SC/56/O13

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 –TAMURA, T. 1), FUJISE, Y. 1), BANDO, T. 1), YASUNAGA, G. 1), KONISHI, K. 1), KIWADA, H. 1), ISODA, T. 1), ITOH, S. 2),
MACHIDA, S. 1), TSUNEKAWA, M. 1), KONAGAI, T. 1), TAKAMATSU, T. 1), OHSHIMA, T. 1), HONJO, K. 1), MATSUOKA, T. 3),
ZHARIKOV, K.A. 4), AN, YONG ROCK 5), TOHYAMA D. 6) AND KAWAHARA, S. 7)
1) The Institute of Cetacean Research, 4-5, Toyomi-cho, Chuo-ku, Tokyo, 104-0055, Japan,2) Hokkaido University, Faculty of Fisheries, 3-1-1, Minato-cho, Hakodate, 041-8611, Japan,3) Obihiro University, Agriculture and Veterinary Medicine, 2-11, Inada-cho, Obihiro, 080-8555, Japan,
4) Marine Mammal Lab, VNIRO –Russian Federal Research Institute of Fisheries & Oceanography,17, V.
Krasnoselskaya, Moscow, 107140, RUSSIA,
5) National Fisheries Research & Development, Cetacean Research Center, 408-1, Shirang-ri, Gijang-up, Gijang-gun,
Busan, 619-902, Republic of Korea,
6) Kyodo Senpaku Co. Ltd., 4-5, Toyomi-cho, Chuo-ku, Tokyo, 104-0055, Japan,
7) 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 (JARPNII) 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 second cruise of the JARPNII survey was conducted from 17 May to 8 August 2003 in sub-areas 7,
8 and 9 of the western North Pacific. In the survey a total of seven research vessels was used: one trawl survey vessel
equipped with scientific echo sounder (TSV), two dedicated sighting vessels (SVs), three sighting/sampling vessels(SSVs) and one research base vessel. A total of 11,903.0n.miles was surveyed for whale searching in a period of 84
days. During that period 125 common minke, 193 Bryde’s, 236 sei and 935 sperm whales were sighted by the SSVs. A
total of 100 common minke, 50 Bryde’s, 50 sei and 10 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 8 and 9 from 10 to 22
June and in a part of sub-area 7 from 26 June to 7 July (excluding 30 June). All whales sampled were examined on
board the research base vessel. Major prey species of common minke whales were Japanese anchovy (Engraulisjaponicus) and Pacific saury (Cololabis saira). Small-sized Japanese anchovy, including larva, was found in thestomach of Bryde’s whales. Major prey species of sei whales were copepods, krill, Pacific saury and Japanese anchovy.
Dominant preys in the stomach of ten sperm whales were different kinds of squids, which inhabit in the mid- and deepwaters.
KEYWORDS: COMMON MINKE WHALE; BRYDE’S WHALE; SEI WHALE; SPERM WHALE; NORTHPACIFIC OCEAN; DISTRIBUTION; FOOD/PREY; ECOSYSTEM; SCIENTIFIC PERMITSINTRODUCTION
The second phase of Japanese Whale Research Program under Special Permit in the North Pacific (JARPNII) planed in2000 and 2001 as a two-year feasibility study (Government of Japan, 2000). The feasibility study was conducted in2000 and 2001 and results were presented to the 2002 SC meeting (Government of Japan, 2002a). Based on the resultsof the feasibility study, Japan presented the research plan for the full-scale JARPN II (Government of Japan, 2002b) to
the 2002 SC meeting.
The full-scale study aimed i) to study the feeding ecology and ecosystem studies, ii) to monitor environmental
pollutants in cetaceans 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 to be covered by the Nisshin Maru
research unit and the ‘coastal’ survey to be covered by small type whaling catcher boats. The coastal component was1necessary to cover the temporal and spatial gaps, which could not be covered by the Nisshin Maru unit (Government ofJapan, 2002b).
The research area was set in sub-areas 7, 8 and 9 and the target species and sample sizes were set as follows: 150
common minke whales (100 to be sampled by the offshore survey and 50 by the coastal survey); 50 Bryde’s whales B.
edeni (offshore survey); 50 sei whales B. borealis (offshore survey) and 10 sperm whales Physeter macrocephalus(offshore survey) (Government of Japan, 2002b).
In this paper, we present an outline of offshore component in the second full scale survey of the JARPNII survey which
was conducted from 17 May to 8 August 2003.

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

Five small blocks (7N, 7MI, 7MO, 7SI and 7SO) were determined for several type of oceanographic
structure using satellite information on water temperature.

Sub-area 8, 9: Four small blocks (8N, 8S, 9N and 9S) were divided at 40ºN.
Whale survey was normally conducted in sub-areas 7, 8 and 9.
In the case of the cooperative survey on ecosystem research, a special block was predetermined in the sub-areas. In thisseason, two special blocks (SBs) were settled in offshore area (A) and coastal area (B) as shown in Fig. 1. We
conducted the whale survey and the prey survey such as trawl sampling and echo sounder survey in the SBs
concurrently.
Research vessels
Seven research vessels were used.
The research base vessel Nisshin Maru (NM: 7,575GT) 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: 812.08GT) 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) and Shonan Maru (SM: 712GT) were engaged as dedicated sighting vessels (SVs). The Shunyo Maru
(SYO: 887GT) was engaged as a trawl survey and an echo sounder survey vessel. This vessel also conducted the trawl
net and MOCNESS net sampling. Furthermore, this vessel conducted the oceanographic observations using CTD.
Research typeIn this survey, three main components (the whale survey, dedicated sighting survey and the cooperative survey withprey survey) were consisted as follows:
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 was expected to be large.
Research period:First period:

Between 17 May and 9 June.

Second period:

Between 23 and 25 June.

Third period:

Between 29 and 30 June.

Forth period:

Between 8 July and 8 August (Table 1).

Dedicating Sighting survey
Vessels: Two research vessels (SM and KS2)
Research area: Sub-areas 7, 8 and 92

Research period (SM):First period:

Between 30 April and 18 May for sub-area 8.

Research period (KS2):First period:

Between 14 May and 11 June for sub-area 7.

Second period:

Between 16 June and 7 July for sub-areas 8 and 9.

Third period:

Between 14 July and 5 September for sub-area 9 (Table 1).

Cooperative survey on the prey species and whale sampling
Vessels: Six research vessels (NM, YS1, YS2, K01, KS2 and SYO)
Research area: In the cooperative survey on ecosystem research, two special blocks (A and B) were settled.
Research periods:
First period (A): Between 10 and 22 June for the A (offshore-block).

Second period (B): Between 26 June and 7 July for the B (excluding 30 June) (Table 1).
Cruise track line for the whale survey
Track line and allocation of vessels was 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). The zigzag-shaped track line wasestablished on an arbitrary basis in each sub-area and month, taking into consideration previous sighting information oftarget whales and sea conditions (Fig. 2).
Furthermore, a ‘special monitoring survey’ (SMS) was conducted in an area where the abundance of common minke
whales, Bryde’s and sei whales was 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 (Figs 3 and 4).
Allocation of the prey survey vessel in the cooperative survey was determined in the following manner. The cruise track
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 thesame time.The whale research fleet surveyed in the following manner: the research course consisted of one main track
and two parallel tracks established six n.miles apart from both sides. Apart from these sampling activities, an
independent track line for dedicated sighting survey, which is shown in Fig. 3, was determined in the research area.
Sighting surveys
Sighting procedure 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). In the research area sighting was conducted mainly
under closing mode. Furthermore two modalities 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 wind force of 4 or below). The NSS mode was used under more critical weather
conditions but under this condition the collection of whale samples was possible. This NSS mode was used only by SSV
vessels. These two mode surveys were recorded 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 made mainly on sightings of common minke, Bryde’s, sei and sperm whales or on schools that looked likethose whales. Furthermore it was planned that closing was made on sightings of large whales, such as blue, humpback,right and fin whales. In these cases, closing was made 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
Sampling activities were conducted with the aim to take 100 common minke whales, 50 Bryde’s whales 50 sei whales
and 10 sperm whales. Most of these 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 collectionof whale samples was considered as possible.

3For schools consisting of two or more animals, numbering was made to 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. As in a previous JARPN survey the sampling was conducted in cooperation with threesighting/sampling vessels in this survey (Fujise et al., 1996, 2000).
Prey species survey
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 Sendai Bay (30 June 2003) 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 routine and acoustic target identification stations. Target trawls
were conducted for 0.5 hour to identify the species compositions of biological backscattering detected by thequantitative echo sounder. Routine trawls were conducted at predetermined stations in each block in daytime andnighttime. The purpose of the routine trawls was to estimate the abundance and distribution patterns of cephalopods andneustonic organisms such as Pacific saury (Cololabis saira) that are difficult to detect by the echo sounder. Threedifferent depth layers were sampled at routine trawl stations; 0-30m (surface) 30-60m and 60-100m (mid-water).
Nighttime routine trawls were conducted twice to examine 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 theship. 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 on attachment of data logger for 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 (SM and KS2), 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)(KS2).

On board the prey survey vessel (SYO), the following experiments were conducted:
1. Feasibility study to estimate abundance of prey species of common minke and other large whale species using anecho sounder system.
2. Oceanographic observations using CTD.

4

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 was 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 research base vessel and the SSVs.

