BAIRD'S BEAKED WHALES CAUGHT ON THE
COAST OF JAPAN IN RECENT 10 YEARSMASAHARU NISHIWAKI* AND NOBUO OGURO*ABSTRACT

It seems there has been no sign of decrease on the stock of Baird's beaked
whale on the coast of Japan in recent years. This may be the result of reduction in number of catcher boats. The length distribution of the whales caught
recently shows a good balance. That is, nearly 80% of the whales were
sexually matured. A migrating population of this species appears at Boso
Peninsula in May, reaches Hokkaido some time between July and August andcomes back again to Kinkazan off shore in the fall and then leaves Japan.
They are likely to prefer waters deeper than 1,000 m. On the Sanriku coast,
the whales eat deepwater fish, but on the coast of Hokkaido, they eat nearlyexclusively squid.
It can be presumed that the whales caught in the Abashiri area in May
through June should be Hyperoodon ampullatus.
INTRODUCTION

There are few countries in which the whaling industry catches Baird's beaked
whales as a harvest and utilize fresh or dried meat for human consumption, andoil extracted from blubber, bones and viscera are used as well as sperm whaleoil.
Biological study has been done on Baird's beaked whales caught in the periodof 1948-1952 by Omura et al. (1955). Present study was done on the whalescaught in the period of 1960-1969. However, data were fewer in the early half
period and considerable number in the latter half. Because of this unbalance,
our consideration was done mainly on the data in the latter five years 1965-1969.
CATCH RECORDS AND ITS ANALYSIS

About 25 years ago, the smaller species whaling industry in Japan made muchprofit from harvests of minke, pilot and beaked whales. And number of catcherboats gradually increased ; in the mean time, number of catch per boat becomeless and less. So the whalers competed each other by extra equipment which
often was a 50 tons boat with 50 mm caliber guns. The result was a folly, theyneed extra catch to pay for such expences. It was not enough for them to catchonly those previously permitted species from certain amount of populations migrating to the coast of Japan. They began to poach banned whales such as the sperm* Ocean Research Institute, University of Tokyo, Tokyo.
Sci. Rep. Whales Res. Inst.,
No. 23, 1971. 111-122.

112

NISHIWAKI AND OGUROTABLE I.

Years

NUMBER OF CATCHER-BOATS AND NUMBER OF BAIRD'S
BEAKED WHALES CAUGHT IN JAPANESE WATERS
IN 1948-1969
Number of
Number of
Number of whales
catcher-boats
per catcherswhales caught

1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
TABLE 2.

Years

1965

1966

1967

1968

1969

Total

Sex
ratio

Sex
Male
FemaleTotal
Male
FemaleTotal
Male
FemaleTotal
MaleFemale
Total
Male
FemaleTotal
Male
FemaleTotal
Male
Female7695
197242
382
270
230
258
297
186229
186
147
133
145
160
189172
171
107
117
134

80
68
65
58544754463532252320191816161587

2.5
3.6
5.9
4.7
4.3
5.5
5.5
4.0
6.5
5.8
5.9
5.8
7.3
8.4
10.5
10.8
10.7
7 .1
14.6
19.1

NUMBER OF BAIRD'S BEAKED WHALES CAUGHT IN JAPANESEWATERS IN 1965-1969.
Areas

41
2768
62
2385
35
2358364480
444791
218
164382
57.0
42.9

IIIII

IVTotalSex ratio

372360332154171027151227221032
124
76
200
62.038.0118196111768
1454922430
3363
47.6
52.4

1312255101562810102
70
172
106
65
171
64
43
107
5760
117
71
63
134
400
301
701
57.1
42.9

59.3
40.7

3
472828
56
50.0
50.0

62.0
38.0
59.8
40.2
48.7
51.3
53.0
47.0
57.1
42.9

Sci. Rep. Whales Res. Inst.,
No. 23, 1971.

113

BAIRD'S BEAKED WHALES IN JAPANand the sei whales by those well equipped boats. The fact became a serious problem for the Fisheries Agency of the Government. To stop that devastating catch,the Agency recomended whalers to change their whaling objectives from the smallerwhales to the larger ones. As a measure, they gave a certain quota equally to agroup of ten 50 tons boats and a single 500 tons boat. In those days larger species
whaling promised considerable interest, many whalers converted to the larger species
whaling. The small boat, therefore, reduced in number and the catch per small
boat was recovered accordingly.
As shown in Tables 1 and 2, the number of Baird's beaked whales caught was
30-40 thirty to forty years ago, and as many as 250-300 about twenty years ago,the peak of which was 382 in 1952. Then, unpleasant tendencies began to appear
in the CPUE (catch per unit effort) by the influence of thoughtless catch. Number

