Cetacean Population Studies
V01日 4

Publication Committee
forthe Cetacean Population Studies2023

CETACEAN POPULATION STUDIES
Online publication: ISSN 2434-558X
Print publication: ISSN 2434-5571
Copyright© 2023, Publication Committee for the Cetacean Population Studies
All rights reserved. Rep roducing or copying this publication, in whole or in part, is p rohibited without
the express written consent of the copyrigh t holder.
Governing Council
Hideh iro KATO, Chairman

Main Affiliation
Professor Emer itus, Tokyo Un ivers ity ofMar ine Science andTechnology
Motoi YOSHIOKA, Chairman Alternate Professor, Mie Un ivers ity
D irector General, Institu te of Cetacean Research
Yosh ihiro FUllSE
Hiroshi HATANAKA
Former D irector General, Fisher ies Research Agency
Koichi KAJI
Professor Emer itus, Tokyo Un iversity of Agricul ture andTechnology
Noriyuki OHTAISHI
Professor Emer itus, Hokkaido Un iversity
Kazumi SAKURAMOTO
Professor Emer itus, Tokyo Univers ity ofMar ine Science andTechnology
Senzo UCHIDA
Special Advisor, Okinawa Churash ima Founda tion
Editorial Board
Hidehiro KATO, Editor in Ch ief
Yoshihiro FUJISE, Editor
Hiroshi HATANAKA, Editor
Kazuhiko H田AMATSU, Editor
Toshiaki ISHIBASHI, Editor
Koichi KAJI, Editor
Toshihide KITAKADO, Editor
Tomio MIYASHITA, Editorfe

Associate Pro ssor, Atmosphere and Ocean Research Institute,
The University of Tokyo
Cha irman, Japan Aquar ium Association
Professor, Tokyo University ofMar ine Science and Technology
Former D ivis ion Director, National Research and Development
Agency, Japan Fisher ies Research and Educa tion Agency,
F isher ies Resources Institute

Noriyuki OHTAISHI, Editor
Luis A. PASTENE, Editor
Sc ien tific Adv isor, Ins titu te of Cetacean Research
Kazumi SAKURAMOTO, Editor
Senzo UCHIDA, Editor
Motoi YOSHIOKA, Editor
Invited Editors: dependin g on editorial needs.
Secretaria t
Gabriel GOMEZ DIAZ, Secretary
Tomoko KUBA, Editorial Officer
Mariko HAYATAKE, Editorial Assistant
Kuniko TAKATA
In terna tional Academic Publ ishing Co., L td.
Editorial correspondence shoud be sent to:
Editor, CPOPS
E-mail: cpopspaper@gmail. com
CPOPS is available online at h ttps://cpops.jp/archive/ index.html
Supporting organizations:
The Institute of Cetacean Research, TokyoJapan Aquarium Association, Tokyo

Cetacean Population Studies
Vol. 3

Volume 4, August 2023
DR.
SEIJIOHSUMIOHSUMI MEMORIAL
MEMORIAL VOLUME
DR.
SEIJI
VOLUME

Publicatiion
Committee
Publication Committee
for the Cetacean Population Studies
2021
2023

Contents
Preface………………………………………………………………………………………………… 1
Foreword ……………………………………………………………………………………………… 3
Full paper
MURASE, H., MATSUOKA, K. and WATANABE, K.
Eﬀect of sea surface temperature on the distribution of common minke whales oﬀ
southeastern Hokkaido, Japan, between 2002 and 2006, with notes on the formation of Paciﬁcsaury ﬁshing grounds ………………………………………………………………………………… 7
Short note
NAKAMURA, G., AL-ZAIDAN, A., BEHBEHANI, M. and KATO, H.
Preliminary report on the cranial measurements of a Bryde’s whale stranded in Failaka Island,
Kuwait in 2014 ………………………………………………………………………………………21
MILMANN, L., CARDOSO, J., FRANCISCO, A., SANTOS, F. P., SEMINARA, C.,ABRAS, D. R., MARQUES, M. L., HILLE, D. A., LEMOS, L. S., RUENES, G. F.,
HAUSER-DAVIS, R. A. and SICILIANO, S.
Dwarf minke whale (Balaenoptera acutorostrata subsp.) interactions with vessels oﬀ thecoast of Brazil …………………………………………………………………………………………27
KATSUMATA, T., ISODA, T., MATSUNO, K., MURASE, H. and MATSUOKA, K.
Observation of ﬁn whale (Balaenoptera physalus) feeding behavior in the austral summer
Southern Hemisphere mid-latitudes. …………………………………………………………………34
OthersINAMORI, D., YOSHIOKA, M. and KATO, H.
Second occurrence of a dolphin with ﬁn-shaped hind appendages from waters oﬀ Taiji,
the Paciﬁc Coast of Japan ……………………………………………………………………………43
KATSUMATA, T. and YOSHIDA, T.
Development progress of a long-range vertical takeoﬀ and landing UAV for the improvementof ship-based cetacean sighting surveys ………………………………………………………………45
Archival Index ………………………………………………………………………………………49
Subject Index …………………………………………………………………………………………51
Author Index …………………………………………………………………………………………54
Guide for Authors ……………………………………………………………………………………57

目

次

はじめに……………………………………………………………………………………………… 1
序文…………………………………………………………………………………………………… 3

論文
村瀬弘人、松岡耕二、渡邉一功
北海道南東部沖のミンククジラ分布に及ぼす海面水温の影響（2002–2006年）並びに
サンマ漁場形成に関する考察……………………………………………………………………… 7

短報
中村玄、AL-ZAIDAN, A.、BEHBEHANI, M.、加藤秀弘
クウェートのファイラカ島で2014年に座礁したニタリクジラの頭蓋骨測定に関する予備報告………………………………………………………………………………………………21

MILMANN, L.、CARDOSO, J., FRANCISCO, A.、 SANTOS, F. P.、 SEMINARA, C.、ABRAS, D. R.、 MARQUES, M. L.、 HILLE, D. A.、 LEMOS, L. S.、 RUENES, G. F.、
HAUSER-DAVIS, R. A.、SICILIANO, S.
ブラジル沖におけるドワーフ（矮小型）ミンククジラ（Balaenoptera acutorostrata subsp.）と船舶との行動的相互作用…………………………………………………………………………27
勝俣太貴、磯田辰也、松野孝平、村瀬弘人、松岡耕二
南半球夏季中緯度海域におけるナガスクジラ（Balaenoptera physalus）の摂食行動の観察 ……34

その他
稲森大樹、吉岡基、加藤秀弘
ヒレ型後肢を持つイルカの二例目の出現、日本太平洋岸の太地町沖からの報告……………43
勝俣太貴、吉田崇
船舶による鯨類目視調査改善のための長距離垂直離着陸UAVの開発進捗 …………………45

著者及びタイトル索引………………………………………………………………………………49
件名索引………………………………………………………………………………………………51
著者索引………………………………………………………………………………………………54
執筆要領………………………………………………………………………………………………57

PREFACE
I am very glad to introduce you to the fourth volume of the Cetacean Population Studies (CPOPS).
The publication of this CPOPS Vol. 4 turned out to be a long and diﬃcult process. This may be in part
because we expended much of our energy in editing the previous CPOPS Vol. 3, Dr. Seiji Ohsumi Memorial Volume, but mainly because I, as Editor-in-Chief, had to temporarily leave the editorial front
for health reasons.
I understand that the burden of the CPOPS editorial board and the secretariat members, especially
Dr. Gabriel Gomez Diaz, who ﬁlled the void, was not negligible. In a nutshell, the publication of thisvolume owes much to their eﬀorts.
This is how CPOPS Vol. 4 came out to light. Although we were unable to cover all the papers submitted, we would like to make a fresh start for the next volume while taking advantage of the uniquecharacteristics of our journal.
August 1, 2023

Hidehiro Kato, Ph. D.
Chairman
Publication Committee for the Cetacean Population Studies

Cetacean Popul. Stud. (CPOPS), Preface
Vol. 4, 2023, 1

1

Foreword*
Remarkable evolution in cetacean studies in recent decades owes much to major journals that have madesigniﬁcant contribution to the development of modern cetology: Discovery Reports, published by the
National Institute of Oceanography in the United Kingdom, and Norwegian Whaling Gazette in Norway,
as well as The Scientiﬁc Reports of the Whales Research Institute in Japan.
The Scientiﬁc Reports of the Whales Research Institute was ﬁrst published in 1948, a year after the
Whales Research Institute was established. Aiming to share valuable research ﬁndings and scientiﬁcknowledge worldwide, the publication was formatted in English since its beginning, quite an ambitious
attempt in Japan still recovering from the devastation of World War II.
Since its ﬁrst publication, a total of 246 scientists contributed 419 scientiﬁc papers to The Scientiﬁc
Reports of the Whales Research Institute. It is widely acknowledged and appreciated that these scientiﬁcpapers were the foundation for the development of cetacean studies worldwide, and in today’s terms, it
was a research journal that had a signiﬁcant impact factor, or high number of citations. Regrettably, however, The Scientiﬁc Reports of the Whales Research Institute was discontinued in 1988 with the 39th
volume after the institute was reorganized into the Institute of Cetacean Research.
In the 30 years since then, various types of journals on cetacean studies have been published globally,each oﬀering diﬀerent perspectives on scientiﬁc research outcomes. As for Japan, no research journal
matching The Scientiﬁc Reports of the Whales Research Institute in its quality has been published. It is
probably because many domestic cetologists have sought to publish their papers in international research
journals based outside Japan.
As the global environment surrounding the issue of whaling became increasingly complex, we haveobserved a shift in publishing policies among these journals, rejecting papers whose ﬁndings are based on
speciﬁc research methods such as lethal sampling. Because of this, no small numbers of papers submitted by biological scientists using samples collected through lethal surveys, even just for some parts, havebeen denied proper reviews. While we agree that animal ethics should be given high priority when writinga research paper, if a paper, the research method of which is allowed under domestic and internationalrules, is rejected, it is a decision made beyond scientiﬁc judgment.
Our new journal for cetacean population studies intends to follow the scientiﬁc policy of The Scientiﬁc
Reports of the Whales Research Institute, that is, to contribute to global development of cetacean studies.
As long as submitted papers conform to scientiﬁcally-accepted animal ethics, we do not make distinctions
based on research methods. At the same time, to maintain the journal’s neutrality in the complex global
environment surrounding whaling issues, the journal will be published from a newly organized committee,
rather than as a bulletin type scientiﬁc report from a speciﬁc research institute. The title of the new journal will be Cetacean Population Studies to be abbreviated CPOPS, and we aim to keep our door wide-open
for researchers worldwide, contribute to the scientiﬁc development of resource studies for marine mammals especially focusing on cetaceans, and nurture many aspiring scientists.

December 31, 2018

Seiji Ohsumi†, Ph. D.
Chairman
Publication Committee for the Cetacean Population Studies*Introductory declaration by the former Chairman of the Cetacean Population Studies Publication Committee on the occasion of the launching of this journal.

3

Full Paper

A blue whale just after blowing, Antarctic.

DOI

https://doi.org/10.34331/cpops.2022F001

J-STAGE Advance published date: October 25, 2022

DISTRIBUTION OF MINKE WHALE OFF HOKKAIDOEFFECT OF SEA SURFACE TEMPERATURE
ON THE DISTRIBUTION OF COMMON MINKEWHALES OFF SOUTHEASTERN HOKKAIDO, JAPAN,
BETWEEN 2002 AND 2006, WITH NOTES ON THE
FORMATION OF PACIFIC SAURY FISHING GROUNDS
Hiroto MURASE1*, Koji MATSUOKA2 and Kazuyoshi WATANABE3
Laboratory of Cetacean Biology, Tokyo University of Marine Science and Technology,
4–7–1 Konan, Minato-ku, Tokyo 108–8477, Japan
2
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan
3
Japan Fisheries Information Center, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan*Corresponding author: hmuras0@kaiyodai.ac.jp
1

Abstract
The relationships between oceanographic conditions and the distribution of common minke
whales oﬀ southeastern Hokkaido was investigated in this study. Sighting surveys of common
minke whales in this region were conducted in September, in 2002 and from 2004 to 2006.
The density index (DI, the number of schools per 100 n.miles) of the whales decreased from
5.6 schools in 2002 to 1.2 schools in 2006. During the 4 years in which surveys were conducted, the monthly mean sea surface temperature (SST) in the survey area increased from 16.6°C
in 2002 to 19.5°C in 2006, while the mean SST recorded at sighting locations was 15.5°C. The
proportions of surveyed areas with a monthly mean SST ≤16°C in 2002 and 2004 were 46.5%
and 17.0% respectively, whereas in 2005 and 2006, none of these areas had a monthly mean
SST of less than 16°C. Paciﬁc saury are among the major prey items of the minke whales inthis region, and the number of the ﬁshing boats was used as an indicator of the presence of thespecies in the surveyed area. The 4 year mean SST at the locations of the boats was 15.1°C. A
reduction in the local abundance of the saury from 2002 to 2006 was inferred from the numberof the boats operating in the region. These ﬁndings suggested that the apparent decline in theabundance of whales in the study area was associated with changes in SST and the availabilityof Paciﬁc saury.
Key words:

Balaenoptera acutorostrata, Cololabis saira, habitat, North Paciﬁc, Oyashio,
spatial distribution.

Introduction
The common minke whale (Balaenoptera acutorostrata, hereafter minke whale) is a small species of baleen whale with body length of approximately 8 m at physical maturity (Kato, 1992), andhas been reported to live to ages of up to 49 years (Maeda et al., 2017). Records of past commercial
catches indicate that the waters oﬀ southeastern Hokkaido (also known as the Doto region), Japan, areamong the most important summer feeding areas for the Okhotsk Sea–West Paciﬁc Stock (O Stock) of
the species, particularly for immature individuals and mature males (Hatanaka and Miyashita, 1997;
Kasamatsu and Tanaka, 1992). The results of the Japanese Whale Research Program under Special
Permit in the western North Paciﬁc (JARPN) and its Phase II (JARPN II) between 1994 and 2016
Cetacean Popul. Stud. (CPOPS), Full paper
Vol. 4, 2023, 7–18

7

MURASE, MATSUOKA AND WATANABE

showed that they fed on a variety of prey species, such as krill, Japanese common squid (Todarodes
paciﬁcus), Japanese anchovy (Engraulis japonicus), Paciﬁc saury (Cololabis saira, hereafter saury) and walleye pollock (Gadus chalcogrammus) in the western North Paciﬁc (Konishi et al., 2009;
Murase et al., 2007; Tamura et al., 2009). It has been suggested that the spatial distribution of minke
whales oﬀ southwestern Hokkaido during September could be associated with the distribution of saury (Tamura and Fujise, 2002). Nevertheless, despite this conjecture, it has yet to be suﬃciently established whether changes in the minke whale spatial distribution are associated with the distribution ofsaury and/or oceanographic conditions (e.g., sea surface temperature, SST).
The saury, along with other small pelagic ﬁshes, such as Japanese sardine (Sardinops melanostictus), Japanese anchovy, and chub mackerel (Scomber japonicus), is regarded as an economicallyimportant species in Japan (Watari et al., 2019). Since the 1900s, the commercial catches and biomassof these small pelagic ﬁsh have ﬂuctuated, reﬂecting decadal changes in species composition (i.e., species replacement) (Yatsu, 2019). Fluctuations in the populations of small pelagic ﬁsh detected during
the 20th century have been linked to cold and warm water temperature regimes, as indicated by the
Paciﬁc Decadal Oscillation (PDO) index. However, the regime around Japan from the 2000s to 2010s
was now deﬁned as an unconventional regime as the relationship did not follow previous ones (Kuroda et al., 2020). It should be noted that the biomass of saury was high in the 2000s in the time series
between 1980 and 2018 (4th Meeting of the Technical Working Group on Paciﬁc Saury Stock Assessment, 2019).
Saury generally (1) spawn during the winter months in the Kuroshio (the subtropical westernboundary current with warm high-salinity water) waters oﬀ the southern coastline of Japan, (2) migrate to the North Paciﬁc subarctic–subtropical transition zone during summer to feed and (3) commence their southbound return migration to the spawning grounds (Fuji et al., 2020; Fukushima,
1979; Kosaka, 2000; Watanabe and Lo, 1989). It is in September during this southbound migrationthat the saury is commercially ﬁshed in grounds oﬀ the southeastern coast of Hokkaido. With thetransition of the seasons from summer to autumn, the ﬁrst branch of the Oyashio (the subarctic western boundary current with cold low-salinity water) extends southward along the coast of Hokkaido
and Honshu, showing annual variation in both pattern and extent. The location of these saury ﬁshinggrounds oﬀ Hokkaido is determined by the location of the Oyashio front (the 5°C water temperature
isotherm at a depth of 100 m), and accordingly shifts from year to year, tracking the variable pattern of
the Oyashio front (Yasuda and Kitagawa, 1996). The primary indicator determining the location of thesaury ﬁshing grounds is SST, and it has been reported that the mode of SST at the ﬁshing grounds inthis area is 15°C (Tseng et al., 2011; Watanabe et al., 2006). It can thus be speculated that the spatial
distribution of minke whales oﬀ southeastern Hokkaido in September is associated with the seasonal
extent of the Oyashio current and/or the southbound saury migration.
The ﬁndings of previous studies have provided evidence indicating that the spatial distribution ofminke whales worldwide is associated with a diverse range of biotic and abiotic factors, including
bottom depth, topography, seaﬂoor substrate, oceanographic conditions (e.g., SST); and the distribution of prey species (Chavez-Rosales et al., 2019; Doniol-Valcroze et al., 2007; Hamazaki, 2002;
Hooker et al., 1999; Ingram et al., 2007; Macleod et al., 2004; Naud et al., 2003; Skern-Mauritzen
et al., 2011; Tetley et al., 2008; Waggitt et al., 2020; Zerbini et al., 2016). However, given that theseassociations tend to diﬀer depending on location and season, it has hitherto not been possible to draw
any general conclusions. Consequently, to gain a better understanding of minke whale ecology, thelocation and season-speciﬁc eﬀects of biotic and abiotic factors on the spatial distribution of thesewhales warrant further investigation.
In this study, it was sought to determine the associations among oceanographic conditions, and the
distribution of saury and minke whales oﬀ southeastern Hokkaido in September. Speciﬁcally, the aims
were to investigate (1) whether the distribution of minke whales in this area in September is related to
SST, and (2) whether the spatial distribution of minke whales is related to the presence of saury. An

8Cetacean Popul. Stud. (CPOPS), Full paper
Vol. 4, 2023, 7–18

DISTRIBUTION OF MINKE WHALE OFF HOKKAIDO

earlier version of this paper was submitted to the International Whaling Commission’s Scientiﬁc Committee as Appendix 4 of paper SC/59/O7 in 2006.

