Photo-identification of Antarctic blue whales 1991 to 2016
Paula A. Olson1, Michael C. Double2, Koji Matsuoka3, Luis A. Pastene3
1

Marine Mammal and Turtle Division, Southwest Fisheries Science Center NMFS/NOAA, 8901 La Jolla Shores
Drive, La Jolla, CA 92037 USA
2Australian Marine Mammal Centre, Australian Antarctic Division, 203 Channel Highway, Kingston, Tasmania
7001 Australia
3

Institute of Cetacean Research, Toyomi 4-5, Chuo-ku Tokyo, 104-0055, Japan

Paula.Olson@noaa.gov
ABSTRACT
Identification photographs of individual Antarctic blue whales were collected from multiple sources, 19912016, and compiled into the Antarctic Blue Whale Catalogue. Sources include the IWC IDCR/SOWER
cruises, IWC-SORP voyages, the Institute of Cetacean Research, and naturalists and collegial scientists
working in the Antarctic region. This year, seventeen new individual Antarctic blue whales were identified
from 260 photographs collected opportunistically in the years 2005-2016. That brings the total number ofidentified whales to 416, represented by 315 left sides and 306 right sides. This is 14-18% of the most recent
accepted estimate of abundance of 2,280 in 1997/1998 (CV=0.36; Branch, 2007). There are fifteen inter-annual
re-sights of fourteen whales, with sighting intervals of 1-12 years, and distances ranging from 19 to 6,650km
between sighting locations. The distance of 6,650km over a six-year period is the longest movement of an
Antarctic blue whale recorded to date. Within-season sighting rates from five survey years ranged from 7-22%.
Both inter-annual and within-season re-sightings reflected small and large scale movements. It isrecommended that the collection of Antarctic blue whale identification photographs be continued as they
provide data for capture-recapture estimates of abundance as well as information on the movement ofindividual blue whales within the Antarctic region.
KEYWORDS: ANTARCTIC, SOUTHERN OCEAN, PHOTO-ID, MOVEMENTINTRODUCTION
The population status of the endangered Antarctic blue whale (Balaenoptera musculus intermedia) is a subject ofinterest of the IWC Scientific Committee, which initiated an in-depth assessment of Southern Hemisphere bluewhales in 2006 (IWC, 2006). In support of the assessment, in 2007 the archiving and analysis of blue whale
identification photographs collected during IWC IDCR/SOWER1 research cruises was undertaken. Photographs
collected during 20 years of circumpolar IWC IDCR/SOWER cruises became the foundation of the Antarctic Blue
Whale Catalogue (Olson, 2010).
The photo-identification data from this catalogue have produced information on inter-annual whale movement(Olson, 2012; Olson et al. 2013a), within season sighting rates (Olson et al., 2015), and a pilot capture-recapture
study (Olson and Kinzey, in press).
The status of blue whales in the Antarctic is also of concern to IWC-SORP2, which in 2009 established the Antarctic
Blue Whale Project (Bell, 2012). The use of photo-identification data in a capture-recapture analysis for theproduction of a contemporary (new) estimate of abundance of Antarctic blue whales is a key component of theAntarctic Blue Whale Project (Bell, 2012).
Since the establishment of the Antarctic Blue Whale Catalogue in 2007, the number of photo-identified Antarctic
blue whales has increased, with photographs collected during voyages conducted under IWC-SORP in 2013 and2015 (Double et al., 2013; Double et al., 2015), with photographs from the Institute of Cetacean Research (ICR),
Japan (Matsuoka and Pastene, 2009; Olson et al., 2013b, Olson et al., 2014), and with opportunistic photographs
contributed by scientists working on other projects in the Antarctic. By June 2015 the total number of photoidentified Antarctic blue whales from all of these sources totalled 399 (Olson et al., 2015).
1
2International Decade of Cetacean Research/Southern Ocean Whale and Ecosystem Research
Southern Ocean Research Partnership1