200.cCJ)

:::>

"'
0(/)

<J)

«i.c"'

0 100.....
<J)
.0

E

:::>

z._

______ _1960--- ----------------- ........ ..... __ ......_ ___ _1963

1966

1969

Fig. 1. Number of Baird's beaked whales caught and number of catcher-boats inJapanese waters according to the years.

of total catch also began to decrease. However, some recovery appeared in recent
10 years as 130-170. Analyzing these recent statistics, it may safe to say that thestock is somehow stabilized than ever. In Fig. I, although the number of total
catch in each year is vary, there is no tendency of decrease. And the number ofcatch per boat (CPUE) is still increasing as a result of the reduction.
There are two land stations in Area I, four in Area II and one in Areas III
and IV respectively.
Distribution of positions of catch is shown in Fig. 2. To analyze conditionsof the stock, the coastal waters was divided into some area as Omura et al. formerly
did (1955). On the other hand, there is no catch in the coast of the Sea of Japan.
It may because of that the smaller species whaling boat owners have given up thearea.
In Area I whaling operation was done by the whalers from the stations inBoso Peninsula (Bosyu ). Operation period of that area is appeared to be longest
Sci. Rep. Whales Res. Inst.,
No. 23, 1971.

114

NISHIWAKI AND OGURO

I145°£OKHOTSKAelEA

SEAN

HOKKAIDO

i , ~--- -,----r-- ••,'...

_,SEA,'o!

....·~1!

AREA

III.. ..

OF40°N - - - - - - - - c - - , . J

JAPAN:.-;r:?

{{3AREA

I140°£
IFig. 2.

II

145°E

Positions of Baird's beaked whales caught in Japanese waters in 1965-1969.

Sci. Rep. Whales Res. Inst.,
No. 23, 1971.

115

BAIRD'S BEAKED WHALES IN JAPANof all others, which is from May to Dec. Area II was of the whalers from the stations
in Oshika Peninsula, Miyagi Pref. Although no catch is seen at Nemuro stationin Area III by Omura et al, there are some catch records in recent years on the coastof Nemuro in the present map. The waters of Hokkaido is divided into two, thePacific coast as Area III and the Okhotsk coast as Area IV, by the line between
Kunashiri and Etolov Island. As shown in Table 3 and Fig. 3, catch appearedin Area I and II in May first. Male is superior in total number as about 57%.
TABLE 3.

MONTHLY CATCH OF BAIRD'S BEAKED WHALES IN JAPANESEWATERS BY THE AREA, IN 1965-1969.
Areas

MonthsSex

IIIMayMale
FemaleTotal
MaleFemale
Total
MaleFemale
Total
MaleFemale
Total
MaleFemale
Total
Male
FemaleTotal
Male
FemaleTotal
Male
FemaleTotal
Male
Female
Total

32532
2052
46
55
1016549
114
34
2054
23
1134
12719303218
164
382

0
2240
4
50
537
1350
33
30
63
20
1131
21
13
34
5611124
76
200

June

July

AugustSeptember

OctoberNovember

December

Total

IIIIV

Total
340
10

3
2
516
22
38
9
716
2
2
42028
7151414
28
45930
33
63

2828
56

736
2157
51
56
107
107
64
171
91
79
170
66
43109
3927668614400
301701

Females seem to migrate to those areas eaner than males do, number of males
incleases after July.
Distance between the positions of catch and the land stations is shown in
Table 4 : 50 % of catch are within 1-30 miles. This may partly because of thatwhaling boats are so small that they have to be towing whales to a station withina day. Even the most distant catches Area about 120 miles from a land stationand the distant catches are scarce. The distance of most abundant catches are
1-30 miles in Area IV, 91-120 miles in Area III, 61-90 miles in Area II and 1-30
Sci. Rep. Whales Res. Inst.,
No. 23, 1971.

NISHIWAKI AND OGURO

11625AREA N

2002550150E250)::0co0(f)co"'.cz

3:"·/;; '\/i \. /\ \c3
er'\0100
L"'

..ClE

::0z

100 !:!;

::;

::r

AREA

'"°'
75 2

I(f)

c::r/I v~0\ \I·,,.~~~""
\\I

I'!

50'1/I//,IALL

I

AREAS

II

Fig. 3.

50I\~,.,

25~~~, ,'1

MayCD

July

Sept.

Nov.

July

Sept.

Nov.

Number of Baird's beaked whales caught by the area and months in 1965-1969.

TABLE 4.