RESULTS
Searching distance
Track line covered by the three sighting/sampling vessels (SSVs) during the 2003 JARPN II survey is shown in Figs 3
and 4. The total searching distance for SSVs and SV were 12,122.8 n.miles and 6,706.8 n.miles, respectively (Table 2).
In the cooperative survey on ecosystem research, the survey was conducted from June to July with two periods; firstfrom 10 to 22 June, and second from 26 June to 7 July (except 30 June: 11 days). Under the cooperative survey,
searching distance for SSVs was 3,024.6 n.miles consisting of 1,716.2 n.miles and 1,308.4 n.miles for first (SB-A) andsecond periods (SB-B) (Table 2).
Sightings of common minke, Bryde’s, sei and sperm whales
Sighting and sampling vessels (SSVs)
During the research cruise, 122 schools (125 individuals) of common minke whales were sighted, consisting of 74
schools (75 individuals) of primary and 48 schools (50 individuals) of secondary sightings. For Bryde’s whale, 148
schools (193 individuals) were sighted, consisting of 102 schools (129 individuals) of primary sightings and 46 schools(64 individuals) of secondary sightings. Sei whale, 145 schools (236 individuals) were sighted, consisting of 99 schools(163 individuals) of primary sightings and 46 schools (73 individuals) of secondary sightings. For sperm whale, 325
schools (935 individuals) were made, consisting of 212 schools (626 individuals) of primary sightings and 113 schools(309 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. Fig.6 shows the
distribution of Bryde’s and sei whales. Common minke whales were usually sighted in northern part of sub-areas 7, 8
and 9, but Bryde’s whales were sighted mainly in southern part of sub-areas 7, 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. 7 shows the distribution of sperm whale sightings in sub-area 7, 8 and 9. This species was widelydistributed in sub-areas 7, 8 and 9.
Dedicated sighting vessel (SV)SM
During the research cruise, 4 schools (4 individuals) of common minke whales were sighted of primary sightings. For
sei whale, 2 schools (3 individuals) were sighted as primary sightings. For sperm whale, 36 schools (72 individuals)
were sighted, consisting of 35 schools (71 individuals) of primary sightings and 1 school (1 individuals) of secondarysightings (Table 4-1).
KS2
During the research cruise, 79 schools (87 individuals) of common minke whales were sighted, consisting of 68 schools(76 individuals) of primary and 11 schools (11 individuals) of secondary sightings. For sei whale, 47 schools (79individuals) were sighted, consisting of 35 schools (58 individuals) of primary sightings and 12 schools (21 individuals)of secondary sightings. For sperm whale, 185 schools (315 individuals) were sighted, consisting of 168 schools (296individuals) of primary sightings and 17 schools (19 individuals) of secondary sightings (Table 4-2).
Sightings of other large cetacean species
Sighting and sampling vessels (SSVs)
Table 3 also shows the number of sightings for other cetacean species made by the SSVs. Large baleen whales such as
blue (11 schs./13 inds.), fin (29 schs./36 inds.) and right whales (2 schs./3 inds.) were found in the sub-areas 7, 8 and 9(Fig. 8).
Dedicated sighting vessel (SV)SM

5

Large baleen whales such as fin (1 sch. /2 inds.), humpback whales (3 schs. /6 inds.) and right whale (1 sch. /1 ind.),were found in the sub-areas 7, 8 and 9 (Table 4-1).
KS2
Large baleen whales such as blue (39 schs. /51 inds.), fin (56 schs. /101 inds.) and humpback whales (18 schs. /31 inds.)
were found in the sub-areas 7, 8 and 9 (Table 4-2).
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 were sampled, 83 during the whale survey component and 17 during thecooperative survey component. The whale samples consisted of 93 males and 7 females. A total of 50 Bryde’s whales
were sampled, 31 during the whale survey component and 19 during the cooperative survey component. The whale
samples consisted of 19 males and 31 females. A total of 50 sei whales were sampled, 30 during the whale survey
component and 20 during the cooperative survey component. These 50 whales consisted of 23 males and 27 females. A
total of ten sperm whales were sampled, 6 during the whale survey component and 4 during the cooperative survey
component. These ten animals consisted of one male and nine females.
Geographical distribution of common minke, Bryde’s and sei whale samples is shown in Figs 9-11 and 13-15 based on
the sighting positions. Distribution of sightings and sampling locations almost coincided. Figs. 12 and 16 show the
distribution of sperm whale samples based on the sighting positions.
Causes of failure to collect the targeted whale were as follows. For common minke whales, a total of 12 individuals
were not sampled, because quick mobility (5), long diving (5) and a sudden turn for the worse of sea condition (1). One
common minke whale was missed by technical reason (struck but lost). For the Bryde’s whales, three individuals were
not sampled because of quick mobility (1) and long diving (2). In the case of sei whale, one individual was not sampled,
because quick mobility (1).
Biological research for minke, Bryde’s and sperm whales sampled
Table 6 summarizes the biological data and samples obtained from the common minke, Bryde’s, sei and sperm whales
sampled. A total of 59 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 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 7.21 m and 7.28 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-areas 7 and 8. For Bryde’s whales, the statistics of body length are shown in
Table 11. Mean body length of Bryde’s whales is 11.64 m and 12.09 m for males and females, respectively. For sei
whales, the statistics of body length are shown in Table 12. Mean body length of sei whales is 13.29 m and 14.09 m formales and females, respectively. For sperm whale, the information of body length and weight are also shown in Table
13. Relationship between body length and body weight of sei, Bryde’s and common minke whales collected are shownin Fig. 18.
Prey species of common minke, Bryde’s, sei and sperm whale
List of prey species found in the stomach contents of common minke, Bryde’s, and sei whales is shown in Table 14.
Common minke whale fed on five prey species consisting of one krill and four fish species. They fed mainly on
Japanese anchovy and Pacific saury. Bryde’s whale fed on three prey species consisting of one krill and two fish species.
They fed mainly on krill and Japanese anchovy. Sei whale fed on seven prey species consisting of some copepods, one
krill and three fish species. They fed mainly on copepods and Japanese anchovy. Sperm whale fed mainly on deep-sea
squids.
Experiments, prey surveys and oceanographic surveys
Biopsy sampling trial for blue, humpback, right, fin, Bryde’s and sei whales
Table 15 shows the result of biopsy skin sampling for blue, humpback, right, fin, Bryde’s, sei and sperm whales. A totalof 10 blue, 2 humpback, 1 right, 2 fin, 22 Bryde’s, 2 sei and 27 sperm whales were targeted for biopsy sampling by the6

SSVs. As a result, two blue, one humpback, one right, four Bryde’s and one fin whale’s biopsy skin samples werecollected, respectively.
Natural marks (photo ID) for blue, humpback and right whales
Table 16 shows the result of recording using photograph for natural marks of blue, humpback, and right whales. A totalof 8 blue, 4 humpback and 3 right whales were targeted by the SSVs. A total of 7, 4 and 3 trials were conducted for blue,
humpback and right whales, respectively. In future, utility of the photographs will be examined.
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 trackline. Target trawls weretowed at 3 stations. Surface routine trawls were towed at 16 stations. Nighttime trawls were towed at 2 stations.
MOCNESS was towed at 13 stations. The details of the prey species survey conducted by SYO are described inAppendix 1 of this document.
CTD and EPCS
The SV (KS2) conducted an experiment to measure the vertical thermal and salinity profiles using CTD. A total of 90
points was conducted. The EPCS recordings operated for 115 days during the research cruise. Details will be reported
in future. CTD casts were made at 29 stations by SYO. In the SYO, CTD (Model SBE 9, Seabird Co.) casts wereconducted down to 500m at each sampling station to measure the temperature and salinity profiles in the study area by
SYO. Two CTD casts were made down to 2,500m and 4,000m to collect water samples for the salinity compensation.
Salinity compensation for CTD data and analysis of oceanographic conditions were made at the laboratory. The detailsof the oceanographic observations are reported in Appendix 1 of this paper.
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 of the 100 sampled common minke, 50 Bryde’s, 50 sei and 10 sperm whales were 286 tons, 415 tons, 651 tons and
34 tons, respectively.

DISCUSSIONS
1. Distribution and food habit of Bryde’s whale
Bryde’s whales were one of focused whales species of the research during JARPNII surveys since 2000. During the
JARPNII surveys of 2000, 2001 and 2002, different distribution patterns of Bryde’s whales have been observed. In thefeasibility studies of 2000 and 2001, Bryde's whales were observed in the north-eastern part of sub-area 7 (block 7MO)
in relatively high concentration. In that area, feeding behaviour of Bryde’s whales was observed frequently. Operationof skipjack tuna fisheries was also observed in that area. Since Japanese anchovy were found in the stomach of Bryde’s
whales sampled, we postulated a relationship between Bryde’s whale and skipjack tuna. This is because the prey ofskipjack tuna is also Japanese anchovy. In contrast, few Bryde’s whales were observed in this block in 2002. Also few
operations of skipjack tuna fisheries were observed. A possible factor affecting Bryde’s whale distribution is the rapidchanges of water temperature. From late July to mid August 2002, relatively large typhoons passed on the research area.
The surface water temperature decreased about two to five degrees than previous years. Future research should examine
relationship between the whale distributions and oceanographic conditions such as water temperatures, water massbalance between warm and cold water masses. In 2003, relatively high density of Bryde’s whales was observed in thesouthern part of sub-areas 8 and 9. There are seasonal changes of their prey species from krill to Japanese anchovy. In
May and June, they fed mainly on krill. On the other hand, they fed mainly on Japanese anchovy after July.
2. Distribution and food habit of sei whale
In this full-scale JARPNII, sei whale is newly included as one of whale species focused for the research objective.
Sample size of the sei whales in this program was also calculated from information on food habitat in the past studies,because no information is available for recent years. In this survey, the information on food habitat was obtained from50 individuals collected in the entire research area. They fed on the various prey species such as copepod, amphipod,7

krill and three species of fish. However, the survey in the last year did not covered fully the feeding season, especiallylately feeding season (August and September).
3. Condition of concurrent survey
As same as previous JARPNII feasibility studies, this second full-scale research plan consisted of two survey groups.
One is whales survey group (NM, YS1, YS2, and K01), and the other is prey survey group (SYO). In this season, thecooperative survey was conducted on two different survey blocks (SBs). The A in the first period was settled in theoffshore area (around 157E, Fig. 1), and the B in the second period was in the 7SO and 7MO stratum. A total of 15
common minke and 15 sei whale samples were collected by the SSVs in this period. Information on the prey species
distribution was also collected by SYO during this period (See Appendix 1). In the second period, a total of 2 common
minke, 19 Bryde’s, 5 sei and 4 sperm whale samples were collected by the SSVs. Information on the prey species
distribution was also collected by SYO during this period.
4. Participation by foreign scientists
In 2003 JARPNII, A total of two foreign scientists participated. They actually learned our sighting and sampling survey
on board. We cooperated and conducted 2003 JARPNII. It is expected that these international collaboration willcontinue in future.

