Cruise report of cetacean survey in the Scotia Sea from British Antarctic Survey vessel RRS James Clark Ross, 7 January to 23 February 2003


Cetacean observations were conducted for the IWC from the British Antarctic Survey vessel RRS James Clark Ross as part of collaborative data collection .   The main aims of the cruise were studies of krill, zooplankton and oceanography in the Scotia Sea and no dedicated ship time was available for cetacean research.    The objective of the cetacean observations were to collect systematic survey data to determine the distribution and abundance of cetaceans.  These data may allow investigations of the relationship between oceanographic processes or prey abundance and cetacean distribution.


The survey design followed a pattern of north-south zig-zag transects conducted from west to east across the Scotia Sea with more detailed transects around the island of South Georgia.  The area covered was similar to that of the IWC-CCAMLR survey in 2000 but did not extend as far west.  All effort was in passing mode.  This involved two crossings of the Polar Front (formerly referred to as the Antarctic Convergence) and eight crossings of the Southern Antarctic Circumpolar Current Front (SACCF).  The southern end of each transect was determined by the northern limit of the pack ice.   Sampling stations were spaced at 60 mile intervals along each transect.  At each sampling station the vessel was stopped and CTD (Conductivity Temperature Depth) casts and plankton samples were collected.  In addition, target fishing for krill was conducted at stations to sample swarms indicated by a Simrad EK60 multiple frequency echo-sounder.   Cetacean observations were conducted whenever weather conditions allowed while the vessel was underway on transect. The usual transect speed was 5ms-1 (10 knots) and a number of underway data were collected including measurements of krill abundance from the EK60 and CTD profiles from an Undulating Oceanographic Recorder (UOR).


Observations were conducted according to the protocol used for single platform observations during the IWC-CCAMLR survey in 2000 (Reilly et al., 2000).   Two observers searched a 180o sector ahead of the vessel with 7x50 binoculars. Observations were made from the roof of the bridge (Monkey Island) behind a wind deflecting screen on the roof of the bridge at an eye height of 18.3m.  If rain made observations from the Monkey Island difficult then observations were made from inside the bridge from an eye height of 16m. Sightings and environmental data were entered directly into a computer running the Wincruz software.   Data from the vessels underway monitoring system were also recorded including wind speed, sea temperature and salinity.  A full description of the database structure, field data codes, and definition of data categories is given in Appendix I.   Range to each sighting was measured from the angle of dip from the horizon to the whale using Fujinon 7x50 reticle binoculars.  Bearings to sightings were recorded by lining up reference marks at 10o intervals in a semicircular pattern of around 1m radius from the observer on the deck, with equivalent 10o marks on the windshield (see photo).  In addition, one observer used a photogrammetric system for measuring range and bearing (Leaper and Gordon, 2001).  It had been hoped that both observers would be able to use the system but one set of equipment was lost by airline baggage handlers.  To ensure consistency between observers and other surveys, priority was given to recording distance and angle using the reticle binoculars and angle reference marks.   Higher magnification, Nikon 10x50, binoculars were also used to assist species identification and group size estimation.  In addition to the cetacean sightings, data on pinniped and penguin sightings were also recorded.  Whenever possible, range and bearing was recorded to all pinniped sightings.  However, in areas of high fur seal density, only fur seals within 150m either side of the vessel were recorded.   Other seabirds were only noted if any unusual behaviours were observed that might relate to the presence of prey species.


Detailed data on ice conditions were recorded using the ASPeCt (Antarctic Sea Ice Processes and Climate) protocol, whenever the area of sea covered by ice was greater than 5%.  If icebergs were present but cover was less than 5% then the number of icebergs in a 180o arc ahead of the vessel were recorded as a comment.


It was not possible to conduct distance and angle experiments using radar on fixed targets.  However, the photogrammetric measures of range and bearing allowed comparison between visual estimates and measured values to actual sightings.  In addition, some measurements were made to fixed targets to allow comparison with angle and distance experiments conducted on other surveys.