DISTANCE BETWEEN LAND STATIONS AND THE POSITIONS OF BAIRD'SBEAKED WHALES CAUGHT IN JAPANESE WATERS IN 1965-1969.
Areas
Distance inPercentage
IVTotal
III
III
miles
42352
50.2%
5
10295
1-30
22.0
2
154
562
81
31-60
15.5
109
107
261-908.4
59
44
1591-1200.966120<3.012
21
5
4
unknown
701
56
63
200
382
Total
Sci. Rep. Whales Res. Inst.,

No. 23, 1971.

BAIRD'S BEAKED WHALES IN JAPAN

117

miles in Area I. If the distance of abandant catch and the water depth of thepositions are put into a map together as in Fig. 2, positions of catch are abandantin the waters deeper than 1,000 m. On the Abashiri and Boso coasts where the1,000 m depth contour line is close to the shore, positions of catch are appeared
to be near to the shore. Whereas on the Kushiro and Kinkazan coasts where
the contour line is far from the shore, the positions of catch are at distance.

40~_a-----MALE----FEMALE·'=
EOJ 30:::J<tl0(/)Q)

cti.<::

20~0©
.0

10E:::JzFig. 4. Size distribution of Baird's beaked whales caught in Japanese waters in1965-1969.

1816/--------------------------?!----.... 14Q)

2c12.<::c;, 10c~

»8CJ0ro 642Jan.

Jun.

Dec.

DateFig. 5.

Recorded foetuses of Baird's beaked whals by the date in 1965-1969.

Sci. Rep. Whales Res. Inst.,
No. 23, 1971.

118

NISHIWAKI AND OGURO

DISTRIBUTION OF BODY LENGTH

Distribution of body length of the whales caught is shown in Fig. 4. The smallest
length of both sexes are appeared to be equal as 24 feet and the largest lengthof those are 39 feet in male and 42 feet in female. Many individuals are seen within
the range of 33-34 feet. Roughly, larger lengths are of females. According toOmura et al., the Baird's beaked whale attains sexual maturity at the length within
32-33 feet by males and 33-34 feet by females. Considered on this condition, it
can be said that 80 % of males and 70 % of females among all the whales caught
are matured.
RECORD OF FOETUSES

Records of foetuses found in the present study are shown in Fig. 5. Six in theseason from June to Oct.: in Area I, two in June, two in Aug., one in Sept. andin Area IV, one in Oct. As the records are so scarce, that they are shown in theadditional points on the growth curve drawn by Omura et al (1955).
FOOD

701 stomachs were examined; 55% of all, namely 383 stomachs contained foodremains and 30% are empty ones. 15% are the stomachs without description
because abdomens of whales are cut open immediately after catch to prevent them
TABLE 5.

STOMACH CONTENTS OF BAIRD'S BEAKED WHALESCAUGHT IN JAPANESE WATERS IN 1965-1969.

kinds of stomach contents

number of whales

percentage

deep-sea fishsquidmackerelsardineflat fish
pollack
sauryunidentified

156
111
155

40.7
28.9

3.9
1.3

193

24.2

from decomposition, so, the contents are washed away. There were various kinds
of food remained in the stomachs as shown in Fig. 5. Most are deep-water fishand squid. There are 24% of unidentified species of food because they have alreadybeen digested.
Distribution of food by area is shown in Fig. 6. Squid is found mostly inAreas IV and III, squid and deep water fish are in Area II and deep-water fish isin the waters south of Area III. Occurrence of squid and deep-water fish is shownin Table 6 by month. Squid is frequent in Area IV from Aug. to Nov., also in
Area III from Aug. to Nov. Naturally, in Areas III and IV, fishing season of squidSci. Rep. Whales Res. Inst.,
No. 23, 1971.

BAIRD'S BEAKED WHALES IN JAPAN

119

begins in July. The whales which had squid in their stomach and caught inArea II, are supposed to have been migrating from north. In Area II, there arerecords of mackerel and sardine as well as squid and deep-water fish. Whales

140°E

45°N

•

SEA OF0JAPANAREA IIla.·.::oo00040°N40°N/)«>(-::,{);".(·0xOo oo• xoxo

AREA II0x~x
f. o exCO! •••0 0.e•

PACIFIC

OCEAN•

Deep-sea fishes

35°N

0 Squidx Mackerel
D Sardine

AREA
140°E

I

6Saury0Poollack

D Flat fish
145°E

Fig. 6. Position of Baird's beaked whales caught with stomach contents in Japanesewaters in 1965-1969.

Sci. Rep. Whales Res. Inst.,
No. 23, 1971.

