SC/57/O3

Cruise Report of the Japanese Whale Research Program
under Special Permit in the western North Pacific -Phase II(JARPN II) in 2004 (part I) - Offshore component – <Draft>
TAMURA, T. 1), FUJISE, Y. 1), MOGOE, T. 1), KANDA, N. 1), YASUNAGA, G. 1), KONISHI, K. 1), KIWADA, H. 1), OGIHARA, M. 1),
HASEGAWA, A. 1), KITAJIMA, M. 1), SUGIYAMA, T. 1), SASAKI, T. 1), MORI, M. 1), TERAOKA, T. 1), TSUNEKAWA, M. 2),
FUKUTOME, K. 2), ZHARIKOV, K.A. 3), NA, JONG-HUN. 4), TOHYAMA D. 2), INAGAKE, D. 5) AND KAWAHARA, S. 5)
1) The Institute of Cetacean Research, 4-5, Toyomi-cho, Chuo-ku, Tokyo, 104-0055, Japan,2) Kyodo Senpaku Co. Ltd., 4-5, Toyomi-cho, Chuo-ku, Tokyo, 104-0055, Japan,
3) Marine Mammal Lab, VNIRO –Russian Federal Research Institute of Fisheries & Oceanography,17, V.
Krasnoselskaya, Moscow, 107140, RUSSIA,
4) Pukyong National University, Collage of Fisheries Science, Dept. Marine Production Management., 559-1, Daeyeon
3 dong Nam-gu Pusan, Korea.
5) National Research Institute of Far Seas Fisheries, 5-7-1, Shizuoka, 424-8633, Japan.
Contact e-mail: tamura@cetacean.jp

ABSTRACTThe full-scale survey of the second phase of the Japanese Whale Research Program under Special Permit in the North
Pacific (JARPN II) started in 2002. The objectives of the full-scale research are (1) to study on feeding ecology andecosystem studies, involving studies of prey consumption by cetaceans, prey preferences of cetaceans and ecosystemmodeling, (2) to monitor environmental pollutants, and (3) to study on stock structure. Target species are common
minke whale Balaenoptera acutorostrata, Bryde’s whale B. edeni, sei whale B. borealis and sperm whale Physeter
macrocephalus. The third cruise of the JARPN II survey -offshore component- was conducted from 15 June to 18
September 2004 in sub-areas 7, 8 and 9 of the western North Pacific. In the survey a total of six research vessels wereused: one trawl survey vessel equipped with scientific echo sounder (TSV), one dedicated sighting vessel (SV), threesighting/sampling vessels (SSVs) and one research base vessel. A total of 10.695.0n.miles was surveyed for whale
searching in a period of 96 days. During that period 119 common minke, 180 Bryde’s, 385 sei and 523 sperm whales
were sighted by the SSVs. A total of 100 common minke, 100 sei, 50 Bryde’s and 3 sperm whales was sampled by the
SSVs. The cooperative survey on ecosystem research with the participation of six vessels was conducted in a part of
sub-area 9 from 15 to 17 September. All whales sampled were examined on board the research base vessel. Common
minke whales fed mainly on Pacific saury (Cololabis saira), Minimal armhook squid (Berryteuthis anonychus) andJapanese anchovy (Engraulis japonicus). Bryde’s whales fed mainly on Japanese anchovy and Chub mackerel(Scomber japonicus). Sei whales fed mainly on Japanese anchovy, copepods and Pacific saury. Dominant preys in thestomach of three sperm whales were various kinds of squids, which inhabit the mid- and deep-waters.
KEYWORDS: COMMON MINKE WHALE; BRYDE’S WHALE; SEI WHALE; SPERM WHALE; NORTHPACIFIC OCEAN; DISTRIBUTION; FOOD/PREY; ECOSYSTEM; SCIENTIFIC PERMITSINTRODUCTION
Feasibility study of the second phase of the Japanese Whale Research Program under Special Permit in the North
Pacific (JARPN II) was conducted in 2000 and 2001 (Government of Japan, 2000). A two year results were presented to
the 2002 SC meeting (Government of Japan, 2002a). Based on these results of the feasibility study, Japan presented theresearch plan for the full-scale JARPN II (Government of Japan, 2002b) to the 2002 SC meeting.
The full-scale study was aimed at i) feeding ecology and ecosystem, ii) monitoring of environmental pollutants incetaceans and the marine ecosystem and iii) to elucidate the stock structure (Government of Japan, 2002b).
The full-scale JARPN II plan involved two survey components: the ‘offshore’ survey was covered by the Nisshin Maru
research unit and the ‘coastal’ survey was covered by catcher boats of small type whaling. The coastal component wasnecessary to cover the temporal and spatial gaps, which could not be covered by the Nisshin Maru unit (Government ofJapan, 2002b).

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The research area was set in sub-areas 7, 8 and 9, and the target species and sample sizes in 2004 were set as follows:
160 common minke whales Balaenoptera acutorostrata (100 were to be sampled by the offshore survey and 60 - by thecoastal survey); 100 sei whales B. borealis (offshore survey), 50 Bryde’s whales B. edeni (offshore survey) and 10
sperm whales Physeter macrocephalus (offshore survey) (Government of Japan, 2004a, 2004b).
In this paper, we present an outline of offshore component in the third full scale survey of the JARPN II -offshore
component-, which was conducted from 15 June to 18 September 2004.

MATERIALS AND METHODS
Research area
Sub-areas 7, 8 and 9, excluding the EEZ zones of foreign countries, were research area (Fig. 1). These sub areas were
further divided as follows:
Sub-area 7:

Five small blocks (7N, 7MI, 7MO, 7SI, 7SO stratified for taking into account satellite information onwater temperature.

Sub-area 8, 9: Four small blocks (8N, 8S, 9N and 9S) were divided at 40ºN.
In the case of the cooperative survey, a special block was predetermined in the survey areas. One special block (SB)was settled in offshore area as shown in Fig. 1. We conducted the whale and prey surveys in the SB concurrently.
Research vessels
Six research vessels were used.
The research base vessel Nisshin Maru (NM: 7,659GT) commanded the research and was engaged in the biologicalexamination of whale samples and of by-products. The Yushin Maru (YS1: 720GT), Yushin Maru No.2 (YS2: 747GT)
and Kyo Maru No.1 (K01: 812.08G) were used as the sighting/sampling vessels (SSVs), which conducted sighting
activities, sampling of targeted whale species and various experiments and observations. The Kyoshin Maru No. 2(KS2: 372GT) was used as dedicated sighting vessel (SV). The Shunyo Maru (SYO: 887GT) was engaged in trawl
surveys and echo sounder surveys. This vessel also conducted the mid-water trawl net and MOCNESS net sampling.
Furthermore, this vessel conducted the oceanographic observations using CTD.
Survey components
The survey was composed of three main components: whale survey, sighting survey and the cooperative survey.
Whale survey
Vessels: Four research vessels (NM, YS1, YS2 and K01)
Research area: Sub-areas 7, 8 and 9. In addition, a ‘special monitoring survey’ (SMS) was settled in an area where thenumber of common minke, Bryde’s and sei whales were expected to be large.
Research period (Table 1):
First period:

Between 15 June and 10 August.

Second period:

Between 11 August and 4 September.

Third period:

Between 15 and 12 September.

Forth period:

18 September

Dedicating Sighting survey (Table 1)
Vessels: One research vessel (KS2)
Research area: Sub-areas 7, 8 and 9
Research period:
Entire period:

Between 14 May and 5 September.

Cooperative survey on the prey species and whale sampling (Table 1)
Vessels: Five research vessels (NM, YS1, YS2, K01 and SYO)
Research area: In the cooperative survey on ecosystem research, one special block (A) was settled.
Reseach period:2

First period (A): Between 5 September and 8 September for the A (offshore-block).