Survey effort

The cetacean survey effort is shown in figures 1-4.  Total effort was 220 hours.  Most of the survey effort was conducted in deep water with only 7% in depths of less than 200m.  Distribution of effort by depth is shown in table 1.  Sea surface temperatures ranged from –1.6 to 8.8oC with the distribution of effort by sea surface temperature shown in table 2.   A total of 95 n. miles of effort were conducted in estimated ice cover of greater than 5%, this amounted to 4% of the total effort.


Environmental variables that could be related to sighting probability included visual estimates of sea state, overall ‘sightability’ and minke whale visibility.  In addition, wind speed and solar radiation were measured by the ship’s instrumentation system. Restricting analysis to effort in sightability ‘moderate to excellent’ and wind speeds of less than 12ms-1 results in 1672nm of effort compared to a total effort of 2237nm.  This would include 203 out of 214 sightings and only exclude 2 sightings identified to species level.


Cetacean sightings

Table 3 lists the number of on-effort sightings and total number of individuals by species.  The locations of some of these are also shown on figures 1 - 4.  In addition, two species, Commerson's dolphin (Cephalorhynchus commersonii) and Gray's beaked whale (Mesoplodon grayi) were also sighted off-effort (table 4).


The locations of all sightings relative to the vessel are shown in figure 5  Some degree of rounding in radial distances is evident corresponding to a division of 0.1 reticles (the Wincruz software rounded all reticle readings to the nearest 0.1 reticles).   Analysis of the ranges and bearings measured photogrammetrically provide additional data with a measured level of accuracy, for comparison.   A preliminary comparison of estimated distances against measured (figure 6) indicates no substantial bias in distance estimation and moderate variance.  Analysis of bearing estimates suggested a root mean square error of around 5o.   Further analysis of these data is planned. Distribution of perpendicular distances to species with similar strength and type of visual cue are shown in figures 7-10.


Fin whales were generally observed north of the SACCF (Southern Antarctic Circumpolar Current Front) whereas minke whales were predominantly observed to the south of this and towards the southern ends of the transects.  Sei whales were also observed to the north of the SACCF and sometimes associated with right whales, but not in the same areas as fin whales.  Of 16 sightings in greater than 5% ice cover, 2 were right whale, 1 was killer whale and 13 were minke whale.


Pinniped sightings

Table 5 lists sightings of pinnipeds with the proportion of sightings of animals hauled out on ice.  Fur seals were the most frequently encountered pinniped, often at great distances from ice or land.  Almost all the sightings of crabeater and leopard seals were on or close to ice.


The generally good weather conditions during the survey allowed a greater amount of survey effort than had been expected.  The amount of effort was around 50% greater than that achieved from the James Clark Ross during the CCAMLR synoptic survey in 2000.   The area covered by both surveys was broadly similar and the two data sets should prove comparable due to similar survey protocols and the fact that both observers on this study were also involved in the CCAMLR survey.


The use of photogrammetric methods proved an effective way of measuring radial distance and bearing to sightings.  In addition, these methods provided the equivalent of distance testing experiments for estimating the variance of distances based on reticle readings and estimated angles.  This is especially important for multi-disciplinary cruises where dedicated ship time is not available for distance experiments.


One encounter of particular interest to the SOWER 2000 objectives was on 4th February 2003.  Observation conditions were ideal and a mixed group of 16 humpback, 3 right whales and 1 minke whale were seen in the vicinity of a large, dense swarm of krill about 0.5nm by 0.3nm and around 60m deep.  Apart from this single swarm, acoustic measurements indicated low krill densities in the area.  The ship passed through the swarm three times and locations of the whales were measured relative to the ship using the video tracking methods. This should allow analysis of the locations of the whales and movements in relation to the swarm together with behavioural observations over a period of several hours.


The detections of six individuals in two groups of sperm whales are unlikely to be sufficient for strip width estimation. This number of sightings is consistent with previous visual and acoustic surveys in the Scotia Sea and around South Georgia from RRS James Clark Ross.   In the detailed surveys around South Georgia, sperm whales were encountered in the same localised area as these previous surveys (Leaper et al., 2000).