In recent months, photographs of blue whales collected opportunistically by naturalists and scientists working in theAntarctic region were forwarded to the first author. This paper presents the results of the comparison of the newphotographs to the existing catalogue (of 399 individuals) and summarizes all findings 1991-2016.
METHODS
An assortment of 260 Antarctic blue whale photographs were collected opportunistically by naturalists aboard tourvessels and by scientists conducting other (non-blue whale) research in east Antarctica, the Ross Sea, the Drake
Passage, South Georgia Island and the Sandwich Islands during the years 2005-2016 (Table 1). Photographs were
judged to meet minimum criteria of quality based on distance to the subject (whale), angle, exposure, and focus.
Only photos containing a whale’s dorsal fin were used for identification, as the fin is necessary for comparison tothe identification photos in the Antarctic catalogue as well as other photo collections. Whales were examined for
unique natural markings and identified as individuals following methods outlined in Sears et al. (1990) and Gendronand Ugalde de la Cruz (2012).
Photographs of identified individuals from this assortment of photographs were compared to one another and to theAntarctic Blue Whale Catalogue.
Note that more rigorous quality coding of photographs based on a 4-tiered system is currently underway and mayslightly alter results presented in the future.
Table 1. Photographs of Antarctic blue whales collected opportunistically, 2005-2016.
DateLocation

IWC
Area

No. ofphotographs
submittedNo. left
side ID’s

No. right
side ID’s

Total no.
identified
blue whales

Contributors

06 Mar 2005

So. Orkney Is.

II

15

202Imberti

Feb 2008

Ross Sea

V

05

011Steele

19 Dec 2010

Commonwealth
BayV

12111

Ovsyanikova

17 Jan 2013

East Antarctica

V07

101

Ovsyanikova

29 Dec 2014

Drake Passage

I28022Carr

06 Feb 2015

South Georgia

II3244428 Feb 2015South Georgia

II116

40417 Dec 2015

Drake Passage

I09011Brehm

26 Feb 2016

So. Sandwich Is.

II36011Brehm, Engelke

Greenfelder,
ImbertiBallance/Pitman,
Lamb

RESULTS AND DISCUSSION
Seventeen new individual whales were identified from the 260 opportunistic photographs (Table 1). No
photographic matches were found. The addition of 17 new photo-identified Antarctic blue whales brings the total
number of identified whales in the Antarctic to 416, represented by 315 left sides and 306 right sides. The minimum(315) and maximum (416) number of unique individuals represents 14% and 18%, respectively, of the most recent
accepted estimate of abundance of Antarctic blue whales, 2,280 in 1997/1998 (Branch, 2007). Whales were photoidentified in the circumpolar Antarctic region in all six IWC Management Areas, 1991-2016.

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Re-sights and movements
A relatively small proportion of individual blue whales were re-sighted inter-annually: 3% (14/416).
Fourteen whales have been re-sighted between years including one whale (#0623) that was sighted in threesubsequent years (Table 2). The time intervals ranged between 1 and 12 years. Five whales were re-sighted within
19–753km of their original location and four whales were re-sighted long distances, over 2,000km from their
original sighting. Whale #0758 exhibits the greatest distance between sighting locations with a distance of 6,650km;
this is the longest movement recorded for an Antarctic blue whale to date.
Table 2. Sighting histories of Antarctic blue whales re-sighted between years. Distanceswere calculated using rhumb lines on a Mercator projection measured between points.
TimeCapture
Recapture
Whale ID
intervalDistance (km)Date/Area
Date/Area(years)#0761

Jan 2005/III

Feb 2007/III

219#1343

Feb 2013/V

Feb 2015/V

2103

2005/III

2006/III1302

2006/III2007/III

1355

#0622

2006/III2007/III

1447

#0104

2001/VI

2004/V

3753

#0607

2006/IIIDec 2007/III

2

1,560

#1005

2010/V

2013/V

3

1,796

#0802

2008/IV

2013/V

5

1,848

#0772

1995/III2007/III

12

2,222

#13222

Feb 2006/IV

Feb 2013/V

7

2,543

#0738

2007/III2010/II

3

2,818

#1313

Feb 2006/IV

Feb 2013/V

7

3,433

#06171

2002/V

2006/III

4

5,677

#0758

2007/III2013/V66,650#0623#0623

1¹ Genetic recapture reported in Sremba et al. (2012), Table 3.
2Whale #1322 satellite tagged in 2013.