Methods for setting cruise track line for the whale survey
Track lines and allocation of vessels were made as in previous JARPN and JARPN II surveys (Fujise et al., 1995, 1996,
1997, 2000, 2001, 2002; 2003, Ishikawa et al., 1997, Zenitani et al., 1999, Tamura et al., 2004). The zigzag-shaped
track line was established on an arbitrary basis in each sub-area and month, taking into consideration previous sighting
information of target whales and sea conditions.
Furthermore, some ‘special monitoring survey’ (SMS) were conducted in areas where the abundance of common minke
whales, Bryde’s and sei whales were expected to be large. Track line in the SMS was designed separately from theoriginal track line. Three SSVs were allocated to these tracks with the allocation being changed every day.
The track line of the prey survey vessel in the cooperative survey was determined in the following manner. The zigzagshaped track line was set independent of whale survey. If the SYO detected the existence of the prey species by
response of echo sounder, the SYO conducted the trawl survey and/or MOCNESS survey for the target depth to identify
these prey species, at the same time. The whale research fleet surveyed in the following manner: the research course
consisted of one main track and two parallel tracks established in six n.miles apart from both sides.
Apart from these sampling activities, an independent track line for dedicated sighting survey was determined in the
research area. The track lines were determined randomly.
Sighting surveys
Sighting procedure both for the whale survey and dedicating sighting survey was similar to the previous surveys of
JARPN and JARPN II (Fujise et al., 1995, 1996, 1997, 2000, 2001, 2002; 2003, Ishikawa et al., 1997; Zenitani et al.,1999, Tamura et al., 2004). In the research area sighting was conducted mainly under closing mode. Furthermore twomodalities of sighting in closing mode were adopted, NSC and NSS modes, by taking into consideration weather and sea
conditions mainly. The NSC and NSS modes were the same as BC and BS modes in the previous JARPN surveys,
respectively. The conditions to conduct surveys under NSC mode were similar to those established in Japanese sighting
surveys conducted by the National Research Institute of Far Seas Fisheries (i.e. visibility of 2 n.miles or more and windforce of 4 or below). The NSS mode was used under more critical weather conditions but under this condition thecollection of whale samples was possible. This NSS mode was used only by SSV vessels. These two mode surveys wererecorded separately for future analysis. Also an ASP mode was used (closing mode survey without sampling activities
under normal sighting conditions).
During the transit from homeport (HP) to research area (RA) and from RA to HP, the NSP mode was adopted (passing
mode without sampling activities under normal sighting conditions).
Closing was performed mainly on sightings of common minke, Bryde’s, sei and sperm whales. Furthermore it wasplanned to use closing was made on sightings of large whales, such as blue, humpback, right and fin whales. In thesecases, closing was done in order to confirm species and school size and in order to conduct some experiments.
Sampling of common minke, Bryde’s, Sei and sperm whales
Most of the target whale species sighted on the trackline were approached for sampling. Furthermore sampling effort
was applied outside the established research hours (SSV: 06:00-19:00, SV: 06:00-18:00), if collection of whale samples
was considered as possible.
For schools consisting of two or more animals, numbering was made for all the whales in the school; to set samplingorder randomly in accordance with the table of random numbers (Kato et al., 1989). Cow and calf pairs were nottargeted for sampling.
Sampled whales were immediately transported to a research base vessel, where biological measurements and sampling
were carried out.
Prey species survey
Detailed report on this activity is shown in Appendix I.
A quantitative echo sounder (Simrad EK60 with program version 1.4.3.64) was used on board SYO to acquire acoustic
data with operating frequency at 38, 70 and 120 kHz. Those data were collected as the reference information for
qualitative analysis. Calibrations were carried out at Kushiro (23 September 2004) using the copper sphere techniquedescribed in EK 60 online help manual.
The mid-water trawl net was 86.3 m long with a mouth opening of ca. 900 m2 and a 6.0 m cod end with a 17.5 x 17.5mm mesh. Surface and mid-water trawl was towed at acoustic identified stations. Trawls were conducted for 0.5 hour toidentify the species compositions of biological backscattering detected by the quantitative echo sounder. Routine trawls
were conducted at predetermined stations in each block in daytime and nighttime. The purpose of the routine trawls was3to estimate the abundance and distribution patterns of cephalopods and neustonic organisms such as Pacific saury(Cololabis saira) that are difficult to detect by the echo sounder. Three different depth layers were sampled at routine
trawl stations; 0-30m (surface) 30-60m and 60-100m (mid-water). Nighttime routine trawls were conducted twice toexamine day-night difference of prey species composition. All samples were identified to the species as much as
possible and wet weight of each species was measured aboard the ship. For the major species, length and weight of 100
individuals were measured to examine their size composition. A part of samples were frozen at –30°C for further
analysis in the laboratory.
MOCNESS was used to collect zooplankton such as copepods and krill. This net with a mouth opening of ca. 1 m2
with a 0.33 x 0.33 mm mesh can take some samples in each depth layer and estimate the quantitative value. Eightdifferent depth layer were sampled at routine trawl stations; 0-20m, 20-40m, 40-60m, 60-80m, 80-100m, 100-150m,
150-200m and 200-250m. Target net samples were conducted to identify the species compositions of biologicalbackscattering detected by the quantitative echo sounder. The depth layer was sampled at target net stations; 0-300m.
Experiments
The following experiments and observations were conducted on board the sighting/sampling vessels:
1. Sighting distance and angle experiments to examine the precision of sighting data (YS1, YS2 and K01).
2. Biopsy sampling on blue, fin, humpback, right, Bryde’s, common minke, sei and sperm whales.
3. Photographic records of natural marks in blue, humpback and right whales.
4. Preliminary examination of attachment of data logger to Bryde’s whales.
5. Feeding behaviour patterns of large whale species (blue, fin, sei, Bryde’s, common minke, humpback, right andsperm whales).
6. Oceanographic observations using EPCS (Electric particle counting and sizing system)(YS2).
On board the SV, the following experiments and observations were conducted:
1. Sighting distance and angle experiment to examine the precision of sighting data.
2. Biopsy sampling on blue, fin, humpback, right, Bryde’s, common minke, sei, grey and sperm whales.
3. Photographic records of natural marks in blue, humpback, grey and right whales.
4. Feeding behaviour patterns of large whales.
5. Oceanographic observations using EPCS (Electric particle counting and sizing system).
6. Oceanographic observations using CTD.
On board the prey survey vessel (SYO), the following experiments were conducted:
1. Estimate abundance of prey species of common minke and other large whale species using an echo sounder system.
2. Oceanographic observations using CTD.
Observations of marine debris in the research area were conducted from the wheelhouse of the research base vessel(NM) (mainly during transit cruises). Marine debris were also investigated in the stomach contents of common minke,
Bryde’s, sei and sperm whales sampled. Experiments on killing method were conducted onboard of both the researchbase vessel and the SSVs.

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RESULTS AND DISCUSSIONS
Searching distance
Track line covered by the three sighting/sampling vessels (SSVs) is shown in Figs 2 and 3. The total searching distancefor SSVs was 10,695.4 n.miles (Table 2).
In the cooperative survey on ecosystem research, the survey was conducted from 5 to 8 September. Under thecooperative survey, searching distance for SSVs was 141.7 n.miles (Table 2).
Track line covered by the dedicated sighting vessel (SV) is shown in Fig 4. The total searching distance was 3,943.8
n.miles, respectively (Table 2).
Sightings of common minke, Bryde’s, sei and sperm whales
Sighting and sampling vessels (SSVs)
A total of 119 schools (119 individuals) of common minke whales was sighted, consisting of 71 schools (71individuals) of primary and 48 schools (48 individuals) of secondary sightings. For sei whale, 257 schools (385individuals) were sighted, consisting of 134 schools (181 individuals) of primary sightings and 123 schools (204individuals) of secondary sightings. For Bryde’s whale, 130 schools (180 individuals) were sighted, consisting of 96
schools (127 individuals) of primary sightings and 34 schools (53 individuals) of secondary sightings. For sperm whale,
292 schools (523 individuals) were observed, consisting of 234 schools (410 individuals) of primary sightings and 58
schools (113 individuals) of secondary sightings (Table 3).
Fig 5 shows the distribution of common minke whales sighted by the SSVs in the sub-areas 7, 8 and 9. Figs.6 and 7
show the distribution of Bryde’s and sei whales. Common minke whales were usually sighted in northern part of subareas 7, 8 and 9, but Bryde’s whales were sighted mainly in southern part of sub-areas 8 and 9. Sei whales were sighted
mainly in offshore of sub-areas 8 and 9. In the sub-areas 8 and 9, some segregation was observed between sei and
Bryde’s whales. Fig. 8 shows the distribution of sperm whale sightings in sub-areas 8 and 9. This species was widelydistributed in sub-areas 8 and 9.
Dedicated sighting vessel (SV)During the research cruise, 29 schools (33 individuals) of common minke whales were sighted, consisting of 29 schools(33 individuals) of primary sightings. For sei whale, 53 schools (80 individuals) were sighted, consisting of 51 schools(77 individuals) of primary sightings and 2 schools (3 individuals) of secondary sightings. For Bryde’s whale, 35
schools (44 individuals) were sighted, consisting of 35 schools (44 individuals) of primary sightings. For sperm whale,
102 schools (239 individuals) were sighted, consisting of 91 schools (207 individuals) of primary sightings and 11
schools (32 individuals) of secondary sightings (Table 4).
Sightings of other large cetacean species
Sighting and sampling vessels (SSVs)
Table 3 shows the number of sightings for other cetacean species made by the SSVs, including large baleen whales suchas blue (61 schs./91 inds.), fin (104 schs./174 inds.) and right whales (2 schs./4 inds.) (Figs. 9, 10 and 11).
Dedicated sighting vessel (SV)
Large baleen whales such as blue (4 schs. /7 inds.), fin (12 schs. /16 inds.) and humpback whales (8 schs. /9 inds.) were
found in the sub-areas 7, 8 and 9 (Table 4).
Sampling of common minke, Bryde’s, sei and sperm whales
Table 5 shows the number of whales sampled in each sub-area or special block for each research component and period.
A total of 100 common minke whales (Male: 90 individuals, Female: 10 individuals) were sampled, 84 during thewhale survey component and 16 during the cooperative survey component. A total of 100 sei whales (Male: 47
individuals, Female: 53 individuals) were sampled, 86 during the whale survey component and 14 during thecooperative survey component. A total of 50 Bryde’s whales (Male: 19 individuals, Female: 31 individuals) were
sampled during the whale survey component. A total of three female sperm whales were sampled during the whale
survey component.
Geographical distribution of common minke, Bryde’s and sei whale samples are shown in Figs 4-6 based on thesighting positions. Fig. 7 shows the distribution of sperm whale samples based on the sighting positions. One Bryde’s
whale was struck but lost due to technical failure.

