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

pp. 22–33

Technical Report (not peer reviewed)

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

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

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

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

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

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

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

Figure 1.

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

Figure 2.

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

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

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

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

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

Figure 3.

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

Figure 4.

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

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

24

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

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

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

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

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

25

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

Date and �me

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

Es�mated angle anddistance training/
experiment

Start

End

Transit survey(Shiogama-Equator)

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

40 : 57 : 38——

02 : 54 : 49—

Transit survey(Equator-Research area)

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

519.7

45 : 42 : 44——

04 : 13 : 33—

Research area
(Area VIE 145°W-130°W)

2023/1/11
06 : 00

2023/2/1
12 : 15347.5

31 : 48 : 56342.7

31 : 36 : 47

16 : 27 : 28

05 : 27 : 16

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

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

09 : 31 : 03

122.9

12 : 00 : 45

01 : 38 : 25—

Transit survey(Research area-Equator)

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

60 : 53 : 25——

01 : 35 : 15—

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

2023/3/10
16 : 20305.9

25 : 33 : 15——

00 : 42 : 28—

2455.0214 : 27 : 01465.6

43 : 37 : 32

27 : 31 : 58

05 : 27 : 16

Vessel: YS3

Date and �me

IO

Photo-ID,
Biopsy,Satellite
tagexperiment

Survey Sec�ons

Total

NSP

Experiments �me (hours: minutes:
seconds)

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

Es�mated angle anddistance training/
experiment

Start

End

Transit survey(Shiogama-Equator)

2022/12/8
07 : 25

2022/12/16
14:00

436.3

36 : 25 : 34——

00 : 46 : 01—

Transit survey(Equator-Research area)

2022/12/16
14:01

2023/1/9
18:00

472.5

40 : 20 : 53——

01 : 20 : 18—

Research area
(Area VIE 145°W-130°W)

2023/1/10
06 : 00

2023/1/31
16 : 42499.7

46 : 11 : 38499.2

46 : 23 : 09

14 : 10 : 21

01 : 29 : 12

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

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

10 : 30 : 23

152.7

14 : 32 : 19

02 : 00 : 09

04 : 12 : 48

Transit survey(Research area-Equator)

2023/2/7
06 : 00

2023/3/2
15 : 20794.8

67 : 29 : 11——

03 : 01 : 48—

Transit survey(Equator-Shimonoseki)

2023/3/3
06 : 00

2023/3/10
16 : 50295.5

24 : 46 : 55——

00 : 00 : 00—

2,603.6

225 : 44 : 34651.9

60 : 55 : 28

21 : 18 : 37

05 : 42 : 00

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

26

IO

Photo-ID,
Biopsy,Satellite tag
experiment

Survey Sec�ons

Total

NSP

Experiments �me (hours: minutes:
seconds)

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

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

Northern stratum

Prim.

Prim.

Second.

Second.

Ind.

Sch.

Sub-total

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

Ind.

Prim.
Sch.

Second.

Sch.

Ind.

Sch.

Ind.

Sch.

Ind.

Sch.

Ind.

Antarc�c blue whale

2

2

0

0

17

27

1

2

0

0

0

0

Fin whale

0

0

0

0

50

117

9

20

0

0

0

0

Prim.
Sch.

Total

Second.

Ind.

Sch.

Ind.

Sch.

19

29

50

117

Ind.

1

2

20

31

9

20

59

137

Antarc�c minke whale

48

85

17

31

48

101

6

9

102

238

21

57

198

424

44

97

242

521

Like minke whale

3

3

1

10

2

3

1

1

8

8

2

3

13

14

4

14

17

28

Like Antarc�c minke whale

0

0

0

0

1

1

0

0

0

0

0

0

1

1

0

0

1

1

Humpback whale

0

0

0

0

20

36

1

10

0

0

0

0

20

36

1

10

21

46

Baleen whales

2

2

0

0

9

9

1

1

2

2

0

0

13

13

1

1

14

14

Sperm whale

1

1

0

0

6

6

0

0

0

0

0

0

7

7

0

0

7

7

Killer whale (Undetermined)

1

3

0

0

1

9

0

0

2

7

0

0

4

19

0

0

4

19

Killer whale (Type A)

0

0

0

0

1

8

0

0

0

0

0

0

1

8

0

0

1

8

Killer whale (Type B)

0

0

0

0

1

13

0

0

2

21

1

9

3

34

1

9

4

43

Killer whale (Type C)

0

0

0

0

0

0

0

0

2

47

0

0

2

47

0

0

2

47

Ziphiidae

0

0

0

0

1

2

0

0

0

0

0

0

1

2

0

0

1

2

Uniden�ﬁed whales

1

1

0

0

4

4

0

0

3

3

0

0

8

8

0

0

8

8

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

Figure 4.

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

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

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

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

Results and descrip�ons

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

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

Biopsy sampling

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

Satellite tagging

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

Oceanographic survey

137 XCTD casts

Marine debris observa�on

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

UAV

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

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

Figure 5a.

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

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

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

Figure 5b.

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

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

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

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

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

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

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

Photo 1.

Antarc�c blue whale.

Photo 3.

Photo 5.
32

Fin whale.

Humpback whale.

Photo 2.

Photo 4.

Antarc�c blue whale mother and calf.

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

Photo 6.

Killer whales (type A).

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

Photo 7.

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

Photo 9.

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

Photo 11.

Biopsy and satellite tagging experiments.

Photo 8.

Photo 10.

Naviga�ng within the pack-ice.

Buoy used in the angle and distance experiment.

Photo 12.

VTOL-UAV ASUKA takes oﬀ from the vessel.
33