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

8

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.
Shimada, H. 1999. Report of western North Pacific Bryde’s whale sighting survey in summer, 1998. Paper SC/51/RMP4 presented to the IWC
Scientific Committee, May 1999 (unpublished). 11pp.
Shimada, H. 2000. Report of sighting survey on western North Pacific Bryde’s whale conducted in August-September 1999. Paper SC/52/RMP9
presented to the IWC Scientific Committee, June 2000 (unpublished). 13pp+Appdx..
Tamura, T. and Ohsumi, S. 1999. Estimation of total food consumption by cetaceans in the world’s oceans. The Institute of Cetacean Research: 16pp.
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.

9

Table 1. Outline of 2003 JARPN II surveyDays・ Whale sampling survey

Research
periods
May 17-Aug. 8, 2003

Research ships and remark

84

Subarea
7,8,9Whale survey (first period)

May 17-June 9, 2003

24

7, 8

NM, YS1, YS2 and K01

Cooperative survey (A: first period)

June 10-22, 2003

13

8+9

NM, YS1, YS2, K01 and SHU

Whale survey (second period)

June 23-25, 2003

3

8

NM, YS1and YS2June 26-29, July 1-7, 2003

10.5

7

NM, YS1, YS2, K01 and SHU

Research

Cooperative survey (B: second period)

Whale survey (third period)

June 29-30, July 8-Aug. 8, 2003 33.5

7, 8, 9 NM, YS1, YS2 and K01

・ Sighting survey

June 23-26, 2003

4

7

Special (K01)・ Sighting survey

April 30 - May 18, 2003

19

8

SM

・ Sighting survey

May 14-Sept. 5, 2003

115

7,8,9 KS2

Table 2. Searching distances made by the three sighting/sampling vessels (YS2, YS1 and K01) and sighting vessels(SM and KS2) in the 2003 JARPN II

Research
SSVｓ

Sub-area

PeriodCombined May 17-Aug. 8, 2003

NSC
9,329.0

Searching distance (n.miles）
ASP
NSS
Combined
570.8
2,003.2
11,903.0

Whale survey (first period)

7, 8

May 17-June 9, 2003

3,519.5

304.1

374.1

4,197.7

Cooperative survey(A: First period)

8+9June 10-22, 2003

1,412.2

30.8

273.2

1,716.2

Whale survey (second period)

8

June 23-25, 2003

291.3

0.0

21.5

312.8

Cooperative survey(B: Second period)

7

June 26-29, July 1-7, 2003

1,016.6

187.9

103.9

1,308.4

Whale survey (third period)

7, 8, 9June 29-30, July 8-Aug. 21, 2003

3,089.4

48.0

1,230.5

4,367.9

SV (K01)

7

June 23-26, 2003

0.0

219.8

0.0

219.8

SV (SM)

8

April 30 - May 18, 2003

0.0

1,044.5

0.0

1,044.5

SV (KS2)7, 8, 9May 14-Sept. 5, 2003

0.0

5,662.3

0.0

5,662.3

10

11

524

168
11
78

Sperm whale

Unidentified large cetacean

Unidentified cetacean

79

13

1

25

84

1

Right whale

21

Humpback whale

140

81
67

Sei whale

Bryde's whale

27

22

Fin whale

1
8

1
6

62

11

74

88

0

6

20

37

6

1

6

38

11

102

255

0

8

27

53

8

1

6

39

NSC
SecondarySch. Ind.

Blue whale

61

PrimarySch. Ind.

Like minke whale

Common minke whale

Cetacean species

18

3

30

0

2

12

12

1

1

4

9

18

3

71

0

2

16

14

1

1

4

9

PrimarySch. Ind.

1

9

11

0

0

6

6

0

0

3

1

6
1
0
14
1
5

0
0
18
9
1

0

0
23

1

0

8

0

3

17

4

5

1

31

0

2

29

9

0

1

0

0

2

3

0

0

4

0

0

0

1

0

0

2

7

0

0

4

0

0

0

1

0

ASP
SecondarySch. Ind.

4

PrimarySch. Ind.

1

NSS
SecondarySch. Ind.

6

8

11

1

0

16

3

0

2

2

9

7

8

29

2

0

25

3

0

2

2

10

OE
SecondarySch. Ind.

101

15

212

1

24

102

99

23

8

5

74

113
93
18

102

1

1
17

6

29
626

46

6

28

46

3
163

12

5
10

129

48

19

121

309

2

8

64

73

8

3

12

50

Total
SecondarySch. Ind.

75

PrimarySch. Ind.

Table 3. List of cetacean species and number of sightings (no. schools/no. individuals) made by three sighting/sampling
vessels in the 2003 JARPN II (Total area: May 17 – August 8).

119

108

325

2

30

148

145

29

11

17

122

121

138

935

3

37

193

236

36

13

17

125

Total
Sch. Ind.

Table 4-1. List of cetacean species and number of sightings (no. schools/no. individuals) made by dedicated sighting
vessel (SM) in the 2003 JARPN II

Cetacean species
Common minke whale

ASP
Primary
SecondarySch. Ind.
Sch. Ind.
4
4
0
0

OE
SecondarySch. Ind.
00PrimarySch. Ind.
4
4

Total
SecondarySch. Ind.
0
0

Total
Sch. Ind.
4
4

Fin whale

1

2

0

0

0

0

1

2

0

0

1

2

Sei whale

2

3

0

0

0

0

2

3

0

0

2

3

Humpback whale

1

1

2

5

0

0

1

1

2

5

3

6

Right whale

1

1

0

0

0

0

1

1

0

0

1

1

Sperm whale

28

57

0

0

1

1

28

57

1

1

29

58

Unidentified large cetacean

1

1

0

0

1

2

1

1

1

2

2

3

Unidentified cetacean

3

3

0

0

0

0

3

3

0

0

3

3

Table 4-2. List of cetacean species and number of sightings (no. schools/no. individuals) made by dedicated sighting
vessel (KS2) in the 2003 JARPN II

Cetacean species
Common minke whale

ASP
Primary
SecondarySch. Ind.
Sch. Ind.
68
76
8
8

OE
SecondarySch. Ind.
3
3

PrimarySch. Ind.
68
76

Total
SecondarySch. Ind.
11
11

Total
Sch. Ind.
79
87

Like minke whale

1

1

0

0

0

0

1

1

0

0

1

1

Blue whale

36

46

3

5

0

0

36

46

3

5

39

51

Fin whale

44

81

11

19

1

1

44

81

12

20

56

101

Sei whale

35

58

12

21

0

0

35

58

12

21

47

79

Bryde's whale

0

0

0

0

0

0

0

0

0

0

0

0

Humpback whale

14

24

3

6

1

1

14

24

4

7

18

31

Right whale

1

1

0

0

0

0

1

1

0

0

1

1

Sperm whale

168

296

15

17

2

2

168

296

17

19

185

315

Unidentified large cetacean

9

9

4

5

0

0

9

9

4

5

13

14

Unidentified cetacean

20

22

0

0

0

0

20

22

0

0

20

22

12

Table 5. Summary of whale sampling in the 2003 JARPN II survey
Research type

Whale samples
Sei
8
13

Research
periods
May 17-June 9, 2003

Sub-area
7, 8

53

Cooperative survey (A: first period)

June 10-22, 2003

8+9

15

0

15

0

Whale survey (second period)

June 23-25, 2003

8

2

7

2

3

7

2

19

5

4

7, 8, 9

28

16

15

3

100

50

50

10

Whale survey (first period)

Cooperative survey (B: second period) June 26-29, July 1-7, 2003

Whale survey (third period)
Total

June 29-30, July 8-Aug. 8, 2003

May 17-Aug. 8, 2003

13

Common minke Bryde's

Sperm
0

Table 6. Summary of whale sampling in the 2003 JARPN II survey
Common minke

Samples and dataM
93
Body length and sex
93
External body proportion
93
Photographic record and external character
93
Diatom film record and sampling
93
Standard measurements of blubber thickness (eleven points)
93
Detailed measurements of blubber thickness (fourteen points)
93
Body weight
26
Body weight by parts
93
Blubber tissues for DNA study
93
Muscle, liver and heart tissues for isozyme analysis
93
Blubber, muscle, liver and kidney tissues for heavy metal analysis
Blubber, muscle, liver and kidney tissues for organochlorines analysis 93
26
Tissues for lipid analysis
93
Blubber, muscle and liver tissues for stable isotope analysis
93
Tissues for chemical analysis
93
Tissues for various analysis
26
Muscle, blubber and intestine content for energy flow analysis
5Intestine contents for prey species identification
34
Tissues for virus test1
Muscle samples for hemoprotein analysis
Mammary grand; lactation status, measurement and histological sample Collection of maternal milk sample
Uterine horn; measurement and endometrium sample
Uterine mucus for sperm detection
Collection of ovary
Photographic record of foetus
Foetal sex (identified by visual observation)
Foetal length and weight
External measurements of foetus
Collection of foetus
93
Testis and epididymis; weight and histological sample
0
Smear samples from testis and epididymis tissues
0
Urine sample for sperm detection
93
Collection of serum sample
89
Collection of whole blood sample
Whole blood samples from umbilical cord
93
Stomach content, conventional record
93
Volume and weight of stomach content in each compartment
93
Stomach contents for feeding study
93
Record of external parasites
3
Collection of external parasites
93
Record of internal parasites
7
Collection of internal parasites
93
Earplug for age determination
93
Tympanic bulla for age determination
Maxillally teeth for age determination
93
Largest baleen plate for morphologic study and age determination
93
Largest baleen plate for stable isotopes
93
Baleen plate measurements (length and breadth)
93
Length of each baleen plate series
93
Vertebral epiphyses sample
0
Number of vertebrae
93
Number of ribs
26
Brain weight93
Skull measurement (length and breadth)0Collection of skull
0
Collection of whole skeleton
17
Reproductive study0Collection of fat tissues*1
One fetus of sex unidentified

