Upper bridge height [m]11.5

Bow height [m]6.5

Engine power [PS/kW]

5303/3900

Research area
The research area was between 40°00ʹN and US andCanadian EEZ boundaries, between 135°00ʹW and155°00ʹW, comprised en�rely of the high seas (Figure 1).
The areas between 150°00ʹW and 155°00ʹW, and between 135°00ʹW and 150°00ʹW were surveyed in the2011 and 2012 POWER surveys, respec�vely, althoughthe �ming of the surveys were diﬀerent from the 2021
POWER survey.
Research vessel and scien�ﬁc personnel
The R/V Yushin-Maru No. 2 was used for this survey. Thevessel is shown in Figure 2 and its speciﬁca�ons in Table 2.
Figure 1.

Figure 2.

Research area and survey track lines with start andend points for the 2021 IWC-POWER survey.

Photograph of the R/V Yushin-Maru No. 2 used inthe 2021 IWC-POWER survey.

I�nerary
The survey was conducted between 2 August and 30 September 2021 by the Japanese R/V Yushin-Maru No. 2. Thei�nerary is shown in Table 1.

Three interna�onal researchers were nominated by theIWC SC for this survey:
Hiroto Murase (Japan)—Cruise Leader (CL)/Chief Scien�stJames W. Gilpatrick, Jr. (US)—Photo-ID
Isamu Yoshimura (Japan)—sigh�ng data, marine debris
and biopsy sample management
Searching eﬀort
Survey trackline coverage in the research area was 77.2%(1,562.5 n.miles of a planned distance of 2,022.4 n.miles),with a total of 833.7 n.miles in Passing with abeam closing
mode (NSP) and 728.8 n.miles in Independent Observer
passing mode (IO). The eﬀort spent in sigh�ng and several experiments are shown in Table 3.
Summary of the sigh�ngs
During the survey in the research area, the followingsigh�ngs were made: blue (6 schools / 7 individuals), ﬁn(77/113), sei (23/37), Brydeʼs (20/22), sperm (14/14) andkiller (1/4) whales (Table 4). These data will be used toes�mate abundance of several species.
47

Technical Reports of the Ins�tute of Cetacean Research (2022)
Table 3
Summary of the searching eﬀort (�me and distance) and experimental �me (hours) in the survey area of the 2021 IWC-POWER survey.
LegNo.

Start

EndStart

DateDateEndTimeTime

Research Area (between150°W and 135°W)

101

17-Aug. 11-Sep.

121

12:43

Research Area (between155°W and 150°W)

121

11-Sep. 16-Sep.

127

14:27

NSP

IO

Photo-ID, Es�mated angle andBiopsy, TDR distance training/tagexperiment

NSP+IO

Area

14:27

13:54

TimeDist.
(n.m.)TimeDist.
(n.m.)

Dist.
(n.m.)

59:04:25624.30

52:33:36

552.83 111:38:01 1177.13 14:08:44

6:40:47

19:45:13

209.44

16:26:07

175.990:00:00

Time

36:11:20

Time385.43

Time

0:24:46

Table 4
Number of sigh�ngs for all species observed in the research area during the 2021 IWC-POWER survey (original track lines), by effort mode. NSP: Normal Passing with abeam closing mode; IO: Independent Observer mode, OE: Top down (TD) and dri�ing (DR).
Numbers of Individuals include the number of calves.
Species

NSP

IO

TotalSch.

Ind.

Calf

Sch.

Ind.

CalfSch.

Ind.

Calf

Sch.

Ind.

CalfBlue whale

230440000670Fin whale

3958137543110771134

Like ﬁn whale

000110000110Sei whale

14260810011023370

Like sei whale

120000000

120Brydeʼs whale

1113199000020221Sperm whale

990

55000014140Bairdʼs beaked whale

130000000

130Ziphiidae

120360000480

Killer whale

140000000140Striped dolphin

00017400001740Common dolphin

1842341080004494

10Paciﬁc white-sided dolphin

385311577000424210

Northern right whale dolphin

110740000001107

4Dalli type Dallʼs porpoise10550542000015970

Unid. type Dallʼs porpoise31102200005130

Unid. dolphin

21300000002130

Unid. small cetacean

110110000220

Unid. cetacean

220330000550Unid. large baleen whale

77056000012130

Geographical distribu�on by species
Blue whale (Balaenoptera musculus)
Blue whales were mainly distributed in the northern part48

OEof the research area (Figure 3). Sea surface temperaturesat the sigh�ng posi�ons were between 12.7°C and 13.6°C.