NISHIWAKI AND OGURO

120

seem to eat common species of the areas without intentional choice. Species ofdeep-water fish and its fishing season could not be investigated, however, it seems
that it is likely to be abundant at Boso off shore. Records of deep-water fish appear in Area I first and to Areas II and III as time passing by. Whales of thepresent population seem to migrate north in spring living on deep-water fish andthen coming back south doing on squid.
TABLE 6. NUMBER OF STOMACHS OF BAIRD'S BEAKED WHALES CAUGHT
IN JAPANESE WATERS WITH CONTENTS OF SQUID OR DEEP-SEA FISH,BY THE AREA AND THE MONTH, IN 1965-1969.
AreasFoodMayJune
July
AugustSeptember
OctoberNovember
December

IIIIII

IV~~~~

squid

deep-sea
fish

squid

deep-sea
fish

10
9

3
3

squid

deep-sea
fish

squid

2
4

2
12

deep-sea
fish

5
14

25
41

25
3
18
7

2

2

3

25
13
4

24

8

SUMMARY

1. Whaling of the Baird's beaked whale in recent years indicates an agreeable
number of catch from the stock as about 150 whales annually, which is a certain
decrease from the number of 250-300 about-twenty years ago. On the other hand,
number of whales caught per catcher-boat has increased because of reduction of
the boats in number.
2. Length distribution of whales caught shows a good balance: nearly 80%of the whales attained at sexual maturity and the male is superior in number. So
that it may safe to say that the stock is well protected.
3. The largest body length investigated was 39 feet of male and was 42
feet of female in the present study.
4. The positions of whales caught are mainly in the waters deeper than
1,000 m. It seems that the whales do not migrate to the shallow waters. In
the whaling season, the whales are found at Boso first and migrate to Kushiro
through Kinkazan in the season from July to Oct., then they come back to Kinkazan
from Aug. to Oct.
5. The whaling commences in Abashiri sometime in May or June, this issimultaneous with that of Boso. Considering the fact, Abashiri population is
supposed to be different from that of Boso. Abashiri population is considered to
be as Hyperoodon ampullatus. Further study is required.
Sci. Rep. Whales Res. Inst.,
No. 23, 1971.

BAIRD'S BEAKED WHALES IN JAPAN121ACKNOWLEDGEMENTOur gratitude are due to the members of the Whaling Inspection Group of theFisheries Agency for presenting the data used in this report.
Thanks are also due to the stuff members of the Biology of Fisheries Resources
Division of the Ocean Research Institute, the University of Tokyo and Mr. S.
Machida of the Whales Research Institute for their helpful advices.
REFERENCES
MATSUURA, Y., 1942. On the Northern Porpoise Whale, Berardius bairdii STEJNEGER in the adjacentwaters of" BOSYU" Z,ool. Mag., 54(12): 466-473.
MAEDA, K. and Y. TERAOKA, 1953. Whaling. Isanashobo, Tokyo, 450 pp. (in Japanese)NISHIIMURA, S. 1970. Recent records of Baird's beaked whale in the Japan Sea. Puhl. Seto Mar. Biol. Lab.
18(1): 61-68.
NrsmWAKI, M., 1965. Whales and Pinnipeds. Univ. of Tokyo Press, Tokyo, 439 pp. (in Japanese)
OGAWA, T., 1936. Studien liber die Zahnwale in Japan. (in German)
OMURA, H., K. FUJINO and S. KrMuRA, 1955. Beaked Whale Berardius bairdi of Japan, with notes on Z,iphiuscavirostris. Sci. Rep. Whales Res. Inst., 10: 89-132.
OMURA, H., K. MAEDA and I. MIYAZAKI, 1953. Whaling in the adjacent waters of Japan. Norsk Hvalfangst-Tidende. 4: 199-212.
PJKE, G. C., 1953. Two Records of Berardius bairdi from the Coast of British Columbia. J. Mamm. Vol. 34,
No. I.
Statistics and Survey Division, Ministry of Agriculture and Forestry, Japanese Government. Agriculture,Forestry and Fishery Statistics Data 1956,-1961,-1966. Association of Agriculture-Forestry Statistics.

Sci. Rep. Whales Res. Inst.,
No. 23, 1971.

NISHIWAKI AND OGURO

122

EXPLANATION OF PLATES
Bird's-eye view of Baird's beaked whales swimming in the waters off Sanriku coast takenby Mr. S. Takashima of the Suisan Koku Co. (Fishery Aviation Co.): Copyright ofthese photographs is reserved by the company.
PLATE I
DatePosition

July 26, 1956
35°-SO'N
141°-20'E

PLATE II
upper figure

DatePosition

lower figure

DatePosition

July 22, 1970
38°-45'N143°-20'E
Sept. 12, 1961
39°-50'N
143°-50'E

The others were taken at the same area by and presented in The Scientific Reports of the Whales Research Institute, No. 23 (1971) by T. Kasuya.

Sci. Rep. Whales Res. Inst.,

No. 23, 1971.

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