Materials and Methods
Sighting surveys of minke whales were conducted oﬀ the coast of southeastern Hokkaido, Japan, in
2002, 2004, 2005, and 2006, as a part of the coastal component of JARPN II (Hakamada et al., 2009).
The longitudinal boundaries of the survey area were set at 143°15′E and 146°00′E, whereas the latitudinal boundaries were set at the 50 m isobath and 41°N (Fig. 1). Surveys were conducted during
the month of September in the aforementioned years (Fig. 2). The survey area between 143°15′E and
146°00′E was stratiﬁed into the following four strata: an Oﬀshore (O) stratum and three coastal strata[coastal-Center (C), coastal-East (E), and coastal-West (W)], with the boundary between the oﬀshore
and coastal strata being set at a distance of 60 n.miles from the Hokkaido coastline. In 2005 and 2006,
an additional stratum (H) was surveyed oﬀ Hidaka sub-prefecture (between 142°30′E and 143°15′E).
Sighting surveys were conducted from onboard the survey vessel (SV) Kyoshin-Maru No. 2 (372
GT; Kyodo Senpaku Co., Ltd). Primary observers were allocated to the top barrel (3 observers) andthe upper bridge (2 observers). Zigzag tracklines with randomly selected starting points were constructed in the survey area. The sighting survey (i.e., on-eﬀort) was conducted during daylight hours
from 1 hour after sunrise to 1 hour before sunset under acceptable weather conditions (i.e., the visibility was 2.0 nautical miles or more, the wind speed was 20 knots or less, and the Beaufort wind force
scale was less than 6), and the nominal steaming speed along the tracklines was 10 knots. Sightings
during the on-eﬀort were treated as primary sightings.
There were two survey modes: Closing Mode and Passing Mode. Closing Mode was applied in
2002 and 2004 while Passing Mode was applied in 2005 and 2006 to increase survey coverages. Whenthe sightings during Closing Mode (primary sightings) were likely to be minke whales, the SV approached them to conﬁrm species and individuals within the schools. Sightings during the approaches
to primary sightings were secondary sightings and were not included in the analysis. During Passing
Mode, no approach was made to sightings. All sightings made in the Passing Mode were treated as

Fig. 1. Surveyed strata oﬀ the coast of southeastern Hokkaido, Japan [coastal-Center (C), coastal-East (E),coastal-West (W), Oﬀshore (O)] and oﬀ Hidaka sub-prefecture (H). Black lines represent the boundaries between strata, and thin gray lines indicate isobaths.
Cetacean Popul. Stud. (CPOPS), Full paper
Vol. 4, 2023, 7–18

9

MURASE, MATSUOKA AND WATANABE

Fig. 2. Surveyed tracklines (black lines) and positions of common minke whale sightings (pink circles) oﬀ
the coast of southeastern Hokkaido, Japan, in September 2002, 2004, 2005, and 2006. The monthly mean sea
surface temperatures (SSTs) derived from GHRSST are also shown. Dashed black lines represent the 16°C
isotherms, and white lines indicate the boundaries between strata.

primary sightings. However, if the identity of the species sighted was uncertain, abeam closing was
conducted during Passing Mode. Given that the minke whales observed during the survey tended tooccur individually rather than in schools, application of the Passing Mode is deemed adequate.
Density indices of schools and individuals (DI, the number of schools and individuals sighted per
100 n.miles) were calculated for each stratum in each survey year to show relative abundance of minke
whales. Mean values of the SSTs recorded at the time of each sighting were obtained for each stratumin each of the survey years. Estimated abundance of minke whales based on the line transect sampling(Hakamada et al., 2009) and amount of saury consumed by the whales (Tamura et al., 2009) at thetime of surveys were also used in this study.
As an indicator of the presence of saury, numbers of commercial saury ﬁshing boats were summarized by each stratum in each survey year. Mean of SST recorded by the ﬁshing boats was also summarized by each stratum in each survey year. The data of ﬁshing positions of the boats and SST were
provided by the Japan Fisheries Information Service Center (JAFIC).
SST data, A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface
temperature analysis (JPL MUR MEaSUREs Project, 2010), were used to characterize oceanographic
conditions at the time of the surveys. Monthly mean September SST data corresponding to the survey periods with a global 0.01 degrees grid spatial resolution were extracted using Marine Geospatial Ecology Tools 0.8a73 (Roberts et al., 2010). Data pertaining to sightings, ﬁshing boat locations,and SST were overlaid on maps using a geographic information system (GIS), ArcGIS Desktop 10.7
(ESRI, US). The area of sea surface classiﬁed by 1°C SST increments was also calculated using the
GIS. ETOPO1 global relief model (Amante and Eakins, 2009) and A Global Self-consistent, Hierarchical, High-resolution Geography Database (GSHHG) (Wessel and Smith, 1996) data were also used10

Cetacean Popul. Stud. (CPOPS), Full paper
Vol. 4, 2023, 7–18

DISTRIBUTION OF MINKE WHALE OFF HOKKAIDO

in the maps. The UTM zone 55N projection was used for the mapping.

Results
All strata
The surveyed tracklines and the sighting positions of minke whales were overlaid on the SST maps
(Fig. 2), as were the positions of the saury ﬁshing boats (Fig. 3). These maps indicated an increase in
the overall SST in the survey area during the course of the survey period from 2002 to 2006. Mean
SST was found to have risen from 16.6°C in 2002 to 19.5°C in 2006 (Table 1). The frequency of thenumber of minke whale sightings with respect to SST (1°C increments) is shown in Fig. 4. During thefour survey years, the mean SST at sightings positions was 15.5°C (CV=12.4%, n=87), whereas thatin the years 2002, 2004, 2005, and 2006 was 14.3°C (CV=8.0%, n=38), 15.4°C (CV=4.5%, n=17),15.6°C (CV=8.4%, n=20), 19.1°C (CV=6.0%, n=12), respectively (Table 1). Correspondingly reductions in the DIs, abundance, and saury consumption of minke whales were detected from 2002
to 2006. The frequency of the number of saury ﬁshing boats with respect to SST (1°C increments) isshown in Fig. 5. Mean SST at the ﬁshing positions of saury ﬁshing boats over the four survey years
was 15.1°C (CV=10.2%, n=2,646), whereas that in 2006 was 16.4°C (CV=10.3%, n=450) (Table 1). Notably, there were fewer boats ﬁshing for saury in 2006. The frequency of area (n.mile2) of
SST ≤16°C and >16°C in all survey strata in September 2002, 2004, 2005, and 2006 is summarizedin Table 1. Given that over the four survey years, the mean SST at the sighing positions of minke
whales was 15.5°C, a temperature of 16°C was set as a cutoﬀ point. From 2002 to 2006, a contraction

Fig. 3. The ﬁshing positions of commercial Paciﬁc saury ﬁshing boats (open squares) oﬀ the coast of southeastern Hokkaido, Japan, in September 2002, 2004, 2005, and 2006. The monthly mean sea surface temperatures (SSTs) derived from GHRSST are also shown. Dashed black lines represent the 16°C isotherms, andwhite lines indicate the boundaries between strata.
Cetacean Popul. Stud. (CPOPS), Full paper
Vol. 4, 2023, 7–18

11

MURASE, MATSUOKA AND WATANABE

Table 1. Summary of the September sightings and Paciﬁc saury consumption of common minke whales, sea
surface temperatures (SST) derived from GHRSST, and commercial Paciﬁc saury ﬁshing boats in the survey
area. The density index (DI) indicates the number of schools/individuals per 100 n.miles. Values for the abundance and Paciﬁc saury consumption of minke whales were obtained from Hakamada et al. (2009) and Tamura et al. (2009). Note that data for Paciﬁc saury consumption are only available for “All strata”.
Common minke whale sightings & saury consumption
Year

Eﬀort
Mean
DI
DI
Sch. Ind.
(n.miles)SST (°C) (Sch.) (Ind.)SST in survey blocks (GHRSST)

Commercial Paciﬁcsaury boats

Abundance

Saury
Mean
Area ≤16°C Area 16°C< Number Mean SST
consumption(%)(%)
of boats(°C)
Ind. CV(mt)°C CV

All strata
2002 681.5
2004 809.4
2005 827.1
2006 994.0

38
17
20
12

40
18
21
12

14.3
15.4
15.6
19.1

5.6
2.1
2.4
1.2

5.9
2.2
2.5
1.2

0.4
0.4
0.4
0.4

861
1,075
39
153

16.6 9.8
17.1 6.6
19.1 4.6
19.5 5.8

46.5
17.0
0.0
0.0

53.5
83.0
100.0
100.0

1,815
256
125
450

14.8
14.9
15.5
16.4

C stratum
2002 272.6
2004 238.7
2005 365.3
2006 247.4

33
12
10
5

34
13
11
5

14.4
15.5
15.4
18.7

12.1
5.0
2.7
2.0

12.5 323 0.2
5.4 175 0.4
3.0 81 0.7
2.0 75 0.4

—
—
—
—

15.1 2.3
16.2 2.6
18.5 2.0
18.6 4.1

100.0
30.2
0.0
0.0

0.0
69.8
100.0
100.0

403
36
47
25

14.6
15.0
15.0
15.7

E stratum
2002 73.5
2004 140.6
2005 127.7
2006 145.0

5
1
9
5

6
1
9
5

13.8
15.1
15.3
18.9

6.8
0.7
7.0
3.4

8.2 117 1.1
0.7 16 1.1
7.0 135 0.3
3.4 65 0.7

—
—
—
—

15.0 3.4
15.4 3.9
17.8 4.3
17.8 2.7

100.0
83.9
0.0
0.0

0.0
16.1
100.0
100.0

431
56
81
324

14.2
15.0
15.5
16.5

W stratum
2002 48.2
2004 164.9
2005 180.3
2006 161.9

0
3
1
1

0
3
1
1

—
14.9
20.7
20.0

0.0
1.8
0.6
0.6

0.0
1.8
0.6
0.6

0
52
15
19

0.0
0.4
1.1
0.9

—
—
—
—

17.1 7.1
17.1 2.2
19.1 1.5
19.7 1.5

28.2
0.0
0.0
0.0

71.8
100.0
100.0
100.0

305
59
0
4

15.2
15.6
—
16.7

O stratum
2002 287.2
2004 265.2
2005 41.7
2006 285.3

0
1
0
0

0
1
0
0

—
17.4
—
—

0.0
0.4
0.0
0.0

0.0
0.4
0.0
0.0

0
27
0
0

0.0
1.0
0.0
0.0

—
—
—
—

16.5 4.7
17.2 3.1
19.3 1.1
20.1 4.4

29.2
3.9
0.0
0.0

70.8
96.1
100.0
100.0

664
105
7
98

15.0
14.5
18.1
16.2

H stratum
2002 —
2004 —
2005 112.1
2006 154.4

—
—
0
1

—
—
0
1

—
—
—
21.3

—
—
0.0
0.6

—
—
0.0
0.6

— —
— —
0 0.0
18 1.0————19.6 3.2
19.1 2.1
20.7 2.1
20.4 2.0

0.0
0.0
0.0
0.0

100.0
100.0
100.0
100.0

17
0
0
0

16.9
—
—
—

601
368
316
241

in the size of the area with an SST ≤16°C was recorded, with none of the areas having an SST of less
16°C in 2005 and 2006.
Coastal-Center (C) stratum
Overall patterns of SST distribution, sightings of minke whales, and the positions of saury ﬁshingboats in the C stratum were similar to those characterizing the entire survey area (Table 1). Most ofsightings during surveys were found in this stratum. Over the four survey years, the mean SST recorded at the positions of minke whale sightings in this stratum was 15.1°C (CV=10.1%, n=60), whereas
in 2006 it was 18.7°C (CV=3.9%, n=5). Comparatively, the mean SST at the ﬁshing positions ofcommercial saury boats during these 4 years was 14.7°C (CV=7.4%, n=511), and that in 2006 was
15.7°C (CV=0.8%, n=25). The location of the 16.0°C isotherm SST front indicated that SST in theentire stratum was lower than 16.0°C in 2002, whereas in 2004, the temperature in only a small portion of the eastern part of the stratum was lower than this value (Fig. 2). Contrastingly, in 2005 and12

Cetacean Popul. Stud. (CPOPS), Full paper
Vol. 4, 2023, 7–18

DISTRIBUTION OF MINKE WHALE OFF HOKKAIDO

Fig. 4. Frequency of the number of common minke whale sightings according to sea surface temperature(SST: 1°C increments) in all surveyed strata oﬀ the coast of southeastern Hokkaido, Japan, in September
2002, 2004, 2005, and 2006. Data from all the years are pooled to calculate the frequency. SSTs recorded atsighting positions were used.

Fig. 5. Frequency of the number of commercial Paciﬁc saury boats according to sea surface temperature (SST:1°C increments) in all surveyed strata oﬀ the coast of southeastern Hokkaido, Japan, in September 2002,
2004, 2005, and 2006. Data from all the years are pooled to calculate the frequency. SSTs recorded at the positions of boats were used.

Cetacean Popul. Stud. (CPOPS), Full paper
Vol. 4, 2023, 7–18

13

MURASE, MATSUOKA AND WATANABE

2006, no evidence of a 16.0°C isotherm SST front in this stratum was detected. Corresponding to anincrease in the mean SST of this stratum from 2002 to 2006, a reduction in DI values was detected,
and similarly a reduction in the frequency of SST ≤16°C during this period was recorded (Table 1).
Strata other than the C stratum
Compared with the C stratum, fewer sightings were made in the O and H strata, where mean SSTs
were high regardless of the year of survey (Table 1). In the W stratum, the DIs and abundance werehighest in 2004, coinciding with a period during which an area of relatively low SST extended overthe stratum (Fig. 2), giving rise to the lowest (Table 1) and spatially homogeneous (Fig. 2) SST. Contrastingly, in the E stratum, DIs and abundance were the lowest in 2004. With respect to other survey
years, the W stratum was found to be characterized by homogeneously high SSTs in 2005 and 2006
and a marked 16.0°C isotherm SST front in 2002, whereas in 2005 and 2006, DIs and abundance inthe E stratum were higher than those in the C stratum.

Discussion
The mean SST (15.1°C) recorded at the positions of minke whale sightings in the C stratum lies
within the range of 7 to 17°C that has previously been reported for sightings of this species in thewestern North Paciﬁc (Matsuoka et al., 2000). Notably, relatively few minke whales were sighted in
the C stratum when the SST was higher than 16.0°C, and thus it is conceivable that the distribution ofminke whales is limited to within the SST range reported by Matsuoka et al. (2000). Consistent withﬁndings in the present study, Watanabe et al. (2006) have reported that mode SST at the saury ﬁshingboat positions was 15.0°C. Consequently, it would appear that minke and saury have a similar suitable
range of SSTs. In this regard, it has been reported that the timing and route of the saury migrationfrom northern waters to those oﬀ the southeastern coast of Hokkaido show considerable changes coinciding with annual ﬂuctuation in oceanographic conditions (Fukushima, 1979; Yasuda and Kitagawa,
1996; Yasuda and Watanabe, 1994).
Historical commercial catch data indicate that the migration and spatial distribution of minke
whales in the western North Paciﬁc diﬀer with respect to sex and maturation stage (Hatanaka andMiyashita, 1997; Ohsumi, 1983; Omura and Sakiura, 1956; Wada, 1989). The ﬁndings of JARPN II
in the C stratum have revealed that immature individuals are generally distributed in coastal waters
whereas mature males tend to be found at both coastal and oﬀshore waters (Kishiro et al., 2009). In
this regard, it has been suggested that mature minke whale males showed prey preference for sauryover other species, such as krill and walleye pollock (Kishiro et al., 2009). The number of mature
males in the C stratum during the period of the JARPN II survey declined from 2002 to 2006 (Kishiro
et al., 2009), coinciding with the decline of DIs and abundance reported in this study.
At least two diﬀerent stocks of minke whales have been identiﬁed in the waters around Japan,
namely the J and O stocks (Goto and Pastene, 1997; Kato, 1992; Ohsumi, 1977; Omura and Sakiura,
1956; Pastene et al., 2007; Wada and Numachi, 1991). Of these, O stock is mainly distributed in thewaters of the western North Paciﬁc, whereas J stock is mainly distributed in the Sea of Japan, although it has been reported that a small proportion of this stock mixed with O stock oﬀ the southeastern coast of Hokkaido (Pastene et al., 2016). Although the exact route whereby mature O stock males
migrate is still under investigation, it is evident that during the summer months, at least a proportionof these individuals migrates northward in oﬀshore regions of the western North Paciﬁc (e.g., east of
150°E) (Zenitani et al., 2000). Moreover, it seems probable that during autumn, they migrate southward along the coastal region of Japan, including waters oﬀ the southeastern coast of Hokkaido in autumn. The migration timing and route of mature male minke whales would thus appear to be similar tothat of the saury, and indeed, these whales are known to feed on saury in both oﬀshore regions and the14

Cetacean Popul. Stud. (CPOPS), Full paper
Vol. 4, 2023, 7–18

DISTRIBUTION OF MINKE WHALE OFF HOKKAIDO

waters oﬀ southeastern coast of Hokkaido (Lindstrøm et al., 1998; Tamura et al., 1998).
Findings in the present study provide evidence in support of the hypothesis that the migration routeof mature male minke whales coincides with a suitable SST (approximately 15°C) and the migrationof their primary prey species, the saury. In the C stratum, these mature males could make a high contribution to the observed changes in DIs and abundance. For example, in response to a suitable SST
and an abundance of saury (as in 2002), many mature males could migrate into the stratum, whereas
in contrast, when SSTs exceed a suitable level, and the availability of saury is low (as in 2006), there
would be relatively few migrants in this stratum.
Collectively, the ﬁndings of this study indicate that the abundance of minke whales in a particulararea is inﬂuenced to varying extents by changes in oceanographic conditions and the availability of
prey. In this regard, abrupt changes in the abundance of minke whales have been reported in other regions of the world. For example, changes in abundance of this species in Icelandic waters have been
linked to changes in oceanographic conditions and the patterns of prey species distribution (Víkingsson et al., 2015). Consequently, to gain a reasonably clear understanding of the factors underlying
such changes, analyses of whale sighting data should simultaneously take into consideration data obtained for a range of environmental variables, thereby enabling us to distinguish between apparent andabsolute changes in abundance.
A stock assessment for a time series between 1980 and 2018, revealed that the overall abundanceof saury was generally high during the period covered by the present study (2002–2006) (4th Meetingof the Technical Working Group on Paciﬁc Saury Stock Assessment, 2019). Furthermore, the ﬁndingsof a population dynamics study appear to indicate no abrupt change in abundance of the O stock ofminke whales during the period between the 1990s and 2010s (Kitakado and Maeda, 2016). On thebasis of these ﬁndings, it can be concluded that observed changes in the abundance of minke whales
in waters oﬀ the southeastern coast of Hokkaido between 2002 and 2006 were apparent rather thanactual changes, attributable to annual variations in oceanographic conditions. These variations similarly inﬂuence the route and timing of saury migrations. It seems probable that the apparent change
in the abundance of minke whales coincided with changes in local oceanographic conditions and theavailability of saury. It was reported that contractions in the size of potential saury ﬁshing grounds
oﬀ southeastern Hokkaido were associated with increases of SST and sea level anomaly, a reduction
in chlorophyll concentration, an increase in the frequency of clockwise eddies, and a reduction in
Oyashio transport (Kuroda and Yokouchi, 2017). It should be noted that the abundance index of sauryin the present study area in August and September was high in 2002, although low between 2004 and2006 in response to the environmental conditions (Kuroda and Yokouchi, 2017).
Nevertheless, given that minke whales also consume other prey items, such as Japanese anchovy,
walleye pollock, and Japanese common squid (Tamura et al., 2009), the interrelationships among minke whales, their prey, and oceanographic conditions in this region might be more complex than hitherto assumed. In this context, minke whales in the surveyed region have in the past fed on Japanesesardine and mackerel when the abundances of these prey were high (Kasamatsu and Tanaka, 1992).
However, it has yet to be ascertained how the minke whale distribution changes in response to thereplacement of pelagic ﬁsh species, along with changes in oceanographic conditions. Accordingly,
long-term monitoring of both the whales and their prey, together with oceanographic conditions, will
be necessary to gain a realistic insight into the factors underlying changes in the distribution of minke
whales in the waters oﬀ southeastern Hokkaido.
Acknowledgements

The authors express their thanks to all the members engaged in the coastal component of JARPN II oﬀ Kushiro. The Japan
Fisheries Information Service Center kindly provided data regarding commercial Paciﬁc saury ﬁsheries boats. This research
was supported by the Fisheries Agency of Japan, the Fisheries Research Agency of Japan, and the Institute of Cetacean Research. We thank these institutions for their support. The authors express their sincere thanks to the anonymous reviewers.