14

F
7
7
7
7
7
7
7
3
7
7
7
7
3
7
7
7
3
0
4
0
7
0
7
0
7
4
4
4
4
4
7
7
1
7
7
7
7
1
7
0
7
7
7
7
7
7
7
0
7
3
7
0
0
2
0

T
100
100
100
100
100
100
100
29
100
100
100
100
29
100
100
100
29
5
38
1
7
0
7
0
7
4
4
4
4
4
93
0
0
100
96
1
100
100
100
100
4
100
7
100
100
100
100
100
100
100
0
100
29
100
0
0
19
0

Sei whale

Bryde's whale Sperm whale

M
23
23
23
23
23
23
23
11
23
23
23
23
11
23
23
23
11
1
23
1
23
23
17
23
23
23
23
23
23
3
23
2
23
23
23
23
23
23
23
23
23
11
23
0
1
12
3

M
19
19
19
19
19
19
19
4
19
19
19
19
4
19
19
19
4
2
3
1
19
19
8
19
19
19
19
19
19
2
19
0
19
19
19
19
19
19
19
4
19
4
19
0
0
7
1

F
27
27
27
27
27
27
27
9
27
27
27
27
9
27
27
27
9
5
17
0
27
4
27
27
27
10
10
10
10
10
27
27
15
27
27
27
27
3
27
3
27
27
27
27
27
27
27
27
27
9
26
0
0
9
1

T
50
50
50
50
50
50
50
20
50
50
50
50
20
50
50
50
20
6
40
1
27
4
27
27
27
10
10
10
10
10
23
23
17
50
50
15
50
50
50
50
6
50
5
50
50
50
50
50
50
50
50
50
20
49
0
1
21
4

F T M
31 50 131 50 131 50 131 50 131 50 131 50 131 50 1
12 16 031 50 131 50 131 50 131 50 1
12 16 031 50 131 50 131 50 1
12 16 03 5
1
11 14 1
0 1
0
31 31
3 3
31 31
31 31
31 31
17 17
*1
16 16
17 17
17 17
17 17
- 19 1- 19 1- 8
031 50 131 50 18 8
31 50 131 50 131 50 131 50 1
9 11 131 50 10 0
031 50 031 50 0
- 1
31 50
31 50
31 50
31 50
31 50 1
12 16 131 50 1
12 16 029 48 10 0
0
0 00
18 25 0
2 3
0

F
9
9
9
9
9
9
9
6
9
9
9
9
6
9
9
9
6
4
3
1
9
1
9
9
9
0
0
0
0
0
9
9
0
9
9
9
9
6
9
4
0
0
9
9
9
9
6
9
0
0
8
0

T
10
10
10
10
10
10
10
6
10
10
10
10
6
10
10
10
6
5
4
1
9
1
9
9
9
0
0
0
0
0
1
1
0
10
10
0
10
10
10
10
7
10
4
0
0
10
10
10
10
6
10
0
0
8
0

Table 7. Compositon of sex and sexual maturity of common minke whales collected by the 2003 JARPN II survey

Sub-area
7
8
9CombinedImm.
8(33.3)
4(10.5)
1(2.6)
13(13.0)

Male
Mat.
14
(58.3)
31(81.6)
35(92.1)
80(80.0)

Total
22(91.7)
35(92.1)
36(94.7)
93(93.0)

Imm
1
(4.2)
1
(2.6)
0
(0.0)
2
(2.0)

FemaleRest. Preg.
01(0.0) (4.2)02(0.0) (5.3)
11(2.6) (2.6)14(1.0) (4.0)

Combined
Total
2
(8.3)
3
(7.9)
2
(5.3)
7
(7.0)

24
(100.0)38(100.0)38(100.0)100(100.0)Sex ratio(% males)
91.7

Maturity
Male Female
63.6 50.0

Pregnancy
rate*)
100.0

92.1

88.6

66.7

100.0

94.7

97.2

100.0

50.0

93.0

86.0

71.4

80.0

*) Apparent pregnancy rate

Table 8. Compositon of sex and sexual maturity of Bryde’s whales collected by the 2003 JARPN II survey
Sub-area
7
8
9Combined

Male
Imm. Mat. Total
65
11(22.2) (18.5) (40.7)
4
3
7(28.6) (21.4) (50.0)011(0.0) (11.1) (11.1)
10
9
19(20.0) (18.0) (38.0)

Imm
5(18.5)
3(21.4)
1(11.1)
9(18.0)

FemaleCombined
Ovu Rest. Preg. Lact. Total
0
5
4
2
16
27
(0.0) (18.5) (14.8) (7.4) (59.3) (100.0)
1
1
2
0
7
14
(7.1) (7.1) (14.3) (0.0) (50.0) (100.0)
0
1
4
2
8
9
(0.0) (11.1) (44.4) (22.2) (88.9) (100.0)
1
7
10
4
31
50
(2.0) (14.0) (20.0) (8.0) (62.0) (100.0)

Sex ratio(% males)
40.7

MaturityPregnancy
Male Female
rate*)
45.5 68.8
36.4

50.0

42.9

57.1

50.0

11.1

100.0

87.5

57.1

38.0

47.4

71.0

45.5

*) Apparent pregnancy rate

Table 9. Compositon of sex and sexual maturity of sei whales collected by the 2003 JARPN II survey

Sub-area
7
8
9Combined

Male
Imm. Mat. Total
21
3(40.0) (20.0) (60.0)
25
7(10.5) (26.3) (36.8)
21113(7.7) (42.3) (50.0)
6
17
23(12.0) (34.0) (46.0)

Imm
1(20.0)
2(10.5)
1
(3.8)
4
(8.0)

Ovu
0
(0.0)
1
(5.3)
0
(0.0)
1
(2.0)

Rest.
0
(0.0)
1
(5.3)
1
(3.8)
2
(4.0)

FemaleCombinedPreg. Lact. Preg&Lact Total
1
0
0
2
5
(20.0) (0.0)(0.0)(40.0) (100.0)
7
1
0
12
19
(36.8) (5.3)(0.0)(63.2) (100.0)
8
2
1
13
26
(30.8) (7.7)(3.8)(50.0) (100.0)
16
3
1
27
50
(32.0) (6.0)(2.0)(54.0) (100.0)*) Apparent pregnancy rate

15

Sex ratio(% males)
60.0

MaturityPregnancy
Male Female
rate*)
33.3 50.0
100.0

36.8

71.4

83.3

70.0

50.0

84.6

92.3

75.0

46.0

73.9

85.2

73.9

Table 10. Statistics of body length (m) of common minke whales collected by the 2003 JARPN II survey

7

Mean
6.7

S.D.
1.0

Male
Min
4.6

Max
7.8

n
22

Mean
6.9

S.D.
1.1

8

7.3

0.7

4.8

8.0

35

6.9

1.6

4.6

8.0

3

9

7.4

0.4

5.7

8.2

36

8.3

0.3

8.0

8.6

2

Combined

7.2

0.8

4.6

8.2

93

7.3

1.4

4.6

8.6

7

Area

FemaleMin Max
5.8
8.0

n
2

Table 11. Statistics of body length (m) of Bryde’s whales collected by the 2003 JARPN II survey

7

Mean
11.5

S.D.
1.2

Male
Min
9.4

Max
13.0

n
11

Mean
11.8

S.D.
1.4

FemaleMin Max
8.8
13.5

n
16

8

11.8

0.8

10.1

12.5

7

11.8

0.9

10.5

13.0

7

9

12.3

-

-

-

1

12.9

0.8

11.0

13.8

8

Combined

11.6

1.1

9.4

13.0

19

12.1

1.3

8.8

13.8

31

n
2

Area

Table 12. Statistics of body length (m) of sei whales collected by the 2003 JARPN II survey

7

Mean
12.9

S.D.
0.2

Male
Min
12.6

8

13.0

1.0

10.6

13.8

7

14.1

0.8

12.5

15.5

12

9

13.6

0.9

11.6

14.8

13

14.2

1.2

10.5

15.5

13

Combined

13.3

0.9

10.6

14.8

23

14.1

1.0

10.5

15.5

27

Area

Max
13.1

n
3

Mean
13.5

FemaleS.D. Min Max
0.1
13.4 13.7

Table 13. Biological data of sperm whales collected by the 2003 JARPN II survey

NSub

Body length (m)Body weight (t)area Male Female

Mean MinMax

Mean Min

Max

7

0

4

10.6

10.1

10.9

16.8

13.8

19.3

8

1

2

8.7

7.9

9.9

8.8

6.3

12.7

9

0

3

11.0

10.4

11.5

20.0

17.9

22.0

16

Table 14. Prey species found in stomach of common minke, Bryde's, sei and sperm whales sampled by the 2003
JARPN II surveys (1st.+2nd. stomachs)

Common minke whale
Prey species

Range of weight (kg)in the stomach<0.1 - 1.1<0.1 - 159.9<0.1 - 106.4
2.8 - 11.2
12.0
13.4

Krill
PiscesKrill*
Japanese anchovy*
Pacific saury*Japanese pomfret*
Chum salmon*
Salmonidae*: dominant prey species

Bryde's whale
Prey species

Range of weight (kg)in the stomach<0.1 - 268.8<0.1 - 10.9
<0.1 - 196.9
89.0

PiscesKrill
Larva of anchovy*
Japanese anchovy*
Chub mackerel*Jacks*: dominant prey species

Sei whale
Prey species

Range of weight (kg)in the stomach

Copepods
Krill
Pisces

Copepods*
Krill*
Japanese anchovy*
Pacific saury*
Chub mackerel*: dominant prey species<0.1 - 50.7
<0.1 - 10.9
<0.1 - 499.6
6.2

17

Table 15. Summary of biopsy skin sampling for some whale species in the 2003 JARPN II survey

NumberTargeted Number Number Numberofindividuals
of
of
of
Ship
experiments
shootshits
samples
(A)
(B)
(C)
(D)
(E)
SSVs
5
10
18
6
2

Humpback
whale

SSVs

1

2

2

1

Right
whale

SSVs

1

1

2

Fin
whale

SSVs

2

2

Sei
whale

SSVs

2

Bryde's
whale

SSVs

Sperm
whale

SSVs

Whale
speciesBlue
whale

Effort
(hr)
(F)
3h15m

sampleper
trial(E)/(C)
0.11

sampleperhit(E)/(D)
0.33

1

0h26m

0.50

1.00

1

1

0h16m

0.50

1.00

5

1

1

1h03m

0.20

1.00

2

0

-

-

1h15m

-

-

16

22

35

7

4

8h14m

0.11

0.57

2

27

6

2

0

1h20m

0.00

0.00

Table 16. Summary of photo ID for blue, humpback, and right whales in the 2003 JARPN II survey

Numberofexperiments(A)

Targeted
individuals(B)

Numberoftrials
(C)

SSVs

7

8

7

Humpback
whale

SSVs

3

4

4

Right
whale

SSVs

2

3

3

Whale
species
Blue

Ship

whale

18

Cooperative A
Cooperative B

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

Fig. 2. Outline of the cruise track-line with mark indicating noon position of Nisshin Maru in the 2003 JARPNII cruise.