5Biological research for common minke, Bryde’s and sei whales
Table 6 summarizes the biological data and samples obtained from the common minke, Bryde’s, sei and sperm whales
sampled. A total of 55 research items were covered. These items are related to the studies conducted under the threemain objectives of the JARPN II: study on feeding ecology of whales and marine ecosystem, pollution studies andelucidation of stock structure.
Composition of sex and sexual maturity of common minke, Bryde’s, and sei whales is shown in Tables 7, 8 and 9. The
rate of mature males in common minke was higher than in Bryde’s and sei whales.
Preliminary analyses of biological data and experiments
Body length of sampled whales
The statistics of body length of common minke whales are shown in Table 10. Mean body length of common minke
whales is 7.45 m and 7.66 m for males and females, respectively. Mean body length of males and females tended to behigher in the sub-area 9 than those in sub-area 7. For Bryde’s whales, the statistics of body length are shown in Table 11.
Mean body length of Bryde’s whales is 11.93 m and 12.68 m for males and females, respectively. For sei whales, thestatistics of body length are shown in Table 12. Mean body length of sei whales is 13.22 m and 13.83 m for males andfemales, respectively. For sperm whale, mean body length and weight are 10.06 m and 15.13 tons.
Distribution and food habit
During summer (from July to September) in offshore area, common minke whales fed mainly on Pacific saury, and theyalso fed on Japanese pomfret, chum salmon and minimal armhook squid. On the other hand, the common minke whales
fed mainly on Japanese anchovy and Japanese common squid in coastal area. The geographical changes of the preyspecies of the common minke whales seem to reflect changes in the distribution of prey species in feeding areas. The
common minke whales seem to be opportunistic feeders with a broad diet and with flexible feeding habits in the
research area (Table 13).
In June, Bryde’s whales distributed in the southern part of research area. They fed mainly on Japanese anchovy andchub mackerel. In previous research, they fed mainly on krill in June, after then, they fed mainly on Japanese anchovy.
There are yearly changes of their prey species (Table 13).
Sei whales distributed widely in the research area. From June to July, they fed mainly on Japanese anchovy and chubmackerel in the southern part of research area (south of 40O N), they fed mainly on copepods, Japanese anchovy andPacific saury in the northern part of research area (north of 40O N) from August to September. The sei whales seem tobe opportunistic feeders with a broad diet and with flexible feeding habits in the research area. There are geographicaland seasonal changes of their prey species (Table 13).
Sperm whales distributed widely in the research area. They fed mainly on deep sea squids in offshore area (sub area 9).
Condition of concurrent survey
In this season, the cooperative survey was conducted on one survey block. The survey area was settled in the offshore
area (Fig. 1). During the period, a total of 14 sei whale samples were collected by the SSVs in this period. Informationon the prey species distribution was also collected by SYO during this period (See Appendix 1).
Experiments, prey surveys and oceanographic surveys
Biopsy sampling trial for blue, humpback, right, fin, Bryde’s and sei whales
Table 14 shows the result of biopsy skin sampling for blue, humpback, right, fin, and Bryde’s whales. A total of 22 blue,
9 humpback, 2 right and 1 Bryde’s were targeted for biopsy sampling by the SVs and SSVs. As a result, three blue, four
humpback and two right whale’s biopsy skin samples were collected.
Natural marks (photo ID) for blue, humpback and right whales
Table 15 shows the result of the photo-ID experiments on blue, humpback, and right whales. A total of 32 blue, 17
humpback and 4 right whales were targeted by the SVs and SSVs. A total of 21, 11 and 2 trials were conducted forthese species whales, respectively.
Feeding behaviour for large baleen whales
The SV and SSVs had a plan to conduct recording the feeding behaviour of large baleen whales using a video recorder.
However, we did not have a chance to record the feeding behaviour of large baleen whales in this year.
Prey species survey
Echo sounder survey was conducted on SYO and they operated to cover the planned track lines. Surface routine trawls
were towed at 6 stations. MOCNESS was towed at 3 stations. The details of the prey species survey conducted by SYO
are described in Appendix 1.
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CTD
CTD casts were made at 29 stations by KS2. In the KS2, CTD (Model SBE 19) casts were conducted down to 500m at
each sampling station to measure the temperature and salinity profiles in the study area by KS2. CTD casts were madeat some stations by SYO. In the SYO, CTD (Model SBE 9, Seabird Co.) casts were conducted down to 500m at eachsampling station to measure the temperature and salinity profiles in the study area by SYO. The details of theoceanographic observations are reported in Appendix 2 of this document.
By-products of whales
After biological measurements and sampling were completed, all the whales were processed according to theInternational Convention for the regulation of whaling, Article VIII. Total production including red meat and blubberfrom 100 sampled common minke, 100 sei, 50 Bryde’s and 3 sperm whales was 321 tons, 1,276 tons, 508 tons and 10
tons, respectively.
Participation by foreign scientists
In 2004 JARPNII, two foreign scientists participated. They joined our sighting and sampling survey on board. It is
expected that these international collaboration will continue in future.

ACKNOWLEDGMENTS
The authors are greatly indebted to Mr. Joji Morishita, the Fisheries Agency of Japan, Dr. Hidehiro Kato, National
Research Institute of Far Seas Fisheries (NRIFSF), and Dr. Hiroshi Hatanaka and Dr. Seiji Ohsumi, The Institute of
Cetacean Research (ICR) for their guidance in the design and implementation of the research. We thank all crew of theresearch vessels (NM, YS1, YS2, K01, KS2 and SYO) and the staff of the ICR, NRIFSF, and Kyodo-Senpaku Co. Ltd.
The present research project (JARPN II) was funded under the subsidy of the Ministry of Agriculture, Forestry and
Fisheries, Government of Japan.