Cetacean Popul. Stud. (CPOPS), Full paper
Vol. 4, 2023, 7–18

15

MURASE, MATSUOKA AND WATANABE

References
4th Meeting of the Technical Working Group on Paciﬁc Saury Stock Assessment. 2019. 4th Meeting Report. NPFC-2019TWG PSSA04-Final Report. 50 pp. (Available at www.npfc.int).
Amante, C. and Eakins, B. W. 2009. ETOPO1 1 Arc-Minute Global Relief Model: Procedures, Data Sources and Analysis.
NOAA Technical Memorandum NESDIS NGDC-24. 19 pp.
Chavez-Rosales, S., Palka, D. L., Garrison, L. P. and Josephson, E. A. 2019. Environmental predictors of habitat suitability
and occurrence of cetaceans in the western North Atlantic Ocean. Sci. Rep. 9: 5833. doi: 10.1038/s41598-019-42288-6.
Doniol-Valcroze, T., Berteaux, D., Larouche, P. and Sears, R. 2007. Inﬂuence of thermal fronts on habitat selection by fourrorqual whale species in the Gulf of St. Lawrence. Mar. Ecol. Prog. Ser. 335: 207–216. doi: 10.3354/meps335207.
Fuji, T., Kurita, Y., Suyama, S. and Ambe, D. 2020. Estimating the spawning ground of Paciﬁc saury Cololabis saira byusing the distribution and geographical variation in maturation status of adult ﬁsh during the main spawning season.
Fish. Oceanogr. 30(4): 382–396. doi: 10.1111/fog.12525.
Fukushima, S. 1979. Synoptic analysis of migration and ﬁshing conditions of saury in the northwest Paciﬁc Ocean. Bull.
Tohoku Reg. Fish. Res. Lab. 41: 1–70 (in Japanese with English abstract).
Goto, M. and Pastene, L. A. 1997. Population structure of the western North Paciﬁc minke whale based on an RFLP analysisof the mtDNA control region. Rep. int. Whal. Commn. 47: 531–537.
Hakamada, T., Matsuoka, K. and Miyashita, T. 2009. The number of western North Paciﬁc common minke whales (Balaenoptera acutorostrata) distributed in JARPN II coastal survey areas. Paper SC/J09/JR8 presented to the IWC Scientiﬁc Committee Expert Workshop to review the JARPN II Programme, Yokohama, January 2009 (unpublished). 12 pp.
[Paper available from the Oﬃce of the IWC].
Hamazaki, T. 2002. Spatiotemporal prediction models of cetacean habitats in the Mid-Western North Atlantic Ocean (fromCape Hatteras, North Carolina, U.S.A. to Nova Scotia, Canada). Mar. Mamm. Sci. 18(4): 920–939. doi: 10.1111/j.17487692.2002.tb01082.x.
Hatanaka, H. and Miyashita, T. 1997. On the feeding migration of the Okhotsk Sea-West Paciﬁc stock of minke whales, estimates based on length composition data. Rep. int. Whal. Commn. 47: 557–564.
Hooker, S. K., Whitehead, H. and Gowans, S. 1999. Marine protected area design and the spatial and temporal distribution of
cetaceans in a submarine canyon. Conserv. Biol. 13(3): 592–602. doi: 10.1046/j.1523-1739.1999.98099.x.
Ingram, S. N., Walshe, L., Johnston, D. and Rogan, E. 2007. Habitat partitioning and the inﬂuence of benthic topography
and oceanography on the distribution of ﬁn and minke whales in the Bay of Fundy, Canada. J. Mar. Biol. Ass. 87(1):149–156. doi: 10.1017/S0025315407054884.
JPL MUR MEaSUREs Project. 2010. GHRSST Level 4 MUR Global Foundation Sea Surface Temperature Analysis. Ver. 2.
PO.DAAC, CA, USA. Dataset accessed 2020-12-19 at https://doi.org/10.5067/GHGMR-4FJ01.
Kasamatsu, F. and Tanaka, S. 1992. Annual changes in prey species of minke whales taken oﬀ Japan 1948–87. Nippon Suisan Gakkaishi 58: 637–651. doi: 10.2331/suisan.58.637.
Kato, H. 1992. Body length, reproduction and stock separation of minke whales oﬀ northern Japan. Rep. int. Whal. Commn.
42: 443–453.
Kishiro, T., Yoshida, H., Tamura, T., Konishi, K., Kanda, N., Okamoto, R. and Kato, H. 2009. Relationship between bodysize, maturity, and feeding habit of common minke whales oﬀ Kushiro in autumn season, from 2002–2007 whale sampling surveys under the JARPN II coastal components oﬀ Kushiro. Paper SC/J09/JR13 presented to the Expert Workshop to Review the Ongoing JARPN II Programme, January 2009. 25 pp. [Paper available from the Oﬃce of the IWC].
Kitakado, T. and Maeda, H. 2016. Fitting to catch-at-age data for North Paciﬁc common minke whales in the Paciﬁc side ofJapan. Paper SC/F16/JR43 presented to the JARPNII special permit expert panel review workshop, February 2016 (unpublished). 15 pp. [Paper available from the Oﬃce of the IWC].
Konishi, K., Tamura, T., Isoda, T., Okamoto, R., Hakamada, T., Kiwada, H. and Matsuoka, K. 2009. Feeding strategies andprey consumption of three baleen whale species within the Kuroshio-Current Extension. J. North. Atl. Fish. Sci. 42:
27–40. doi: 10.2960/J.v42.m648.
Kosaka, S. 2000. Life history of the Paciﬁc saury Cololabis saira in the northwest Paciﬁc and considerations on resource
ﬂuctuations based on it. Bull. Tohoku Nat. Fish. Res. Inst. 63: 1–95 (in Japanese with English abstract).
Kuroda, H. and Yokouchi, K. 2017. Interdecadal decrease in potential ﬁshing areas for Paciﬁc saury oﬀ the southeastern
coast of Hokkaido, Japan. Fish. Oceanogr. 26(4): 439–454. doi: 10.1111/fog.12207.
Kuroda, H., Saito, T., Kaga, T., Takasuka, A., Kamimura, Y., Furuichi, S. and Nakanowatari, T. 2020. Unconventional sea
surface temperature regime around Japan in the 2000s–2010s: Potential inﬂuences on major ﬁsheries resources. Front.
Mar. Sci. 7. doi: 10.3389/fmars.2020.574904.
Lindstrøm, U., Fujise, Y., Haug, T. and Tamura, T. 1998. Feeding habits of western North Paciﬁc minke whales, Balaenoptera acutorostrata, as observed in July–September 1996. Rep. int. Whal. Commn. 48: 463–469.
Macleod, K., Fairbairns, R., Gill, A., Fairbairns, B., Gordon, J., Blair-Myers, C. and Parsons, E. C. M. 2004. Seasonal distribution of minke whales Balaenoptera acutorostrata in relation to physiography and prey oﬀ the Isle of Mull, Scotland.
Mar. Ecol. Prog. Ser. 277: 263–274. doi: 10.3354/meps277263.
Maeda, H., Fujise, Y., Kishiro, T. and Kato, H. 2017. Utility of the transition phase in earplugs of the North Paciﬁc common
minke whale as an indicator of age at sexual maturity. Open J. Anim. Sci. 7: 414–424. doi: 10.4236/ojas.2017.74032.
Matsuoka, K., Hakamada, T., Fujise, Y. and Miyashita, T. 2000. Distribution pattern of minke whales based on sighting data

16

Cetacean Popul. Stud. (CPOPS), Full paper
Vol. 4, 2023, 7–18

DISTRIBUTION OF MINKE WHALE OFF HOKKAIDO
during the JARPN 1994–1999. Paper SC/F2K/J16 presented to the workshop to review the Japanese whale research
programme under special permit for North Paciﬁc minke whales (JARPN), February 2000. (unpublished). 17 pp. [Paper available from the Oﬃce of the IWC].
Murase, H., Tamura, T., Kiwada, H., Fujise, Y., Watanabe, H., Ohizumi, H., Yonezaki, S., Okamura, H. and Kawahara, S.
2007. Prey selection of common minke (Balaenoptera acutorostrata) and Bryde’s (Balaenoptera edeni) whales in thewestern North Paciﬁc in 2000 and 2001. Fish. Oceanogr. 16: 186–201. doi: 10.1111/j.1365-2419.2006.00426.x.
Naud, M. J., Long, B., Brêthes, J. C. and Sears, R. 2003. Inﬂuences of underwater bottom topography and geomorphology on
minke whale (Balaenoptera acutorostrata) distribution in the Mingan Islands (Canada). J. Mar. Biol. Ass. U.K. 83(4):889–896. doi: 10.1017/S0025315403008002h.
Ohsumi, S. 1977. Minke whales in the coastal waters of Japan. Rep. int. Whal. Commn. 27: 164–166.
Ohsumi, S. 1983. Minke whales in the coastal waters of Japan in 1981, with special reference to their stock boundary. Rep.
int. Whal. Commn. 33: 365–371.
Omura, H. and Sakiura, H. 1956. Studies on the little piked whale from the coast of Japan. Sci. Rep. Whal. Inst. 11: 1–37.
Pastene, L. A., Goto, M., Kanda, N., Zerbini, A. N., Kerem, D., Watanabe, K., Bessho, Y., Hasegawa, M., Nielsen, R., Larsen, F. and Palsbøll, P. J. 2007. Radiation and speciation of pelagic organisms during periods of global warming: Thecase of the common minke whale, Balaenoptera acutorostrata. Mol. Ecol. 16(7): 1481–1495. doi: 10.1111/j.1365294X.2007.03244.x.
Pastene, L. A., Goto, M., Taguchi, M. and Kitakado, T. 2016. Temporal and spatial distribution of the ‘J’ and ‘O’ stocksof common minke whale in waters around Japan based on microsatellite DNA. Paper SC/F16/JR38 presented to the
JARPNII special permit expert panel review workshop, February 2016 (unpublished). 14 pp. [Paper available from theOﬃce of the IWC].
Roberts, J. J., Best, B. D., Dunn, D. C., Treml, E. A. and Halpin, P. N. 2010. Marine Geospatial Ecology Tools: An integrated framework for ecological geoprocessing with ArcGIS, Python, R, MATLAB, and C++. Environ. Modell. Softw.
25(10): 1197–1207. doi: 10.1016/j.envsoft.2010.03.029.
Skern-Mauritzen, M., Johannesen, E., Bjørge, A. and Øien, N. 2011. Baleen whale distributions and prey associations in the
Barents Sea. Mar. Ecol. Prog. Ser. 426: 289–301. doi: 10.3354/meps09027.
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(3): 516–528. doi: 10.1006/jmsc.2002.1199.
Tamura, T., Fujise, Y. and Shimazaki, K. 1998. Diet of minke whales Balaenoptera acutorostrata in the northwestern part of
the north Paciﬁc in summer, 1994 and 1995. Fish. Sci. 64(1): 71–76. doi: 10.2331/ﬁshsci.64.71.
Tamura, T., Konishi, K., Goto, M., Bando, T., Kishiro, T., Yoshida, H., Okamoto, R. and Kato, H. 2009. Prey consumption
and feeding habits of common minke whales in coastal areas oﬀ Sanriku and Kushiro. Paper SC/J09/JR9 presented to
the IWC Scientiﬁc Committee Expert Workshop to review the JARPN II Programme, Yokohama, January 2009 (unpublished). 18 pp. [Paper available from the Oﬃce of the IWC].
Tetley, M. J., Mitchelson-Jacob, E. G. and Robinson, K. P. 2008. The summer distribution of coastal minke whales (Balaenoptera acutorostrata) in the southern outer Moray Firth, NE Scotland, in relation to co-occurring mesoscale oceanographic features. Remote Sens. Environ. 112(8): 3449–3454. doi: 10.1016/j.rse.2007.10.015.
Tseng, C. T., Sun, C. L., Yeh, S. Z., Chen, S. C., Su, W. C. and Liu, D. C. 2011. Inﬂuence of climate-driven sea surface temperature increase on potential habitats of the Paciﬁc saury (Cololabis saira). ICES J. Mar. Sci. 68(6): 1105–1113. doi:
10.1093/icesjms/fsr070.
Víkingsson, G. A., Pike, D. G., Schleimer, A., Valdimarsson, H., Gunnlaugsson, T., Silva, T., Elvarsson, B. Þ., Mikkelsen, B.,Öien, N., Desportes, G., Bogason, V. and Hammond, P. 2015. Distribution, abundance and feeding ecology of baleen
whales in Icelandic waters: Have recent environmental changes had an eﬀect? Front. Ecol. Evol. 3: 6. doi: 10.3389/
fevo.2015.00006.
Wada, S. 1989. Latitudinal segregation of the Okhotsk Sea-West Paciﬁc stock of minke whales. Rep. int. Whal. Commn. 39:
229–233.
Wada, S. and Numachi, K. 1991. Allozyme analyses of genetic diﬀerentiation among the populations and species of Balaenoptera. Rep. int. Whal. Commn. (Special issue) 13: 125–154.
Waggitt, J. J., Evans, P. G. H., Andrade, J., Banks, A. N., Boisseau, O., Bolton, M., Bradbury, G., Brereton, T., Camphuysen, C. J., Durinck, J., Felce, T., Fijn, R. C., Garcia-Baron, I., Garthe, S., Geelhoed, S. C. V., Gilles, A., Goodall,M., Haelters, J., Hamilton, S., Hartny-Mills, L., Hodgins, N., James, K., Jessopp, M., Kavanagh, A. S., Leopold, M.,
Lohrengel, K., Louzao, M., Markones, N., Martinez-Cedeira, J., O’Cadhla, O., Perry, S. L., Pierce, G. J., Ridoux, V.,
Robinson, K. P., Santos, M. B., Saavedra, C., Skov, H., Stienen, E. W. M., Sveegaard, S., Thompson, P., Vanermen, N.,
Wall, D., Webb, A., Wilson, J., Wanless, S. and Hiddink, J. G. 2020. Distribution maps of cetacean and seabird populations in the North-East Atlantic. J. Appl. Ecol. 57(2): 253–269. doi: 10.1111/1365-2664.13525.
Watanabe, Y. and Lo, N. C. H. 1989. Larval production and mortality of Paciﬁc saury, Cololabis saira, in the Northwestern
Paciﬁc Ocean. Fish. Bull. U. S. 87(3): 601–613.
Watanabe, K., Tanaka, E., Yamada, S. and Kitakado, T. 2006. Spatial and temporal migration modeling for stock of Pacific saury Cololabis saira (Brevoort), incorporating eﬀect of sea surface temperature. Fish. Sci. 72: 1153–1165. doi:
10.1111/j.1444-2906.2006.01272.x.
Watari, S., Murase, H., Yonezaki, S., Okazaki, M., Kiyofuji, H., Tamura, T., Hakamada, T., Kanaji, Y. and Kitakado, T. 2019.
Ecosystem modeling in the western North Paciﬁc using Ecopath, with a focus on small pelagic ﬁshes. Mar. Ecol. Prog.

Cetacean Popul. Stud. (CPOPS), Full paper
Vol. 4, 2023, 7–18

17

MURASE, MATSUOKA AND WATANABE
Ser. 617–618: 295–305. doi: 10.3354/meps12508.
Wessel, P. and Smith, W. H. F. 1996. A global, self-consistent, hierarchical, high-resolution shoreline database. J. Geophys.
Res: Solid Earth 101(B4): 8741–8743. doi: 10.1029/96JB00104.
Yasuda, I. and Kitagawa, D. 1996. Locations of early ﬁshing grounds of saury in the north-western Paciﬁc. Fish. Oceanogr.
5(1): 63–69. doi: 10.1111/j.1365-2419.1996.tb00018.x.
Yasuda, I. and Watanabe, Y. 1994. On the relationship between the Oyashio front and saury ﬁshing grounds in thenorth-western Paciﬁc: A forecasting method for ﬁshing ground locations. Fish. Oceanogr. 3(3): 172–181. doi: 10.1111/
j.1365-2419.1994.tb00094.x.
Yatsu, A. 2019. Review of population dynamics and management of small pelagic ﬁshes around the Japanese Archipelago.
Fish. Sci. 85: 611–639. doi: 10.1007/s12562-019-01305-3.
Zenitani, R., Kato, H. and Fujise, Y. 2000. Some analyses on biological parameters of western North Paciﬁc minke whales,from a view point of stock identiﬁcation. Paper SC/F2K/J13 presented to the workshop to review the Japanese whale
research programme under special permit for North Paciﬁc minke whales (JARPN), February 2000. (unpublished). 17
pp. [Paper available from the Oﬃce of the IWC].
Zerbini, A. N., Friday, N. A., Palacios, D. M., Waite, J. M., Ressler, P. H., Rone, B. K., Moore, S. E. and Clapham, P. J. 2016.
Baleen whale abundance and distribution in relation to environmental variables and prey density in the Eastern Bering
Sea. Deep Sea Res. II: Top. Stud. Oceanogr. 134: 312–330. doi: 10.1016/j.dsr2.2015.11.002.

Received: March 1, 2021
Accepted: July 26, 2022
Published online: October 25, 2022

18

Cetacean Popul. Stud. (CPOPS), Full paper
Vol. 4, 2023, 7–18

Short note

Surface feeding of a sei whale, North Paciﬁc.