Generally it is not known if Antarctic blue whales show site tenacity for feeding areas or if they forage widely andrandomly. The small sample size of re-sights here does not shed light on a specific pattern as both small and large
inter-annual movements are represented, and occurred during varying oceanographic conditions. An interestingsighting history is that of whale #0623, which was sighted three years in a row, within 400km of its initial detection,
seemingly to indicate fidelity for that region in Area III. Whale #0761 was re-sighted only 19km from its firstdetection two years earlier, also in Area III. That contrasts with the sighting history of whale #1322 which was firstsighted in Area IV in February 2006, then re-sighted over 2,500km to the east in Area V in February 2013. This
whale was also satellite tagged in February 2013 and tracked for 74 days as it moved 5300km westward (AndrewsGoff et al., 2013), passing the location where it was initially sighted in 2006. Results of the Discovery tag data show
similar small and large inter-annual movement patterns (Branch et al., 2007).
The within-season movements of Antarctic blue whales also varied between smaller and larger scale movements.
The minimum daily movement ranged of Antarctic blue whales ranged between 1.5 and 162km/day (Table 3). Thisis generally consistent with foraging and transiting behaviors as observed by blue whales in the North Pacific (Mateet al., 1999; Bailey et al., 2009). The two satellite tagged whales from 2013 also exhibited these behaviors(Andrews-Goff et al., 2013). In 2013 three whales moved over 1,000km during the course of 2-4 weeks (Olson et3

al., 2013a). Yet many whales re-sighted within season do not move far from their initial sighting location, even after
1-3 weeks. Movement within a season is likely related to prey availability/density that particular summer.
Table 3. Sighting histories of Antarctic blue whales re-sighted within a season. Distances represent aminimum straight-line distance between points.
TimeDistance
Average
Percentage of rebetween
betweenminimumYear
AreaSurvey
sighted whales
re-sights
re-sights
distance(days)(km)(km/day)
20052006

IIISOWER

5/45
11%

4 -15

108 - 248

10 - 46

20052006

III/IV

ICR

1/15
7%

20619

31

20062007

III

SOWER

14/80
18%

1-8

32 - 250

31 - 162

20082009

IVSOWER

2/9
22%

2-4

99 - 176

25 - 88

2013

VSORP

8/50
16%

1 - 2715 – 1,172

15 - 93

2015

VSORP

7/46
15%

1 - 203 - 268

1.5 - 53

Opportunistic photos
The 17 new identifications provide a considerable contribution to the Antarctic Blue Whale Catalogue. In addition tothe sizable number of new identifications (relative to the total number in the catalogue), 14 of the identifications
came from Areas underrepresented in the catalogue, Areas I and II. In recent summer seasons, there are anecdotalreports that blue whales are occurring more frequently now at South Georgia and in the Drake Passage. It is hoped
this will provide the opportunity for identification photographs to be collected opportunistically in the future fromthese areas. Previously, opportunistically collected photographs have yielded valuable data on recaptured whales.
Two of the total 15 inter-annual recaptures include whales photographed opportunistically: whales #0738 and #1005(Table 2).
The caveat with opportunistic photos is quality. Often it is the case that the vessel of opportunity is unable to follow
blue whales and the photographs are obtained at a distance too far to determine detail needed for individualidentification. Yet all opportunistic photographers are encouraged to obtain photographs regardless. The
photographs of highly distinctive individuals, even taken at a distance, can be useful (if later matched) for
information on movement even if the photo would be excluded from capture-recapture analysis. Distant photographscan also be useful in documenting general body condition and occasionally, behavior.
Conclusion
A cornerstone of the Antarctic Blue Whale Project is to generate new estimates of abundance using photo-ID datafor capture-recapture analysis (Bell, 2015; Peel et al., 2015). The most recent accepted estimate of abundance(Branch, 2007) is based on line-transect data now over 18 years old. The continued collection of identification
photographs from the Antarctic will provide data toward a set eventually large enough to obtain new estimates ofabundance. This subpopulation of blue whales remains on the IUCN Red List as Critically Endangered.
More data are needed to fully understand the movements of Antarctic blue whales between and within seasons,especially with the major climate changes taking place in the Antarctic. The continued collection and analysis ofphotographs from the Antarctic, along with other research methods, will yield more information on these patterns
and will contribute to the understanding of blue whale population structure in the Southern Hemisphere.