Observations of Gray's beaked whale were also of particular interest. The long-held view on the occurrence of Gray’s beaked whale is that it covers a circumglobal distribution in temperate or cold temperate waters of the southern hemisphere between 30º and 45º (e.g. Marcuzzi and Pilleri, 1971; Ross, 1979; Rice, 1998; Pitman, 2002). For a detailed review of documented specimen and sighting localities see Mead (1989).


Goodall and Galeazzi (1985) first referred to some 53 stranding observations or specimens of M. grayi recorded from the tips of the southern continents, the southernmost being Tierra del Fuego at ca. 54ºS. Mead (1989), repeated by Ohsumi et al. (1994), discusses a particular specimen in the National Museum of New Zealand (nmnz 612) which he says was collected from an unknown locality in the Antarctic; Mead adds ‘it is difficult to attach much importance to this record because M. grayi has been known to stray before‘ (referring to the only record from the northern hemisphere, in The Netherlands). However, the origin of this specimen should be of interest. Anton van Helden, curator of marine mammals at Te Papa museum (in litt. to KVW, 8 April 2003) disputes Mead’s (1989) conclusion and believes the specimen is from the Chatham islands[1].


While Pitman (2002) cites for the distribution of M. grayi ‘circumglobal in temperate waters of the southern hemisphere’, in the same paper an excellent photo by Richard A. Rowlett ‘taken in Antarctic waters’ is printed. Ohsumi et al. (1994) indicate a single sighting of Gray’s beaked whale in the Antarctic based on the IDCR/SOWER survey programme since 1987/88, at about 62º30’S, 150ºE (estimated from map) in the Australian Antarctic basin. So far we are aware, there exist no other similar, published records.


These observations of Gray’s beaked whale sighting from the Scotia Sea, south of the Polar Front widens the possibility that the subantarctic and Antarctic oceans may be part of the  normal distribution area for M. grayi like it is now becoming increasingly recognized for M. layardii (e.g. Pitman, 2002). The issue should become clearer still in the future with an increasing percentage of the hitherto lumped ‘ziphiids’ sightings identified to species.


Goodall, R.N.P. and Galeazzi, A.R. 1985. A review of the food habits of the small cetaceans of the Antarctic and Sub-antarctic. pp. 566-72. In:  W.R. Siegfried, P.R. Condy & R.M. Laws (eds.). Antarctic Nutrient Cycles and Food Web.

Leaper, R., Gillespie, D. and Papastavrou, V. (2000).  Results of passive acoustic surveys for odontocetes in the Southern Ocean.  J. Cetacean Res. Manage. 2(3): 187-196

Leaper, R. and Gordon, J. (2001).  Application of photogrammetric methods for locating and tracking cetacean movements at sea J. Cetacean Res. Manage. 3(2):

Marcuzzi, G. and Pilleri, G. 1971. On the zoogeography of cetacea. Investigations on Cetacea 3(1): 101-170.

Mead, J.G. 1989. Beaked whales of the genus Mesoplodon. pp. 349-430. In: S.H. Ridgway and R. Harrison. Handbook of Marine Mammals.Vol. 4. Academic Press.

Ohsumi, S., Kawasaki, M., and Nishiwaki, S. 1994. Biological results of beaked whales surveyed by Japanese whale research programme underspecial permit in the Antarctic and the need of their research take. Paper SC/46/SM15 presented at IWC SC meeting.

Pitman, R.L. 2002. Mesoplodont whales (Mesoplodon spp.). pp. 738-742. In: W.F. Perrin, B. Würsig and J.G.M. Thewissen (eds.). Encyclopedia of marine mammals.  Academic Press.

Reilly, S., Hedley, S., Hewitt, R., Leaper, R., Thiele, D., Pitman, R.L., Naganobu, M., Watkins, J. and Holland, R. 2000.  SOWER 2000:  Initial results from the IWC-CCAMLR program to study whales and krill in the Southern Ocean. Paper SC/51/E21 presented to the IWC Scientific Committee, June 2000 (unpublished).