19

Fig. 3. Track-line covered by the three sighting/sampling vessels (SSVs) during the cooperative ecosystem survey of the2003 JARPN II.

Fig. 4. Track - line covered by the three sighting/sampling vessels (SSVs) during the whale survey of the2003 JARPN II.

20

10℃

13℃

15℃
10 ℃
13℃

15 ℃

Those temperature lines are made by using the information from the telex Nos. 20 (5 – 8 June, 2003) and 36 (31 July – 3 August, 2003)
by the Fishing Information Service Centre in Japan.

Fig. 5. Position of the sightings of the common minke whales (●).

10 ℃

13℃

15 ℃
10 ℃
13℃

15 ℃

Those temperature lines are made by using the information from the telex Nos. 20 (5 – 8 June, 2003) and 36 (31 July – 3 August, 2003)
by the Fishing Information Service Centre in Japan.

Fig. 6. Position of the sightings of the Bryde’s whales (▲) and sei whales (▲).

21

Fig. 7. Position of the sightings of the sperm whales (■).

Fig. 8. Position of the sightings of the Blue whales (■), fin whales (△) and right whales (●).

22

Fig. 9. Comparison of positions of the sightings and samplings of the common minke whales(●: sighted and sampled, ○: sighted only).

Fig. 10. Comparison of positions of the sightings and samplings of the Bryde’s whales(▲: sighted and sampled, △: sighted only).

23

Fig. 11. Comparison of positions of the sightings and samplings of the sei whales(▲: sighted and sampled, △: sighted only).

Fig. 12. Comparison of positions of the sightings and samplings of the sperm whales(■: sighted and sampled, □: sighted only).

24

Fig. 13. Geographical position of common minke whales sampled in the 2003 JARPN II survey, based on the sighting
position (●: Male; ○: Female).

Fig. 14. Geographical position of Bryde’s whales sampled in the 2003 JARPN II survey, based on the sighting position(▲: Male; △: Female).

25

Fig. 15. Geographical position of sei whales sampled in the 2003 JARPN II survey, based on the sighting position(▲: Male; △: Female).

Fig. 16. Geographical position of sperm whales sampled in the 2003 JARPN II survey, based on the sighting position(■: Male; □: Female).

26

Appendx 1
Preliminary results of the prey survey of JARPN II (offshore
component) in 2003
SHIGEYUKI KAWAHARA1, HIROTO MURASE2, HIKARU WATANABE1 AND MORIO ICHIHARA3
1

National Research Institute of Far Seas Fisheries, 5-7-1, Shimizu-Orido, Shizuoka, 424-8633, JapanThe Institute of Cetacean Research, 4-18 Toyomi-cho, Chuo-ku Tokyo, 104-0055, Japan
3
Field Center for Northern Biosphere, Hokkaido University 3-1-1 Minato-cho Hakodata Hokkaido 041-8611 Japankawahara@fra.affrc.go.jp
2

ABSTRACTA prey survey was conducted concurrently with the whale survey off the coast of eastern Honsyu, Japan in June andJuly 2003 as a part of offshore component of JARPN II full scale study. The primary objective of cooperative study wasestimation of prey selection by cetaceans. Two blocks with a zigzag track line were set. A trawler-type research vessel,
Shunyo-maru equipped with the quantitative echosounder dedicated to the prey survey. The acoustic survey using a
Simrad EK60 echosounder operating frequencies at 38, 70 and 120 kHz was carried out to quantify pray abundance aswell as to elucidate the distribution patterns. Species compositions of acoustical backscatterings were identified using
midwater trawl and plankton nets. In addition, trawls were towed at predetermined stations independently from theacoustic survey. MOCNESS was used to collect zooplanktons. Oceanographic observations were made with CTD down
to 500m at 29 points. Trawlings were made at 21 stations. MOCNESS was towed at 19 stations. Five major cetacean
preys, Japanese anchovy, Pacific saury, Japanese common squid, krill and copepods were distributed in the survey area
reflecting the oceanographic structure. Most of the nighttime trawl catches consisted of fishes dominated byLanternfishes.

INTRODUCTION
The Japanese Whale Research Program under Special Permit in the North Pacific (JARPN) was conducted between
1994 and 1999. The main objective was to clarify the stock structure of common minke whales (Balaenoptera
acutorostrata) in the western North Pacific. As it proved that minke whales feed on a good deal of fisheries resources
such as Japanese anchovy (Engraulis japonicus) and Pacific saury (Cololabis saira) (Tamura and Fujise, 2002), thefeeding ecology was added in 1996 as a feasibility study. At the JARPN review meeting held in February 2000, theworkshop agreed that the sampling regime must be designed to allow for a more quantitative estimation of temporal andgeographical variation in diet, and recommended that acoustic and trawl surveys should be conducted cooperatively
with whale survey (IWC 2001). In response to the recommendation, the government of Japan submitted the Research
Plan for Cetacean Studies in the Western North Pacific under Special Permit (JARPN II) (Feasibility Study Plan for2000 and 2001) to the 52nd IWC/SC (Government of Japan 2000) The overall goal of JARPN II is to contribute to theconservation and sustainable use of marine living resources including whales in the western North Pacific, especiallywithin Japan’s EEZ. The priority in this second phase is on feeding ecology, involving the studies on prey consumption
by cetaceans, prey selection of cetaceans and ecosystem model.
As the cooperative whale and prey surveys had never been conducted in the western North Pacific, a two-year
feasibility study was conducted in 2000 and 2001 (Fujise et al. 2002). Preliminary analysis of prey selection of common
minke and Bryde’s (Balaenoptera edeni) whales using feasibility study data suggested that minke whale selected
Japanese anchovy while they seemed to avoid krill while Bryde’s whale showed seasonal prey selection change fromkrill to Japanese anchovy (Murase et al. 2002). After the success in two feasibility studies, the study was expanded tofull scale in 2002 (Government of Japan 2002). Sei whale (Balaenoptera borealis) was added as target cetacean species
in addition to minke, Bryde’s and sperm (Physeter macrocephalus) whales in the full scale study. The full scale study in2003 was conducted in Sub-areas 7, 8 and 9, off the coast of eastern Honsyu, Japan in July and August. The whale
survey is conducted to collect diet data as well as other biological parameters of sei, Bryde’s, minke, and sperm whales,
whereas the prey survey was conducted mainly for the former three baleen whale species. In this document, thepreliminary results of the prey survey in 2003 were presented.
27

When food use patterns were discussed, the term selection and preference have been used interchangeably raising some
confusion (Litvaitis 2000). In this paper preference is defined as the likelihood that animal selects a resource given
equal amount with others whereas selection is defined as the animal chooses a resource irrespective of amount of
resources according to Jhonson (1980). Prey selection of cetaceans is inevitable to most ecosystem models andestimated with the cooperative whale and prey surveys.
MATERIALS AND METHOD
Survey area and research vessels
The area of the cooperative whale and prey surveys was in Sub-areas 7, 8 and 9 off the coast of eastern Honsyu, Japan(Fig. 1). Within the survey area, two blocks, Block A and Block B were set considering the oceanographic conditions
such as positions of fronts and water masses as well as anticipated distribution pattern of the target whale species. In
each block, a zigzag track line was set independently from whale survey (Fig.1). Waypoints were listed in Table 1. Prey
distribution and abundance surveys using the quantitative echosounder, midwater trawl, Multiple Opening and Closing
Nets Environmental Sampling System (MOCNESS) were conducted on Shunyo-maru (SYO, 887 GT). During thedaytime, SYO steamed at about 10 knots along the tracklines to record acoustic data and to correct biological samples
using the trawls and the MOCNESS.
Survey timing and survey hours
The cooperative survey was conducted from June to July, 2003 with two periods; first from June 15 to 25 in Block A
and second from July 1 to 9 in Block B. Details of the itinerary of the survey were shown in Table 2. Time difference
between the whale and prey surveys was less than about one week so that results of prey and cetacean surveys werecomparable. 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 end at 18:00 at local time.
Acoustic data acquisition
A quantitative echo sounder (Simrad EK60 with program version 1.4.3.64) with operating frequency at 38, 70 and 120
kHz was used on board SYO to acquire acoustic data. The transducers were hull-mounted at the depth of 4.3m from thesurface. Calibrations were carried out at off the coast of Shiogama on June 30, 2003 using the copper sphere techniquedescribed in EK 60 online help manual.
Surface and midwater trawlings
The midwater 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 inner. The sampling depth and the height of the mouth of the net were monitored with the scammertransducers attached to the head and the bottom rope of the trawl. Towing speed of the trawl net was 4-5 knot. Surface
and midwater trawl was towed at predetermined and acoustic target identification stations. Surface trawls wereconducted using the midwater trawls with the floats attached the bridle so that the trawl could be towed at the surface.
Surface trawl was designed for collecting Pacific saury. Target trawls were conducted for 0.5 to 1 hour to identify the
species and size compositions of biological backscattering detected by the quantitative echosounder.
Another type of trawl was conducted at predetermined (routine) stations in each block in daytime. Several
nighttime predetermined trawls were also made. The purpose of the predetermined trawls was to estimate the abundanceand distribution patterns of cephalopods and neustnic organisms such as Pacific saury that are difficult to detect by theechosounder. Three different depth layers were sampled at predetermined trawl stations; 0-30m (surface) and 0-100m(midwater). Surface predetermined trawls were conducted in northern part of Block A where Pacific saury seemed to beabundant. Nighttime trawls were conducted to examine day-night difference of prey species composition. Daytime
trawls were towed before nighttime trawls were tow on the same day. Midwater predetermined trawl was towed for 20
minutes at each depth layer, 0-30 m, 30-60 m, and 60-100 m whereas surface predetermined trawl was towed for 30
minutes.
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 of 100 individuals was measured to examine their size composition. A
part of samples were frozen at –30°C for further analysis in the laboratory.
Net sampling of zooplankton
In addition to the trawl net, MOCNESS (mouth opening size 1m2 and mesh size 0.33mm x 0.33mm) was used to collectmacro and mesozooplanktons. At the predetermined station, following depth layers were towed; 0-20m, 20-40m, 4060m, 60-80m, 80-100m, 100-150m, 150-200m and 200-250m. Target towing was also made to identify species and size
compositions of biological backscattering detected by the quantitative echo sounder. Nighttime towing was conductedat several stations to examine day-night difference of prey species composition. Daytime towing was made before
28