DOI

https://doi.org/10.34331/cpops.2022S001

J-STAGE Advance published date: June 6, 2023

CRANIAL MEASUREMENTS OF A STRANDED BRYDE’S WHALE FROM KUWAITPRELIMINARY REPORT ON THE CRANIAL
MEASUREMENTS OF A BRYDE’S WHALE STRANDEDIN FAILAKA ISLAND, KUWAIT IN 2014
Gen NAKAMURA1*, Abdullah AL-ZAIDAN2, Manaf BEHBEHANI3 andHidehiro KATO1, 4
1

Laboratory of Cetacean Biology, Tokyo University of Marine Science and Technology,
4–5–7 Konan, Minato-ku, Tokyo, 108–8477, Japan
2
Kuwait Environment Public Authority (EPA), P.O. Box: 24395, Safat 13104, Kuwait
3
Kuwait Science Company, P.O. Box 56 Dasman, State of Kuwait 15451
4
Institute of Cetacean Research, Toyomi Shinko Building 5F, 4–5 Toyomi-cho,
Chuo-ku, Tokyo, 104–0055, Japan*Corresponding author: gnakam1@kaiyodai.ac.jp

Abstract
On 28 February 2014, a dead baleen whale was stranded and found by residents on the east
coast of Failaka Island, Kuwait. The specimen was a female with a total length of 14 m. Aftermuscle and internal organ removal and sample collection, the remains of this animal wereburied in situ. The Japanese authors of this paper visited Failaka Island to check the conditionof the skeleton after about nine months since the stranding event. A total of 44 measurements,
including condylobasal length, were made from the dorsal side of the skull. Skull length was
3.222 m, which represented 26.85% of the body length. The skull of the specimen possesses
diagnostic characteristics of Bryde’s whale, such as the outer edge of the rostrum being rounded and ﬂattened in dorsal and lateral views, respectively. The number of ribs were 13 on theleft, and 12 on the right side. The skeleton was reburied to allow natural decomposition of theremaining soft tissue. As of 2022 we have not been able to excavate this skeleton, but we hope
to do so in the near future and hope the specimen will be properly catalogued and permanently
stored at some museum or institution in Kuwait.
Key words:

Skeletal measurement, Balaenopteridae, Bryde’s whale, Balaenoptera edeni
morphometric, large whale.

The Bryde’s whale Balaenoptera edeni Anderson, 1879, is a medium-sized balaenopterid with a
total length of about 13 to 15 meters. While most baleen whales have a clear seasonal migration andantitropical distribution, the Bryde’s whale inhabits tropical and warm temperate waters of the Indian,Paciﬁc, and Atlantic Oceans of 40°N to 40°S with a circannual water temperature of 16.3°C or warmer(Kato and Perrin, 2018).
Two genetically and morphologically distinct populations exist within this species, namely B. edeni
brydei (Olsen, 1913) and B. edeni edeni (Committee on Taxonomy, 2022). Balaenoptera e. brydei islarger and inhabits oﬀshore waters, whereas B. e. edeni is smaller and found closer to shore (Wadaet al., 2003; Sasaki et al., 2006; Kanda et al., 2007; Kato and Perrin, 2018; Committee on Taxonomy, 2022). In recent years, some scientists have suggested that these two populations should be separated at the species level and named as B. brydei and B. edeni, but no agreement has been reached yet(Rosel et al., 2021). In 2021 Bryde’s-like whales from the northern Gulf of Mexico were described asa new species, B. ricei (Rosel et al., 2021).
Morphological information, such as external and skeletal characteristics, is one of the essential taxonomical traits along with genetics to determine cetacean species. However, for large whales such as
Cetacean Popul. Stud. (CPOPS), Short noteVol. 4, 2023, 21–26

21NAKAMURA, AL-ZAIDAN, BEHBEHANI AND KATO

Bryde’s whales, the number of available skeletal specimens is small and makes a signiﬁcant challenge
for taxonomic studies. Although several sightings and strandings of Bryde’s whale have been reported
from the Arabian Sea and adjacent waters, the number of skeletal specimens of this species is limited.
Only ﬁve skeletal remains of Bryde’s whale have been reported from the Iranian coast of the Arabian (Persian) Gulf and the Gulf of Oman since 1971 (Braulik et al., 2010). Some of the other Bryde’s
whales strandings from the Arabian (Persian) Gulf include the following: (1) a 12.5 m male stranded at
Qasr, Iraq on 5 February 1967 (Al-Robaae, 1967, Mahdi, 1967), (2) a 14.5 m individual stranded near
the ARAMCO causeway at Abu Ali Island, Saudi Arabia in March 1995 (Robineau and Fiquet, 1996),
and (3) a dead specimen stranded in May 1995 at the Saudi Arabia-Bahrain causeway (Robineau andFiquet, 1996).
Stranding events are the only way of obtaining skeletal specimens of large whales in areas where
whaling is not conducted. However, especially in the case of large whales, they are not always collected from all stranded animals due to the high cost of cleaning, preparing and maintaining such skeletal
specimens and the problem of securing storage space. Therefore, the number of scientiﬁcally valuableskeletal specimens available for academic research is limited.
In early 2014, a baleen whale was stranded on Failaka Island in Kuwait. This animal was buried
after being examined by local scientists. About nine months later, following the request of a Kuwait
scientiﬁc institute to make a skeletal specimen, the whale carcass was temporarily dug out to verify its
conditions and to conduct preliminary research on skeletal measurements by Japanese researchers. Asof 2022, the skeleton has not yet been excavated for various reasons. However, the data obtained fromour brief examination are valuable to further understand the ecology of the Bryde’s whale. Therefore,
they are provided in this preliminary report.

Fig. 1. Location of the Bryde’s whale that stranded in 28th February, 2014. a) Wider area map, around theArabian (Persian) Gulf. b) Map showing the position of Kuwait and Failaka Island. c) Failaka Island map. The
black circle indicates the Bryde’s whale stranding location.

22

Cetacean Popul. Stud. (CPOPS), Short noteVol. 4, 2023, 21–26

CRANIAL MEASUREMENTS OF A STRANDED BRYDE’S WHALE FROM KUWAIT

Fig. 2. December 2014 excavation of the Bryde’s whale to check the skeletal conditions and to conduct scientiﬁc observations.

Fig. 3. Cranial measurement points and values of the Bryde’s whale stranded in Failaka Island, Kuwait, inFebruary 2014. a) and b) dorsal view, c) caudal view, d) dorsal view of the vertex, and e) lateral view of theskull. For measurement point explanation and values, see Table 1.

On 28 February 2014, a dead baleen whale was found stranded by residents on the east coast of
Failaka Island (29°24′50.9″N, 48°23′44.86″E), Kuwait. This island is located about 20 km oﬀ the coastof Kuwait City, in the northern part of the Arabian (Persian) Gulf (Fig. 1). In response to the stranding
report, on 1 March 2014 Kuwaiti researchers visited the site to examine the carcass and to make anassessment on the possible causes of the whale’s death. After their conducting external measurements
followed by autopsy and examination of the internal organs, this animal was initially identiﬁed as a ﬁn
whale having a body length of 14 m (Khalaf, 2014). After sample collection and removal of muscles
Cetacean Popul. Stud. (CPOPS), Short noteVol. 4, 2023, 21–26

23

NAKAMURA, AL-ZAIDAN, BEHBEHANI AND KATO

Table 1.
No.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.

Cranium measurements of the Bryde's whale stranded in Failaka Island, Kuwait, in 2014.
Measurement points

cm

Condylobasal length
Length of rostrum
Length of premaxillary (L)Length of premaxillary (R)Length of maxillary (L)Length of maxillary (R)Tip of premaxillary to tip of maxillary (L)Tip of premaxillary to tip of maxillary (R)Tip of premaxillary to nares, anterior
Tip of premaxillary to vertex
Breadth of maxillary, posterior edge
Breadth of premaxillary, posterior edge
Breadth of rostrum at base
Breadth of premaxillary at base
Breadth of rostrum at middle
Breadth of premaxillary at middle
Greatest breadth of premaxillary
Breadth of cranium, maxillary
Breadth of cranium, middle of orbital foramen
Breadth of cranium, anterior edge of zygomatic process
Breadth of cranium, middle of zygomatic process
Breadth of occipital bone
Length from upper ridge of foramen magnum to superior part of occipital bone
Minimum breadth of parietal bone
Length of nasals
Breadth of nasals, anterior
Breadth of nasals at middle
Breadth of nasals, posterior
Height of foramen magnum
Breadth of foramen magnum
Breadth across occipital condyles
Breadth of occipital condyle (L)Breadth of occipital condyle (R)Height of occipital condyle (L)Height of occipital condyle (R)Breadth of orbit (L)Breadth of orbit (R)

322.2
209.1
245.7
246.7
227.5
227.5
20.0
19.7
224.2
248.7
23.6
17.4
90.5
29.3
63.3
28.8
34.2
135.6
134.8
146.6
145.6
97.0
71.4
23.4
22.2
17.6
13.1
5.8
10.0
7.3
25.6
11.3
11.4
17.4
18.2
24.0
23.3

and internal organs, the remaining parts of the animal were placed in a pit four to six meters deep andburied in the sand.
From 20 to 22 December 2014, the authors of this paper visited Failaka Island to unbury and checkthe skeleton’s condition and to obtain photographic and measurement records (Fig. 2). The left ﬂipper
was ﬁrst excavated. The orientation of ﬁnger bones was photographed and traced with a clear plastic
sheet. The soft tissue was almost decomposed and liqueﬁed but still remained within the ﬁnger bones.
As regards the rest of the skeleton, the residual muscle and fatty tissue had not completely decomposed and were still remaining, especially at the underside of the bones. Ribs, cervical, and dorsal ver-24

Cetacean Popul. Stud. (CPOPS), Short noteVol. 4, 2023, 21–26

CRANIAL MEASUREMENTS OF A STRANDED BRYDE’S WHALE FROM KUWAIT

Fig. 4. Dorsal (a) and lateral (b) view of the skull. Note that ventral part of the skull is ﬁlled with sand. The
scale bar indicates 1 meter.

tebral bones were assigned numbers and labeled with plastic tags. The remnant bones (right ﬂipper’s,
vertebrae, ribs, and chevrons) were also collected. Measurements and photographic records were taken of the skull for the purpose of academic use before burying them again. Except for the pelvic bones
and some (maybe three to ﬁve) tips of the right ﬁnger bones and the left tympanic bulla, all skeletal
parts have been collected. About 17 neural spines of the dorsal and lumbar vertebras were broken.
This would probably have been caused by the following reasons: ﬁrst, that the spines were also decaying within the ﬂesh, which was not removed completely. And a second reason may be the neuralspines’ position, which stayed level and under pressure from the above sand.
A total of 44 measurements, including skull length, were taken from the dorsal side of the cranium.
The skull length (condylobasal length) was 3.222 m, which represented 26.85% of the specimen’sbody length (Fig. 3, Table 1). Omura (1959) compared the osteological characteristics of Bryde’s andsei (B. borealis) whales. The skull shape of the animal possesses diagnostic characteristics of Bryde’s
whale, such as the outer edge of the rostrum being rounded and ﬂattened in dorsal and lateral view, respectively, which was reported by Omura (1959) (Fig. 4). Numbers of ribs were 13 and 12 in left andright, respectively. The 13th left rib was separated into two pieces (not broken). The vertebral formula
was as follows:

C7 + D13 + L13 + Ca17 + α .
After measuring and photographing the skull, the skeletal pieces were transported from Failaka
Island to a protected area on mainland Kuwait and buried again. This will allow the remaining soft
tissues still attached to the bones to decompose so that a skeletal specimen of this animal may be prepared later on. We hope to do so in the near future so that this scientiﬁcally valuable specimen may bepermanently stored in a museum or another appropriate institution in Kuwait.
We would like to express our appreciation to everyone who coutributed to this mission, including
the Kuwait Environmental Public Authority (EPA) personnel, the technical staﬀ of the Nishio BiologiCetacean Popul. Stud. (CPOPS), Short noteVol. 4, 2023, 21–26

25

NAKAMURA, AL-ZAIDAN, BEHBEHANI AND KATO

cal Models, Co. Ltd., and the Sakamoto Taxidermy Studio of Kyoto, Japan.

References
Al-Robaae, K. 1967. Bryde’s whale on the coast of Iraq. Zeitschrift fur Saugetierkunde 34(2): 120–125.
Braulik, G. T. S., Ranjbar, S., Owﬂ, F., Aminrad, T., Dakhteh, S. M. H., Kamrani, E. and Mohsenizadeh, F. 2010. Marine
mammal records from Iran. J. Cetacean Res. Manage. 11(1): 49–63.
Committee on Taxonomy. 2022. List of marine mammal species and subspecies. Society for Marine Mammalogy. www.
marinemammalscience.org, consulted on 21 November, 2022.
Kanda, N., Goto, M., Kato, H., McPhee, M. V. and Pastene, L. A. 2007. Population genetic structure of Bryde’s whales (Balaenoptera brydei) at the inter-oceanic and trans-equatorial levels. Conserv. Genet. 8: 853–864. doi: 10.1007/s10592006-9232-8.
Kato, H., and Perrin, W. F. 2018. Bryde’s whale Balaenoptera edeni. pp. 143–45. In: Würsig, B., Thewissen, J. G. M., andKovaks, K. M. (eds.) Encyclopedia of Marine Mammals (Third Edition). Academic Press, London. 1157 pp.
Khalaf, N. A. B. 2014. A ﬁn whale (Balaenoptera physalus) stranding on Failaka Island, State of Kuwait. Gazelle—The Palestinian Biological Bulletin 119: 1–13.
Omura, H. 1959. Bryde’s whale from the coast of Japan. Sci. Rep. Whales Res. Inst. 14: 1–33.
Olsen, Ö. 1913. On the external characters and biology of Bryde’s whale (Balaenoptera brydei), a new rorqual from the coastof South Africa. Proc. Zool. Soc. Lond. 83(4): 1073–1090. doi: 10.1111/j.1096-3642.1913.tb02005.x.
Mahdi, N. 1967. First records of Bryde’s whale Balaenoptera edeni Anderson from Arab Gulf, with notes on earlier literature. Bull. Iraq Nat. His. Mus. 3(7): 1–7.
Robineau, D. and Fiquet, P. 1996. The Cetacea of the Jubail marine wildlife sanctuary, Saudi Arabia. pp. 438–458. In: Krupp,
F., Abuzinada, A. H. and Nader, I. A. (eds.) A Marine Wildlife Sanctuary for the Arabian Gulf: Environmental Researchand Conservation Following the 1991 Gulf War oil spill. Riyadh and Senckenberg Research Institute, Frankfurt. 511
pp.
Rosel E. P., Wilcox A. L., Yamada K. T. and Mullim, D. K. 2021. A new species of baleen whale (Balaenoptera) from theGulf of Mexico, with a review of its geographic distribution. Mar Mam. Sci. 37(2): 577–610. doi: 10.1111/mms.12776.
Sasaki, T., Nikaido, M., Wada, S., Yamada, T. K., Cao, Y., Hasegawa, M. and Okada, N. 2006. Balaenoptera omurai is a
newly discovered baleen whale that represents an ancient evolutionary lineage. Mol. Phylogenet. Evol. 41(1): 40–52.
doi: 10.1016/j.ympev.2006.03.032.
Wada, S., Oishi, M. and Yamada, T. K. 2003. A newly discovered species of living baleen whale. Nature. 426(6964): 278–
281. doi: 10.1038/nature02103.

Received: October 14, 2022
Accepted: March 9, 2023
Published online: June 6, 2023

26

Cetacean Popul. Stud. (CPOPS), Short noteVol. 4, 2023, 21–26

DOI

https://doi.org/10.34331/cpops.2022S002

J-STAGE Advance published date: June 9, 2023

DWARF MINKE WHALE (BALAENOPTERA ACUTOROSTRATA SUBSP.) BEHAVIOR IN BRAZILDWARF MINKE WHALE (BALAENOPTERAACUTOROSTRATA SUBSP.) INTERACTIONS WITH
VESSELS OFF THE COAST OF BRAZIL
Lucas MILMANN1*, Júlio CARDOSO2, Arlaine FRANCISCO2,Frank P. SANTOS2, Cecilia SEMINARA3, Daniela R. ABRAS4,
Marina L. MARQUES4, 5, Denis A. HILLE6, Leila S. LEMOS7,
Greicy F. RUENES8, Rachel Ann HAUSER-DAVIS9and Salvatore SICILIANO10*
Grupo de Estudos de Mamíferos Aquáticos do Rio Grande do Sul (GEMARS),
Rua Saldanha da Gama, 937, Tôrres, RS, 95560–000, Brazil
2
Projeto Baleia à Vista, Rua Manuel da Silva Junior 237, Ilhabela, SP, 11630–000, Brazil
3
Universidade Estadual de Santa Cruz–UESC, PRODEMA,
Rodovia Jorge Amado, Km 16, Ilhéus, BA, 45662–900, Brazil
4
VIVA Instituto Verde Azul (VIVA), Av. Engenheiro Luiz Carlos Berrini, 550, Conj. 41,
Cidade Monções, São Paulo, SP, 04571–925, Brazil
5
Universidade Estadual de Santa Cruz–UESC, PPGZOO,
Rodovia Jorge Amado, km 16, Ilhéus, BA, 45662–900, Brazil
6
Programa de Pós-Graduação em Ecologia, Departamento de Ecologia e Zoologia, Universidade Federal
de Santa Catarina, Laboratório de Mamíferos Aquáticos, Florianópolis, SC, 88040–970, Brazil
7
Institute of Environment, Florida International University,
3000 NE 151st St, North Miami Beach, FL 33181, United States
8
Universidade Estadual do Norte Fluminense Darcy Ribeiro, Programa de Pós-Graduação em Ecologia e
Recursos Naturais (PGERN), Universidade Estadual do Norte Fluminense – UENF,
Av. Alberto Lamego, 2000, Campos dos Goytacazes, RJ, 28013–602, Brazil
9
Laboratório de Avaliação e Promoção da Saúde Ambiental, IOC/Fiocruz,
Av. Brasil, 4365, Rio de Janeiro, RJ, 21040–360, Brazil
10
Escola Nacional de Saúde Pública/Fiocruz, Departamento de Ciências Biológicas, Rua Leopoldo Bulhões,1480–sala 10, Manguinhos, Rio de Janeiro, RJ, 21040–900 Brazil*Corresponding authors: lcmilmann@gmail.com, gemmlagos@gmail.com
1

Abstract
The dwarf minke whale (Balaenoptera acutorostrata subsp.) is a hard to detect small baleen whale whose behavior towards vessels and man-made structures in South Atlantic waters
is still not well characterized. This study compiles records on the behavior of this species in
Brazil, employing citizen science reports and data from ship and sailboat surveys. A total of 16
records were obtained from 2001 to 2021. The data indicate a consistently curious approach
toward boats (81.25% of all identiﬁed behaviors). Other identiﬁed behaviors included traveling/ﬂeeing (6.25%), and breaching (6.25%). These assessments comprise valuable tools forﬁeld identiﬁcation of this species, as color patterns may become exposed during diﬀerent aerial displays. This is the ﬁrst approach to understand the ephemeral behavior of the dwarf minke
whale along the southeastern coast of Brazil.
Key words:

Mysticetes, dwarf minke whale, Balaenoptera acutorostrata subsp., anthropogenic activities, behavioral responses.