Results of the IWC-Pacific Ocean Whale and Ecosystem Research (IWC-POWER) dedicated sighting survey in 2021—An overview—

Figure 3.

The searching eﬀort (black line) and sigh�ng posi�ons (blue circles) of blue whales during the 2021
IWC-POWER survey.

Figure 6.

The searching eﬀort (black line) and sigh�ng posi�ons (green circles) of Brydeʼs whales during the2021 IWC-POWER survey.

Figure 4.

The searching eﬀort (black line) and sigh�ng posi�ons (red circles) of ﬁn whales during the 2021
IWC-POWER survey.

Figure 7.

The searching eﬀort (black line) and sigh�ng posi�ons of sperm and killer whales (brown circles
and black cross, respec�vely) during the 2021
IWC-POWER survey.

Fin whale (Balaenoptera physalus)
Fin whales were mainly distributed in the northern partof the research area (Figure 4). Sea surface temperaturesat the sigh�ng posi�ons were between 12.7°C and 19.7°C.
Sei whale (Balaenoptera borealis)
Sei whales were distributed in mid-la�tudes of the research area (Figure 5). Sea surface temperatures at thesigh�ng posi�ons were between 13.0°C and 16.1°C.

Figure 5.

The searching eﬀort (black line) and sigh�ng posi�ons (orange circles) of sei whales during the 2021
IWC-POWER survey.

Brydeʼs whale (Balaenoptera edeni brydei)
Brydeʼs whales were distributed in the southern part ofthe research area (Figure 6). Sea surface temperatures atthe sigh�ng posi�ons were between 17.4°C and 21.3°C.

49Technical Reports of the Ins�tute of Cetacean Research (2022)
Table 5
Summary of the Photo-ID experiments for each species conducted in the 2021 IWC-POWER research area.
Photo-IDBlueFinSei

BrydeʼsKiller

Total

703101502113058
11Between longitude 150°W and 135°W
Between longitude 155°W and 150°W

Table 6Summary of the number of species-speciﬁc biopsy samples collected in the 2021 IWC-POWER research area.
Biopsy samples

BlueFinSeiBrydeʼsKiller

Total

3090401110

181

Between longitude 150°W and 135°W
Between longitude 155°W and 150°W

Figure 8.

Researchers and crew of the 2021 IWC-POWER survey with the Yushin-Maru No. 2 in the background. The
picture was taken at the end of the cruise in Shiogama.

Sperm (Physeter macrocephalus) and killer whales(Orcinus Orca)
Sperm whales were widely distributed in the researcharea (Figure 7). Sea surface temperatures at the sigh�ng
posi�ons were between 12.7°C and 20.0°C. A total of 1
school (4 individuals) of killer whales was sighted in thenorthern part of the research area where the sea surface
temperature was 13.1°C.
Iden�ﬁca�on of duplicated sigh�ngs
Resight data were recorded for a total of 108 sigh�ngs
during IO Mode involving several baleen whale species.
These data will be used to es�mate g(0), which in turnwill be used to adjust abundance es�mates.
Photo-ID experiments
Photo-ID data were obtained for a total of 69 whales:
blue (7 individuals), ﬁn (31), sei (15) Brydeʼs (13) and killer(3) whales (Table 5). Images collected during the survey
were uploaded to the IWC master photographic databasein Adobe Lightroom (LR) (Anon, 2020). Photo-ID data will50

