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

pp. 47–54

Technical Report (not peer reviewed)

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

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

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

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

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

Figure 1.

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

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

Event

2022/08/01

Pre-cruise mee�ng at Shiogama

2022/08/02

Vessel departed Shiogama

2022/08/10

Vessel arrived at Dutch Harbor2022/08/15

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

Survey commenced in the research area

2022/09/13

Survey ﬁnished in the research area

2022/09/15

Vessel arrived at Dutch Harbor2022/09/18

Vessel departed Dutch Harbor2022/09/30

Vessel arrived at Shiogama

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

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

Figure 2.

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

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

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

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

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

JPPV

Length overall [m]69.61

Molded breadth [m]11.5Gross tonnage (GT)

747

Barrel height [m]19.5

IO barrel height [m]13.5

Upper bridge height [m]11.5

Bow height [m]6.5

Engine power [PS/kW]

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

5303/3900

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

Area

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

Leg No.

Start

End

Start

Date

Date

End

Time

Time

87

134

20-Aug. 5-Sep.

US EEZ

114

6:40

86

112

5-Sep. 13-Sep.

US EEZ

101

11:49

Area
Code

NSP

11:49

17:35

20-Aug. 13-Sep.

Total

6:40

17:35

IO

NSP+IOTime

Dist.
(n.m.)

TimeDist.
(n.m.)

TimeDist.
(n.m.)

25:09:19

287.4

23:05:16

265.2

48:14:35

552.6

17:32:14

203.8

13:46:41

160.9

31:18:55

364.7

42:41:33

491.2

36:51:57

426.1

79:33:30

917.3

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

NSP

IO

OE

Total

Sch.

Ind.

Calf

Sch.

Ind.

Calf

Sch.

Ind.

Calf

Sch.

Ind.

Calf

Blue whale

12

13

0

7

7

0

1

1

0

20

21

0

Fin whale

18

28

2

17

25

1

1

1

0

36

54

3

Sei whale

10

11

0

10

11

0

1

1

0

21

23

0

Common minke whale

2

2

0

1

1

0

0

0

0

3

3

0

Humpback whale

6

6

0

5

5

0

1

1

0

12

12

0

Sperm whale

22

22

0

14

14

0

2

2

0

38

38

0

Killer whale

3

15

0

10

47

1

1

1

0

14

63

1
49

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

Minimum SST

Maximum SST Temperature range

25th to 75th Quar�leBlue whale

20

6.8

10.8

4.0

7.9–10.1

Fin whale

36

5.4

11.2

5.8

8.7–9.6

Sei whale

21

9.3

12.0

2.7

10.0–11.6

Common minke whale

3

8.0

9.9

1.9

8.7–9.6

Humpback whale

12

6.5

12.0

5.5

7.2–9.3

Sperm whale

38

5.7

11.2

5.5

8.9–10.2

Killer whale

14

3.4

11.9

8.5

6.8–10.1aBlue whale

Figure 3a.

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

b

Fin whale

Figure 3b.

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

c

Sei whale

Figure 3c.

50

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

dCommon minke whale

Figure 3d.

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

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

Humpback whale

Figure 3e.

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

fg

Sperm whale

Killer whale

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

Figure 3g.

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

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

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

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

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

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

Duplicate Status

Number of all schoolssighted by TOP and IOP

Number of all schoolssighted by IOP

D

P

R

N

12
21
10
1
3
21
13

5
10
5
0
3
11
4

5
6
2
0
0
7
4

0
0
0
0
0
0
0

0
0
0
0
0
0
0

0
4
3
0
3
4
0

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

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

Fin whale

Sei whale

Humpback whale

Killer whale

Total

Research area
Transit

14
2

7
0

7
1

2
4

8
0

38
7

Total

16

7

8

6

8

45

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

Blue whale

Fin whale

Sei whale

Humpback whale

Total

Research area
Transit

4
0

4
0

5
1

2
0

15
1

Total

4

4

6

2

16

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

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

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

Number of days
with data obtained

type

n

dura�onmean (sec.)

SD

207833

4.6

Dive
Surfacing

573
570

83.48
60.60

144.57185.28Figure 4.

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

772
2728

768
2726

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

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

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

53

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

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

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54

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