Nine baleen whale species comprise the Balaenoptera genus, including the common minke whale(B. acutorostrata) (Wada et al., 2003; Rosel et al., 2021), the smallest of all (Stewart et al., 2002).
This species is further categorized into three subspecies, the North Atlantic common minke whale (B.
acutorostrata acutorostrata), the North Paciﬁc common minke whale (B. acutorostrata scammoni),
Cetacean Popul. Stud. (CPOPS), Short noteVol. 4, 2023, 27–33

27

MILMANN ET AL.

and a Southern Hemisphere, still unnamed subspecies generally referred to as the dwarf minke whale(B. acutorostrata subsp., Best, 1985), whose geographical distribution encompasses tropical, temperate, and polar waters of the South Atlantic, South Paciﬁc, and Indian Oceans (NOAA Fisheries, 2022).
A clear taxonomical separation between the dwarf minke whale and the Antarctic minke whale (B.
bonaerensis) is noted, as well as diﬀerences in size and coloration (Best, 1985; Arnold et al., 1987).
Furthermore, genetic evidence suggests a separation between the Western South Atlantic and WesternSouth Paciﬁc dwarf minke whale populations (Pastene et al., 2010; Milmann et al., 2021). However,both species can reach similar sizes, depending on their age class, exhibiting certain common morphological traits, such as a third white shoulder patch near the ﬂuke insertion (da Rocha and Braga, 1982;
Secchi et al., 2009; Milmann et al., 2018) that hinder their ﬁeld identiﬁcation in geographical areas
where they can be sympatric. This is of signiﬁcant interest, as the International Union for Conservation of Nature categorization of “Least Concern” refers to all B. acutorostrata subspecies, with nospeciﬁc separate category assigned to dwarf minke whales, and is based on estimates from parts of thespecies range in the Northern Hemisphere only (The Minke Whale Project, 2022). The species, however, is at risk for several threats common to other whale species, comprising entanglement in ﬁshinggear, ocean noise, vessel strikes and climate change eﬀects (NOAA Fisheries, 2022).
Concerning behavior, common minke whales have been known to swim close to ships (Leatherwood et al., 1976), while dwarf minke whales have been known to voluntarily approach dive tourism
vessels and passengers and maintain contact for prolonged periods oﬀ Australia’s Great Barrier Reef,
in the Western South Paciﬁc (Arnold et al., 1987; Mangott et al., 2011). Very limited information on
this species behavior and reactions to vessels and man-made structures is, however, available, especially for Western South Atlantic waters.
In this regard, dwarf minke whales appear in most lists and reviews concerning stranded or opportunistically sighted cetaceans oﬀ the coast of Brazil (Geise and Borobia, 1988; Simões-Lopes andXiménez, 1993; Magalhães et al., 2008; Zerbini et al. 1996, 1997; Santos et al., 2010; Costa et al.,2017; Mayorga et al., 2020), and dedicated surveys on land, oil platforms and at sea, have proveninvaluable in detecting this species oﬀ the coasts of the states of Rio de Janeiro (Hassel et al., 2003),
Santa Catarina (Cremer et al., 2009), São Paulo (Santos et al., 2019; Figueiredo et al., 2020) and in
Northeastern Brazil (Zerbini and da Rocha, 1999). Incidental dwarf minke whale entanglements inﬁshing gear have also been reported in the state of Rio Grande do Sul, Southern Brazil (Secchi etal., 2003). See Milmann et al. (2020) for a recent compilation on minke whale stranding records oﬀ
the coast of Brazil.
Concerning general dwarf minke whale behavior, it has been reported interacting with other species, such as humpback whales (Megaptera novaeangliae) and small odontocetes like bottlenose
dolphins (Tursiops truncatus) and rough-toothed dolphins (Steno bredanensis) oﬀ the state of Bahia,
Northeastern Brazil (Rossi-Santos et al., 2006). Data on reactions to anthropogenic activities for thisspecies oﬀ the coast of Brazil, however, are sorely lacking. In this regard, one of the few studies available indicates that dwarf minke whales can swim close to oﬀshore structures, as reported by Cremer etal. (2009) for Southern Brazil, as well as near tourist and ﬁshing boats, during feeding in the summer
in coastal waters oﬀ Arraial do Cabo, in Southeastern Brazil (Hassel et al., 2003). Another, ethnobiological approach study conducted oﬀ the central Bahia coast, in Northeastern Brazil, described dwarf
minke whale (locally known as “tauaçu”) interactions with ﬁsheries activities, noting that ﬁshers there
believe that the minke whale attacks people, mainly due to its vessel-approaching behavior, and, in
this regard, they may have negative attitudes reﬂected in behaviors that can harm these animals (Seminara et al., 2019).
In this context, it is relevant to report unpublished records concerning dwarf minke whale approaches to vessels and interactions with other man-made structures oﬀ the coast of Brazil. This study, therefore, compiles unpublished records from multiple sources on dwarf minke whale reactions to humanactivities along the SE and NE Brazilian coastlines. The categorized reactions motivated by human28

Cetacean Popul. Stud. (CPOPS), Short noteVol. 4, 2023, 27–33

DWARF MINKE WHALE (BALAENOPTERA ACUTOROSTRATA SUBSP.) BEHAVIOR IN BRAZIL

activities follow Watkins (1986) for four baleen whales (common minke whale, ﬁn whale B. physalus,
northern right whale Eubalaena glacialis and humpback whale M. novaeangliae), deﬁned as Positive(P), Uninterested (U) and Negative (N). “Positive” reactions include apparent curiosity to the presenceof the vessel, “Uninterested” reactions comprise events in which stimuli were apparently ignored, andthe whales continued their activities uninterruptedly, and “Negative” reactions include sudden changes in behavior (e.g., activity to inactivity, inactivity to activity, or changes in activity). Behaviors thatwere not clearly identiﬁed as P, U, or N, or that could not be identiﬁed due to lack of information,
were classiﬁed as Undetermined (Und).
A total of 16 dwarf minke whale records concerning reactions to anthropogenic activities wereobtained for Brazil, comprising 13 positives (boat attraction), two negatives (traveling/ﬂeeing andintensive breaching), and one undetermined. These behaviors were identiﬁed by both research (n=9;platform D) and platform of opportunity vessels (n=5; platform C), as well as literature reports (n=2;platform L). Geo-referenced available records are listed in Table 1 and depicted in Fig. 1. Sightingsfrom dedicated surveys were performed by experienced observers when the boats were in motion,
while “platform C” refers to opportunistic sightings with or without the boat in motion. Remarkably,
the only two cases of negative behavior were recorded from opportunistic platforms, which could be
related to a sudden movement of the boat towards the animal or even a sudden stop from the boat for
observation.
Dwarf minke whales oﬀ the coast of Brazil are seemingly very inquisitive, similar to behavior
observed in Australia, where whales voluntarily approach dive tourism vessels and passengers andmaintain contact for prolonged periods of time (Mangott et al., 2011). This behavior was detected in
two areas in Brazil, along the Northeastern coast for both Antarctic and dwarf minke whales, and inCampos Basin, in Southeastern Brazil, where whales approached vessels curiously after perceiving
them and remained immobile while the vessels passed by. This curious approach towards vessels may
comprise a valuable tool to detect and identify dwarf minke whales in the ﬁeld, considering their lower detectability when compared to other baleen whales (Zerbini et al., 2006; Martin et al., 2013) due
to their smaller size and almost undetectable respiratory blow in tropical areas.
The traveling/ﬂeeing behavior reported herein has been described as depending on the number ofwhales in the group and type of group (Argüelles et al., 2022). This behavior has been noted for otherwhale species, such as blue whales (B. musculus) (McKenna et al., 2015), and southern right whale
mother-calf pairs or solitary individuals (Argüelles et al., 2022), where whales dive to deeper depths
when at the surface or delay their surfacing following a diving period when near ships. However,avoidance behavior seems to be species-speciﬁc to a certain extent (Argüelles et al., 2022), and the
low number of records reported herein for this category may seem to indicate low dwarf minke whale
sensitivity to vessels, potentially increasing vessel collision events and comprising a threat to the species.
Finally, the breaching behavior is more frequent in certain species, such as humpback and rightwhales (Segre et al., 2020), and rarer in others, like ﬁn whales (Aguilar and García-Vernet, 2018).
Dwarf minke whales do not usually exhibit this behavior, although some records are available in theliterature (Arnold and Birtles, 1999; Segre et al., 2020). Concerning the present study, breaching wasobserved for one dwarf minke whale individual, which breached 17 times in a period of 15 minutes(13 h35 to 13 h50) on 1 May 2020 oﬀ Ilha de São Sebastião, in SE Brazil (Fig. 2). This high number ofbreaches in such a small period of time is likely to add up to a signiﬁcant amount of spent energy, as
breaching comprises a high energy expenditure in whales (Segre et al., 2020), potentially associatedwith vessel proximity. However, ultimately, the reasons for this behavior are still unknown, althoughsome hypotheses have been put forth, such as courtship, parasite dislodgement, communication, andreactions to nearby activities, including the presence of vessels, noise, and others (Werth and Lemon, 2020). Thus, breaching behavior when noted in association with nearby vessels should be interpreted cautiously. Further, this behavior may comprise a valuable tool for dwarf minke whale identiﬁCetacean Popul. Stud. (CPOPS), Short noteVol. 4, 2023, 27–33

29

30

Platform
L
L
D
D
D
D
C
D
C
C
C
D
C
D
D
D

Location

Pontal do Atalaia, Arraial do Cabo, RJ
NE Brazil continental shelfCampos Basin, RJ
Campos Basin, RJ
Campos Basin, RJ
Campos Basin, RJ
Campos Basin, RJ
Santos Basin, RJ
36 nm oﬀ S. Sebastião, Ilhabela, SP
ca. Parcel da Itapecirica, S. Ilhabela, SP
8 nm oﬀ Ilhéus, BA
Ilha de Búzios, Ilhabela, SP
São Sebastião, Ilhabela, SP
28 nm oﬀ São Sebastião, Ilhabela, SPSE oﬀshore area, RJ
70 nm oﬀ Ilhabela. São Sebastião, SP

2001
1998–2001
13-April-2008
10-May-2008
23-May-2008
28-May-2008
23-Sep-2014
10-Mar-2020
28-April-2020
01-May-2020
04-Jun-2020
23-Jun-2020
09-Jul-2020
20-Jan-2021
27-May-2021
21-Nov-2021

Date/Period
22
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

No.
sightings
P
P
P
P
P
P
P
P
Und
N
P
P
N
P
P
P

Behavior
Hassel et al. (2003)
Zerbini and da Rocha (1999)
This study
This study
This study
This study
This study
This study
This study
This study
This study
This study
This study
This study
This study
This study

Source

—
—
—
—
—
—
—
−25.72809−24.39166−23.91270—−23.77620−23.82055−24.18333−23.65395−24.56666Latitude

—
—
—
—
—
—
—
−46.03487−45.47201−45.07871—−45.07871−45.38898−44.90000−40.98630−44.55933

Longitude

Table 1. Records from multiple sources on the ‘reaction’ behavior of dwarf minke whales (Balaenoptera acutorostrata subsp.) to anthropogenic activities. Abbreviations: Positive (P), Uninterested (U), Negative (N), Undetermined (Und), Rio de Janeiro State (RJ), São Paulo State (SP), Northeastern (NE), Bahia State (BA). Platform: C=citizen report, D=direct observation, L=literature.

MILMANN ET AL.

Cetacean Popul. Stud. (CPOPS), Short noteVol. 4, 2023, 27–33

DWARF MINKE WHALE (BALAENOPTERA ACUTOROSTRATA SUBSP.) BEHAVIOR IN BRAZIL

Fig. 1. Locations of the southeastern Brazil dwarf minke whale (Balaenoptera acutorostrata subsp.) records
concerning reactions to anthropogenic activities reported in this study. The digits indicate number of records
at each position. Five records at Santos Basin are not indicated by a star because location was derived from a
description of the locale instead of geographic coordinates. Abbreviations: Rio de Janeiro State (RJ), São Paulo
State (SP).

Fig. 2. Breaching behavior of a dwarf minke whale (Balaenoptera acutorostrata subsp.) oﬀ Ilha de São
Sebastião, SE Brazil, May 2020. Photos: (A) Jurandir Paulo and (B) Frank Santos.

cation in the ﬁeld, as the white patches present above the pectoral ﬁn in this subspecies become visible
during diﬀerent aerial displays (see Fig. 2).
Changes in dwarf minke whale reactions to stimuli from anthropogenic activities are gradual andvary with increasing exposure periods (Mangott et al., 2011). Therefore, the descriptions concerning
dwarf minke whale behaviors reported herein comprise a starting point to detect potential changes
over time through continuous monitoring eﬀorts. Furthermore, it seems that dwarf minke whales
display slightly more diverse behavior while in the tropics than previously described, seemingly engaging in more positive behaviors while oﬀ the Brazilian coastline, exhibiting interest in boats andpotentially comprising an attraction for the whale watching industry. In addition, breaching behavior
is noted as a potentially valuable tool for dwarf whale minke ﬁeld identiﬁcation.
Cetacean Popul. Stud. (CPOPS), Short noteVol. 4, 2023, 27–33

31

MILMANN ET AL.

Acknowledgements

L. Milmann was ﬁnancially supported by Cetacean Society International (CSI), Ruﬀord, USA (Small Grant No 24023-1),
and Fundação de Apoio a Pesquisa da Bahia (FAPESB), Brazil through a PhD scholarship to the ﬁrst author. G. F. Ruenes is
supported by a PhD scholarship from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior–CAPES). S. Siciliano
is supported by CNPq (Bolsa de Produtividade em Pesquisa: 306076/2019-5). L. A. Pastene (Institute of Cetacean Research)kindly revised the manuscript and provided valuable comments.

References
Aguilar, A., and García-Vernet, R. 2018. Fin Whale: Balaenoptera physalus. pp. 368–371. In: Würsig, B., Thewissen, J. G.
M., and Kovaks, K. M. (eds.). Encyclopedia of Marine Mammals (Third Edition). Academic Press, London. 1157 pp.
Argüelles, M. B., Coscarella, M. A., Fiorito, C., and Bertellotti, M. 2022. Southern right whales generally appear not to react
to transiting research vessels. Mar. Mamm. Sci. 38: 6–17. doi: 10.1111/mms.12843.
Arnold, P. W. and Birtles, R. A. 1999. Towards sustainable management of the developing dwarf minke whale tourism industry in northern Queensland. CRC Reef Research Centre. Technical Report No. 27. CRC Reef Research Centre, Townsville. 30 pp.
Arnold, P. W., Marsh H. and Heinsohn, G. 1987. The occurrence of two forms of minke whales in east Australian waters witha description of external characters and skeleton of the diminutive or dwarf form. Sci. Rep. Whales Res. Inst. 38: 1–46.
Best, P. B. 1985. External characters of southern minke whales and the existence of a diminutive form. Sci. Rep. Whales Res.
Inst. 36: 1–33.
Costa, A.F., Siciliano, S., Emin-Lima, R., Martins, B. M. L., Sousa, M. E. M., Giarrizzo, T., and Silva Júnior, J. S. 2017.
Stranding survey as a framework to investigate rare cetacean records of the north and north-eastern Brazilian coasts.
ZooKeys 688: 111–134. doi: 10.3897/zookeys.688.12636.
Cremer, M. J., Barreto, A. S., Hardt, F. A. Z., Tonello Júnior, A. J., and Mounayer, R. 2009. Cetacean occurrence near an oﬀshore oil platform in southern Brazil. Biotemas 22(3): 247–251.
Geise, L., and Borobia, M., 1988. Sobre a ocorrência de cetáceos no litoral do estado do Rio de Janeiro entre 1968 e 1984.
Rev. Bras. Zool. 4(4): 341–346. doi: 10.1590/S0101-81751987000400006.
Figueiredo, G. C., do Amaral, K. B., and Santos, M. C. O. 2020. Cetaceans along the southeastern Brazilian coast: occurrence, distribution and niche inference at local scale. PeerJ. 8: e10000. doi: 10.7717/peerj.10000.
Hassel, L. B., Venturotti, A., Magalhães, F.A., Cuenca, S., Siciliano, S. and Marques F. F. C. 2003. Summer sightings ofdwarf minke whales (Balaenoptera acutorostrata) oﬀ the eastern coast of Rio de Janeiro state, Brazil. Lat. Am. J.
Aquat. Mamm. 2(1): 47–50. doi: 10.5597/lajam00030.
Leatherwood, S., Caldwell, D. K., and Winn, H. E. 1976. Whales, dolphins, and porpoises of the western North Atlantic: A
guide to their identiﬁcation. U.S. National Marine Fisheries Service, NOAA Technical Report, NMFS Circular 396.
Washington, D.C. 176 pp.
Magalhães, F. A., Tosi, C. H., Garri, R. G., Chellappa, S., and Silva, F. L. 2008. Cetacean diversity on the Parnaíba Delta,
Maranhão state, northeastern Brazil. Braz. J. Biol. 68(3): 545–551. doi: 10.1590/s1519-69842008000300012.
Mangott, A. H., Birtles, R. A. and Marsh, H. 2011. Attraction of dwarf minke whales Balaenoptera acutorostrata to vessels
and swimmers in the Great Barrier Reef World Heritage Area—the management challenges of an inquisitive whale, J.
Ecotourism, 10(1): 64–76. doi: 10.1080/14724041003690468.
Martin, S. W., Marques, T. A., Thomas, L., Morrissey, R. P., Jarvis, S., DiMarzio, N., Moretti, D., and Mellinger, D. K.
2013. Estimating minke whale (Balaenoptera acutorostrata) boing sound density using passive acoustic sensors. Mar.
Mamm. Sci. 29(1): 142–158. doi: 10.1111/j.1748-7692.2011.00561x.
Mayorga, L. F. S. P., Vanstreels, R. E. T., Bhering, R. C. C., Mamede, N., Costa, L. M. B., Pinheiro, F. C. F., Reis, L. W. D.,
Trazzi, A., Meirelles, W. L. C., Ribeiro, A. M., and Siciliano, S. 2020. Strandings of cetaceans on the Espírito Santo
coast, southeast Brazil, 1975–2015. ZooKeys 948: 129–152. doi: 10.3897/zookeys.948.50468.
McKenna, M. F., Calambokidis, J., Oleson, E. M., Laist, D. W., and Goldbogen, J. A. 2015. Simultaneous tracking of blue
whales and large ships demonstrates limited behavioral responses for avoiding collision. Endanger. Species Res. 27:
219–232. doi: 10.3354/esr00666.
Milmann, L., Machado, R., Sucunza, F., Oliveira, L. R., Santos, R. A., Di Beneditto, A. P. M., Rezende, C. E., Baumgarten,
J. and Ott, P. H. 2018. New trophic link and potential feeding area of dwarf minke whale (Balaenoptera acutorostrata
subsp.) in mid latitude waters of the southwestern Atlantic Ocean. Mammalia. 83(1): 49–52. doi: 10.1515/mammalia-2017-0127.
Milmann, L., Siciliano, S., Morais, I., Tribulato, A. S, Machado, R., Zerbini, A. N., Baumgarten, J. E. and Ott, P. H. 2020.
A review of Balaenoptera strandings along the east coast of South America. Reg. Stud. Mar. Sci. 37: 101343. doi:
10.1016/j.rsma.2020.101343.
Milmann, L., Taguchi, M., Siciliano, S., Baumgarten, J. E., Oliveira, L. R., Valiati, V. H., Goto, M., Ott, P. H. and Pastene, L.
A. 2021. New genetic evidences for distinct populations of the common minke whale (Balaenoptera acutorostrata) in
the Southern Hemisphere. Polar Biol. doi: 10.1007/s00300-021-02897-2.
NOAA Fisheries. 2022. Minke Whale. Available at https://www.ﬁsheries.noaa.gov/species/minke-whale.
Pastene, L. A., Acevedo, J., Goto, M., Zerbini, A. N., Acuña, P. and Aguayo-Lobo, A. 2010. Population structure and possible