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ACKNOWLEDGEMENTS
We are grateful to the people that shared their photos of Antarctic blue whales, including Lisa Ballance, Tobias
Brehm, Eric Carr, Christian Engelke, Claire Garrigue, Mike Greenfelder, Santiago Imberti, Bob Lamb, RussManning, Stephanie Martin, Katya Ovsyanikova and Heritage Expeditions, and Bob Pitman. Thank you also to Ted
Cheeseman and Mike Steele for forwarding photographs. The work of Paul Ensor and Bob Brownell greatly
facilitated the collection and the analysis of Antarctic blue whale photographs. Warm thanks to our fellow scientists,
especially Brian Miller, and the captains and crews aboard the RV Tangaroa, the FV Amaltal Explorer, the ShonanMaru, the Shonan Maru No. 2, and other vessels contracted by the Institute of Cetacean Research.
LITERATURE CITED
Andrews-Goff, V., Olson, P.A., Gales, N.J and Double, M.C. 2013. Satellite telemetry derived summer movementsof Antarctic blue whales. Paper submitted to the IWC Scientific Committee. IWC SC/65a/SH03.
Bailey, H., Mate, B. R., Palacios, D. M., Irvine, L., Bograd, S. J. and Costa, D. P. 2009. Behavioural estimation ofblue whale movements in the Northeast Pacific from state space model analysis of satellite tracks.
Endangered Species Research 10: 93-106.
Bell, E.M. 2012. Annual report of the Southern Ocean Research Partnership (SORP) 2011/12. Paper submitted tothe IWC Scientific Committee. IWC SC/64/O13.
Bell, E.M. 2015. Annual report of the Southern Ocean Research Partnership (IWC-SORP) 2014/2015. Paper
submitted to the IWC Scientific Committee. IWC SC/66a/SH8.
Branch, T.A. 2007. Abundance of Antarctic blue whales south of 60°S from three complete circumpolar sets ofsurveys. J. Cetacean Res. Manage. 9: 253-262.
Branch, T.A. and 41 co-authors. Past and present distribution, densities and movements of blue whales
Balaenoptera musculus in the Southern Hemisphere and northern Indian Ocean. 2007. Mammal Rev. 37(2):116-175.
Double, M.C., Barlow, J., Miller, B.S., Olson, P., Andrews-Goff, V., Leaper, R., Ensor, P., Kelly, N., Wadley, V.,
Lindsay, M., Peel, D., Calderan, S., Collins, K., Davidson, M., Deacon, C., Donnelly, D., Olavarria, C.,Owen, K., Rekdahl, M., Schmitt, N. and Gales, N. 2013. Cruise report of the 2013 Antarctic blue whale
voyage of the Southern Ocean Research Partnership. Paper submitted to the IWC Scientific Committee.
IWC SC/65a/SH21.
Double, M.C., Miller, B.S., Leaper, R., Olson, P., Cox, M.J., Miller, E., Calderan, S., Collins, K., Donnelly, D.,Ensor, P., Goetz, K., Schmitt, N., Andrews-Goff, V., Bell, E. and O’Driscoll, R. 2015. Cruise report onblue whale research from the NZ/Australia Antarctic Ecosystems Voyage 2015 of the Southern Ocean
Research Partnership. Paper submitted to the IWC Scientific Committee. IWC SC/66a/SH7.
Gendron, D. and A. Ugalde de la Cruz. 2012. A new classifcation method to simplify blue whale photoidentification technique. J. Cetacean Res. Manage. 12:79-84.