REFERENCES
Fujise, Y., Kishiro, T., Zenitani, R., Matsuoka, K., Kawasaki, M. and Shimamoto, K. 1995. Cruise report of the Japanese whale research program
under a special permit for North Pacific minke whales in 1994. Paper SC/47/NP3 presented to the IWC Scientific Committee, May 1995
(unpublished). 29pp.
Fujise, Y., Iwasaki, T., Zenitani, R., Araki, J., Matsuoka, K., Tamura, T., Aono, S., Yoshida, T., Hidaka, H., Nibe, T. and Tohyama, D. 1996. Cruise
report of the Japanese whale research program under a special permit for North Pacific minke whales in 1995 with the results of a preliminary
analysis of data collected. Paper SC/48/Np13 presented to the IWC Scientific Committee, June 1996 (unpublished). 39pp.
Fujise, Y., Shimada, H., Zenitani, R., Goto, M., Tamura, T., Lindstrøm, U., Uchida, A., Yoshida, H., Shimamoto, K., Yuzu, S., Kasai, H., Kinoshita,T., Iwata, T. and Tohyama, D. 1997. Cruise report of the Japanese Whale Research Program under a Special Permit in the North Pacific (JARPN) in
1996 with some preliminary analysis of data collected during the 1994-1996 JARPN surveys. Paper SC/49/NP8 presented to the IWC ScientificCommittee, September 1997 (unpublished). 38pp.
Fujise, Y., Zenitani, R., Tamura, T., Bando, T., Ohtani, S., Takeda, S., Kitajima, A., Kimura, T., Masaki, T. and Tohyama, D. 2000. Cruise report of
the Japanese whale research program under special permit in the North Pacific (JARPN) in 1999. Paper SC/F2K/J9 presented to the JARPN review
meeting, February 2000 (unpublished). 32pp.
Fujise, Y., Pastene, L.A, Tamura, T., Bando, T., Murase, H., Kawahara, S., Watanabe, H., Ohizumi, H., Mogoe, T., Kiwada, H., Nemoto, K. andNarita, H. 2001. Progress Report of the Feasibility study of the Japanese whale research program under special permit in the western North PacificPhase II (JARPN II) in 2000. Paper SC/53/O10 presented to the IWC Scientific Committee, July 2001 (unpublished). 77pp.
Fujise, Y., Tamura, T., Bando, T., Hikaru Watanabe, Hiroshi Kiwada, Otani, S., Kanda, N., Yasunaga, G., Mogoe, T., Konishi, K., Inamori, M.,
Shigemune, H. and Tohyama, D. 2002. Cruise report of the feasibility study of the Japanese whale research program under special permit in thewestern North Pacific – Phase II (JARPNII) in 2001. Paper SC/54/O16 presented to the IWC Scientific Committee, May 2002 (unpublished). 51pp.
Fujise, Y., Tamura, T., Bando, T., Yasunaga, G., Konishi, K., Murase, H., Yoshida, T., Itoh, S. Ogawa, R., Oka, T., Sasaki, T., Fukutome, K., Isoda,T., Birukawa, N., Horii, N., Zharikov, K.A., Park, K.J., Tohyama, D. and Kawahara, S. 2003. Cruise report of the Japanese whale research program
under special permit in the western North Pacific – Phase II (JARPNII) in 2002 (Part I). Paper SC/55/O7 presented to the IWC Scientific Committee,
May 2003 (unpublished). 41pp.
Government of Japan. 2000. Research Plan for Cetacean Studies in the Western North Pacific under Special Permit (JARPN II) (Feasibility Study
Plan for 2000 and 2001). Paper SC/52/01 presented to the IWC Scientific meeting, 68pp.
Government of Japan. 2002a. Report of the 2000 and 2001 feasibility study of the Japanese whale research program under special permit in thewestern North Pacific-phase II (JARPN II). Paper SC/54/O17 presented to the IWC Scientific Committee, May 2002 (unpublished). 202pp.
Government of Japan. 2002b. Research Plan for Cetacean Studies in the Western North Pacific under Special Permit (JARPN II) Paper SC/54/O2
presented to the IWC Scientific Committee, May 2002 (unpublished). 115pp.

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Government of Japan. 2004a. Revised research plan for cetacean studies in the western North Pacific under special permit (JARPN II). Paper
SC/56/O1 presented to the IWC Scientific Committee, May 2004 (unpublished). 14pp.
Government of Japan. 2004b. Some considerations of the feasibility components of the JARPN II research plan. Paper SC/56/O2 presented to the
IWC Scientific Committee, May 2004 (unpublished). 36pp
Ishikawa, H., Yuzu, S., Shimamoto, K., Bando, T., Ohshima, K., Kasai, H., Kinoshita, T., Mizushima, Y., Iwakami, H., Nibe, T., Hosoyama, T.,
Kuramochi, T., Numano, K. and Miyamoto, M. 1997. Cruise report of the Japanese Whale Research Program under a Special Permit in the North
Pacific (JARPN) in 1997. Paper SC/49/NP9 presented to the IWC Scientific Committee, September 1997 (unpublished). 28pp.
Kato, H., Hiroyama, H., Fujise, Y. and Ono, K. 1989. Preliminary report of the 1987/88 Japanese feasibility study of the special permit proposal forSouthern Hemisphere minke whales. Report of the International Whaling Commission, 39: 235-248.
Tamura, T., Fujise, Y., Bando, T., Yasunaga, G., Konishi, K., Kiwada, H., Isoda, T., Itoh, S. Machida, S., Tsunekawa, M., Konagai, T., Takamatsu, T.,
Ohshima, T., Honjo, K., Matsuoka, T., Zharikov, K.A., Yong, Rock AN, Tohyama, D. and Kawahara, S. 2004. Cruise Report of the Japanese Whale
Research Program under Special Permit in the western North Pacific -Phase II (JARPN II) in 2003 (part I) - Offshore component –. Paper
SC/56/O13 presented to the IWC Scientific Committee, June 2004 (unpublished). 46pp.
Zenitani, R., Fujise, Y., Matsuoka, K., Tamura, T., Bando, T., Ichihashi, H., Shimokawa, T., Krasnenko, A.S., Taguchi F., Kinoshita, T., Mori, M.,
Watanabe, M., Ichinomiya, D., Nakamura, M., Sakai, K., Matsuzaka, K., Kamei, H. and Tohyama, D. 1999. Cruise report of the Japanese Whale
Research Program under a Special Permit in the North Pacific in 1998. Paper SC/51/RMP7 presented to the IWC Scientific Committee, May 1999
(unpublished). 20pp.

8

Table 1. Outline of 2004 JARPN II survey

・ Whale sampling survey
Research
periods
June 15-August 10
June 15-18
June 19-July 18
July 19-20
July 21-August 10

Days
57
4
30
2
21

Subarea
8, 9
8
9
8
9

Whale survey (Second period)

August 11-September 425

9NM, YS1, YS2 and K01

Cooperative survey (SB-A)

September 5-8

4

9

NM, YS1, YS2, K01 and SHU

Whale survey (Third period)

September 9-12

4

9NM, YS1, YS2 and K01

TransitSeptember 13-14

2

8

NM, YS1, YS2 and K01

Whale survey (Forth period)

September 15-18

4

7June 15-September 18

96

7, 8, 9Days

Subarea
7, 8, 9Research
Whale survey (First period)

Total

Small Research ships and remark
block
NM, YS1, YS2 and K01

7N, 7MO NM, YS1, YS2, K01 and SHU

NM, YS1, YS2, K01 and SHU・ Sighting survey by Kyoshin Maru No.2
Research
Dedicated sighting survey

Research
periods
May 14-September 5

115

Small
block

Remarks

Research base ship: Nisshin Maru (NM)
Sighting and Sampling vessels (SSVs) : Yushin Maru (YS1), Yushin Maru No.2 (YS2) and Kyo Maru No.1 (K01)
Sighting vessel (SV) : Kyoshin Maru No.2 (KS2)Prey species survey vessel : Shunyo Maru (SHU)

9

Table 2. Searching distances made by the three sighting/sampling vessels (YS2, YS1 and K01) and sighting vessels
(KS2)

SSVs
Sub-area

PeriodWhale survey (first period)

8, 9
8
9
8
9

June 15-August 10
June 15-18
June 19-July 18
July 19-21
July 21-August 10

Whale survey (Second period)

9

August 11-September 4

1,677.7

29.8

601.7

2,309.2

Cooperative survey (SB-A)

9

September 5-8

100.9

0.0

40.8

141.7

Whale survey (Third period)

9

September 9-12

600.3

48.1

92.0

740.4

Transit8

September 13-14

0.0

239.9

0.0

239.9

Whale survey (Forth period)

7

September 15-18

494.6

0.0

78.2

572.8

7, 8, 9June 15-September 18

7,885.2613.7

2,196.5

10,695.4

Sub-area

Period7,8,9
7

May 14 - Aug. 23
May 14 - May 29
May 30 - June 8June 10 - June 16
June 22 - June 30
June 30 - July 2
July 7 - July 8
July 18 - July 31
Aug. 2 - Aug. 23

Total

Searching distance (n.miles）
NSC
ASP
NSS
Combined
5,011.7295.9
1,383.8
6,691.4
202.1
39.0
0.0
241.1
2,540.6202.8
494.6
3,238.0
319.7
0.0
199.3
519.0
1,949.3
54.1
689.9
2,693.3

SV (KS2)

Dedicated sighting survey

8
9Transit

Combined

Searching distance (n.miles）
ASP
3,840.3
637.8
743.6
462.4
454.9
100.8
92.6
771.4
576.8

June 16 - June 21
July 3 - July 7
July 9 - July 17
July 31 - Aug. 1
Aug. 23 - Aug. 29
Aug. 30 - Sept. 5

103.5
0.0
0.0
0.0
0.0
0.0
103.5

May 14-Sept. 5

3,943.8

10

Table 4. List of cetacean species and number of sightings (no. schools/no. individuals) made by three sighting/sampling
vessels
Cetacean species

NSC
SecondarySch. Ind.