32

Cetacean Popul. Stud. (CPOPS), Short noteVol. 4, 2023, 27–33

DWARF MINKE WHALE (BALAENOPTERA ACUTOROSTRATA SUBSP.) BEHAVIOR IN BRAZIL
migratory links of common minke whales, Balaenoptera acutorostrata, in the Southern Hemisphere. Conserv. Genet.
11(4): 1553–1558. doi: 10.1007/s10592-009-9944-7.
Rocha, J. M., and Braga, N. M. A. 1982. Brazil. Progress report on cetacean research June 1980 to May 1981. Rep. Int. Whal.
Commn. 32: 155–159.
Rosel, E. P., Wilcox, L. A., Yamada, T. K., and Mullin, K. D. 2021. A new species of baleen whale (Balaenoptera) fromthe Gulf of Mexico, with a review of its geographic distribution. Mar. Mamm. Sci. 37(2): 577–610. doi: 10.111/
mms.12776.
Rossi-Santos, M., Wedekin, L. L. and Sousa-Lima, R. S. 2006. Distribution and habitat use of small cetaceans oﬀ Abrolhos
Bank, eastern Brazil. Lat. Am. J. Aquat. Mamm. 5(1): 23–28. doi: 10.5597/lajam00088.
Santos M. C. de O., Siciliano, S., Vicente, A. F. de C., Alvarenga, F. S., Zampirolli, E., De Souza, S.P., Maranho, A. 2010.
Cetacean records along São Paulo state coast, southeastern Brazil. Braz. J. Ocean. 58(2):123–142. doi: 10.1590/S167987592010000200004.
Santos, M. C. de O., Laílson-Brito, J., Flach, L., Oshima, J. E. F., Figueiredo, G. C., Carvalho, R. R., Ventura, E. S., Molina,
J. M. B., Azevedo, A. F. 2019. Cetacean movements in coastal waters of the Southwestern Atlantic Ocean. Biota
Neotrop. 19(2): e20180670. doi: 10.1590/1676-0611-BN-2018-0670.
Secchi, E. R., Barcellos, L., Zerbini, A. N. and Dalla-Rosa, L. 2003. Biological observations on a dwarf minke whale,
Balaenoptera acutorostrata, caught in southern Brazilian waters, with a new record of prey for the species. Lat. Am. J.
Aquat. Mamm. 2(2): 109–115. doi: 10.5597/lajam00039.
Segre, P. S., Potvin, J., Cade, D. E., Calambokidis, J., Di Clemente, J., Fish, F. E., Friedlaender, A. S., Gough, W. T., Kahane-Rapport, S. R., Oliveira, C., Parks, S. E., Penry, G. S., Simon, M., Stimpert, A. K., Wiley, D. N., Bierlich, K. C.,
Madsen, P. T. and Goldbogen, J. A. 2020. Energetic and physical limitations on the breaching performance of large
whales. eLife. 9: e51760. doi: 10.7554/eLife.51760.
Seminara, C.I., Barbosa-Filho, M. L. V., and Le Pendu, Y. 2019. Interactions between cetaceans and artisanal ﬁshermen from
Ilhéus, Bahia – Brazil. Biota Neotrop. 19(4): e20190742. doi: 10.1590/1676-0611-bn-2019-0742.
Simões-Lopes, P.C., Ximenez, A., 1993. Annotated list of the cetaceans of Santa Catarina coastal waters, southern Brazil.
Biotemas 6(1): 67–92.
Stewart, B. S., Clapham, P. J., Powell, J. A. and Reeves, R. R. 2002. Guide to Marine Mammals of the World. (National
Audubon Society Field Guides). National Audubon Society. Alfred A. Knopf. New York, USA. 528 pp.
The Minke Whale Project. 2022. Risks & Threats. Available at: https://minkewhaleproject.org/research/risks-threats/.
Wada, S., Oishi, M. and Yamada, T. K. 2003. A newly discovered species of living baleen whale. Nature. 426(6964): 278–
281. doi: 10.1038/nature02103.
Watkins, W. A. 1986. Whale reactions to human activities in Cape Cod waters. Mar. Mamm. Sci. 2(4): 251–262. doi: 10.1111/
j.1748-7692.1986.tb00134.x.
Werth, A. J. and Lemon, C. L. 2020. Whale breaching says it loud and clear. eLife. 9: e55722. doi: 10.7554/eLife.55722.
Zerbini, A.N., Secchi, E.R., Siciliano, S., Simões-Lopes, P.C., 1996. The dwarf form of the minke whale, Balaenoptera
acutorostrata Lacépède 1804, in Brazil. Rep. int. Whal. Commn. 46: 333–339.
Zerbini, A. N. and da Rocha, J. M. 1999. Relatório de Atividades: Cruzeiro de avistagem de baleias no litoral do nordeste do
Brasil. Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis-IBAMA, Secretaria da Comissão
Interministerial para os Recursos do Mar-SECIRM. 23 pp.
Zerbini, A.N., Secchi, E.R., Siciliano, S. and Simões-Lopes, P.C. 1997. A Review of the occurrence and distribution ofwhales of the genus Balaenoptera along the Brazilian Coast. Rep. int. Whal. Commn. 47: 407–417.
Zerbini, A. N., Waite, J. M., Laake, J. F. and Wade, P. R. 2006. Abundance, trends and distribution of baleen whales oﬀ Western Alaska and the central Aleutian Islands. Deep-Sea Res. I: Oceanogr. Res. Pap. 53(11): 1772–1790. doi: 10.1016/j.
dsr.2006.08.009..

Received: October 22, 2022
Accepted: January 31, 2023
Published online: June 9, 2023

Cetacean Popul. Stud. (CPOPS), Short noteVol. 4, 2023, 27–33

33

DOI

https://doi.org/10.34331/cpops.2022S003

J-STAGE Advance published date: June 13, 2023

KATSUMATA, ISODA, MATSUNO, MURASE AND MATSUOKAOBSERVATION OF FIN WHALE (BALAENOPTERAPHYSALUS) FEEDING BEHAVIOR IN THE AUSTRALSUMMER SOUTHERN HEMISPHERE MID-LATITUDES
Taiki KATSUMATA1*, Tatsuya ISODA1, Kohei MATSUNO2,
Hiroto MURASE3 and Koji MATSUOKA1
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan
2
Faculty/Graduate School of Fisheries Sciences, Hokkaido University,
3–1–1 Minato-cho, Hakodate, Hokkaido 041–8611, Japan
3
Laboratory of Cetacean Biology, Tokyo University of Marine Science and Technology,
4–5–7 Konan, Minato-ku, Tokyo 108–8477, Japan*Corresponding author: katsumata@cetacean.jp
1

Abstract
In the Southern Hemisphere, ﬁn whales (Balaenoptera physalus) feed mainly in the latitudinal range between 50°S and 60°S during the austral summer. In February 2021, ﬁve ﬁnwhales were sighted about 1,000 km south of the Cape of Good Hope, South Africa at position
43°49′S, 19°12′E. Feeding behavior was evident as the whales were lunging laterally into surrounding red patches with their mouth open. Examination of sampled red patches revealed thatthe ﬁn whales were feeding on either Calanus australis or C. agulhensis. This is the ﬁrst reportof ﬁn whales preying on Calanus spp. in this sea area and time of the year.
Key words:

Balaenoptera physalus, Southern Hemisphere, ﬁn whale, distribution, feeding
behavior.

In austral summer, ﬁn whales (Balaenoptera physalus) mainly distribute in the latitudinal range between 50°S–60°S for feeding (Mackintosh, 1966; Miyashita et al., 1995; Edwards et al., 2015; Aguilar
and Garcia-Vernet, 2018). They prey on krill, mostly Euphausia valentini and E. superba, and rarely on copepods and amphipods in the Southern Hemisphere (Kawamura, 1980). In recent years, ﬁnwhales have been reported to feed on krill between 29°S and 43°S, along the coast of Chile (Perez etal., 2006; Toro et al., 2016; Buchan et al., 2021).
On 13 February, 2021, one school of ﬁve ﬁn whales was ﬁrst sighted at position 43°49′S, 19°12′E,
approximately 1,000 km south of the Cape of Good Hope, South Africa by the captain (Nobuo Abe)on board the Yushin Maru No.2 (747GT), a research vessel engaged in the 2020/21 austral summer
survey of the Japanese Abundance and Stock-structure Surveys in the Antarctic (JASS-A; Isoda etal., 2021) program. The sighting was made during the vessel’s transit between the Antarctic and thehome port in Shiogama, Japan.
At the time of the observations, visibility was 5 n. miles, and the wind speed was 14 knots in direction southeast. Air and sea surface temperatures were 9.9°C and 10.9°C, respectively. Each of the ﬁve
whales was swimming in separate directions about 200 m apart. The behavior of two of them (designated as Whale-A and Whale-B) was observed from the upper deck of the vessel and aerial video
footage was recorded using an unmanned aerial vehicle (UAV; Phantom Pro4 Ver2.0, DJI, China).
The body lengths of the two whales recorded in the UAV footage were visually estimated by an experienced observer onboard: 19.7 m (Whale-A) and 19.3 m (Whale-B). The other three individuals were
estimated to be 20.3 m, 18.5 m and 17.2 m, but were not videotaped because they were too spread apartto be spotted by the UAV monitor.
According to UAV observation, multiple reddish patches approximately 20–50 m long scattered on

34

Cetacean Popul. Stud. (CPOPS), Short noteVol. 4, 2023, 34–39

SOUTHERN HEMISPHERE MID-LATITUDE FIN WHALE FEEDING BEHAVIOR

Fig. 1. Lateral lunge feeding of a ﬁn whale (Whale-A) with its right jaw down. A detailed behavior sequenceand the shape of prey patches are shown in the supplement video.

Fig. 2.

Lunge feeding of Whale-A without turning the body sideways.

the sea surface around the whales. Both whales A and B were feeding on the sea surface and no deep
diving was observed. The swimming direction of Whale-B was not constant, and the feeding was
made in circular movements. When the patch formed longitudinally on the sea surface, the whales
were either lunging parallel to it or passing through when they were intersecting perpendicular to thepatch. The change in the direction of lunging relative to the patch could be for increasing prey capture eﬃciency. More detailed observation of the feeding behavior indicated the whales were lunging
laterally with their right jaw down (Fig. 1). A total of four blows and six lateral lunge feedings wereobserved in Whale-A during a period of 225 seconds for a distance of about 620 m (distance calculated
from the UAV ﬂight log). Most of the time, lunge feeding was carried out laterally, however, non-lateral lunge feeding was observed twice on Whale-A (Fig. 2). Whale-B made lateral lunge feedings
three times and blew twice during a period of 143 seconds for a distance of approximately 280 m withno display of non-lateral lunge feeding.
Samples of sea surface red patch at the location of the sighting were collected using 10 L buckets.
Identiﬁcation of the prey species in the red patches was subsequently conducted in the laboratory
through morphological examination. The result suggested the occurrence of either Calanus australis
or C. agulhensis at its stage C5 (Fig. 3). The identiﬁcation was based on the characteristics of the
prosome, which was rounded in the posterior end and measured 2.65–2.70 mm. According to BradCetacean Popul. Stud. (CPOPS), Short noteVol. 4, 2023, 34–39

35

KATSUMATA, ISODA, MATSUNO, MURASE AND MATSUOKA

Fig. 3. Copepod sampled at 43°47′S, 19°14′E on 13 February, 2021, and identiﬁed as either Calanus australis
or C. agulhensis.

ford-Grieve et al. (1999), the candidate species that ﬁt the prosome length in stage C5 are C. australis and C. agulhensis. Eﬀort was made to discern between the two species by examining the ﬁfth
swimming leg and the arrangement of the inner spines, but results were not conclusive. Therefore,
it was not possible to discern between these two species using morphology, conﬁrming the diﬃculty mentioned by Bradford-Grieve (1994) for the identiﬁcation of C. australis from C. agulhensis.
Furthermore, the location of the sampling corresponded to the distribution areas of both species. The
copepod species that have been reported as prey of ﬁn whales include C. tonsus (Neocalanus tonsus)
in the Southern Ocean and oﬀ South Africa (Kawamura, 1980) and Calanoides carinatus and Nannocalanus minor oﬀ South Africa (32°40′S–36°30′S) (Best, 1967), and C. chilensis oﬀ northern Chile(43°S) (Buchan et al., 2021). According to Best (1967), 94.1% of ﬁn whales caught oﬀ South Africa
fed on krill, 3.8% on copepods, and 2.0% on amphipods. Kawamura (1980) discussed that rorquals oﬀ
South Africa have a highly variable species composition because of their feeding grounds were concentrated in small areas. The location where ﬁn whales were sighted in this study is within a narrowand productive area due to the Agulhas Current System (Fig. 4). It is considered that ﬁn whales in thisarea feed not only on krill but also several available species, including copepods as a secondary preysource. However, recent information on the prey species of ﬁn whales in the Southern Hemisphere islimited, and their diet may have changed from the time when the previous studies had been conducted.
In the Northern Hemisphere, Jory et al. (2021) reported an expanded dietary niche for ﬁn whales in
the St. Lawrence Estuary due to changes in the marine environment caused by climate change in the
2000s. On the other hand, the major whaling grounds of ﬁn whales in the past were reported on the
coast of South Africa and south of 50°S (Mackintosh, 1966). The small catches of ﬁn whales around
45°S might have made it unknown that copepods possibly are major prey items for ﬁn whales in theSouthern Hemisphere mid-latitudes.
Fin whale feeding behavior in non-Antarctic Ocean waters in austral summer was reported for anear-shore productive zone in the Humboldt Current System oﬀ Chile (Perez et al., 2006; Toro et al.,2016; Buchan et al., 2021).
Chlorophyll-a (Chl-a) concentration at the sighting position of ﬁn whales in this study (43°49′S,
19°12′E) was relatively high. The monthly average Chl-a concentration in February 2021 observedby MODIS-Aqua at the location of the ﬁn whale sighting is shown in Fig. 4. The Chl-a concentration
missing values were complemented using the ﬁll no data feature with default values in QGIS (Version
3.16.13-Hannover). The concentration of Chl-a at the sighting position was 0.35 mg/m3. The Chl-a
concentration in the latitudinal range between 40°S–45°S is relatively higher than that outside of thisrange (Fig. 4). In the latitudinal range between 40°S–44°S between South Africa and Antarctica, the36

Cetacean Popul. Stud. (CPOPS), Short noteVol. 4, 2023, 34–39

SOUTHERN HEMISPHERE MID-LATITUDE FIN WHALE FEEDING BEHAVIOR

Fig. 4. The sighting location of a ﬁve-ﬁn whale school (red circle) on 13 February, 2021 with searching tracks(black lines) of the survey vessel. Monthly average chlorophyll-a concentration for February 2021 is also
shown (Original data: Ocean color web, from https://oceancolor.gsfc.nasa.gov/ (Accessed 2022-7-8)).

eddies that separated from the Agulhas Current System transported nutrient-rich water southwardand mixed with the surrounding water in a shallow depth (the mixed layer was formed at 35 m depth,
on average) resulting in the high concentration of Chl-a (Luis and Lotlicar, 2021). Read et al. (2000)
reported high concentrations of surface Chl-a (in the range 0.5–0.8 mg/m3) between 41°S–44°S and
35°E–45°E where diﬀerent currents converge. These studies have shown that oﬀshore waters of South
African middle latitudes are highly productive and are likely an important feeding area for ﬁn whales.
Venkataramana et al. (2020) investigated the community of zooplankton using the horizontal towing bongo net (200 µm mesh) and the multiple plankton sampler (upper 1000 m) between 40°S–56°S
and 47°E–57°E from January to February and reported copepods were the dominant group across theentire region. In addition, past commercial catches and post-whaling sighting information have also
shown that ﬁn whales distribute oﬀshore South Africa, around 45°S, from December to February(Miyashita et al., 1995; Matsuoka et al., 2006; Edwards et al., 2015). These results suggested thatﬁn whales may be using copepods as prey in this area, as reported in this study. Fin whales in the
Northern Hemisphere have been associated with copepod concentrations (Nemoto, 1963; Flinn et al.,
2002; Baraﬀ, 2006), and copepods are considered the second most abundant prey after krill (Flinn etal., 2002; Baraﬀ, 2006; García-Vernet et al., 2021), or the primary prey for ﬁn whales (Witteveen and
Wynne, 2016).
The oﬀshore waters of South Africa are possibly an important feeding area for ﬁn whales. However, few survey eﬀorts have been made in this area; most sighting surveys after the late 1970s wereconducted south of 60°S (Branch and Butterworth, 2001; Matsuoka and Hakamada, 2014) targeting
mainly Antarctic minke whales (B. bonaerensis). Additional sighting survey eﬀort in mid-latitude
waters (i.e., 35°S–50°S) would warrant further understanding the feeding ecology of ﬁn whales in theSouthern Hemisphere.

Cetacean Popul. Stud. (CPOPS), Short noteVol. 4, 2023, 34–39

37

KATSUMATA, ISODA, MATSUNO, MURASE AND MATSUOKA

Supplement
Video footage of the feeding observations of whales A and B is available at: https://cpops.jp/archive/
2022S003Whale-A.mp4 and https://cpops.jp/archive/2022S003Whale-B.mp4.
Acknowledgements

We thank Captain Nobuo Abe and oﬃcers and crew of the Yushin-Maru No.2 for their hard work and dedication that led
to the successful observations reported in this paper. We express our deep gratitude to Drs. Yoshihiro Fujise and Tsutomu Tamura and the staﬀ of the Institute of Cetacean Research and Kyodo Senpaku Co. Ltd. for their assistance in arrangements andsupport for the cruise. Finally, we thank Dr. Luis A. Pastene (Institute of Cetacean Research) for his assistance in preparing
this paper.