nighttime trawls were towed on the same day. The samples were preserved in 10 % formalin for species identification at
the laboratory.
Acoustic data analyses
Acoustic data were analyzed with the aid of SonarData Echoview (version 3.00.74.01) at the laboratory. In principle,
backscattering on the echosounder was identified based mainly on the result of trawl and MOCNESS samplings. For
fishes, data collected at 38 kHz were used with the threshold set at -60dB and the depth range from 10m to 250m. For
Japanese anchovy that was the most common fish, school shape and backscattering intensity of backscattering were also
used for species identification. The integration was made at an interval of one nautical mile by 50 m depth zone. For
krills, data collected at 120 kHz were used with the threshold set at –80 dB. The analyzed depth range was from 12m to250m (maximum depth at 120 kHz). Backscattering was identified as krills if ∆Sv (the difference of Sv between 38 and120) falls between 10 and 15 dB (Miyashita et al. 1997). Because most of krill species in the survey area have the bodylength similar to isada krill (Euphausia pacifica) taken in the coastal area off Tohoku, this ∆Sv value was applied to.
Species identification was based on both ∆Sv and the samples form MOCNESS. For copepods, data collected at 120
kHz were used with the threshold set at –110 dB. Target strengths (TS) of copepods were calculated using the Distorted
Wave Born Approximation based seformed cylinder model (Stanton and Chu, 2000). Based on the TS, ∆Sv (thedifference of Sv between 38 and 120) falls between 10 and 30dB were identified as copepods. Net sampling results aswell as school shape were considered to distinguish between krill and copepods. The integration was made at an intervalof one nautical mile by 50 m depth zone.
Oceanographic observations
CTD (Model SBE 9, Seabird Co.) casts were conducted down to 500m at each sampling station to measure thetemperature and salinity profiles in the study area by SYO. Two CTD casts were made down to 2500m and 4000m tocollect water samples for the salinity compensation. Salinity compensation for CTD data and analysis of oceanographic
conditions were made after the cruise.

RESULTS AND DISCUSSION
A summary of the cooperative whale and prey surveys was shown on Table 3. Summary of trawl and MOCNESS
sampling in the first and second survey periods were shown on Table 4 and 5, and 6 and 7, respectively. CTD stations
were listed in Table 8. Positions of trawls, MOCNESS and CTD stations were shown on Figs. 2 and 3.
Results of echosounder survey
Currently, acoustic data are analyzed to estimate the cetacean prey abundance at the laboratory. Some preliminary
results were presented here.
Calibration
The results of the calibration for 38, 70 and 120kHz were shown on Table 9. Those results were applied to the collected
data.
Block A
Planned tracklines were almost surveyed using the echosounder. To identify acoustical backscattering, midwater trawls
were towed at 2 stations. In addition, samples from predetermined trawl and MOCNESS stations were also used forspecies identification.
Krill distributed in the entire survey area. Three pelagic fish species, Japanese anchovy, Pacific, saury andchub mackerel were identified in the trawl. It is difficult to determine the fish species based on school morphology(shape, size, etc.) of backscattering. Species allocation of backscattering will be made using proportion of individual
number by species in the trawl samples.
Result of MOCNESS sampling suggested that copepods species form species specific school. They formed
layer shape school at specific depth. Acoustical abundance estimation will be conducted based on the contents of
MOCNESS samples.
Block B
Planned tracklines were almost surveyed using the echosounder. To identify acoustical backscattering, midwater trawls
and MOCNESS were towed at 1 and 5 stations, respectively. Japanese anchovy and krill were abundant prey species inBlock B as in the past cruise. Japanese anchovy was distributed throughout Block B but the length frequencies weredifferent from the northern part to the southern part.
29

Backscatterings that were assumed as krill were scarce and weak. Krill might be distributed at deeper water
depth than we expected. This point will be considered further in the laboratory.
Trawls at predetermined stations
Block A
Midwater predetermined trawls were conducted at 13 stations (seven 0-100m water depth station and six 0-30m
stations) in Block A. Small size Japanese anchovy and chub mackerel were caught in southern part of the survey area
whereas large size Japanese anchovy and Pacific saury were caught in northern part.
Block B
Midwater routine trawls were conducted at 5 stations. Japanese anchovy was dominant species.

MOCNESS at predetermined stations
Block A
Predetermined MOCNESS tows were made at 3 stations. At each station, both day and night tows were made. Vertical
distribution patterns zooplanktons will be examined using the collected samples.
Block B
Predetermined MOCNESS tows were made at 3 stations in only daytime. At each station, both day and night tows were
made. Vertical distribution patterns zooplanktons will be examined using the collected samples.
Preliminary analysis suggested that length size of krill in the MOCNESS sample was smaller than we expected.
Due to small mouth opening of MOCNESS, large size krill might avoid the net. Large size plankton net, such as IKMT
(16 feet) should be also used in the future prey survey.

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 Miyasita (Hokkaido University)
provided useful comments on acoustic data analysis.

REFERENCES
Fujise, Y., Kawahara, S., Pastene, L. A. and Hatanaka, H. 2002. Report of 2000 and 2001 feasibility study of the Japanese whale research program
under special permit in the western North Pacific – phase II. Paper SC/54/O17 submitted to the 54th IWC Scientific Committee Meeting, 202 pp(available from the IWC secretariat).
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 52th IWC Scientific Committee Meeting,, 68 pp.
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 52th IWC Scientific Committee Meeting,,
International Whaling Commission. 2001. Report of the workshop to review the Japanese whale research programme under special permit for North
Pacific minke whales. J. Cetacean Res. Manage. (Suppl.) 3:377-413.
Jhonson, D. H. 1980. The comparison of usage and availability measurements for evaluating resource preference. Ecology 61:65-71.
Litvaitis, J. A. 2000. Investigating food habits of terrestrial vertebrates. In: Research techniques in animal ecology: controversies and consequences,
pp. 165-190. Boitani, L. and Fuller, T. K. (eds), Columbia University press, New York, pp.442.
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.
Murase, H., Tamura, T., Kiwada, H., Fujise, Y., Watanabe, H., Ohizumi, H. and Kawahara, S. 2002. Preliminary estimation of prey preference ofminke and Bryde’s whales based on JARPN II. Appendix 5, pp 97-117. In: Fujise, Y., Kawahara, S., Pastene, L. A. and Hatanaka, H. 2002. Reportof 2000 and 2001 feasibility study of the Japanese whale research program under special permit in the western North Pacific – phase II. Paper
SC/54/O17 submitted to the 54th IWC Scientific Committee Meeting, 202 pp (available from the IWC secretariat)
Tamura, T. and Fujise, Y. 2002. Geographical and seasonal changes of the prey species of minke whale in the Northwestern Pacific. ICES J. Mar. Sci.
59:516-528.
Stanton, T., K. and Chu, D. 2000. Review and recommendations for the modelling of acoustic scattering by fluid-like elongated zooplankton:
euphausiids and copepods. ICES J. Mar. Sci. 57:793-807

30

Table 1. List of waypoints.

Block A
ＷＰ
1
2
3
4
5
6

Distance
Lat
Long Course (n.mile)
38-00N 156-00E 67
15339-00N 159-00E 293
151
40-00N 156-00E 57
16341-30N 159-00E 304
161
43-00N 156-00E 65
14444-00N 159-00E
Total
772

Block B

Distance
Lat
Long Course (n.mile)ＷＰ
1 40-00N 146-30E 117
130
2 39-00N 149-00E 243
130
3 38-00N 146-30E 127
150
4 36-30N 149-00E 234
150
5 35-00N 146-30E
Total
560

Table 2. Itinerary of the survey

Date
6/12
6/15
6/25
6/27
6/28
6/30
7/1
7/8
7/9
7/11

Event
Departed Shimizu, Japan.
Started Block A survey.
Ended Block A survey.
Conducting CTD and water sampling casts (ST-17 and ST-18).
Arrived Shiogama, Japan
Departed Shiogama, Japan. Counducting echo sounder calibration.
Started Block B survey.
Conducting echo sounder noise measurement.
Ended Block B survey.
Arrived Shimizu, Japan.

31Prey survey
date

6/15-25
7/1-9

SurveyBlockAB

6/10-22
6/26-29, 7/1-7Whale survey date

Table 3. Summary of the survey.

54

No. oftracklines

2
1

No. of target
trawl stations

11
5

2
0

32

0
4

3
3

NO. ofNo. ofroutineNo. of routine NO. of target
routine trawl
trawl stations MOCNESS MOCNESS
stations
stations
stations(Nighttime)(daytime)(daytime)

30

NO. ofroutine
MOCNESS
stations(Nighttime)

16
13

No. ofCTD
stations

15
1

No. ofsampledcommon
minke
whale

15
2

19

No. ofNo. ofsampledsampled
Bryde's
sei whale
whale

P
P
T
P
P
P
P
P
P
P
T
P
P
P
P

D
N
D
D
D
D
D
D
D
D
D
D
D
N
D

2003/6/15
2003/6/15
2003/6/17
2003/6/17
2003/6/18
2003/6/18
2003/6/19
2003/6/19
2003/6/20
2003/6/21
2003/6/21
2003/6/22
2003/6/22
2003/6/22
2003/6/23

Predetermined/t
Day/night Datearget

38-13N38-13N
39-24N
39-31N
39-54N40-08N
40-31N
40-55N
41-32N42-08N
42-15N42-50N43-10N43-10N43-30N

Lat.