PrimarySch. Ind.

PrimarySch. Ind.

NSS
SecondarySch. Ind.

PrimarySch. Ind.

ASP
SecondarySch. Ind.

OE
SecondarySch. Ind.

Total
SecondarySch. Ind.

PrimarySch. Ind.

Total
Sch. Ind.

Common minke whale

57

57

35

35

14

14

6

6

0

0

0

0

7

7

71

71

48

48

119

Like minke whale

1

1

4

4

0

0

0

0

0

0

0

0

6

6

1

1

10

10

11

119
11

Sei whale

98

137

92

156

33

40

23

31

3

4

1

1

7

16

134

181

123

204

257

385

Bryde's whale

52

71

30

44

6

8

0

0

38

48

4

9

0

0

96

127

34

53

130

180

Sperm whale

187

312

42

77

32

33

7

21

15

65

3

3

6

12

234

410

58

113

292

523

Blue whale

47

70

7

11

2

2

1

2

0

0

2

3

2

3

49

72

12

19

61

91

Fin whale

71

119

18

33

6

8

3

4

1

1

0

0

5

9

78

128

26

46

104

174

Humpback whale

42

56

15

21

0

0

0

0

0

0

1

1

5

9

42

56

21

31

63

87

Right whale

2

4

0

0

0

0

0

0

0

0

0

0

0

0

2

4

0

0

2

4

Table 4. List of cetacean species and number of sightings (no. schools/no. individuals) made by dedicated sighting
vessel (KS2)

Cetacean species
Common minke whale

ASP
Primary
SecondarySch. Ind.
Sch. Ind.
29
33
0
0

OE
SecondarySch. Ind.
0
0

Total
SecondarySch. Ind.
00PrimarySch. Ind.
29
33

Total
Sch. Ind.
29
33

Sei whale

51

77

0

0

2

3

51

77

2

3

53

80

Bryde's whale

35

44

0

0

0

0

35

44

0

0

35

44

Sperm whale

91

207

8

27

3

5

91

207

11

32

102

239

Blue whale

4

7

0

0

0

0

4

7

0

0

4

7

Fin whale

12

16

0

0

0

0

12

16

0

0

12

16

Humpback whale

7

8

1

1

0

0

7

8

1

1

8

9

Table 5. Summary of whale sampling
Research type

Whale samples
Sei
Bryde's
49
44
2
12
44
32
0
0
3
0

Research
periods
June 15-August 10
June 15-18
June 19-July 18
July 19-20
July 21-August 10

Sub-area
8, 9
8
9
8
9

59
0
1
0
58

August 11-September 12

9

25

37

0

0

Cooperative survey

September 5-8

9

0

14

0

0

Whale survey (Third period)

September 9-12

9

0

0

6

3

TransitSeptember 14

8

-

-

-

-

Whale survey (Forth period)

September 15-18

7

16

0

0

0

June 15-September 18

7, 8, 9

100

100

50

3

Whale survey (First period)

Whale survey (Second period)

Total

Common minke

11

Sperm
0
0
0
0
0

Table 6. Summary of biological data and samples collected during the 2004 JARPN II survey
Common minke

Sei whale

Bryde's whale

Sperm whale

M F T
90 10 100
Body length and sex
90 10 100External body proportion
90 10 100
Photographic record and external character90 10 100
Diatom film record and sampling
90 10 100
Standard measurements of blubber thickness (eleven points)
25 3 28
Detailed measurements of blubber thickness (fourteen points)
90 10 100
Body weight
25 3 28
Body weight by parts
90 10 100
Blubber tissues for DNA study
90 10 100
Muscle, liver and heart tissues for isozyme analysis
Blubber, muscle, liver and kidney tissues for heavy metal analysis 90 10 100
Blubber, muscle, liver and kidney tissues for organochlorines analy 90 10 100
25 3 28
Tissues for lipid analysis
90 10 100
Muscle and liver tissues for stable isotope analysis
90 10 100
Tissues for various analysis
25 3 28
Muscle, blubber and intestine content for energy flow analysis
4 1 5Intestine contents for prey species identification
57 5 62
Tissues for virus test
1 0 1
Muscle samples for hemoprotein analysis
Mammary grand; lactation status, measurement and histological sam- 10 10- 0 0
Collection of maternal milk sample- 10 10
Uterine horn; measurement and endometrium sample- 10 10
Uterine mucus for sperm detection- 10 10
Collection of ovary
3 3 6
Photographic record of foetus
3 3 6
Foetal sex (identified by visual observation)
3 3 6
Foetal length and weight3 3 6External measurements of foetus
3 3 6
Collection of foetus
90 - 90
Testis and epididymis; weight and histological sample
0 - 0Urine sample for sperm detection
90 10 100
Collection of serum sample
90 10 100
Collection of whole blood sample- 3 3Whole blood samples from umbilical cord
90 10 100
Stomach content, conventional record
90 10 100Volume and weight of stomach content in each compartment
90 10 100
Stomach contents for feeding study
90 10 100
Record of external parasites
5 0 5
Collection of external parasites
90 10 100
Record of internal parasites
11 1 12
Collection of internal parasites
90 10 100
Earplug for age determination
90 10 100
Tympanic bulla for age determination- Maxillally teeth for age determination
Largest baleen plate for morphologic study and age determination 90 10 100
90 10 100
Baleen plate measurements (length and breadth)90 10 100
Length of each baleen plate series
90 10 100
Vertebral epiphyses sample
0 0 0
Number of vertebrae
90 10 100
Number of ribs
25 3 28
Brain weight
90 10 100
Skull measurement (length and breadth)0 0 0Collection of skull
0 0 0
Collection of whole skeleton*1
including a fetus of sex unidentified

M F T
47 53 100
47 53 100
47 53 100
47 53 100
47 53 100
13 19 32
47 53 100
13 19 32
47 53 100
47 53 100
47 53 100
47 53 100
14 20 34
47 53 100
47 53 100
13 19 32
1 4 5
0 28 28
1 0 1- 53 53- 4 4- 53 53- 51 51- 53 53*1
15 13 29*1
15 13 29*1
15 13 29*1
15 13 29*1
15 13 2947 - 47
21 - 2147 53 100
47 53 100
- 24 24
47 53 100
47 53 100
47 53 100
47 53 100
2 3 5
47 53 100
7 7 1447 53 100
47 53 100
- - 47 53 100
47 53 100
47 53 100
47 53 100
47 53 100
47 53 100
13 19 32
47 53 100
0 0 0
0 0 0

M F T
19 31 50
19 31 50
19 31 50
19 31 50
19 31 50
6 10 16
19 31 50
6 10 16
19 31 50
19 31 50
19 31 50
19 31 50
6 10 16
19 31 50
19 31 50
6 10 16
1 5 6
0 21 211 0 1- 31 31- 1 1- 31 31- 29 29- 31 3111 11 22
11 11 22
11 11 22
11 11 22
11 11 2219 - 198 - 8
19 31 50
19 31 50
- 10 1019 31 50
19 31 50
19 31 50
19 31 50
2 2 4
19 31 50
4 5 9
19 31 50
19 31 50
- - 19 31 50
19 31 50
19 31 50
19 31 50
6 10 16
19 31 50
6 10 16
19 31 50
0 0 0
0 0 0

M
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

Samples and data

12

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

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

Table 7. Compositon of sex and sexual maturity of common minke whales sampled
Sub-area
7
8
9Combined

Male
Imm. Mat.
3
11(18.8) (68.8)
0
0

Total
14
(87.5)
0

FemaleCombined
Imm Rest. Preg. Total
2
0
0
2
16
(12.5) (0.0) (0.0) (12.5) (100.0)
0
0
0
0
0

3
(3.6)
6
(6.0)

76
(90.5)
90(90.0)

0
(0.0)
2
(2.0)

73
(86.9)
84(84.0)

2
(2.4)
2
(2.0)

6
8
(7.1) (9.5)610(6.0) (10.0)

Sex ratio(% males)
87.5

84(100.0)100(100.0)Maturity
Male Female
78.6
0.0

Pregnancy
rate*)
0.0

-

-

-

-

90.5

96.1

100.0

75.0

90.0

93.3

80.0

75.0

*) Apparent pregnancy rate

Table 8. Compositon of sex and sexual maturity of Bryde’s whales sampled
Sub-area
7
8
9Combined