References
Aguilar, A. and García-Vernet, R. 2018. Fin whale: Balaenoptera physalus. pp. 368–371. In: Würsig, B., Thewissen, J. G. M.
and Kovacs, K. M. (eds.) Encyclopedia of Marine Mammals (Third Edition). Academic Press, London. 1157 pp.
Baraﬀ, L. S. 2006. Summer Distribution and Habitat Characteristics of Fin Whales (Balaenoptera physalus) and Humpback
Whales (Megaptera novaeangliae) oﬀ Northeast Kodiak Island, Alaska. M.S. Thesis, University of Alaska Fairbanks,
Fairbanks, AK. 173 pp.
Best, P. B. 1967. Distribution and feeding habits of baleen whales oﬀ the Cape Province. Invest. Rep. Div. Sea Fish. S. Afr.
57: 1–44.
Bradford-Grieve, J. M., Markhaseva, E., Rocha, C. E. F. and Abiahy, B. B. 1999. Copepoda. In: Boltovskoy, D. (ed.). South
Atlantic Zooplankton. Backhuys Publishers, Leiden, The Netherlands. 2: pp. 869–1098.
Bradford-Grieve, J. M. 1994. The marine fauna of New Zealand: Pelagic Calanoid Copepoda: Megacalanidae, Calanidae,
Paracalanidae, Mecynoceridae, Eucalanidae, Spinocalanidae, Clausocalanidae. Mem. New Zealand Oceanogr. Inst.
102: 1–160.
Branch, T. and Butterworth, D. 2001. Estimates of abundance south of 60°S for cetacean species sighted frequently on the
1978/79 to 1997/98 IWC/IDCR-SOWER sighting surveys. J. Cetacean Res. Manage. 3(3): 251–270.
Buchan, S. J., Vásquez, P., Olavarría, C. and Castro, L. R. 2021. Prey items of baleen whale species oﬀ the coast of Chilefrom fecal plume analysis. Mar. Mamm. Sci. 37(3): 1116–1127. doi: 10.1111/mms.12782.
Edwards, E. F., Hall, C., Moore, T. J., Sheredy, C. and Redfern, J. V. 2015. Global distribution of ﬁn whales Balaenoptera
physalus in the post-whaling era (1980–2012). Mamm. Rev. 45(4): 197–214. doi: 10.1111/mam.12048.
Flinn, R. D., Trites, A. W., Gregr, E. J. and Perry, R. I. 2002. Diets of ﬁn, sei, and sperm whales in British Columbia: An
analysis of commercial whaling records, 1963–1967. Mar. Mamm. Sci. 18(3): 663–679. doi: 10.1111/j.1748-7692.2002.
tb01065.x.
García-Vernet, R., Borrell, A., Víkingsson, G., Halldórsson, S. D. and Aguilar, A. 2021. Ecological niche partitioning between baleen whales inhabiting Icelandic waters. Prog. Oceanogr. 199(465): 102690. doi: 10.1016/j.
pocean.2021.102690.
Isoda, T., Katsumata, T. and Matsuoka, K. 2021. Results of the dedicated sighting survey under the Japanese Abundance andStock structure Surveys in the Antarctic (JASS-A) in the western part of Area III in the 2020/21 austral summer season.
Technical Reports of the Institute of Cetacean Research (TEREP-ICR) No. 5: 7–15.
Jory, C., Lesage, V., Leclerc, A., Giard, J., Iverson, S., Bérubé, M., Michaud, R. and Nozais, C. 2021. Individual and population dietary specialization decline in ﬁn whales during a period of ecosystem shift. Scientiﬁc Reports 11(1): 17181.
doi:10.1038/s41598-021-96283-x.
Kawamura, A. 1980. A review of food of balaenopterid whales. Sci. Rep. Whales Res. Inst. 32 : 1 55–197.
Luis, A. J. and Lotlikar, V. R. 2021. Hydrographic characteristics along two XCTD sections between Africa and Antarctica
during austral summer 2018. Polar Science 30(1): 100705. doi: 10.1016/j.polar.2021/100705.
Mackintosh, N. A. 1966. Distribution of southern blue and ﬁn whales. pp. 125–144. In: K. S. Norris (ed.) Whales, Dolphins,
and Porpoises. University of California Press, Berkeley, CA. 789 pp.
Matsuoka, K., Hakamada, T., Kiwada, H., Murase, H. and Nishiwaki, S. 2006. Distributions and standardized abundance
estimates for humpback, ﬁn and blue whales in the Antarctic Areas IIIE, IV, V and VIW (35°E–145°W), south of 60°S.
Paper SC/D06/J7 presented to the Intersessional Workshop to Review Data and Results from Special Permit Researchon Minke Whales in the Antarctic, December 2006 (unpublished). 33 pp. [Paper available from the Oﬃce of the IWC].
Matsuoka, K. and Hakamada, T. 2014. Estimates of abundance and abundance trend of the blue, ﬁn and southern rightwhales in Areas IIIE–VIW, south of 60°S, based on JARPA and JARPAII sighting data (1989/90–2008/09). Paper SC/
F14/J5 presented to the IWC/SC Review Workshop of the Japanese Whale Research Program under Special Permit in
the Antarctic-Phase II (JARPAII), February 2014 (unpublished). 27 pp. [Paper available from the Oﬃce of the IWC].
Miyashita, T., Kato, H. and Kasuya, T. 1995. Worldwide Map of Cetacean Distribution based on Japanese Sighting Data
(Volume 1). National Research Institute of Far Seas Fisheries, Shimizu, Shizuoka, Japan. 140 pp.
Nemoto, T. 1963. Some aspects of the distribution of Calanus cristatus and C. plumchrus in the Bering and its neighbouring38

Cetacean Popul. Stud. (CPOPS), Short noteVol. 4, 2023, 34–39

SOUTHERN HEMISPHERE MID-LATITUDE FIN WHALE FEEDING BEHAVIOR
waters, with reference to the feeding of baleen whales. Sci. Rep. Whales Res. Inst. 17: 157–170.
Pérez, M. J., Thomas, F., Uribe, F., Sepúlveda, M., Flores, M. and Moraga, R. 2006. Fin whales (Balaenoptera physalus)
feeding on Euphausia mucronata in nearshore waters oﬀ north-central Chile. Aquat. Mamm. 32(1): 109–113. doi:
10.1578/AM.32.1.2006.109.
Read, J. F., Lucas, M. I., Holley, S. E. and Pollard, R. T. 2000. Phytoplankton, nutrients and hydrography in the frontal zone
between the Southwest Indian Subtropical Gyre and the Southern Ocean. Deep-Sea Research Part I: Oceanographic
Research Papers 47(12): 2341–2367. doi: 10.1016/S0967-0637(00)00021-2.
Toro, F., Vilina, Y. A., Capella, J. J. and Gibbons, J. 2016. Novel coastal feeding area for Eastern South Paciﬁc ﬁn whales(Balaenoptera physalus) in mid-latitude Humboldt Current waters oﬀ Chile. Aquat. Mamm. 42(1): 47–55. doi:
10.1578/AM.42.1.2016.47.
Venkataramana, V., Anilkumar, N., Swadling, K., Mishra, R. K., Tripathy, S. C., Sarkar, A., Soares Melena Augusta, Sabu,
P. and Honey U. K. Pillai. 2020. Distribution of zooplankton in the Indian sector of the Southern Ocean. Antarct. Sci.
32(3): 168–179. doi: 10.1017/S0954102019000579.
Witteveen, B. H. and Wynne, K. M. 2016. Trophic niche partitioning and diet composition of sympatric ﬁn (Balaenoptera
physalus) and humpback whales (Megaptera novaeangliae) in the Gulf of Alaska revealed through stable isotope analysis. Mar. Mamm. Sci. 32(4): 1319–1339. doi: 10.1111/mms.12333.

Received: November 26, 2022
Accepted: April 20, 2023
Published online: June 13, 2023

Cetacean Popul. Stud. (CPOPS), Short noteVol. 4, 2023, 34–39

39

Others

Snouting of an old Bryde’s whale, North Paciﬁc.

DOI

https://doi.org/10.34331/cpops.2023O001

J-STAGE Advance published date: March 29, 2023

A STRIPED DOLPHIN WITH FIN-SHAPED HIND APPENDAGES

Short Communication

SECOND OCCURRENCE OF A DOLPHIN WITH
FIN-SHAPED HIND APPENDAGES FROM WATERS
OFF TAIJI, THE PACIFIC COAST OF JAPAN
Daiki INAMORI (Director)*,Motoi YOSHIOKA (Scientiﬁc Adviser)1,
Hidehiro KATO (Emeritus Director)2, 3
Taiji Whale Museum, Taiji, Higashimuro, Wakayama 649–5171, Japan*Corresponding author: inamori@kujirakan.jp

Key words:

hind appendages, Tursiops truncatus, Stenella coeruleoalba, striped dolphin, Taiji.

Ohsumi and Kato (2008) reported on a very unique bottlenose dolphin (Tursiops truncatus) having
ﬁn-shaped hind appendages, captured from waters oﬀ Taiji (33°35′N, 135°57′E), Wakayama Prefecture,
Japan in 2006. We have currently conﬁrmed the ﬁnding of another such animal with hind appendages
occurring from waters oﬀ Taiji.
The recently discovered dolphin was found among dolphin ﬁsheries harvest in Taiji. The animal
was from a striped dolphin (Stenella coeruleoalba) school which consisted of 20 individuals seen on
January 5th, 2023, 7 nautical miles oﬀ Taiji. The Taiji Whale Museum staﬀs successfully conﬁrmed thedolphin among the 16 dolphins that were visually examined on their ventral surfaces for sex determination.

Fig. 1. Lateral view of the striped dolphin with ﬁn-shaped hind appendages just after an initial dissection(upper), magniﬁed lateral view (left bottom) and ventral view of the appendages (right bottom).
Cetacean Research Center, Graduate School of Bioresources, Mie University, Kurimamachiya, Tsu, Mie 514–8507, JapanTokyo University of Marine Science and Technology, 4–5–7 Konan, Minato-ku, Tokyo 108–8477, Japan
3
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan
1
2

Cetacean Popul. Stud. (CPOPS), Others
Vol. 4, 2023, 43–44

43

INAMORI, YOSHIOKA AND KATO

The dolphin (Taiji Whale Museum serial specimen ID 230105) was a male, 182 cm long; sex was
conﬁrmed by the external shape of genitalia. The hind appendages arose obliquely at both front sidesof the anus slit and were ventrally located about 56 cm (left side, 30.8% of body length) anterior to thenotch of the tail ﬂukes (Fig. 1). They were of similar size and shape, 4.3 cm (left side) to 5.8 cm (rightside) in straight length, with the right one being slightly larger. The shape was similar to that of thepectoral ﬂippers but more sticklike exterior (Fig. 1; left bottom). The ventral aspect of the left side appendage was the same color as the dorsal appearance of the left side ﬁn, while coloration of the rightside one was a lighter shade of gray. Also, we note the white line surrounding the base of both hindappendages, like in the previous animal having such appendages documented in Ohsumi and Kato
(2008). Further details will be followed in later reports.
Body trunk parts including the hind appendages are kept in lab freezer conditions, and lots of tissue
samples, including blood and serum samples are kept frozen and ﬁxed in formalin or ethanol solutions. These are expected to be used in future studies.

References
Ohsumi, S. and Kato, H. 2008. A bottlenose dolphin (Tursiops truncatus) with ﬁn-shaped hind appendages. Mar. Mamm. Sci.
24(3): 743–745. doi: 10.1111/j.1748-7692.2008.00202.x.

44

Cetacean Popul. Stud. (CPOPS), Others
Vol. 4, 2023, 43–44

DOI

https://doi.org/10.34331/cpops.2022O001

J-STAGE Advance published date: June 9, 2023

DEVELOPMENT PROGRESS OF A LONG-RANGE VERTICAL TAKEOFF AND LANDING UAV

Short Communication

DEVELOPMENT PROGRESS OF A LONG-RANGEVERTICAL TAKEOFF AND LANDING UAV FOR
THE IMPROVEMENT OF SHIP-BASED CETACEAN
SIGHTING SURVEYS
Taiki KATSUMATA* and Takashi YOSHIDA
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan*Corresponding author: katsumata@cetacean.jp

Key words:

aerial survey, cetacean, drone, unmanned aircraft systems, unmanned aerial vehicle, VTOL-UAV/ASUKA.

Estimating the abundance of cetaceans is critical to the conservation and management of those species concerned. Abundance estimates are based primarily on sighting data collected during shipboard
sighting surveys. However, these useful and standardized survey methods have their limitations. In
some cases, surveys may not be able to entirely cover the cetacean distribution areas, such as coastal
areas with high density of ﬁshing gear, or pack ice areas in polar regions. To improve the abundance
estimates in such undersurveyed areas, in 2019 we started developing an unmanned aerial vehicle(UAV) which was subsequently given the name of ASUKA (Matsuoka and Yoshida, 2021). The newaircraft would have to combine the following four characteristics. First, be able to takeoﬀ and land
vertically, allowing deployement from and to conﬁned spaces on the research ship’s deck. Second, be
able of long ﬂight time required to cover large survey areas. Third, be able to carry suﬃcient payload
for installing a camera or cameras, which can capture a wide range with a high resolution to detectand identify cetacean species. The ﬁnal point is the UAV’s resistance to windy conditions. Because
cetacean sighting surveys are conducted oﬀshore, an aircraft that can operate in windy conditions isrequired.
After repeated trials with ﬂight tests at sea in 2019 and 2020, the ASUKA Mk 4 was completed in
2021. In March 2021, ASUKA Mk 4 achieved an autonomous ﬂight distance of 51 km from a research
vessel in the North Paciﬁc. Then, in March 2022, it autonomously ﬂew 104 km in 1 hour and 20 minutes at an altitude of approximately 110 m, setting a new Japanese record for distance traveled in asingle ﬂight by a small UAV (Fig. 1). In addition, a preliminary ﬁn whale (Balaenoptera physalus)ﬁeld survey oﬀ Abashiri, Hokkaido (Fig. 2) and another for ﬁnless porpoise (Neophocaena sunameri)in Mikawa Bay, Aichi, were conducted. Equipped with a Sony DSC-RX0M2 camera, ASUKA Mk 4
successfully detected both target species. In the near future, the ASUKA Mk 5 (Fig. 3 and Table 1),
developed as a commercial model, will be used in actual whale research in the Antarctic Ocean to conduct aerial visual surveys in areas of pack ice where vessels cannot navigate.
UAVs are increasingly being used to observe and study marine mammals, including cetaceans. A
Google Scholar search (https://scholar.google.com) on the number of articles containing “UAVs” and“marine mammals” showed that it quadrupled from 2012 to 2021. In addition to visual surveys of marine mammals, UAVs have been used for photogrammetry, photo ID, and tagging (Leslie et al., 2020;
Ryan et al., 2022; Murakami et al., 2021). This suggests that UAVs are replacing helicopters andsmall aircraft that require airﬁelds for takeoﬀ and landing, and that UAVs are becoming a necessary
survey tool. Cetacean research using UAVs has already begun (e.g., Hodgson et al., 2017), and they
are being used for various observational purposes in polar regions (e.g., Funaki et al., 2014; Angliss etCetacean Popul. Stud. (CPOPS), Others
Vol. 4, 2023, 45–47

45

KATSUMATA AND YOSHIDA

Fig. 1. VTOL-ASUKA (Mk 4 Type 2)during vertical take-oﬀ from the research
vessel in Mikawa Bay on 27 March 2022.

Fig. 2. An underwater ﬁn whale photograph taken by ASUKA (Mk 4 Type 2) oﬀ Abashiri, Hokkaido, on 27 May 2022.
The approximate ﬂying altitude was 80 m.
Table 1. Speciﬁcation of the newly-developed
VTOL-UAV in 2022.
Item

Fig. 3. The latest VTOL-UAV aircraft (ASUKA
Mk 5) developed in 2022.

ASUKA Mk 5*

Overall length
1,904 mm
Wingspan
3,335 mm
Overall height
843 mmBody weight22.9 kg
Cruising range
Over 100 km
Maximum
160 km/h
speed(Long-range ﬂight cruising speed 80 km/h)
Payload5 kg maximum(104 km range achieved with a 2 kg payload)
Seaworthiness Regular operation at 25-knot wind speed
Level ﬂight maintained at 40-knot wind
speed
* The acronym ‘Mk’ and ‘Type’ followed by a number
indicate the UAV prototype series identiﬁer.

al., 2018). In addition, in anticipation of the widespread use of UAVs, methods have been developed
for abundance estimation using digital data captured by cameras (Borchers et al., 2020). Given theabove, it is highly probable that abundance estimation of marine mammals using data obtained with
UAVs will become more widespread. Accordingly, we anticipate that ASUKA, which can take oﬀ
from and land on a ship and has a long-range, and suﬃcient payload capacity, will be used in visualand various other surveys.
Acknowledgements

We thank the Fisheries Agency of Japan for granting research permits and funding for developing and implementing the
UAV project. We also thank Drs. Hiroto Murase, Koji Matsuoka and Yoshihiro Fujise for their assistance with survey designand logistical support.

46

Cetacean Popul. Stud. (CPOPS), Others
Vol. 4, 2023, 45–47

DEVELOPMENT PROGRESS OF A LONG-RANGE VERTICAL TAKEOFF AND LANDING UAVReferences
Angliss, R. P., Ferguson, M. C., Hall, P., Helker, V., Kennedy, A. and Sformo, T. 2018. Comparing manned to unmanned
aerial surveys for cetacean monitoring in the Arctic: Methods and operational results. J. Unmanned Veh. Sys. 6(3):
109–127. doi: 10.1139/juvs-2018-0001.
Borchers, D. L., Nightingale, P., Stevenson, B. C. and Fewster, R. M. 2020. A latent capture history model for digital aerial
surveys. Biometrics 78(1): 274–285. doi: 10.1111/biom.13403.
Funaki, M., Higashino, S.-I., Sakanaka, S., Iwata, N., Nakamura, N., Hirasawa, N., Obara, N. and Kuwabara, M. 2014. Small
unmanned aerial vehicles for aeromagnetic surveys and their ﬂights in the South Shetland Islands, Antarctica. Polar
Sci. 8(4): 342–356. doi: 10.1016/j.polar.2014.07.001.
Hodgson, A., Peel, D. and Kelly, N. 2017. Unmanned aerial vehicles for surveying marine fauna: Assessing detection probability. Ecol. Appl. 27(4): 1253–1267. doi: 10.1002/eap.1519.
Matsuoka, K. and Yoshida, T. 2021. Geirui shigen chousa ni mochiiru doron (mujin koukuuki: UAV) no Kaihatsu (Development of drones (unmanned aerial vehicles-UAV) for whale research). Geiken Tsuushin 491: 1–8. (In Japanese).
Leslie, M., Perkins-Taylor, C., Durban, J., Moore, M., Miller, C., Chanarat, P., Bahamonde, P., Chiang, G. and Apprill, A.
2020. Body size data collected non-invasively from drone images indicate a morphologically distinct Chilean blue
whale (Balaenoptera musculus) taxon. Endanger. Species Res. 43: 291–304. doi: 10.3354/esr01066.
Murakami, R., Toyoshima, T., Furusawa, D., Suzuki, M., Masumoto, K., Owada, S., Tsumaki, Y. and Mori, K. 2021. Logger
attaching system for sperm whales using a drone. J. Robot. Mechatron. 33(3): 475–483. doi: 10.20965/jrm.2021.p0475.
Ryan, K. P., Ferguson, S. H., Koski, W. R., Young, B. G., Roth, J. D. and Watt, C. A. 2022. Use of drones for the creationand development of a photographic identiﬁcation catalogue for an endangered whale population. Arct. Sci. 8(4): 1191–
1201. doi: 10.1139/as-2021-0047.