156-39E
156-39E
157-44E
157-28E
156-17E
156-16E
157-02E
157-50E
158-55E
157-44E
157-28E
156-18E
156-30E
156-29E
157-26E

Long.

0-100
0-100
0-30
0-30
0-100
0-30
0-100
0-30
0-100
0-30
0-30
0-30
0-100
0-100
0-30

30
30
30
30
30
30
30
30
30
30
20
30
30
30
30

4.1
32.5
31.3
188.5
0.2
+
5.5
158.2
1.4
464.3
232.2
+
8.0
29.9
377.2

Towing Total
Targetduration sample wt.
depth (m)(min.)
(kg)

21
22
24
26
28
31

Station

P
P
P
T
P
P

D
D
D
D
D
D

Predetermined/
Day/night
target2003/7/1
2003/7/2
2003/7/4
2003/7/4
2003/7/6
2003/7/8

Date39-45N
39-36N
38-24N38-01N37-09N36-00NLat.

147-06E
147-43E
147-30E
146-33E
147-53E
148-09E

Long.

1.9
6.8
24.3
150.8
-

0.1
-

Engraulis E. japonicus
japonicus (juv)

1.2
0.2
2.6
1.8
-

Scomberjaponiccus

0-30
0-100
0-100
0-30
0-100
0-100

30
30
30
30
30
30

16.7
90.9
0.1
0.2
0.7
4.1

Towing
Total
Targetduration sample wt.
depth (m)(min.)(kg)

Table 5. Results of target and predetermined trawls in Block B.

1
1
3
4
5
6
7
8
9
11
12
13
14
14
15

StationTable 4. Results of target and predetermined trawls in Block A.

16.0
83.5
+
+
+

33

Sampled weight by species (kg)

2.3
-

+
+
+
2.4

+
+
+
+
+

E. japonicus Scomber(juv)
japoniccus

1.1
1.3
2.8
-

- 3.1
- 0.3
- 5.2
8.0 20.0
-

0.8
0.8
4.1
35.9
-

Todarodes
pacificus

0.1
+
+
+

Trachurus
japonicus

0.6-

Cololabis
saira

2.1
+

Other
Fish

0.2
+
+
-

Todarodes
pacificus

+
-

Other
cephalopod

1.7
0.5
-

0.1
4.8
+
0.1
0.7
1.7

+
+

Other

+
- 10.6
- 0.3
0.1
+
+
+
-

Gelatinous
Other
zooplankton

Gelatinous
zooplankton

+
0.3
+
+
1.3
-

Onychoteuthis Other
borealijaponca cephalopod

Sampled weight by species (kg)9.2-

Oncorhynchus Oncorhynchus Ceratoscopelus Stenobrachius Other
gorbuschakisutchwarmingii
leucopsarus Fish

Engraulis
japonicus

0.1
4.4
158.2
434.0
232.2
377.2

CololabissairaTable 6. Results of MOCNESS in Block A.

Station

Predetermined/ Day/night
targetDate

Lat

Targetdepth (m)

Long

2

P

D

2003/6/16

38-54N

158-41E

2

pN

2003/6/16

38-54N

158-41E

10PD

2003/6/20

41-41N

158-40E

10pN

2003/6/20

41-40N

158-40E

16

PD

2003/6/25

43-58N

158-53E

16

p

N

2003/6/24

43-58N

158-53E34

250→200
200→150
150→100
100→80
80→60
60→40
40→20
20→0
250→200
200→150
150→100
100→80
80→60
60→40
40→20
20→0
250→200
200→150
150→100
100→80
80→60
60→40
40→20
20→0
250→200
200→150
150→100
100→80
80→60
60→40
40→20
20→0
250→200
200→150
150→100
100→80
80→60
60→40
40→20
20→0
250→200
200→150
150→100
100→80
80→60
60→40
40→20
20→0

Amount offilteredwater (m^2)
534.6
383.6
432.7
207.7
229.7
167.0
185.6
200.6
686.8
311.8
243.4
150.5
281.1
281.8
238.8
250.5
474.8
358.1
468.0
238.4
280.6
220.3
292.4
291.8
446.3
471.3
435.8
205.4
209.8
225.6
164.8
239.5
386.0
442.2
439.2
176.2
250.1
229.3
231.2
288.7
383.9
524.9
411.7
219.9
218.0
165.0
252.5
301.1

Table 7. Results of MOCNESS in Block B
Station

Predetermined Day/
/target
night

Date

Lat

Long

20

P

D

2003/7/1

39-53N

146-43E

23

T

D

2003/7/3

39-11N

148-32E

25

P

D

2003/7/4

38-15N

147-06E

27

T

D

2003/7/6

37-35N

147-07E

29

T

D

2003/7/3

36-55N

148-19E

30

T

D

2003/7/7

36-44N

148-41E

32

P

D

2003/7/9

35-10N

146-49E

35

Target depth(m)
250→200
200→150
150→100
100→80
80→60
60→40
40→20
20→0
100→200
200→200
200→150
150→240240→230230→250
250→220220→260
250→200
200→150
150→100
100→80
80→60
60→40
40→20
20→0
160→140140→120120→100
100→80
80→60
60→40
40→20
20→0
230→250
250→210210→230230→230230→260
260→280
280→230230→260
270→250240→200
200→150
150→100
100→75
75→50
50→25
25→0
250→200
200→150
150→100
100→80
80→60
60→40
40→20
20→0

Amount offilteredwater (m^2)
383.4
492.6
681.2
167.1
173.0
176.0
177.3
267.4
1104.8
670.8
829.5
475.5
575.8
460.5
482.6
479.5
627.4
425.7
671.5
252.4
256.0
285.4
281.1
231.4
329.0
314.4
311.0
445.0
266.5
299.5
208.5
301.0
801.9
293.4
868.8
879.1
672.4
1075.8
424.1
511.4
434.2
324.0
158.0
276.4
307.1
123.3
236.6
296.2
391.9
467.5
395.9
266.4
375.7
272.0
250.5
467.8

Table 8. Results of CTD casts.

Station
ST-01
ST-02
ST-03
ST-04
ST-05
ST-06
ST-07
ST-08
ST-09
ST-10
ST-11
ST-13
ST-14
ST-15
ST-16
ST-17
ST-18

Date
2003/6/15
2003/6/16
2003/6/17
2003/6/17
2003/6/18
2003/6/18
2003/6/19
2003/6/19
2003/6/20
2003/6/20
2003/6/21
2003/6/22
2003/6/22
2003/6/23
2003/6/24
2003/6/27
2003/6/27

Block B
StationDate
ST-19 2003/6/30
ST-20 2003/7/1
ST-21 2003/7/2
ST-22 2003/7/2
ST-23 2003/7/3
ST-24 2003/7/4
ST-25 2003/7/4
ST-26 2003/7/5
ST-27 2003/7/6
ST-28 2003/7/6
ST-29 2003/7/7
ST-30 2003/7/7
ST-31 2003/7/8
ST-32 2003/7/9

Lat.
Long. Depth (m)Note
38-13N 156-39E
500
38-54N 158-41E
500
39-25N 157-48E
500
39-30N 157-28E
500
39-54N 156-16E
500
40-09N 156-11E
500
40-31N 157-01E
500
40-55N 157-51E
500
41-32N 158-55E
500
41-40N 158-40E
500
42-08N 157-44E
500
42-50N 156-18E
500
43-10N 156-30E
500
43-29N 157-27E
500
43-58N 158-54E
500
38-30N 146-00E 4000 Water sampling
38-30N 143-30E 2500 Water sampling
Lat.
Long. Depth (m)Note
38-14N 141-22E
36
Data for calibration
39-54N 146-44E
500
39-45N 147-07E
500
39-35N 147-43E
500
39-08N 148-37E
500
38-24N 147-31E
500
38-14N 147-06E
500
38-03N 146-36E
500
37-33N 147-05E
500
37-09N 147-53E
500
36-57N 148-14E
500
36-47N 148-42E
500
36-00N 148-09E
500
35-07N 146-48E
500

36

Table 9. Results of the calibration of the echosounder.
38 kHzFrequency
70 kHz120 kHzCalibration version 1.0.0.5
6/30/2003
38°14N141°22E

Calibration version 1.0.0.5
6/30/2003
38°14N141°22E

Calibration version 1.0.0.5
6/30/2003
38°14N141°22E

Referecne targetTS
TS deviation
Minimum distance
Maximum distance-33.60 dB
3.0 dB
23.00 m25.00 m-39.20 dB
3.0 dB
19.00 m24.00 m-40.40 dB
3.0 dB
12.00 m17.00 mTransducer
Transducer typeTransducer serial No.
Frequency
Gain
Athwartship angle sensitivity
Athwartship Beam angle
Athwartship Offset angle
Alongship angle sensitivity
Alongship beam angle
Alongship offset angle
Sa correction
Beamtype
Two way beam angle
Depth

ES38B
30128
38000 Hz26.08 dB
21.90
7.05 deg-0.04 deg
21.90
7.10 deg-0.01 deg
-0.72 dB
Split
-20.6 dB
0.00 m

ES70-1129897
70000 Hz21.82dB
13.00
11.51 deg
-0.08 deg
13.00
11.60 deg
0.09 deg
0.00dB
Split-16.8 dB
0.00 m

ES120-729415
120000 Hz
25.49 dB
21.00
7.36 deg-0.18 deg
21.00
7.42 deg
0.17 deg-0.57dB
Split-20.8 dB
0.00 mGPT 38 kHz 0090720120f 1 ES38B

GPT 70 kHz 0090720171e5 1 ES70-11

GPT 120 kHz 009072017195 1 ES120-7

1.024 ms
2000 W
0.192 m2.43 kHz

1.024 ms
800 W
0.192 m2.86 kHz

1.024 ms
500 W
0.190 m3.03 kHzEK60 version 1.4.4.66

EK60 version 1.4.4.66

EK60 version 1.4.4.66

TS detection
Minimum value
Maximum beam compensation
Maximum phase deviation
Minimum echolength
Maximum echolength-60.0 dB
6.0 dB
8.0
80 %
180 %

-60.0 dB
6.0 dB
8.0
80 %
180 %

-60.0 dB
6.0 dB
8.0
80 %
180 %

Environment
Water temperature
Salinity
Absorption coefficientSound velocity

14.05°C
33.29 PSU
8.6 dB/km
1502.5 m/s

14.05°C
33.29 PSU
22.1 dB/km
1502.5 m/s

14.05°C
33.29 PSU
40.2 dB/km
1502.5 m/s

Beam model results
Transducer gain
Athwartship Beam angle
Athwartship Offset angle
Alongshipship Beam angle
Alongshipship Offset angle
Sa correction

25.91 dB
7.12 deg-0.03 deg
7.07 deg-0.06 deg
-0.66 dB

21.41 dB
11.50 deg
-0.04 deg
12.01 deg
-0.06 deg
-0.38 dB

25.88 dB
7.39 deg-0.19 deg
7.46 deg-0.16 deg
-0.78 dB

Software
Date
LatitudeLogitudeTransceiver
Transceiver type
Pulse duration
Power
Sample interval
Receiver bandwidth
Sounder type37

Fig. 1 Survey area and planned tracklines. Sub-area 7 was divided to 5 small areas.
.