be used to study movement, distribu�on and stock structure of the species involved.
Biopsy sampling
Biopsy samples were collected using the Larsen sampling system from 19 individual whales: 3 blue, 9 ﬁn, 4sei, 2 Brydeʼs and 1 killer whales (Table 6). Every biopsy
sampling was documented photographically. All biopsy
samples were catalogued and stored in cryo-vials frozen
at a temperature of −30°C on the vessel. These samples
will be used for molecular gene�cs analyses on stock
iden�ﬁca�on.
Marine macro debris observa�on
During the survey, a total of 88 marine macro debris objects were observed. All items were recorded ʻon eﬀortʼ
(i.e. during the ﬁrst 15 minutes of each hour).
Feasibility experiment of dive behavior tagging
During the survey, satellite linked dive behavior tags wereexperimentally deployed as a feasibility study at the dis-Results of the IWC-Pacific Ocean Whale and Ecosystem Research (IWC-POWER) dedicated sighting survey in 2021—An overview—cre�on of Japan. The tags were a�ached to 2 ﬁn and 3 sei
whales and the data were obtained via satellite. Detailed
analysis will be conducted by Japanese scien�sts and theresults will be reported to relevant scien�ﬁc communi�es.

HIGHLIGHTS OF THE SURVEY
It is concluded that the 2021 IWC-POWER survey wascompleted successfully by a group of interna�onal scien�sts (Figure 8) and that valuable data were collected forseveral cetacean species. Such data will allow for studies
on distribu�on, abundance and stock structure of large
cetaceans in this par�cular area of the North Paciﬁc.
There are two aspects of this survey that should behighlighted. The ﬁrst aspect is a seasonal change in thedistribu�on of baleen whales. Although the 2021 POWER
survey area was covered by the 2011 and 2012 POWER
surveys, the survey �ming in 2021 was approximately
a month later than the previous two surveys. From theresults, it appeared that the distribu�on of baleen whales
has shi�ed northward. For instance, the Brydeʼs whale, atropical species, was sighted in the southern part of the2021 survey area while none was sighted in the previous
two surveys. Such a change will be inves�gated in futurestudies.
The second aspect is the success of the feasibility
experiment of dive behavior tagging. This was the ﬁrst
a�empt of this kind of experiment in the IWC-POWER
surveys. The obtained data could be used to correct availability bias in future abundance es�ma�on work.
Although the IWC-POWER survey within the Russian
EEZ has not been completed, it is an�cipated that theIWC-POWER program will move toward its second phase,
which will be designed a�er examining in details the results from the ﬁrst phase between 2010 and 2021.

ACKNOWLEDGEMENTS
I am grateful to the Governments of the United States(NOAA Fisheries) and Japan (Fisheries Agency of Japan)
for funding this cruise. I also acknowledge the Government of Japan for their assistance in arranging the research permit. I extend my thanks to Iain Staniland andthe Secretariat of the IWC for their support and funding
for this cruise. I appreciate the ongoing support by thePOWER Steering Group and the Technical Advisory Group(TAG). I thank Takashi Hakamada, Megumi Takahashi andMioko Taguchi from the Ins�tute of Cetacean Researchand the staﬀ of Kyodo Senpaku Co. Ltd. for making arrangements and suppor�ng the cruise. I also wish toexpress my gra�tude to the crew of the R/V Yushin-Maru
No.2 for their hard work and dedica�on. I thank theEditorial Team of TEREP-ICR for the editorial work on thismanuscript.

REFERENCESAnon. 2020. IWCʼs IDCR/SOWER and POWER cruise photographic database manual. 21 pp. [Available from the IWCSecretariat].
Interna�onal Whaling Commission. 2021. Report of theMee�ng of the IWC-POWER Technical Advisory Group(TAG) and 2021 Planning Mee�ng: November 2020. Paper
SC/68C/REP/01Rev01 presented to the IWC Scien�ﬁcCommi�ee, April–May 2021 (unpublished). 24 pp. [Availablefrom the IWC Secretariat].
Matsuoka, K. 2020. An outline of the IWC-Paciﬁc Ocean Whaleand Ecosystem Research (IWC-POWER) including resultsof the 2019 survey. Technical Reports of the Institute ofCetacean Research (TEREP-ICR) No. 4: 23–34.
Murase, H., Gilpatrick, J.W. Jr., Yoshimura, I. and Eguchi, H.
2022. Cruise report of the 2021 IWC-Paciﬁc Ocean Whale andEcosystem Research (IWC-POWER). Paper SC/68D/ASI/03
presented to the IWC Scien�ﬁc Commi�ee, May 2022 (unpublished). 34 pp. [Available from the IWC Secretariat].

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