Rice, D.W. 1998. Marine Mammals of the World. Systematics and Distribution. Special Publication No. 4. The Society for Marine Mammalogy. 231pp.






Table 1.  Distribution of effort (in nautical miles) by depth of water (metres)






No depth reading










Table 2. Distribution of effort (in nautical miles) by sea surface temperature (oC)

-2 to 0

0 to 2

2 to 4

4 to 6

6 to 8

8 to 10

No  temp reading












Table 3.  On-effort cetacean sightings


Number of sightings

Total individuals

Fin whale (Balaenoptera physalus)



Sei whale (Balaenoptera borealis)



Antarctic minke whale (Balaenoptera bonaerensis)



Undetermined minke whale (Balaenoptera bonaerensis/acutorostrata)



Sperm whale (Physeter macrocephalus)



Humpback whale (Megaptera novaeangliae)



Right whale (Eubalaena australis)



Southern bottlenose whale (Hyperoodon planifrons)



Undetermined beaked whale of genus Mesoplodon (Mesoplodon sp.)



Undetermined beaked whale (Ziphiidae)



Killer whale (Orcinus orca)



Pilot whale (Globicephala sp.)



Hourglass dolphin (Lagenorhynchus cruciger)



Peale's dolphin (Lagenorhynchus australis)




Table 4.  Observations of Gray's beaked whale




Group size


SST (ºC)



long, white rostra sticking out above water surface; no teeth seen.


in 1 individual: long rostrum seen before whitish head surfaces; body grey-brown, no scars seen on 3.5-5m body

M. grayi

4 Feb. 2003

61.39º S

031.19º W

6 (5-7)


1.16  ºC

like – M.grayi

8 Feb 2003

56.85º S

031.60º W

4 (4-5)


2.64  ºC



Table 5.  Pinniped sightings on effort.


Number of sightings

Total individuals

Proportion on ice

Fur seal (Arctocephalus sp.)




Crabeater seal (Lobodon carcinophagus)




Leopard seal (Hydrurga leptonyx)




Weddell seal (Leptonychotes weddellii)




Unidentified Phocid








Figure 1.  On effort sightings of fin whales (upward pointing triangles), sei whales (downward pointing triangles), and minke whales (open circles)



Figure 2.  On effort sightings of humpback whales (open circles)




Figure 3.  On effort sightings of right whales (open circles)



Figure 4.  On effort sightings of sperm whales, killer whales and southern bottlenose whales



Figure 5.  Location of all cetacean sightings relative to the vessel




Figure 6.  Comparison of estimated and measured radial distances to sightings




Figure 7.  Perpendicular distances to fin and sei whale sightings combined  (distances are shown as the mid-point of 250m wide bins).




Figure 8. Perpendicular distances to minke whale sightings (distances are shown as the mid-point of 250m wide bins).



Figure 9. Perpendicular distances to humpback and right whale sightings combined (distances are shown as the mid-point of 250m wide bins).



Figure 10. Perpendicular distances to all baleen whale sightings combined (distances are shown as the mid-point of 250m wide bins).



Figure 11. Perpendicular distances to all small whale sightings combined (distances are shown as the mid-point of 250m wide bins).



Appendix – Definitions of data categories entered into Wincruz software

1.  Viewing conditions

1.1 Swell code

When entering swell codes, swell was defined to be waves generated by wind elsewhere.  Thus any waves generated by the wind that was currently being experienced were not considered as swell.

1.2  Sightability

Sightability category was a subjective judgement of overall conditions related to detecting a blow from a large baleen whale.  This was a combination of sea conditions and meteorological visibility with more emphasis on meteorological visibility than for the minke whale visibility distance.  If it was not possible to discern the horizon at all then sightability was classed as ‘Poor=2’ or ‘Too poor to survey=1” if visibility was less than 1 n.mile.  If the horizon was visible and allowed reticle readings but had poor contrast for detecting blows then sightability was classed as ‘Moderate=3’.  ‘Good=4’ sightability required a clear horizon with enough contrast to allow a blow to be detected at the horizon.  ‘Excellent=5’ was limited to near perfect conditions.