38

(a)

(c)

(b)

Fig. 2. Positions of trawl (a), MOCNESS (b), and CTD casts (c) in Block A.

39

(a)

(c)

(b)

Fig. 3. Positions of trawl (a), MOCNESS(b) and CTD casts (c) in Block B.

40

Appendx 2
Oceanographic conditions in the Kuroshio-Oyashio Interfrontal zone in June to July 2003
DENZO INAGAKE, MAKOTO OKAZAKI, KAZUYUKI UEHARA AND SHIGEYUKI KAWAHARANational Research Institute of Far Seas Fisheries, 5-7-1, Shimizu-Orido, Shizuoka, 424-8633, Japankawahara@fra.affrc.go.jp

INTRODUCTION

The Kuroshio is one of the strongest west-boundary current of subtropical gyre and flows northward with warm highsalinity water from the offshore area of the Philippine to the waters off Japan. The Oyashio flows southwestward along
the Kuril Islands with cold low-salinity water. The Kuroshio and the Oyashio flows eastward from the Japan coast, andthe area between the Kuroshio and Oyashio east off Japan was usually called the Kuroshio-Oyashio Inter-frontal zone.
In this area, there are a lot of oceanic fronts and water masses. In the offshore area east of around 150 ﾟ E, the Oyashio
front branches to the Subarctic Front (temperature front defined by 4℃) and the Subarctic Boundary (salinity front
defined by 34.0psu). Distributions of water masses and fronts in June to July 2003 will be described.

METHOD
Hydrographic observations with a conductivity-temperature-depth profiler (CTD; SBE 911plus) were carried out
from 15th June to 9th July 2003 in the Kuroshio-Oyashio Inter-frontal Zone using R/V Shunyo Maru (Fig. 1). Salinity
compensation for CTD data was done using water sampling data at two CTD stations. The accuracy of the salinity was
expected 0.002 psu after the compensation.

The oceanographic conditions in June and July 2003 were analyzed by Tohoku National Fisheries ResearchInstitute (TNFRI), which used quasi-real-time data from several cooperative organs and prefectures, that was Fisheries
Research Agency, Meteorological Agency, Hydrographic Department and Fisheries Experiment Stations, etc. TNFRI
published temperature maps and schematic hydrographic maps using World Wide Web(http://www.myg.affrc.go.jp/index-j.html). Oceanic fronts and water masses are usually detected by subsurface
temperature map, because they are obscure in sea surface temperature distributions in warming seasons and the Oyashio
water spreads into the subsurface layer. The Kuroshio Extension is defined by the 14℃ isotherm at the depth of 200m
(Kawai , 1969). The Kuroshio warm-core rings and cold rings are defined by closed isothermal lines in a 200 m
temperature map. The warm water spread from Kuroshio Extension is defied by temperature more than 10℃ at thedepth of 100 m . The Tsugaru warm water is defined by an oceanic front in a 100 m temperature map. The first and thesecond Oyashio Intrusions are defined by temperature lass than 5℃ at the depth of 100 m (Murakami, 1994).

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 Oyashio water in the lower part of Fig. 2) and the mixed water of theKuroshio water and Oyashio water.

Figure 3 shows the schematic hydrographic map in June and July 2003, presented by TNFRI. The northern limit of
the Kuroshio Extension at the first crest was 36ﾟ20’N in June and 36ﾟ10’N (lower red area in Fig.3), which are almost
mean position. The northern limit of the warm water spread from the Kuroshio Extension shifts northward from March
to November. Its position in June 2003 was at 39ﾟ10’N on 145ﾟ30’E line and 40ﾟ10'N on 152ﾟE line. In July 2003, it
was 39ﾟ10’N on 146ﾟE line and 40ﾟ30'N on 158ﾟ30’E line. The Kuroshio warm-core ring was detected by 200 m
temperature map (Fig. 4) around 41ﾟN, 146ﾟ30’E and it moved westward to 40ﾟ50’N, 145ﾟ50’E. Tsugaru warm water
spread eastward to 143ﾟ50’E in June and 142ﾟ50’E in July along 41ﾟ30’N. The southern limit of the first Oyashio
41Intrusion was located 39ﾟN on 144ﾟ40’E line in June and 38ﾟ30’N on 142ﾟ40’E line in July, which were more southern
position from monthly mean location. The southern limit of the second Oyashio Intrusion in June was 39ﾟ10’N, 146ﾟ
20'E where was in the south from the mean position. In July, it was obscure in Fig 3 but maybe existed around 39ﾟ
30’N, 146ﾟ30'E, where was in a slightly south from the mean.
Figure 5 shows the 100 m depth temperature map observed by R/V Shunyo Maru. The Oyashio water colder than
5℃ was spreading at the northern part of the observation area. The warm water spreading from the Kuroshio area wasobserved in the southern part of this area. The Subarctic Boundary (defined by 34 psu) was observed around 40ﾟN in
the eastern part of this area.
Figure 6 shows the vertical temperature sections between 146ﾟE -149ﾟE and 156ﾟE-159ﾟE, which were zigzag
lines. The warm water spread from the Kuroshio Extension was limited in the southern part of the 156ﾟE -159ﾟE
section but observed in the almost whole area, north of the warm water (north of 40ﾟN). In contrast, the warm water
was observed at the upper layer in almost whole area in the 146ﾟE -149ﾟE section without the Oyashio water in thenorthern part of this section (north of 39ﾟ30’N). There was a sharp temperature front around 39ﾟ30’N between thewarm water and the Oyashio water in this section. Similar pattern was also found in the salinity section, namely, asharp salinity front was observed around 39ﾟ30’N where was between southern high-salinity water higher than 34psu
and northern low-salinity water less than 33.5psu (lower left panel in Fig. 6). That is to say, a warm and high-salinity
water originating from subtropical water and cold law-salinity water originating from Subarctic water were also foundin this section, and the Oyashio front (defined by 5℃ at 100m depth), the Subarctic Front (defined by temperature front
of 4℃ isotherm), the Subarctic Boundary (defined by salinity front of 34psu) and the northern edge of the warm water
spreading from the Kuroshio (defined by 10℃ at 100 m depth) were concentrated into almost same location (around39ﾟ30’N) in the 146ﾟE -149ﾟE section. In the 156ﾟE -159ﾟE section, the Subarctic Boundary (34psu isohaline) and thenorthern edge of the warm water (10℃ isotherm) were detected in the almost same location around 39ﾟ30’N, but theSubarctic Front (4℃ isotherm) was between 42ﾟ30’N -43ﾟN separated from the Subarctic Boundary.

REFERENCES
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).

42

Fig. 1. Station map observed by R/V Shunyo Maru in 15 June – 9 July 2003. Green triangles, light blue stars and blue
circles denote CTD stations in the warm area (100 m temperature was over 10℃ and 200 m temperature was less than
14℃), the cold area (100 m temperature was over 5℃ and less than 10℃) and the Oyashio area (100 m temperature
was less than 5℃), respectively

Fig. 2. Temperature-Salinity diagrams using CTD station data observe by R/V Shunyo Maru in 15 June – 9 July 2003.
Each thin line in this figure denotes a density line of sigma-t. Green, light blue and blue points corresponded to thewarm area, the cold area and the Oyashio area, respectively.

43

Oyashio Area
Tsugaru
WarmWarm
core
Water
1st Oyashio Ring
Intrusion
2nd Oyashio
Intrusion
Warmcore
Ring
Warm
water
Kuroshio
AreaOyashio Area

Tsugaru
Warm
Water

WarmcoreRing
2nd Oyashio
Intrusion
1st Oyashio
WarmIntrusion
core
Ring
Warm
water

Kuroshio
Area

Fig. 3. Schematic hydrographic map in Tohoku area, northwestern Pacific, in June (upper panel) and July (lower panel)
2002. (Presented by Tohoku National Research Institute.) Blue area, green area, yellow area and red area denote the
Oyashio (100 m temperature was less than 5℃), cold area (100 m temperature was over 5℃ and less than 10℃), warm
water (100 m temperature was over 10℃ and 200 m temperature was less than 14℃) spreading from the Kuroshio
Extension and the Kuroshio area (200 m temperature was over 14℃), respectively. Green triangles, light blue stars andblue circles denote CTD stations observed by R/V Shunyo Maru in the warm area, cold area and the Oyashio area,
respectively

44

Fig. 4. Temperature map at the depth of 200m in June (upper panel) and July (lower panel) 2003, presented by Tohoku
National Research Institute.

45

Fig.5.

100m temperature (upper left panel) and salinity (lower panel) maps observed by R/V Shunyo Maru in

15 June – 9 July 2003.

46

Fig. 6. Temperature (upper panels) and salinity (lower panels) between 146 ﾟ E-149 ﾟ E (left panels) and between 156 ﾟ
E-159 ﾟ E (right panels) observed by R/V Shunyo Maru in 16-24 June and 1-7 July 2003.

47