Imm.
0

Male
Mat. Total
0
0

1
3
4
(8.3) (25.0) (33.3)
4
11
15(10.5) (28.9) (39.5)
5
14
19(10.0) (28.0) (38.0)

Imm
0

Ovu
0

0
1
(0.0) (8.3)
71(18.4) (2.6)
72(14.0) (4.0)

Rest.
0

FemaleCombinedPreg. Lact. Preg&Lact Total
0
0
0
0
0

0
7
0
(0.0) (58.3) (0.0)0140(0.0) (36.8) (0.0)0210(0.0) (42.0) (0.0)

0
(0.0)
1
(2.5)
1
(2.0)

8
12
(66.7) (100.0)
23
38(60.5) (100.0)
3150(62.0) (100.0)

Sex ratio(% males)MaturityPregnancy
Male Female
rate*)

33.3

75.0

100.0

87.5

39.5

73.3

69.6

93.8

38.0

73.7

77.4

91.7

*) Apparent pregnancy rate

Table 9. Compositon of sex and sexual maturity of sei whales sampled
Sub-area
7
8
9Combined

Imm.
0

Male
Mat. Total
0
0

0
1
1
(0.0) (50.0) (50.0)
1531
46(15.3) (31.6) (46.9)
1532
47(15.0) (32.0) (47.0)

Imm
0

Ovu
0

0
0
(0.0) (0.0)
141(14.3) (1.0)
141(14.0) (1.0)

Rest.
0

FemalePreg. Lact.
0
0

0
1
0
(0.0) (50.0) (0.0)4275(4.1) (27.6) (5.1)
428
5(4.0) (28.0) (5.0)*) Apparent pregnancy rate

13

Combined
0

Total
0

0

0
(0.0)
1
(1.0)
1
(1.0)

1
(50.0)
52(53.1)
53(53.0)

2(100.0)98(100.0)100(100.0)

Preg&Lact

Sex ratio(% males)MaturityPregnancy
Male Female
rate*)

50.0

100.0 100.0

100.0

46.9

67.4

73.1

73.7

47.0

68.1

73.6

74.4

Table 10. Statistics of body length (m) of common minke whales sampled
Sub area
7

Mean S.D.
7.25 0.44

Male
Min
6.41

Max
7.83

n
14

FemaleMean S.D. Min Max
6.01 0.22 5.85 7.83

n
2

8

-

-

-

-

0

-

-

-

-

0

9

7.48

0.24

6.76

7.94

76

8.07

0.25

7.68

8.47

8

Combined

7.45

0.29

6.41

7.94

90

7.66

0.90

5.85

8.47

10

Table 11. Statistics of body length (m) of Bryde’s whales sampled

7

Mean
-

S.D.
-

Male
Min
-

Max
-

n
0

Mean
-

S.D.
-

FemaleMin Max
-

n
0

8

12.10

1.39

10.03 13.01

4

13.69

0.53

12.45 14.14

8

9

11.89

1.16

8.90

12.98

15

12.33

1.29

9.40

14.04

23

Combined

11.93

1.17

8.90

13.01

19

12.68

1.28

9.40

14.14

31

FemaleMin Max-n0

Sub area

Table 12. Statistics of body length (m) of sei whales sampled

7

Mean
-

S.D.
-

Male
Min
-

Max
-

n
0

Mean
-

S.D.
-

8

12.68

-

-

-

1

15.01

-

-

-

1

9

13.23

1.12

9.28

14.60

46

13.81

1.37

9.39

15.22

52

Combined

13.22

1.11

9.28

14.60

47

13.83

1.36

9.39

15.22

53

Sub area14

Table 13. Prey species found in stomach of common minke, Bryde's and sei whales sampled(1st.+2nd. stomachs)

Common minke whale (Broken 8; Empty 4)
Prey species
Krill
Fish

Krill
Japanese anchovy
Pacific saury
Japanese common squids
Minimal armhook squid
Kitano hokke
Japanese pomfret*
Chum salmon*
Salmonidae**: Minor prey species

N(Dominant)
1
11
61
2
12
1

Range of weight (kg)in the stomachs
14.4
2.2 - 109.3
2.9 - 53.1
27.7 - 63.7
9.7 - 68.7
27.4
-

N
(Dominant)1
31
4

Range of weight (kg)in the stomachs
48.9
1.3 - 461.3
120.0 - 529.2

N(Dominant)
18
1
33
8
3

Range of weight (kg)in the stomachs<0.1 - 153.2
115.4<0.1 - 953.5
0.4 - 142.2
7.7 - 279.5

Bryde's whale (Broken 1; Empty 13)
Prey species
Krill
Fish

Krill
Japanese anchovy
Chub mackerel
Frigate mackerel**: Minor prey species

Sei whale (Broken 8; Empty 29)
Prey species
Copepods
Krill
Fish

Copepods
Krill
Japanese anchovy
Pacific saury
Chub mackerel

15

Table 14. Summary of biopsy skin sampling for some large whale species
NumberTargeted Number Number Numberofindividuals
of
of
of
Ship
experiments
shootshits
samples
(A)
(B)
(C)
(D)
(E)
SSVs
13
19
18
6
3

Blue
whale

SV

2

3

23

11

Humpback
whale

SSVs

6

9

7

Right
whale

SSVs

1

2

Bryde's
whale

SSVs

1

1

Whale
species
Blue
whale

(hr)
(F)
6h44m

sampleper
trial(E)/(C)
0.17

sampleperhit(E)/(D)
0.50

0

3h24m

0.00

0.00

4

4

2h36m

0.57

1.00

4

2

2

0h43m

0.50

1.00

4

0

0

0h32m

0.00

0.00

Table 15. Summary of photo ID for blue, humpback, and right whales

Numberofexperiments(A)

Targeted
individuals(B)

Numberoftrials
(C)

SSVs

21

29

18

Blue
whale

SV

2

3

3
*Digital Photo

Humpback
whale

SSVs

12

17

11

Right
whale

SSVs

2

4

2

Whale
species
Blue

Ship

whale

16

Effort9

7N

Cooperative A

7MI 7MO
7SI

8

7SO

Fig 1. Map showing the research area and strata of the 2004 JARPN II full-scale program.

Fig. 2. Track-line covered by the three sighting/sampling vessels (SSVs) during the whale survey of the 2004 JARPN II
survey. (Red line: BC/NSC, ASP modes, Blue line: BS / NSS modes)

17Fig. 3. Track - line covered by the three sighting/sampling vessels (SSVs) during the special monitoring survey (SMS)
the 2004 JARPN II survey. (Red line: BC/NSC, ASP modes, Blue line: BS / NSS modes)

Fig. 4. Track - line covered by the dedicated sighting vessels (SSV:KS2) in the 2004 JARPN II survey.

18

Fig. 5. Comparison of positions of the sightings and samplings of the common minke whales(●: sighted and sampled, 〇: sighted only).

Fig. 6. Comparison of positions of the sightings and samplings of the Bryde’s whales(◆: sighted and sampled, ◇: sighted only) .

19

Fig. 7. Comparison of positions of the sightings and samplings of the sei whales(■: sighted and sampled, □: sighted only) .

Fig. 8. Comparison of positions of the sightings and samplings of the sperm whales(▼: sighted and sampled, ▽: sighted only)20

Fig. 9. Distribution of the sightings of the blue whales

Fig. 10. Distribution of the sightings of the fin whales

21

Fig. 11. Distribution of the sightings of the humpback whales (〇) and right whales (□).

22

Appendx 1
Offshore prey species survey of JARPN II in 2004
HIKARU WATANABE1, SHIROH YONEZAKI1, HIROYUKI MATSUKURA2, HIROTO MURASE3, SHIGEYUKI KAWAHARA1
1

National Research Institute of Far Seas Fisheries, Orido 5-7-1, Shimizu-ku, Shizuoka 424-8633, Japan
Field Center for Northern Biosphere, Hokkaido University, Minato-cho 3-1-1, Hakodata, Hokkaido 041-8611, Japan
3
The Institute of Cetacean Research, Toyomi-cho 4-5, Chuo-ku, Tokyo 104-0055, Japan
2

Contact e-mail: hikaru1@fra.affrc.go.jp
ABSTRACT0
A prey species survey was conducted in cooperation with the sampling survey for sei and common minke whales in
September 2004 as a part of JARPN II study. The primary objective of the offshore survey was to examine preyenvironment and prey preference of sei whale during autumn. The distribution and abundance of the prey species were
investigated with the quantitative echosounder (EK60), midwater trawl, and MOCNESS of a trawler-type research vessel,
Shunyo-maru, during the daytime. Acoustic data were acquired by steaming at about 10 knots along the track lines with
operating frequency at 38, 70 and 120 kHz. Species and size compositions of acoustical backscatterings were identified by
midwater trawl and MOCNESS. In the offshore region, Japanese anchovy and Pacific saury were main component of the
trawl samples, but their abundances were relatively low. The result of MOCNESS sampling indicated that Neocalanus
cristatus, N. plumchrus, and N. flemingeri, which were main prey of sei whale in spring and summer seasons, were foundbelow 150 m. The result indicates that there were little prey species for sei whale above 100 m in early autumn.