Received: November 26, 2022
Published online: June 9, 2023

Cetacean Popul. Stud. (CPOPS), Others
Vol. 4, 2023, 45–47

47

ARCHIVAL INDEXCETACEAN POPULATION STUDIES, TOKYO, JAPAN
Volume 4, August 2023
Murase, H., Matsuoka, K. and Watanabe, K. Eﬀect of sea surface temperature on the distribution ofcommon minke whales oﬀ southeastern Hokkaido, Japan, between 2002 and 2006, with notes on
the formation of Paciﬁc saury ﬁshing grounds 7–18.
Nakamura, G., Al-Zaidan, A., Behbehani, M. and Kato, H. Preliminary report on the cranial measurements of a Bryde’s whale stranded in Failaka Island, Kuwait in 2014 21–26.
Milmann, L., Cardoso, J., Francisco, A., Santos, F. P., Seminara, C., Abras, D. R., Marques, M. L.,
Hille, D. A., Lemos, L. S., Ruenes, G. F., Hauser-DavisS, R. A. and Siciliano, S. Dwarf minke
whale (Balaenoptera acutorostrata subsp.) interactions with vessels oﬀ the coast of Brazil 27–33.
Katsumata, T., Isoda, T., Matsuno, K., Murase, H. and Matsuoka, K. Observation of ﬁn whale (Balaenoptera physalus) feeding behavior in the austral summer Southern Hemisphere mid-latitudes
34–39.
Inamori, D., Yoshioka, M. and Kato, H. Second occurrence of a dolphin with ﬁn-shaped hind appendages from waters oﬀ Taiji, the Paciﬁc Coast of Japan 43–44.
Katsumata, T. and Yoshida, T. Development progress of a long-range vertical takeoﬀ and landing UAV
for the improvement of ship-based cetacean sighting surveys 45–47.

Volume 3, December 2021
Kato, H., Fujise, Y., Nakamura, G., Hakamada, T., Pastene, L. A. and Best, P. B. Dwarf minke whales:
Morphology, growth and life history based on samples collected from the higher latitudes in theSouthern Hemisphere 93–128.
Pastene, L. A., Goto, M., Taguchi, M. and Matsuoka, K. Genetic matches of southern right whalesin the Indian sector of the Antarctic: A Contribution towards understanding their movement andsite-ﬁdelity 129–138.
Ohashi, Y., Goto, M., Taguchi, M., Pastene, L. A. and Kitakado, T. Evaluation of a paternity method
based on microsatellite DNA genotypes for estimating the abundance of Antarctic minke whales(Balaenoptera bonaerensis) in the Indo-Paciﬁc region of the Antarctic 139–151.
Taguchi, M., Goto, M., Milmann, L., Siciliano, S., Tiedemann, R. and Pastene, L. A. New insights into
the genetic structure of sei whales (Balaenoptera borealis) at the inter-oceanic scale 152–163.
Katsumata, T., Hirose, A., Nakajo, K., Shibata, C., Murata, H., Yamakoshi, T., Nakamura, G. andKato, H. Evidence of winter migration of humpback whales to the Hachijo island, Izu Archipelagooﬀ the southern coast of Tokyo, Japan 164–174.
Takahashi, M., Nakamura, G. and Kato, H. Growth-related changes in the cranium of killer whales in
the western North Paciﬁc 175–188.
Lockyer, C. and Garrigue, C. Age estimation from teeth in Longman’s beaked whales (Indopacetus
paciﬁcus) stranded in New Caledonia (South Paciﬁc) 189–197.
Isoda, T., Matsuoka, K., Tamura, T. and Pastene, L. A. Spatial and temporal distribution of ﬂoating
marine macro debris in the Indo-Paciﬁc region of the Antarctic 198–211.
Nakamura, G., Zenitani, R., Bando, T., Fujise, Y., Yamamoto, R., Nishimura, F., Hirose, A., Kim, Y.

Cetacean Popul. Stud. (CPOPS),
Vol. 4, 2023, 49–50

and Kato, H. Skeletal measurements on some large cetacean species done by scientists of TUMSAT
and ICR 215–230.
Kim, Y., Nishimura, F., Bando, T., Fujise, Y., Nakamura, G., Murase, H. and Kato, H. Fetal development in tail ﬂukes of the Antarctic minke whale 231–238.
Bando, T. Improved estimates of some life-history parameters of the pelagic subspecies of Bryde’s
whale in the western North Paciﬁc 239–245.
Maeda, H. and Kato, H. Seasonal changes in the earplug germinal layers of North Paciﬁc common
minke whales 246–251.
Matsuoka, K., Hakamada, T. and Miyashita, T. A note on recent surveys for right whales Eubalaena
japonica in the western North Paciﬁc 252–257.
Diallo, S. T., Sane, A., Nelson, T., Katsumata, T. and Hakamada, T. Cetaceans oﬀ Gabon based on a2011 sighting survey, with a preliminary density estimate of the humpback whale Megaptera novaeangliae 258–264.
Sekiguchi, K. Historical Japanese whale sighting surveys in the Chukchi Sea 265–272.
Katsumata, E., Naruse, S., Hosono, T. and Katsumata, H. Sexual dimorphism in the dorsal ﬁn of
Paciﬁc white-sided dolphins (Lagenorhynchus obliquidens) from coastal waters oﬀ Japan 273–280.
Konishi, K. and Tamura, T. Preliminary use of near-infrared spectroscopy to estimate the biochemicalcomponents of the muscles of the Antarctic minke whale Balaenoptera bonaerensis 281–285.
Isoda, T., Tamura, T. and Pastene, L. A. Ingestion of marine debris and evidence of entanglements involving Antarctic minke whales (Balaenoptera bonaerensis) sampled in the Indo-Paciﬁc sector of
the Antarctic 286–294.
Akamatsu, T. A short review of acoustic monitoring of large whales in Japanese waters 297–300.
Kaji, K. Impact of whale resource management research on sika deer management 301–304.
Walløe, L. An analysis of Japanese whale killing data with special emphasis on the use of the electric
lance as a secondary killing method 307–316.
Miyazaki, N. Remembering Dr. Seiji Ohsumi: A dream for establishing a research center of marine
mammals in the Indian Ocean 317–318.

Volume 2, June 2020
Goto, M., Kitakado, T., and Pastene, L. A. A preliminary study of epigenetic estimation of age of the
Antarctic minke whale Balaenoptera bonaerensis 5–14.
Matsuoka, K., and Hakamada, T. Density distribution of several major whale species in the Indo-Paciﬁc region of Antarctic using JARPA and JARPAII sighting data obtained through 1987/88–
2008/09 seasons 15–38.
Yasunaga, G., and Fujise Y. Concentration of persistent organic pollutants (POPs) in three species ofbaleen whales in the western North Paciﬁc 39–53.

Volume 1, December 2018
Kishiro, T. Satellite tracking of coastal Bryde’s whales Balaenoptera edeni along the southwest coastof Japan 3–13.
Nakamura, G., Ryeng, K. A., Kadowaki, I., Hayashi, R., Nagatsuka, S., Hirose, A., Fujise, Y., andHaug, T. Comparison of shapes of the white ﬂipper patch between two sub-species of common minke whales (Balaenoptera acutorostrata) 15–24.
Hirose, A., Kishida, T., and Nakamura, G. Nasal mucosa resembling an olfactory system in the common minke whale (Balaenoptera acutorostrata) 25–28.

Cetacean Popul. Stud. (CPOPS),
Vol. 4, 2023, 49–50

SUBJECT INDEX

accumulation rate 3: 246–251
adaptive management 3: 301–304
aerial survey 4: 45–47
age determination 3: 246–251
age estimation 2: 5–14, 3: 189–197
allometry 3: 273–280
Antarctic 2: 15–38, 3: 129–138, 3: 198–211, 3: 286–294
Antarctic minke whale 2: 5–14, 2: 15–38, 3: 139–151, 3: 231–238, 3: 281–285, 3: 286–294
anthropogenic activities 4: 27–33
Balaenoptera acutorostrata 1: 15–24, 4: 7–18
Balaenoptera acutorostrata subsp. 4: 27–33
Balaenoptera edeni: 4: 21–26
Balaenoptera physalus 4: 34–39
Balaenopteridae 3: 215–230, 3: 231–238, 4: 21–26
baleen whale(s) 1: 25–28, 2: 15–38
behavioral responses 4: 27–33
blue whale 2: 15–38
Bryde’s whales 2: 39–53, 3: 239–245, 4: 21–26
cetacean 4: 45-47
Chukchi Sea 3: 265–272
coastal Bryde’s whale 1: 3–13
Cololabis saira 4: 7–18
common minke whale 1: 15–24, 2: 39–53, 3: 246–251
control region 3: 152–163
Cox regression 3: 307–316
density estimation 3: 258–264
diminutive minke whale 3: 93–128
distance sampling 3: 258–264
distribution 2: 15–38, 3: 129–138, 3: 252–257, 4: 34–39
DNA methylation 2: 5–14
dorsal ﬁn 3: 273–280
drone 4: 45–47
dwarf minke whale 3: 93–128, 4: 27–33
earplug 3: 239–245, 3: 246–251
electric lance 3: 307–316
embryology 3: 231–238
entanglements 3: 286–294
epigenetics 2: 5–14
Eschrichtiidae 3: 215–230
Eubalaena japonica 3: 252–257
feedback management 3: 301–304
feeding behavior 4: 34–39
fetus 3: 231–238
ﬁshing buoy 3: 198–211
ﬁn whale 2: 15–38, 3: 297–300, 4: 34–39
ﬂipper 1: 15–24
ﬂuke 3: 231–238
Gabon 3: 258–264
genetic tagging 3: 129–138
germinal layer 3: 246–251
growth 3: 273–280
Cetacean Popul. Stud. (CPOPS),
Vol. 4, 2023, 51–53

growth-related change 3: 175–188
habitat 4: 7–18
Hachijo Island 3: 164–174
hind appendages 4: 43–44
histology 1: 25–28
humpback whale 2: 15–38, 3: 164–174, 3: 258–264, 3: 297–300
Indopacetus paciﬁcus 3: 189–197
ingestion 3: 286–294
Japanese sighting survey 3: 198–211
Japanese whale sighting survey 3: 265–272
Kaplan–Meier plots 3: 307–316
killer whale 2: 15–38, 3: 175–188
large whale 3: 215–230, 4: 21–26
large whale species 3: 265–272
life history parameter 3: 93–128, 3: 239–245
line transect 3: 258–264
lipid contents 3: 281–285
marine macro debris 3: 198–211, 3: 286–294
microsatellite DNA 3: 139–151
minke whale clade 3: 93–128
minke whales 3: 307–316
monitoring 3: 301–304
morphology 3: 93–128, 3: 273–280
morphometric 3: 215–230, 4: 21-26
movement 1: 3–13, 3: 129–138
muscle tissue 3: 281–285
Mysticetes 4: 27–33
nasal cavity 1: 25–28
North Paciﬁc 2: 39–53, 4: 7–18
North Paciﬁc right whale 3: 252–257
nutritional condition 3: 281–285
olfaction 1: 25–28
olfactory epithelium 1: 25–28
ontogeny 3: 231–238
organic pollutants 2: 39–53
Oyashio 4: 7–18
Paciﬁc white-sided dolphin 3: 273–280
passive acoustic monitoring 3: 297–300
paternity analysis 3: 139–151
photo-ID 3: 164–174
phylogeography 3: 152–163
POPs 2: 39–53
population structure 3: 139–151
proxy of earplugs 2: 5–14
residency 3: 164–174
revised management procedure 3: 301–304
satellite tracking 1: 3–13
sei whale 2: 39–53, 3: 152–163
sighting survey 3: 252–257
sika deer 3: 301–304
site ﬁdelity 3: 129–138, 3: 164–174
skeletal measurement 3: 215–230, 4: 21–26
skull morphology 3: 175–188
subspecies 1: 15–24
southern bottlenose whale 2: 15–38
Cetacean Popul. Stud. (CPOPS),
Vol. 4, 2023, 51–53

Southern Hemisphere 4: 34–39
southern right whale 2: 15–38, 3: 129–138
spatial distribution 4: 7–18
sperm whale 2: 15–38, 3: 297–300
Stenella coeruleoalba 4: 43-44
stock structure 3: 152–163
striped dolphin 4: 43–44
Taiji 4: 43–44
taxonomy 1: 15–24
teeth 3: 189–197
toothed whales 2: 15–38
Tursiops truncatus 4: 43-44
underwater sound 3: 297–300
unmanned aerial vehicle 4: 45–47
unmanned aircraft systems 4: 45–47
VTOL-UAV/ASUKA 4: 45–47
western North Paciﬁc 3: 175–188, 3: 239–245, 3: 252–257
whale 3: 301–304
whale killing methods 3: 307–316
white patch morphology 1: 15–24
wintering ground 3: 164–174
worldwide 3: 152–163
ziphioid whales 3: 189–197

Cetacean Popul. Stud. (CPOPS),
Vol. 4, 2023, 51–53

AUTHOR INDEXA
Abras, D. R. 4: 27–33
Akamatsu, T. 3: 297–300
Al-Zaidan, A. 4: 21–26

B
Bando, T. 3: 215–230, 3: 231–238, 3: 239–245
Behbehani, M. 4: 21–26
Best, P. B. 3: 93–128

C
Cardoso, J.

4: 27–33

D
Diallo, S. T.

3: 258–264

F
Fujise, Y. 1: 15–24, 2: 39–53, 3: 93–128, 3: 215–230, 3: 231–238
Francisco, A. 4: 27–33

G
Goto, M. 2: 5–14, 3: 129–138, 3: 139–151, 3: 152–163
Garrigue, C. 3: 189–197

H
Hakamada, T. 2: 15–38, 3: 93–128, 3: 252–257, 3: 258–264
Haug, T. 1: 15–24
Hauser-Davis, R. A. 4: 27–33
Hayashi, R. 1: 15–24
Hille, D. A. 4: 27–33
Hirose, A. 1: 15–24, 1: 25–28, 3: 164–174, 3: 215–230
Hosono, T. 3: 273–280

I
Inamori, D. 4: 43–44
Isoda, T. 3: 198–211, 3: 286–294, 4: 34–39

Cetacean Popul. Stud. (CPOPS),
Vol. 4, 2023, 54–56

KKaji, K. 3: 301–304
Katsumata, E. 3. 273–280
Katsumata, H. 3: 273–280
Katsumata, T. 3: 164–174, 3: 258–264, 4: 34–39, 4: 45–47
Kadowaki, I. 1: 15–24
Kato, H. 3: 93–128, 3: 164–174, 3: 175–188, 3: 215–230, 3: 231–238, 3: 246–251, 4: 21–26, 4: 43–44
Kim, Y. 3: 215–230, 3: 231–238
Kishida, T. 1: 25–28
Kishiro, T. 1: 3–13
Kitakado, T. 2: 5–14, 3: 139–151
Konishi, K. 3: 281–285

L
Lemos, L. S. 4: 27–33
Lockyer, C. 3: 189–197

M
Maeda, H. 3: 246–251
Marques, M. L. 4: 27–33
Matsuno, K. 4: 34–39
Matsuoka, K. 2: 15–38, 3: 129–138, 3: 198–211, 3: 252–257, 4: 7–18, 4: 34–39
Milmann, L. 3: 152–163, 4: 27–33
Miyashita, T. 3: 252–257
Miyazaki, N. 3: 317–318
Murase, H. 3: 231–238, 4: 7–18, 4: 34–39
Murata, H. 3: 164–174

N
Nagatsuka, S. 1: 15–24
Nakajo, K. 3: 164–174
Nakamura, G. 1: 15–24, 1: 25–28, 3: 93–128, 3: 164–174, 3: 175–188, 3: 215–230, 3: 231–238,
4: 21–26
Naruse, S. 3: 273–280
Nelson, T. 3: 258–264
Nishimura, F. 3: 215–230, 3: 231–238

O
Ohashi, Y.

3: 139–151

P
Pastene, L. A.

2: 5–14, 3: 93–128, 3: 129–138, 3: 139–151, 3: 152–163, 3: 198–211, 3: 286–294

R
Ruenes, G. F. 4: 27–33
Ryeng, K. A. 1: 15–24

Cetacean Popul. Stud. (CPOPS),
Vol. 4, 2023, 54–56

S
Sane, A. 3: 258–264
Santos, F. P. 4: 27–33
Sekiguchi, K. 3: 265–272
Seminara, C. 4: 27–33
Shibata C. 3: 164–174
Siciliano, S. 3: 152–163, 4: 27–33

T
Taguchi, M. 3: 129–138, 3: 139–151, 3: 152–163
Takahashi, M. 3: 175–188
Tamura, T. 3: 198–211, 3: 281–285, 3: 286–294
Tiedemann, R. 3: 152–163

W
Walløe, L. 3: 307–316
Watanabe, K. 4: 7–18

Y
Yamakoshi, T. 3: 164–174
Yamamoto, R. 3: 215–230
Yasunaga, G. 2: 39–53
Yoshida, T. 4: 45–47
Yoshioka, M. 4: 43–44

Z
Zenitani, R.

3: 215–230

Cetacean Popul. Stud. (CPOPS),
Vol. 4, 2023, 54–56

Guide for Authors
CETACEAN POPULATION STUDIES (CPOPS) is an English peer reviewed on-line journal which
publishes scientiﬁc articles on cetaceans and other marine mammals in the form of (1) Original study– Full paper, (2) Original study – Short note, (3) Review of studies, (4) Photo gallery with explanatory note as well as (5) Others, subject to authorization by the Editor-in-Chief in advance of formal
submission. CPOPS welcomes contributions from accredited scientists in any country. Copyright forarticles published in CPOPS is transferred to CPOPS when the article is accepted for publication. Articles published in CPOPS may not be reproduced, in whole or in part, without written permission fromCPOPS. CPOPS does not charge any submission or publication fee.
Full paper and Short note
A Full paper is a self-contained piece of work composed of systematic analyses which are scientiﬁcally organized using a signiﬁcant number of samples or a signiﬁcant quality of information. For clariﬁcation of structure, the paper should be subdivided into meaningful sections such as introduction,materials and methods, results and discussion, etc. The paper should include an appropriate abstract(less than 300 words) and keywords (less than 6 words), and a list of references cited in the text.
A Short note should be composed of important information or analyses which are also scientiﬁcallyorganized, but it is not necessary that the information is based on a suﬃcient number of samples orobservations. The short note contents do not need to be subdivided by sections as in the case of a full
paper. It should include an appropriate abstract (less than 100 words) and key words. The short noteshould not exceed 6 printed pages in length and include some thoughtfully selected tables and ﬁgures.
For more information, please visit our website (https://cpops.jp).
Submission of Manuscripts
Manuscripts should be original work not previously published. Manuscripts must (in principle) be
prepared in Microsoft WORD or PDF ﬁles and submitted to the email address below.
cpopspaper@gmail.com
The information obtained through paper submission will not be used for purposes other than those of
publication without the consent of the author himself/herself.
Manuscripts are peer-reviewed typically by three anonymous referees nominated by the Editorial
Board. Contributors, if they wish, can suggest speciﬁc names of up to two experts with suﬃcientknowledge and experience to review the paper. The Editor-in-Chief will attempt to include one
reviewer from the nominated experts.
When contributors are requested to revise their manuscripts, they can resubmit, within 30 days, therevised manuscript incorporating comments and suggestions by referees, together with an attachednote describing how the revision has been carried out. The ﬁnal decision on acceptance or rejection for
publication is that of the Editor-in-Chief in consultation with other members of the Editorial Board.
You can ﬁnd the Instructions to Contributors, Organization of Manuscripts, General Instructions andthe Cover Page Template for manuscript submission in the following link.
https://cpops.jp/paper_submission/index.html
The Instructions to Contributors may be revised from time to time according to development of
CPOPS and discussions in the Editorial Board.
Cetacean Popul. Stud. (CPOPS),
Vol. 4, 2023, 57