1.3  Beaufort

The Beaufort scale was designed as a way of estimating wind speed from the appearance of the sea.  In this context however, Beaufort is used as a proxy for sea state.   Sea state was categorised as Beaufort N if it was judged to affect viewing conditions similarly to the sea conditions generated by a wind of Beaufort force N blowing across the open sea for some hours.  Thus for example, the sea state from an increasing wind which had not yet had time to build up the waves or areas sheltered by ice, would be given lower Beaufort categories than the corresponding wind speed.

2.  Weather Conditions

2.1 Visibility

Visibility is defined in Wincruz as an estimate of the maximum distance (in nautical miles) that a blow from a minke whale could be detected.  Most of the minke whales encountered during the survey did not produce a strong blow but visibility was defined assuming a strong blow.   In conditions that were judged to be optimum, visibility was recorded as 2.5 n.mile.

2.2  Ice cover was rounded to the nearest 10% by the software.  If total cover was less than 5%, which was frequently the case in areas of scattered ice bergs, then the number of bergs in sight in a 180o arc ahead of the vessel was entered as a comment.   When ice cover was greater than 5%, detailed ice records were made using the Aspect (Antarctic Sea Ice Processes and Climate) recording procedures.

3.  Sighting data

3.1  Species codes

The species codes and definitions of ‘like’ sightings were the same as for the CCAMLR survey. 

3.2  Group size

For sightings surveys where a variety of species from small odontocetes to large mysticetes are likely to be encountered, it is not possible to have a single, consistent, biologically meaningful definition of ‘group’.  Instead, group needs to be defined in relation to the sighting process and spatial resolution of the data that can be collected.  For line transect surveys, based on perpendicular distances, the main considerations are the way in which groups of animals affect their probability of detection and assigning an appropriate perpendicular distance to clusters of animals when these are considered as a single group.  For the purposes of this survey we classified clusters of whales as a group if

(i) The whales were close enough to each other and with some degree of behavioural synchronisation such that the presence of more than one whale increased the probability of detection of an individual.  In this case, the recorded sighting location was that of the first sighting location of the group.

(ii) Whales were not necessarily showing any degree of behavioural synchronisation but aggregations were sufficiently dense that it was not possible to distinguish sightings of new individuals from resightings of whales that had already been seen.  In this case, the recorded sighting location in Wincruz was to the first animal to be detected, but video scans were performed to allow an estimate of the location of the ‘centre’ of the group.


Appendix II

Structure of database

Cetacean Sightings (on effort)

Cetacean Sightings (off effort - these were sightings made while Wincruz was running but not on effort)

Non-Wincruz off effort cetaceans (these were off-effort sightings which were not entered into Wincruz)

Pinniped sightings (on effort)

All visual data (every entry in Wincruz with corresponding ship data)

Ice Photos


Data fields from Excel file

Observer codes

RL           - Russell Leaper

KVW      - Koen Van Waerebeek

DS           - Debbie Salmon

AS          - Ana Sirovic

OBS        - any of ship’s crew or other scientists


Pinniped sightings

                Species code 25 was added as ‘Unidentified phocid seal’


Effort code

This is MI for normal observations from the Monkey Island.  If watching from the bridge due to rain then this code is set to 'BR'.  Note reticle readings should be calculated using the height of eye on the bridge (16m).


[1] M.grayi specimen nmnz 612 was donated to the Museum [National Museum of New Zealand, Wellington] by Lady Kinsey. The next specimen in the register, a mandible of T. shepherdi, listed as coming from the Chatham islands, is from the same donor. The previous record is a southern right whale earbone that is listed as ‘Antarctic ?’. A ditto mark is below this associated with the M. grayi specimen, however this has been crossed out (probably a product of the transfer of information from the old register). Anton van Helden concludes that in his opinion ‘the most likely origin of the M. grayi specimen is the Chatham islands’.