INTRODUCTION
The government of Japan submitted the Research Plan for Cetacean Studies in the Western North Pacific under Special
Permit (JARPN II) (Feasibility Study Plan for 2000 and 2001) to the 52nd IWC/SC (Government of Japan 2000). The
overall goal of JARPN II is to contribute to the conservation and sustainable use of marine living resources including
whales in the western North Pacific, especially within Japan’s EEZ (Government of Japan, 2002). The priority of thisplan is to examine feeding habits of major cetacean species and ecosystem studies, including studies on prey
consumption by cetaceans, prey preference (selection) of cetaceans, and ecosystem model. In JARPN II, prey species
surveys are conducted in cooperation with the whale surveys to estimate the prey selection of cetaceans. In 2004, thecooperative whale/prey surveys were conducted in the offshore region of the western North Pacific and the coastal
region off Kushiro, Hokkaido. The objective of the offshore prey species survey was to examine prey environment inautumn for sei whales. This document presents the preliminary results of this survey in the offshore region.

MATERIALS AND METHOD
Survey area and period
The cooperative prey species survey was conducted from September 15 to 19 in the offshore region (Sub-area 9) by
Shunyo-maru (887 GT) of National Research Institute of Far Seas Fisheries (Fig. 1). The itinerary of the survey was
shown in Table 1. Time difference between the whale and prey species surveys was less than about one week so that
results of prey species and cetacean surveys were comparable. Research hour was from an hour after sunrise to an hour
before sunset while the maximum research hours were set at 13 hours. Generally, the survey started at 5:00 and ended at
18:00 at local time.

For the offshore survey, one block with a zigzag track line was set to cover the dense distribution area of sei whale andits adjacent area (Fig. 2). The track line was set independently from whale survey. The waypoints of track line wereshown in Table 2. The distribution and abundance of the prey species were investigated with the quantitativeechosounder, the midwater trawl, and the Multiple Opening and Closing Nets Environmental Sampling System(MOCNESS). CTD casts were conducted down to 500 m at each sampling station to measure vertical temperature andsalinity profiles in the study area.
23

Trawl sampling
The midwater trawl net used was 86.3 m long with a mouth opening of ca. 900 m2 and a 6.0 m cod end with a 17.5 x
17.5 mm mesh inner. The sampling depth and the height of the mouth of the net were monitored with the Scanmer
transducers attached to the head and the bottom rope of the trawl. Towing speed of the trawl net was 4-5 knot. In thisstudy, all samples were collected during daylight period. Two types of trawl samplings, the trawlings with floats in thesurface layer and the stairs-like mid-water trawlings from the depths around 100 m, were conducted. The purpose of
these samplings was to examine the abundance and distribution pattern of squids and neustonic animals like Pacificsaury that are difficult to detect with the echosounder. Also the samples were used to identify the species and size of
acoustical backscatterings. Surface trawlings were made with floats at 0-30 m layer for 30 minutes in the area where
Pacific saury seemed to be distributed. Stairs-like trawlings were made at three layers (0-30 m, 30-60 m, and 60-90 m).
During the offshore survey, we conducted surface and stairs-like trawlings for four and two times, respectively (Table3).

All samples were identified to the lowest taxonomic level possible and wet weight of each species was measured aboard
the ship. For the major species, body length of 100 individuals was measured to examine their size composition. A partof samples were frozen at –30°C for further analysis in the laboratory.
MOCNESS sampling
During the offshore survey period we used MOCNESS to examine species/size compositions and vertical distribution
pattern of meso- and macro-zooplanktons. The mouth opening and mesh size of the net were 1 m2 and 0.33 x 0.33 mm,
respectively. At the three predetermined stations, this net was towed at about 2 knots in 8 target depths (0-20m, 20-40m,
40-60m, 60-80m, 80-100m, 100-150m, 150-200m, and 200-250m) during the daytime (Table 5). The volume of water
filtered by each net was measured with a flow meter mounted at the net mouth. Samples were preserved in 10 %formalin-buffered seawater at sea for further analysis in the laboratory.
Acoustic data acquisition and analyses
During the daytime, the ship steamed at around 10 knots along the track line. To record acoustic data a quantitativeecho sounder (Simrad EK60 with program version 1.4.3.64) with operating frequency at 38, 70 and 120 kHz was used.
The transducers were hull-mounted at the depth of 4.3 m from the surface. Calibrations were carried out off the coast ofKushiro in September 23 using the copper sphere technique described in EK 60 online help manual.

Acoustic data are being analyzed now with the aid of Sonar Data Echoview (version 3.00.74.01) at the laboratory. In
principle, backscattering on the echosounder is identified based mainly on the results of trawl and MOCNESS
samplings. For fishes, data collected at 38 kHz are used with the threshold set at -60dB and the depth range from 10 m
to 250 m. For Japanese anchovy, school shape and backscattering intensity of backscattering are also used for species
identification. For krills, data collected at 120 kHz are used with the threshold set at –80 dB. The analyzed depth range
is from 12 m to 250 m (maximum depth at 120 kHz). Backscattering is identified as krills if ΔSv (the difference of Sv
between 38 and 120 kHz) falls between 10 and 15 dB (Miyashita et al. 1997). Because most of krill species in thesurvey area have the body length similar to isada krill (Euphausia pacifica) taken in the coastal area off Tohoku, thisΔSv value is applied to. Species identification is based on both ΔSv and the samples form MOCNESS. For copepods,
data collected at 120 kHz are used with the threshold set at –110 dB. Target strengths (TS) of copepods are calculatedusing the Distorted Wave Born Approximation based seformed cylinder model (Stanton and Chu, 2000). Based on the
TS, ΔSv (the difference of Sv between 38 and 120 kHz) falls between 10 and 30dB are identified as copepods. Net
sampling results as well as school shape are considered to distinguish between krill and copepods. The integration ismade at an interval of one nautical mile by 50 m depth zone.

RESULTS AND DISCUSSION
While the acoustic data, plankton samples, and oceanographic conditions are being analyzing now, the preliminary
results are as follows.

CTD data indicated that the offshore region was located in the transitional region south of the sub-arctic front. Planned
track lines were surveyed about 80 % using the echosounder. We recognized no remarkable echoes during the survey.
Small catches of trawl and MOCNESS well reflected this result. Japanese anchovy and Pacific saury were the main
components of the trawl sample, but their CPUE (kg/h) was less than 25 kg at each sampling station (Table 3). Resultsof MOCNESS sampling indicated low abundance of copepods and euphausiids in the 0-100 m layer. Neocalanus
cristatus, N. plumchrus, and N. flemingeri, which were mainly distributed in the top 50 m and the main prey of sei
24whale during spring and summer, were deepened below 150 m depth due to ontogenetic vertical migration. These
results indicate that there were little prey species for sei whale above the depths of 100 m in early autumn of this study
area, contrasting with spring and summer seasons. According to Tamura (personal communication), stomach content
weight of sei whales sampled in autumn of this year was much lower than in the summer of 2003, which werecorresponded with seasonal change in prey abundance above 100 m.

ACKNOWLEDGEMENT
A special thank is given to the crews and researchers for their dedication in collecting data. The authors would like tothank Dr. Hiroshi Hatanaka (The Institute of Cetacean Research, Japan). Dr. Kazushi Miyashita (Hokkaido University)
provided useful comments on acoustic data analysis.

REFERENCES
Government of Japan. 2000. Research plan for cetacean studies in the western North Pacific under Special Permit(JARPN II) (Feasibility Study Plan for 2000 and 2001). Paper SC/52/O1 submitted to the 52nd IWC ScientificCommittee Meeting.
Government of Japan. 2002. Research plan for cetacean studies in the western North Pacific under Special Permit(JARPN II). Paper SC/54/O2 submitted to the 54th IWC Scientific Committee Meeting.
Miyashita, K., Aoki, I., Seno, K., Taki, K. and Ogishima. 1997. Acoustic identification of isada krill, Euphausia
pacifica Hansen, off the Sanriku coast, north-eastern Japan. Fish. Oceanogr. 6. 266-271.
Stanton, T., K. and Chu, D. 2000. Review and recommendations for the modelling of acoustic scattering by fluid-likeelongated zooplankton: euphausiids and copepods. ICES J. Mar. Sci. 57:793-807.