International Whaling Commission. 2006. Report of the Scientific Committee (IWC/SC/58). p. 40.
Mate, B.R., Lagerquist, B.A. and Calambokidis, J. 1999. Movements of north Pacific blue whales during the feeding
season off southern California and their southern fall migration. Mar. Mamm. Sci. 15(4): 1246-1257.
Matsuoka and Pastene, 2009. Summary of photo-id information of blue whales collected by JARPA/JARPA II andpreliminary analysis of matches in the feeding grounds. Paper submitted to the IWC Scientific Committee.
IWC SC/61/SH3.
Olson, P.A. 2010. Blue whale photo-identification from IWC IDCR/SOWER cruises 1987/1988 to 2008/2009.
Paper submitted to the IWC Scientific Committee. IWC SC/62/SH29.
Olson, P.A. 2012. Antarctic blue whale photo-identification catalogue summary. Paper submitted to the IWC
Scientific Committee. IWC SC/64/SH8.
Olson, P.A., Ensor, P., Andrews-Goff, V. and Double, M.C. 2013a. Inter-annual and within season movements ofphoto-identified Antarctic blue whales. Abstracts. 20th Biennial Conference on the Biology of Marine
Mammals, Dunedin, New Zealand, December 9-13, 2013.
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Olson, P.A. and Kinzey, D. In press. Using Antarctic blue whale photo-ID data from IDCR/SOWER: capturerecapture estimates of abundance. J. Cetacean Res. Manage., Special Issue. (Available from the author.)
Olson, P.A., Matsuoka, K. and Pastene, L.A. 2013b. Comparison of Antarctic blue whale photographs from JARPA
to the Antarctic Blue Whale Catalogue. 2013. Paper submitted to the IWC Scientific Committee. IWC
SC/65a/SH16.
Olson, P.A., Matsuoka, K. and Pastene, L.A. 2014. Comparison of Antarctic blue whale photographs from JARPA II
to the Antarctic Blue Whale Catalogue. Paper submitted to the IWC Scientific Committee. IWCSC/65b/SH20.
Olson, P.A., Schmitt, N., Ensor, P., Collins, K., Donnelly, D., Leaper, R., Calderan, S., Miller, B.S., Goetz, K. andDouble, M.C. 2015. Photo-identification of Antarctic blue whales during the New Zealand-Australia
Antarctic Ecosystems Voyage 2015. Paper submitted to the IWC Scientific Committee. IWC SC/66a/SH26.
Peel, D., Bravington, M.V., Kelly, N. and Double, M.C. 2015. Designing an effective mark-recapture study ofAntarctic blue whales. Ecological Applications 25: 1003-1015.
Sears, R.J., Williamson, M.J., Wenzel, F.W., Bérubé, M., Gendron, D. and Jones, P. 1990. Photographic
identification of the Blue Whale (Balaenoptera musculus) in the Gulf of St. Lawrence, Canada. Rep. Int.
Whal. Commn., Special Issue 12, pp. 335-342.
Sremba, A.L., Hancock-Hanser, B., Branch, TA, LeDuc, R.L. and Baker, C.S. 2012 Circumpolar diversity andgeographic differentiation of mtDNA in the critically endangered Antarctic blue whale (Balaenoptera
musculus intermedia). PLoS ONE 7(3): e32579. doi:10.1371/journal.pone.0032579.

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