25

Table 1. Itinerary of the prey species survey in 2004
Date
5-Sep
14-Sep19-Sep23-Sep23-Sep24-Sep24-Sep29-Sep2-OctEvident
Departed Shimizu, Japan
Started offshore survey
Ended offshore survey
Conducting echo sounder calibration
Arrived Kushiro, Japan
Departed Kushiro, Japan
Started coastal survey
Ended coastal survey
Arrived Shimizu, Japan

Table 2. List of waypoints of track line
y
ＷＰ
1
2
3
4
5
6

Lat
44-30N44-00N43-30N43-00N42-30N42-00NLong
165-30E
167-00E
165-30E
167-00E
165-30E
167-00E
Total

Distance(n. mil)
71
72
72
73
73
361

Table 3. Results of trawlings during the offshore survey in 2004

Stn

Date

SST

Lat

Long

（℃）

Sampling

Towing

Total

depth

duration

catch

Japanese

Sampled weight by species (kg)Pacific
Japanese Squids

(m)

(min)

(kg)

anchovy

saury

0-100

30

0.1

-

-

-

< 0.1

0.1

Salps

sardine1

2004.9.15

13.8

44-26N

165-48E

2

2004.9.16

13.6

44-16N

166-03E

0-30

30

9.5

0.3

9.3

-

-

-

4

2004.9.17

13.9

43-53N

166-36E

0-100

30

0

-

-

-

-

-

5

2004.9.18

14.1

43-22N

165-55E

0-30

30

10.4

10.4

-

< 0.1

-

-

6

2004.9.18

14.6

43-10N

166-28E

0-30

30

2.5

1.7

0.8

-

-

-

8

2004.9.19

15.4

42-47N

166-24E

0-30

30

12.0

-

12.0

-

-

-

26

Table 4. Results of MOCNESS during the offshore survey in 2004.

Stn

Date

Lat

Long

Targetdepth (m)Volume water
filtered (m^3)

3
3
3
3

2004.9.16
2004.9.16
2004.9.16
2004.9.16

43-60N43-60N43-60N43-60N

167-01E
167-01E
167-01E
167-01E

250→200
200→150
150→100
100→80

239
310
243
183

3
3
3
3

2004.9.16
2004.9.16
2004.9.16
2004.9.16

43-60N43-60N43-60N43-60N

167-01E
167-01E
167-01E
167-01E

80→60
60→40
40→20
20→10

188
137
167
68

7
7
7
7

2004.9.18
2004.9.18
2004.9.18
2004.9.18

43-01N43-01N43-01N43-01N

166-57E
166-57E
166-57E
166-57E

250→200
200→150
150→100
100→80

253
305
209
177

7
7
7
7

2004.9.18
2004.9.18
2004.9.18
2004.9.18

43-01N43-01N43-01N43-01N

166-57E
166-57E
166-57E
166-57E

80→60
60→40
40→20
20→10

84
13
102
65

9
9
9

2004.9.19
2007.7.5
2007.7.5

42-38N
42-38N
42-38N

165-55E
165-55E
165-55E

250→200
200→150
150→100

250
296
334

9
9
9
9
9

2007.7.5
2007.7.5
2007.7.5
2007.7.5
2007.7.5

42-38N
42-38N
42-38N
42-38N
42-38N

165-55E
165-55E
165-55E
165-55E
165-55E

100→80
80→60
60→40
40→20
20→10

148
121
121
131
38

27

Coastal region

Offshore region

Fig. 1. Prey species survey area in September 2004

○Surface trawling with floats◎Stairs-like mid-water trawling□MOCNESS

Fig. 2. The block with a zigzag track line and sampling positions of trawls and MOCNESS in Sub-area 9(Dotted and solid lines show planned and actual lines, respectively)

28

Appendix 2.
Oceanographic conditions in the western North Pacific in
September 2004
DENZO INAGAKE* AND SHIGEYUKI KAWAHARA** National Research Institute of Far Seas Fisheries, Orido 5-7-1, Shimizu-ku, Shizuoka 424-8633, Japan

1. Introduction

A prey specific survey was conducted as a part of JARPN II study in the western North Pacific in September 2004
using R/V Shunyo Maru. There are a lot of water masses and fronts in the western North Pacific. The Oyashio flows
southwestward along the Kuril Islands with cold low-salinity water and turns eastward from the northern coast of Japan.
In the high sea of the North Pacific Ocean, there are Subarctic front (temperature front defined by 4°C) and theSubarctic Boundary (salinity front defined by 34.0psu) with a week eastward flow, and the area between these fronts iscalled the Transition Domain (Favorite et al. 1976). Subarctic waters and subtropical waters lie around these fronts, andeach water mass has its own ecosystem. In this paper, distributions of water masses and fronts in this survey will be
described to make clear the environment of the prey of sei and minke whales.

2. Methods

Hydrographic observations with a conductivity-temperature-depth profiler (CTD; SBE 911plus) were carried out
from 15th to 19th September 2004 in the Kuroshio-Oyashio Inter-frontal Zone using R/V Shunyo Maru (Fig. 1).
Salinity compensation for CTD data was not done using water sampling data.
Oceanic fronts and water masses are usually detected by subsurface temperature map, because they are obscure insea surface temperature distributions from summer to fall seasons and the Oyashio water spreads into the subsurface
layer (Table 1). The Kuroshio Extension is defined by the 14°C isotherm at the depth of 200m (Kawai, 1969). The
warm water spread from Kuroshio Extension is defied by temperature more than 10°C at the depth of 100 m . The first
and the second Oyashio Intrusions are defined by temperature lass than 5°C at the depth of 100 m (Murakami, 1994).
Subarctic front and the Subarctic Boundary is defined by 4°C temperature front and 34.0psu salinity front, respectively(Favorite et al. 1976). We use these indices to know the distribution of water mass in the observation area.

3. Oceanographic conditions in the research area

Figure 2 shows the Temperature-Salinity diagrams using CTD station data. Water masses in the research area havecharacteristics of cold low-salinity water (the subarctic water in the lower part of Fig. 2). Some of these stations show
warm surface water above the subarctic water (left upper part of Fig.2).
Figure 3 shows the 100 m depth temperature map observed by R/V Shunyo Maru. The cold water less than 5°C was
distributed in almost all of the survey area. A little warm water (around 6°C) was observed only one station. The
Subarctic front (defined by 4°C isotherm) was observed around 43ﾟN in Fig. 3, that is to say, the subarctic water lies
from western part to the middle part in this survey area.

REFERENCES
Favorite, F., A. J. Dodimead and K.Nasu (1976): Oceanography of the Subarctic Pacific Region, 1960-71. Bull. 33,
International North Pacific Fisheries Commission, 187 pp.

Kawai, H. (1969): Statistical estimation of isotherms indicative of the Kuroshio axis, Deep-Sea Res., 16, 109-115.
Murakami, M. (1994): On long-term variations in hydrographic conditions in the Tohoku area, Bull. Tohoku Natl. Fish.
Res. Inst., No. 56, 47-56 (in Japanese with English abstract).
29

Table 1. Extraction method from temperature map to determine the position of each water mass.
Target characteristics

Extraction method

Kuroshio Extension Axis

14°C isotherm at 200m

Warm-core ringTemperature front at 200m

Oyashio front

5 °C isotherm at 100m

Oyashio water

Area with T<5 °C at 100m

Cold water

Area with 5°C <T<10 °C at 100m

Warm water

Area with T>10 °C at 100m and T<14 °C at 200m

Subarctic Boundary

Salinity front defined by 34.0psu

Subarctic Front

Temperature front defined by 4°C30

Fig. 1. Station map observed by R/V Shunyo Maru in 15 – 19 September 2004. Light blue stars and blue circles denote
CTD stations in the cold area (100 m temperature was over 5°C and less than 10°C) and the Oyashio area (100 m
temperature was less than 5°C), respectively

31

Fig. 2. Temperature-Salinity diagrams using CTD station data observe by R/V Shunyo Maru in 15 – 29 September 2004.
Each thin line in this figure denotes a density line of sigma-t.

32

Fig.3. 100m temperature map observed by R/V Shunyo Maru in 15 – 19 September 2004.

33